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Sample records for whiteflies homoptera aleyrodidae

  1. Migration, trapping and local dynamics of whiteflies (Homoptera: Aleyrodidae)

    DEFF Research Database (Denmark)

    Riis, Lisbeth; Nachman, Gösta

    2006-01-01

    to population growth. 4 A model for changes in whitefly density during an entire bean (Phaseolus vulgaris L.) crop cycle, including an immigration parameter, was also developed. 5 Non-attractant window traps surrounding an annual field crop were assumed to intercept whiteflies immigrating into and emigrating...

  2. Whitefly Pest Species (Homoptera: Aleyrodidae) on Citrus Trees

    OpenAIRE

    Katja Žanić; Sonja Kačić; Miro Katalinić

    2000-01-01

    Today, the Citrus whitefly, Dialeurodes citri (Ashmead), is a very important pest on all Citrus species throughout the citrus growing areas in Croatia. It causes direct damage by sucking the plant juice from the leaves. Furthermore, immatures excrete honeydew that stimulates sooy mold. The presence of sooty mold on contaminated leaves interferes with the photosynthesis of plants. Citrus fruits coated by sooty mold lose its market value. Because Dialeurodes citri is poorly known in Croatia, th...

  3. Comparative efficacy of some insecticides against cotton whitefly, bemisia tabaci (gennadius) (homoptera: aleyrodidae) under natural field conditions

    International Nuclear Information System (INIS)

    Nadeem, M.K.; Hasnain, M.; Ahmed, S.; Ashfaq, M.

    2011-01-01

    Comparative efficacy of five commonly used insecticides viz., acetamiprid, buprofezin, diafenthiuron, imidacloprid and endosulfan against nymph and adult population of cotton whitefly, Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) under natural field conditions has been studied. Results showed that buprofezin was the most effective insecticide against nymph population of whitefly among the tested insecticides where nymphal population of B. tabaci was 0.2/leaf after 24h spray as compared to 1.9/leaf in control. Acetamiprid was the most effective against adult population of whitefly (0.3 to 1.3/leaf post 72 h spray, as compared to control with 6.9 to 8.2/leaf) followed by diafenthiuron and imidaclopirid. whereas, endosulfan was found to be the least effective on both populations as adult and nymph of whitefly. From the tested insecticides, acetamaprid gave effective control of both nymph and adult population of B. tabaci. (author)

  4. Extended survival of spiders (Aranaeae) feeding on whitefly (Homoptera: Aleyrodidae) honeydew

    Science.gov (United States)

    Honeydew produced by homopteran insects such as aphids, whiteflies and mealybugs, can be abundant in some crops and may represent an important food resource for spiders and other honeydew feeding natural enemies. Woolly whiteflies are common in south Texas citrus, and spiders consistently make up a...

  5. Evaluation of insecticides against cotton whitefly, bemisia tabachi (Genn.) (Homoptera: Aleyrodidae)

    International Nuclear Information System (INIS)

    Razaq, M.; Aslam, M.; Sharif, K.; Salman, B.; Aleem, F.

    2003-01-01

    The experiment was conducted to evaluate the efficacy of lmidacloprid (Confidor 200SL), Acetamaprid (Mospilon 20SP), Methamidophos (Tamaron 600SL), Endosulfan (Thioluxon 35EC), Buprofezin (Sitara 25WP), Fenpropathrin (Fenthrin 20EC) and Diafenthiuron (Polo 500 SC) against whitefly, Bemisia tabaci (Genn.) on cotton variety CIM-473 during the crop year 2002. The crop was sprayed twice in September. After seven days of the first spray, the lowest population (0.6/leaf) of whitefly was observed in plots treated with Endosulfan 35EC followed by Acetamaprid 20SP(1.1/leaf), while the plots receiving Buprofezin 25 WP + Fenpropathrin 20 EC, Methamidophos 600SL and Imidacloprid 200SL had population of whitefly statistically similar. Seven days after second spray Acetamaprid 20SP and Diafenthiuron 500SC treated plots had the lowest population (1.4 per leaf) of whitefly followed by Imidacloprid 200SL (1.8 per leaf) and Fenpropathrin 20EC (1.9 per leaf).(author)

  6. RESULTS OF THE THREE-YEAR MONITORING (2001.-2003. OF TOBACCO WHITEFLY Bemisia tabaci (Gennadius, 1889, (HOMOPTERA: ALEYRODIDAE IN CROATIA

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    Tatjana Masten

    2004-06-01

    Full Text Available The quarantine pest tobacco whitefly Bemisia tabaci (Gennadius, 1889 was for the first time found in Croatia in 2000 on some culture and weed plants in greenhouses and in the open field in the area from Trogir to Omiš. Monitoring of tobacco whitefly was organized in all counties (21. Eventual presence of tobacco whitefly adults on the plants in glasshouses was established by the hanging of yellow sticky traps. In the course of monitoring the undersides of leaves on host plants were inspected for the purpose of discovering pest nymphal and pupal stages. The plants of poinsettia (Euphorbia pulcherrima produced as pest free plants have been used as catch plants in the conditions of lower infestation of host plants by tobacco whitefly adults. In three-year monitoring it was found out that poinsettia is the most atractive host plant for this pest between 38 host plants being registered during this monitoring. The fact that tobacco whitefly during the summer was found on the vegetables, ornamentals and weeds in the open fields in Dalmatia indicate that tobacco whitefly became domesticated and it can successfully overwinter in mediteranean climate conditions. During the monitoring tobacco whitefly was detected in 13 counties in our country, indicating shows that tobacco whitefly has been spreading progresivly since it was found in Croatia for the first time.

  7. Understanding biological control of greenhouse whitefly with the parasitoid Encarsia formosa : from individual behaviour to population dynamics

    NARCIS (Netherlands)

    Roermund, van H.J.W.

    1995-01-01

    The greenhouse whitefly, Trialeurodes vaporariorum (Westwood) (Homoptera, Aleyrodidae), is a very common, highly polyphagous pest insect all over the world. Biological control of whiteflies with the parasitoid Encarsia formosa Gahan (Hymenoptera, Aphelinidae) was already applied in the 1920s in

  8. The complete mitochondrial genome of a spiraling whitefly, Aleurodicus dispersus Russell (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Ming-Xing, Lu; Zhi-Teng, Chen; Wei-Wei, Yu; Yu-Zhou, Du

    2017-03-01

    We report the complete mitochondrial genome (mitogenome) of a spiraling whitefly, Aleurodicus dispersus (Hemiptera: Aleyrodidae). The 16 170 bp long genome consists of 13 protein-coding genes, 20 transfer RNAs, 2 ribosomal RNAs, and a control region. The A. dispersus mitogenome also includes a cytb-like non-coding region and shows several variations relative to the typical insect mitogenome. A phylogenetic tree has been constructed using the 13 protein-coding genes of 12 related species from Hemiptera. Our results would contribute to further study of phylogeny in Aleyrodidae and Hemiptera.

  9. Prey Preference of Predatory mite Amblyseius swirskii (Athias-Henriot (Acari: Phytoseiidae on untreated and Beauveria bassiana-treated of Trialeurodes vaporariorum (Homoptera: Aleyrodidae

    Directory of Open Access Journals (Sweden)

    Marjan Seiedy

    2018-01-01

    Full Text Available Introduction The predator Amblyseius swirskii and entomopathogenic fungus Beauveria bassiana are important biocontrol agents of Trialeurodes vaporariorum. Determination of the host preference of predators in the fields when receiving signals related to either untreated and Beauveria bassiana-treated pest is important. Materials and Methods In this research, the prey preference of adult female (2 days old of A. swirskii was determined on untreated and Beauveria bassiana-treated of Trialeurodes vaporariorum (Homoptera: Aleyrodidae in various treatments base on Manly Index. These different treatments consisted of two time intervals; 24 and 48 h post-inoculation of greenhouse whiteflies with 1×105 conidia /ml of B. bassiana with 13 replicates. 24-h starved predators were added to the leaf discs singly then the number of consumed untreated and B. bassiana-treated T. vaporariorum in each Petri dish was assessed after 24 h. Results and Discussion The results revealed that mean number of consumed B. bassiana-treated T. vaporariorum in two time intervals; 24 and 48 h. after inoculation were 4/15±0/19 and 2.23±0/12, respectively. This investigation showed a significant preference of A. swirskii towards untreated T. vaporariorum in 24 (P< 0.0034 and 48 h. (P

  10. Spatiotemporal Dynamics of Whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) in Commercial Watermelon Crops.

    Science.gov (United States)

    Lima, Carlos H O; Sarmento, Renato A; Galdino, Tarcísio V S; Pereira, Poliana S; Silva, Joedna; Souza, Danival J; Dos Santos, Gil R; Costa, Thiago L; Picanço, Marcelo C

    2018-04-16

    Spatiotemporal dynamics studies of crop pests enable the determination of the colonization pattern and dispersion of these insects in the landscape. Geostatistics is an efficient tool for these studies: to determine the spatial distribution pattern of the pest in the crops and to make maps that represent this situation. Analysis of these maps across the development of plants can be used as a tool in precision agriculture programs. Watermelon, Citrullus lanatus (Thunb.) Matsum. and Nakai (Cucurbitales: Cucurbitaceae), is the second most consumed fruit in the world, and the whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is one of the most important pests of this crop. Thus, the objective of this work was to determine the spatiotemporal distribution of B. tabaci in commercial watermelon crops using geostatistics. For 2 yr, we monitored adult whitefly densities in eight watermelon crops in a tropical climate region. The location of the samples and other crops in the landscape was georeferenced. Experimental data were submitted to geostatistical analysis. The colonization of B. tabaci had two patterns. In the first, the colonization started at the outermost parts of the crop. In the second, the insects occupied the whole area of the crop since the beginning of cultivation. The maximum distance between sites of watermelon crops in which spatial dependence of B. tabaci densities was observed was 19.69 m. The adult B. tabaci densities in the eight watermelon fields were positively correlated with rainfall and relative humidity, whereas wind speed negatively affected whiteflies population.

  11. Characterization of a Newly Discovered Symbiont of the Whitefly Bemisia tabaci (Hemiptera: Aleyrodidae)

    Science.gov (United States)

    Bing, Xiao-Li; Yang, Jiao; Zchori-Fein, Einat; Wang, Xiao-Wei

    2013-01-01

    Bemisia tabaci (Hemiptera: Aleyrodidae) is a species complex containing >28 cryptic species, some of which are important crop pests worldwide. Like many other sap-sucking insects, whiteflies harbor an obligatory symbiont, “Candidatus Portiera aleyrodidarum,” and a number of secondary symbionts. So far, six genera of secondary symbionts have been identified in B. tabaci. In this study, we report and describe the finding of an additional bacterium in the indigenous B. tabaci cryptic species China 1 (formerly known as B. tabaci biotype ZHJ3). Phylogenetic analysis based on the 16S rRNA and gltA genes showed that the bacterium belongs to the Alphaproteobacteria subdivision of the Proteobacteria and has a close relationship with human pathogens of the genus Orientia. Consequently, we temporarily named it Orientia-like organism (OLO). OLO was found in six of eight wild populations of B. tabaci China 1, with the infection rate ranging from 46.2% to 76.8%. Fluorescence in situ hybridization (FISH) of B. tabaci China 1 in nymphs and adults revealed that OLOs are confined to the bacteriome and co-occur with “Ca. Portiera aleyrodidarum.” The vertical transmission of OLO was demonstrated by detection of OLO at the anterior pole end of the oocytes through FISH. Quantitative PCR analysis of population dynamics suggested a complex interaction between “Ca. Portiera aleyrodidarum” and OLO. Based on these results, we propose “Candidatus Hemipteriphilus asiaticus” for the classification of this symbiont from B. tabaci. PMID:23144129

  12. DNA barcode development for three recent exotic whitefly (Hemiptera: Aleyrodidae) invaders in Florida

    Science.gov (United States)

    Several new whitefly species have become established in Florida in the past decade. Three, in particular, have caused noticible damage to residential plants in the landscape such as ficus hedges, palms, and bird of paradise. These are fig whitefly (FW), rugose spiraling whitefly (RSW), and Bondar’s ...

  13. Leaf Morphological Characters Can Be a Factor for Intra-Varietal Preference of Whitefly Bemisia tabaci (Hemiptera: Aleyrodidae among Eggplant Varieties.

    Directory of Open Access Journals (Sweden)

    Abu Tayeb Mohammad Hasanuzzaman

    Full Text Available The sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae MEAM1, is considered a serious pest of horticultural and many other crops. While eggplant (Solanum melongena is one of the most favored host plants, the whiteflies exhibit preferences among different varieties. We hypothesized that certain morphological leaf characteristics of different varieties, like leaf trichome density, trichome length, leaf lamina thickness and leaf color, may affect whitefly landing, feeding and oviposition. In this study, we investigated the variation in leaf morphological characters among selected eggplant varieties and evaluated the effect of these leaf characteristics in rendering eggplant varieties either susceptible or resistant to B. tabaci. We evaluated eight eggplant varieties in choice feeding tests, and we found that the varieties JinSheng Zilongchangqie (JSZ and H149 were the highly preferred varieties with the highest numbers of whitefly adults and eggs. Significantly lower numbers of whitefly adult eggs were found on the resistant variety Tuo Lu Bamu (TLB. The varieties JinGuangbo Luqie (JGL, JinGuangbo Ziquanqie (JGZ, DaYang Ziguanqie (DYZ, QinXing Ziguanqie (QXZ, and QinXing Niuxinqie (QXN were moderately favored by B. tabaci. Leaf trichome density, trichome length and leaf lamina thickness were positively correlated with numbers of whitefly adults and eggs. B. tabaci was less attracted to the leaves that reflect long and middle wavelength light (higher R and G values than to the bright green leaves (medium G value, but the short wavelength light (higher B value had no significant effect on whitefly preference. The degree of hue had a positive effect, and saturation and brightness had a negative effect on whitefly attraction.

  14. Six New Record Species of Whiteflies (Hemiptera: Aleyrodidae) Infesting Morus alba in China

    Science.gov (United States)

    Wang, Ji-Rui; Song, Zao-Qin; Du, Yu-Zhou

    2014-01-01

    Abstract To determine the species of whiteflies occurring on mulberry, Morus alba L. (Rosales: Moraceae) in China, we collected samples in more than 87 sites in 16 provinces of China from 2008 to 2011. In total, 10 species, representing seven genera of the subfamily Aleyrodinae, were identified. Of these, six species are newly recorded on mulberry in China, namely, Aleuroclava ficicola Takahashi, Aleuroclava gordoniae (Takahashi), Aleurotrachelus camelliae (Kuwana), Bemisia afer (Priesner & Hosny), Bemisia tabaci Gennadius, and Pealius machili Takahashi. Information on the taxonomy, distribution, and host plants of the whitefly species found on mulberry in China, along with a brief description and illustrations of each species are provided. PMID:25368095

  15. Identification of unique volatile compounds associated with repelling whiteflies (Hemiptera: Aleyrodidae) in desert watermelon (Citrullus colocynthis)

    Science.gov (United States)

    Commercial watermelon cultivars (Citrullus lanatus var. lanatus) share a narrow genetic base and are susceptible to many insect pests and diseases. The insects include whiteflies which cause serious economic damages to this important cucurbit crop. However, several United States Plant Introduction a...

  16. Pathogenicity of Two Species of Entomopathogenic Nematodes Against the Greenhouse Whitefly, Trialeurodes vaporariorum (Hemiptera: Aleyrodidae), in Laboratory and Greenhouse Experiments.

    Science.gov (United States)

    Rezaei, Nastaran; Karimi, Javad; Hosseini, Mojtaba; Goldani, Morteza; Campos-Herrera, Raquel

    2015-03-01

    The greenhouse whitefly Trialeurodes vaporariorum (Hemiptera: Aleyrodidae) is a polyphagous pest in greenhouse crops. The efficacy of two entomopathogenic nematodes (EPN), Steinernema feltiae and Heterorhabditis bacteriophora, as biological control agents against T. vaporariorum was evaluated using two model crops typical of vegetable greenhouse productions: cucumber and pepper. Laboratory tests evaluated adults and second nymphal instars for pest susceptibility to different EPN species at different concentrations of infective juveniles (IJ; 0, 25, 50, 100, 150, 200, and 250 IJ per cm(2)); subsequent greenhouse trials against second nymphal instars on cucumber and pepper plants evaluated more natural conditions. Concentrations were applied in combination with Triton X-100 (0.1% v/v), an adjuvant for increasing nematode activity. In laboratory studies, both life stages were susceptible to infection by the two nematode species, but S. feltiae recorded a lower LC50 than H. bacteriophora for both insect stages. Similarly, in greenhouse experiments, S. feltiae required lower concentrations of IJ than H. bacteriophora to reach the same mortality in nymphs. In greenhouse trials, a significant difference was observed in the triple interaction among nematode species × concentration × plant. Furthermore, the highest mortality rate of the second nymphal instars of the T. vaporariorum was obtained from the application of S. feltiae concentrated to 250 IJ/cm(2) on cucumber (49 ± 1.23%). The general mortality caused by nematodes was significantly higher in cucumber than in pepper. These promising results support further investigation for the optimization of the best EPN species/concentration in combination with insecticides or adjuvants to reach a profitable control of this greenhouse pest.

  17. Toxicity of insecticides to the sweetpotato whitefly (Hemiptera: Aleyrodidae) and its natural enemies.

    Science.gov (United States)

    Bacci, Leandro; Crespo, André L B; Galvan, Tederson L; Pereira, Eliseu J G; Picanço, Marcelo C; Silva, Gerson A; Chediak, Mateus

    2007-07-01

    Efficient chemical control is achieved when insecticides are active against insect pests and safe to natural enemies. In this study, the toxicity of 17 insecticides to the sweetpotato whitefly, Bemisia tabaci (Gennadius), and the selectivity of seven insecticides to natural enemies of this insect pest were evaluated. To determine the insecticide toxicity, B. tabaci adults were exposed to abamectin, acephate, acetamiprid, cartap, imidacloprid, malathion, methamidophos, bifenthrin, cypermethrin, deltamethrin, esfenvalerate, fenitrothion, fenpropathrin, fenthion, phenthoate, permethrin and trichlorphon at 50 and 100% of the field rate (FR), and to water (untreated control). To determine the insecticide selectivity, adults of Encarsia sp., Acanthinus sp., Discodon sp. and Lasiochilus sp. were exposed to abamectin, acephate, acetamiprid, cartap, imidacloprid, malathion and methamidophos at 50 and 100% FR, and to water. Groups of each insect species were exposed to kale leaves preimmersed in each treatment under laboratory conditions. Mortality of exposed individuals was recorded 24 h after treatment. Cartap and imidacloprid at 50 and 100% FR and abamectin and acetamiprid at 100% FR showed insecticidal activity to B. tabaci adults. Abamectin at 50 and 100% FR was the least insecticidal compound to the natural enemies Acanthinus sp., Discodon sp. and Lasiochilus sp. The present results suggest that abamectin at 100% FR may decrease B. tabaci field populations but can still be harmless to predators. Implications of these results within an integrated pest management context are discussed. Copyright (c) 2007 Society of Chemical Industry.

  18. Densidades y frecuencias de liberación de Encarsia formosa (Hymenoptera: Aphelinidae sobre Trialeurodes vaporariorum (Homoptera: Aleyrodidae en tomate

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    Tello Paola

    2007-12-01

    Full Text Available

    La mosca blanca de los invernaderos, Trialeurodes vaporariorum (Westwood (Homoptera: Aleyrodidae es una de las plagas más importantes de cultivos de tomate bajo invernadero en la Sabana de Bogotá. Para su control tradicionalmente se acude a la aplicación de insecticidas. Sin embargo, también son contempladas liberaciones del parasitoide Encarsia formosa (Gahan (Hymenoptera: Aphelinidae. Para estandarizar el proceso de cría masiva de E. formosa, se evaluaron tres densidades diferentes de liberación de las avispas (6, 12 y 18 avispas/planta en tres frecuencias de liberación (1, 2 y 3 veces/semana, sobre plantas de tomate de ocho semanas de edad con tres niveles de infestación (15, 30 y 45 ninfas de mosca blanca/hoja, susceptibles de ser parasitadas. El mayor porcentaje de parasitismo (70% en ninfas de tercer instar se logró cuando se liberaron seis avispas por planta, dosificadas en tres momentos diferentes en la misma semana. El menor porcentaje de parasitismo (50%, se obtuvo cuando se realizó una sola liberación de 6, 12 o 18 avispas. Los resultados anteriores permiten concluir que se puede lograr un porcentaje de parasitismo en torno a un 70% de la infestación de mosca blanca (hasta 45 ninfas/hoja en plantas de tomate con pocas avispas de E. formosa (seis cuando se liberan en tres momentos diferentes.

  19. Sensitivity of Bemisia Tabaci (Hemiptera: Aleyrodidae) to Several New Insecticides in China: Effects of Insecticide Type and Whitefly Species, Strain, and Stage

    Science.gov (United States)

    Xie, Wen; Liu, Yang; Wang, Shaoli; Wu, Qingjun; Pan, Huipeng; Yang, Xin; Guo, Litao; Zhang, Youjun

    2014-01-01

    Abstract Whitefly biotypes B and Q are the two most damaging members of the Bemisia tabaci (Hemiptera: Aleyrodidae) species complex. Control of B. tabaci (and especially of Q) has been impaired by resistance to commonly used insecticides. To find new insecticides for B. tabaci management in China, we investigated the sensitivity of eggs, larvae, and adults of laboratory strains of B and Q (named Lab-B and Lab-Q) and field strains of Q to several insecticides. For eggs, larvae, and adults of B. tabaci and for six insecticides (cyantraniliprole, chlorantraniliprole, pyriproxyfen, buprofezin, acetamiprid, and thiamethoxam), LC 50 values were higher for Lab-Q than for Lab-B; avermectin LC 50 values, however, were low for adults of both Lab-Q and Lab-B. Based on the laboratory results, insecticides were selected to test against eggs, larvae, and adults of four field strains of B. tabaci Q. Although the field strains differed in their sensitivity to the insecticides, the eggs and larvae of all strains were highly sensitive to cyantraniliprole, and the adults of all strains were highly sensitive to avermectin. The eggs, larvae, and adults of B. tabaci Q were generally more resistant than those of B. tabaci B to the tested insecticides. B. tabaci Q eggs and larvae were sensitive to cyantraniliprole and pyriproxyfen, whereas B. tabaci Q adults were sensitive to avermectin. Field trials should be conducted with cyantraniliprole, pyriproxyfen, and avermectin for control of B. tabaci Q and B in China. PMID:25434040

  20. Action threshold for applying insect growth regulators to tomato for management of irregular ripening caused by Bemisia argentifolii (Homoptera: Aleyrodidae).

    Science.gov (United States)

    Schuster, D J

    2002-04-01

    The whitefly Bemisia argentifolii Bellows & Perring is a major pest of tomatoes, causing an irregular ripening disorder characterized externally by incomplete or inhibited reddening of fruit, especially in longitudinal sections, and internally by an increase in the amount of white tissue. Experiments were undertaken during the spring and fall of 1997 and 1998 and the spring of 1999 to develop an action threshold for applying the insect growth regulators (IGRs) buprofezin and pyriproxyfen to manage B. argentifolii and irregular ripening. The IGRs were applied when predetermined thresholds were reached and were compared with a high rate of the systemic insecticide imidacloprid, which was applied at transplanting and provided season-long whitefly control. Only plots treated when the numbers of sessile nymphs (second through fourth instars) reached five per 10 leaflets consistently had both external and internal irregular ripening severity ratings similar to the imidacloprid standard. Results were similar for buprofezin and pyriproxyfen even though the modes of action differ. The five nymphs per 10 leaflets threshold lends itself to field scouting because nymphal counts completed in the field using the unaided eye supplemented with a 10x hand lens were linearly and significantly related to counts completed in the laboratory with a dissecting microscope.

  1. Comparision of the Efficiency of the Current Oils and Insecticide Compounds in Control of Greenhouse Whitefly, Trialeurodes vaporariorum (Westwood, (Hem.: Aleyrodidae on Rose and their Interaction

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    Asghar Hosseininia

    2017-03-01

    Full Text Available Introduction: Rose plant (R osa hybrid is cultivated in nearly all regions of Iran and they are more common in the western areas of Iran. The intensive cultivation of rose often leads to injuries by pathogens or noxious animals and may require the implementation of pest control measures. Among the insect pests of roses, the greenhouse whitefly, Trialeurodes vaporariorum (Westwood (Hem.: Aleyrodidae, is fairly common pest that it is considered as major pests on roses in Iran. This pest infests the undersides of rose leaves, where the feeding adults and nymphs produce honeydew on which sooty mould grows. Considering the importance of oils in the integrated management program of this pest, in the present survey the possibility of whitefly control on rose plant were carried out to assess mortality rate (MR, synergistic rate (SR and Lc50 of the oils and common insecticide. Materials and Methods: The experiment was conducted in a greenhouse located at the experimental site of National Ornamental Plant Institute, Mahallt, Iran. The plants (Rosa hybrid Apollo were cut to stimulate rooting and then grown in plot containing a mixture of sand and sheep manure. Nine rose plant cuttings were planted in each plot with 1m2 space and 0.5 m distance each plot. So, each treatment had 9 shrubs of rose. The greenhouse whitefly T. vaporariorum were collected from infested rose plants and reared on rose. Each rose plant with one-year old was infested via 200 different stages of the whitefly. Fourteen days after infesting, compounds were sprayed on the infested plants with electrostatic atomizer backpack sprayer. Before spraying, plots were separated by plastic. Whitefly different stages from behind of three leaflets that separated from 15, 20 and 25 cm tip of plant were counted under a stereomicroscope (10 X one day before and seven days after treatment. The effect of oils and common insecticide on whitefly mortality rate (MR was performed in completely randomized

  2. Detection of resistance, cross-resistance, and stability of resistance to new chemistry insecticides in Bemisia tabaci (Homoptera: Aleyrodidae).

    Science.gov (United States)

    Basit, Muhammad; Saeed, Shafqat; Saleem, Mushtaq Ahmad; Denholm, Ian; Shah, Maqbool

    2013-06-01

    Resistance levels in whitefly, Bemisia tabaci (Gennadius) collections from cotton and sunflower (up to four districts) for five neonicotinoids and two insect growth regulators (IGRs) were investigated for two consecutive years. Based on the LC50(s), all collections showed slight to moderate levels of resistance for the tested insecticides compared with the laboratory susceptible population. The data also indicated that cotton and sunflower collections had similar resistance levels. In comparison (four collections), Vehari collections showed higher resistance for acetamiprid, thiacloprid, and nitenpyram compared with those of others. Average resistance ratios for acetamiprid, thiacloprid, and nitenpyram ranged from 5- to 13-, 4- to 8-, and 9- to 13-fold, respectively. Multan and Vehari collections also exhibited moderate levels (9- to 16-fold) of resistance to buprofezin. Furthermore, toxicity of neonicotinoids against immature stages was equal to that of insect growth regulators. The data also suggested that resistance in the field populations was stable. After selection for four generations with bifenthrin (G1 to G4), resistance to bifenthrin increased to 14-fold compared with the laboratory susceptible population. Selection also increased resistance to fenpropathrin, lambdacyhalothrin, imidacloprid, acetamiprid, and diafenthuron. Cross-resistance and stability of resistance in the field populations is of some concern. Rotation of insecticides having no cross-resistance and targeting the control against immature stages may control the resistant insects, simultaneously reducing the selection pressure imposed.

  3. The Effects of Some Botanical Insecticides and Pymetrozine on Life Table Parameters of Silver Leaf Whitefly Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae

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    Reihaneh Barati

    2013-01-01

    Full Text Available The objective of this research was to assess the effects of extracts of two medicinalplant species: Allium sativum (Linn and Calotropis procera (Aiton, and a formulation containingazadirachtin on life table parameters of silver leaf whitefly (SLW, Bemisia tabaci biotypeB (Gennadius (Hemiptera: Aleyrodidae, grown on greenhouse tomato plants. Theeffects were compared to that of pymetrozine, a synthetic insecticide. Bioassays were carriedout in a greenhouse under controlled conditions of 27 ± 2°C, R.H. of 55 ± 5% and 16:8h (L:D photo period.All treatments significantly affected the survivorship and fertility of SLW female adults,reducing the net reproduction rate, mean generation time and intrinsic rate of increase ofthis insect.The net reproductive rate [R0] values for the populations treated with garlic extract,milkweed extract, pymetrozine, azadirachtin, control for extracts (ethanol + distilled waterand control for pesticides (distilled water were 23.58, 19.32, 10.78, 8.23, 49.66, 57.55; theintrinsic rate of increases [rm] were 0.134, 0.139, 0.110, 0.090, 0.177, 0.178; the mean generationtimes [T] were 23.49, 21.23, 21.66, 23.50, 22.06, 22.69; the doubling times [DT] were 5.14,4.95, 6.27, 7.56, 3.91, 3.87, and the finite rates of increase [λ] were 1.144, 1.149, 1.116, 1.094, 1.193,1.195, respectively. Azadirachtin had the highest effect on the life table parameters of SLW.Our findings indicated that, although herbal extracts were not effective as much asthe chemical insecticides, they can be effective in pest control. Therefore, they are suitablechoices for replacing chemical insecticides and for alternative use with azadirachtin inSLW IPM program.

  4. Sensitivity of Bemisia tabaci (Hemiptera: Aleyrodidae) to several new insecticides in China: effects of insecticide type and whitefly species, strain, and stage.

    Science.gov (United States)

    Xie, Wen; Liu, Yang; Wang, Shaoli; Wu, Qingjun; Pan, Huipeng; Yang, Xin; Guo, Litao; Zhang, Youjun

    2014-01-01

    Whitefly biotypes B and Q are the two most damaging members of the Bemisia tabaci (Hemiptera: Aleyrodidae) species complex. Control of B. tabaci (and especially of Q) has been impaired by resistance to commonly used insecticides. To find new insecticides for B. tabaci management in China, we investigated the sensitivity of eggs, larvae, and adults of laboratory strains of B and Q (named Lab-B and Lab-Q) and field strains of Q to several insecticides. For eggs, larvae, and adults of B. tabaci and for six insecticides (cyantraniliprole, chlorantraniliprole, pyriproxyfen, buprofezin, acetamiprid, and thiamethoxam), LC50 values were higher for Lab-Q than for Lab-B; avermectin LC50 values, however, were low for adults of both Lab-Q and Lab-B. Based on the laboratory results, insecticides were selected to test against eggs, larvae, and adults of four field strains of B. tabaci Q. Although the field strains differed in their sensitivity to the insecticides, the eggs and larvae of all strains were highly sensitive to cyantraniliprole, and the adults of all strains were highly sensitive to avermectin. The eggs, larvae, and adults of B. tabaci Q were generally more resistant than those of B. tabaci B to the tested insecticides. B. tabaci Q eggs and larvae were sensitive to cyantraniliprole and pyriproxyfen, whereas B. tabaci Q adults were sensitive to avermectin. Field trials should be conducted with cyantraniliprole, pyriproxyfen, and avermectin for control of B. tabaci Q and B in China. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

  5. A new whitefly genus and species, Himalayaleyrodes sarcococcae Dubey (Hemiptera: Aleyrodidae) infesting Christmas box (Buxaceae) in Western Himalaya, India.

    Science.gov (United States)

    Dubey, Anil Kumar; Singh, Sudhir

    2017-05-24

    Puparia, immatures and adults of a new whitefly genus and species, Himalayaleyrodes sarcococcae Dubey are described from the Western Himalaya, India. The new species was found feeding on leaves as well as on green stems of Sarcococca saligna (D. Don) Muell. Biological information, habitus, line arts, photomicrographs of holotype and Scanning Electron Microscope (SEM) images are given for this new taxon. Also, we discuss similarities and dissimilarities of puparia of the new genus with its closely related genus Bemisia Quaintance & Baker. Feeding behaviour is discussed.

  6. Genetic variation of the greenhouse whitefly, Trialeurodes vaporariorum (Hemiptera: Aleyrodidae), among populations from Serbia and neighbouring countries, as inferred from COI sequence variability.

    Science.gov (United States)

    Prijović, M; Skaljac, M; Drobnjaković, T; Zanić, K; Perić, P; Marčić, D; Puizina, J

    2014-06-01

    The greenhouse whitefly Trialeurodes vaporariorum Westwood, 1856 (Hemiptera: Aleyrodidae) is an invasive and highly polyphagous phloem-feeding pest of vegetables and ornamentals. Trialeurodes vaporariorum causes serious damage due to direct feeding and transmits several important plant viruses. Excessive use of insecticides has resulted in significantly reduced levels of susceptibility of various T. vaporariorum populations. To determine the genetic variability within and among populations of T. vaporariorum from Serbia and to explore their genetic relatedness with other T. vaporariorum populations, we analysed the mitochondrial cytochrome c oxidase I (COI) sequences of 16 populations from Serbia and six neighbouring countries: Montenegro (three populations), Macedonia (one population) and Croatia (two populations), for a total of 198 analysed specimens. A low overall level of sequence divergence and only five variable nucleotides and six haplotypes were found. The most frequent haplotype, H1, was identified in all Serbian populations and in all specimens from distant localities in Croatia and Macedonia. The COI sequence data that was retrieved from GenBank and the data from our study indicated that H1 is the most globally widespread T. vaporariorum haplotype. A lack of spatial genetic structure among the studied T. vaporariorum populations, as well as two demographic tests that we performed (Tajima's D value and Fu's Fs statistics), indicate a recent colonisation event and population growth. Phylogenetic analyses of the COI haplotypes in this study and other T. vaporariorum haplotypes that were retrieved from GenBank were performed using Bayesian inference and median-joining (MJ) network analysis. Two major haplogroups with only a single unique nucleotide difference were found: haplogroup 1 (containing the five Serbian haplotypes and those previously identified in India, China, the Netherlands, the United Kingdom, Morocco, Reunion and the USA) and haplogroup 3

  7. Low levels of mitochondrial DNA and symbiont diversity in the worldwide agricultural pest, the greenhouse whitefly Trialeurodes vaporariorum (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Kapantaidaki, Despoina E; Ovčarenko, Irina; Fytrou, Natasa; Knott, K Emily; Bourtzis, Kostas; Tsagkarakou, Anastasia

    2015-01-01

    Trialeurodes vaporariorum, the greenhouse whitefly, is a cosmopolitan agricultural pest. Little is known about the genetic diversity of T. vaporariorum and the bacterial symbionts associated with this species. Here, we undertook a large phylogeographic study by investigating both the mitochondrial (mt) diversity and the infection status of 38 T. vaporariorum collections from 18 countries around the world. Genetic diversity of T. vaporariorum was studied by analyzing sequence data from the mt cytochrome oxidase I, cytochrome b, and NADH dehydrogenase subunit 5 genes. Maximum-likelihood (ML) phylogeny reconstruction delineated 2 clades characterized by limited sequence divergence: one clade comprised samples only from the Northern hemisphere whereas the other comprised samples from a broader geographical range. The presence of secondary symbionts was determined by PCR using primers specific for Hamiltonella, Rickettsia, Arsenophonus, Cardinium, Wolbachia, and Fritschea. Most individuals examined harbored at least one secondary endosymbiont, and Arsenophonus was detected in almost all male and female individuals. Wolbachia was present at a much lower frequency, and Cardinium was detected in only a few individuals from Greece. Rickettsia, Hamiltonella, and Fritschea were not found. Additionally, we set out to further analyze Arsenophonus diversity by multilocus sequence typing analysis; however, the Arsenophonus sequences did not exhibit any polymorphism. Our results revealed remarkably low diversity in both mtDNA and symbionts in this worldwide agricultural pest, contrasting sharply with that of the ecologically similar Bemisia tabaci. © The American Genetic Association 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Genome-Wide Characterization and Expression Profiling of Sugar Transporter Family in the Whitefly, Bemisia tabaci (Gennadius (Hemiptera: Aleyrodidae

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    Zezhong Yang

    2017-05-01

    Full Text Available Sugar transporters (STs play pivotal roles in the growth, development, and stress responses of phloem-sucking insects, such as the whitefly, Bemisia tabaci. In this study, 137 sugar transporters (STs were identified based on analysis of the genome and transcriptome of B. tabaci MEAM1. B. tabaci MEAM1 encodes a larger number of STs than other selected insects. Phylogenetic and molecular evolution analysis showed that the 137 STs formed three expanded clades and that the genes in Sternorrhyncha expanded clades had accelerated rates of evolution. B. tabaci sugar transporters (BTSTs were divided into three groups based on their expression profiles across developmental stages; however, no host-specific BTST was found in B. tabaci fed on different host plants. Feeding of B. tabaci adults with feeding diet containing dsRNA significantly reduced the transcript level of the target genes in B. tabaci and mortality was significantly improved in B. tabaci fed on dsRNA compared to the control, which indicates the sugar transporters may be used as potential RNAi targets for B. tabaci bio-control. These results provide a foundation for further studies of STs in B. tabaci.

  9. Efficacy of an entomopathogenic fungus, Isaria fumosorosea and an insect growth regulator against the rugose spiraling whitefly, Aleurodicus rugioperculatus Martin (Hemiptera: Aleyrodidae)

    Science.gov (United States)

    Aleurodicus rugioperculatus Martin, infamous as gumbo limbo or rugose spiraling whitefly is a new addition in the list of devastating whitefly species found in Florida. It is a newly introduced pest of Central American origin, reported first time in Florida from Miami-Dade County in 2009. Since then...

  10. Inter-regional differences in baseline toxicity of Bemisia argentifolii (Homoptera: Aleyrodidae) to the two insect growth regulators, buprofezin and pyriproxyfen.

    Science.gov (United States)

    Toscano, N C; Prabhaker, N; Castle, S J; Henneberry, T J

    2001-12-01

    A survey of 53 Bemisia argentifolii Bellows & Perring populations from different agricultural regions in California and Arizona was conducted from 1997 to 1999 to establish baseline toxicological responses to buprofezin and pyriproxyfen. Although both compounds proved to be highly toxic even in minute quantities to specific stages, geographical and temporal differences in responses were detected using a leaf spray bioassay technique. Monitoring for three years revealed that six to seven populations had higher LC50 values but not greater survival when exposed to these two insecticides. A significant difference in relative susceptibility to buprofezin was first observed in late season 1997 in San Joaquin Valley populations with LC50s ranging from 16 to 22 microg (AI)/liter(-1) compared with IC50s of 1 to 3 mg (AI)/liter(-1) in Imperial, Palo Verde Valley and Yuma populations. Whiteflies collected in subsequent years from these and other locations showed an increase in susceptibility to buprofezin. Regional differences in susceptibilities to pyriproxyfen were minimal within the same years. Three years of sampling revealed consistently higher LC50s to pyriproxyfen in populations from Palo Verde Valley, CA, compared with whiteflies from Imperial, San Joaquin Valley or Yuma. As was the case with buprofezin, a decline in LC50s to pyriproxyfen was observed in whiteflies from all locations sampled in 1999. However, no correlation was observed between buprofezin and pyriproxyfen toxicity in any of the strains. The variable toxicities observed to both compounds over a period of 3 yr may be due principally to inherent differences among geographical populations or due to past chemical use which may confer positive or negative cross-resistance to buprofezin or pyriproxyfen.

  11. Whiteflies: Developing host plant resistance in watermelon from wild sources

    Science.gov (United States)

    The whitefly (Aleyrodidae) Bemisia tabaci causes serious damage to horticultural crops, including watermelon (Citrullus lanatus var. lanatus) and it is known to transmit many plant viruses. This whitefly is highly polyphagous, with over 1,000 known species, and can adapt to the environment. Yet, th...

  12. Pre shipping dip treatments using soap, natural oils, and Isaria fumosorosea: potential biopesticides for mitigating the spread of whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) invasive insects on ornamental plants

    Science.gov (United States)

    The whitefly Bemisia tabaci (Hemiptera: Aleyodidae) is an invasive insect pest affecting different crops including vegetables, fruits, cereals, and ornamentals. The efficacy of some products such as commercial soap, natural oils and Preferal® (based on the entomopathogenic fungus Isaria fumosorosea ...

  13. Compatibility of the insect pathogenic fungus Beauveria bassiana with neem against sweetpotato whitefly, Bemisia tabaci, on eggplant

    Science.gov (United States)

    A study on the compatibility of the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin (Ascomycota: Hypocreales) with neem was conducted against sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), on eggplant. Initially, three concentrations of B. bassiana (106, 1...

  14. Indutores de resistência à mosca-branca Bemisia tabaci Biótipo B (GENN., 1889 (Hemiptera: Aleyrodidae em soja Resistance inducers to the whitefly Bemisia tabaci Biotype B (GENN., 1889 (Hemiptera: Aleyrodidae in soybeans

    Directory of Open Access Journals (Sweden)

    Jair Campos Moraes

    2009-10-01

    Full Text Available Objetivou-se, neste trabalho, avaliar o efeito da aplicação de indutores na resistência de duas cultivares de soja à mosca-branca Bemisia tabaci biótipo B. O experimento foi conduzido no Departamento de Entomologia - UFLA. As sementes de soja, cultivar IAC-19 e MONSOY-8001, foram previamente tratadas com o fungicida captan. Foram testados os seguintes tratamentos: T1- irrigação no solo, ao redor das plantas de cada vaso, de 250 mL de solução de ácido silícico a 1%; T2- pulverização das plantas, até o ponto de escorrimento, com solução a 0,3% de acibenzolar-s-methyl; T3- pulverização das plantas, até o ponto de escorrimento, com calda a 0,24% de pyraclostrobin+epoxiconazole e T4- testemunha. As plantas foram infestadas com 100 adultos da mosca-branca por vaso que liberados oito dias após a aplicação dos tratamentos. Avaliaram-se o número de ovos na face abaxial de cada folha, que foi marcada para posterior avaliação de ninfas; teores de taninos e de lignina; peso seco das raízes e da parte aérea. Não houve diferença para número de ovos e ninfas entre as cultivares de soja, porém, a viabilidade média de B. tabaci foi menor a cultivar IAC-19. O cultivar de soja IAC-19 demonstrou moderada resistência ao biótipo B de B. tabaci. A aplicação de silício ou acibenzolar-s-methyl induz um aumento no teor de lignina na cultivar de soja IAC-19.The objective of this paper was to evaluate the effect of the application of inducers on the resistance of two soybean cultivars to the whitefly B. tabaci Biotype B. The experiment was carried out at the Entomology Department - UFLA. The soybean seeds of cultivars IAC-19 and MONSOY-8001 were previously treated with Captan fungicide. The following treatments were tested: T1- irrigating the soil around the plants of each pot with 250 mL of solution of 1% silicic acid; T2- spraying of the plants, to the 'point of dripping', with a solution of 0.3% acibenzolar-s-methyl; T3- spraying of

  15. Asymmetric consequences of host plant occupation on the competition between the whiteflies Bemisia tabaci cryptic species MEAM1 and Trialeurodes vaporariorum (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Zhang, Gui-Fen; Lövei, Gábor L; Hu, Man; Wan, Fang-Hao

    2014-12-01

    The two common whitefly species, Bemisia tabaci (Gennadius) MEAM1 and Trialeurodes vaporariorum (Westwood), often co-occur on their host plants. The effect of host plant occupation by one species on later-arriving conspecific individuals or on the other competing species was examined. Resource preoccupied by T. vaporariorum had mostly negative effects on the life history parameters of later-arriving conspecifics. Red-eyed nymph and immature survival of T. vaporariorum decreased when resource was preoccupied by conspecifics, irrespective of the previous occupation scenario. However, resource preoccupied by T. vaporariorum had only minor detrimental effects on the performance of later-arriving B. tabaci MEAM1. In the opposite colonisation sequence, previous occupation by B. tabaci MEAM1 had no significant effects on the life history parameters of later-arriving conspecifics, but severe detrimental effects were observed on the performance of later-arriving T. vaporariorum. Total immature survival of T. vaporariorum decreased in both weak and strong previous occupation situations by B. tabaci MEAM1. The interspecific interactions between B. tabaci MEAM1 and T. vaporariorum were asymmetric, with B. tabaci MEAM1 being the superior competitor. This superiority could partially explain the rapid spread of B. tabaci MEAM1 in China. © 2013 Society of Chemical Industry.

  16. Identifikasi kutukebul (Hemiptera: Aleyrodidae dari beberapa tanaman inang dan perkembangan populasinya

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    Purnama Hidayat

    2017-02-01

    Full Text Available Whiteflies (Hemiptera: Aleyrodidae can cause direct and indirect damages on plants, especially vegetables. There is only limited information regarding taxonomy and population dynamic of whiteflies attacking vegetables in Indonesia. This research is conducted to identify species of whitefly collected from chili pepper, tomato, and soybean, and to study their population dynamic. The information gathered from these studies will be useful to support whitefly management in the field. Based on morphology identification of the puparium collected directly from the host plants, there were four species of whitefly identified from chili pepper, tomato, and soybean in Bogor, Cianjur, and Sukabumi, i.e. Bemisia tabaci, Aleurodicus dispersus, Trialeurodes vaporariorum, and Dialeurodes sp. The presence of B. tabaci on chili pepper and tomato was associated with virus infection that causes yellowing and leaf curl disease. This population of B. tabaci tended to increase along with plant growth and generally reached the highest population when the plant was 60-70 days after planting.

  17. Sources of wild germplasm to improve whitefly resistance in commercial watermelon (Citrullus lanatus var. lanatus)

    Science.gov (United States)

    Host plant resistance is a fundamental component of crop sustainability. The Bemisia tabaci (Hemiptera: Aleyrodidae) whitefly complex is well known as a key pest of many crops around the world. It is adaptive to its environment and feeds on an impressive number of plant species (over 1,000). Yet, th...

  18. Effectiveness of two insect growth regulators against Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) and Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) and their impact on population densities of arthropod predators in cotton in Pakistan.

    Science.gov (United States)

    Gogi, Muhammad D; Sarfraz, Rana M; Dosdall, Lloyd M; Arif, Muhammad J; Keddie, Andrew B; Ashfaq, Muhammad

    2006-10-01

    Field efficacies of two insect growth regulators (IGRs) at two recommended application rates, buprofezin at 370 and 555 g AI ha(-1) and lufenuron at 37 and 49 g AI ha(-1), were determined against the sweet potato whitefly, Bemisia tabaci (Gennadius), and the cotton bollworm, Helicoverpa armigera (Hübner), in experimental plots of cotton at the Directorate of Cotton Research, Faisalabad, Pakistan. Adverse effects of the IGRs on populations of associated arthropod predators, namely geocorids, chrysopids, coccinellids, formicids and arachnids, were also assessed. Both IGRs significantly reduced populations of B. tabaci at each application rate 24, 48 and 72 h after treatment, and higher doses were more effective than lower doses. Buprofezin was not effective against H. armigera at any tested dose for any time of treatment in any spray. Lufenuron applied at 37 and 49 g AI ha(-1) effectively suppressed H. armigera populations, resulting in significant reductions in crop damage. At lower doses, both IGRs appeared safe to predator populations, which did not differ significantly in IGR-treated versus untreated control plots. Population densities of formicids and coccinellids were significantly lower at high concentrations of both IGRs in treatment plots, possibly as a result of reduced prey availability. The potential role of buprofezin and lufenuron for control of B. tabaci and H. armigera in a spray programme and the likelihood of direct toxic effects of IGRs on predatory fauna of cotton are discussed.

  19. Effect of solid and aqueous extract of vermicompost on growth characteristics of tomato and greenhouse whitefly (Trialeurodes vaporariorum)

    OpenAIRE

    A. Peimani Foroushani; N. Poorjavad; M. Haghigh; J. Khajehali

    2016-01-01

    Considering the increase of using vermicompost fertilizers in greenhouse cultivation, effect of vermicompost application on growth characteristics of tomato and one of its major pests [greenhouse whitefly, Trialeurodes vaporariorum (Hem:Aleyrodidae)] was investigated. The experiment consisted of five treatments: control (without vermicompost), 30% and 60% solid vermicompost fertilizer, and 40% and 20% aqueous extracts of vermicompost. Effect of vermicompost on greenhouse whitefly was tested f...

  20. Oviposition behavior of the silver leaf whitefly Bemisia tabaci biotype B on tomato; Comportamento de oviposicao da mosca-branca Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae) biotipo B em tomateiro

    Energy Technology Data Exchange (ETDEWEB)

    Vendramim, Jose D. [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Dept. de Entomologia, Fitopatologia e Zoologia Agricola]. E-mail: jdvendra@esalq.usp.br; Souza, Antonio P. de [Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS (Brazil). Dept. de Morfofisiologia. Lab. de Anatomia Humana]. E-mail: apsouza@nin.ufms.br; Ongarelli, Maria das G. [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Lab. de Fisiologia e Bioquimica Pos-Colheita]. E-mail: mgong@esalq.usp.br

    2009-01-15

    The objective of this work was to evaluate the influence of the leaf surface, the insect geotropic behavior and the type of foliar trichome on Bemisia tabaci (Genn.) biotype B oviposition on tomato leaves. Bemisia tabaci females were confined in acrylic boxes in which tomato leaflets were fixed at the bottom and top part of the boxes to allow insects to access the leaf surface to be tested (adaxial and/or abaxial) in both no-choice and free choice tests. Oviposition was always higher when the leaf was offered at the top of the box and preferably at the abaxial leaf surface. The effects of leaf trichomes (glandular and non glandular) on B. tabaci oviposition was evaluated by offering the abaxial surface of tomato leaflets to females after a 70% ethanol wash to remove glandular exsudates against a control treatment (without a ethanol wash). Oviposition was concentrated mostly near to non glandular trichomes, showing whitefly females can discriminate among the trichomes. (author)

  1. Whitefly species (Hemiptera: Aleyrodidae on wild and cultivated plants in the horticultural region of Rosario, Santa Fe, Argentina Especies de moscas blancas (Hemiptera: Aleyrodidae sobre plantas silvestres y cultivadas en la región hortícola de Rosario, Santa Fe, Argentina

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    Gustavo G. Gonsebatt

    2012-06-01

    Full Text Available Whiteflies of economic importance are polyphagous, being able to develop on a large number of cultivated and spontaneous plants. We recorded the whitefly species on vegetable and flower crops and the wild plants associated, under greenhouse and field conditions, for two years. We observed two species: Trialeurodes vaporariorum (Westwood and the Bemisia tabaci complex (Gennadius. T vaporariorum was recorded on 24 plant species (11 families, 12 and 8 of which are new hosts in Argentina and in the world, respectively. The B. tabaci complex was recorded only on flower production systems, on 19 plant species (11 families, 14 and 7 of which are new hosts in Argentina and in the world, respectively. The crops Glycine max (L. and Chrysanthemum morifolium Ramat., the wild species Amaranthus blitum L., Amaranthus quitensis Kunth, Conyza bonariensis (L., Galinsoga parviflora Cav., Sonchus oleraceus L. and Wedelia glauca (Ortega O. Hoffm. ex Hicken were hosts of both species. The only parasitoid recorded was Eretmocerus californicus near corni Haldeman (Hymenoptera: Aphelinidae from T. vaporariorum. This study, which is the first systematic survey of host plants in the region, intends to provide a better knowledge of the range of whiteflies host plants in Argentina.Las moscas blancas de importancia económica son polífagas y capaces de desarrollarse sobre numerosas plantas cultivadas y espontáneas. Registramos las especies de moscas blancas sobre cultivos hortícolas y de flores, y sobre las plantas silvestres asociadas. Observamos dos especies: Trialeurodes vaporariorum (Westwood y el complejo Bemisia tabaci (Gennadius. T. vaporariorum fue registrada sobre 24 especies de plantas (11 familias, 12 y 8 de las cuales son hospedantes nuevos para Argentina y a nivel mundial, respectivamente. El complejo B. tabaci fue registrado solo en sistemas de producción de flores, sobre 19 especies de plantas (11 familias, 14 y 7 de las cuales son nuevos hospedantes para

  2. The sterile insect technique in the integrated pest management of whitefly species in greenhouses

    International Nuclear Information System (INIS)

    Calvitti, M.; Remotti, P.C.; Cirio, U.

    2000-01-01

    Insect pests commonly known as whiteflies are Hemiptera belonging to the family of Aleyrodidae Trialeurodes vaporariorum Westwood (greenhouse whitefly) and the B-biotype of Bemisia tabaci Gennadius (=Bemisia argentifolii Bellows and Perring) are pests whose economic importance is constantly increasing within the European agriculture. The B-biotype of B. tabaci, in particular, has become more problematic by causing damage over a wide range, from the temperate climates of Californian squash fields to European greenhouses and field crops. In the absence of valid alternatives, many growers have resorted to intensive application of insecticides to control these pests, creating a severe environmental and health hazard. Several new environmentally safe technologies are currently available and have opened up new opportunities in the integrated pest management (IPM) of whiteflies under greenhouse conditions. In particular, biological or biologically-based control means, including a number of fungi, insects, and compounds have been recently developed. However, the limitation of whitefly population outbreaks in greenhouses is a problem that needs to be solved. The idea to extend the use of sterile insect technique (SIT) to a confined environment against whitefly species is novel, and especially when we consider that the target species undergo arrhenotoky (unfertilised females generate only male progenies). The possibility to join this approach to the Integrated Pest Management (IPM) of the whitefly species in the greenhouse may open new perspectives in the safe application of nuclear technology for pest control. The present work reviews recent advances in research and practice related to the development of SIT for the control of whiteflies in greenhouses. Explanations on whitefly radiation biology, with data on Bemisia spp. radio-sterilisation, methods for whitefly mass rearing and collection, and the definition of a complete SIT procedure tested against the greenhouse

  3. Sublethal effects of some synthetic and botanical insecticides on Bemisia tabaci (Hemiptera: Aleyrodidae

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    Esmaeily Saeideh

    2014-07-01

    Full Text Available In addition to direct mortality caused by insecticides, some biological traits of insects may also be affected by sublethal insecticide doses. In this study, we used the age-stage, two-sex life table method to evaluate the sublethal effects of the four synthetic insecticides: abamectin, imidacloprid, diazinon, and pymetrozin as well as the botanical insecticide taken from Calotropis procera (Asclepiadaceae extract, on eggs of the cotton whitefly, Bemisia tabaci (Hem.: Aleyrodidae. The lowest and highest survival rates and oviposition periods were observed in whiteflies treated by diazinon and imidacloprid, respectively. We found significant differences in the net reproductive rate (R0, the intrinsic rate of increase (r, the finite rate of increase (?, and the gross reproductive rate (GRR among different insecticides. Altogether, our results showed that pymetrozin and C. procera induced the most sublethal effects, thus they may be suitable candidates for use in integrated pest management programs of B. tabaci.

  4. Aleurotrachelus trachoides (pepper whitefly)

    Science.gov (United States)

    Aleurotrachelus trachoides Back also known as solanum or pepper whitefly is a new addition to the list of serious whitefly pests found in Florida. According to EPPO global database, it is a pest of over 70 different crops worldwide, which include a combination of edibles, ornamentals, palms, and wee...

  5. Facultative symbiont Hamiltonella confers benefits to Bemisia tabaci (Hemiptera: Aleyrodidae), an invasive agricultural pest worldwide.

    Science.gov (United States)

    Su, Qi; Oliver, Kerry M; Pan, Huipeng; Jiao, Xiaoguo; Liu, Baiming; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Xu, Baoyun; White, Jennifer A; Zhou, Xuguo; Zhang, Youjun

    2013-12-01

    Bacterial symbionts infect most insect species, including important pests such as whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), and often exert important effects on host ecology. The facultative symbiont Hamiltonella is found at high frequencies in the B. tabaci MED (type: Mediterranean-MED) in China. The prevalence of this symbiont in natural populations suggests beneficial effects of infection or manipulation of host reproduction. To date, however, no empirical studies on the biological role of Hamiltonella on the host B. tabaci have been reported. Here, we investigated the effects of Hamiltonella infection on the sex ratio and several fitness parameters in B. tabaci MED by comparing Hamiltonella-infected whiteflies with Hamiltonella-free ones. We found that Hamiltonella-infected whiteflies produced significantly more eggs, exhibited significantly higher nymphal survival, faster development times, and larger adult body size in comparison with Hamiltonella-free whiteflies, while no evidence of reproductive manipulation by Hamiltonella were found in B. tabaci MED. In conclusion, Hamiltonella infection substantially enhanced B. tabaci MED performance. This beneficial role may, at least partially, explain the high prevalence of Hamiltonella in B. tabaci MED populations and may also contribute to their effectiveness in spread of the plant pathogens tomato yellow leaf curl virus.

  6. First report on the whitefly, Aleurodicus pseudugesii on the coconut palm, Cocos nucifera in Brazil.

    Science.gov (United States)

    de Omena, Rose Paula Mendonça; Guzzo, Elio Cesar; Ferreira, Joana Maria Santos; de Mendonça, Fernando Antônio Cavalcante; de Lima, Aurino Florencio; Racca-Filho, Francisco; Santana, Antônio Euzébio Goulart

    2012-01-01

    The coconut palm, Cocos nucifera L. (Arecales: Arecaceae), is currently grown extensively throughout the intertropical zones of the world, including Brazil, where it constitutes an important source of income for growers. Although whiteflies are not normally considered coconut pests, these insects can damage crops directly by sucking the sap, which weakens the plant; indirect damage may be caused by sooty mold formation over the excreted honeydew and by the transmission of pathogens. Whiteflies have infested coconut plants in the northeastern, northern, and southeastern regions of Brazil. Infested materials were collected and the causative insect was identified as Aleurodicus pseudugesii Martin (Hemiptera: Aleyrodidae). This is the first report of A. pseudugesii in Brazil as a pest of the coconut palm.

  7. (Brief report Evaluation of Suitable Host Plant, as Banker Plant for Eretmocerus mundus, Whiteflies Parasitoid

    Directory of Open Access Journals (Sweden)

    M. J. Ardeh

    2016-03-01

    Full Text Available Introduction: Whiteflies (Homoptera; Aleyrodidae are the key pests of agricultural crops worldwide. Two species, which seriously damage crops, are the Silver leaf whitefly “Bemisia tabaci (Gennadius” and the Greenhouse whitefly “Trialeorodes vaporariorum (Westwood”. These pests are active on the underside of the leaves where they are relatively protected from insecticide. Moreover, emergence of resistant biotypes of whitelies impose much more costs on its chemical control. Therefore, during falling the past population, several researches have been carried out to find and use efficient biocontrol methods. One of the biocontrol agents to control B. tabaci is “Eretmocerus mundus” (Hy., Aphelinidae. The parasitoid should be introduced to control pest in the greenhouses. One of the methods, which is used in introducing of biological control agents, is ‘Banker Plant System’. In this system, the host plant has a population of reproducing natural enemy used as a reservoir. Therefore, as soon as the pest infection occurs, the parasitoids can find them and control the damage. İn a banker plant system, several aspects should be considered. Some of the behavioral and biological aspects are important. For example characteristics of leaf surface influence on the host finding time of the parasitoid. The biochemical characteristics of the host plants affect the parasitoid fitness. Therefore, we tried to compare these aspects of E. mundus in two host plants (eggplant and cotton from banker plant point of view, to control B. tabaci in the greenhouses. Materials and Methods: The two host plants (eggplant and cotton, were planted in the greenhouse and a culture of B. tabaci was reared on the plants. After two weeks, some of the infested plants were put in separate cages, and the parasitoid, E. mundus, that was collected from the egg plant and cotton fields of the Varamin region were released on the plants. Then, the biological characteristics of

  8. Bioactivity of indigenous medicinal plants against the cotton whitefly, Bemisia tabaci.

    Science.gov (United States)

    Hammad, E Abou-Fakhr; Zeaiter, A; Saliba, N; Talhouk, S

    2014-01-01

    Forty-one methanol extracts of 28 indigenous medicinal plant species were tested for their insecticidal bioactivity against cotton whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), adults and second nymphal instars under controlled conditions. This study is within a bioprospection context, in the form of utilizing local plant species as an alternative in sustainable agriculture development. Eighteen and nine plant extracts caused a significant decrease in number of live adult and nymphal whiteflies, respectively, compared to the control. This is the first report for the potential effect on survival of insects for 22 out of 28 tested medicinal plant species. Whole plant extracts of Ranunculus myosuroudes Boiss. and Kotschy (Ranunculaceae), Achillea damascena L. (Asteraceae), and Anthemis hebronica Boiss. and Kotschy (Asteraceae) and leaf extracts of Verbascum leptostychum DC. (Scrophulariaceae) and Heliotropium rotundifolium Boiss. (Borangiaceae) caused both repellent and toxic effects against the adult and second nymphal instars, respectively. Extracts of leaves and stems of Anthemis scariosa Boiss. (Asteraceae) and Calendula palestina Pers. (Asteraceae) were found to be more bioactive against the adult and nymphal instars, respectively, than extracts of other plant parts, such as flowers. Thus, the bioactive extracts of these medicinal plants have the potential to lower whitefly populations in a comprehensive pest management program in local communities, pending cultivation of these medicinal plant species.

  9. Bioactivity of indigenous medicinal plants against the cotton whitefly, Bemisia tabaci

    Science.gov (United States)

    Hammad, E. Abou-Fakhr; Zeaiter, A.; Saliba, N.; Talhouk, S.

    2014-01-01

    Abstract Forty-one methanol extracts of 28 indigenous medicinal plant species were tested for their insecticidal bioactivity against cotton whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), adults and second nymphal instars under controlled conditions. This study is within a bioprospection context, in the form of utilizing local plant species as an alternative in sustainable agriculture development. Eighteen and nine plant extracts caused a significant decrease in number of live adult and nymphal whiteflies, respectively, compared to the control. This is the first report for the potential effect on survival of insects for 22 out of 28 tested medicinal plant species. Whole plant extracts of Ranunculus myosuroudes Boiss. and Kotschy (Ranunculaceae), Achillea damascena L. (Asteraceae), and Anthemis hebronica Boiss. and Kotschy (Asteraceae) and leaf extracts of Verbascum leptostychum DC. (Scrophulariaceae) and Heliotropium rotundifolium Boiss. (Borangiaceae) caused both repellent and toxic effects against the adult and second nymphal instars, respectively. Extracts of leaves and stems of Anthemis scariosa Boiss. (Asteraceae) and Calendula palestina Pers. (Asteraceae) were found to be more bioactive against the adult and nymphal instars, respectively, than extracts of other plant parts, such as flowers. Thus, the bioactive extracts of these medicinal plants have the potential to lower whitefly populations in a comprehensive pest management program in local communities, pending cultivation of these medicinal plant species. PMID:25204756

  10. Radiation sterilization of the greenhouse white fly (Trialeurodes vaporariorum Westw., Homoptera, Aleyrodidae). Part 2

    International Nuclear Information System (INIS)

    Genchev, N.

    1987-01-01

    Results are reported of studies of the sterilizing effect on puparia and imagoes of the greenhouse white fly (T. vaporariorum). The irradiation was made by gamma rays at the rate of 12+-5% rad/s. The parameters of radiation-induced sterility were sex determined. The sterilizing effect was expressed in emergence of dominant lethal mutations in spermatozoa accompanied by partial sperm inactivation and of partial aspermia. The absolute sterilizing doses for the two ontogenetic stage are 6 and 7 krad respectively. Radiation induced sterilization of the male parent resulted in forced arrhenotoky in F 1 and was regarded as a transformation of parthogenesis factor necessary for the normal propagation in the insect process into one that is lethal to the population factor. Radiation induced female sterility in females was expressed in the emergence of dominant lethals in oocytes. The absolute sterilizing doses for the puparium and the imago were 5 and 6 krad, respectively. Doses ≥4 krad caused partial infertility

  11. Aleyrodes proletella (Linnaeaus, 1758) (Homoptera: Aleyrodidae) puede desarrollarse en plantas de tomate en condiciones controladas

    OpenAIRE

    Alonso, D.; Gómez, Azahara A.; Nombela, Gloria; Muñiz, Mariano

    2007-01-01

    La mosca blanca de la col, Aleyrodes proletella L. causa importantes daños directos en cultivos del género Brassica en Europa, entre los que se incluyen la coliflor, brócoli, lombarda y romanesco. En España se ha observado un incremento de sus poblaciones, especialmente en Islas Canarias, Navarra y Murcia. La aplicación prolongada de plaguicidas de amplio espectro origina la aparición de poblaciones resistentes y efectos medioambientales adversos. Tras una infestación accidental de adult...

  12. Electrostatic Insect Sweeper for Eliminating Whiteflies Colonizing Host Plants: A Complementary Pest Control Device in An Electric Field Screen-Guarded Greenhouse.

    Science.gov (United States)

    Takikawa, Yoshihiro; Matsuda, Yoshinori; Kakutani, Koji; Nonomura, Teruo; Kusakari, Shin-Ichi; Okada, Kiyotsugu; Kimbara, Junji; Osamura, Kazumi; Toyoda, Hideyoshi

    2015-05-12

    Our greenhouse tomatoes have suffered from attacks by viruliferous whiteflies Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) over the last 10 years. The fundamental countermeasure was the application of an electric field screen to the greenhouse windows to prevent their entry. However, while the protection was effective, it was incomplete, because of the lack of a guard at the greenhouse entrance area; in fact, the pests entered from the entrance door when workers entered and exited. To address this, we developed a portable electrostatic insect sweeper as a supplementary technique to the screen. In this sweeper, eight insulated conductor wires (ICWs) were arranged at constant intervals along a polyvinylchloride (PVC) pipe and covered with a cylindrical stainless net. The ICWs and metal net were linked to a DC voltage generator (operated by 3-V alkaline batteries) inside the grip and oppositely electrified to generate an electric field between them. Whiteflies on the plants were attracted to the sweeper that was gently slid along the leaves. This apparatus was easy to operate on-site in a greenhouse and enabled capture of the whiteflies detected during the routine care of the tomato plants. Using this apparatus, we caught all whiteflies that invaded the non-guarded entrance door and minimized the appearance and spread of the viral disease in tomato plants in the greenhouse.

  13. Populations of predators and parasitoids of Bemisia tabaci (Hemiptera: Aleyrodidae) after the application of eight biorational insecticides in vegetable crops.

    Science.gov (United States)

    Simmons, Alvin M; Shaaban, Abd-Rabou

    2011-08-01

    The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is an important pest of vegetables and many other crops worldwide. Eight biorational insecticides (based on oil, plant derivatives, insect growth regulator and fungus) were evaluated in the field for their influence on populations of six natural enemies of B. tabaci. Natural populations of two predators [Chrysoperla carnea Stephen (Neuroptera: Chrysopidae) and Orius spp. (Hemiptera: Anthocoridae)] and two genera of parasitoids [Encarsia spp. and Eretmocerus spp. (Hymenoptera: Aphelinidae)] were evaluated in eggplant (Solanum melongena L.). Also, augmented field populations of three predators [C. carnea, Coccinella undecimpunctata L. (Coleoptera: Coccinellidae) and Macrolophus caliginosus (Wagner) (Hemiptera: Miridae)] were evaluated in cabbage (Brassica oleracea var. capitata L.), cucumber (Cucumis sativus L.) and squash (Cucurbita pepo L.). Regardless of natural enemy or crop, jojoba oil, Biovar and Neemix had the least effect on abundance of the natural enemies in comparison with the other insecticides during a 14 day evaluation period. Conversely, Admiral, KZ oil, Mesrona oil, Mesrona oil + sulfur and natural oil had a high detrimental effect on abundance of the natural enemies. These results demonstrate the differential effects of biorational insecticides for whitefly control on predators and parasitoids in the field. This article is a US Government work and is in the public domain in the USA. Published 2011 by John Wiley & Sons, Ltd.

  14. Whitefly population dynamics in okra plantations Dinâmica populacional de mosca-branca em quiabo

    Directory of Open Access Journals (Sweden)

    Germano Leão Demolin Leite

    2005-01-01

    Full Text Available The control of whitefly Bemisia tabaci (Gennadius biotype B (Hemiptera: Aleyrodidae on okra (Abelmoschus esculentus L. consists primarily in the use of insecticides, due to the lack of information on other mortality factors. The objective of this study was to evaluate the spatial and temporal population dynamics of the whitefly B. tabaci biotype B on two successive A. esculentus var. "Santa Cruz" plantations. Leaf chemical composition, leaf nitrogen and potassium contents, trichome density, canopy height, plant age, predators, parasitoids, total rainfall and median temperature were evaluated and their relationships with whitefly on okra were determined. Monthly number estimates of whitefly adults, nymphs (visual inspection and eggs (magnifying lens occurred on bottom, middle and apical parts of 30 plants/plantation (one leaf/plant. Plants senescence and natural enemies, mainly Encarsia sp., Chrysoperla spp. and Coccinellidae, were some of the factors that most contributed to whitefly reduction. The second okra plantation, 50 m apart from the first, was strongly attacked by whitefly, probably because of the insect migration from the first to the second plantation. No significant effects of the plant canopy on whitefly eggs and adults distribution were found. A higher number of whitefly nymphs was found on the medium part than on the bottom part.O controle da mosca-branca Bemisia tabaci (Gennadius biótipo B (Hemiptera: Aleyrodidae em quiabeiro (Abelmoschus esculentus L. consiste principalmente no uso de inseticidas, em virtude da falta de informação sobre outros fatores de mortalidade. O objetivo deste trabalho foi compreender a dinâmica populacional, espacial e temporal da mosca-branca em dois cultivos sucessivos de quiabeiro "Santa Cruz". Avaliaram-se a composição química foliar, os níveis foliares de nitrogênio e de potássio, a densidade de tricomas, a altura de dossel, a idade de planta, predadores, parasitóides, pluviosidade total

  15. Temperature stress effects in Bemisia tabaci (Hemiptera: Aleyrodidae) type B whiteflies

    Science.gov (United States)

    Oxidative stress occurs in response to changes in the redox equilibiurm, which may be caused by increases in reactive oxygen species (ROS), a decrease in antioxidant protection or failure of cells to repair oxidative damage. ROS are either free radicals, reactive molecules containing oxygen atoms or...

  16. Assessing Compatibility of Isaria fumosorosea and Buprofezin for Mitigation of Aleurodicus rugioperculatus (Hemiptera: Aleyrodidae): An Invasive Pest in the Florida Landscape.

    Science.gov (United States)

    Kumar, Vivek; Francis, Antonio; Avery, Pasco B; McKenzie, Cindy L; Osborne, Lance S

    2018-05-28

    Rugose spiraling whitefly (RSW), Aleurodicus rugioperculatus Martin (Hemiptera: Aleyrodidae) is a new invasive whitefly pest in the Florida landscape, known to feed on a wide range of plants including palms, woody ornamentals, shrubs, and fruits. With the objective to find an alternative to neonicotinoid insecticides, and develop an ecofriendly management program for RSW, in the current study we evaluated the efficacy of a biopesticide containing the entomopathogenic fungi, Isaria fumosorosea Wize (Hypocreales: Clavicipitaceae), and an insect growth regulator buprofezin applied alone and in combination under laboratory and field conditions. Before assessing the two products, their compatibility was studied at six different concentrations of buprofezin. No significant inhibitive effect of buprofezin was observed on I. fumosorosea spore germination, and the average linear growth of the colony measured 14 d postinoculation. Under laboratory conditions, I. fumosorosea treatments (alone or mixed with buprofezin) provided higher RSW mortality than buprofezin alone. However, in both outdoor cage studies, the efficacy of buprofezin treatments (alone or mixed with I. fumosorosea) was higher than I. fumosorosea alone. A significant reduction in RSW population was reported for more than 5 wk in buprofezin alone and more than 7 wk in the combination treatments. In fall of 2014 and summer of 2015, the mean whitefly mortality observed during the 10-wk assessment period was 52.4 and 42.1% for I. fumosorosea, 79.6 and 79.0% for buprofezin, and 87.6 and 84.3% in mixed treatments, respectively. Results suggest that buprofezin can offer an effective alternate in the battle against invasive whiteflies such as RSW in Florida ecosystems, either as a stand-alone strategy or in an integrated approach.

  17. Aschersonia aleyrodis as a microbial control agent of greenhouse whitefly

    NARCIS (Netherlands)

    Fransen, J.J.

    1987-01-01

    Various aspects of the development of the entomopathogenic fungus Aschersoniaaleyrodis as a control agent of greenhouse whitefly, Trialeurodesvaporariorum , were investigated. For control of greenhouse whitefly in tomato

  18. Whitefly and aphid inducible promoters from Arabidopsis thaliana L.

    Indian Academy of Sciences (India)

    Aphids, whitefly, inducible promoter, sap sucking insects, biotic stress. Whitefly and aphid ..... pathway related genes in cotton plants (Dubey et al. 2013). ... and coordination of work, data analysis and interpretation, and revised the article.

  19. Fatores que influenciam o ataque de mosca-branca em jiloeiro Factors affecting attack rate of the whitefly on Solanum gilo

    Directory of Open Access Journals (Sweden)

    Germano Leão Demolin Leite

    2002-07-01

    Full Text Available Este trabalho objetivou determinar os efeitos de pluviosidade e temperatura, predadores e parasitóides, dossel e idade das plantas, tipos e densidades de tricomas foliares, compostos químicos foliares, níveis de N e de K foliares, sobre a intensidade de ataque de mosca-branca Bemisia tabaci (Hemiptera: Aleyrodidae em jiloeiro Solanum gilo var. 'Gigante Portuguesa'. As densidades de ninfas e de adultos de B. tabaci foram maiores nas folhas baixeiras do que nas apicais das plantas de jiloeiro. Com o aumento da temperatura do ar, observou-se incremento na densidade de adultos de B. tabaci nas folhas de jiloeiro.The objective of this study was to determine the effect of rainfall and temperature, predators and parasitoids, height within the canopy and plant age, chemical composition of leaves, levels of nitrogen and potassium in leaves and density of trichomes in leaves, on attack intensity of the whitefly Bemisia tabaci (Hemiptera: Aleyrodidae on Solanum gilo var. 'Portuguese giant'. Densities of nymphs and of adults of B. tabaci were higher on leaves of the lower part than on those of the apical parts of plants of S. gilo. The number of adults of B. tabaci on leaves of S. gilo increased with temperature.

  20. Diversity and Distribution of Cryptic Species of the Bemisia tabaci (Hemiptera: Aleyrodidae) complex in Pakistan.

    Science.gov (United States)

    Masood, Mariyam; Amin, Imran; Hassan, Ishtiaq; Mansoor, Shahid; Brown, Judith K; Briddon, Rob W

    2017-12-05

    Bemisia tabaci (Gennadius; Hempitera: Aleyrodidae) is considered to be a cryptic (sibling) species complex, the members of which exhibit morphological invariability while being genetically and behaviorally distinct. Members of the complex are agricultural pests that cause direct damage by feeding on plants, and indirectly by transmitting viruses that cause diseases leading to reduced crop yield and quality. In Pakistan, cotton leaf curl disease, caused by multiple begomovirus species, is the most economically important viral disease of cotton. In the study outlined here, the diversity and geographic distribution of B. tabaci cryptic species was investigated by analyzing a taxonomically informative fragment of the mitochondrial cytochrome c oxidase 1 gene (mtCOI-3'). The mtCOI-3' sequence was determined for 285 adult whiteflies and found to represent six cryptic species, the most numerous being Asia II-1 and Middle East Asia Minor 1 (MEAM-1), the later also referred to as the B-biotype, which was previously thought to be confined to Sindh province but herein, was also found to be present in the Punjab province. The endemic Asia I was restricted to Sindh province, while an individual in the Asia II-8 was identified in Pakistan for the first time. Also for the first time, samples were collected from northwestern Pakistan and Asia II-1 was identified. Results indicate that in Pakistan the overall diversity of B. tabaci cryptic species is high and, based on comparisons with findings from previous studies, the distribution is dynamic. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Biología de Eretmocerus mundus (Hymenoptera: Aphelinidae, parasitoide del complejo Bemisia tabaci (Homoptera: Aleyrodidae, en condiciones de laboratorio Biology of Eretmocerus mundus (Hymenoptera: Aphelinidae, parasitoid of Bemisia tabaci complex (Homoptera: Aleyrodidae under laboratory conditions

    Directory of Open Access Journals (Sweden)

    Yerlin Chacón Castro

    2010-06-01

    Full Text Available La estimación de los atributos biológicos de un enemigo natural, previa a su empleo en el campo, constituye un aspecto de importancia en todo proyecto de control biológico. El objetivo de este trabajo fue evaluar los principales parámetros biológicos de Eretmocerus mundus Mercet, parasitoide de Bemisia tabaci (Gennadius, bajo condiciones de laboratorio.La emergencia del adulto, longevidad y fecundidad de la hembra, proporción sexual de la descendencia, tasa intrínseca de crecimiento poblacional (r m, tasa neta de reproducción (Ro y tiempo generacional (T; se estimaron mediante la técnica de tabla de vida y fecundidad, utilizando el pimiento (Capsicum annuum L. y el tomate (Solanum lycopersicum L. como plantas hospederas. Los resultados obtenidos en pimiento y tomate fueron respectivamente: supervivencia pupal: 86.86 ± 1.94 y 83,45 ± 2,13%; longevidad de la hembra: 18,19 ± 1,61 y 17,00 ± 0,92 días; proporción sexual: 0,34 ± 0,06 y 0,47 ± 0,05 hembras/(machos + hembras; l x50: 21 y 18 días; r m: 0,226 ± 0,061 y 0,228 ± 0,057 ninfas parasitadas/hembra/día; Ro: 189,71 ± 24,25 y 154,65 ± 17,58 ninfas parasitadas/hembra; T: 25,88 ± 0,42 y 24,03 ± 0,34 días. Los resultados obtenidos son una contribución al conocimiento de la población local del parasitoide y su posible papel como agente de control biológico de B. tabaci.The estimation of biological attributes of natural enemies prior to its use in the field is an important tool in a biological control program. The objective of the present paper was to evaluate the main biological parameters of Eretmocerus mundus Mercet, a parasitoid of Bemisia tabaci (Gennadius, under controlled laboratory conditions. Parasitoid survival, female longevity, fecundity, sex rate, intrinsic rate of natural increase (r m, net reproductive rate (Ro and generational time (T were studied using life tables, with pepper (Capsicum annuum L. and tomato (Solanum lycopersicum L. as host plants. Results obtained on pepper and tomato, respectively, were: pupal survival: 86.86 ± 1.94 and 83,45 ± 2,13%; female longevity: 18,19 ± 1,61 and 17,00 ± 0,92 days; sex rate: 0,34 ± 0,06 and 0,47 ± 0,05 female/(male + female; l x50: 21 and 18 days; r m: 0,226 ± 0,061 and 0,228 ± 0,057 parasitized nymphs/female/day; Ro: 189,71 ± 24,25 and 154,65 ± 17,58 parasitized nymphs/female; T: 25,88 ± 0,42 and 24,03 ± 0,34 days. Results lead to a better understanding of the local population of this parasitoid and its potential role as a biological control agent of B. tabaci.

  2. Occurrence of Entomopathogenic Fungi from Agricultural and Natural Ecosystems in Saltillo, México, and their Virulence Towards Thrips and Whiteflies

    Science.gov (United States)

    Sánchez-Peña, Sergio R.; Lara, Jorge San-Juan; Medina, Raúl F.

    2011-01-01

    Entomopathogenic fungi were collected from soil in four adjacent habitats (oak forest, agricultural soil, pine reforestation and chaparral habitat) in Saltillo, México using the insect bait method with Tenebrio molitor (L.) (Coleoptera: Tenebrionidae) larvae as bait. Overall, of the larvae exposed to soil, 171 (20%) hosted Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Cordycipitaceae), 25 (3%) hosted Metarhizium anisopliae (Metschnikoff) Sorokin (Hypocreales: Clavicipitaceae) and 1 (0.1%) hosted lsaria (=Paecilomyces) sp. (Hypocreales: Cordycipitaceae). B. bassiana was significantly more frequent on larvae exposed to oak forest soil. M. anisopliae was significantly more frequent on larvae exposed to agricultural soil. From the infected bait insects, 93 isolates of B. bassiana and 24 isolates of M. anisopliae were obtained. Strains were tested for their infectivity against Cuban laurel thrips, Gynaikothrips uzeli Zimmerman (Thysanoptera: Phlaeothripidae) and the greenhouse whitefly, Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae). B. bassiana isolates caused the highest mortality on thrips (some causing 88% mortality after 6 days); both fungal species caused similarly high mortality levels against whiteflies (75%) after 6 days. Large amounts of germplasm of entomopathogenic fungi, fundamentally B. bassiana and M. anisopliae, exist in the habitats sampled; pathogenicity varied among strains, and some strains possessed significant virulence. Soils in these habitats are reservoirs of diverse strains with potential for use in biocontrol. PMID:21521145

  3. Antifeedant activity of botanical crude extracts and their fractions on Bemisia tabaci (Homoptera: Aleyrodidae adults: I. Gliricidia sepium (Fabaceae

    Directory of Open Access Journals (Sweden)

    Guillermo Flores

    2008-12-01

    Full Text Available Bemisia tabaci is an important virus vector on a number of crops worldwide. Therefore, a preventive approach to deal with viral epidemics may be the deployment of repellents or phagodeterrents at earlier stages of plant development (critical period. Thus, the crude extract and four fractions thereof (water, water:methanol, methanol, and diethyl ether of mother-of-cocoa (Gliricidia sepium, Fabaceae were tested for phagodeterrence to B. tabaci adults under greenhouse conditions, on tomato plants, in Costa Rica. Both restricted-choice and unrestricted-choice experiments showed that the crude extract and some fractions exerted such effect on the insect. In the former (in sleeve cages, three fractions caused deterrence at doses as low as 0.1% (methanol, 0.5% (water:methanol and 1.5% (diethyl ether. However, in the latter (plants exposed in a greenhouse no one of the fractions performed well, suggesting that the deterrent principles somehow decomposed under the experimental conditions. Rev. Biol. Trop. 56 (4: 2099-2113. Epub 2008 December 12.Mundialmente, Bemisia tabaci es un importante vector de virus en numerosos cultivos. Por tanto, un enfoque preventivo para enfrentar las epidemias virales podría ser el empleo de sustancias repelentes o fagodisuasivas en las etapas tempranas del desarrollo de las plantas (período crítico. Así, tanto el extracto crudo como cuatro fracciones (agua, agua:metanol, metanol y éter dietílico del madero negro (Gliricidia sepium, Fabaceae fueron evaluadas en cuanto a su actividad fagodisuasiva sobre los adultos de B. tabaci en condiciones de invernadero, utilizando plantas de tomate, en Turrialba, Costa Rica. Tanto los experimentos de escogencia restringida como los de escogencia irrestricta revelaron que el extracto crudo y algunas fracciones mostraron dicha actividad. En los primeros experimentos (en jaulas de manga, tres fracciones causaron fagodisuasión a dosis tan bajas como 0.1% (metanol, 0.5% (agua:metanol y 1.5% (éter dietílico. Sin embargo, en los segundos (plantas expuestas dentro de un invernadero ninguna de las fracciones lo hizo, lo cual sugiere que los principios fagodisuasivos perdieron su actividad en esas condiciones experimentales.

  4. Biología de Eretmocerus mundus (Hymenoptera: Aphelinidae, parasitoide del complejo Bemisia tabaci (Homoptera: Aleyrodidae, en condiciones de laboratorio

    Directory of Open Access Journals (Sweden)

    Yerlin CHACÓN CASTRO

    2010-01-01

    Full Text Available La estimación de los atributos biológicos de un enemigo natural, previa a su empleo en el campo, constituye un aspecto de importancia en todo proyecto de control biológico. El objetivo de este trabajo fue evaluar los principales parámetros biológicos de Eretmocerus mundus Mercet, parasitoide de Bemisia tabaci (Gennadius, bajo condiciones de laboratorio. La emergencia del adulto, longevidad y fecundidad de la hembra, proporción sexual de la descendencia, tasa intrínseca de crecimiento poblacional (r m , tasa neta de reproducción (R o y tiempo generacional (T; se estimaron mediante la técnica de tabla de vida y fecundidad, utilizando el pimiento ( Capsicum annuum L. y el tomate ( Solanum lycopersicum L. como plantas hospederas. Los resultados obtenidos en pimiento y tomate fueron respectivamente: supervivencia pupal: 86.86 ± 1.94 y 83,45 ± 2,13%; longevidad de la hembra: 18,19 ± 1,61 y 17,00 ± 0,92 días; proporción sexual: 0,34 ± 0,06 y 0,47 ± 0,05 hembras/(machos + hembras; l x50 : 21 y 18 días; r m : 0,226 ± 0,061 y 0,228 ± 0,057 ninfas parasitadas/hembra/día; Ro: 189,71 ± 24,25 y 154,65 ± 17,58 ninfas parasitadas/hembra; T: 25,88 ± 0,42 y 24,03 ± 0,34 días. Los resultados obtenidos son una contribución al conocimiento de la población local del parasitoide y su posible papel como agente de control biológico de B. tabaci.

  5. Antifeedant activity of botanical crude extracts and their fractions on Bemisia tabaci (Homoptera: Aleyrodidae adults: II. Sechium pittieri (Cucurbitaceae

    Directory of Open Access Journals (Sweden)

    Guillermo Flores

    2008-12-01

    Full Text Available Bemisia tabaci is a key pest of vegetables and other crops worldwide, but it is a particularly serious problem in the tropics, due to its ability to transmit several types of viruses, especially begomoviruses (Geminiviridae. Therefore, a preventive approach to deal with viral epidemics may be the deployment of repellents or phagodeterrents at earlier stages of plant development (critical period. Thus, the crude extract and four fractions thereof (water, water: methanol, methanol, and diethyl ether of wild "tacaco" (Sechium pittieri, Cucurbitaceae, were tested for phagodeterrence to B. tabaci adults under greenhouse conditions, on tomato plants, in Costa Rica. Both restricted-choice and unrestricted-choice experiments showed that the crude extract as well as some fractions exert such effect on the insect. In the former (in sleeve cages, fractions caused deterrence at doses as low as 0.1% (ether and 0.5% (water and water: methanol, with the methanol fraction showing no activity. However, in the latter (plants exposed in a greenhouse no one of the fractions performed well, suggesting that the deterrent principles somehow decomposed under the experimental conditions. Rev. Biol. Trop. 56 (4: 2115-2129. Epub 2008 December 12.Bemisia tabaci es una plaga clave de hortalizas y otros cultivos, mundialmente, y representa un problema particularmente serio en los trópicos, debido a su habilidad para transmitir varios tipos de virus, especialmente begomovirus (Geminiviridae. Por tanto, un enfoque preventivo para enfrentar las epidemias virales podría consistir en la utilización de sustancias repelentes o disuasivas en las eta-pas tempranas del desarrollo de la planta (período crítico. Así, el extracto crudo y cuatro fracciones (agua, agua: metanol, metanol, y éter dietílico de tacaco cimarrón (Sechium pittieri, Cucurbitaceae, fueron evaluadas por su posible actividad fagodisuasiva sobre B. tabaci en un invernadero, utilizando plantas de tomate, en Turrialba, Costa Rica. Tanto los experimentos de escogencia restringida como los de escogencia irrestricta mostraron dicha actividad en el extracto crudo y en algunas de sus fracciones. En el primer tipo de experimento (en jaulas de manga, las fracciones causaron fagodisuasión a dosis tan bajas como 0.1% (éter dietílico y 0.5% (agua y agua: metanol, mientras que la fracción metanólica no la causó. Sin embargo, en los otros experimentos (plantas expuestas a B. tabaci dentro de un invernadero ninguna de las fracciones funcionó bien, lo cual sugiere que los principios disuasivos se disiparon bajo esas condiciones experimentales.

  6. Flatidae (Homoptera: Fulgoroidea) of Indonesia, exclusive of Irian Jaya

    NARCIS (Netherlands)

    Medler, J.T.

    1999-01-01

    Taxa of the fulgoroid family Flatidae (Homoptera) occurring in Indonesia exclusive of Irian Jaya are treated. One hundred twenty seven species are recorded under 50 genera. Keys, descriptions, illustrations and collection data are presented. New genera described: Insulume, type species - Insulume

  7. Population Structure of the Greenhouse Whitefly, Trialeurodes vaporariorum (Westwood, an Invasive Species from the Americas, 60 Years after Invading China

    Directory of Open Access Journals (Sweden)

    Rui-Rui Gao

    2014-08-01

    Full Text Available Though the greenhouse whitefly, Trialeurodes vaporariorum (Westwood (Hemiptera: Aleyrodidae was introduced into China more than 60 years ago, the genetic diversity and structure of this exotic insect pest and virus vector have not been studied. To investigate the population genetic characteristics of this invasive species and to identify potential invasion routes, the genetic diversity and population structure of 17 collections of T. vaporariorum from nine provinces in China were analyzed using seven microsatellite loci. The results of the analyses indicated that the genetic diversity for the populations examined from the four provinces: Jilin, Ningxia, Guizhou and Qinghai, was lower than the genetic diversity of populations from the five provinces: Yunnan, Shandong, Shanxi, Liaoning, and Gansu. The T. vaporariorum populations analyzed in this study grouped as two distinct genetic clusters based on the analysis using STRUCTURE, whereas, 8 clusters were identified based on the BAPS analysis. Of the 136 genetic distance (Fst values, 128 (94% were associated with a significant exact test. However, there was no significant relationship between Fst and geographical distance. These results demonstrate that populations of T. vaporariorum in China exhibit significant genetic differentiation, indicating the likelihood that multiple introductions of T. vaporariorum into China have occurred. Also, the populations collected from the provinces of Jilin, Ningxia, Guizhou and Qinghai appear to represent secondary introductions originating from other Chinese provinces.

  8. Two cytochrome P450 genes are involved in imidacloprid resistance in field populations of the whitefly, Bemisia tabaci, in China.

    Science.gov (United States)

    Yang, Xin; Xie, Wen; Wang, Shao-li; Wu, Qing-jun; Pan, Hui-peng; Li, Ru-mei; Yang, Ni-na; Liu, Bai-ming; Xu, Bao-yun; Zhou, Xiaomao; Zhang, You-jun

    2013-11-01

    The sweet potato whitefly, Bemisia tabaci (Gennadius) (Hemiptera:Aleyrodidae), is an invasive and damaging pest of field crops worldwide. The neonicotinoid insecticide imidacloprid has been widely used to control this pest. We assessed the species composition (B vs. Q), imidacloprid resistance, and association between imidacloprid resistance and the expression of five P450 genes for 14-17 B. tabaci populations in 12 provinces in China. Fifteen of 17 populations contained only B. tabaci Q, and two populations contained both B and Q. Seven of 17 populations exhibited moderate to high resistance to imidacloprid, and eight populations exhibited low resistance to imidacloprid, compared with the most susceptible field WHHB population. In a study of 14 of the populations, resistance level was correlated with the expression of the P450 genes CYP6CM1 and CYP4C64 but not with the expression of CYP6CX1, CYP6CX4, or CYP6DZ7. This study indicates that B. tabaci Q has a wider distribution in China than previously reported. Resistance to imidacloprid in field populations of B. tabaci is associated with the increased expression of two cytochrome P450 genes (CYP6CM1 and CYP4C64). Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

  9. RNA viral metagenome of whiteflies leads to the discovery and characterization of a whitefly-transmitted carlavirus in North America.

    Science.gov (United States)

    Rosario, Karyna; Capobianco, Heather; Ng, Terry Fei Fan; Breitbart, Mya; Polston, Jane E

    2014-01-01

    Whiteflies from the Bemisia tabaci species complex have the ability to transmit a large number of plant viruses and are some of the most detrimental pests in agriculture. Although whiteflies are known to transmit both DNA and RNA viruses, most of the diversity has been recorded for the former, specifically for the Begomovirus genus. This study investigated the total diversity of DNA and RNA viruses found in whiteflies collected from a single site in Florida to evaluate if there are additional, previously undetected viral types within the B. tabaci vector. Metagenomic analysis of viral DNA extracted from the whiteflies only resulted in the detection of begomoviruses. In contrast, whiteflies contained sequences similar to RNA viruses from divergent groups, with a diversity that extends beyond currently described viruses. The metagenomic analysis of whiteflies also led to the first report of a whitefly-transmitted RNA virus similar to Cowpea mild mottle virus (CpMMV Florida) (genus Carlavirus) in North America. Further investigation resulted in the detection of CpMMV Florida in native and cultivated plants growing near the original field site of whitefly collection and determination of its experimental host range. Analysis of complete CpMMV Florida genomes recovered from whiteflies and plants suggests that the current classification criteria for carlaviruses need to be reevaluated. Overall, metagenomic analysis supports that DNA plant viruses carried by B. tabaci are dominated by begomoviruses, whereas significantly less is known about RNA viruses present in this damaging insect vector.

  10. RNA viral metagenome of whiteflies leads to the discovery and characterization of a whitefly-transmitted carlavirus in North America.

    Directory of Open Access Journals (Sweden)

    Karyna Rosario

    Full Text Available Whiteflies from the Bemisia tabaci species complex have the ability to transmit a large number of plant viruses and are some of the most detrimental pests in agriculture. Although whiteflies are known to transmit both DNA and RNA viruses, most of the diversity has been recorded for the former, specifically for the Begomovirus genus. This study investigated the total diversity of DNA and RNA viruses found in whiteflies collected from a single site in Florida to evaluate if there are additional, previously undetected viral types within the B. tabaci vector. Metagenomic analysis of viral DNA extracted from the whiteflies only resulted in the detection of begomoviruses. In contrast, whiteflies contained sequences similar to RNA viruses from divergent groups, with a diversity that extends beyond currently described viruses. The metagenomic analysis of whiteflies also led to the first report of a whitefly-transmitted RNA virus similar to Cowpea mild mottle virus (CpMMV Florida (genus Carlavirus in North America. Further investigation resulted in the detection of CpMMV Florida in native and cultivated plants growing near the original field site of whitefly collection and determination of its experimental host range. Analysis of complete CpMMV Florida genomes recovered from whiteflies and plants suggests that the current classification criteria for carlaviruses need to be reevaluated. Overall, metagenomic analysis supports that DNA plant viruses carried by B. tabaci are dominated by begomoviruses, whereas significantly less is known about RNA viruses present in this damaging insect vector.

  11. How to Start with a Clean Crop: Biopesticide Dips Reduce Populations of Bemisia tabaci (Hemiptera: Aleyrodidae on Greenhouse Poinsettia Propagative Cuttings

    Directory of Open Access Journals (Sweden)

    Rosemarije Buitenhuis

    2016-09-01

    Full Text Available (1 Global movement of propagative plant material is a major pathway for introduction of Bemisia tabaci (Hemiptera: Aleyrodidae into poinsettia greenhouses. Starting a poinsettia crop with high pest numbers disrupts otherwise successful biological control programs and widespread resistance of B. tabaci against pesticides is limiting growers’ options to control this pest; (2 This study investigated the use of several biopesticides (mineral oil, insecticidal soap, Beauveria bassiana, Isaria fumosorosea, Steinernema feltiae and combinations of these products as immersion treatments (cutting dips to control B. tabaci on poinsettia cuttings. In addition, phytotoxicity risks of these treatments on poinsettia cuttings, and effects of treatment residues on mortality of commercial whitefly parasitoids (Eretmocerus eremicus and Encarsia formosa were determined; (3 Mineral oil (0.1% v/v and insecticidal soap (0.5% + B. bassiana (1.25 g/L were the most effective treatments; only 31% and 29%, respectively, of the treated B. tabaci survived on infested poinsettia cuttings and B. tabaci populations were lowest in these treatments after eight weeks. Phytotoxicity risks of these treatments were acceptable, and dip residues had little effect on survival of either parasitoid, and are considered highly compatible; (4 Use of poinsettia cutting dips will allow growers to knock-down B. tabaci populations to a point where they can be managed successfully thereafter with existing biocontrol strategies.

  12. Whitefly species (Hemiptera: Aleyrodidae on wild and cultivated plants in the horticultural region of Rosario, Santa Fe, Argentina

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    Gustavo G. GONSEBATT

    2012-01-01

    Full Text Available Las moscas blancas de importancia económica son polífagas y capaces de desarrollarse sobre numerosas plantas cultivadas y espontáneas. Registramos las especies de moscas blancas sobre cultivos hortícolas y de flores, y sobre las plantas silvestres asociadas. Observamos dos especies: Trialeurodes vaporariorum (Westwood y el complejo Bemisia tabaci (Gennadius. T. vaporariorum fue registrada sobre 24 especies de plantas (11 familias, 12 y 8 de las cuales son hospedantes nuevos para Argentina y a nivel mundial, respectivamente. El complejo B. tabaci fue registrado solo en sistemas de producción de flores, sobre 19 especies de plantas (11 familias, 14 y 7 de las cuales son nuevos hospedantes para Argentina y a nivel mundial, respectivamente. Los cultivos Glycine max (L. y Chrysanthemum morifolium Ramat., las especies silvestres Amaranthus blitum L., Amaranthus quitensis Kunth, Conyza bonariensis (L., Galinsoga parviflora Cav., Sonchus oleraceus L. y Wedelia glauca (Ortega O. Hoffm. ex Hicken fueron hospedantes de ambas especies. El único parasitoide registrado fue Eretmocerus californicus cercano a corni Haldeman (Hymenoptera: Aphelinidae sobre T. vaporariorum. Este estudio que constituye el primer relevamiento sistemático de plantas hospedantes en la región, aporta un mayor conocimiento sobre el rango de plantas hospedantes de las moscas blancas en Argentina.

  13. Analysis of a native whitefly transcriptome and its sequence divergence with two invasive whitefly species

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    Wang Xiao-Wei

    2012-10-01

    Full Text Available Abstract Background Genomic divergence between invasive and native species may provide insight into the molecular basis underlying specific characteristics that drive the invasion and displacement of closely related species. In this study, we sequenced the transcriptome of an indigenous species, Asia II 3, of the Bemisia tabaci complex and compared its genetic divergence with the transcriptomes of two invasive whiteflies species, Middle East Asia Minor 1 (MEAM1 and Mediterranean (MED, respectively. Results More than 16 million reads of 74 base pairs in length were obtained for the Asia II 3 species using the Illumina sequencing platform. These reads were assembled into 52,535 distinct sequences (mean size: 466 bp and 16,596 sequences were annotated with an E-value above 10-5. Protein family comparisons revealed obvious diversification among the transcriptomes of these species suggesting species-specific adaptations during whitefly evolution. On the contrary, substantial conservation of the whitefly transcriptomes was also evident, despite their differences. The overall divergence of coding sequences between the orthologous gene pairs of Asia II 3 and MEAM1 is 1.73%, which is comparable to the average divergence of Asia II 3 and MED transcriptomes (1.84% and much higher than that of MEAM1 and MED (0.83%. This is consistent with the previous phylogenetic analyses and crossing experiments suggesting these are distinct species. We also identified hundreds of highly diverged genes and compiled sequence identify data into gene functional groups and found the most divergent gene classes are Cytochrome P450, Glutathione metabolism and Oxidative phosphorylation. These results strongly suggest that the divergence of genes related to metabolism might be the driving force of the MEAM1 and Asia II 3 differentiation. We also analyzed single nucleotide polymorphisms within the orthologous gene pairs of indigenous and invasive whiteflies which are helpful for

  14. Aboveground Whitefly Infestation-Mediated Reshaping of the Root Microbiota.

    Science.gov (United States)

    Kong, Hyun G; Kim, Byung K; Song, Geun C; Lee, Soohyun; Ryu, Choong-Min

    2016-01-01

    Plants respond to various types of herbivore and pathogen attack using well-developed defensive machinery designed for self-protection. Infestation from phloem-sucking insects such as whitefly and aphid on plant leaves was previously shown to influence both the saprophytic and pathogenic bacterial community in the plant rhizosphere. However, the modulation of the root microbial community by plants following insect infestation has been largely unexplored. Only limited studies of culture-dependent bacterial diversity caused by whitefly and aphid have been conducted. In this study, to obtain a complete picture of the belowground microbiome community, we performed high-speed and high-throughput next-generation sequencing. We sampled the rhizosphere soils of pepper seedlings at 0, 1, and 2 weeks after whitefly infestation versus the water control. We amplified a partial 16S ribosomal RNA gene (V1-V3 region) by polymerase chain reaction with specific primers. Our analysis revealed that whitefly infestation reshaped the overall microbiota structure compared to that of the control rhizosphere, even after 1 week of infestation. Examination of the relative abundance distributions of microbes demonstrated that whitefly infestation shifted the proteobacterial groups at week 2. Intriguingly, the population of Pseudomonadales of the class Gammaproteobacteria significantly increased after 2 weeks of whitefly infestation, and the fluorescent Pseudomonas spp. recruited to the rhizosphere were confirmed to exhibit insect-killing capacity. Additionally, three taxa, including Caulobacteraceae, Enterobacteriaceae, and Flavobacteriaceae, and three genera, including Achromobacter, Janthinobacterium, and Stenotrophomonas, were the most abundant bacterial groups in the whitefly infested plant rhizosphere. Our results indicate that whitefly infestation leads to the recruitment of specific groups of rhizosphere bacteria by the plant, which confer beneficial traits to the host plant. This

  15. Aboveground Whitefly Infestation-mediated Reshaping of the Root Microbiota

    Directory of Open Access Journals (Sweden)

    Hyun Gi Kong

    2016-09-01

    Full Text Available Plants respond to various types of herbivore and pathogen attack using well-developed defensive machinery designed for self-protection. The phloem-sucking insect infestation such as whitefly and aphid on plant leaves were previously shown to influence both the saprophytic and pathogenic bacterial community in the plant rhizosphere. However, the modulation of the root microbial community by plants following insect infestation has been largely unexplored. Only limited studies of culture-dependent bacterial diversity caused by whitefly and aphid have been conducted. In this study, to obtain a complete picture of the belowground microbiome community, we performed high-speed and high-throughput next-generation sequencing. We sampled the rhizosphere soils of pepper seedlings at 0, 1, and 2 weeks after whitefly infestation versus the water control. We amplified a partial 16S ribosomal RNA gene (V1–V3 region by polymerase chain reaction with specific primers. Our analysis revealed that whitefly infestation reshaped the overall microbiota structure compared to that of the control rhizosphere, even after 1 week of infestation. Examination of the relative abundance distributions of microbes demonstrated that whitefly infestation shifted the proteobacterial groups at week 2. Intriguingly, the population of Pseudomonadales of the class Gammaproteobacteria significantly increased after 2 weeks of whitefly infestation and confirmed the recruitment of fluorescent Pseudomonas spp. exhibiting the insect-killing capacity. Additionally, three taxa, including Caulobacteraceae, Enterobacteriaceae, and Flavobacteriaceae, and three genera, including Achromobacter, Janthinobacterium, and Stenotrophomonas, were the most abundant bacterial groups in the whitefly-infested plant rhizosphere. Our results indicate that whitefly infestation leads plant recruiting specific group of rhizosphere bacteria conferring beneficial traits for host plant. This study provides a new

  16. Preparing soft-bodied arthropods for microscope examination: Whiteflies (Insecta: Hemiptera: Alyrodidae)

    Science.gov (United States)

    Proper identification of whiteflies (Hemiptera:Alyrodidae) requires preparation of the specimen on a microscope slide. This training video provides visual instruction on how to prepare whitefly specimens on microscope slides for examination and identification. Steps ranging from collection, specimen...

  17. Studying genetic diversity of whitefly B. tabaci Egyptian isolates in relation to some worldwide isolates

    Directory of Open Access Journals (Sweden)

    Inas Farouk Fahmy

    2015-06-01

    Full Text Available Bemisia tabaci (Gennadius (Hemiptera, Aleyrodidae is considered to be one of the most damaging pests in agriculture, causing severe losses in crops worldwide, affecting the tropical and subtropical regions. Random Amplified Polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR was used to assess the genetic diversity between different isolates collected from different regions in Egypt compared with some other worldwide isolates of this insect pest. Out of 12 primers 8 primers from Operon technology have shown to differentiate between 13 collected B. tabaci samples from all over Egypt and some other samples collected from different countries with two other populations representing biotypes A and B collected from the US used for biotype demarcation. Using 13 insect samples, RAPD analysis has produced a total number of 72 markers; about 68 polymorphic markers were revealed. The total number of bands obtained for each primer ranged from 4 to 14 within an average of 9 bands per primer. Of the pair wise combination among fifteen populations Ismailia population showed the highest similarity index (0.947, while US biotype A scored the lowest similarity index (0.326. Two major clusters were formed from the UPGMA dendrogram, which was constructed based on Dice similarity coefficient. RAPD-PCR screening demarcated the whitefly population based on the host species and genetic biotypes. Two major clusters have been revealed as A and B with two other minor clusters A1, A2, and B1, B2. Most of the samples collected from Egypt were clustered together in a minor cluster named A1. A1 group is divided into two sub-groups. A1a comprises the populations from Beni-Sweif in Upper Egypt, Ismailia, Kalyobia, El-Fayoum, Tanta, Kafr El-Sheikh, Alexandria, and A1b comprises Spain and Sudan. Group A1a is clustered together based on their host which belongs to the Cucurbitaceae family while Alexandria was separated individually based on its host which is cauliflower. Through

  18. Pathogenicity of Aschersonia spp. against whiteflies Bemisia argentifolii and Trialeurodes vaporariorum

    NARCIS (Netherlands)

    Meekes, E.T.M.; Fransen, J.J.; Lenteren, van J.C.

    2002-01-01

    Entomopathogenic fungi of the genus Aschersonia are specific for whitefly and scale insects. They can be used as biological control agents against silverleaf whitefly, Bemisia argentifolii and greenhouse whitefly, Trialeurodes vaporariorum. Forty-four isolates of Aschersonia spp. were tested for

  19. Treehoppers (Homoptera, Membracidae in southeastern Brazil: use of host plants

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    Benedito C. Lopes

    1995-09-01

    Full Text Available A survey on the use of host plants by treehoppers in plants in cerrado (savanna vegetation at Moji-Guaçu (São Paulo, Southeastern Brazil was made. Fifty-two species of treehoppers were recorded in association with 40 host plant species from October 1980 to February 1982. The families Araliaceae, Asteraceae, Leguminosae, Malpighiaceae, Myrtaceae and Nyctaginaceae were the most commonly used for oviposition. Byrsonima intermedia A. Juss. (Malpighiaceae had the highest number of associated treehopper species (10 species. The abundance of treehopper individuals was related to the hot and rainy season (from October to February, while during the cold and dry season (from March to September there was a decrease in the number of these Homoptera. After the occurrence of a frost, few adults and nymphs were observed on the host plants for one to two months.

  20. Status of cassava mosaic disease and whitefly population in Zambia ...

    African Journals Online (AJOL)

    Cassava mosaic disease is the most important disease affecting cassava in Zambia. A study was conducted through a survey to determine the status of cassava mosaic disease incidence, severity and whitefly abundance in farmers' fields in six provinces: Lusaka, Northern, North-Western, Luapula, Eastern and Western ...

  1. Identification of whitefly resistance in tomato and hot pepper

    NARCIS (Netherlands)

    Firdaus, S.

    2012-01-01

    Key words: Capsicum, Bemisia tabaci, trichome density, cuticle thickness
    Whitefly is economically one of the most threatening pests of pepper worldwide, which is mainly caused by its ability to transmit many different viruses. In this research, we characterized pepper germplasm to identify

  2. [Phagodeterrent activity of the plants Tithonia diversifolia and Montanoa hibiscifolia (Asteraceae) on adults of the pest insect Bemisia tabaci (Homoptera: Aleyrodidae)].

    Science.gov (United States)

    Bagnarello, Gina; Hilje, Luko; Bagnarello, Vanessa; Cartín, Victor; Calvo, Marco

    2009-12-01

    Bemisia tabaci (Gennadius) is a polyphagous, cosmopolitan and worldwide relevant pest, mainly acting as a virus vector on many crops. A sound preventive approach to deal with it would be the application of repellent or deterrent substances hopefully present in tropical plants, which in turn may contribute to take advantage of the remarkable rich Mesoamerican biodiversity. Therefore, extracts of two wild plants belonging to family Asteraceae, titonia (Tithonia diversifolia) and "tora" (Montanoa hibiscifolia), were tested for phagodeterrence to B. tabaci adults. The crude leaf extract of each one, as well as four fractions thereof (hexane, dichlorometane, ethyl acetate, and methanol) were tested under greenhouse conditions; in addition, the extracts were submitted to a phytochemical screening to determine possible metabolites causing phagodeterrence. Both restricted-choice and unrestricted-choice experiments were conducted. In the former ones, each fraction was tested at four doses (0.1, 0.5, 1.0 and 1.5% v/v), which were compared with four control treatments: distilled water, endosulfan, an agricultural oil (Aceite Agricola 81 SC), and the emulsifier Citowett. Tomato plants were sprayed and placed inside sleeve cages, where 50 B. tabaci adults were released. The criterion to appraise phagodeterrence was the number of landed adults on plants at 48h. For the unrestricted-choice experiments, only the two highest doses (1.0 and 1.5%) of the crude extracts of each species were tested, and compared to distilled water and the agricultural oil. The titonia and "tora" crude extracts caused phagodeterrence, and for both plant species the methanol fraction stood out. Results suggest that metabolites causing phagodeterrence are several sesquiterpenic lactones, polyphenolic compounds (flavonoids and tannins) and saponins.

  3. Insecticide resistance in Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) and Anopheles gambiae Giles (Diptera: Culicidae) could compromise the sustainability of malaria vector control strategies in West Africa.

    Science.gov (United States)

    Gnankiné, Olivier; Bassolé, Imael H N; Chandre, Fabrice; Glitho, Isabelle; Akogbeto, Martin; Dabiré, Roch K; Martin, Thibaud

    2013-10-01

    Insecticides from the organophosphate (OP) and pyrethroid (PY) chemical families, have respectively, been in use for 50 and 30 years in West Africa, mainly against agricultural pests, but also against vectors of human disease. The selection pressure, with practically the same molecules year after year (mainly on cotton), has caused insecticide resistance in pest populations such as Bemisia tabaci, vector of harmful phytoviruses on vegetables. The evolution toward insecticide resistance in malaria vectors such as Anopheles gambiae sensus lato (s.l.) is probably related to the current use of these insecticides in agriculture. Thus, successful pest and vector control in West Africa requires an investigation of insect susceptibility, in relation to the identification of species and sub species, such as molecular forms or biotypes. Identification of knock down resistance (kdr) and acetylcholinesterase gene (Ace1) mutations modifying insecticide targets in individual insects and measure of enzymes activity typically involved in insecticide metabolism (oxidase, esterase and glutathion-S-transferase) are indispensable in understanding the mechanisms of resistance. Insecticide resistance is a good example in which genotype-phenotype links have been made successfully. Insecticides used in agriculture continue to select new resistant populations of B. tabaci that could be from different biotype vectors of plant viruses. As well, the evolution of insecticide resistance in An. gambiae threatens the management of malaria vectors in West Africa. It raises the question of priority in the use of insecticides in health and/or agriculture, and more generally, the question of sustainability of crop protection and vector control strategies in the region. Here, we review the susceptibility tests, biochemical and molecular assays data for B. tabaci, a major pest in cotton and vegetable crops, and An. gambiae, main vector of malaria. The data reviewed was collected in Benin and Burkina Faso between 2008 and 2010 under the Corus 6015 research program. This review aims to show: (i) the insecticide resistance in B. tabaci as well as in An. gambiae; and (ii) due to this, the impact of selection of resistant populations on malaria vector control strategies. Some measures that could be beneficial for crop protection and vector control strategies in West Africa are proposed. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Diversity and Phylogenetic Analyses of Bacterial Symbionts in Three Whitefly Species from Southeast Europe

    Science.gov (United States)

    Skaljac, Marisa; Zanic, Katja; Puizina, Jasna; Lepen Pleic, Ivana; Ghanim, Murad

    2017-01-01

    Bemisia tabaci (Gennadius), Trialeurodes vaporariorum (Westwood), and Siphoninus phillyreae (Haliday) are whitefly species that harm agricultural crops in many regions of the world. These insects live in close association with bacterial symbionts that affect host fitness and adaptation to the environment. In the current study, we surveyed the infection of whitefly populations in Southeast Europe by various bacterial symbionts and performed phylogenetic analyses on the different symbionts detected. Arsenophonus and Hamiltonella were the most prevalent symbionts in all three whitefly species. Rickettsia was found to infect mainly B. tabaci, while Wolbachia mainly infected both B. tabaci and S. phillyreae. Furthermore, Cardinium was rarely found in the investigated whitefly populations, while Fritschea was never found in any of the whitefly species tested. Phylogenetic analyses revealed a diversity of several symbionts (e.g., Hamiltonella, Arsenophonus, Rickettsia), which appeared in several clades. Reproductively isolated B. tabaci and T. vaporariorum shared the same (or highly similar) Hamiltonella and Arsenophonus, while these symbionts were distinctive in S. phillyreae. Interestingly, Arsenophonus from S. phillyreae did not cluster with any of the reported sequences, which could indicate the presence of Arsenophonus, not previously associated with whiteflies. In this study, symbionts (Wolbachia, Rickettsia, and Cardinium) known to infect a wide range of insects each clustered in the same clades independently of the whitefly species. These results indicate horizontal transmission of bacterial symbionts between reproductively isolated whitefly species, a mechanism that can establish new infections that did not previously exist in whiteflies. PMID:29053633

  5. Diversity and Phylogenetic Analyses of Bacterial Symbionts in Three Whitefly Species from Southeast Europe

    Directory of Open Access Journals (Sweden)

    Marisa Skaljac

    2017-10-01

    Full Text Available Bemisia tabaci (Gennadius, Trialeurodes vaporariorum (Westwood, and Siphoninus phillyreae (Haliday are whitefly species that harm agricultural crops in many regions of the world. These insects live in close association with bacterial symbionts that affect host fitness and adaptation to the environment. In the current study, we surveyed the infection of whitefly populations in Southeast Europe by various bacterial symbionts and performed phylogenetic analyses on the different symbionts detected. Arsenophonus and Hamiltonella were the most prevalent symbionts in all three whitefly species. Rickettsia was found to infect mainly B. tabaci, while Wolbachia mainly infected both B. tabaci and S. phillyreae. Furthermore, Cardinium was rarely found in the investigated whitefly populations, while Fritschea was never found in any of the whitefly species tested. Phylogenetic analyses revealed a diversity of several symbionts (e.g., Hamiltonella, Arsenophonus, Rickettsia, which appeared in several clades. Reproductively isolated B. tabaci and T. vaporariorum shared the same (or highly similar Hamiltonella and Arsenophonus, while these symbionts were distinctive in S. phillyreae. Interestingly, Arsenophonus from S. phillyreae did not cluster with any of the reported sequences, which could indicate the presence of Arsenophonus, not previously associated with whiteflies. In this study, symbionts (Wolbachia, Rickettsia, and Cardinium known to infect a wide range of insects each clustered in the same clades independently of the whitefly species. These results indicate horizontal transmission of bacterial symbionts between reproductively isolated whitefly species, a mechanism that can establish new infections that did not previously exist in whiteflies.

  6. First results in the use of sterile insect technique against Trialeurodes vaporariorum (Homoptera: Aleyroididae) in greenhouses

    International Nuclear Information System (INIS)

    Calvitti, M.; Remotti, P.C.; Pasquali, A.; Cirio, U.

    1998-01-01

    Trials for the evaluation of the effectiveness of the sterile insect technique for the suppression of greenhouse whitefly, Trialeurodes vaporariorum (Westwood), both in cage and in greenhouse conditions are described. The results show a significant reduction of the reproductive capacity of the untreated whitefly populations interacting with sterile insects. Untreated whiteflies, co-existing in a mixed population together with sterile insects, attained less than the half (44%) of their potential reproductive capacity. This trend was also evident in the cage test where the untreated whitefly population, crossed with the sterile whiteflies, increased without exceeding 2/3 of the density recorded in the control cages. These results may be based on 2 joint sterile insect technique effects: primarily a drastic reduction of the progeny of normal untreated females, when mating with sterile males, carriers of dominant lethal mutations, and secondarily a progressive reduction of the females in the population due to an increasing rate of unsuccessful matings resulting in a condition of forced arrhenotoky. No deleterious effects, on plant health and fruit quality, were observed on plants exposed to high sterile whitefly pressures

  7. Direct and indirect impacts of infestation of tomato plant by Myzus persicae (Hemiptera: Aphididae on Bemisia tabaci (Hemiptera: Aleyrodidae.

    Directory of Open Access Journals (Sweden)

    Xiao-Ling Tan

    Full Text Available The impacts of infestation by the green peach aphid (Myzus persicae on sweetpotato whitefly (Bemisia tabaci settling on tomato were determined in seven separate experiments with whole plants and with detached leaves through manipulation of four factors: durations of aphid infestation, density of aphids, intervals between aphid removal after different durations of infestation and the time of whitefly release, and leaf positions on the plants. The results demonstrated that B. tabaci preferred to settle on the plant leaves that had not been infested by aphids when they had a choice. The plant leaves on which aphids were still present (direct effect had fewer whiteflies than those previously infested by aphids (indirect effect. The whiteflies were able to settle on the plant which aphids had previously infested, and also could settle on leaves with aphids if no uninfested plants were available. Tests of direct factors revealed that duration of aphid infestation had a stronger effect on whitefly landing preference than aphid density; whitefly preference was the least when 20 aphids fed on the leaves for 72 h. Tests of indirect effects revealed that the major factor that affected whitefly preference for a host plant was the interval between the time of aphid removal after infestation and the time of whitefly release. The importance of the four factors that affected the induced plant defense against whiteflies can be arranged in the following order: time intervals between aphid removal and whitefly release > durations of aphid infestation > density of aphids > leaf positions on the plants. In conclusion, the density of aphid infestation and time for which they were feeding influenced the production of induced compounds by tomatoes, the whitefly responses to the plants, and reduced interspecific competition.

  8. First record of Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae severely damaging field grown potato crops in South Sulawesi, Indonesia

    Directory of Open Access Journals (Sweden)

    Nasruddin Andi

    2016-04-01

    Full Text Available Greenhouse whitefly, Trialeurodes vaporariorum Westwood was reported for the first time in the South Sulawesi Province of Indonesia, and is causing significant damage to field grown potato crops. In an insecticide trial, the tuber yield in infested, untreated plants was reduced by 39%, and the plants had an average number of 68 adult whiteflies per leaflet.

  9. Asymmetric consequences of host plant occupation on the competition between the whiteflies Bemisia tabaci cryptic species MEAM1 and Trialeurodes vaporariorum (Hemiptera: Aleyrodidae)

    DEFF Research Database (Denmark)

    Zhang, Gui-Fen; Lövei, Gabor L; Hu, Man

    2014-01-01

    . RESULTS: Resource preoccupied by T. vaporariorum had mostly negative effects on the life history parameters of later-arriving conspecifics. Red-eyed nymph and immature survival of T. vaporariorum decreased when resource was preoccupied by conspecifics, irrespective of the previous occupation scenario...

  10. Elevated O3 enhances the attraction of whitefly-infested tomato plants to Encarsia formosa

    Science.gov (United States)

    Cui, Hongying; Su, Jianwei; Wei, Jianing; Hu, Yongjian; Ge, Feng

    2014-01-01

    We experimentally examined the effects of elevated O3 and whitefly herbivory on tomato volatiles, feeding and oviposition preferences of whiteflies and behavioural responses of Encarsia formosa to these emissions on two tomato genotypes, a wild-type (Wt) and a jasmonic acid (JA) defence-enhanced genotype (JA-OE, 35S). The O3 level and whitefly herbivory significantly increased the total amount of volatile organic compounds (VOCs), monoterpenes, green leaf volatiles (GLVs), and aldehyde volatiles produced by tomato plants. The 35S plants released higher amount of total VOCs and monoterpene volatiles than Wt plants under O3+herbivory treatments. The feeding and oviposition bioassays showed that control plants were preferred by adult whiteflies whereas the 35S plants were not preferred by whiteflies. In the Y-tube tests, O3+herbivory treatment genotypes were preferred by adult E. Formosa. The 35S plants were preferred by adult E. formosa under O3, herbivory and O3+herbivory treatments. Our results demonstrated that elevated O3 and whitefly herbivory significantly increased tomato volatiles, which attracted E. formosa and reduced whitefly feeding. The 35S plants had a higher resistance to B. tabaci than Wt plant. Such changes suggest that the direct and indirect defences of resistant genotypes, such as 35S, could strengthen as the atmospheric O3 concentration increases. PMID:24939561

  11. The Facultative Symbiont Rickettsia Protects an Invasive Whitefly against Entomopathogenic Pseudomonas syringae Strains.

    Science.gov (United States)

    Hendry, Tory A; Hunter, Martha S; Baltrus, David A

    2014-12-01

    Facultative endosymbionts can benefit insect hosts in a variety of ways, including context-dependent roles, such as providing defense against pathogens. The role of some symbionts in defense may be overlooked, however, when pathogen infection is transient, sporadic, or asymptomatic. The facultative endosymbiont Rickettsia increases the fitness of the sweet potato whitefly (Bemisia tabaci) in some populations through mechanisms that are not yet understood. In this study, we investigated the role of Rickettsia in mediating the interaction between the sweet potato whitefly and Pseudomonas syringae, a common environmental bacterium, some strains of which are pathogenic to aphids. Our results show that P. syringae multiplies within whiteflies, leading to host death, and that whiteflies infected with Rickettsia show a decreased rate of death due to P. syringae. Experiments using plants coated with P. syringae confirmed that whiteflies can acquire the bacteria at a low rate while feeding, leading to increased mortality, particularly when the whiteflies are not infected with Rickettsia. These results suggest that P. syringae may affect whitefly populations in nature and that Rickettsia can ameliorate this effect. This study highlights the possible importance of interactions among opportunistic environmental pathogens and endosymbionts of insects. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  12. Omnivore-herbivore interactions: thrips and whiteflies compete via the shared host plant.

    Science.gov (United States)

    Pappas, Maria L; Tavlaki, Georgia; Triantafyllou, Anneta; Broufas, George

    2018-03-05

    Phytophagy is a common feature among pure herbivorous insects and omnivores that utilise both plant and prey as food resources; nevertheless, experimental evidence for factors affecting their interactions is restricted to intraguild predation and predator-mediated competition. We herein focused on plant-mediated effects that could result from plant defence activation or quality alteration and compared the performance of an omnivore, the western flower thrips Frankliniella occidentalis, and a pure herbivore, the greenhouse whitefly Trialeurodes vaporariorum, on cucumber plants previously infested with either species. Furthermore, we recorded their behavioural responses when given a choice among infested and clean plants. Whiteflies laid less eggs on plants previously exposed to thrips but more on whitefly-infested plants. Thrips survival was negatively affected on whitefly-infested than on thrips-infested or clean plants. Notably, whiteflies developed significantly faster on plants infested with conspecifics. In accordance, whiteflies avoided thrips-infested plants and preferred whitefly-infested over clean plants. Thrips showed no preference for either infested or clean plants. Our study is a first report on the role of plant-mediated effects in shaping omnivore-herbivore interactions. Considering the factors driving such interactions we will likely better understand the ecology of the more complex relationships among plants and pest organisms.

  13. Mitigating trans-boundary movement of Bemisia tabaci (Hemiptera: Aleyrodidae) on Mentha sp. by pre-shipping treaments of biopesticides

    Science.gov (United States)

    Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a major pest of several important crops including vegetables, cereals, fruits, and ornamentals grown worldwide. One important mode of its dispersal is through the trans-boundary movement of infested plant materials. In order to prevent the sprea...

  14. Factors affecting oviposition of Bemisia tabaci (Genn.) biotype B (Hemiptera: Aleyrodidae) in sweet pepper

    International Nuclear Information System (INIS)

    Lima, Larissa C. de; Campos, Alcebiades R.

    2008-01-01

    Bemisia tabaci (Gen.) biotype B is considered a pest of economical importance for several vegetables. The oviposition behaviour of the while fly was evaluated in sweet pepper plants. The trials were carried out under greenhouse condition and in the Laboratory of Entomology of DEFERS/ UNESP, Campus of Ilha Solteira-SP, with the sweet pepper Magali-R genotype. The effect of plant age on the whitefly oviposition was evaluated in free-choice tests, in plants, 25, 30, 35, 40 and 45- day-old, as egg distribution in the plant and on the leaf blade was evaluated in 35-days-old plants. In a no-choice tests, 35-day-old plants were used to evaluate the effect of the densities of 50, 100, 150, 200 and 250 adults per plant on the number of eggs laid by insects. The silver leaf whitefly preferred to oviposition the third to sixth leaflets, of the medium and superior part of plants of sweet pepper; the leaf blade areas, located in the lobes right and left close the base of the leaf were the preferential site for whitefly oviposition. Older plants, 40- and 45-day-old, were preferentially used for oviposition, and 200 and 250 adults per plant were both enough to lay a number of eggs that allowed to differentiate among sweet pepper genotypes with different whitefly resistance levels. (author)

  15. Pest species diversity enhances control of spider mites and whiteflies by a generalist phytoseiid predator

    NARCIS (Netherlands)

    Messelink, G.J.; Maanen, van R.; Holstein-Saj, van R.; Sabelis, M.W.; Janssen, A.

    2010-01-01

    To test the hypothesis that pest species diversity enhances biological pest control with generalist predators, we studied the dynamics of three major pest species on greenhouse cucumber: Western flower thrips, Frankliniella occidentalis (Pergande), greenhouse whitefly, Trialeurodes vaporariorum

  16. Vector-virus mutualism accelerates population increase of an invasive whitefly.

    Directory of Open Access Journals (Sweden)

    Min Jiu

    2007-01-01

    Full Text Available The relationships between plant viruses, their herbivore vectors and host plants can be beneficial, neutral, or antagonistic, depending on the species involved. This variation in relationships may affect the process of biological invasion and the displacement of indigenous species by invaders when the invasive and indigenous organisms occur with niche overlap but differ in the interactions. The notorious invasive B biotype of the whitefly complex Bemisia tabaci entered China in the late 1990s and is now the predominant or only biotype in many regions of the country. Tobacco curly shoot virus (TbCSV and Tomato yellow leaf curl China virus (TYLCCNV are two whitefly-transmitted begomoviruses that have become widespread recently in south China. We compared the performance of the invasive B and indigenous ZHJ1 whitefly biotypes on healthy, TbCSV-infected and TYLCCNV-infected tobacco plants. Compared to its performance on healthy plants, the invasive B biotype increased its fecundity and longevity by 12 and 6 fold when feeding on TbCSV-infected plants, and by 18 and 7 fold when feeding on TYLCCNV-infected plants. Population density of the B biotype on TbCSV- and TYLCCNV-infected plants reached 2 and 13 times that on healthy plants respectively in 56 days. In contrast, the indigenous ZHJ1 performed similarly on healthy and virus-infected plants. Virus-infection status of the whiteflies per se of both biotypes showed limited effects on performance of vectors on cotton, a nonhost plant of the viruses. The indirect mutualism between the B biotype whitefly and these viruses via their host plants, and the apparent lack of such mutualism for the indigenous whitefly, may contribute to the ability of the B whitefly biotype to invade, the displacement of indigenous whiteflies, and the disease pandemics of the viruses associated with this vector.

  17. Diversity and Phylogenetic Analyses of Bacterial Symbionts in Three Whitefly Species from Southeast Europe

    OpenAIRE

    Skaljac, Marisa; Kanakala, Surapathrudu; Zanic, Katja; Puizina, Jasna; Lepen Pleic, Ivana; Ghanim, Murad

    2017-01-01

    Bemisia tabaci (Gennadius), Trialeurodes vaporariorum (Westwood), and Siphoninus phillyreae (Haliday) are whitefly species that harm agricultural crops in many regions of the world. These insects live in close association with bacterial symbionts that affect host fitness and adaptation to the environment. In the current study, we surveyed the infection of whitefly populations in Southeast Europe by various bacterial symbionts and performed phylogenetic analyses on the different symbionts dete...

  18. Feeding by whiteflies suppresses downstream jasmonic acid signaling by eliciting salicylic acid signaling.

    Science.gov (United States)

    Zhang, Peng-Jun; Li, Wei-Di; Huang, Fang; Zhang, Jin-Ming; Xu, Fang-Cheng; Lu, Yao-Bin

    2013-05-01

    Phloem-feeding whiteflies in the species complex Bemisia tabaci cause extensive crop damage worldwide. One of the reasons for their "success" is their ability to suppress the effectual jasmonic acid (JA) defenses of the host plant. However, little is understood about the mechanisms underlying whitefly suppression of JA-regulated defenses. Here, we showed that the expression of salicylic acid (SA)-responsive genes (EDS1 and PR1) in Arabidopsis thaliana was significantly enhanced during feeding by whitefly nymphs. Whereas upstream JA-responsive genes (LOX2 and OPR3) also were induced, the downstream JA-responsive gene (VSP1) was repressed, i.e., whiteflies only suppressed downstream JA signaling. Gene-expression analyses with various Arabidopsis mutants, including NahG, npr-1, ein2-1, and dde2-2, revealed that SA signaling plays a key role in the suppression of downstream JA defenses by whitefly feeding. Assays confirmed that SA activation enhanced whitefly performance by suppressing downstream JA defenses.

  19. Enhanced whitefly resistance in transgenic tobacco plants expressing double stranded RNA of v-ATPase A gene.

    Science.gov (United States)

    Thakur, Nidhi; Upadhyay, Santosh Kumar; Verma, Praveen C; Chandrashekar, Krishnappa; Tuli, Rakesh; Singh, Pradhyumna K

    2014-01-01

    Expression of double strand RNA (dsRNA) designed against important insect genes in transgenic plants have been shown to give protection against pests through RNA interference (RNAi), thus opening the way for a new generation of insect-resistant crops. We have earlier compared the efficacy of dsRNAs/siRNAs, against a number of target genes, for interference in growth of whitefly (Bemisia tabaci) upon oral feeding. The v-ATPase subunit A (v-ATPaseA) coding gene was identified as a crucial target. We now report the effectiveness of transgenic tobacco plants expressing siRNA to silence v-ATPaseA gene expression for the control of whitefly infestation. Transgenic tobacco lines were developed for the expression of long dsRNA precursor to make siRNA and knock down the v-ATPaseA mRNA in whitefly. Molecular analysis and insecticidal properties of the transgenic plants established the formation of siRNA targeting the whitefly v-ATPaseA, in the leaves. The transcript level of v-ATPaseA in whiteflies was reduced up to 62% after feeding on the transgenic plants. Heavy infestation of whiteflies on the control plants caused significant loss of sugar content which led to the drooping of leaves. The transgenic plants did not show drooping effect. Host plant derived pest resistance was achieved against whiteflies by genetic transformation of tobacco which generated siRNA against the whitefly v-ATPaseA gene. Transgenic tobacco lines expressing dsRNA of v-ATPaseA, delivered sufficient siRNA to whiteflies feeding on them, mounting a significant silencing response, leading to their mortality. The transcript level of the target gene was reduced in whiteflies feeding on transgenic plants. The strategy can be taken up for genetic engineering of plants to control whiteflies in field crops.

  20. Enhanced whitefly resistance in transgenic tobacco plants expressing double stranded RNA of v-ATPase A gene.

    Directory of Open Access Journals (Sweden)

    Nidhi Thakur

    Full Text Available BACKGROUND: Expression of double strand RNA (dsRNA designed against important insect genes in transgenic plants have been shown to give protection against pests through RNA interference (RNAi, thus opening the way for a new generation of insect-resistant crops. We have earlier compared the efficacy of dsRNAs/siRNAs, against a number of target genes, for interference in growth of whitefly (Bemisia tabaci upon oral feeding. The v-ATPase subunit A (v-ATPaseA coding gene was identified as a crucial target. We now report the effectiveness of transgenic tobacco plants expressing siRNA to silence v-ATPaseA gene expression for the control of whitefly infestation. METHODOLOGY/PRINCIPAL FINDINGS: Transgenic tobacco lines were developed for the expression of long dsRNA precursor to make siRNA and knock down the v-ATPaseA mRNA in whitefly. Molecular analysis and insecticidal properties of the transgenic plants established the formation of siRNA targeting the whitefly v-ATPaseA, in the leaves. The transcript level of v-ATPaseA in whiteflies was reduced up to 62% after feeding on the transgenic plants. Heavy infestation of whiteflies on the control plants caused significant loss of sugar content which led to the drooping of leaves. The transgenic plants did not show drooping effect. CONCLUSIONS/SIGNIFICANCE: Host plant derived pest resistance was achieved against whiteflies by genetic transformation of tobacco which generated siRNA against the whitefly v-ATPaseA gene. Transgenic tobacco lines expressing dsRNA of v-ATPaseA, delivered sufficient siRNA to whiteflies feeding on them, mounting a significant silencing response, leading to their mortality. The transcript level of the target gene was reduced in whiteflies feeding on transgenic plants. The strategy can be taken up for genetic engineering of plants to control whiteflies in field crops.

  1. Transcriptomics-guided development of RNA interference strategies to manage whiteflies: a globally distributed vector of crop viruses

    Science.gov (United States)

    Over 300 viruses are transmitted by the whitefly, Bemisia tabaci, with 90% of them belonging to the genus, Begomovirus. Begomoviruses are exclusively transmitted by whiteflies to a range of agriculture crops, resulting in billions of dollars lost annually, while jeopardizing food security worldwide....

  2. The entomopathogenic fungus Isaria fumosorosea and its compatibility with buprofezin: effects on the rugose spiraling whitefly Aleurodicus rugioperculatus

    Science.gov (United States)

    The gumbo limbo or rugose spiraling whitefly is a new invasive pest of palms, woody ornamentals, and fruits in Florida. The pathogenicity of a naturally occurring entomopathogenic fungus, Isaria fumosorosea (PFR 97) is well known for its activity against commonly found whiteflies species in the regi...

  3. Infection of the whitefly Bemisia tabaci with Rickettsia spp. alters its interactions with Tomato yellow leaf curl virus

    Science.gov (United States)

    Numerous animal and plant viruses are transmitted by arthropod vectors in a persistent, circulative manner. Tomato yellow leaf curl virus (TYLCV) is transmitted by the sweet potato whitefly Bemisia tabaci. Here we report that infection with Rickettsia spp., a facultative endosymbiont of whiteflies...

  4. Co-infection and localization of secondary symbionts in two whitefly species

    Science.gov (United States)

    2010-01-01

    Background Whiteflies are cosmopolitan phloem-feeding pests that cause serious damage to many crops worldwide due to direct feeding and vectoring of many plant viruses. The sweetpotato whitefly Bemisia tabaci (Gennadius) and the greenhouse whitefly Trialeurodes vaporariorum (Westwood) are two of the most widespread and damaging whitefly species. To complete their unbalanced diet, whiteflies harbor the obligatory bacterium Portiera aleyrodidarum. B. tabaci further harbors a diverse array of secondary symbionts, including Hamiltonella, Arsenophonus, Cardinium, Wolbachia, Rickettsia and Fritschea. T. vaporariorum is only known to harbor P. aleyrodidarum and Arsenophonus. We conducted a study to survey the distribution of whitefly species in Croatia, their infection status by secondary symbionts, and the spatial distribution of these symbionts in the developmental stages of the two whitefly species. Results T. vaporariorum was found to be the predominant whitefly species across Croatia, while only the Q biotype of B. tabaci was found across the coastal part of the country. Arsenophonus and Hamiltonella were detected in collected T. vaporariorum populations, however, not all populations harbored both symbionts, and both symbionts showed 100% infection rate in some of the populations. Only the Q biotype of B. tabaci was found in the populations tested and they harbored Hamiltonella, Rickettsia, Wolbachia and Cardinium, while Arsenophonus and Fritschea were not detected in any B. tabaci populations. None of the detected symbionts appeared in all populations tested, and multiple infections were detected in some of the populations. All endosymbionts tested were localized inside the bacteriocyte in both species, but only Rickettsia and Cardinium in B. tabaci showed additional localization outside the bacteriocyte. Conclusions Our study revealed unique co-infection patterns by secondary symbionts in B. tabaci and T. vaporariorum. Co-sharing of the bacteriocyte by the primary

  5. Plant-mediated horizontal transmission of Rickettsia endosymbiont between different whitefly species.

    Science.gov (United States)

    Li, Yi-Han; Ahmed, Muhammad Z; Li, Shao-Jian; Lv, Ning; Shi, Pei-Qiong; Chen, Xiao-Sheng; Qiu, Bao-Li

    2017-12-01

    A growing number of studies have revealed the presence of closely related endosymbionts in phylogenetically distant arthropods, indicating horizontal transmission of these bacteria. Here we investigated the interspecific horizontal transmission of Rickettsia between two globally invasive whitefly species, Bemisia tabaci MEAM1 and B. tabaci MED, via cotton plants. We found both scattered and confined distribution patterns of Rickettsia in these whiteflies. After entering cotton leaves, Rickettsia was restricted to the leaf phloem vessels and could be taken up by both species of the Rickettsia-free whitefly adults, but only the scattered pattern was observed in the recipient whiteflies. Both the relative quantity of Rickettsia and the efficiency of transmitting Rickettsia into cotton leaves were significantly higher in MEAM1 females than in MED females. The retention time of Rickettsia transmitted from MEAM1 into cotton leaves was at least 5 days longer than that of MED. Phylogenetic analysis based on 16S rRNA and gltA genes confirmed that the Rickettsia extracted from the donor MEAM1, the cotton leaves, the recipient MEAM1 and the recipient MED were all identical. We conclude that cotton plants can mediate horizontal transmission of Rickettsia between different insect species, and that the transmission dynamics of Rickettsia vary with different host whitefly species. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Assessing compatibility of Isaria fumosorosea and buprofezin for mitigation of Aleurodicus rugioperculatus (Hemiptera: Aleyrodidae) - an invasive pest in the Florida landscape

    Science.gov (United States)

    A significant reduction in Rugose spiraling whitefly (RSW) population was reported for more than 5 weeks in buprofezin alone and more than 7 weeks in the combination treatments. In fall 2014 and summer 2015, the mean whitefly mortality observed during the 10 week assessment period were 52.4 and 42....

  7. Whiteflies interfere with indirect plant defense against spider mites in Lima bean

    Science.gov (United States)

    Zhang, Peng-Jun; Zheng, Si-Jun; van Loon, Joop J. A.; Boland, Wilhelm; David, Anja; Mumm, Roland; Dicke, Marcel

    2009-01-01

    Plants under herbivore attack are able to initiate indirect defense by synthesizing and releasing complex blends of volatiles that attract natural enemies of the herbivore. However, little is known about how plants respond to infestation by multiple herbivores, particularly if these belong to different feeding guilds. Here, we report the interference by a phloem-feeding insect, the whitefly Bemisia tabaci, with indirect plant defenses induced by spider mites (Tetranychus urticae) in Lima bean (Phaseolus lunatus) plants. Additional whitefly infestation of spider-mite infested plants resulted in a reduced attraction of predatory mites (Phytoseiulus persimilis) compared to attraction to plants infested by spider mites only. This interference is shown to result from the reduction in (E)-β-ocimene emission from plants infested by both spider mites and whiteflies. When using exogenous salicylic acid (SA) application to mimic B. tabaci infestation, we observed similar results in behavioral and chemical analyses. Phytohormone and gene-expression analyses revealed that B. tabaci infestation, as well as SA application, inhibited spider mite-induced jasmonic acid (JA) production and reduced the expression of two JA-regulated genes, one of which encodes for the P. lunatus enzyme β-ocimene synthase that catalyzes the synthesis of (E)-β-ocimene. Remarkably, B. tabaci infestation concurrently inhibited SA production induced by spider mites. We therefore conclude that in dual-infested Lima bean plants the suppression of the JA signaling pathway by whitefly feeding is not due to enhanced SA levels. PMID:19965373

  8. Effect of foliar application of pymetrozine on Bemisia tabaci (MED whitefly) and Amblyseius swirskii, 2016

    Science.gov (United States)

    Bemisia tabaci is a polyphagous pest known to feed upon over 900 plant taxa, and is an effective vector of more than 100 plant damaging viruses. Among different biotypes of this cryptic species complex, MEAM1 and MED whitefly are the two most destructive members posing threats of several crops of ec...

  9. Predicting the presence of whiteflies and tomato yellow leaf curl virus in Florida tomato fields

    Science.gov (United States)

    Florida is one of the leading states for production of fresh market tomatoes. Production is severely affected by Tomato yellow leaf curl virus (TYLCV). The objective of this study was to identify landscape and climatic factors that drive whitefly populations and TYLCV incidence in commercial tomato ...

  10. Scale insects, mealybugs, whiteflies and psyllids (Hemiptera, Sternorrhyncha) as prey of ladybirds. (Review)

    Czech Academy of Sciences Publication Activity Database

    Hodek, Ivo; Honěk, A.

    2009-01-01

    Roč. 51, č. 2 (2009), s. 232-243 ISSN 1049-9644 Grant - others:MzeČR(CZ) 002700604; GA ČR(CZ) GA522/08/1300 Institutional research plan: CEZ:AV0Z50070508 Keywords : scale insects * mealybugs * whiteflies Subject RIV: EH - Ecology, Behaviour Impact factor: 1.612, year: 2009

  11. A Tomato necrotic dwarf virus isolate from Datura with poor transmissibility by the whitefly, Bemisia tabaci

    Science.gov (United States)

    Tomato necrotic dwarf virus (ToNDV); genus Torradovirus, is a whitefly-transmitted virus that caused significant losses for tomato production in the Imperial Valley of California during the 1980s. The virus causes severe stunting, dwarfing of leaves, foliar and fruit necrosis, and greatly reduced f...

  12. Management of whitefly-transmitted viruses in open-field production systems

    Science.gov (United States)

    Whiteflies are a key pest of crops in open field production throughout the tropics and subtropics. This is due in large part to the long and diverse list of devastating plant viruses transmitted by these vectors. Open field production provides many challenges to manage these viruses and in many case...

  13. Effect of buprofezin and Isaria fumosorosea against rugose spiraling whitefly, 2015

    Science.gov (United States)

    The objective of this study was to evaluate the efficacy of selected insecticides alone or in combination against Aleurodicus rugioperculatus Martin, the rugose spiraling whitefly (RSW), a new invasive pest of ornamentals in Florida. The trial was conducted on an ornamental host, white bird of parad...

  14. Effect of Zohar LQ-215, a biorational surfactant, on the sweetpotato whitefly Bemisia tabaci (biotype b).

    Science.gov (United States)

    Ishaaya, I; Khasdan, V; Horowitz, A Rami

    2006-01-01

    Zohar LQ-215, a surfactant based on plant oils, able to control nymphs of the whitefly, Bemisia tabaci (Gennadius), under laboratory and field conditions. To evaluate the effects of the surfactant on the nymph stages of whitefly under laboratory conditions, potted cotton seedlings infested with 1st- or 3rd-instars were treated with the compound aqueous solutions. LC90 values of Zohar LQ-215 on 1st and 3rd-nymphs, based on mortality curves, were 0.78% and 1.14%, respectively. Adult mortality of 12% and 19% was obtained at concentrations of 0.5% and 1%, respectively. Under both laboratory and, in some cases, under field conditions, greater mortality was achieved when combining Zohar LQ-215 with the insect growth regulator buprofezin than when either insecticide was applied separately. Our results indicate that Zohar LQ-215 could serve as a potential compound for controlling whiteflies under light to moderate infestation and could be used in combination with other rational insecticides such as buprofezin for controlling whiteflies in integrated pest management programs.

  15. Isaria poprawskii sp. nov. (Hypocreales: Cordycipitacae), a new entomopathogenic fungus from Texas affecting sweet potato whitefly

    Science.gov (United States)

    Isaria poprawskii is described as a new entomopathogenic species similar to Isaria javanica (=Paecilomyces javanicus). It was discovered ont he sweet potato whitefly, Bemisia tabaci biotype B in the Lower Rio Grande Valley of Texas (LRGV), USA. Morphological and DNA examinations indicated the dist...

  16. RNAi-mediated resistance to whitefly (Bemisia tabaci) in genetically engineered lettuce (Lactuca sativa).

    Science.gov (United States)

    Ibrahim, Abdulrazak B; Monteiro, Tatiane R; Cabral, Glaucia B; Aragão, Francisco J L

    2017-10-01

    RNA interference (RNAi)-based transgenic technologies have evolved as potent biochemical tools for silencing specific genes of plant pathogens and pests. The approach has been demonstrated to be useful in silencing genes in insect species. Here, we report on the successful construction of RNAi-based plasmid containing an interfering cassette designed to generate dsRNAs that target a novel v-ATPase transcript in whitefly (Bemisia tabaci), an important agricultural pest in tropical and sub-tropical regions. The presence of the transgene was confirmed in T 0 and T 1 generations of transgenic lettuce lines, segregating in a Mendelian fashion. Seven lines were infested with whiteflies and monitored over a period of 32 days. Analysis of mortality showed that within five days of feeding, insects on transgenic plants showed a mortality rate of 83.8-98.1%. In addition, a reduced number of eggs (95 fold less) was observed in flies feeding on transgenic lettuce plants than insects on control lines. Quantitative reverse transcription PCR showed decreased expression level of endogenous v-ATPase gene in whiteflies feeding on transgenic plants. This technology is a foundation for the production of whitefly-resistant commercial crops, improving agricultural sustainability and food security, reducing the use of more environmentally aggressive methods of pest control.

  17. Whitefly (Paraleyrodes sp. preference for avocado cultivars (Persea americana Mill. in Fresno, Tolima

    Directory of Open Access Journals (Sweden)

    Paola Vanessa Sierra

    2014-07-01

    Full Text Available The whitefly is a major pest that affects avocado and there is not enough information about the biolog y and management of this insect in Colombia. In this paper the incidence of the whitefly Paraleyrodes sp. pos. bondarion four avocado cultivars was studied (Choquette, Hass, Lorena, Santana. The crop management carried out by farmers was characterized and its effect on the white fly presence on three cultivars was evaluated (Choquette, Hass, Lorena. Presence of secondary metabolites on leaves from Hass and Lorena was measured and the effect of their leaf extracts on the mortality and repellency index of whitefly adults was established. There were interactions between crop management and cultivar for the presence of the insect; moderately chemical management had the lowest infestation in all cultivars. The increase in soil fertilization and chemical insecticides increased insect population, and removal of the hemiparasite decreased it. Lorena cultivar had the highest fly preference, insect population increase when there was interaction between cultivar and mature leaves, neutral repellency index, and high percentage of total and non-reducing carbohydrates. The Hass cultivar showed higher amount of coumarins, terpenes and steroids, and high rate of repellency. Lorena attracting the insect is due to the presence of carbohydrates; and Hass repellency is due to the terpene and / or steroids. Research works should be done on whitefly in avocado crops toward cultivars Lorena

  18. Reproduction now or later: optimal host-handling strategies in the whitefly parasitoid Encarsia formosa

    NARCIS (Netherlands)

    Burger, J.M.S.; Hemerik, L.; Lenteren, van J.C.; Vet, L.E.M.

    2004-01-01

    We developed a dynamic state variable model for studying optimal host-handling strategies in the whitefly parasitoid Encarsia formosa Gahan (Hymenoptera: Aphelinidae). We assumed that (a) the function of host feeding is to gain nutrients that can be matured into eggs, (b) oogenesis is continuous and

  19. Reproduction now or later: optimal host-hanling strategies in the whitefly parasitoid Encarsia formosa

    NARCIS (Netherlands)

    Burger, J.S.M.; Hemerik, L.; Van Lenteren, J.C.; Vet, L.E.M.

    2004-01-01

    We developed a dynamic state variable model for studying optimal host-handling strategies in the whitefly parasitoid Encarsia formosa Gahan (Hymenoptera: Aphelinidae). We assumed that (a) the function of host feeding is to gain nutrients that can be matured into eggs, (b) oögenesis is continuous and

  20. How to behave? : evolution of host-handling behaviour in the whitefly parasitoid Encarsia formosa

    NARCIS (Netherlands)

    Burger, J.M.S.

    2002-01-01

    The main aim of evolutionary ecology is to explain the adaptation of form, function and behaviour of organisms to their environment. In this thesis, I studied host-handling behaviour of the whitefly parasitoid Encarsia formosa form such an evolutionary point of view.

  1. Organization of the mitochondrial genomes of whiteflies, aphids, and psyllids (Hemiptera, Sternorrhyncha

    Directory of Open Access Journals (Sweden)

    Baumann Paul

    2004-08-01

    Full Text Available Abstract Background With some exceptions, mitochondria within the class Insecta have the same gene content, and generally, a similar gene order allowing the proposal of an ancestral gene order. The principal exceptions are several orders within the Hemipteroid assemblage including the order Thysanoptera, a sister group of the order Hemiptera. Within the Hemiptera, there are available a number of completely sequenced mitochondrial genomes that have a gene order similar to that of the proposed ancestor. None, however, are available from the suborder Sternorryncha that includes whiteflies, psyllids and aphids. Results We have determined the complete nucleotide sequence of the mitochondrial genomes of six species of whiteflies, one psyllid and one aphid. Two species of whiteflies, one psyllid and one aphid have mitochondrial genomes with a gene order very similar to that of the proposed insect ancestor. The remaining four species of whiteflies had variations in the gene order. In all cases, there was the excision of a DNA fragment encoding for cytochrome oxidase subunit III(COIII-tRNAgly-NADH dehydrogenase subunit 3(ND3-tRNAala-tRNAarg-tRNAasn from the ancestral position between genes for ATP synthase subunit 6 and NADH dehydrogenase subunit 5. Based on the position in which all or part of this fragment was inserted, the mitochondria could be subdivided into four different gene arrangement types. PCR amplification spanning from COIII to genes outside the inserted region and sequence determination of the resulting fragments, indicated that different whitefly species could be placed into one of these arrangement types. A phylogenetic analysis of 19 whitefly species based on genes for mitochondrial cytochrome b, NADH dehydrogenase subunit 1, and 16S ribosomal DNA as well as cospeciating endosymbiont 16S and 23S ribosomal DNA indicated a clustering of species that corresponded to the gene arrangement types. Conclusions In whiteflies, the region of the

  2. Intraguild predation by the generalist predator Orius majusculus on the parasitoid Encarsia formosa

    DEFF Research Database (Denmark)

    Sohrabi, Fariba; Enkegaard, Annie; Shishehbor, Parviz

    2013-01-01

    Intraguild predation of Orius majusculus (Reuter) (Heteroptera: Anthocoridae) on Encarsia formosa (Gahan) (Hymenoptera: Aphelinidae), both natural enemies of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae), was studied under laboratory conditions. The experiments quantified prey consumption b...

  3. Severity of cotton whitefly (bemisia tabaci genn.) population with special reference to abiotic factors

    International Nuclear Information System (INIS)

    Zia, K.; Bashir, M.H.; Khan, B.S.; Khan, R.R.; Hafeez, F.

    2013-01-01

    Bemisia tabaci is serious insect and constantly destabilizing the cotton production. The research was conducted to evaluate cotton cultivars (transgenic and non transgenic) for resistance against whitefly and further correlated with weather factors such as temperature, relative humidity and rainfall, during the cropping seasons 2010 and 2011. However, peak population (6.36 per leaf) was recorded from FH-113 followed FH-167 and FH-114, whereas minimum population was recorded from FH-4243 in transgenic group whereas peak population (5.24 per leaf) was recorded from FH- 941 followed by FH-100 and FH- 901 while minimum population was recorded from FH-207, in non transgenic group of cultivars in the year 2010. The incidence and abundance was much high and reaching towards two folds in the year 2011 but the trend of whitefly varied with peak population (11.03 per leaf) recorded from FH -167 followed by FH- 4243 and FH113 (from transgenic group of cultivars) whereas a peak of 10.77 per leaf population of whitefly, recorded followed by FH-901 and FH-941 (from non transgenic group of cultivars). FH-207 found more resistant from all ten cultivars studied in 2011. Correlation among weather factors and whitefly population showed that rainfall was negatively correlated while temperature and relative humidity were positively correlated with whitefly population. In addition to that situation is becoming worse because of shifting from conventional to more advanced transgenic cultivars that are susceptible and serve as host. Moreover, climatic conditions provide addition favor and helps in population buildup, abundance and incidence. (author)

  4. Biological aspects of Bemisia tabaci (Genn.) B biotype (Hemiptera: Aleyrodidae) on six bean genotypes

    International Nuclear Information System (INIS)

    Oriani, Maria A. de G.

    2008-01-01

    The silverleaf whitefly is one of the most harmful pests that attack bean crops, mainly for extracting large quantities of phloem sap and transmitting the bean golden mosaic virus. Resistant germplasm plants can be an important method for controlling this pest. The biological aspects of Bemisia tabaci B biotype on bean (Phaseolus vulgaris) genotypes were evaluated. The tests were conducted under laboratory conditions, with the following genotypes: Arc 1, Arc 3s, Arc 5s, G13028, G11056 and Porrillo 70. The bean plants in a stage IV-1 were infested during one day with silverleaf white flies. Afterwards the eggs and nymphs were observed until adult emergence. Longevity and fecundity of emerged insects were also evaluated. The longest development time occurred for nymphs fed on Arc 3s genotype (26.5 days), following by G11056 (25.9 days) and G13028 (25.3 days). The development period was 5.5 days longer in Arc 3s when compared with Porrillo 70. Also, the wild genotypes Arc 3s and G11056 showed higher mortality rates (94.7% and 83.1%, respectively), which may suggest antibiosis and/or feeding non preference resistance type. For this reason, although longevity and fecundity were not influenced when the whitefly fed on resistant genotypes (Arc 3s, G11056, G13028 and Arc 5s), those genotypes can be used for bean breeding program towards B. tabaci B biotype. (author)

  5. Factors affecting oviposition of Bemisia tabaci (Genn.) biotype B (Hemiptera: Aleyrodidae) in sweet pepper; Fatores que afetam a oviposicao de Bemisia tabaci (Genn.) biotipo B (Hemiptera: Aleyrodidae) em pimentao

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Larissa C. de; Campos, Alcebiades R. [UNESP, Ilha Solteira, SP (Brazil). Dept. de Fitossanidade, Engenharia Rural e Solos]. E-mail: lclima@aluno.feis.unesp.br; campos@bio.feis.unesp.br

    2008-03-15

    Bemisia tabaci (Gen.) biotype B is considered a pest of economical importance for several vegetables. The oviposition behaviour of the while fly was evaluated in sweet pepper plants. The trials were carried out under greenhouse condition and in the Laboratory of Entomology of DEFERS/ UNESP, Campus of Ilha Solteira-SP, with the sweet pepper Magali-R genotype. The effect of plant age on the whitefly oviposition was evaluated in free-choice tests, in plants, 25, 30, 35, 40 and 45- day-old, as egg distribution in the plant and on the leaf blade was evaluated in 35-days-old plants. In a no-choice tests, 35-day-old plants were used to evaluate the effect of the densities of 50, 100, 150, 200 and 250 adults per plant on the number of eggs laid by insects. The silver leaf whitefly preferred to oviposition the third to sixth leaflets, of the medium and superior part of plants of sweet pepper; the leaf blade areas, located in the lobes right and left close the base of the leaf were the preferential site for whitefly oviposition. Older plants, 40- and 45-day-old, were preferentially used for oviposition, and 200 and 250 adults per plant were both enough to lay a number of eggs that allowed to differentiate among sweet pepper genotypes with different whitefly resistance levels. (author)

  6. Cryptic Species Identification and Composition of Bemisia tabaci (Hemiptera: Aleyrodidae) Complex in Henan Province, China

    Science.gov (United States)

    Hu, Jian; Wang, Lun-Ji; Dong, Jun-Feng; Song, Yue-Qin; Sun, Hui-Zhong

    2017-01-01

    Abstract Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a cryptic species complex, causing significant crop losses in China during the last decade. Although knowledge of cryptic species composition and dynamics within B. tabaci complex is critical for developing sustainable pest management strategies, limited information is available on this pest in the Henan province of China. A systematic survey of the cryptic species composition and distribution of B. tabaci complex in different locations of Henan province was conducted in 2012. The results of RAPD-PCR and the gene for the mitochondrial cytochrome oxidase subunit-1 (mtCOI) based phylogenetic relationships established using Bayesian method indicated there were four known cryptic species MEAM1, MED, Asia II 3, Asia II 9 and a new cryptic species named China 6 in Henan province. In the survey, the invasive cryptic species MED and MEAM1 were found to be predominant with wide spread distribution across the surveyed regions. On the contrary, the indigenous B. tabaci cryptic species including Asia II 3, Asia II 9 and China 6 remained with low prevalence in some surveyed regions. Cryptic species MEAM1 and MED have not completely displaced the native B. tabaci in Henan province. This current study for the first time unifies our knowledge of the diversity and distribution of B. tabaci across Henan province of China. PMID:28973577

  7. Cryptic Species Identification and Composition of Bemisia tabaci (Hemiptera: Aleyrodidae) Complex in Henan Province, China.

    Science.gov (United States)

    Jiu, Min; Hu, Jian; Wang, Lun-Ji; Dong, Jun-Feng; Song, Yue-Qin; Sun, Hui-Zhong

    2017-05-01

    Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a cryptic species complex, causing significant crop losses in China during the last decade. Although knowledge of cryptic species composition and dynamics within B. tabaci complex is critical for developing sustainable pest management strategies, limited information is available on this pest in the Henan province of China. A systematic survey of the cryptic species composition and distribution of B. tabaci complex in different locations of Henan province was conducted in 2012. The results of RAPD-PCR and the gene for the mitochondrial cytochrome oxidase subunit-1 (mtCOI) based phylogenetic relationships established using Bayesian method indicated there were four known cryptic species MEAM1, MED, Asia II 3, Asia II 9 and a new cryptic species named China 6 in Henan province. In the survey, the invasive cryptic species MED and MEAM1 were found to be predominant with wide spread distribution across the surveyed regions. On the contrary, the indigenous B. tabaci cryptic species including Asia II 3, Asia II 9 and China 6 remained with low prevalence in some surveyed regions. Cryptic species MEAM1 and MED have not completely displaced the native B. tabaci in Henan province. This current study for the first time unifies our knowledge of the diversity and distribution of B. tabaci across Henan province of China. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  8. CASOS SELECTOS DE RESISTENCIA A INSECTICIDAS EN MOSCAS BLANCAS (Hemiptera: Aleyrodidae EN EL MUNDO

    Directory of Open Access Journals (Sweden)

    Macías-flores A

    2013-01-01

    Full Text Available Las moscas blancas (Hemíptera: Aleyrodidae son un problema a escala global. En México, llamó la atención como plaga agrícola en la década de los años 80´s y 90´s del siglo pasado por las pérdidas económicas que ocasionaron en los cultivos agrícolas, debido a los daños directos por la succión de savia y a los daños indirectos por la transmisión de enfermedades de origen viral. El hombre en su intento fallido por erradicarlas ha hecho uso desmedido de insecticidas químicos, quizás por su accesibilidad por costo bajo o por efectos de control inmediatos, por lo cual ha causado daño al medio ambiente y a la salud humana, con la consecuencia de desarrollo de resistencia. En un intento por disminuir los efectos de tales sustancias, muchas investigaciones alrededor del mundo se han conducido para encontrar productos insecticidas más efectivos con el menor impacto ambiental y a la salud humana, y que contribuyan a incrementar las herramientas de control disponibles en los sistemas de producción agrícola.

  9. Mortality of Bemisia tabaci biotype B (sternorrhyncha: aleyrodidae adults by aliphatic and aromatic synthetic sucrose esters

    Directory of Open Access Journals (Sweden)

    Mariangela Alves

    2008-12-01

    Full Text Available The B-strain of Bemisia tabaci Gennadius is a key pest of several crops and chemical control is the main control method used by growers, although reduction in efficacy due to insecticide resistance has already been reported. The aim of this work was to investigate the insecticidal effect of an array of synthetic sucrose esters with the aliphatic and aromatic groups on whitefly adults. Sucrose butyrate, caprate, octanoate, palmitate, oleate, octaacetate, phthalate, benzoate, and sucrose diacetate hexaisobutyrate were tested. The solutions were prepared and applied on the adults caught on yellow sticky traps using the Potter spray tower. Long-chains sucrose aliphatic esters were more effective against the silverleaf whiteflies and the highest mortality was obtained with sucrose oleate and sucrose octanoate. Since these compounds were tensoactive, sodium dodecylsulphate was also tested for the comparison but no effect was observed. Sucrose butyrate and other aliphatic and aromatic sucrose polyesters showed negligible effect on the silverleaf whiteflies.O biótipo B de B. tabaci Gennadius tem se destacado como uma praga-chave de diversas culturas. O controle químico tem sido a principal tática de controle utilizada, embora já se tenha observado redução na eficiência dos produtos devido ao desenvolvimento de resistência. Assim, o objetivo do presente trabalho foi avaliar o efeito de diversos ésteres de sacarose com grupos alifáticos ou aromáticos sobre adultos de mosca-branca. Butirato de sacarose, caprato, octanoato, palmitato, oleato, actaacetato, ftlato, benzoato e diacetato hexaisobutirato de sacarose foram testados. Soluções de éster de sacarose foram preparadas e aplicadas sobre adultos capturados em armadilhas adesivas utilizando Torre de Potter. Ésteres alifáticos de sacarose com longas cadeias foram mais efetivos contra mosca-branca e as maiores taxas de mortalidade foram obtidas com oleato e octanoato de sacarose. Uma vez que

  10. Taxonomic notes on some Polyglyptini: descriptions of new genus and new species (Homoptera, Membracidae, Smiliinae

    Directory of Open Access Journals (Sweden)

    Albino M. Sakakibara

    1996-01-01

    Full Text Available Taxonomic notes on some Polyglyptini; descriptions of new genus and new species (Homoptera, Membracidae, Smiliinae. The genera Hemiptycha Germar, Metheisa Fowler, Maturnaria Metcalf, Aphetea Fowler, Dioclophara Kirkaldy, and Phormophora Stål, are redescribed; Creonus, gen.n. (type species: Maturna lloydi Funkhouser, 1914, and Aphetea robustula, sp.n. (from Bolivia, are described. Some nomenclatural changes are introduced, as follow: - Hemiptycha Germar, 1833 = Polyrhyssa Stål, 1869, syn.n.: - Hemiptycha cultrata (Coquebert, 1801, comb.n., = Polyglyptodes flavocostatus Haviland, 1925, syn.n., = Polyrhyssa cultrata maculata Fonseca, 1942, syn.n. - Hemiptycha obtecta (Fabricius, 1803 = Hille herbicola Haviland, 1925, syn.n. - Maturnaria ephippigera (Fairmaire, 1846 = Publilia tumulata Buckton, 1903, syn.n., = Metheisa fowleri Funkhouser, 1927, syn.n. - Creonus lloydi (Funkhouser, 1914, comb.n. - Aphetea parvula (Fabricius, 1803, comb.n., = Aphetea affinis Haviland, 1925, syn.n. - Dioclophara Kirkaldy, 1904 = lncolea Goding, 1926, syn.n. - Dioclophara viridula (Fairmaire, 1846 = Maturna multilineata Fonseca, 1942, syn.n. - Dioclophara variegata (Goding, 1926, comb.n. = lncolea viridis Goding, 1926, syn.n. - Phormophora maura (Fabricius, 1803 = Darnis dorsata Fabricius, 1803, syn.n.

  11. Responses of Nasonovia ribisnigri (Homoptera: Aphididae) to susceptible and resistant lettuce.

    Science.gov (United States)

    Liu, Yong-Biao; McCreight, James D

    2006-06-01

    Nymphs and alates of aphid Nasonovia ribisnigri (Mosley) (Homoptera: Aphididae) were tested on 10 lettuce cultivars with N. ribisnigri resistance gene Nr and 18 cultivars without the resistance gene in various bioassays. Bioassays used whole plants, leaf discs, or leaf cages to determine susceptibility of commercial lettuce cultivars to N. ribisnigri infestation and to evaluate screening methods for breeding lettuce resistance to N. ribisnigri. Resistant and susceptible plants were separated in 3 d when using whole plant bioassays. Long-term (> or =7 d) no-choice tests using leaf cages or whole plants resulted in no survival of N. ribisnigri on resistant plants, indicating great promise of the Nr gene for management of N. ribisnigri. Effective screening was achieved in both no-choice tests where resistant or susceptible intact plants were tested separately in groups or individually and in choice tests where susceptible and resistant plants were intermixed. Leaf discs bioassays were not suitable for resistance screening. All lettuce cultivars without the resistance gene were suitable hosts for N. ribisnigri, indicating the great importance of this pest to lettuce production and the urgency in developing resistant lettuce cultivars to manage N. ribisnigri.

  12. Distribution and population development of Nasonovia ribisnigri (Homoptera: Aphididae) in iceberg lettuce.

    Science.gov (United States)

    Liu, Yong-Biao

    2004-06-01

    A field study was conducted to determine the distribution and development of aphid Nasonovia ribisnigri (Mosley) (Homoptera: Aphididae) populations in iceberg lettuce, Lactuca sativa L. 'Salinas'. Lettuce plants were transplanted and caged individually in the field and inoculated with apterous N. ribisnigri at 0, 1, 2, 3, and 4 wk after transplanting in spring and fall 2002. Plants were harvested 15-50 d after inoculations; numbers of alates and apterous N. ribisnigri were counted or estimated on each leaf for each plant. Inoculations during all 5 wk of plant development resulted in successful colonization of lettuce heads. Results indicated that head formation did not reduce the risk of colonization by N. ribisnigri to iceberg lettuce; plants were susceptible to colonization by N. ribisnigri throughout their development. For later inoculations, N. ribisnigri populations were relatively smaller, and aphids were found mostly within the heads. For earlier inoculations, N. ribisnigri populations were larger, and within-plant distributions shifted toward frame leaves. The shift of population distributions toward frame leaves correlated significantly with increases in N. ribisnigri population density. For most inoculations, more aphids were present on wrapper leaves than on other leaves. The proportion of alates did not vary significantly with population density. Population development of N ribisnigri also correlated significantly with heat unit accumulation. Yellow sticky cards were used to monitor alates in each cage. Catches of N. ribisnigri alates on yellow sticky cards were significantly correlated with total numbers of alates as well as with total population sizes on individual lettuce plants.

  13. Homoptera, Cicadidae

    African Journals Online (AJOL)

    1988-10-24

    Oct 24, 1988 ... There are also morphological differences between the two taxa which parallel the differences in their .... Female 5 31,0 29,9--32,2 9 26,8 25,3-28,7 -8,11 0,0001. • Student's t test. [. 1mm. A. B. Figure 2 Male genitalia (pygophore and urite). A, P. stridula; ... mainly on trees, all of which were exotics, e.g. Port.

  14. Homoptera: Cicadidae

    African Journals Online (AJOL)

    1988-10-24

    Oct 24, 1988 ... The geographical distributions, habitat preferences, plant associations and seasonal appearance of the platypleurine cicadas occurring on the Natal coastal plain, South Africa, are reported for the first time, and a key to the species is provided. Die geografiese verspreiding, habitatvoorkeur, plantassosiasies ...

  15. Homoptera: Aphididae

    African Journals Online (AJOL)

    and parasitoids per plant, ladybird beetles per plot, and finally grain yield per plot were recorded. Based on the results of the ANOVA, plant ... is a food, fodder and feed crop belonging to the family Leguminosae (= Fabaceae) ... use of predators, parasitoids and pathogens for pest control, either by introduction from other ...

  16. Understanding cross-communication between aboveground and belowground tissues via transcriptome analysis of a sucking insect whitefly-infested pepper plants.

    Science.gov (United States)

    Park, Yong-Soon; Ryu, Choong-Min

    2014-01-03

    Plants have developed defensive machinery to protect themselves against herbivore and pathogen attacks. We previously reported that aboveground whitefly (Bemisia tabaci Genn.) infestation elicited induced resistance in leaves and roots and influenced the modification of the rhizosphere microflora. In this study, to obtain molecular evidence supporting these plant fitness strategies against whitefly infestation, we performed a 300 K pepper microarray analysis using leaf and root tissues of pepper (Capsicum annuum L.) applied with whitefly, benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH), and the combination of BTH+whitefly. We defined differentially expressed genes (DEGs) as genes exhibiting more than 2-fold change (1.0 based on log2 values) in expression in leaves and roots in response to each treatment compared to the control. We identified a total of 16,188 DEGs in leaves and roots. Of these, 6685, 6752, and 4045 DEGs from leaf tissue and 6768, 7705, and 7667 DEGs from root tissue were identified in the BTH, BTH+whitefly, and whitefly treatment groups, respectively. The total number of DEGs was approximately two-times higher in roots than in whitefly-infested leaves subjected to whitefly infestation. Among DEGs, whitefly feeding induced salicylic acid and jasmonic acid/ethylene-dependent signaling pathways in leaves and roots. Several transporters and auxin-responsive genes were upregulated in roots, which can explain why biomass increase is facilitated. Using transcriptome analysis, our study provides new insights into the molecular basis of whitefly-mediated intercommunication between aboveground and belowground plant tissues and provides molecular evidence that may explain the alteration of rhizosphere microflora and root biomass by whitefly infestation. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Evaluation of Insecticides and Agril Polyester Cover against Whitefly (Bemisia Tabaci Gennadius in Tomato Crops

    Directory of Open Access Journals (Sweden)

    K.M. Azam

    1996-01-01

    Full Text Available Field experiments were conducted on tomato crops over a two year period to evaluate the efficacy of six insecticides, viz., triazophos, phosphamidon, dimethoate, buprofezin and Aflix (endosulfan + dimethoate each at 0.05% and Repelin (plant insecticide at 1% concentration along With a cultural treatment by covering the plants with Agril (a polyester material for the control of whitefly, Bemisia tabaci. The insecticides were applied eight times at weekly interval immediately after transplantation. The whitefly eggs,  nymphal population counts and the per cent incidence of tomato leaf curl virus (TLCV were recorded every week for eight weeks in all the treatments including untreated control. The incidence of whitefly was more severe in the second year (i.e, 1992-93 as compared to the previous season. Among the various treatments, the Agril cover, a newly introduced cultural practice, recorded the least incidence of whitefly and of TLCV. The average of counts of eggs were 0.0 and 5.47 and of nymphs 0.54 and 0.58 per 10 leaflets and TLCV were 4.32% and 4.76% in Agril cover treatment during the first and second year, respectively. Among the insecticides tested only Aflix recorded less incidence of the pest, being 3.46 and 30.4 eggs per 10 leaflets and 0.94 and 5.34 nymphs per 10 leaflets during the two years of study, respectively. The other treatments were less effective in reducing pest and disease incidence. The crop under Agril-cover recorded the maximum yield of 34.57 and 26.15 t/ha of tomatoes as compared to 16.48 and 10.82 t/ha in control during the first and second year, respectively.

  18. Management of whitefly-transmitted viruses in open-field production systems.

    Science.gov (United States)

    Lapidot, Moshe; Legg, James P; Wintermantel, William M; Polston, Jane E

    2014-01-01

    Whiteflies are a key pest of crops in open-field production throughout the tropics and subtropics. This is due in large part to the long and diverse list of devastating plant viruses transmitted by these vectors. Open-field production provides many challenges to manage these viruses and in many cases adequate management has not been possible. Diseases caused by whitefly-transmitted viruses have become limiting factors in open-field production of a wide range of crops, i.e., bean golden mosaic disease in beans, tomato yellow leaf curl disease in tomato, cassava mosaic disease and cassava brown streak disease in cassava, and cotton leaf crumple disease in cotton. While host resistance has proven to be the most cost-effective management solution, few examples of host resistance have been developed to date. The main strategy to limit the incidence of virus-infected plants has been the application of insecticides to reduce vector populations aided to some extent by the use of selected cultural practices. However, due to concerns about the effect of insecticides on pollinators, consumer demand for reduced pesticide use, and the ability of the whitefly vectors to develop insecticide-resistance, there is a growing need to develop and deploy strategies that do not rely on insecticides. The reduction in pesticide use will greatly increase the need for genetic resistance to more viruses in more crop plants. Resistance combined with selected IPM strategies could become a viable means to increase yields in crops produced in open fields despite the presence of whitefly-transmitted viruses.

  19. EFICIÊNCIA DO CONTROLE QUÍMICO SOBRE A MOSCA BRANCA Bemisia tabaci biótipo B (HEMIPTERA: ALEYRODIDAE EM MELOEIRO

    Directory of Open Access Journals (Sweden)

    Antônio Lindemberg Martins Mesquita

    2007-01-01

    efficient to control eggs, nymphs and adults of the whitefly, while the insect growth regulators buprofezin and pyriproxyfen did not control eggs and adults, but they controled nymphs, being pyriproxyfen more efficient than buprofezin.

  20. Novel Genes Affecting the Interaction between the Cabbage Whitefly and Arabidopsis Uncovered by Genome-Wide Association Mapping.

    Directory of Open Access Journals (Sweden)

    Colette Broekgaarden

    Full Text Available Plants have evolved a variety of ways to defend themselves against biotic attackers. This has resulted in the presence of substantial variation in defense mechanisms among plants, even within a species. Genome-wide association (GWA mapping is a useful tool to study the genetic architecture of traits, but has so far only had limited exploitation in studies of plant defense. Here, we study the genetic architecture of defense against the phloem-feeding insect cabbage whitefly (Aleyrodes proletella in Arabidopsis thaliana. We determined whitefly performance, i.e. the survival and reproduction of whitefly females, on 360 worldwide selected natural accessions and subsequently performed GWA mapping using 214,051 SNPs. Substantial variation for whitefly adult survival and oviposition rate (number of eggs laid per female per day was observed between the accessions. We identified 39 candidate SNPs for either whitefly adult survival or oviposition rate, all with relatively small effects, underpinning the complex architecture of defense traits. Among the corresponding candidate genes, i.e. genes in linkage disequilibrium (LD with candidate SNPs, none have previously been identified as a gene playing a role in the interaction between plants and phloem-feeding insects. Whitefly performance on knock-out mutants of a number of candidate genes was significantly affected, validating the potential of GWA mapping for novel gene discovery in plant-insect interactions. Our results show that GWA analysis is a very useful tool to gain insight into the genetic architecture of plant defense against herbivorous insects, i.e. we identified and validated several genes affecting whitefly performance that have not previously been related to plant defense against herbivorous insects.

  1. The ecology and epidemiology of whitefly-transmitted viruses in Latin America.

    Science.gov (United States)

    Morales, Francisco J; Jones, Peter G

    2004-03-01

    Whitefly-transmitted geminiviruses are the most important constraint to the production of common bean and vegetable crops in the tropical lowlands and mid-altitude valleys of Latin America. Currently, over 30 distinct species of geminiviruses that are transmitted by the whitefly Bemisia tabaci infect common bean, tomato, pepper, cucurbits and other horticultural crops. A climate probability model (using FloraMap) was obtained using data from 304 geo-referenced locations where B. tabaci and geminiviruses cause significant damage. Clustering of the 304 points produced a simple model with two climatic variables: a dry season of at least 4 months each with less than 80 mm of rain and a mean temperature of the hottest month exceeding 21 degrees C. A modified Koeppen climate classification showed that 55% of the geminivirus-affected localities are in the tropical wet/dry region, 22% in the tropical and subtropical dry/humid climates and the remaining locations belonged to the wet equatorial and trade wind litoral climates. These findings contribute to understanding whitefly/geminivirus epidemics and implementation of sustainable integrated pest and disease management practices.

  2. Efficacy of plant derived oils and extracts against white-fly, bemisia tabaci (gennadius) on sesame crop

    International Nuclear Information System (INIS)

    Iram, A.; Irfan, M.; Aslam, S.

    2014-01-01

    Whitefly, Bemisia tabaci (Genn.) is a polyphagous pest and is reported on more than 600 host plants worldwide. Different methods are being used for its control. The present experiment was conducted to determine the effect of some plant extracts of mint (Mentha spp.) and gera-nium (Pelargonium graveolens) and soybean oil (Glycine max), mustard oil (Brassica spp.) and taramera oil (Eruca sativa) against whitefly, Bemisia tabaci on sesame crop. The data were recorded 24h before and 24h, 48h, 72h and 168h after application of each spray material. The results showed that whitefly population was significantly suppressed by both the botanical oils and extracts as compared to the control treatment but in general botanical oils showed significant results as compared to plant extracts. Soybean oil was quite effective in reducing whitefly population per leaf, while after second spray soybean oil and extract of Mentha spp. was more effective in the reducing whitefly population per leaf. The results indicated that plant derived oils and extracts have the potential to be used in plant protection strategies but still more research has to be incorporated in the pest management programmes. (author)

  3. High Level of Nitrogen Makes Tomato Plants Releasing Less Volatiles and Attracting More Bemisia tabaci (Hemiptera: Aleyrodidae)

    Science.gov (United States)

    Islam, Md. Nazrul; Hasanuzzaman, Abu Tayeb Mohammad; Zhang, Zhan-Feng; Zhang, Yi; Liu, Tong-Xian

    2017-01-01

    Tomato (Solanum lycopersicum) production is seriously hampered by the infestation of the sweetpotato whitefly, Bemisia tabaci MEAM 1 (Middle East-Asia Minor 1). The infestation behavior of the whiteflies could be affected by the quantity of plant released volatile organic compounds (VOCs) related to nitrogen concentrations of the plant. In this study, we determined the infestation behavior of B. tabaci to the tomato plants that produced different levels of VOCs after application of different levels of nitrogen with a wind tunnel and an olfactometer. We also analyzed the VOCs released from nitrogen-treated tomato plants using solid phase microextraction and gas chromatography-mass spectrometry. The results revealed that the production of eight VOCs (β-pinene, (+)-4-carene, α-terpinene, p-cymene, β-phellandrene, α-copaene, β-caryophyllene, and α-humulene) was reduced after the plants were treated with high levels of nitrogen. However, more whiteflies were attracted to the tomato plants treated with high levels of nitrogen than to the plants treated with normal or below normal levels of nitrogen. These results clearly indicated that nitrogen can change the quality and quantity of tomato plant volatile chemicals, which play important roles in B. tabaci host plant selection. PMID:28408917

  4. Molecular systematics of aphids (Homoptera: Aphididae): new insights from the long-wavelength opsin gene.

    Science.gov (United States)

    Ortiz-Rivas, Benjamín; Moya, Andrés; Martínez-Torres, David

    2004-01-01

    Viviparous aphids (Aphididae) constitute a monophyletic group within the Homoptera with more than 4000 extant species worldwide but higher diversity in temperate regions. Several aspects of their biology account for attention paid to this group of insects. Their plant-sap-sucking way of feeding with many species transmitting viruses to crop plants has important implications on crop management strategies. Cyclical parthenogenesis associated in many groups to host alternation and elaborate polyphenisms is of special interests for evolutionists. Finally, the ancient association of most aphid species with intracellular endosymbiotic bacteria (Buchnera sp.) has also received much attention from evolutionists interested in mechanisms involved in the symbiotic process. Knowing the phylogenetic relationships among major aphid taxa is of special interest to evolutionists interested in the above issues. However, until recently, molecular approaches to aphid phylogeny were absent and discussions on the evolution of aphid life-cycles and on evolutionary aspects of their symbiotic association with Buchnera were framed by morphology-based phylogenies. Recently, two reports using molecular approaches attempted to address the yet unresolved phylogeny of Aphididae with limited although somehow different conclusions. In the present report we study the utility of the long-wave opsin gene in resolving phylogenetic relationships among seven subfamilies within the Aphididae. Our results corroborate some previously proposed relationships and suggest a revision of some others. In particular, our data support grouping the analysed aphid species into three main clades, being the subfamily Lachninae one of them, which contradicts its generally accepted sistership relationship with the subfamily Aphidinae. Moreover, our data also suggest a basal position of Lachninae which has implications on current discussions about the ancestrality of conifer-feeding in modern aphids.

  5. Analysis of whitefly transcriptional responses to Beauveria bassiana infection reveals new insights into insect-fungus interactions.

    Science.gov (United States)

    Xia, Jun; Zhang, Chang-Rong; Zhang, Shan; Li, Fang-Fang; Feng, Ming-Guang; Wang, Xiao-Wei; Liu, Shu-Sheng

    2013-01-01

    The fungal pathogen, Beauveria bassiana, is an efficient biocontrol agent against a variety of agricultural pests. A thorough understanding of the basic principles of insect-fungus interactions may enable the genetic modification of Beauveria bassiana to enhance its virulence. However, the molecular mechanism of insect response to Beauveria bassiana infection is poorly understood, let alone the identification of fungal virulent factors involved in pathogenesis. Here, next generation sequencing technology was applied to examine the expression of whitefly (Bemisia tabaci) genes in response to the infection of Beauveria bassiana. Results showed that, compared to control, 654 and 1,681genes were differentially expressed at 48 hours and 72 hours post-infected whiteflies, respectively. Functional and enrichment analyses indicated that the DNA damage stimulus response and drug metabolism were important anti-fungi strategies of the whitefly. Mitogen-activated protein kinase (MAPK) pathway was also likely involved in the whitefly defense responses. Furthermore, the notable suppression of general metabolism and ion transport genes observed in 72 hours post-infected B. tabaci might be manipulated by fungal secreted effectors. By mapping the sequencing tags to B. bassiana genome, we also identified a number of differentially expressed fungal genes between the early and late infection stages. These genes are generally associated with fungal cell wall synthesis and energy metabolism. The expression of fungal cell wall protein genes might play an important role in fungal pathogenesis and the dramatically up-regulated enzymes of carbon metabolism indicate the increasing usage of energy during the fungal infection. To our knowledge, this is the first report on the molecular mechanism of fungus-whitefly interactions. Our results provide a road map for future investigations on insect-pathogen interactions and genetically modifying the fungus to enhance its efficiency in whitefly

  6. Whitefly attraction to rosemary (Rosmarinus officinialis L. is associated with volatile composition and quantity.

    Directory of Open Access Journals (Sweden)

    Dganit Sadeh

    Full Text Available Whitefly (Bemisia tabaci is an important insect pest, causing severe damage to agricultural crops. The pest was recorded in a commercial rosemary (Rosmarinus officinalis, Lamiaceae field, colonizing rosemary variety (var. '2', but not '11'. A series of field and controlled laboratory choice bioassays confirmed the observed phenomenon. Mature potted plants of the two varieties were randomly organized in a lemon verbena (Lippia citrodora and lemon grass (Cymbopogon spp. fields. Seven days later var. '2' was significantly more colonized by whiteflies than var. '11'. Under lab conditions, whiteflies were significantly more attracted to var. '2' plantlets than to var. '11' following choice bioassays. Furthermore, cotton plants dipped in an essential oil emulsion of var. '2' had significantly greater colonization than cotton plants dipped in the essential oil emulsion of var. '11'. Similar results were obtained in 'plant-plant', 'plant-no plant' as well as, 'essential oil-essential oil' choice bioassay designs. Analyses of the essential oils of the two varieties identified a set of common and unique volatiles in each variety. Among these volatiles were β-caryophyllene and limonene, two compounds known to be associated with plant-insect interactions. The attraction of B. tabaci to pure (>95% β-caryophyllene and limonene using a range of concentrations was examined in vitro by choice bioassays. The compounds were attractive to the insect at moderate concentration, but not at the lowest or highest concentrations used, where the insect was not attracted or repelled, respectively. Limonene attracted the insects at rates that were 10-fold lower than β-caryophyllene. The results emphasized the role of host plant volatiles in shaping the structure of B. tabaci populations in nature and in agricultural systems, and provided insights into the factors that contribute to the development of insect populations with unique characteristics. The results could also

  7. Transcriptome analysis and comparison reveal divergence between two invasive whitefly cryptic species

    Directory of Open Access Journals (Sweden)

    Xia Jun

    2011-09-01

    Full Text Available Abstract Background Invasive species are valuable model systems for examining the evolutionary processes and molecular mechanisms associated with their specific characteristics by comparison with closely related species. Over the past 20 years, two species of the whitefly Bemisia tabaci species complex, Middle East-Asia Minor 1 (MEAM1 and Mediterranean (MED, have both spread from their origin Middle East/Mediterranean to many countries despite their apparent differences in many life history parameters. Previously, we have sequenced the transcriptome of MED. In this study, we sequenced the transcriptome of MEAM1 and took a comparative genomic approach to investigate the transcriptome evolution and the genetic factors underlying the differences between MEAM1 and MED. Results Using Illumina sequencing technology, we generated 17 million sequencing reads for MEAM1. These reads were assembled into 57,741 unique sequences and 15,922 sequences were annotated with an E-value above 10-5. Compared with the MED transcriptome, we identified 3,585 pairs of high quality orthologous genes and inferred their sequence divergences. The average differences in coding, 5' untranslated and 3' untranslated region were 0.83%, 1.66% and 1.43%, respectively. The level of sequence divergence provides additional support to the proposition that MEAM1 and MED are two species. Based on the ratio of nonsynonymous and synonymous substitutions, we identified 24 sequences that have evolved in response to positive selection. Many of those genes are predicted to be involved in metabolism and insecticide resistance which might contribute to the divergence of the two whitefly species. Conclusions Our data present a comprehensive sequence comparison between the two invasive whitefly species. This study will provide a road map for future investigations on the molecular mechanisms underlying their biological differences.

  8. Genetic variability of the whitefly Bemisia tabaci and its secondary endosymbionts in the Arabian Peninsula

    KAUST Repository

    Ragab, Alaa I.

    2013-05-01

    The whitefly Bemisia tabaci species complex has been well documented as one of the most economically important emergent plant virus vectors, through serious feeding damage to its broad range of plant hosts and transmission of plant viruses to important agricultural crops. It has been shown to have associations with endosymbionts which have significant effects on the insect fitness. The purpose of this study was to provide information for the biotype and secondary endosymbiont distribution for B. tabaci populations in the relatively unstudied Arabian peninsula. The geographical localization and variation in endosymbiont populations across the region were identified using a sequence-driven analysis of the population genetics of the secondary endosymbiont. Live field specimens were collected from 22 different locations in the region and preserved in 70% ethanol for genetic studies. Previously established procedures were used to extract and purify total insect DNA from 24-30 individual whiteflies for each location (Frohlich et al., 1999; Chiel et al., 2007). Specimens were subjected to PCR amplification using the respective 16S rDNAprimers for the Rickettsia, Hamiltonella, and Wolbachia to amplify endosymbiont DNA. PCR was run with primers for the highly conserved whitefly mitochondrial cytochrome oxidase subunit I (COI) gene for biotyping. Samples were sequenced using the Sanger method and the data analyzed to correlate the presence, prevalence and geographical distribution of endosymbionts in B. tabaci. Phylogenies 5 were constructed to track evolutionary differences amongst the endosymbionts and insects and how they have influenced the evolution of the regional populations. Samples were characterized by differences in the genomes and endosymbionts of common whitefly ‘biotypes’ that have different host plant preferences, vector capacities and insecticide resistance characteristics. It was found that the B biotype is the predominant haplotype, with no evidence of

  9. Aboveground Whitefly Infestation Modulates Transcriptional Levels of Anthocyanin Biosynthesis and Jasmonic Acid Signaling-Related Genes and Augments the Cope with Drought Stress of Maize.

    Directory of Open Access Journals (Sweden)

    Yong-Soon Park

    Full Text Available Up to now, the potential underlying molecular mechanisms by which maize (Zea mays L. plants elicit defense responses by infestation with a phloem feeding insect whitefly [Bemisia tabaci (Genn.] have been barely elucidated against (abiotic stresses. To fill this gap of current knowledge maize plants were infested with whitefly and these plants were subsequently assessed the levels of water loss. To understand the mode of action, plant hormone contents and the stress-related mRNA expression were evaluated. Whitefly-infested maize plants did not display any significant phenotypic differences in above-ground tissues (infested site compared with controls. By contrast, root (systemic tissue biomass was increased by 2-fold by whitefly infestation. The levels of endogenous indole-3-acetic acid (IAA, jasmonic acid (JA, and hydrogen peroxide (H2O2 were significantly higher in whitefly-infested plants. The biosynthetic or signaling-related genes for JA and anthocyanins were highly up-regulated. Additionally, we found that healthier plants were obtained in whitefly-infested plants under drought conditions. The weight of whitefly-infested plants was approximately 20% higher than that of control plants at 14 d of drought treatment. The drought tolerance-related genes, ZmbZIP72, ZmSNAC1, and ZmABA1, were highly expressed in the whitefly-infected plants. Collectively, our results suggest that IAA/JA-derived maize physiological changes and correlation of H2O2 production and water loss are modulated by above-ground whitefly infestation in maize plants.

  10. Development of a lateral flow test to detect metabolic resistance in Bemisia tabaci mediated by CYP6CM1, a cytochrome P450 with broad spectrum catalytic efficiency.

    Science.gov (United States)

    Nauen, Ralf; Wölfel, Katharina; Lueke, Bettina; Myridakis, Antonis; Tsakireli, Dimitra; Roditakis, Emmanouil; Tsagkarakou, Anastasia; Stephanou, Euripides; Vontas, John

    2015-06-01

    Cotton whitefly, Bemisia tabaci (Genn.) (Homoptera: Aleyrodidae) is a major sucking pest in many agricultural and horticultural cropping systems globally. The frequent use of insecticides of different mode of action classes resulted in populations resisting treatments used to keep numbers under economic damage thresholds. Recently it was shown that resistance to neonicotinoids such as imidacloprid is linked to the over-expression of CYP6CM1, a cytochrome P450 monooxygenase detoxifying imidacloprid and other neonicotinoid insecticides when recombinantly expressed in insect cells. However over-expression of CYP6CM1 is also known to confer cross-resistance to pymetrozine, an insecticide not belonging to the chemical class of neonicotinoids. In addition we were able to demonstrate by LC-MS/MS analysis the metabolisation of pyriproxyfen by recombinantly expressed CYP6CM1. Based on our results CYP6CM1 is one of the most versatile detoxification enzymes yet identified in a pest of agricultural importance, as it detoxifies a diverse range of chemical classes used to control whiteflies. Therefore we developed a field-diagnostic antibody-based lateral flow assay which detects CYP6CM1 protein at levels providing resistance to neonicotinoids and other insecticides. The ELISA based test kit can be used as a diagnostic tool to support resistance management strategies based on the alternation of different modes of action of insecticides. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Biological control of whitefly on Gerbera: success or failure? : tritrophic interactions between Gerbera jamesonii, Trialeurodes vaporariorum and Encarsia formosa

    NARCIS (Netherlands)

    Sütterlin, S.

    2000-01-01

    In this thesis fundamental and applied research is described that was initiated to develop biological control of whitefly with the parasitoid Encarsia formosa in the ornamental Gerbera jamesonii Hook (Campanulales: Compositae).

    To

  12. Torradoviruses are transmitted in a semi-persistent and stylet-borne manner by three whitefly vectors

    NARCIS (Netherlands)

    Verbeek, M.; Bekkum, van P.J.; Dullemans, A.M.; Vlugt, van der R.A.A.

    2014-01-01

    Members of the genus Torradovirus (family Secoviridae, type species Tomato torrado virus, ToTV) are spherical plant viruses transmitted by the whitefly species Trialeurodes vaporariorum and Bemisia tabaci. Knowledge on the mode of vector transmission is lacking for torradoviruses. Here, the mode of

  13. Transovarial Transmission of Rickettsia spp. and Organ-Specific Infection of the Whitefly Bemisia tabaci

    Science.gov (United States)

    Brumin, Marina; Levy, Maggie

    2012-01-01

    The whitefly Bemisia tabaci is a cosmopolitan insect pest that harbors Portiera aleyrodidarum, the primary obligatory symbiotic bacterium, and several facultative secondary symbionts. Secondary symbionts in B. tabaci are generally associated with the bacteriome, ensuring their vertical transmission; however, Rickettsia is an exception and occupies most of the body cavity, except the bacteriome. The mode of Rickettsia transfer between generations and its subcellular localization in insect organs have not been investigated. Using electron and fluorescence microscopy, we show that Rickettsia infects the digestive, salivary, and reproductive organs of the insect; however, it was not observed in the bacteriome. Rickettsia invades the oocytes during early developmental stages and resides in follicular cells and cytoplasm; it is mostly excluded when the egg matures; however, some bacterial cells remain in the egg, ensuring their transfer to subsequent generations. Rickettsia was localized to testicles and the spermatheca, suggesting a horizontal transfer between males and females during mating. The bacterium was further observed at large amounts in midgut cells, concentrating in vacuole-like structures, and was located in the hemolymph, specifically at exceptionally large amounts around bacteriocytes and in fat bodies. Organs further infected by Rickettsia included the primary salivary glands and stylets, sites of possible secretion of the bacterium outside the whitefly body. The close association between Rickettsia and the B. tabaci digestive system might be important for digestive purposes. The vertical transmission of Rickettsia to subsequent generations occurs via the oocyte and not, like other secondary symbionts, the bacteriome. PMID:22660706

  14. Genome sequencing of the sweetpotato whitefly Bemisia tabaci MED/Q.

    Science.gov (United States)

    Xie, Wen; Chen, Chunhai; Yang, Zezhong; Guo, Litao; Yang, Xin; Wang, Dan; Chen, Ming; Huang, Jinqun; Wen, Yanan; Zeng, Yang; Liu, Yating; Xia, Jixing; Tian, Lixia; Cui, Hongying; Wu, Qingjun; Wang, Shaoli; Xu, Baoyun; Li, Xianchun; Tan, Xinqiu; Ghanim, Murad; Qiu, Baoli; Pan, Huipeng; Chu, Dong; Delatte, Helene; Maruthi, M N; Ge, Feng; Zhou, Xueping; Wang, Xiaowei; Wan, Fanghao; Du, Yuzhou; Luo, Chen; Yan, Fengming; Preisser, Evan L; Jiao, Xiaoguo; Coates, Brad S; Zhao, Jinyang; Gao, Qiang; Xia, Jinquan; Yin, Ye; Liu, Yong; Brown, Judith K; Zhou, Xuguo Joe; Zhang, Youjun

    2017-05-01

    The sweetpotato whitefly Bemisia tabaci is a highly destructive agricultural and ornamental crop pest. It damages host plants through both phloem feeding and vectoring plant pathogens. Introductions of B. tabaci are difficult to quarantine and eradicate because of its high reproductive rates, broad host plant range, and insecticide resistance. A total of 791 Gb of raw DNA sequence from whole genome shotgun sequencing, and 13 BAC pooling libraries were generated by Illumina sequencing using different combinations of mate-pair and pair-end libraries. Assembly gave a final genome with a scaffold N50 of 437 kb, and a total length of 658 Mb. Annotation of repetitive elements and coding regions resulted in 265.0 Mb TEs (40.3%) and 20 786 protein-coding genes with putative gene family expansions, respectively. Phylogenetic analysis based on orthologs across 14 arthropod taxa suggested that MED/Q is clustered into a hemipteran clade containing A. pisum and is a sister lineage to a clade containing both R. prolixus and N. lugens. Genome completeness, as estimated using the CEGMA and Benchmarking Universal Single-Copy Orthologs pipelines, reached 96% and 79%. These MED/Q genomic resources lay a foundation for future 'pan-genomic' comparisons of invasive vs. noninvasive, invasive vs. invasive, and native vs. exotic Bemisia, which, in return, will open up new avenues of investigation into whitefly biology, evolution, and management. © The Author 2017. Published by Oxford University Press.

  15. Entomopathogenic fungi from 'El Eden' Ecological Reserve, Quintana Roo, Mexico.

    Science.gov (United States)

    Torres-Barragán; Anaya, Ana Luisa; Alatorre, Raquel; Toriello, Conchita

    2004-07-01

    Entomopathogenic fungi were isolated and identified from insects collected from the tropical forest and an agricultural area at El Eden Ecological Reserve, Quintana Roo, Mexico. These fungi were studied to determine their potential as biological control agents of greenhouse Trialeurodes vaporariorum (Homoptera: Aleyrodidae), and to contribute to the knowledge of biodiversity of this area. No pest insects were observed in the tropical forest. In contrast, all insects collected in the agricultural area were considered important pests by the local farmers, with the whitefly, as the most relevant, plentiful in Cucurbitaceae plants. From approximately 3400 collected insects in three different surveys, different anamorphic Ascomycetes were recovered. One isolate of Aspergillus sp., two of Penicillium sp., three of Paecilomyces marquandii, and three of Verticillium sp. out of 308 insects (2.9%) from three insect orders, Hymenoptera, Diptera and Isoptera in the tropical forest. In contrast, a higher number of fungal isolates were recovered from the agricultural area: three isolates from Aspergillus parasiticus, 100 of Fusarium moniliforme, one of Aschersonia sp., and 246 of Fusarium oxysporum out of 3100 insects (11.3%) from three insect orders, Homoptera, Coleoptera and Lepidoptera. The results of this study show Fusarium moniliforme and F oxysporum as highly virulent to infected insects in the agricultural area, with 100 and 246 isolates respectively, out of 350 infected insects of 3100 studied specimens. Laboratory whitefly nymph bioassays with isolates Ed29a of F. moniliforme, Ed322 of F. oxysporum, and Ed22 of P marquandii showed 96 to 97.5% insect mortality with no significant differences (P < 0.05) among them. F. oxysporum Ed322 produced no mortality when inoculated on tomato, bean, squash and maize seedlings (with and without injuries) compared to the 100% mortality caused by phytopathogenic strains, F. oxysporum f. sp. lycopersici and F. oxysporum f. sp. radicis

  16. Characterization of Antixenosis in Soybean Genotypes to Bemisia tabaci (Hemiptera: Aleyrodidae) Biotype B.

    Science.gov (United States)

    Baldin, E L L; Cruz, P L; Morando, R; Silva, I F; Bentivenha, J P F; Tozin, L R S; Rodrigues, T M

    2017-08-01

    Bemisia tabaci biotype B (Gennadius) is one of the most important soybean pest worldwide. Herein, 15 soybean genotypes were evaluated, to characterize the occurrence of antixenosis to B. tabaci biotype B. Initially, a multiple-choice test with all genotypes was carried out, evaluating the settling and oviposition preference at 3 d after infestation, and the colonization by nymphs after 48 d of infestation. Subsequently, a no-choice test, using 14 genotypes, was conducted with infested plants individually, and the number of eggs was counted after 72 h. Then, 10 genotypes were selected (indicative of resistance and susceptibility), which were evaluated for whitefly settling 24, 48, and 72 h after infestation and for oviposition 72 h after infestation. The trichomes of the leaflets were characterized for density, size, and inclination to establish possible correlations with the settling and oviposition in the genotypes. In the first multiple-choice test, involving 15 genotypes, 'IAC-17,' 'IAC-19,' and UX-2569-159 expressed antixenosis against B. tabaci. 'Jackson,' 'P98Y11,' and PI-229358 exhibited the same behavior in the no-choice test. In the multiple-choice test, 'Jackson,' 'P98Y11,' and 'TMG1176 RR' were the least attractive and least used for oviposition. The antixenosis shown by 'Jackson,' 'P98Y11,' and PI-229358 may be related to the characteristics of the trichomes (lower density and inclined). Based on the experiments carried out, 'IAC-17,' 'IAC-19,' 'Jackson,' 'P98Y11,' PI-229358, TMG1176 RR, and UX-2569-159 are considered promising for resistance to B. tabaci biotype B and may be exploited in soybean breeding programs for resistance to insects. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Sequencing and comparison of the Rickettsia genomes from the whitefly Bemisia tabaci Middle East Asia Minor I.

    Science.gov (United States)

    Zhu, Dan-Tong; Xia, Wen-Qiang; Rao, Qiong; Liu, Shu-Sheng; Ghanim, Murad; Wang, Xiao-Wei

    2016-08-01

    The whitefly, Bemisia tabaci, harbors the primary symbiont 'Candidatus Portiera aleyrodidarum' and a variety of secondary symbionts. Among these secondary symbionts, Rickettsia is the only one that can be detected both inside and outside the bacteriomes. Infection with Rickettsia has been reported to influence several aspects of the whitefly biology, such as fitness, sex ratio, virus transmission and resistance to pesticides. However, mechanisms underlying these differences remain unclear, largely due to the lack of genomic information of Rickettsia. In this study, we sequenced the genome of two Rickettsia strains isolated from the Middle East Asia Minor 1 (MEAM1) species of the B. tabaci complex in China and Israel. Both Rickettsia genomes were of high coding density and AT-rich, containing more than 1000 coding sequences, much larger than that of the coexisted primary symbiont, Portiera. Moreover, the two Rickettsia strains isolated from China and Israel shared most of the genes with 100% identity and only nine genes showed sequence differences. The phylogenetic analysis using orthologs shared in the genus, inferred the proximity of Rickettsia in MEAM1 and Rickettsia bellii. Functional analysis revealed that Rickettsia was unable to synthesize amino acids required for complementing the whitefly nutrition. Besides, a type IV secretion system and a number of virulence-related genes were detected in the Rickettsia genome. The presence of virulence-related genes might benefit the symbiotic life of the bacteria, and hint on potential effects of Rickettsia on whiteflies. The genome sequences of Rickettsia provided a basis for further understanding the function of Rickettsia in whiteflies. © 2016 Institute of Zoology, Chinese Academy of Sciences.

  18. Distribuição espacial de Aphis gossypii (Glover (Hemiptera, Aphididae e Bemisia tabaci (Gennadius biótipo B (Hemiptera, Aleyrodidae em algodoeiro Bt e não-Bt Spatial distribution of Aphis gossypii (Glover (Hemiptera, Aphididae and Bemisia tabaci (Gennadius biotype B (Hemiptera, Aleyrodidae on Bt and non-Bt cotton

    Directory of Open Access Journals (Sweden)

    Tatiana Rojas Rodrigues

    2010-03-01

    Full Text Available Distribuição espacial de Aphis gossypii (Glover (Hemiptera, Aphididae e Bemisia tabaci (Gennadius biótipo B (Hemiptera, Aleyrodidae em algodoeiro Bt e não-Bt. O estudo da distribuição espacial de adultos de Bemisia tabaci e de Aphis gossypii nas culturas do algodoeiro Bt e não-Bt é fundamental para a otimização de técnicas de amostragens, além de revelar diferenças de comportamento de espécies não-alvo dessa tecnologia Bt entre as duas cultivares. Nesse sentido, o experimento buscou investigar o padrão da distribuição espacial dessas espécies de insetos no algodoeiro convencional não-Bt e no cultivar Bt. As avaliações ocorreram em dois campos de 5.000 m² cada, nos quais se realizou 14 avaliações com contagem de adultos da mosca-branca e colônias de pulgões. Foram calculados os índices de agregação (razão variância/média, índice de Morisita e Expoente k da Distribuição Binomial Negativa e realizados os testes ajustes das classes numéricas de indivíduos encontradas e esperadas às distribuições teóricas de freqüência (Poisson, Binomial Negativa e Binomial Positiva. Todas as análises mostraram que, em ambas as cultivares, a distribuição espacial de B. tabaci ajustou-se a distribuição binomial negativa durante todo o período analisado, indicando que a cultivar transgênica não influenciou o padrão de distribuição agregada desse inseto. Já com relação às análises para A. gossypii, os índices de agregação apontaram distribuição agregada nas duas cultivares, mas as distribuições de freqüência permitiram concluir a ocorrência de distribuição agregada apenas no algodoeiro convencional, pois não houve nenhum ajuste para os dados na cultivar Bt. Isso indica que o algodão Bt alterou o padrão normal de dispersão dos pulgões no cultivo.The study of spatial distribution of the adults of Bemisia tabaci and the colonies of Aphis gossypii on Bt and non-Bt cotton crop is fundamental for

  19. Biological aspects of Bemisia tabaci (Genn.) B biotype (Hemiptera: Aleyrodidae) on six bean genotypes; Aspectos biologicos de Bemisia tabaci (Genn.) biotipo B (Hemiptera: Aleyrodidae) em seis genotipos de feijoeiro

    Energy Technology Data Exchange (ETDEWEB)

    Oriani, Maria A. de G. [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Ecologia e Biologia Evolutiva; Vendramin, Jose D. [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Dept. de Entomologia, Fitopatologia e Zoologia Agricola; Brunherotto, Rogerio [Fundacao Municipal de Ensino Superior de Braganca Paulista, SP (Brazil)

    2008-03-15

    The silverleaf whitefly is one of the most harmful pests that attack bean crops, mainly for extracting large quantities of phloem sap and transmitting the bean golden mosaic virus. Resistant germplasm plants can be an important method for controlling this pest. The biological aspects of Bemisia tabaci B biotype on bean (Phaseolus vulgaris) genotypes were evaluated. The tests were conducted under laboratory conditions, with the following genotypes: Arc 1, Arc 3s, Arc 5s, G13028, G11056 and Porrillo 70. The bean plants in a stage IV-1 were infested during one day with silverleaf white flies. Afterwards the eggs and nymphs were observed until adult emergence. Longevity and fecundity of emerged insects were also evaluated. The longest development time occurred for nymphs fed on Arc 3s genotype (26.5 days), following by G11056 (25.9 days) and G13028 (25.3 days). The development period was 5.5 days longer in Arc 3s when compared with Porrillo 70. Also, the wild genotypes Arc 3s and G11056 showed higher mortality rates (94.7% and 83.1%, respectively), which may suggest antibiosis and/or feeding non preference resistance type. For this reason, although longevity and fecundity were not influenced when the whitefly fed on resistant genotypes (Arc 3s, G11056, G13028 and Arc 5s), those genotypes can be used for bean breeding program towards B. tabaci B biotype. (author)

  20. Compatibility of the entomopathogenic fungus Lecanicillium muscarium and insecticides for eradication of sweetpotato whitefly, Bemisia tabaci.

    Science.gov (United States)

    Cuthbertson, Andrew G S; Walters, Keith F A; Deppe, Carola

    2005-08-01

    The compatibility of the entomopathogenic fungus Lecanicillium muscarium and chemical insecticides used to control the second instar stages of the sweetpotato whitefly, Bemisia tabaci, was investigated. The effect on spore germination of direct exposure for 24 h to the insecticides imidacloprid, buprofezin, teflubenzuron and nicotine was determined. Only exposure to buprofezin was followed by acceptable spore germination. However, all chemicals significantly reduced spore germination when compared to a water control. Infectivity of L. muscarium in the presence of dry residues of buprofezin, teflubenzuron and nicotine (imidacloprid is a systemic pesticide) on foliage were also investigated. No significant detrimental effects on the level of control of B. tabaci was recorded when compared with fungi applied to residue free foliage on either tomato or verbena plants. Fungi in combination with imidacloprid gave higher B. tabaci mortality on verbena foliage compared to either teflubenzuron or nicotine and fungi combinations. Use of these chemical insecticides with L. muscarium in integrated control programmes for B. tabaci is discussed.

  1. Bemisia tabaci MED (Q biotype) (Hemiptera: Aleyrodidae)is on the move in Florida to residential landscapes and may impact open field agriculture

    Science.gov (United States)

    Bemisia tabaci MED (Mediterranean) have been in the United States for approximately a dozen years spreading to 26 states since it was first detected in Arizona at a retail outlet on poinsettia in 2004. Indistinguishable morphologically from silverleaf whitefly (Bemisia tabaci MEAM1 (Middle Eastern A...

  2. Metabolic Coevolution in the Bacterial Symbiosis of Whiteflies and Related Plant Sap-Feeding Insects.

    Science.gov (United States)

    Luan, Jun-Bo; Chen, Wenbo; Hasegawa, Daniel K; Simmons, Alvin M; Wintermantel, William M; Ling, Kai-Shu; Fei, Zhangjun; Liu, Shu-Sheng; Douglas, Angela E

    2015-09-15

    Genomic decay is a common feature of intracellular bacteria that have entered into symbiosis with plant sap-feeding insects. This study of the whitefly Bemisia tabaci and two bacteria (Portiera aleyrodidarum and Hamiltonella defensa) cohoused in each host cell investigated whether the decay of Portiera metabolism genes is complemented by host and Hamiltonella genes, and compared the metabolic traits of the whitefly symbiosis with other sap-feeding insects (aphids, psyllids, and mealybugs). Parallel genomic and transcriptomic analysis revealed that the host genome contributes multiple metabolic reactions that complement or duplicate Portiera function, and that Hamiltonella may contribute multiple cofactors and one essential amino acid, lysine. Homologs of the Bemisia metabolism genes of insect origin have also been implicated in essential amino acid synthesis in other sap-feeding insect hosts, indicative of parallel coevolution of shared metabolic pathways across multiple symbioses. Further metabolism genes coded in the Bemisia genome are of bacterial origin, but phylogenetically distinct from Portiera, Hamiltonella and horizontally transferred genes identified in other sap-feeding insects. Overall, 75% of the metabolism genes of bacterial origin are functionally unique to one symbiosis, indicating that the evolutionary history of metabolic integration in these symbioses is strongly contingent on the pattern of horizontally acquired genes. Our analysis, further, shows that bacteria with genomic decay enable host acquisition of complex metabolic pathways by multiple independent horizontal gene transfers from exogenous bacteria. Specifically, each horizontally acquired gene can function with other genes in the pathway coded by the symbiont, while facilitating the decay of the symbiont gene coding the same reaction. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  3. Taxonomic status of the Bemisia tabaci complex (Hemiptera: Aleyrodidae and reassessment of the number of its constituent species.

    Directory of Open Access Journals (Sweden)

    Wonhoon Lee

    Full Text Available Bemisia tabaci (Hemiptera: Aleyrodidae is one of the most important insect pests in the world. In the present study, the taxonomic status of B. tabaci and the number of species composing the B. tabaci complex were determined based on 1059 COI sequences of B. tabaci and 509 COI sequences of 153 hemipteran species. The genetic divergence within B. tabaci was conspicuously higher (on average, 11.1% than interspecific genetic divergence within the respective genera of the 153 species (on average, 6.5%. This result indicates that B. tabaci is composed of multiple species that may belong to different genera or subfamilies. A phylogenetic tree constructed based on 212 COI sequences without duplications revealed that the B. tabaci complex is composed of a total of 31 putative species, including a new species, JpL. However, genetic divergence within six species (Asia II 1, Asia II 7, Australia, Mediterranean, New World, and Sub Saharan Africa 1 was higher than 3.5%, which has been used as a threshold of species boundaries within the B. tabaci complex. These results suggest that it is necessary to increase the threshold for species boundaries up to 4% to distinguish the constituent species in the B. tabaci complex.

  4. Nitrogen in Hydroponic Growing Medium of Tomato Affects the Demographic Parameters of Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Hosseini, R S; Madadi, H; Hosseini, M; Delshad, M; Dashti, F

    2015-12-01

    We evaluated the effects of different nitrogen levels (380, 310, 240, and 174 ppm) on the life history parameters of Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) on hydroponically cultured tomato plants. Our data show that there is a positive correlation between the nitrogen content and the demographic parameters, as the intrinsic rate of increase of T. vaporariorum was the lowest (0.059 ± 0.007 day(-1)) at 174 ppm and the highest (0.088 ± 0.005 day(-1)) at 380 ppm of nitrogen. The net reproduction rate (R 0), finite rate of increase (λ), and mean developmental time (T) were significantly influenced by the nitrogen levels. The mean longevity of males and females showed a positive relationship with the nitrogen level, ranging from 64.8 ± 3.96 to 76.3 ± 2.44 for males and 61.6 ± 5.35 to 71.2 ± 2.44 for females, observed in the lowest and highest nitrogen levels, respectively. The relationship between nitrogen fertilization and T. vaporariorum management on tomato crops is discussed.

  5. Pre-infestation of Tomato Plants by Aphids Modulates Transmission-Acquisition Relationship among Whiteflies, Tomato Yellow Leaf Curl Virus (TYLCV and Plants

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    Xiao L. Tan

    2017-09-01

    Full Text Available Herbivory defense systems in plants are largely regulated by jasmonate-(JA and salicylate-(SA signaling pathways. Such defense mechanisms may impact insect feeding dynamic, may also affect the transmission-acquisition relationship among virus, plants and vectoring insects. In the context of the tomato – whitefly – Tomato Yellow Leaf Curl Virus (TYLCV biological model, we tested the impact of pre-infesting plants with a non-vector insect (aphid Myzus persicae on feeding dynamics of a vector insect (whitefly Bemisia tabaci as well as virus transmission-acquisition. We showed that an aphid herbivory period of 0–48 h led to a transient systemic increase of virus concentration in the host plant (root, stem, and leaf, with the same pattern observed in whiteflies feeding on aphid-infested plants. We used real-time quantitative PCR to study the expression of key genes of the SA- and JA-signaling pathways, as well as electrical penetration graph (EPG to characterize the impact of aphid pre-infestation on whitefly feeding during TYLCV transmission (whitefly to tomato and acquisition (tomato to whitefly. The impact of the duration of aphid pre-infestation (0, 24, or 48 h on phloem feeding by whitefly (E2 during the transmission phase was similar to that of global whitefly feeding behavior (E1, E2 and probing duration during the acquisition phase. In addition, we observed that a longer phase of aphid pre-infestation prior to virus transmission by whitefly led to the up-regulation and down-regulation of SA- and JA-signaling pathway genes, respectively. These results demonstrated a significant impact of aphid pre-infestation on the tomato – whitefly – TYLCV system. Transmission and acquisition of TYLCV was positively correlated with feeding activity of B. tabaci, and both were mediated by the SA- and JA-pathways. TYLCV concentration during the transmission phases was modulated by up- and down-regulation of SA- and JA-pathways, respectively. The two

  6. Acanthaleyrodes elevatus sp. n. (Hemiptera: Aleyrodidae) from India, with key to species and discussion of tuberculate setae.

    Science.gov (United States)

    Dubey, Anil Kumar; Singh, Sudhir; Martin, Jon H

    2014-11-03

    The genus Acanthaleyrodes Takahashi is reported for the first time from India. Acanthaleyrodes elevatus sp. n. is described from Bridelia retusa in Kerala, India, with a key to puparia of Acanthaleydes species. The new species differs in its exceptionally elevated eighth abdominal tergite, circular vasiform orifice and eight pairs of subdorsal setae. The generic characteristics of Acanthaleyrodes are redefined and distinguished from those of Tuberaleyrodes Takahashi. A. styraci Takahashi is re-described in detail with illustrations of puparia and immatures from Hong Kong. A lectotype puparium is designated for A. callicarpae Takahashi. The development of tuberculate setae is discussed, in whitefly puparia and earlier nymphal instars, and considered to be subject to environmental modification.

  7. Controle da pérola-da-terra, Eurhizococcus brasiliensis (Hempel) (Homoptera:Margarodidae), através da insetigação

    OpenAIRE

    Hickel, Eduardo R.; Peruzzo, Edegar L.; Schuck, Enio

    2001-01-01

    A pérola-da-terra, Eurhizococcus brasiliensis (Hempel) (Homoptera: Margarodidae), é a principal praga da videira no Sul do Brasil. As estratégias normais de controle desta praga não afetam a população do inseto porque os indivíduos estão no subsolo e desenvolvem um corpo globoso resistente a intempéries. Assim sendo, um ensaio foi conduzido em laboratório para verificar a possibilidade de aplicar a insetigação no controle da pérola-da-terra. Tubos de 50 mm de altura de cano PVC (150 mm fi) fo...

  8. Characterization of Phenacoccus solenopsis (Tinsley) (Homoptera: Pseudococcidae) Resistance to Emamectin Benzoate: Cross-Resistance Patterns and Fitness Cost Analysis.

    Science.gov (United States)

    Afzal, M B S; Shad, S A

    2016-06-01

    Cotton mealybug Phenacoccus solenopsis (Tinsley) (Homoptera: Pseudococcidae) is a sucking pest of worldwide importance causing huge losses by feeding upon cotton in various parts of the world. Because of the importance of this pest, this research was carried out to select emamectin resistance in P. solenopsis in the laboratory to study cross-resistance, stability, realized heritability, and fitness cost of emamectin resistance. After selection from third generation (G3) to G6, P. solenopsis developed very high emamectin resistance (159.24-fold) when compared to a susceptible unselected population (Unsel pop). Population selected to emamectin benzoate conferred moderate (45.81-fold), low (14.06-fold), and no cross-resistance with abamectin, cypermethrin, and profenofos, respectively compared to the Unsel pop. A significant decline in emamectin resistance was observed in the resistant population when not exposed to emamectin from G7 to G13. The estimated realized heritability (h (2)) for emamectin resistance was 0.84. A high fitness cost was associated with emamectin resistance in P. solenopsis. Results of this study may be helpful in devising insecticide resistance management strategies for P. solenopsis.

  9. Potential damages, seasonal abundance and distribution of Empoasca terminalis Distant (Homoptera: Cicadellidae on soybean in South Sulawesi

    Directory of Open Access Journals (Sweden)

    Andi Nasruddin

    2015-09-01

    Full Text Available Plant damages caused by leafhopper, Empoasca terminalis Distant (Homoptera: Cicadellidae on soybean were first encountered in 2007 in Makassar, South Sulawesi. The insect has been constantly associated with soybean crops in the province ever since. The purposes of the present study were to (i evaluate potential yield loss attributable to the leafhopper in an experimental set up, (ii seasonal abundance of E. terminalis, and (iii distribution of E. terminalis in all major soybean-producing areas in the province. Potential yield loss due to the leafhopper was assessed in a field experiment using two large plots. One of the plots was kept leafhopper-free by weekly insecticide sprays; and the other plot was left unsprayed to allow leafhopper infestation to occur. Adult abundance was weekly monitored using a sweep net throughout the season. Nymph abundance was determined by direct count on the plant leaves. Leafhopper distribution was assessed through surveys conducted in all major soybean-producing areas in South Sulawesi, from 2009–2013. The results of the study showed that E. terminalis caused an average yield loss of 26% on susceptible crops without insecticide use. First leafhopper infestation in all planting seasons occurred two weeks after the plant emergence. Rainfall negatively correlated with the leafhopper abundance. The leafhopper existed in all major soybean production areas in the province. Therefore, our results confirmed the status of E. terminalis as an important soybean pest in the region. In addition, crops planted early in the dry season could escape from heavy leafhopper infestation.

  10. A quantum dot-immunofluorescent labeling method to investigate the interactions between a crinivirus and its whitefly vector

    Directory of Open Access Journals (Sweden)

    James C. K. Ng

    2013-04-01

    Full Text Available Successful vector-mediated plant virus transmission entails an intricate but poorly understood interplay of interactions among virus, vector, and plant. The complexity of interactions requires continually improving/evaluating tools and methods for investigating the determinants that are central to mediating virus transmission. A recent study using an organic fluorophore (Alexa Fluor-based immunofluorescent localization assay demonstrated that specific retention of Lettuce infectious yellows virus (LIYV virions in the anterior foregut or cibarium of its whitefly vector is required for virus transmission. Continuous exposure of organic fluorophore to high excitation light intensity can result in diminished or loss of signals, potentially confounding the identification of important interactions associated with virus transmission. This limitation can be circumvented by incorporation of photostable fluorescent nanocrystals, such as quantum dots (QDs, into the assay. We have developed and evaluated a QD-immunofluorescent labeling method for the in vitro and in situ localization of LIYV virions based on the recognition specificity of streptavidin-conjugated QD605 (S-QD605 for biotin-conjugated anti-LIYV IgG (B-αIgG. IgG biotinylation was verified in a blot overlay assay by probing SDS-PAGE separated B-αIgG with S-QD605. Immunoblot analyses of LIYV using B-αIgG and S-QD605 resulted in a virus detection limit comparable to that of DAS-ELISA. In membrane feeding experiments, QD signals were observed in the anterior foregut or cibarium of virion-fed whitefly vectors but absent in those of virion-fed whitefly non-vectors. Specific virion retention in whitefly vectors corresponded with successful virus transmission. A fluorescence photobleaching assay of viruliferous whiteflies fed B-αIgG and S-QD605 vs. those fed anti-LIYV IgG and Alexa Fluor 488-conjugated IgG revealed that QD signal was stable and deteriorated ∼7 to 8 fold slower than that of Alexa

  11. Analysis of Species, Subgroups, and Endosymbionts of Bemisia tabaci (Hemiptera: Aleyrodidae) From Southwestern Cotton Fields in Turkey.

    Science.gov (United States)

    Karut, Kamil; Mete Karaca, M; Döker, Ismail; Kazak, Cengiz

    2017-08-01

    Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is one of the most important insect pests worldwide including Turkey. Although there are substantial data regarding species composition of Turkish B. tabaci populations, the situation is still not clear and further investigations are needed. Therefore, in this study, species and subgroups of B. tabaci collected from cotton fields in southwestern part of Turkey (Antalya, Aydın, Denizli, and Muğla) were determined using microsatellite analysis, AluI-based mtCOI polymerase chain reaction-random length polymorphism, and sequencing. Secondary endosymbionts were also determined using diagnostic species-specific PCR. Middle East Asia Minor 1 (MEAM1), Mediterranean (MED) Q1, and MED Q2 were the species and subgroups found in this study. The MED species (85.3%) were found to be more dominant than MEAM1. Species status of B. tabaci varied depending on the location. Although all samples collected from Aydın were found to be Q1, three species and subgroups were found in Muğla. Secondary endosymbionts varied according to species and subgroups. Arsenophonus was found only from Q2, while Hamiltonella was detected in MEAM1 and Q1. In addition, high Rickettsia and low Wolbachia infections were detected in MEAM1 and Q1 populations, respectively. In conclusion, for the first time, we report the presence and symbiotic communities of Q1 from Turkey. We also found that the symbiont complement of the Q1 is more congruent with Q1 from Greece than other regions of the world, which may have some interesting implications for movement of this invasive subgroup. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Thermotolerance and Heat-Shock Protein Gene Expression Patterns in Bemisia tabaci (Hemiptera: Aleyrodidae) Mediterranean in Relation to Developmental Stage.

    Science.gov (United States)

    Jiang, Rui; Qi, Lan-Da; Du, Yu-Zhou; Li, Yuan-Xi

    2017-10-01

    Temperature plays an important role in the growth, development, and geographic distribution of insects. There is convincing evidence that heat-shock proteins (HSPs) play important roles in helping organisms adapt to thermal stress. To better understand the physiological and ecological influence of thermal stress on the different development stages of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) Mediterranean species (MED), nymphs and adults were shocked with temperatures of 35, 38, and 41℃ for 1 and 2 h, respectively, and the survival rate, fecundity, and developmental duration were investigated in the laboratory. The expression levels of the hsp40, hsp70, and hsp90 genes were assessed using real-time PCR. The results indicate that the survival rates of the nymphs and adults decreased with increased temperature. A 2-h heat shock at 41℃ induced a significant reduction in fecundity in adults and an increase in developmental duration in young nymphs. Hsp90 showed higher temperature responses to thermal stress than hsp40 or hsp70. The expression levels of the hsps in the adults were significantly down-regulated by a 2-h heat shock at 41℃ compared with that by a 1-h treatment. A significant decrease in the expression levels of the hsps also occurred in the adults when the temperature increased from 38 to 41℃ for the 2-h treatment, whereas no significant decrease occurred in the nymphs. Compared with previous studies, we provide some evidence indicating that MED has the potential to adapt to a wider temperature range than the Middle East-Asia Minor 1 species. © The Author 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Mosca-Branca, Bemisia tabaci (Genn. (Hemiptera: Aleyrodidae em feijoeiro: Características gerais, bioecologia e métodos de controle

    Directory of Open Access Journals (Sweden)

    Anderson Silva

    2017-04-01

    Abstract. Common bean plants are infested by insects, which can ultimately affect the crop production before and after harvest, with estimated losses ranging from 33 to 86%. Among the insect pests infesting the common beans the whitefly Bemisia tabaci (Genn. stands out. This species cause direct injury by feeding on the plants and indirect injury by excreting sugary honeydew that is after colonized by the sooty mold. In addition, the most serious damage caused by B. tabaci is the transmission of virus diseases, especially the common bean golden mosaic, responsible for economic losses varying from 30 to 100%. This review aims at providing information on important aspects of B. tabaci including its geographical distribution, bioecology, population dynamics, host plants, and methods of pest control. We expect that this review can provide valuable subsidies for future studies on the whitefly in common beans.

  14. Oviposition behavior of the silver leaf whitefly Bemisia tabaci biotype B on tomato

    International Nuclear Information System (INIS)

    Vendramim, Jose D.; Souza, Antonio P. de; Ongarelli, Maria das G.

    2009-01-01

    The objective of this work was to evaluate the influence of the leaf surface, the insect geotropic behavior and the type of foliar trichome on Bemisia tabaci (Genn.) biotype B oviposition on tomato leaves. Bemisia tabaci females were confined in acrylic boxes in which tomato leaflets were fixed at the bottom and top part of the boxes to allow insects to access the leaf surface to be tested (adaxial and/or abaxial) in both no-choice and free choice tests. Oviposition was always higher when the leaf was offered at the top of the box and preferably at the abaxial leaf surface. The effects of leaf trichomes (glandular and non glandular) on B. tabaci oviposition was evaluated by offering the abaxial surface of tomato leaflets to females after a 70% ethanol wash to remove glandular exsudates against a control treatment (without a ethanol wash). Oviposition was concentrated mostly near to non glandular trichomes, showing whitefly females can discriminate among the trichomes. (author)

  15. Effects of Bioinsecticides in Control of Greenhouse Whitefly (Trialeurodes vaporariorum Westwood on Tomato

    Directory of Open Access Journals (Sweden)

    Dejan Marčić

    2011-01-01

    Full Text Available The effects of commercial products of entomopathogenic fungus Beauveria bassiana(Naturalis; 0.1%, 0.2% and 0.3%, azadirachtin (NeemAzal T/S; 1% and 2% and oxymatrin(KingBo; 0.1% and 0.2% in the control of greenhouse whitefly (Trialeurodes vaporariorumWestwood on tomato were tested in plastic covered greenhouse. The effects of the bioinsecticides,applied twice at five-day interval, were compared to effects of abamectin (AbastateEW; 0.075% and thiamethoxam (Actara 25-WG; 0.05%. Tested bioinsecticides reducedthe number of larvae by 82-97% (Naturalis, 90-99% (NeemAzal T/S and 90-96% (KingBo,with the efficacy of >96% according to Henderson-Tilton, in the assessment 16 days aftertreatment. In the same assessment, achieved percentages in adults reduction and efficacyamounted 24-89% and 67-95% (Naturalis, 85-93% and 93-97% (NeemAzal T/S, 86-96%and 94-98% (KingBo. Percentages of abundance reduction and efficacy after treatment withAbastate EW were 31% and 88% (larvae and 64% and 84% (adults, while after treatmentwith Actara 25-WG they amounted 96% and 99% (larvae and 83% and 92% (adults. The resultsobtained show that NeemAzal T/S, Naturalis and KingBo can be an efficient alternativeto current insecticides in control of T. vaporariorum populations.

  16. A landscape genetic analysis of important agricultural pest species in Tunisia: The whitefly Bemisia tabaci.

    Directory of Open Access Journals (Sweden)

    Ahmed Ben Abdelkrim

    Full Text Available Combining landscape ecology and genetics provides an excellent framework to appreciate pest population dynamics and dispersal. The genetic architectures of many species are always shaped by environmental constraints. Because little is known about the ecological and genetic traits of Tunisian whitefly populations, the main objective of this work is to highlight patterns of biodiversity, genetic structure and migration routes of this pest. We used nuclear microsatellite loci to analyze B. tabaci populations collected from various agricultural areas across the country and we determine their biotype status. Molecular data were subsequently interpreted in an ecological context supplied from a species distribution model to infer habitat suitability and hereafter the potential connection paths between sampling localities. An analysis of landscape resistance to B. tabaci genetic flow was thus applied to take into account habitat suitability, genetic relatedness and functional connectivity of habitats within a varied landscape matrix. We shed light on the occurrence of three geographically delineated genetic groups with high levels of genetic differentiation within each of them. Potential migration corridors of this pest were then established providing significant advances toward the understanding of genetic features and the dynamic dispersal of this pest. This study supports the hypothesis of a long-distance dispersal of B. tabaci followed by infrequent long-term isolations. The Inference of population sources and colonization routes is critical for the design and implementation of accurate management strategies against this pest.

  17. A landscape genetic analysis of important agricultural pest species in Tunisia: The whitefly Bemisia tabaci.

    Science.gov (United States)

    Ben Abdelkrim, Ahmed; Hattab, Tarek; Fakhfakh, Hatem; Belkadhi, Mohamed Sadok; Gorsane, Faten

    2017-01-01

    Combining landscape ecology and genetics provides an excellent framework to appreciate pest population dynamics and dispersal. The genetic architectures of many species are always shaped by environmental constraints. Because little is known about the ecological and genetic traits of Tunisian whitefly populations, the main objective of this work is to highlight patterns of biodiversity, genetic structure and migration routes of this pest. We used nuclear microsatellite loci to analyze B. tabaci populations collected from various agricultural areas across the country and we determine their biotype status. Molecular data were subsequently interpreted in an ecological context supplied from a species distribution model to infer habitat suitability and hereafter the potential connection paths between sampling localities. An analysis of landscape resistance to B. tabaci genetic flow was thus applied to take into account habitat suitability, genetic relatedness and functional connectivity of habitats within a varied landscape matrix. We shed light on the occurrence of three geographically delineated genetic groups with high levels of genetic differentiation within each of them. Potential migration corridors of this pest were then established providing significant advances toward the understanding of genetic features and the dynamic dispersal of this pest. This study supports the hypothesis of a long-distance dispersal of B. tabaci followed by infrequent long-term isolations. The Inference of population sources and colonization routes is critical for the design and implementation of accurate management strategies against this pest.

  18. Silverleaf whitefly induces salicylic acid defenses and suppresses effectual jasmonic acid defenses.

    Science.gov (United States)

    Zarate, Sonia I; Kempema, Louisa A; Walling, Linda L

    2007-02-01

    The basal defenses important in curtailing the development of the phloem-feeding silverleaf whitefly (Bemisia tabaci type B; SLWF) on Arabidopsis (Arabidopsis thaliana) were investigated. Sentinel defense gene RNAs were monitored in SLWF-infested and control plants. Salicylic acid (SA)-responsive gene transcripts accumulated locally (PR1, BGL2, PR5, SID2, EDS5, PAD4) and systemically (PR1, BGL2, PR5) during SLWF nymph feeding. In contrast, jasmonic acid (JA)- and ethylene-dependent RNAs (PDF1.2, VSP1, HEL, THI2.1, FAD3, ERS1, ERF1) were repressed or not modulated in SLWF-infested leaves. To test for a role of SA and JA pathways in basal defense, SLWF development on mutant and transgenic lines that constitutively activate or impair defense pathways was determined. By monitoring the percentage of SLWF nymphs in each instar, we show that mutants that activate SA defenses (cim10) or impair JA defenses (coi1) accelerated SLWF nymphal development. Reciprocally, mutants that activate JA defenses (cev1) or impair SA defenses (npr1, NahG) slowed SLWF nymphal development. Furthermore, when npr1 plants, which do not activate downstream SA defenses, were treated with methyl jasmonate, a dramatic delay in nymph development was observed. Collectively, these results showed that SLWF-repressed, JA-regulated defenses were associated with basal defense to the SLWF.

  19. Silverleaf Whitefly Induces Salicylic Acid Defenses and Suppresses Effectual Jasmonic Acid Defenses1[W][OA

    Science.gov (United States)

    Zarate, Sonia I.; Kempema, Louisa A.; Walling, Linda L.

    2007-01-01

    The basal defenses important in curtailing the development of the phloem-feeding silverleaf whitefly (Bemisia tabaci type B; SLWF) on Arabidopsis (Arabidopsis thaliana) were investigated. Sentinel defense gene RNAs were monitored in SLWF-infested and control plants. Salicylic acid (SA)-responsive gene transcripts accumulated locally (PR1, BGL2, PR5, SID2, EDS5, PAD4) and systemically (PR1, BGL2, PR5) during SLWF nymph feeding. In contrast, jasmonic acid (JA)- and ethylene-dependent RNAs (PDF1.2, VSP1, HEL, THI2.1, FAD3, ERS1, ERF1) were repressed or not modulated in SLWF-infested leaves. To test for a role of SA and JA pathways in basal defense, SLWF development on mutant and transgenic lines that constitutively activate or impair defense pathways was determined. By monitoring the percentage of SLWF nymphs in each instar, we show that mutants that activate SA defenses (cim10) or impair JA defenses (coi1) accelerated SLWF nymphal development. Reciprocally, mutants that activate JA defenses (cev1) or impair SA defenses (npr1, NahG) slowed SLWF nymphal development. Furthermore, when npr1 plants, which do not activate downstream SA defenses, were treated with methyl jasmonate, a dramatic delay in nymph development was observed. Collectively, these results showed that SLWF-repressed, JA-regulated defenses were associated with basal defense to the SLWF. PMID:17189328

  20. Intra- and interspecific competition between western flower thrips and sweetpotato whitefly.

    Science.gov (United States)

    Wu, Qing-Jun; Hou, Wen-Jie; Li, Fei; Xu, Bao-Yun; Xie, Wen; Wang, Shao-Li; Zhang, You-Jun

    2014-01-01

    The western flower thrips, Frankliniella occidentalis (Pergande), and the sweetpotato whitefly, Bemisia tabaci (Gennadius), are both invasive insect pests and are present in most of the same agricultural crops without a clear dominance of either species. Here, intra- and interspecific competition in B. tabaci and F. occidentalis was determined under controlled experiments. The results showed that intraspecific competition was distinct in F. occidentalis and that the co-occurrence of B. tabaci had a strong effect on F. occidentalis, resulting in a decrease in oviposition. Significant intraspecific competition was found in B. tabaci, and the coexistence of F. occidentalis had limited effect on the oviposition of B. tabaci. In a selective host plant preference experiment, both F. occidentalis and B. tabaci preferred eggplants most, followed by cucumbers and tomatoes. On cucumber plants, B. tabaci was predominant, whereas on eggplant and tomato plants, F. occidentalis and B. tabaci exhibited comparative competitive abilities during the initial stage. However, over time, higher numbers of B. tabaci than that of F. occidentalis were found on the two host plants. Our in vitro and potted plant experiments indicate that B. tabaci is competitively superior to F. occidentalis, which might help to explain their differential distribution patterns in China. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

  1. Description of a new species, Setaleyrodes machili Dubey, sp. nov. (Hemiptera: Aleyrodidae) infesting Machilus odoratissima Nees (Lauraceae) in Western Himalaya, India.

    Science.gov (United States)

    Dubey, Anil Kumar

    2017-12-10

    A new species of whitefly, Setaleyrodes machili Dubey sp. nov. found infesting Machilus odoratissima Nees (Lauraceae) is described from Kufri in Himachal Pradesh and Dhanaulti and Nainital in Uttarakhand, India. The diagnostic characteristics of puparia and habitus, are illustrated with line drawings and scanning electron microphotographs. Sexual dimorphism and variation in pigmentation during the transformation of instars are noted. An identification key to puparia of Setaleyrodes species so far described is presented.

  2. Factors affecting herbivory of Thrips palmi (Thysanoptera: Thripidae and Aphis gossypii (Homoptera: Aphididae on the eggplant (Solanum melongena

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    Germano Leão Demolin Leite

    2006-05-01

    Full Text Available The objective of this study was to evaluate effects of total rainfall, mean temperature, natural enemies, chemical composition of leaves, levels of nitrogen and potassium on leaves and density of leaf trichomes on attack intensity of Thrips palmi Karny (Thysanoptera: Thripidae and Aphis gossypii (Glover (Homoptera: Aphididae on plantations of the eggplant (Solanum melongena in two regions of Minas Gerais, Brazil. Higher numbers of A. gossypii/leaf and T. palmi/leaf were observed in plantations of this eggplant in the Municipalities of Viçosa and Guidoval, respectively. Guidoval had a rainy and hotter weather than Viçosa. T. palmi was almost positivelly correlated with rainfall (r= 0.49, P= 0.0538 while A. gossypii seemed to be more affected by mean temperature (r= -0.31; P= 0.1134. Higher number of aphids in eggplants in Viçosa than in Guidoval could be explained by the higher number of natural enemies such as Adialytus spp. (Hymenoptera: Braconidae, Cycloneda sanguinea (L. and Exochomus bimaculosus Mulsant (Coleoptera: Coccinellidae and Chrysoperla spp. (Neuroptera: Chrysopidae in this municipality. However, only Adialytus spp. was significativelly correlated with aphid populations. Higher number of T. palmi in eggplant plantations of Guidoval than in Viçosa could be due to the absence of its possible Eulophidae parasitoid in the first municipality. The spiders were significativelly correlated with this pest in both municipalities.O objetivo deste estudo foi avaliar os efeitos de pluviosidade total, temperatura média, inimigos naturais, composição química foliar, níveis de nitrogênio e potássio foliar e densidade de tricomas na intensidade de ataque de Thrips palmi Karny (Thysanoptera: Thripidae e Aphis gossypii (Glover (Homoptera: Aphididae em plantações de berinjela (Solanum melongena em dois municípios de Minas Gerais, Brasil. Observou-se maiores números de A. gossypii e T. palmi por folha em plantações de berinjela nos

  3. Leaf endophytic fungi of chili (Capsicum annuum and their role in the protection against Aphis gossypii (Homoptera: Aphididae

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    HENY HERNAWATI

    2011-10-01

    Full Text Available Hernawati H, Wiyono S, Santoso S (2011 Leaf endophytic fungi of chili (Capsicum annuum and their role in the protection against Aphis gossypii (Homoptera: Aphididae. Biodiversitas 12: 187-191. The objectives of the research were to study the diversity of leaf endophytic fungi of chili, and investigate its potency in protecting host plants against Aphis gossypii Glov. Endophytic fungi were isolated from chili leaves with two categories: aphid infested plants and aphid-free plants, collected from farmer’s field in Bogor, West Java. Abundance of each fungal species from leave samples was determined by calculating frequency of isolation. The isolated fungi were tested on population growth of A. gossypii. The fungal isolates showed suppressing effect in population growth test, was further tested on biology attributes i.e. life cycle, fecundity and body length. Five species of leaf endophytic fungi of chili were found i.e. Aspergillus flavus, Nigrospora sp., Coniothyrium sp., and SH1 (sterile hypha 1, SH2 (sterile hypha 2. Eventhough the number of endophytic fungi species in aphid-free and aphid-infested plant was same, the abundance of each species was different. Nigrospora sp., sterile hyphae 1 and sterile hyphae 2 was more abundant in aphid-free plants, but there was no difference in dominance of Aspergillus flavus and Coniothyrium sp. Nigrospora sp., SH1 and SH2 treatment reduced significantly fecundity of A. gossypii. Only SH2 treatment significantly prolonged life cycle and suppress body length, therefore the fungus had the strongest suppressing effect on population growth among fungi tested. The abundance and dominance of endophytic fungal species has relation with the infestation of A. gossypii in the field.

  4. Incidence of cassava mosaic disease and associated whitefly vectors in South West and North Central Nigeria: Data exploration.

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    Eni, Angela O; Efekemo, Oghenevwairhe P; Soluade, Mojisola G; Popoola, Segun I; Atayero, Aderemi A

    2018-08-01

    Cassava mosaic disease (CMD) is one of the most economically important viral diseases of cassava, an important staple food for over 800 million people in the tropics. Although several Cassava mosaic virus species associated with CMD have been isolated and characterized over the years, several new super virulent strains of these viruses have evolved due to genetic recombination between diverse species. In this data article, field survey data collected from 184 cassava farms in 12 South Western and North Central States of Nigeria in 2015 are presented and extensively explored. In each State, one cassava farm was randomly selected as the first farm and subsequent farms were selected at 10 km intervals, except in locations were cassava farms are sporadically located. In each selected farm, 30 cassava plants were sampled along two diagonals and all selected plant was scored for the presence or absence of CMD symptoms. Cassava mosaic disease incidence and associated whitefly vectors in South West and North Central Nigeria are explored using relevant descriptive statistics, box plots, bar charts, line graphs, and pie charts. In addition, correlation analysis, Analysis of Variance (ANOVA), and multiple comparison post-hoc tests are performed to understand the relationship between the numbers of whiteflies counted, uninfected farms, infected farms, and the mean of symptom severity in and across the States under investigation. The data exploration provided in this data article is considered adequate for objective assessment of the incidence and symptom severity of cassava mosaic disease and associated whitefly vectors in farmers' fields in these parts of Nigeria where cassava is heavily cultivated.

  5. Is agriculture driving the diversification of the Bemisia tabaci species complex (Hemiptera: Sternorrhyncha: Aleyrodidae)?: Dating, diversification and biogeographic evidence revealed.

    Science.gov (United States)

    Boykin, Laura M; Bell, Charles D; Evans, Gregory; Small, Ian; De Barro, Paul J

    2013-10-18

    Humans and insect herbivores are competing for the same food crops and have been for thousands of years. Despite considerable advances in crop pest management, losses due to insects remain considerable. The global homogenisation of agriculture has supported the range expansion of numerous insect pests and has been driven in part by human-assisted dispersal supported through rapid global trade and low-cost air passenger transport. One of these pests, is the whitefly, Bemisia tabaci, a cryptic species complex that contains some of the world's most damaging pests of agriculture. The complex shows considerable genetic diversity and strong phylogeographic relationships. One consequence of the considerable impact that members of the B. tabaci complex have on agriculture, is the view that human activity, particularly in relation to agricultural practices, such as use of insecticides, has driven the diversification found within the species complex. This has been particularly so in the case of two members of the complex, Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED), which have become globally distributed invasive species. An alternative hypothesis is that diversification is due to paleogeographic and paleoclimatological changes. The idea that human activity is driving speciation within the B. tabaci complex has never been tested, but the increased interest in fossil whiteflies and the growth in molecular data have enabled us to apply a relaxed molecular clock and so estimate divergence dates for the major lineages within the B. tabaci species complex. The divergence estimates do not support the view that human activity has been a major driver of diversification. Our analysis suggests that the major lineages within the complex arose approximately 60-30 mya and the highly invasive MED and MEAM1 split from the rest of the species complex around 12 mya well before the evolution of Homo sapiens and agriculture. Furthermore, the divergence dates coincide with a period

  6. Implication of the Bacterial Endosymbiont Rickettsia spp. in Interactions of the Whitefly Bemisia tabaci with Tomato yellow leaf curl virus

    Science.gov (United States)

    Kliot, Adi; Cilia, Michelle; Czosnek, Henryk

    2014-01-01

    ABSTRACT Numerous animal and plant viruses are transmitted by arthropod vectors in a persistent, circulative manner. Tomato yellow leaf curl virus (TYLCV) is transmitted by the sweet potato whitefly Bemisia tabaci. We report here that infection with Rickettsia spp., a facultative endosymbiont of whiteflies, altered TYLCV-B. tabaci interactions. A B. tabaci strain infected with Rickettsia acquired more TYLCV from infected plants, retained the virus longer, and exhibited nearly double the transmission efficiency compared to an uninfected B. tabaci strain with the same genetic background. Temporal and spatial antagonistic relationships were discovered between Rickettsia and TYLCV within the whitefly. In different time course experiments, the levels of virus and Rickettsia within the insect were inversely correlated. Fluorescence in situ hybridization analysis of Rickettsia-infected midguts provided evidence for niche exclusion between Rickettsia and TYLCV. In particular, high levels of the bacterium in the midgut resulted in higher virus concentrations in the filter chamber, a favored site for virus translocation along the transmission pathway, whereas low levels of Rickettsia in the midgut resulted in an even distribution of the virus. Taken together, these results indicate that Rickettsia, by infecting the midgut, increases TYLCV transmission efficacy, adding further insights into the complex association between persistent plant viruses, their insect vectors, and microorganism tenants that reside within these insects. IMPORTANCE Interest in bacterial endosymbionts in arthropods and many aspects of their host biology in agricultural and human health systems has been increasing. A recent and relevant studied example is the influence of Wolbachia on dengue virus transmission by mosquitoes. In parallel with our recently studied whitefly-Rickettsia-TYLCV system, other studies have shown that dengue virus levels in the mosquito vector are inversely correlated with

  7. The Whitefly Bemisia tabaci Knottin-1 Gene Is Implicated in Regulating the Quantity of Tomato Yellow Leaf Curl Virus Ingested and Transmitted by the Insect

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    Aliza Hariton Shalev

    2016-07-01

    Full Text Available The whitefly Bemisia tabaci is a major pest to agricultural crops. It transmits begomoviruses, such as Tomato yellow leaf curl virus (TYLCV, in a circular, persistent fashion. Transcriptome analyses revealed that B. tabaci knottin genes were responsive to various stresses. Upon ingestion of tomato begomoviruses, two of the four knottin genes were upregulated, knot-1 (with the highest expression and knot-3. In this study, we examined the involvement of B. tabaci knottin genes in relation to TYLCV circulative transmission. Knottins were silenced by feeding whiteflies with knottin dsRNA via detached tomato leaves. Large amounts of knot-1 transcripts were present in the abdomen of whiteflies, an obligatory transit site of begomoviruses in their circulative transmission pathway; knot-1 silencing significantly depleted the abdomen from knot-1 transcripts. Knot-1 silencing led to an increase in the amounts of TYLCV ingested by the insects and transmitted to tomato test plants by several orders of magnitude. This effect was not observed following knot-3 silencing. Hence, knot-1 plays a role in restricting the quantity of virions an insect may acquire and transmit. We suggest that knot-1 protects B. tabaci against deleterious effects caused by TYLCV by limiting the amount of virus associated with the whitefly vector.

  8. Tomato Infection by Whitefly-Transmitted Circulative and Non-Circulative Viruses Induce Contrasting Changes in Plant Volatiles and Vector Behaviour.

    Science.gov (United States)

    Fereres, Alberto; Peñaflor, Maria Fernanda G V; Favaro, Carla F; Azevedo, Kamila E X; Landi, Carolina H; Maluta, Nathalie K P; Bento, José Mauricio S; Lopes, Joao R S

    2016-08-11

    Virus infection frequently modifies plant phenotypes, leading to changes in behaviour and performance of their insect vectors in a way that transmission is enhanced, although this may not always be the case. Here, we investigated Bemisia tabaci response to tomato plants infected by Tomato chlorosis virus (ToCV), a non-circulative-transmitted crinivirus, and Tomato severe rugose virus (ToSRV), a circulative-transmitted begomovirus. Moreover, we examined the role of visual and olfactory cues in host plant selection by both viruliferous and non-viruliferous B. tabaci. Visual cues alone were assessed as targets for whitefly landing by placing leaves underneath a Plexiglas plate. A dual-choice arena was used to assess whitefly response to virus-infected and mock-inoculated tomato leaves under light and dark conditions. Thereafter, we tested the whitefly response to volatiles using an active air-flow Y-tube olfactometer, and chemically characterized the blends using gas chromatography coupled to mass spectrometry. Visual stimuli tests showed that whiteflies, irrespective of their infectious status, always preferred to land on virus-infected rather than on mock-inoculated leaves. Furthermore, whiteflies had no preference for either virus-infected or mock-inoculated leaves under dark conditions, but preferred virus-infected leaves in the presence of light. ToSRV-infection promoted a sharp decline in the concentration of some tomato volatiles, while an increase in the emission of some terpenes after ToCV infection was found. ToSRV-viruliferous whiteflies preferred volatiles emitted from mock-inoculated plants, a conducive behaviour to enhance virus spread, while volatiles from ToCV-infected plants were avoided by non-viruliferous whiteflies, a behaviour that is likely detrimental to the secondary spread of the virus. In conclusion, the circulative persistent begomovirus, ToSRV, seems to have evolved together with its vector B. tabaci to optimise its own spread. However

  9. Tomato Infection by Whitefly-Transmitted Circulative and Non-Circulative Viruses Induce Contrasting Changes in Plant Volatiles and Vector Behaviour

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    Alberto Fereres

    2016-08-01

    Full Text Available Virus infection frequently modifies plant phenotypes, leading to changes in behaviour and performance of their insect vectors in a way that transmission is enhanced, although this may not always be the case. Here, we investigated Bemisia tabaci response to tomato plants infected by Tomato chlorosis virus (ToCV, a non-circulative-transmitted crinivirus, and Tomato severe rugose virus (ToSRV, a circulative-transmitted begomovirus. Moreover, we examined the role of visual and olfactory cues in host plant selection by both viruliferous and non-viruliferous B. tabaci. Visual cues alone were assessed as targets for whitefly landing by placing leaves underneath a Plexiglas plate. A dual-choice arena was used to assess whitefly response to virus-infected and mock-inoculated tomato leaves under light and dark conditions. Thereafter, we tested the whitefly response to volatiles using an active air-flow Y-tube olfactometer, and chemically characterized the blends using gas chromatography coupled to mass spectrometry. Visual stimuli tests showed that whiteflies, irrespective of their infectious status, always preferred to land on virus-infected rather than on mock-inoculated leaves. Furthermore, whiteflies had no preference for either virus-infected or mock-inoculated leaves under dark conditions, but preferred virus-infected leaves in the presence of light. ToSRV-infection promoted a sharp decline in the concentration of some tomato volatiles, while an increase in the emission of some terpenes after ToCV infection was found. ToSRV-viruliferous whiteflies preferred volatiles emitted from mock-inoculated plants, a conducive behaviour to enhance virus spread, while volatiles from ToCV-infected plants were avoided by non-viruliferous whiteflies, a behaviour that is likely detrimental to the secondary spread of the virus. In conclusion, the circulative persistent begomovirus, ToSRV, seems to have evolved together with its vector B. tabaci to optimise its own

  10. Climatic factors and populational dynamics of Mahanarva posticata (Stal-1855) (Homoptera-Cercopidae) as a contribution to a possible regional implantation of the sterile male technique

    International Nuclear Information System (INIS)

    Oliveira, M.L. de

    1981-01-01

    A field study on the population dynamics of M. posticata (STAL, 1855) (Homoptera-Cercopidae) was carried out from 1971 to 1978 under the ecological conditions prevailing in the Litoral-Mata-Sul Zone of Pernambuco, Brazil. The results indicated that maximal infestation of the sugar cane crops by the insect generally occured in June and in July, and it was dependent on rainfall, temperature and relative humidity. The population density of adults was decreased markedly during the months of January, February and March. Technical and economical viability of the insect control by the male-sterilization-techniques through radiation was also demonstrated. The technique is to be used isolated or with other conventional procedures in the combat of froghopper infestations in the sugar cane growing in Pernambuco, Brazil. (Author) [pt

  11. Whitefly feeding behavior and retention of a foregut-borne crinivirus exposed to artificial diets with different pH values.

    Science.gov (United States)

    Zhou, Jaclyn S; Chen, Angel Y S; Drucker, Martin; Lopez, Nicole H; Carpenter, Alyssa; Ng, James C K

    2017-12-01

    Transmission of plant viruses by phytophagous hemipteran insects encompasses complex interactions underlying a continuum of processes involved in virus acquisition, retention and inoculation combined with vector feeding behavior. Here, we investigated the effects of dietary pH on whitefly (Bemisia tabaci) feeding behavior and release of Lettuce infectious yellows virus (LIYV) virions retained in the vector's foregut. Electrical penetration graph analysis revealed that variables associated with whitefly probing and ingestion did not differ significantly in pH (4, 7.4, and 9) adjusted artificial diets. To investigate virus retention and release, whiteflies allowed to acquire LIYV virions in a pH 7.4 artificial diet were fed pH 4, 7.4, or 9 virion-free artificial (clearing) diets. Immunofluorescent localization analyses indicated that virions remained bound to the foreguts of approximately 20%-24% of vectors after they fed on each of the 3 pH-adjusted clearing diets. When RNA preparations from the clearing diets were analyzed by reverse transcription (RT) nested-PCR and, in some cases, real-time qPCR, successful amplification of LIYV-specific sequence was infrequent but consistently repeatable for the pH 7.4 diet but never observed for the pH 4 and 9 diets, suggesting a weak pH-dependent effect for virion release. Viruliferous vectors that fed on each of the 3 pH-adjusted clearing diets transmitted LIYV to virus-free plants. These results suggest that changes in pH values alone in artificial diet do not result in observable changes in whitefly feeding behaviors, an observation that marks a first in the feeding of artificial diet by whitefly vectors; and that there is a potential causal and contingent relationship between the pH in artificial diet and the release/inoculation of foregut bound virions. © 2017 Institute of Zoology, Chinese Academy of Sciences.

  12. Analysis of the populations genetic variability of Tagosodes orizicolus (Homoptera: Delphacidae), virus vector of the rice white leaf

    International Nuclear Information System (INIS)

    Hernandez Alfaro, Myriam

    2006-01-01

    Tagosodes orizicolus (Homoptera: Delphacidae), is a monophagous insect of the rice and virus vector of the white leaf (RHBV). It is distributed in America Central, El Caribe, part of the America del Sur and in Costa Rica it is in all the producing zones of rice. The genetic variability was analyzed by means of RAPD-PCR of individuals from three populations of Costa Rica: Parrita, Guanacaste (Liberia) y San Carlos (Santa Clara), that they are found separated geographically. The technique consisted of amplifying regions at random of the genome of these insects utilizing five primers. A total of 72 polymorphic bands were obtained, that upon being analyzed statistically by means of the multivariate analysis program of numerical taxonomy could show a clear genetic distancing among said populations. The genetic distance observed in the molecular analysis can be explained for the climatic and/or geographical isolation of the populations or by the incident of Wolbachia, riquettsia that induces cytoplasmic sterility in insects. These symbionts are transmitted of generation in generation, of the mother to their offspring and they cause reproductive alterations as cytoplasmic incompatibility, parthenogenesis and feminization. The presence of Wolbachia was determined by means of transmission electronic microscopy being observed in the greasy and muscular weave of the abdomen of T. orizicolus. Rickettsias present pleomorphic morphology and form small groups, that are characterized for the presence of electrondense material semidetached to the cell wall with an interior electronlucent. Its size in transverse cuts ranged between 520 nm of length X 470 nm of width. In addition, its presence was detected by means of the amplification by PCR of the genomic DNA of the insects; a specific primer for the DNA ribosomal 16S of Wolbachia was utilized for it. A 86% of insects of the San Carlos population were positive, a 96% was determined for Guanacaste, a 37% for Parrita and a 100% for

  13. Effects of Three Insect Growth Regulators on Encarsia formosa (Hymenoptera: Aphelinidae), an Endoparasitoid of Bemisia tabaci (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Wang, Q L; Liu, T-X

    2016-12-01

    Insect growth regulators (IGRs) disrupt the normal activity of the endocrine or hormone system of insects, affecting the development, reproduction, or metamorphosis of the target insects, and normally causing less detrimental effects to beneficial insects. The effects of three IGRs (pyriproxyfen, fenoxycarb, and buprofezin) on Encarsia formosa Gahan, an endoparasitoid of whiteflies, were determined using B. tabaci as a host. We assessed the effects of the IGRs on parasitoid's larval development, pupation, emergence, and contact effects of the dry residues on plant leaf and glass vial surface on adult mortality and parasitism. When the three IGRs were applied at larval stage, no or few larvae pupated in the pyriproxyfen treatments and the highest concentration of fenoxycarb, and a majority of larvae pupated in the buprofezin treatments; of those pupated, 62.3-88.1% became adults. When the IGRs were applied at the pupal stage, 2.3-17.5% developed to adults in the pyriproxyfen treatments, 59.7-89.0% in the fenoxycarb treatments, and 58.4-83.6% in the buprofezin treatments. The leaf residues of the IGRs had no appreciable effects on adults, whereas the residues on glass vial caused significantly lower adult survival than on plant leaves. The residues of pyriproxyfen and fenoxycarb slightly reduced parasitism as compared with buprofezin and controls. However, the rates of parasitoids that became adults were significantly lower, especially in the pyriproxyfen treatments. According to the standards of International Organization of Biological Control (IOBC), pyriproxyfen was harmful, while fenoxycarb and buprofezin were slightly or moderately harmful to larvae and harmless to E. formosa pupae. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Interação entre Formigas e Aleirodídeos (Sternorrhyncha, Aleyrodidae em Cultivo Orgânico de Tangerina cv. Poncã (Citrus reticulata Blanco

    Directory of Open Access Journals (Sweden)

    William Rodrigues

    2011-11-01

    Abstract. The whiteflies are tending by ants, which give protection and dispersion make the control of those suckers more difficult. The interaction ant-Sternorrhyncha occurs, mainly due to the production of a sugared material named honeydew. The aim of the study as realized sampling, diversity study, frequency, constancy and dominance of the ant’s whiteflies tending species in night and day period. The sampling were conducted from October 2002 to October 2003. The species of whiteflies detected were Aleurothrixus floccosus Maskell, Aleurotrachelus cruzi Cassino, Singhiella citrifolii (Morgan and Paraleyrodes bondari Peracchi. The study concluded that 12 species of ants were associated with A. floccossus, 4 species with A. cruzi and 3 species with P. bondari. Associations between ants and S. citrifolli where not observed. Among the species of ants associated with whiteflies, those ones associated with A. floccosus presented the major diversity (0.743 and the minor dominance (0.3194 and equitability J (0.6882. Brachymyrmex sp. was the most frequent species (31.94% and also the most constant. P. bondari showed a diversity of 0.477, the dominance of 0.3333 and the equitability J 1. To A. cruzi, the diversity was of 0.422, dominance of 0.6098 e equitability J of 0.7013. This species of whiteflies show a dominance of the species Crematogaster sp. 1, with the frequency of 60.98% although it was secondary. The close relationship between A. floccosus and 12 ants demonstrates a preference for the excrements (honeydew of the whiteflies, for the quantity as well as for the quality of the honeydew.

  15. Age-specific interaction between the parasitoid, Encarsia formosa and its host, the silverleaf whitefly, Bemisia tabaci (Strain B

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    Jing S. Hu

    2003-08-01

    Full Text Available The effect of hostage, the instar of Bemisia tabaci (Gennadius parasitized, on the growth and development of Encarsia formosa (Gahan was studied. E. formosa was able to parasitize and complete its life cycle no matter which instar of B. tabaci (Strain B, [also identified as B. argentifolii (Bellows and Perring], was provided for oviposition, but parasitoid development was significantly slower when 1st or 2nd instar B. tabaci rather than 3rd or 4th instars were parasitized. Host age influenced the day on which E. formosa nymphs hatching from eggs was first observed. Mean embryonic development was significantly longer when 1st (5.4 days rather than 2nd, 3rd or 4th instars (4.1, 3.4 and 3.5 days, respectively were parasitized. The duration of the 1st instar parasitoid and the pupa, but not the 2nd or 3rd instar parasitoid, were also significantly greater when 1st instars were parasitized than when older host instars were parasitized. Interestingly, no matter which instar was parasitized, the parasitoid did not molt to the 3rd instar until the 4th instar host had reached a depth of about 0.23 mm (Stage 4-5 and had initiated the nymphal-adult molt and adult development. Histological studies revealed that whitefly eye and wing structures had either disintegrated or were adult in nature whenever a 3rd instar parasitoid was present. It appears, then, that the molt of the parasitoid to its last instar is associated with the host whitefly's nymphal-adult molt. However, the initiation of the host's final molt, while a prerequisite for the parasitoid's 2nd-3rd instar molt, did not necessarily trigger this molt. In contrast to its significant effect on various aspects of parasitoid development, host instar did not significantly influence the mean size of the parasitoid larva, pupa, or adult. Larval and pupal length and adult head width were similar for all parasitoids, regardless of which host instar was parasitized as was adult longevity. Adult parasitoid

  16. Whitefly (Bemisia tabaci genome project: analysis of sequenced clones from egg, instar, and adult (viruliferous and non-viruliferous cDNA libraries

    Directory of Open Access Journals (Sweden)

    Czosnek Henryk

    2006-04-01

    Full Text Available Abstract Background The past three decades have witnessed a dramatic increase in interest in the whitefly Bemisia tabaci, owing to its nature as a taxonomically cryptic species, the damage it causes to a large number of herbaceous plants because of its specialized feeding in the phloem, and to its ability to serve as a vector of plant viruses. Among the most important plant viruses to be transmitted by B. tabaci are those in the genus Begomovirus (family, Geminiviridae. Surprisingly, little is known about the genome of this whitefly. The haploid genome size for male B. tabaci has been estimated to be approximately one billion bp by flow cytometry analysis, about five times the size of the fruitfly Drosophila melanogaster. The genes involved in whitefly development, in host range plasticity, and in begomovirus vector specificity and competency, are unknown. Results To address this general shortage of genomic sequence information, we have constructed three cDNA libraries from non-viruliferous whiteflies (eggs, immature instars, and adults and two from adult insects that fed on tomato plants infected by two geminiviruses: Tomato yellow leaf curl virus (TYLCV and Tomato mottle virus (ToMoV. In total, the sequence of 18,976 clones was determined. After quality control, and removal of 5,542 clones of mitochondrial origin 9,110 sequences remained which included 3,843 singletons and 1,017 contigs. Comparisons with public databases indicated that the libraries contained genes involved in cellular and developmental processes. In addition, approximately 1,000 bases aligned with the genome of the B. tabaci endosymbiotic bacterium Candidatus Portiera aleyrodidarum, originating primarily from the egg and instar libraries. Apart from the mitochondrial sequences, the longest and most abundant sequence encodes vitellogenin, which originated from whitefly adult libraries, indicating that much of the gene expression in this insect is directed toward the production

  17. Controle químico de ovos e ninfas de Bemisia tabaci biótipo B (Hemiptera: aleyrodidae Chemical control of Bemisia tabaci B biotype (Hemiptera: aleyrodidae eggs and nymphs

    Directory of Open Access Journals (Sweden)

    Giuliana Etore do Valle

    2002-06-01

    Full Text Available Moscas brancas são pragas de diversas culturas, causam redução na produção e na qualidade do produto. Inseticidas, com diferentes modos de ação vêm sendo utilizados, sem muito sucesso. Neste trabalho avaliou-se a eficiência de inseticidas sobre ovos de diferentes idades (1, 3 e 5 dias e de ninfas de 1° ínstar da mosca branca Bemisia tabaci biótipo B. Os experimentos foram realizados em condições de laboratório, sob temperatura de 25 ± 2°C e fotofase de 12 horas. Piriproxifem (75 mg L-1 atuou como excelente ovicida, sendo altamente eficiente, 3 dias de idade. Cartape (500 mg L-1 não teve efeito satisfatório, mas a 1000 mg L-1 foi eficiente em ovos com até 5 dias de idade. Quanto à ação sobre ninfas de 1° ínstar, para pulverizações na face superior das folhas, piriproxifem, a 75 mg L-1, apresentou eficiência na supressão da emergência de adultos, caracterizando presença de ação translaminar; buprofezim, cartape, acefato e fempiroximate não apresentaram eficiência no controle de ninfas. Quando aplicado na face inferior das folhas, buprofezim (375 mg L-1 apresentou eficiência comparável à de piriproxifem, impedindo a emergência de adultos.Whiteflies are pests of many crops, cause severe yield losses and reduce crop quality. Insecticides of different modes of action have been used without success. In this work, the efficiency of five insecticides on Bemisia tabaci B biotype (= B. argentifolii eggs and nymphs was evaluated under laboratory conditions (T = 25 ± 2°C; 12 h photophase. In relation to the ovicidal effect, pyriproxyfen (75 mg L-1 caused egg hatching inhibition up to three day old eggs. Cartap showed efficiency only at the concentration of 1000 mg L-1, supressing the viability of eggs up to five days. Soybean leaves with first instar nymphs were treated in the upper surface with pyriproxyfen (75 mg L-1, buprofezin (375 mg L-1, cartap (1000 mg L-1, acephate (750 mg L-1 and fenpyroximate (100 mg L-1; in

  18. Nigerian Journal of Horticultural Science - Vol 13, No 1 (2008)

    African Journals Online (AJOL)

    Spread of the spiraling white fly Aleurodicus dispersus (Homoptera: Aleyrodidae) and its parasitoids Encarcia species (Hymenoptera: Aphelinidae) on horticultural plants in ... Nutrient release patterns of kola pod husk and pacesetter grade b fertilizer during incubation in the laboratory · EMAIL FULL TEXT EMAIL FULL TEXT

  19. The broadly insecticidal Photorhabdus luminescens toxin complex a (Tca): Activity against the Colorado potato beetle, Leptinotarsa decemlineata, and sweet potato whitefly, Bemisia tabaci

    OpenAIRE

    Blackburn, Michael B.; Domek, John M.; Gelman, Dale B.; Hu, Jing S.

    2005-01-01

    Toxin complex a (Tca), a high molecular weight insecticidal protein complex produced by the entomopathogenic bacterium Photorhabdus luminescens, has been found to be orally toxic to both the Colorado potato beetle, Leptinotarsa decemlineata, and the sweet potato whitefly, Bemisia tabaci biotype B. The 48 hour LC50 for Tca against neonate L. decemlineata was found to be 2.7 ppm, and the growth of 2nd instar L. decemlineata exposed to Tca for 72 hours was almost entirely inhibited at concentrat...

  20. Members of Bemisia tabaci (Hemiptera: Aleyrodidae) Cryptic Species and the Status of Two Invasive Alien Species in the Yunnan Province (China)

    Science.gov (United States)

    Hu, Jian; Jiang, Zhi-Lin; Nardi, Francesco; Liu, Yuan-Yuan; Luo, Xiao-Rong; Li, Hong-Xiang; Zhang, Zhong-Kai

    2014-01-01

    Abstract Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a cryptic species complex that includes some of the most significant pests of agriculture and horticulture worldwide. To understand the diversity and distribution of B. tabaci cryptic species in Yunnan, a famous biodiversity hotspot in China, a large-scale sampling was conducted from year 2010 to 2013 in 10 prefectures. Mitochondrial cytochrome oxidase I gene sequences were used to identify different cryptic species. Phylogenetic analyses were performed using Bayesian methods to assess the position of a new B. tabaci cryptic species in the context of the B. tabaci diversity in Asia. The survey indicates at least eight B. tabaci cryptic species are present in Yunnan, two invasive (MEAM1 and MED) and six indigenous (China 2, China3, China 4, Asia I, Asia II 1, and Asia II 6), MEAM1, MED, and Asia I being the three predominant cryptic species in Yunnan. Compared with MEAM1, MED has a wider distribution. Based on molecular data, a new cryptic species, here named China 4, was identified that appears to be related to China 1, China 2, and China 3. Future efforts should focus on the interactions between predominant B. tabaci cryptic species and begomoviruses and on the development of effective control strategies. PMID:25502045

  1. Salicylic acid is required for Mi-1-mediated resistance of tomato to whitefly Bemisia tabaci, but not for basal defense to this insect pest.

    Science.gov (United States)

    Rodríguez-Álvarez, C I; López-Climent, M F; Gómez-Cadenas, A; Kaloshian, I; Nombela, G

    2015-10-01

    Plant defense to pests or pathogens involves global changes in gene expression mediated by multiple signaling pathways. A role for the salicylic acid (SA) signaling pathway in Mi-1-mediated resistance of tomato (Solanum lycopersicum) to aphids was previously identified and its implication in the resistance to root-knot nematodes is controversial, but the importance of SA in basal and Mi-1-mediated resistance of tomato to whitefly Bemisia tabaci had not been determined. SA levels were measured before and after B. tabaci infestation in susceptible and resistant Mi-1-containing tomatoes, and in plants with the NahG bacterial transgene. Tomato plants of the same genotypes were also screened with B. tabaci (MEAM1 and MED species, before known as B and Q biotypes, respectively). The SA content in all tomato genotypes transiently increased after infestation with B. tabaci albeit at variable levels. Whitefly fecundity or infestation rates on susceptible Moneymaker were not significantly affected by the expression of NahG gene, but the Mi-1-mediated resistance to B. tabaci was lost in VFN NahG plants. Results indicated that whiteflies induce both SA and jasmonic acid accumulation in tomato. However, SA has no role in basal defense of tomato against B. tabaci. In contrast, SA is an important component of the Mi-1-mediated resistance to B. tabaci in tomato.

  2. Effect of Two Entomopathogenic Fungi in Controlling Aleurodicus cocois (Curtis, 1846 (Hemiptera: Aleyrodidae Efecto de Dos Hongos Entomopatógenos en el Control de Aleurodicus cocois (Curtis, 1846 (Hemiptera: Aleyrodidae

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    Elizabeth Núñez del Prado

    2008-03-01

    Full Text Available Aleurodicus cocois (Curtis, 1846, the coconut whitefly, is a very damaging pest in Peru, mainly in avocado trees (Persea americana Mill.. It has been determined that entomopathogenic fungi can infect and kill white flies and can be used as biological control agents. The object of this research was to determine if there is any synergic action of the entomopathogenic fungi Paecilomyces fumosoroseus (Wize Brown & Smith 1957 and Verticillium lecanii (Zimmerman, 1892 Viégas 1939, in controlling A. cocois. Plastic sterile dishes were prepared where 5 mL 2% agar were used for each stage; leaves infested with A. cocois were placed upon these. Three different treatments were applied by sprinkling: P. fumosoroseus (P, V. lecanii (V or the mixture of the two fungi. These treatments were evaluated at one, two and seven days in the case of nymph I and eggs, and after four, eight and 12 days for nymph II, NIII and NIV. The lethal effect of V. lecanii on the second nymph instar of A. cocois was better than that of P. fumosoroseus and than the mixture of both fungi; the highest mortality percentage appeared from day eight to day 12. A small increase was observed in the effect of the mixture of the two entomopathogenic fungi on the IV nymph instar; and the effect of P. fumosoroseus was the lowestAleurodicus cocois (Curtis, 1846, la mosca blanca del cocotero, constituye una plaga muy importante en el Perú, principalmente en el palto (Persea americana Mill.. Se ha determinado que los hongos entomopatógenos pueden infectar y matar a la mosca blanca, por lo que podrían ser usados como agentes de control biológico. El objetivo del presente trabajo fue determinar si existe alguna acción conjunta de dos hongos entomopatógenos Paecilomyces fumosoroseus (Wize Brown & Smith 1957 y Verticillium lecanii (Zimmerman, 1892 Viégas 1939, en el control de A. cocois. Para ello se prepararon previamente placas de plástico estériles en las que se sirvieron aproximadamente

  3. Surtos populacionais de Bemisia tabaci no estado de São Paulo Outbreaks of Bemisia tabaci in the São Paulo State, Brazil

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    André Luiz Lourenção

    1994-01-01

    Full Text Available A partir de 1991, tem sido observada a presença da mosca-branca Bemisia tabaci (Genn. (Homoptera: Aleyrodidae em altas populações em hortaliças e orna-mentais nos municípios paulistas de Paulínia, Holambra, Jaguariúna e Artur Nogueira. Foram constatadas infestações severas em tomateiro, brócolos, berinjela e aboboreira; nesta última, o sintoma observado em plantas infestadas pela mosca-branca é o prateamento da face superior das folhas, em conjunto com queda drástica da produção. Uma lavoura de tomate severamente infestada por B. tabaci apresentava o sintoma referido colo amadurecimento irregular dos frutos do tomateiro; plantas invasoras presentes nessa área também foram intensamente colonizadas, principalmente Sida rhombifolia L., Sonchus oleraceus L., Solanum viarum Dun. e Ipomoea acuminata Roem. & Schult. Em Holambra, verificaram-se ataques intensos em plantas ornamentais, principalmente crisântemo (Chrysantemum morifolium Ramat. e bico-de-papagaio (Euphorbia pulcherrima Willd.; roseiras foral pouco colonizadas. Nessas hortaliças e nas ornamentais, a aplicação quase diária de inseticidas não reduziu a infestação do inseto. Além dessas plantas, campos de algodão, em Holambra, e de feijão, em Paulínia, também foram infestados por B. tabaci. Nos E.U.A., a capacidade de certas populações de B. tabaci de induzir o prateamento da folha em aboboreira e de colonizar intensamente E. pulcherrima, entre outros fatores, têm levado à distinção do biótipo "B" ou "poinsétia", nome vulgar dessa euforbiácea; todavia, estudos recentes na Califórnia (E.U.A. mostram a possibilidade de se tratar de duas espécies distintas. Dada a similaridade entre as infestações associadas a B. tabaci que vêm ocorrendo naquele país e, mais recentemente, no Brasil, é provável que o biótipo B ou essa nova espécie tenha sido aqui introduzido.Since 1991, an increase in the populations of the whitefly Bemisia tabaci (Genn. (Homoptera

  4. Over-expression of a cytochrome P450 is associated with resistance to pyriproxyfen in the greenhouse whitefly Trialeurodes vaporariorum.

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    Nikos Karatolos

    Full Text Available The juvenile hormone mimic, pyriproxyfen is a suppressor of insect embryogenesis and development, and is effective at controlling pests such as the greenhouse whitefly Trialeurodes vaporariorum (Westwood which are resistant to other chemical classes of insecticides. Although there are reports of insects evolving resistance to pyriproxyfen, the underlying resistance mechanism(s are poorly understood.Bioassays against eggs of a German (TV8 population of T. vaporariorum revealed a moderate level (21-fold of resistance to pyriproxyfen. This is the first time that pyriproxyfen resistance has been confirmed in this species. Sequential selection of TV8 rapidly generated a strain (TV8pyrsel displaying a much higher resistance ratio (>4000-fold. The enzyme inhibitor piperonyl butoxide (PBO suppressed this increased resistance, indicating that it was primarily mediated via metabolic detoxification. Microarray analysis identified a number of significantly over-expressed genes in TV8pyrsel as candidates for a role in resistance including cytochrome-P450 dependent monooxygenases (P450s. Quantitative PCR highlighted a single P450 gene (CYP4G61 that was highly over-expressed (81.7-fold in TV8pyrsel.Over-expression of a single cytochrome P450 gene (CYP4G61 has emerged as a strong candidate for causing the enhanced resistance phenotype. Further work is needed to confirm the role of the encoded P450 enzyme CYP4G61 in detoxifying pyriproxyfen.

  5. Susceptibility of MED-Q1 and MED-Q3 Biotypes of Bemisia tabaci (Hemiptera: Aleyrodidae) Populations to Essential and Seed Oils.

    Science.gov (United States)

    Samuel Fogné, Drabo; Olivier, Gnankine; Bassolé, Imael H N; Nébié, Roger Charles; Laurence, Mouton

    2017-06-01

    Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a major pest of many agricultural and ornamental crops in tropical and subtropical regions causing damages that result in important economic losses. Insecticides are commonly used in greenhouses or fields to control B. tabaci populations leading to rapid evolution of resistance that render treatments inefficient. Therefore, and for environmental and human health concerns, other approaches must be developed for this pest management. In the present study, we compare, using the leaf dip method, the toxicity of three essential oils (Cymbopogon citratus, Ocimum americanum, and Hyptis spicigera) and three seed oils (Lannea microcarpa, Lannea acida, and Carapa procera) with three chemical insecticides (acetamiprid, deltamethrin, and chlorpyrifos-ethyl) on adults. Two B. tabaci biotypes (MED-Q1 and MED-Q3) belonging to the Mediterranean species and collected in Burkina Faso were used. Essential oils were analyzed by gas chromatography-mass spectrometry and gas chromatography-flame ionization detector. We showed that these two biotypes have different levels of resistance to the three insecticides, MED-Q3 being more sensitive than MED-Q1. Moreover, they differ in the frequency of resistance alleles to insecticides, especially for organophosphates, as these alleles are almost fixed in MED-Q1. On the other hand, the two biotypes prove to be more susceptible to the plant extracts than to insecticides except for chlorpyrifos-ethyl, with essential oils that showed the highest insecticidal activities. Monoterpenes content were the most abundant and showed the highest insecticidal activities. Our results indicated that essential oils, but also seed oils, have the potential to constitute an alternative strategy of pest management. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Ocorrência de Tuthillia cognata Hodkinson, Brown & Burckhardt, 1986(Hemiptera: Homoptera, Psyllidae em plantios experimentais de camu-camu Myrciaria dubia (H.B.K. Mc Vaugh em Manaus (Amazonas, Brasil Occurrence of Tuthillia cognata Hodkinson, Brown & Burckhardt, 1986 (Hemiptera: Homoptera, Psyllidae in experimental plantations of camu-camu Myrciaria dubia (H.B.K. Mc Vaugh in Manaus (Amazonas, Brazil

    Directory of Open Access Journals (Sweden)

    Márcio Luís Leitão Barbosa

    2004-01-01

    Full Text Available O cultivo de camu-camu Myrciaria dubia (H.B.K. Mc Vaugh tem apresentado inúmeros problemas fitossanitários, dentre os quais, Tuthillia cognata Hodkinson et al. (Hemiptera: Homoptera, Psyllidae, que constantemente é citada como praga secundária. Os objetivos deste estudo foram determinar o nível e a intensidade de infestação (% por T. cognata e estudar aspectos do ciclo biológico e do comportamento de T. cognata, em plantios experimentais de camu-camu. Foram selecionados, de forma aleatória, 17 e 14 exemplares nos plantios I e II, respectivamente. Para cada uma das variáveis estudadas, foram calculados a média aritmética, o desviopadrão, a variância e a amplitude de variação. Foi verificado um nível de infestação de 82% (plantio I e 57% (plantio II, uma intensidade de infestação de 94% (plantio I e 75% (plantio II e uma média de seis ninfas/folha em cada plantio, o que indica que T. cognata representa uma das pragas-chave dessa cultura. Foram observados adultos de Chrysoperla sp. (Neuroptera: Chrysopidae e ninfas de Reduviidae (Hemiptera: Heteroptera, que podem atuar como prováveis agentes de controle biológico de T. cognata.The cultivation of camu-camu Myrciaria dubia (H.B.K. Mc Vaugh has presented countless phytosanitary problems, among them, Tuthillia cognata Hodkinson et al. (Hemiptera: Homoptera, Psyllidae, which often is noticed as a secondary pest. This study aimed to determine the level and the intensity of infestation (% for T. cognata, as well as to study the biological cycle and behavioural aspects of T. cognata, in experimental plantation of camu-camu. 17 and 14 specimens from plantation I and II, respectively, were randomly selected. The arithmetic average, the standard deviation, the variance and the total amplitude were calculated for each studied variable. A level of infestation of 82% (plantation I and 57% (plantation II, an intensity of infestation of 94% (plantation I and 75% (plantation II and an

  7. Phylogenetic position of the yeast-like symbiotes of Tagosodes orizicolus (Homoptera: Delphacidae based on 18S ribosomal DNA partial sequences

    Directory of Open Access Journals (Sweden)

    Ana M Xet-Mull

    2004-09-01

    Full Text Available Tagosodes orizicolus Muir (Homoptera: Delphacidae, the endemic delphacid species of tropical America carries yeast-like symbiotes (YLS in the abdominal fat bodies and the ovarial tissues, like other rice planthoppers of Asia. These YLS are obligate symbiotes, which are transmitted transovarially, and maintain a mutualistic relationship with the insect host. This characteristic has made in vitro culture and classification of YLS rather difficult using conventional methods. Nevertheless, microorganisms of similar characteristics have been successfully classified by using molecular taxonomy. In the present work, the YLS of Tagosodes orizicolus(YLSTo were purified on Percoll® gradients, and specific segments of 18S rDNA were amplified by PCR, cloned and sequenced. Sequences were aligned by means of the CLUSTAL V (DNASTAR program; phylogenetic trees were constructed with the Phylogeny Inference Package (PHYLIP, showing that YLSTo belong to the fungi class Pyrenomycetes, phylum Ascomycota. Similarities between 98% and 100% were observed among YLS of the rice delphacids Tagosodes orizicolus, Nilaparvata lugens, Laodelphax striatellus and Sogatella furcifera, and between 89.8% and 90.8% when comparing the above to YLS of the aphid Hamiltonaphis styraci. These comparisons revealed that delphacid YLS are a highly conserved monophyletic group within the Pyrenomycetes and are closely related to Hypomyces chrysospermus. Rev. Biol. Trop. 52(3: 777-785. Epub 2004 Dic 15.Tagosodes orizicolus Muir (Homoptera: Delphacidae es una especie endémica de América tropical que al igual que otros saltahojas de Asia, tiene simbiontes levaduriformes (YLS, por sus siglas en Inglés en los cuerpos grasos del abdomen y en los tejidos de los ovarios. Los YLS son simbiontes obligados que se transmiten transovarialmente y que mantienen relaciones mutualística con el insecto hospedero. Esta característica ha hecho muy difícil su cultivo in vitro y por ende su clasificaci

  8. Effect of insecticides on mealybug destroyer (Coleoptera: Coccinellidae) and parasitoid Leptomastix dactylopii (Hymenoptera: Encyrtidae), natural enemies of citrus mealybug (Homoptera: Pseudococcidae).

    Science.gov (United States)

    Cloyd, Raymond A; Dickinson, Amy

    2006-10-01

    In this study, we measured, under laboratory conditions, the direct and indirect effects of insecticides on mealybug destroyer, Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae), and parasitoid Leptomastix dactylopii Howard (Hymenoptera: Encyrtidae), natural enemies of citrus mealybug, Planococcus citri (Risso) (Homoptera: Pseudococcidae). The adult stages of both natural enemies were exposed to sprays of the insecticides buprofezin, pyriproxyfen, flonicamid, acetamiprid, dinotefuran, and clothianidin at label-recommended rates to assess direct mortality after 24, 48, and 72 h, respectively. The effects of the insecticides on L. dactylopii parasitization rate and percentage of parasitoid emergence also were monitored using the label and 4x the recommended label rate. Dinotefuran was extremely detrimental to the adult parasitoid at the label rate with 100% mortality after 24 h. Buprofezin, pyriproxyfen, and flonicamid were not harmful to L. dactylopii when applied at the label rate. At 4x the recommended label rate, dinotefuran, acetamiprid, and clothianidin were all harmful to the parasitoid with 100% mortality 72 h after application. Both buprofezin and flonicamid were not toxic to L. dactylopii with 100% adult survival after 72 h. Pyriproxyfen and flonicamid, at both the label and 4x the recommended label rate, did not negatively affect L. dactylopii parasitization rate or percentage of parasitoid emergence. Acetamiprid, dinotefuran, and clothianidin were toxic to C. montrouzieri adults with 100% mortality after 48 h, whereas buprofezin, pyriproxyfen, and flonicamid demonstrated minimal (10-20% mortality after 48 h) harmful effects to the predator. Based on the results from our study, the indirect effects of the insect growth regulator (IGR) buprofezin were not decisive; however, the IGR pyriproxyfen and the insecticide flonicamid were not directly or indirectly harmful to the predator C. montrouzieri and parastioid L. dactylopii, indicating that

  9. Pyrosequencing the transcriptome of the greenhouse whitefly, Trialeurodes vaporariorum reveals multiple transcripts encoding insecticide targets and detoxifying enzymes

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    Gorman Kevin

    2011-01-01

    Full Text Available Abstract Background The whitefly Trialeurodes vaporariorum is an economically important crop pest in temperate regions that has developed resistance to most classes of insecticides. However, the molecular mechanisms underlying resistance have not been characterised and, to date, progress has been hampered by a lack of nucleotide sequence data for this species. Here, we use pyrosequencing on the Roche 454-FLX platform to produce a substantial and annotated EST dataset. This 'unigene set' will form a critical reference point for quantitation of over-expressed messages via digital transcriptomics. Results Pyrosequencing produced around a million sequencing reads that assembled into 54,748 contigs, with an average length of 965 bp, representing a dramatic expansion of existing cDNA sequences available for T. vaporariorum (only 43 entries in GenBank at the time of this publication. BLAST searching of non-redundant databases returned 20,333 significant matches and those gene families potentially encoding gene products involved in insecticide resistance were manually curated and annotated. These include, enzymes potentially involved in the detoxification of xenobiotics and those encoding the targets of the major chemical classes of insecticides. A total of 57 P450s, 17 GSTs and 27 CCEs were identified along with 30 contigs encoding the target proteins of six different insecticide classes. Conclusion Here, we have developed new transcriptomic resources for T. vaporariorum. These include a substantial and annotated EST dataset that will serve the community studying this important crop pest and will elucidate further the molecular mechanisms underlying insecticide resistance.

  10. Genome-wide analysis of ATP-binding cassette (ABC) transporters in the sweetpotato whitefly, Bemisia tabaci.

    Science.gov (United States)

    Tian, Lixia; Song, Tianxue; He, Rongjun; Zeng, Yang; Xie, Wen; Wu, Qingjun; Wang, Shaoli; Zhou, Xuguo; Zhang, Youjun

    2017-04-26

    ABC transporter superfamily is one of the largest and ubiquitous groups of proteins. Because of their role in detoxification, insect ABC transporters have gained more attention in recent years. In this study, we annotated ABC transporters from a newly sequenced sweetpotato whitefly genome. Bemisia tabaci Q biotype is an emerging global invasive species that has caused extensive damages to field crops as well as ornamental plants. A total of 55 ABC transporters containing all eight described subfamilies (A to H) were identified in the B. tabaci Q genome, including 8 ABCAs, 3 ABCBs, 6 ABCCs, 2 ABCDs, 1 ABCE, 3 ABCFs, 23 ABCGs and 9 ABCHs. In comparison to other species, subfamilies G and H in both phloem- and blood-sucking arthropods are expanded. The temporal expression profiles of these 55 ABC transporters throughout B. tabaci developmental stages and their responses to imidacloprid, a neonicotinoid insecticide, were investigated using RNA-seq analysis. Furthermore, the mRNA expression of 24 ABC transporters (44% of the total) representing all eight subfamilies was confirmed by the quantitative real-time PCR (RT-qPCR). Furthermore, mRNA expression levels estimated by RT-qPCR and RNA-seq analyses were significantly correlated (r = 0.684, p analysis of the entire repertoire of ABC transporters in B. tabaci. The identification of these ABC transporters, their temporal expression profiles during B. tabaci development, and their response to a neonicotinoid insecticide lay the foundation for functional genomic understanding of their contribution to the invasiveness of B. tabaci.

  11. Implication of the Whitefly Bemisia tabaci Cyclophilin B Protein in the Transmission of Tomato yellow leaf curl virus.

    Science.gov (United States)

    Kanakala, Surapathrudu; Ghanim, Murad

    2016-01-01

    Tomato yellow leaf curl virus (TYLCV) is a single-stranded (ssDNA) begomoviruses that causes severe damage to tomato and several other crops worldwide. TYLCV is exclusively transmitted by the sweetpotato whitefly, Bemisia tabaci in a persistent circulative and propagative manner. Previous studies have shown that the transmission, retention, and circulation of TYLCV in its vector involves interaction with insect and endosymbiont proteins, which aid in the transmission of the virus, or have a protective role in response to the presence of the virus in the insect body. However, only a low number of such proteins have been identified. Here, the role of B. tabaci Cyclophilin B (CypB) in the transmission of TYLCV protein was investigated. Cyclophilins are a large family of cellular prolyl isomerases that have many molecular roles including facilitating protein-protein interactions in the cell. One cyclophilin protein has been implicated in aphid-luteovirus interactions. We demonstrate that the expression of CypB from B. tabaci is altered upon TYLCV acquisition and retention. Further experiments used immunocapture-PCR and co-immunolocalization and demonstrated a specific interaction and colocalization between CypB and TYLCV in the the midgut, eggs, and salivary glands. Membrane feeding of anti-CypB antibodies and TYLCV-infected plants showed a decrease in TYLCV transmission, suggesting a critical role that CypB plays in TYLCV transmission. Further experiments, which used membrane feeding with the CypB inhibitor Cyclosporin A showed decrease in CypB-TYLCV colocalization in the midgut and virus transmission. Altogether, our results indicate that CypB plays an important role in TYLCV transmission by B. tabaci .

  12. Implication of the whitefly Bemisia tabaci Cyclophilin B protein in the transmission of Tomato yellow leaf curl virus

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    Surapathrudu Kanakala

    2016-11-01

    Full Text Available Tomato yellow leaf curl virus (TYLCV is a single-stranded (ssDNA begomoviruses that causes severe damage to tomato and several other crops worldwide. TYLCV is exclusively transmitted by the sweetpotato whitefly, Bemisia tabaci in a persistent circulative and propagative manner. Previous studies have shown that the transmission, retention and circulation of TYLCV in its vector involves interaction with insect and endosymbiont proteins, which aid in the transmission of the virus, or have a protective role in response to the presence of the virus in the insect body. However, only a low number of such proteins have been identified. Here, the role of B. tabaci Cyclophilin B (CypB in the transmission of TYLCV protein was investigated. Cyclophilins (Cyps are a large family of cellular prolyl isomerases that have many molecular roles including facilitating protein-protein interactions in the cell. One cyclophilin protein has been implicated in aphid-luteovirus interactions. We demonstrate that the expression of CypB from B. tabaci is altered upon TYLCV acquisition and retention. Further experiments used immunocapture-PCR and co-immunolocalization and demonstrated a specific interaction and colocalization between CypB and TYLCV in the the midgut, eggs and salivary glands. Membrane feeding of anti-CypB antibodies and TYLCV infected plants showed a decrease in TYLCV transmission, suggesting a critical role that CypB plays in TYLCV transmission. Further experiments, which used membrane feeding with the CypB inhibitor Cyclosporin A (CsA showed decrease in CypB-TYLCV colocalization in the midgut and virus transmission. Altogether, our results indicate that CypB plays an important role in TYLCV transmission by B. tabaci.

  13. Efeito inseticida sistêmico de nanoformulações à base de nim sobre Bemisia tabaci (Hemiptera: Aleyrodidae biótipo B em tomateiro

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    Sheila Salles de Carvalho

    2015-01-01

    Full Text Available Este estudo avaliou a ação inseticida sistêmica e o efeito residual de nanoformulações à base de derivados de nim (Azadirachta indica A. Juss, Meliaceae sobre ninfas de Bemisia tabaci biótipo B (Hemiptera: Aleyrodidae, espécie-praga de diversas culturas de importância econômica. Suspensões coloidais contendo nanocápsulas carregadas com produtos derivados de A. indica foram preparadas utilizando polímeros biodegradáveis como poli-ε-caprolactona (PCL e poli-β-hidroxibutirato (PHB. A matriz encapsulada era composta por uma formulação comercial contendo uma quantidade enriquecida e conhecida dos limonoides azadiractina e 3-tigloilazadiractol (Azamax® 1,2 CE. Inicialmente foi estimada a CL50, para ninfas de B. tabaci, de soluções contendo óleo de nim, que foram aplicadas via água de irrigação (solo em tomateiro. Posteriormente, dois lotes de nanoformulações, com variação no tipo e quantidade dos polímeros e na quantidade do óleo comercial, foram testados quanto à ação sistêmica. As nanoformulações NC L5-2 (com nanocápsulas de PCL e NC L6-1 (com nanocápsulas de PHB, as mais eficazes entre as testadas, foram avaliadas quanto ao efeito residual. A CL50 estimada foi de 180,67 mg L–1 de azadiractina. Constatou-se também que a ação sistêmica de óleos e nanoformulações contendo compostos de nim dependem das condições ambientais em que são aplicados. O Azamax® não apresenta efeito deterrente sobre a oviposição, nem age sobre o desenvolvimento embrionário da mosca-branca quando aplicado via água de irrigação no solo no momento da infestação. As nanoformulações selecionadas são bioativas mesmo cerca de 30 dias após a aplicação, não diferindo do produto comercial.

  14. A review of the genus Tuberaleyrodes Takahashi (Hemiptera: Aleyrodidae) with description of five new species from Brunei, Hong Kong and Malaysia.

    Science.gov (United States)

    Dubey, Anil Kumar; Martin, Jon H

    2018-03-28

    The whitefly genus Tuberaleyrodes Takahashi is reviewed using types and determined specimens. The generic diagnosis is redefined together with description of five new species: T. bruneiensis Dubey Martin sp. nov. from Brunei, T. crypta Dubey Martin sp. nov. from Hong Kong, and T. ordo Dubey Martin sp. nov., T. aequalis Dubey Martin sp. nov. and T. variabilis Dubey Martin sp. nov. from Malaysia. New species descriptions are accompanied with camera lucida drawings and microphotographs of holotype and paratypes. Tuberaleyrodes actinodaphnis Takahashi is elevated from its status as a variety of T. machili Takahashi to species level. Lectotypes are selected for T. actinodaphnis Takahashi Stat. nov. and T. bobuae Takahashi. Tuberaleyrodes actinodaphnis Takahashi is a new record to Taiwan. A new combination, Tuberaleyrodes glutae (Corbett) Comb. nov. is proposed for Dialeurodes glutae Corbett. Two species, T. glutae (Corbett) and Tuberaleyrodes spiniferosa (Corbett) are re-described, and placement of T. spiniferosa in the genus Tuberaleyrodes is confirmed. The genus Tuberaleyrodes is newly recorded from Borneo and Sulawesi. An identification key to puparia of Tuberaleyrodes species so far described is provided along with the countries of present records. Four plants families viz., Annonaceae, Fabaceae, Myristicaceae and Pentaphylacaeae are recorded as new hosts for Tuberaleyrodes species. New host plant records are indicated.

  15. Biochemical evaluation of interactions between synergistic molecules and phase I enzymes involved in insecticide resistance in B- and Q-type Bemisia tabaci (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Panini, Michela; Tozzi, Francesco; Zimmer, Christoph T; Bass, Chris; Field, Linda; Borzatta, Valerio; Mazzoni, Emanuele; Moores, Graham

    2017-09-01

    Metabolic resistance is an important consideration in the whitefly Bemisia tabaci, where an esterase-based mechanism has been attributed to pyrethroid resistance and over-expression of the cytochrome P450, CYP6CM1, has been correlated to resistance to imidacloprid and other neonicotinoids. In vitro interactions between putative synergists and CYP6CM1, B and Q-type esterases were investigated, and structure-activity relationship analyses allowed the identification of chemical structures capable of acting as inhibitors of esterase and oxidase activities. Specifically, methylenedioxyphenyl (MDP) moieties with a polyether chain were preferable for optimum inhibition of B-type esterase, whilst corresponding dihydrobenzofuran structures were potent for the Q-esterase variation. Potent inhibition of CYP6CM1 resulted from structures which contained an alkynyl chain with a terminal methyl group. Synergist candidates could be considered for field control of B. tabaci, especially to abrogate neonicotinoid resistance. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  16. Influence des facteurs écologiques (température et hygrométrie sur le développement de la cochenille farineuse du manioc (Phenacoccus manihoti Matile-Ferrero, Homoptera: Pseudococcidae

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    Obame Minko, D.

    2009-01-01

    Full Text Available The Influence of Ecological Factors (such as Temperature and Hygrometry on the Development of Cassava Mealybug (Phenacoccus manihoti Matile-Ferrero, Homoptera: Pseudococcidae. Phenacoccus manihoti Matile-Ferrero cassava mealybug was accidentally carried away from South America to Africa by early 70s. Since then, it has been inducing a lot of damage to cassava cultures, which cassava remains the main foodstuff in the southern Sahara inhabitant's nutrition. Being anxious to understand the depredator population evolution in the nature, we have studied the temperature and hygrometry as main ecological factors helpful to development. The temperature favours eggs hatching and reduces the duration of embryonic, larval and cycle development whereas hygrometry's action on mealybug development can be neglected. As both factors are opposite functions in the nature, mutual influence on the field can be possible.

  17. Synergistic Effects of Agronet Covers and Companion Cropping on Reducing Whitefly Infestation and Improving Yield of Open Field-Grown Tomatoes

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    Stella Mutisya

    2016-09-01

    Full Text Available Tomatoes (Lycopersicon esculentum Mill are one of the biggest vegetable crops in the world, supplying a wide range of vitamins, minerals and fibre in human diets. In the tropics, tomatoes are predominantly grown under sub-optimal conditions by subsistence farmers, with exposure to biotic and abiotic stresses in the open field. Whitefly (Bemisia tabaci Gennadius is one of the major pests of the tomato, potentially causing up to 100% yield loss. To control whitefly, most growers indiscriminately use synthetic insecticides which negatively impact the environment, humans, and other natural pest management systems, while also increasing cost of production. This study sought to investigate the effectiveness of agronet covers and companion planting with aromatic basil (Ocimum basilicum L. as an alternative management strategy for whitefly in tomatoes and to evaluate the use of these treatments ontomato growth and yield. Two trials were conducted at the Horticulture Research and Training Field, Egerton University, Njoro, Kenya. Treatments comprised a combination of two factors, (1 growing environment (agronet and no agronet and (2 companion planting with a row of basil surrounding tomato plants, a row of basil in between adjacent rows of tomato, no companion planting. Agronet covers and companion cropping with a row of basil planted between adjacent tomato rows significantly lowered B. tabaci infestation in tomatoes by 68.7%. Better tomato yields were also recorded in treatments where the two treatments were used in combination. Higher yield (13.75 t/ha was obtained from tomatoes grown under agronet cover with a basil row planted in between adjacent rows of the tomato crop compared to 5.9 t/ha in the control. Non-marketable yield was also lowered to5.9 t/ha compared to 9.8 t/ha in the control following the use of the two treatments in combination. The results of this study demonstrate the potential viability of using companion cropping and agronet

  18. Population Growth of Rhopalosiphum padi L. (Homoptera: Aphididae on Different Cereal Crops from the Semiarid Pampas of Argentina under Laboratory Conditions Crecimiento Poblacional de Rhopalosiphum padi L. (Homoptera: Aphididae sobre Diferentes Cereales de la Pampas Semiárida de Argentina en Condiciones de Laboratorio

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    Lilian R Descamps

    2011-09-01

    Full Text Available The bird cherry-oat aphid Rhopalosiphum padi L. (Homoptera: Aphididae is one of the main pests in a number of crops in the semiarid Pampas of Argentina. In the present study, the effect of different host plants, including Triticum aestivum L., ×Triticosecale Wittm., Hordeum vulgare L., Hordeum distichum L., Avena sativa L., and Secale cereale L. on biological parameters of R. padi L. was studied in the laboratory at 24 ± 1 °C, 65 ± 10% RH and a 14:10 photoperiod. Longevity, intrinsic rate of natural increase (r m, net reproductive rate (R0, mean generation time (T, doubling time (DT, and finite rate of increase (λ of the bird cherry-oat aphid on the different cereal crops were estimated. Differences in fertility life table parameters of R. padi among host plants were analyzed using pseudo-values, which were produced by Jackknife re-sampling. Results indicated that beer barley might be the most suitable food for R. padi due to greater adult longevity (20.88 d, higher fecundity (41 nymphs female-1, higher intrinsic rate of natural increase (0.309 females female-1 d-1, lower doubling time (2.24, and lower nymphal mortality (22.2%. Therefore, it can be concluded from the present study that R. padi prefers beer barley for fast and healthy development over other cereal crops.El áfido Rhopalosiphum padi L. (Homoptera: Aphididae es una de las principales plagas de numerosos cultivos de la región semiárida pampeana de Argentina. En el presente trabajo se estudió el efecto de diferentes cereales incluidos Triticum aestivum L., ×Triticosecale Wittm., Hordeum vulgare L., Hordeum distichum L., Avena sativa L. and Secale cereale L. sobre los parámetros biológicos de R. padi en laboratorio. Se estimaron longevidad, tasa intrínseca de crecimiento natural (r m, tasa neta de reproducción (R0, tiempo generacional medio (T, tiempo de duplicación (TD, y tasa finita de incremento (λ del pulgón de la avena en diferentes cereales. Las diferencias de

  19. Nuevos registros de especies del género Eretmocerus (Hymenoptera: Aphelinidae, parasitoides de Trialeurodes vaporariorum y el complejo Bemisia tabaci (Hemiptera: Aleyrodidae en Argentina New records of species of the genus Eretmocerus (Hymenoptera: Aphelinidae, parasitoids of Trialeurodes vaporariorum and Bemisia tabaci complex (Hemiptera: Aleyrodidae in Argentina

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    Silvia N. López

    2008-06-01

    Full Text Available El objetivo de este trabajo es dar a conocer nuevos registros y distribuciones de las especies del género Eretmocerus Haldeman, parasitoides de las dos especies de mosca blanca que tienen mayor importancia económica en cultivos hortícolas y ornamentales en Argentina. Una especie de Eretmocerus Haldeman fue hallada parasitando a Trialeurodes vaporariorum (Westwood en Santa Fe y Buenos Aires; por sus caracteres morfológicos, se encuentra en el grupo californicus, cercana a corni Haldeman, podría tratarse de una nueva especie. Asimismo, se amplía la distribución geográfica de Eretmocerus mundus Mercet, enemigo natural del complejo Bemisia tabaci (Gennadius, a las provincias de San Juan y Buenos Aires.The objective of this paper is to report new records of species of the genus Eretmocerus Haldeman, parasitoids of the most important whitefly pest species in vegetables and ornamental crops in Argentina. One species was found parasitizing Trialeurodes vaporariorum (Westwood in Santa Fe and Buenos Aires provinces and it is grouped into californicus group near corni Haldeman, due to its morphological characters. It could be a new species. The known distribution of Eretmocerus mundus Mercet, a parasitoid of Bemisia tabaci (Gennadius, is enlarged to include the provinces of San Juan and Buenos Aires of Argentina.

  20. New developments in insecticide resistance in the glasshouse whitefly (Trialeurodes vaporariorum) and the two-spotted spider mite (Tetranychus urticae) in the UK.

    Science.gov (United States)

    Gorman, Kevin; Hewitt, Fiona; Denholm, Ian; Devine, Gregor J

    2002-02-01

    A recent survey of insecticide resistance in two of the most problematic pests in UK glasshouses revealed some new developments. At least some individuals in all UK samples of Trialeurodes vaporariorum that were tested resisted the insect growth regulator (IGR) buprofezin. The most strongly resistant strains were unaffected by the field application rate of this compound, and even samples from populations that had never been exposed to buprofezin contained individuals that survived the highest concentration applied (10,000 mg litre-1). The field rate of buprofezin was shown to select for resistance through vapour action alone. The benzophenylurea teflubenzuron, an unrelated IGR, was cross-resisted by buprofezin-resistant individuals. There was no evidence of resistance to imidacloprid, but all T vaporariorum strains tested, regardless of origin, exhibited a high innate tolerance to nicotine, when compared with another whitefly species, Bemisia tabaci. Marked resistance to fenbutatin oxide and tebufenpyrad was found in single glasshouse populations of Tetranychus urticae, but these compounds and abamectin appeared to remain highly effective against all other strains collected.

  1. Novos acessos de tomateiro resistentes à mosca-branca biótipo B New accessions of tomato resistant to whitefly biotype B

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    Maria Elisa de Sena Fernandes

    2009-11-01

    Full Text Available O objetivo deste trabalho foi selecionar novas fontes de resistência a Bemisia tabaci biótipo B, entre 34 acessos de tomateiro (Lycopersicon esculentum, do Banco de Germoplasma de Hortaliças da UFV. Avaliaram-se os números de adultos, ovos e ninfas por planta, além da densidade de tricomas. Detectaram-se diferenças entre os acessos nas variáveis avaliadas. Os acessos BGH-166, BGH-616, BGH-850, BGH-990, BGH-2102 e BGH-2125 apresentaram menor número de adultos, ovos e ninfas por planta e tiveram menor densidade de tricomas. A resistência dos acessos de tomate à mosca-branca foi associada a uma menor densidade de tricomas.The objective of this work was to evaluate resistance to Bemisia tabaci biotype B in 34 tomato (Lycopersicon esculentum accessions from the Banco de Germoplasma de Hortaliças of UFV. The number of adults, eggs and nymphs per plant besides of trichome density were evaluated. Differences between accessions were found for the evaluated variables. Accessions BGH-166, BGH-616, BGH-850, BGH-990, BGH-2102 and BGH-2125 presented less infestation of adults, eggs and nymphs per plant and showed lower trichome density. The resistance of these tomato accessions to whitefly was associated to a lower trichome density.

  2. New experimental tools for bioassays with whitefly in laboratory Novas ferramentas experimentais para ensaios com mosca-branca em laboratório

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    Thiago Luis Martins Fanela

    2012-12-01

    Full Text Available The objective of this work was to develop an experimental kit for assessments of repellency, deterrence for oviposition, and insecticidal activity on adults of the whitefly Bemisia tabaci biotype B. The kit, which consisted of arenas and nebulizer, was effective for conducting bioassays, and the application of aqueous extracts by inhaler was adequate. The techniques are simple, cheap, and may contribute to research on this insect.O objetivo deste trabalho foi desenvolver um kit experimental para avaliações de repelência, deterrência à oviposição e atividade inseticida a adultos de mosca-branca, Bemisia tabaci biótipo B. O kit, constituído de arenas e nebulizador, foi eficaz para realização dos bioensaios, e a aplicação de extratos aquosos com o inalador foi adequada. As técnicas são simples, baratas e podem contribuir para as pesquisas com este inseto.

  3. Chemical composition of Clinopodium menthifolium aqueous extract and its influence on antioxidant system in black nightshade (Solanum nigrum and pepper (Capsicum annuum seedlings and mortality rate of whitefly (Trialeurodes vaporariorum adults

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    J. Šućur

    2017-11-01

    Full Text Available The use of allelochemicals as weed control agents is becoming widely investigated. However, the impact of these bioherbicides on cultivated plants is less known. This study was carried out in order to evaluate the allelopathic effects of the aqueous extract of Clinopodium menthifolium on black nightshade (Solanum nigrum antioxidant properties to explore the potential of this species in weed control and on pepper (Capsicum annuum antioxidant properties so as to assess its possible side effects when applied as bioherbicide in organic production. Taking into account that plant extracts should be an alternative source for insect control, additional aim was also to evaluate contact effect of C. menthifolium aqueous extract against the greenhouse whitefly (Trialeurodes vaporariorum. Analysis by HPLC confirmed the presence of gallic acid, caffeic acid and 2-hidroxy-cinnamic acid as major components in the C. menthifolium aqueous extract. Both tested concentrations of C. menthifolium aqueous extract induced lipid peroxidation in black nightshade leaves and roots. It was observed that the aqueous extract with a concentration of 0.1% showed a toxic effect with 50% mortality of greenhouse whitefly adults.

  4. Caracterización in silico de las proteínas del choque térmico Hsp70 y Hsp90 deBemisia tabaci (Hemiptera: Aleyrodidae y su posible actividad adaptativa

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    Eneida Torres Cabra

    2014-06-01

    Full Text Available La mosca blanca, Bemisia tabaci (Hemiptera: Aleyrodidae es una de las plagas más destructivas e invasivas en el mundo, ataca una gran cantidad de cultivos. Se adapta fácilmente a plantas hospederas y a nuevas regiones geográficas, lo que sugiere el desarrollo de mecanismos de control a daños producidos por factores estresantes. Las proteínas Hsp se expresanen los organismos como mecanismo de defensa, actúan como chaperonas en el correcto ensamblaje de las proteínas. En este estudio se realizó una caracterizaciónin silico de las proteínas Hsp70 y Hsp90 de B. tabaci, secuencias obtenidas de NCBI. La determinaciónde los perfiles de hidrofobicidad, polaridad, accesibilidady flexibilidad se obtuvieron con “ProScale” de ExPASy, el perfil de antigenicidad con JaMBW. La secuencia aminoacídica se analizó con GOR IV y SOPMA y la composición de aminoácidos con ProtParam. Para analizar el peso molecular, índice deinestabilidad, índice alifático y gradiente hidropático,con GRAVY. La estructura terciaria se obtuvo con HHpred, y ESyPred3D. Para validar las estructuras 3D se utilizó Procheck, What_check y errat. Hsp70 y Hsp90 de B. tabaci presentan valores bajos de hidrofobicidady altos de polaridad, flexibilidad y accesibilidad, características que le permiten a las proteínas extender su capacidad como chaperonas. La Hsp70tiene una estructura secundaria compuesta por 41-45% alfa hélices, 30-43% coil y menos del 6% en hoja plegada y la Hsp90 por 52 y 53% hélices, 26-34% coily 6% hoja plegada. Las Hsp juegan un rol importante en los insectos debido a su tamaño y corto ciclo de vida, pues la temperatura influye en su distribución y abundancia.

  5. Transmissão de begomovírus de plantas daninhas para tomateiros pela mosca-branca Begomovirus transmission from weeds to tomato by the whitefly

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    A.K.F. Silva

    2010-01-01

    affecting tomato plants (Lycopersicon esculentum. They are transmitted by the whitefly, Bemisia tabaci biotype B, and natural infections of those viruses have been reported in weeds, which can constitute important sources of the pathogen for the tomato. In Chapada da Ibiapaba-CE, the begomovirus has been found in numerous areas where tomatoes are cultivated causing serious damage to the production. The aim of this study was to investigate the transmission of begomovirus from infected tomatoes to weeds and from infected weeds to tomatoes. Healthy weed seedlings commonly found in tomato crops, such as Amaranthus spinosus, Amaranthus viridis, Ageratum conyzoides and Bidens pilosa, as well as healthy tomato seedlings were inoculated with the viruses by using the vector or grafting. After 15 days of inoculation, leaves of the weed and tomato plants were collected for DNA extraction. Using specific oligonucleotides for begomovirus in a PCR reaction, the presence of begomovirus could be detected in all four weed species tested when tomato was used as a source of inoculum and whiteflies were used as vector. By grafting, only B. pilosa showed to be infected by begomovirus in the PCR reaction. When the four weed species infected with begomovirus were used as inoculum for the tomato seedlings, the transmission was also detected by PCR. When the vector acquired the virus in A. conyzoides, A. spinosus, B. pilosa and A. viridis, the percentage of transmission to the tomato plants was 70, 50, 20 and 12.5%, respectively.The viral transmission through grafting from infected weeds to tomatoes only occurred when infected A. spinosus or B. pilosa were used as grafts. The investigated weeds demonstrated to be alternative hosts of the tomato begomovirus, and, under natural conditions and in the presence of the vector,they can be important begomovirus sources for the tomato plants.

  6. Controle de mosca-branca com extratos vegetais, em tomateiro cultivado em casa-de-vegetação Use of plant extracts on whitefly control in tomato grown in greenhouse

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    Edson LL Baldin

    2007-12-01

    Full Text Available Visando buscar métodos alternativos no controle da mosca-branca Bemisia tabaci (Gennadius biótipo B em tomateiro, foram realizados testes de atratividade e preferência para oviposição em casa-de-vegetação, utilizando-se quatorze extratos aquosos a 3% (peso/volume. Os extratos foram preparados com partes de Azadirachta indica, Trichilia pallida,Chenopodium ambrosioides,Piper nigrum,Melia azedarach,Ruta graveolens,Ricinus communis,Mentha pulegium,Tagetes erecta,Eucalyptus citriodora,Cymbopogon nardus e Coriandrum sativum. Numa segunda etapa, os extratos mais eficientes em casa-de-vegetação foram observados em laboratório, a fim de avaliar o possível efeito sistêmico dos mesmos sobre ninfas da mosca-branca. Constatou-se que as plantas de tomateiro pulverizadas com extratos à base de folhas de M. pulegium e folhas e sementes de A. indica foram menos atrativas aos adultos do inseto. Plantas pulverizadas com extratos de folhas de A. indica e folhas + ramos de R. communis mostraram efeitos deterrentes à oviposição do inseto, reduzindo o número de ovos; em contrapartida, o extrato à base de folhas de C. nardus estimulou a oviposição da mosca-branca sobre as plantas. O uso dos extratos por via sistêmica não afetou o período de desenvolvimento (ovo-adulto da mosca-branca; entretanto, a presença de extratos de sementes e folhas de A. indica e de folhas de M. pulegium provocou aumento significativo na mortalidade de ninfas de B. tabaci biótipo B.Looking for alternative methods of control to silverleaf whitefly Bemisia tabaci (Gennadius biotype B in tomato, attractiveness and oviposition preference tests were accomplished in greenhouse using fourteen aqueous extracts at 3% (weight/volume. The extracts were prepared with parts from Azadirachta indica,Trichilia pallida,Chenopodium ambrosioides,Piper nigrum,Melia azedarach,Ruta graveolens,Ricinus communis,Mentha pulegium,Tagetes erecta,Eucalyptus citriodora, Cymbopogon nardus and

  7. Aspectos biológicos de Chrysoperla externa (Hagen, 1861 (Neuroptera: Chrysopidae alimentada com Bemisia tabaci (Gennadius, 1889 biótipo B (Hemiptera: Aleyrodidae criada em três hospedeiros Biological aspects of Chrysoperla externa (Hagen, 1861 (Neuroptera: Chrysopidae fed on Bemisia tabaci (Gennadius, 1889 biotype B (Hemiptera: Aleyrodidae reared in three hosts

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    Cláudio Gonçalves Silva

    2004-04-01

    , and reared on leaves of cucumber (Cucumis sativus, kale (Brassica oleracea and wild poinsettia (Euphorbia heterophylla. Leaf discs from the hosts containing third and fourth stage nymphs of whitefly, were placed in Petri dishes containing 1% agar. One recently hatched larvae of C. externa was placed in each dish, until adult emergence. The weight after emergence,eoviposition, oviposition, effective oviposition and postoviposition periods, the total number of eggs per female and longevity were evaluated. The embryonic period and the survival rate of the eggs were also recorded by collecting weekly samples of 10% of the daily egg production, throughout the reproductive period. The weights of males and females did not differ in relation to the hosts, the average being 4.7 mg. In general, adults of C. externa, coming from larvae fed on B. tabaci biotype B nymphs reared on leaves of the host wild poinsettia, had their biological characters affected, in comparison with those on leaves of cucumber and kale. The oviposition period averaged 49.5 days for cucumber and kale, and 31.6 days for wild poinsettia. Egg laying capacity was reduced by 50% on wild poinsettia, its being 293.8 eggs. In cucumber and kale, the average was 591.3 eggs. Nymphs of B. tabaci biotype B reared on wild poinsettia caused increase of the embrionic period and a reduction of the survival rate of the eggs, its being 62.8% and 57.7% lower than that presented by the ones reared on cucumber and kale, respectively.

  8. Release of Hormones from Conjugates: Chloroplast Expression of β-Glucosidase Results in Elevated Phytohormone Levels Associated with Significant Increase in Biomass and Protection from Aphids or Whiteflies Conferred by Sucrose Esters1[C][OA

    Science.gov (United States)

    Jin, Shuangxia; Kanagaraj, Anderson; Verma, Dheeraj; Lange, Theo; Daniell, Henry

    2011-01-01

    Transplastomic tobacco (Nicotiana tabacum) plants expressing β-glucosidase (Bgl-1) show modified development. They flower 1 month earlier with an increase in biomass (1.9-fold), height (1.5-fold), and leaf area (1.6-fold) than untransformed plants. Trichome density on the upper and lower leaf surfaces of BGL-1 plants increase by 10- and 7-fold, respectively, harboring 5-fold more glandular trichomes (as determined by rhodamine B staining), suggesting that BGL-1 lines produce more sugar esters than control plants. Gibberellin (GA) levels were investigated because it is a known regulator of flowering time, plant height, and trichome development. Both GA1 and GA4 levels are 2-fold higher in BGL-1 leaves than in untransformed plants but do not increase in other organs. In addition, elevated levels of other plant hormones, including zeatin and indole-3-acetic acid, are observed in BGL-1 lines. Protoplasts from BGL-1 lines divide and form calli without exogenous hormones. Cell division in protoplasts is enhanced 7-fold in the presence of exogenously applied zeatin-O-glucoside conjugate, indicating the release of active hormones from their conjugates. Whitefly (Bemisia tabaci) and aphid (Myzus persicae) populations in control plants are 18 and 15 times higher than in transplastomic lines, respectively. Lethal dose to kill 50% of the test population values of 26.3 and 39.2 μg per whitefly and 23.1 and 35.2 μg per aphid for BGL-1 and untransformed control exudates, respectively, confirm the enhanced toxicity of transplastomic exudates. These data indicate that increase in sugar ester levels in BGL-1 lines might function as an effective biopesticide. This study provides a novel strategy for designing plants for enhanced biomass production and insect control by releasing plant hormones or sugar esters from their conjugates stored within their chloroplasts. PMID:21068365

  9. Release of hormones from conjugates: chloroplast expression of β-glucosidase results in elevated phytohormone levels associated with significant increase in biomass and protection from aphids or whiteflies conferred by sucrose esters.

    Science.gov (United States)

    Jin, Shuangxia; Kanagaraj, Anderson; Verma, Dheeraj; Lange, Theo; Daniell, Henry

    2011-01-01

    Transplastomic tobacco (Nicotiana tabacum) plants expressing β-glucosidase (Bgl-1) show modified development. They flower 1 month earlier with an increase in biomass (1.9-fold), height (1.5-fold), and leaf area (1.6-fold) than untransformed plants. Trichome density on the upper and lower leaf surfaces of BGL-1 plants increase by 10- and 7-fold, respectively, harboring 5-fold more glandular trichomes (as determined by rhodamine B staining), suggesting that BGL-1 lines produce more sugar esters than control plants. Gibberellin (GA) levels were investigated because it is a known regulator of flowering time, plant height, and trichome development. Both GA(1) and GA(4) levels are 2-fold higher in BGL-1 leaves than in untransformed plants but do not increase in other organs. In addition, elevated levels of other plant hormones, including zeatin and indole-3-acetic acid, are observed in BGL-1 lines. Protoplasts from BGL-1 lines divide and form calli without exogenous hormones. Cell division in protoplasts is enhanced 7-fold in the presence of exogenously applied zeatin-O-glucoside conjugate, indicating the release of active hormones from their conjugates. Whitefly (Bemisia tabaci) and aphid (Myzus persicae) populations in control plants are 18 and 15 times higher than in transplastomic lines, respectively. Lethal dose to kill 50% of the test population values of 26.3 and 39.2 μg per whitefly and 23.1 and 35.2 μg per aphid for BGL-1 and untransformed control exudates, respectively, confirm the enhanced toxicity of transplastomic exudates. These data indicate that increase in sugar ester levels in BGL-1 lines might function as an effective biopesticide. This study provides a novel strategy for designing plants for enhanced biomass production and insect control by releasing plant hormones or sugar esters from their conjugates stored within their chloroplasts.

  10. Acyrthosiphon pisum (Harris) (Homoptera: Aphididae) infestation ...

    African Journals Online (AJOL)

    Plant height, plant density per 0.25 m2, number of pea aphids and parasitoids per plant, ladybird beetles per plot, and finally grain yield per plot were recorded. Based on the results of the ANOVA, plant height was significantly different between treated and untreated plots especially after the vegetative stage. The density of ...

  11. The Salicylic Acid-Mediated Release of Plant Volatiles Affects the Host Choice of Bemisia tabaci

    Directory of Open Access Journals (Sweden)

    Xiaobin Shi

    2016-06-01

    Full Text Available The whitefly Bemisia tabaci (Gennadius (Hemiptera: Aleyrodidae causes serious crop losses worldwide by transmitting viruses. We have previously shown that salicylic acid (SA-related plant defenses directly affect whiteflies. In this study, we applied exogenous SA to tomato plants in order to investigate the interaction between SA-induced plant volatiles and nonviruliferous B. tabaci B and Q or B- and Q-carrying tomato yellow leaf curl virus (TYLCV. The results showed that exogenous SA caused plants to repel nonviruliferous whiteflies, but the effect was reduced when the SA concentration was low and when the whiteflies were viruliferous. Exogenous SA increased the number and quantity of plant volatiles—especially the quantity of methyl salicylate and δ-limonene. In Y-tube olfactometer assays, methyl salicylate and δ-limonene repelled the whiteflies, but the repellency was reduced for viruliferous Q. We suggest that the release of plant volatiles as mediated by SA affects the interaction between whiteflies, plants, and viruses. Further studies are needed to determine why viruliferous Q is less sensitive than nonviruliferous Q to repellent plant volatiles.

  12. Efeito de derivados de nim aplicados por pulverização sobre a mosca-branca em meloeiro Effects of neem derivatives sprayed on melon crop to control silverleaf whitefly

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    Ervino Bleicher

    2007-03-01

    Full Text Available A mosca-branca é uma das principais pragas do meloeiro na região Nordeste do Brasil. Estudou-se neste trabalho o efeito de extratos aquosos de folhas e de sementes de nim (Azadirachta indica A. Juss. e uma formulação à base de azadiractina comparados com o inseticida buprofezin, aplicados por pulverização, sobre ninfas da mosca-branca, Bemisia tabaci biotipo B, em melão cv. Torreon, sob condições de casa de vegetação. Três experimentos independentes foram realizados no delineamento inteiramente casualizado, com sete tratamentos e número variável de cinco a sete repetições. Cada planta constituiu uma unidade experimental. No primeiro experimento, os tratamentos foram: testemunha absoluta (água, Neemazal® (1,2% de azadiractina nas doses 12; 24; 48; 96 e 192 ppm de azadiractina. No segundo: testemunha absoluta (água, extrato de semente a 1; 2; 4; 8 e 16 g/100ml. No terceiro, o extrato de folhas foi aplicado nas mesmas proporções que o de sementes. Para cada experimento aplicou-se como testemunha positiva, o produto comercial Applaud® (buprofezin na dose de 1,5g. p.c./L, que corresponde a 0,375 g de ingrediente ativo(i.a/L de calda. A azadiractina foi eficiente em todas as doses causando redução de até 98% na média de ninfas vivas. Quando aplicado acima de 24 ppm, este composto apresentou desempenho semelhante ao inseticida padrão buprofezin. Os extratos de sementes a 1; 2; 4; 8 e 16g/100 ml reduziram significativamente a média de ninfas vivas, não diferindo da ação do inseticida padrão. Os extratos de folha não foram eficientes no controle de ninfas.Whitefly is one of the main pests of melon in the Northeast area of Brazil. In this research, the effect of leaf and seed aqueous extracts of the neem plant (Azadirachta indica A. Juss. and a formulation containing azadirachtin compared to buprofezin were studied as a spray application against nymphs of the silverleaf, Bemisia tabaci biotype B, whitefly in greenhouse

  13. Resposta à mosca-branca (Bemisia tabaci e ao Tomato severe rugose virus de acessos de Solanum subgênero Leptostemonum Reaction to whitefly (Bemisia tabaci and Tomato severe rugose virus of Solanum subgenus Leptostemonum accessions

    Directory of Open Access Journals (Sweden)

    Miguel Michereff-Filho

    2012-09-01

    ção. Desta forma, esses acessos do subgênero Leptostemonum podem ser considerados potenciais fontes de genes de resistência tanto para B. tabaci quanto para ToSRV. Essa diversidade genética pode ser transferida para outras espécies do gênero Solanum via técnicas de biologia celular e/ou isolamento e mobilização desses genes via transgenia. Os resultados também sugerem que, em condições naturais, espécies do subgênero Leptostemonum não representam importantes fontes de inóculo de ToSRV e/ou hospedeiras alternativas para B. tabaci.The whitefly (Bemisia tabaci and the infection by Begomovirus species are two major problems affecting yield and quality of the tomato (Solanum lycopersicum crop as well as other Solanaceae species of economic importance. The present work was conducted aiming to characterize the reaction of 36 accessions of the genus Solanum subgenus Leptostemonum (= spiny Solanum species and closely related species to Tomato severe rugose virus (ToSRV and B. tabaci. Seedlings of the accessions (43 days after sowing were exposed under greenhouse conditions to viruliferous whiteflies (B. tabaci biotype B carrying an isolate of ToSRV. Two susceptible tomato cultivars were used as susceptible controls. Reaction to the virus was evaluated using a symptom severity scale and the systemic ToSRV infection was evaluated via PCR with universal begomovirus primers. A group of accessions from S. stramonifolium, S. asperolanatum, and S. jamaiscense displayed mild symptoms and low virus accumulation. The accession S. mammosum 'CNPH 035', even though tolerant, was the only one displaying clear ToSRV symptoms and conspicuous systemic spread of the virus. The remaining accessions were found to be free of ToSRV symptoms and with no indication of systemic infection. This germplasm collection was also evaluated to B. tabaci in a free-choice assay under greenhouse conditions. Significant differences were observed for the number of eggs and number of 4th instar nymphs. A

  14. Alternative phytosanitary products to control of whitefly (Bemisia tuberculata (Matile-Ferrero, in cassavaProdutos fitossanitários alternativos no controle da mosca-branca (Bemisia tuberculata (Matile-Ferrero, na mandioca

    Directory of Open Access Journals (Sweden)

    Aline Monsani Miranda

    2012-08-01

    Full Text Available This study aimed to evaluate the efficiency of alternative phytossanitary products on the oviposition and mortality of nymphs and adults of whitefly (Bemisia tuberculata. It was evaluated the insecticidal action of commercial products Plant Clean®, Pironin®, Mattan Plus® and Calda fertilizante foliar® on third instar nymphs, by products direct spraying, being the mortality observed during 10 days. To evaluate the effects of these products in oviposition deterrence and adult mortality, the four upper leaves of 25 plants were treated with products and then were infested with 30 adults of B. tuberculata. The insects were kept in cages adapted to plant leaves and evaluation of the number of dead adults and eggs on the leaves was done 48h after the beginning of the study. Plant Clean® stood out on nymphs control (54% mortality and for adults, the best product was Pironin® (86.8%. All products caused deterrence in oviposition.Este estudo teve como objetivo avaliar a eficiência de produtos fitossanitários alternativos sobre a oviposição e mortalidade de ninfas e adultos da mosca-branca (Bemisia tuberculata. Foi avaliada a ação inseticida dos produtos comerciais Planta Clean®, Pironin®, Mattan Plus® e Calda fertilizante foliar®, sobre ninfas de terceiro ínstar, por meio da pulverização direta dos produtos, sendo observada a mortalidade durante 10 dias. Para avaliar os efeitos desses produtos na deterrência de oviposição e mortalidade de adultos, as quatro folhas apicais de 25 plantas receberam aplicação dos produtos e foram posteriormente infestadas com 30 adultos de B. tuberculata. Os insetos foram mantidos em gaiolas adaptadas às folhas da planta e a avaliação do número de adultos mortos e o número de ovos nas folhas foi realizada 48h após o início do experimento. Planta Clean® destacou-se no controle de ninfas (54% de mortalidade e para adultos, o melhor produto foi Pironin® (86,8%. Todos os produtos causaram deterr

  15. REARING TOMATO WHITEFLY AND FIELD EVALUATION OF ...

    African Journals Online (AJOL)

    ACSS

    2015-05-27

    May 27, 2015 ... important agricultural and ornamental crops in all agro-ecological regions in the world. This study evaluated the ... conidia: (a) modified conidia (conidia with improved ecological competence), and (b) unmodified conidia of the three isolates were subjected ..... control of cotton spider mites. There was a wide ...

  16. DIVERSITY AND DISTRIBUTION OF WHITEFLIES IN ...

    African Journals Online (AJOL)

    ACSS

    ecosystems and are valuable indicators of their health. Insects are extremely diverse and important to ecosystems ... essential economic benefits and services to human society - such ..... Bemisia tabaci on cotton and cucumber. Environmental.

  17. Avaliação de extratos vegetais no controle de mosca-branca, Bemisia tabaci biótipo B em abóbora Evaluation of plant extracts in the control of whitefly Bemisia tabaci biotype B in squash

    Directory of Open Access Journals (Sweden)

    Bruno Marcus Freire Vieira Lima

    2013-09-01

    Full Text Available A abóbora (Cucurbita moschata Duch. é uma cultura de importância para a agricultura familiar da região Nordeste do Brasil. No entanto, a ocorrência do prateamento das folhas da aboboreira ocasionado pela mosca-branca, Bemisia tabaci biótipo B limita sua produção, causando prejuízos aos agricultores. O objetivo deste trabalho foi avaliar a eficiência de extratos vegetais sobre o nível populacional de ninfas de mosca-branca em abóbora cv. Jacarezinho. O experimento foi instalado em campo experimental, em blocos casualizados, constituído de seis tratamentos e três repetições. As aplicações dos extratos vegetais foram feitas com intervalo de sete dias, fazendo-se uso de substâncias extraídas das seguintes plantas: canudo (Ipomoea carnea subsp. fistulosa, mamona (Ricinus communis L., tinguí (Mascagnia rigida Griseb, cardo-santo (Argemone mexicana L., e o óleo comercial Natuneem®. Todos os extratos vegetais obtiveram eficiência no controle de ninfas B. tabaci, sendo o R. communis (75,49%, M. rigida (73,99%, I. carnea (72,24%, óleo de nim (70,4% e A. mexicana (69,16%.The squash (Cucurbita moschata Duch. is an important crop for family farmers in the northeast of Brazil. However, the occurrence of leaf silvering caused by the whitefly, Bemisia tabaci biotype B, limits production, causing losses to farmers. The aim of this study was to evaluate the efficiency of plant extracts on the population levels of whitefly nymphs on the squash cv. Jacarezinho. The experiment was conducted at an experimental field, in a randomized block design consisting of six treatments and three replications. Applications of plant extracts were made at an interval of seven days, making use of substances extracted from the following plants: Ipomoea carnea subsp. Fistulosa, castor bean (Ricinus communis L., Tingui (Mascagnia rigida Griseb, cardo-santo (Argemone mexicana L., and the commercial oil product Natuneem ®. All of the plant extracts were

  18. (Neuroptera: Chrysopidae fed with Aleurocanthus woglumi (Hemiptera: Aleyrodidae

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    Robério de Oliveira

    2016-02-01

    Full Text Available This study evaluated the development and reproduction of Ceraeochrysa cubana when fed the citrus blackfly Aleurocanthus woglumi. The study was carried out at the Laboratory of Entomology, Department of Plant and Environmental Sciences, Federal University of Paraíba – Areia/PB. It used a completely randomized design. The study was conducted in climate chambers, regulated to 26 ± 2°C and a relative humidity of 70 ± 10% with a 12 h photoperiod. The treatments were as follows: eggs, nymphs of only the 1st, 2nd, 3rd, or 4th instars, and nymphs of multiple instars (1st, 2nd, 3rd, and 4th instars of A. woglumi, with eggs of Sitotroga cerealella as a control. The 1st instar of C. cubana lasted 5.8 to 10.7 days, the 2nd instar lasted 6.0 to 13.3 days, and the 3rd instar lasted 8.2 to 18.5 days. The larvae of C. cubana did not survive when the food provided was only the eggs of A. woglumi, since the predator could not eat them. C. cubana, when provided nymphs of multiple instars (1st, 2nd, 3rd, and 4th instars of the citrus blackfly, had a shorter pre-pupal period and lower longevity than when consuming the eggs of S. cerealella, but the sex ratio and oviposition period were not affected. However, changes occurred in the pre-oviposition period, the total number of eggs, and the number of viable eggs.

  19. Calling songs of some South African cicadas (Homoptera: Cicadidae)

    African Journals Online (AJOL)

    1987-07-13

    Jul 13, 1987 ... Figure 11 Posture of male cicadas during calling song, illustrated by a specimen ... parameters of the smaller samples falls within that of the largest conspecific ... under the control of the neuromuscular system (Pringle. 1954b).

  20. Comparative cytogenetics of Auchenorrhyncha (Hemiptera, Homoptera): a review

    Science.gov (United States)

    Kuznetsova, Valentina; Aguin-Pombo, Dora

    2015-01-01

    Abstract A comprehensive review of cytogenetic features is provided for the large hemipteran suborder Auchenorrhyncha, which currently contains approximately 42,000 valid species. This review is based on the analysis of 819 species, 483 genera, and 31 families representing all presently recognized Auchenorrhyncha superfamilies, e.i. Cicadoidea (cicadas), Cercopoidea (spittle bugs), Membracoidea (leafhoppers and treehoppers), Myerslopioidea (ground-dwelling leafhoppers), and Fulgoroidea (planthoppers). History and present status of chromosome studies are described, as well as the structure of chromosomes, chromosome counts, trends and mechanisms of evolution of karyotypes and sex determining systems, their variation at different taxonomic levels and most characteristic (modal) states, occurrence of parthenogenesis, polyploidy, B-chromosomes and chromosome rearrangements, and methods used for cytogenetic analysis of Auchenorrhyncha. PMID:26807037

  1. Distributional patterns and possible origin of leafhoppers (Homoptera, Cicadellidae

    Directory of Open Access Journals (Sweden)

    Mervin W. Nielson

    2000-03-01

    Full Text Available The zoogeographical distribution of 42 cicadellid subfamilies and their assigned tribes and genera is compiled with distributional maps and proposed dispersal pathways of genera that are shared interzoogeographically. Possible origin of the subfamilies and tribes is proposed in an ancestral context from which the more modern extant groups evolved whereas origin of genera is in a more modern context. Notwithstanding their complex biogeography, the distributional data of the higher groups indicate that all of the cosmopolitan and near cosmopolitan subfamilies arose during early Cretaceous or possibly the late Jurassic period (140-116 m.y.a. when continental drift was in its early stages. Nearly all of the New World and some Old World subfamilies are considered of more recent origin (late Cretaceous-Tertiary. Ninety percent of the known genera (2,126 are endemic to their respective zoogeographical region and subregion, thus indicating relatively high host specificity and low rate of dispersal. The majority (76% of known extant genera are pantropical in origin, suggesting early or possible Gondwanaland origin of their ancestors. Dispersal pathways of genera shared by more than one zoogeographical region were generally south to north (Neotropical/Nearctic, Oriental/Palaearctic or west to east (Palaearctic/Nearctic, Oriental/Australian, from regions of high diversity to regions of low diversity and from warmer climates to cooler climates. The most diverse and richest leafhopper fauna are present in the Neotropical and Ethiopian regions although taxal affinities between them are poorest. The most depauperate fauna are in the Nearctic region and in Australia, reflecting the impact of isolating and ecological factors on distribution and radiation. Ecological barriers were more evident between the Ethiopian and Oriental fauna than between any other zoogeographical combination. Taxal affinities appeared to be correlated with close continental proximities. Vicariance (physical was the principal event that appealed to explain the distribution of many subfamilies and tribes whereas dispersal accounted for distribution of the majority of interzoogeographical genera.

  2. Particle film affects black pecan aphid (Homoptera: Aphididae) on pecan.

    Science.gov (United States)

    Cottrell, Ted E; Wood, Bruce W; Reilly, Charles C

    2002-08-01

    Three species of aphids attack pecan foliage, Carya illinoensis (Wang.) K. Koch, and cause economic damage. We tested a kaolin-based particle film against one of these aphid species, black pecan aphid, Melanocallis caryaefoliae (Davis). Effect of particle film on host selection, adult mortality, and production of nymphs by M. caryaefoliae was tested on seedling pecans in the laboratory. Fewer M. caryaefoliae adults selected treated foliage compared with untreated foliage. A higher percentage of adults that did select treated foliage were recovered from upper leaf surfaces compared with the percentage of adults recovered from upper leaf surfaces of untreated leaves. Observations with a microscope revealed an accumulation of particle film on aphid body parts, especially on tarsi, and strongly suggests that aphid mobility was restricted. Adult mortality was higher on treated foliage and led to an overall decrease in production of nymphs on those seedlings. In addition, we measured spectral properties of treated seedling pecan foliage. Light reflectance by treated foliage was increased and absorptance decreased compared with control foliage whereas transmittance of light through control and particle film-treated leaves was similar. We did not detect any phytotoxic effect on pecan due to application of particle film.

  3. A synopsis of the tribe Micrutalini Haupt (Homoptera, Membracidae, Smiliinae

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    Albino M. Sakakibara

    1999-01-01

    Full Text Available The tribe Micrutalini and its two genera, Trachytalis Fowler and Micrutalis Fowler, are redescribed. The following species are treated and, in some cases, nomenclatura! changes introduced: Trachytalis isabellina Fowler, 1895; T. distinguenda Fowler, 1895; T. retrofasciata (Lethierry, 1890, comb.n.; Micrutalis alrovena Goding, 1930; M. balteata (Fairmaire, 1846 = Aculalis lucidus Buckton, 1902, syn.n.; M. bella Goding, 1929; M. biguttula (Fairmaire, 1846, comb.n.; M. binaria (Fairmaire, 1846 = Acutalis flavivenlris Lethierry, 1890, syn.n.; M. callan-gensis Goding, 1930; M. calva (Say, 1830; M. discalis (Walker, 1858; M. dorsalis (Fitch, 1851; M. dubia Fowler, 1895 = M. zeteki Goding, 1928, syn.n.; M. flava Goding, 1929; M. flavozonala (Fairmaire, 1846, comb.n. = Acutalis geniculata Stál, 1862, syn.n. = Acutalis modesta Stál, 1862, syn.n.; M. godfreyi Sakakibara, 1976; M. incerla Sakakibara, 1976; M. lata Goding, 1930; M. litlerala (Fairmaire, 1846, comb.n.;M lugubrina(Stál, 1862;M malleiferaFovj]er, 1895 = M binariamutabilis Fowler, 1895, syn.n.; M. minutus Buckton, 1902; M. nigrolineata (Stál, 1864; M. nigromarginata Funkhouser, 1940; M. notalipennis Fowler, 1895; M. occidentalis (Goding, 1893; M. pollens Fowler, 1895; M. parva (Goding, 1893; M. plagíala (Stál, l&62 = AcutalisvariabiIisBerg, 1879,syn.n. =M. chapadensisGoding, 1930,syn.n.; M. punctifera (Walker, 1858; M. semialba (Stál, 1862; M. stipulipennis Buckton, 1902; M. tau Goding, 1930; M. trifurcala Goding, 1893; M. tripunctata (Fairmaire, 1846 = Acutalis moesta Stál, 1859, syn.n. = M. tartaredoides Goding, 1930, syn.n.. New species: Micrutalis diminuta sp.n. (Ecuador, Pichincha; Micrutalis divisa sp.n. (Brazil, Mato Grosso; Micrutalis henki sp.n. (Panama, Canal Zone; Micrutalis infúscala sp.n. (Venezuela, Portuguesa; Micrutalis margínala sp.n. (Brazil, Mato Grosso; Micrutalis meridana sp.n. (Venezuela, Mérida; Micrutalis mucuya sp.n. (Venezuela, Mérida; Micrutalis robustula sp.n. (Venezuela, Caracas; M. seminigra sp.n. (Brazil, Paraná; Micrutalis turriba sp.n. (Costa Rica, Turrialba. Lectotypes are designated for: Acutalis balteata Fairmaire, 1846, Aculalis binaria Fairmaire, 1846, Acutalis flavozonala Fairmaire, 1846, una Acutalis tripunctata Fairmaire, 1846. New taxonomic position: Micrutalis melanogramma (Petty, 1833 is transferred to Melu-sinella Metcalf, 1952 (Ceresini - Melusinella melanogramma (Petty, 1833, comb.n. = Melusinella nervosa (Fairmaire, 1846, syn.n.. Species incertae sedis: Tragopa ephippium Burmeister, 1836.

  4. Appearance of Neotoxoptera formosana (Homoptera: Aphididae) in The Netherlands

    NARCIS (Netherlands)

    Piron, P.G.M.

    2010-01-01

    Neotoxoptera formosana (Takahashi) is a pest of wild and cultivated Allium species, but never iwht disastrous consequences. In 1984, N. formosana was found in France. This was the first finding in Europe. Since then, N. formosana has been observed also in other European countries. The first record

  5. Aspects of the ecology of spittlebugs (Homoptera: Cercopidae) in ...

    African Journals Online (AJOL)

    Species type and pattern of distribution of spittlebugs was studied from 6th March to 15th December 2009 within the University of Nigeria, Nsukka campus. Three spittlebug species namely, Deois flavopicta, Aphrophora saratogensis and Philaenus spumarius were identified within the University campus. Whereas A.

  6. Eficiência de Azadiractina no controle de mosca-branca em meloeiro sob condições de casa de vegetação e de campo Efficiency of Azadirachtin against whitefly in melon crop in greenhouse and field conditions

    Directory of Open Access Journals (Sweden)

    Leonardo D. da Silva

    2003-06-01

    Full Text Available O melão é um dos principais produtos agrícolas de exportação do nordeste brasileiro, sendo, atualmente, sua produção gravemente afetada pela mosca-branca (Bemisia argentifolii, que por sua vez só é controlada por inseticidas convencionais. Estudou-se a potencialidade de um inseticida formulado à base de Azadiractina a 1% para o controle desta praga em meloeiro sob condições de casa de vegetação e de campo. O delineamento experimental utilizado foi de blocos ao acaso, com seis tratamentos e quatro repetições. Avaliou-se a média de ninfas no ensaio de casa de vegetação e a média de adultos e de ninfas no campo. Obteve-se uma resposta progressiva de controle de ninfas em casa de vegetação. No campo, os melhores resultados foram obtidos com do uso de Azadiractina, a 4 e 8 ml/L de calda, com eficiência de 67,83 e 70,13%, respectivamente, para controle de adultos, e Azadiractina a 8,0 ml/L, com eficiência de 88,10% e Azadiractina + Permethrin, cuja eficência foi de 85,71%, para controle de ninfas.Melons are of great importance for exportation by the Brazilian northeast region, actually being threatened by the whitefly pest, which is only controlled by the use of the conventional chemical insecticides actually used in the crop. In this study a potential botanical insecticide containing 1% Azadirachtin was evaluated against Bemisia argentifolii on melon, under greenhouse and field conditions. A randomized complete block design was used in both cases, with four replicates. Evaluating nymphs in greenhouse and nymphs and adults in field, we observed an increase in mortality by increasing dosages. In field, efficiency was 67.83 and 70.13% for adults and 80.36 and 88.10% for nymphs using 4.0 and 8.0 ml/L of the commercial Azadirachtin formulation, respectively.

  7. New cost-effective bioconversion process of palm kernel cake into bioinsecticides based on Beauveria bassiana and Isaria javanica.

    Science.gov (United States)

    do Nascimento Silva, Jaqueline; Mascarin, Gabriel Moura; Dos Santos Gomes, Isabel Cristina; Tinôco, Ricardo Salles; Quintela, Eliane Dias; Dos Reis Castilho, Leda; Freire, Denise Maria Guimarães

    2018-03-01

    The present study aimed to add value to palm oil by-products as substrates to efficiently produce conidia of Beauveria bassiana and Isaria javanica (Hypocreales: Cordycipitaceae) for biological control of the whitefly Bemisia tabaci (Hemiptera: Aleyrodidae), through a solid-state fermentation process using palm kernel cake and palm fiber as nutrient source and solid matrix, respectively. The optimum culture conditions yielded high concentrations of viable conidia after air-drying, when the fungi were grown on palm kernel cake (B. bassiana 7.65 × 10 9 and I. javanica 2.91 × 10 9  conidia g -1 dry substrate) after 6 days under optimal growth conditions set to 60% substrate moisture and 32 °C. Both fungal strains exhibited high efficacy against third-instar whitefly nymphs, inducing mortality up to 62.9 and 56.6% by B. bassiana and I. javanica, respectively, assessed after 9 days post-application in a screenhouse. Furthermore, we noted that insect mortality was strongly correlated with high atmospheric moisture, while B. bassiana appeared to require shorter accumulative hours under high moisture to kill whitefly nymphs compared to I. javanica. Our results underpin a feasible and cost-effective mass production method for aerial conidia, using palm kernel as the main substrate in order to produce efficacious fungal bioinsecticides against an invasive whitefly species in Brazil. Finally, our fermentation process may offer a sustainable and cost-effective means to produce eco-friendly mycoinsecticides, using an abundant agro-industrial by-product from Brazil that will ultimately assist in the integrated management of agricultural insect pests.

  8. Resposta de fêmeas de Encarsia formosa Gahan (Hymenoptera: Aphelinidae aos odores do hospedeiro e da planta-hospedeira em olfatômetro de quatro vias Response of female Encarsia formosa Gahan (Hymenoptera: Aphelinidae to host and plant-host odors

    Directory of Open Access Journals (Sweden)

    Kátia Maria Medeiros de Siqueira

    2003-01-01

    Full Text Available A crescente importância da mosca-branca Bemisia tabaci raça B (Hemiptera: Aleyrodidae como praga agrícola tem incentivado a busca de inimigos naturais que possam ser utilizados em programas de controle biológico. Estudou-se a atração de fêmeas de Encarsia formosa (Hymenoptera: Aphelinidae aos odores emanados pelo seu hospedeiro - a mosca-branca B. tabaci raça B - em plantas de tomate, em olfatômetro de quatro vias. O parasitóide não apresentou atração aos odores da planta de tomate nem ao complexo planta de tomate-ninfas de B. tabaci.The increasing importance of the whitefly Bemisia tabaci race B (Hemiptera: Aleyrodidae as one of the major agricultural pest of this century, has resulted in a search for natural enemies that can be used in biological control programs. The response of naive females of Encarsia formosa (Hymenoptera: Aphelinidaeto volatiles from its hostspecies: insect (B. tabacci race B and plant (Lycopersicom esculentum Mill. were tested using 4-nose olfactometre. Parasitoid was not attracted by neither or insect hostspecies volatile.

  9. Host plant selection and oviposition behaviour of whitefly Bemisia ...

    African Journals Online (AJOL)

    user

    2010-11-19

    Nov 19, 2010 ... habitat at 34 - 36°C, 70 - 80% relative humidity (RH) in a normal day light. ... higher on S. malagna L. leaves as compare to other two host plants ... 1468 Afr. J. Biotechnol. ... each species were arranged in the demarcated plot shape covered ... ficant Difference (LSD) test (Steel and Tori, 1980) and was run.

  10. Relative abundance of sweetpotato whitefly in orange-fleshed ...

    African Journals Online (AJOL)

    ACSS

    effect on sweetpotato yield in Peru. Plant Diseases 87: 297-302. Karyeija, R.F., Gibson, R.W. and. Valkonen, J.P.T. 1998. The significance of sweetpotato feathery mottle virus in subsistence sweetpotato production in Africa. Plant Diseases. 82:4-15. Legg, J.P. 1996. Host-associated strains within Ugandan populations of the.

  11. Whitefly and aphid inducible promoters of Arabidopsis thaliana L.

    Indian Academy of Sciences (India)

    NEERAJ KUMAR DUBEY

    2018-02-16

    Feb 16, 2018 ... binary expression vector to validate the inducible behaviour of these promoters in eight independent transgenic Nicotiana ..... a 50-fold induction of the W250 gene was observed in ..... indicate the involvement of ABA and ACC cross-talk in ... Hosokawa C. D. and Shinozaki K. 1997 Role of arabidopsis.

  12. Status of cassava mosaic disease and whitefly population in Zambia

    African Journals Online (AJOL)

    User

    2015-08-19

    Aug 19, 2015 ... replication [AC1 (Rep), and AC3 (Ren)], regulation of gene expression ... Africa Development Community (SADC) countries such .... PCR amplification of coat protein of ACMV (774 bp) and EACMV (556 bp) from cassava samples using specific primers ... be recycling of seed by the farmers and as a result of.

  13. Bemisia tabaci : the whitefly vector of cassava mosaic geminiviruses ...

    African Journals Online (AJOL)

    Significant gaps in our understanding of this system remain, particularly concerning the importance of interactions of B. tabaci with other arthropod pests of cassava and the influence of ecological factors such as soil nutrients indirectly through their effects upon cassava. An holistic ecological approach to future work on B.

  14. Bemisia tabaci : the whitefly vector of cassava mosaic geminiviruses ...

    African Journals Online (AJOL)

    The ecology of the Bemisia tabaci/cassava/African cassava mosaic virus (ACMV) pathosystem is reviewed briefly with special attention given to the parameters affecting the pattern of population development of B. tabaci. Significant gaps in our understanding of this system remain, particularly concerning the importance of ...

  15. Biochemical factors associated with cassava resistance to whitefly

    African Journals Online (AJOL)

    ACSS

    2017-08-17

    Aug 17, 2017 ... interactions having been suggested to be ... (Achidi et al., 2008); free sugars, protein and ... would elucidate the contribution of these ...... mays. Journal of Molecular Plant-Microbe .... Population dynamics of Bemisia tabaci and.

  16. RNA Interference Based Approach to Down Regulate Osmoregulators of Whitefly (Bemisia tabaci): Potential Technology for the Control of Whitefly

    Science.gov (United States)

    Over the past decade RNA interference (RNAi) technology has emerged as a successful tool not only for functional genomics, but in planta expression of short interfering RNAs (siRNAs) could offer potential for insect pest management. Insects feeding exclusively on plant sap depend on osmotic pressure...

  17. Side effects of some pesticides on the silverleaf whitefly’s parasitoid, Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae under laboratory conditions

    Directory of Open Access Journals (Sweden)

    Mustafa PORTAKALDALI

    2015-12-01

    Full Text Available The silverleaf whitefly, Bemisia tabaci (Gennadius (Hemiptera: Aleyrodidae is one of major pests in greenhouses vegetable cultivation. Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae has an important role among effective parasitoids used in biological control of the silverleaf whitefly. Nondestructive or less destructive pesticides against this parasitoid should be preferred in the scope of biological control. For this goal, side effects of 8 plant protection products, including spinosad, pyriproxyfen, abamectin, emamectin benzoate, copper oxychloride, kresoxim-methyl+boscalid, dimethoate and propineb+cymoxanil on pupae and adults of E. mundus were tested in this laboratory study conducted according to IOBC standards. As a result, pesticides containing spinosad, abamectin and dimethoate were determined as highly destructive to pupae and adults of E. mundus, and pesticide containing emamectin benzoate was found as moderately harmful. As for propineb+cymoxanil, pyriproxyfen, kresoxim-methyl+boscalid and copper oxychloride, they were determined as ineffective on the parasitoid under laboratory conditions. These results obtained from experiments that were conducted under laboratory conditions also have to be supported by field or semi-field experiment’s results.

  18. Biological control of fruit flies (Diptera: Tephritidae) through parasitoid augmentative releases: Current status

    International Nuclear Information System (INIS)

    Montoya, Pablo; Liedo, Pablo

    2000-01-01

    Fruit flies are among the main pests affecting the world fruit industry (Aluja 1993). Bait sprays have traditionally been used successfully to control them; however, the side effects on the environment and health hazards commonly associated with pesticides, have resulted in strong public opposition to the use of bait sprays. This is particularly so when sprays are applied in urban areas or in coffee plantations where, although Medflies are present, they do not pose a danger to crops. Alternative methods that are effective and environmental friendly to suppress fruit fly populations are highly desirable. Biological control, the use of natural enemies to suppress pest populations, represents such an alternative. Some of the most successful cases of biological control are the control of Iceria purchasi Maskell (Homoptera: Margarodidae) by Rodolia cardinalis Mulsant (Coleoptera: Coccinellidae) in California (De Bach 1968, van den Bosch et al. 1982), and the control of Aleurocanthus woglumi Ashby (Homoptera: Aleyrodidae) mainly by Encarsia (=Prospaltella) opulenta Silv. (Hymenoptera: Aphelinidae) in Mexico (Jimenez 1961, 1971), both using the classical approach. However, this approach has been limited to certain conditions of environmental stability and biodiversity which are only found in a few ecosystems. Other factors, such as types of pests, the economic threshold and product quality requirements represent additional limitations. The best option in many cases could be augmentative biological control, which could overcome some of the deficiencies of the classical approach (Sivinski 1996). According to Knipling (1992) and Barclay (1987), augmentative biological control can be considered as a formal alternative for suppressing pest populations and even for use in eradication programmes, after integration with the sterile insect technique (SIT). In this approach, mass production of natural enemies is required and this production has to be cost effective

  19. Use of biorational for the vegetable pest control in the north of Sinaloa

    Directory of Open Access Journals (Sweden)

    María Berenice González Maldonado

    2012-09-01

    Full Text Available In Sinaloa the vegetable and cucurbits production are important agricultural activities, so each year a high volume of chemicalinsecticides are applied to pest control that attack these crops. This paper present the main pests insects in the region, as wellas an analysis about effects of biorational insecticides on these pests. Was found that for control of Bemisia argentifolii Bellows & Perring (Hemiptera: Aleyrodidae is used Neem oil 0.2%., for kill nymphs of Bactericera cockerelli Sulc. (Homoptera: Psyllidae soursop Annona muricata L. (Annonales: Annonaceae at doses of 2500-5000 mg/L., for Liriomyza trifolii Burgess (Diptera: Agromyzidae neem seeds 2%., to Myzus persicae Sulzer (Hemiptera: Aphididae rapeseed oil at doses 920 g/L (2% v/v., to Frankliniella occidentalis Pergande (Thysanoptera: Thripidae spinosad (Conserve® 48-60 mg/L., and for Phthorimaea operculella Zeller (Lepidoptera: Gelechiidae granular viruses (105 OBs/mL combined with neem (DalNeem TM emulsifiable oil and NeemAzal TM -T/S at doses of 8 mg/L, everyone. The use of these products and the dose depends on the type of pest and crop. In general these products cause insect mortality greater than 95%, besides having low toxicity on natural enemies, so that these can be used individually or in combination in integrated pest control schemes against vegetable pests, and also for disease vectors insects in the northern of Sinaloa.

  20. Original Article. An evaluation of some eco-friendly biopesticides against Bemisia tabaci on two greenhouse tomato varieties in Egypt

    Directory of Open Access Journals (Sweden)

    Abdel-Razek Atef S.

    2016-08-01

    Full Text Available This study has two main approaches. First, it exploits the susceptibility of tomato cultivars as a prophylactic measure to detect auto resistance characters of the tested tomato varieties against Bemisia tabaci (Gennadius (Homoptera: Aleyrodidae. Secondly, it evaluates the efficacy of different bio-rational insecticides against B. tabaci under greenhouse conditions. The results exhibited a special significance in B. tabaci infestation suitability between the two tomato varieties with a high infestation significance found in the Shifa F1 hybrid tomato variety compared to the Savera F1 hybrid tomato variety in the first plantation period. Subsequently, in the second plantation period, there was a significant difference between the two tomato varieties. Bemisia tabaci showed a preference for the Shifa F1 hybrid over the Savera F1 hybrid tomato variety. These differences occurred during the 1st, 2nd, 4th, 6th, 7th, 8th, and 10th weeks. In the experimental trial for the efficacy of eco-friendly biorational insecticides, spinosad, azadirachtin, Beauveria bassiana and Metarhizium anisopliae, there were significant differences between the treated and untreated plants during the two plantation periods. A high efficacy of spinosad on the B. tabaci population was found. Bemisia tabaci infestation under all the applications was reduced from 50 to 94.61% for the two plantation periods. This obvious decrease in B. tabaci population increase attention to benefits of the different bio-rational insecticides.

  1. Biology of the citrus blackfly, Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae), in three host plants

    International Nuclear Information System (INIS)

    Pena, Marcia R.; Silva, Neliton M. da

    2009-01-01

    The citrus blackfly, Aleurocanthus woglumi Ashby, was detected in Brazil in 2001. The aim of this research was to evaluate the biology, biometry and host preference of A. woglumi in sweet orange, acid lime Tahiti and mango. Experiments were set in laboratory conditions with insects collected in rangpur lime plants in Manaus, State of Amazonas, from January to June of 2006. The following parameters were evaluated: number of spirals (ovo positions) and eggs per plant, number of eggs by spiral per plant, survival of the immature (eggs, 1st, 2nd, 3rd and 4th instars), and length and survival of the immature stage. The mean embrionary period was 15 days for the three hosts. The 4th nymph (puparium) was the longest during nymph development. Second and third instars had the highest survival. The mean length of the egg-adult cycle was 70 days for the three hosts evaluated. The eggs were laid in a spiral shape on the adaxial leaf surface. The 1st instars moved to short distances from the spiral, while the 2nd, 3rd and 4th are sessile and have bristles on the whole body. Based on the highest oviposition and the highest survival of the immature stage of the citrus blackfly in acid lime Tahiti, this plant can be considered the most suitable host to A. woglumi. (author)

  2. Quantifying conservation biological control for management of Bemisia tabaci (Hemiptera: Aleyrodidae) in cotton

    Science.gov (United States)

    Conservation biological control can be an effective tactic for minimizing insect-induced damage to agricultural production. The most effective manner of applying CBC is through an Integrated Pest Management (IPM) strategy, combining many tactics including cultural controls, pest sampling, the use of...

  3. [Occurrence of Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae) in the state of Maranhão, Brazil].

    Science.gov (United States)

    de Lemos, Raimunda N S; da Silva, Gilson S; Araújo, José R G; Das Chagas, Evandro F; Moreira, Aldenise A; Soares, Ana T M

    2006-01-01

    Aleurocanthus woglumi Ashby in citrus and mango crops in the state of Maranhão, Brazil, is recorded. Samples of 2003 and 2004 from several counties were identified and deposited in the Insect Collection of the Laboratório de Entomologia of the Núcleo de Biotecnologia Agronômica, Universidade Estadual do Maranhão.

  4. Preferência de Bemisia tabaci biótipo B em linhagens mutantes de algodoeiro Bemisia tabaci biotype B preference in mutant cotton lines

    Directory of Open Access Journals (Sweden)

    Francisco das Chagas Vidal Neto

    2008-02-01

    Full Text Available Os efeitos de caracteres mutantes morfológicos do algodoeiro (Gossypium hirsutum L. r. latifolium Hutch.: folha okra, bráctea frego e planta vermelha, em relação à resistência à mosca-branca (Bemisia tabaci biótipo B Hemiptera: Aleyrodidae, foram avaliados em experimentos com ou sem chance de escolha. Os experimentos foram conduzidos em casa-de-vegetação, no delineamento de blocos ao acaso, em fatorial 23 + 1, com quatro repetições. O mutante com a característica planta vermelha foi menos atrativo e menos preferido para oviposição, em relação à planta verde, em ambos os ensaios, com ou sem escolha. Não houve preferência quanto à forma da folha e ao tipo de bráctea.The effects of cotton lines (Gossypium hirsutum L. r. latifolium Hutch. with mutants morphologic characteristics: okra leaf, frego bract and red plant in relation to host plant resistance to whitefly (Bemisia tabaci bioyipe B Hemiptera: Aleyrodidae, were evaluated in choice or no choice assays. The assays were carried out in the greenhouse conditions, according to a completely randomized block design, in a 23 + 1 in a factorial arrangement with four replications. The mutant with red plant characteristic was less attractive and less preferred for oviposition than the normal green plant does, in both, whit or without choice tests. It did not have preference in relation to the form of the leaf and bract type.

  5. Annual Fire, Mowing and Fertilization Effects on Two Cicada Species (Homoptera: Cicadidae) in Tallgrass Prairie

    Science.gov (United States)

    Mac A. Callaham; Matt R. Whiles; John M. Blair

    2002-01-01

    In tallgrass prairie, cicadas emerge annually, are abundant and their emergence can be an important flux of energy and nutrients. However, factors influencing the distribution and abundance of these cicadas are virtually unknown. We examined cicada emergence in plots from a long-term (13 y) experimental manipulation involving common tallgrass prairie management...

  6. Responses of Russian Wheat Aphid (Homoptera: Aphididae) to Aphid Alarm Pheromone

    OpenAIRE

    Shah, P. A.; Pickett, J. A.; Vandenberg, J. D.

    2017-01-01

    In a series of laboratory tests, Russian wheat aphids, Diuraphis noxia (Mordvilko), responded to synthetic aphid alarm pheromone, (E)-β-farnesene, by removing stylets and leaving feeding sites or by crawling out of test arenas. Late instars and adults were more responsive than early instars. In dose-response assays, EC50 estimates ranged from 0.94 to 8.95 mg/ml among 3 experiments. In arenas, D. noxia also responded to the proximity of cornicle-damaged nymphs of either the green peach aphid, ...

  7. The tribe Acutalini Fowler (Homoptera, Membracidae, Smiliinae: new genera, new species and some nomenclatural changes

    Directory of Open Access Journals (Sweden)

    Albino M Sakakibara

    1997-09-01

    Full Text Available The tribe Acutalini Fowler is redescribed as well as the genera Acutalis Fairmaire, Euritea Stål, and Thrasymedes Kirkaldy. The following new taxa and nomenclatural changes are presented: Thrasymedes mexicana sp.n. (from Mexico, Oaxaca; Bordonia gen.n., with B. venezuelana sp.n. (type-species (from Venezuela, Portachuelo, B. clypeata sp.n. (from Colombia, Cuesta Boba, B. majuscula sp.n. (from Venezuela, Portachuelo, and Cornutalis gen.n., with C. cauca sp.n. (type-species (from Colombia, Cauca, and C. validu sp.n. (from Ecuador, Sto. Domingo. Acutalis fusconervosa Fairmaire, 1846 = Horiola venosa Walker, 1858, syn.n.; Euritea munda (Walker, 1858 = Stictolobus nitidus Funkhouser, 1940, syn.n.; Bordonia nigricosta (Goding, 1926, comb.n.; Bordonia virescens (Funkhouser, 1940, comb.n.. One species is transferred to Smiliinae-Ceresini: Tapinolobus curvispina (Walker, 1858, comb.n. (formerly in Thrasymedes = Tapinolobus fasciatus Sakakibara, 1969, syn.n.; another one is transferred to Darninae-Cymbomorphini: Eumela darnioides (Walker, 1858, comb.n. (formerly in Euritea.

  8. Mechanisms of Oryza sativa (Poaceae resistance to Tagosodes orizicolus (Homoptera: Delphacidae under greenhouse condition in Venezuela

    Directory of Open Access Journals (Sweden)

    Alex González

    2012-03-01

    Full Text Available Tagosodes orizicolus is one of the main plagues of rice in tropical America causing two types of damages, the direct one, feeding and oviposition effect, and an indirect one, by the transmission of the “Rice hoja blanca virus”. During 2006-2007 we carried out research under greenhouse conditions at Fundación Danac, Venezuela, in order to determine the mechanisms of antixenosis, antibiosis and tolerance to T. orizicolus, which could be acting in commercial varieties and advanced lines of the rice genetic breeding programs of INIA and Fundación Danac. The method of free feeding was used for the antixenosis evaluation, whereas the method of forced feeding was used for antibiosis evaluation (effect on survival and oviposition. Additionally, we used the indirect method based on biomass depression to estimate the tolerance. Some of the evaluated traits included: grade of damage, number of insects settling on rice plants, percentage of sogata mortality at the mature state, number of eggs in the leaf midrib and an index of tolerance. The results showed that rice genotypes possess different combinations of resistance mechanisms, as well as different grades of reactions. The susceptible control ‘Bluebonnet 50’ was consistently susceptible across experiments and the resistant control ‘Makalioka’ had high antixenosis and high antibiosis based on survival and oviposition. The rest of the genotypes presented lower or higher degrees of antixenosis and antibiosis for survival and viposition. The genotype ‘FD0241-M-17-6-1-1-1-1’ was identified with possible tolerance to the direct damage of sogata.Tagosodes orizicolus es una de las principales plagas del cultivo del arroz en América tropical causando dos tipos de daños a la planta, el directo, por efecto de la alimentación y oviposición; el indirecto, por la transmisión del virus de la hoja blanca del arroz. Durante el período 2006-2007 se llevó a cabo una investigación bajo condiciones de umbráculo en la Fundación Danac, Venezuela, con el objeto de determinar los mecanismos de resistencia de antixenosis, antibiosis y tolerancia a T. orizicolus que pudieran estar actuando en líneas avanzadas y cultivares del programa de mejoramiento enético de arroz de las instituciones INIA y Fundación Danac. Para la evaluación de antixenosis se utilizó el método de libre elección, para antibiosis (efecto sobre sobrevivencia y oviposición de los insectos el de alimentación forzada, adicionalmente se usó un método indirecto para estimar la tolerancia. Dentro de los principales parámetros determinados se encontraban: grado de daño, número de insectos posados sobre plantas de arroz, porcentaje de mortalidad de sogata en estado adulto, número de huevos y se calculó un índice de tolerancia con base en la biomasa. Los resultados mostraron que los genotipos de arroz evaluados poseen diferentes combinaciones en cuanto a los mecanismos de resistencia, así como el grado de su efecto. El testigo ‘Bluebonnet 50’ se mantuvo consistentemente susceptible en las evaluaciones y el testigo resistente ‘Makalioka’ fue el único genotipo que presentó alta antixenosis y alta antibiosis para sobrevivencia y oviposición. El resto de los genotipos presentaron un menor o mayor grado de resistencia de tipo antixenosis y antibiosis para sobrevivencia y oviposición. Se identificó el genotipo ‘FD0241-M-17-6-1-1-1-1’ con posible tolerancia al daño directo de sogata.

  9. Cytogenetic and taxonomic studies of some legless mealybugs (Homoptera, Coccinea, Pseudococcidae

    Directory of Open Access Journals (Sweden)

    Ilya A. Gavrilov-Zimin

    2016-11-01

    Full Text Available A new monotypic genus and species, Komodesia circuliplurima gen. et sp. n., from Flores Is. (Indonesia and the new species, Antonina diversiglandulosa sp. n., from Southern Thailand are described and illustrated. Chromosomes of these species and also the ones of Antonina purpurea Signoret, 1872 and A. thaiensis Takahashi, 1942 are studied for the first time: 2n = 30, 20, 12 and 22+Bs correspondingly; the male embryos of all four species demonstrate Lecanoid paternal heterochromatinization of one haploid set of chromosomes. The karyotypes of three widely distributed species, Antonina pretiosa Ferris, 1953, A. graminis (Maskell, 1897 and Chaetococcus bambusae (Maskell, 1893, are studied based on material from other regions in comparison with previously published data. Photographs of the karyotypes are provided for the first time for all seven species. The terminological problems connected with the identification and naming of the three scale insect genetic systems, Lecanoid, Comstockioid and Diaspidoid, are discussed.

  10. Influences of pea morphology and interacting factors on pea aphid (Homoptera: Aphididae) reproduction.

    Science.gov (United States)

    Buchman, N; Cuddington, K

    2009-08-01

    It has been claimed that plant architecture can alter aphid reproductive rates, but the mechanism driving this effect has not been identified. We studied interactions between plant architecture, aphid density, environmental conditions, and nutrient availability on the reproduction of pea aphids [Acyrthosiphon pisum (Harris)] using four near-isogenic peas (Pisum sativum L.) that differ in morphology. Manipulations of aphid density (1, 5, and 10 adults per plant) allowed us to examine any effects of plant morphology on crowding and consequently reproduction. Pea morphology per se did not alter pea aphid crowding, as measured by mean nearest neighbor distance, and there was no effect on reproduction. In addition, reproduction increased with increasing adult density, indicating positive density dependence. In a separate experiment, peas were fertilized to determine whether differences between nutrient availability of the four different morphologies might drive any observed differences in aphid reproduction. Although plant nitrogen content was altered by fertilization treatments, this did not have an impact on aphid reproduction. Greenhouse experiments, however, suggested that pea morphology can interact with environmental conditions to reduce aphid reproduction under some conditions. We conclude that plant morphology only influences aphid reproduction when environmental conditions are less than optimal.

  11. The genus Baeturia Stål as represented in New Guinea (Homoptera, Cicadidae)

    NARCIS (Netherlands)

    Blöte, H.C.

    1960-01-01

    Until now only three species of the genus Baeturia have been recorded from New Guinea, viz., B. bicolorata Distant, B. viridicata Distant, and B. nana Jacobi. As I had the opportunity to study a fairly large collection of this group from different sources, collected in New Guinea, it appeared to me

  12. Bioacoustic investigations and taxonomic considerations on the Cicadetta montana species complex (Homoptera: Cicadoidea: Tibicinidae

    Directory of Open Access Journals (Sweden)

    Matija Gogala

    2004-06-01

    Full Text Available Recent bioacoustic investigations have shown that Cicadetta montana Scopoli 1772 is a complex of morphologically similar sister species that are best characterized by their song patterns. At the type locality of C. montana, only mountain cicadas with simple, long lasting song phrases were heard, recorded and collected. Therefore, we have good reasons to suggest that this type of song is characteristic for C. montana s. str. Boulard described a song of C. montana from France with phrases composed of a long and a short echeme; this type of song is characteristic for cicadas morphologically corresponding to C. montana var. brevipennis Fieber 1876; we suggest to raise this taxon to species level. On the basis of specific song, Puissant and Boulard described C. cerdaniensis from Pyrénées. A similar case was the discovery and description of C. montana macedonica Schedl 1999 from Macedonia; since these Macedonian cicadas are sympatric with at least two other cryptic species in the C. montana group and molecular investigations showed substantial genetic differences between C. macedonica and C. montana or C. brevipennis, we conclude that this taxon should also be raised to species level. Songs of closely related C. podolica and Korean mountain cicada are presented as well.Pesquisas recentes de bioacústica mostraram que Cicadetta montana Scopoli 1772 é um complexo de espécie-irmãs morfologicamente semelhantes e melhor caracterizadas por seus padrões de canto. Na localidade-tipo de C. montana somente cigarras serranas de longas frases de canto foram ouvidas, gravadas e coletadas. Portanto, temos boas razões para propor este tipo de canto como característico de C. montana s. str. Boulard descreveu um canto de C. montana da França com frases compostas de uma estridulação longa e uma curta; este tipo de canto é característico das cigarras correspondendo morfologicamente a C. montana var. brevipennis Fieber 1876; sugerimos elevar este táxon ao nível de espécie. Baseando-se nos cantos específicos, Puissant e Boulard descreveram C. cerdaniensis dos Pirineus. Um caso similar foi a descoberta e descrição de C. montana macedonica Schedl 1999 da Macedônia; desde que essas cigarras macedônicas são simpátricas com pelo menos duas outras espécies crípticas dentro do grupo C. montana e as análises moleculares mostraram diferenças genéticas substanciais entre C. montana e C. brevipennis, concluímos que este táxon também deve ser elevado ao nível de espécie. Cantos de espécies próximas, C. podolica e a cigarra serrana da Korea, são também apresentados.

  13. Appearance of cicada fauna (Homoptera: Cicadoidea) by altitudes in Johor National Park, Mount Ledang, Johor

    Science.gov (United States)

    Tahir, Aliadi Mohd; Sulaiman, Azman

    2015-09-01

    A total of 31 cicada species in 15 genera under two families (Cicadidae, 27 species in 11 genera; Tibicinidae, four species in three genera) was recorded for Johor National Park, Mount Ledang, Johor. This was based on 666 individuals were obtained through six sampling occasions in November 2012 until October 2013, each time using light trap set in six sampling locations (L1, L2, L3, L4a, L4b, L4c) that were selected based on altitudes. The most common and abundant species in L1 is Pomponia sp1 and recognized as new species that need to be described as new to science. Orientopsaltria saudarapadda Duffles & Zaidi appeared as the most common and abundant species in L2, represented by 21 individuals which covers 34.43 % of the total cicadas specimen in that area. In the location of L3, Dundubia vaginata (Fabricius) appeared as the most abundant species represented by 37 individuals or 26.81% while Abroma maculicollis Guerin appeared as the most common species. Shannon's Species Diversity Index (H') in L3 was the highest (H'=2.28) followed by L4b (H'=2.21), L2 (H'=1.93) L4a (H'=1.92), L4c (H'=1.84) and L1 (H'=1.58), and the evenness index in L1 was the highest (E= 0.88), followed by L4b (E= 0.79), L3 (E= 0.77), L2 (E= 0.75), L4c (E= 0.74) and L4a (E= 0.79). Margalef Species Richness Index in L3 was the highest (R'=3.65), followed by oleh L4b (R'=3.01), L4a (R'=2.97), L2 (R'=2.92), L4c (R'=2.4), and L1 (R'=2.01). Generally shows that L3 at the altitude 350 m appear as the best sampling site for cicadas species in Mount Ledang Johor with the highest value of species diversity and richness index.

  14. Metcalfa pruinosa (Say (Homoptera: Auchenorrhyncha anew harmful species for entomofauna of Serbia

    Directory of Open Access Journals (Sweden)

    Mihajlović Ljubodrag

    2007-01-01

    Full Text Available In the early autumn 2006, a Nonarctic species of cicadas Metcalfa pruinosa (Say (Auchenorrhyncha: Flatidae was identified in Belgrade (Košutnjak. In Europe, this species was identified for the first time in Italy in 1979. In Slovenia, it was identified in 1990 in west Istria, and in 2001 in the neighbourhood of Ljubljana. In the park forest Košutnjak (Belgrade mass occurrence of M. pruinosa was recorded in the area of about 5 ha. The larvae developed on woody species in the genera: Acer, Aesculus, Gleditchia Robinia, Ailanthus, Populus, Platanus, Prunus, Pyrus, Ulmus, Tilia, Cornus Fraxinus, Quercus and Thuja, što is konstatovano based on damages of larvae while numerous adults were found on trees and branches of the same plants.

  15. Energetics of emergence in the cicadas, Cyclochila australasiae and Abricta curvicosta (Homoptera: Cicadidae).

    Science.gov (United States)

    Harvey, Prudence M; Thompson, Michael B

    2006-09-01

    The final moult in cicadas marks a major transition in lifestyle and is a behaviour that makes the cicada vulnerable to predation. Consequently, emergence times are short and, we predict, therefore the rate of energy consumption would be high. Hence, we measured the energetic cost of emergence in Cyclochila australasiae (green grocer) and Abricta curvicosta (floury baker) cicadas during the final moult from nymph to adult cicada. Maximum energy expended whilst emerging was compared between the sexes and species. Even though C. australasiae take longer to emerge than A. curvicosta, the mass-specific cost of emergence is not different between the two species (C. australasiae: 11.34+/-2.55 J g(-1); A. curvicosta: 12.91+/-1.90 J g(-1)). The mass-specific metabolic rates of fully emerged adults of both species are approximately twice those of the nymphs and the maximum metabolic rate during emergence is about 1.5 times higher than the resting metabolic rate of emerged adults. Emergence times, as indicated by rates of oxygen consumption, are longer than expected and probably reflect limitations in the oxygen capacity of the cicadas during moulting.

  16. The taxonomy and biogeography of the genus Thaumastopsaltira Kirkaldy, 1900 (Homoptera, Tibicinidae)

    NARCIS (Netherlands)

    Boer, de A.J.

    1992-01-01

    The taxonomic concept of the genus Thaumastopsaltria Kirkaldy is redefined on the basis of the shape of postclypeus and the length of the ovipositor. Tegmen venation is shown to be unreliable for this purpose. T. nana (Jacobi) does not fit this new concept and is, pending its transfer to another

  17. Distributional patterns and possible origins of the tribes and genera of Coelidiinae (Homoptera, Membracoidea, Cicadellidae

    Directory of Open Access Journals (Sweden)

    Mervin W Nielson

    2000-12-01

    Full Text Available Leafhoppers are well known biological indicators of zoogeographical regions owing, in part, to their phytodependency, high host plant specificity and relatively low vagility. In this connection, we discuss distributional patterns and possible zoogeographical origins of nine constituent tribes and their genera of the pantropical subfamily Coelidiinae. Among 118 known genera, only eight currently occupy more than one zoogeographical region, indicating an extremely high endemic profile which supports the proposed centers of origin and relatively low rate of intercontinental dispersal. The pantropical tribe Coelidiini is suggested as the basal group of the subfamily which is believed to have arisen prior to continental drift (late Jurassic-early Cretaceous because there appears to be no other evidence at the present time to explain its near cosmopolitan distribution. Possible origins of three Old World tribes, Hikangiini (Ethiopian, Thagriini (Oriental and Thanini (Australian and four New World -(Neotropical tribes, Teruliini, Tinobregmini, Gabritini and Sandersellini are elucidated. The tribe Youngolidiini occupies the Neotropical and Ethiopian realms but its origin is problematical. There appears to be ample evidence that origin/dispersal patterns are related to the geological history of the areas occupied by its faunal members.

  18. Mechanisms of Oryza sativa (Poaceae) resistance to Tagosodes orizicolus (Homoptera: Delphacidae) under greenhouse condition in Venezuela.

    Science.gov (United States)

    González, Alex; Labrín, Natalia; Alvarez, Rosa M; Jayaro, Yorman; Gamboa, Carlos; Reyes, Edicta; Barrientos, Venancio

    2012-03-01

    Tagosodes orizicolus is one of the main plagues of rice in tropical America causing two types of damages, the direct one, feeding and oviposition effect, and an indirect one, by the transmission of the "Rice hoja blanca virus". During 2006-2007 we carried out research under greenhouse conditions at Fundaci6n Danac, Venezuela, in order to determine the mechanisms of antixenosis, antibiosis and tolerance to T. orizicolus, which could be acting in commercial varieties and advanced lines of the rice genetic breeding programs of INIA and Fundaci6n Danac. The method of free feeding was used for the antixenosis evaluation, whereas the method of forced feeding was used for antibiosis evaluation (effect on survival and oviposition). Additionally, we used the indirect method based on biomass depression to estimate the tolerance. Some of the evaluated traits included: grade of damage, number of insects settling on rice plants, percentage of sogata mortality at the mature state, number of eggs in the leaf midrib and an index of tolerance. The results showed that rice genotypes possess different combinations of resistance mechanisms, as well as different grades of reactions. The susceptible control 'Bluebonnet 50' was consistently susceptible across experiments and the resistant control 'Makalioka' had high antixenosis and high antibiosis based on survival and oviposition. The rest of the genotypes presented lower or higher degrees of antixenosis and antibiosis for survival and oviposition. The genotype 'FD0241-M-17-6-1-1-1-1' was identified with possible tolerance to the direct damage of sogata.

  19. The authority and types for the hackberry gall psyllid genus Pachypsylla (Riley) (Hemiptera-Homoptera: Psyllidae)

    Science.gov (United States)

    The nomenclatural problems with the hackberry gall psyllid species names are rectified. The genus Pachypsylla Riley, 1883, type species, Psylla venusta Osten-Sacken, includes 14 nominal species. These are: Pachypsylla venusta (Osten-Sacken, 1861); P. celtidismamma Riley, 1875; P. celtidisgemma Ri...

  20. Microsatellite marker analysis of peach-potato aphids (Myzus persicae, Homoptera: Aphididae) from Scottish suction traps.

    Science.gov (United States)

    Malloch, G; Highet, F; Kasprowicz, L; Pickup, J; Neilson, R; Fenton, B

    2006-12-01

    The peach-potato aphid Myzus persicae (Sulzer) is an important vector of plant viruses. A network of suction traps collects aerial samples of this aphid in order to monitor and help predict its spatial distribution and likely impact on virus transmission in crops. A suction trap catch is thought to be a good representation of the total aphid pool. Sensitive molecular markers have been developed that determine the genetic composition of the M. persicae population. In Scotland, UK, these were applied to field collections revealing a limited number of clones. Molecular markers are less successful when applied to specimens that have been preserved in an ethanol-based trap fluid designed to preserve morphology. An assessment of different DNA extraction and PCR techniques is presented and the most efficient are used to analyse M. persicae specimens caught in the Dundee suction trap in 2001, a year when exceptionally high numbers were caught. The results reveal that the majority of the M. persicae caught belonged to two highly insecticide resistant clones. In addition, it was possible to compare the relative frequencies of genotypes caught in the trap with those collected at insecticide treated and untreated field sites in the vicinity. These results indicate that, in addition to suction trap data, the ability to sample field sites provides valuable early warning data which have implications for pest control and virus management strategies.

  1. The Toxicity and Detoxifying Mechanism of Cycloxaprid and Buprofezin in Controlling Sogatella furcifera (Homoptera: Delphacidae).

    Science.gov (United States)

    Chang, Xiaoli; Yuan, Yongda; Zhang, Tianshu; Wang, Dongsheng; Du, Xingbin; Wu, Xiangwen; Chen, Haixia; Chen, Yaozhong; Jiao, Yuetong; Teng, Haiyuan

    2015-01-01

    The effects of cycloxaprid (a modified neonicotinoid insecticide) and buprofezin (a thiadiazine insecticide) on mortality of the white-backed planthopper (WBPH), Sogatella furcifera, were determined in laboratory assays. Cycloxaprid killed WBPH nymphs and adults but buprofezin killed only nymphs, and cycloxaprid acted faster than buprofezin. One day after infestation, mortality of third-instar nymphs was >65% with cycloxaprid at 125 mg liter(-1) but was buprofezin at 148 mg liter(-1). By the 4th day after infestation, however, control of nymphs by the two insecticides was similar, and cycloxaprid at 125 mg liter(-1) caused ≥ 80% mortality of adults but buprofezin at 148 mg liter(-1) (the highest rate tested) caused almost no adult mortality. LC50 values for cycloxaprid were lowest with nymphs, intermediate with adult males, and highest with adult females. Although buprofezin was slower acting than cycloxaprid, its LC50 for nymphs 5 d after infestation was 3.79-fold lower than that of cycloxaprid. Mean carboxylesterase (CarE) specific activity of nymphal WBPH treated with cycloxaprid and buprofezin was higher than that of control, but there was no significant difference between cycloxaprid and control (no insecticide), and it was significantly higher for buprofezin than those of cycloxaprid and control. For glutathione S-transferase and mixed function oxygenase, the specific activity of nymphal WBPH treated with buprofezin was significantly higher than those of cycloxaprid and control, too. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

  2. The Toxicity and Detoxifying Mechanism of Cycloxaprid and Buprofezin in Controlling Sogatella furcifera (Homoptera: Delphacidae)

    OpenAIRE

    Chang, Xiaoli; Yuan, Yongda; Zhang, Tianshu; Wang, Dongsheng; Du, Xingbin; Wu, Xiangwen; Chen, Haixia; Chen, Yaozhong; Jiao, Yuetong; Teng, Haiyuan

    2015-01-01

    The effects of cycloxaprid (a modified neonicotinoid insecticide) and buprofezin (a thiadiazine insecticide) on mortality of the white-backed planthopper (WBPH), Sogatella furcifera, were determined in laboratory assays. Cycloxaprid killed WBPH nymphs and adults but buprofezin killed only nymphs, and cycloxaprid acted faster than buprofezin. One day after infestation, mortality of third-instar nymphs was >65% with cycloxaprid at 125?mg liter?1 but was

  3. Repellency and toxicity of three Impatients species (Balsaminaceae) extracts on Myzus persicae Sulzer (Homoptera: Aphididae)

    Czech Academy of Sciences Publication Activity Database

    Pavela, R.; Vrchotová, Naděžda; Šerá, Božena

    2009-01-01

    Roč. 2009, - (2009), s. 48-51 ISSN 0974-391X R&D Projects: GA MZe(CZ) QH72117 Institutional research plan: CEZ:AV0Z60870520 Keywords : Impatiens * repellency * toxicity Subject RIV: EH - Ecology, Behaviour

  4. Hemlock woolly adelgid (Homoptera: Adelgidae): stylet bundle insertion and feeding sites

    Science.gov (United States)

    Rebecca F. Young; Kathleen S. Shields; Graeme P. Berlyn

    1995-01-01

    Stylet bundle insertion site, path traveled, and feeding site were examined for the hemlock woolly adelgid, Adelges tsugae Annand, on needles from current and previous years of eastern hemlock, Tsuga canadensis Carriere. The stylet bundle is composed of 4 individual stylets--2 outer mandibular stylets and 2 inner maxillary stylets...

  5. Dinamika Populasi Diaphorina citri Kuwayama (Homoptera: Psyllidae dan Deteksi CVPD dengan Teknik PCR

    Directory of Open Access Journals (Sweden)

    I NYOMAN WIJAYA

    2015-09-01

    Full Text Available The research was conducted in the field of Taro village Gianyar regency and Katung village Bangli regency and at the Laboratory of Biotechnology Faculty of Agricultural Udayana University. The purpose of the research were to investigate population dynamic of Diaphorina citri Kuwayama and other insects that were assosiated with citrus cv. siam; and molecular detection of CVPD patogen in its vector, other phytophagous insects on citrus cv.siam and kemuning [Murraya paniculata (L. Jack.] The result of this study showed that in six month period there was one peak of D. citri population which was associated with the flushing period of citrus at Taro as well Katung villages. The peak of D. citri population of Taro village was higher than that of Katung village. Two species of parasitoids and four spesies of predators were found in the field and may contribute in the suppression of D. citri population. The parasitoids identified were Tamarixia radiata Wat. and Diaphorencyrtus alligharensi Shaffe, whereas the predators were Curinus coeruleus Mulsant, Phiddipus sp., Menochilus sexmaculatus Fabricius and Oxyopes javanus Thorell. T. radiata has been proven to be an effective nymph parasitoid that could suppress the population development of D. citri in citrus orchads. The research revealed that kemuning could serve as a source of infection because it is also a host of CVPD disease as well as of D. citri. Toxoptera citricidus Kirkaldy and Maleuterpes dentipes Hell. were not proven to contain CVPD disease.

  6. The Hawaiian cave planthoppers (Homoptera: Fulgoroidea: Cixiidae - A model for rapid subterranean speciation?

    Directory of Open Access Journals (Sweden)

    Hannelore Hoch

    1997-01-01

    Full Text Available After the successful colonization of a single ancestral species in the Hawaiian Islands, planthoppers of the cixiid genus Oliarus underwent intensive adaptive radiation resulting in 80 described endemic species. Oliarus habitats range from montaneous rain forests to dry coastal biotopes and subterranean environments. At least 7 independant evolutionary lines represented by different species have adapted to lava tubes on Molokai (1, Maui (3, and Hawaii Island (3. Behavioral and morphological studies on one of these evolutionary lines on Hawaii Island, the blind, flight- and pigmentless Oliarus polyphentus have provided evidence for reproductive isolation between allopatric populations which may in fact be separate species. Significant differences in song parameters were observed even between populations from neighbouring lava tubes, although the planthoppers are capable of underground migration through the voids and cracks of the mesocavernous rock system which is extant in young basalt: after a little more than 20 years, lava tubes within the Mauna Ulu 1974 flow had been colonized by O. ‘polyphenius” individuals, most probably originating from a near-by forestkipuka. Amazingly, this species complex is found on the youngest of the Hawaiian Islands, with probably less than 0.5 m.y., which suggests rapid speciation processes. Field observations have led to the development of a hypothesis to match underground speciation with the dynamics of vegetational succession on the surface of active volcanoes. Planthopper range partitioning and geographic separation of populations by young lava flows, founder events and small population size may be important factors involved in rapid divergence.

  7. Collective defense of Aphis nerii and Uroleucon hypochoeridis (Homoptera, Aphididae against natural enemies.

    Directory of Open Access Journals (Sweden)

    Manfred Hartbauer

    2010-04-01

    Full Text Available The prevalent way aphids accomplish colony defense against natural enemies is a mutualistic relationship with ants or the occurrence of a specialised soldier caste typical for eusocial aphids, or even both. Despite a group-living life style of those aphid species lacking these defense lines, communal defense against natural predators has not yet been observed there. Individuals of Aphis nerii (Oleander aphid and Uroleucon hypochoeridis, an aphid species feeding on Hypochoeris radicata (hairy cat's ear, show a behavioral response to visual stimulation in the form of spinning or twitching, which is often accompanied by coordinated kicks executed with hind legs. Interestingly, this behaviour is highly synchronized among members of a colony and repetitive visual stimulation caused strong habituation. Observations of natural aphid colonies revealed that a collective twitching and kicking response (CTKR was frequently evoked during oviposition attempts of the parasitoid wasp Aphidius colemani and during attacks of aphidophagous larvae. CTKR effectively interrupted oviposition attempts of this parasitoid wasp and even repelled this parasitoid from colonies after evoking consecutive CTKRs. In contrast, solitary feeding A. nerii individuals were not able to successfully repel this parasitoid wasp. In addition, CTKR was also evoked through gentle substrate vibrations. Laser vibrometry of the substrate revealed twitching-associated vibrations that form a train of sharp acceleration peaks in the course of a CTKR. This suggests that visual signals in combination with twitching-related substrate vibrations may play an important role in synchronising defense among members of a colony. In both aphid species collective defense in encounters with different natural enemies was executed in a stereotypical way and was similar to CTKR evoked through visual stimulation. This cooperative defense behavior provides an example of a surprising sociality that can be found in some aphid species that are not expected to be social at all.

  8. Ultralow oxygen treatment for postharvest control of Nasonovia ribisnigri (Homoptera: Aphididae) on iceberg lettuce.

    Science.gov (United States)

    Liu, Yong-Biao

    2005-12-01

    The aphid Nasonovia ribisnigri (Mosley) is a common pest of lettuce in the United States. It hinders export of U.S. lettuce to the overseas market such as Japan where it is a quarantined pest. Ultralow oxygen treatments were studied for control of the insect on iceberg lettuce. Small-scale ultralow oxygen treatments in plastic jars were conducted at 1, 5, and 10 degrees C for different durations to determine effective treatment against nymphs and alates of N. ribisnigri. At oxygen levels of 0.015-0.025%, N. ribisnigri can be controlled in 3 d at 1 degrees C, 2 d at 5 degrees C, and 1 d at 10 degrees C. Large-scale ultralow oxygen treatments were conducted in bulk container treatment chambers with commercial iceberg lettuce heads for 2 d at 6 degrees C with oxygen levels of 0.015 and 0.025% and for 3 d at 3 degrees C with oxygen level of 0.015%. All treatments achieved complete control of N. ribisnigri. No negative impact on lettuce quality was detected after 2 wk of posttreatment storage. Therefore, the selected treatments have potential to be commercially developed for postharvest control of N. ribisnigri on iceberg lettuce.

  9. Oxygenated phosphine fumigation for control of Nasonovia ribisnigri (Homoptera: Aphididae) on harvested lettuce.

    Science.gov (United States)

    Liu, Yong-Biao

    2012-06-01

    Low temperature regular phosphine fumigations under the normal oxygen level and oxygenated phosphine fumigations under superatmospheric oxygen levels were compared for efficacy against the aphid, Nasonovia ribisnigri (Mosley), and effects on postharvest quality of romaine and head lettuce. Low temperature regular phosphine fumigation was effective against the aphid. However, a 3 d treatment with high phosphine concentrations of > or = 2,000 ppm was needed for complete control of the aphid. Oxygen greatly increased phosphine toxicity and significantly reduced both treatment time and phosphine concentration for control of N. ribisnigri. At 1,000 ppm phosphine, 72 h regular fumigations at 6 degrees C did not achieve 100% mortality of the aphid. The 1,000 ppm phosphine fumigation under 60% O2 killed all aphids in 30 h. Both a 72 h regular fumigation with 2,200 ppm phosphine and a 48 h oxygenated fumigation with 1,000 ppm phosphine under 60% O2 were tested on romaine and head lettuce at 3 degrees C. Both treatments achieved complete control of N. ribisnigri. However, the 72 h regular fumigation resulted in significantly higher percentages of lettuce with injuries and significantly lower lettuce internal quality scores than the 48 h oxygenated phosphine fumigation. Although the oxygenated phosphine fumigation also caused injuries to some treated lettuce, lettuce quality remained very good and the treatment is not expected to have a significant impact on marketability of the lettuce. This study demonstrated that oxygenated phosphine fumigation was more effective and less phytotoxic for controlling N. ribisnigri on harvested lettuce than regular phosphine fumigation and is promising for practical use.

  10. Identification of Russian wheat aphid (Homoptera : Aphididae) populations virulent to the Dn4 resistance gene

    Czech Academy of Sciences Publication Activity Database

    Smith, C. M.; Belay, T.; Stauffer, CH.; Starý, Petr; Kubečková, I.; Starkey, S.

    2004-01-01

    Roč. 97, č. 3 (2004), s. 1112-1117 ISSN 0022-0493 R&D Projects: GA AV ČR IBS5007102 Grant - others:Kansas Agricultural Experiment Station(US) 04-120-J Institutional research plan: CEZ:AV0Z5007907 Keywords : Diuraphis noxia * barley * virulence Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection Impact factor: 1.283, year: 2004

  11. Biology and taxonomy of Tuthillia cognata (Homoptera : Psylloidea), a pest on Myrciaria dubia (Myrtaceae)

    OpenAIRE

    Burckhardt, D.; Couturier, Guy

    1988-01-01

    #Tuthillia cognata$ est découvert comme ravageur de #Myrciaria dubia$ (#Myrtaceae$) au Pérou et Brésil. Tenant compte de la morphologie de la larve, le genre est transféré des #Ciriacreminae$ dans les #Anomoneurinae$. (Résumé d'auteur)

  12. Isolation and characterization of polymorphic microsatellite loci in the green leafhopper Empoasca vitis Goethe (Homoptera).

    Science.gov (United States)

    Papura, D; Giresse, X; Chauvin, B; Caron, H; Delmotte, F; VAN Helden, M

    2009-05-01

    Eight dinucleotide microsatellite loci were isolated and characterized within the green leafhopper Empoasca vitis (Goethe) using an enrichment cloning procedure. Primers were tested on 171 individuals collected in the southwest of France from the vine plants. The identified loci were polymorphic, with allelic diversity ranging from two to 18 alleles per locus. Observed heterozygosities were from 0.021 to 0.760. These microsatellite markers should prove to be a useful tool for estimating the population genetic structure, host-plant specialization and migration capacity of this insect. © 2009 The Authors. Journal compilation © 2009 Blackwell Publishing Ltd.

  13. Assesing Bemisia tabaci (Genn. biotype B resistance in soybean genotypes: Antixenosis and antibiosis Evaluación de la resistencia de genotipos de soya a Bemisia tabaci (Genn. biotipo B: Antixenosis y antibiosis

    Directory of Open Access Journals (Sweden)

    José Paulo Gonçalves Franco da Silva

    2012-12-01

    Full Text Available Since it was first reported in Brazil in the 1990s, the B biotype of silverleaf whitefly (Bemisia tabaci Genn., Hemiptera: Aleyrodidae has been recognized as an important pest in soybeans (Glycine max L., reducing the productivity of this legume species in some areas of the country. As an alternative to chemical control, the use of resistant genotypes represents an important tool for integrated pest management (IPM. This study evaluated the performance of 10 soybean genotypes prior to whitefly infestation, by testing attractiveness and preference for oviposition in the greenhouse and antibiosis in the laboratory. In a multiple-choice test, 'IAC-17' was the least attractive to insects. In a no-choice test, 'IAC-17' was the least attractive for egg deposition, indicating the occurrence of non-preference for oviposition on this genotype. Trichome density was positively correlated with the oviposition site and may be associated with the resistance of 'IAC-17' to infestation. The genotypes 'IAC-PL1', 'IAC-19', 'Conquista', 'IAC-24' and 'IAC-17' extended the insect's life cycle, indicating the occurrence of a small degree of antibiosis and/or non-preference for feeding.Desde que se registró por primera vez en Brasil en la década de 1990, el biotipo B de la mosca-blanca (Bemisia tabaci Genn., Hemiptera: Aleyrodidae, se reconoce como una importante plaga de la soya (Glycine max L. y es lo que reduce la productividad de estas especies de leguminosas en algunas zonas del pais. Como una alternativa al control químico, el uso de genotipos resistentes representa una herramienta importante para la gestión integrada de plagas (MIP. Este trabajo evaluó el comportamiento de 10 genotipos de soya frente al ataque de la mosca-blanca, por medio de ensayos de atractividad y preferencia para ovipostura en invernaderos y antibiosis en laboratorio. En una prueba de elección multiple, 'IAC-17' fue el menos atractivo para los insectos. En una prueba sin elecci

  14. Dinâmica populacional de Bemisia tabaci biótipo B em tomate monocultivo e consorciado com coentro sob cultivo orgânico e convencional Population dynamic of Benisua tabaci B biotype in monoculture tomato crop and consortium with coriander in organic and conventional crop system

    Directory of Open Access Journals (Sweden)

    Pedro HB Togni

    2009-06-01

    Full Text Available A mosca-branca Bemisia tabaci Biótipo B (Hemiptera: Aleyrodidae, é um herbívoro de difícil controle devido à alta plasticidade genotípica da espécie. No tomateiro pode causar danos severos principalmente pela transmissão de diversas viroses. O manejo do sistema de produção e o consórcio de culturas podem ter um efeito direto nas populações desse herbívoro, sem que seja necessária a aplicação de inseticidas. Avaliou-se a influência dos sistemas de produção orgânico e convencional e o consórcio tomate-coentro na dinâmica populacional da mosca-branca no campo experimental da Embrapa Hortaliças, de maio a setembro/06. O monitoramento dos adultos da mosca-branca e de seus inimigos naturais foi realizado utilizando-se armadilhas adesivas amarelas fixadas nas bordas e no interior das parcelas experimentais e a amostragem de ninfas foi realizada por observação direta das folhas de tomate no campo. Embora as populações ao redor dos diferentes tratamentos fossem equivalentes, a abundância de adultos de mosca-branca foi significativamente menor nas parcelas de tomate consorciado com coentro, tanto no sistema convencional como orgânico. Apenas o consórcio tomatecoentro em sistema orgânico apresentou redução significativa na quantidade de ninfas por planta em relação aos demais tratamentos. Os inimigos naturais foram significativamente mais abundantes em sistema orgânico e foi verificada uma correlação negativa da abundância dos inimigos naturais e a quantidade de ninfas por planta. A associação tomate-coentro e o manejo orgânico do agroecossistema favoreceram ao controle biológico natural da mosca-branca.Due to its high genotypic plasticity, the control of the silverleaf whitefly Bemisia tabaci B biotype (Hemiptera: Aleyrodidae, is difficult. This insect may cause severe damage to the tomato crop as a vector of several viruses. The management of the production system and the consortium with other crops may have a

  15. Formation of Stylet Sheaths in āere (in air from eight species of phytophagous hemipterans from six families (Suborders: Auchenorrhyncha and Sternorrhyncha.

    Directory of Open Access Journals (Sweden)

    J Kent Morgan

    Full Text Available Stylet sheath formation is a common feature among phytophagous hemipterans. These sheaths are considered essential to promote a successful feeding event. Stylet sheath compositions are largely unknown and their mode of solidification remains to be elucidated. This report demonstrates the formation and solidification of in āere (in air produced stylet sheaths by six hemipteran families: Diaphorina citri (Psyllidae, Asian citrus psyllid, Aphis nerii (Aphididae, oleander/milkweed aphid, Toxoptera citricida (Aphididae, brown citrus aphid, Aphis gossypii (Aphididae, cotton melon aphid, Bemisia tabaci biotype B (Aleyrodidae, whitefly, Homalodisca vitripennis (Cicadellidae, glassy-winged sharpshooter, Ferrisia virgata (Pseudococcidae, striped mealybug, and Protopulvinaria pyriformis (Coccidae, pyriform scale. Examination of in āere produced stylet sheaths by confocal and scanning electron microscopy shows a common morphology of an initial flange laid down on the surface of the membrane followed by continuous hollow core structures with sequentially stacked hardened bulbous droplets. Single and multi-branched sheaths were common, whereas mealybug and scale insects typically produced multi-branched sheaths. Micrographs of the in āere formed flanges indicate flange sealing upon stylet bundle extraction in D. citri and the aphids, while the B. tabaci whitefly and H. vitripennis glassy-winged sharpshooter flanges remain unsealed. Structural similarity of in āere sheaths are apparent in stylet sheaths formed in planta, in artificial diets, or in water. The use of 'Solvy', a dissolvable membrane, for intact stylet sheath isolation is reported. These observations illustrate for the first time this mode of stylet sheath synthesis adding to the understanding of stylet sheath formation in phytophagous hemipterans and providing tools for future use in structural and compositional analysis.

  16. Morphological characterization of Capsicum annuum L. accessions from southern Mexico and their response to the Bemisia tabaci-Begomovirus complex

    Directory of Open Access Journals (Sweden)

    Horacio Ballina-Gomez

    2013-12-01

    Full Text Available The high diversity of chili pepper (Capsicum annuum L. in Mexico offers an excellent alternative to search for wild and semi-domesticated genotypes as sources of resistance to the complex Bemisia tabaci (Genn. (Hemiptera: Aleyrodidae-Begomovirus, which has caused enormous losses in commercial production of various horticultural crops. The goal of the present work was to characterize ex situ 18 genotypes of C. annuum from southern Mexico through 47 morphological descriptors, and to evaluate its response to the B. tabaci-Begomovirus complex. Morphological characterization showed the variables calyx annular constriction (CAC, number of branch bifurcation (NBB, and calyx pigmentation (CP had the highest variation. Principal components analysis (PCA of 47 morphological characteristics showed that 12 components were selected as meaningful factors. These components explained 94% of the variation. Cluster analysis showed three major clusters and seven sub-clusters. On the other hand, evaluation of the response to B. tabaci-Begomovirus showed that the genotypes have differential susceptibility to this vector-pathogen complex. Genotypes 'Chawa', 'Blanco', 'Maax' and 'X'catic' were into the low susceptibility to B. tabaci and low severity of viral symptoms. Surprisingly, the genotype 'Simojovel' showed high susceptibility to whitefly, but was grouped into genotypes with low symptom severity. This study shows the potential of native germplasm of pepper to explore sources of resistance to the B. tabaci-Begomovirus complex.

  17. Feeding of Whitefly on Tobacco Decreases Aphid Performance via Increased Salicylate Signaling.

    Directory of Open Access Journals (Sweden)

    Haipeng Zhao

    Full Text Available The feeding of Bemisia tabaci nymphs trigger the SA pathway in some plant species. A previous study showed that B. tabaci nymphs induced defense against aphids (Myzus persicae in tobacco. However, the mechanism underlying this defense response is not well understood.Here, the effect of activating the SA signaling pathway in tobacco plants through B. tabaci nymph infestation on subsequent M. persicae colonization is investigated. Performance assays showed that B. tabaci nymphs pre-infestation significantly reduced M. persicae survival and fecundity systemically in wild-type (WT but not salicylate-deficient (NahG plants compared with respective control. However, pre-infestation had no obvious local effects on subsequent M. persicae in either WT or NahG tobacco. SA quantification results indicated that the highest accumulation of SA was induced by B. tabaci nymphs in WT plants after 15 days of infestation. These levels were 8.45- and 6.14-fold higher in the local and systemic leaves, respectively, than in controls. Meanwhile, no significant changes of SA levels were detected in NahG plants. Further, biochemical analysis of defense enzymes polyphenol oxidase (PPO, peroxidase (POD, β-1,3-glucanase, and chitinase demonstrated that B. tabaci nymph infestation increased these enzymes' activity locally and systemically in WT plants, and there was more chitinase and β-1, 3-glucanase activity systemically than locally, which was opposite to the changing trends of PPO. However, B. tabaci nymph infestation caused no obvious increase in enzyme activity in any NahG plants except POD.In conclusion, these results underscore the important role that induction of the SA signaling pathway by B. tabaci nymphs plays in defeating aphids. It also indicates that the activity of β-1, 3-glucanase and chitinase may be positively correlated with resistance to aphids.

  18. Intraguild predation among plant pests: western flower thrips larvae feed on whitefly crawlers

    NARCIS (Netherlands)

    van Maanen, R.; Broufas, G.; Oveja, M.F.; Sabelis, M.W.; Janssen, A.

    2012-01-01

    Omnivores obtain resources from more than one trophic level, and choose their food based on quantity and quality of these resources. For example, omnivores may switch to feeding on plants when prey are scarce. Larvae of the western flower thrips Frankiniella occidentalis Pergande (Thysanoptera:

  19. Whiteflies glycosylate salicylic acid and secrete the conjugate via their honeydew

    NARCIS (Netherlands)

    VanDoorn, A.; de Vries, M.; Kant, M.R.; Schuurink, R.C.

    2015-01-01

    During insect feeding, a complex interaction takes place at the feeding site, with plants deciphering molecular information associated with the feeding herbivore, resulting in the upregulation of the appropriate defenses, and the herbivore avoiding or preventing these defenses from taking effect.

  20. Pollen subsidies promote whitefly control through the numerical response of predatory mites

    NARCIS (Netherlands)

    Nomikou, M.; Sabelis, M.W.; Janssen, A.

    2010-01-01

    Several studies have shown that biological control of pests can be improved by supplying extra food to natural enemies. This increases population levels of the enemies, resulting in decreases in pest densities. In theory, however, supplying food can also have negative effects on biological control.

  1. RNA interference for the control of whiteflies (Bemisia tabaci) by oral ...

    Indian Academy of Sciences (India)

    respective primers (table 2), and actin served as the internal control. Each reaction ..... emerged adults and variation in the quality and the quantity of siRNA synthesized ... Environment News Service, 21 August (countercurrents.org). Febvay G ...

  2. Efficiency of neem oil nanoformulations to Bemisia tabaci (GENN. Biotype B (Hemiptera: AleyrodidaeEficiência de nanoformulações a base de óleo de nim sobre Bemisia tabaci (GENN. Biótipo B (Hemiptera: Aleyrodidae

    Directory of Open Access Journals (Sweden)

    Sheila Salles Carvalho

    2012-04-01

    Full Text Available The nanotechnology, through encapsulation of active ingredients, has showed an important way to avoid problems with quickly degradation of the pesticide molecules. Thus, neem (Azadirachta indica oil nanoformulations containing ?-ciclodextrin and poli-?-caprolactone (PCL were tested as to their control efficiency against eggs and nymphs of Bemisia tabaci (Genn. biotype B reared in soybean. The Lethal Concentration (LC50 was estimated using a commercial neem oil (Organic Neem® on first-instar nymphs to establish the adequate volume of the nanoformulations per treatment. After that, they were sprayed on eggs and first-instar nymphs in laboratory and greenhouse and on third-instar nymphs in greenhouse. The commercial neem oil and distilled water were used as controls. Egg viability was not affected by any treatment. Among six nanoformulations, only one was efficient against the first-instar nymphs in laboratory conditions. However, its effective period was not increased as expected. In greenhouse, first-instar nymphs were more affected by two nanoformulations which were significantly different of the commercial neem oil - the most effective one. No mortality differences among the formulations in the third-instar test were observed. The nanoformulations were less efficient to control the B. tabaci biotype B nymphs than the commercial neem oil. A nanotecnologia, através do encapsulamento de ingredientes ativos, tem-se revelado uma importante estratégia para evitar problemas com a rápida degradação de moléculas inseticidas. Assim, nanoformulações à base de óleo de nim (Azadirachta indica utilizando os polímeros ?-ciclodextrina e poli-?-caprolactona (PCL foram testadas quanto a sua eficiência de controle de ovos e ninfas de Bemisia tabaci (Genn. biótipo B mantidas em soja. Foi estimada a CL50 utilizando uma formulação comecial de óleo de nim (Organic Neem® sobre ninfas em 1º ínstar da qual se estipulou o volume das nanoformulações a serem utilizadas por tratamento. Depois disso, os tratamentos foram aplicados sobre ovos e ninfas de 1º ínstar em laboratório e em casa de vegetação e sobre ninfas de 3º ínstar em casa de vegetação. O óleo comercial e água destilada foram utilizados como controles. A viabilidade dos ovos não foi afetada por qualquer dos tratamentos. Das seis formulações testadas, somente uma delas mostrou-se eficiente para ninfas de 1º ínstar em condições de laboratório, embora não tenha apresentado aumento do período residual como esperado. Em casa de vegetação, ninfas de 1º ínstar foram mais afetadas por duas das formulações, que diferenciaram do óleo de nim que causou maior controle. No teste com ninfas de 3º ínstar, não houve diferenciação de mortalidade entre as formulações. As nanoformulações foram menos eficientes para controlar ninfas de B. tabaci biótipo B do que o óleo de nim comercial.

  3. Biology of the citrus blackfly, Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae), in three host plants; Biologia da mosca-negra-dos-citros, Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae), em tres plantas hospedeiras

    Energy Technology Data Exchange (ETDEWEB)

    Pena, Marcia R.; Silva, Neliton M. da [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil).Lab. de Entomologia Agricola], e-mail: marciarpena@yahoo.com.br, e-mail: nmarques@ufam.edu.br; Venframim, Jose D.; Haddad, Marineia de L. [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Lab. de Resistencia de Plantas e Plantas Inseticidas], e-mail: jdvendra@esalq.usp.br, e-mail: mlhaddad@esalq.usp.br; Lourencao, Andre L. [Instituto Agronomico de Campinas (IAC), SP (Brazil)], e-mail: andre@iac.sp.gov.br

    2009-03-15

    The citrus blackfly, Aleurocanthus woglumi Ashby, was detected in Brazil in 2001. The aim of this research was to evaluate the biology, biometry and host preference of A. woglumi in sweet orange, acid lime Tahiti and mango. Experiments were set in laboratory conditions with insects collected in rangpur lime plants in Manaus, State of Amazonas, from January to June of 2006. The following parameters were evaluated: number of spirals (ovo positions) and eggs per plant, number of eggs by spiral per plant, survival of the immature (eggs, 1st, 2nd, 3rd and 4th instars), and length and survival of the immature stage. The mean embrionary period was 15 days for the three hosts. The 4th nymph (puparium) was the longest during nymph development. Second and third instars had the highest survival. The mean length of the egg-adult cycle was 70 days for the three hosts evaluated. The eggs were laid in a spiral shape on the adaxial leaf surface. The 1st instars moved to short distances from the spiral, while the 2nd, 3rd and 4th are sessile and have bristles on the whole body. Based on the highest oviposition and the highest survival of the immature stage of the citrus blackfly in acid lime Tahiti, this plant can be considered the most suitable host to A. woglumi. (author)

  4. Revisão do gênero Potnia Stål (Homoptera, Membracidae, Membracinae, Hoplophorionini Revision of the genus Potnia Stål (Homoptera, Membracidae, Membracinae, Hoplophorionini

    Directory of Open Access Journals (Sweden)

    Antônio J Creão-Duarte

    1996-01-01

    Full Text Available Fifteen species of Potnia Stål, 1866 are presented with descriptions, illustrations and a key for identification. The following nomenclatural changes are introduced: P. knightae sp.n. (from Guiana, P. miracyae sp.n. (from Costa Rica, P. diringshofeni sp.n. (from Brasil, P. webbi sp.n. (from Brazil, P. turrialbensis sp.n. (from Costa Rica, P. pinheiroi sp.n. (from Brazil, P. tapuruquarensis sp.n. (from Brasil, P. cornigera sp.n. (from Brazil and P. inca sp.n. (from Peru. Potnia venosa (Germar, 1821 = Aconophora nigrivittata Walker, 1851, syn.n. = Potnia perobtusa Fowler, 1894, syn.n.. Potnia brevicornis Fowler, 1894, sp. reval. = Potnia brunneifrontis Funkhouser, 1943, syn.n. = Potnia maculata Funkhouser, 1943, syn.n.. Potnia jacula (Fabricius, 1803 = Potnia orthosoma Fonseca & Diringshofen, 1974, syn.n.

  5. Avaliação de inseticidas no controle de Myzus persicae (sulz. (homoptera: aphididae na cultura da alface Evaluation of insecticides to control Myzus persicae (Sulz (Homoptera: Aphididae on lettuce crop

    Directory of Open Access Journals (Sweden)

    Jeferson Zagonel

    2002-09-01

    Full Text Available Foi avaliada a eficiência de inseticidas no controle de Myzus persicae (Sulz. na cultura da alface, cv. Verônica, em experimento conduzido na UEPG, em 1999. Usou-se delineamento experimental de blocos ao acaso com seis tratamentos e quatro repetições. Os tratamentos constaram de thiamethoxam nas doses de 50; 75 e 100 g i.a./ha; imidacloprid na dose de 140 g i.a./ha; pymetrozine na dose de 150 g i.a./ha e testemunha sem pulverização. Os tratamentos foram aplicados nas mudas em bandejas, um dia antes do transplantio. Avaliou-se a fitotoxicidade, o número de pulgões por planta, a porcentagem de plantas com pulgões e a eficiência dos inseticidas. O thiamethoxam nas doses de 50; 75 e 100 g i.a./ha foi eficiente no controle de M. persicae durante todo o ciclo, mostrando eficiência igual ou superior a 98,6%, similar ao imidacloprid. O pymetrozine apresentou eficiência no controle de M. persicae até 21 dias após o transplante das mudas. Os inseticidas não causaram efeitos fitotóxicos nas plantas de alface; além disso, houve produção de plantas com maior massa fresca em relação à testemunha.A field trial was carried out at Universidade Estadual de Ponta Grossa, State of Paraná, Brazil, in 1999, to evaluate the efficiency of insecticides in controlling Myzus persicae (Sulz on lettuce cv. Veronica. The experimental design was of completely randomized blocks with six treatments and four replications. The treatments consisted of thiamethoxam (50; 75 and 100 g i.a/ha imidacloprid (140 g i.a/ha; pymetrozine (150 g i.a/ha and control. The treatments were applied to seedlings grown in polyestyrene trays one day before the transplanting. The fitotoxicity, the number of aphids/plant, the percentage of plants with aphids and the efficiency of the insecticides were evaluated. Thiamethoxan at doses of 50; 75 and 100 g i.a/ha was efficient to control M. persicae from transplanting till 43 days after showing equal or higher efficiency than 98.6%, similar to imidacloprid. The pymetrozine was efficient to control M. persicae until 21 days after transplanting. Effects of fitotoxicity on lettuce plants were not observed. Higher fresh weight was observed in treated plants in comparison to the one of the control.

  6. Susceptibility of Bemisia tabaci MEAM1 (Hemiptera: Aleyrodidae to Imidacloprid, Thiamethoxam, Dinotefuran and Flupyradifurone in South Florida

    Directory of Open Access Journals (Sweden)

    Hugh A. Smith

    2016-10-01

    Full Text Available Populations of Bemisa tabaci MEAM1 were established from nineteen locations in south Florida, primarily from commercial tomato fields, and were tested using a cotton leaf petiole systemic uptake method for susceptibility to the nicotinic acetylcholine agonist insecticides imidacloprid, thiamethoxam, dinotefuran and flupyradifurone. Eleven populations produced LC50s for one or more chemicals that were not significantly different from the susceptible laboratory colony based on overlapping fiducial limits, indicating some degree of susceptibility. LC50s more than a 100-fold the laboratory colony were measured in at least one population for each material tested, indicating tolerance. LC50s (ppm from field populations ranged from 0.901–24.952 for imidacloprid, 0.965–24.430 for thiamethoxam, 0.043–3.350 for dinotefuran and 0.011–1.471 for flupyradifurone. Based on overlapping fiducial limits, there were no significant differences in relative mean potency estimates for flupyradifurone and dinotefuran in relation to imidacloprid and thiamethoxam.

  7. Response of Bemisia tabaci Genn. (Hemiptera: Aleyrodidae) biotype B to genotypes of pepper Capsicum annuum (Solanales: Solanaceae).

    Science.gov (United States)

    Ballina-Gomez, H; Ruiz-Sanchez, E; Chan-Cupul, W; Latournerie-Moreno, L; Hernández-Alvarado, L; Islas-Flores, I; Zuñiga-Aguilar, J J

    2013-04-01

    Bemisia tabaci Genn. biotype B is a widely distributed plant pest that represents one of the major constraints for horticultural crop production. The purpose of the present work was to evaluate the oviposition preference, survivorship, and development of B. tabaci biotype B on semi-cultivated genotypes of Capsicum annuum from southeast Mexico. In free-choice experiments to evaluate the oviposition preference, lower number of eggs laid by B. tabaci biotype B was observed in the genotypes Maax and Xcat´ik relative to that in the commercial genotype Parado. Egg hatchability was significantly lower in Pico Paloma, Bolita, Blanco, Chawa, Payaso, and Xcat´ik than in the rest of the genotypes, including the commercial genotype Jalapeño. Likewise, survivorship of nymphs was significantly lower in Pico Paloma, Bolita, and Blanco than in the remaining genotypes. Nymph developmental time and the period of development from egg to adult were the shortest in Amaxito. Therefore, sources of resistance to B. tabaci biotype B by antibiosis (accumulation of plant defense compounds) might be found in the semi-cultivated genotypes Pico Paloma, Bolita, and Blanco.

  8. Estudio de la resistencia a Bemisia tabaci (Gennadius (Hemiptera: Aleyrodidae en germoplasma cultivado y silvestre de tomate (Solanum lycopersicum L.

    Directory of Open Access Journals (Sweden)

    Yeimy García Valencia

    2013-12-01

    Full Text Available En la Universidad Nacional de Colombia sede Palmira, en condiciones de campo y casa de malla, se evaluaron por preferencia para oviposición y número de ninfas de mosca blanca (Bemisia tabaci (Gennadius varias accesiones silvestres y poblaciones segregantes de tomate resistentes al pasador del fruto, Neoleucinodes elegantalis (Guenée. Se utilizó un diseño de bloques completos al azar con cuatro repeticiones, donde se evaluaron como variables el número de huevos y de ninfas del insecto por hoja. En cada observación se incluyeron tres hojas del tercio superior, medio e inferior del tallo de la planta. Las poblaciones de mosca blanca fueron muy bajas en los dos primeros ciclos de cultivo (en campo debido, probablemente, a las altas precipitaciones. Estas condiciones no permitieron una selección de materiales resistentes o susceptibles a este insecto. En el tercer ciclo de cultivo, bajo condiciones de casa de malla, no se encontraron diferencias significativas entre los retrocruzamientos respecto al testigo susceptible para la variable preferencia por oviposición. El genotipo 4212P4 presentó el menor número de ninfas, mostrando que tiene posiblemente un mecanismo que le confiere menor atracción para B. tabaci. Se encontró que los genotipos menos preferidos para oviposición y con menor número de ninfas fueron PI 134417, PI 134418 y PI 126449 (Solanum habrochaites var. Glabratum S. Knapp y D. M Spooneer.

  9. Susceptibility of Bemisia tabaci MEAM1 (Hemiptera: Aleyrodidae) to imidacloprid, thiamethoxam, dinotefuran and flupyradifurone in south Florida

    Science.gov (United States)

    Populations of Bemisa tabaci Middle East Asia Minor 1 (MEAM 1) were established from nineteen locations in south Florida, primarily from commercial tomato fields, and were tested using a cotton leaf petiole systemic uptake method for susceptibility to the nicotinic acetylcholine agonist insecticides...

  10. First report and differential colonization of Passiflora species by the B biotype of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) in Brazil

    International Nuclear Information System (INIS)

    Nunes, Endson S.; Vieira, Maria L.C.; Lourencao, Andre L.; Piedade, Sonia M.S.

    2008-01-01

    This note is the first report of Bemisia tabaci (Gennadius) biotype B colonizing passionvine in Brazil. We examined the colonization of nine Passiflora species by a wild B type population under greenhouse conditions. P. amethystina Mikan was the most preferred species for oviposition and colonization, whereas P. suberosa L., P. coriacea Juss. and two commercially cultivated species, P. alata Curtis and P. edulis Sims f. flavicarpa Degener, were mostly uncolonised. P. morifolia Mast., P. cincinnata Mast., P. foetida L. and P. caerulea L. showed intermediate levels of colonization. Such differential colonization might suggest some degree of resistance by certain Passiflora species or oviposition preference by B. tabaci. (author)

  11. Life-history parameters of Encarsia formosa, Eretmocerus eremicus and E. Mundus, aphelinid parasitoids of Bemisia argentifolii (Hemiptera: Aleyrodidae)

    NARCIS (Netherlands)

    Qiu, Y.T.; Lenteren, van J.C.; Drost, Y.C.; Posthuma-Doodeman, J.A.M.

    2004-01-01

    Life-history parameters (juvenile development time, adult longevity, host instar preference and rate of parasitism) offour parasitoids of Bemisia argentifolii (two strains of Encarsia formosa (D and B), Eretmocerus eremicus and Eretmocerus mundus) Were Studied in the laboratory. At 15degreesC

  12. Plan de muestreo directo para Trialeurodes vaporariorum (Westwood (Hemiptera: Aleyrodidae en cultivos comerciales de tomate

    Directory of Open Access Journals (Sweden)

    Bernal Liliana

    2008-08-01

    Full Text Available

    Los daños ocasionados por Trialeurodes vaporariorum generan pérdidas económicas que disminuyen la producción y pueden contribuir en el alza de los precios del tomate. Para su control se acude a aplicaciones continuas de insecticidas, sin obtener resultados satisfactorios. Como alternativa de control se realizan liberaciones del parasitoide E. formosa. Sin embargo, el éxito de este sistema implica estimar la densidad de la plaga a través de un método de muestreo adecuado. Por ello, se estandarizó un plan de muestreo directo, económicamente viable, para ninfas de mosca blanca en un cultivo comercial de tomate bajo invernadero. Se determinó la incidencia de prácticas de manejo y de la fenología en la distribución espacial de ninfas. En términos generales, el muestreo se dividió en tres etapas: 1 muestreo totalmente aleatorio, entre las 5 y 7 semanas después de la siembra (sds, para plantas no divididas en tercios; 2 muestreo aleatorio, entre las 8 y 16 sds, los conteos se realizaron en hojas del tercio inferior; 3 muestreo bietápico: planta y hoja, entre las 17 y 24 sds, los conteos se efectuaron sobre hojas de los tercios medio y superior. Se encontró que prácticas culturales como el despunte influyeron en la distribución espacial de las ninfas. La implementación del muestreo directo generó un incremento en la producción del 0,06% y permitió estimar la densidad de ninfas de Trialeurodes vaporariorum en el cultivo (con precisiones de 5%, 10% y 25% como criterio para liberar E. formosa.

  13. Status of Resistance of Bemisia tabaci (Hemiptera: Aleyrodidae) to Neonicotinoids in Iran and Detoxification by Cytochrome P450-Dependent Monooxygenases.

    Science.gov (United States)

    Basij, M; Talebi, K; Ghadamyari, M; Hosseininaveh, V; Salami, S A

    2017-02-01

    Nine Bemisia tabaci (Gennadius) populations were collected from different regions of Iran. In all nine populations, only one biotype (B biotype) was detected. Susceptibilities of these populations to imidacloprid and acetamiprid were assayed. The lethal concentration 50 values (LC 50 ) for different populations showed a significant discrepancy in the susceptibility of B. tabaci to imidacloprid (3.76 to 772.06 mg l -1 ) and acetamiprid (4.96 to 865 mg l -1 ). The resistance ratio of the populations ranged from 9.72 to 205.20 for imidacloprid and 6.38 to 174.57 for acetamiprid. The synergistic effects of piperonylbutoxide (PBO) and S,S,S-tributylphosphorotrithioate (DEF) were evaluated for the susceptible (RF) and resistant (JR) populations for the determination of the involvement of cytochrome P450-dependent monooxygenase and carboxylesterase, respectively, in their resistance mechanisms. The results showed that PBO overcame the resistance of the JR population to both imidacloprid and acetamiprid, with synergistic ratios of 72.7 and 106.9, respectively. Carboxylesterase, glutathione S-transferase and cytochrome P450-dependent monooxygenase were studied biochemically, for the purpose of measuring the activity of the metabolizing enzymes in order to determine which enzymes are directly involved in neonicotinoid resistance. There was an increase in the activity of cytochrome P450-dependent monooxygenase up to 17-fold in the resistant JR population (RR = 205.20). The most plausible activity of cytochrome P450-dependent monooxygenase correlated with the resistances of imidacloprid and acetamiprid, and this suggests that cytochrome P450-dependent monooxygenase is the only enzyme system responsible for neonicotinoid resistance in the nine populations of B. tabaci.

  14. First report and differential colonization of Passiflora species by the B biotype of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Endson S.; Vieira, Maria L.C. [Escola Superior de Agricultura Luiz de Queiroz (ESALQ-USP), Piracicaba, SP (Brazil). Dept. de Genetica]. E-mail: esnunes@carpa.ciagri.usp.br; mlcvieir@esalq.usp.br; Brown, Judith K. [University of Arizona, Tucson, AZ (United States). Dept. of Plant Sciences]. E-mail: jbrown@Ag.arizona.edu; Moreira, Adriana G.; Rezende, Jorge A.M. [Escola Superior de Agricultura Luiz de Queiroz (ESALQ-USP), Piracicaba, SP (Brazil). Dept. de Entomologia, Fitopatologia e Zoologia Agricola]. E-mails: agmoreir@esalq.usp.br; amrezen@esalq.usp.br; Watson, Gillian [California Dept. of Food and Agriculture, Sacramento, CA (United States)]. E-mail: gwatson@cdfa.ca.gov; Lourencao, Andre L. [Instituto Agronomico, Campinas, SP (Brazil). Centro de Pesquisa e Desenvolvimento de Fitossanidade]. E-mail: andre@iac.sp.gov.br; Piedade, Sonia M.S. [Escola Superior de Agricultura Luiz de Queiroz (ESALQ-USP), Piracicaba, SP (Brazil). Dept. de Ciencias Exatas]. E-mail: jsoniamsp@esalq.usp.br

    2008-11-15

    This note is the first report of Bemisia tabaci (Gennadius) biotype B colonizing passionvine in Brazil. We examined the colonization of nine Passiflora species by a wild B type population under greenhouse conditions. P. amethystina Mikan was the most preferred species for oviposition and colonization, whereas P. suberosa L., P. coriacea Juss. and two commercially cultivated species, P. alata Curtis and P. edulis Sims f. flavicarpa Degener, were mostly uncolonised. P. morifolia Mast., P. cincinnata Mast., P. foetida L. and P. caerulea L. showed intermediate levels of colonization. Such differential colonization might suggest some degree of resistance by certain Passiflora species or oviposition preference by B. tabaci. (author)

  15. Phenology, natural enemies, and efficacy of horticultural oil for control of Chionaspis heterophyllae (Homoptera: Diaspididae) on Christmas tree plantations.

    Science.gov (United States)

    Fondren, Kirsten M; McCullough, Deborah G

    2005-10-01

    Pine needle scale, Chionaspis pinifoliae (Fitch), and Chionaspis heterophyllae Cooley are important pests of Scots pine, Pinus sylvestris L., and other conifers in much of North America. On Christmas tree plantations, these insects are typically controlled by spraying broad-spectrum insecticides when the vulnerable immature stages are present. However, effective control of bivoltine populations can be difficult to achieve due to asynchronous hatch and development of the second generation. Our objectives were to 1) determine the phenology of the second generation of C. heterophyllae in Michigan; 2) characterize the natural enemy complex; and 3) assess the effectiveness of horticultural oil for control of C. heterophyllae on P. sylvestris Christmas tree plantations. We monitored scale populations in three counties in lower Michigan for 3 yr. Scale phenology was consistently associated with cumulative degree-days base 10 degrees C (DD(10 degrees C)). Second-generation egg hatch began at approximately 1230-1300 DD(10 degrees C), and continued for approximately 3 wk. The peak of the second instar coincided with 1500-1600 DD(10 degrees C). Common predators included the coccinellids Chilocorus stigma (Say) and Microweisia misella (LeConte). On average, 70% of the C. heterophyllae population in unsprayed fields was killed by predators in 1999. Two endoparasitic wasps, Encarsia bella Gahan and Marietta mexicana Howard (Hymenoptera: Aphelinidae), also were recovered. In 2000 and 2001, we applied a highly refined horticultural spray oil with a backpack mist blower at 1500-1600 DD(10 degrees). Scale mortality on trees treated with oil ranged from 66 to 80% and was similar to control achieved using conventional insecticides in both years.

  16. Pear transformed with a lytic peptide gene for disease control affects nontarget organism, pear psylla (Homoptera: Psyllidae).

    Science.gov (United States)

    Puterka, Gary J; Bocchetti, Chris; Dang, Phat; Bell, R L; Scorza, Ralph

    2002-08-01

    The biology and behavior of pear psylla, Cacopsylla pyricola Foerster, on a transgenic clone of 'Bartlett' pear, Pyrus communis L., containing a synthetic antimicrobial gene, D5C1, was compared with that of a nontransgenic parental clone to determine whether there were any nontarget effects. The gene construct also contained the marker gene nptII (aminoglycoside 3'-phosphotransferase II) that encodes for antibiotic resistance to identify transformed plants. The purpose of the original transformation was to enhance pear resistance to the bacterial disease fireblight caused by Erwinia amylovora (Burr.) Winslow et al. The biology and behavior of pear psylla on a transgenic clone were compared with a nontransgenic parental pear clone in short- (crops.

  17. Scale insects and mealy bugs (Homoptera: Coccoidea) attacking deciduous fruit trees in the western north coast of Alexandria, Egypt.

    Science.gov (United States)

    Mourad, A K; Moursi Khadiga, S; Mesbah, H A; Abdel-Razak Soad, I

    2008-01-01

    This investigation covered a survey of scale insects and mealy bugs infesting ten growing species of deciduous fruit trees in three localities in Alexandria govemorate. These localities were Merghem, Burg El-Arab, and El-Nahda about 50 Km. West of Alexandria under both rain-fed and irrigation system conditions. The common inspected fruit trees were fig, white mulberry, pomegranate, apple, pear, apricot, European plum, peach, almond, and persimmon. It was shown that a group of twenty scale insects and meaty bug species pertaining to fifteen genera belonging to six families of the super family: Coccoidea were collected and identified during the elapsing period from January to December, 2004. Among these species, Diaspidiotus perniciosus (Comstock) was recorded for the first time in Egypt. In the present study, many insect and non-insect parasitoids and predators were also found associated with these scale insects and mealy bugs on deciduous fruit trees in the three concerned localities throughout this investigation. These natural enemies were identified and recorded.

  18. Life table analysis of the performance of aphid Sitobion avenae (Homoptera: Aphididae nymphs exposed to a static magnetic field

    Directory of Open Access Journals (Sweden)

    He Juan

    2013-01-01

    Full Text Available Using the age-stage two-sex life table, this work was undertaken in order to determine the effect of static magnetic fields (SMFs at two flux densities (0.176T and 0.065T applied at increasing times of duration (0.25, 0.5, 1 and 2 h on the development, fecundity and reproduction of the aphid, Sitobion avenae. Exposed nymphs had a statistically significant shortened first instar period and adult longevity and prolonged fourth instar periods compared to controls. There were significant differences in the population parameters for two exposure combinations, 0.176T for 0.5 h and 0.065T for 1 h. The intrinsic rate of increase (r, net reproductive rate (R0 and mean generation time (T were 0.1165, 3.5 and 11.7 days, respectively, 0.176 T for 0.5 h and -0.0198, 0.7 and 11.8 days, respectively, 0.065T for 1 h. We therefore recommend using the age-stage, two-sex life table to study the effect of the static magnetic field on development and growth of the aphid, Sitobion avenae.

  19. Bacterial symbionts, Buchnera, and starvation on wing dimorphism in English grain aphid, Sitobion avenae (F. (Homoptera: Aphididae

    Directory of Open Access Journals (Sweden)

    Fangmei eZhang

    2015-05-01

    Full Text Available Wing dimorphism in aphids can be affected by multiple cues, including both biotic (nutrition, crowding, interspecific interactions, the presence of natural enemies, maternal and transgenerational effects, and alarm pheromone and abiotic factors (temperature, humidity, and photoperiod. The majority of the phloem-feeding aphids carry Buchnera, an obligate symbiotic proteobacteria. Buchnera has a highly reduced genome size, but encode key enzymes in the tryptophan biosynthetic pathway and is crucial for nutritional balance, development and reproduction in aphids. In this study, we investigated the impact of two nutritional-based biotic factors, symbionts and starvation, on the wing dimorphism in the English grain aphid, Sitobion avenae, a devastating insect pest of cereal crops (e.g., wheat worldwide. Elimination of Buchnera using the antibiotic rifampicin significantly reduced the formation of winged morphs, body mass and fecundity in S. avenae. Furthermore, the absence of this primary endosymbiont may disrupt the nutrient acquisition in aphids and alter transgenerational phenotypic expression. Similarly, both survival rate and the formation of winged morphs were substantially reduced after neonatal (< 24h old offspring were starved for a period of time. The combined results shed light on the impact of two nutritional-based biotic factors on the phenotypic plasticity in aphids. A better understanding of the wing dimorphism in aphids will provide the theoretical basis for the prediction and integrated management of these phloem-feeding insect pests.

  20. A new genus and new species of felt scales (Homoptera: Coccinea: Eriococcidae from Tierra del Fuego (Chile

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    Ilya A. Gavrilov-Zimin

    2016-10-01

    Full Text Available Telmatococcus igniumterrae gen. nov. et sp. nov. is described and illustrated based on the material collected from a sphagnum bog in the extreme southern part of South America (Tierra del Fuego. The new monotypic genus differs from all known genera of Eriococcidae in having short cylindrical truncated setae of the anal apparatus and pouches with numerous quinquelocular pores near the anal apparatus. The habitat of the new taxon is characterized.

  1. The environmental plasticity of diverse body color caused by extremely long photoperiods and high temperature in Saccharosydne procerus (Homoptera: Delphacidae

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    Haichen Yin

    2016-09-01

    Full Text Available Melanization reflects not only body color variation but also environmental plasticity. It is a strategy that helps insects adapt to environmental change. Different color morphs may have distinct life history traits, e.g., development time, growth rate, and body weight. The green slender planthopper Saccharosydne procerus (Matsumura is the main pest of water bamboo (Zizania latifolia. This insect has two color morphs. The present study explored the influence of photoperiod and its interaction with temperature in nymph stage on adult melanism. Additionally, the longevity, fecundity, mating rate, and hatching rate of S. procerus were examined to determine whether the fitness of the insect was influenced by melanism under different temperature and photoperiod. The results showed that a greater number of melanic morphs occurred if the photoperiod was extremely long. A two-factor ANOVA showed that temperature and photoperiod both have a significant influence on melanism. The percentages of variation explained by these factors were 45.53% and 48.71%, respectively. Moreover, melanic morphs had greater advantages than non-melanic morphs under an environmental regime of high temperatures and a long photoperiod, whereas non-melanic morphs were better adapted to cold temperatures and a short photoperiod. These results cannot be explained by the thermal melanism hypothesis. Thus, it may be unavailable to seek to explain melanism in terms of only one hypothesis.

  2. The impact of some physiomorphic characters of sugarcane genotypes on their resistance against sugarcane pyrilla, pyrilla perpusilla wlk. (lophopidae: homoptera)

    International Nuclear Information System (INIS)

    Rasul, A.; Hassan, M.; Suhail, A.; Sahi, S.T.

    2010-01-01

    Field trials were conducted in the Research Area, Directorate of Sugarcane, Ayub Agricultural Research Institute, Faisalabad to study he physio-morphic characters of sugarcane resistance to the sucking pest Pyrilla perpusilla. Twenty genotypes of sugarcane were tested for their resistance susceptibility against P. perpusilla, as a preliminary screening experiment, during 2006. Based on the population-density count, 3 genotypes, viz., HSF- 240, CPF-243 and S-2002-US-114 showing resistance responses, 3 genotypes viz. CPHS-35, S-2003-US-394 and S-2003-US-623 showing susceptible trends and 3 genotypes viz. S-2003-US-809, S-2002-US-140 and S- 2002-US-104 exerting intermediate trends against the pest under test were selected for the final screening trials during 2007.The genotype S-2003-US-623, was found to be comparatively susceptible; whereas, HSF-240, showed resistance responses. The leaf-width and cane length showed a positive and significant correlation whereas the leaf-spine density had a significant negative effect with pest-population. The Leaf-length and Cane-Diameter did not show a significant correlation with the pest population. (author)

  3. Insecticide susceptibility of the green plant bug, Apolygus lucorum Meyer-Dür (Homoptera: Miridae and two predatory arthropods

    Directory of Open Access Journals (Sweden)

    Zhang Zhengqun

    2015-12-01

    Full Text Available The green plant bug (Apolygus lucorum Meyer-Dür is a key pest of Bt cotton in China. Along with biological control, chemical control is one of the most important strategies in A. lucorum Integrated Pest Management (IPM. The goal of this study was to evaluate the toxicity of eight conventional insecticides to A. lucorum and to assess the susceptibility of two generalist predators Chrysopa sinica (Jieder and Propylaea japonica (Thunbery to insecticides that are commonly used in A. lucorum management. Via glass-vial and leaf-dip bioassay, toxicity tests with selected insecticides at two different life-stages of A. lucorum indicated significant differences between the LD50 or LC50 values for these compounds within different insecticidal classes. Phenylpyrazole fipronil had the highest toxicity to 4th-instar nymphs and adults of A. lucorum, whereas neonicotinoid imidacloprid had the lowest toxicity among the insecticides. Females were more tolerant to insecticides than were males, as shown by the higher LD50 values for females. Furthermore, laboratory tests showed that endosulfan had the highest selectivity to C. sinica and P. japonica: the selective toxicity ratios (STRs were superior to other tested insecticides, particularly imidacloprid, and were 5.396 and 4.749-fold higher than baseline STRs, respectively. From this study, we conclude that fipronil can potentially be used to efficiently control A. lucorum. An alternative control agent worth consideration is endosulfan, owing to its relative safety to non-targeted natural enemies.

  4. Performance of novel vs traditional insecticides for the control of amrascs biguttula biguttula (homoptera, cicadellidae) on cotton

    International Nuclear Information System (INIS)

    Karar, H.; Babar, T.K.; Shahzad, F.; Saleem, M.; Ali, A.; Akram, M.

    2013-01-01

    Amrasca biguttula biguttula (ishida) can reduce the yield of cotton approximately 25%. no potential predators have been recorded in the field for its control. to overcome this pest insecticides play significant role in the improvement of crop yields all over the world during the last four to five decades. to save the crop from this notorious pest, ten formulations of insecticides viz., acephate 75sp (acephate) at the rate 625g, imidacloprid 25wp (imidacloprid) at the rate188g, thiamethaxim 25wg (actara) at the rate 60g, imidacloprid 70wg (confidor) at the rate 43g, dimethoat e 40ec (sanitox) at the rate 1000 ml, nytonpyron 10sl (pyramid) at the rate 500ml, lambdacyhlothrin 2.5e (kango) at the rate 825 ml, thiachloprid 480sc (talent) at the rate 63 ml, imidacloprid 25sl (confidor) at the rate 500ml, and diafenthiuron 500sc (polo), at the rate 500ml, per hectare were sprayed in the field having maximum population of nymphs and adults of jassid at cotton research station, multan on cotton variety bt-886 in the month of july, 2011 and 2012. the maximum mortality of Jassid was observed in those treatments, where acephate was applied with 79, 72, 65 mortality, nytonpyron with 69, 63, 55 and imidacloprid 68, 63, 57 percent mortality after 24, 72 and 168 h of spray. minimum mortality of jassid was observed in the treatments where talent was applied having 25, 17 and 16 percent mortality 24, 72 and 168 h after spray. By the application of acephate, pyramid and confidor 25sl on cotton crop the yield can be increased. (author)

  5. Inheritance Mode and Realized Heritability of Resistance to Imidacloprid in the Brown Planthopper, Nilaparvata lugens (Stal) (Homoptera: Delphacidae)

    Science.gov (United States)

    BACKGROUND: The brown planthopper, Nilaparvata lugens (Stål) is a serious pest which causes enormous losses to the rice crop in Asia. The genetic basis of imidacloprid resistance was investigated in N. lugens. RESULTS: The resistant strain, selected for imidacloprid resistance from a laboratory pop...

  6. Effect of different humidity levels on the biology of longtailed mealy bug pseudococcus longispinus (targioni and tozzetti) (homoptera: pseudococidae)

    International Nuclear Information System (INIS)

    Gillani, W.A.

    2009-01-01

    On determining the effects of different humidity levels on the biology of mealy bug Pseudococcus longispinus (Targioni and Tozzetti), it was found that the relative humidity (RH) at 35%, 55% and 75% had no effect on pre-adult development, adult longevity, life span and fecundity of P. longispinus. The survival of pre-adult stages was minimal at 35% RH. Sex ratio was male-biased at 35% RH and female-biased at 75% RH. (author)

  7. Comparison of AC electronic monitoring and field data for estimating tolerance to Empoasca kraemeri (Homoptera: Cicadellidae) in common bean genotypes.

    Science.gov (United States)

    Serrano, M S; Backus, E A; Cardona, C

    2000-12-01

    Two methods for estimating the tolerance of common bean genotypes to Empoasca kraemeri Ross & Moore were compared, using a yield trial carried out at Centro Internacional de Agricultura Tropical (CIAT), Cali, Colombia, versus stylet penetration tactics measured by AC electronic feeding monitors. A stylet penetration index was devised based on principal component scores of three penetration tactics identified (pulsing laceration, cell rupturing, and lancing sap ingestion), combined with knowledge of the hopperburn symptoms caused by each tactic. Tolerant genotypes, as classified by the CIAT yield index, showed significantly more unprotected yield and lower hopperburn scores than the susceptible control. They also induced performance of less pulsing laceration (the tactic considered most damaging to the plant), and more of the other two, mitigating tactics, especially cell rupturing. When index values were calculated for each genotype, stylet penetration index values matched those of the yield index for three out of five genotypes: two EMP-coded tolerant lines ('EMP 385' and 'EMP 392') and the susceptible control 'BAT 41'. Thus, for these three genotypes, all subsequent hoppereburn symptoms are predictable by the type of feeding behavior performed on them. 'Porrillo Sintético' and 'EMP 84', considered borderline genotypes by the yield index, were overestimated and underestimated respectively, by the stylet penetration index. We postulate that, for these two genotypes, plant physiological responses to feeding (either compensatory or heightened sensitivity, respectively) synergize with type of feeding performed to generate the overall hopperburn condition. This multivariate analysis of electronic monitoring data was successfully used to devise an index of resistance. The implications of using the stylet penetration index and the advantages of using electronic monitoring in a bean-breeding program are discussed.

  8. Buprofezin susceptibility survey, resistance selection and preliminary determination of the resistance mechanism in Nilaparvata lugens (Homoptera: Delphacidae).

    Science.gov (United States)

    Wang, Yanhua; Gao, Congfen; Xu, Zhiping; Zhu, Yu Cheng; Zhang, Jiushuang; Li, Wenhong; Dai, Dejiang; Lin, Youwei; Zhou, Weijun; Shen, Jinliang

    2008-10-01

    Buprofezin has been used for many years to control Nilaparvata lugens (Stål). Assessment of susceptibility change in the insect is essential for maintaining control efficiency and resistance management. Eleven-year surveys showed that most field populations were susceptible before 2004. However, substantially higher levels of resistance (up to 28-fold) were found in most of the rice fields in China after 2004. A field population was collected and periodically selected for buprofezin resistance in the laboratory. After 65 generations (56 were selected), the colony successfully obtained 3599-fold resistance to buprofezin. Synergism tests showed that O,O-diethyl-O-phenyl phosphorothioate (SV1), piperonyl butoxide (PBO) and diethyl maleate (DEM) increased buprofezin toxicity in the resistant strain by only 1.5-1.6 fold, suggesting that esterases, P450-monooxygenases and glutathione S-transferases had no substantial effect on buprofezin resistance development. The results from this study indicate that N. lugens has the potential to develop high resistance to buprofezin. A resistance management program with rotation of buprofezin and other pesticides may efficiently delay or slow down resistance development in the insect. Further investigation is also necessary to understand the resistance mechanisms in N. lugens.

  9. Susceptibility to neonicotinoids and risk of resistance development in the brown planthopper, Nilaparvata lugens (Stål) (Homoptera: Delphacidae).

    Science.gov (United States)

    Wang, Yanhua; Chen, Jin; Zhu, Yu Cheng; Ma, Chongyong; Huang, Yue; Shen, Jinliang

    2008-12-01

    In recent years, outbreaks of the brown planthopper, Nilaparvata lugens (Stål), have occurred more frequently in China. The objective of this study was to determine the susceptibility of N. lugens to neonicotinoids and other insecticides in major rice production areas in China. Results indicated that substantial variations in the susceptibility to different insecticides existed in N. lugens. Field populations had developed variable resistance levels to neonicotinoids, with a high resistance level to imidacloprid (RR: 135.3-301.3-fold), a medium resistance level to imidaclothiz (RR: 35-41.2-fold), a low resistance level to thiamethoxam (up to 9.9-fold) and no resistance to dinotefuran, nitenpyram and thiacloprid (RR buprofezin. In addition, N. lugens had been able to develop 1424-fold resistance to imidacloprid in the laboratory after the insect was selected with imidacloprid for 26 generations. Long-term use of imidacloprid in a wide range of rice-growing areas might be associated with high levels of resistance in N. lugens. Therefore, insecticide resistance management strategies must be developed to prevent further increase in resistance.

  10. Varietals resistance and susceptibility in mustard (brassica campestris l.) genotypes against aphid myzus persicae (sulzer) (homoptera: aphididae)

    International Nuclear Information System (INIS)

    Sarwar, M.; Ahmad, N.; Khan, G.Z.; Tofique, M.

    2009-01-01

    The exploitation of resistant cultivars is an imperative, simple, practical and flexible way to cope with insect pests incidence. Thirty genotypes of mustard (Brassica campestris L.) were tested for their resistance and susceptibility to aphid Myzus persicae (Sulzer) exposed under natural field conditions. Data on pest tolerance of genotypes were judged by quantitative traits such as number of aphids on each infested plant and mean dry weight of seeds per genotype. Studies observed the discrepancy in overall rates of pest invasion and seed yield contained by trailed mustard genotypes. Agati sarson (P), S-9-S-97-100/45 and S-9-S-97-100/45 were the least damaged genotypes showing their moderate resistance. Amongst other genotypes, MM-I/01-5, MM-I285 and MM-I/01-6 were the most damaged showing oversensitive response. Although the majority of genotypes were found vulnerable to pest, Agati sarson (P) and S-9-S-97-100/45 due to their lowest hypersensitive response toward aphid contamination and increased pods yield could be used for the development of essential resistance in mustard plant. A marked mode of damage inflicted by aphid on the crop was noticed and the abiotic factors contributing variations in aphid infestation levels during both growing seasons were determined. Knowledge about the host plant resistance investigated can facilitate growers to choose the most appropriate cultivars as pest control strategy. (author)

  11. Interplant movement and spatial distribution of alate and apterous morphs of Nasonovia ribisnigri (Homoptera: Aphididae) on lettuce.

    Science.gov (United States)

    Diaz, B M; Barrios, L; Fereres, A

    2012-08-01

    Knowledge on colonization modes and interplant movement of Nasonovia ribisnigri can contribute to the development of optimal control of this pest. The aim of this study was to determine the spatio-temporal distribution and the mode of spread between adult morphs of Nasonovia ribisnigri, comparing spring and autumn lettuce protected crops. The spatial and temporal pattern was analyzed using the spatial analysis by distance indices (SADIE) methodology and other related displacement indices. The population size of N. ribisnigri was greater in the autumn than in the spring growing seasons due to milder temperatures. The percentage of plants colonized by aphids was higher in spring than in autumn, showing the great dispersal potential of this aphid species independent of their population size. Differential propensity for initial displacement from the central plant was observed between adult morphs in spring, resulting in a greater ability of apterous than alate aphids to spread far away from the source plant. In autumn, both adult morphs showed an initial reduced displacement; however, the number of plants infested (≈20%) with at least one aphid at this initial time (seven days) was similar for both adult morphs and both growing seasons. Analysis of the spatial pattern of both adult morphs revealed a predominantly random distribution for both spring and autumn trials. This pattern was achieved by a prevalent random movement over the area (γ≈0.5). These results highlight the ability of the apterous N. ribisnigri to spread within greenhouse lettuce crops early in the spring, suggesting that detection of the pest by deep visual inspection is required after lettuce emergence.

  12. Effects of insecticides used in Bemisia tabaci (Gennadius biotype B control and their selectivity to natural enemies in soybean cropEfeitos dos inseticidas utilizados no controle de Bemisia tabaci (Gennadius biótipo B e sua seletividade aos inimigos naturais na cultura da soja

    Directory of Open Access Journals (Sweden)

    Simone Silva Vieira

    2012-10-01

    Full Text Available In recent crop seasons, the whitefly, Bemisia tabaci biotype B has become a serious pest in soybean crops due to high infestations and its control difficulties. Therefore, it is important to search control alternatives in the integrated pest management approach. Thus, it was evaluated in this study the efficacy of the whitefly control using different insecticides in greenhouse conditions and their selectivity to the parasitoids Encarsia formosa, Trichogramma pretiosum and Telenomus remus. Buprofezin 150 g. a.i.ha-1 + mineral oil 0.2% v/v and pyriproxyfen 100 g. a.i.ha-1 were considered the best options for the whitefly management due to combine good pest control efficacy with higher selectivity to the parasitoids except Encarsia formosa for which no treatment was classified as harmless. Betacyflutrin 9.375 + imidacloprid 75 g. i.a. ha-1 was efficient on controlling whiteflies nymphs but was not harmless to the studied natural enemies. In general, the treatments including pyretroids compounds (betacyflutrin 9.375 + imidacloprid 75 + spiromesifen 60, betacyflutrin 9.375 + imidacloprid 75 and lambda-cyhalothrin 26.5 + thiametoxan 35.25 g. a.i. ha-1 were the most harmful to the evaluated parasitoids and therefore it use should be avoid whenever possible. Nas últimas safras a mosca-branca, Bemisia tabaci biótipo B (Hemiptera: Aleyrodidae tornou-se praga de importância econômica para a cultura da soja devido à ocorrência de altas infestações e à dificuldade de controle desta praga. Sendo assim, é importante buscar alternativas de manejo com base em um programa de manejo integrado de pragas. Assim, avaliaram-se neste trabalho a eficiência de diferentes inseticidas no controle da mosca-branca em casa-de-vegetação e a seletividade destes aos parasitoides Encarsia formosa, Trichogramma pretiosum e Telenomus remus. Buprofezina 150 g i.a. ha-1 + óleo mineral 0,2% v/v e piriproxifem 100 g. i.a. ha-1 foram consideradas as melhores opções para

  13. Developing an Alternanthera mosaic virus vector for efficient clonging of Whitefly cDNA RNAi to screen gene function

    Science.gov (United States)

    Alternanthera mosaic virus (AltMV; genus Potexvirus) is distinguished from the type member of the genus, Potato virus X by features of viral movement and variation within triple gene block protein 1 (TGB1). AltMV TGB1 variants TGB1L88 and TGB1P88 confer strong and weak silencing suppression, respect...

  14. Keanekaragaman dan Kelimpahan Musuh Alami Bemisia tabaci (Gennadius (Hemiptera: Aleyrodidae pada Pertanaman Cabai Merah di Kecamatan Pakem, Kabupaten Sleman, Daerah Istimewa Yogyakarta

    Directory of Open Access Journals (Sweden)

    Hendrival Hendrival

    2015-09-01

    Full Text Available Research on natural enemies of Bemisia tabaci was conducted in the chili pepper fields in Sub-district of Pakem, District of Sleman, The Special Province of Yogyakarta during the dry season of May-October 2009. The aims of this research were to study the diversity and abundance of parasitoid and predator species associated with B. tabaci. Samplings of insect species were done using yellow pan trap, sweep net, direct observation of insects colonized young leaves, and collection of nymphs for B. tabaci. Measurement of insect diversity was calculated using Shannon’s index diversity and Evenness index. Nine species of insect predator were identified, i.e. Harmonia octomaculata (Fabricius, Menochilus sexmaculata (Fabricius, Scymnus sp., Micraspis inops Mulsant, Coccinella sp. (Coleoptera: Coccinellidae, Paederus fuscipes Curtis (Coleoptera: Staphylinidae, Orius sp. (Hemiptera: Anthocoridae, Linyphiidae sp.1 (Araneae, and Syrphidae sp.1 (Diptera. Eretmocerus sp. (Hymenoptera: Aphelinidae was the only parasitoid found in the nymphs B. tabaci collected and has the potential to control B. tabaci in the red pepper fields.

  15. A study of the super-abundant Bemisia tabaci (Gennadius) species complex (Hemiptera: Aleyrodidae) in cassava Mosaic disease pandemic areas in Tanzania

    DEFF Research Database (Denmark)

    Tajebe, Lensa Sefera

    (Manihot esculenta Crantz) – one of the most important food security crops in sub-Saharan Africa. After the outbreak and spread of a severe form of CMD from Uganda to several East and African countries, the production of cassava has been impaired causing severe yield loss resulting in food shortages....../Hamiltonella/Wolbachia with Arsenophonus or Cardinium. Similarly, double and multiple infections were also common in the IO and EA1 putative species where EA1 individuals commonly harboured Cardinium/Wolbachia with several additional combinations of Rickettsia, Hamiltonella or Arsenophonus. The secondary endosymbiont Fritschea was never...... in the area in general and in understanding this super-abundant pandemicassociated population in particular. Specific studies to assess the presence of other secondary endosymbionts, antibiotic treatments to eliminate certain endosymbionts or to artificially introduce endosymbionts are paramount to fully...

  16. Medición indirecta de la tasa de consumo de adultos e inmaduros de Trialeurodes vaporariorum (Hemiptera: Aleyrodidae sobre fríjol

    Directory of Open Access Journals (Sweden)

    Luisa Fernanda Suarez Gonzalez

    2015-09-01

    Full Text Available La biología y ecología de la mosca blanca de los invernaderos, Trialeurodes vaporariorum (Westwood (Hemiptera: Aleyroridae, se encuentra ampliamente documentada. Sin embargo, hasta el momento no hay reportes acerca de la tasa de consumo de alimento por este fitófago, un parámetro necesario para modelos de simulación. Por tal motivo, el objetivo de esta investigación fue la medición indirecta del consumo de alimento por el adulto e instares inmaduros de T. vaporariorum basado en metodologías encontradas en la literatura científica. La estimación de la tasa de consumo de alimento por adultos se realizó bajo condiciones de laboratorio, utilizando como unidad experimental una planta de fríjol de dos semanas de edad. El experimento consistió de dos tratamientos: (T1 plantas libres de cualquier fitófago y (T2 plantas sometidas a infestaciones con T. vaporariorum, cada tratamiento con 20 repeticiones y una réplica en el tiempo de todo el experimento. Se registró el peso fresco diariamente en ambos tratamientos. Para el caso de los inmaduros, la unidad experimental consistió en una hoja cotiledónea de fríjol, infestada con una población determinada de inmaduros de cada instar de mosca blanca teniendo así cinco tratamientos (Instar I, II, III, IV y Control cada uno con 17 repeticiones. Se registró diariamente el peso fresco de las hojas. Se obtuvo un consumo promedio de alimento por el adulto de 0,277 ± 0,0042 mg.dia-1. Para los dos primeros instares ninfales se estimó una tasa de consumo de 0,052 mg.dia-1, en el tercer instar de 0,14 mg.dia-1, y para el cuarto instar de 0,19 mg.dia-1. Un adulto de mosca blanca puede consumir en un día seis veces su peso y un inmaduro ocho veces, gracias a su rápido metabolismo y la constante excreción de mielecilla.

  17. Primer registro de “la mosca negra de los cítricos” Aleurocanthus woglumi (Hemiptera: Aleyrodidae en la Argentina

    Directory of Open Access Journals (Sweden)

    Silvia N. LÓPEZ

    2011-01-01

    Full Text Available Aleurocanthus woglumi Ashby es una especie polífaga que ataca principalmente cultivos de Citrus spp. El objetivo de este trabajo es dar a conocer la primera detección de A. woglumi en Argentina. Los especímenes estudiados fueron recolectados en cultivos de pomelo en Tres Lagunas, departamento de Pilagá, Formosa, en febrero de 2011.

  18. Female-induced increase of host-plant volatiles enhance specific attraction of aphid male Dysaphis plantaginea (Homoptera: Aphididae) to the sex pheromone

    NARCIS (Netherlands)

    Tol, van R.W.H.M.; Helsen, H.H.M.; Griepink, F.C.; Kogel, de W.J.

    2009-01-01

    All aphid species studied so far share the same sex pheromone components, nepetalactol and nepetalactone. Variation by different enantiomers and blends of the two components released by different aphid species are limited and can only partially explain species-specific attraction of males to

  19. Comparative field evaluation of some newer versus conventional insecticides for the control of aphids (homoptera: aphididae) on oilseed rape (brassica napus l.)

    International Nuclear Information System (INIS)

    Sarwar, M.; Ahmad, N.; Bux, M.; Nasrullah, A.; Tofique, M.

    2011-01-01

    This study was designed to evaluate the effects of new insecticides like, Imidacloprid (Confidor 200 EC), Thiomethoxam (Actara 25 WG) and Acetamiprid (Megamos 20 SL) belonging to Nitroguanidine group along with conventional insecticides such as, Chlorpyrifos (Lorsban 40 EC) and Dimethoate (Systoate 40 EC) belonging to Organophosphate group against aphids' population on oilseed rape (Brassica napus L.). A perusal of data, based on the overall performance of the test compounds, reflected that newer insecticides were superior in reducing the population of aphids and yield enhancement as compared to conventional insecticides. The best results were achieved with the application of Imidacloprid by recording the lowest number of aphids (2.2 per plant) than obtained with Thiomethoxam and Acetamiprid (3.22 and 4.66, respectively). Other insecticides, viz., Chlorpyrifos and Dimethoate were also found to be effective in maintaining the aphids' population at lower levels per plant (16.2 and 17.5, respectively) over untreated control (227.7). Imidacloprid was responsible for increasing the grain yield to 3722.85 Kg per Hectare, approached by Thiomethoxam, Acetamiprid, Chlorpyrifos and Dimethoate as against unsprayed control (2980.0, 2542.85, 1542.85, 540.0 and 604.85 Kg per Hectare, respectively). Study indicated that selective use of newer insecticides would seem a reasonable strategy in aphids controlling and integration of such chemicals in insects' management package could help to reduce pest densities. (author)

  20. Host Plant-Herbivore-Predator Interactions in Chrysoperla carnea (Neuroptera: Chrysopidae) and Myzus persicae (Homoptera: Aphididae) on Four Plant Species Under Laboratory Conditions.

    Science.gov (United States)

    Farrokhi, Milad; Gharekhani, Gholamhossein; Iranipour, Shahzad; Hassanpour, Mahdi

    2017-12-05

    The common green lacewing, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae), is a well-known biocontrol agent. The current study examined host plant-herbivore-predator interactions with C. carnea and Myzus persicae on four host plants (peach, almond, pepper, and potato). The experiments were carried out at 25 ± 1°C and 65 ± 5% RH at a photoperiod of 16:8 (L:D) h). Duration of the preadult growth period, adult longevity, fecundity, and population growth parameters were analyzed based on the age-stage, two-sex life table theory. The shortest and longest preadult developmental times of the predator were observed on the peach and potato, respectively. The highest and lowest predation rate, oviposition period, and male and female longevity of predator were also observed on the peach and potato, respectively. The lowest intrinsic rate of increase (r) and finite rate of increase (λ) were observed on the potato (0.1087 and 1.11 d-1, respectively) and the highest on the peach (0.1460 and 1.15 d-1, respectively). The maximum and minimum mean generation times (T) were 41.84 and 35.59 d in the potato and peach, respectively. Overall, peach was found to be a more appropriate host than the other host plants for development and predation fitness of C. carnea. These findings reveal that information on tritrophic interactions and subsequent life table evaluation of natural enemies improves integrated pest management programs. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  1. Source Areas for the Early Immigration of Sogatella furcifera (Homoptera: Delphacidae) at Xiushan in the Middle Reach of Yangtze River of China.

    Science.gov (United States)

    Jiang, C X; Chen, X L; Bi, J C; Li, J J; Xiao, X H; Li, Q; Wang, H J; Yang, Q F

    2015-12-01

    The spatiotemporal distribution of source areas for the early immigration of the white-backed planthopper, Sogatella furcifera (Horvάth), at Xiushan in the middle reach of Yangtze River of China, was analyzed with HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory) and ArcGIS 10.0. The analysis was based on light trap data collected during April-July in 2000-2012. The synoptic meteorology backgrounds during the immigration periods were analyzed by GrADS (Grid Analysis and Display System). The light trap catches of S. furcifera varied monthly and annually. S. furcifera started immigration in Xiushan in early April to early May, whereas the main immigration period was in July. The distribution of the source areas varied monthly, and the core was moved from the south to the north gradually. The main source areas of S. furcifera in May were in southwestern Guangxi and northern Vietnam. The source areas of S. furcifera in June were located in southwestern Guangxi and western Hunan. Additionally, some of the pests were from southeastern Yunnan. The source areas in July were in northwestern Guangxi, southwestern Guizhou, eastern Yunnan, and the transitional parts of Guangxi, Guizhou, and Yunnan. The sum frequencies of southwest and south winds on the 850 hPa isobaric surface of Xiushan of May-July in heavy occurrence years were more than the light occurrence years. The key meteorological factors were suggested to be vertical perturbation, precipitation, and wind shear during S. furcifera immigration periods. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Cosmopsaltria halmaherae n. sp. endemic to Halmahera, Maluku, Indonesia (Homoptera, Cicadidae). The relationship of cicadas of Maluku Utara and Maluku Selatan

    NARCIS (Netherlands)

    Duffels, J.P.

    1988-01-01

    Cosmopsaltria halmaherae n. sp. is described from Halmahera, Maluku and placed in the C. doryca group. The characters of this group are reconsidered and the relationships of its members are discussed. The C. doryca group and two other monophyletic groups of cicadas demonstrate a vicariant

  3. The eye-catching cicada Hamza ciliaris (Linnaeus, 1758) comb. n. in Indonesia and the Pacific: taxonomie status, synonymy, and distribution (Homoptera, Cicadoidea)

    NARCIS (Netherlands)

    Duffels, J.P.

    1991-01-01

    The new combination Hamza ciliaris (Linnaeus) is proposed for a cicada species widely distributed in Maluku ( = Moluccas), Timor, Banda, Kei and Banggai Islands, the Philippines, and the Palau group of the Caroline Islands. The synonymy of five species, treated in the literature as junior synonyms

  4. Resistance and susceptibility of alfalfa (Medicago sativa L.) cultivars to the aphid Therioaphis maculata (Homoptera:Aphididae): insect biology and cultivar evaluation

    Institute of Scientific and Technical Information of China (English)

    ALEXANDRE DE ALMEIDA E SILVA; ELENICE MOURO VARANDA; JOS(E) RICARDO BAROSELA

    2006-01-01

    Biology of the aphid Therioaphis maculata was studied on alfalfa (Medicago sativa L.), including four resistant (Mesa-Sirsa, CUF101, Baker and Lahontan) and two susceptible (ARC and Caliverde) alfalfa cultivars, and one of the most cropped Brazilian cultivars, Crioula. Under controlled conditions, antibiosis (i.e., reduced longevity, fecundity and increased mortality of the aphid) was observed mainly on the resistant alfalfa cultivars,except on Lahontan. Crioula seemed to be tolerant to aphids. Present data support geographic limitation usage of cultivars, and we suggest Baker and Mesa-Sirsa as sources of antibiosis,and provide biological information of a tropical T. maculata biotype on alfalfa.

  5. New species of the family Triozidae (Homoptera: Psylloidea) from China, and the first record of Psylloidea as host of Braconidae (Hymenoptera)

    NARCIS (Netherlands)

    Li, F.; Achterberg, van C.; He, J.

    2000-01-01

    Two new species of Triozidae (Psylloidea) from China producing sphere-shaped leaf galls on Ficus hainanensis Merr. & Shun., are illustrated and described. For the first time Psylloidea are reported as host of a species of Braconidae. The parasitoid belonging to the genus Bracon Fabricius, 1804, is

  6. Reproducción de cochinilla silvestre Dactylopius opuntiae (Homóptera: Dactylopiidae Reproduction of wild cochineal Dactylopius opuntiae (Homoptera: Dactylopiidae

    Directory of Open Access Journals (Sweden)

    Arnoldo Flores-Hernández

    2006-06-01

    Full Text Available Por sus características, la cochinilla silvestre ofrece perspectivas de aprovechamiento como fuente de carmín y para el mejoramiento genético de la grana fina. Por lo anterior, se estableció una multiplicación y crianza de cochinilla silvestre, proveniente de la zona árida del norte de México para caracterizarla, utilizando como hospedero a Opuntia megacantha Salm Dyck. Los resultados indican que la especie silvestre pertenece al género-especie Dactylopius opuntia. Se determinó la presencia de partenogénesis en hembras. La duración de los estadios biológicos depende del sexo del insecto; el adulto hembra permaneció durante 38.4 días y 4.2 días para machos, los primeros estadios ninfales fueron similares en duración (18.1-19.8 días. El ciclo biológico de las hembras fue de 77 días mientras que el de los machos fue de 43 días. Para las hembras se estimó un periodo de preoviposición de 18.8 días, manteniéndose en oviposición durante 21 días con un promedio de 131 insectos por hembra. La proporción sexual hembras: machos fue 1:1. El tipo de reproducción fue predominantemente sexual, aunque hubo hembras partenogénicas. Este es el primer reporte de Dactylopius opuntiae como cochinilla silvestre asociada a la zona árida del noreste de México, específicamente en el Bolsón de Mapimí, Durango, México.Wild cochineal has characteristics that offer advantage as a source of carmine and for fine cochineal improvement. To characterize wild cochineal, we initiated a breeding effort raising wild cochineal from the arid zone of the north oh Mexico, using as a host organism Opuntia megacantha Salm dick. The results indicate that the wild specie is Dactylopius opuntiae. The presence of parthenogenesis in females was determined. The duration of ontogenetic stages depends on the sex of the insect. The adult female lasted 38.4 days and 4.2 days for males, the first stage nymphs were similar in duration (18-19.8 days. The complete biological cycle of the females was 77 days, and in the males 43 days. A period of preoviposition of 18.8 days for the females was found, laying eggs during 21 days with an average of 131 insects per female. The sex ratio female: male was 1:1. The reproduction generally was sexual although there were parthenogenetic females. This is the first report of Dactylopius opuntiae as a source of wild cochineal in the arid zone of North, Central and Norwest of Mexico specifically in the Bolson of Mapimí, Durango, Mexico.

  7. Interactive Effects of Southern Rice Black-Streaked Dwarf Virus Infection of Host Plant and Vector on Performance of the Vector, Sogatella furcifera (Homoptera: Delphacidae).

    Science.gov (United States)

    Lei, Wenbin; Liu, Danfeng; Li, Pei; Hou, Maolin

    2014-10-01

    Performance of insect vectors can be influenced by the viruses they transmit, either directly by infection of the vectors or indirectly via infection of the host plants. Southern rice black-streaked dwarf virus (SRBSDV) is a propagative virus transmitted by the white-backed planthopper, Sogatella furcifera (Hovath). To elucidate the influence of SRBSDV on the performance of white-backed planthopper, life parameters of viruliferous and nonviruliferous white-backed planthopper fed rice seedlings infected or noninfected with SRBSDV were measured using a factorial design. Regardless of the infection status of the rice plant host, viruliferous white-backed planthopper nymphs took longer to develop from nymph to adult than did nonviruliferous nymphs. Viruliferous white-backed planthopper females deposited fewer eggs than nonviruliferous females and both viruliferous and nonviruliferous white-backed planthopper females laid fewer eggs on infected than on noninfected plants. Longevity of white-backed planthopper females was also affected by the infection status of the rice plant and white-backed planthopper. Nonviruliferous white-backed planthopper females that fed on infected rice plants lived longer than the other three treatment groups. These results indicate that the performance of white-backed planthopper is affected by SRBSDV either directly (by infection of white-backed planthopper) or indirectly (by infection of rice plant). The extended development of viruliferous nymphs and the prolonged life span of nonviruliferous adults on infected plants may increase their likelihood of transmitting virus, which would increase virus spread. © 2014 Entomological Society of America.

  8. Herencia de la resistencia al daño mecánico causado por Tagosodes orizicolus (Muir (Homoptera-Delphacidae en arroz Oryza sativa

    Directory of Open Access Journals (Sweden)

    Cuevas P. Federico

    1996-12-01

    Full Text Available

    In Colombia all rice varieties developed are reported as resistant to Tagosodes orizicolus. Given the narrow genetic base of the resistant sources, this study was undertaken to identify the resistant parents or donors more oftenly used in Latin America. The materials were characterized as resistant (Mudgo, Amistad 82, IRAT 120, IRAT 124, Makalioka or susceptible based on the free chosen test and non chosen test and on the survival and oviposition of the insect (Chianan 8, Colombia 1, Bluebonnet 50, IR 8 (lCA, IR 8 (IRRI, Tetep and Cica 8. The damage was associated with insect survival, oviposition and eggs eclotion. To determine heritability two parents (Makalioka and Mudgo, were crossed with IR 8 F1 and F3 populations were also evaluated based on the free chosen test.

     

     

    En Colombia las variedades de arroz desarrolladas se consideran como resistentes a Tagosodes orizicolus. Dada la estrechez genética de las fuentes de resistencia, se inició este estudio para identificar los progenitores donantes de resistencia usados con mayor frecuencia en América Latina. Los materiales se caracterizaron como resistentes (Mudgo, Amistad 82, IRAT, 120, IRAT 124 Y Makalioka o susceptibles (Chianan 8, Colombia 1, Bluebonnet 50, IR 8 (lCA, IR (IRRI, Tetep y Cica 8, con base en las pruebas de libre escogencia, no escogencia, sobre vivencia y oviposición. El daño estuvo asociado con la supervivencia, oviposición y eclosión de huevos del insecto. Para la determinación de la herencia se cruzaron los progenitores Makalioka y Mudgo con IR8. En la Progenie F1 del cruzamiento resistente x resistente el 111% de las plantas fueron susceptibles; Mudgo y Makalioka segregaron 23 y 41% de plantas susceptibles.

  9. Molecular dynamics of detoxification and toxin-tolerance genes in brown planthopper (Nilaparvata lugens Stål., Homoptera: Delphacidae) feeding on resistant rice plants.

    Science.gov (United States)

    Yang, Zhifan; Zhang, Futie; He, Qing; He, Guangcun

    2005-06-01

    To investigate the molecular response of brown planthopper, Nilaparvata lugens (BPH) to BPH-resistant rice plants, we isolated cDNA fragments of the genes encoding for carboxylesterase (CAR), trypsin (TRY), cytochrome P450 monooxygenase (P450), NADH-quinone oxidoreductase (NQO), acetylcholinesterase (ACE), and Glutathione S-transferase (GST). Expression profiles of the genes were monitored on fourth instar nymphs feeding on rice varieties with different resistance levels. Northern blot hybridization showed that, compared with BPH reared on susceptible rice TN1, expression of the genes for P450 and CAR was apparently up-regulated and TRY mRNA decreased in BPH feeding on a highly resistant rice line B5 and a moderately resistant rice variety MH63, respectively. Two transcripts of GST increased in BPH feeding on B5; but in BPH feeding on MH63, this gene was inducible and its expression reached a maximum level at 24 h, and then decreased slightly. The expression of NQO gene was enhanced in BPH on B5 plants but showed a constant expression in BPH on MH63 plants. No difference in ACE gene expression among BPH on different rice plants was detected by the RT-PCR method. The results suggest these genes may play important roles in the defense response of BPH to resistant rice.

  10. Inheritance mode and realized heritability of resistance to imidacloprid in the brown planthopper, Nilaparvata lugens (Stål) (Homoptera: Delphacidae).

    Science.gov (United States)

    Wang, Yan Hua; Liu, Xu Gan; Zhu, Yu Cheng; Wu, Sheng Gan; Li, Shu Yong; Chen, Wen Ming; Shen, Jin Liang

    2009-06-01

    The brown planthopper, Nilaparvata lugens (Stål), is a serious pest that causes enormous losses to the rice crop in Asia. The genetic basis of imidacloprid resistance was investigated in N. lugens. The resistant strain, selected for imidacloprid resistance from a field population of N. lugens collected from Nanjing, Jiangsu Province, China, showed a 964-fold resistance compared with the laboratory strain. Progenies of reciprocal crosses (F(1) and F(1)') showed similar dose-mortality responses (LC(50)) to imidacloprid, and also exhibited a similar degree of dominance (D), 0.58 for F(1) and 0.63 for F(1)'. Chi-square analyses of self-bred and backcross progenies (F(2), F(2)' and BC respectively) rejected the hypothesis for a single gene control of the resistance. The estimated realized heritability (h(2)) of imidacloprid resistance was 0.1141 in the resistant strain of N. lugens. The results showed that imidacloprid resistance in N. lugens was autosomal and was expressed as an incompletely dominant trait, probably controlled by multiple genes.

  11. Insect growth regulator effects of azadirachtin and neem oil on survivorship, development and fecundity of Aphis glycines (Homoptera: Aphididae) and its predator, Harmonia axyridis (Coleoptera: Coccinellidae).

    Science.gov (United States)

    Kraiss, Heidi; Cullen, Eileen M

    2008-06-01

    Aphis glycines Matsumura, an invasive insect pest in North American soybeans, is fed upon by a key biological control agent, Harmonia axyridis Pallas. Although biological control is preferentially relied upon to suppress insect pests in organic agriculture, approved insecticides, such as neem, are periodically utilized to reduce damaging pest populations. The authors evaluated direct spray treatments of two neem formulations, azadirachtin and neem seed oil, under controlled conditions for effects on survivorship, development time and fecundity in A. glycines and H. axyridis. Both azadirachtin and neem seed oil significantly increased aphid nymphal mortality (80 and 77% respectively) while significantly increasing development time of those surviving to adulthood. First-instar H. axyridis survival to adulthood was also significantly reduced by both neem formulations, while only azadirachtin reduced third-instar survivorship. Azadirachtin increased H. axyridis development time to adult when applied to both instars, while neem oil only increased time to adult when applied to first instar. Neither neem formulation affected the fecundity of either insect. Results are discussed within the context of future laboratory and field studies aimed at clarifying if neem-derived insecticides can be effectively integrated with biological control for soybean aphid management in organic soybeans. Copyright (c) 2008 Society of Chemical Industry.

  12. Evaluación de extractos cetónicos de paraíso, eucalipto y ricino sobre Myzus persicae (Homoptera: Aphididae)

    OpenAIRE

    Carrizo, Paola; Pelicano, Alicia; Caffarini, Patricia

    2004-01-01

    En el cultivo de pimiento, Myzus persicae es una plaga cuyo manejo se basa en el uso de agroquímicos de síntesis. Una alternativa de menor impacto ambiental para su control es la aplicación de extractos naturales. El objetivo del trabajo fue evaluar el efecto de extractos provenientes de Melia azedarach, Eucalyptus globulus y Ricinus communis sobre este pulgón. Se escogió la técnica del film residual en papel de filtro, manteniendo los individuos sobre hojas de pimiento ornamental. Se uti...

  13. A reliable bioassay procedure to evaluate per os toxicity of Bacillus thuringiensis strains against the rice delphacid, Tagosodes orizicolus (Homoptera: Delphacidae

    Directory of Open Access Journals (Sweden)

    Rebeca Mora

    2007-06-01

    Full Text Available A reliable bioassay procedure was developed to test ingested Bacillus thuringiensis (Bt toxins on the rice delphacid Tagosodes orizicolus. Initially, several colonies were established under greenhouse conditions, using rice plants to nurture the insect. For the bioassay, an in vitro feeding system was developed for third to fourth instar nymphs. Insects were fed through Parafilm membranes on sugar (10 % sucrose and honey bee (1:48 vol/vol solutions, observing a natural mortality of 10-15 % and 0-5 %, respectively. Results were reproducible under controlled conditions during the assay (18±0.1 °C at night and 28±0.1 °C during the day, 80 % RH and a 12:12 day:light photoperiod. In addition, natural mortality was quantified on insect colonies, collected from three different geographic areas of Costa Rica, with no significant differences between colonies under controlled conditions. Finally, bioassays were performed to evaluate the toxicity of a Bt collection on T. orizicolus. A preliminary sample of twenty-seven Bt strains was evaluated on coarse bioassays using three loops of sporulated colonies in 9 ml of liquid diet, the strains that exhibited higher percentages of T. orizicolus mortality were further analyzed in bioassays using lyophilized spores and crystals (1 mg/ml. As a result, strains 26-O-to, 40-X-m, 43S-d and 23-O-to isolated from homopteran insects showed mortalities of 74, 96, 44 and 82 % respectively while HD-137, HD-1 and Bti showed 19, 83 and 95 % mortalities. Controls showed mortalities between 0 and 10 % in all bioassays. This is the first report of a reliable bioassay procedure to evaluate per os toxicity for a homopteran species using Bacillus thuringiensis strains. Rev. Biol. Trop. 55 (2: 373-383. Epub 2007 June, 29.Se desarrolló una metodología de bioensayo para evaluar toxinas de Bacillus thuringiensis (Bt ingeridas por Tagosodes orizicolus, plaga del arroz y vector del virus de la hoja blanca. Se establecieron colonias del insecto en condiciones de invernadero usando plantas de arroz como alimento. Para el bioensayo, se desarrolló un sistema de alimentación in vitro para ninfas de tercer y cuarto estadío. Los insectos se alimentaron de soluciones de miel de abeja (1:48 vol/vol y sacarosa (10 % a través de membranas de Parafilm. Se observaron mortalidades del 10-15 % y 0-5 %, respectivamente, en ambas dietas. Los resultados fueron reproducibles en condiciones controladas de humedad y temperatura (18±0.1 °C de noche y 28±0.1 °C de día, 80 % H.R y a 12:12 fotoperíodo día:noche. Asimismo, se analizó la mortalidad natural de los insectos según su procedencia, sin embargo, no se observaron diferencias significativas en condiciones controladas. Finalmente, se elaboraron bioensayos para evaluar la toxicidad de una colección de cepas de Bt contra T. orizicolus. Se evaluó preliminarmente, una submuestra de 27 cepas de Bt en bioensayos burdos usando tres asadas como inóculo para 9 ml de dieta líquida. Posteriormente, las cepas que mostraron los mayores porcentajes de mortalidad se evaluaron en bioensayos usando esporas y cristales liofilizados (1 mg/ml. Como resultado, las cepas aisladas a partir de homópteros 26-O-to, 40-X-m, 43-S-d y 23-O-to mostraron mortalidades de 74, 96, 44 y 82 % respectivamente, mientras que las HD-137, HD-1 y Bti mostraron 19, 83 y 95 % de mortalidad. Los controles presentaron mortalidades de 0 y 10 % en los bioensayos. Este es el primer informe de un bioensayo para evaluar la toxicidad de cepas de Bt utilizando la especie T. orizicolus.

  14. The jacoona assemblage of the genus Dundubia Amyot & Serville (Homoptera: Cicadidae): a taxonomic study of its species and a discussion of its phylogenetic relationships

    NARCIS (Netherlands)

    Beuk, Paul L.Th.

    1996-01-01

    The species of Orientopsaltria with unicolorous opercula and three related species of Platylomia are transferred to the genus Dundubia and allocated in the ‘Dundubia jacoona assemblage’ pending further investigation. The assemblage comprises eleven species in total; all are found in the

  15. Tri-trophic interactions between Bt cotton, the herbivore Aphis gossypii Glover (Homoptera: Aphididae), and the predator Chrysopa pallens (Rambur) (Neuroptera: Chrysopidae).

    Science.gov (United States)

    Guo, Jian-Ying; Wan, Fang-Hao; Dong, Liang; Lövei, Gábor L; Han, Zhao-Jun

    2008-02-01

    Tri-trophic impacts of transgenic Bacillus thuringiensis (Bt) cotton GK12 and NuCOTN 99B were studied using a predator, the great lacewing Chrysopa pallens (Rambur), and its prey, the cotton aphid Aphis gossypii Glover, in laboratory feeding experiments. The parental nontransgenic cotton cultivar of GK12 was used as control. The predator was fed with uniform (aphids from a single cultivar) or mixed prey (aphids from the three cotton cultivars provided on alternate days). Mortality and development of the immature stages, pupal body mass, adult sex ratio, fecundity, and egg viability of C. pallens were measured. When fed GK12-originated aphid prey, pupal body mass of C. pallens was significantly higher than that of the control, more females emerged, and these females laid significantly more eggs. Other parameters were not impacted. Females emerging from larvae maintained on NuCOTN 99B-originated prey laid fewer eggs than those maintained on GK12. Other measurements did not differ significantly between the two Bt cotton cultivars. Compared with the control, mixed feeding significantly prolonged pupal development time and increased pupal body mass and percentage of females but did not affect other parameters. These results indicate that C. pallens is sensitive to aphid prey from different cotton cultivars. Transgenic Bt cotton GK12-originated aphid prey has no adverse impact on survival, development, and fecundity of C. pallens. Between the two Bt cotton cultivars, NuCOTN 99B-originated aphid prey provided to C. pallens in the larval stage may lower female fecundity. Mixed feeding of C. pallens with the two Bt cotton-originated prey and non-Bt prey may have some adverse impacts on pupal development.

  16. Microsatellite markers reveal a predominant sugarcane aphid (Homoptera: Aphididae) clone is found on sorghum in seven states and one territory of the USA

    Science.gov (United States)

    The sugarcane aphid, Melanaphis sacchari, has become a serious pest causing severe economic losses to sorghum grown in the southern United States (U.S.). Since its original detection in four states in 2013, M. sacchari on sorghum has now, for 2016, spread to 19 states. The presence of one or multip...

  17. Dispersal of Dactylopius opuntiae Cockerell (Homoptera: Dactylopiidae, a biological control agent of Opuntia stricta (Haworth. Haworth. (Cactaceae in the Kruger National Park

    Directory of Open Access Journals (Sweden)

    L.C. Foxcroft

    2000-07-01

    Full Text Available Chemical control efforts, the introduction of Cactoblastis cactorum and attempted releases of Dactylopius opuntiae Cockerell into the expanding infestation of Opuntia stricta in the Skukuza region of the Kruger National Park (KNP have had limited suc- cess in preventing the spread and densification of 0. stricta. To boost the biological control component, a new strain of D. opuntiae was introduced into KNP during 1997. The new strain established readily and has destroyed large clumps of plants in the vicin- ity of the release site. A large-scale redistribution programme with D. opuntiae is now needed to exploit this biological control agent to the full. In order to match the frequency of manual releases with the natural rates of spread of the insects, surveys were conducted under field conditions to determine the dispersal abilities ofD. opuntiae, with regard to rate and direction of movement. Dispersal of D. opuntiae was found to be slow and restricted and that the insects need to be redistributed by placing them onto plants at approximately 10 m intervals to ensure that they become quickly and evenly distributed on the weed. This information will be crucial in the revision of the integrated management plan for 0. stricta in the KNP, in integrating the cochineal and other control mechanisms.

  18. Establishment of Lipolexis oregmae (Hymenoptera: Aphidiidae) in a classical biological control program directed against the brown citrus aphid (Homoptera: Aphididae) in Florida

    International Nuclear Information System (INIS)

    Persad, A.B.; Hoy, M.A.; Ru Nguyen

    2007-01-01

    The parasitoid Lipolexis oregmae Gahan (introduced as L. scutellaris Mackauer) was imported from Guam, evaluated in quarantine, mass reared, and released into citrus groves in Florida in a classical biological control program directed against the brown citrus aphid, Toxoptera citricida Kirkaldy. Releases of 20,200, 12,100, and 1,260 adults of L. oregmae were made throughout Florida during 2000, 2001, and 2002, respectively. To determine if L. oregmae had successfully established, surveys were conducted throughout the state beginning in the summer of 2001 and continuing through the summer of 2003. Parasitism during 2001 and 2002 was evaluated by holding brown citrus aphids in the laboratory until parasitoid adults emerged. Lipolexis oregmae was found in 10 sites in 7 counties and 4 sites in 3 counties with parasitism rates ranging from 0.7 to 3.3% in 2001 and 2002, respectively. Laboratory tests indicated that high rates of mortality occurred if field-collected parasitized aphids were held in plastic bags, so a molecular assay was used that allowed immature L. oregmae to be detected within aphid hosts immediately after collection. The molecular assay was used in 2003 with the brown citrus aphids and with other aphid species collected from citrus, weeds, and vegetables near former release sites; immatures of L. oregmae were detected in black citrus aphids, cowpea aphids, spirea aphids, and melon aphids, as well as in the brown citrus aphid, in 4 of 8 counties sampled, with parasitism ranging from 2.0 to 12.9%, indicating that L. oregmae is established and widely distributed. Samples taken in Polk County during Oct 2005 indicated that L. oregmae has persisted. The ability of L. oregmae to parasitize other aphid species on citrus, and aphids on other host plants, enhances the ability of L. oregmae to persist when brown citrus aphid populations are low. (author) [es

  19. Les cochenilles des Myrtaceae en Amazonie péruvienne : 1. Description de deux nouveaux ravageurs de Myrciaria dubia (Homoptera, Coccidae et Kerriidae)

    OpenAIRE

    Matile-Ferrero, D.; Couturier, Guy

    1993-01-01

    #Ceroplastes flosculoides$ Matile-Ferrero n.sp. (Coccidae) et #Austrotachardiella sexcordata$ Matile-Ferrero n.sp. (Kerriidae), sont décrits et illustrés. Les deux espèces sont des ravageurs d'une Myrtacée cultivée, #Myrciaria dubia$, en Amazonie péruvienne. #Austrotachardiella trilobata$ (Mendes) n.comb. est transférée de #Tachardiella$ Cockerell. (Résumé d'auteur)

  20. Toxicidade do extrato aquoso das folhas de Anacardium humile para Bemisia tuberculata Toxicity of aqueous extract of Anacardium humile leaves on Bemisia tuberculata

    Directory of Open Access Journals (Sweden)

    Nézio Nery de Andrade Filho

    2010-08-01

    Full Text Available A mosca-branca Bemisia tuberculata (Bondar, 1923 (Hem.: Aleyrodidae é uma das principais pragas da cultura da mandioca no Estado do Mato Grosso do Sul; no entanto, não há produtos registrados para seu controle. Produtos vegetais podem constituir em alternativa viável de controle de insetos e, por sua fotodegradabilidade, diminuir os riscos ao ambiente e ao homem. Objetivou-se, por meio deste trabalho, avaliar o efeito do extrato aquoso do "cajuzinho-do-cerrado" Anacardium humile St Hill (Anacardeaceae, nas concentrações de 2,0; 0,8; 0,4 e 0,05%, sobre a biologia de B. tuberculata, bem como identificar a classe de metabólitos secundários presentes no referido extrato. O experimento foi conduzido em casa de vegetação, sob temperatura de 26±4°C. O extrato aquoso de A. humile causou aumento da duração da fase larval e mortalidade significativamente superior à testemunha em todas as concentrações testadas. Concluiu-se que o extrato aquoso de folhas de A. humile provoca mortalidade em ninfas de B. tuberculata e alongamento da fase das ninfas sobreviventes. O extrato aquoso de folhas de A. humile apresenta taninos, açúcares redutores e saponinas, e o seu índice de espuma (Índice Afrosimétrico é de 1250.The whitefly Bemisia tuberculata (Bondar, 1923 (Hem.: Aleyrodidae is the main pest of cassava crops in Mato Grosso do Sul state, however there are no products registered for its control. Plant products may represent a viable alternative for insect pest control and, due to their photo-degradability, they may reduce risks to the environment and to man. The aim of this study is to assess the effect of "cajuzinho-do-cerrado" Anacardium humile St Hill (Anacardeaceae aqueous leaf extract on the biology of B. tuberculata at the concentrations 2.0; 0.8; 0.4; 0.05%, as well as to identify the class of secondary metabolites present in the referred extract. The experiment was carried out in a greenhouse at a temperature of 26±4°C. The

  1. Luta biológica clássica com Hyperaspis pantherina Fürsch (Coleoptera: Coccinellidae no combate à Orthezia insignis Browne (Homoptera: Ortheziidae em jacarandá Biological control with Hyperaspis pantherina Fürsch (Coleoptera: Coccinellidae to control Orthezia insignis Browne (Homoptera: Ortheziidae on blue jacaranda

    Directory of Open Access Journals (Sweden)

    Ana Paula Félix

    2008-12-01

    Full Text Available Os jacarandás e várias plantas ornamentais que ornamentam passeios e áreas ajardinadas da cidade do Funchal encontram-se infestados pela cochonilha Orthezia insignis Browne. Para combater esta praga foi importada do Quénia, uma joaninha, Hyperaspis pantherina Fürsch. Este predador é específico de O. insignis e tem sido utilizado, com sucesso em programas de luta biológica, em vários países de África, no Peru, Hawai e na Ilha de Santa Helena. Na Ilha da Madeira, desde Julho de 2002, H. pantherina está a ser criado em laboratório e largado em jacarandás infestados com o objectivo de combater a cochonilha-dojacarandá através da luta biológica clássica. Referem-se as largadas de H. pantherina e o sistema de monitorização adoptado para verificar a aclimatação do predador.The Jacaranda trees and other ornamental plants used in sidewalks and gardenlike areas of sidewalks and other gardened areas of the downton Capital city of Madeira Island (Funchal, are infested by the Jacaranda or Lantana Bug, Orthezia insignis Browne. A ladybird, Hyperaspis pantherina Fürsch, was imported from Kenya to control this pest. This ladybird is a specific predator of O. insignis and it has been used, successfully in biological control programs, in several countries of Africa, in Peru, Hawaii and in Santa Helena Island. In Madeira Island, H. pantherina is being reared in laboratory and released into infested jacarandas since July 2002, in a classical biological control way. The releasing of H. pantherina is described in detail as well as the adopted monitoring system to verify its acclimation.

  2. Membracidos de Colombia - I. Revisión parcial de las especies del género Alchisme Kirkaldy (Homoptera: Membracidae: Hoplophorioninae Membracidos de Colombia - I. Revisión parcial de las especies del género Alchisme Kirkaldy (Homoptera: Membracidae: Hoplophorioninae

    Directory of Open Access Journals (Sweden)

    Restrepo Mejía Ruben

    1980-09-01

    Full Text Available Se revisó el género Alchisme Kirkaldy. De las diecinueve especies anotadas por Metcalf (1965 no se obtuvieron especímenes de A. apicalis (Walker, A. costaricensis Goding, A. elevata Goding, A. laticornis Funkhouser, A. pinguicornisFunkhouser, A. recurva (Stäl, A. spinosa Funkhouser y A. truncaticornis (Germar. Se incluyen las descripciones originales de estas especies y tentativamente se localizan en la clave presentada. Se redescriben: A. bos (Fairmaire, A. fastidiosa (Fairmaire, A. grossa (Fairmaire, A. inermis (Fairmaire, A. nigrocarinata (Fairmaire, A. rubrocostata (Spinola, A. turrita (Germar, A. ustulata (Fairmaire, A. virescens (Fairmaire y A. nigrocarinata var. tridentata (Fairmaire, para la cual se usa su combinación original A. tridentata (Fairmaire. Se sinonimizóa A. projecta Funkhouser en favor de A. bos (Fairmaire.Se ilustran las principales características del pronoto y de los genitales de los machos; se observaron y se obtuvieron fotografías de los edeagos en un microscopio electrónico "rastreador" (Scanning Electro Microscope, las cualesse incluyen como parte de las ilustraciones. Se analizó la distribución geográfica del género y se ilustró por medio de mapas.The genus Alchisme Kirkaldy was revised. From nineteen species listed by Metcalf (1965 not specimens were obtained of eight of them. Original descriptions of these species are included and tentatively are localized in the key.  A redescription is given for the species A. bos (Fairmaire, A. fastidiosa (Fairmaire, A. grossa (Fairmaire, A. inermis (Fairmaire, A. nigrocarinata (Fairmaire, A. rubrocostata (Spinola, A. turrita (Germar, A. ustulata (Fairmaire, A. virescens (Fairmaire y A. nigrocarinata var. tridentata (Fairmaire, for which was used the original combination A. tridentata (Fairmaire. A. projecta Funkhouser was synonymized in A. bos (Fairmaire. The main pronotum characters and male genitalia are illustred; Scanning Electro Microscope pictures of the aedeagus of the insects were observed and obtained and are included as part of the illustrations. Geographic distributionsof the genus was analized and maps were prepared.

  3. Efecto de la configuración de lotes de gramíneas invernales sobre poblaciones de Delphacidae (Insecta: Homoptera en dispersión The effect of the configuration of winter grass plots on dispersing populations of Delphacidae (Insecta: Homoptera

    Directory of Open Access Journals (Sweden)

    M.A. Bruno

    2007-12-01

    Full Text Available Las características del paisaje afectan la distribución y abundancia de los insectos dentro y entre los lotes de cultivos. El objetivo de este trabajo fue determinar el efecto de los elementos del paisaje agrícola sobre la abundancia de los individuos en dispersión de las especies de Delphacidae. Éstas son vectores de virus patogénicos que transmiten enfermedades de importancia económica para la producción agropecuaria. El estudio se realizó en el área central de la provincia de Córdoba, Argentina; los insectos fueron capturados con trampas pegajosas ubicadas dentro de parches de hospedadores. Las métricas del paisaje analizadas fueron: área del parche, índice de proximidad media y porcentaje del paisaje cubierto por parches de una clase de hospedador. La abundancia de Delphacodes kuscheli tuvo relación positiva con el área de los parches de pasturas de invierno. El índice de proximidad media tuvo relación positiva con las abundancias de D. kuscheli y D . balboae en los parches de pasturas de invierno y el porcentaje del paisaje cubierto con parches de pasturas de invierno se relacionó positivamente con las abundancias de D. kuscheli, D. balboae y D. haywardi. Las abundancias de Toya propincua no mostraron relación con ninguna de las métricas del paisaje analizadas.Landscape configuration can affect the distribution and abundance of insect species. The objective of this work was to determine the effect of landscape elements configuration on the abundance of dispersing individuals of Delphacidae species. Delphacid species are important vectors of pathogenic viruses causing diseases of economic importance on grain production. The study was performed in the central area of Córdoba Province, Argentina; the insects were collected with sticky traps placed in plant host patches. The landscape metrics estimated were: host patch area, Mean Proximity Index (MPI and the Percentage of Landscape occupied (PLAND by host patches of the same class. The abundance of Delphacodes kuscheli showed a positive relationship with patch area of the winter pastures. There was a positive relationship between Mean Proximity Index of winter pastures patches and D. kuscheli and D . balboae abundances. The Percentage of Landscape occupied by the winter pastures patches also showed a positive relationship with Delphacodes kuscheli, Delphacodes balboae and Delphacodes haywardi abundances. Finally we found no relationship between Toya propinqua abundance and any of the landscape metrics analyzed in this work. These results show that landscape configuration has a different effect on the dispersing population of the different species of Delphacidae.

  4. Attraction of Three Mirid Predators to Tomato Infested by Both the Tomato Leaf Mining Moth Tuta absoluta and the Whitefly Bemisia tabaci

    NARCIS (Netherlands)

    Silva, Diego B.; Bueno, Vanda H.P.; Loon, van Joop J.A.; Peñaflor, Maria Fernanda G.V.; Bento, José Maurício S.; Lenteren, van Joop C.

    2018-01-01

    Plants emit volatile compounds in response to insect herbivory, which may play multiple roles as defensive compounds and mediators of interactions with other plants, microorganisms and animals. Herbivore-induced plant volatiles (HIPVs) may act as indirect plant defenses by attracting natural enemies

  5. On-farm evaluation of integrated pest management of thrips and whiteflies in herb cuttings in Ethiopia : report to the Ministry of Agriculture and Rural Development

    NARCIS (Netherlands)

    Belder, den E.; Elings, A.

    2010-01-01

    Integrated Pest Management reduces the use of chemicals and therewith the impact of greenhouse horticulture on the environment. It improves working conditions and enables access of Ethiopian products on the world market. In response to such concerns the Ethiopian Horticulture Producers and Exporters

  6. Effect of Iranian Bt cotton on life table of Bemisia tabaci (Hemiptera: Alyrodidae and Cry 1Ab detection in the whitefly honeydew

    Directory of Open Access Journals (Sweden)

    Solmaz Azimi

    2016-09-01

    Full Text Available Transgenic cotton expressing the Cry 1Ab protein of Bacillus thuringiensis developing against Helocoverpa armigera may be affect on secondary pest such as Bemisia tabaci. In this study effects of Bt cotton on demographic parameters of B. tabaci were assessed and the data analyzed using the age specific, two-sex life table parameters. Results showed that getting to the adulthood stage, was faster on non-Bt cotton in comparison with Bt cotton. Also the fecundity was higher on non-Bt cotton than that on Bt cotton. Some of the population parameters (r, R0 and T of B. tabaci were affected by the Bt cotton significantly. The intrinsic rate of increase (r on Bt and non-Bt cotton was 0.07 day-1 and 0.1 day-1 , respectively. The net reproductive rate (R0 was 20.68 and 15.04 offspring/individual on Bt and non-Bt cotton, respectively. Mean generation time (T in non-Bt cotton was 27.22 and 34.62 days in Bt cotton. The results indicated that the life history of B. tabaci in the laboratory condition was influenced by host plant quality and Bt cotton was not a suitable host for B. tabaci. The western immunoblot method showed that the Cry protein detection in honeydew was positive which indicated that the Cry protein was ingested. Results revealed that the transgenic cotton could adversely affect the secondary pest and the natural enemies which feed on such pests as a host or their honeydew as a food source should be considered.

  7. La ruta de señalización del acido salicílico juega un papel importante en la resistencia en tomate a Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) mediada por el gen Mi-1

    OpenAIRE

    Muñiz, Mariano; Rodriguez, C.I.; Kaloshian, I.; Nombela, Gloria

    2009-01-01

    Es bien conocido que la resistencia en tomate a Bemisia tabaci (Gennadius), a Macrosiphum euphorbiae (Thomas) y a tres especies de nematodos formadores de nódulos (Meloidogyne spp.) está mediada por el gen Mi-1. Asimismo, está documentado que el ácido salicílico interviene en los mecanismos de resistencia frente a nematodos formadores de nódulos y áfidos. Recientemente se ha descrito que, en Arabidopsis, el biotipo B de B. tabaci induce defensas activadas por este ácido e inhibe las del ácido...

  8. Criterios de liberación de Encarsia formosa Gahan (Hymenoptera: Aphelinidae para el control de Trialeurodes vaporariorum (Westwood (Hemiptera: Aleyrodidae en tomate

    Directory of Open Access Journals (Sweden)

    Aragón Sandra

    2008-08-01

    Full Text Available

    Para la toma adecuada de decisiones en el manejo de la mosca blanca de los invernaderos, se han propuesto diferentes criterios que buscan reducir el impacto producido por el uso indiscriminado de insecticidas. Sin embargo, estos criterios de decisión son aplicables principalmente al control químico de plagas y no se conoce su uso en programas de control biológico. Por lo tanto, con este trabajo se propuso generar unos criterios de decisión para el control biológico de la mosca blanca de los invernaderos T. vaporariorum con el parasitoide Encarsia formosa, teniendo en cuenta su respuesta funcional y porcentaje de control. En un diseño completamente al azar se ubicaron 18 plantas de tomate de 8 semanas de edad infestadas con 500 ninfas de mosca blanca y 3 plantas como control absoluto. En cada planta se liberaron 0, 10, 20, 30, 40 y 50 adultos de E. formosa, con tres repeticiones por densidad. Se registró el número de ninfas melanizadas por efectos del parasitismo de E. formosa a los 12; 19 y 26 días después de la primera liberación y, al finalizar la cosecha, se realizó un conteo de las ninfas de mosca blanca totales. Los resultados de este trabajo sugieren que para obtener un control cercano a 80% se debe liberar un parasitoide por cada 17 ninfas de mosca blanca de tercer instar, evaluando el control después de 35 días. Se pueden realizar nuevas liberaciones de E. formosa dirigidas al control de las nuevas ninfas encontradas en los muestreos periódicos del cultivo.

  9. Occurrence of Diaretiella rapae (Mc´Intosh, 1855 (Hymenoptera: Aphidiidae Parasitising Lipaphis erysimi (Kaltenbach, 1843 and Brevicoryne brassicae (L. 1758 (Homoptera: Aphididae in Brassica napus in Mato Grosso do Sul

    Directory of Open Access Journals (Sweden)

    Mussury Rosilda Mara

    2002-01-01

    Full Text Available The occurrence of Diaretiella rapae parasitising Lipaphis erysimi and Brevicoryne brassicae in canola field (Brassica napus was evaluated through two sample methods in Dourados-MS. The methods, used weekly, were: entomologic sweep net and plants sacking. The aphids population was observed from initial to the senescence plant development. Aphids were more abundant during the flowering phase, and they were usually located in the stems of the inflorescence and development fruits. In this phase the largest parasitism level for D. rapae (89,7% occurred. The sample method with a sweep net captured significantly (t=4,484, P <= 0,01 more D. rapae while sacking method captured more parasitise aphids (t=2,199 with P <= 0,05 and active aphids (t=3,513, P <= 0,01.

  10. 贵州斑大叶蝉属三新种(同翅目:大叶蝉科)%THREE NEW SPECIES OF THE GENUS ANATKINA FROM GUIZHOU PROVINCE,CHINA(HOMOPTERA:CICADELLIDAE)

    Institute of Scientific and Technical Information of China (English)

    杨茂发; 李子忠

    2001-01-01

    In this paper three new species of the genus Anatkina are described from Guizhou,China.All the type specimens are deposited in the Agricultural College of Guizhou University. 1 Anatkina livimacula sp.nov. (Figs.1-7)   Length(incl.teg.):♂ 9.6?mm,♀9.0-9.3?mm.   This species resembles A.xanthomacula Kuoh in appearance,but can be distinguished from the latter by its crown with three distinct black markings;pronotum with four or two brown spots near anterior margin and a transverse black band in posterior portion;scutellum uniform black;forewing red with a blue marking on claval base and a pink marking in middle part of costal area;the shape of male pygofer process,subgenital plate,aedeagus and style also distinctly different.   Holotype ♂,Guizhou:Maolan(25°30′N,108°10′E),30 May 1998,collected by LI Zi-Zhong.Paratype 1♀,same location as holotype,18 May 1995,by CHEN Xiang-Sheng;1♀,Guizhou:Ziyun,18 Jul. 1988,by WEI Lian-Meng. 2 Anatkina rubipennis sp.nov. (Figs.8-16)   Length (incl.teg.):♂ 13.2?mm.   This species is similar to A.nigriventris Li,but can be easily distinguished from the latter by the pronotum black-brown without distinct black spots;forewing dark red with a black spot in base of clavus and confluent dark markings bordering base of apical cells;the end of male paraphysis furcate,pygofer process smooth,subgenital plate curved abruptly dorsad with macrosetae not uniseriate.   Holotype ♂,Guizhou:Maolan (25°30′N,108°10′E),19 May 1995,collected by CHEN Xiang-Sheng. 3 Anatkina bistriata sp.nov. (Figs.17-25)   Length (incl.teg.):♂10.0?mm-10.6?mm,♀10.0?mm.   This species has unique colour pattern on head and pronotum,forewing black with two red stripes in basal half,which are different from those of any other species of the genus.   Holotype ♂,Guizhou:Maolan(25°30′N,108°10′E),21 May 1995,by CHEN Xiang-Sheng.Paratypes 2 ♂♂,1♀,same data as holotype.%记述斑大叶蝉属Anatkina Young 3新种,即蓝斑大叶蝉A.livimacula sp.nov.;红翅斑大叶蝉A.rubipennis sp.nov.;双条斑大叶蝉A.bistriata sp.nov.,模式标本保存在贵州大学农学院。

  11. Effect of an alternate weed host, hairy nightshade, Solanum sarrachoides, on the biology of the two most important potato leafroll virus (Luteoviridae: Polerovirus) vectors, Myzus persicae and Macrosiphum euphorbiae (Aphididae: Homoptera).

    Science.gov (United States)

    Srinivasan, Rajagopalbabu; Alvarez, Juan M; Bosque-Pérez, Nilsa A; Eigenbrode, Sanford D; Novy, Richard G

    2008-04-01

    Hairy nightshade, Solanum sarrachoides (Sendtner), is a ubiquitous weed in potato agro-ecosystems and nonagricultural lands of southeastern Idaho and the Pacific Northwest. This weed increases the complexity of the Potato leafroll virus (PLRV) (Luteoviridae: Polervirus)-potato pathosystem by serving as aphid and virus reservoir. Previous field studies showed higher densities of green peach aphid, Myzus persicae (Sulzer), and potato aphid, Macrosiphum euphorbiae (Thomas), the two most important vectors of PLRV, on S. sarrachoides compared with potato plants in the same fields. Some of the S. sarrachoides plants sampled in these surveys tested positive for PLRV. Viral infections can alter the physiology of plant hosts and aphid performance on such plants. To understand better the potential effects of S. sarrachoides on the PLRV-potato-aphid pathosystem, the life histories of M. persicae and M. euphorbiae were compared on virus-free and PLRV-infected S. sarrachoides and potato. Individual nymphs of each aphid species were held in clip cages on plants from each treatment to monitor their development, survival, and reproductive output. Nymphal survival for both aphids across plant species was higher on S. sarrachoides than on potato, and, within plant species, it was higher on PLRV-infected plants than on noninfected plants. With a few exceptions, similar patterns occurred for fecundity, reproductive periods, adult longevity, and intrinsic rate of increase. The enhanced performance of aphids on S. sarrachoides and on PLRV-infected plants could alter the vector population dynamics and thus the PLRV-disease epidemiology in fields infested with this weed.

  12. Aboveground insect infestation attenuates belowground Agrobacterium-mediated genetic transformation.

    Science.gov (United States)

    Song, Geun Cheol; Lee, Soohyun; Hong, Jaehwa; Choi, Hye Kyung; Hong, Gun Hyong; Bae, Dong-Won; Mysore, Kirankumar S; Park, Yong-Soon; Ryu, Choong-Min

    2015-07-01

    Agrobacterium tumefaciens causes crown gall disease. Although Agrobacterium can be popularly used for genetic engineering, the influence of aboveground insect infestation on Agrobacterium induced gall formation has not been investigated. Nicotiana benthamiana leaves were exposed to a sucking insect (whitefly) infestation and benzothiadiazole (BTH) for 7 d, and these exposed plants were inoculated with a tumorigenic Agrobacterium strain. We evaluated, both in planta and in vitro, how whitefly infestation affects crown gall disease. Whitefly-infested plants exhibited at least a two-fold reduction in gall formation on both stem and crown root. Silencing of isochorismate synthase 1 (ICS1), required for salicylic acid (SA) synthesis, compromised gall formation indicating an involvement of SA in whitefly-derived plant defence against Agrobacterium. Endogenous SA content was augmented in whitefly-infested plants upon Agrobacterium inoculation. In addition, SA concentration was three times higher in root exudates from whitefly-infested plants. As a consequence, Agrobacterium-mediated transformation of roots of whitefly-infested plants was clearly inhibited when compared to control plants. These results suggest that aboveground whitefly infestation elicits systemic defence responses throughout the plant. Our findings provide new insights into insect-mediated leaf-root intra-communication and a framework to understand interactions between three organisms: whitefly, N. benthamiana and Agrobacterium. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  13. The immune strategy and stress response of the Mediterranean species of the Bemisia tabaci complex to an orally delivered bacterial pathogen.

    Directory of Open Access Journals (Sweden)

    Chang-Rong Zhang

    Full Text Available BACKGROUND: The whitefly, Bemisia tabaci, a notorious agricultural pest, has complex relationships with diverse microbes. The interactions of the whitefly with entomopathogens as well as its endosymbionts have received great attention, because of their potential importance in developing novel whitefly control technologies. To this end, a comprehensive understanding on the whitefly defense system is needed to further decipher those interactions. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a comprehensive investigation of the whitefly's defense responses to infection, via oral ingestion, of the pathogen, Pseudomonas aeruginosa, using RNA-seq technology. Compared to uninfected whiteflies, 6 and 24 hours post-infected whiteflies showed 1,348 and 1,888 differentially expressed genes, respectively. Functional analysis of the differentially expressed genes revealed that the mitogen associated protein kinase (MAPK pathway was activated after P. aeruginosa infection. Three knottin-like antimicrobial peptide genes and several components of the humoral and cellular immune responses were also activated, indicating that key immune elements recognized in other insect species are also important for the response of B. tabaci to pathogens. Our data also suggest that intestinal stem cell mediated epithelium renewal might be an important component of the whitefly's defense against oral bacterial infection. In addition, we show stress responses to be an essential component of the defense system. CONCLUSIONS/SIGNIFICANCE: We identified for the first time the key immune-response elements utilized by B. tabaci against bacterial infection. This study provides a framework for future research into the complex interactions between whiteflies and microbes.

  14. Dual infections of ToMV and TYLCV, or ToMV and ToCV, detected in tomato fields located in Chungchungnam-Do in 2017

    Science.gov (United States)

    Demand for tomatoes has been increasing every year as people desire more healthful food. In Korea tomatoes are mainly grown in Chungnam, Chunnam and Kyungnam provinces. Recently, reports of whitefly-transmitted viral diseases have increased due to newly emerging whitefly pressures caused by climate ...

  15. The invasive MED/Q Bemisia tabaci genome: a tale of gene loss and gene gain

    Science.gov (United States)

    Whiteflies are a group of invasive crop pests that impact global agriculture. An analysis was conducted to compare draft genomes of two whitefly strains, which demonstrated the relative conserved gene order, but a number of genes were either novel (added) or omitted (deleted) between genomes. This...

  16. Save money the easy way with bio-control

    Science.gov (United States)

    Sweet potato whitefly is a key insect pests affecting cotton and many other agronomic and horticultural crops in the southwestern U.S. Prior research has shown that arthropod natural enemies, particularly predators, can have a significant impact on whitefly population dynamics and can regulate popul...

  17. Controlled transmission of African cassava mosaic virus (ACMV) by ...

    African Journals Online (AJOL)

    Jatropha curcas, a plant with great biodiesel potential is also used to reduce the population of whiteflies, Bemisia tabaci on cassava fields when planted as a hedge. We therefore, investigated the transmission of African cassava mosaic virus (ACMV) by the whitefly vector from cassava to seedlings of 10 accessions of J.

  18. A case to study population dynamics of bemisia tabaci and thrips tabaci on bt and non-bt cotton genotypes

    International Nuclear Information System (INIS)

    Akram, M.; Hussain, M.; Ahmed, S.; Hafeez, F.; Farooq, M.; Arshad, M.

    2013-01-01

    Studies were conducted to investigate the performance of eight bt and five non-bt cotton genotypes against whitefly and thrips and impact of abiotic factors on the population fluctuation of these sucking pests, at cotton research station, multan, during 2010 and 2011. The results exhibited that bt genotypes found more susceptible host for the whitefly and thirps than non-bt genotypes, during the course of years of study. Among bt genotypes, maximum and minimum temperature showed significant and positive effect on whitefly population whereas relative humidity exerted negative effect during 2010. During 2011, the effect of all the factors was non significant. On cumulative basis, there was positive correlation between population of whitefly and minimum temperature. But in case of non-bt, it has negative with maximum temperature whereas relative humidity had a positive effect on whitefly population. similar trend was observed for thrips population on bt varieties during both years but on non-bt varieties only minimum temperature exerted strong positive impact on thrips population. Hierarchical regression models for whitefly and thrips revealed that minimum temperature was the most important factor (Bt and non-Bt varieties). Maximum temperature was the major contributing factor for whitefly fluctuation on bt varieties during 2010. (author)

  19. Previsual detection of two conifer-infesting adelgid species in North American forest

    Science.gov (United States)

    Stephen Cook; Karen Humes; Ryan Hruska; Christopher Williams; Grant Fraley

    2010-01-01

    The balsam woolly adelgid, Adelges piceae, and hemlock woolly adelgid, A. tsugae (Homoptera: Adelgidae), are invasive pests of coniferous forests in both the Eastern and Western United States. Balsam woolly adelgid is capable of attacking and killing native North American firs, with Fraser fir (Abies fraseri...

  20. Characterizing pathways of invasion using Sternorryhncha on imported plant material in cargo

    Science.gov (United States)

    Timothy T. Work

    2011-01-01

    Non-indigenous Homoptera, mainly scales, aphids, and mealy bugs, intercepted on plants destined for cultivation represent an elevated risk for the establishment of invasive insects in North America. These insects [grouped as the suborder Sternorrhyncha] are often parthenogenic and are imported on viable host plants.

  1. Tissue location of resistance in apple to the rosy apple aphid established by electrical penetration graphs

    NARCIS (Netherlands)

    Marchetti, E.; Civolani, S.; Leis, M.; Chicca, M.; Tjallingii, W.F.; Pasqualini, E.; Baroni, P.

    2009-01-01

    A study of the constitutive resistance of the apple cultivar Florina, Malus domestica Borkh. (Rosaceae), to the rosy apple aphid, Dysaphis plantaginea (Passerini) (Homoptera Aphididae), was performed for the first time by the electrical penetration graph (DC-EPG) system, using the susceptible apple

  2. Significance and transmission of maize streak virus disease in Africa ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-29

    Dec 29, 2008 ... soil nutrients, altitude and temperature on the biology of maize streak virus (MSV) / vector populations is discussed. ... status of maize host plants and its effects on population dynamics of Cicadulina mbila Naudé. (Homoptera: ..... time necessary for the leafhopper to reach the mesophyll of the leaf and ingest ...

  3. Short Communication: Occurrence of the pea aphid, Acyrthosiphon ...

    African Journals Online (AJOL)

    The occurrence of pea aphid, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae), on wild annual and perennial leguminous plants was studied at two locations (Adet and Wondata) in West Gojam, Ethiopia in 1999/2000 seasons. Annual and perennial leguminous wild or volunteer plants encountered in the study areas ...

  4. Resistance to lettuce aphid (Nasonovia ribisnigri) biotype 0 in wild lettuce accessions PI 491093 and PI 274378

    Science.gov (United States)

    Lettuce aphid, Nasonovia ribisnigri Mosley (Homoptera : Aphididae), is a major insect pest of lettuce, Lactuca sativa L, in many commercial lettuce productions areas around the world. Resistance to lettuce aphid was first reported in Lactuca virosa L. accession IVT 280 and characterized as complete,...

  5. Fungal Endophytes of Wild Barley and their Effects on Diuraphis noxia Population Development

    Science.gov (United States)

    S.L. Clement; A. Dan Wilson; D.G. Lester; C.M. Davitt

    1997-01-01

    Laboratory experiments were conducted to compare the expression of Diuraphis noxia (Mordvilko) (Homoptera: Aphididae) resistance in four plant introduction (PI) lines of wild barley (Hordeum) infected with different species or strains of endophytic fungi (tribe Balansieae, family Clavicipitaceae, Neotyphodium gen. nov. [formerly...

  6. Infection of potato plants with potato leafroll virus changes attraction and feeding behaviour of Myzus persicae

    NARCIS (Netherlands)

    Alvarez, A.E.; Garzo, E.; Verbeek, M.; Vosman, B.; Dicke, M.; Tjallingii, W.F.

    2007-01-01

    Potato leafroll virus (PLRV; genus Polerovirus, family Luteoviridae) is a persistently transmitted circulative virus that depends on aphids for spreading. The primary vector of PLRV is the aphid Myzus persicae (Sulzer) (Homoptera: Aphididae). Solanum tuberosum L. potato cv. Kardal (Solanaceae) has a

  7. Stimulation des défenses naturelles par l’application d’un Lombricompost. Effet sur les paramètres populationnels d’Aphis fabae scop. (Homoptera: Aphididae et la qualité Phytochimique de la fève

    Directory of Open Access Journals (Sweden)

    Zahr-Eddine Djazouli

    2017-06-01

    Full Text Available Chaichi, W. Djazouli, Z. Djemai, I. Abdelkader, S. Ribera, I. and Nancé, J. 2017. Stimulation of natural defences by the application of lombricompost. Effect on the Aphis fabae scop. (Homoptéra: Aphididae population and phytochemical quality of faba bean. Lebanese Science Journal, 18(1: 81-97. The integrated production in durable agriculture aims to improve the efficiency of biological inputs through formulations extending the remanence in the field or the incorporation of synergistic products which, being themselves nontoxic at used quantities, increase the protective action of the viabe cultivations. The lombricultivation represents an appropriate technology to enhance the value of the farm residues and manage, on a long term basis, plant health. The study focused on the stimulation of natural defenses of bean through the use of a lombricompost dilutions produced in two different seasons. The effect of lombricompost has been evaluated based on the Aphis fabae population density in relation to the phytochemical quality of the nutritional support. Variations of biochemical molecule contents and major mineral elements during the leaf expanding phase have been noticed. These changes affect the biological performance as well as the density of A. fabae population. The results allowed detecting a positive effect of lombricompost on plant chemistry. On the other hand, enrichment in proteins and proline under the effect of strong dilution was noticed. Finally, results related to the repressive effect of the different forms of lombricompost showed a marked difference between treatments and the control, with a stronger effect on the winged forms. Results also indicated some variability of the Aphis Fabae populational structure in relation to the phytochemical enrichments established by the application of lombricompost.

  8. Identification and validation of a virus-inducible ta-siRNA-generating ...

    Indian Academy of Sciences (India)

    2016-02-01

    Feb 1, 2016 ... and bacterial spot disease resistance protein Bs4 gene. ... whitefly (Bemisia tabaci) and infect a variety of crops, both monocot and dicot, causing ..... virus variant associated with newly emerging yellow mosaic disease of ...

  9. Non-Vector Mechanisms for Transmission and Infection of Cassava ...

    African Journals Online (AJOL)

    user

    designing of practical CBSD management techniques. Transmission by the whitefly ..... normal agronomic operations. CBSV transmission to .... Grasmick ME and SA Slack Detection of potato spindle tuber viroid in true potato seed by bioassay ...

  10. Small RNAs from Bemisia tabaci are transferred to Solanum lycopersicum phloem during feeding

    Directory of Open Access Journals (Sweden)

    Paula J.M. Van Kleeff

    2016-11-01

    Full Text Available The phloem-feeding whitefly Bemisia tabaci is a serious pest to a broad range of host plants, including many economically important crops such as tomato. These insects serve as a vector for various devastating plant viruses. It is known that whiteflies are capable of manipulating host-defense responses, potentially mediated by effector molecules in the whitefly saliva. We hypothesized that, beside putative effector proteins, small RNAs (sRNA are delivered by B. tabaci into the phloem, where they may play a role in manipulating host plant defenses. There is already evidence to suggest that sRNAs can mediate the host-pathogen dialogue. It has been shown that Botrytis cinerea, the causal agent of gray mold disease, takes advantage of the plant sRNA machinery to selectively silence host genes involved in defense signaling.Here we identified sRNAs originating from B. tabaci in the phloem of tomato plants on which they are feeding. sRNAs were isolated and sequenced from tomato phloem of whitefly-infested and control plants as well as from the nymphs themselves, control leaflets and from the infested leaflets. Using stem-loop RT-PCR, three whitefly sRNAs have been verified to be present in whitefly-infested leaflets that were also present in the whitefly-infested phloem sample. Our results show that whitefly sRNAs are indeed present in tomato tissues upon feeding, and they appear to be mobile in the phloem. Their role in the host-insect interaction can now be investigated.

  11. Foraging behavior and prey interactions by a guild of predators on various lifestages of Bemisia tabaci

    Directory of Open Access Journals (Sweden)

    James R. Hagler

    2004-01-01

    Full Text Available The sweetpotato whitefly, Bemisia tabaci (Gennadius is fed on by a wide variety of generalist predators, but there is little information on these predator-prey interactions. A laboratory investigation was conducted to quantify the foraging behavior of the adults of five common whitefly predators presented with a surfeit of whitefly eggs, nymphs, and adults. The beetles, Hippodamia convergens Guérin-Méneville and Collops vittatus (Say fed mostly on whitefly eggs, but readily and rapidly preyed on all of the whitefly lifestages. The true bugs, Geocoris punctipes (Say and Orius tristicolor (Say preyed almost exclusively on adult whiteflies, while Lygus hesperus Knight preyed almost exclusively on nymphs. The true bugs had much longer prey handling times than the beetles and spent much more of their time feeding (35-42% than the beetles (6-7%. These results indicate that generalist predators vary significantly in their interaction with this host, and that foraging behavior should be considered during development of a predator-based biological control program for B. tabaci.

  12. Ocorrência de mosca-branca em Annona squamosa no estado de São Paulo

    Directory of Open Access Journals (Sweden)

    Maria José De Marchi Garcia

    2013-12-01

    Full Text Available No Brasil, é restrito o conhecimento sobre distribuição geográfica e plantas hospedeiras de moscas-brancas (Hemiptera: Aleyrodidae, principalmente em plantas cultivadas. Nesta comunicação, é registrada a ocorrência de Aleurodicus mirabilis (Cockerell, 1898 em altas infestações em fruta-do-conde (Annona squamosa Linnaeus, 1753 no estado de São Paulo, Brasil.

  13. Differential profiles of direct and indirect modification of vector feeding behaviour by a plant virus.

    Science.gov (United States)

    He, Wen-Bo; Li, Jie; Liu, Shu-Sheng

    2015-01-08

    Plant viruses interact with their insect vectors directly and indirectly via host plants, and this tripartite interaction may produce fitness benefits to both the vectors and the viruses. Our previous studies show that the Middle East-Asia Minor 1 (MEAM1) species of the whitefly Bemisia tabaci complex improved its performance on tobacco plants infected by the Tomato yellow leaf curl China virus (TYLCCNV), which it transmits, although virus infection of the whitefly per se reduced its performance. Here, we use electrical penetration graph recording to investigate the direct and indirect effects of TYLCCNV on the feeding behaviour of MEAM1. When feeding on either cotton, a non-host of TYLCCNV, or uninfected tobacco, a host of TYLCCNV, virus-infection of the whiteflies impeded their feeding. Interestingly, when viruliferous whiteflies fed on virus-infected tobacco, their feeding activities were no longer negatively affected; instead, the virus promoted whitefly behaviour related to rapid and effective sap ingestion. Our findings show differential profiles of direct and indirect modification of vector feeding behaviour by a plant virus, and help to unravel the behavioural mechanisms underlying a mutualistic relationship between an insect vector and a plant virus that also has features reminiscent of an insect pathogen.

  14. Annual predictions of the peak numbers of Sitobion avenae infesting winter wheat

    Czech Academy of Sciences Publication Activity Database

    Honěk, A.; Martinková, Z.; Dixon, Anthony F. G.; Saska, P.

    2017-01-01

    Roč. 141, č. 5 (2017), s. 352-362 ISSN 0931-2048 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:86652079 Keywords : metopolophium-dirhodum wlk * cereal aphid populations * rhopalosiphum-padi l * english grain aphid * field populations * growth-stages * fixed levels * yield loss * homoptera * dynamics * abundance * ears * growth * leaves * maximum * population Subject RIV: EH - Ecology, Behaviour OBOR OECD: Biodiversity conservation Impact factor: 1.641, year: 2016

  15. A Molecular Phylogeny of Hemiptera Inferred from Mitochondrial Genome Sequences

    Science.gov (United States)

    Song, Nan; Liang, Ai-Ping; Bu, Cui-Ping

    2012-01-01

    Classically, Hemiptera is comprised of two suborders: Homoptera and Heteroptera. Homoptera includes Cicadomorpha, Fulgoromorpha and Sternorrhyncha. However, according to previous molecular phylogenetic studies based on 18S rDNA, Fulgoromorpha has a closer relationship to Heteroptera than to other hemipterans, leaving Homoptera as paraphyletic. Therefore, the position of Fulgoromorpha is important for studying phylogenetic structure of Hemiptera. We inferred the evolutionary affiliations of twenty-five superfamilies of Hemiptera using mitochondrial protein-coding genes and rRNAs. We sequenced three mitogenomes, from Pyrops candelaria, Lycorma delicatula and Ricania marginalis, representing two additional families in Fulgoromorpha. Pyrops and Lycorma are representatives of an additional major family Fulgoridae in Fulgoromorpha, whereas Ricania is a second representative of the highly derived clade Ricaniidae. The organization and size of these mitogenomes are similar to those of the sequenced fulgoroid species. Our consensus phylogeny of Hemiptera largely supported the relationships (((Fulgoromorpha,Sternorrhyncha),Cicadomorpha),Heteroptera), and thus supported the classic phylogeny of Hemiptera. Selection of optimal evolutionary models (exclusion and inclusion of two rRNA genes or of third codon positions of protein-coding genes) demonstrated that rapidly evolving and saturated sites should be removed from the analyses. PMID:23144967

  16. A molecular phylogeny of Hemiptera inferred from mitochondrial genome sequences.

    Directory of Open Access Journals (Sweden)

    Nan Song

    Full Text Available Classically, Hemiptera is comprised of two suborders: Homoptera and Heteroptera. Homoptera includes Cicadomorpha, Fulgoromorpha and Sternorrhyncha. However, according to previous molecular phylogenetic studies based on 18S rDNA, Fulgoromorpha has a closer relationship to Heteroptera than to other hemipterans, leaving Homoptera as paraphyletic. Therefore, the position of Fulgoromorpha is important for studying phylogenetic structure of Hemiptera. We inferred the evolutionary affiliations of twenty-five superfamilies of Hemiptera using mitochondrial protein-coding genes and rRNAs. We sequenced three mitogenomes, from Pyrops candelaria, Lycorma delicatula and Ricania marginalis, representing two additional families in Fulgoromorpha. Pyrops and Lycorma are representatives of an additional major family Fulgoridae in Fulgoromorpha, whereas Ricania is a second representative of the highly derived clade Ricaniidae. The organization and size of these mitogenomes are similar to those of the sequenced fulgoroid species. Our consensus phylogeny of Hemiptera largely supported the relationships (((Fulgoromorpha,Sternorrhyncha,Cicadomorpha,Heteroptera, and thus supported the classic phylogeny of Hemiptera. Selection of optimal evolutionary models (exclusion and inclusion of two rRNA genes or of third codon positions of protein-coding genes demonstrated that rapidly evolving and saturated sites should be removed from the analyses.

  17. Real-time PCR protocols for the quantification of the begomovirus tomato yellow leaf curl Sardinia virus in tomato plants and in its insect vector.

    Science.gov (United States)

    Noris, Emanuela; Miozzi, Laura

    2015-01-01

    Tomato yellow leaf curl Sardinia virus (TYLCSV) (Geminiviridae) is an important pathogen, transmitted by the whitefly Bemisia tabaci, that severely affects the tomato production in the Mediterranean basin. Here, we describe real-time PCR protocols suitable for relative and absolute quantification of TYLCSV in tomato plants and in whitefly extracts. Using primers and probe specifically designed for TYLCSV, the protocols for relative quantification allow to compare the amount of TYLCSV present in different plant or whitefly samples, normalized to the amount of DNA present in each sample using endogenous tomato or Bemisia genes as internal references. The absolute quantification protocol allows to calculate the number of genomic units of TYLCSV over the genomic units of the plant host (tomato), with a sensitivity of as few as ten viral genome copies per sample. The described protocols are potentially suitable for several applications, such as plant breeding for resistance, analysis of virus replication, and virus-vector interaction studies.

  18. Rickettsia ‘In’ and ‘Out’: Two Different Localization Patterns of a Bacterial Symbiont in the Same Insect Species

    Science.gov (United States)

    Caspi-Fluger, Ayelet; Inbar, Moshe; Mozes-Daube, Netta; Mouton, Laurence; Hunter, Martha S.; Zchori-Fein, Einat

    2011-01-01

    Intracellular symbionts of arthropods have diverse influences on their hosts, and their functions generally appear to be associated with their localization within the host. The effect of localization pattern on the role of a particular symbiont cannot normally be tested since the localization pattern within hosts is generally invariant. However, in Israel, the secondary symbiont Rickettsia is unusual in that it presents two distinct localization patterns throughout development and adulthood in its whitefly host, Bemisia tabaci (B biotype). In the “scattered” pattern, Rickettsia is localized throughout the whitefly hemocoel, excluding the bacteriocytes, where the obligate symbiont Portiera aleyrodidarum and some other secondary symbionts are housed. In the “confined” pattern, Rickettsia is restricted to the bacteriocytes. We examined the effects of these patterns on Rickettsia densities, association with other symbionts (Portiera and Hamiltonella defensa inside the bacteriocytes) and on the potential for horizontal transmission to the parasitoid wasp, Eretmocerus mundus, while the wasp larvae are developing within the whitefly nymph. Sequences of four Rickettsia genes were found to be identical for both localization patterns, suggesting that they are closely related strains. However, real-time PCR analysis showed very different dynamics for the two localization types. On the first day post-adult emergence, Rickettsia densities were 21 times higher in the “confined” pattern vs. “scattered” pattern whiteflies. During adulthood, Rickettsia increased in density in the “scattered” pattern whiteflies until it reached the “confined” pattern Rickettsia density on day 21. No correlation between Rickettsia densities and Hamiltonella or Portiera densities were found for either localization pattern. Using FISH technique, we found Rickettsia in the gut of the parasitoid wasps only when they developed on whiteflies with the “scattered” pattern. The

  19. Author Details

    African Journals Online (AJOL)

    Borisade, OA. Vol 23, No 2 (2015) - Articles Rearing tomato whitefly and field evaluation of modified and unmodified conidia of Beauveria bassiana, Isaria farinosa, Metarhizium anisopliae and low rates of Chlorpyrifos under tropical conditions. Abstract PDF. ISSN: 2072-6589. AJOL African Journals Online. HOW TO USE ...

  20. genotypes for okra yellow vein mosaic virus incidence

    African Journals Online (AJOL)

    SAM

    2014-03-19

    Mar 19, 2014 ... by whitefly (Bemisia tabaci Gen.) (Rana et al., 2006). ... Solankey et al. 1337. Table 1. Scale for classifying disease reaction in okra to OYVMV disease. Symptom. Severity grade. Response value. Coefficient of infection. Reaction ..... On the basis of two season research work, it was observed that the okra ...

  1. How active ingredient localisation in plant tissues determines the targeted pest spectrum of different chemistries

    DEFF Research Database (Denmark)

    Buchholz, Anke; Trapp, Stefan

    2016-01-01

    information sets revealed that the intracellular localisation of active ingredients determines the performance of test compounds against different target pests because of different feeding behaviours: mites feed on mesophyll, and aphids and whiteflies mostly in the vascular system. Polar compounds have a slow...

  2. Suppressors of RNA silencing encoded by tomato leaf curl

    Indian Academy of Sciences (India)

    Whitefly-transmitted begomoviruses infecting tomato crop code for five different proteins, ORF AC4, ORF AC2 and ORF AV2 in DNA-A component, ORF BV1 in DNA-B ... In the present study suppressor function of ORF C1 of three betasatellites Tomato leaf curl Bangalore betasatellite ToLCBB-[IN:Hess:08], Cotton leaf curl ...

  3. IPM of specialty crops and community gardens in north Florida

    Science.gov (United States)

    Insect pests post serious challenges to specialty crops (vegetables, fruits and nut crops) and community gardens in North Florida. The major vegetable pests include silverleaf whitefly, Bemisia argentifolii; the green peach aphid, Myzus persicae; southeastern green stinkbug, Nezara viridula; brown s...

  4. by fermented plant extracts of neem leaf and wild garlic

    African Journals Online (AJOL)

    Bombiti

    1Department of Soil Science, Plant Production and Agricultural Engineering, Faculty of Science and Agriculture,. University of ... Additionally, due to frequent use of .... Average number of whitefly adults as affected by fermented plant extracts of garlic, neem and garlic + neem (CarNeem) at five sampling intervals. Application.

  5. Tomato yellow leaf curl virus can be acquired and transmitted by Bemisia tabaci (Gennadius) from tomato fruits

    NARCIS (Netherlands)

    Delatte, H.; Dalmon, A.; Rist, D.; Soustrade, I.; Wuster, G.; Lett, J.M.; Goldbach, R.W.; Peterschmitt, M.; Reynaud, B.

    2003-01-01

    The whitefly Bemisia tabaci is an insect pest causing worldwide economic losses, especially as a vector of geminiviruses such as Tomato yellow leaf curl virus (TYLCV). Currently, imported and exported tomato fruit are not monitored for TYLCV infection because they are not considered to represent a

  6. Ion chromatography separation of cotton surface melezitose and raffinose: entomological vs. plant sugars

    Science.gov (United States)

    According to previous studies, certain levels of the carbohydrates melezitose and trehalulose deposited on the surface of cotton are indicative of either whitefly or aphid contamination, which may cause problems during cotton processing. Obtaining reliable IC values for those surface sugars is para...

  7. Accelerating the transfer of improved production technologies ...

    African Journals Online (AJOL)

    Since 1988, epidemics of African cassava mosaic disease (ACMD) caused by a whitefly-transmitted geminivirus have caused severe devastation in Uganda resulting in food shortages and famine in some areas. In order to control the disease and restore food security in the country, appropriate technologies had to be ...

  8. Wild tomato introgressions that confer resistance to begomoviruses in Guatemala

    Science.gov (United States)

    Begomoviruses, whitefly-transmitted geminiviruses, are one of the major diseases of tomatoes in subtropical and tropical regions. In Guatemala, several bipartite begomoviruses and the monopartite geminivirus, Tomato yellow leaf curl virus, are present. Three experiments were conducted to evaluate th...

  9. Is the begomovirus, sweet potato leaf curl virus, really seed transmitted in sweetpotato?

    Science.gov (United States)

    Sweetpotato is one of the major root crops in the world and is also widely grown in the southern United States. Sweet potato leaf curl virus (SPLCV) is a begomovirus posing a serious threat to sweetpotato production worldwide and is primarily transmitted by whitefly (Bemisia tabaci) or through veget...

  10. Alternatieven voor neonicotinoïden in de sierteelt onder glas : bestrijding van tabakswittevlieg en bladluis in kuipplanten en perkgoed

    NARCIS (Netherlands)

    Messelink, Gerben; Vijverberg, Roland; Bloemhard, Chantal; Leman, Ada

    2016-01-01

    The control of phloem feeding insects such as aphids, whiteflies, cicadas, mealybugs, scales and plant feeding bugs in greenhouse crops still largely depends on the use of neonicotinoids. However, the increased found negative effects on the environment will soon results in a total ban on the use of

  11. Dissipation rate of thiacloprid and its control effect against Bemisia tabaci in greenhouse tomato after soil application.

    Science.gov (United States)

    Dong, Sa; Qiao, Kang; Wang, Hongyan; Zhu, Yukun; Xia, Xiaoming; Wang, Kaiyun

    2014-08-01

    Thiacloprid is a chloronicotinyl insecticide that is quite effective against sucking insects. In this study, when thiacloprid was applied at two different rates (normal rate 15 kg ha(-1) , double rate 30 kg ha(-1) ), the systemic distribution and residue of thiacloprid as well as its control effect against whitefly (Bemisia tabaci) were investigated in greenhouse tomato after soil application. The results showed that thiacloprid was present in the tomato leaves until day 25, and then its amount was less than 0.005 mg kg(-1) and could not be detected. Thiacloprid residue in the tomato stems basically remained at a stable low level throughout the experimental period. Thiacloprid in soil had half-lives of 11.8 and 12.5 days for the normal treatment and the double treatment respectively. The control efficiency of whiteflies was about 90% from day 1 to day 10. This was followed by a slow decline, but efficiency was still higher than 50% until day 21. In addition, no significant differences were noted in the control effect of thiacloprid on whiteflies between the two different rates. Soil application of thiacloprid at the normal rate can effectively control whiteflies, with high efficiency and long persistence. © 2013 Society of Chemical Industry.

  12. Download this PDF file

    African Journals Online (AJOL)

    SAM

    r: 4E2A612496. 5. 015 n the copyrigh cademicjourn. Research ficatio on in c er resis on1, T. M. K ..... whitefly (A. socialis) infestation, a fundamental part of our ..... by high-throughput sequencing systems and transfers them for. BLAST alignment against a database of choice, followed by Ka/Ks analysis of ... ed in Namiko.

  13. Host feeding in insect parasitoids: why destructively feed upon a host that excretes an alternative?

    NARCIS (Netherlands)

    Burger, J.S.M.; Reijnen, T.M.; Van Lenteren, J.C.; Vet, L.E.M.

    2004-01-01

    Host feeding is the consumption of host tissue by the adult female parasitoid. We studied the function of destructive host feeding and its advantage over non-destructive feeding on host-derived honeydew in the whitefly parasitoid Encarsia formosa Gahan (Hymenoptera: Aphelinidae). We allowed

  14. Study of drimane sesquiterpenoids from the Persicaria genus and zigiberene from Callitropsis noorkatensis and their effect on the feeding behaviour of Myzus persicae and Bemisia tabaci

    NARCIS (Netherlands)

    Prota, N.

    2015-01-01

    Summary

    Whitefly is an insect pest that has systematically spread into colder latitudes for the past two decades and it poses a serious threat to crops, mainly due to the viruses for which it acts as a vector. As the application of synthetic pesticides is often less effective due to

  15. Horizontal transmission of the insect symbiont Rickettsia is plant-mediated

    Science.gov (United States)

    Caspi-Fluger, Ayelet; Inbar, Moshe; Mozes-Daube, Netta; Katzir, Nurit; Portnoy, Vitaly; Belausov, Eduard; Hunter, Martha S.; Zchori-Fein, Einat

    2012-01-01

    Bacteria in the genus Rickettsia, best known as vertebrate pathogens vectored by blood-feeding arthropods, can also be found in phytophagous insects. The presence of closely related bacterial symbionts in evolutionarily distant arthropod hosts presupposes a means of horizontal transmission, but no mechanism for this transmission has been described. Using a combination of experiments with live insects, molecular analyses and microscopy, we found that Rickettsia were transferred from an insect host (the whitefly Bemisia tabaci) to a plant, moved inside the phloem, and could be acquired by other whiteflies. In one experiment, Rickettsia was transferred from the whitefly host to leaves of cotton, basil and black nightshade, where the bacteria were restricted to the phloem cells of the plant. In another experiment, Rickettsia-free adult whiteflies, physically segregated but sharing a cotton leaf with Rickettsia-plus individuals, acquired the Rickettsia at a high rate. Plants can serve as a reservoir for horizontal transmission of Rickettsia, a mechanism which may explain the occurrence of phylogenetically similar symbionts among unrelated phytophagous insect species. This plant-mediated transmission route may also exist in other insect–symbiont systems and, since symbionts may play a critical role in the ecology and evolution of their hosts, serve as an immediate and powerful tool for accelerated evolution. PMID:22113034

  16. The perspective of sweetpotato chlorotic stunt virus in sweetpotato ...

    African Journals Online (AJOL)

    The virus is transmitted by the whitefly species, Bemisia tabaci and Trialeurodes abutilonea, in a semi-persistent fashion. ... yields being small, and the major effect of SPCSV in constraining the yields of sweetpotato is perhaps through preventing the cultivation of high yielding but SPVD-susceptible sweetpotato cultivars.

  17. Journal of Biosciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    RNA interference (RNAi)-mediated gene silencing was explored for the control of sap-sucking pest Bemisia tabaci, commonly known as whitefly. dsRNAs and siRNAs were synthesized from five different genes – actin ortholog, ADP/ATP translocase, -tubulin, ribosomal protein L9 (RPL9) and V-ATPase A subunit.

  18. Almost there: transmission routes of bacterial symbionts between trophic levels.

    Directory of Open Access Journals (Sweden)

    Elad Chiel

    Full Text Available Many intracellular microbial symbionts of arthropods are strictly vertically transmitted and manipulate their host's reproduction in ways that enhance their own transmission. Rare horizontal transmission events are nonetheless necessary for symbiont spread to novel host lineages. Horizontal transmission has been mostly inferred from phylogenetic studies but the mechanisms of spread are still largely a mystery. Here, we investigated transmission of two distantly related bacterial symbionts--Rickettsia and Hamiltonella--from their host, the sweet potato whitefly, Bemisia tabaci, to three species of whitefly parasitoids: Eretmocerus emiratus, Eretmocerus eremicus and Encarsia pergandiella. We also examined the potential for vertical transmission of these whitefly symbionts between parasitoid generations. Using florescence in situ hybridization (FISH and transmission electron microscopy we found that Rickettsia invades Eretmocerus larvae during development in a Rickettsia-infected host, persists in adults and in females, reaches the ovaries. However, Rickettsia does not appear to penetrate the oocytes, but instead is localized in the follicular epithelial cells only. Consequently, Rickettsia is not vertically transmitted in Eretmocerus wasps, a result supported by diagnostic polymerase chain reaction (PCR. In contrast, Rickettsia proved to be merely transient in the digestive tract of Encarsia and was excreted with the meconia before wasp pupation. Adults of all three parasitoid species frequently acquired Rickettsia via contact with infected whiteflies, most likely by feeding on the host hemolymph (host feeding, but the rate of infection declined sharply within a few days of wasps being removed from infected whiteflies. In contrast with Rickettsia, Hamiltonella did not establish in any of the parasitoids tested, and none of the parasitoids acquired Hamiltonella by host feeding. This study demonstrates potential routes and barriers to horizontal

  19. Molecular and Biochemical Characterization of Cotton Epicuticular Wax in Defense Against Cotton Leaf Curl Disease.

    Science.gov (United States)

    Khan, Muhammad Azmat Ullah; Shahid, Ahmad Ali; Rao, Abdul Qayyum; Bajwa, Kamran Shehzad; Samiullah, Tahir Rehman; Muzaffar, Adnan; Nasir, Idrees Ahmad; Husnain, Tayyab

    2015-12-01

    Gossypium arboreumis resistant to Cotton leaf curl Burewala virus and its cognate Cotton leaf curl Multan beta satellite ( CLCuBuV and CLCuMB ). However, the G. arboreum wax deficient mutant (GaWM3) is susceptible to CLCuV . Therefore, epicuticular wax was characterized both quantitatively and qualitatively for its role as physical barrier against whitefly mediated viral transmission and co-related with the titer of each viral component (DNA-A, alphasatellite and betasatellite) in plants. The hypothesis was the CLCuV titer in cotton is dependent on the amount of wax laid down on plant surface and the wax composition. Analysis of the presence of viral genes, namely alphasatellite, betasatellite and DNA-A, via real-time PCR in cotton species indicated that these genes are detectable in G. hirsutum , G. harknessii and GaWM3, whereas no particle was detected in G. arboreum . Quantitative wax analysis revealed that G. arboreum contained 183 μg.cm -2 as compared to GaWM3 with only 95 μg.cm -2 . G. hirsutum and G. harknessii had 130 μg.cm -2 and 146 μg.cm -2 , respectively. The GCMS results depicted that Lanceol, cis was 45% in G. harknessii . Heptadecanoic acid was dominant in G. arboreum with 25.6%. GaWM3 had 18% 1,2,-Benenedicarboxylic acid. G. hirsutum contained 25% diisooctyl ester. The whitefly feeding assay with Nile Blue dye showed no color in whiteflies gut fed on G. arboreum . In contrast, color was observed in the rest of whiteflies. From results, it was concluded that reduced quantity as well as absence of (1) 3-trifluoroacetoxytetradecane, (2) 2-piperidinone,n-|4-bromo-n-butyl|, (3) 4-heptafluorobutyroxypentadecane, (4) Silane, trichlorodocosyl-, (5) 6- Octadecenoic acid, methyl ester, and (6) Heptadecanoicacid,16-methyl-,methyl ester in wax could make plants susceptible to CLCuV , infested by whiteflies.

  20. Comparison of exclusion and imidacloprid for reduction of oviposition damage to young trees by periodical cicadas (Hemiptera: Cicadidae).

    Science.gov (United States)

    Ahern, Robert G; Frank, Steven D; Raupp, Michael J

    2005-12-01

    Insecticides are traditionally used to control periodical cicadas (Homoptera: Cicadidae) and to reduce associated injury caused by oviposition. However, research has shown that conventional insecticides have low or variable season-long efficacy in reducing injury caused by cicadas. New systemic neonicotinoid insecticides provide excellent levels of control against a variety of sucking insects. We compared the efficacy of a neonicotinoid insecticide, imidacloprid, and a nonchemical control measure, netting, to reduce cicada injury. Netted trees sustained very little injury, whereas unprotected trees were heavily damaged. Fewer eggnests, scars, and flags were observed on trees treated with imidacloprid compared with unprotected trees; however, the hatching of cicada eggs was unaffected by imidacloprid.

  1. Plantas hospederas de Aphis gossypii (Aphididae), vector de virus del melón Cucumis melo (Cucurbitaceae) en Costa Rica

    OpenAIRE

    Sánchez, M.V.; Agüero, R.; Rivera, C.

    2001-01-01

    Se identificaron las especies hospederas naturales de Aphis gossypii Glover (Aphididae: Homoptera) en plantaciones comerciales de melón para la exportación en Costa Rica. El estudio se realizó en dos fincas, ubicadas una en la provincia de Guanacaste y la otra en la provincia de Puntarenas, correspondientes a dos zonas de vida vegetal diferentes. Se identificaron como especies hospederas del áfido todas aquellas especies vegetales en las que se observó la presencia del áfido en su forma ápter...

  2. Food Composition of the Snake-Eyed Lizard, Ophisops elegans Ménétriés, 1832 (Reptilia: Sauria: Lacertidae from Gökçeada (Imbros, Turkey

    Directory of Open Access Journals (Sweden)

    Cemal Varol Tok

    2016-06-01

    Full Text Available The study presents data on the food composition of the snake-eyed lizard (Ophisops elegans, from Gökçeada (Imbros, Çanakkale, Turkey. A total of 94 preys were determined in thedigestive systems of 20 individuals (10 males, 10 females examined in the study. Insects (67%constitute most of its food composition. Major prey groups in the food composition are included inAranea (13%, Lepidoptera (13%, Coleoptera (19%, and Homoptera (20% in numeric proportion.No significant difference was observed between sexes considering food composition.

  3. Assessing the effects of cultivating genetically modified glyphosate-tolerant varieties of soybeans (Glycine max (L.) Merr.) on populations of field arthropods.

    Science.gov (United States)

    Imura, Osamu; Shi, Kun; Iimura, Keiji; Takamizo, Tadashi

    2010-01-01

    We assessed the effects of cultivating two genetically modified (GM) glyphosate-tolerant soybean varieties (Glycine max (L.) Merr.) derived from Event 40-3-2 and a Japanese conventional variety on arthropods under field conditions, with weed control using glyphosate and conventional weed control for two years. Plant height and dry weight of the conventional variety were significantly larger than those of the GM varieties, but the GM varieties bore more pods than the conventional variety. We found arthropods of nine taxonomic orders (Araneae, Acari, Thysanoptera, Homoptera, Heteroptera, Coleoptera, Diptera, Lepidoptera, and Hymenoptera) on the plants. The arthropod incidence (number per plant unit weight pooled for each taxonomic order) on the soybean stems and leaves generally did not differ significantly between the GM and conventional varieties. However, the incidence of Thysanoptera and total incidence (all orders combined) were greater on the GM variety in the second year. The weed control regimes had no significant influence on the arthropod incidence on the soybean stems and leaves. The number of flower-inhabiting Thysanoptera (the dominant arthropod in the flowers) was not significantly different between the GM and conventional varieties. Asphondylia yushimai (Diptera, Cecidomyiidae) was more numerous on the pods of the GM variety in both years. Neither the soybean variety nor the weed control regime significantly affected the density of soil macro-organisms. However, the glyphosate weed control affected arthropods between the rows of plants by decreasing the abundances of Homoptera, Heteroptera, Coleoptera and Lepidoptera, and diversity of arthropods. © ISBR, EDP Sciences, 2011.

  4. Intercropping System for Protection the Potato Plant from Insect Infestation

    Directory of Open Access Journals (Sweden)

    Aziza Sharaby

    2015-06-01

    Full Text Available The use of intercropping system provides an option for insect control for organic farmers that are limited in their chemical use. Additionally, intercropping systems can be attractive to conventional growers as a cost-effective insect control solution. A study was carried out for two seasons 2011-2012 and 2012-2013 to evaluate the effect of intercropping of potato (Solanum tuberosum L. with onion (Allium cepa L. on whitefly (Bemicia tabasi Gennadius and aphids’ Myzus persicae Sulz. and Aphis gossypii Glover infestation in potato fields. Results indicated that intercropping significantly reduced potato plant infestation with whitefly by 42.7, 51.3% while it was 62.69% reduction with aphids during the two successive winter seasons than when potato plants were cultivated alone. Therefore, intercropping could be recommended as a protection method of reducing pest population in the fields.

  5. Evaluation of some varieties and breeding lines of tomato (Lycopersison sp) against tomato yellow leaf curl disease in the Greater Accra Region (Ghana)

    International Nuclear Information System (INIS)

    Kusi-Adjei, R.

    2011-01-01

    A series of experiments were conducted to evaluate ten (10) tomato varieties and breeding lines against tomato yellow leaf curl virus disease in Ghana. The research was undertaken at the research farm of the Biotechnology and Nuclear Agriculture Research Institute of the Ghana Atomic Energy Commission. Ten tomato varieties and breeding lines were evaluated in the field under natural whitefly inoculation in insect-proof cages. The field trial was done in the dry season from October, 2010 to February, 2011 and wet season from March, 2011 to July, 2011. Plants in the fields and in the cage exhibited varied symptoms such as leaf curling, leaf yellowing and reduced leaf sizes. Assessment of disease incidence and symptom severity using a four point scale (0-4) showed that, in the field there was higher disease incidence in the dry season as compared to the wet season. This was attributed to the higher number of whiteflies in the dry season as demonstrated through a whitefly population survey conducted in the field. Differences among means for disease incidence and whitefly surveys on the ten tomato varieties and breeding lines were statistically significant (p≤ 0.05). Wild Tomato (Solanum pimpinellifollium) and two hybrids, Wosowoso x Wild Tomato and Cherry Red x Wild Tomato exhibited signs of resistance in the field and did not show any symptoms of TYLCV disease symptoms. All the commercial varieties were highly susceptible and showed severe symptoms. Evaluation of fruit yield in the field revealed that the commercial variety Tomato Advanta had the heaviest fruit weight (42 g/ fruit) whilst Wosowoso had the highest total fruit yield (5.74 t/ha) in the wet season. Wild Tomato and the hybrids produced higher number of fruits compared to the commercial varieties. There were highly significant differences in the means of number of fruits, fruit weight (g) and total fruit yield (t/ha) among the ten tomato varieties and breeding lines in both the wet and dry seasons

  6. Statement on the dossier for a derogation request of the US authorities concerning cold-treated strawberry plants intended for planting

    DEFF Research Database (Denmark)

    Baker, R.; Candresse, T.; Dormannsné Simon, E.

    2009-01-01

    Following a request from the European Commission, the EFSA Panel on Plant Health examined the report “Evaluation of Strawberry Nursery Plant Cold Treatments on Survival of the Whitefly, Bemisia tabaci”, submitted to the European Commission by the United States Department of Agriculture (USDA...... the effectiveness of the cold treatment proposed for the elimination of B. tabaci from strawberry plant consignments prepared for shipment to the EU. In addition, the Panel conducted a preliminary review of the available literature on viruses of strawberry and concluded that no B. tabaci-transmitted viruses...... are currently known to infect strawberry and that no viruses of Fragaria listed in European Council Directive 2000/29/EC are known to be transmitted by B. tabaci. However, adult whiteflies of B. tabaci on strawberry consignments can carry plant viruses irrespective of whether strawberry is a host plant...

  7. Entomopathogenic Potential of Verticillium and Acremonium Species (Deuteromycotina: Hyphomycetes)

    DEFF Research Database (Denmark)

    Steenberg, Tove; Humber, Richard A

    1999-01-01

    their entomopathogenicity. A test was also conducted with a coleopteran (lesser mealworm, Alphitobius diaperinus) to further evaluate the host range for some of the fungi. V. lamellicola was not pathogenic to the two species of insects treated, while varying levels of pathogenicity were shown for the other species....... In general, V. lecanii was the most pathogenic species. Immature whiteflies appeared to be more susceptible to fungal infection than adult houseflies, and the host range for several of the fungi also included lesser mealworm....

  8. Lack of resistance development in Bemisia tabaci to Isaria fumosorosea after multiple generations of selection

    OpenAIRE

    Tianni Gao; Zhaolei Wang; Yü Huang; Nemat O. Keyhani; Zhen Huang

    2017-01-01

    The emergence of insecticide resistant insect pests is of significant concern worldwide. The whitefly, Bemisia tabaci, is an important agricultural pest and has shown incredible resilience developing resistance to a number of chemical pesticides. Entomopathogenic fungi such as Isaria fumosorosea offer an attractive alternative to chemical pesticides for insect control, and this fungus has been shown to be an effective pathogen of B. tabaci. Little is known concerning the potential for the dev...

  9. USSR Report, Agriculture, No. 1406.

    Science.gov (United States)

    1983-10-25

    to combating the greenhouse whitefly, virus diseases and brown patch in tomatoes and in cucumbers — powdery mildew, anthracnose and root rots. In...crops cultivated on covered ground. Here extensive use is being made of trichodermin, phytoseyulyus, enkarziya and verticillin and with tomatoes being...vineyards. And indeed, under conditions involving the use of an industrial technology for the cultivation of tomatoes , for example, an increase

  10. A novel synthetic quantification standard including virus and internal report targets: application for the detection and quantification of emerging begomoviruses on tomato

    OpenAIRE

    Péréfarres, Frédéric; Hoareau, Murielle; Chiroleu, Frédéric; Reynaud, Bernard; Dintinger, Jacques; Lett, Jean-Michel

    2011-01-01

    Abstract Background Begomovirus is a genus of phytopathogenic single-stranded DNA viruses, transmitted by the whitefly Bemisia tabaci. This genus includes emerging and economically significant viruses such as those associated with Tomato Yellow Leaf Curl Disease, for which diagnostic tools are needed to prevent dispersion and new introductions. Five real-time PCRs with an internal tomato reporter gene were developed for accurate detection and quantification of monopartite begomoviruses, inclu...

  11. Aphid transmission of Lettuce necrotic leaf curl virus, a member of a tentative new subgroup within the genus Torradovirus.

    Science.gov (United States)

    Verbeek, Martin; Dullemans, Annette M; van der Vlugt, René A A

    2017-09-15

    Lettuce necrotic leaf curl virus (LNLCV) was described as the first non-tomato-infecting member of the genus Torradovirus. Until today, the virus was found only in The Netherlands in two different areas in open field crops of lettuce. In 2015, LNLCV was accepted by the ICTV as a new member of the genus Torradovirus. The tomato-infecting (TI) torradoviruses Tomato torrado virus (ToTV), Tomato marchitez virus (ToMarV) and Tomato chocolàte virus (ToChV) are transmitted by at least three whitefly species in a semi-persistent and stylet-borne manner. As LNLCV was transmitted in open fields in The Netherlands, where whiteflies are present only in low incidence, transmission studies were set up to identify the natural vector of LNLCV. Whitefly species which survive Dutch open field conditions during summer, as well as lettuce colonizing aphid species, were tested for their ability to transmit LNLCV. Lengths of acquisition and inoculation periods were chosen in accordance with the conditions for TI torradoviruses. Transmission experiments involving whiteflies were never successful. Transmission with aphids was only successful in case of the lettuce-currant aphid, Nasonovia ribisnigri. Localization of LNLCV virions in N. ribisnigri with a nested RT-PCR indicated the stylets as possible retention sites. The willow-carrot aphid Cavariella aegopodii did not transmit LNLCV in our transmission experiment but the virus could be detected in the stylets of this aphid, leaving C. aegopodii as a possible vector for LNLCV. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  12. RNA Interference in Insect Vectors for Plant Viruses

    OpenAIRE

    Kanakala, Surapathrudu; Ghanim, Murad

    2016-01-01

    Insects and other arthropods are the most important vectors of plant pathogens. The majority of plant pathogens are disseminated by arthropod vectors such as aphids, beetles, leafhoppers, planthoppers, thrips and whiteflies. Transmission of plant pathogens and the challenges in managing insect vectors due to insecticide resistance are factors that contribute to major food losses in agriculture. RNA interference (RNAi) was recently suggested as a promising strategy for controlling insect pests...

  13. Management of white flies (Bemisia tabaci) in tomato with a combination of plastic mulch and insecticides in Costa Rica

    International Nuclear Information System (INIS)

    Cubillo, D.; Hilje, L.; Valverde, B.E.; Carazo, E.

    1999-01-01

    A combination of silver plastic soil cover and application of endosulfan or imidacloprid for the control of whiteflies (Bemisia tabaci) in tomato was compared to farmer's practice in Guayabo, Turrialba, Costa Rica. None of the treatments affected the whitefly infestation which was very low, the highest value being 2.25 adults/10 plants. Viral disease incidence amounted only 2.4 to 4.4% by the end of the crop season, the highest incidence levels were consistently observed in control treatments. Such negligible incidence values precluded evaluation of disease severity. Fruit number or weight and total yield were not affected by the treatments. No detectable residues of endosulfan or its metabolites were present in either foliage or fruit tissues. In soil samples, minute amounts of α- and β-endosulfan were found as well as endosulfan sulphate, the most important metabolite. Insecticide residues were always higher in the plots that were treated twice compared to those that were sprayed only once with endosulfan. No endosulfan or metabolites were detected in control plots. The lack of residues in plant tissues and the minute amounts found in soils indicate that endosulfan can be used as part as an integrated program for whitefly control in tomato. (author)

  14. Differential and Synergistic Functionality of Acylsugars in Suppressing Oviposition by Insect Herbivores.

    Directory of Open Access Journals (Sweden)

    Brian M Leckie

    Full Text Available Acylsugars are secondary metabolites exuded from type IV glandular trichomes that provide broad-spectrum insect suppression for Solanum pennellii Correll, a wild relative of cultivated tomato. Acylsugars produced by different S. pennellii accessions vary by sugar moieties (glucose or sucrose and fatty acid side chains (lengths and branching patterns. Our objective was to determine which acylsugar compositions more effectively suppressed oviposition of the whitefly Bemisia tabaci (Gennadius (Middle East--Asia Minor 1 Group, tobacco thrips, Frankliniella fusca (Hinds, and western flower thrips, Frankliniella occidentalis (Pergande. We extracted and characterized acylsugars from four S. pennellii accessions with different compositions, as well as from an acylsugar-producing tomato breeding line. We also fractionated the acylsugars of one S. pennellii accession to examine the effects of its components. Effects of acylsugars on oviposition were evaluated by administering a range of doses to oviposition sites of adult whiteflies and thrips in non-choice and choice bioassays, respectively. The acylsugars from S. pennellii accessions and the tomato breeding line demonstrated differential functionality in their ability to alter the distribution of whitefly oviposition and suppress oviposition on acylsugar treated substrates. Tobacco thrips were sensitive to all compositions while western flower thrips and whiteflies were more sensitive to acylsugars from a subset of S. pennellii accessions. It follows that acylsugars could thus mediate plant-enemy interactions in such a way as to affect evolution of host specialization, resistance specificity, and potentially host differentiation or local adaptation. The acylsugars from S. pennellii LA1376 were separated by polarity into two fractions that differed sharply for their sugar moieties and fatty acid side chains. These fractions had different efficacies, with neither having activity approaching that of the

  15. Respon Fungsional Menochilus sexmaculatus Fabricius terhadap Aphis Gossypii Glover

    Directory of Open Access Journals (Sweden)

    F. X. Wagiman

    1996-12-01

    Full Text Available Laboratory and field-cage experiments were conducted at the Universiti Pertanian Malaysia. Objective of the study was to determine the functional response of Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae predating on chilli aphid Aphis gossypii Glover (Homoptera: Aphididae. The larvae and adults of the predaceous coccinellid exhibited the Hulling's Type II functional response. A first instar of the coccinellid predating on single first instar of the aphid within 24.6 minutes in the laboratory and 16.8 minutes in the field. While a fourth instar and an adult of the coccinellid predating on single fourth instar of the aphid within 4.2 and 1.5 minutes respectively.

  16. Secondary metabolites from the endophytic fungus Talaromyces pinophilus.

    Science.gov (United States)

    Vinale, F; Nicoletti, R; Lacatena, F; Marra, R; Sacco, A; Lombardi, N; d'Errico, G; Digilio, M C; Lorito, M; Woo, S L

    2017-08-01

    Endophytic fungi have a great influence on plant health and growth, and are an important source of bioactive natural compounds. Organic extracts obtained from the culture filtrate of an endophytic strain of Talaromyces pinophilus isolated from strawberry tree (Arbutus unedo) were studied. Metabolomic analysis revealed the presence of three bioactive metabolites, the siderophore ferrirubin, the platelet-aggregation inhibitor herquline B and the antibiotic 3-O-methylfunicone. The latter was the major metabolite produced by this strain and displayed toxic effects against the pea aphid Acyrthosiphon pisum (Homoptera Aphidiidae). This toxicity represents an additional indication that the widespread endophytic occurrence of T. pinophilus may be related to a possible role in defensive mutualism. Moreover, the toxic activity on aphids could promote further study on 3-O-methylfunicone, or its derivatives, as an alternative to synthetic chemicals in agriculture.

  17. Etude morphologique et biologique de la coccinelle Scymnus couturieri Chazeau (Coleoptera-Coccinellidae prédatrice de la cochenille farineuse du manioc Phenacoccus manihoti Matile-Ferrero

    Directory of Open Access Journals (Sweden)

    Obame Minko, D.

    1999-01-01

    Full Text Available Morphological and Biological Study of Scymnus couturieri Chazeau (Coleoptera-Coccinellidae, Predator of Cassava Mealybug Phenacoccus manihoti Matile-Ferrero (Homoptera-Pseudococcidae in Ivory Coast. Scymnus couturieri is a coccinellidae which was first described from Ivory Coast (2. But that morphological description was just based on the adult. The trophic action developed by Scymnus couturieri in the regulation of the abundance of the cassava mealybug led us to precise that description and to extend our knowledge of the coccinellidae by studying the morphological aspects and the biological parameters. The study brings to the fore the holometaboly development, the low fecondity and the long-lasting biological cycle of the predator.

  18. Ant tending influences soldier production in a social aphid.

    Science.gov (United States)

    Shingleton, A W; Foster, W A

    2000-09-22

    The aphid Pseudoregma sundanica (Van der Goot) (Homoptera: Aphididae) has two defence strategies. It is obligatorily tended by various species of ant and also produces sterile soldiers. We investigated how they allocate their investment in these two strategies. We measured the size, number of soldiers, number and species of tending ant, and number and species of predators in P. sundanica populations. We found that the level of ant tending correlated negatively with soldier investment in P. sundanica. The species of tending ant also influenced soldier investment. We excluded ants from aphid populations and recorded changes in population size and structure over four weeks. Ant exclusion led to population decline and extinction. At the same time, surviving populations showed a significant increase in soldier investment. The data demonstrate that social aphids can adjust their investment in soldiers in direct response to environmental change.

  19. [Anthropoentomophagic biodiversity of the Zongolica region, Veracruz, Mexico].

    Science.gov (United States)

    Ramos-Elorduy, Julieta; Landero-Torres, Ivonne; Murguía-González, Joaquín; Pino, José M M

    2008-03-01

    Anthropoentomophagic biodiversity of the Zongolica region, Veracruz, Mexico. During two and a half years (2003-2005) we recorded the insect species used as food at Zongolica, Veracruz State, Mexico. Interviews were made among people (200) of this municipality to know which insects they consumed. The total of registered species was 57 (Orthoptera, Hemiptera, Homoptera, Megaloptera, Coleoptera, Lepidoptera and Hymenoptera). The Orthoptera was the most frequently ingested. Twenty-four of these species were new records for edible insects of Mexico. They are eaten in immature stages or as adults, generally only roasted. Consumption is seasonal. Some species are commercialized in the "tianguis" (little town markets) and/or in the larger Zongolica market. There is a "protoculture" of three species, one cockroach (Periplaneta australasiae Fabricius) and two moths (Latebraria amphipyroides Guenée and Arsenura armida armida Cramer). In Zongolica, anthropoentomophagy is an ancestral habit.

  20. Shallot aphids, Myzus ascalonicus, in strawberry

    DEFF Research Database (Denmark)

    Enkegaard, Annie; Sigsgaard, Lene; Kristensen, Kristian

    2013-01-01

    The parasitization capacity of 3 parasitoids and the predation capacity of 3 predators towards the shallot aphid, Myzus ascalonicus Doncaster (Homoptera: Aphididae), on strawberry, Fragaria x ananassa Duchesne (Rosales: Rosaceae) cv. Honeoye, were examined in laboratory experiments. In Petri dish...... other parasitoid-induced causes. However, the host feeding rate was reduced to only 1.2 ± 0.8%, and no significant parasitization mortality was observed on strawberry plants, suggesting that host plants interfered with A. abdominalis activity. This parasitoid does not, therefore, seem to be suited...... to either inoculative or inundative biocontrol of shallot aphids in strawberry. The three predators studied were the green lacewing, Chrysoperla carnea Steph. (Neuroptera: Chrysopi-dae), the two-spotted lady beetle, Adalia bipunctata L. (Coleoptera: Coccinellidae), and the gall midge Aphidoletes aphidimyza...

  1. Food habits of Nyctinomops macrotis at a maternity roost in New Mexico, as indicated by analysis of guano

    Science.gov (United States)

    Sparks, D.W.; Valdez, E.W.

    2003-01-01

    We examined 56 fecal pellets from under a maternity colony of big free-tailed bats (Nyctinomops macrotis) in the Jemez Mountains of northern New Mexico. The most important food items, listed in order of decreasing percent volume, were Cicadellidae, leafhoppers (26.7% volume, 58.9% frequency); Ichneumonidae, Ichneumon wasps (19.3% volume, 35.7% frequency); and Lepidoptera, moths (17.2% volume, 82.1% frequency). Overall, the most important orders as prey consumed, listed by decreasing percent volume, were Homoptera (27.6% volume, 62.5% frequency), Hymenoptera (19.5% volume, 37.5% frequency), Lepidoptera (17.2% volume, 82.1% frequency), Hemiptera (11.7% volume, 37.5% frequency), and Diptera (10.6% volume, 50.0% frequency). Our study documents an unusually varied diet, as previous studies indicated that these bats fed almost exclusively on moths.

  2. Food habits of introduced rodents in high-elevation shrubland of Haleakala National Park, Maui, Hawai'i

    Science.gov (United States)

    Cole, F. Russell; Loope, Lloyd L.; Medeiros, Arthur C.; Howe, Cameron E.; Anderson, Laurel J.

    2000-01-01

    Mus musculus and Rattus rattus are ubiquitous consumers in the high-elevation shrubland of Haleakala National Park. Food habits of these two rodent species were determined from stomach samples obtained by snaptrapping along transects located at four different elevations during November 1984 and February, May, and August 1985. Mus musculus fed primarily on fruits, grass seeds, and arthropods. Rattus rattus ate various fruits, dicot leaves, and arthropods. Arthropods, many of which are endemic, were taken frequently by Mus musculus throughout the year at the highest elevation where plant food resources were scarce. Araneida, Lepidoptera (primarily larvae), Coleoptera, and Homoptera were the main arthropod taxa taken. These rodents, particularly Mus musculus, exert strong predation pressure on populations of arthropod species, including locally endemic species on upper Haleakala Volcano.

  3. Insect symbiosis: derivation of yeast-like endosymbionts within an entomopathogenic filamentous lineage.

    Science.gov (United States)

    Suh, S O; Noda, H; Blackwell, M

    2001-06-01

    Yeast-like endosymbionts (YLSs) of insects often are restricted to specific hosts and are essential to the host's survival. For example, in planthoppers (Homoptera: Delphacidae), endosymbionts function in sterol utilization and nitrogen recycling for the hosts. Our study, designed to investigate evolutionary changes in the YLS lineage involved in the planthopper association, strongly suggests an origin of the YLSs from within the filamentous ascomycetes (Euascomycetes), not the true yeasts (Saccharomycetes), as their morphology might indicate. During divergence of the planthopper YLSs, dramatic changes would have occurred in the insect-fungus interaction and the fungal morphology that have previously been undescribed in filamentous ascomycetes. Phylogenetic trees were based on individual and combined data sets of 2.6 kb of the nuclear small- and large-subunit ribosomal RNA genes for YLSs from three rice planthoppers (Laodelphax striatellus, Nilaparvata lugens, and Sogatella furcifera) compared with 56 other fungi. Parsimony analysis placed the planthopper YLSs within Cordyceps (Euascomycetes: Hypocreales: Clavicipitaceae), a genus of filamentous insects and a few fungal pathogenic ascomycetes. Another YLS species restricted to the aphid Hamiltonaphis styraci (Homoptera: Aphididae) was a sister taxon to the planthopper YLSS: Filamentous insect pathogens (Metarhizium and Beauveria) specific to the same species of insect hosts as the YLSs also formed lineages within the Clavicipitaceae, but these were distinct from the clade comprising YLS species. Trees constrained to include the YLSs in families of the Hypocreales other than the Clavicipitaceae were rejected by the Kishino-Hasegawa test. In addition, the results of this study support a hypothesis of two independent origins of insect-associated YLSs from among filamentous ascomycetes: the planthopper YLSs in the Clavicipitaceae and the YLSs associated with anobiid beetles (Symbiotaphrina species). Several lineages of

  4. Selecting native perennial plants for ecological intensification in Mediterranean greenhouse horticulture.

    Science.gov (United States)

    Rodríguez, E; González, M; Paredes, D; Campos, M; Benítez, E

    2017-12-04

    Natural control by predators and parasitoids provides an important and often unnoticed ecosystem service to agricultural landscapes by reducing pest populations in crops. The current model of horticultural intensification in south-eastern Spain produces high yields but has also resulted in a landscape almost completely covered by plastic. Promoting natural areas among greenhouses could enhance biodiversity, by being beneficial insects, and reduce pest pressure outdoors. The first step is to ascertain how pests and their natural enemies (NEs) use Mediterranean vegetation for selecting the best plants for pest suppression outdoors. The abundance of the two major horticultural pests, the tobacco whitefly, Bemisia tabaci, and the western flower thrips, Frankliniella occidentalis, together with their NEs, were assayed in 22 flowering perennial plants, which were newly planted in an experimental field surrounded by greenhouses. Eight plant species were identified as the most critical species for sustaining pest populations outdoors. A set of five plant species supported a medium level of pests, and another set of ten plant species supported the lowest level of both pests. Tobacco whitefly occurred in a few plants species, whereas western flower thrips occurred on almost all the plant species studied, and was favoured by the presence of flowers in perennial plants. The results suggest that plant diversity may provide relatively few acceptable host plants for tobacco whitefly than for western flower thrips. NEs were generally collected in plants that also supported abundance of pests, indicating that host/prey availability, more than food resources from flowers, was a stronger predictor of NE abundance in perennial plants. Field trials using the plants with the lowest host acceptance by pests are needed in order to ascertain whether pest abundance outdoors is reduced.

  5. Relative efficacy of some insecticides against the sucking insect pest complex of cotton

    International Nuclear Information System (INIS)

    Asif, M.U.; Muhammad, R.; Tofique, M.

    2016-01-01

    The comparative efficacy of some conventional and neonicotinoid insecticides for the management of sucking insect pests of cotton (whitefly, jassid and thrips) was determined. Six insecticides viz., Confidor 200 SL (imidacloprid) at the rate acre /sup -1/, Karate 1.5 EC (lambda cyhalothrin) at the rate 330 ml acre /sup -1/, Nockout 25 SP (nitenpyram) at the rate 100 gm acre /sup -1/, Polytrin-C 44 EC (profenofos+cypermethrin) at the rate 600 ml acre /sup -1/, Talstar 10 EC (bifenthrin) at the rate 250 ml acre /sup -1/ and Advantage 20 EC (carbosulfan) at the rate of 1000 ml acre /sup -1/ were sprayed twice in order to ascertain the reduction of the pests population on Sadori variety of cotton sown at experimental area of Nuclear Institute of Agriculture, Tandojam. All the tested insecticides caused significant reduction of whitefly, jassid and thrips at 24 hours, 72 hours and even 7 days after application. Imidacloprid followed by the nitenpyram proved to be most effective for bringing about a significant reduction in the populations of whitefly and thrips. Nitenpyram had the highest percentage reduction (73.80%) against jassid at 7th day after application but that was nonsignificantly different from imidacloprid(63.49%). Whereas, the conventional insecticides i.e. lambda cyhalothrin, profenofos+cypermethrin, bifenthrin and carbosulfan showed 57.93%, 52.38%, 47.61% and 42.06% reduction, respectively. Maximum extrapolated yield (2.99 tons ha /sup -1/) was also obtained in imidacloprid treated plots followed by nitenpyram (2.66 tons ha /sup -1/). Thus, these two insecticides were most effective for the sucking pests and in increasing seed cotton yield as compared to the conventional ones. (author)

  6. Density and Seasonal Dynamics of Bemisia tabaci (Gennadius) Mediterranean on Common Crops and Weeds around Cotton Fields in Northern China

    DEFF Research Database (Denmark)

    Zhang, Xiao-ming; Yang, Nian-wan; Wan, Fang-hao

    2014-01-01

    theophrasti Medicus), sunflower (Helianthus annuus L.), sweet potato (Ipomoea batatas L.), soybean (Glycine max L.), and maize (Zea mays L.). The whitefly species identity was repeatedly tested and confirmed; seasonal dynamics on the various host plants was standardized by the quartile method. B. tabaci MED......The density seasonal dynamics of Bemisia tabaci MED were evaluated over two-years in a cotton-growing area in Langfang, Hebei Province, northern China on cotton (Gossypium hirsutum L.) and six other, co-occurring common plants: common ragweed (Ambrosia artemisiifolia L.), piemarker (Abutilon...

  7. Genetic diversity of Bemisia tabaci (Genn. Populations in Brazil revealed by RAPD markers

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    L.H.C. Lima

    2002-01-01

    Full Text Available Bemisia tabaci (Genn. was considered a secondary pest in Brazil until 1990, despite being an efficient geminivirus vector in beans and soybean. In 1991, a new biotype, known as B. tabaci B biotype (=B. argentifolii was detected attacking weed plants and causing phytotoxic problems in Cucurbitaceae. Nowadays, B. tabaci is considered one of the most damaging whitefly pests in agricultural systems worldwide that transmits more than 60 different plant viruses. Little is known about the genetic variability of these populations in Brazil. Knowledge of the genetic variation within whitefly populations is necessary for their efficient control and management. The objectives of the present study were to use RAPD markers (1 to estimate the genetic diversity of B. tabaci populations, (2 to study the genetic relationships among B. tabaci biotypes and two other whitefly species and (3 to discriminate between B. tabaci biotypes. A sample of 109 B. tabaci female individuals obtained from 12 populations in Brazil were analyzed and compared to the A biotype from Arizona (USA and B biotype from California (USA and Paraguay. Trialeurodes vaporariorum and Aleurodicus cocois samples were also included. A total of 72 markers were generated by five RAPD primers and used in the analysis. All primers produced RAPD patterns that clearly distinguished the Bemisia biotypes and the two other whitefly species. Results also showed that populations of the B biotype have considerable genetic variability. An average Jaccard similarity of 0.73 was observed among the B biotype individuals analyzed. Cluster analysis demonstrated that, in general, Brazilian biotype B individuals are scattered independently in the localities where samples were collected. Nevertheless, some clusters were evident, joining individuals according to the host plants. AMOVA showed that most of the total genetic variation is found within populations (56.70%, but a significant portion of the variation is found

  8. Evaluation of Jatropha curcas as an alternative host of African cassava mosaic virus

    International Nuclear Information System (INIS)

    Appiah, A.S.

    2010-01-01

    A study was conducted to evaluate ten local accessions of Jatropha curcas L. (physic nut) as an alternative host of African cassava mosaic virus (ACMV). The ten local accessions of J. curcas were planted in a field trial at the research farm of the Biotechnology and Nuclear Agriculture Research Institute, intercropped with ACMV-infected cassava cultivar 'Afisiafi' and left to natural spread of ACMV from the cassava to J. curcas. The J. curcas plants which became infected generally showed mild symptoms, with severity ranging from 1.00 at eight weeks after planting (WAP) to 3.00 at 16 WAP on a scale of 1 (no symptoms) to 5 (severe symptoms). Whitefly populations recorded on the J. curcas accessions in the wet (Sept. - Oct., 2008) and dry (Jan. - Feb., 2009) seasons were generally low. However, significant differences (p < 0.05) were found in the mean whitefly numbers found on the individual J. curcas accessions in the dry season. Disease incidence as determined by symptom expression varied among accessions at eight, twelve and sixteen weeks after planting, though the differences not statistically significant. Leaf samples from the ten J. curcas accessions were tested at six, nine and twelve months after planting (MAP) for the presence of ACMV by enzyme-linked immunosorbent assays (ELISA) and by polymerase chain reaction (PCR). ELISA tests using monoclonal antibody SCRI 33, in a double antibody sandwich ELISA (DAS-ELISA) showed ACMV infection in the J. curcas accessions. Infection ranged from 0% at 6MAP to 50% at 12MAP. Molecular analysis by PCR with a virus-specific primer (JSP001/JSP002) of the viral DNA extracted from leaves of the number of samples tested, as against 37.7% by ELISA. Infection among the accessions as shown by to PCR varied significantly (p < 0.05) and ranged from as low as 16.6% to as high as 91.6%. ACMV infection of the J. curcas plants was further confirmed by infectivity tests on Nicotiana benthamiana indicator plants. Three of (3) out of 132

  9. Effectiveness of BPMC Application against Bemisia tabaci (Gennadius Population and CMMV Disease Incidence on Soybean

    Directory of Open Access Journals (Sweden)

    Wartono Wartono

    2015-09-01

    Full Text Available Control of whitefly (Bemisia tabaci (Gennadius is the starting point in suppressing the CMMV disease (cowpea mild mottle virus. This study aims to determine the influence of applications BPMC (500 g a.i./l against B. tabaci populations and disease incidence of CMMV on soybean plants. Research was conducted in the field with randomized complete block design consisting of 5 treatments i.e. five concentration levels: 0.75, 1.50,2.25, and 3.00 ml/l including control (untreated with 5 replications. The results showed that BPMC is effective in suppressing the adult population of B. tabaci and disease incidence of CMMV.

  10. Insecticide effects of Ruta graveolens, Copaifera langsdorffii and Chenopodium ambrosioides against pests and natural enemies in commercial tomato plantation = Ação inseticida de Ruta graveolens, Copaifera langsdorffii e Chenopodium ambrosioides sobre pragas de tomate

    Directory of Open Access Journals (Sweden)

    Flávia Silva Barbosa

    2011-01-01

    Full Text Available The aim of this study was to evaluate the insecticide effect of watery leaf extracts of Ruta graveolens (Rutaceae, alcoholic leaf extracts of Copaifera langsdorffii (Caesalpinaceae and Chenopodium ambrosioides (Chenopodiaceae in the concentration of 5% under field conditions. The experiment design was randomized blocks with six replications. The parcels treated with plant extracts showed reduction in the population of pests when compared with the controlparcels. The extract elaborated with C. langsdorffii presented greater insecticidal effect under Bemisia tabaci (Hemiptera: Aleyrodidae and sum of pests. It was verified that after 24 hours ofspraying, the parcels treated with the extract of C. ambrosioides presented minor numbers of adults of Tuta absoluta (Lepidoptera: Gelechiidae, followed by the parcels treated with extract of R.graveolens. There were smaller numbers of parasitoid eggs of epidopterans Trichogramma sp. (Hymenoptera: Trichogrammatidae and sum of natural enemies (predators + parasitoids in the parcels that had received spraying with extracts from the plants of C. langsdorffii and C. ambrosioides, followed by R. graveolens, compared to the control. There were a smaller number of parasitoids from the family Eulophidae (Hymenoptera attacking caterpillars of T. absoluta in plants treated with R. graveolens, followed by C. langsdorffii and C. ambrosioides than in the control.O objetivo deste trabalho foi avaliar o efeito inseticida dos extratos aquosos de folhas de Ruta graveolens (Rutaceae e alcoólicos de folhas de Copaifera langsdorffii (Caesalpinaceae e de folhas de Chenopodium ambrosioides (Chenopodiaceae a 5%. O experimento foi em blocos casualizados com seis repetições. As parcelas tratadas tiveram redução na população de pragas, quando comparadas às parcelas sem nenhum tratamento. O extrato elaborado com C. langsdorffii apresentou maior efeito inseticida em Bemisia tabaci (Hemiptera: Aleyrodidae e soma das pragas

  11. Biotype Characterization, Developmental Profiling, Insecticide Response and Binding Property of Bemisia tabaci Chemosensory Proteins: Role of CSP in Insect Defense.

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    Guoxia Liu

    Full Text Available Chemosensory proteins (CSPs are believed to play a key role in the chemosensory process in insects. Sequencing genomic DNA and RNA encoding CSP1, CSP2 and CSP3 in the sweet potato whitefly Bemisia tabaci showed strong variation between B and Q biotypes. Analyzing CSP-RNA levels showed not only biotype, but also age and developmental stage-specific expression. Interestingly, applying neonicotinoid thiamethoxam insecticide using twenty-five different dose/time treatments in B and Q young adults showed that Bemisia CSP1, CSP2 and CSP3 were also differentially regulated over insecticide exposure. In our study one of the adult-specific gene (CSP1 was shown to be significantly up-regulated by the insecticide in Q, the most highly resistant form of B. tabaci. Correlatively, competitive binding assays using tryptophan fluorescence spectroscopy and molecular docking demonstrated that CSP1 protein preferentially bound to linoleic acid, while CSP2 and CSP3 proteins rather associated to another completely different type of chemical, i.e. α-pentyl-cinnamaldehyde (jasminaldehyde. This might indicate that some CSPs in whiteflies are crucial to facilitate the transport of fatty acids thus regulating some metabolic pathways of the insect immune response, while some others are tuned to much more volatile chemicals known not only for their pleasant odor scent, but also for their potent toxic insecticide activity.

  12. Performance of some transgenic cotton cultivars against insect pest complex, virus incidence and yield

    International Nuclear Information System (INIS)

    Babar, T.K.; Karar, H.; Hasnain, M.; Saleem, M.; Ali, A.

    2013-01-01

    Five cultivars of cotton i.e., IR4-NIBGE, IR5-NIBGE Bt-121, Sitara-10M and Sitara-11M were screened for resistance against insect pest complex and Cotton Leaf Curl Virus (CLCuV) incidence in the research area of Cotton Research Station, Multan. The result depicted that the most resistant variety against jassids was IR4-NIBGE and Sitara-11M whereas IR4-NIBGE showed the maximum resistance against whitefly infestation. The least susceptible variety to the infestation of thrips was Sitara-10M. The most susceptible variety to the prevalence of Red Cotton Bug (RCB) was IR4-NIBGE. The genotype Bt-121 showed the attack of spotted bollworm. The high population of Dusky Cotton Bug (DCB) was observed on Bt-121 throughout the season. The incidence of virus percentage increased with the passage of time; however, the variety IR5-NIBGE exhibited maximum level of tolerance. Variety Bt-121 gave the maximum yield i.e., 1852 kg per acre followed by IR5-NIBGE, Sitara-11M, Sitara-10M 1584, 1503, 1466 kg per acre respectively. Our results suggest that IR4-NIBGE and Sitara -11M are comparatively tolerant to jassids and whitefly which are the yield losing pest. So IR4-NIBGE and Sitara -11M varieties can be included in IPM programme for the management of these voracious pests. (author)

  13. Rme1 is necessary for Mi-1-mediated resistance and acts early in the resistance pathway.

    Science.gov (United States)

    Martinez de Ilarduya, Oscar; Nombela, Gloria; Hwang, Chin-Feng; Williamson, Valerie M; Muñiz, Mariano; Kaloshian, Isgouhi

    2004-01-01

    The tomato gene Mi-1 confers resistance to root-knot nematodes (Meloidogyne spp.), potato aphid, and whitefly. Using genetic screens, we have isolated a mutant, rme1 (resistance to Meloidogyne spp.), compromised in resistance to M. javanica and potato aphid. Here, we show that the rme1 mutant is also compromised in resistance to M. incognita, M. arenaria, and whitefly. In addition, using an Agrobacterium-mediated transient assay in leaves to express constitutive gain-of-function mutant Pto(L205D), we demonstrated that the rme1 mutation is not compromised in Pto-mediated hypersensitive response. Moreover, the mutation in rme1 does not result in increased virulence of pathogenic Pseudomonas syringae or Mi-1-virulent M. incognita. Using a chimeric Mi-1 construct, Mi-DS4, which confers constitutive cell death phenotype and A. rhizogenes root transformation, we showed that the Mi-1-mediated cell death pathway is intact in this mutant. Our results indicate that Rme1 is required for Mi-1-mediated resistance and acts either at the same step in the signal transduction pathway as Mi-1 or upstream of Mi-1.

  14. Transcriptomic dissection of sexual differences in Bemisia tabaci, an invasive agricultural pest worldwide.

    Science.gov (United States)

    Xie, Wen; Guo, Litao; Jiao, Xiaoguo; Yang, Nina; Yang, Xin; Wu, Qingjun; Wang, Shaoli; Zhou, Xuguo; Zhang, Youjun

    2014-02-14

    Sex difference involving chromosomes and gene expression has been extensively documented. In this study, the gender difference in the sweetpotato whitefly Bemisia tabaci was investigated using Illumina-based transcriptomic analysis. Gender-based RNAseq data produced 27 Gb reads, and subsequent de novo assembly generated 93,948 transcripts with a N50 of 1,853 bp. A total of 1,351 differentially expressed genes were identified between male and female B. tabaci, and majority of them were female-biased. Pathway and GO enrichment experiments exhibited a gender-specific expression, including enriched translation in females, and enhanced structural constituent of cuticle in male whiteflies. In addition, a putative transformer2 gene (tra2) was cloned, and the structural feature and expression profile of tra2 were investigated. Sexually dimorphic transcriptome is an uncharted territory for the agricultural insect pests. Molecular understanding of sex determination in B. tabaci, an emerging invasive insect pest worldwide, will provide potential molecular target(s) for genetic pest control alternatives.

  15. Investigating contact toxicity of Geranium and Artemisia essential oils on Bemisia tabaci Gen.

    Directory of Open Access Journals (Sweden)

    Fatemeh Yarahmadi

    2013-04-01

    Full Text Available Objective: Sweet potato whitefly, Bemisia tabaci Gen. (B. tabaci, is one of the most important pests of various greenhouse crops in Iran. Nowadays, chemical insecticides are broadly used for control of the pests that causes risk to consumer's health. For the first time, contact toxicity of Pelargonium roseum Andrews and Artemisia sieberi Besser essential oils on B. tabaci and its possible application against the whitefly was evaluated in 2012. Materials and Methods: Essential oil with concentrations of 2500, 1250, 125, and 12 ppm were used. Infested leaves of greenhouse cucumber were treated by mentioned concentrations. After 24 hours, mortality of B. tabaci was recorded and compared after correcting by Abbot's formula. Results: Results showed that all concentrations of the essential oil could significantly reduce population of B. tabaci compared with the control treatment. Phytotoxicity of the treated leaves were recorded after 24, 48, and 72 hours and compared with the control. Concentrations of 2500, 1250, and 125 ppm caused severe phytotoxicity on greenhouse cucumber leaves and therefore are not suitable for greenhouse application. Phytotoxicity of 12 ppm was relatively low. Conclusions: This data implicated suitable protective effects of the essential oils to the pest infestation. Therefore, essential oils distillated from Geranium and Artemisia could be applied to control B. tabaci in greenhouse cucumber at V/V 12 ppm.

  16. Toxicological and biochemical basis of synergism between the entomopathogenic fungus Lecanicillium muscarium and the insecticide matrine against Bemisia tabaci (Gennadius)

    Science.gov (United States)

    Ali, Shaukat; Zhang, Can; Wang, Zeqing; Wang, Xing-Min; Wu, Jian-Hui; Cuthbertson, Andrew G. S.; Shao, Zhenfang; Qiu, Bao-Li

    2017-04-01

    The sweetpotato whitefly Bemisia tabaci (Gennadius) was challenged with different combinations of matrine (insecticide) and Lecanicillium muscarium (entomopathogenic fungus). Our results revealed a synergistic relationship between matrine and L. muscarium on mortality and enzyme activities of B. tabaci. To illustrate the biochemical mechanisms involved in detoxification and immune responses of B. tabaci against both control agents, activities of different detoxifying and antioxidant enzymes were quantified. After combined application of matrine and L. muscarium, activities of carboxylestrease (CarE), glutathione-s-transferase (GSTs) and chitinase (CHI) decreased during the initial infection period. Acetylcholinestrase (AChE) activities increased during the entire experimental period, whereas those of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) decreased during the later infection period. The increased mortality and suppression of enzymatic response of B. tabaci following matrine and L. muscarium application suggests a strong synergistic effect between both agents. The strong synergistic effect is possibly related to the disturbance of acetylcholine balance and changes in AchE activities of the whitefly as both matrine and L. muscarium target insect acetylcholine (Ach) receptors which in turn effects AchE production. Therefore, our results have revealed the complex biochemical processes involved in the synergistic action of matrine and L. muscarium against B. tabaci.

  17. Natal Host Plants Can Alter Herbivore Competition.

    Science.gov (United States)

    Pan, Huipeng; Preisser, Evan L; Su, Qi; Jiao, Xiaoguo; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Zhang, Youjun

    2016-01-01

    Interspecific competition between herbivores is widely recognized as an important determinant of community structure. Although researchers have identified a number of factors capable of altering competitive interactions, few studies have addressed the influence of neighboring plant species. If adaptation to/ epigenetic effects of an herbivore's natal host plant alter its performance on other host plants, then interspecific herbivore interactions may play out differently in heterogeneous and homogenous plant communities. We tested wether the natal host plant of a whitefly population affected interactions between the Middle-east Asia Minor 1 (MEAM1) and Mediterranean (MED) cryptic species of the whitefly Bemisia tabaci by rearing the offspring of a cabbage-derived MEAM1 population and a poinsettia-derived MED population together on three different host plants: cotton, poinsettia, and cabbage. We found that MED dominated on poinsettia and that MEAM1 dominated on cabbage, results consistent with previous research. MED also dominated when reared with MEAM1 on cotton, however, a result at odds with multiple otherwise-similar studies that reared both species on the same natal plant. Our work provides evidence that natal plants affect competitive interactions on another plant species, and highlights the potential importance of neighboring plant species on herbivore community composition in agricultral systems.

  18. Biodiversidad antropoentomofágica de la región de Zongolica, Veracruz, México

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    Julieta Ramos-Elorduy

    2008-03-01

    Full Text Available Durante dos años y medio (2003-2005 se rastrearon a los insectos que se ingieren en el área de Zongolica, Veracruz: para ello se entrevistó a la gente de ese municipio (200, para conocer cuáles especies ingerían. El total de especies registradas, ascendió a 57 distribuidas en los órdenes Orthoptera, Hemiptera, Homoptera, Megaloptera, Coleoptera, Lepidoptera e Hymenoptera, correspondiendo el mayor consumo al primer orden. De las especies registradas, 24 son nuevos registros de insectos comestibles para México. Estos se consumen tanto en estado inmaduro como en estado adulto y generalmente se ingieren asados. Hay una secuenciación estacional en el consumo de las diferentes especies y algunas de ellas (las cucarachas, la cuetla, la cuecla, los chapulines, los toritos, etc. se comercializan en los tianguis (puestos de venta callejeros informales que se realizan un día a la semana en diversos lugares del país o en el día de mercado en Zongolica. Existe el "protococultivo" de tres especies: una cucaracha (Periplaneta australasiae Fabricius y dos mariposas (Latebraria amphipyroides Guenée y Arsenura armida armida Cramer. La antropoentomofagía es un hábito ancestral en Zongolica.Anthropoentomophagic biodiversity of the Zongolica region, Veracruz, Mexico. During two and a half years (2003-2005 we recorded the insect species used as food at Zongolica, Veracruz State, Mexico. Interviews were made among people (200 of this municipality to know which insects they consumed. The total of registered species was 57 (Orthoptera, Hemiptera, Homoptera, Megaloptera, Coleoptera, Lepidoptera and Hymenoptera. The Orthoptera was the most frequently ingested. Twenty-four of these species were new records for edible insects of Mexico. They are eaten in immature stages or as adults, generally only roasted. Consumption is seasonal. Some species are commercialized in the "tianguis" (little town markets and/or in the larger Zongolica market. There is a

  19. Application of RNA-seq for mitogenome reconstruction, and reconsideration of long-branch artifacts in Hemiptera phylogeny

    Science.gov (United States)

    Song, Nan; An, Shiheng; Yin, Xinming; Cai, Wanzhi; Li, Hu

    2016-01-01

    Hemiptera make up the largest nonholometabolan insect assemblage. Despite previous efforts to elucidate phylogeny within this group, relationships among the major sub-lineages remain uncertain. In particular, mitochondrial genome (mitogenome) data are still sparse for many important hemipteran insect groups. Recent mitogenomic analyses of Hemiptera have usually included no more than 50 species, with conflicting hypotheses presented. Here, we determined the nearly complete nucleotide sequence of the mitogenome for the aphid species of Rhopalosiphum padi using RNA-seq plus gap filling. The 15,205 bp mitogenome included all mitochondrial genes except for trnF. The mitogenome organization and size for R. padi are similar to previously reported aphid species. In addition, the phylogenetic relationships for Hemiptera were examined using a mitogenomic dataset which included sequences from 103 ingroup species and 19 outgroup species. Our results showed that the seven species representing the Aleyrodidae exhibit extremely long branches, and always cluster with long-branched outgroups. This lead to the failure of recovering a monophyletic Hemiptera in most analyses. The data treatment of Degen-coding for protein-coding genes and the site-heterogeneous CAT model show improved suppression of the long-branch effect. Under these conditions, the Sternorrhyncha was often recovered as the most basal clade in Hemiptera. PMID:27633117

  20. Compatibilidad in vitro de Isaria fumosorosea (Wize Brown y Smith (Hypocreales: Clavicipitaceae con plaguicidas comerciales

    Directory of Open Access Journals (Sweden)

    Érika Paola Grijalba Bernal

    2014-01-01

    Full Text Available Los agricultores colombianos utilizan productos químicos con categorías toxicológicas I, II y III para el control de insectos como la mosca blanca Bemisia tabaci (Gennadius, 1889 (Hemiptera: Aleyrodidae; pero su uso indiscriminado genera un riesgo para la salud y el medio ambiente. El control microbiológico con hongos entomopatógenos surge como alternativa de control ambientalmente sostenible. No obstante, su empleo exitoso dentro de una estrategia de manejo integrado de plagas (MIP depende, en gran parte, del efecto de los productos químicos sobre el bioplaguicida. El objetivo del presente trabajo fue determinar la compatibilidad in vitro de un bioplaguicida con base en el hongo Isaria fumosorosea formulado como polvo mojable con cuatro fungicidas y cinco insecticidas comerciales. Para esto, se evaluó el efecto de tres concentraciones de los productos químicos: FR = dosis recomendada en campo, 0.5 x FR y 0.25 x FR sobre la germinación de los conidios y el número de unidades formadoras de colonia UFC/g de I. fumosorosea. Los cuatro fungicidas (Benlate, Carboxin Captan, Metalaxil-Mancozeb y Mancozeb en las tres dosis evaluadas fueron incompatibles con el bioplaguicida, mientras que el insecticida Thiametoxam fue compatible cuando se utilizó la dosis de 0.25 x FR.

  1. Polyol specificity of recombinant Arabidopsis thaliana sorbitol dehydrogenase studied by enzyme kinetics and in silico modeling

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    María Francisca eAguayo

    2015-02-01

    Full Text Available Polyols are enzymatically-produced plant compounds which can act as compatible solutes during periods of abiotic stress. NAD+-dependent SORBITOL DEHYDROGENASE (SDH, E.C. 1.1.1.14 from Arabidopsis thaliana L. (AtSDH is capable of oxidizing several polyols including sorbitol, ribitol and xylitol. In the present study, enzymatic assays using recombinant AtSDH demonstrated a higher specificity constant for xylitol compared to sorbitol and ribitol, all of which are C2 (S and C4 (R polyols. Enzyme activity was reduced by preincubation with ethylenediaminetetraacetic acid (EDTA, indicating a requirement for zinc ions. In humans, it has been proposed that sorbitol becomes part of a pentahedric coordination sphere of the catalytic zinc during the reaction mechanism. In order to determine the validity of this pentahedric coordination model in a plant SDH, homology modeling and Molecular Dynamics simulations of AtSDH ternary complexes with the three polyols were performed using crystal structures of human and Bemisia argentifolii (Genn. (Hemiptera: Aleyrodidae SDHs as scaffolds. The results indicate that the differences in interaction with structural water molecules correlate very well with the observed enzymatic parameters, validate the proposed pentahedric coordination of the catalytic zinc ion in a plant SDH, and provide an explanation for why AtSDH shows a preference for polyols with a chirality of C2 (S and C4 (R.

  2. Factors affecting population dynamics of maternally transmitted endosymbionts in Bemisia tabaci.

    Directory of Open Access Journals (Sweden)

    Huipeng Pan

    Full Text Available While every individual of Bemisia tabaci (Hemiptera: Aleyrodidae harbors the primary symbiont (P-symbiont Portiera, the infection frequencies of the six secondary symbionts (S-symbionts including Hamiltonella, Arsenophonus, Cardinium, Wolbachia, Rickettsia and Fritschea vary greatly among different populations. To characterize the factors influencing the infection dynamics of the six S-symbionts in B. tabaci, gene-specific PCR were conducted to screen for the presence of the P-symbiont Portiera and the six S-symbionts in 61 (17 B and 44 Q biotypes field populations collected from different plant species and locations in China. All individuals of the 61 populations hosted the P-symbiont Portiera, but none of them harbored Arsenophonus and Fritschea. The presence and infection rates of Hamiltonella, Cardinium, Rickettsia, Wolbachia and their co-infections Rickettsia + Hamiltonella (RH, Rickettsia + Cardinium (RC, Hamiltonella + Cardinium (HC and Rickettsia + Hamiltonella + Cardinium (RHC varied significantly among the 61 field populations; and the observed variations can be explained by biotypes, sexes, host plants and geographical locations of these field populations. Taken together, at least three factors including biotype, host plant and geographical location affect the infection dynamics of S-symbionts in B. tabaci.

  3. Evidence of diversity and recombination in Arsenophonus symbionts of the Bemisia tabaci species complex

    Directory of Open Access Journals (Sweden)

    Mouton Laurence

    2012-01-01

    Full Text Available Abstract Background Maternally inherited bacterial symbionts infecting arthropods have major implications on host ecology and evolution. Among them, the genus Arsenophonus is particularly characterized by a large host spectrum and a wide range of symbiotic relationships (from mutualism to parasitism, making it a good model to study the evolution of host-symbiont associations. However, few data are available on the diversity and distribution of Arsenophonus within host lineages. Here, we propose a survey on Arsenophonus diversity in whitefly species (Hemiptera, in particular the Bemisia tabaci species complex. This polyphagous insect pest is composed of genetic groups that differ in many ecological aspects. They harbor specific bacterial communities, among them several lineages of Arsenophonus, enabling a study of the evolutionary history of these bacteria at a fine host taxonomic level, in association to host geographical range and ecology. Results Among 152 individuals, our analysis identified 19 allelic profiles and 6 phylogenetic groups, demonstrating this bacterium's high diversity. These groups, based on Arsenophonus phylogeny, correlated with B. tabaci genetic groups with two exceptions reflecting horizontal transfers. None of three genes analyzed provided evidence of intragenic recombination, but intergenic recombination events were detected. A mutation inducing a STOP codon on one gene in a strain infecting one B. tabaci genetic group was also found. Phylogenetic analyses of the three concatenated loci revealed the existence of two clades of Arsenophonus. One, composed of strains found in other Hemiptera, could be the ancestral clade in whiteflies. The other, which regroups strains found in Hymenoptera and Diptera, may have been acquired more recently by whiteflies through lateral transfers. Conclusions This analysis of the genus Arsenophonus revealed a diversity within the B. tabaci species complex which resembles that reported on the

  4. Comparing the regional epidemiology of the cassava mosaic and cassava brown streak virus pandemics in Africa.

    Science.gov (United States)

    Legg, J P; Jeremiah, S C; Obiero, H M; Maruthi, M N; Ndyetabula, I; Okao-Okuja, G; Bouwmeester, H; Bigirimana, S; Tata-Hangy, W; Gashaka, G; Mkamilo, G; Alicai, T; Lava Kumar, P

    2011-08-01

    The rapid geographical expansion of the cassava mosaic disease (CMD) pandemic, caused by cassava mosaic geminiviruses, has devastated cassava crops in 12 countries of East and Central Africa since the late 1980s. Region-level surveys have revealed a continuing pattern of annual spread westward and southward along a contiguous 'front'. More recently, outbreaks of cassava brown streak disease (CBSD) were reported from Uganda and other parts of East Africa that had been hitherto unaffected by the disease. Recent survey data reveal several significant contrasts between the regional epidemiology of these two pandemics: (i) severe CMD radiates out from an initial centre of origin, whilst CBSD seems to be spreading from independent 'hot-spots'; (ii) the severe CMD pandemic has arisen from recombination and synergy between virus species, whilst the CBSD pandemic seems to be a 'new encounter' situation between host and pathogen; (iii) CMD pandemic spread has been tightly linked with the appearance of super-abundant Bemisia tabaci whitefly vector populations, in contrast to CBSD, where outbreaks have occurred 3-12 years after whitefly population increases; (iv) the CMGs causing CMD are transmitted in a persistent manner, whilst the two cassava brown streak viruses appear to be semi-persistently transmitted; and (v) different patterns of symptom expression mean that phytosanitary measures could be implemented easily for CMD but have limited effectiveness, whereas similar measures are difficult to apply for CBSD but are potentially very effective. An important similarity between the pandemics is that the viruses occurring in pandemic-affected areas are also found elsewhere, indicating that contrary to earlier published conclusions, the viruses per se are unlikely to be the key factors driving the two pandemics. A diagrammatic representation illustrates the temporal relationship between B. tabaci abundance and changing incidences of both CMD and CBSD in the Great Lakes region

  5. Responses of prairie arthropod communities to fire and fertilizer: Balancing plant and arthropod conservation

    Science.gov (United States)

    Hartley, M.K.; Rogers, W.E.; Siemann, E.; Grace, J.

    2007-01-01

    Fire is an important tool for limiting woody plant invasions into prairies, but using fire management to maintain grassland plant communities may inadvertently reduce arthropod diversity. To test this, we established twenty-four 100 m2 plots in a tallgrass prairie in Galveston County, Texas, in spring 2000. Plots were assigned a fire (no burn, one time burn [2000], two time burn [2000, 2001]) and fertilization treatment (none, NPK addition) in a full factorial design. Fertilization treatments allowed us to examine the effects of fire at a different level of productivity. We measured plant cover by species and sampled arthropods with sweep nets during the 2001 growing season. Path analysis indicated that fertilization reduced while annual fires increased arthropod diversity via increases and decreases in woody plant abundance, respectively. There was no direct effect of fire on arthropod diversity or abundance. Diptera and Homoptera exhibited particularly strong positive responses to fires. Lepidoptera had a negative response to nutrient enrichment. Overall, the negative effects of fire on the arthropod community were minor in contrast to the strong positive indirect effects of small-scale burning on arthropod diversity if conservation of particular taxa is not a priority. The same fire regime that minimized woody plant invasion also maximized arthropod diversity.

  6. The Effects of Dispersal and Predator Density on Prey Survival in an Insect-Red Clover Metacommunity.

    Science.gov (United States)

    Stasek, David J; Radl, James N; Crist, Thomas O

    2018-01-01

    Trophic interactions are often studied within habitat patches, but among-patch dispersal of individuals may influence local patch dynamics. Metacommunity concepts incorporate the effects of dispersal on local and community dynamics. There are few experimental tests of metacommunity theory using insects compared to those conducted in microbial microcosms. Using connected experimental mesocosms, we varied the density of the leafhopper Agallia constricta Van Duzee (Homoptera: Cicadellidae) and a generalist insect predator, the damsel bug (Nabis spp., Heteroptera: Nabidae), to determine the effects of conspecific and predator density and varying the time available to dispersal among mesocosms on predation rates, dispersal rates, and leafhopper survival. Conspecific and damsel bug density did not affect dispersal rates in leafhoppers, but this may be due to leafhoppers' aversion to leaving the host plants or the connecting tubes between mesocosms hindering leafhopper movement. Leafhopper dispersal was higher in high-dispersal treatments. Survival rates of A. constricta were also lowest in treatments where dispersal was not limited. This is one of the first experimental studies to vary predator density and the time available to dispersal. Our results indicate that dispersal is the key to understanding short-term processes such as prey survival in predator-prey metacommunities. Further work is needed to determine how dispersal rates influence persistence of communities in multigenerational studies. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  7. Isolation and in vitro cultivation of the aphid pathogenic fungus Entomophthora planchoniana.

    Science.gov (United States)

    Freimoser, F M; Jensen, A B; Tuor, U; Aebi, M; Eilenberg, J

    2001-12-01

    Entomophthora planchoniana is an important fungal pathogen of aphids. Although Entomophthora chromaphidis has been considered a synonym for E. planchoniana, the two species are now separated, and E. planchoniana is reported not to grow in vitro. In this paper, we describe for the first time the isolation and cultivation of this species. Entomophthora planchoniana was isolated from a population of Ovatus crataegarius (Homoptera, Aphididae), which was infected by E. planchoniana only. The isolates did not sporulate, but the sequence of the small subunit rDNA and the restriction fragment length polymorphism patterns of the first part of the large subunit rDNA and the ITS II region confirm that the isolates were E. planchoniana. The isolated fungus grew in a medium consisting of Grace's insect cell culture medium supplemented with lactalbumin hydrolysate, yeastolate, and 10% fetal bovine serum or in GLEN medium with 10% fetal bovine serum. Vegetative cells of E. planchoniana were long and club-shaped and did not stain with Calcofluor, thus suggesting that they were protoplasts.

  8. Presence of the aphid, Chaetosiphon fragaefolii, on strawberry in Argentina.

    Science.gov (United States)

    Cédola, Claudia; Grecob, Nancy

    2010-01-01

    Seasonal abundance of the strawberry aphid complex under different agronomic practices in the outskirts of La Plata, Argentina was studied on strawberry, Fragaria x ananassa Duchesne (Rosales: Rosaceae). Aphid densities were low in strawberry fields in which insecticides and fungicides were used. In addition to Aphis gossypii, Aphis fabae, Mysus persicae and Macrosiphum euphorbiae, the aphid, Chaetosiphon fragaefolii (Cockerell) (Homoptera: Aphididae), was recorded for the first time in this horticultural area. Life history and some demographic parameters were calculated for C. fragaefolii. The mean duration of nymphal stages was 10.44 days, the oviposition period was 11.8 days, and the mean number of nymph/female/day was 2.4 +/- 0.3. Demographic parameters analyzed included the net reproductive rate R(o) = 14.55 +/- 0.096 nymph/female, generation time T=16.91 +/- 0.035 days, and the intrinsic rate of increase r(m) = 0.158 +/- (0.004). No parasites were found associated with C. fragaefolli. The pathogenic fungus, Entomophthora planchoniana Cornu (Zygomycetes: Entomophthorales) was the main mortality factor. Although aphids are not the main pests in strawberry fields, C. fragaefolii can be a serious problem because it can transmit several virus diseases of strawberry. Greater knowledge of life history traits and mortality factors of this species is needed in order to design appropriate control strategies.

  9. Mutualisme pucerons – fourmis : étude des bénéfices retirés par les colonies d'Aphis fabae en milieu extérieur

    Directory of Open Access Journals (Sweden)

    Verheggen F.

    2009-01-01

    Full Text Available Aphid – ant mutualism: an outdoor study of the benefits for Aphis fabae. Aphid – ant relationships are common examples of mutualism. Aphids are indeed submitted to predation and therefore require protection, while ants are continuously looking for new sugar sources. The present work aimed to study the benefits that a mutualistic relationship with Lasius niger (Hymenoptera, Formicidae could bring to the black bean aphid Aphis fabae (Homoptera, Aphididae. Several parameters were observed in the field, on broad bean plants infested with an initial amount of 100 A. fabae and in presence or not of a L. niger colony. More aphids were observed on plants being visited by ants as well as a higher proportion of winged individuals. One explanation is that fewer predators were observed on plants being visited by ants, demonstrating their protective role. However, the number of parasitized aphids was not reduced in presence of L. niger. On the other hand, fewer different aphid species were present on plants foraged by ants, what suggests that they could exert a predation on unattended aphids. Our observations do not allow to conclude on any impact of L. niger on the fitness of the aphid host plant, although fewer exuvia and honeydew spots were observed when they were present. All these results confirm that L. niger increase the fitness of A. fabae colonies mainly by decreasing the number of predators and by reducing competition from aphid species unattended by ants.

  10. Relative degree of susceptibility and resistance of different brassica campestris l. genotypes against aphid myzus persicae- a field investigation

    International Nuclear Information System (INIS)

    Sarwar, M.

    2013-01-01

    Field evaluation of twenty three Brassica campestris L. genotypes was conducted for aphid (Homoptera: Aphididae) resistance during 2008 crop season. The parameters used to assess tolerance of germplasm lines included pest population during growth season and grain yield at crop maturity. Aphids showed obvious preferences for all of the germplasm investigated; however, the evaluation for resistance to pest identified several genotypes with variable potential for tolerance and sensitivity. Estimated grain yield also varied significantly due to variable pest intensity noted, and seemed to be more appropriately dependent on the pest population conditions at the experimental site. Among the germplasm, the estimation obtained regarding both the parameters sorted out MM-II/02-3 and MM-I285 genotypes as most tolerant due to less pest infestation and damage. Peak infestations by aphid caused severe crop fatalities on S-9-S-97-0.75+75/55 and S-9-1006/95 genotypes, affecting the seed weight and resulting an immense reduction in grain Brassica genotypes appeared to be governed by means of varietals characteristics of diverse germplasms. The result of resistance test conducted under field environment is an effective and consistent approach in the practical selection of crop lines resistant or partially resistant to pests for use in future breeding programs. (author)

  11. Temporal and spatial changes in the diet of Hyla pulchella (Anura, Hylidae in southern Uruguay

    Directory of Open Access Journals (Sweden)

    Inés da Rosa

    2004-12-01

    Full Text Available In this article we report the diet of a population of the hylid frogHyla pulchella from southeastern Uruguay. We collected the specimens in ponds, where we identified microenvironments defined by the invertebrate assemblage, during one year divided into two seasons (warm and cold. We taxonomically determined 10365 invertebrates belonging to 21 categories in the digestive tracts of frogs. Weestimated the diversity of the diet and alimentary preference according to microenvironments and seasons. We estimated the expected richness of both diet and prey availability using a null model based on the hypergeometric distribution. We performed Discriminant Analyses and Kruskal-Wallis tests to detect changes in prey availability among microenvironments and between seasons. The overall diet in terms of frequencies was composed primarily of arthropods (mainly Araneae, Diptera, Hymenoptera, and Coleoptera and in terms of volume, by larvae. The most relevantitems to study the microenvironmental and seasonal variation in the available preys were Araneae, Collembola, Homoptera, Hymenoptera, Diptera, Dictioptera, Lepidoptera, Coleoptera, and larvae. Based on the null model curves and preference indexes we inferred positive selection by larvae, Isopoda, Dictioptera, Lepidoptera, and Diptera, and negative selection by Collembola and Hymenoptera. The diversityof diet and the null model curves indicated that the diet changes among microenvironments and seasons. This frog may be considered as a middle generalist predator, with some selective behavior and a combined search strategy (active and sit-and-wait. We conclude that the knowledge about the availability of preys is a relevant tool for trophic studies.

  12. For the Aphid fauna in the territory of Yenisei river basin. Communication 1. Aphids on coniferous plants

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    A. V. Gurov

    2016-02-01

    Full Text Available The paper reports on new and previously not well-known data on insufficiently studied fauna of aphids living on coniferous trees in Central Siberia of the basin of Yenisei river. This region is the extensive transect of latitudinal geographic zones from semi-desert in the South to the arctic deserts in the North. That is why this region is very peculiar. This is the reason for insufficient study of regional entomological fauna. Aphids (Homoptera: Aphidoideaare a very taxonomically and ecologically heterogeneous group of insects. The aphids living on conifer trees are notstudied completely on the territory of Yenisei basin. Due to this, the studying of not well-known and economicallyimportant aphids is actual. For example, the insufficient study of regional aphids is confirmed by the fact, that duringthree weeks only of the work for INTAS-94-0930 Project two new aphid species were found and described on thisterritory. Also, the new species of family Mindaridae, which was described in Mongolia in 1980, was found in Siberiafor the first time. These finds indicate the real possibility to describe an interesting conifer aphid complex in the absolutely unstudied forested territory between Angara and Lower Tunguska rivers. Geographical location, dates ofcollection and feeding preferences of different species are described. A general review of Yenisei basin Siberian aphidfauna is suggested for the first time ever.

  13. Ovary structure in a presocial insect, Elasmucha grisea (Heteroptera, Acanthosomatidae).

    Science.gov (United States)

    Ogorzałek, Antoni; Trochimczuk, Artur

    2009-11-01

    First generation egg clusters of Elasmucha grisea are more closely guarded than second generation clusters. The ovaries of this species are structured to enhance this behavior. The population of E. grisea from S-W Poland breeds in the spring (May-June) and late summer (July-August). The second generation clutches contain fewer eggs and are destroyed 3-4 days after oviposition by predators and parasitoids. The ovary structure in the studied species differs from that found in other Heteroptera. The average number of ovarioles per ovary is 24 while in the other investigated species the number of ovarioles per ovary is 6-7. Lateral oviducts are elongated and the ovarioles are arranged in a pennate pattern. Each ovariole contains only one growing ovarian follicle. Differentiation of the ovarioles and ovarian follicles is synchronised thus enabling simultaneous oviposition. A comparative analysis of the ovary structure during the life cycle, particularly the presence of atresive ovarian follicles in the ovarioles of egg- and nymph guarding females, as well as the shape and structure of the apical part of the tropharium all support the hypothesis of cooperation between females in E. grisea. A similar ovary structure has been observed in the Coccoidea (Hemiptera, Homoptera) which indicates presocial behavior.

  14. Are cicadas (Diceroprocta apache) both a "keystone" and a "critical-link" species in lower Colorado River riparian communities?

    Science.gov (United States)

    Andersen, Douglas C.

    1994-01-01

    Apache cicada (Homoptera: Cicadidae: Diceroprocta apache Davis) densities were estimated to be 10 individuals/m2 within a closed-canopy stand of Fremont cottonwood (Populus fremontii) and Goodding willow (Salix gooddingii) in a revegetated site adjacent to the Colorado River near Parker, Arizona. Coupled with data drawn from the literature, I estimate that up to 1.3 cm (13 1/m2) of water may be added to the upper soil layers annually through the feeding activities of cicada nymphs. This is equivalent to 12% of the annual precipitation received in the study area. Apache cicadas may have significant effects on ecosystem functioning via effects on water transport and thus act as a critical-link species in this southwest desert riverine ecosystem. Cicadas emerged later within the cottonwood-willow stand than in relatively open saltcedar-mesquite stands; this difference in temporal dynamics would affect their availability to several insectivorous bird species and may help explain the birds' recent declines. Resource managers in this region should be sensitive to the multiple and strong effects that Apache cicadas may have on ecosystem structure and functioning.

  15. BIOLOGY OF CHRYSOPA PHYLLOCHROMA WESMAEL (NEUROPTERA: CHRYSOPIDAE). Ⅱ: INTRASPECIFIC INTERFERENCE AND SEARCHING CAPACITY

    Institute of Scientific and Technical Information of China (English)

    Jian-weiSu; Xiang-huiLiu; Neng-wenXiao; FengGe

    2004-01-01

    The present study examined intraspecific interference and searching behavior of Chrysopa phyllochroma Wesmael (Neuroptera: Chrysopidae) for Aphis gossypii Glover (Homoptera: Aphididae) nymphs under laboratory and greenhouse conditions. The results were shown as follow: 1) In four different arenas (i.e. Petri dish, glass vessel, glass vessel with barriers in it, and cage with potted cotton plant), the predaceous efficiency of C. phyllochroma larvae varied with the predator density, the hunt constant (Q) and the intraspecific interference (m)increased with the prey density but decreased with the space heterogeneity; 2) In cage with potted cotton plant, the first- and second-instar green lacewing larvae consumed 13.6 and 29.4 cotton aphids/day respectively. The number of cotton aphids consumed by C. phyllochroma on lower leaves was significantly less than that on upper leaves; and 3) In cage with potted cotton plant, the percentage of the first- and second-instar green lacewing larvae located on upper leaves was significant less than that on lower leaves.

  16. Insectes ravageurs et propriétés biocides de Jatropha curcas L. (Euphorbiaceae : synthèse bibliographique

    Directory of Open Access Journals (Sweden)

    Abdoul Habou, Z.

    2013-01-01

    Full Text Available Insect pests and biocidal properties of Jatropha curcas L. (Euphorbiaceae. A review. Jatropha curcas is a Euphorbiaceae shrub widely distributed in many tropical countries. Its seeds are rich in oil that can be used as biofuel in modified diesel engines. Several insect species, mainly belonging to Hemiptera, Coleoptera and Orthoptera, have been referenced as insect pests of J. curcas. These insects attack the plant and cause damage to fruits, inflorescences and leaves. The most frequently observed pests belong to the genus Pachycoris (Heteroptera: Scutelleridae, which are widely distributed in Mexico, Australia, United States of America, Brazil and Nicaragua. Pachycoris spp. cause significant damage to the fruits, leading to the malformation of seeds and a reduction in their oil content. Although Jatropha shrubs are subjected to insect infestations, the oil has been shown to demonstrate biocidal activity, including insecticidal effects against several insect pests, including Busseola fusca (Fuller (Lepidoptera: Noctuidae, Sesamia calamistis Hampson (Lepidoptera: Noctuidae, Aphis gossypii Glover (Homoptera: Aphididae and Callosobruchus chinensis L. (Coleoptera: Bruchidae. In the present paper, we summarize the work carried out on inventories of J. curcas insect pests as well as on the biocidal activity of its oil.

  17. Anagrus breviphragma Soyka Short Distance Search Stimuli

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    Elisabetta Chiappini

    2015-01-01

    Full Text Available Anagrus breviphragma Soyka (Hymenoptera: Mymaridae successfully parasitises eggs of Cicadella viridis (L. (Homoptera: Cicadellidae, embedded in vegetal tissues, suggesting the idea of possible chemical and physical cues, revealing the eggs presence. In this research, three treatments were considered in order to establish which types of cue are involved: eggs extracted from leaf, used as a control, eggs extracted from leaf and cleaned in water and ethanol, used to evaluate the presence of chemicals soluble in polar solvents, and eggs extracted from leaf and covered with Parafilm (M, used to avoid physical stimuli due to the bump on the leaf surface. The results show that eggs covered with Parafilm present a higher number of parasitised eggs and a lower probing starting time with respect to eggs washed with polar solvents or eggs extracted and untreated, both when the treatments were singly tested or when offered in sequence, independently of the treatment position. These results suggest that the exploited stimuli are not physical due to the bump but chemicals that can spread in the Parafilm, circulating the signal on the whole surface, and that the stimuli that elicit probing and oviposition are not subjected to learning.

  18. Food habits of the southwestern willow flycatcher during the nesting season

    Science.gov (United States)

    Drost, Charles A.; Paxton, Eben H.; Sogge, Mark K.; Whitfield, Mary J.

    2003-01-01

    The food habits and prey base of the endangered Southwestern Willow Flycatcher (Empidonax traillii extimus) are not well known. We analyzed prey remains in 59 fecal samples from an intensively-studied population of this flycatcher at the Kern River Preserve in southern California. These samples were collected during the nesting season in 1996 and 1997 from adults caught in mist nets, and from nestlings temporarily removed from the nest for banding. A total of 379 prey individuals were identified in the samples. Dominant prey taxa, both in total numbers and in percent occurrence, were true bugs (Hemiptera), flies (Diptera), and beetles (Coleoptera). Leafhoppers (Homoptera: Cicadellidae), spiders (Araneae), bees and wasps (Hymenoptera), and dragonflies and damselflies (Odonata) were also common items. Diet composition was significantly different between years, due to a large difference in the numbers of spiders between 1996 and 1997. There was also a significant difference between the diet of young and adults, with the diet of young birds having significantly higher numbers of odonates and beetles. There was a trend toward diet differences between males and females, but this was not significant at the P = 0.05 level.

  19. Aspectos biológicos y poblacionales de Nasonovia ribisnigri y Aulacorthum solani sobre lechuga

    Directory of Open Access Journals (Sweden)

    Vasicek Araceli

    2002-01-01

    Full Text Available Se estimó la influencia de los cultivares Criolla Blanca, Cuatro Estaciones y Gallega, sobre la biología y los parámetros poblacionales de Nasonovia ribisnigri y Aulacorthum solani (Homoptera: Aphidoidea a 10±1ºC y HR de 90%. Los períodos ninfal, pre-reproductivo y post-reproductivo de N. ribisnigri fueron más largos sobre Cuatro Estaciones, no así el reproductivo. En A. solani el período ninfal fue más largo sobre Criolla Blanca y Cuatro Estaciones resultando el reproductivo mayor sobre Cuatro Estaciones. Las tasas intrínsecas de crecimiento natural (r m de N. ribisnigri y A. solani fueron mayores sobre Criolla Blanca y Gallega, respectivamente. De acuerdo a la especie predominante convendría utilizar Cuatro Estaciones para N. ribisnigri y Criolla Blanca para A. solani, en épocas frías.

  20. Comparison of the ionizing radiation effects on cochineal, annatto and turmeric natural dyes

    Science.gov (United States)

    Cosentino, Helio M.; Takinami, Patricia Y. I.; del Mastro, Nelida L.

    2016-07-01

    As studies on radiation stability of food dyes are scarce, commercially important natural food grade dyes were evaluated in terms of their sensitivity against gamma ionizing radiation. Cochineal, annatto and turmeric dyes with suitable concentrations were subjected to increasing doses up to 32 kGy and analyzed by spectrophotometry and capillary electrophoresis. The results showed different pattern of absorbance versus absorbed dose for the three systems. Carmine, the glucosidal coloring matter from the scale insect Coccus cacti L., Homoptera (cochineal) remained almost unaffected by radiation up to doses of about 32 kGy (absorbance at 494 nm). Meanwhile, at that dose, a plant-derived product annatto or urucum (Bixa orellana L.) tincture presented a nearly 58% reduction in color intensity. Tincture of curcumin (diferuloylmethane) the active ingredient in the eastern spice turmeric (Curcuma longa) showed to be highly sensitive to radiation when diluted. These data shall be taken in account whenever food products containing these food colors were going to undergo radiation processing.

  1. Entomofauna associated to horticultural crops under organic and conventional practices in Cordoba, Argentina

    International Nuclear Information System (INIS)

    Zalazar, Laura; Salvo, Adriana

    2007-01-01

    Farming practices and the addition of chemical synthetic substances in conventional agroecosystems are detrimental mainly to natural enemies of phytophagous insects, diminishing the natural regulation of pest insects. On the other hand, in organic agriculture, biological processes and care of the environment are favoured, hence an increase in insect biodiversity is predicted in this type of systems. In this work, abundance, richness of insects and proportion of functional groups were compared through a single quantitative sampling of insects in horticultural crop fields, three under organic and three under conventional management practices. Insect species richness, total and for guilds (phytophagous and entomophagous insects) were significantly higher in organic orchards, and also was the abundance of entomophagous insects. Richness and abundance of all insect orders (with exception of Homoptera abundance), were higher in orchards under organic management, being significant the differences for richness of Coleoptera and richness and abundance of Hymenoptera. Similar tendencies were observed in data obtained through sweep net in weeds. These results suggest that organic practices increase the diversity of species, particularly that of natural enemies. (author)

  2. Arthropod prey of Wilson's Warblers in the understory of Douglas-fir forests

    Science.gov (United States)

    Hagar, J.C.; Dugger, K.M.; Starkey, E.E.

    2007-01-01

    Availability of food resources is an important factor in avian habitat selection. Food resources for terrestrial birds often are closely related to vegetation structure and composition. Identification of plant species important in supporting food resources may facilitate vegetation management to achieve objectives for providing bird habitat. We used fecal analysis to describe the diet of adult Wilson's Warblers (Wilsonia pusilla) that foraged in the understory of Douglas-fir (Pseudotsuga menziesii) forests in western Oregon during the breeding season. We sampled arthropods at the same sites where diet data were collected, and compared abundance and biomass of prey among seven common shrub species. Wilson's Warblers ate more caterpillars (Lepidoptera larvae), flies (Diptera), beetles (Coleoptera), and Homoptera than expected based on availability. Deciduous shrubs supported higher abundances of arthropod taxa and size classes used as prey by Wilson's Warblers than did evergreen shrubs. The development and maintenance of deciduous understory vegetation in conifer forests of the Pacific Northwest may be fundamental for conservation of food webs that support breeding Wilson's Warblers and other shrub-associated, insectivorous songbirds.

  3. Diet of Wilson's warblers and distribution of arthropod prey in the understory of Douglas-fir forests

    Science.gov (United States)

    Hagar, Joan C.; Dugger, Kate; Starkey, Edward E.

    2007-01-01

    Availability of food resources is an important factor in avian habitat selection. Food resources for terrestrial birds often are closely related to vegetation structure and composition. Identification of plant species important in supporting food resources may facilitate vegetation management to achieve objectives for providing bird habitat. We used fecal analysis to describe the diet of adult Wilson's Warblers (Wilsonia pusilla) that foraged in the understory of Douglas-fir (Pseudotsuga menziesii) forests in western Oregon during the breeding season. We sampled arthropods at the same sites where diet data were collected, and compared abundance and biomass of prey among seven common shrub species. Wilson's Warblers ate more caterpillars (Lepidoptera larvae), flies (Diptera), beetles (Coleoptera), and Homoptera than expected based on availability. Deciduous shrubs supported higher abundances of arthropod taxa and size classes used as prey by Wilson's Warblers than did evergreen shrubs. The development and maintenance of deciduous understory vegetation in conifer forests of the Pacific Northwest may be fundamental for conservation of food webs that support breeding Wilson's Warblers and other shrub-associated, insectivorous songbirds.

  4. With or without pheromone habituation: possible differences between insect orders?

    Science.gov (United States)

    Suckling, David Maxwell; Stringer, Lloyd D; Jiménez-Pérez, Alfredo; Walter, Gimme H; Sullivan, Nicola; El-Sayed, Ashraf M

    2018-06-01

    Habituation to sex pheromones is one of the key mechanisms in mating disruption, an insect control tactic. Male moths often show reduced sexual response after pre-exposure to female sex pheromone. Mating disruption is relatively rare in insect orders other than Lepidoptera. As a positive control we confirmed habituation in a moth (Epiphyas postvittana) using 24 h pre-exposure to sex pheromone to reduce subsequent activation behaviour. We then tested the impact of pre-exposure to sex or trail pheromone on subsequent behavioural response with insects from three other orders. Similar pre-exposure for 24 h to either sex pheromone [Pseudococcus calceolariae (Homoptera) and apple leaf curling midge Dasineura mali (Diptera), or trail pheromone of Argentine ants (Linepithema humile (Hymenoptera)], followed by behavioural assay in clean air provided no evidence of habituation after pre-exposure in these latter cases. The moths alone were affected by pre-exposure to pheromone. For pests without habituation, sustained attraction to a point source may make lure and kill more economical. Improved knowledge of behavioural processes should lead to better success in pest management and mechanisms should be investigated further to inform studies and practical efforts generally enhancing effectiveness of pheromone-based management. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  5. Aphid wing induction and ecological costs of alarm pheromone emission under field conditions.

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    Eduardo Hatano

    2010-06-01

    Full Text Available The pea aphid, Acyrthosiphon pisum Harris, (Homoptera: Aphididae releases the volatile sesquiterpene (E-beta-farnesene (EBF when attacked by a predator, triggering escape responses in the aphid colony. Recently, it was shown that this alarm pheromone also mediates the production of the winged dispersal morph under laboratory conditions. The present work tested the wing-inducing effect of EBF under field conditions. Aphid colonies were exposed to two treatments (control and EBF and tested in two different environmental conditions (field and laboratory. As in previous experiments aphids produced higher proportion of winged morphs among their offspring when exposed to EBF in the laboratory but even under field conditions the proportion of winged offspring was higher after EBF application (6.84+/-0.98% compared to the hexane control (1.54+/-0.25%. In the field, the proportion of adult aphids found on the plant at the end of the experiment was lower in the EBF treatment (58.1+/-5.5% than in the control (66.9+/-4.6%, in contrast to the climate chamber test where the numbers of adult aphids found on the plant at the end of the experiment were, in both treatments, similar to the numbers put on the plant initially. Our results show that the role of EBF in aphid wing induction is also apparent under field conditions and they may indicate a potential cost of EBF emission. They also emphasize the importance of investigating the ecological role of induced defences under field conditions.

  6. Entomofauna associated to horticultural crops under organic and conventional practices in Cordoba, Argentina; Entomofauna asociada a cultivos horticolas organicos y convencionales en Cordoba, Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Zalazar, Laura; Salvo, Adriana [Universidade Nacional de Cordoba (Argentina). Facultad de Ciencias Exactas Fisicas y Naturales. Centro de Investigaciones Entomologicas de Cordoba (CIEC)

    2007-09-15

    Farming practices and the addition of chemical synthetic substances in conventional agroecosystems are detrimental mainly to natural enemies of phytophagous insects, diminishing the natural regulation of pest insects. On the other hand, in organic agriculture, biological processes and care of the environment are favoured, hence an increase in insect biodiversity is predicted in this type of systems. In this work, abundance, richness of insects and proportion of functional groups were compared through a single quantitative sampling of insects in horticultural crop fields, three under organic and three under conventional management practices. Insect species richness, total and for guilds (phytophagous and entomophagous insects) were significantly higher in organic orchards, and also was the abundance of entomophagous insects. Richness and abundance of all insect orders (with exception of Homoptera abundance), were higher in orchards under organic management, being significant the differences for richness of Coleoptera and richness and abundance of Hymenoptera. Similar tendencies were observed in data obtained through sweep net in weeds. These results suggest that organic practices increase the diversity of species, particularly that of natural enemies. (author)

  7. Comparison of the ionizing radiation effects on cochineal, annatto and turmeric natural dyes

    International Nuclear Information System (INIS)

    Cosentino, Helio M.; Takinami, Patricia Y.I.; Mastro, Nelida L. del

    2016-01-01

    As studies on radiation stability of food dyes are scarce, commercially important natural food grade dyes were evaluated in terms of their sensitivity against gamma ionizing radiation. Cochineal, annatto and turmeric dyes with suitable concentrations were subjected to increasing doses up to 32 kGy and analyzed by spectrophotometry and capillary electrophoresis. The results showed different pattern of absorbance versus absorbed dose for the three systems. Carmine, the glucosidal coloring matter from the scale insect Coccus cacti L., Homoptera (cochineal) remained almost unaffected by radiation up to doses of about 32 kGy (absorbance at 494 nm). Meanwhile, at that dose, a plant-derived product annatto or urucum (Bixa orellana L.) tincture presented a nearly 58% reduction in color intensity. Tincture of curcumin (diferuloylmethane) the active ingredient in the eastern spice turmeric (Curcuma longa) showed to be highly sensitive to radiation when diluted. These data shall be taken in account whenever food products containing these food colors were going to undergo radiation processing. - Highlights: • Comparison of radiosensitivity of food colors was performed. • Carmine showed the highest resistance to radiation. • Annatto and turmeric behaved sensitive to radiation when diluted. • Turmeric was the most affected by ionizing radiation.

  8. Hairy nightshade as a potential Potato leafroll virus (Luteoviridae: Polerovirus) inoculum source in Pacific Northwest potato ecosystems.

    Science.gov (United States)

    Srinivasan, R; Alvarez, J M

    2008-09-01

    Hairy nightshade, Solanum sarrachoides, is a solanaceous weed found abundantly in Pacific Northwest potato ecosystems. It serves as a reservoir for one of the important potato viruses, Potato leafroll virus (PLRV) (Luteoviridae: Polerovirus), and its most important vector, the green peach aphid, Myzus persicae (Homoptera: Aphididae). Laboratory research indicated an increased green peach aphid settling and performance on S. sarrachoides than on potato. It also revealed that green peach aphids transmitted PLRV more efficiently from S. sarrachoides to potato than from potato to potato. To test the efficiency of S. sarrachoides as an inoculum source in the field, a two season (2004 and 2005) trial was conducted at Kimberly, Idaho. Two inoculum sources, PLRV-infected potato and PLRV-infected S. sarrachoides, were compared in this trial. Green peach aphid density and temporal and spatial PLRV spread were monitored at weekly intervals. Higher densities of green peach aphids were observed on plots with S. sarrachoides and inoculum sources (PLRV-infected S. sarrachoides and potato) than on plots without S. sarrachoides and inoculum sources. PLRV infection in plots with PLRV-infected S. sarrachoides was similar to or slightly higher than in plots with PLRV-infected potato as an inoculum source. Temporal and spatial PLRV spread was similar in plots with either inoculum source. Thus, S. sarrachoides is as efficient as or a better PLRV inoculum source than potato.

  9. Analysis of the feeding habits of the swallow-tailed hummingbird, Eupetomena macroura (Gmelin, 1788, in an urban park in southeastern Brazil

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    MCB. Toledo

    Full Text Available The aim of this work was to observe and describe the feeding habits and available food resources of the swallow-tailed hummingbird, Eupetomena macroura. The study was carried out in a municipal park located in the city of Taubaté, in the state of São Paulo. The observations took place between December 2003 and October 2004, recording the following variables: 1 the plant species visited for feeding and territorial defense; 2 the kinds of food resources; and 3 the kinds of flight to procure and obtain food. E. macroura visited 12 plant species. For territorial defense, Mangifera indica was the most visited, whereas Malvaviscus arboreus was most visited for feeding. The foliage was the plant part that received the most frequent visits. In order to obtain nectar, the only species visited was M. arboreus; to obtain arthropods, the species most visited were Mangifera indica and Hymenaea stilbocarpa. In the dry season, the hummingbirds visited flowers, whereas in the rainy season they visited leaves to acquire food. The arthropod groups most frequently found on leafy branches were Homoptera and Psocoptera. Finally, the results of the type of flight analysis showed that flight used to capture food was more often observed than were flights to search for food. In conclusion, these observations suggest that E. macroura shows plasticity in feeding behavior, which can help it to persist in urban areas.

  10. ON THE PALEOFAUNA INVERTEBRATES (MOLLUSCA, ARTROPODA; INSECTA OF DIATOMITE DEPOSITS OF SHAMB–1 LOCALITY (SISIAN SUITE, EARLY PLEISTOCENE, ARMENIA

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    М. A. Маrjanyan

    2016-01-01

    Full Text Available Aim. The study of fossil insects from diatomaceous sediments of Shamb-1 locality of Sisian Suite (Early Pleistocene. The collection of fossils plants and animals of Institute of Botany of NAS RA and authors' findings served as material for study.Methods. The material is processed and prepared for study by conventional methods in paleontology for prints and fossils of insects from diatomaceous sediments. There are 654 samples studied: 2 samples were with mollusks’ imprints and 652 samples with imprints of insects, from which preserved marks on 291samples allowed to identify them up to order, family, genus and species.Results. The studied material refers to the Mollusca and Arthropoda (Insecta types. Insects are represented by species of orders Orthoptera (2 fam., Homoptera (1 fam., Heteroptera (2 fam., Coleoptera (15 fam., Hymenoptera (2 fam., Diptera (1 fam.. Coleopteras dominate among them and are presented with following species of the family – Carabidae, Dytiscidae, Hydrophilidae, Histeridae, Staphylinidae, Silphidae, Elateridae, Buprestidae, Lampyridae, Scarabaeidae, Chrysomelidae, Tenebrionidae, Coccinellidae, Cerambycidae, Curculionidae.Main conclusions. An analysis of the taxonomic composition of paleofauna was done, which corresponds to the recent fauna and with considering modern ecological characteristics of systematical groups and species. In the investigated location of Shamb-1 a version is suggested about the palaeolandscapes and palaeoclimate in the Early Pleistocene.

  11. Búsqueda y reconocimiento de los enemigos naturales y hospedantes alternos de las principales plagas. En flores bajo invernadero en la sabana de Bogotá

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    Martha E. Andrade

    1989-01-01

    Full Text Available Las plagas que atacan cultivos de llores bajo invernadero son cada vez más importantes por la gravedad de su daño y por la alta densidad con que suelen presentarse. Para su control se ha acudido principalmente a la utilización de productos químicos, lo cual conduce a un aumento en los costos de producción, a contaminar el medio ambiente, a afectar la salud humana y a crear resistencia de los insectos a los insecticidas. Debido a esto, es necesario incluír dentro de los programas de control a los reguladores naturales de las plagas: parasitoides, depredadores y microorganismos entornógenos. En el presente trabajo se registran los enemigos naturales más importantes de las principales plagas en llores bajo invernadero (crisantemo, rosa y clavel: Liriomyza huidobrensis Blanchard, L. trifolii Burgess (Diptera: Agrornyzídae; Myzuz persicae Sulzer (Homoptera: Aphididae; Tetranychus urticae Koch y T. cinnabarinus Boísduval (Acarina: Tetranychidae; también se señalan las plantas hospedantes alternas presentes en las localidades donde se realizó la investigación.

  12. A survey of syrphid predators of Nasonovia ribisnigri in organic lettuce on the central coast of California.

    Science.gov (United States)

    Smith, Hugh A; Chaney, William E

    2007-02-01

    Organic lettuce, Lactuca sativa L., producers on California's Central Coast rely on endemic syrphid flies (Diptera: Syrphidae) to suppress populations of Nasonovia ribisnigri Mosley (Homoptera: Aphididae) and other aphids affecting lettuce. Growers are using various forms of habitat manipulation to enhance biological control. We surveyed syrphids collected from organic romaine in and around the Salinas Valley from March through September 2005 to gain a better understanding of the species responsible for aphid suppression and to examine possible implications for biocontrol. The primary species of syrphid fly reared were Toxomerus marginatus (Say) (39%), Platycheirus stegnus (Say) (27%), Sphaerophoria sulfuripes (Thomson) (13%), and Allograpta obliqua (Say) (10%). Syrphus opinator Osten Sacken (2%), Toxomerus occidentalis (Curran) (1.3%), and Eupeodes volucris Osten Sacken (1%) were less common. Sphaerophoria pyrrhina Bigot, Scaeva pyrastri (L.), Platycheirus obscurus Say, Allograpta exotica Wiedemann, and Eupeodes americanus Wiedemann each made up aphids. P. stegnus was observed to deposit in clusters of eggs, and was only reared in significant numbers from highly infested fields. Approximately 5% of syrphid larvae overall were parasitized by either Diplazon sp. (Hymenoptera: Ichneumonidae) or Pachyneuron sp. (Hymenoptera: Pteromalidae).

  13. Dietary analysis of Homonota darwini (Squamata: Gekkoni-dae in Northern Patagonia

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    Marcelo E. KUN, Carla PIANTONI, John D. KRENZ, Nora R. IBARGÜENGOYTÍA

    2010-08-01

    Full Text Available Our study investigated the diet of the southernmost gecko in the world, Homonota darwini. Fifty-three specimens were captured during spring and summer in four locations in Patagonia, Argentina. The stomach contents of the specimens were identified, and we found that prey consisted of six main groups: Coleoptera, Hymenoptera, Homoptera and Araneae, and the adults and larvae of moth Lepidoptera. Lepidoptera was the major dietary component. The presence of ants and moths as common prey suggests an ambush feeding strategy. In spring, females consumed more ants than males although no other dietary differences between males and females were evident. We found nine geckos with empty stomachs and six parasitized by nematodes. Presence of empty stomachs corroborates previous observations of other nocturnal geckos and non-gecko lizards. Reduced foraging success of nocturnal lizards could be due to difficulty in prey detection due to dim light, reduced or erratic activity of insect prey at night, or shorter activity times of geckos relative to diurnal success. Sex and season were not associated with the incidence of empty stomachs. Principal component analysis showed that four food alternatives correlated with season. The constraint of nocturnality, coupled with low night-time temperatures restricting feeding to only a few hours after sunset, appear to have caused a generality of diet which may limit energy acquisition. We conclude that H. darwini is an arthropod generalist and likely an ambush forager, as are many other nocturnal gekkonids [Current Zoology 56 (4: 406–410, 2010].

  14. Biodiversidad del complejo de artrópodos asociados al follaje de la vegetación del norte de Chile, II región Biodiversity of the canopy arthropods associated to vegetation of the north of Chile, II region

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    FRANCISCO SAIZ

    2000-12-01

    , estableciéndose el siguiente gradiente decreciente: DL > DI > TM > TA. El contenido de cenizas de hojas y tallos también varía considerablemente y sigue el mismo patrón de variación que el contenido de agua. El contenido de nitrógeno foliar en las distintas zonas ecológicas estudiadas no varía tanto como el de agua, a excepción de TA en que son marcadamente inferiores. En cambio, en tallos es poco variable y no sigue el patrón de distribución foliar de este elemento, ni los patrones de distribución de los otros nutrientes considerados. En un enfoque global de las cuatro zonas se establece un gradiente decreciente de contenidos de agua, nitrógeno y cenizas desde el DL hasta la zona TA, concordante con el incremento en altitud, especialmente en lo referente a hojas. La familia Asteraceae muestra un definido gradiente decreciente del contenido de agua desde la costa a la alta cordillera. En cuanto al contenido foliar de cenizas difiere significativamente sólo entre DL y TM. En tallos no difiere significativamente. En total se colectaron 12.893 individuos de artrópodos asociados al follaje, distribuidos en 464 morfoespecies y 19 grupos zoológicos, considerando aparte a los antiguos Homoptera. Este grupo, junto a Hemiptera y larvas de Lepidoptera, destaca en cuanto a abundancia de especies dentro de los insectos fitófagos, así como Hymenoptera dentro de los parasitoides y Araneae entre los depredadores. En cuanto a las zonas ecológicas, el DL y TM presentan la mayor abundancia de artrópodos, tanto en especies como en individuos, así como de especies de plantas sobre las cuales se colectaron. La similaridad de la artropodofauna entre zonas ecológicas es mínima desde el punto de vista de la presencia de especies; en cambio, considerando sus abundancias, se detecta una tendencia a asociarse DI con TM y a aislarse el DL, al igual que ocurre con la vegetación. Desde el punto de vista de las diversidades específicas globales (H´ de los artrópodos se

  15. Toxins for Transgenic Resistance to Hemipteran Pests

    Science.gov (United States)

    Chougule, Nanasaheb P.; Bonning, Bryony C.

    2012-01-01

    The sap sucking insects (Hemiptera), which include aphids, whiteflies, plant bugs and stink bugs, have emerged as major agricultural pests. The Hemiptera cause direct damage by feeding on crops, and in some cases indirect damage by transmission of plant viruses. Current management relies almost exclusively on application of classical chemical insecticides. While the development of transgenic crops expressing toxins derived from the bacterium Bacillus thuringiensis (Bt) has provided effective plant protection against some insect pests, Bt toxins exhibit little toxicity against sap sucking insects. Indeed, the pest status of some Hemiptera on Bt-transgenic plants has increased in the absence of pesticide application. The increased pest status of numerous hemipteran species, combined with increased prevalence of resistance to chemical insecticides, provides impetus for the development of biologically based, alternative management strategies. Here, we provide an overview of approaches toward transgenic resistance to hemipteran pests. PMID:22822455

  16. Test for Local Insect Traps against some Solanacea Insects Plant under Green House Conditions in Riyadh, Saudi Arabia

    International Nuclear Information System (INIS)

    Al-Ayedh, Hassan Ibn Yahiya

    2005-01-01

    Trapping efficiency of seven different colored sticky traps (Green, Fluorescent yellow, Orange, Pink, red, White and Yellow) was evaluated in some solanacea plants, tomatoes (Lycopersicon esculentum), eggplant (Solanum Magellan) and sweet pepper (Capsicum spp.) crops, for whitefly (Bemis ia airlifting), leaf miners (Liriomyza trifolii), thrips (Thrips tabaci) in Riyadh, Saudi Arabia. The traps were placed at four different heights (0.5, 1.0, 1.5 and 2.0 m above the ground). The experiment was laid out in a Completely Randomized Block Design (CRBD) with four replications during autumn 2001, spring and autumn 2002. Significantly high insect populations were trapped on Fluorescent yellow, yellow and green colored sticky traps. No significant differences were witnessed between mean numbers of various insects caught on sticky traps placed at different heights but more insects were trapped at 0.5 - 1.5m. (author)

  17. SAR studies directed toward the pyridine moiety of the sap-feeding insecticide sulfoxaflor (Isoclast™ active).

    Science.gov (United States)

    Loso, Michael R; Benko, Zoltan; Buysse, Ann; Johnson, Timothy C; Nugent, Benjamin M; Rogers, Richard B; Sparks, Thomas C; Wang, Nick X; Watson, Gerald B; Zhu, Yuanming

    2016-02-01

    Sap-feeding insect pests constitute a major insect pest complex that includes a range of aphids, whiteflies, planthoppers and other insect species. Sulfoxaflor (Isoclast™ active), a new sulfoximine class insecticide, targets sap-feeding insect pests including those resistant to many other classes of insecticides. A structure activity relationship (SAR) investigation of the sulfoximine insecticides revealed the importance of a 3-pyridyl ring and a methyl substituent on the methylene bridge linking the pyridine and the sulfoximine moiety to achieving strong Myzus persicae activity. A more in depth QSAR investigation of pyridine ring substituents revealed a strong correlation with the calculated logoctanol/water partition coefficient (SlogP). Model development resulted in a highly predictive model for a set of 18 sulfoximines including sulfoxaflor. The model is consistent with and helps explain the highly optimized pyridine substitution pattern for sulfoxaflor. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Engineering cotton (Gossypium hirsutum L.) for resistance to cotton leaf curl disease using viral truncated AC1 DNA sequences.

    Science.gov (United States)

    Hashmi, Jamil A; Zafar, Yusuf; Arshad, Muhammad; Mansoor, Shahid; Asad, Shaheen

    2011-04-01

    Several important biological processes are performed by distinct functional domains found on replication-associated protein (Rep) encoded by AC1 of geminiviruses. Two truncated forms of replicase (tAC1) gene, capable of expressing only the N-terminal 669 bp (5'AC1) and C-terminal 783 bp (3'AC1) nucleotides cloned under transcriptional control of the CaMV35S were introduced into cotton (Gossypium hirsutum L.) using LBA4404 strain of Agrobacterium tumefaciens to make use of an interference strategy for impairing cotton leaf curl virus (CLCuV) infection in transgenic cotton. Compared with nontransformed control, we observed that transgenic cotton plants overexpressing either N-terminal (5'AC1) or C-terminal (3'AC1) sequences confer resistance to CLCuV by inhibiting replication of viral genomic and β satellite DNA components. Molecular analysis by Northern blot hybridization revealed high transgene expression in early and late growth stages associated with inhibition of CLCuV replication. Of the eight T(1) transgenic lines tested, six had delayed and minor symptoms as compared to nontransformed control lines which developed disease symptoms after 2-3 weeks of whitefly-mediated viral delivery. Virus biological assay and growth of T(2) plants proved that transgenic cotton plants overexpressing 5'- and 3'AC1 displayed high resistance level up to 72, 81%, respectively, as compared to non-transformed control plants following inoculation with viruliferous whiteflies giving significantly high cotton seed yield. Progeny analysis of these plants by polymerase chain reaction (PCR), Southern blotting and virus biological assay showed stable transgene, integration, inheritance and cotton leaf curl disease (CLCuD) resistance in two of the eight transgenic lines having single or two transgene insertions. Transgenic cotton expressing partial AC1 gene of CLCuV can be used as virus resistance source in cotton breeding programs aiming to improve virus resistance in cotton crop.

  19. Physical control possibilities of Bemisia tabaci (Gennadius) and Tomato yellow leaf curl disease (TYLCD) in protected crops

    International Nuclear Information System (INIS)

    Rapisarda, C.; Cascone, G.; Tropea Garzia, G.; Mazzarella, R.; Colombo, A.; Serges, T.

    2005-01-01

    Among alternatives to chemical control for reducing virus epidemics in protected tomato crops, physical management of vectors populations through the application of insect-proof screens to greenhouse openings has been investigated since many years and satisfactory results have been obtained so far, especially regarding the incidence of the whitefly Bemisia tabaci (Gennadius), which is the vector of Tomato yellow leaf curl disease (TYLCD). Nevertheless, although effective from the phytosanitary point of view, these insect-proof screens negatively affect the climate inside the greenhouse, by reducing ventilation, increasing air temperature, etc.. Recently, a low incidence of whitefly infestations on crops has been observed inside greenhouses which have been covered with photoselective plastic films absorbing the ultra-violet component (200-380 nm) of solar radiation. The present study, carried out in Sicily by means of three trials during three consecutive years, allowed to evaluate the ability of two different UV-absorbing plastic films to reduce B. tabaci infestations, in comparison to UV-unabsorbing plastic films and insect-proof screens commonly used to cover and protect tomato greenhouses. The results show the good efficiency of both the tested UV-absorbing films to reduce the witefly presence on tomato crops and the consequent TYLCD spreading. Furthermore, it may be observed that UV-absorbing films do not determine sensible variations of greenhouse climate conditions, compared to greenhouses covered with conventional films. These data not only confirm the physical validity of the UV-absorbing films, but also show that they may fit properly within strategies of integrated control of pests and viruses in protected cultivations [it

  20. Modified atmosphere treatments as a potential disinfestation technique for arthropod pests in greenhouses.

    Science.gov (United States)

    Held, D W; Potter, D A; Gates, R S; Anderson, R G

    2001-04-01

    Incidental transport of arthropods on plant material can be a significant mode of pest entry into greenhouses. We evaluated the use of controlled atmosphere treatments as a potential way to eliminate arthropod pests on plant propagules (i.e., cuttings or small rooted plants). Lethal exposures to CO2 or N2 were determined for common greenhouse pests including fungus gnat larvae, Bradysia sp.; green peach aphid, Myzus persicae (Sulzer); sweetpotato whitefly, Bemisia sp.; twospotted spider mite, Tetranychus urticae Koch; and western flower thrips, Frankliniella occidentalis (Pergande). We also studied the effect of pest species, life stage, and presence or absence of plants on efficacy of modified atmosphere treatments. Finally, effects of modified atmospheres on plant quality were evaluated for several bedding plant species including begonia, Begonia semperflorens-cultorum Hort. 'Cocktail Series', chrysanthemum, Dendranthema grandiflora Tzvelev., geranium, Pelargonium X hortorum L.H. Bailey, and impatiens, Impatiens wallerana Hook f., and among cultivars of geranium and chrysanthemum. Exposure for 12-18 h to >99% N2 or CO2 caused complete mortality of aphids, mites, thrips, and whiteflies. Fungus gnat larvae were more tolerant of hypoxic conditions. Adult mites and eggs were equally susceptible. For most pests, there was no difference in response to atmospheres modified by CO2 or N2. However, there was variation in response among plant species and cultivars, with effects ranging from delayed flowering to mortality. Despite the possibility of adverse effects on some plants, this work indicates that use of modified atmospheres has potential to eliminate arthropod pests on plant propagules before they are introduced into greenhouses.