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Sample records for bean aphid aphis

  1. Large interclone differences in melezitose secretion in the facultatively ant-tended black bean aphid Aphis fabae.

    Science.gov (United States)

    Vantaux, A; Van den Ende, W; Billen, J; Wenseleers, T

    2011-12-01

    Many aphids are known to engage in a trophic mutualism with ants, whereby the aphids secrete sugary-rich honeydew which is collected by the ants for food, and the ants, in exchange, protect the aphids against natural enemies. Previous results, however, suggest that the production of some of the honeydew sugars, such as the ant-attractant trisaccharide melezitose, may induce an indirect cost to the aphids. This led us to believe that large differences in the nature of the secreted honeydew might exist, due to some clones capitalizing more or less on their mutualistic interaction with ants, or due to some "cheater" clones foregoing the production of particular sugars, instead taking advantage of the ant-attracting effect of other non sugar-deficient clones, co-occurring on the same plant. Here we present data on clonal variation in the composition of honeydew of the black bean aphid Aphis fabae which confirm this prediction. In particular, our results show that there was large interclone variation in the amount of glucose, melezitose and total sugar produced. The variation in the production of melezitose, however, showed particularly large differences, with 54% (7 out of 13) of the clones screened being virtually deficient for the production of this sugar, irrespective of whether the aphid colonies were ant-tended or not. The consequences of this finding in the context of the evolution and maintenance of the ant-aphid mutualism, as well as the adaptive benefits of oligosaccharide synthesis in aphids and other insects are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Dual action of phosphonate herbicides in plants affected by herbivore--model study on black bean aphid Aphis fabae rearing on broad bean Vicia faba plants.

    Science.gov (United States)

    Lipok, Jacek

    2009-09-01

    The interactions between plants, herbicides and herbivore insects were studied as an aspect of possible side effect of the using of phosphonate herbicides. The experimental system was composed of phosphonate herbicides, broad bean Vicia faba (L.) plants and black bean aphid Aphis fabae (Scopoli). Two means of herbicide application, namely standard spraying and direct introduction of the herbicide into stem via glass capillary, were examined. The results obtained for N-2-piridylaminomethylene bisphosphonic acid and its derivatives show 10 times higher inhibition of the plant growth if glass capillary mode was used. When plants were infested by aphids 24h after the use of herbicide, a significant decrease in plant growth rate was observed in relation to plants treated with herbicides alone. Moreover, the sensitivity of aphids towards glyphosate, N-2-piridylaminomethylene bisphosphonic acid and its 3-methyl derivative introduced to artificial diet indicated that these herbicidal phosphonates possessed also insecticidal activity if applied in a systemic manner. Additionally, olfactometer measurements revealed that aphids preferred intact V. faba leaves over those that had been treated with sublethal doses of herbicides. The results achieved in these experiments indicate that the use of phosphonate herbicides decreases plant resistance and influences the number of aphids accompanied with treated plants. Regarding these facts it can be concluded that the combined effect of herbicide-induced stress and insect herbivory reduced plant fitness and thus should be considered as also a factor enabling the reduction of herbicide doses.

  3. Effect of petroleum-derived substances on life history traits of black bean aphid (Aphis fabae Scop.) and on the growth and chemical composition of broad bean

    OpenAIRE

    Rusin, Milena; GOSPODAREK, Janina; Nadgórska-Socha, Aleksandra; Barczyk, Gabriela

    2017-01-01

    The aim of the study was to determine the effects of various petroleum-derived substances, namely petrol, diesel fuel and spent engine oil, on life history traits and population dynamics of the black bean aphid Aphis fabae Scop. and on growth and chemical composition of its host plant Vicia faba L. Each substance was tested separately, using two concentrations (9 g kg−1 and 18 g kg−1). The experiment was conducted in four replications (four pots with five plants in each pot per treatment). Pl...

  4. Effect of petroleum-derived substances on life history traits of black bean aphid (Aphis fabae Scop.) and on the growth and chemical composition of broad bean.

    Science.gov (United States)

    Rusin, Milena; Gospodarek, Janina; Nadgórska-Socha, Aleksandra; Barczyk, Gabriela

    2017-04-01

    The aim of the study was to determine the effects of various petroleum-derived substances, namely petrol, diesel fuel and spent engine oil, on life history traits and population dynamics of the black bean aphid Aphis fabae Scop. and on growth and chemical composition of its host plant Vicia faba L. Each substance was tested separately, using two concentrations (9 g kg(-1) and 18 g kg(-1)). The experiment was conducted in four replications (four pots with five plants in each pot per treatment). Plants were cultivated in both control and contaminated soils. After six weeks from soil contamination and five weeks from sowing the seeds, observations of the effect of petroleum-derived substances on traits of three successive generations of aphids were conducted. Aphids were inoculated separately on leaves using cylindrical cages hermetically closed on both sides. Contamination of aphid occurred through its host plant. Results showed that all tested substances adversely affected A. fabae life history traits and population dynamics: extension of the prereproductive period, reduction of fecundity and life span, reduction of the population intrinsic growth rate. In broad bean, leaf, roots, and shoot growth was also impaired in most conditions, whereas nutrient and heavy metal content varied according to substances, their concentration, as well as plant part analysed. Results indicate that soil contamination with petroleum-derived substances entails far-reaching changes not only in organisms directly exposed to these pollutants (plants), but also indirectly in herbivores (aphids) and consequently provides information about potential negative effects on further links of the food chain, i.e., for predators and parasitoids.

  5. Action of some micronutrients on the infestation and yield components of faba bean by the aphid, Aphis craccivora Koch (Aphididae, Homoptera) and the leaf miner, Liriomyza trifolii (Burgess) (Agromyzidae, Diptera).

    Science.gov (United States)

    Mourad, A K; Hammad, S A; Guirguis, G Z; Zaghloul, O A; Sadek, Hanan A

    2004-01-01

    Field experiments were carried out in the two growing seasons of 1999/2000 and 2000/2001 on faba bean (Vicia faba) plants in the Experimental Farm of Agriculture Research Station at Nubaria region, Alexandria, which is considered as a newly reclaimed calcareous soil. The present investigation aimed to evaluate the effect of spraying faba bean plants with certain micronutrients, i.e. Iron, Manganese and Zinc either in single double or triple combinations on the infestation by the aphid, Aphis craccivora Koch (Aphididae, Homoptera) and the leaf miner, Liriomyza trfolü (Burgess) (Agromyzidae, Diptera). The infestation by these insects was assessed using the parameters of Infestation grades as well as the injury indices. Faba bean plants cv. Giza Blanca were sprayed twice (45 and 66 days) after planting with the above-mentioned micronutrients. However, results of this investigation showed, with no doubt, that Mn, Zn and Fe individually or in double or triple combinations have increased to varied extents the infestation rates (%) of faba bean plants compared to the untreated ones. Such varied increases were mainly due to the metabolic roles of the used foliar sprays and their interactions, which indirectly affect the physio-biological actions of plants that may render them suitable for either A. craccivora or L. trifoii reproduction. This phenomenon might be also due to the different environmental factors. In both seasons, the relationship between nutrients applications and pests Infestation followed the same trend of increase in the percentages of infested plants. This assures and confirms the constant metabolic roles of such micronutrients. The biological seed weight (ton/fed.) was positively affected by the application of the used micronutrients. It is worth mentioning that the maximum response was observed in case of the triple treatment followed by the double and single treatments in a descending order. Application of the investigated micronutrients alone or in

  6. Why the aphid Aphis spiraecola is more abundant on clementine tree than Aphis gossypii?

    Science.gov (United States)

    Mostefaoui, Houda; Allal-Benfekih, Leila; Djazouli, Zahr-Eddine; Petit, Daniel; Saladin, Gaëlle

    2014-02-01

    Aphis spiraecola and Aphis gossypii cause harmful damages on clementine tree orchards. Weekly surveys measured the abundance of aphids (larvae, winged and wingless adults) as well as of auxiliary insects and parameters of energy metabolism. Correlatively, soluble carbohydrates, total free amino acids, free proline and condensed tannins were quantified in control and infested leaves. Both aphid species showed parallel temporal variations, but A. spiraecola was consistently more abundant regardless of the stage. Amino acids had a positive effect on both aphid species abundance, but neither condensed tannins nor auxiliary insects seemed to modulate aphid populations. Interestingly, the leaf carbohydrate content was positively correlated with the abundance of A. spiraecola, but not with that of A. gossypii. Moreover, A. gossypii's abundance was significantly down-regulated by high proline concentrations. Thus, the higher abundance of A. spiraecola could be explained by a better tolerance to high proline contents and a better conversion of foliar energy metabolites.

  7. National Plant Diagnostic Network, Taxonomic training videos: Aphids under the microscope - Aphis gossypii

    Science.gov (United States)

    Training is a critical part of aphid (Hemiptera: Aphididae) identification. This video provides provides training to identify the cotton aphid, Aphis gossypii, using a compound microscope and an electronic identification key called “LUCID.” The video demonstrates key morphological structures that ca...

  8. THE ROLE OF BACTERIAL SYMBIONTS IN AMINO ACID COMPOSITION OF BLACK BEAN APHIDS

    Institute of Scientific and Technical Information of China (English)

    MingGan; De-ChengDing; Xue-xiaMiao

    2003-01-01

    To evaluate the role of bacterial symbionts ( Buchnera spp. ) in the black bean aphids ( Aphis craccivora Koch), the aphids were treated with the antibiotic, rifampicin, to eliminate their intracellular symbiotic bacteria. Analysis of protein and amino acid concentration in 7-day-old of aposymbiotic aphids showed that the total protein content per mg fresh weight was significantly reduced by 29 %, but free amino acid titers were increased by 17% . The ratio of the essential amino acids was in general only around 20% essential amino acids in phloem sap of broad bean, whereas it was 44% and 37% in symbiotic and aposymbiotic aphids, respectively,suggesting that the composition of the free amino acids was unbalanced. For example, the essential amino acid,threonine represented 21. 6% of essential amino acids in symbiotic aphids, but it was only 16.7% in aposymbiotic aphids. Likewise, two nonessential amino acids, tyrosine and serine, represented 8.9% and 5.6% of total amino acids in symbiontic aphids, respectively, but they enhanced to 21.1% and 13.6% in aposymbiotic aphids. It seems likely that the elevated free amino acid concentration in aposymbiotic aphids was caused by the limited protein anabolism as the result of the unbalanced amino acid composition.

  9. Functional response of the ladybird, Cydonia vicina nilotica to cowpea aphid, Aphis craccivora in the laboratory

    Institute of Scientific and Technical Information of China (English)

    NASSER SAID MANDOUR; NESREN ABDEL-SALLAM EL-BASHA; TONG-XIAN LIU

    2006-01-01

    The functional response of Cydonia vicina nilotica Muls. (Coleoptera:Coccinellidae) to six densities of Aphis craccivora Koch (Homoptera: Aphididae) nymphs on broad bean (Vicia faba Linn.) was investigated in the laboratory. A linear relationship between the rate of consumption and prey density was observed with r2 values between 0.58 and 0.97. Plotting prey density against prey killed by four larval instars, and adult males and females of C. vicina nilotica fit well with the type Ⅱ model of Holling' s disc equation.Adult females consumed the highest number of prey, followed by fourth instars and adult males. Based on the functional response data, the model predicts a maximum of 144.9, 116.3,86.2, 80.0, 72.5 and 20.0 nymphs to be consumed per day by an individual adult female,fourth instar, adult male, third, second and first instars, respectively. The differences in the responses of the predator to aphid densities are discussed.

  10. Biological control of cotton aphid (Aphis gossypii Glover) in cotton (inter)cropping systems in China; a simulation study.

    NARCIS (Netherlands)

    Xia, J.

    1997-01-01

    Cotton aphid ( Aphis gossypii Glover) is the key insect pest of seedling cotton ( Gossypium hirsutum L. ) in China, particularly in the North China cotton region. The resulting annual losses amount to 10-15% of the attainable yield. Sole reliance on insecticides against the cotton aphid in the past

  11. A cost of alarm pheromone production in cotton aphids, Aphis gossypii

    Science.gov (United States)

    Byers, John A.

    2005-02-01

    The sesquiterpene, (E)-β-farnesene, is used by many aphid species as an alarm pheromone to warn related individuals of predation. Disturbed cotton aphids, Aphis gossypii Glover, released (E)-β-farnesene into the air as detected by solid phase microextraction and gas chromatography mass spectrometry (GC MS). Solvent extracts of cotton aphids of various life stages and weights also were analyzed by GC MS for sums of ions 69 and 93, which discriminated (E)-β-farnesene from coeluting compounds. Aphids of all life stages and sizes reared on cotton plants in both an environmental chamber and glasshouse contained (E)-β-farnesene in amounts ranging from 0.1 to 1.5 ng per individual. The quantities of (E)-β-farnesene in aphids increased in relation to increasing body weight, and variation in individual weights explained about 82% of the variation in alarm pheromone. However, the concentrations (ng/mg fresh weight) declined exponentially with increasing body weight. These findings indicate that aphid nymphs try to compensate for their smaller size by producing relatively more pheromone per weight than adults but still cannot approach an evolutionary optimal load, as assumed in adults with the greatest total amounts. This suggests that young aphids need to balance costs of growth and maturation with costs of producing the alarm pheromone.

  12. The Nerium oleander aphid Aphis nerii is tolerant to a local isolate of Aphid lethal paralysis virus (ALPV).

    Science.gov (United States)

    Dombrovsky, Aviv; Luria, Neta

    2013-04-01

    In a survey that was conducted during the year 2011, a local strain of Aphid lethal paralysis virus (ALPV) was identified and isolated from a wild population of Aphis nerii aphids living on Nerium oleander plants located in northern Israel. The new strain was tentatively named (ALPV-An). RNA extracted from the viral particles allowed the amplification and determination of the complete genome sequence. The virus genome is comprised of 9835 nucleotides. In a BLAST search analysis, the ALPV-An sequence showed 89 % nucleotide sequence identity with the whole genome of a South African ALPV and 96 and 94 % amino acid sequence identity with the ORF1 and ORF2 of that strain, respectively. In preliminary experiments, spray-applied, purified ALPV virions were highly pathogenic to the green peach aphid Myzus persicae; 95 % mortality was recorded 4 days post-infection. These preliminary results demonstrate the potential of ALPV for use as a biologic agent for some aphid control. Surprisingly, no visible ALPV pathogenic effects, such as morphological changes or paralysis, were observed in the A. nerii aphids infected with ALPV-An. The absence of clear ALPV symptoms in A. nerii led to the formulation of two hypotheses, which were partially examined in this study. The first hypothesis suggest that A. nerii is resistant or tolerant of ALPV, while the second hypothesis propose that ALPV-An may be a mild strain of ALPV. Currently, our results is in favor with the first hypothesis since ALPV-An is cryptic in A. nerii aphids and can be lethal for M. persicae aphids.

  13. All 37 Mitochondrial Genes of Aphid Aphis craccivora Obtained from Transcriptome Sequencing: Implications for the Evolution of Aphids.

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    Nan Song

    Full Text Available The availability of mitochondrial genome data for Aphididae, one of the economically important insect pest families, in public databases is limited. The advent of next generation sequencing technology provides the potential to generate mitochondrial genome data for many species timely and cost-effectively. In this report, we used transcriptome sequencing technology to determine all the 37 mitochondrial genes of the cowpea aphid, Aphis craccivora. This method avoids the necessity of finding suitable primers for long PCRs or primer-walking amplicons, and is proved to be effective in obtaining the whole set of mitochondrial gene data for insects with difficulty in sequencing mitochondrial genome by PCR-based strategies. Phylogenetic analyses of aphid mitochondrial genome data show clustering based on tribe level, and strongly support the monophyly of the family Aphididae. Within the monophyletic Aphidini, three samples from Aphis grouped together. In another major clade of Aphididae, Pterocomma pilosum was recovered as a potential sister-group of Cavariella salicicola, as part of Macrosiphini.

  14. Establishment of in vitro soybean aphids, Aphis glycines (Hemiptera: Aphididae): a tool to facilitate studies of aphid symbionts, plant-insect interactions and insecticide efficacy.

    Science.gov (United States)

    Gunadi, Andika; Bansal, Raman; Finer, John J; Michel, Andy

    2017-06-01

    Studies on plant-insect interactions of the soybean aphid, Aphis glycines (Matsumura), can be influenced by environmental fluctuations, status of the host plant and variability in microbial populations. Maintenance of aphids on in vitro-grown plants minimizes environmental fluctuations, provides uniform host materials and permits the selective elimination of aphid-associated microbes for more standardized controls in aphid research. Aphids were reared on sterile, in vitro-grown soybean seedlings germinated on plant tissue culture media amended with a mixture of antimicrobials. For initiation and maintenance of in vitro aphid colonies, single aphids were inoculated onto single in vitro seedlings. After three rounds of transfer of 'clean' aphids to fresh in vitro seedlings, contamination was no longer observed, and aphids performed equally well when compared with those reared on detached leaves. The addition of the insecticides thiamethoxam and chlorantraniliprole to the culture medium confirmed uptake and caused significant mortality to the in vitro aphids. The use of the antimicrobial mixture removed the associated bacteria Arsenophonus but retained Buchnera and Wolbachia within the in vitro aphids. The in vitro aphid system is a novel and highly useful tool to understand insecticidal efficacy and expand our knowledge of tritrophic interactions among plants, insects and symbionts. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  15. Biological control of cotton aphid (Aphis gossypii Glover) in cotton (inter)cropping systems in China; a simulation study.

    OpenAIRE

    Xia, J

    1997-01-01

    Cotton aphid ( Aphis gossypii Glover) is the key insect pest of seedling cotton ( Gossypium hirsutum L. ) in China, particularly in the North China cotton region. The resulting annual losses amount to 10-15% of the attainable yield. Sole reliance on insecticides against the cotton aphid in the past four decades has brought about a rapid development of insecticide resistance, serious outbreaks of key pests, resurgence of secondary pests, and risk for man and environment. Biological control of ...

  16. Biological control of cotton aphid (Aphis gossypii Glover) in cotton (inter)cropping systems in China : a simulation study

    NARCIS (Netherlands)

    Xia, J.

    1997-01-01

    Cotton aphid ( Aphis gossypii Glover) is the key insect pest of seedling cotton ( Gossypium hirsutum L. ) in China, particularly in the North China cotton region. The resulting annual losses amount to 10-15% of the attainable yield. Sole reliance on

  17. Reciprocal interactions between native and introduced populations of common milkweed, Asclepias syriaca, and the specialist aphid, Aphis nerii

    NARCIS (Netherlands)

    Bukovinszky, T.; Gols, R.; Agrawal, A.A.; Roge, C.; Bezemer, T.M.; Biere, A.; Harvey, J.A.

    2014-01-01

    Following its introduction into Europe (EU), the common milkweed (Asclepias syriaca) has been free of most specialist herbivores that are present in its native North American (NA) range, except for the oleander aphid Aphis nerii. We compared EU and NA populations of A. nerii on EU and NA milkweed po

  18. Reciprocal interactions between native and introduced populations of common milkweed, Asclepias syriaca, and the specialist aphid, Aphis nerii

    NARCIS (Netherlands)

    Bukovinszky, T.; Gols, R.; Agrawal, A.A.; Roge, C.; Bezemer, T.M.; Biere, A.; Harvey, J.A.

    2014-01-01

    Following its introduction into Europe (EU), the common milkweed (Asclepias syriaca) has been free of most specialist herbivores that are present in its native North American (NA) range, except for the oleander aphid Aphis nerii. We compared EU and NA populations of A. nerii on EU and NA milkweed

  19. Microbiome diversity of the soybean aphid (Aphis glycines) with extensive superinfection of Arsenophonus and Wolbachia in native and invasive populations

    Science.gov (United States)

    The interaction among insects and microbes can lead to either symbiotic cooperation which could promote ecological and evolutionary adaptation, or a parasitic relationship through reproductive manipulation. We characterized the microbiome of the soybean aphid (Aphis glycines), with the long-term goa...

  20. THE EFFECT OF WATER EXTRACTS FROM WINTER SAVORY ON BLACK BEAN APHID MORTALITY

    Directory of Open Access Journals (Sweden)

    Milena Rusin

    2016-01-01

    Full Text Available The aim of this study was to determine the effect of water extracts prepared from fresh and dry matter of winter savory (Satureja montana L. on mortality of wingless females and larvae of black bean aphid (Aphis fabae Scop.. The experiment was conducted in the laboratory, in six replicates. Dry extracts were prepared at concentration of 2%, 5% and 10%, while the fresh plant at concentration of 10%, 20% and 30%. Stomach poisoning of extracts was determined by soaking broad bean leaves in the respective solutions, and then determining mortality of wingless female and larvae feeding on leaves thus prepared at 12 hour intervals. The results of the experiment showed that the extract prepared from dry matter at the highest concentration (10%, as well as the extracts from fresh matter at concentration of 20% and 30% contributed to an increase in mortality of wingless female of black bean aphid. Meanwhile, extracts prepared from both dry and fresh matter at two highest concentrations caused an increase in mortality of larvae of this pest. Furthermore, with increasing concentrations of analysed extracts prepared from both fresh and dry matter of winter savory, their negative effect on wingless females and larvae usually increase.

  1. Aboveground feeding by soybean aphid, Aphis glycines, affects soybean cyst nematode, Heterodera glycines, reproduction belowground.

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    Michael T McCarville

    Full Text Available Heterodera glycines is a cyst nematode that causes significant lost soybean yield in the U.S. Recent studies observed the aphid Aphis glycines and H. glycines interacting via their shared host, soybean, Glycine max. A greenhouse experiment was conducted to discern the effect of A. glycines feeding on H. glycines reproduction. An H. glycines-susceptible cultivar, Kenwood 94, and a resistant cultivar, Dekalb 27-52, were grown in H. glycines-infested soil for 30 and 60 d. Ten days after planting, plants were infested with either zero, five, or ten aphids. At 30 and 60 d, the number of H. glycines females and cysts (dead females and the number of eggs within were counted. In general, H. glycines were less abundant on the resistant than the susceptible cultivar, and H. glycines abundance increased from 30 to 60 d. At 30 d, 33% more H. glycines females and eggs were produced on the resistant cultivar in the ten-aphid treatment compared to the zero-aphid treatment. However, at 30 d the susceptible cultivar had 50% fewer H. glycines females and eggs when infested with ten aphids. At 60 d, numbers of H. glycines females and cysts and numbers of eggs on the resistant cultivar were unaffected by A. glycines feeding, while numbers of both were decreased by A. glycines on the susceptible cultivar. These results indicate that A. glycines feeding improves the quality of soybean as a host for H. glycines, but at higher herbivore population densities, this effect is offset by a decrease in resource quantity.

  2. Increased population of the aphid Aphis pomi at a motorway. Part 3. The effect of exhaust gases. [Crataegus spp

    Energy Technology Data Exchange (ETDEWEB)

    Braun, S.; Flueckiger, W.

    1985-01-01

    The effect of motorway air pollution on the infestation of Crataegus spp. by Aphis pomi was examined using chambers with ambient and filtered air. In the chamber with ambient air the aphid population increased to up to 4.4 times the aphid number in the chamber with filtered air. Analysis of a phloem exudate revealed a significant increase in glutamine relative to the sugar content in the plants grown in the polluted air. Some substantial changes in phenolic compounds were also recorded. The results indicate that air pollution around motorways can alter the host plant-parasite relationship to increase the susceptibility of the plant.

  3. Interspecific Associations between Cycloneda sanguinea and Two Aphid Species (Aphis gossypii and Hyadaphis foeniculi) in Sole-Crop and Fennel-Cotton Intercropping Systems

    OpenAIRE

    Francisco S Fernandes; Ramalho, Francisco S.; Malaquias,José B.; Godoy, Wesley A. C.; Santos, Bárbara Davis B.

    2015-01-01

    Aphids cause significant damage to crop plants. Studies regarding predator-prey relationships in fennel (Foeniculum vulgare Mill.) and cotton (Gossypium hirsutum L.) crops are important for understanding essential ecological interactions in the context of intercropping and for establishing pest management programs for aphids. This study evaluated the association among Hyadaphis foeniculi (Passerini) (Hemiptera: Aphididae), Aphis gossypii Glover (Hemiptera: Aphididae) and Cycloneda sanguinea (...

  4. Identification of semiochemicals released by cotton, Gossypium hirsutum, upon infestation by the cotton aphid, Aphis gossypii.

    Science.gov (United States)

    Hegde, Mahabaleshwar; Oliveira, Janser N; da Costa, Joao G; Bleicher, Ervino; Santana, Antonio E G; Bruce, Toby J A; Caulfield, John; Dewhirst, Sarah Y; Woodcock, Christine M; Pickett, John A; Birkett, Michael A

    2011-07-01

    The cotton aphid, Aphis gossypii (Homoptera: Aphididae), is increasing in importance as a pest worldwide since the introduction of Bt-cotton, which controls lepidopteran but not homopteran pests. The chemical ecology of interactions between cotton, Gossypium hirsutum (Malvaceae), A. gossypii, and the predatory lacewing Chrysoperla lucasina (Neuroptera: Chrysopidae), was investigated with a view to providing new pest management strategies. Behavioral tests using a four-arm (Pettersson) olfactometer showed that alate A. gossypii spent significantly more time in the presence of odor from uninfested cotton seedlings compared to clean air, but significantly less time in the presence of odor from A. gossypii infested plants. A. gossypii also spent significantly more time in the presence of headspace samples of volatile organic compounds (VOCs) obtained from uninfested cotton seedlings, but significantly less time with those from A. gossypii infested plants. VOCs from uninfested and A. gossypii infested cotton seedlings were analyzed by gas chromatography (GC) and coupled GC-mass spectrometry (GC-MS), leading to the identification of (Z)-3-hexenyl acetate, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), methyl salicylate, and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene (TMTT), which were produced in larger amounts from A. gossypii infested plants compared to uninfested plants. In behavioral tests, A. gossypii spent significantly more time in the control (solvent) arms when presented with a synthetic blend of these four compounds, with and without the presence of VOCs from uninfested cotton. Coupled GC-electroantennogram (EAG) recordings with the lacewing C. lucasina showed significant antennal responses to VOCs from A. gossypii infested cotton, suggesting they have a role in indirect defense and indicating a likely behavioral role for these compounds for the predator as well as the aphid.

  5. Colonization of the biomass energy crop miscanthus by the three aphid species, Aphis fabae, Myzus persicae, and Rhopalosiphum padi.

    Science.gov (United States)

    Coulette, Q; Couty, A; Lasue, P; Rambaud, Z C; Ameline, A

    2013-04-01

    Miscanthus is a perennial C4-grass that has received much interest as a potential of impact on the local agroecosytem. In this context, laboratory experiments were conducted to investigate the potential colonization of this new exotic plant species by three of the main aphid pest species of common crops in Picardie, northern France. In host preference experiments, the two polyphagous aphid species studied, Aphis fabae (Scop) and Myzus persicae (Sulzer), exhibited an xclusive preference for their host plant, whereas the cereal specialist Rhopalosiphum padi (L.) showed no preference between its host plant and miscanthus. When assessed by electrical penetration graph technique, plant tissue probing activity by all three species always was characterized by pathway phases including potential drops that are typically associated to the transmission of noncirculative viruses. Phloem ingestion was observed in 5% of the polyphagous aphid individuals tested and in 20% of the R. padi tested. Aphids kept in clip-cages on miscanthus had a low survival rate and were unable to reproduce. These results demonstrate that miscanthus is not a suitable host for these three main aphid pest species but could act as a potential host for some viruses transmitted in a noncirculative manner and also in a circulative nonpropagative manner. The use of miscanthus as a barrier crop to limit the flow of aphid vectors and their phytoviruses is discussed.

  6. Characterization of a Chitin Synthase Encoding Gene and Effect of Diflubenzuron in Soybean Aphid, Aphis Glycines

    Directory of Open Access Journals (Sweden)

    Raman Bansal, M. A. Rouf Mian, Omprakash Mittapalli, Andy P. Michel

    2012-01-01

    Full Text Available Chitin synthases are critical enzymes for synthesis of chitin and thus for subsequent growth and development in insects. We identified the cDNA of chitin synthase gene (CHS in Aphis glycines, the soybean aphid, which is a serious pest of soybean. The full-length cDNA of CHS in A. glycines (AyCHS was 5802 bp long with an open reading frame of 4704 bp that encoded for a 1567 amino acid residues protein. The predicted AyCHS protein had a molecular mass of 180.05 kDa and its amino acid sequence contained all the signature motifs (EDR, QRRRW and TWGTR of chitin synthases. The quantitative real-time PCR (qPCR analysis revealed that AyCHS was expressed in all major tissues (gut, fat body and integument; however, it had the highest expression in integument (~3.5 fold compared to gut. Interestingly, the expression of AyCHS in developing embryos was nearly 7 fold higher compared to adult integument, which probably is a reflection of embryonic molts in hemimetabolus insects. Expression analysis in different developmental stages of A. glycines revealed a consistent AyCHS expression in all stages. Further, through leaf dip bioassay, we tested the effect of diflubenzuron (DFB, Dimilin ®, a chitin-synthesis inhibitor, on A. glycines' survival, fecundity and body weight. When fed with soybean leaves previously dipped in 50 ppm DFB solution, A. glycines nymphs suffered significantly higher mortality compared to control. A. glycines nymphs feeding on diflubenzuron treated leaves showed a slightly enhanced expression (1.67 fold of AyCHS compared to nymphs on untreated leaves. We discussed the potential applications of the current study to develop novel management strategies using chitin-synthesis inhibitors and using RNAi by knocking down AyCHS expression.

  7. Peripheral odour perception by adult aphid forms with the same genotype but different host-plant preferences

    NARCIS (Netherlands)

    Hardie, J.; Visser, J.H.; Piron, P.G.M.

    1995-01-01

    As adults, the summer (alate virginopara) and autumn (gynopara) winged forms of the black bean aphid, Aphis fabae, utilise different host plants, the bean Vicia faba, and the spindle tree, Euonymus europaeus, respectively. Electroantennograms (EAGs) were recorded from the antennae of these aphid for

  8. Evidence for an invasive aphid "superclone": extremely low genetic diversity in Oleander aphid (Aphis nerii populations in the southern United States.

    Directory of Open Access Journals (Sweden)

    John Scott Harrison

    Full Text Available BACKGROUND: The importance of genetic diversity in successful biological invasions is unclear. In animals, but not necessarily plants, increased genetic diversity is generally associated with successful colonization and establishment of novel habitats. The Oleander aphid, Aphis nerii, though native to the Mediterranean region, is an invasive pest species throughout much of the world. Feeding primarily on Oleander (Nerium oleander and Milkweed (Asclepias spp. under natural conditions, these plants are unlikely to support aphid populations year round in the southern US. The objective of this study was to describe the genetic variation within and among US populations of A. nerii, during extinction/recolonization events, to better understand the population ecology of this invasive species. METHODOLOGY/PRINCIPAL FINDINGS: We used five microsatellite markers to assess genetic diversity over a two year period within and among three aphid populations separated by small (100 km and large (3,700 km geographic distances on two host plant species. Here we provide evidence for A. nerii "superclones". Genotypic variation was absent in all populations (i.e., each population consisted of a single multilocus genotype (MLG or "clone" and the genetic composition of only one population completely changed across years. There was no evidence of sexual reproduction or host races on different plant species. CONCLUSIONS/SIGNIFICANCE: Aphis nerii is a well established invasive species despite having extremely low genetic diversity. As this aphid appears to be obligatorily asexual, it may share more similarities with clonally reproducing invasive plants, than with other animals. Patterns of temporal and geographic genetic variation, viewed in the context of its population dynamics, have important implications for the management of invasive pests and the evolutionary biology of asexual species.

  9. The endosymbiont Arsenophonus is widespread in soybean aphid, Aphis glycines, but does not provide protection from parasitoids or a fungal pathogen.

    Directory of Open Access Journals (Sweden)

    Jason A Wulff

    Full Text Available Aphids commonly harbor bacterial facultative symbionts that have a variety of effects upon their aphid hosts, including defense against hymenopteran parasitoids and fungal pathogens. The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae, is infected with the symbiont Arsenophonus sp., which has an unknown role in its aphid host. Our research goals were to document the infection frequency and diversity of the symbiont in field-collected soybean aphids, and to determine whether Arsenophonus is defending soybean aphid against natural enemies. We performed diagnostic PCR and sequenced four Arsenophonus genes in soybean aphids from their native and introduced range to estimate infection frequency and genetic diversity, and found that Arsenophonus infection is highly prevalent and genetically uniform. To evaluate the defensive role of Arsenophonus, we cured two aphid genotypes of their natural Arsenophonus infection through ampicillin microinjection, resulting in infected and uninfected isolines within the same genetic background. These isolines were subjected to parasitoid assays using a recently introduced biological control agent, Binodoxys communis [Braconidae], a naturally recruited parasitoid, Aphelinus certus [Aphelinidae], and a commercially available biological control agent, Aphidius colemani [Braconidae]. We also assayed the effect of the common aphid fungal pathogen, Pandora neoaphidis (Remaudiere & Hennebert Humber (Entomophthorales: Entomophthoraceae, on the same aphid isolines. We did not find differences in successful parasitism for any of the parasitoid species, nor did we find differences in P. neoaphidis infection between our treatments. Our conclusion is that Arsenophonus does not defend its soybean aphid host against these major parasitoid and fungal natural enemies.

  10. APHiD: Hierarchical Task Placement to Enable a Tapered Fat Tree Topology for Lower Power and Cost in HPC Networks

    Energy Technology Data Exchange (ETDEWEB)

    Michelogiannakis, George; Ibrahim, Khaled Z.; Shalf, John; Wilke, Jeremiah J.; Knight, Samuel; Kenny, Joseph P.

    2017-05-14

    The power and procurement cost of bandwidth in system-wide networks has forced a steady drop in the byte/flop ratio. This trend of computation becoming faster relative to the network is expected to hold. In this paper, we explore how cost-oriented task placement enables reducing the cost of system-wide networks by enabling high performance even on tapered topologies where more bandwidth is provisioned at lower levels. We describe APHiD, an efficient hierarchical placement algorithm that uses new techniques to improve the quality of heuristic solutions and reduces the demand on high-level, expensive bandwidth in hierarchical topologies. We apply APHiD to a tapered fat-tree, demonstrating that APHiD maintains application scalability even for severely tapered network configurations. Using simulation, we show that for tapered networks APHiD improves performance by more than 50% over random placement and even 15% in some cases over costlier, state-of-the-art placement algorithms.

  11. Comparative efficacy of emulsifiable-oil, wettable-powder, and unformulated-powder preparations of Beauveria bassiana against the melon aphid Aphis gossypii

    Science.gov (United States)

    Aphicidal efficacy of two commercial formulations of Beauveria bassiana strain GHA conidia, an emulsifiable-paraffinic oil dispersion (OD) and a clay-based wettable powder (WP), were compared to unformulated conidia in laboratory tests with adult melon aphids (Aphis gossypii). For the initial 24 hou...

  12. The role of detoxifying enzymes in the resistance of the cowpea aphid (Aphis craccivora Koch to thiamethoxam

    Directory of Open Access Journals (Sweden)

    Abdallah Ibrahim Saleh

    2016-01-01

    Full Text Available The cowpea aphid (Aphis craccivora Koch is considered a serious insect pest attacking several crops. We carried out biochemical studies to elucidate the role of the metabolising enzymes in conferring resistance to thiamethoxam, in two strains (resistant and susceptible of the cowpea aphid. Bioassay experiments showed that the thiamethoxam selected strain developed a 48 fold resistance after consecutive selection with thiamethoxam for 12 generations. This resistant strain also exhibited cross-resistance to the tested carbamates; pirimicarb and carbosulfan, organophosphorus (malathion, fenitrothion, and chlorpyrifos-methyl, and the neonicotinoid (acetamiprid. Synergism studies have indicated that S,S,S-tributyl phosphorotrithioate (DEF, a known inhibitor for esterases, increased thiamethoxam toxicity 5.58 times in the resistant strain compared with the susceptible strain. Moreover, the biochemical determination revealed that carboxylestersae activity was 30 times greater in the resistant strain than in the susceptible strain. In addition, the enzyme activity of glutathione S-transferase (GST and mixed function oxidases (mfo increased only in the resistant strain 3.7 and 2.7 times, respectively, in relation to the susceptible (the control. Generally, our results suggest that the higher activity of the detoxifying enzymes, particularly carboxylesterase, in the resistant strain of the cowpea aphid, apparently have a significant role in endowing resistance to thiamethoxam, although additional mechanisms may contribute.

  13. Host races of the cotton aphid, Aphis gossypii, in asexual populations from wild plants of taro and brinjal.

    Science.gov (United States)

    Agarwala, B K; Choudhury, Parichita Ray

    2013-01-01

    Worldwide, several studies have shown that adaptation to different host plants in phytophagous insects can promote speciation. The cotton aphid, Aphis gossypii Glover (Homoptera: Aphididae: Aphidini), is a highly polyphagous species, but its populations increase by parthenogenetic reproduction alone in Indian subcontinent. This study showed that genotypes living in wild plants of taro, Colocasia esculenta var. esculenta (L.) Schott (Alismatales: Araceae), and brinjal, Solanum torvum Swartz (Solanales: Solanaceae), behave as distinct host races. Success rates of colonization after reciprocal host transfers were very poor. Clones of A. gossypii from wild taro partly survived in the first generation when transferred to wild brinjal, but nymph mortality was 100% in the second generation. In contrast, brinjal clones, when transferred to taro, could not survive even in the first generation. Significant differences between the clones from two host species were also recorded in development time, generation time, fecundity, intrinsic rate of increase, net reproductive rate, and mean relative growth rate. Morphologically, aphids of wild taro clones possessed longer proboscis and fore-femora than the aphids of the brinjal clones. The results showed that A. gossypii exists as distinct host races with different abilities of colonizing host plants, and its populations appear to have more potential of sympatic evolution than previously regarded.

  14. Identification of novel resistance gene sources to cowpea aphid (Aphis craccivora Koch) in cowpea (Vigna unguiculata L.).

    Science.gov (United States)

    Aliyu, H; Ishiyaku, M F

    2013-08-01

    The development of cowpea aphid larvae was monitored on seven cowpea genotypes (IAR-48, TVu-15866, IT84S-2246-4, SAKA BABBA SATA, IT90K-76, KANANNADO and TVX 3236). The aim of the study was to determine the developmental response of the larvae as an indication of antibiotic resistance of the genotypes. Highly significant differences (p < 0.01) were observed with respect to fertility, larval development, adult longevity, life span, multiplication rate and intrinsic rate of increase. KANANNADO and TVX 3236 show minimum antibiotic effects while a landrace SAKA BABBA SATA shows relatively high antibiotic effects. This result further reveals the potential of SAKA BABBA SATA as a resistance source to aphid. The reaction of IT84S-2246-4, a hitherto aphid resistant genotype, which supported higher levels of survival of the larvae relative to other known susceptible genotype IAR-48, may be an indication of the presence of a new biotype of Aphis craccivora endemic to Zaria environs, or that of the ability of insects to overcome hindrances to their survival including various forms of resistance.

  15. The effect of host plants on genotype variability in fitness and honeydew composition of Aphis fabae.

    Science.gov (United States)

    Schillewaert, Sharon; Vantaux, Amélie; Van den Ende, Wim; Wenseleers, Tom

    2016-05-26

    Aphid species can be polyphagous, feeding on multiple host plants across genera. As host plant species can have large variation in their phloem composition, this can affect aphid fitness and honeydew composition. Previous research showed significant intraspecific genotype variation in the composition of the honeydew carbohydrates of the black bean aphid Aphis fabae, with the ant attractant trisaccharide melezitose showing especially large variation across different genotypes. In this study, we test if variation in melezitose and carbohydrate composition of aphid honeydew could be linked to the adaptation of specific aphid genotypes to particular host plants. To this end, 4 high and 5 low melezitose secreting genotypes of the black bean aphid Aphis fabae were reared on 4 common host plants: broad bean, goosefoot, beet, and poppy. The carbohydrate composition, and in particular melezitose secretion, showed important aphid genotype and host plant interactions, with some genotypes being high melezitose secreting on 1 host plant but not on another. However, the interaction effects were not paralleled in the fitness measurements, even though there were significant differences in the average fitness across the different host plants. On the whole, this study demonstrates that aphid honeydew composition is influenced by complex herbivore-plant interactions. We discuss the relevance of these findings in the context of ant-aphid mutualisms and adaptive specialization in aphids. © 2016 Institute of Zoology, Chinese Academy of Sciences.

  16. Effects on the non-target aphid Aphis Gossypii Glover (Homoptera ...

    African Journals Online (AJOL)

    bych76-zhjh77

    2012-05-22

    May 22, 2012 ... studies comparing aphid populations in Bt and non-Bt cotton fields gave ..... reported that Bt maize affected the development, reproduction and intrinsic .... Global Status of Commercialized Biotech/GM Crops: 2011. ISAAA Brief ...

  17. Genetic variation and phylogeographic structure of the cotton aphid, Aphis gossypii, based on mitochondrial DNA and microsatellite markers.

    Science.gov (United States)

    Wang, Xing-Ya; Yang, Xian-Ming; Lu, Bin; Zhou, Li-Hong; Wu, Kong-Ming

    2017-05-15

    Aphis gossypii, one of the most important agricultural pests in the world, can cause serious economic losses in the main crop-producing areas. To clarify issues such as the genetic differentiation, genetic structure, and demographic history of A. gossypii populations, we used 10 nuclear microsatellite loci (SSR) and two mitochondrial gene sequences (COI and Cytb) to investigate genetic diversity and population structure of A. gossypii populations that were collected from 33 sampling sites in China from different climatic zones. SSR and mtDNA data suggested low to moderate levels of genetic diversity. A star-shaped network of mtDNA haplotypes indicated that the maternal ancestor of China cotton aphids likely originated in Xinjiang. The POPTREE, STRUCTURE and principal coordinate analysis (PCoA) revealed two genetic clusters: an eastern and a western region group. Isolation by distance (IBD) results showed a positive correlation between geographic distance and genetic distance in the vast eastern region but not in the western region. Neutrality testing and mismatch distribution analysis provided strong evidence for a recent rapid expansion in most populations. Genetic bottleneck was not detected in A. gossypii populations of China. The present work can help us to develop strategies for managing this pest.

  18. Identification and expression profiling of odorant binding proteins and chemosensory proteins between two wingless morphs and a winged morph of the cotton aphid Aphis gossypii glover.

    Directory of Open Access Journals (Sweden)

    Shao-Hua Gu

    Full Text Available Insects interact with their environment and respond to the changes in host plant conditions using semiochemicals. Such ecological interactions are facilitated by the olfactory sensilla and the use of olfactory recognition proteins. The cotton aphid Aphis gossypii can change its phenotype in response to ecological conditions. They reproduce mainly as wingless asexual morphs but develop wings to find mates or new plant hosts under the influence of environmental factors such as temperature, plant nutrition and population density. Two groups of small soluble proteins, odorant binding proteins (OBPs and chemosensory proteins (CSPs are believed to be involved in the initial biochemical recognition steps in semiochemical perception. However, the exact molecular roles that these proteins play in insect olfaction remain to be discovered. In this study, we compared the transcriptomes of three asexual developmental stages (wingless spring and summer morphs and winged adults and characterised 9 OBP and 9 CSP genes. The gene structure analysis showed that the number and length of introns in these genes are much higher and this appears to be unique feature of aphid OBP and CSP genes in general. Another unique feature in aphids is a higher abundance of CSP transcripts than OBP transcripts, suggesting an important role of CSPs in aphid physiology and ecology. We showed that some of the transcripts are overexpressed in the antennae in comparison to the bodies and highly expressed in the winged aphids compared to wingless morphs, suggesting a role in host location. We examined the differential expression of these olfactory genes in ten aphid species and compared the expression profile with the RNA-seq analyses of 25 pea aphid transcriptome libraries hosted on AphidBase.

  19. Identification and Expression Profiling of Odorant Binding Proteins and Chemosensory Proteins between Two Wingless Morphs and a Winged Morph of the Cotton Aphid Aphis gossypii Glover

    Science.gov (United States)

    Gu, Shao-Hua; Wu, Kong-Ming; Guo, Yu-Yuan; Field, Linda M.; Pickett, John A.; Zhang, Yong-Jun; Zhou, Jing-Jiang

    2013-01-01

    Insects interact with their environment and respond to the changes in host plant conditions using semiochemicals. Such ecological interactions are facilitated by the olfactory sensilla and the use of olfactory recognition proteins. The cotton aphid Aphis gossypii can change its phenotype in response to ecological conditions. They reproduce mainly as wingless asexual morphs but develop wings to find mates or new plant hosts under the influence of environmental factors such as temperature, plant nutrition and population density. Two groups of small soluble proteins, odorant binding proteins (OBPs) and chemosensory proteins (CSPs) are believed to be involved in the initial biochemical recognition steps in semiochemical perception. However, the exact molecular roles that these proteins play in insect olfaction remain to be discovered. In this study, we compared the transcriptomes of three asexual developmental stages (wingless spring and summer morphs and winged adults) and characterised 9 OBP and 9 CSP genes. The gene structure analysis showed that the number and length of introns in these genes are much higher and this appears to be unique feature of aphid OBP and CSP genes in general. Another unique feature in aphids is a higher abundance of CSP transcripts than OBP transcripts, suggesting an important role of CSPs in aphid physiology and ecology. We showed that some of the transcripts are overexpressed in the antennae in comparison to the bodies and highly expressed in the winged aphids compared to wingless morphs, suggesting a role in host location. We examined the differential expression of these olfactory genes in ten aphid species and compared the expression profile with the RNA-seq analyses of 25 pea aphid transcriptome libraries hosted on AphidBase. PMID:24073197

  20. Oral delivery mediated RNA interference of a carboxylesterase gene results in reduced resistance to organophosphorus insecticides in the cotton Aphid, Aphis gossypii Glover.

    Directory of Open Access Journals (Sweden)

    You-Hui Gong

    Full Text Available BACKGROUND: RNA interference (RNAi is an effective tool to examine the function of individual genes. Carboxylesterases (CarE, EC 3.1.1.1 are known to play significant roles in the metabolism of xenobiotic compounds in many insect species. Previous studies in our laboratory found that CarE expression was up-regulated in Aphis gossypii (Glover (Hemiptera: Aphididae adults of both omethoate and malathion resistant strains, indicating the potential involvement of CarE in organophosphorus (OP insecticide resistance. Functional analysis (RNAi is therefore warranted to investigate the role of CarE in A. gossypii to OPs resistance. RESULT: CarE expression in omethoate resistant individuals of Aphis gossypii was dramatically suppressed following ingestion of dsRNA-CarE. The highest knockdown efficiency (33% was observed at 72 h after feeding when dsRNA-CarE concentration was 100 ng/µL. The CarE activities from the CarE knockdown aphids were consistent with the correspondingly significant reduction in CarE expression. The CarE activity in the individuals of control aphids was concentrated in the range of 650-900 mOD/per/min, while in the individuals of dsRNA-CarE-fed aphids, the CarE activity was concentrated in the range of 500-800 mOD/per/min. In vitro inhibition experiments also demonstrated that total CarE activity in the CarE knockdown aphids decreased significantly as compared to control aphids. Bioassay results of aphids fed dsRNA-CarE indicated that suppression of CarE expression increased susceptibility to omethoate in individuals of the resistant aphid strains. CONCLUSION: The results of this study not only suggest that ingestion of dsRNA through artificial diet could be exploited for functional genomic studies in cotton aphids, but also indicate that CarE can be considered as a major target of organophosphorus insecticide (OPs resistance in A. gossypii. Further, our results suggest that the CarE would be a propitious target for OPs resistant

  1. Interspecific Associations between Cycloneda sanguinea and Two Aphid Species (Aphis gossypii and Hyadaphis foeniculi) in Sole-Crop and Fennel-Cotton Intercropping Systems.

    Science.gov (United States)

    Fernandes, Francisco S; Ramalho, Francisco S; Malaquias, José B; Godoy, Wesley A C; Santos, Bárbara Davis B

    2015-01-01

    Aphids cause significant damage to crop plants. Studies regarding predator-prey relationships in fennel (Foeniculum vulgare Mill.) and cotton (Gossypium hirsutum L.) crops are important for understanding essential ecological interactions in the context of intercropping and for establishing pest management programs for aphids. This study evaluated the association among Hyadaphis foeniculi (Passerini) (Hemiptera: Aphididae), Aphis gossypii Glover (Hemiptera: Aphididae) and Cycloneda sanguinea (L.) (Coleoptera: Coccinellidae) in cotton with coloured fibres, fennel and cotton intercropped with fennel. Association analysis was used to investigate whether the presence or absence of prey and predator species can indicate possible interactions between aphids and ladybugs. Significant associations among both apterous and alate H. foeniculi and C. sanguinea were observed in both the fennel and fennel-cotton intercropping systems. The similarity analysis showed that the presence of aphids and ladybugs in the same system is significantly dependent on the type of crop. A substantial amount of evidence indicates that the presence of the ladybug C. sanguinea, is associated with apterous or alate A. gossypii and H. foeniculi in fennel-cotton intercropping system. We recommend that future research vising integrated aphid management taking into account these associations for take decisions.

  2. Pathogenicity of conidia-based preparations of entomopathogenic fungi against the greenhouse pest aphids Myzus persicae, Aphis gossypii, and Aulacorthum solani (Hemiptera: Aphididae).

    Science.gov (United States)

    Jandricic, S E; Filotas, M; Sanderson, J P; Wraight, S P

    2014-05-01

    Seeking new isolates of entomopathogenic fungi with greater virulence against greenhouse aphid pests than those currently registered in North America for control of these insects, single-dose screening assays of 44 selected fungal isolates and 4 commercially available strains were conducted against first-instar nymphs of Myzus persicae and Aphis gossypii. The assays identified a number of Beauveria and Metarhizium isolates with virulence equal to or greater than that of the commercial strains against the nymphal aphids, but none exhibited exceptionally high virulence. Virulence of Isaria isolates was unexpectedly low (1000conidia/mm(2)). In dose-response assays, Beauveria ARSEF 5493 proved most virulent against M. persicae and A. gossypii; however, LC50s of this isolate did not differ significantly from those of B. bassiana commercial strain JW-1. Dose-response assays were also conducted with Aulacorthum solani, the first reported evaluations of Beauveria and Metarhizium against this pest. The novel isolate Metarhizium 5471 showed virulence⩾that of Beauveria 5493 in terms of LC25 and LC50, but 5493 produced a steeper dose response (slope). Additional tests showed that adult aphids are more susceptible than nymphs to fungal infection but confirmed that infection has a limited pre-mortem effect on aphid reproduction. Effects of assay techniques and the potential of fungal pathogens as aphid-control agents are discussed.

  3. Interspecific Associations between Cycloneda sanguinea and Two Aphid Species (Aphis gossypii and Hyadaphis foeniculi in Sole-Crop and Fennel-Cotton Intercropping Systems.

    Directory of Open Access Journals (Sweden)

    Francisco S Fernandes

    Full Text Available Aphids cause significant damage to crop plants. Studies regarding predator-prey relationships in fennel (Foeniculum vulgare Mill. and cotton (Gossypium hirsutum L. crops are important for understanding essential ecological interactions in the context of intercropping and for establishing pest management programs for aphids. This study evaluated the association among Hyadaphis foeniculi (Passerini (Hemiptera: Aphididae, Aphis gossypii Glover (Hemiptera: Aphididae and Cycloneda sanguinea (L. (Coleoptera: Coccinellidae in cotton with coloured fibres, fennel and cotton intercropped with fennel. Association analysis was used to investigate whether the presence or absence of prey and predator species can indicate possible interactions between aphids and ladybugs. Significant associations among both apterous and alate H. foeniculi and C. sanguinea were observed in both the fennel and fennel-cotton intercropping systems. The similarity analysis showed that the presence of aphids and ladybugs in the same system is significantly dependent on the type of crop. A substantial amount of evidence indicates that the presence of the ladybug C. sanguinea, is associated with apterous or alate A. gossypii and H. foeniculi in fennel-cotton intercropping system. We recommend that future research vising integrated aphid management taking into account these associations for take decisions.

  4. Multiple Mutations on the Second Acetylcholinesterase Gene Associated With Dimethoate Resistance in the Melon Aphid, Aphis gossypii (Hemiptera: Aphididae).

    Science.gov (United States)

    Lokeshwari, D; Krishna Kumar, N K; Manjunatha, H

    2016-04-01

    The melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is an important cosmopolitan and extremely polyphagous species capable of causing direct and indirect damage to various crops. Insecticide resistance in melon aphids is of particular concern. To determine the basis of resistance, organophosphate (OP)-resistant strains of A. gossypii were obtained by continuous selection with dimethoate in the laboratory, and resistance mechanisms were investigated along with susceptible strains. Three resistant strains LKR-1, LKR-2, and LKR-3 exhibiting 270-, 243-, and 210-fold resistance obtained after 30 generations of selection with dimethoate, respectively, were utilized in this study. The role of acetylcholinesterase (AChE), a target enzyme for OPs and carbamates (CMs), was investigated. AChE enzyme assay revealed that there was no significant change in the activities of AChE in resistant and susceptible strains. However, AChE inhibitory assay showed that 50% of the enzyme activity in resistant strains was inhibited at significantly higher concentration of dimethoate (131.87, 158.65, and 99.29 µmolL(−1)) as compared with susceptible strains (1.75 and 2.01 µmolL(−1)), indicating AChE insensitivity owing to altered AChE. Molecular diagnostic tool polymerase chain reaction-restriction fragment length polymorphism revealed the existence of two consistent non-synonymous point mutations, single-nucleotide polymorphism, viz., A302S (equivalent to A201 in Torpedo californica Ayres) and S431F (equivalent to F331 in T. californica), in the AChE gene Ace2 of resistant strains. Further, cloning and sequencing of a partial fragment of Ace2 (897 bp) gene from susceptible and resistant strains revealed an additional novel mutation G221A in resistant strains, LKR-1 and LKR-2. Susceptible Ace2 genes shared 99.6 and 98.9% identity at the nucleic acid and amino acid levels with resistant ones, respectively. Functional analysis of these point mutations was assessed by in

  5. Development of controlled release formulations of carbofuran and imidacloprid and their bioefficacy evaluation against aphid, Aphis gossypii and leafhopper, Amrasca biguttula biguttula Ishida on potato crop.

    Science.gov (United States)

    Kumar, Jitendra; Shakil, N A; Khan, M A; Malik, Kamlesh; Walia, Suresh

    2011-01-01

    Controlled release (CR) formulations of carbofuran and imidacloprid were prepared employing polyvinyl chloride and carboxymethyl cellulose (CMC) and their bioefficacy was evaluated against the aphid, Aphis gossypii and leafhopper, Amrasca biguttula biguttula Ishida on potato crop. The CR formulations of carbofuran and imidacloprid provided better or equal control of the pests than commercial formulations. CMC-based formulation provided a superior control of both the pests. The Imida-CMC, which showed the lowest population of leaf hopper (10.50 leafhopper/100 cl), provided significantly superior control among all treatments after 35 days after germination (DAG). The residue of carbofuran and imidacloprid in potato tuber and soils were not detectable at the time of harvesting in any one of the formulations.

  6. A Study of Blackfly (Aphis fabae Scop.) on Broad Bean plants, and of Insects Associated Directly or Indirectly with the Colony

    Science.gov (United States)

    Backhouse, Mary

    1972-01-01

    Describes the results of a study of the ecology of the bean plant/aphid/ant/associated insects/fungi system and suggests a series of experiments that secondary school students could undertake by observing or manipulating this system. (Species recorded are British) (AL)

  7. 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.

  8. Interactions between extrafloral nectaries, aphids and ants: are there competition effects between plant and homopteran sugar sources?

    NARCIS (Netherlands)

    Engel, V.; Fischer, M.D.; Wäckers, F.L.; Volkl, W.

    2001-01-01

    Broad bean (Vicia faba), an annual plant bearing extrafloral nectaries (EFN) at the base of the upper leaves, is regularly infested by two aphid species, Aphis fabae and Acyrthosiphon pisum. EFN and A. fabae are commonly attended by the ant, Lasius niger, while Ac. pisum usually remains uninfested.

  9. Cloning of Partial Sodium Channel Gene From Strains of Fenvalerate-Resistant and Susceptible Cotton Aphid(Aphis gossypii Glover)

    Institute of Scientific and Technical Information of China (English)

    SUN Lu-juan; GAO Xi-wu; ZHENG Bing-zong

    2003-01-01

    The strain of fenvalerate-resistant cotton aphids was selected using fenvalerate insecticide in the laboratory, the resistance factor of the strain was 199.54. Three degenerate primers were designed and used to perform PCR amplification. A cDNA encoding partial sodium channel gene was cloned from the fenvalerate-resistant and -susceptible strains. There were two nucleotide acid differences between fenvalerate-resistant strain and -susceptible strain, resulting in an amino acid mutation, Met→Leu. It is predicted that the mutation is related to the cotton aphid resistance to fenvalerate.

  10. The Joint Action of Destruxins and Botanical Insecticides (Rotenone, Azadirachtin and Paeonolum Against the Cotton Aphid, Aphis gossypii Glover

    Directory of Open Access Journals (Sweden)

    Meiying Hu

    2012-06-01

    Full Text Available The joint action of destruxins and three botanical insecticides, rotenone (Rot, azadirachtin (Aza and paeonolum (Pae against the cotton aphid, Aphis gossypii, was bioassayed. In laboratory experiment, several synergistic groups of destruxins with botanical insecticides were found by means of Sun’s Co-toxicity Coefficients (CTC and Finney’s Synergistic Coefficient (SC. The best synergistic effect was discovered in the ratio group Des/Rot 1/9 with the CTC or SC and LC50 values of 479.93 or 4.8 and 0.06 μg/mL, respectively. The second and third synergistic effects were recorded in the ratio groups Des/Rot 7/3 and 9/1. Although the ratio groups Des/Aza 6/4, Des/Pae 4/6, 3/7 and 2/8 indicated synergism by Sun’s CTC, they were determined as additive actions by Finney’s SC. Additive actions were also found in most of the ratio groups, but antagonism were recorded only in three ratio groups: Des/Pae 9/1, 7/3 and 6/4. In greenhouse tests, the highest mortality was 98.9% with the treatment Des/Rot 1/9 at 0.60 μg/mL, meanwhile, the treatments Des/Pae 4/6 and Des/Aza 6/4 had approximately 88% mortality.

  11. Increasing phosphorus supply is not the mechanism by which arbuscular mycorrhiza increase attractiveness of bean (Vicia faba) to aphids.

    Science.gov (United States)

    Babikova, Zdenka; Gilbert, Lucy; Randall, Kate C; Bruce, Toby J A; Pickett, John A; Johnson, David

    2014-10-01

    Arbuscular mycorrhizal (AM) fungi, important plant mutualists, provide plants with nutrients such as phosphorus (P) in return for carbon. AM fungi also enhance the attractiveness of plants to aphids via effects on emissions of plant volatiles used in aphid host location. We tested whether increased P uptake by plants is the mechanism through which AM fungi alter the volatile profile of plants and aphid behavioural responses by manipulating the availability of P and AM fungi to broad beans (Vicia faba L.) in a multi-factorial design. If AM fungi affect plant volatiles only via increased P acquisition, we predicted that the emission of volatiles and the attractiveness of mycorrhizal beans to aphids would be similar to those of non-mycorrhizal beans supplied with additional P. AM fungi and P addition increased leaf P concentrations by 40 and 24%, respectively. The production of naphthalene was less in mycorrhizal plants, regardless of P addition. By contrast, production of (S)-linalool, (E)-caryophyllene and (R)-germacrene D was less in plants colonized by AM fungi but only in the absence of P additions. The attractiveness of plants to pea aphids (Acyrthosiphon pisum Harris) was positively affected by AM fungi and correlated with the extent of root colonization; however, attractiveness was neither affected by P treatment nor correlated with leaf P concentration. These findings suggest that increased P uptake is not the main mechanism by which mycorrhiza increase the attractiveness of plants to aphids. Instead, the mechanism is likely to operate via AM fungi-induced plant systemic signalling. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  12. Increasing phosphorus supply is not the mechanism by which arbuscular mycorrhiza increase attractiveness of bean (Vicia faba) to aphids

    Science.gov (United States)

    Babikova, Zdenka; Gilbert, Lucy; Randall, Kate C.; Bruce, Toby J. A.; Pickett, John A.; Johnson, David

    2014-01-01

    Arbuscular mycorrhizal (AM) fungi, important plant mutualists, provide plants with nutrients such as phosphorus (P) in return for carbon. AM fungi also enhance the attractiveness of plants to aphids via effects on emissions of plant volatiles used in aphid host location. We tested whether increased P uptake by plants is the mechanism through which AM fungi alter the volatile profile of plants and aphid behavioural responses by manipulating the availability of P and AM fungi to broad beans (Vicia faba L.) in a multi-factorial design. If AM fungi affect plant volatiles only via increased P acquisition, we predicted that the emission of volatiles and the attractiveness of mycorrhizal beans to aphids would be similar to those of non-mycorrhizal beans supplied with additional P. AM fungi and P addition increased leaf P concentrations by 40 and 24%, respectively. The production of naphthalene was less in mycorrhizal plants, regardless of P addition. By contrast, production of (S)-linalool, (E)-caryophyllene and (R)-germacrene D was less in plants colonized by AM fungi but only in the absence of P additions. The attractiveness of plants to pea aphids (Acyrthosiphon pisum Harris) was positively affected by AM fungi and correlated with the extent of root colonization; however, attractiveness was neither affected by P treatment nor correlated with leaf P concentration. These findings suggest that increased P uptake is not the main mechanism by which mycorrhiza increase the attractiveness of plants to aphids. Instead, the mechanism is likely to operate via AM fungi-induced plant systemic signalling. PMID:25200735

  13. Cycloxaprid: A novel cis-nitromethylene neonicotinoid insecticide to control imidacloprid-resistant cotton aphid (Aphis gossypii).

    Science.gov (United States)

    Cui, Li; Qi, Haoliang; Yang, Daibin; Yuan, Huizhu; Rui, Changhui

    2016-09-01

    Imidacloprid is a nicotinic acetylcholine receptor (nAChR) agonist with potent insecticidal activity. However, resistance to imidacloprid is a significant threat and has been identified in several pest species. Cycloxaprid with cis-configuration is a novel neonicotinoid insecticide, which shows high activity against imidacloprid-resistant pests. The LC50 of imidacloprid against the resistant Aphis gossypii was 14.33mgL(-1) while it was only 0.70mgL(-1) for the susceptible population, giving a resistance ratio of 20.47. In this imidacloprid-resistant population, a point mutation (R81T) located in the loop D region of the nAChR β1 subunit was found out. But this point mutation did not decrease the activity of cycloxaprid against A. gossypii. The LC50 of cycloxaprid was 1.05 and 1.36mgL(-1) for the imidacloprid-susceptible and imidacloprid-resistant populations, respectively. In addition, cycloxaprid provided better efficacies against resistant A. gossypii than imidacloprid in the fields. Although cycloxaprid was highly toxic to A. gossypii, it showed high selective activity between A. gossypii and its predominant natural enemies, Harmonia axyridis and Chrysoperla sinica. These results demonstrate that cycloxaprid is a promising insecticide against imidacloprid-resistant A. gossypii and suitable for the integrated pest management.

  14. Reliable screening technique for evaluation of wild crucifers against mustard aphid Lipaphis erysimi (Kalt.).

    Science.gov (United States)

    Singh, S P; Kumar, Sandeep; Singh, Y P; Singh, Ram

    2014-12-01

    Wild crucifers namely Arabidopsis thaliana, Brassica fruticulosa, B. rugosa, B. spinescens, B. tournefortii, Camelina sativa, Capsella bursa-pastoris, Crambe abysinnica, Cronopus didymus, Diplotaxis assurgens, D. gomez-campoi, D. muralis, D. siettiana, D. tenuisiliqua, Enatharocarpus lyratus, Lepidium sativum and Sinapis alba along with five cultivated Brassica species including B. rapa (BSH-1), B. juncea (Rohini), B. napus (GSC-6), B. carinata (DLSC-2) and Eruca sativa (T-27) were screened against mustard aphid Lipaphis erysimi (Kalt.) with a standardized technique under definite level of aphid pressure developed using specially designed cages. Observations have revealed that B. fruticulosa, B. spinescens, Camelina sativa, Crambe abysinnica and Lepidium sativum were resistant to mustard aphid L. erysimi with aphid infestation index (AII) ≤ 1. Capsella bursa-pastoris was highly susceptible to bean aphid, Aphis fabae during its vegetative stage (with 100% mortality). Other genotypes were found in the range of 'susceptible' to 'highly susceptible' with AII ranging 3-5.

  15. Biologia de aphis gossypii em plantas infectadas pelo vírus do mosaico das nervuras do algodoeiro Biology Of cotton aphid on plants infected by cotton vein mosaic virus

    Directory of Open Access Journals (Sweden)

    Marcos Doniseti Michelotto

    2009-01-01

    Full Text Available O objetivo deste trabalho foi avaliar a biologia do pulgão-do-algodoeiro, Aphis gossypii Glover (Hemiptera: Aphididae, em plantas de algodoeiro (Gossypium hirsutum L. sadias e infectadas com o vírus causador do mosaico das nervuras. O experimento foi realizado em câmara climatizada mantida a 25±1 ºC, umidade relativa de 70±10% e fotofase de 12 horas. Os dois tratamentos corresponderam a pulgões que se alimentaram de plantas sadias e infectadas com o vírus. As unidades experimentais consistiram de placas de Petri contendo ágar-água a 1% solidificado e um disco foliar de plantas sadias ou infectadas, com 30 repetições cada uma. Os pulgões que se alimentaram de plantas infectadas tiveram menor duração da fase ninfal (4,5 dias em relação àqueles que se alimentaram de plantas sadias (4,9 dias. Os períodos pré-reprodutivo, reprodutivo e pós-reprodutivo e a longevidade não foram influenciados pelo vírus. A maior mortalidade também foi observada em pulgões alimentados com plantas infectadas. O tempo decorrido entre gerações (T e o tempo necessário para duplicar em número (TD foram menores para pulgões que se alimentaram de plantas infectadas (9,74 e 1,66 dias respectivamente, as quais também acarretaram maior mortalidade ninfal. A taxa líquida de reprodução (Ro, a capacidade inata de aumentar em número (r m e a razão finita de aumento (λ foram favoráveis aos pulgões que se alimentaram de folhas de algodoeiro infectadas. Conclui-se que os pulgões mantidos em folhas de algodoeiro sadias atingiram melhores índices de desenvolvimento enquanto na reprodução os melhores índices são observados em pulgões mantidos em folhas infectadas.The objective of this work was to study the biology of cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae on cotton plants (Gossypium hirsutum L. healthy and infected by cotton vein mosaic virus. The assay was performed in climatic chambers at 25±1ºC, under relative humidity

  16. Identification of Aphis gossypii Glover (Hemiptera: Aphididae Biotypes from Different Host Plants in North China.

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    Li Wang

    Full Text Available The cotton-melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae, is a polyphagous species with a worldwide distribution and a variety of biotypes. North China is a traditional agricultural area with abundant winter and summer hosts of A. gossypii. While the life cycles of A. gossypii on different plants have been well studied, those of the biotypes of North China are still unclear.Host transfer experiments showed that A. gossypii from North China has two host-specialized biotypes: cotton and cucumber. Based on complete mitochondrial sequences, we identified a molecular marker with five single-nucleotide polymorphisms to distinguish the biotypes. Using this marker, a large-scale study of biotypes on primary winter and summer hosts was conducted. All A. gossypii collected from three primary hosts-hibiscus, pomegranate, and Chinese prickly ash-were cotton biotypes, with more cotton-melon aphids found on hibiscus than the other two species. In May, alate cotton and cucumber biotypes coexisted on cotton and cucumber seedlings, but each preferred its natal host. Both biotypes existed on zucchini, although the cucumber biotype was more numerous. Aphids on muskmelon were all cucumber biotypes, whereas most aphids on kidney bean were cotton biotypes. Aphids on seedlings of potato and cowpea belong to other species. In August, aphids on cotton and cucumber were the respective biotypes, with zucchini still hosting both biotypes as before. Thus, the biotypes had different fitnesses on different host plants.Two host-specialized biotypes (cotton and cucumber are present in North China. Hibiscus, pomegranate, and Chinese prickly ash can serve as winter hosts for the cotton biotype but not the cucumber biotype in North China. The fitnesses of the two host-specialized biotypes differ on various summer hosts. When alate aphids migrate to summer hosts, they cannot accurately land on the corresponding plant.

  17. Adaptation of the dwarf forms of soybean aphid, Aphis glycines to environment and impact on soybean yield%大豆蚜对环境的适应及对大豆产量的影响

    Institute of Scientific and Technical Information of China (English)

    许国庆; 陈彦; 王兴亚; 刘培斌; 徐蕾; 赵彤华

    2011-01-01

    The population dynamics of the dwarf form of the soybean aphid, Aphis glycines Matsumura, was investigated in 2009 and 2010 in Xiuyan County, eastern Liaoning, one of the main soybean production areas in China. Fungal parasitism of this pest by Verticillium lecanii( Zimmerman) Viegas and Lysiphlebus fabarum Marshall and predation on it by Harmonia axyridis(Pallas) were also investigated. In addition, research was conducted on the effect on this species of rainfall, and on its impact on soybean yield. The results indicate that the earliest damage to soybean plants occurred in mid-June. Heavy infestations of aphids occurred in late July and early August with densities of up to 80 722 aphids per hundred plants. Normal aphids excreted significantly more honey-dew than dwarf forms. Dwarf forms had a lower incidence of parasitism by V. Lecanii than normal forms. However, normal forms had a higher incidence of parasitism by L fabarum(43. 41% ) than dwarf forms(0. 58% ) . The 3rd larval stage of H. Axyriiis had a predation rate on normal and dwarf aphids of 80. 24% and 36. 36% respectively. Dwarf forms were less affected by rainfall than normal forms. Moreover, a One-Way ANOVA indicated no significant relationship between the number of dwarf aphids per plant and yield(F = 0.378; df/=7,l; P>0.05).%2009-2010年,以辽东山区大豆主产区岫岩县作为试验点,系统调查了大豆蚜Aphis glycines Matsumura 正常型蚜和小型蚜的种群动态,研究了蜡蚧轮枝菌Verticillium lecanii( Zimmerman) Viegas、豆柄瘤蚜茧蜂Lysiphlebus fabarum Marshall、异色瓢虫Harmonia axyridis( Pallas)对大豆蚜正常型蚜和小型蚜的寄生与捕食作用;另外,也研究了降雨对小型蚜和正常型蚜的冲刷作用,以及小型蚜对大豆产量的影响等.研究结果表明,7月上中旬为大豆蚜小型蚜发生初期,7月下旬-8月上旬为小型蚜发生高峰期,2010年小型蚜平均蚜量达10000头/百株以上.此外,通过比较大豆蚜正常

  18. Presence of the Aphid, Chaetosiphon fragaefolii, on Strawberry in Argentina

    OpenAIRE

    Claudia CÉDOLA; 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 ...

  19. 77 FR 46373 - Field Release of Aphelinus glycinis for the Biological Control of the Soybean Aphid in the...

    Science.gov (United States)

    2012-08-03

    ... the Biological Control of the Soybean Aphid in the Continental United States; Availability of an... release of Aphelinus glycinis for the biological control of the soybean aphid, Aphis glycines, in the...-2323. SUPPLEMENTARY INFORMATION: Background The soybean aphid, Aphis glycinis, which is native to...

  20. Preferência do pulgão-preto, Aphis craccivora Koch, a diferentes genótipos de feijão-de-corda, Vigna unguiculata (L. Walp Black aphid, Aphis craccivora Koch, preference to different cowpea, Vigna unguiculata (L. Walp. cultivars

    Directory of Open Access Journals (Sweden)

    João Gutemberg Leite Moraes

    2007-12-01

    Full Text Available Este trabalho foi desenvolvido visando a avaliar a resposta de cultivares de feijão-de-corda, Vigna unguiculata (L. Walp., à presença do pulgão-preto (Aphis craccivora Koch. Os experimentos foram conduzidos de agosto a outubro de 2004, em casa-de-vegetação da Universidade Federal do Ceará (UFC. As cultivares foram: "Epace-10", "Epace-11", "Patativa", "Pingo de Ouro", "Pitiúba", "BR-10 Piauí", "BR-12 Canindé", "BR-14 Mulato" e "BR-17 Gurguéia". O experimento constou de três ensaios, cada um com cinco tratamentos e seis repetições, sendo o delineamento estatístico inteiramente casualizado. Os genótipos foram cultivados em copos plásticos de 300ml e mantidos em gaiolas protegidas por tela antiafídeos. As plantas foram infestadas após doze dias do plantio através da liberação de cinco fêmeas adultas do pulgão-preto por planta. As avaliações foram realizadas após o terceiro e o quinto dia da infestação, constando da contagem direta das formas adulta e jovem do inseto presentes nas plantas. Os dados obtidos foram analisados através de análise de variância e pelo teste de Tukey em 5% de probabilidade de erro. As cultivares "Epace-10" e "Patativa" foram as menos preferidas por A. craccivora.This research was conducted with the intention of evaluating the response of different cowpea, Vigna unguiculata (L. Walp, cultivars to the black aphid (Aphis craccivora Koch. The bioassays were conducted from August through October of 2004 in a greenhouse at the Ceará Federal University (UFC campus. The cowpea cultivars used were: Epace-10, Epace-11, Patativa, Pingo de Ouro, Pitiúba, BR-10 Piauí, BR-12 Canindé, BR-14 Mulato and BR-17 Gurguéia. Each assay had five treatments and six replications in a completely randomized block design. The genotypes were raised in a 300ml plastic cup and maintained in cages protected by an insect proof net. Plants were infested twelve days after planting with five adult females per plant

  1. Predators of the Alfalfa Aphids Acyrthosiphon pisum (Harris, Aphis craccivora Koch, and Therioaphis trifolii (Monell (Hemiptera: Aphidoidea as Determined by the Serological Technique

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    Suzan Cunha

    2016-08-01

    Resumo. A serologia é uma técnica imunológica baseada em reações antígeno/anticorpo, em que suas principais vantagens são a alta sensibilidade e especificidade que permitem o reconhecimento biológico em nível molecular. Este trabalho avalia o uso da técnica serológica para determinar os predadores dos pulgões da alfafa, Acyrthosiphon pisum (Harris, Aphis craccivora Koch e Therioaphis trifolii (Monell (Hemiptera: Aphidoidea. As coletas dos pulgões para a obtenção dos anticorpos e de seus possíveis predadores para serem utilizados como antígenos foram realizadas nos campos de alfafa da Unidade da Embrapa Pecuária Sudeste, São Carlos, SP. no período de agosto de 2011 a julho de 2012. Foram testados 2.161 artrópodes predadores, incluindo insetos e aranhas. Os anticorpos obtidos para os pulgões A. craccivora, A. pisum, e T. trifolii mostraram identidade parcial mas, ainda assim, permitiu reconhecer os predadores dos pulgões da alfafa. Dentre os insetos, sirfídeos e crisopídeos foram os que apresentaram as maiores porcentagens de resultados positivos nos testes serológicos. A. craccivora foi o afídeo mais consumido pelos predadores.

  2. Do aphid carcasses on the backs of larvae of green lacewing work as chemical mimicry against aphid-tending ants?

    Science.gov (United States)

    Hayashi, Masayuki; Choh, Yasuyuki; Nakamuta, Kiyoshi; Nomura, Masashi

    2014-06-01

    Ants attack and exclude natural enemies of aphids in ant-aphid mutualisms. However, larvae of the green lacewing, Mallada desjardinsi, prey on the cowpea aphid, Aphis craccivora, without exclusion by aphid-tending ants. Lacewing larvae are protected from ants by carrying aphid carcasses on their backs. Here, we tested whether cuticular hydrocarbons (CHCs) of aphid carcasses affected the aggressiveness of aphid-tending ants. Aphid carcasses were washed with n-hexane to remove lipids. Lacewing larvae with washed aphid carcasses were attacked by aphid-tending ants more frequently than those with untreated aphid carcasses. We measured the aggressiveness of aphid-tending ants to lacewing larvae that were either carrying a piece of cotton wool (a dummy aphid carcass) treated with CHCs from aphids or lacewing larvae, or carrying aphid carcasses. The rates of attack by ants on lacewing larvae carrying CHCs of aphids or aphid carcasses were lower than that of attack on lacewing larvae with conspecific CHCs. Chemical analysis by gas chromatography/mass spectrometry showed similarity of CHCs between aphids and aphid carcasses. These results suggest that aphid carcasses on the backs of lacewing larvae function via chemical camouflage to limit attacks by aphid-tending ants.

  3. Inhibitional effects of metal Zn²⁺ on the reproduction of Aphis medicaginis and its predation by Harmonia axyridis.

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    Guoqiang Xie

    Full Text Available BACKGROUND: Contamination, including metals, can disturb the reproductive processes of many organisms, including both prey and predatory insects. However, there is virtually no information on the effects of high level Zinc (Zn pollution on aphids and ladybirds. The high concentrations of Zn²⁺ or Zn pollution inhibit reproduction in the phytophagous aphid, Aphis medicaginis, and the predatory ladybird Harmonia axyridis could provide important information. RESULTS: It was observed in this study that Zn concentrations in Vicia faba (broad bean seeds and seedlings in all Zn²⁺ treatments were significantly higher than that in the control group, and increased with increasing Zn²⁺ concentrations in the solution. The rate of reproduction in A. medicaginis declined significantly (p<0.05 over time in the five groups fed on broad bean seedlings treated with different concentrations of Zn²⁺ solution compared with the control group. These results showed that higher concentrations of Zn²⁺ significantly inhibited the reproductive capacity of A. medicaginis. We also cloned and identified a gene encoding vitellogenin (Vg from A. medicaginis, which has an important role in vitellogenesis, and therefore, reproduction was affected by exposure to Zn²⁺. Expression of AmVg was reduced with increasing exposure to Zn²⁺ and also in the F1-F3 generations of aphids exposed to different Zn²⁺ concentrations. Predation by H. axyridis was also reduced in aphids exposed to high-levels of Zn²⁺. Similarly, ovipositioning by H. axyridis was also reduced. CONCLUSIONS: Our results suggest that Zn²⁺ can significantly affect the reproductive capacity of both A. medicaginis and its predator H. axyridis, the former through effects on the expression of AmVg and the latter through avoidance of aphids containing high levels of Zn²⁺.

  4. Exploring the bacterial microbiota associated with native South American species of Aphis (Hemiptera: Aphididae).

    Science.gov (United States)

    Arneodo, J D; Ortego, J

    2014-06-01

    Aphids harbor a variety of bacterial endosymbionts, including the obligate symbiont Buchnera aphidicola and diverse facultative symbionts. The former supplies its host with essential amino acids. The latter are not indispensable for insect survival, but often improve their host's fitness. To date, the study of such associations was restricted to aphids of Holarctic origin. The bacterial microbiota of seven Aphis species from Argentina was investigated. The presence of B. aphidicola was assessed by specific PCR. Additional symbionts were identified through PCR with eubacterial universal primers, cloning, and sequencing of nearly complete 16S rRNA gene, intergenic spacer region, and partial 23S rRNA gene and subjected to phylogenetic analysis. Infection with B. aphidicola was confirmed in every species analyzed. The facultative symbiont Serratia symbiotica was detected in Aphis malalhuina Mier Durante, Nieto Nafría & Ortego, 2003, Aphis senecionicoides Blanchard, 1944, and Aphis schinifoliae Blanchard, 1939, while Hamiltonella defensa was identified in Aphis mendocina Mier Durante, Ortego & Nieto Nafría, 2006. Arsenophonus sp. was found infecting Aphis melosae Mier Durante & Ortego, 1999, and a new, undescribed Aphis sp. In Aphis danielae Remaudière, 1994, no facultative symbionts could be recorded. When analyzing the highly conserved 16S rRNA gene, the phylogenetic tree grouped the S. symbiotica, H. defensa, and Arsenophonus isolates into three well-defined clusters showing little variability among clones corresponding to the same aphid host species. This article reports for the first time the endosymbionts associated with aphids native to South America. Despite their geographic origin, the qualitative composition of their microbiota revealed no evident differences from that described for aphids in the Northern Hemisphere.

  5. Aphids (Hemiptera, Aphididae) on ornamental plants in greenhouses in Bulgaria.

    Science.gov (United States)

    Yovkova, Mariya; Petrović-Obradović, Olivera; Tasheva-Terzieva, Elena; Pencheva, Aneliya

    2013-01-01

    Investigations on the species composition and host range of aphids on ornamental greenhouse plants in Bulgaria was conducted over a period of five years, from 2008 to 2012. Twenty greenhouses, growing ornamentals for landscaping, plant collections and other purposes were observed. They were located in the regions of Sofia, Plovdiv, Smolyan, Pavlikeni, Varna and Burgas. The total number of collected aphid samples was 279. Their composition included 33 aphid species and one subspecies from 13 genera and 5 subfamilies. Twenty-eight species were found to belong to subfamily Aphidinae. Almost 70 % of all recorded species were polyphagous. The most widespread aphid species was Myzus persicae, detected in 13 greenhouses all year round, followed by Aulacorthum solani (10 greenhouses) and Aphis gossypii (9 greenhouses). The widest host range was shown by Myzus persicae (43 hosts), Aulacorthum solani (32 hosts) and Aulacorthum circumflexum (23 hosts). The list of host plants includes 114 species from 95 genera and 58 families. The greatest variety of aphid species was detected on Hibiscus (9 species). Out of all aphid samples 12.9 % were collected on Hibiscus and 6.8 %, on Dendranthema. The greatest variety of aphid species was detected on Hibiscus (9 species). Periphyllus californiensis and Aphis (Aphis) fabae mordvilkoi are reported for the first time for Bulgaria. Furthermore, Aphis spiraecola has been found in new localities and has widened its host range in this country.

  6. Maintaining genetic diversity and population panmixia through dispersal and not gene flow in a Holocyclic heteroecious aphid species

    Science.gov (United States)

    Heteroecious holocyclic aphids alternate between sexual and asexual reproduction on primary and secondary hosts, respectively. Most of these aphids are generalists, but the aphid specialist Aphis glycines survives only on the primary host buckthorn (Rhamnus spp.) and the secondary host soybean (Gly...

  7. Kaolin particle films suppress many apple pests, disrupt natural enemies and promote woolly apple aphid

    NARCIS (Netherlands)

    Markó, V.; Blommers, L.H.M.; Bogya, S.; Helsen, H.H.M.

    2008-01-01

    Multiple applications of hydrophobic kaolin particle film in apple orchards suppressed numbers of blossom weevil (Anthonomus pomorum), brown leaf weevil (Phyllobius oblongus), attelabid weevil (Caenorhinus pauxillus), leafhoppers (Empoasca vitis and Zygina flammigera) and green apple aphid (Aphis

  8. Aphid alarm pheromone as a cue for ants to locate aphid partners.

    Directory of Open Access Journals (Sweden)

    François J Verheggen

    Full Text Available The mutualistic relationships that occur between myrmecophilous aphids and ants are based on the rich food supply that honeydew represents for ants and on the protection they provide against aphid natural enemies. While aphid predators and parasitoids actively forage for oviposition sites by using aphid semiochemicals, scouts of aphid-tending ant species would also benefit from locating honeydew resources by orienting toward aphid pheromone sources. The present study aims to provide additional information on the use of Aphis fabae alarm pheromone, i.e. (E-β-farnesene (EβF, by ant scouts. The perception and behavioral impact of EβF on Lasius niger were investigated using electroantennography and two bio-assays measuring their attraction and orientation towards aphid semiochemicals. Pronounced electrical depolarizations were observed from L. niger scout antennae to stimulations of A. fabae alarm pheromone, while other sesquiterpenes elicited weak or no responses. L. niger scouts were significantly attracted toward EβF in a four-arm olfactometer, as well as in an two-choice bioassay. These laboratory results suggest for the first time that low amounts of aphid alarm pheromone can be used by L. niger scouts as a cue indicating the presence of aphid colonies and could therefore mediate the aphid-ant partnership in the field.

  9. Differential reactions of soybean isolines with combinations of aphid resistance genes Rag1, Rag2, and Rag3 to four soybean aphid biotypes

    Science.gov (United States)

    With the discovery of the soybean aphid (Aphis glycines Matsumura) as a devastating insect pest of soybean (Glycine max (L.) Merr.) in the United States, host resistance was recognized as an important management option. However, the identification of soybean aphid isolates exhibiting strong virulenc...

  10. 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.

  11. Plant genotype shapes ant-aphid interactions: implications for community structure and indirect plant defense.

    Science.gov (United States)

    Mooney, Kailen A; Agrawal, Anurag A

    2008-06-01

    Little is known about the mechanisms by which plant genotype shapes arthropod community structure. In a field experiment, we measured the effects of milkweed (Asclepias syriaca) genotype and ants on milkweed arthropods. Populations of the ant-tended aphid Aphis asclepiadis and the untended aphid Myzocallis asclepiadis varied eight- to 18-fold among milkweed genotypes, depending on aphid species and whether ants were present. There was no milkweed effect on predatory arthropods. Ants increased Aphis abundance 59%, decreased Myzocallis abundance 52%, and decreased predator abundance 56%. Milkweed genotype indirectly influenced ants via direct effects on Aphis and Myzocallis abundance. Milkweed genotype also modified ant-aphid interactions, influencing the number of ants attracted per Aphis and Myzocallis. While ant effects on Myzocallis were consistently negative, effects on Aphis ranged from antagonistic to mutualistic among milkweed genotypes. As a consequence of milkweed effects on ant-aphid interactions, ant abundance varied 13-fold among milkweed genotypes, and monarch caterpillar survival was negatively correlated with genetic variation in ant abundance. We speculate that heritable variation in milkweed phloem sap drives these effects on aphids, ants, and caterpillars. In summary, milkweed exerts genetic control over the interactions between aphids and an ant that provides defense against foliage-feeding caterpillars.

  12. Biological parameters of the non-target pest Aphis gossypii Glover ...

    African Journals Online (AJOL)

    Thiago Mota

    2013-04-17

    Apr 17, 2013 ... genetically modified cotton variety (Bt) NuOpal, on the biological parameters of a non-target pest, Aphis gossypii .... Aphids have an important role in food chains within ... noticed, they were compared using the t test at 5% probability. ..... herbivores feeding on transgenic maize and consequences for the.

  13. Two Species of Symbiotic Bacteria Present in the Soybean Aphid (Hemiptera: Aphididae)

    Science.gov (United States)

    Aphids, which feed solely on plant phloem sap, have developed symbiotic associations with bacteria that provide them with the amino acids that are lacking in phloem. Three soybean aphid (Aphis glycines Mat samura) populations were screened for the presence of Buchnera aphidicola and three common spe...

  14. Mind your elders: wild soybean’s contribution to soybean aphid resistance

    Science.gov (United States)

    Currently, biotype 4 soybean aphid (Aphis glycines Matsamura, SBA) is the most virulent SBA biotype. Overcoming the most aphid resistant genes, SBA biotype 4 has become the greatest challenge in utilizing plant resistance in soybean [Glycine max (L.) Merr.]. Soybean’s wild ancestor Glycine soja (Sie...

  15. Characterization and genetics of multiple soybean aphid biotype resistance in five soybean plant introductions

    Science.gov (United States)

    Soybean aphid (Aphis glycines Matsumura) is the most important soybean [Glycine max (L.) Merr.] insect pest in the USA. The objectives of this study were to characterize the resistance expressed in the five plant introductions (PIs) to four soybean aphid biotypes, determine the mode of resistance in...

  16. Rag1 aphid resistant soybeans alter the movement and distribution of soybean aphid (Hemiptera: Aphididae).

    Science.gov (United States)

    Whalen, Rebecca; Harmon, Jason P

    2012-12-01

    Herbivorous insects often move and distribute according to the quality of the plant they are on, and this behavior could influence interactions with plants bred for herbivore resistance. However, when an insect is normally considered sedentary, less is known about the potential importance of movement. We performed experiments to determine if a resistant soybean variety alters the movement and distribution, both within and between plants, of the soybean aphid Aphis glycines Matsumura. We did this by counting apterous aphids on leaves of resistant and susceptible soybean plants across several days. In individual plant tests aphid distribution was different between susceptible and resistant soybeans. Most notably aphids on resistant plants were quickly found off the original leaf on which they were placed and were ultimately distributed throughout the resistant soybean. Aphids on susceptible plants, however, tended to stay on their initial leaf of placement. Follow up experiments indicated this was primarily because of the movement of individuals and not differential demography on various plant parts. In experiments where aphids were able to walk to an adjacent plant there appeared to be a net movement of aphids off resistant plants and on to susceptible plants. Aphid populations on susceptible plants were higher when the plant was adjacent to a resistant plant than when adjacent to another susceptible plant. The effect of resistant plants on aphid movement and distribution could lead to unintended side-effects such as greater spread of plant viruses or altered effectiveness of biological control agents.

  17. Aphid pheromones.

    Science.gov (United States)

    Dewhirst, Sarah Y; Pickett, John A; Hardie, Jim

    2010-01-01

    Aphids are the main insect pests of agricultural crops in temperate regions causing major economic losses. Although broad-spectrum insecticides are available for control, alternative and more targeted methods are needed due to insecticide resistance and increasing environmental pressures. An alternative control method for aphids is to exploit their pheromones, which have been extensively studied in recent years. For example, aphids release alarm pheromones in response to natural enemy attack and these could be used to deter aphids from the crops. Sex pheromones have also been identified which could be used to interfere males locating conspecific females (oviparae), as well as for manipulating natural enemies. Several hypotheses relating to how species integrity is maintained via the aphid sex pheromone have been proposed. The composition and behavioral activity of these pheromones, and how their use could be implemented in integrated pest management systems to control aphids, is discussed. Copyright © 2010 Elsevier Inc. All rights reserved.

  18. Application of some insecticides and plant crude extracts for controlling insect pests in yard long bean

    Directory of Open Access Journals (Sweden)

    Wipawadee Chamnan

    2003-05-01

    Full Text Available Tests on plant crude extracts of neem seeds, galanga and citronella grass at the rates of 200 ml/20 L of water together with synthetic insecticides, cypermethrin, methamidophos, carbosulfan and carbofuran, at the recommended rates showed that none of the treatments was effective in controlling plant damage caused by adult of bean fly (Ophiomyia phaseoli Tryon. The application of the synthetic insecticide, methamidophos, and plant crude extracts of neem seeds + galanga + citronella grass provided the highest effectiveness tocontrol aphids (Aphis craccivora Koch. Control of A. craccivora was not significantly different between the synthetic insecticide and plant crude extracts, except methamidophos. Pod damage caused by pod borer (Maruca testulalis Geyer and yields were also not significantly different among treatments. However, the highest yield of 1,224.7 kg/rai was recorded in plots treated with neem seed extracts and the synthetic insecticide, carbosulfan. In untreated plots, the lowest yield of 587.3 kg/rai was collected.

  19. Molecular characterization of the Aphis gossypii olfactory receptor gene families.

    Directory of Open Access Journals (Sweden)

    Depan Cao

    Full Text Available The cotton aphid, Aphis gossypii Glover, is a polyphagous pest that inflicts great damage to cotton yields worldwide. Antennal olfaction, which is extremely important for insect survival, mediates key behaviors such as host preference, mate choice, and oviposition site selection. In insects, odor detection is mediated by odorant receptors (ORs and ionotropic receptors (IRs, which ensure the specificity of the olfactory sensory neuron responses. In this study, our aim is to identify chemosensory receptors in the cotton aphid genome, as a means to uncover olfactory encoding of the polyphagous feeding habits as well as to aid the discovery of new targets for behavioral interference. We identified a total of 45 candidate ORs and 14 IRs in the cotton aphid genome. Among the candidate AgoORs, 9 are apparent pseudogenes, while 19 can be clustered with ORs from the pea aphid, forming 16 AgoOR/ApOR orthologous subgroups. Among the candidate IRs, we identified homologs of the two highly conserved co-receptors IR8a and IR25a; no AgoIR retain the complete glutamic acid binding domain, suggesting that putative AgoIRs bind different ligands. Our results provide the necessary information for functional characterization of the chemosensory receptors of A. gossypii, with potential for new or refined applications of semiochemicals-based control of this pest insect.

  20. Influences of Soil Fertility on Spatial Patterns of Aphis Gossypii Glover (Homoptera: Aphididae Occurred in Bt-cotton Plants

    Directory of Open Access Journals (Sweden)

    Zhi-Qiang Tan

    2012-12-01

    Full Text Available With the widespread planting of bacterium Bacillus thuringiensis (Bt-cotton, non-target piercing-sucking insects such as Aphis gossypii Glover (Homoptera: Aphididae have become the main hazard of cotton. Fertilization influences the distribution and population dynamics of aphid seriously. In this study, the effects of Nitrogen (N and Phosphorus (P on aphid population density were investigated on Bt-cotton; the combinational impacts of nitrogen and potassium (K fertilizers on the distribution of aphid were examined as to guide rational fertilization to reduce pests and environmental pollution. Aphid density in cotton plants fertilized with 72 kg/ha N (84.2±22.7 aphids/plant was significantly higher than fertilized with 0 and 108 kg/ha N (36.7±4.0 and 47.8±18.7 aphids/plant. Compared to cotton plants treated with 23 and 69 kg/ha P, aphid density was higher (61.67±21.08 aphids/plant in cotton plants treated with 46 kg/ha P. Comparison of spatial distribution of aphid population showed that aphid preferred to suck the sap of bottom fruit branches in cotton plants treated by single K fertilizer and combinational fertilizers of N and K. Thus, these results suggested that proper application of fertilizers should be beneficial to controlling phytophagous insects in Bt-cotton production.

  1. Tritrophic associations and taxonomic notes on Lysiphlebus fabarum (Marshall (Hymenoptera: Braconidae: Aphidiinae, a keystone aphid parasitoid in Iran

    Directory of Open Access Journals (Sweden)

    Rakhshani Ehsan

    2013-01-01

    Full Text Available An investigation of host associations, distribution and types of reproduction (sexual, asexual of Lysiphlebus fabarum (Marshall across 20 provinces of Iran during 2006-2011 was undertaken. The parasitoid was reared from three groups of host aphids belonging to genera Aphis and Brachycaudus, and occasional host aphid genera. Aphis craccivora Koch was the most frequent host aphid for L. fabarum on various host plants, including economically important crops. The field sex ratio generally favored females, but in some cases, only thelytokous (uniparental populations were found. In those cases, the host was always an Aphis species. Specimens reared from Brachycaudus aphids were all biparental, indicating the presence of a sibling biological species. Overall analysis of diagnostic morphological characters in the forewing indicated intra-specific variability in forewing marginal setae as well as variations in length of the R1 vein. [Projekat Ministarstva nauke Republike Srbije, br. 43001

  2. Antibiosis and antixenosis to Aphis gossypii (Homoptera: Aphididac) in Colocasia esculenta.

    Science.gov (United States)

    Coleson, Jenifer L; Miller, Ross H

    2005-06-01

    Fifty cultivars of taro, Colocasia esculenta (L.) Schott (Araceae), collected from islands in Micronesia and Polynesia, eight cultivars from the University of Hawaii's taro germplasm collection, and a closely related aroid, Xanthosorna sagittifolium (L.) (Araceae), were screened for antibiosis and antixenosis to Aphis gossypii Clover. Life history data for A. gossypii were collected by assessing survivorship and fecundity of aphids caged on taro leaves in the field. Significant differences in aphid reproductive rate and longevity were observed among the taro cultivars, and cultivars were ranked from most resistant to most susceptible. Antixenosis was assayed in the laboratory in a multiround choice test where A. gossypii were offered four leaf discs excised from different taro cultivars. Additionally, field observations of aphid abundance on taro cultivars were made to corroborate clip cage studies and laboratory experiments. 'Iliuaua','Rumung Mary','Maria', 'Ketan 36', and'Agaga' were the most resistant in terms of reducing aphid fecundity and survivorship, whereas the Iliuana,'Purple', 'TC-83001', and 'Putih 24' were least preferred in aphid choice tests. X. sagittifolium consistently exhibited strong aphid resistance. Resistant cultivars identified in this study may form the basis of breeding programs seeking to combine aphid resistance with other desirable agronomic traits in taro.

  3. Study on Joint Effect of Neonicotinoid and Pyrethroid Insecticides Against Bean Aphid%新烟碱类与拟除虫菊酯类杀虫剂对蚜虫的联合作用研究

    Institute of Scientific and Technical Information of China (English)

    曾霞; 马亚芳; 马聪; 倪龙博; 施娟娟; 倪珏萍

    2014-01-01

    In order to provide reference for development of insecticides, the joint effects of four neonicotinoid insecticides and two pyrethroid insecticides were tested against bean aphid, the four neonicotinoid insecticides were thiamethoxam, thiacloprid, nitenpyram, imidaclothiz and the two pyrethroid insecticides were lambda-cyhalothrin, bifenthrin. The bioassays were carried out by dipping method for bean aphid and the type of joint action was evaluated by equivalent linear method and the co-toxicity coefficient method. Contact activities of eight neonicotinoid insecticides against aphid from high to low were thiamethoxam, imidacloprid, thiacloprid, nitenpyram, acetamiprid, clothianidin, imidaclothiz and dinotefuran. Contact activities of four pyrethroid insecticides against aphid were lambda-cyhalothrin, deltamethrin, beta-cypermethrin and bifenthrin. The joint effects of the eighteen mixtures showed synergistic, additive or antagonistic. Two mixtures of nitenpyram + lambda-cyhalothrin (5∶1) and thiamethoxam + bifenthrin (5∶1) were recommended among the eighteen mixtures. In the research and development of insecticide mixtures, blind imitation was harmful and actual screening results were necessary. Also, the insecticides mixtures should be scientific and practical, and could play a role in resistance management and reduction use.%研究比较了噻虫嗪、噻虫啉、烯啶虫胺、氯噻啉等4个新烟碱类杀虫剂与高效氯氟氰菊酯、联苯菊酯等2个拟除虫菊酯类杀虫剂的联合作用,为复配制剂的研发提供科学依据。室内采用浸渍法对蚕豆蚜进行毒力测定,采用等效线法和共毒系数法评价联合作用类型。结果表明:8个新烟碱类杀虫剂对蚜虫的活性从高到低依次为噻虫嗪、吡虫啉、噻虫啉、烯啶虫胺、啶虫脒、噻虫胺、氯噻啉、呋虫胺,4个拟除虫菊酯类杀虫剂对蚜虫的活性从高到低依次为高效氯氟氰菊酯、溴氰菊酯、高效

  4. A report on occurrence of aphidophagous predators of Aphis odinae (van der Goot) (Hemiptera: Aphididae) in cashew ecosystem from Goa, India

    OpenAIRE

    Ramasamy Maruthadurai; Narendra Pratap Singh

    2017-01-01

    The aphid, Aphis odinae (Van der Goot) (Hemiptera: Aphididae) is a polyphagous, occasional insect pest of cashew.  A field survey was conducted from 2014 to 2015 in cashew plantations to record the incidence of aphid and its predators.  Periodical sampling revealed, the occurrence of six species of aphidophagous predators comprising three species of coccinellids, viz., Scymnus castaneus Sicard, Cheilomenes sexmaculata (Fabricius) and Pseudaspidimerus flaviceps (Walker) and three species of sy...

  5. Ants Learn Aphid Species as Mutualistic Partners: Is the Learning Behavior Species-Specific?

    Science.gov (United States)

    Hayashi, Masayuki; Nakamuta, Kiyoshi; Nomura, Masashi

    2015-12-01

    In ant-aphid associations, many aphid species provide ants with honeydew and are tended by ants, whereas others are never tended and are frequently preyed upon by ants. In these relationships, ants must have the ability to discriminate among aphid species, with mutualistic aphids being accepted as partners rather than prey. Although ants reportedly use cuticular hydrocarbons (CHCs) of aphids to differentiate between mutualistic and non-mutualistic species, it is unclear whether the ability to recognize mutualistic aphid species as partners is innate or involves learning. Therefore, we tested whether aphid recognition by ants depends on learning, and whether the learning behavior is species-specific. When workers of the ant Tetramorium tsushimae had previously tended the cowpea aphid, Aphis craccivora, they were less aggressive toward this species. In addition, ants also reduced their aggressiveness toward another mutualistic aphid species, Aphis fabae, after tending A. craccivora, whereas ants remained aggressive toward the non-mutualistic aphid, Acyrthosiphon pisum, regardless of whether or not they had previous experience in tending A. craccivora. When ants were offered glass dummies treated with CHCs of these aphid species, ants that had tended A. craccivora displayed reduced aggression toward CHCs of A. craccivora and A. fabae. Chemical analyses showed the similarity of the CHC profiles between A. craccivora and A. fabae but not with A. pisum. These results suggest that aphid recognition of ants involves learning, and that the learning behavior may not be species-specific because of the similarity of CHCs between different aphid species with which they form mutualisms.

  6. Predator efficiency reconsidered for a ladybird-aphid system

    Directory of Open Access Journals (Sweden)

    Pavel eKindlmann

    2015-03-01

    Full Text Available Some experiments indicate that ladybirds can significantly suppress aphid abundance. For example, exclusion of predators by caging aphid-infested plants repeatedly results in higher aphid populations and faster aphid population growth rates. However, aphidophagous ladybirds have never proved effective in controlling aphid populations in the field, which is consistent with the theoretical prediction that long-lived predators cannot be effective in controlling a short-lived prey (the generation time ratio hypothesis, GTR. To resolve this paradox, field experiments, involving two species of ladybirds, Coccinella septempunctata bruckii and Harmonia axyridis were used to determine their efficiency in suppressing populations of the aphid, Aphis gossypii, on small shrubs of Hibiscus syriacus under natural conditions. Instead of by caging, the effect of each ladybird species on aphid population dynamics was determined by removing all the eggs of C. septempunctata from 8 shrubs, those of H. axyridis from a further 8 shrubs, all those of both species from an additional 12 shrubs and leaving the eggs on 6 control shrubs. These predators did not have a negative effect on the peak numbers of the aphids. Thus one should be cautious when interpreting the results of cage experiments, used to assess the efficiency of predators in reducing the abundance of their prey.

  7. Identification of Soybean Resources of Resistance to Aphids

    Institute of Scientific and Technical Information of China (English)

    WU Tian-long; MA Xiao-hong; YAO Lu-ming; WANG Biao

    2009-01-01

    Four soybean [Glycine max (L.) Merr.] cultivars with soybean aphid resistance (Aphis glycines Matsmura), P189, P203, P574,and P746, were identified in field test, choice test, and non-choice test. The grade of resistance to aphids and the damage index of P189, P203, and P746 were significantly different from the susceptible cultivars (P=0.05). P574 and P746 showed antibiosis resistance, preventing aphids from reproducing on the plants. P203 showed antixenosis resistance, preventing aphids from reproducing in field test and choice test, but susceptible in non-choice test. Population development on plants was significantly different in field test, choice test, and non-choice test, which was caused by different selective pressures.

  8. An Attractant of the Aphidophagous Gall Midge Aphidoletes aphidimyza From Honeydew of Aphis gossypii.

    Science.gov (United States)

    Watanabe, Hiroshi; Yano, Eizi; Higashida, Keita; Hasegawa, Syouichi; Takabayashi, Junji; Ozawa, Rika

    2016-02-01

    Many natural enemies of insects use honeydew as a volatile cue to locate hosts or prey, as an oviposition stimulant, and as an arrestant for foraging. The aphidophagous gall midge Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae) has predacious larval stages and can be used to control aphid populations, especially in greenhouses. Previous studies have shown that the honeydew, excreted by the aphid Myzus persicae, attracts A. aphidimyza, but the crucial attractants have not been identified. Using an olfactometer, we studied behavioral responses of female A. aphidimyza to volatiles emitted from honeydew excreted by the aphid Aphis gossypii on eggplants. The volatiles attracted female midges and induced oviposition. Moreover, using gas chromatography coupled with mass spectrometry (GC/MS), we identified phenylacetaldehyde as the attractant compound in the honeydew, although it did not induce oviposition in olfactometer experiments.

  9. Differential Life History Trait Associations of Aphids with Nonpersistent Viruses in Cucurbits.

    Science.gov (United States)

    Angelella, G M; Egel, D S; Holland, J D; Nemacheck, J A; Williams, C E; Kaplan, I

    2015-06-01

    The diversity of vectors and fleeting nature of virus acquisition and transmission renders nonpersistent viruses a challenge to manage. We assessed the importance of noncolonizing versus colonizing vectors with a 2-yr survey of aphids and nonpersistent viruses on commercial pumpkin farms. We quantified aphid alightment using pan traps, while testing leaf samples with multiplex RT-PCR targeting cucumber mosaic virus (CMV), zucchini yellow mosaic virus (ZYMV), watermelon mosaic virus (WMV), and papaya ringspot virus (PRSV). Overall, we identified 53 aphid species (3,899 individuals), from which the melon aphid, Aphis gossypii Glover, a pumpkin-colonizing species, predominated (76 and 37% of samples in 2010 and 2011, respectively). CMV and ZYMV were not detected, but WMV and PRSV were prevalent, both regionally (WMV: 28/29 fields, PRSV: 21/29 fields) and within fields (infection rates = 69 and 55% for WMV in 2010 and 2011; 28 and 25% for PRSV in 2010 and 2011). However, early-season samples showed extremely low infection levels, suggesting cucurbit viruses are not seed-transmitted and implicating aphid activity as a causal factor driving virus spread. Interestingly, neither noncolonizer and colonizer alightment nor total aphid alightment were good predictors of virus presence, but community analyses revealed species-specific relationships. For example, cowpea aphid (Aphis craccivora Koch) and spotted alfalfa aphid (Therioaphis trifolii Monell f. maculata) were associated with PRSV infection, whereas the oleander aphid (Aphis nerii Bover de Fonscolombe) was associated with WMV spread within fields. These outcomes highlight the need for tailored management plans targeting key vectors of nonpersistent viruses in agricultural systems.

  10. Relationship of soybean aphid (Hemiptera: Aphididae) to soybean plant nutrients, landscape structure, and natural enemies.

    Science.gov (United States)

    Noma, Takuji; Gratton, Claudio; Colunga-Garcia, Manuel; Brewer, Michael J; Mueller, Emily E; Wyckhuys, Kris A G; Heimpel, George E; O'Neal, Matthew E

    2010-02-01

    In the north central United States, populations of the exotic soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), are highly variable across space, complicating effective aphid management. In this study we examined relationships of plant nutrients, landscape structure, and natural enemies with soybean aphid abundance across Iowa, Michigan, Minnesota, and Wisconsin, representing the range of conditions where soybean aphid outbreaks have occurred since its introduction. We sampled soybean aphid and its natural enemies, quantified vegetation land cover and measured soybean nutrients (potassium [K] and nitrogen [N]) in 26 soybean sites in 2005 and 2006. Multiple regression models found that aphid abundance was negatively associated with leaf K content in 2005, whereas it was negatively associated with habitat diversity (Simpson's index) and positively associated with leaf N content in 2006. These variables accounted for 25 and 27% of aphid variability in 2005 and 2006, respectively, suggesting that other sources of variability are also important. In addition, K content of soybean plants decreased with increasing prevalence of corn-soybean cropland in 2005, suggesting that landscapes that have a high intensification of agriculture (as indexed by increasing corn and soybean) are more likely to have higher aphid numbers. Soybean aphid natural enemies, 26 species of predators and parasitoids, was positively related to aphid abundance; however, enemy-to-aphid abundance ratios were inversely related to aphid density, suggesting that soybean aphids are able to escape control by resident natural enemies. Overall, soybean aphid abundance was most associated with soybean leaf chemistry and landscape heterogeneity. Agronomic options that can ameliorate K deficiency and maintaining heterogeneity in the landscape may reduce aphid risk.

  11. Aphid Transmission of the Ontario Isolate of Plum Pox Virus.

    Science.gov (United States)

    Lowery, D Thomas; Vickers, Patricia M; Bittner, Lori A; Stobbs, Lorne W; Foottit, Robert G

    2015-10-01

    Utilization of timed virus acquisition access probes in studies of plum pox virus (PPV) transmission by aphids demonstrated that endemic species transmitted the virus readily from plum, Prunus domestica (L.) Batsch; peach, P. persica (L.); or dwarf flowering almond, P. glandulosa Thunberg., to peach seedlings. The green peach aphid, Myzus persicae (Sulzer), was shown to be the most efficient vector. Acquisition of virus by green peach aphids from infected peach leaves resulted in 18-28% infected peach seedlings, while aphids previously fed on infected leaves of plum transferred virus to 36% of peach seedlings. Although the spirea aphid, Aphis spiraecola (Patch), was a less efficient vector than M. persicae it is perhaps more important for the spread of PPV due to its greater abundance and occurrence earlier in the season when peach trees are thought to be more susceptible to infection. Virus transmission rates varied depending on the virus source and healthy test plant species. In contrast to many previous studies, aphid inoculation of the experimental host Nicotiana benthamiana Domin occurred at a low rate, never exceeding 4%. Acquisition of PPV by M. persicae from infected peach fruit was greatly reduced compared with acquisition from leaves. The results of this research indicate that the Ontario isolate of PPV-D is readily transmissible by aphids to peach and natural spread of the virus needs to be considered in future management or eradication programs.

  12. Inventory and assessment of foliar natural enemies of the soybean aphid (Hemiptera: Aphididae) in South Dakota

    Science.gov (United States)

    Soybean aphid (Aphis glycines Matsumura) (Hemiptera: Aphididae) is a major pest of soybean in northern production regions of North America, and insecticides have been the primary management approach while alternative methods are developed. Knowledge of arthropod natural enemies and their impact on ...

  13. Plant-derived differences in the composition of aphid honeydew and their effects on colonies of aphid-tending ants

    OpenAIRE

    Pringle, Elizabeth G.; Novo, Alexandria; Ableson, Ian; Barbehenn, Raymond V; Vannette, Rachel L.

    2014-01-01

    In plant–ant–hemipteran interactions, ants visit plants to consume the honeydew produced by phloem-feeding hemipterans. If genetically based differences in plant phloem chemistry change the chemical composition of hemipteran honeydew, then the plant's genetic constitution could have indirect effects on ants via the hemipterans. If such effects change ant behavior, they could feed back to affect the plant itself. We compared the chemical composition of honeydews produced by Aphis nerii aphid c...

  14. Impact of Rag1 aphid resistant soybeans on Binodoxys communis (Hymenoptera: Braconidae), a parasitoid of soybean aphid (Hemiptera: Aphididae).

    Science.gov (United States)

    Ghising, Kiran; Harmon, Jason P; Beauzay, Patrick B; Prischmann-Voldseth, Deirdre A; Helms, Ted C; Ode, Paul J; Knodel, Janet J

    2012-04-01

    Multiple strategies are being developed for pest management of the soybean aphid, Aphis glycines Matsumura; however, there has been little published research thus far to determine how such strategies may influence each other, thereby complicating their potential effectiveness. A susceptible soybean (Glycine max L.) variety without the Rag1 gene and a near isogenic resistant soybean variety with the Rag1 gene were evaluated in the laboratory for their effects on the fitness of the soybean aphid parasitoid, Binodoxys communis (Gahan). The presence or absence of the Rag1 gene was verified by quantifying soybean aphid growth. To test for fitness effects, parasitoids were allowed to attack soybean aphids on either a susceptible or resistant plant for 24 h and then aphids were kept on the same plant throughout parasitoid development. Parasitoid fitness was measured by mummy and adult parasitoid production, adult parasitoid emergence, development time, and adult size. Parasitoids that attacked soybean aphids on susceptible plants produced more mummies, more adult parasitoids, and had a higher emergence rate compared with those on resistant plants. Adult parasitoids that emerged from resistant plants took 1 d longer and were smaller compared with those from susceptible plants. This study suggests that biological control by B. communis may be compromised when host plant resistance is widely used for pest management of soybean aphids.

  15. Impacts of thiamethoxam seed treatment and host plant resistance on the soybean aphid fungal pathogen, Pandora neoaphidis.

    Science.gov (United States)

    Koch, Karrie A; Ragsdale, David W

    2011-12-01

    Since the introduction of soybean aphid, Aphis glycines Matsumura, from Asia, insecticide use in soybean has increased substantially in the north central United States. Insecticide seed treatments and aphid resistant soybean varieties are management tactics that may reduce reliance on foliar applications of broad-spectrum insecticides. Exploring potential nontarget impacts of these technologies will be an important step in incorporating them into aphid management programs. We investigated impacts of thiamethoxam seed treatment and Rag1 aphid resistant soybean on a fungal pathogen of soybean aphid, Pandora neoaphidis (Remaudière & Hennebert) Humber, via open plot and cage studies. We found that although thiamethoxam seed treatment did significantly lower aphid pressure in open plots compared with an untreated control, this reduction in aphid density translated into nonsignificant decreases in fungal disease prevalence in aphids. Furthermore, when aphid densities were approximately equal in seed treated and untreated soybean, no impact on aphid fungal disease was observed. In open plots, Rag1 resistant soybean experienced lower aphid pressure and aphid disease prevalence compared with a nonresistant isoline. However, in cages when aphid densities were equivalent in both resistant and susceptible soybean, resistance had no impact on aphid disease prevalence. The addition of thiamethoxam seed treatment to resistant soybean yielded aphid densities and aphid disease prevalence similar to untreated, resistant soybean. These studies provide evidence that thiamethoxam seed treatments and Rag1 resistance can impact P. neoaphidis via decreased aphid densities; however, this impact is minimal, implying use of seed treatments and host plant resistance are compatible with P. neoaphidis.

  16. Soybean aphid intrabiotype variability based on colonization of specific soybean genotypes.

    Science.gov (United States)

    Pawlowski, Michelle; Hill, Curtis B; Voegtlin, David J; Hartman, Glen L

    2015-12-01

    The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is one of the most destructive insect pests on soybeans in the United States. One method for managing this pest is through host plant resistance. Since its arrival in 2000, 4 aphid biotypes have been identified that are able to overcome soybean aphid resistance (Rag) genes. A soybean aphid isolate collected from Moline, Illinois readily colonized soybean plants with the soybean aphid resistance gene Rag2, unlike biotypes 1 and 2, but similar to soybean aphid biotype 3. Two no-choice experiments compared the virulence of the Moline isolate with biotype 3. In both experiments, differences in aphid population counts were not significant (P > 0.05) on soybean genotypes LD08-12957a (Rag2) and LD11-5413a (Rag2), but the aphid counts for the Moline isolate were significantly (P soybean genotypes Dowling (Rag1), LD05-16611 (Rag1), LD11-4576a (Rag1), and PI 567598B (rag1b and rag3). The Moline isolate was a variant of aphid biotype 3, which is the first report showing that soybean aphid isolates classified as the same biotype, based on virulence against specific Rag genes, can differ in aggressiveness or ability to colonize specific host genotypes.

  17. Reduced Fitness of Virulent Aphis glycines (Hemiptera: Aphididae) Biotypes May Influence the Longevity of Resistance Genes in Soybean.

    Science.gov (United States)

    Varenhorst, Adam J; McCarville, Michael T; O'Neal, Matthew E

    2015-01-01

    Sustainable use of insect resistance in crops require insect resistance management plans that may include a refuge to limit the spread of virulence to this resistance. However, without a loss of fitness associated with virulence, a refuge may not prevent virulence from becoming fixed within a population of parthenogenetically reproducing insects like aphids. Aphid-resistance in soybeans (i.e., Rag genes) prevent outbreaks of soybean aphid (Aphis glycines), yet four biotypes defined by their capacity to survive on aphid-resistant soybeans (e.g., biotype-2 survives on Rag1 soybean) are found in North America. Although fitness costs are reported for biotype-3 on aphid susceptible and Rag1 soybean, it is not clear if virulence to aphid resistance in general is associated with a decrease in fitness on aphid susceptible soybeans. In laboratory assays, we measured fitness costs for biotype 2, 3 and 4 on an aphid-susceptible soybean cultivar. In addition, we also observed negative cross-resistance for biotype-2 on Rag3, and biotype-3 on Rag1 soybean. We utilized a simple deterministic, single-locus, four compartment genetic model to account for the impact of these findings on the frequency of virulence alleles. When a refuge of aphid susceptible was included within this model, fitness costs and negative cross-resistance delayed the increase of virulence alleles when virulence was inherited recessively or additively. If virulence were inherited additively, fitness costs decreased the frequency of virulence. Combined, these results suggest that a refuge may prevent virulent A. glycines biotypes from overcoming Rag genes if this aphid-resistance were used commercially in North America.

  18. Relationships Between Aphids (Insecta: Homoptera: Aphididae) and Slugs (Gastropoda: Stylommatophora: Agriolimacidae) Pests of Legumes (Fabaceae: Lupinus).

    Science.gov (United States)

    Kozłowski, Jan; Strażyński, Przemysław; Jaskulska, Monika; Kozłowska, Maria

    2016-01-01

    Lupin plants are frequently damaged by various herbivorous invertebrates. Significant among these are slugs and aphids, which sometimes attack the same plants. Relationships between aphids, slugs and food plant are very interesting. Grazing by these pests on young plants can lead to significant yield losses. There is evidence that the alkaloids present in some lupin plants may reduce grazing by slugs, aphids and other invertebrates. In laboratory study was analyzed the relationships between aphid Aphis craccivora and slug Deroceras reticulatum pests of legumes Lupinus angustifolius. It was found that the presence of aphids significantly reduced slug grazing on the plants. The lupin cultivars with high alkaloid content were found to be less heavily damaged by D. reticulatum, and the development of A. craccivora was found to be inhibited on such plants.

  19. Spectral Detection of Soybean Aphid (Hemiptera: Aphididae) and Confounding Insecticide Effects in Soybean

    Science.gov (United States)

    Alves, Tavvs Micael

    Soybean aphid, Aphis glycines (Hemiptera: Aphididae) is the primary insect pest of soybean in the northcentral United States. Soybean aphid may cause stunted plants, leaf discoloration, plant death, and decrease soybean yield by 40%. Sampling plans have been developed for supporting soybean aphid management. However, growers' perception about time involved in direct insect counts has been contributing to a lower adoption of traditional pest scouting methods and may be associated with the use of prophylactic insecticide applications in soybean. Remote sensing of plant spectral (light-derived) responses to soybean aphid feeding is a promising alternative to estimate injury without direct insect counts and, thus, increase adoption and efficiency of scouting programs. This research explored the use of remote sensing of soybean reflectance for detection of soybean aphids and showed that foliar insecticides may have implications for subsequent use of soybean spectral reflectance for pest detection. (Abstract shortened by ProQuest.).

  20. Aphids (Homoptera, Aphidodea inhabiting the trees Crataegus x media Bechst. in the urban green area. Part I. The population dynamics

    Directory of Open Access Journals (Sweden)

    Bożena Jaśkiwicz

    2013-12-01

    Full Text Available The studies were conducted in the years 1999-2001 in the green areas of Lublin, on the trees of Crataegus x media Bechst. The purpose of the studies was to establish the species composition and the population dynamics of aphids inhabiting hawthorn in the street and park sites. The studies found out the presence of four aphid species on the examined trees, namely Aphis pomi De Geer, aphids from the genus Dysaphis Börn., Ovatus crataegarius (Walk. and Rhopalosiphum insertum (Walk.. More aphid species and bigger populations were found in the street site (A as compa red with the park site (B.The weather conditions (air temperatures of over 30°C and stormy rainfalls limited the population of all aphid species. On the other hand, a mild winter and a warm spring with the rainfalls within the norm caused that the number of aphids decreased considerably.

  1. Effects of thiamethoxam seed treatments on soybean aphid (Hemiptera: Aphididae) feeding behavior.

    Science.gov (United States)

    Stamm, M D; Heng-Moss, T M; Baxendale, F P; Reese, J C; Siegfried, B D; Hunt, T E; Gaussoin, R E; Blankenship, E E

    2013-12-01

    Since its discovery in North America in 2000, the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), has rapidly become an important pest of soybean [Glycine max (L.) Merrill], sometimes resulting in significant yield losses. Previous research has documented the toxicity of neonicotinoid seed treatments to soybean aphids, but control under field conditions has been inconsistent. Imidacloprid, a popular neonicotinoid insecticide, has been shown to exhibit antifeedant effects on aphids. Antifeedant activity has not been demonstrated for other neonicotinoids, including thiamethoxam. This research investigated the effects of a thiamethoxam seed treatment on soybean aphid feeding behavior by using electronic penetration graphs (EPG) to visualize stylet penetration behavior. Soybean aphid feeding behavior was assessed for 9 h on thiamethoxam-treated and untreated soybeans (V2 and V4 stages). Because results were inconclusive from initial experiments, a study was conducted to document the effects of thiamethoxam-treated soybeans on soybean aphid survival. The seed treatment was shown to negatively affect aphid survival at 4, 8, and 11 d after aphid introduction. A subsequent EPG study then was designed to document soybean aphid feeding behavior for 15 h, after an initial exposure of 9 h to thiamethoxam-treated soybeans. In this study, the exposed aphids exhibited significant differences in feeding behavior compared with those aphids feeding on untreated soybeans. Soybean aphids on thiamethoxam-treated soybeans spent significantly less time feeding in the sieve element phase, with a greater duration of nonprobing events. These studies suggest soybean aphids are unable to ingest phloem sap, which may be another important element in seed treatment protection.

  2. Differential effects of weather and natural enemies on coexisting aphid populations.

    Science.gov (United States)

    Alyokhin, Andrei; Drummond, Francis A; Sewell, Gary; Storch, Richard H

    2011-06-01

    Study of mechanisms responsible for regulating populations of living organisms is essential for a better comprehension of the structure of biological communities and evolutionary forces in nature. Aphids (Hemiptera: Sternorrhyncha) comprise a large and economically important group of phytophagous insects distributed worldwide. Previous studies determined that density-dependent mechanisms play an important role in regulating their populations. However, only a few of those studies identified specific factors responsible for the observed regulation. Time series data used in this study originated from the untreated control plots that were a part of potato (Solanum tuberosum L.) insecticide trials in northern Maine from 1971 to 2004. The data set contained information on population densities of three potato-colonizing aphid species (buckthorn aphid, Aphis nasturtii; potato aphid, Macrosiphum euphorbiae; and green peach aphid, Myzus persicae) and their natural enemies. We used path analysis to explore effects of weather and natural enemies on the intrinsic growth rates of aphid populations. Weather factors considered in our analyses contributed to the regulation of aphid populations, either directly or through natural enemies. However, direct weather effects were in most cases detectable only at P ≤ 0.10. Potato aphids were negatively affected by both fungal disease and predators, although buckthorn aphids were negatively affected by predators only. Parasitoids did not have a noticeable effect on the growth of any of the three aphid species. Growth of green peach aphid populations was negatively influenced by interspecific interactions with the other two aphid species. Differential population regulation mechanisms detected in the current study might at least partially explain coexistence of three ecologically similar aphid species sharing the same host plant.

  3. Plant chemical defense indirectly mediates aphid performance via interactions with tending ants.

    Science.gov (United States)

    Züst, Tobias; Agrawal, Anurag A

    2017-03-01

    The benefits of mutualistic interactions are often highly context dependent. We studied the interaction between the milkweed aphid Aphis asclepiadis and a tending ant, Formica podzolica. Although this interaction is generally considered beneficial, variation in plant genotype may alter it from mutualistic to antagonistic. Here we link the shift in strength and relative benefit of the ant-aphid interaction to plant genotypic variation in the production of cardenolides, a class of toxic defensive chemicals. In a field experiment with highly variable genotypes of the common milkweed (Asclepias syriaca), we show that plant cardenolides, especially polar forms, are ingested by aphids and excreted in honeydew proportionally to plant concentrations without directly affecting aphid performance. Ants consume honeydew, and aphids that excreted high amounts of cardenolides received fewer ant visits, which in turn reduced aphid survival. On at least some plant genotypes, aphid numbers per plant were reduced in the presence of ants to levels lower than in corresponding ant-exclusion treatments, suggesting antagonistic ant behavior. Although cardenolides appear ineffective as direct plant defenses against aphids, the multi-trophic context reveals an ant-mediated negative indirect effect on aphid performance and population dynamics. © 2016 by the Ecological Society of America.

  4. Effects of nitrogen fertilization in cotton crop on Aphis gossypii Glover (Hemiptera: Aphididae) biology; Efeitos da adubacao nitrogenada em algodoeiro sobre a biologia de Aphis gossypii Glover (Hemiptera: Aphididae)

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Ricardo; Degrande, Paulo E.; Fernandes, Marcos G.; Nogueira, Rodrigo F. [Universidade Federal da Grande Dourados, MS (Brazil). Faculdade de Ciencias Agrarias]. E-mail: rbarrosufms@yahoo.com.br, degrande@ufgd.edu.br

    2007-09-15

    The cotton aphid, Aphis gossypii Glove, is one of the pests of cotton crop and its relation with the host seem to depend on the amount of nitrogen available to the plant. The biology of A. gossypii using different cotton nitrogen fertility regimes was studied under greenhouse conditions, in Dourados, MS. A completely randomized design with nine replications in a factorial scheme (2x4x2)+1 was used. Two nitrogen sources (sulphate of ammonium and urea), four doses of nitrogen (50, 100, 150 and 200 kg ha-1), two different times of nitrogen application and one additional treatment without nitrogen were taken as factors. The nymphal phases, the pre-reproductive, reproductive and pos-reproductive periods, longevity, the life cycle and fecundity of the cotton aphid were evaluated. The doses of nitrogen influenced the cotton aphid biology in both sources and times of application, favoring its development and fecundity. (author)

  5. Predation determines different selective pressure on pea aphid host races in a complex agricultural mosaic.

    Directory of Open Access Journals (Sweden)

    Adalbert Balog

    Full Text Available Field assessments were conducted to examine the interplay between host plant and predation in complex agricultural mosaic on pea aphid clover and alfalfa races. In one experiment, we examined the relative fitness on clover race (CR and alfalfa race (AR pea aphids on broad bean, red clover and alfalfa alone. But because clover is typically grown in a more complex agricultural mosaic with alfalfa and broad bean, a second experiment was conducted to assess the fitness consequences under predation in a more complex agricultural field setting that also included potential apparent competition with AR pea aphids. In a third experiment we tested for the effect of differential host race density on the fitness of the other host race mediated by a predator effect. CR pea aphids always had fitness losses when on broad bean (had lower fitness on broad bean relative to red clover and fitness benefits when on red clover (higher fitness on red clover relative to broad bean, whether or not in apparent competition with alfalfa race aphids on bean and alfalfa. AR suffered fitness loss on both alfalfa and bean in apparent competition with CR on clover. Therefore we can conclude that the predation rate between host races was highly asymmetrical. The complexity of the agricultural mosaic thus can influence prey selection by predators on different host plants. These may have evolutionary consequences through context dependent fitness benefits on particular host plants.

  6. Seasonal phenology and species composition of the aphid fauna in a northern crop production area.

    Directory of Open Access Journals (Sweden)

    Sascha M Kirchner

    Full Text Available BACKGROUND: The species diversity of aphids and seasonal timing of their flight activity can have significant impacts on crop production, as aphid species differ in their ability to transmit plant viruses and flight timing affects virus epidemiology. The aim of the study was to characterise the species composition and phenology of aphid fauna in Finland in one of the northernmost intensive crop production areas of the world (latitude 64°. METHODOLOGY/PRINCIPAL FINDINGS: Flight activity was monitored in four growing seasons (2007-010 using yellow pan traps (YPTs placed in 4-8 seed potato fields and a Rothamsted suction trap. A total of 58,528 winged aphids were obtained, identified to 83 taxa based on morphology, and 34 species were additionally characterised by DNA barcoding. Seasonal flight activity patterns analysed based on YPT catch fell into three main phenology clusters. Monoecious taxa showed early or middle-season flight activity and belonged to species living on shrubs/trees or herbaceous plants, respectively. Heteroecious taxa occurred over the entire potato growing season (ca. 90 days. Abundance of aphids followed a clear 3-year cycle based on suction trap data covering a decade. Rhopalosiphum padi occurring at the end of the potato growing season was the most abundant species. The flight activity of Aphis fabae, the main vector of Potato virus Y in the region, and Aphis gossypii peaked in the beginning of potato growing season. CONCLUSIONS/SIGNIFICANCE: Detailed information was obtained on phenology of a large number aphid species, of which many are agriculturally important pests acting as vectors of plant viruses. Aphis gossypii is known as a pest in greenhouses, but our study shows that it occurs also in the field, even far in the north. The novel information on aphid phenology and ecology has wide implications for prospective pest management, particularly in light of climate change.

  7. Inventory and assessment of foliar natural enemies of the soybean aphid (Hemiptera: Aphididae) in South Dakota.

    Science.gov (United States)

    Hesler, Louis S

    2014-06-01

    Soybean aphid (Aphis glycines Matsumura) (Hemiptera: Aphididae) is a major pest of soybean in northern production regions of North America, and insecticides have been the primary management approach while alternative methods are developed. Knowledge of arthropod natural enemies and their impact on soybean aphid is critical for developing biological control as a management tool. Soybean is a major field crop in South Dakota, but information about its natural enemies and their impact on soybean aphid is lacking. Thus, this study was conducted in field plots in eastern South Dakota during July and August of 2004 and 2005 to characterize foliar-dwelling, arthropod natural enemies of soybean aphid, and it used exclusion techniques to determine impact of natural enemies and ants (Hymenoptera: Formicidae) on soybean aphid densities. In open field plots, weekly soybean aphid densities reached a plateau of several hundred aphids per plant in 2004, and peaked at roughly 400 aphids per plant in 2005. Despite these densities, a relatively high frequency of aphid-infested plants lacked arthropod natural enemies. Lady beetles (Coleoptera: Coccinellidae) were most abundant, peaking at 90 and 52% of all natural enemies sampled in respective years, and Harmonia axyridis Pallas was the most abundant lady beetle. Green lacewings (Neuroptera: Chrysopidae) were abundant in 2005, due mainly to large numbers of their eggs. Abundances of arachnids and coccinellid larvae correlated with soybean aphid densities each year, and chrysopid egg abundance was correlated with aphid density in 2005. Three-week cage treatments of artificially infested soybean plants in 2004 showed that noncaged plants had fewer soybean aphids than caged plants, but abundance of soybean aphid did not differ among open cages and ones that provided partial or total exclusion of natural enemies. In 2005, plants within open cages had fewer soybean aphids than those within cages that excluded natural enemies, and aphid

  8. Soybean Aphid Infestation Induces Changes in Fatty Acid Metabolism in Soybean.

    Directory of Open Access Journals (Sweden)

    Charles Kanobe

    Full Text Available The soybean aphid (Aphis glycines Matsumura is one of the most important insect pests of soybeans in the North-central region of the US. It has been hypothesized that aphids avoid effective defenses by inhibition of jasmonate-regulated plant responses. Given the role fatty acids play in jasmonate-induced plant defenses, we analyzed the fatty acid profile of soybean leaves and seeds from aphid-infested plants. Aphid infestation reduced levels of polyunsaturated fatty acids in leaves with a concomitant increase in palmitic acid. In seeds, a reduction in polyunsaturated fatty acids was associated with an increase in stearic acid and oleic acid. Soybean plants challenged with the brown stem rot fungus or with soybean cyst nematodes did not present changes in fatty acid levels in leaves or seeds, indicating that the changes induced by aphids are not a general response to pests. One of the polyunsaturated fatty acids, linolenic acid, is the precursor of jasmonate; thus, these changes in fatty acid metabolism may be examples of "metabolic hijacking" by the aphid to avoid the induction of effective defenses. Based on the changes in fatty acid levels observed in seeds and leaves, we hypothesize that aphids potentially induce interference in the fatty acid desaturation pathway, likely reducing FAD2 and FAD6 activity that leads to a reduction in polyunsaturated fatty acids. Our data support the idea that aphids block jasmonate-dependent defenses by reduction of the hormone precursor.

  9. Aphis Glycines Virus 2, a Novel Insect Virus with a Unique Genome Structure

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    Sijun Liu

    2016-11-01

    Full Text Available The invasive soybean aphid, Aphis glycines, is a major pest in soybeans, resulting in substantial economic loss. We analyzed the A. glycines transcriptome to identify sequences derived from viruses of A. glycines. We identified sequences derived from a novel virus named Aphis glycines virus 2 (ApGlV2. The assembled virus genome sequence was confirmed by reverse transcription polymerase chain reaction (RT-PCR and Sanger sequencing, conserved domains were characterized, and distribution, and transmission examined. This virus has a positive sense, single-stranded RNA genome of ~4850 nt that encodes three proteins. The RNA-dependent RNA polymerase (RdRp of ApGlV2 is a permuted RdRp similar to those of some tetraviruses, while the capsid protein is structurally similar to the capsid proteins of plant sobemoviruses. ApGlV2 also encodes a larger minor capsid protein, which is translated by a readthrough mechanism. ApGlV2 appears to be widespread in A. glycines populations and to persistently infect aphids with a 100% vertical transmission rate. ApGlV2 is susceptible to the antiviral RNA interference (RNAi pathway. This virus, with its unique genome structure with both plant- and insect-virus characteristics, is of particular interest from an evolutionary standpoint.

  10. Soybean aphid (Hemiptera: Aphididae) response to soybean plant defense: stress levels, tradeoffs, and cross-virulence.

    Science.gov (United States)

    Enders, Laramy; Bickel, Ryan; Brisson, Jennifer; Heng-Moss, Tiffany; Siegfried, Blair; Zera, Anthony; Miller, Nick

    2014-02-01

    A variety of management methods to control the soybean aphid (Aphis glycines Matsumura) have been investigated since its invasion into North America in 2000, among them plant resistance has emerged as a viable option for reducing aphid damage to soybeans and preventing outbreaks. Plant resistance methods often use natural soybean plant defenses that impose stress on aphids by reducing fitness and altering behavior. Research efforts have heavily focused on identification and development of aphid resistant soybean varieties, leaving much unknown about soybean aphid response to stressful host plant defenses. In this study, we aimed to 1) evaluate lifetime fitness consequences and phenotypic variation in response to host plant-induced stress and 2) investigate whether trade-offs involving fitness costs and/or cross-virulence to multiple antibiotic soybean varieties exists. We compared aphid survival and reproduction during and after a short period of exposure to soybeans with the Rag2 resistance gene and measured aphid clonal variation in response to Rag2 soybeans. In addition, we measured the performance of Rag2 virulent and avirulent aphids on five soybean varieties with various forms of antibiotic resistance. Our results indicate that plant defenses impose high levels of stress and have long-term fitness consequences, even after aphids are removed from resistant plants. We identified one aphid clone that was able to colonize Rag2 among the seven clones tested, suggesting that virulent genotypes may be prevalent in natural populations. Finally, although we did not find evidence of cross-virulence to multiple antibiotic soybean varieties, our results suggest independent mechanisms of aphid virulence to Rag1 and Rag2 that may involve fitness costs.

  11. Ability of Aphis gossypii and Myzus persicae to Transmit Cucumber mosaic virus in Single and Mixed Infection with Two Potyviruses to Zucchini Squash

    OpenAIRE

    Pinto, Zayame Vegette [UNESP; Rezende,Jorge Alberto Marques; Yuki, Valdir Atsushi; Piedade,Sônia Maria de Stefano

    2008-01-01

    The main objective of this work was to investigate the ability of Aphis gossypii and Myzus persicae to transmit Cucumber mosaic virus (CMV) singly and mixed with two potyviruses (Papaya ringspot virus - type W, PRSV-W and Zucchini yellow mosaic virus, ZYMV), to zucchini squash plants (Cucurbita pepo). The results showed that the potyviruses in general were more efficiently transmitted by both species of aphids as compared to CMV. The transmission of PRSV-W, ZYMV and CMV separately was more ef...

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

    Directory of Open Access Journals (Sweden)

    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.

  13. New invasive species of aphids (Hemiptera, Aphididae in Serbia and Montenegro

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    Petrović-Obradović Olivera

    2010-01-01

    Full Text Available Three new invasive species of aphids have been found in Serbia: Chaitophorus populifolli Essig, Myzocallis walshii (Monell and Trichosiphonaphis polygonifoliae (Shinji and two have been found in Montenegro: Aphis illinoisensis Shimer and Tinocallis kahawaluokalani (Kirkaldy. A. illinoisensis is a pest of the grapevine, T. polygonifoliae, feeds on a decorative shrub (Lonicera and the other three feed on trees (Populus, Quercus and Lagerostroemia. Three of the species are American aphids and two are of Asian origin. Their morphology, illustrated by original drawings and data on the biology and distribution are given. .

  14. Multivariate approach to quantitative analysis of Aphis gossypii Glover (Hemiptera: Aphididae) and their natural enemy populations at different cotton spacings

    Science.gov (United States)

    Malaquias, José B.; Ramalho, Francisco S.; Dos S. Dias, Carlos T.; Brugger, Bruno P.; S. Lira, Aline Cristina; Wilcken, Carlos F.; Pachú, Jéssica K. S.; Zanuncio, José C.

    2017-02-01

    The relationship between pests and natural enemies using multivariate analysis on cotton in different spacing has not been documented yet. Using multivariate approaches is possible to optimize strategies to control Aphis gossypii at different crop spacings because the possibility of a better use of the aphid sampling strategies as well as the conservation and release of its natural enemies. The aims of the study were (i) to characterize the temporal abundance data of aphids and its natural enemies using principal components, (ii) to analyze the degree of correlation between the insects and between groups of variables (pests and natural enemies), (iii) to identify the main natural enemies responsible for regulating A. gossypii populations, and (iv) to investigate the similarities in arthropod occurrence patterns at different spacings of cotton crops over two seasons. High correlations in the occurrence of Scymnus rubicundus with aphids are shown through principal component analysis and through the important role the species plays in canonical correlation analysis. Clustering the presence of apterous aphids matches the pattern verified for Chrysoperla externa at the three different spacings between rows. Our results indicate that S. rubicundus is the main candidate to regulate the aphid populations in all spacings studied.

  15. Leaf temperature of soybean grown under elevated CO2 increases Aphis glycines (Hemiptera: Aphididae)population growth

    Institute of Scientific and Technical Information of China (English)

    Bridget F. O'Neill; Arthur R. Zangerl; Evan H. DeLucia; Clare Casteel; Jorge A. Zavala; May R. Berenbaum

    2011-01-01

    Plants grown under elevated carbon dioxide (CO2) experience physiological changes that influence their suitability as food for insects.To determine the effects of living on soybean (Glycine max Linnaeus) grown under elevated CO2,population growth of the soybean aphid (Aphis glycines Matsumura) was determined at the SoyFACE research site at the University of Illinois,Urbana-Champaign,Illinois,USA,grown under elevated (550μL/L) and ambient (370μL/L) levels of CO2.Growth of aphid populations under elevated CO2 was significantly greater after 1 week,with populations attaining twice the size of those on plants grown under ambient levels of CO2.Soybean leaves grown under elevated levels of CO2 were previously demonstrated at SoyFACE to have increased leaf temperature caused by reduced stomatal conductance.To separate the increased leaf temperature from other effects of elevated CO2,air temperature was lowered while the CO2 level was increased,which lowered overall leaf temperatures to those measured for leaves grown under ambient levels of CO2.Aphid population growth on plants grown under elevated CO2 and reduced air temperature was not significantly greater than on plants grown under ambient levels of CO2.By increasing Glycine max leaf temperature,elevated CO2 may increase populations of Aphis glycines and their impact on crop productivity.

  16. Studies on the Host Biotypes and Its Cause of Cotton Aphid in Nanjing, China

    Institute of Scientific and Technical Information of China (English)

    LIU Xiang-dong; ZHAI Bao-ping; ZHANG Xiao-xi

    2002-01-01

    The fitness of cotton aphid, Aphis gossypii Glover, on different host plants was studied. The results showed that the cotton aphid population in Nanjing formed host preference bio-types on cucumber and cotton. The aphids from cotton and cucumber could not inter-transplant successfully between the two host plants. The apterous and alate offspring of stem mother from hibiscus could not survive, reproduce and form population normally when they were transplanted to cucumber and water melon, but they could form normally when transplanted to cotton and muskmelon. There was no significant difference between the stylet length of cotton aphids from cucumber and cotton, so the stylet length was not the cause of the host preference. When the aphids originated on hibiscus were transplanted to cotton, water melon and muskmelon, the stylet could reach host phloem to absorb host plant's nutrients, but it couldn't when transplanted to cucumber. Cotton aphid can feed on muskmelon without secretion of water-soluble saliva. It could be concluded that the two host biotypes of cotton aphid came from different winter host plants.

  17. Cucumis melo microRNA expression profile during aphid herbivory in a resistant and susceptible interaction.

    Science.gov (United States)

    Sattar, Sampurna; Song, Yan; Anstead, James A; Sunkar, Ramanjulu; Thompson, Gary A

    2012-06-01

    Aphis gossypii resistance in melon (Cucumis melo) is due to the presence of a single dominant virus aphid transmission (Vat) gene belonging to the nucleotide-binding site leucine-rich repeat family of resistance genes. Significant transcriptional reprogramming occurs in Vat(+) plants during aphid infestation as metabolism shifts to respond to this biotic stress. MicroRNAs (miRNAs) are involved in the regulation of many biotic stress responses. The role of miRNAs was investigated in response to aphid herbivory during both resistant and susceptible interactions. Small RNA (smRNA) libraries were constructed from bulked leaf tissues of a Vat(+) melon line following early and late aphid infestations. Sequence analysis indicated that the expression profiles of conserved and newly identified miRNAs were altered during different stages of aphid herbivory. These results were verified by quantitative polymerase chain reaction experiments in both resistant Vat(+) and susceptible Vat(-) interactions. The comparative analyses revealed that most of the conserved miRNA families were differentially regulated during the early stages of aphid infestation in the resistant and susceptible interactions. Along with the conserved miRNA families, 18 cucurbit-specific miRNAs were expressed during the different stages of aphid herbivory. The comparison of the miRNA profiles in the resistant and susceptible interactions provides insight into the miRNA-dependent post-transcriptional gene regulation in Vat-mediated resistance.

  18. A new active piggyBac-like element in Aphis gossypii

    Institute of Scientific and Technical Information of China (English)

    Guana-Hua Luo; Min Wu; Xiao-Fang Wang; Wei Zhang; Zhao-Jun Han

    2011-01-01

    Nine piggyBac-like elements (PLEs) were identified from the cotton aphid Aphis gossypii Glover.All the PLEs shared high sequence similarity with each other.However,eight of the nine PLEs were unlikely to encode functional transposase due to the existence of disruptive mutations within the coding regions.The other one PLE contained major characteristics of members in the piggyBac family,including TTAA target site duplications,inverted terminal repeats (ITRs),and an open reading frame (ORF) coding for a transposase with a putative DDD domain.This one with an intact transposase ORF was named AgoPLE1.1.The predicted transposase shared 47% similarity with that of Trichoplusia ni piggyBac IFP2.Phylogenetic analyses showed that AgoPLE1.1 was most related to the Heliothis virescens PLEl.1 (HvPLEl.1) element,with 45% and 60% similarity at the nucleotide and amino acid levels,respectively.A functional assay demonstrated that AgoPLEl.1 encoded a functional transposase and was able to cause precise excision in cell cultures.On the other hand,few genomic insertion polymorphisms of AgoPLE1 were observed in the genome of the cotton aphid.These observations suggested that AgoPLEl.1 was a PLE that invaded the cotton aphid genome in recent periods and retained its activity.

  19. DL-β-aminobutyric acid-induced resistance in soybean against Aphis glycines Matsumura (Hemiptera: Aphididae.

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    Yunpeng Zhong

    Full Text Available Priming can improve plant innate capability to deal with the stresses caused by both biotic and abiotic factors. In this study, the effect of DL-β-amino-n-butyric acid (BABA against Aphis glycines Matsumura, the soybean aphid (SA was evaluated. We found that 25 mM BABA as a root drench had minimal adverse impact on plant growth and also efficiently protected soybean from SA infestation. In both choice and non-choice tests, SA number was significantly decreased to a low level in soybean seedlings drenched with 25 mM BABA compared to the control counterparts. BABA treatment resulted in a significant increase in the activities of several defense enzymes, such as phenylalanine ammonia-lyase (PAL, peroxidase (POX, polyphenol oxidase (PPO, chitinase (CHI, and β-1, 3-glucanase (GLU in soybean seedlings attacked by aphid. Meanwhile, the induction of 15 defense-related genes by aphid, such as AOS, CHS, MMP2, NPR1-1, NPR1-2, and PR genes, were significantly augmented in BABA-treated soybean seedlings. Our study suggest that BABA application is a promising way to enhance soybean resistance against SA.

  20. Methyl salicylate attracts natural enemies and reduces populations of soybean aphids (Hemiptera: Aphididae) in soybean agroecosystems.

    Science.gov (United States)

    Mallinger, Rachel E; Hogg, David B; Gratton, Claudio

    2011-02-01

    Methyl salicylate, an herbivore-induced plant volatile, has been shown to attract natural enemies and affect herbivore behavior. In this study, methyl salicylate was examined for its attractiveness to natural enemies of the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), and for its direct effects on soybean aphid population growth rates. Methyl salicylate lures were deployed in plots within organic soybean [Glycine max (L.) Merr.] fields. Sticky card traps adjacent to and 1.5 m from the lure measured the relative abundance of natural enemies, and soybean aphid populations were monitored within treated and untreated plots. In addition, exclusion cage studies were conducted to determine methyl salicylate's effect on soybean aphid population growth rates in the absence of natural enemies. Significantly greater numbers of syrphid flies (Diptera: Syrphidae) and green lacewings (Neuroptera: Chrysopidae) were caught on traps adjacent to the methyl salicylate lure, but no differences in abundance were found at traps 1.5 m from the lure. Furthermore, abundance of soybean aphids was significantly lower in methyl salicylate-treated plots. In exclusion cage studies, soybean aphid numbers were significantly reduced on treated soybean plants when all plants were open to natural enemies. When plants were caged, however, soybean aphid numbers and population growth rates did not differ between treated and untreated plants suggesting no effect of methyl salicylate on soybean aphid reproduction and implicating the role of natural enemies in depressing aphid populations. Although aphid populations were reduced locally around methyl salicylate lures, larger scale studies are needed to assess the technology at the whole-field scale.

  1. What is the economic threshold of soybean aphids (Hemiptera: Aphididae) in enemy-free space?

    Science.gov (United States)

    McCarville, M T; Kanobe, C; MacIntosh, G C; O'Neal, M

    2011-06-01

    Soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is a serious pest of soybean, Glycine max (L.) Merr., in the North Central United States. Current management recommendations rely on the application of insecticides based on an economic threshold (ET) of 250 aphids per plant. Natural enemies are important in slowing the increase of aphid populations and can prevent them from reaching levels that can cause economic losses. However, biological control of A. glycines is inconsistent and can be affected negatively by the intensity of agricultural activity. We measured the impact of a natural-enemy-free environment on the capacity of the current ET to limit yield loss. In 2008 and 2009, caged microplots were assigned to one of three treatments: plants kept aphid-free (referred to as the control), plants that experienced a population of 250 aphids per plant (integrated pest management [IPM]), and plants that experienced unlimited aphid population growth (unlimited). The population growth rate of aphids in the unlimited treatment for the 10 d after the application of insecticides to the IPM treatment was calculated using linear regression. The linear equation was solved to determine the mean number of days between the ET and the EIL for an aphid population in absence of predators. The number of days was determined to be 6.97 +/- 1.11 d. The 2-yr average yield for the IPM treatment was 99.93% of the control treatment. Our study suggests the current soybean aphid ET of 250 aphids per plant can effectively protect yield even if the impact of natural enemies is reduced.

  2. Ability of Aphis gossypii and Myzus persicae to Transmit Cucumber mosaic virus in Single and Mixed Infection with Two Potyviruses to Zucchini Squash Eficiência dos afídeos Aphis gossypii e Myzus persicae na transmissão do Cucumber mosaic virus em infecção simples e mista com dois Potyvirus para abobrinha de moita

    OpenAIRE

    Zayame Vegette Pinto; Jorge Alberto Marques Rezende; Valdir Atsushi Yuki; Sônia Maria de Stefano Piedade

    2008-01-01

    The main objective of this work was to investigate the ability of Aphis gossypii and Myzus persicae to transmit Cucumber mosaic virus (CMV) singly and mixed with two potyviruses (Papaya ringspot virus - type W, PRSV-W and Zucchini yellow mosaic virus, ZYMV), to zucchini squash plants (Cucurbita pepo). The results showed that the potyviruses in general were more efficiently transmitted by both species of aphids as compared to CMV. The transmission of PRSV-W, ZYMV and CMV separately was more ef...

  3. Effect of silicon and acibenzolar-s-methyl on colored cotton plants infested or not with Aphis gossypii Glover (Hemiptera, Aphididae

    Directory of Open Access Journals (Sweden)

    Eliana Alcantra

    2011-06-01

    Full Text Available Effect of silicon and acibenzolar-s-methyl on colored cotton plants infested or not with Aphis gossypii Glover (Hemiptera, Aphididae. The aphid Aphis gossypii is an insect pest that causes damage mainly at the beginning of the cotton plant development. The effect of resistance inductors silicon and acibenzolar-s-methyl (ASM on the development of colored cotton plants were researched in the presence and absence of A. gossypii. Three colored cotton cultivars were sown in pots and individually infested with 25 apterous aphids, 13 days after the application of the inductors. Fifteen days after plant emergence, the silicon was applied at a dosage equivalent to 3 t/ha and acibenzolar-s-methyl in 0.2% solution of the product BION 500®. After 21 days of infestation the following parameters were evaluated: plant height, stem diameter, dry matter of aerial part and root, and total number of aphids replaced. It was verified that the plant height was reduced in the presence of aphids and all variables were negatively affected by the application of ASM. However, silicon did not affect plant development.

  4. Energy budgets of the Chinese green lacewing (Neuroptera: Chrysopidae) and its potential for biological control of the cotton aphid (Homoptera: Aphididae)

    Institute of Scientific and Technical Information of China (English)

    FENG GAO; XIANG-HUI LIU; FENG GE

    2007-01-01

    Energy budgets of larval stages of the Chinese green lacewing, Chrysopa sinica (Tjeder) (Neuroptera: Chrysopidae) were determined under laboratory conditions at photoperiod of 14:10 L:D, 27±1℃ and 75%±2% RH. The energy used as ingestion,assimilation, respiration, productivity and feces was constructed for each developmental stage. In addition, under these experimental conditions, the potential of C.sinica as a biological control agent was evaluated according to the ingestion by this predator and the energy content of cotton aphid, Aphis gossypii (Glover) (Homoptera: Aphididae). The larval stage of C. sinica was able to consume 1281.4 1-day-old aphids, 1018.7 2-day-old aphids,626.9 3-day-old aphids, 393.5 4-day-old aphids, 312.1 5-day-old aphids or 203.5 9-day-old aphids, respectively. No significant difference was detected between the estimated number of aphids consumed by the lacewings using energetic methods and the actual number of aphids consumed by the lacewings in this experiment. Our results showed that C. sinica is an important natural enemy of the cotton aphid, and energetic methods are very useful to quantify biological control efficacy of natural enemies.

  5. A protein from the salivary glands of the pea aphid, Acyrthosiphon pisum, is essential in feeding on a host plant.

    Science.gov (United States)

    Mutti, Navdeep S; Louis, Joe; Pappan, Loretta K; Pappan, Kirk; Begum, Khurshida; Chen, Ming-Shun; Park, Yoonseong; Dittmer, Neal; Marshall, Jeremy; Reese, John C; Reeck, Gerald R

    2008-07-22

    In feeding, aphids inject saliva into plant tissues, gaining access to phloem sap and eliciting (and sometimes overcoming) plant responses. We are examining the involvement, in this aphid-plant interaction, of individual aphid proteins and enzymes, as identified in a salivary gland cDNA library. Here, we focus on a salivary protein we have arbitrarily designated Protein C002. We have shown, by using RNAi-based transcript knockdown, that this protein is important in the survival of the pea aphid (Acyrthosiphon pisum) on fava bean, a host plant. Here, we further characterize the protein, its transcript, and its gene, and we study the feeding process of knockdown aphids. The encoded protein fails to match any protein outside of the family Aphididae. By using in situ hybridization and immunohistochemistry, the transcript and the protein were localized to a subset of secretory cells in principal salivary glands. Protein C002, whose sequence contains an N-terminal secretion signal, is injected into the host plant during aphid feeding. By using the electrical penetration graph method on c002-knockdown aphids, we find that the knockdown affects several aspects of foraging and feeding, with the result that the c002-knockdown aphids spend very little time in contact with phloem sap in sieve elements. Thus, we infer that Protein C002 is crucial in the feeding of the pea aphid on fava bean.

  6. Coexistence of three specialist aphids on common milkweed, Asclepias syriaca.

    Science.gov (United States)

    Smith, R A; Mooney, K A; Agrawal, A A

    2008-08-01

    Coexistence of host-specific herbivores on plants is believed to be governed by interspecific interactions, but few empirical studies have systematically unraveled these dynamics. We investigated the role of several factors in promoting coexistence among the aphids Aphis nerii, Aphis asclepiadis, and Myzocallis asclepiadis that all specialize on common milkweed (Asclepias syriaca). Competitive exclusion is thought to occur when interspecific competition is stronger than intraspecific competition. Consequently, we investigated whether predators, mutualists, or resource quality affected the strength of intra- vs. interspecific competition among aphids in factorial manipulations of competition with exposure to predation, ants, and variable plant genotypes in three separate experiments. In the predation x competition experiment, predators reduced aphid per capita growth by 66%, but the strength of intra- and interspecific competition did not depend on predators. In the ants x competition experiment, ants reduced per capita growth of A. nerii and M. asclepiadis (neither of which were mutualists with ants) by approximately one-half. In so doing, ants ameliorated the negative effects of these competitors on ant-tended A. asclepiadis by two-thirds, representing a novel benefit of ant-aphid mutualism. Nevertheless, ants alone did not explain the persistence of competitively inferior A. asclepiadis as, even in the presence of ants, interspecific competition remained stronger than intraspecific competition. In the plant genotype x competition experiment, both A. asclepiadis and M. asclepiadis were competitively inferior to A. nerii, with the strength of interspecific competition exceeding that of intraspecific competition by 83% and 23%, respectively. Yet these effects differed among milkweed genotypes, and there were one or more plant genotypes for each aphid species where coexistence was predicted. A synthesis of our results shows that predators play little or no role in

  7. Rapid evolution of symbiotic bacteria populations in spirotetramat-resistant Aphis gossypii glover revealed by pyrosequencing.

    Science.gov (United States)

    Zhang, Juhong; Pan, Yiou; Zheng, Chao; Gao, Xiwu; Wei, Xiang; Xi, Jinghui; Peng, Tianfei; Shang, Qingli

    2016-12-01

    Aphis gossypii is one of the most economically important insect pests for agriculture worldwide. Aphids have developed symbiotic associations with bacterial species, which has led to morphological and molecular differences, such as body color and insecticide resistance. Adults and 3rd instar nymphs of a laboratory-selected spirotetramat-resistant strain of cotton aphid presented 579-fold and 15-fold higher resistance to spirotetramat, respectively, than a susceptible strain (Pan et al., 2015; Peng et al., 2016). In this study, we found that antibiotics, especially ampicillin and tetracycline, increased spirotetramat toxicity in resistant aphids. We also characterized all of the bacterial endosymbionts in these two clones by sequencing the 16S rRNA genes of the endosymbiont. The total reads could be clustered into 3534 operational taxonomic units (OTUs) that showed 97% similarity and belonged to six abundant phyla. Proteobacteria and Firmicutes dominated in the two strains, and the most abundant families were Enterobacteriaceae, Lactobacillaceae and Rhodobiaceae. The genera Arsenophonus, Anderseniella, Buchnera and Lactobacillus were most abundant in the susceptible strain, whereas a significant decrease in abundance of Anderseniella and a great increase in abundance of Arsenophonus and Lactobacillus were observed in the resistant strain. Certain identified species had low sequence similarity to the reported species, which indicates the possibility of novel taxa. The type and abundance of different bacterial groups varied significantly between the two strains. The insecticide selection pressure could be the reason for the observed shift in the bacteria groups. These results increase our understanding of the symbiotic relationships between bacteria and their hosts under insecticide stress and provide clues for the development of potential control techniques against this cotton aphid. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Identification of differentially expressed genes related to aphid resistance in cucumber (Cucumis sativus L.).

    Science.gov (United States)

    Liang, Danna; Liu, Min; Hu, Qijing; He, Min; Qi, Xiaohua; Xu, Qiang; Zhou, Fucai; Chen, Xuehao

    2015-05-11

    Cucumber, a very important vegetable crop worldwide, is easily damaged by pests. Aphids (Aphis gossypii Glover) are among the most serious pests in cucumber production and often cause severe loss of yield and make fruit quality get worse. Identifying genes that render cucumbers resistant to aphid-induced damage and breeding aphid-resistant cucumber varieties have become the most promising control strategies. In this study, a Illumina Genome Analyzer platform was applied to monitor changes in gene expression in the whole genome of the cucumber cultivar 'EP6392' which is resistant to aphids. Nine DGE libraries were constructed from infected and uninfected leaves. In total, 49 differentially expressed genes related to cucumber aphid resistance were screened during the treatment period. These genes are mainly associated with signal transduction, plant-pathogen interactions, flavonoid biosynthesis, amino acid metabolism and sugar metabolism pathways. Eight of the 49 genes may be associated with aphid resistance. Finally, expression of 9 randomly selected genes was evaluated by qRT-PCR to verify the results for the tag-mapped genes. With the exception of 1-aminocyclopropane-1-carboxylate oxidase homolog 6, the expression of the chosen genes was in agreement with the results of the tag-sequencing analysis patterns.

  9. Evaluation of late vegetative and reproductive stage soybeans for resistance to soybean aphid (Hemiptera: Aphididae).

    Science.gov (United States)

    Prochaska, T J; Pierson, L M; Baldin, E L L; Hunt, T E; Heng-Moss, T M; Reese, J C

    2013-04-01

    The soybean aphid, Aphis glycines Matsumura, has become the most significant soybean [Glycine max (L.) Merrill] insect pest in the north central soybean production region of North America. The objectives of this research were to measure selected genotypes for resistance to the soybean aphid in the later vegetative and reproductive stages under field conditions, and confirm the presence of tolerance in KS4202. The results from 2007 to 2011 indicate that KS4202 can support aphid populations with minimal yield loss at levels where significant yield loss would be expected in most other genotypes. The common Nebraska cultivar, 'Asgrow 2703', appears to show signs of tolerance as well. None of the yield parameters were significantly different between the aphid infested and noninfested treatments. Based on our results, genotypes may compensate for aphid feeding in different ways. Asgrow 2703 appears to produce a similar number of seeds as its noninfested counterpart, although the seeds produced are slightly smaller. Field evaluation of tolerance in KS4202 indicated a yield loss of only 13% at 34,585-53,508 cumulative aphid-days, when 24-36% yield loss would have been expected.

  10. Occurrence of Lysiphlebus testaceipes parasitizing Aphis gossypii in watermelon in the State of Rio Grande do Norte, Brazil Ocorrência de Lysiphlebus testaceipes parasitando Aphis gossypii em melancia, no Estado do Rio Grande do Norte, Brasil

    Directory of Open Access Journals (Sweden)

    Luciano Pacelli Medeiros Macedo

    2010-09-01

    Full Text Available This is the first report of the parasitoid Lysiphlebus testaceipes (Cresson as a biological control agent of the aphid Aphis gossypii Glover in watermelon crop in Vale do Açu, RN. It was observed that near the harvest, almost all collected aphids were mummified, and after analyzing the emerged parasitoids, the parasitoid L. testaceipes was identified. Therefore, in the future, this species may be included in A. gossypii integrated management programs.Este é o primeiro relato do parasitoide Lysiphlebus testaceipes (Cresson como agente de controle biológico do pulgão Aphis gossypii Glover na cultura da melancia, na região do Vale do Açu, Rio Grande do Norte (RN. Observou-se que próximo da colheita quase todos os pulgões coletados encontravam-se mumificados e, na análise dos parasitoides emergidos, constatou-se o parasitismo por L. testaceipes. Essa espécie, portanto, poderá ser incluída em um programa de manejo integrado de A. gossypii futuramente.

  11. EFISIENSI PENULARAN VIRUS MOSAIK BENGKUANG DENGAN Aphis craccivora Koch. DAN A. gossypii Glover.

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    Tri Asmira Damayanti

    2010-09-01

    Full Text Available Yambean mosaic virus is the most important virus infecting yam bean in Indonesia. The virus were transmitted either mechanically or via aphid.  This study to test the transmission efficiency of the virus via A. craccivora and A. gossypii by using different number of aphid such 1, 3, 5, 7, and 10 for each treatment. To determine the transmission efficiency, incubation period, type of symptom and incidence were used as parameter. Transmission of virus by A. craccivora showed incidence range 90 to 100%, significant differences in incubation time of 1 aphid compared to other treatments and showed severe leaf mosaic, vein-banding and severe leaf malformation such as string. However, the incidence of transmission of virus by A. gossypii was range 70 to 100%, with longer incubation period in compare with A. craccivora. There was no significant differences of incubation period among treatments by A. gossypii. The infected plants showed leaf malformation, vein-banding, wrinkle and blotch on the leaves. Based on these, both aphids species could transmitted virus efficiently, and among them A. craccivora considerate has higher ability as efficient insect vector to transmit the virus in compare with A. gossypii.

  12. Resistance of squash cultivars to Aphis gossypii Resistência de cultivares de abobrinha italiana a Aphis gossypii

    Directory of Open Access Journals (Sweden)

    Edson LL Baldin

    2009-09-01

    Full Text Available The Cucurbitaceae plants are damaged by attack of a wide spectrum of insects and microorganisms. Among the sucker insects causing damages on squash Cucurbita pepo (L., the aphid Aphis gossypii (Glover (Hemiptera: Aphididae is pointed as one of the most important, once their nymphs and adults suck the sap of the leaves continuously, besides being potential vector of virus. The present research evaluated different cultivars, aiming to identify the resistance against this aphid. The cultivars Novita, Sandy, Caserta Cac Melhorada, Novita Plus, Samira, AF-2858 and Caserta TS were used in laboratory assays (T= 25±2ºC; RH= 70±10% and fotophase= 12 h. In the immature phase the duration of nymphal instars was evaluated, the total duration and their viability, confining individuals on leaf disks from cultivars. In the adult phase the duration of reproductive period, the fecundity and the biological cycle were observed. The cultivar 'Sandy' expressed high level of antibiosis and feeding non-preference against A. gossypii, increasing the nymphal stage and causing mortality near to 70%. Besides, this cultivar reduced the production of nymphs and the longevity of the insects. The 'Novita Plus' cultivar also induced significant nymphal mortality, however in lower levels than those verified in 'Sandy', indicating a moderate resistance.As plantas da família Cucurbitaceae são prejudicadas pelo ataque de um amplo espectro de insetos e microrganismos. Dentre os insetos sugadores que atacam a abobrinha Cucurbita pepo (L., o pulgão Aphis gossypii (Glover (Hemiptera: Aphididae merece destaque, uma vez que suas ninfas e adultos sugam a seiva das folhas constantemente, além de ser potencial vetor de vírus. A presente pesquisa foi realizada com o objetivo de avaliar diferetes cultivares de abobrinha italiana quanto à resistência a esse pulgão. Utilizaram-se as cultivares Novita, Sandy, Caserta Cac Melhorada, Novita Plus, Samira, AF-2858 e Caserta TS em ensaios

  13. DNA barcoding and the associated PhylAphidB@se website for the identification of European aphids (Insecta: Hemiptera: Aphididae.

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    Armelle Coeur d'Acier

    Full Text Available Aphids constitute a diverse group of plant-feeding insects and are among the most important crop pests in temperate regions. Their morphological identification is time-consuming and requires specific knowledge, training and skills that may take years to acquire. We assessed the advantages and limits of DNA barcoding with the standard COI barcode fragment for the identification of European aphids. We constructed a large reference dataset of barcodes from 1020 specimens belonging to 274 species and 87 genera sampled throughout Europe and set up a database-driven website allowing species identification from query sequences.In this unbiased sampling of the taxonomic diversity of European aphids, intraspecific divergence ranged from 0.0% to 3.9%, with a mean value of 0.29%, whereas mean congeneric divergence was 6.4%, ranging from 0.0% to 15%. Neighbor-joining analysis generated a tree in which most species clustered in distinct genetic units. Most of the species with undifferentiated or overlapping barcodes belonged to the genus Aphis or, to a lesser extent, the genera Brachycaudus, Dysaphis and Macrosiphum. The taxa involved were always morphologically similar or closely related and belonged to species groups known to present taxonomic difficulties.These data confirm that COI barcoding is a useful identification tool for aphids. Barcode identification is straightforward and reliable for 80% of species, including some difficult to distinguish on the basis of morphological characters alone. Unsurprisingly, barcodes often failed to distinguish between species from groups for which classical taxonomy has also reached its limits, leading to endless revisions and discussions about species and subspecies definitions. In such cases, the development of an effective procedure for the accurate identification of aphid specimens continues to pose a difficult challenge.

  14. Identification of top-down forces regulating cotton aphid population growth in transgenic Bt cotton in central China.

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    Peng Han

    Full Text Available The cotton aphid Aphis gossypii Glover is the main aphid pest in cotton fields in the Yangtze River Valley Cotton-planting Zone (YRZ in central China. Various natural enemies may attack the cotton aphid in Bt cotton fields but no studies have identified potential specific top-down forces that could help manage this pest in the YRZ in China. In order to identify possibilities for managing the cotton aphid, we monitored cotton aphid population dynamics and identified the effect of natural enemies on cotton aphid population growth using various exclusion cages in transgenic Cry1Ac (Bt+CpTI (Cowpea trypsin inhibitor cotton field in 2011. The aphid population growth in the open field (control was significantly lower than those protected or restricted from exposure to natural enemies in the various exclusion cage types tested. The ladybird predator Propylaea japonica Thunberg represented 65% of Coccinellidae predators, and other predators consisted mainly of syrphids (2.1% and spiders (1.5%. The aphid parasitoids Aphidiines represented 76.7% of the total count of the natural enemy guild (mainly Lysiphlebia japonica Ashmead and Binodoxys indicus Subba Rao & Sharma. Our results showed that P. japonica can effectively delay the establishment and subsequent population growth of aphids during the cotton growing season. Aphidiines could also reduce aphid density although their impact may be shadowed by the presence of coccinellids in the open field (likely both owing to resource competition and intraguild predation. The implications of these results are discussed in a framework of the compatibility of transgenic crops and top-down forces exerted by natural enemy guild.

  15. Identification of top-down forces regulating cotton aphid population growth in transgenic Bt cotton in central China.

    Science.gov (United States)

    Han, Peng; Niu, Chang-ying; Desneux, Nicolas

    2014-01-01

    The cotton aphid Aphis gossypii Glover is the main aphid pest in cotton fields in the Yangtze River Valley Cotton-planting Zone (YRZ) in central China. Various natural enemies may attack the cotton aphid in Bt cotton fields but no studies have identified potential specific top-down forces that could help manage this pest in the YRZ in China. In order to identify possibilities for managing the cotton aphid, we monitored cotton aphid population dynamics and identified the effect of natural enemies on cotton aphid population growth using various exclusion cages in transgenic Cry1Ac (Bt)+CpTI (Cowpea trypsin inhibitor) cotton field in 2011. The aphid population growth in the open field (control) was significantly lower than those protected or restricted from exposure to natural enemies in the various exclusion cage types tested. The ladybird predator Propylaea japonica Thunberg represented 65% of Coccinellidae predators, and other predators consisted mainly of syrphids (2.1%) and spiders (1.5%). The aphid parasitoids Aphidiines represented 76.7% of the total count of the natural enemy guild (mainly Lysiphlebia japonica Ashmead and Binodoxys indicus Subba Rao & Sharma). Our results showed that P. japonica can effectively delay the establishment and subsequent population growth of aphids during the cotton growing season. Aphidiines could also reduce aphid density although their impact may be shadowed by the presence of coccinellids in the open field (likely both owing to resource competition and intraguild predation). The implications of these results are discussed in a framework of the compatibility of transgenic crops and top-down forces exerted by natural enemy guild.

  16. Lethal and sublethal effects of neem on Aphis gossypii and Cycloneda sanguinea in watermelon

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    Cíntia Ribeiro Souza

    2015-05-01

    Full Text Available The objective of this study was to evaluate the impact of oil extract of neem, Azadirachta indica, on the watermelon aphid Aphis gossypii and its natural enemy Cycloneda sanguinea. Toxicity bioassays were conducted with the commercial product DalNeem (1,475 g L-1 azadirachtin at 0.0037 µg a.i. mL-1, 0.0074 µg a.i. mL-1 and 0.0148 µg a.i. mL-1, Malathion at 1 µg a.i. mL-1 and distilled water as a control treatment. The products were sprayed to watermelon leaf discs, and the insects were exposed to the product residues. The instantaneous population growth rate of A. gossypii and the survival of C. sanguinea larvae exposed to the different treatments were calculated. A decrease in the instantaneous population growth rate of A. gossypii with increasing concentrations of neem was observed, and the aphids did not reproduce on the leaf discs treated with malathion during the first 24 hours of exposure due to its rapid lethal effect on adult insects. The larvae of the predator C. sanguinea exposed to malathion survived only for 24 hours. The survival of the predator exposed to different concentrations of neem was also significantly reduced compared to the predators exposed only to water. However, laboratory experiments may overestimate the effect of neem on predators because the individuals cannot employ escape behavior caused by neem repellency.

  17. The effects of Aphis fabae infestation on the antioxidant response and heavy metal content in field grown Philadelphus coronarius plants

    Energy Technology Data Exchange (ETDEWEB)

    Kafel, Alina, E-mail: akafel@us.edu.pl [University of Silesia, Department of Animal Physiology and Ecotoxicology, Bankowa 9, PL 40-007, Katowice (Poland); Nadgorska-Socha, Aleksandra [University of Silesia, Department of Ecology, Bankowa 9, PL 40-007, Katowice (Poland); Gospodarek, Janina [Agricultural University of Krakow, Department of Agricultural Environment Protection, Mickiewicza 21, PL 31-120, Krakow (Poland); Babczynska, Agnieszka; Skowronek, Magda [University of Silesia, Department of Animal Physiology and Ecotoxicology, Bankowa 9, PL 40-007, Katowice (Poland); Kandziora, Marta [University of Silesia, Department of Ecology, Bankowa 9, PL 40-007, Katowice (Poland); Rozpedek, Katarzyna [University of Silesia, Department of Animal Physiology and Ecotoxicology, Bankowa 9, PL 40-007, Katowice (Poland)

    2010-02-01

    The purpose of this study was to explore a possible relationship between the soil availability of metals and their concentrations in various parts of Philadelphuscoronarius plants. Moreover, the possible impact of an aphid infestation on the contamination and antioxidant response of plants from the urban environment of Krakow and the reference rural area of Zagaje Stradowskie (southern Poland) was analyzed. The contents of the glutathione, proline, non-protein - SH groups, antioxidants, and phosphorous and the levels of guaiacol peroxidase and catalase activity in leaves and shoots either infested or not by the aphid Aphis fabae Scop., were measured. The potential bioavailability of metals (Cd; Cu; Ni; Pb; Zn) in the soil and their concentrations in P. coronarius plants originating from both sites were compared. The antioxidant responses were generally elevated in the plants in the polluted area. Such reactions were additionally changed by aphid infestation. Generally, the concentrations of metals in the HNO{sub 3} and CaCl{sub 2} extractants of the soils from two layers at the 0-20 and 20-40 cm depths from the polluted area were higher than in those from the reference area. Such differences were found for nickel and lead (in all examined extractants), zinc (in soil extractants from the layer at 20-40 cm) and cadmium (in HNO{sub 3} extractants). Significant positive relationships between the lead concentrations in the soil and in the plants were found. In the parts of plants from the polluted area, higher concentrations of Pb and Zn (leaves and shoots) and Cd (shoots) were recorded. The shoots and leaves of plants infested with aphids had higher concentrations of Zn but lower Pb. Moreover, their leaves had higher contaminations of Cu and Ni. In conclusion, aphids affected not only the antioxidant response of the plants but also their contamination with metals, especially contamination of the leaves.

  18. Special plant species determines diet breadth of phytophagous insects: a study on host plant expansion of the host-specialized Aphis gossypii Glover.

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    Wei Wu

    Full Text Available Host specialization is a ubiquitous character of phytophagous insects. The polyphagous population is usually composed of some subpopulations that can use only a few closely related plants. Cotton-melon aphids, Aphis gossypii Glover exhibited strong host specialization, and the cotton- and cucurbits-specialized biotypes had been clearly identified. However, the experimental work that addressed the roles of plant species in determining diet breadth of phytophagous insects is rare. In the present study, we took the artificial host transfer method to assess the role of two special plants, zucchini Cucurbita zucchini L. and cowpea Vigna unguiculata (Linn. Walp, in regulating diet breadth of cotton- and cucurbits-specialized A. gossypii collected from cotton and cucumber fields and reared separately on the native host plant for ten years. The results showed that the cotton-specialized aphids did not directly use cucumber whereas the cucurbits-specialized did not use cotton regardless of the coexistence or separation of cotton and cucumber plants. Neither of the cotton- and cucurbits-specialized aphids could use capsicum Capsicum annuum, eggplant Solanum melongenahttp://en.wikipedia.org/wiki/Carolus_Linnaeus, tomato Solanum lycopersicum, maize Zea mayshttp://en.wikipedia.org/wiki/Carl_Linnaeus, and radish Raphanus sativus, however, both of them could use zucchini and cowpea. Moreover, the feeding experience on zucchini led the cotton-specialized aphids to use cucumber well and finally to be transformed into the cucurbits-specialized biotype. The short-term feeding experience on cowpea resulted in the diet breadth expansion of the cucurbits-specialized aphids to use cotton. On the other hand, the diet breadth expansion of the cucurbits- and cotton-specialized aphids was only realized by different species of plant. It concluded that the special host plant did induce the conversion of feeding habits in the cotton- and cucurbits-specialized aphids, and

  19. Returns to integrated pest management research and outreach for soybean aphid.

    Science.gov (United States)

    Song, Feng; Swinton, Scott M

    2009-12-01

    Soybean aphid, Aphis glycines Matsumura, is a major invasive pest that has caused substantial yield loss and increased insecticide use in the United States since its discovery in 2000. Using the economic surplus approach, we estimate the economic benefits of U.S. research and outreach for integrated pest management (IPM) of soybean aphid. We calculate ex ante net benefits from adoption of an IPM economic threshold (ET). The ET triggers insecticide application only if the value of predicted yield damage from pest scouting is expected to exceed the cost of pest control. Our research finds that gradual adoption of an ET for soybean aphid management will generate a projected economic net benefit of $1.3 billion, for an internal rate of return of 124%, over the 15 yr since soybean aphid IPM research began in 2003. Lower and upper bound sensitivity analysis brackets the estimated net benefit to U.S. consumers and soybean, Glycine max (L.) Merr., growers in the range of $0.6 to $2.6 billion in 2005 dollars. If a 10% rate of return is attributed to IPM applied research and outreach on soybean aphid, that would leave nearly $800 million to compensate prior activities that contribute to the development and adoption of IPM.

  20. Assessment of patch quality by aphidophagous ladybirds: laboratory study on the minimum density of aphids required for oviposition

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    B. C. Das

    2011-12-01

    Full Text Available Many studies indicate that there is a density of aphids below which ladybirds are unlikely to lay eggs. This is adaptive as theory indicates that a certain minimum population density of aphids is required if hatchling larvae are to survive. The responses of gravid females of the two spot ladybird, Adalia bipunctata (L. (Coleoptera: Coccinellidae, recorded over a period of an hour, to colonies of 5 and 50 pea aphids on bean plants and similar plants each previously infested with the same number of aphids for 48 hours were determined. Proportionally more of the ladybirds on plants with 50 aphids or that were previously infested with the same number of aphids for 48 hours laid eggs and larger clusters of eggs, and were less active than those on plants that were infested with or had previously been infested with five aphids. That is, gravid females showed similar oviposition and activity responses to aphid abundance and different levels of honeydew contamination. This indicates that honeydew contamination may be an important cue used by ladybirds when locating and assessing the abundance of prey in aphid colonies.

  1. Tanggap fungsional Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae terhadap Aphis gossypii (Glover (Homoptera: Aphididae pada umur tanaman cabai berbeda

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    Novri Nelly

    2015-09-01

    Full Text Available The lady beetle, Menochilus sexmaculatus is one of the biological control agents that can be used to control aphids. Presently, there is a lack of information about the effectiveness of this beetle to control aphids. The objective of this research was to study the functional response of M. sexmaculatus on Aphis gossypii at different ages of plants. All preys were exposed to one M. sexmaculatus adult for an hour at five different densities of aphids (10, 20, 30, 40, and 50 individuals is four different ages of chilli plants (2,4,6, and 8 weeks. Data were analyzed by ANOVA and logistic regression to determine the type of functional response. The results showed that the ability of M. sexmaculatus to prey was not significant at 2 to 4 and 6 to 8 weeks old chilli plants. At 2 week old chilli plants M. sexmaculatus showed type I of functional response, while at 4, 6 and 8 weeks the functional response were type III.

  2. 75 FR 75170 - APHIS User Fee Web Site

    Science.gov (United States)

    2010-12-02

    ... to submit comments or questions to APHIS on either the Web page itself (e.g., ease of use, content... to sign up to receive notifications when changes are made to the user fee Web page. Done in... Animal and Plant Health Inspection Service APHIS User Fee Web Site AGENCY: Animal and Plant...

  3. The entomopathogenic fungal endophytes Purpureocillium lilacinum (formerly Paecilomyces lilacinus) and Beauveria bassiana negatively affect cotton aphid reproduction under both greenhouse and field conditions.

    Science.gov (United States)

    Castillo Lopez, Diana; Zhu-Salzman, Keyan; Ek-Ramos, Maria Julissa; Sword, Gregory A

    2014-01-01

    The effects of two entomopathogenic fungal endophytes, Beauveria bassiana and Purpureocillium lilacinum (formerly Paecilomyces lilacinus), were assessed on the reproduction of cotton aphid, Aphis gossypii Glover (Homoptera:Aphididae), through in planta feeding trials. In replicate greenhouse and field trials, cotton plants (Gossypium hirsutum) were inoculated as seed treatments with two concentrations of B. bassiana or P. lilacinum conidia. Positive colonization of cotton by the endophytes was confirmed through potato dextrose agar (PDA) media plating and PCR analysis. Inoculation and colonization of cotton by either B. bassiana or P. lilacinum negatively affected aphid reproduction over periods of seven and 14 days in a series of greenhouse trials. Field trials were conducted in the summers of 2012 and 2013 in which cotton plants inoculated as seed treatments with B. bassiana and P. lilacinum were exposed to cotton aphids for 14 days. There was a significant overall effect of endophyte treatment on the number of cotton aphids per plant. Plants inoculated with B. bassiana had significantly lower numbers of aphids across both years. The number of aphids on plants inoculated with P. lilacinum exhibited a similar, but non-significant, reduction in numbers relative to control plants. We also tested the pathogenicity of both P. lilacinum and B. bassiana strains used in the experiments against cotton aphids in a survival experiment where 60% and 57% of treated aphids, respectively, died from infection over seven days versus 10% mortality among control insects. Our results demonstrate (i) the successful establishment of P. lilacinum and B. bassiana as endophytes in cotton via seed inoculation, (ii) subsequent negative effects of the presence of both target endophytes on cotton aphid reproduction using whole plant assays, and (iii) that the P. lilacinum strain used is both endophytic and pathogenic to cotton aphids. Our results illustrate the potential of using these

  4. The entomopathogenic fungal endophytes Purpureocillium lilacinum (formerly Paecilomyces lilacinus and Beauveria bassiana negatively affect cotton aphid reproduction under both greenhouse and field conditions.

    Directory of Open Access Journals (Sweden)

    Diana Castillo Lopez

    Full Text Available The effects of two entomopathogenic fungal endophytes, Beauveria bassiana and Purpureocillium lilacinum (formerly Paecilomyces lilacinus, were assessed on the reproduction of cotton aphid, Aphis gossypii Glover (Homoptera:Aphididae, through in planta feeding trials. In replicate greenhouse and field trials, cotton plants (Gossypium hirsutum were inoculated as seed treatments with two concentrations of B. bassiana or P. lilacinum conidia. Positive colonization of cotton by the endophytes was confirmed through potato dextrose agar (PDA media plating and PCR analysis. Inoculation and colonization of cotton by either B. bassiana or P. lilacinum negatively affected aphid reproduction over periods of seven and 14 days in a series of greenhouse trials. Field trials were conducted in the summers of 2012 and 2013 in which cotton plants inoculated as seed treatments with B. bassiana and P. lilacinum were exposed to cotton aphids for 14 days. There was a significant overall effect of endophyte treatment on the number of cotton aphids per plant. Plants inoculated with B. bassiana had significantly lower numbers of aphids across both years. The number of aphids on plants inoculated with P. lilacinum exhibited a similar, but non-significant, reduction in numbers relative to control plants. We also tested the pathogenicity of both P. lilacinum and B. bassiana strains used in the experiments against cotton aphids in a survival experiment where 60% and 57% of treated aphids, respectively, died from infection over seven days versus 10% mortality among control insects. Our results demonstrate (i the successful establishment of P. lilacinum and B. bassiana as endophytes in cotton via seed inoculation, (ii subsequent negative effects of the presence of both target endophytes on cotton aphid reproduction using whole plant assays, and (iii that the P. lilacinum strain used is both endophytic and pathogenic to cotton aphids. Our results illustrate the potential of

  5. Comparative transcriptional analysis of asexual and sexual morphs reveals possible mechanisms in reproductive polyphenism of the cotton aphid.

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    Li-Jun Liu

    Full Text Available Aphids, the destructive insect pests in the agriculture, horticulture and forestry, are capable of reproducing asexually and sexually upon environmental change. However, the molecular basis of aphid reproductive mode switch remains an enigma. Here we report a comparative analysis of differential gene expression profiling among parthenogenetic females, gynoparae and sexual females of the cotton aphid Aphis gossypii, using the RNA-seq approach with next-generation sequencing platforms, followed by RT-qPCR. At the cutoff criteria of fold change ≥2 and P<0.01, we identified 741 up- and 879 down-regulated genes in gynoparae versus parthenogenetic females, 2,101 up- and 2,210 down-regulated genes in sexual females compared to gynoparae, and 1,614 up- and 2,238 down-regulated genes in sexual females relative to parthenogenetic females. Gene ontology category and KEGG pathway analysis suggest the involvement of differentially expressed genes in multiple cellular signaling pathways into the reproductive mode transition, including phototransduction, cuticle composition, progesterone-mediated oocyte maturation and endocrine regulation. This study forms a basis for deciphering the molecular mechanisms underlying the shift from asexual to sexual reproduction in the cotton aphid. It also provides valuable resources for future studies on this host-alternating aphid species, and the insight into the understanding of reproductive mode plasticity in different aphid species.

  6. Selection of entomopathogenic fungi for aphid control.

    Science.gov (United States)

    Vu, Van Hanh; Hong, Suk Il; Kim, Keun

    2007-12-01

    Twelve strains of entomopathogenic fungi such as Lecanicillium lecanii, Paecilomyces farinosus, Beauveria bassiana, Metarhizium anisopliae, Cordyceps scarabaeicola, and Nomuraea rileyi were screened for aphid control. At 25 degrees C and 75% relative humidity (RH), among tested entomopathogenic fungi, L. lecanii 41185 showed the highest virulent pathogenicity for both Myzus persicae and Aphis gossypii, and their control values were both nearly 100% 5 and 2 d after treatment, respectively. Moreover, at an RH of 45% and in a wide temperature range (20-30 degrees C), L. lecanii 41185 also exhibited the highest virulence to M. persicae. The control value of M. persicae and the 50% lethal time (LT50) decreased significantly as the applied conidial concentration increased. The 50% lethal concentration (LC50) of the conidial suspension of this fungus was determined to be 6.55x10(5) conidia/ml. The control values of M. persicae resulting from the application of 1x10(7) and 1x10(8) conidia/ml were nearly the same and were significantly higher than that of 1x10(6) conidia/ml. The tested entomopathogenic fungi grew in a broad temperature range (15-30 degrees C). Lecanicillium strains showed optimum growth at 25 degrees C. The aerial conidia of Lecanicillium strains also could germinate in a broad temperature range (15-30 degrees C) and L. lecanii 41185 was the only strain with conidial germination at 35 degrees C.

  7. The control and protection of cotton plants using natural insecticides against the colonization by Aphis gossypii Glover (Hemiptera: Aphididae - doi: 10.4025/actasciagron.v35i2.15764

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    Ezio Santos Pinto

    2012-12-01

    Full Text Available The cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae, is a key pest of cotton, irrespective of the use of conventional or organic management. In organic systems, however, the use of synthetic insecticides is not allowed, increasing the difficulty of controlling this pest. This work evaluated aphid control and the ability of products to prevent aphid infestation using natural insecticides compared to a standard synthetic insecticide. The control trial was conducted with four products [Beauveria bassiana (Boveril®, neem oil (Neemseto®, and cotton seed oil compared to thiamethoxam (Actara®], and untreated plants served as the control group. The trial testing the efficacy of these products in preventing aphid infestation was conducted using the same products, excluding Boveril®. The evaluations were conducted 72 and 120h post-treatment for the efficacy and the protection against colonization trials, respectively. The aphid control by cotton seed oil, Neemseto®, and thiamethoxam was similar, with 100% control being achieved on the thiamethoxam-treated plants. Regarding the plant protection against aphid colonization, the insecticide thiamethoxam exhibited a better performance compared to the other tested products with steady results over the evaluation period. The natural products exhibited variable results with low protection against plant colonization throughout the evaluation period.

  8. Natural occurrence of entomophthoroid fungi of aphid pests on Medicago sativa L. in Argentina.

    Science.gov (United States)

    Manfrino, Romina G; Zumoffen, Leticia; Salto, César E; Lastra, Claudia C López

    2014-01-01

    Four species of entomophthoroid fungi, Pandora neoaphidis (Entomophthorales: Entomophthoraceae), Zoophthora radicans (Entomophthorales: Entomophthoraceae), Entomophthora planchoniana (Entomophthorales: Entomophthoraceae) and Neozygites fresenii (Neozygitales: Neozygitaceae) were found to infect Aphis craccivora, Therioaphis trifolii, and Acyrthosiphon pisum and unidentified species of Acyrthosiphon on lucerne in Argentina. Samples were collected from five sites (Ceres, Rafaela, Sarmiento, Monte Vera and Bernardo de Irigoyen) in the province of Santa Fe. In this study, Zoophthora radicans was the most important pathogen and was recorded mainly on Acyrthosiphon sp. Zoophthora radicans was successfully isolated and maintained in pure cultures. This study is the first report of entomophthoroid fungi infecting lucerne (Medicago sativa L.) aphids in Argentina.

  9. Natural occurrence of entomophthoroid fungi of aphid pests on Medicago sativa L. in Argentina

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    Romina G Manfrino

    Full Text Available Four species of entomophthoroid fungi, Pandora neoaphidis (Entomophthorales: Entomophthoraceae, Zoophthora radicans (Entomophthorales: Entomophthoraceae, Entomophthora planchoniana (Entomophthorales: Entomophthoraceae and Neozygites fresenii (Neozygitales: Neozygitaceae were found to infect Aphis craccivora, Therioaphis trifolii, and Acyrthosiphon pisum and unidentified species of Acyrthosiphon on lucerne in Argentina. Samples were collected from five sites (Ceres, Rafaela, Sarmiento, Monte Vera and Bernardo de Irigoyen in the province of Santa Fe. In this study, Zoophthora radicans was the most important pathogen and was recorded mainly on Acyrthosiphon sp. Zoophthora radicans was successfully isolated and maintained in pure cultures. This study is the first report of entomophthoroid fungi infecting lucerne (Medicago sativa L. aphids in Argentina.

  10. Barcoding of aphids (Hemiptera, Aphididae and Adelgidae): proper usage of the global data set.

    Science.gov (United States)

    Rakauskas, Rimantas; Bašilova, Jekaterina

    2013-01-01

    Basics of DNA barcoding suppose the creation and operation of an extensive library based on reliably (including possibility for validation) identified specimens. Therefore, information concerning morphological identification of the individual samples used for DNA barcoding, for example, identification keys and descriptions used, must be clearly explained. In addition, the maximum available data set of sequences must be used. Access to currently private data appears to be of special interest, especially when such possibility is provided by the database regulations, because it encourages the cooperation of research and saves both time and resources. The cryptic aphid species complexes Aphis oenotherae-holoenotherae and A. pomi-spiraecola are used to illustrate the above statements.

  11. Over-expression of CYP6A2 is associated with spirotetramat resistance and cross-resistance in the resistant strain of Aphis gossypii Glover.

    Science.gov (United States)

    Peng, Tianfei; Pan, Yiou; Yang, Chen; Gao, Xiwu; Xi, Jinghui; Wu, Yongqiang; Huang, Xiao; Zhu, E; Xin, Xuecheng; Zhan, Chao; Shang, Qingli

    2016-01-01

    A laboratory-selected spirotetramat-resistant strain (SR) of cotton aphid developed 579-fold and 15-fold resistance to spirotetramat in adult aphids and 3rd instar nymphs, respectively, compared with a susceptible strain (SS) [26]. The SR strain developed high-level cross-resistance to alpha-cypermethrin and bifenthrin and very low or no cross-resistance to the other tested insecticides. Synergist piperonyl butoxide (PBO) dramatically increased the toxicity of spirotetramat and alpha-cypermethrin in the resistant strain. RT-qPCR results demonstrated that the transcriptional levels of CYP6A2 increased significantly in the SR strain compared with the SS strain, which was consistent with the transcriptome results [30]. The depletion of CYP6A2 transcripts by RNAi also significantly increased the sensitivity of the resistant aphid to spirotetramat and alpha-cypermethrin. These results indicate the possible involvement of CYP6A2 in spirotetramat resistance and alpha-cypermethrin cross-resistance in the cotton aphid. These together with other cross-resistance results have implications for the successful implementation of resistance management strategies for Aphis gossypii.

  12. The effect of Chrysoperla carnea (Neuroptera: Chrysopidae) and Adalia bipunctata (Coleoptera: Coccinellidae) on the spread of cucumber mosaic virus (CMV) by Aphis gossypii (Hemiptera: Aphididae).

    Science.gov (United States)

    Garzón, A; Budia, F; Medina, P; Morales, I; Fereres, A; Viñuela, E

    2015-02-01

    The effects of two aphidophagous predators, the larvae of Chrysoperla carnea and adults of Adalia bipunctata, on the spread of cucumber mosaic virus (CMV) transmitted in a non-persistent manner by the cotton aphid Aphis gossypii were studied under semi-field conditions. Natural enemies and aphids were released inside insect-proof cages (1 m × 1 m × 1 m) with a central CMV-infected cucumber plant surrounded by 48 healthy cucumber seedlings, and the spatiotemporal dynamics of the virus and vector were evaluated in the short and long term (1 and 5 days) in the presence and absence of the natural enemy. The spatial analysis by distance indices methodology together with other indices measuring the dispersal around a single focus was used to assess the spatial pattern and the degree of association between the virus and its vector. Both natural enemies significantly reduced the number of aphids in the CMV-source plant after 5 days but not after 1 day. The CMV transmission rate was generally low, especially after 1 day, due to the limited movement of aphids from the central CMV-source plant, which increased slightly after 5 days. Infected plants were mainly located around the central virus-infected source plant, and the percentage of aphid occupation and CMV-infected plants did not differ significantly in absence and presence of natural enemies. The distribution patterns of A. gossypii and CMV were only coincident close to the central plant. The complexity of multitrophic interactions and the role of aphid predators in the spread of CMV are discussed.

  13. A report on occurrence of aphidophagous predators of Aphis odinae (van der Goot (Hemiptera: Aphididae in cashew ecosystem from Goa, India

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    Ramasamy Maruthadurai

    2017-02-01

    Full Text Available The aphid, Aphis odinae (Van der Goot (Hemiptera: Aphididae is a polyphagous, occasional insect pest of cashew.  A field survey was conducted from 2014 to 2015 in cashew plantations to record the incidence of aphid and its predators.  Periodical sampling revealed, the occurrence of six species of aphidophagous predators comprising three species of coccinellids, viz., Scymnus castaneus Sicard, Cheilomenes sexmaculata (Fabricius and Pseudaspidimerus flaviceps (Walker and three species of syrphids, viz., Paragus serratus (Fabricius, Dideopsis aegrota (Fabricius and Ischidon scutellaris (Fabricius were found predating on A. odinae.  All the immature stages of predators were found predating on first, second, third and fourth instars of the aphid.  Among the coccinellids, the dominant species were S. castaneus (4.26 grubs/nut followed by C. sexmaculata (0.42 grubs/leaf and P. flaviceps (0.14 grubs/nut.  Of the syrphids, P. serratus 2.39 larvae/nut was the major predator. The species D. aegrota (1.2 larvae/leaf and I. scutellaris (0.5 larvae/nut were recorded as minor predators.  Seasonal abundance of predators was synchronized with the aphid with a maximum occurrence during February 2015.  The aphid population gradually reduced from April onwards due to the voracious feeding activity of the predators.  The study concluded that the aphidophagous predators, viz., coccinellids and syrphids play a  major role in managing the aphid A. odinae in cashew and could be encouraged for augmentation and conservation of these predators in a cashew based ecosystem.

  14. Effect of vermicompost and cucumber cultivar on population growth attributes of the melon aphid (Hemiptera: Aphididae).

    Science.gov (United States)

    Razmjou, J; Mohammadi, M; Hassanpour, M

    2011-08-01

    Worldwide, the developing industry of cucumbers (Cucumis sativus L.) grown in greenhouses is threatened by damage from sucking pests, especially aphids. Among these, the melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is the most serious. We tested the effect of two cucumber cultivars ('Royal' and'Storm') and three vermicompost concentrations (0 [control], 20, and 30%) in field soil on the development and fecundity rates of A. gossypii, by using a randomized complete block design with four replicates as a factorial experiment. The developmental times of nymphs reared on plants grown into the three vermicompost concentrations ranged from 5.5 (0%) to 8.7 (30%) d (on Storm) and from 4.3 (0%) to 7 (30%) d (on Royal). The developmental time of melon aphid's nymphs was greatest on plants grown in the culture medium with 30% vermicompost rate and least on plants reared in the soil without vermicompost. The intrinsic rate of natural increase (r,,) of A. gossypii ranged from 0.204 d(-1) on plants grown in the soil amended with 30% vermicompost rate (on Storm seedlings) to 0.458 d(-1) on plants grown in the soil without vermicompost (on Royal seedlings). Accordingly, our findings confirm that a combination of a low level of vermicompost and a partially resistant cucumber cultivar might play an important role in managing this aphid on cucumbers in greenhouses.

  15. Resistance to Cucurbit aphid-borne yellows virus in Melon Accession TGR-1551.

    Science.gov (United States)

    Kassem, Mona A; Gosalvez, Blanca; Garzo, Elisa; Fereres, Alberto; Gómez-Guillamón, Maria Luisa; Aranda, Miguel A

    2015-10-01

    The genetic control of resistance to Cucurbit aphid-borne yellows virus (CABYV; genus Polerovirus, family Luteoviridae) in the TGR-1551 melon accession was studied through agroinoculation of a genetic family obtained from the cross between this accession and the susceptible Spanish cultivar 'Bola de Oro'. Segregation analyses were consistent with the hypothesis that one dominant gene and at least two more modifier genes confer resistance; one of these additional genes is likely present in the susceptible parent 'Bola de Oro'. Local and systemic accumulation of the virus was analyzed in a time course experiment, showing that TGR-1551 resistance was expressed systemically as a significant reduction of virus accumulation compared with susceptible controls, but not locally in agroinoculated cotyledons. In aphid transmission experiments, CABYV inoculation by aphids was significantly reduced in TGR-1551 plants, although the virus was acquired at a similar rate from TGR-1551 as from susceptible plants. Results of feeding behavior studies using the DC electrical penetration graph technique suggested that viruliferous aphids can salivate and feed from the phloem of TGR-1551 plants and that the observed reduction in virus transmission efficiency is not related to reduced salivation by Aphis gossypii in phloem sieve elements. Since the virus is able to accumulate to normal levels in agroinoculated tissues, our results suggest that resistance of TGR-1551 plants to CABYV is related to impairment of virus movement or translocation after it reaches the phloem sieve elements.

  16. Aphid honeydew quality as a food source for parasitoids is maintained in Bt cotton.

    Science.gov (United States)

    Hagenbucher, Steffen; Wäckers, Felix L; Romeis, Jörg

    2014-01-01

    Bt-transgenic cotton has proven to be highly efficient in controlling key lepidopteran pests. One concern with the deployment of Bt cotton varieties is the potential proliferation of non-target pests. We previously showed that Bt cotton contained lower concentrations of insecticidal terpenoids as a result of reduced caterpillar damage, which benefited the aphid Aphis gossypii. It is thus important that non-target herbivores are under biological control in Bt cotton fields. The induction or lack of induction of terpenoids could also influence the quality of aphid honeydew, an important food source for beneficial insects. We therefore screened A. gossypii honeydew for cotton terpenoids, that are induced by caterpillars but not the aphids. We then tested the influence of induced insect-resistance of cotton on honeydew nutritional quality for the aphid parasitoid Lysiphlebus testaceipes and the whitefly parasitoid Eretmocerus eremicus. We detected the cotton terpenoids gossypol and hemigossypolone in A. gossypii honeydew. Although a feeding assay demonstrated that gossypol reduced the longevity of both parasitoid species in a non-linear, dose-dependent manner, the honeydew was capable of sustaining parasitoid longevity and reproduction. The level of caterpillar damage to Bt and non-Bt cotton had no impact on the quality of honeydew for the parasitoids.These results indicate that the nutritional quality of honeydew is maintained in Bt cotton and is not influenced by induced insect resistance.

  17. Aphid honeydew quality as a food source for parasitoids is maintained in Bt cotton.

    Directory of Open Access Journals (Sweden)

    Steffen Hagenbucher

    Full Text Available Bt-transgenic cotton has proven to be highly efficient in controlling key lepidopteran pests. One concern with the deployment of Bt cotton varieties is the potential proliferation of non-target pests. We previously showed that Bt cotton contained lower concentrations of insecticidal terpenoids as a result of reduced caterpillar damage, which benefited the aphid Aphis gossypii. It is thus important that non-target herbivores are under biological control in Bt cotton fields. The induction or lack of induction of terpenoids could also influence the quality of aphid honeydew, an important food source for beneficial insects. We therefore screened A. gossypii honeydew for cotton terpenoids, that are induced by caterpillars but not the aphids. We then tested the influence of induced insect-resistance of cotton on honeydew nutritional quality for the aphid parasitoid Lysiphlebus testaceipes and the whitefly parasitoid Eretmocerus eremicus. We detected the cotton terpenoids gossypol and hemigossypolone in A. gossypii honeydew. Although a feeding assay demonstrated that gossypol reduced the longevity of both parasitoid species in a non-linear, dose-dependent manner, the honeydew was capable of sustaining parasitoid longevity and reproduction. The level of caterpillar damage to Bt and non-Bt cotton had no impact on the quality of honeydew for the parasitoids.These results indicate that the nutritional quality of honeydew is maintained in Bt cotton and is not influenced by induced insect resistance.

  18. Silencing of Two Insulin Receptor Genes Disrupts Nymph-Adult Transition of Alate Brown Citrus Aphid

    Science.gov (United States)

    Ding, Bi-Yue; Shang, Feng; Zhang, Qiang; Xiong, Ying; Yang, Qun; Niu, Jin-Zhi; Smagghe, Guy; Wang, Jin-Jun

    2017-01-01

    Insulin receptors play key roles in growth, development, and polymorphism in insects. Here, we report two insulin receptor genes (AcInR1 and AcInR2) from the brown citrus aphid, Aphis (Toxoptera) citricidus. Transcriptional analyses showed that AcInR1 increased during the nymph–adult transition in alate aphids, while AcInR2 had the highest expression level in second instar nymphs. AcInR1 is important in aphid development from fourth instar nymphs to adults as verified by dsRNA feeding mediated RNAi. The silencing of AcInR1 or/and AcInR2 produced a variety of phenotypes including adults with normal wings, malformed wings, under-developed wings, and aphids failing to develop beyond the nymphal stages. Silencing of AcInR1 or AcInR2 alone, and co-silencing of both genes, resulted in 73% or 60%, and 87% of aphids with problems in the transition from nymph to normal adult. The co-silencing of AcInR1 and AcInR2 resulted in 62% dead nymphs, but no mortality occurred by silencing of AcInR1 or AcInR2 alone. Phenotypes of adults in the dsInR1 and dsInR2 were similar. The results demonstrate that AcInR1 and AcInR2 are essential for successful nymph–adult transition in alate aphids and show that RNAi methods may be useful for the management of this pest. PMID:28230772

  19. Fertility life table of Lysiphlebus testaceipes (Cresson) (Hymenoptera, Braconidae, Aphidiinae) in Rhopalosiphum maidis (Fitch) and Aphis gossypii Glover (Hemiptera, Aphididae); Tabela de vida de fertilidade de Lysiphlebus testaceipes (Cresson) (Hymenoptera, Braconidae, Aphidiinae) em Rhopalosiphum maidis (Fitch) e Aphis gossypii Glover (Hemiptera, Aphididae)

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    Silva, Robson Jose da; Bueno, Vanda Helena Paes; Silva, Diego Bastos [Universidade Federal de Lavras (UFLA), MG (Brazil). Dept. de Entomologia. Lab. de Controle Biologico], e-mail: ecosbio@yahoo.com.br, e-mail: vhpbueno@ufla.br; Sampaio, Marcus Vinicius [Universidade Federal de Uberlandia, Umuarama, MG (Brazil). Inst. de Ciencias Agrarias], e-mail: mvsampaio@iciag.ufu.br

    2008-07-01

    Fertility life table of Lysiphlebus testaceipes (Cresson) (Hymenoptera, Braconidae, Aphidiinae) in Rhopalosiphum maidis (Fitch) and Aphis gossypii Glover (Hemiptera, Aphididae). The evaluation of the growth potential of Lysiphlebus testaceipes (Cresson) is important for its use in biological control programs of aphids. This work aimed to evaluate the fertility life table of L. testaceipes in Rhopalosiphum maidis (Fitch) and Aphis gossypii Glover. To determine the immature mortality, development and the sex ratio of the parasitoid, 12 females parasitoid, and 480 nymphs of each aphids were used. To evaluate the longevity and fertility 15 female parasitoid were used. Nymphs of each aphid (3 day old) were offered for each parasitoid female daily, until the female died, being 300 (first day); 250 (second day); 200 (third day); 150 (fourth day) and 50 nymphs in the other days. L. testaceipes showed immature mortality rates of 5.6 % in R. maidis and 9.2 % in A. gossypii. The development time of L. testaceipes in R. maidis and A. gossypii was 10.2 and 10.1 days, and the sex ratio of 0.71 and 0.66, respectively. The female of L. testaceipes had a fecundity of 498.8 eggs in R. maidis and 327.8 eggs in A. gossypii. The growth parameters the L. testaceipes in R. maidis and A. gossypii were, respectively R{sub o}= 205.38 and 164.08 females; r{sub m}= 0.449 and 0.431 females/females/day; {lambda}= 1.57 and 1.54 females/day; T= 11.86 and 11.83 days and TD= 10.78 and 11.27 days. L. testaceipes showed great growth potential on both aphid hosts. R. maidis could be a suitable host for proposals of mass-rearing and open rearing system using L. testaceipes. (author)

  20. Compatible plant-aphid interactions: how aphids manipulate plant responses.

    Science.gov (United States)

    Giordanengo, Philippe; Brunissen, Laurence; Rusterucci, Christine; Vincent, Charles; van Bel, Aart; Dinant, Sylvie; Girousse, Christine; Faucher, Mireille; Bonnemain, Jean-Louis

    2010-01-01

    To access phloem sap, aphids have developed a furtive strategy, their stylets progressing towards sieve tubes mainly through the apoplasmic compartment. Aphid feeding requires that they overcome a number of plant responses, ranging from sieve tube occlusion and activation of phytohormone-signalling pathways to expression of anti-insect molecules. In addition to bypassing plant defences, aphids have been shown to affect plant primary metabolism, which could be a strategy to improve phloem sap composition in nutrients required for their growth. During compatible interactions, leading to successful feeding and reproduction, aphids cause alterations in their host plant, including morphological changes, modified resource allocation and various local as well as systemic symptoms. Repeated salivary secretions injected from the first probe in the epidermal tissue up to ingestion of sieve-tube sap may play a crucial role in the compatibility between the aphid and the plant.

  1. Plant-derived differences in the composition of aphid honeydew and their effects on colonies of aphid-tending ants

    Science.gov (United States)

    Pringle, Elizabeth G; Novo, Alexandria; Ableson, Ian; Barbehenn, Raymond V; Vannette, Rachel L

    2014-01-01

    In plant–ant–hemipteran interactions, ants visit plants to consume the honeydew produced by phloem-feeding hemipterans. If genetically based differences in plant phloem chemistry change the chemical composition of hemipteran honeydew, then the plant's genetic constitution could have indirect effects on ants via the hemipterans. If such effects change ant behavior, they could feed back to affect the plant itself. We compared the chemical composition of honeydews produced by Aphis nerii aphid clones on two milkweed congeners, Asclepias curassavica and Asclepias incarnata, and we measured the responses of experimental Linepithema humile ant colonies to these honeydews. The compositions of secondary metabolites, sugars, and amino acids differed significantly in the honeydews from the two plant species. Ant colonies feeding on honeydew derived from A. incarnata recruited in higher numbers to artificial diet, maintained higher queen and worker dry weight, and sustained marginally more workers than ants feeding on honeydew derived from A. curassavica. Ants feeding on honeydew from A. incarnata were also more exploratory in behavioral assays than ants feeding from A. curassavica. Despite performing better when feeding on the A. incarnata honeydew, ant workers marginally preferred honeydew from A. curassavica to honeydew from A. incarnata when given a choice. Our results demonstrate that plant congeners can exert strong indirect effects on ant colonies by means of plant-species-specific differences in aphid honeydew chemistry. Moreover, these effects changed ant behavior and thus could feed back to affect plant performance in the field. PMID:25505534

  2. Plant-derived differences in the composition of aphid honeydew and their effects on colonies of aphid-tending ants.

    Science.gov (United States)

    Pringle, Elizabeth G; Novo, Alexandria; Ableson, Ian; Barbehenn, Raymond V; Vannette, Rachel L

    2014-11-01

    In plant-ant-hemipteran interactions, ants visit plants to consume the honeydew produced by phloem-feeding hemipterans. If genetically based differences in plant phloem chemistry change the chemical composition of hemipteran honeydew, then the plant's genetic constitution could have indirect effects on ants via the hemipterans. If such effects change ant behavior, they could feed back to affect the plant itself. We compared the chemical composition of honeydews produced by Aphis nerii aphid clones on two milkweed congeners, Asclepias curassavica and Asclepias incarnata, and we measured the responses of experimental Linepithema humile ant colonies to these honeydews. The compositions of secondary metabolites, sugars, and amino acids differed significantly in the honeydews from the two plant species. Ant colonies feeding on honeydew derived from A. incarnata recruited in higher numbers to artificial diet, maintained higher queen and worker dry weight, and sustained marginally more workers than ants feeding on honeydew derived from A. curassavica. Ants feeding on honeydew from A. incarnata were also more exploratory in behavioral assays than ants feeding from A. curassavica. Despite performing better when feeding on the A. incarnata honeydew, ant workers marginally preferred honeydew from A. curassavica to honeydew from A. incarnata when given a choice. Our results demonstrate that plant congeners can exert strong indirect effects on ant colonies by means of plant-species-specific differences in aphid honeydew chemistry. Moreover, these effects changed ant behavior and thus could feed back to affect plant performance in the field.

  3. Identification of aphid (Hemiptera: Aphididae) species of economic importance in Kenya using DNA barcodes and PCR-RFLP-based approach.

    Science.gov (United States)

    Kinyanjui, G; Khamis, F M; Mohamed, S; Ombura, L O; Warigia, M; Ekesi, S

    2016-02-01

    Aphids are among pests of economic importance throughout the world. Together with transmitting plant viruses, aphids are capable of inflicting severe crop production losses. They also excrete honeydew that favours the growth of sooty mold which reduces the quality of vegetables and fruits and hence their market values. Rapid and accurate identification of aphids to the species level is a critical component in effective pest management and plant quarantine systems. Even though morphological taxonomy has made a tremendous impact on species-level identifications, polymorphism, morphological plasticity and immature stages are among the many challenges to accurate identification. In addition, their small size, presence of cryptic species and damaged specimens dictate the need for a strategy that will ensure timely and accurate identification. In this study, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)-based on mitochondrial cytochrome c oxidase subunit I gene and DNA barcoding were applied to identify different aphid species collected from different agro-ecological zones of Kenya. Three restriction enzymes RsaI, AluI and Hinf1 produced patterns that allowed unambiguous identification of the species except Aphis craccivora and Aphis fabae. Analyses of the barcode region indicated intraspecific and interspecific sequence divergences of 0.08 and 6.63%, respectively. DNA barcoding identified all species, including the morphologically indistinguishable A. craccivora and A. fabae and separated two subspecies of A. fabae. Based on these results, both PCR-RFLPs and DNA barcoding could provide quick and accurate tools for identification of aphid species within Aphididae subsequently aiding in effective pest management programmes and enhance plant quarantine systems.

  4. Monitoring of aphid flight activities in seed potato crops in Serbia

    Directory of Open Access Journals (Sweden)

    Andja Vucetic

    2013-07-01

    Full Text Available Aphid flight activities in seed potato fields have been studied by the yellow water traps. It is a good method for monitoring aphids as vectors of viruses, but this study also showed it is a suitable method for insect-diversity research. During the four-year studies, over 11.500 specimens were collected and a total of 107 different taxa of aphids were identified. The most abundant species were polyphagous species, such as: Acyrthosiphon pisum (Haris, Aphis fabae Scopoli, Aphis gossypii Glover and Brachycaudus helichrysi (Kaltenbach. The results of the studies show that diversity of aphids in different regions of Serbia is similar regardless of the altitude and the diversity of terrain. At most sites it ranged from 2 to 3. The highest value was recorded in Begeč, locality in northern part of Serbia, in year 2008, and it was 2.92. The maximum values of the Shannon-Weaver diversity index at all sites were recorded in the first weeks of the monitoring of aphid flight activities. Morisita-Horn similarity index shows no significant differences between sites regardless of altitudes. The sites are grouped by year, not by similarity of relief. In spite of these results, the Chi-square analysis showed highly significant difference in vector frequencies among seasons and sites with more pronounced differences for PVY. As a consequence of differences in vector frequencies, the vector pressure index in some regions was different also. The number of vectors and vector pressure index vary depending on the altitude of localities. At localities at altitudes under 1000 m, they were high. The highest index was at Kotraža, locality in central part of Serbia, in 2007, when PVY index exceeded the value of 180, while for PLRV it was 60. At high altitudes on mountain Golija, above 1100 m, the number of aphids was low, as well as the vector pressure index which indicates that these regions are suitable for producing virus-free seed potato.

  5. Resistance to imidacloprid in different field populations of Aphis gossypii Glover (Hem.: Aphididae in South of Iran

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    S.S. Seyedebrahimi

    2016-04-01

    Full Text Available The cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae, is a key cucurbits pest in Iran and is managed with repeated insecticide applications. Reports of insecticide control failures have recently increased, particularly with imidacloprid. To quantify resistance to imidacloprid in cotton aphid, seven populations were collected from 7 different places in South of Iran (Shiraz, Jahrom, Saadatshahr, Marvdasht, Kavar, Sadra1 and Sadra2, all in Fars province. To estimate the response of 5 days old A. gossypii populations to imidacloprid, leaf dip bioassays were performed in the laboratory. Lethal concentrations at 50% (LC50 values were estimated by probit analysis and used to calculate the resistance ratios (RR. The bioassay results showed significant discrepancy in susceptibility to imidacloprid among the populations. The lowest and highest LD50 were estimated for Shiraz population with 37.09 and Sadra1 with 636.80 µg mL–1 respectively. The highest levels of resistance to imidacloprid were detected for Sadra1 (RR=17.17 fold. In the other populations some levels of resistance were detected. In Jahrom, Kavar, Marvdasht and SaadatShahr populations the RRs were from 3.85 to 7.11. As emphasized by the slope of responses and after a comparison of RRs with other studies it is supposed that resistant populations appear in first stages of development and have the ability to become more resistant with age.

  6. Leaf surface factors of transgenic Bt cotton associated with the feeding behaviors of cotton aphids: a case study on non-target effects.

    Science.gov (United States)

    Xue, Kun; Deng, Su; Wang, RongJiang; Yan, FengMing; Xu, ChongRen

    2008-02-01

    The present paper reports case study results of the risk assessment of transgenic Bt cotton on a non-target pest, cotton aphid, Aphis gossypii. Several types of techniques, i.e., electrical penetration graph (EPG), light and electron microscopy, bioassays and chemical analysis, were applied to investigate physical and chemical leaf factors of 2 transgenic Bt cotton lines (GK12 and GK19) and their parental non-Bt cotton line (Simian3) associated with searching and feeding behaviors of cotton aphids on leaves or leaf extracts of cotton plants. EPG results showed that there were some differences among behaviors of cotton aphids on 2 Bt cotton and 1 non-Bt cotton lines. Cotton aphids performed similarly to leaf surface extracts from 3 cotton lines; and leaf surface chemicals, mainly volatiles and waxes, were almost identical in the components and concentrations among the cotton lines. However, three cotton lines were quite different from each other in the densities of certain kinds of covering trichomes. Therefore, the relationships between the physical characteristics and the searching behaviors of cotton aphids on the three cotton lines were constructed as the regression equations. Glandular trichomes and covering trichomes with 5 branches influenced the cotton aphids' searching behaviors effectively; and other trichomes with other branches affected aphids in varying ways. These results demonstrated that leaf surface physical factors of transgenic Bt cotton lines different from their parental non-Bt line could affect the penetration behaviors of non-target cotton aphids. Cotton aphids penetrate and feed more easily on two Bt cotton lines than on the non-Bt cotton line.

  7. Leaf surface factors of transgenic Bt cotton associated with the feeding behaviors of cotton aphids: A case study on non-target effects

    Institute of Scientific and Technical Information of China (English)

    XUE Kun; DENG Su; WANG RongJiang; YAN FengMing; XU ChongRen

    2008-01-01

    The present paper reports case study results of the risk assessment of transgenic Bt cotton on a non-target pest, cotton aphid, Aphis gossypii. Several types of techniques, i.e., electrical penetration graph (EPG), light and electron microscopy, bioessays and chemical analysis, were applied to investigate physical and chemical leaf factors of 2 transgenic Bt cotton lines(GK12 and GK19) and their parental non-Bt cotton line (Simian3) associated with searching and feeding behaviors of cotton aphids on leaves or leaf extracts of cotton plants. EPG results showed that there were some differences among behaviors of cotton aphids on 2 Bt cotton and 1 non-Bt cotton lines. Cotton aphids performed similarly to leaf surface extracts from 3 cotton lines; and leaf surface chemicals, mainly volatiles and waxes,were almost identical in the components and concentrations among the cotton lines. However, three cotton lines were quite different from each other in the densities of certain kinds of covering trichomes.Therefore, the relationships between the physical characteristics and the searching behaviors of cotton aphids on the three cotton lines were constructed as the regression equations. Glandular trichomes and covering trichomes with 5 branches Influenced the cotton aphids' searching behaviors effectively;and other trichomes with other branches affected aphids in varying ways. These results demonstrated that leaf surface physical factors of transgenic Bt cotton lines different from their parental non-Bt line could affect the penetration behaviors of non-target cotton aphids. Cotton aphids penetrate and feed more easily on two Bt cotton lines than on the non-Bt cotton line.

  8. [Effects of host plants on the life table parameters of experimental populations of Aphis gossypii].

    Science.gov (United States)

    Li, Yan-Yan; Zhou, Xiao-Rong; Pang, Bao-Ping; Chang, Jing

    2013-05-01

    A comparative study was conducted on the life table parameters of Aphis gossypii reared on five host plant species at (25 +/- 1) degrees C in laboratory. There existed significant differences in the durations of various developmental stages, adult longevity, mean offspring number per day, net reproductive rate, intrinsic rate of increase, finite rate of increase, mean generation time, and population doubling time for the A. gossypii populations reared on the host plants. For the aphids on Lagenaria siceraria var. turbinate, they needed the longest time (5.84 days) to complete one generation, but for those on the other four plants, no significant differences were observed, with the time needed ranged from 5.24 to 5.45 days. The adult longevity was the longest (20.04 days) on Cucumis sativus, but had no significant differences on the other four host plants, being from 14.76 to 16.03 days. The populations' survival curves on all test host plants were of Deevey I, i. e., the death mainly occurred during late period. The survival rate on C. sativus was higher than those on the other four host plants. Based on the intrinsic rates of increase of A. gossypii, its host suitability was in the order of Cucumis melo var. saccharinus > Lagenaria siceraria var. turbinate > Cucurbita moschata var. melonaeformis > Cucumis sativus > Cucurbita pepo var. medullosa.

  9. The Effect of an Interspersed Refuge on Aphis glycines (Hemiptera: Aphididae), Their Natural Enemies, and Biological Control.

    Science.gov (United States)

    Varenhorst, A J; O'Neal, M E

    2016-02-01

    Soybean production in the north central United States has relied heavily on the use of foliar and seed applied insecticides to manage Aphis glycines (Hemiptera: Aphididae). An additional management strategy is the use soybean cultivars containing A. glycines resistance genes (Rag). Previous research has demonstrated that Rag cultivars are capable of preventing yield loss equivalent to the use of foliar and seed-applied insecticides.However, the presence of virulent biotypes in North America has raised concern for the durability of Rag genes. A resistance management program that includes a refuge for avirulent biotypes could limit the frequency at which virulent biotypes increase within North America. To what extent such a refuge reduces the effectiveness of aphid-resistant soybean is not clear. We conducted an experiment to determine whether a susceptible refuge mixed into resistant soybean (i.e., interspersed refuge or refuge-in-a-bag) affects the seasonal exposure of aphids, their natural enemies, biological control, and yield protection provided by aphid resistance. We compared three ratios of interspersed refuges (resistant: susceptible; 95:5, 90:10, 75:25) to plots grown with 100%susceptible or resistant soybean. We determined that an interspersed refuge of at least 25% susceptible seed would be necessary to effectively produce avirulent individuals. Interspersed refuges had negligible effects onyield and the natural enemy community. However, there was evidence that they increased the amount of biological control that occurred within a plot. We discuss the compatibility of interspersed refuges for A. glycines management and whether resistance management can prolong the durability of Rag genes.

  10. Within-plant distribution of cotton aphid (Hemiptera: Aphididae in cotton cultivars with colored fibers

    Directory of Open Access Journals (Sweden)

    Francisco S. Fernandes

    2012-09-01

    Full Text Available We describe the vertical and horizontal distribution of the cotton aphid Aphis gossypii Glover within a cotton plant in two cotton (Gossypium hirsutum Linnaeus cultivars (BRS Safira and BRS Rubí with colored fiber over the time. Measurements of aphid population dynamics and distribution in the cotton plants were recorded in intervals of seven days. The number of apterous or alate aphids and their specific locations were recorded, using as a reference point the location of nodes on the mainstem of the plant and also those on the leaves present on branches and fruit structures. The number of apterous aphids found on the cultivar BRS Safira (56,515 aphids was greater than that found on BRS Rubí (50,537 aphids. There was no significant difference between the number of alate aphids found on the cultivars BRS Safira (365 aphids/plant and BRS Rubí (477 aphids/plant. There were interactions between cotton cultivar and plant age, between plant region and plant age, and between cultivar and plant region for apterous aphids. The results of this study are of great importance in improving control strategies for A. gossypii in the naturally-colored cotton cultivars BRS Safira and BRS Rubí.Nós descrevemos a distribuição vertical e horizontal do pulgão do algodoeiro Aphis gossypii Glover dentro da planta de algodão (Gossypium hirsutum Linnaeus, em dois cultivares com fibras coloridas (BRS Safira and BRS Rubí ao longo do seu desenvolvimento. Medidas de dinâmicas de populações e distribuição de A. gossypii nas plantas de algodão foram registradas em intervalos de sete dias. O número de afídeos ápteros ou alados e suas localizações específicas foram registrados, usando-se como ponto de referência a localização do nó no caule principal da planta e também aqueles presentes nas folhas de ramos e estruturas frutíferas. O número de afídeos ápteros encontrados na cultivar BRS Safira (56.515 afídeos foi maior do que o encontrado na BRS Rub

  11. Volatile communication in plant-aphid interactions.

    Science.gov (United States)

    de Vos, Martin; Jander, Georg

    2010-08-01

    Volatile communication plays an important role in mediating the interactions between plants, aphids, and other organisms in the environment. In response to aphid infestation, many plants initiate indirect defenses through the release of volatiles that attract ladybugs, parasitoid wasps, and other aphid-consuming predators. Aphid-induced volatile release in the model plant Arabidopsis thaliana requires the jasmonate signaling pathway. Volatile release is also induced by infection with aphid-transmitted viruses. Consistent with mathematical models of optimal transmission, viruses that are acquired rapidly by aphids induce volatile release to attract migratory aphids, but discourage long-term aphid feeding. Although the ecology of these interactions is well-studied, further research is needed to identify the molecular basis of aphid-induced and virus-induced changes in plant volatile release.

  12. What do spring migrants reveal about sex and host selection in the melon aphid?

    Directory of Open Access Journals (Sweden)

    Thomas Sophie

    2012-04-01

    Full Text Available Abstract Background Host plants exert considerable selective pressure on aphids because the plants constitute their feeding, mating and oviposition sites. Therefore, host specialisation in aphids evolves through selection of the behavioural and chemical mechanisms of host-plant location and recognition, and through metabolic adaptation to the phloem content of the host plant. How these adaptive traits evolve in an aphid species depends on the complexity of the annual life cycle of that species. The purpose of this field study was to determine how winged spring-migrant populations contribute to the evolution and maintenance of host specialisation in Aphis gossypii through host-plant choice and acceptance. We also assessed whether host-specialised genotypes corresponded exclusively to anholocyclic lineages regardless of the environmental conditions. Results The spring populations of cotton-melon aphids visiting newly planted melon crops exhibited an unexpectedly high level of genetic diversity that contrasted with the very low diversity characterising the host-specialised populations of this aphid species. This study illustrated in natura host-plant-selection pressure by showing the great differences in genetic diversity between the spring-migrant populations (alate aphids and the melon-infesting populations (the apterous offspring of the alate aphids. Moreover, an analysis of the genetic composition of these alate and apterous populations in four geographic regions suggested differences in life-history strategies, such as host choice and reproductive mode, and questioned the common assertion that A. gossypii is an anholocyclic species throughout its distribution area, including Europe. Conclusions Our results clearly demonstrate that the melon plant acts as a selective filter against the reproduction of non-specialised individuals. We showed that olfactory cues are unlikely to be decisive in natura for host recognition by spring-migrant aphid

  13. Functional Response of Aphidoletes aphidimyza Rondani (Diptera: Cecidomyiidae) to Aphis gossypii Glover (Hemiptera: Aphididae): Effects of Vermicompost and Host Plant Cultivar.

    Science.gov (United States)

    Mottaghinia, L; Hassanpour, M; Razmjou, J; Hosseini, M; Chamani, E

    2016-02-01

    Interactions between natural enemies and herbivores may be affected by application of fertilizers and different cultivars. We investigated the functional response of the predatory gall midge, Aphidoletes aphidimyza Rondani (Diptera: Cecidomyiidae) larvae to the nymphs of the melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), reared on two commonly grown cucumber cultivars in Iran (Khasib and Karim) treated with different vermicompost/soil ratios (0:100, 10:90, 20:80, and 30:70%). Based on logistic regression analysis, A. aphidimyza revealed a type II functional response to the aphid in all treatments. Attack rates and handling times of A. aphidimyza larvae on different vermicompost/soil ratios ranged from 0.076 to 0.140 h(-1) and 0.969 to 1.164 h on Khasib and from 0.092 to 0.123 h(-1) and 0.905 to 1.229 h on Karim, respectively. Furthermore, increasing the density of the melon aphid on both cultivars amended with vermicompost/soil ratios resulted in increased prey consumption by the predator. Density of trichomes increased when plants received higher concentrations of vermicompost. So, trichomes may be responsible for different attack rates and handling times of A. aphidimyza on both cultivars.

  14. Population growth of Aphis gossypii and Myzus persicae (Hemiptera: Aphididae) in the presence of Linepithema humile and Tapinoma sessile (Hymenoptera: Formicidae).

    Science.gov (United States)

    Powell, Bradford E; Silverman, Jules

    2010-10-01

    Invasive ant species can have dramatic impacts on native ants, through direct predation and by usurping common resources. Most invasive ants and many native ants use honeydew, produced by phloem-sucking hemipterans. Because colonies of invasive ants can become very large after establishment, these ants may facilitate greater hemipteran trophobiont population growth compared with their sympatric native ant counterparts. We examined the population growth of an aphid mutualist, Aphis gossypii, and a nonmutualist, Myzus persicae, exposed to two Dolichoderine ants, Linepithema humile, a globally widespread invasive species, and Tapinoma sessile, a widespread co-occurring native ant, in North America in an enemy-free laboratory study. L. humile worker foraging activity was at least twice that of T. sessile, and populations of the myrmecophile, A. gossypii, were greater when exposed to L. humile than T. sessile, possibly caused, in part, by more frequent encounters with L. humile. L. humile ignored M. persicae when A. gossypii was absent, whereas T. sessile preyed on it. Both ant species preyed on M. persicae when A. gossypii was also present. This suggested that both ants may assess nutritional gains from aphid species (i.e., honeydew versus body tissue), eliminating less productive aphids competing for host plant space. Through their impact on populations of hemipteran mutualists, we suggest that colonies of L. humile and perhaps other invasive ants may acquire more honeydew than native ants, thereby fueling colony growth that leads to numerical dominance and widespread success in introduced environments.

  15. Vat, an Amazing Gene Conferring Resistance to Aphids and Viruses They Carry: From Molecular Structure to Field Effects

    Science.gov (United States)

    Boissot, Nathalie; Schoeny, Alexandra; Vanlerberghe-Masutti, Flavie

    2016-01-01

    We review half a century of research on Cucumis melo resistance to Aphis gossypii from molecular to field levels. The Vat gene is unique in conferring resistance to both A. gossypii and the viruses it transmits. This double phenotype is aphid clone-dependent and has been observed in 25 melon accessions, mostly from Asia. It is controlled by a cluster of genes including CC-NLR, which has been characterized in detail. Copy-number polymorphisms (for the whole gene and for a domain that stands out in the LLR region) and single-nucleotide polymorphisms have been identified in the Vat cluster. The role of these polymorphisms in plant/aphid interactions remains unclear. The Vat gene structure suggests a functioning with separate recognition and response phases. During the recognition phase, the VAT protein is thought to interact (likely indirectly) with an aphid effector introduced during cell puncture by the aphid. A few hours later, several miRNAs are upregulated in Vat plants. Peroxidase activity increases, and callose and lignin are deposited in the walls of the cells adjacent to the stylet path, disturbing aphid behavior. In aphids feeding on Vat plants, Piwi-interacting RNA-like sequences are abundant and the levels of other miRNAs are modified. At the plant level, resistance to aphids is quantitative (aphids escape the plant and display low rates of reproduction). Resistance to viruses is qualitative and local. Durability of NLR genes is highly variable. A. gossypii clones are adapted to Vat resistance, either by introducing a new effector that interferes with the deployment of plant defenses, or by adapting to the defenses it triggered. Viruses transmitted in a non-persistent manner cannot adapt to Vat resistance. At population level, Vat reduces aphid density and genetic diversity. The durability of Vat resistance to A. gossypii populations depends strongly on the agro-ecosystem, including, in particular, the presence of other cucurbit crops serving as

  16. Vat, an amazing gene conferring resistance to aphids and viruses they carry: from molecular structure to field effects

    Directory of Open Access Journals (Sweden)

    Nathalie Boissot

    2016-09-01

    Full Text Available We review half a century of research on Cucumis melo resistance to Aphis gossypii from molecular to field levels. The Vat gene is unique in conferring resistance to both A. gossypii and the viruses it transmits. This double phenotype is aphid clone-dependent and has been observed in 25 melon accessions, mostly from Asia. It is controlled by a cluster of genes including CC-NLR, which has been characterized in detail. Copy-number polymorphisms (for the whole gene and for a domain that stands out in the LLR region and single-nucleotide polymorphisms have been identified in the Vat cluster. The role of these polymorphisms in plant aphid/interactions remains unclear. The Vat gene structure suggests a functioning with separate recognition and response phases. During the recognition phase, the VAT protein is thought to interact (likely indirectly with an aphid effector introduced during cell puncture by the aphid. A few hours later, several miRNAs are upregulated in Vat plants. Peroxidase activity increases, and callose and lignin are deposited in the walls of the cells adjacent to the stylet path, disturbing aphid behavior. In aphids feeding on Vat plants, Piwi-interacting RNA-like sequences are abundant and the levels of other miRNAs are modified. At the plant level, resistance to aphids is quantitative (aphids escape the plant and display low rates of reproduction. Resistance to viruses is qualitative and local.Durability of NLR genes is highly variable. A. gossypii clones are adapted to Vat resistance, either by introducing a new effector that interferes with the deployment of plant defenses, or by adapting to the defenses it triggered. Viruses transmitted in a non-persistent manner cannot adapt to Vat resistance. At population level, Vat reduces aphid density and genetic diversity. The durability of Vat resistance to A. gossypii populations depends strongly on the agro-ecosystem, including, in particular, the presence of other cucurbit crops

  17. 77 FR 15033 - Privacy Act Systems of Records; APHIS Veterinary Services User Fee System

    Science.gov (United States)

    2012-03-14

    ... Animal and Plant Health Inspection Service Privacy Act Systems of Records; APHIS Veterinary Services User..., as amended. The system of records being proposed is the APHIS Veterinary Services User Fee System... Department of Agriculture (USDA) is proposing to add a new system of records, entitled APHIS...

  18. Leaf surface factors of transgenic Bt cotton associated with the feeding behaviors of cotton aphids:A case study on non-target effects

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The present paper reports case study results of the risk assessment of transgenic Bt cotton on a non-target pest, cotton aphid, Aphis gossypii. Several types of techniques, i.e., electrical penetration graph (EPG), light and electron microscopy, bioassays and chemical analysis, were applied to investigate physical and chemical leaf factors of 2 transgenic Bt cotton lines (GK12 and GK19) and their pa-rental non-Bt cotton line (Simian3) associated with searching and feeding behaviors of cotton aphids on leaves or leaf extracts of cotton plants. EPG results showed that there were some differences among behaviors of cotton aphids on 2 Bt cotton and 1 non-Bt cotton lines. Cotton aphids performed similarly to leaf surface extracts from 3 cotton lines; and leaf surface chemicals, mainly volatiles and waxes, were almost identical in the components and concentrations among the cotton lines. However, three cotton lines were quite different from each other in the densities of certain kinds of covering trichomes. Therefore, the relationships between the physical characteristics and the searching behaviors of cotton aphids on the three cotton lines were constructed as the regression equations. Glandular trichomes and covering trichomes with 5 branches influenced the cotton aphids’ searching behaviors effectively; and other trichomes with other branches affected aphids in varying ways. These results demonstrated that leaf surface physical factors of transgenic Bt cotton lines different from their parental non-Bt line could affect the penetration behaviors of non-target cotton aphids. Cotton aphids penetrate and feed more easily on two Bt cotton lines than on the non-Bt cotton line.

  19. miRNA-mediated auxin signalling repression during Vat-mediated aphid resistance in Cucumis melo.

    Science.gov (United States)

    Sattar, Sampurna; Addo-Quaye, Charles; Thompson, Gary A

    2016-06-01

    Resistance to Aphis gossypii in melon is attributed to the presence of the single dominant R gene virus aphid transmission (Vat), which is biologically expressed as antibiosis, antixenosis and tolerance. However, the mechanism of resistance is poorly understood at the molecular level. Aphid-induced transcriptional changes, including differentially expressed miRNA profiles that correspond to resistance interaction have been reported in melon. The potential regulatory roles of miRNAs in Vat-mediated aphid resistance were further revealed by identifying the specific miRNA degradation targets. A total of 70 miRNA:target pairs, including 28 novel miRNA:target pairs, for the differentially expressed miRNAs were identified: 11 were associated with phytohormone regulation, including six miRNAs that potentially regulate auxin interactions. A model for a redundant regulatory system of miRNA-mediated auxin insensitivity is proposed that incorporates auxin perception, auxin modification and auxin-regulated transcription. Chemically inhibiting the transport inhibitor response-1 (TIR-1) auxin receptor in susceptible melon tissues provides in vivo support for the model of auxin-mediated impacts on A. gossypii resistance.

  20. Comparative analysis of mitochondrial genomes of five aphid species (Hemiptera: Aphididae and phylogenetic implications.

    Directory of Open Access Journals (Sweden)

    Yuan Wang

    Full Text Available Insect mitochondrial genomes (mitogenomes are of great interest in exploring molecular evolution, phylogenetics and population genetics. Only two mitogenomes have been previously released in the insect group Aphididae, which consists of about 5,000 known species including some agricultural, forestry and horticultural pests. Here we report the complete 16,317 bp mitogenome of Cavariella salicicola and two nearly complete mitogenomes of Aphis glycines and Pterocomma pilosum. We also present a first comparative analysis of mitochondrial genomes of aphids. Results showed that aphid mitogenomes share conserved genomic organization, nucleotide and amino acid composition, and codon usage features. All 37 genes usually present in animal mitogenomes were sequenced and annotated. The analysis of gene evolutionary rate revealed the lowest and highest rates for COI and ATP8, respectively. A unique repeat region exclusively in aphid mitogenomes, which included variable numbers of tandem repeats in a lineage-specific manner, was highlighted for the first time. This region may have a function as another origin of replication. Phylogenetic reconstructions based on protein-coding genes and the stem-loop structures of control regions confirmed a sister relationship between Cavariella and pterocommatines. Current evidence suggest that pterocommatines could be formally transferred into Macrosiphini. Our paper also offers methodological instructions for obtaining other Aphididae mitochondrial genomes.

  1. Tests for host-associated fitness trade-offs in the milkweed-oleander aphid.

    Science.gov (United States)

    Groeters, Francis R

    1993-03-01

    The milkweed-oleander aphid, Aphis nerii (Boyer de Fonscolombe) (Homoptera: Aphididae), feeds on different milkweed species in northern California than in Puerto Rico. The hosts vary, primarily between regions, for both identity and quantity of cardenolides that the aphid sequesters for its own defense. In tests for hostassociated fitness trade-offs only one case was found in which host plant and fitness corresponded, but the effect was not significant. However, power to detect fitness trade-offs was limited and the possibility of considerable differences in fitness on a particular host for aphids from different hosts cannot be excluded. On Californian host species, among which migration is common, generalized host use could result from selection for general-purpose genotypes. However, this explanation cannot apply to generalized host use of Californian and Puerto Rican milkweeds because the regions are isolated by distance. A cardenolide sequestration mechanism that is free of substantial energy costs could provide the basis for fitness homeostasis on variable host plants that makes trade-offs unlikely even on hosts from different regions.

  2. Transgenic Bt Cotton Does Not Disrupt the Top-Down Forces Regulating the Cotton Aphid in Central China

    Science.gov (United States)

    Yao, Yong-Sheng; Han, Peng; Niu, Chang-Ying; Dong, Yong-Cheng; Gao, Xi-Wu; Cui, Jin-Jie; Desneux, Nicolas

    2016-01-01

    Top-down force is referred to arthropod pest management delivered by the organisms from higher trophic levels. In the context of prevalent adoption of transgenic Bt crops that produce insecticidal Cry proteins derived from Bacillus thuringiensis (Bt), it still remains elusive whether the top-down forces are affected by the insect-resistant traits that introduced into the Bt crops. We explored how Bt cotton affect the strength of top-down forces via arthropod natural enemies in regulating a non-target pest species, the cotton aphid Aphis gossypii Glover, using a comparative approach (i.e. Bt cotton vs. conventional cotton) under field conditions. To determine top-down forces, we manipulated predation/parasitism exposure of the aphid to their natural enemies using exclusion cages. We found that the aphid population growth was strongly suppressed by the dominant natural enemies including Coccinellids, spiders and Aphidiines parasitoids. Coccinellids, spiders and the assemblage of other arthropod natural enemies (mainly lacewings and Hemipteran bugs) are similarly abundant in both plots, but with the parasitoid mummies less abundant in Bt cotton plots compared to the conventional cotton plots. However, the lower abundance of parasitoids in Bt cotton plots alone did not translate into differential top-down control on A. gossypii populations compared to conventional ones. Overall, the top-down forces were equally strong in both plots. We conclude that transgenic Bt cotton does not disrupt the top-down forces regulating the cotton aphid in central China. PMID:27870914

  3. Efficacy of Chemical Mimicry by Aphid Predators Depends on Aphid-Learning by Ants.

    Science.gov (United States)

    Hayashi, Masayuki; Nomura, Masashi; Nakamuta, Kiyoshi

    2016-03-01

    Chemical mimicry is an effective strategy when signal receivers recognize and discriminate models by relying on chemical cues. Some aphid enemies mimic the cuticular chemicals of aphids through various means thus avoiding detection and attack by aphid-tending ants. However, because ants have been reported to learn the chemical signatures of aphids in order to distinguish the aphids, the efficacy of chemical mimicry is predicted to depend on the experience of the ants that had tended aphids. The present study tested this hypothesis using two predator species: larvae of the green lacewing Mallada desjardinsi, and larvae of the ladybeetle Scymnus posticalis. Lacewing larvae carry the carcasses of aphids on which they have preyed upon their backs, and these function via chemical camouflage to reduce the aggressiveness of aphid-tending ants toward the larvae. Ladybeetle larvae reportedly produce a covering of wax structures, and their chemicals appear to attenuate ant aggression. We examined whether the behavior of the ant Tetramorium tsushimae toward these predators changed depending on their aphid-tending experience. Ants moderated their aggressiveness toward both predators when they had previously tended aphids, indicating that chemical mimicry by both aphid predators is dependent on previous experience of the ants in tending aphids. Chemical mimicry by the predators of ant-tended aphids is therefore considered to exploit learning-dependent aphid recognition systems of ants.

  4. Stylet penetration activities by aphids

    NARCIS (Netherlands)

    Tjallingii, W.F.

    1985-01-01

    The composition of stylet penetration behaviour in aphids and its possible role in food-plant selection is the subject of these studies. Evidence is presented that the labium is devoid of external chemoreceptors (Chapter 1). In addition to other morphological data (Wensler & Filshie, 1969; Wensler,

  5. Separate and Combined Effects of Mentha piperata and Mentha pulegium Essential Oils and a Pathogenic Fungus Lecanicillium muscarium Against Aphis gossypii (Hemiptera: Aphididae).

    Science.gov (United States)

    Ebadollahi, Asgar; Davari, Mahdi; Razmjou, Jabrael; Naseri, Bahram

    2017-06-01

    In the present study, the toxicity of essential oils of Mentha piperata L. and Mentha pulegium L. and pathogenicity of Lecanicillium muscarium (Zare & Gams) were studied in the melon aphid, Aphis gossypii Glover. Analyses of the essential oils by GC-MS indicated limonene (27.28%), menthol (24.71%), menthone (14.01%), and carvol (8.46%) in the M. piperata essential oil and pulegone (73.44%), piperitenone (5.49%), decane (4.99%), and limonene (3.07%) in the essential oil of M. pulegium as the main components. Both essential oils and the pathogenic fungus had useful toxicity against A. gossypii. Probit analysis indicated LC50 values (lethal concentrations to kill 50% of population; 95% confidence limits in parentheses) of M. piperata and M. pulegium essential oils as 15.25 (12.25-19.56) and 23.13 (19.27-28.42) µl/liter air, respectively. Susceptibility to the pathogenic fungus increased with exposure time. Aphid mortality also increased when the essential oils were combined with L. muscarium, although the phenomena was additive rather than synergistic. Mycelial growth inhibition of L. muscarium exposed to the essential oils was also very low. Based on our results, M. piperata and M. pulegium essential oils and the pathogenic fungus L. muscarium have some potential for management of A. gossypii. © 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. Nano-formulation enhances insecticidal activity of natural pyrethrins against Aphis gossypii (Hemiptera: Aphididae) and retains their harmless effect to non-target predators.

    Science.gov (United States)

    Papanikolaou, Nikos E; Kalaitzaki, Argyro; Karamaouna, Filitsa; Michaelakis, Antonios; Papadimitriou, Vassiliki; Dourtoglou, Vassilis; Papachristos, Dimitrios P

    2017-02-16

    The insecticidal activity of a new nano-formulated natural pyrethrin was examined on the cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), and the predators Coccinella septempunctata L. (Coleoptera: Coccinellidae) and Macrolophus pygmaeus Rambur (Hemiptera: Miridae), in respect with the nano-scale potential to create more effective and environmentally responsible pesticides. Pyrethrin was nano-formulated in two water-in-oil micro-emulsions based on safe biocompatible materials, i.e., lemon oil terpenes as dispersant, polysorbates as stabilizers, and mixtures of water with glycerol as the dispersed aqueous phase. Laboratory bioassays showed a superior insecticidal effect of the pyrethrin micro-emulsions compared to two commercial suspension concentrates of natural pyrethrins against the aphid. The nano-formulated pyrethrins were harmless, in terms of caused mortality and survival time, to L3 larvae and four-instar nymphs of the predators C. septempunctata and M. pygmaeus, respectively. We expect that these results can contribute to the application of nano-technology in optimization of pesticide formulation, with further opportunities in the development of effective plant protection products compatible with integrated pest management practices.

  7. COMPARATIVE DEMOGRAPHICS OF A GENERALIST PREDATORY LADYBIRD ON FIVE APHID PREY: A LABORATORY STUDY

    Institute of Scientific and Technical Information of China (English)

    Omkar; AhmadPervez

    2004-01-01

    Prey driven demographic parameters of an aphidophagous ladybird, Propylea dissecta (Mulsant) were studied in attempt to answer how ladybird overcomes the problem of seasonally fluctuating food base. The ladybird reared for five generations in laboratory derived differential nutrition from five food sources (i.e. aphid species, Rhopalosiphum maidis (Fitch), Aphis craccivora Koch, Aphis gossypii Glover, Uroleucon compositae (Theobald) and Lipaphis erysimi (Kalt.)). The order of relative prey suitability was A. gossypii, A. craccivora, R. maidis, U. compositae and L.erysimi. Neonates suffered maximum mortality followed by eggs. Estimates of net reproductive rate,intrinsic rate of increase and finite rate of increase were highest (407.18, 0.2274 day-1, 1.2553 day-1) on A. gossypii and lowest (176.02, 0.1533 day-1, 1.1657 day-1) on L. erysimi. Generation time was shortest (26.43 days) on A. gossypii and longest (33.73 days) on L. erysimi. The present study thus,provides an explanation to the high incidence of P. dissecta on A. gossypii, as it experienced high intrinsic rate of increase and optimal values for related demographic parameters.

  8. Bioefficacy of some biorational insecticides for the control of Aphis gossypii Glover, 1877, (Hemiptera: Aphididae on greenhouse grown cucumber

    Directory of Open Access Journals (Sweden)

    Mohammad Saeed Emami

    2016-10-01

    Full Text Available Aphis gossypii Glover, 1877 is a serious pest of cucumber in greenhouse plantings. Biorational insecticides are an alternative of broad spectrum insecticides for aphid suppression in greenhouse. In this regards, the efficiency of some biorational insecticides including soap based on coconut oil, surfactant based on sodium sulfosuccinate and antifeeding based on potassium nicotinate were assayed on A. gossypii in the cucumber greenhouse. The trials were set up in a randomized complete block design with four replications. Samplings were carried out one day before spraying and 3, 7, 14 and 21 days after spraying. The data were submitted to ANOVA and the means comparison was performed using Duncan’s test. The results indicated that the highest mortality in insecticidal soap, surfactant and antifeeding treatments occurred after 3 days, with 78.47 %, 67.16 % and 60.48 % mortality, respectively. The results of the trials are discussed in terms of improving management of the populations of A. gossypii.

  9. Ability of Aphis gossypii and Myzus persicae to Transmit Cucumber mosaic virus in Single and Mixed Infection with Two Potyviruses to Zucchini Squash Eficiência dos afídeos Aphis gossypii e Myzus persicae na transmissão do Cucumber mosaic virus em infecção simples e mista com dois Potyvirus para abobrinha de moita

    Directory of Open Access Journals (Sweden)

    Zayame Vegette Pinto

    2008-06-01

    Full Text Available The main objective of this work was to investigate the ability of Aphis gossypii and Myzus persicae to transmit Cucumber mosaic virus (CMV singly and mixed with two potyviruses (Papaya ringspot virus - type W, PRSV-W and Zucchini yellow mosaic virus, ZYMV, to zucchini squash plants (Cucurbita pepo. The results showed that the potyviruses in general were more efficiently transmitted by both species of aphids as compared to CMV. The transmission of PRSV-W, ZYMV and CMV separately was more efficient than in mixture.O objetivo desse trabalho foi estudar a eficiência de Aphis gossypii e Myzus persicae na transmissão do vírus do mosaico do pepino (Cucumber mosaic virus, CMV, isoladamente e em mistura com duas espécies de potyvirus (Vírus do mosaico do mamoeiro = Papaya ringspot virus - type W, PRSV-W e Vírus do mosaico amarelo da abobrinha = Zucchini yellow mosaic virus, ZYMV, para planta-testes de abobrinha de moita (Cucurbita pepo. Os dois potyvirus em geral foram transmitidos com mais eficiência pelas duas espécies de afídeos do que o CMV. A transmissão do PRSV-W, ZYMV e CMV, separadamente, foi mais eficiente do que em mistura.

  10. Altruistic defence behaviours in aphids

    Directory of Open Access Journals (Sweden)

    Brodeur Jacques

    2010-01-01

    Full Text Available Abstract Background Altruistic anti-predatory behaviours pose an evolutionary problem because they are costly to the actor and beneficial to the recipients. Altruistic behaviours can evolve through indirect fitness benefits when directed toward kin. The altruistic nature of anti-predatory behaviours is often difficult to establish because the actor can obtain direct fitness benefits, or the behaviour could result from selfish coercion by others, especially in eusocial animals. Non-eusocial parthenogenetically reproducing aphids form colonies of clone-mates, which are ideal to test the altruistic nature of anti-predatory defence behaviours. Many aphids release cornicle secretions when attacked by natural enemies such as parasitoids. These secretions contain an alarm pheromone that alerts neighbours (clone-mates of danger, thereby providing indirect fitness benefits to the actor. However, contact with cornicle secretions also hampers an attacker and could provide direct fitness to the actor. Results We tested the hypothesis that cornicle secretions are altruistic by assessing direct and indirect fitness consequences of smearing cornicle secretions onto an attacker, and by manipulating the number of clone-mates that could benefit from the behaviour. We observed parasitoids, Aphidius rhopalosiphi, foraging singly in patches of the cereal aphid Sitobion avenae of varied patch size (2, 6, and 12 aphids. Aphids that smeared parasitoids did not benefit from a reduced probability of parasitism, or increase the parasitoids' handling time. Smeared parasitoids, however, spent proportionately more time grooming and less time foraging, which resulted in a decreased host-encounter and oviposition rate within the host patch. In addition, individual smearing rate increased with the number of clone-mates in the colony. Conclusions Cornicle secretions of aphids were altruistic against parasitoids, as they provided no direct fitness benefits to secretion

  11. Ultrastructure of the antennal sensilla of aphids. I. Coeloconic and placoid sensilla.

    Science.gov (United States)

    Bromley, A K; Dunn, J A; Anderson, M

    1979-01-01

    An electron microscopical study was made of the coeloconic and placoid sensilla on the antennae of the aphids Aphis pomi, Macrosiphum euphorbiae, Nasonovia ribis-nigri, and Pemphigus bursarius. Scanning electron microscopy revealed some variation in morphology which may be functionally important but is more likely to reflect the evolution of these species. The placoid sensilla were shown by tranwo or three neurons is surrounded by two ensheathing cells. The ciliary regions of the dendrites pass through a vacuole into a cavity between an outer and an inner cuticle where they may be connected to the dendritic branches although such connections were no seen. Small pores (8 nm diameter) partially penetrate the cuticle implying that these sensilla have an olfactory function. They are suggested to be important in host selection by alate aphids. The coeloconic sensilla are poreless pegs with nonsensory cuticular projections at their tips. The distal portions of their dendrites contain densely packed microtubules and the cellular arrangement of the sensila is similar to that of the placoid sensilla. It is suggest that they may function as thermoreceptors.

  12. Evaluation and application of parasitoids for biological control of Aphis gossypii in glasshouse cucumber crops

    NARCIS (Netherlands)

    Steenis, van M.

    1995-01-01

    Introduction
    Aphids are an important problem in glasshouse vegetables. Already at low aphid densities fruits can get contaminated with honeydew, which decreases the economical value of the fruits. When aphids feed on the growing tips of the plants, the new shoots can

  13. Aphid-proof plants: biotechnology-based approaches for aphid control.

    Science.gov (United States)

    Will, Torsten; Vilcinskas, Andreas

    2013-01-01

    Aphids are economically significant agricultural pests that are responsible for large yield losses in many different crops. Because the use of insecticides is restricted in the context of integrated pest management and aphids develop resistance against them rapidly, new biotechnology-based approaches are required for aphid control. These approaches focus on the development of genetically modified aphid-resistant plants that express protease inhibitors, dsRNA, antimicrobial peptides, or repellents, thus addressing different levels of aphid-plant interactions. However, a common goal is to disturb host plant acceptance by aphids and to disrupt their ability to take nutrition from plants. The defense agents negatively affect different fitness-associated parameters such as growth, reproduction, and survival, which therefore reduce the impact of infestations. The results from several different studies suggest that biotechnology-based approaches offer a promising strategy for aphid control.

  14. A functional genomics approach identifies candidate effectors from the aphid species Myzus persicae (green peach aphid).

    Science.gov (United States)

    Bos, Jorunn I B; Prince, David; Pitino, Marco; Maffei, Massimo E; Win, Joe; Hogenhout, Saskia A

    2010-11-18

    Aphids are amongst the most devastating sap-feeding insects of plants. Like most plant parasites, aphids require intimate associations with their host plants to gain access to nutrients. Aphid feeding induces responses such as clogging of phloem sieve elements and callose formation, which are suppressed by unknown molecules, probably proteins, in aphid saliva. Therefore, it is likely that aphids, like plant pathogens, deliver proteins (effectors) inside their hosts to modulate host cell processes, suppress plant defenses, and promote infestation. We exploited publicly available aphid salivary gland expressed sequence tags (ESTs) to apply a functional genomics approach for identification of candidate effectors from Myzus persicae (green peach aphid), based on common features of plant pathogen effectors. A total of 48 effector candidates were identified, cloned, and subjected to transient overexpression in Nicotiana benthamiana to assay for elicitation of a phenotype, suppression of the Pathogen-Associated Molecular Pattern (PAMP)-mediated oxidative burst, and effects on aphid reproductive performance. We identified one candidate effector, Mp10, which specifically induced chlorosis and local cell death in N. benthamiana and conferred avirulence to recombinant Potato virus X (PVX) expressing Mp10, PVX-Mp10, in N. tabacum, indicating that this protein may trigger plant defenses. The ubiquitin-ligase associated protein SGT1 was required for the Mp10-mediated chlorosis response in N. benthamiana. Mp10 also suppressed the oxidative burst induced by flg22, but not by chitin. Aphid fecundity assays revealed that in planta overexpression of Mp10 and Mp42 reduced aphid fecundity, whereas another effector candidate, MpC002, enhanced aphid fecundity. Thus, these results suggest that, although Mp10 suppresses flg22-triggered immunity, it triggers a defense response, resulting in an overall decrease in aphid performance in the fecundity assays. Overall, we identified aphid

  15. Jumping-ship can have its costs: implications of predation and host plant species for the maintenance of pea aphid (Acyrthosiphon pisum Harris) colour polymorphism.

    Science.gov (United States)

    Balog, Adalbert

    2013-10-01

    The interplay between the host plant of an insect herbivore and an insect predator (here two-spot ladybird beetles; Adalia bipunctata (L).; Coleoptera: Coccinellidae), feeding upon such a herbivore was examined in the laboratory as factors possibly determining the differential abundance and success of green and red host races of pea aphid, Acyrthosiphon pisum Harris. The experiment comprised three treatments: two host plants (bean and clover), two treatment levels (control and predation) and three colour morph levels (green alone, red alone and green and red in mixture). Green morphs had higher fitness on the general host plant, bean Vicia faba, than on the derived host, clover (Trifolium pratense), in the absence of predation. Although green morph fitness was reduced by predation when infesting bean together with reds, there was no observable net fitness loss due to predation on clover in mixed colonies with red morphs. Red morphs exhibited fitness loss alone on both bean and clover, while clover plants seemingly prevented fitness loss in the presence of predation when red morphs were mixed with green ones. According to this scenario, when colour morphs existed as a mixed colony, the net fitness of either pea aphid morph was not influenced by predation on clover. Predators had significant effects only on red morphs on broad bean either when alone or were mixed together with green morphs. Thus, only red morphs experienced the benefits of switching from the general to the derived host red clover in the presence of predation. For green morphs, there was no apparent cost of switching host plants when they faced predation. Hence, the co-existence of green-red colour polymorphism of pea aphids on single host plants appears to be maintained by the morph gaining fitness on the derived host due to a host plant– and predation–reduction effect. These findings have important implications for understanding the ecology and evolution of host switching by different colour

  16. Effects of elevated CO2 and plant genotype on interactions among cotton, aphids and parasitoids

    Institute of Scientific and Technical Information of China (English)

    Yu-Cheng Sun; Li Feng; Feng Gao; Feng Ge

    2011-01-01

    Effects of CO2 level (ambient vs.elevated) on the interactions among three cotton (Gossypium hirsutum) genotypes,the cotton aphid (Aphis gossypii Glover),and its hymenoptera parasitoid (Lysiphlebiajaponica Ashrnead) were quantified.It was hypothesized that aphid-parasitoid interactions in crop systems may be altered by elevated CO2,and that the degree of change is influenced by plant genotype.The cotton genotypes had high (M9101),medium (HZ401) and low (ZMS 13) gossypol contents,and the response to elevated CO2 was genotype-specific.Elevated CO2 increased the ratio of total non-structural carbohydrates to nitrogen (TNC:N) in the high-gossypol genotype and the mediumgossypol genotype.For all three genotypes,elevated CO2 had no effect on concentrations of gossypol and condensed tannins.A.gossypii fitness declined when aphids were reared on the high-gossypol genotype versus the low-gossypol genotype under elevated CO2.Furthermore,elevated CO2 decreased the developmental time of L.japonica associated with the high-gossypol genotype and the low-gossypol genotype,but did not affect parasitism or emergence rates.Our study suggests that the abundance of A.gossypii on cotton will not be directly affected by increases in atmospheric CO2.We speculate that A.gossypii may diminish in pest status in elevated CO2 and high-gossypol genotype environments because of reduced fitness to the high-gossypol genotype and shorter developmental time of L.japonica.

  17. Management of Sugarcane Aphid in Sorghum

    Science.gov (United States)

    Zerger, Sarah

    2017-01-01

    Sugarcane aphids are becoming a more prevalent pest in sorghum in the United States, especially in the south and are making their way north. There are many management practices that can be used on sugarcane aphids, the most important being scouting and maintaining populations. The most common mistake once a pest has been found is to immediately…

  18. Peppery Hot Bean Curd

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    Peppery Hot Bean Curd is a famous dish that originated in Chengdu,Sichuan Province.Dating back to the year under the reign of Emperor Tongzhi during the Qing Dynasty(1862-1875),a woman chef named Chen created this dish.In Chinese it is called Mapo Bean Curd. Ingredients:Three pieces of bean curd,100 grams lean pork,25 grams green soy beans or garlic

  19. Induction of phenylalanine ammonia-lyase and lipoxygenase in cotton seedlings by mechanical wounding and aphid infestation

    Institute of Scientific and Technical Information of China (English)

    QIN Qiuju; SHI Xueyan; LIANG Pei; GAO Xiwu

    2005-01-01

    It has been suggested that infestation of plants causes increases in the activities of phenylalanine ammonia-lyase (PAL)and lipoxygenase (LOX), key enzymes in the phenolic compounds synthesis pathway and the octadecanoid pathway, respectively. The purpose of this work is to investigate whether the infestation of cotton aphid (Aphis gossypii ) and mechanical wound can cause the induction of PAL and LOX activities in cotton seedlings, and whether the induction occurs in healthy seedlings growing nearby the attacked ones. The specific activities of PAL and LOX were measured using spectrophotometric method after aphid infestation and mechanical wounding. Result indicated that PAL activity and LOX activity were greatly induced by mechanical wounding and aphid infestation in cotton seedlings. The induction of PAL and LOX occurred not only in wounded and infested seedlings but also in intact healthy seedlings growing nearby. After exposed to the aphid infestation-induced volatiles, the specific activity of PAL in cotton seedlings increased by 6 % at 24 h, 80 % at 48 h, 235 % at 72 h compared to the control, and the specific activity of LOX increased by 18 % at 24 h, 34 % at 48 h,24 % at 72 h, respectively. In comparison, the specific activity of PAL in unwounded seedlings exposed to wound-induced volatiles increased by 0.0 at 24 h, 200% at 48 h, 164% at 72 h, respectively and the specific activity of LOX increased by 28% at 24 h, 37% at 48 h, 8 % at 72 h, respectively. It suggests that the induced volatiles are involved in plant-plant communication as airborne transferred signals.

  20. Effects of heat shock on resistance to parasitoids and on life history traits in an aphid/endosymbiont system.

    Directory of Open Access Journals (Sweden)

    Luis Cayetano

    Full Text Available Temperature variation is an important factor determining the outcomes of interspecific interactions, including those involving hosts and parasites. This can apply to variation in average temperature or to relatively short but intense bouts of extreme temperature. We investigated the effect of heat shock on the ability of aphids (Aphis fabae harbouring protective facultative endosymbionts (Hamiltonella defensa to resist parasitism by Hymenopteran parasitoids (Lysiphlebus fabarum. Furthermore, we investigated whether heat shocks can modify previously observed genotype-by-genotype (G x G interactions between different endosymbiont isolates and parasitoid genotypes. Lines of genetically identical aphids possessing different isolates of H. defensa were exposed to one of two heat shock regimes (35°C and 39°C or to a control temperature (20°C before exposure to three different asexual lines of the parasitoids. We observed strong G x G interactions on parasitism rates, reflecting the known genetic specificity of symbiont-conferred resistance, and we observed a significant G x G x E interaction induced by heat shocks. However, this three-way interaction was mainly driven by the more extreme heat shock (39°C, which had devastating effects on aphid lifespan and reproduction. Restricting the analysis to the more realistic heat shock of 35°C, the G x G x E interaction was weaker (albeit still significant, and it did not lead to any reversals of the aphid lines' susceptibility rankings to different parasitoids. Thus, under conditions feasibly encountered in the field, the relative fitness of different parasitoid genotypes on hosts protected by particular symbiont strains remains mostly uncomplicated by heat stress, which should simplify biological control programs dealing with this system.

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

    Directory of Open Access Journals (Sweden)

    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

  2. Evaluation of the Synergistic Effect Between Ethyl Formate and Phospine for Control of Aphis gossypii (Homoptera: Aphididae).

    Science.gov (United States)

    Lee, Byung Ho; Kim, Hye Min; Kim, Bong Soo; Yang, Jeong Oh; Moon, Young Mi; Ren, Yonglin

    2016-02-01

    Cotton aphid, Aphis gossypii Glover, is known as a quarantine pest that is hard to control with short periods of fumigation with phosphine (PH(3)) or low concentrations of ethyl formate. Moreover, low-temperature fumigation with ethyl formate can lead to phototoxic damage of some perishable commodities. Therefore, a laboratory study was conducted to evaluate the synergistic effect of mixing ethyl formate and PH(3) for the treatment of adults and nymphs of A. gossypii. Combined toxicity was observed and compared with a single dose of eitherrethyl formate or PH(3). When insects were exposed to 0.5 g/m(3) of PH(3) combined with different levels of ethyl formate from 1.6 to 16.3 g/m(3) at 5 and 20C for 2 h, L(Ct)(50) and L(Ct)(99) values were greatly reduced in comparison with a single dose of either ethyl formate or PH(3). The synergistic ratio (SR) is described as L(Ct) of ethyl formate alone/L(Ct) of ethyl formate + PH(3). The SR values of L(Ct)(50) and L(Ct)(99) for adult A. gossypii at 5C were 4.55 and 2.33, respectively. However, at 20C the SR levels of L(Ct)(50) and L(Ct)(99) were 2.22 and 1.45, respectively, but still showed significant synergism (significant difference, P<0.5). This new technology could meet quarantine and preshipment requirements for shorter exposure times and less damage of perishable commodities, and could also be extended for controlling other quarantine pests and thereby be a useful alternative to methyl bromide for fruit and vegetable applications.

  3. How accurate is the phenotype? – An analysis of developmental noise in a cotton aphid clone

    Directory of Open Access Journals (Sweden)

    Babbitt Gregory A

    2008-02-01

    Full Text Available Abstract Background The accuracy by which phenotype can be reproduced by genotype potentially is important in determining the stability, environmental sensitivity, and evolvability of morphology and other phenotypic traits. Because two sides of an individual represent independent development of the phenotype under identical genetic and environmental conditions, average body asymmetry (or "fluctuating asymmetry" can estimate the developmental instability of the population. The component of developmental instability not explained by intrapopulational differences in gene or environment (or their interaction can be further defined as internal developmental noise. Surprisingly, developmental noise remains largely unexplored despite its potential influence on our interpretations of developmental stability, canalization, and evolvability. Proponents of fluctuating asymmetry as a bioindicator of environmental or genetic stress, often make the assumption that developmental noise is minimal and, therefore, that phenotype can respond sensitively to the environment. However, biologists still have not measured whether developmental noise actually comprises a significant fraction of the overall environmental response of fluctuating asymmetry observed within a population. Results In a morphometric study designed to partition developmental noise from fluctuating asymmetry in the wing morphology of a monoclonal culture of cotton aphid, Aphis gossipyii, it was discovered that fluctuating asymmetry in the aphid wing was nearly four times higher than in other insect species. Also, developmental noise comprised a surprisingly large fraction (≈ 50% of the overall response of fluctuating asymmetry to a controlled graded temperature environment. Fluctuating asymmetry also correlated negatively with temperature, indicating that environmentally-stimulated changes in developmental instability are mediated mostly by changes in the development time of individuals

  4. 缩节胺对棉蚜种群繁殖的影响%Effects of Mepiquat Chloride (DPC) on Species Reproduction of Aphis gossypii Glover

    Institute of Scientific and Technical Information of China (English)

    周运刚; 王俊刚; 马天文; 何泽敏

    2011-01-01

    The contact toxicity, repellent effect, adult longevity and reproductive capacity and population growth of Aphis gossypii were studied by different concentrations of mepiquat chloride (DPC).The results show that there was no contact effect. Within the same time after treatment,the repellent effect on aphids was enhanced with the concentration gradient increased. 48h repellent rate was 33.3% treated by concentration of 400 mg o L-1; and 48 h repellent rate was 18.2% treated by 25 mg· L-1. In the same concentration,the repellent effect increased with the processing time. On the 7 th day,48 h repellent was 66.4% treated by concentration of 400 mg · L 1; 48 h repellent rate of 46.2% treated by 25 mg · L-1. On the first day,the Aphis gossypii life span and reproductive capacity of adults were not inhibited, and life expectancy was reduced only in the treatment of 400 mg · L-1. As time moved on,Aphis gossypii adult life and reproductive capacity were tapered,which indicated that Aphis gossypii life and reproductive capacity of adult were affected with cotton growth in DPC treatments. DPC also had good effects on Aphis gossypii inhibition.%研究不同质量浓度缩节胺对棉蚜触杀作用、忌避作用、成虫寿命及生殖能力和种群增长的影响.结果表明,缩节胺对棉蚜没有触杀作用.在处理后的同一时间内,随处理质量浓度的升高,对棉蚜的忌避作用增强.400 mg·L-1、48 h的忌避率为33.3%,25 mg·L、48 h的忌避率为18.2%.在同一质量浓度下,随处理时间的延长,对棉蚜的忌避作用增强.到第7天时,400 mg·L-1、48 h的忌避率为66.4%,25mg·L-1、48 h的忌避率为46.2%.处理第1天,棉蚜成虫寿命和生殖能力均未受到抑制,仅400 mg·L-1处理的蚜虫寿命减少.随处理时间的延长,棉蚜成虫寿命和生殖能力逐渐下降,说明缩节胺处理对棉蚜成虫寿命和生殖能力的影响与棉花生长时间有关,同时缩节胺对棉蚜种群有较好的抑制作用.

  5. Is the Multicolored Asian Ladybeetle, Harmonia axyridis, the Most Abundant Natural Enemy to Aphids in Agroecosystems?

    Science.gov (United States)

    Vandereycken, Axel; Durieux, Delphine; Joie, Emilie; Sloggett, John J.; Haubruge, Eric; Verheggen, François J.

    2013-01-01

    The multicolored Asian ladybeetle, Harmonia axyridis Pallas (Coleoptera: Coccinellidae), was introduced into Western Europe in the late 1990s. Since the late 2000s, this species has been commonly considered one of the most abundant aphid predators in most Western European countries. In spite of the large amount of research on H. axyridis, information concerning its relative abundance in agroecosystems is lacking. This study aims to evaluate the abundance of H. axyridis within the aphidophage community in four crops situated in southern Belgium: wheat, Triticum aestivum L. (Poales: Poaceae), corn, Zea mays, potato, Solanum tuberosum (Solanales: Solanaceae), and broad bean Vicia faba (Fabales: Fabaceae). In order to assess the species diversity, the collected data were analyzed by considering (1) the species richness and (2) the evenness according to the Shannon diversity index. Eleven aphidophages were observed in every inventoried agroecosystem, including five abundant species: three coccinellids, the seven-spotted ladybug, Coccinella septempunctata L. (Coleoptera: Coccinellidae), the 14-spotted Ladybird, Propylea quatuordecimpunctata, and H. axyridis; one hoverfly, the marmalade hoverfly, Episyrphus balteatus De Geer (Diptera: Syrphidae); and one lacewing, the common green lacewing, Chrysoperla carnea Stephens sensu lato (= s.l.) (Neuroptera: Chrysopidae). Harmonia axyridis has been observed to thrive, breed, and reproduce on the four studied crops. Harmonia axyridis is the most abundant predator of aphids in corn followed by C. septempunctata, which is the main aphid predator observed in the three other inventoried crops. In wheat and potato fields, H. axyridis occurs in low numbers compared to other aphidophage. These observations suggest that H. axyridis could be considered an invasive species of agrosystems, and that potato and wheat may intermittently act as refuges for other aphidophages vulnerable to intraguild predation by this invader. Harmonia axyridis

  6. Is the multicolored Asian ladybeetle, Harmonia axyridis, the most abundant natural enemy to aphids in agroecosystems?

    Science.gov (United States)

    Vandereycken, Axel; Durieux, Delphine; Joie, Emilie; Sloggett, John J; Haubruge, Eric; Verheggen, François J

    2013-01-01

    The multicolored Asian ladybeetle, Harmonia axyridis Pallas (Coleoptera: Coccinellidae), was introduced into Western Europe in the late 1990s. Since the late 2000s, this species has been commonly considered one of the most abundant aphid predators in most Western European countries. In spite of the large amount of research on H. axyridis, information concerning its relative abundance in agroecosystems is lacking. This study aims to evaluate the abundance of H. axyridis within the aphidophage community in four crops situated in southern Belgium: wheat, Triticum aestivum L. (Poales: Poaceae), corn, Zea mays, potato, Solanum tuberosum (Solanales: Solanaceae), and broad bean Vicia faba (Fabales: Fabaceae). In order to assess the species diversity, the collected data were analyzed by considering (1) the species richness and (2) the evenness according to the Shannon diversity index. Eleven aphidophages were observed in every inventoried agroecosystem, including five abundant species: three coccinellids, the seven-spotted ladybug, Coccinella septempunctata L. (Coleoptera: Coccinellidae), the 14-spotted Ladybird, Propylea quatuordecimpunctata, and H. axyridis; one hoverfly, the marmalade hoverfly, Episyrphus balteatus De Geer (Diptera: Syrphidae); and one lacewing, the common green lacewing, Chrysoperla carnea Stephens sensu lato (= s.l.) (Neuroptera: Chrysopidae). Harmonia axyridis has been observed to thrive, breed, and reproduce on the four studied crops. Harmonia axyridis is the most abundant predator of aphids in corn followed by C. septempunctata, which is the main aphid predator observed in the three other inventoried crops. In wheat and potato fields, H. axyridis occurs in low numbers compared to other aphidophage. These observations suggest that H. axyridis could be considered an invasive species of agrosystems, and that potato and wheat may intermittently act as refuges for other aphidophages vulnerable to intraguild predation by this invader. Harmonia axyridis

  7. RNAi-mediated plant protection against aphids.

    Science.gov (United States)

    Yu, Xiu-Dao; Liu, Zong-Cai; Huang, Si-Liang; Chen, Zhi-Qin; Sun, Yong-Wei; Duan, Peng-Fei; Ma, You-Zhi; Xia, Lan-Qin

    2016-06-01

    Aphids (Aphididae) are major agricultural pests that cause significant yield losses of crop plants each year by inflicting damage both through the direct effects of feeding and by vectoring harmful plant viruses. Expression of double-stranded RNA (dsRNA) directed against suitable insect target genes in transgenic plants has been shown to give protection against pests through plant-mediated RNA interference (RNAi). Thus, as a potential alternative and effective strategy for insect pest management in agricultural practice, plant-mediated RNAi for aphid control has received close attention in recent years. In this review, the mechanism of RNAi in insects and the so far explored effective RNAi target genes in aphids, their potential applications in the development of transgenic plants for aphid control and the major challenges in this regard are reviewed, and the future prospects of using plant-mediated RNAi for aphid control are discussed. This review is intended to be a helpful insight into the generation of aphid-resistant plants through plant-mediated RNAi strategy. © 2016 Society of Chemical Industry.

  8. AphID (Lucid key) http://AphID.AphidNet.org

    Science.gov (United States)

    This peer-reviewed web site concentrates on the 66 adult alate and apterous aphids that are the world's most cosmopolitan and polyphagous species. The site includes fact sheets about the various aphids species, a glossary of terms helpful to the student, hundreds of photographs and illustrations, a...

  9. Influences of elevated CO2 and pest damage on the allocation of plant defense compounds in Bt-transgenic cotton and enzymatic activity of cotton aphid

    Institute of Scientific and Technical Information of China (English)

    Gang Wu; Fa-Jun Chen; Neng-Wen Xiao; Feng Ge

    2011-01-01

    Plant allocation to defensive compounds by elevated CO2-grown nontransgenic and transgenic Bt cotton in response to infestation by cotton aphid,Aphis gossypii (Glover) in open-top chambers under elevated CO2 were studied.The results showed that significantly lower foliar nitrogen concentration and Bt toxin protein occurred in transgenic Bt cotton with and without cotton aphid infestation under elevated CO2.However,significantly higher carbon/nitrogen ratio,condensed tannin and gossypol were observed in transgenic Bt cotton "GK-12" and non-transgenic Bt cotton ‘Simian-3' under elevated CO2.The CO2 level and cotton variety significantly influenced the foliar nitrogen,condensed tannin and gossypol concentrations in the plant leaves after feeding by A.gossypii.The interaction between CO2 level × infestation time (24 h,48 h and 72 h)showed a significant increase in cotton condensed tannin concentrations,while the interaction between CO2 level × cotton variety significantly decreased the true choline esterase (TChE) concentration in the body ofA.gossypi.This study exemplified the complexities of predicting how transgenic and non-transgenic plants will allocate defensive compounds in response to herbivorous insects under differing climatic conditions.Plant defensive compound allocation patterns and aphid enzyme changes observed in this study appear to be broadly applicable across a range of plant and herbivorous insect interactions as CO2 atmosphere rises.

  10. Olfactory Responses of Three Species of Ladybird Beetles to the Aphids and the Leaves of Their Host Plants%3种瓢虫对蚜虫及其寄主植物的嗅觉反应

    Institute of Scientific and Technical Information of China (English)

    王进忠; 缪昆; 孙淑玲; 苏红田

    2001-01-01

    本试验测试了七星瓢虫、龟纹瓢虫和异色瓢虫对麦蚜、中国槐蚜、绣线菊蚜、棉蚜及其寄主植物的嗅觉反应.结果表明七星瓢虫对带白杨毛蚜的杨树叶片的反应比较显著,龟纹瓢虫对带绣线菊蚜的苹果叶片的反应比较显著,而异色瓢虫成虫对带有棉蚜的木槿叶片反应比较显著.%The olfactory responses of the Coccinella septempunctata Lewis, Prophlaea japonica Lewis and Harmonia axyridis (Pallas) to Macrosiphum avenae (Fabricius). Aphis sophoricola Zhong, Chaito phoruspopuleti (Pznzer), A. citricola van der Goot, A. gossypii Glover and their host plants were examined using a four-arm olfactometer. The results showed that the C. septempunctata Lewis was strongly attracted towards the combination of the aphid-infested leaves of the poplar tree and C. populeti (Pznzer) odors, P. japonica Lewis was strongly attracted towards the combination of the aphid: A. citricola van der Goot and the aphid-infested leaves of the apple tree and H. aryridis (Pallas) was strongly attracted towards the combination of A. gossypii Glover and the aphid-infested leaves of the rose mallow.

  11. Biological and Molecular Characterization of a Korean Isolate of Cucurbit aphid-borne yellows virus Infecting Cucumis Species in Korea.

    Science.gov (United States)

    Choi, Seung-Kook; Yoon, Ju-Yeon; Choi, Gug-Seoun

    2015-12-01

    Surveys of yellowing viruses in plastic tunnels and in open field crops of melon (Cucumis melo cultivar catalupo), oriental melon (C. melo cultivar oriental melon), and cucumber (C. sativus) were carried out in two melon-growing areas in 2014, Korea. Severe yellowing symptoms on older leaves of melon and chlorotic spots on younger leaves of melon were observed in the plastic tunnels. The symptoms were widespread and included initial chlorotic lesions followed by yellowing of whole leaves and thickening of older leaves. RT-PCR analysis using total RNA extracted from diseased leaves did not show any synthesized products for four cucurbit-infecting viruses; Beet pseudo-yellows virus, Cucumber mosaic virus, Cucurbit yellows stunting disorder virus, and Melon necrotic spot virus. Virus identification using RT-PCR showed Cucurbit aphid-borne yellows Virus (CABYV) was largely distributed in melon, oriental melon and cucumber. This result was verified by aphid (Aphis gossypii) transmission of CABYV. The complete coat protein (CP) gene amplified from melon was cloned and sequenced. The CP gene nucleotide and the deduced amino acid sequence comparisons as well as phylogenetic tree analysis of CABYV CPs showed that the CABYV isolates were undivided into subgroups. Although the low incidence of CABYV in infections to cucurbit crops in this survey, CABYV may become an important treat for cucurbit crops in many different regions in Korea, suggesting that CABYV should be taken into account in disease control of cucurbit crops in Korea.

  12. Biological and Molecular Characterization of a Korean Isolate of Cucurbit aphid-borne yellows virus Infecting Cucumis Species in Korea

    Directory of Open Access Journals (Sweden)

    Seung-Kook Choi

    2015-12-01

    Full Text Available Surveys of yellowing viruses in plastic tunnels and in open field crops of melon (Cucumis melo cultivar catalupo, oriental melon (C. melo cultivar oriental melon, and cucumber (C. sativus were carried out in two melon-growing areas in 2014, Korea. Severe yellowing symptoms on older leaves of melon and chlorotic spots on younger leaves of melon were observed in the plastic tunnels. The symptoms were widespread and included initial chlorotic lesions followed by yellowing of whole leaves and thickening of older leaves. RT-PCR analysis using total RNA extracted from diseased leaves did not show any synthesized products for four cucurbit-infecting viruses; Beet pseudo-yellows virus, Cucumber mosaic virus, Cucurbit yellows stunting disorder virus, and Melon necrotic spot virus. Virus identification using RT-PCR showed Cucurbit aphid-borne yellows Virus (CABYV was largely distributed in melon, oriental melon and cucumber. This result was verified by aphid (Aphis gossypii transmission of CABYV. The complete coat protein (CP gene amplified from melon was cloned and sequenced. The CP gene nucleotide and the deduced amino acid sequence comparisons as well as phylogenetic tree analysis of CABYV CPs showed that the CABYV isolates were undivided into subgroups. Although the low incidence of CABYV in infections to cucurbit crops in this survey, CABYV may become an important treat for cucurbit crops in many different regions in Korea, suggesting that CABYV should be taken into account in disease control of cucurbit crops in Korea.

  13. PREFACE: First International Meeting on Applied Physics (APHYS-2003)

    Science.gov (United States)

    Méndez-Vilas, A.; Chacón, R.

    2005-01-01

    This special issue of Physica Scripta contains papers presented at the 1st International Meeting on Applied Physics (APHYS-2003), held in Badajoz (Spain), from 13th to 18th October 2003, and more specifically, selected papers presented during the conference sessions mainly on Applied Optics, Laser Physics, Ultrafast Phenomena, Optical Materials, Semiconductor Materials and Devices, Optoelectronics, Quantum Electronics and Applied Solid State Physics-Chemistry. APHYS-2003 was born as an attempt to create a new international forum on Applied Physics in Europe. Since Applied Physics is not really a branch of Physics, but the application of all the branches of Physics to the broad realms of practical problems in Science, Engineering and Industry, this conference was a truly multi and inter-disciplinary event. The organizers called for papers relating Physics with other sciences such as Biology, Chemistry, Information Science, Medicine, etc, or relating different Physics areas, and aimed at solving practical problems. In other words, the Conference was specifically interested in reports applying the techniques, the training, and the culture of Physics to research areas usually associated with other scientific and engineering disciplines. It was extremely rewarding that over 800 researchers, from over 65 countries, attended the conference, where more than 1000 research papers were presented. We feel really proud of this excellent response obtained (in number and quality), for this first edition of the conference. We are very grateful to all the members of the Organizing Committee, for the hard work done for the preparation of the Conference (which began one year before the conference start), and to the members of the International Advisory Committee, for the valuable contribution to the evaluation of submitted works. Also thank to the referees for the excellent work done in the revision of submitted papers. Finally, we would like to thank the Department of Physics of the

  14. A non-persistently transmitted-virus induces a pull-push strategy in its aphid vector to optimize transmission and spread.

    Science.gov (United States)

    Carmo-Sousa, Michele; Moreno, Aranzazu; Garzo, Elisa; Fereres, Alberto

    2014-06-24

    Plant viruses are known to modify the behaviour of their insect vectors, both directly and indirectly, generally adapting to each type of virus-vector relationship in a way that enhances transmission efficiency. Here, we report results of three different studies showing how a virus transmitted in a non-persistent (NP) manner (Cucumber mosaic virus; CMV, Cucumovirus) can induce changes in its host plant, cucumber (Cucumis sativus cv. Marumba) that modifies the behaviour of its aphid vector (Aphis gossypii Glover; Hemiptera: Aphididae) in a way that enhances virus transmission and spread non-viruliferous aphids changed their alighting, settling and probing behaviour activities over time when exposed to CMV-infected and mock-inoculated cucumber plants. Aphids exhibited no preference to migrate from CMV-infected to mock-inoculated plants at short time intervals (1, 10 and 30 min after release), but showed a clear shift in preference to migrate from CMV-infected to mock-inoculated plants 60 min after release. Our free-choice preference assays showed that A. gossypii alates preferred CMV-infected over mock-inoculated plants at an early stage (30 min), but this behaviour was reverted at a later stage and aphids preferred to settle and reproduce on mock-inoculated plants. The electrical penetration graph (EPG) technique revealed a sharp change in aphid probing behaviour over time when exposed to CMV-infected plants. At the beginning (first 15 min) aphid vectors dramatically increased the number of short superficial probes and intracellular punctures when exposed to CMV-infected plants. At a later stage (second hour of recording) aphids diminished their feeding on CMV-infected plants as indicated by much less time spent in phloem salivation and ingestion (E1 and E2). This particular probing behaviour including an early increase in the number of short superficial probes and intracellular punctures followed by a phloem feeding deterrence is known to enhance the transmission

  15. Transcription factor aryl hydrocarbon receptor/aryl hydrocarbon receptor nuclear translocator is involved in regulation of the xenobiotic tolerance-related cytochrome P450 CYP6DA2 in Aphis gossypii Glover.

    Science.gov (United States)

    Peng, T; Chen, X; Pan, Y; Zheng, Z; Wei, X; Xi, J; Zhang, J; Gao, X; Shang, Q

    2017-10-01

    The cotton aphid, Aphis gossypii, is one of the most economically important agricultural pests worldwide as it is polyphagous and resistant to many classes of insecticides. Overexpression of the cytochrome P450 monooxygenase (P450) CYP6DA2 has previously been found to be associated with gossypol and spirotetramat tolerance in the cotton aphid. In the present study, the elements located in the promoter region (-357:-343; -250:-241; -113:-104) of CYP6DA2 were shown to control promoter activity, and gossypol induction was observed. We hypothesized that the expression of CYP6DA2 is subject to transcriptional regulation. To investigate the underlying mechanism, we assessed two transcription factors, aryl hydrocarbon receptor (AhR) and aryl hydrocarbon receptor nuclear translocator (ARNT), and found that the abundance of AhR was highly correlated with CYP6DA2 abundance. RNA interference of AhR or ARNT significantly decreased the levels of the target gene as well as those of its counterpart, and both dramatically repressed CYP6DA2 expression. Cotransfection of the ARNT, AhR, or AhR plus ARNT and CYP6DA2 promoter constructs elevated CYP6DA2 promoter activity, with the AhR plus ARNT cotransfection being the most effective. Thus, these elements located in the promoter were responsible for CYP6DA2 transcription, and CYP6DA2 expression was regulated by the transcription factors AhR and ARNT. © 2017 The Royal Entomological Society.

  16. Predators exert top-down control of soybean aphid across a gradient of agricultural management systems.

    Science.gov (United States)

    Costamagna, Alejandro C; Landis, Douglas A

    2006-08-01

    The discovery of soybean aphid, Aphis glycines Matusumura, in North America in 2000 provided the opportunity to investigate the relative strength of top-down and bottom-up forces in regulating populations of this new invasive herbivore. At the Kellogg Biological Station Long Term Ecological Research site in agroecology, we contrasted A. glycines establishment and population growth under three agricultural production systems that differed markedly in disturbance and fertility regimes. Agricultural treatments consisted of a conventional-tillage high-input system, a no-tillage high-input system, and a zero-chemical-input system under conventional tillage. By selectively restricting or allowing predator access we simultaneously determined aphid response to top-down and bottom-up influences. Irrespective of predator exclusion, our agricultural manipulations did not result in bottom-up control of A. glycines intrinsic rate of increase or realized population growth. In contrast, we observed strong evidence for top-down control of A. glycines establishment and overall population growth in all production systems. Abundant predators, including Harmonia axyridis, Coccinella septempunctata, Orius insidiosus, and various predaceous fly larvae, significantly reduced A. glycines establishment and population increase in all trials. In contrast to other systems in which bottom-up forces control herbivore populations, we conclude that A. glycines is primarily controlled via top-down influences of generalist predators under a wide range of agricultural management systems. Understanding the role of top-down and bottom-up forces in this context allows agricultural managers to focus on effective strategies for control of this invasive pest.

  17. Impact of reduced-risk insecticides on soybean aphid and associated natural enemies.

    Science.gov (United States)

    Ohnesorg, Wayne J; Johnson, Kevin D; O'Neal, Matthew E

    2009-10-01

    Insect predators in North America suppress Aphis glycines Matsumura (Hemiptera: Aphididae) populations; however, insecticides are required when populations reach economically damaging levels. Currently, insecticides used to manage A. glycines are broad-spectrum (pyrethroids and organophosphates), and probably reduce beneficial insect abundance in soybean, Glycine max (L.) Merr. Our goal was to determine whether insecticides considered reduced-risk by the Environmental Protection Agency could protect soybean yield from A. glycines herbivory while having a limited impact on the aphid's natural enemies. We compared three insecticides (imidacloprid, thiamethoxam, and pymetrozine,) to a broad-spectrum insecticide (lamda-cyhalothrin) and an untreated control using two application methods. We applied neonicotinoid insecticides to seeds (imidacloprid and thiamethoxam) as well as foliage (imidacloprid); pymetrozine and lamda-cyhalothrin were applied only to foliage. Foliage-applied insecticides had lower A. glycines populations and higher yields than the seed-applied insecticides. Among foliage-applied insecticides, pymetrozine and imidacloprid had an intermediate level of A. glycines population and yield protection compared with lamda-cyhalothrin and the untreated control. We monitored natural enemies with yellow sticky cards, sweep-nets, and direct observation. Before foliar insecticides were applied (i.e., before aphid populations developed) seed treatments had no observable effect on the abundance of natural enemies. After foliar insecticides were applied, differences in natural enemy abundance were observed when sampled with sweep-nets and direct observation but not with yellow sticky cards. Based on the first two sampling methods, pymetrozine and the foliage-applied imidacloprid had intermediate abundances of natural enemies compared with the untreated control and lamda-cyhalothrin.

  18. [Quality of different aphids as hosts of the parasitoid Lysiphlebus testaceipes (Cresson) (Hymenoptera: Braconidae, Aphidiinae)].

    Science.gov (United States)

    Silva, Robson J; Bueno, Vanda H P; Sampaio, Marcus V

    2008-01-01

    Lysiphlebus testaceipes (Cresson) has a broad aphid host range; however the quality of these preys may interfere in its biological feature. This study aimed to evaluate the quality of three Macrosiphini, Brevicoryne brassicae (L.), Lipaphis erysimi (Kaltenbach) and Myzus persicae (Sulzer), and three Aphidini Schizaphis graminum (Rondani) Rhopalosiphum maidis (Fitch) and Aphis gossypii Glover as hosts to L. testaceipes and to determine the relation possible of host preference, of size and quality of the host. The tests were carried out in climatic chamber at 25 +/- 1 degrees C, RH 70 +/- 10% and 12h photophase. The parasitoid did not oviposite in B. brassicae and L. erysimi, while the other species were nutritionally suitable to the parasitoid. L. testaceipes showed preference for aphids from tribe Aphidini and these hosts presented better quality to the parasitoid when compared to Macrosiphini. Interactions among size, preference and quality between the Aphidini were found. L testaceipes showed preference (parasitism rate 76.7%) for R. maidis, the bigger host (hind tibia with 0.281 mm). This host provided bigger size (hind tibia with 0.49 mm) and higher emergence rate (95.6%) to the parasitoid when compared to A. gossypii (parasitism rate of 55.7%). Also the smaller host A. gossypii (0.266 mm) provided smaller size hind tibia (0.45 mm) and higher mortality of the parasitoid (emergence rate 72.1%). However, the development time was shorter and the longevity was higher in A. gossypii (6.3 and 5.4 days, respectively) when compared to the host R. maidis (6.7 and 3.8 days, respectively), and not been related to host size.

  19. Nitenpyram, Dinotefuran, and Thiamethoxam Used as Seed Treatments Act as Efficient Controls against Aphis gossypii via High Residues in Cotton Leaves.

    Science.gov (United States)

    Zhang, Zhengqun; Zhang, Xuefeng; Wang, Yao; Zhao, Yunhe; Lin, Jin; Liu, Feng; Mu, Wei

    2016-12-14

    The effects of eight neonicotinoid seed treatments against the cotton aphid Aphis gossypii and its natural enemies in Bt cotton fields were evaluated, and the concentrations of these neonicotinoids in cotton leaves and soil were also investigated. The results showed that all neonicotinoid seed treatments efficiently reduced A. gossypii populations throughout the cotton seedling stage. The percentages of curly leaf plants in all of the neonicotinoid seed treatments were below the threshold for economic loss. Among the eight tested neonicotinoid seed treatments, nitenpyram, dinotefuran, and thiamethoxam showed high control efficiency against A. gossypii. Residues of the three neonicotinoids were higher than those of other neonicotinoids in cotton leaves. Moreover, residues of dinotefuran and nitenpyram remained at low levels in the soil. However, the abundance of natural enemies in the cotton field was to some extent influenced by neonicotinoid seed treatments. Therefore, neonicotinoids nitenpyram, dinotefuran, and thiamethoxam used as seed treatment can provide effective protection that should play an important role in the management of early-season A. gossypii in Bt cotton fields; however, the risks of neonicotinoids to the environment should also be considered.

  20. Aphid-AutoEPG software for analysing electrically monitored feeding behaviour of aphids

    Directory of Open Access Journals (Sweden)

    Toni Prüfer

    2014-06-01

    Full Text Available Aphid-AutoEPG is a new software program, developed to acquire and automatically analyse electrical penetration graph (EPG signals used for monitoring plant penetration by aphids. Characteristically EPG signals include waveforms that allow one to study the effects of plants on the acquisition and transmission of viruses, plant protection substances on pests and identify the location of resistance in plants to aphids. The success of electrical monitoring arises from the fact that different species of aphids generate similar EPG patterns. But the visual analysis of EPG waveforms in recorded signals is very time consuming, which has greatly hampered the wider application of EPG technology. To overcome this Aphid-AutoEPG software was developed, which has been extensively tested using data files for several different species of aphids, M. persicae, A. frangulae gossypii, M. albifrons, S. avenae, B. brassicae and N. ribis-nigri. The results have also been compared with visual analyses using Stylet+ software. When used in combination with the user friendly correction options Aphid-AutoEPG is not only easy to use but can also result in a considerable saving in terms of time.

  1. Root-Lesion Nematodes Suppress Cabbage Aphid Population Development by Reducing Aphid Daily Reproduction.

    Science.gov (United States)

    Hol, W H G; Raaijmakers, Ciska E; Mons, Ilse; Meyer, Katrin M; van Dam, Nicole M

    2016-01-01

    Empirical studies have shown that belowground feeding herbivores can affect the performance of aboveground herbivores in different ways. Often the critical life-history parameters underlying the observed performance effects remain unexplored. In order to better understand the cause for the observed effects on aboveground herbivores, these ecological mechanisms must be better understood. In this study we combined empirical experiments with a modeling approach to analyze the effect of two root feeding endoparasitic nematodes with different feeding strategies on the population growth of the aboveground feeding specialist aphid Brevicoryne brassicae on Brassica nigra. The aim was to test whether emerging differences in life history characteristics (days until reproduction, daily reproduction) would be sufficient to explain observed differences in aphid population development on plants with and without two species of nematodes. Aphid numbers were lower on plants with Pratylenchus penetrans in comparison to aphid numbers on plants with Meloidogyne spp. A dedicated experiment showed that aphid daily reproduction was lower on plants with P. penetrans (3.08 offspring female(-1) day(-1)) in comparison to both uninfested plants and plants with Meloidogyne spp. (3.50 offspring female(-1) day(-1)). The species-specific reduction of aphid reproduction appeared independent of changes in amino acids, soluble sugars or the glucosinolate sinigrin in the phloem. An individual-based model revealed that relatively small differences in reproduction rate per female were sufficient to yield a similar difference in aphid populations as was found in the empirical experiments.

  2. Factors affecting colonization and abundance of Aphis gossypii glover (hemiptera: aphididae on okra plantations Fatores que afetam a colonização e abundância de Aphis gossypii glover (Hemiptera: Aphididae em plantações de quiabeiro

    Directory of Open Access Journals (Sweden)

    Germano Leão Demolin Leite

    2007-04-01

    Full Text Available The control of Aphis gossypii Glover (Hemiptera: Aphididae on okra Abelmoschus esculentus (L. (Malvaceae consist primarily in the use of insecticides, due to the lack of information on other mortality factors. The objective of this study was to determine the effects of predators and parasitoids, height of canopy, plant age, leaf areas, organic compounds leaves, levels of leaf nitrogen and potassium, density of leaf trichomes, total rainfall and median temperature on attack intensity of A. gossypii on two successive A. esculentus var. Santa Cruz plantations. Monthly number estimates of A. gossypii and natural enemies (visual inspection occurred on bottom, middle and apical parts of 30 plants/plantation (one leaf/plant. Plants senescence, leaf areas and natural enemies, mainly Adialytus spp., spiders and Coccinellidae, were some of the factors that most contributed to aphid reduction. A higher number of aphids was found on the bottom part than medium and apical parts of okra plants. Total rainfall can reduce the aphid population. Trichomes non-glandular or low density, organic compounds leaves and levels of N and K were not important for reducing aphid population.O controle de Aphis gossypii Glover (Hemiptera: Aphididae em quiabeiro Abelmoschus esculentus (L. (Malvaceae consiste principalmente no uso de inseticidas, em virtude da falta de informação sobre outros fatores de mortalidade. Objetivou-se com este estudo determinar os efeitos de predadores e parasitóides, altura de dossel, idade da planta, área foliar, compostos orgânicos foliares, níveis de nitrogênio e potássio, densidade de tricomas, pluviosidade e temperatura na intensidade de ataque de A. gossypii em dois cultivos sucessivos de Abelmoschus esculentus var. Santa Cruz. Estimou-se, mensalmente, o número de A. gossypii e de inimigos naturais (inspeção visual ocorridos nas folhas (uma folha/planta localizadas nas partes basal, mediana e apical de 30 plantas/plantação. Os

  3. [Relationships between Aphis gossypii and its natural enemies in megranate field].

    Science.gov (United States)

    Zou, Yunding; Li, Lei; Bi, Shoudong; Lou, Zhi; Ding, Chengcheng; Gao, Caiqiu; Li, Changgen

    2004-12-01

    In this paper, the relevancy of Aphis gossypii with its natural enemies was studied by using grey systematic analysis. The results showed that the major natural enemies of Aphis gossypii were Tetragnathidae (0.8607), Therdion octomaculatum (0.8058), Therdion octomaculatum (0.7989), Haramonia aiyridis (0.7881) and Chrysopa sepetempunctata (0.7758). As for the daily total predation, the natural enemies which highly associated with the ideal dominant natural enemies were Erigonidium graminicola (0.8975), Tromobidiidae (0.8132), Propylacea japonica (0.7806) and Chrysopa sepetempunctata (0.7669); while for the quantity, Erigonidium graminicola (0.8482), Chrysopa sinica (0.7533), Tetragnathidae (0.7532), Therdion octomaculatum (0.7411) and Chrysopa sepetempunctata (0.7716) were the major natural enemies. According to the relational grade of the individuals between various natural enemies and ideal dominant natural enemies, the major natural enemies were Erigonidium graminicola (0.8461), Tromobidiidae (0.7325), Propylacea japonica (0.6983), Chrysopa sepetempunctata (0.6815) and Chrysopa sinica (0.6757). The species having >0.9567 horizontal and vertical niche overlaps with Aphis gossyppii were Erigonidium graminicola, Chrysopa sepetempunctata and Tetragnathidae, while the temporal niche overlaps between Erigonidium graminicola, Chrysopa sepetempunctata, tetragnathidae and Aphis gossyppii were >0.4020. It could be concluded that the main natural enemies of Aphis gossyppii were Erigonidium graminicola, Chrysopa sepetempunctata and Tetragnathidae.

  4. Early interactions during the encounter of plants, aphids and arboviruses.

    Science.gov (United States)

    Bak, Aurélie; Martinière, Alexandre; Blanc, Stéphane; Drucker, Martin

    2013-06-01

    Aphids infest many plants and cause damage by depriving them of nutrients and by transmitting many viral diseases. Aphid infestation and arbovirus transmission are controlled by establishment (or not) of a compatible reaction between the insects and the plants. This reaction is the result of defense reactions of the plant and counter-defense reactions of the parasite. Contrarily to plant-bacteria, plant-fungi and plant-herbivorous insects pathosystems, the plant-aphid pathosystem is understudied, although recent advances have begun to uncover some of its details. Especially the very early steps in plant-aphid interactions are hardly known. We here resume the present knowledge of these interactions. We discuss further how an aphid-transmitted plant virus that is transmitted during the first moments of the plant-aphid encounter, might help to study the very early plant aphid interactions.

  5. Intraguild Predation Responses in Two Aphidophagous Coccinellids Identify Differences among Juvenile Stages and Aphid Densities

    Directory of Open Access Journals (Sweden)

    Gabriele Rondoni

    2014-12-01

    Full Text Available (1 Intraguild predation (IGP can occur among aphidophagous predators thus reducing their effectiveness in controlling crop pests. Among ladybirds, Coccinella septempunctata L. and Hippodamia variegata Goeze are the most effective predators upon Aphis gossypii Glov., which is an economically important pest of melon. Understanding their likelihood to engage in reciprocal predation is a key point for conservation of biological control. Here, we aim to investigate, under laboratory conditions, the level of IGP between the two above mentioned aphidophagous species. (2 Fourth-instars of the two species were isolated in petri dishes with combinations of different stages of the heterospecific ladybird and different densities of A. gossypii. The occurrence of IGP events was recorded after six hours. (3 C. septempunctata predated H. variegata at a higher rate than vice versa (70% vs. 43% overall. Higher density of the aphid or older juvenile stage of the IG-prey (22% of fourth instars vs. 74% of eggs and second instars reduces the likelihood of predation. (4 To our knowledge, IGP between C. septempunctata and H. variegata was investigated for the first time. Results represent a baseline, necessary to predict the likelihood of IGP occurrence in the field.

  6. Intraguild Predation Responses in Two Aphidophagous Coccinellids Identify Differences among Juvenile Stages and Aphid Densities.

    Science.gov (United States)

    Rondoni, Gabriele; Ielo, Fulvio; Ricci, Carlo; Conti, Eric

    2014-12-08

    (1) Intraguild predation (IGP) can occur among aphidophagous predators thus reducing their effectiveness in controlling crop pests. Among ladybirds, Coccinella septempunctata L. and Hippodamia variegata Goeze are the most effective predators upon Aphis gossypii Glov., which is an economically important pest of melon. Understanding their likelihood to engage in reciprocal predation is a key point for conservation of biological control. Here, we aim to investigate, under laboratory conditions, the level of IGP between the two above mentioned aphidophagous species. (2) Fourth-instars of the two species were isolated in petri dishes with combinations of different stages of the heterospecific ladybird and different densities of A. gossypii. The occurrence of IGP events was recorded after six hours. (3) C. septempunctata predated H. variegata at a higher rate than vice versa (70% vs. 43% overall). Higher density of the aphid or older juvenile stage of the IG-prey (22% of fourth instars vs. 74% of eggs and second instars) reduces the likelihood of predation. (4) To our knowledge, IGP between C. septempunctata and H. variegata was investigated for the first time. Results represent a baseline, necessary to predict the likelihood of IGP occurrence in the field.

  7. Insecticied effect of silver and zinc nanoparticles against Aphis nerii Boyer of fonscolombe (Hemiptera: Aphididae Efecto insecticida de nanopartículas de plata y zinc contra Aphis nerii Boyer de Fonscolombe (Hemiptera: Aphididae

    Directory of Open Access Journals (Sweden)

    Mohammad Rouhani

    2012-12-01

    Full Text Available The oleander aphid, Aphis nerii Boyer de Fonscolombe, is one of the common pests of ornamental plants in the families of Apocynaceae and Sclepiadaceae and distributed throughout the world, which has been responsible for the mortality of a large number of oleander (Nerium oleander L. shrubs each year. In this research, the insecticidal activity of Ag nanoparticles against the A. nerii was investigated. Nanoparticles of Ag and Ag-Zn were synthesized through a solvothermal method, and using them, insecticidal solutions of different concentrations were prepared and tested on A. nerii. For comparison purposes, imidacloprid was also used as a conventional insecticide. In the experiments, the LC50 value for imidacloprid, Ag and Ag-Zn nanoparticles were calculated to be 0.13 μL mL-1, 424.67 mg mL-1, and 539.46 mg mL-1, respectively. The result showed that Ag nanoparticles can be used as a valuable tool in pest management programs of A. nerii. Additionally, the study showed that imidacloprid at 1 μL mL-1 and nanoparticles at 700 mg mL-1 had the highest insect mortality effect.El áfido de la adelfa, Aphis nerii Boyer de Fonscolombe, es una de las plagas más comunes de plantas ornamentales en las familias Apocynaceae y Sclepiadaceae y tiene distribución mundial, ha sido responsable de la mortalidad de un gran número de arbustos de adelfa (Nerium oleander L. cada ano. En este estudio se investigó la actividad insecticida de nanopartículas de Ag contra A. nerii. Nanopartículas de Ag y Ag-Zn fueron sintetizadas a través de un método solvotérmico, y con ellas se prepararon soluciones insecticidas de diferentes concentraciones y se probaron contra A. nerii. Con fines de comparación, también se usó imidacloprid como un insecticida convencional. En los experimentos, el valor LC50 para imidacloprid, nanopartículas de Ag y Ag-Zn se calculó como 0.13 μL mL-1, 424.67 mg mL-1, y 539.46 mg mL-1, respectivamente. El resultado mostró que nanopart

  8. EVALUATION OF BEANS DEHULLER

    African Journals Online (AJOL)

    M echanical/Production Engineering Department. Federal ... of food production, there has been more demand for beans as part of our .... hopper, dehulling unit, power unit and the ma- chine frame. - ... Operation of the machine. The machine ...

  9. Baked Bean Curd

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    Ingredients: Two pieces of tender bean curd, shredded shrimp, minced fat and lean pork, minced ham, minced fresh mushrooms, fried dried shrimps, mashed scallion, ginger and garlic, cooking wine, salad oil, salt, MSG and pepper powder. Directions:

  10. Healthy food trends -- beans and legumes

    Science.gov (United States)

    Healthy food trends - pulses; Healthy eating - beans and legumes; Weight loss - beans and legumes; Healthy diet - beans and legumes; ... My Plate.gov. Beans and Peas Are Unique Foods. Updated January 12, 2016. www.choosemyplate.gov/vegetables- ...

  11. 9 CFR 98.38 - Restrictions on the importation of swine semen from the APHIS-defined EU CSF region.

    Science.gov (United States)

    2010-01-01

    ... swine semen from the APHIS-defined EU CSF region. 98.38 Section 98.38 Animals and Animal Products ANIMAL... Semen § 98.38 Restrictions on the importation of swine semen from the APHIS-defined EU CSF region. In...-defined EU CSF region must meet the following conditions, except as noted in paragraph (h) of this...

  12. Plant-aphid interactions under elevated CO2: some cues from aphid feeding behavior

    Directory of Open Access Journals (Sweden)

    Yu-Cheng eSun

    2016-04-01

    Full Text Available Although the increasing concentration of atmospheric carbon dioxide (CO2 accelerates the accumulation of carbohydrates and increases the biomass and yield of C3 crop plants, it also reduces their nitrogen status. The consequent changes in primary and secondary metabolites affect the palatability of host plants and the feeding of herbivorous insects. Aphids are phloem feeders and are considered the only feeding guild that positively responds to elevated CO2. In this review, we consider how elevated CO2 modifies host defenses, nutrients, and water-use efficiency by altering concentrations of the phytohormones jasmonic acid, salicylic acid, ethylene, and abscisic acid. We will describe how these elevated CO2-induced changes in defenses, nutrients, and water status facilitate specific stages of aphid feeding, including penetration, phloem-feeding, and xylem absorption. We conclude that a better understanding of the effects of elevated CO2 on aphids and on aphid damage to crop plants will require research on the molecular aspects of the interaction between plant and aphid but also research on aphid interactions with their intra- and inter-specific competitors and with their natural enemies.

  13. A new species of Aphis Linnaeus, 1758 (Hem. Aphididae collected on Gymnophyton Clos (Apiaceae in Argentina

    Directory of Open Access Journals (Sweden)

    Sara I. López Ciruelos

    2017-02-01

    Full Text Available Aphis cuyana López Ciruelos & Ortego, sp. n. (Aphididae, Aphidinae is described from apterous and alate viviparous females collected on Gymnophyton polycephalum (Apiaceae in localities of the Argentinean provinces of La Rioja, San Juan and Mendoza. A table with differences of the apterous viviparous females of the new species from the species of Aphis and its close genera Andinaphis and Protaphis known in South America is presented. http://urn:lsid:zoobank.org:pub:4834FEF4-171C-4EBD-BF91-2137B517491E

  14. Pathogenicity of conidia-based preparations of entomopathogenic fungi against the greenhouse pest aphids: green peach aphid, melon aphid, and foxglove aphid

    Science.gov (United States)

    Seeking new isolates of entomopathogenic fungi with greater virulence against greenhouse aphid pests than those currently registered in North America for control of these insects, single-dose screening assays of 44 selected fungal isolates and 4 commercially available strains were conducted against ...

  15. Behavioral responses of Hippodamia variegata (Coleoptera:Coccinellidae) to volatiles from plants infested by Aphis gossypii (Hemiptera: Aphidae) and analysis of volatile components%多异瓢虫对瓜蚜为害后植物挥发物的行为反应及挥发物成分分析

    Institute of Scientific and Technical Information of China (English)

    李艳艳; 周晓榕; 庞保平; 韩海斌; 闫锋

    2013-01-01

    In order to investigate the roles of volatiles from host plants in the process of Hippodamia variegata ( Goeze) searching for preys, the behavioral responses of the lady beetle adults to volatiles from Aphis gossypii Glover, intact plants, aphid-plant complex and aphid-infested plants were observed with a Y-tube olfactometer. The results showed that the adults were significantly attracted to volatiles from high-density (≥700 individuals/L) aphids, aphid-plant complex, and aphid-infested Cucumis sativus plants (aphid density≥400 individuals/pot) and Cucurbita pepo var. medullosa plants (aphid density ≥200 individuals/pot) , while not to volatiles from low-density ( ≤500 individuals/L) aphids and the intact plants. Dynamic headspace collection was used to extract volatiles from the intact plants, aphid-plant complex and aphid-infested plants, respectively, and the extracted volatiles were analyzed by gas chromatography-mass spectrometry (GC-MS). Eight, twelve and eighteen components were identified from the extracts of the intact plants, aphid-infested plants and aphid-plant complex of C. sativus, respectively. The main components include 1-octadecene, [ E ]-5-eicosene, hexadecane and heptadecane, and aphid-induced components are p-xylene, 1, 2-dimethy-benzene, tridecane, 1-tetradecene, a-farnesene, cedrol, octadecane, hexacosane and other seven unknown components. Eleven, eighteen and twenty components were identified from the extracts of the intact plants, aphid-infested plants and aphid-plant complex of C. pepo var. medullosa, respectively. The main components include a-caryophyllene, 1-octadecene, hexadecane and heptadecane, and aphid-induced components are ethylbenzene, p-xylene, m-xylene, a-pinene, tetradecane, longifolene, a-caryophyllene and other two unknown components. The results lay a necessary foundation for further research on the effective components to attract lady beetles.%为明确寄主植物挥发物在多异瓢虫Hippodamia variegata

  16. Evolving aphids: one genome-one organism insects or holobionts?

    Directory of Open Access Journals (Sweden)

    M Mandrioli

    2013-01-01

    Full Text Available Aphids have obligate mutualistic relationships with microorganisms that provide them with essential substances lacking in their diet, together with symbionts conferring them conditional adaptive advantages related, for instance, to the thermal tolerance and to the resistance to parasitoid wasps. The presence/absence of a secondary symbiont may have a relevant phenotypic effect so that aphid microbial symbionts constitute a sort of second genome with its own genetic inheritance. On the whole, genes important for aphid survival and reproduction are not uniquely present in the aphid nuclear and mitochondrial genomes, but also in the chromosomes of each symbiont. As a consequence, aphids should be viewed as holobionts with an extended genome (the hologenome including the host and its symbiotic microbiome. In this connection, the true unit of selection in evolution must be considered the aphid holobiont, in place of the single host as individual separated from its symbionts.

  17. Phylogenetic relationships in the "grossulariae" species group of the genus Aphis (Hemiptera: Sternorrhyncha: Aphididae): Molecular evidence

    DEFF Research Database (Denmark)

    Turcinaviciene, Jorga; Rakauskas, Rimantas; Pedersen, Bo Vest

    2006-01-01

    Phylogenetic relationships among Palaearctic Ribes and/or Onagraceae inhabiting Aphis species from five countries were examined using mitochondrial gene cytochrome oxidase I (CO-I) and nuclear gene elongation factor 1 a (EF-1a) sequences. There was no major conflict between the trees obtained from...

  18. 9 CFR 72.9 - Interstate movements of cattle; inspection and certification by APHIS inspector required.

    Science.gov (United States)

    2010-01-01

    ... ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS TEXAS (SPLENETIC) FEVER IN CATTLE § 72.9 Interstate... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Interstate movements of cattle; inspection and certification by APHIS inspector required. 72.9 Section 72.9 Animals and Animal...

  19. Conservation of Genetic Diversity in Beans (Phaseolus vulgaris

    Directory of Open Access Journals (Sweden)

    Aurel Maxim

    2016-11-01

    Full Text Available In the last two decades, both on International and European level a series of treaties and laws have been devised in order to save local varieties of crop plants. The most important methods of traditional seed conservation are on farm and ex situ (Maxim et al., 2010; Kontoleonet al., 2009. The identification of local Romanian varieties of bean, their morphological and agronomic description, seed production and its spreading in the purpose of genetic erosion reduction. Their have been taken into study 13 local varieties of bean. For the morphological description descriptors have been used accordingly to the IPGRI (International Plant Genetic Resources Institute. For the evaluation of the diseases attack, frequency (F%, intensity (I% and degree of attack (GA% have been calculated.The exchanges of seed between farmers were facilitated through the online catalog edited by the Eco Ruralis Association that promotes traditional seeds. Of the 13 local varieties of beean taken into study, two are with determined growth(15.3%, and 11 are with undetermined growth(84.7%. The most significant production of pods on the plant was documented on local variety MM 1039 (2.736kg, and the most significant production of beans on plant was documented on local variety HD 904 (1.156kg. The most resistant varieties against bacterian attack, anthracnose, aphids and rust were: SJ 890, CJ 909, CV 917 şi HD 1159. The growing phenomenon of genetic erosion implies the indentification and the conservation of crop plants. In the year 2015, 13 local varieties of bean have been taken into study that were used for conservation in seeds’ genbank and for the exchange of seeds between farmers.

  20. Genome sequence of the pea aphid Acyrthosiphon pisum

    DEFF Research Database (Denmark)

    Richards, S.; Gibbs, R. A.; Gerardo, N. M.

    2010-01-01

    Aphids are important agricultural pests and also biological models for studies of insect-plant interactions, symbiosis, virus vectoring, and the developmental causes of extreme phenotypic plasticity. Here we present the 464 Mb draft genome assembly of the pea aphid Acyrthosiphon pisum. This first...... from bacteria; thus the reduced gene count of Buchnera does not reflect gene transfer to the host genome. The inventory of metabolic genes in the pea aphid genome suggests that there is extensive metabolite exchange between the aphid and Buchnera, including sharing of amino acid biosynthesis between...

  1. Watery Saliva Secreted by the Grain Aphid Sitobion avenae Stimulates Aphid Resistance in Wheat.

    Science.gov (United States)

    Zhang, Yong; Fan, Jia; Francis, Frédéric; Chen, Julian

    2017-09-27

    Infestation with Sitobion avenae induces localized defense responses in wheat; in this study, the role of S. avenae watery saliva in resistance induction was examined by infiltrating aphid saliva into wheat leaves. After feeding S. avenae on an artificial diet for 48 h, we first collected watery saliva from them and then separated the salivary proteins using one-dimensional gel electrophoresis. Gene expression studies showed that infiltration of S. avenae watery saliva in wheat leaves induced a strong salicylic acid-responsive defense but moderate jasmonic acid-dependent defense. Feeding on wheat leaves infiltrated with aphid saliva, compared with untreated leaves, significantly decreased the number of nymphs produced per day and the intrinsic rate of increase of the population of S. avenae. In a choice test against untreated wheat, saliva-infiltrated wheat had repellent effects on aphids. Additionally, electrical penetration graph results showed that the feeding behavior of S. avenae on saliva-treated wheat was negatively affected compared with that on untreated wheat. These findings provided direct evidence that salivary components of S. avenae are involved in the induction of wheat resistance against aphids and further demonstrated the important roles of watery saliva in aphid-plant interactions.

  2. Effects of elevated CO2 on the interspecific competition between two sympatric species of Aphis gossypii and Bemisia tabaci fed on transgenic Bt cotton

    Institute of Scientific and Technical Information of China (English)

    Zhi-Yi Li; Tong-Jin Liu; Neng-Wen Xiao; Jun-Sheng Li; Fa-Jun Chen

    2011-01-01

    Effects of elevated CO2 (twice ambient vs.ambient) and Bt CrylAc transgene (Bt cotton cv.33B vs.its nontransgenic parental line cv.DP5415) on the interspecific competition between two ecologically similar species of cotton aphid Aphis gossypii and whitefly biotype-Q Bemisia tabaci were studied in open-top chambers.The results indicated that elevated CO2 and Bt cotton both affected the population abundances of A.gossypii and biotype-Q B.tabaci when introduced solely (i.e.,without interspecific competition) or two species coexisted (i.e.,with interspecific competition).Compared with ambient CO2,elevated CO2 increased the population abundances ofA.gossypii and biotype-Q B.tabaci as fed on Bt and nontransgenic cotton on 45 (i.e.,seedling stage) and 60 (i.e.,flowering stage) days after planting (DAP),but only significantly enhanced aphid abundance without interspecific competition on the 45-DAP nontransgenic cotton and 60-DAP Bt cotton,and significantly increased whitefly abundance with interspecific competition on the 45-DAP Bt cotton and 60-DAP nontransgenic cotton.In addition,compared with nontransgenic cotton at elevated CO2,Bt cotton significantly reduced biotype-Q B.tabaci abundances without and with interspecific competition during seedling and flowering stage,while only significantly decreasing A.gossypii abundances without interspecific competition during the seedling stage.When the two insect species coexisted,the proportions ofbiotype-Q B.tabaci were significantly higher than those ofA.gossypii on Bt and nontransgenic cotton at the same CO2 levels,and elevated CO2 only significantly increased the percentages of biotype-Q B.tabaci and significantly reduced the proportions ofA.gossypii on seedling and flowering nontransgenic cotton.Therefore,the effects of elevated CO2 were favorable for biotype-Q B.tabaci to out-compete A.gossypii under the predicted global climate change.

  3. The mortality and repellency effect of a formulation of spearmint essential oil on the cotton-melon aphid under greenhouse conditions

    Directory of Open Access Journals (Sweden)

    M. Riazi

    2016-02-01

    Full Text Available In recent years, application of essential oils derived from aromatic plants has been considered as low-risk insecticides. These compounds have repellency, insecticidal and growth-reducing effects on immature stages of a variety of insects. Since it is not possible to use pure essential oils in agricultural fields and greenhouses, development of commercial formulations essential-oils is necessary. In this study, the insecticidal activity and repellency effect of essential oil from spearmint (Mentha spicata and its formulation was tested against the melon aphid (Aphis gossypii, which is one of the key pests of greenhouse crops. The LC50 values of fumigation bioassay of the essential oil against the first instar nymph, third instar nymph and adult of A. gossypii were 2.70, 3.41 and 5.24 µl/L, respectively. For contact toxicity bioassay, based on preliminary tests, a formulation of essential oil from spearmint was used in four concentrations (8000, 12500, 16000 and 25000 mg/L. Results revealed that spearmint essential-oil formulation caused 88.7% adult mortality when applied at a concentration of 25000 mg/L. The repellency index was calculated when aphids were exposed for 24 h to LC20 concentration. This index was -10%. These results showed that formulation of spearmint essential oil could be used as a commercial substitute for chemical insecticides to control A. gossypii under greenhouse conditions.

  4. Descriptive Epizootiology of an Aphid Mycosis

    OpenAIRE

    Soper, Richard S.; Macleod, D. M.

    1981-01-01

    The epizootiology of Entomophthora canarjensis Macleod, Tyrrell, & Soper in populations of the woolly pine needle aphid (Schizolachnus piniradiatae (Davidson)) was investigated during a 5-year period in an isolated plantation of red pine (Pinus resinosa Aitj in northern Ontario. Climatic factors did not limit the spread of the fungus; the major controlling factors were the density of the fungus inoculum and the density and spatial distribution of ti1tl host. An epizootic killed nearly 100 per...

  5. Aphid reproductive investment in response to mortality risks

    Directory of Open Access Journals (Sweden)

    Barribeau Seth M

    2010-08-01

    Full Text Available Abstract Background Aphids are striking in their prodigious reproductive capacity and reliance on microbial endosymbionts, which provision their hosts with necessary amino acids and provide protection against parasites and heat stress. Perhaps as a result of this bacterial dependence, aphids have limited immune function that may leave them vulnerable to bacterial pathogens. An alternative, non-immunological response that may be available to infected aphids is to increase reproduction, thereby ameliorating fitness loss from infection. Such a response would reduce the need to mount a potentially energetically costly immune response, and would parallel that of other hosts that alter life-history traits when there is a risk of infection. Here we examined whether pea aphids (Acyrthosiphon pisum respond to immunological challenges by increasing reproduction. As a comparison to the response to the internal cue of risk elicited by immunological challenge, we also exposed pea aphids to an external cue of risk - the aphid alarm pheromone (E-β-farnesene (EBF, which is released in the presence of predators. For each challenge, we also examined whether the presence of symbionts modified the host response, as maintaining host fitness in the face of challenge would benefit both the host and its dependent bacteria. Results We found that aphids stabbed abdominally with a sterile needle had reduced fecundity relative to control aphids but that aphids stabbed with a needle bearing heat-killed bacteria had reproduction intermediate, and statistically indistinguishable, to the aphids stabbed with a sterile needle and the controls. Aphids with different species of facultative symbiotic bacteria had different reproductive patterns overall, but symbionts in general did not alter aphid reproduction in response to bacterial exposure. However, in response to exposure to alarm pheromone, aphids with Hamiltonella defensa or Serratia symbiotica symbiotic infections

  6. Cannibalism in the pea aphid, Acyrthosiphon pisum.

    Science.gov (United States)

    Cooper, Lucy C; Desjonqueres, Camille; Leather, Simon R

    2014-12-01

    Previous observations of cannibalism have been made in the aphid Acyrthosiphon pisum (L.): this article seeks to quantify factors contributing to such behaviors. We observed and quantified the responses of a number of clones and life stages to varying levels of starvation, in the form of increasingly desiccated Vica faba L. plants (receiving 50, 25, or 10 mL every second day) or a complete absence of host plant. We found that, while the longest incidences of cannibalism are carried out by juveniles (F = 3.45, P = 0.019, df = 3) and targeted at adults, the starvation treatments had the most significant effect on the prevalence of cannibalism in mature A. pisum (F = 2.24, P = 0.025, df = 9). Furthermore, there was no difference between the prevalence or duration of cannibalistic activities within and between different clones (P ≥ 0.05 in all cases), though juveniles were more likely to target unrelated aphids (V = 6 112, P = 0.011), and spent more time feeding on aphids from the same culture (V = 6 062, P = 0.018).

  7. Seasonal Abundance of Aphids and Aphidophagous Insects in Pecan

    Directory of Open Access Journals (Sweden)

    Ghulam Abbas

    2012-12-01

    Full Text Available Seasonal occurrence of aphids and aphidophagous insects was monitored for six years (2006–2011 from full leaf expansion in May to leaf fall in October in “Desirable” variety pecan trees that were not treated with insecticides. Aphid outbreaks occurred two times per season, once in the spring and again in the late summer. Yellow pecan and blackmargined aphids exceeded the recommended treatment thresholds one time and black pecan aphids exceeded the recommended treatment levels three times over the six seasons. Increases in aphidophagous insect abundance coincided with aphid outbreaks in five of the six seasons. Among aphidophagous insects Harmonia axyridis and Olla v-nigrum were frequently collected in both the tree canopy and at the ground level, whereas, Coccinella septempunctata, Hippodamia convergens were rarely found in the tree canopy and commonly found at the ground level. Green lacewing abundance was higher in the ground level than in the tree canopy. Brown lacewings were more abundant in the tree canopy than at the ground level. Dolichopodid and syrphid fly abundance, at the ground level increased during peak aphid abundance in the tree canopy. Application of an aqueous solution of fermenting molasses to the pecan foliage during an aphid outbreak significantly increased the abundance of ladybeetles and lacewings and significantly reduced the abundance of yellow pecan, blackmargined and black pecan aphids.

  8. Aphid-plant interactions at phloem level, a behavioural study.

    NARCIS (Netherlands)

    Prado, E.C.

    1997-01-01

    Aphid-plant interactions occurring during plant penetration, or probing, have determined the evolution of these insects as well as the abilities of plants to survive huge densities of these insects. For aphids, as phloem sap feeders, the interactions at sieve element level must be of special importa

  9. Detection of novel QTLs for foxglove aphid resistance in soybean

    Science.gov (United States)

    Foxglove aphid, Aulacorthum solani (Kaltenbach), is a Hemipteran insect that infected a wide variety of plants worldwide and caused serious yield losses in crops. The objective of this study was to identify the putative QTL for foxglove aphid resistance in wild soybean, PI 366121, (Glycine soja Sieb...

  10. Anomalous stylet punctures of phloem sieve elements by aphids

    NARCIS (Netherlands)

    Tjallingii, W.F.; Gabrys, B.

    1999-01-01

    A deviating type of potential drop (pd), i.e. the electrically recorded intracellular punctures during the pathway phase of plant penetration by aphids, is described and discussed. This so-called repetitive pd (R-pd) has been observed in 4 aphid species, two on herbs and two on sycamore. Apart from

  11. Ants farm subterranean aphids mostly in single clone groups

    DEFF Research Database (Denmark)

    Ivens, Aniek B.F.; Kronauer, Daniel Jan Christoph; Pen, Ido

    2012-01-01

    a single aphid species, a significantly higher percentage than expected from a random distribution. Over 60% of these single-species mounds had a single aphid clone, and clones tended to persist across subsequent years. Whenever multiple species/clones co-occurred in the same mound, they were spatially...... separated with more than 95% of the aphid chambers containing individuals of a single clone. Conclusions L. flavus “husbandry” is characterized by low aphid “livestock” diversity per colony, especially at the nest-chamber level, but it lacks the exclusive monocultures known from other cultivation mutualisms...... benefitting the domesticated aphids as long as their clone-mates reproduce successfully. The cost-benefit logic of this type of polyculture husbandry has striking analogies with human farming practices based on slaughtering young animals for meat to maximize milk-production by a carefully regulated adult...

  12. Predatory Functional Response of Harmonias axyridis Pallas to Two Kinds of Aphids Damaging Apple Trees%异色瓢虫对两种苹果蚜虫的捕食作用

    Institute of Scientific and Technical Information of China (English)

    孙丽娟; 衣维贤; 顾耘; 董向丽

    2012-01-01

    为了明确异色瓢虫对两种常见苹果蚜虫绣线菊蚜(Aphis citricola Von der Goot)和苹果瘤蚜(Myzus malisuctus Matsumura)的控制作用,于.2010年6月,在青岛农业大学实验室内,研究异色瓢虫成虫和4龄幼虫对两种蚜虫的捕食功能反应,同时也研究异色瓢虫4龄幼虫对两种蚜虫的捕食选择性.结果表明,异色瓢虫成虫和4龄幼虫对两种苹果蚜虫的捕食功能反应类型均属于Holling Ⅱ型;异色瓢虫成虫对绣线菊蚜和苹果瘤蚜的最大捕食量分别为123.91和180.98头/d,瞬时攻击率分别为1.029 1和1.335 7;4龄幼虫对绣线菊蚜和苹果瘤蚜的最大捕食量分别为128.88和187.29头/d,瞬时攻击率分别为1.156 0和1.163 4.在两种蚜虫的混合种群中,异色瓢虫4龄幼虫对苹果瘤蚜的选择效应略大于绣线菊蚜,但这种选择性差异在两种蚜虫之间并不明显.%In order to make clear the controlling effect of Harmonias axyridis Pallas on aphids usually damaging apple trees, Aphis citricola Von der Goot and Myzus malisuctus Matsumura, predatory functional response of adult and 4th instars of H. Axyridis Pallas to the two kinds of aphids were studied in the laboratory of Qingdao Agricultural University, and selective efficiency of 4th instars of H. Axyridis Pallas to the two kinds of aphids was studied at the same time. The result showed that the predatory functional response of adult and 4th instars of H. Axyridis Pallas to two kinds of aphids all belonged to Holling Ⅱ. The largest amounts of caught per day of the adult of H. Axyridis Pallas to A. Citricola Von der Goot and M. Malisuctus Matsumura were 123. 91 and 180. 98 per day respectively, and the moment attack parameters were 1. 029 1 and 1. 335 7 respectively; and the Namax of 4th instars of H. Axyridis Pallas to A. Citricola Von der Goot and M. Malisuctus Matsumura were 128. 88 and 187. 29 respectively, and the moment attack parameters were 1. 156 0 and 1. 163 4 per day

  13. Chlorotic feeding injury by the black pecan aphid (hemiptera: aphididae) to pecan foliage promotes aphid settling and nymphal development.

    Science.gov (United States)

    Cottrell, Ted E; Wood, Bruce W; Ni, Xinzhi

    2009-04-01

    The nature of the interaction between the black pecan aphid, Melanocallis caryaefoliae (Davis) (Hemiptera: Aphididae), and the chlorosis it causes to foliage of its pecan [Carya illinoinensis (Wangenh.) K. Koch)] host is poorly understood. Laboratory experiments were conducted on the settling behavior of the black pecan aphid, when provided chlorotic pecan leaf discs resulting from previous black pecan aphid feeding and nonchlorotic leaf discs, under a normal photoperiod and constant dark. Additionally, aphid development from the first instar to the adult stage was examined when nymphs were either allowed to feed on the same leaf disc or moved daily to a new, nondamaged, same age leaf disc. After 24 h, a significantly higher percentage of black pecan aphids settled on chlorotic than on nonchlorotic leaf discs, regardless of photoperiod. When starting from the first instar, nymphs that were prevented from inducing leaf chlorosis by moving daily to new, same-age leaf discs took approximately 5 d longer to complete development, had a shorter body length, and had higher mortality than when aphids remained on the same leaf disc. These results show that black pecan aphid-induced leaf chlorosis plays an important role in the interaction of the black pecan aphid with its pecan host.

  14. Integrated Pest Management of Aphis spiraecola (Hemiptera: Aphididae) in clementines: enhancing its biological control

    OpenAIRE

    GOMEZ MARCO, FRANCESC

    2016-01-01

    [EN] Aphis spiraecola Patch. (Hemiptera: Aphididae) is a key pest of clementines. Biological control of A. spiraecola is still poorly known and efforts were based on the use and conservation of parasitoids but it did not success. With all this said, the aims of this thesis were: i) to disentangle the reasons behind the low parasitism of A. spiraecola; ii) to determine when and how predators can control A. spiraecola populations; and, finally, iii) to evaluate whether a ground cover of Poaceae...

  15. Faba bean in cropping systems

    DEFF Research Database (Denmark)

    Steen Jensen, Erik; Peoples, Mark B.; Hauggaard-Nielsen, Henrik

    2010-01-01

    bean may prove to be a key component of future arable cropping systems where declining supplies and high prices of fossil energy are likely to constrain the affordability and use of fertilizers. This will help address the increasing demand by consumers and governments for agriculture to reduce its...... impact on the environment and climate through new, more sustainable approaches to food production. The aims of this paper are to review the role of faba bean in global plant production systems, the requirements for optimal faba bean production and to highlight the beneficial effects of faba bean...

  16. Genetic mapping and legume synteny of aphid resistance in African cowpea (Vigna unguiculata L. Walp.) grown in California.

    Science.gov (United States)

    Huynh, Bao-Lam; Ehlers, Jeffrey D; Ndeve, Arsenio; Wanamaker, Steve; Lucas, Mitchell R; Close, Timothy J; Roberts, Philip A

    The cowpea aphid Aphis craccivora Koch (CPA) is a destructive insect pest of cowpea, a staple legume crop in Sub-Saharan Africa and other semiarid warm tropics and subtropics. In California, CPA causes damage on all local cultivars from early vegetative to pod development growth stages. Sources of CPA resistance are available in African cowpea germplasm. However, their utilization in breeding is limited by the lack of information on inheritance, genomic location and marker linkage associations of the resistance determinants. In the research reported here, a recombinant inbred line (RIL) population derived from a cross between a susceptible California blackeye cultivar (CB27) and a resistant African breeding line (IT97K-556-6) was genotyped with 1,536 SNP markers. The RILs and parents were phenotyped for CPA resistance using field-based screenings during two main crop seasons in a 'hotspot' location for this pest within the primary growing region of the Central Valley of California. One minor and one major quantitative trait locus (QTL) were consistently mapped on linkage groups 1 and 7, respectively, both with favorable alleles contributed from IT97K-556-6. The major QTL appeared dominant based on a validation test in a related F2 population. SNP markers flanking each QTL were positioned in physical contigs carrying genes involved in plant defense based on synteny with related legumes. These markers could be used to introgress resistance alleles from IT97K-556-6 into susceptible local blackeye varieties by backcrossing.

  17. Multiple cues for winged morph production in an aphid metacommunity.

    Directory of Open Access Journals (Sweden)

    Mohsen Mehrparvar

    Full Text Available Environmental factors can lead individuals down different developmental pathways giving rise to distinct phenotypes (phenotypic plasticity. The production of winged or unwinged morphs in aphids is an example of two alternative developmental pathways. Dispersal is paramount in aphids that often have a metapopulation structure, where local subpopulations frequently go extinct, such as the specialized aphids on tansy (Tanacetum vulgare. We conducted various experiments to further understand the cues involved in the production of winged dispersal morphs by the two dominant species of the tansy aphid metacommunity, Metopeurum fuscoviride and Macrosiphoniella tanacetaria. We found that the ant-tended M. fuscoviride produced winged individuals predominantly at the beginning of the season while the untended M. tanacetaria produced winged individuals throughout the season. Winged mothers of both species produced winged offspring, although in both species winged offspring were mainly produced by unwinged females. Crowding and the presence of predators, effects already known to influence wing production in other aphid species, increased the percentage of winged offspring in M. tanacetaria, but not in M. fuscoviride. We find there are also other factors (i.e. temporal effects inducing the production of winged offspring for natural aphid populations. Our results show that the responses of each aphid species are due to multiple wing induction cues.

  18. Aphid Identification and Counting Based on Smartphone and Machine Vision

    Directory of Open Access Journals (Sweden)

    Suo Xuesong

    2017-01-01

    Full Text Available Exact enumeration of aphids before the aphids outbreak can provide basis for precision spray. This paper designs counting software that can be run on smartphones for real-time enumeration of aphids. As a first step of the method used in this paper, images of the yellow sticky board that is aiming to catch insects are segmented from complex background by using GrabCut method; then the images will be normalized by perspective transformation method. The second step is the pretreatment on the images; images of aphids will be segmented by using OSTU threshold method after the effect of random illumination is eliminated by single image difference method. The last step of the method is aphids’ recognition and counting according to area feature of aphids after extracting contours of aphids by contour detection method. At last, the result of the experiment proves that the effect of random illumination can be effectively eliminated by using single image difference method. The counting accuracy in greenhouse is above 95%, while it can reach 92.5% outside. Thus, it can be seen that the counting software designed in this paper can realize exact enumeration of aphids under complicated illumination which can be used widely. The design method proposed in this paper can provide basis for precision spray according to its effective detection insects.

  19. The function of ecological regulation to aphids in the wheat intercropping field%麦田间作对麦长管蚜的生态调控作用

    Institute of Scientific and Technical Information of China (English)

    解海翠; 陈巨莲; 程登发; 周海波; 孙京瑞; 刘勇; Frederic Francis

    2012-01-01

    [Objective] This study tried to evaluate the ecological regulation of intercropping to Macrosiphum miscanthi populations. [Method] Wheat intercropping with mung bean or pea were designed by row ratio of 8:2 (wheat: mung bean or pea) in the field experiments to investigate the quantity and dynamic changes of M. Miscanthi population with time. Selective preference of M. Miscanthi to the volatiles of wheat, mung bean, pea and their different combination were analyzed by Y-tube in laboratory tests. [Result] The curve of aphid's population dynamics with time was not affected by intercropping, while compared with the monoculture, the quantity of aphids, to some extent, was decreased in intercropping fields. In the laboratory, the odour of host were significantly selected by M. Miscanthi apterae and alatae, and the mixture odour of wheat with mung bean or with pea had no appeal to the aphids. [Conclusion]The odour of non-hosts could cover the odour of hosts, which interfered the aphid's host location, suggesting that intercropping significantly reduced the quantity of aphids populations.%[目的]探讨麦田间作对麦长管蚜种群的生态调控作用.[方法]田间调查小麦单作田、小麦与绿豆、小麦与豌豆以8:2行距间作田麦长管蚜种群数量及其时间动态变化;室内利用“Y”型嗅觉仪测定麦长管蚜对小麦、小麦与绿豆、小麦与豌豆不同组合气味的选择性.[结果]麦田间作不能影响麦蚜种群随时间动态变化曲线,但能在一定程度上降低麦长管蚜无翅蚜和有翅蚜的数量.室内麦长管蚜无翅蚜和有翅蚜显著选择寄主植物的气味.当小麦与绿豆或小麦与豌豆组合时对麦长管蚜没有吸引作用.[结论]非寄主植物的气味对寄主植物气味起掩盖作用,干扰蚜虫的寄主定位,这可能是间作低于单作蚜量的原因之一.

  20. Conserved odorant-binding proteins from aphids and eavesdropping predators.

    Directory of Open Access Journals (Sweden)

    Sophie Vandermoten

    Full Text Available BACKGROUND: The sesquiterpene (E-ß-farnesene is the main component of the alarm pheromone system of various aphid species studied to date, including the English grain aphid, Sitobion avenae. Aphid natural enemies, such as the marmalade hoverfly Episyrphus balteatus and the multicolored Asian lady beetle Harmonia axyridis, eavesdrop on aphid chemical communication and utilize (E-ß-farnesene as a kairomone to localize their immediate or offspring preys. These aphid-predator systems are important models to study how the olfactory systems of distant insect taxa process the same chemical signal. We postulated that odorant-binding proteins (OBPs, which are highly expressed in insect olfactory tissues and involved in the first step of odorant reception, have conserved regions involved in binding (E-ß-farnesene. METHODOLOGY: We cloned OBP genes from the English grain aphid and two major predators of this aphid species. We then expressed these proteins and compare their binding affinities to the alarm pheromone/kairomone. By using a fluorescence reporter, we tested binding of (E-ß-farnesene and other electrophysiologically and behaviorally active compounds, including a green leaf volatile attractant. CONCLUSION: We found that OBPs from disparate taxa of aphids and their predators are highly conserved proteins, with apparently no orthologue genes in other insect species. Properly folded, recombinant proteins from the English grain aphid, SaveOBP3, and the marmalade hoverfly, EbalOBP3, specifically bind (E-ß-farnesene with apparent high affinity. For the first time we have demonstrated that insect species belonging to distinct Orders have conserved OBPs, which specifically bind a common semiochemical and has no binding affinity for related compounds.

  1. Galling Aphids (Hemiptera: Aphidoidea in China: Diversity and Host Specificity

    Directory of Open Access Journals (Sweden)

    Jing Chen

    2012-01-01

    Full Text Available Gall formation is an interesting plant response to aphid feeding. This paper presents a review of galling aphids in China. Altogether, 157 species and subspecies in ten families and subfamilies are found to induce galls on their host plants. As many as 39% species are endemic to China. The Eriosomatinae include the highest percentage of gall-inducing species. The great diversity of gall morphology may be described in terms of five characteristics: type, site, size, shape, and structure. The host association and host specificity of galling aphids are also discussed.

  2. For the Aphid fauna in the territory of Yenisei river basin. Communication 1. Aphids on coniferous plants

    Directory of Open Access Journals (Sweden)

    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.

  3. Modification of whole flours of navy bean, pinto bean, black bean and chickpea by steam jet cooking and drum drying

    Science.gov (United States)

    Whole bean flours of navy bean, pinto bean, black bean and chickpea were processed by excess steam jet cooking, drum drying, and milling to a state resembling the raw flours. Analysis of the structure and size of the particles, color, solubility and pasting characteristics, dietary fiber, and protei...

  4. 瓜蚜为害对寄主植物主要营养物质和次生物质的影响%Influences of Aphis gossypii Glover feeding on the contents of main nutrients and secondary compounds in host plants

    Institute of Scientific and Technical Information of China (English)

    李艳艳; 周晓榕; 庞保平; 常静

    2013-01-01

    为明确瓜蚜Aphis gossypii Glover与其寄主植物相互作用关系及其机理,本文采用蒽酮比色法、考马斯亮蓝法、磷钼酸-磷钨酸比色法及索氏回流法,分别测定了瓜蚜为害对黄瓜、哈密瓜、南瓜、瓢葫芦和搅瓜等5种寄主植物叶片内可溶性总糖、可溶性蛋白质、单宁及黄酮含量的影响.结果表明,瓜蚜为害后,供试寄主植物叶片中可溶性糖和可溶性蛋白含量显著降低,而单宁和黄酮的含量明显上升.说明瓜蚜为害导致寄主植物营养质量下降,而次生代谢物质含量上升,从而对植食者产生诱导抗性.%In order to investigate the interaction between Aphis gossypii Glover and its host plants, it was determined how the aphid feeding affected the contents of soluble sugar, soluble protein, tannin and flavone in the leaves of its five host plants ( Cucumis sativus, Cucumis melo var. saccharinus, Cucurbita moschata var. melonaeformis, Lagenaria siceraria var. turbinate and Cucurbita pepo var. medullosa) , using anthrone colorimetric method, Coomassie brilliant blue staining, phosphor - molybdenum acid -phosphor - tungstenic acid colorimetry and Soxhlet extraction, respectively. The results showed that the contents of soluble sugar and soluble protein in the leaves of its host plants decreased while the contents of tannin and flavone increased after the host plants were fed by the aphids. This indicated that the aphid feeding caused the decrease of host plant' s nutrition quality while the increase of harmful secondary metabolite contents, and therefore, induced the resistance to herbivores.

  5. Control Four Species of Aphid on Vegetables with Diaeretiella rapae (McIntosh) (Hymenoptera:Braconidae)%菜蚜茧蜂对4种蔬菜蚜虫的控制作用研究

    Institute of Scientific and Technical Information of China (English)

    张立猛; 田泽华; 计思贵; 谷星慧; 周文兵; 杨海林

    2016-01-01

    菜蚜茧蜂(Diaeretiella rapae)是蔬菜蚜虫的重要天敌。为了明确菜蚜茧蜂对我国常见4种蔬菜蚜虫的控制作用,通过室内试验,研究了菜蚜茧蜂对萝卜蚜、甘蓝蚜、豌豆蚜和蚕豆蚜的寄生作用。结果表明:菜蚜茧蜂对萝卜蚜和甘蓝蚜具有较好的控制作用,放蜂后21 d,其寄生率多在20%以上;对豌豆蚜的寄生作用较弱,放蜂后21 d,寄生率最高不超过10%;对蚕豆蚜寄生率最低,多在1%左右,只有极少数蚜虫被寄生。%Diaeretiella rapae, an important parasitoid of aphids in the world, was released with 6 ratio to controlLipaphis erysimi, Brevicoryne brassicae,Acyrthosiphon pisum andAphis craccivorain Yuxi City Yunnan Province. The results showed that the parasitoid could controlLipaphis erysimi andBrevicoryne brassicae availably, and the parasitism was above 20% after releasing the parasitoid in 21 days, but the parasitism was only 10% to controlAcyrthosiphon pisum, and only 1% to controlAphis craccivora. The results provided evidence to control the aphids on vegetables by releasingDiaeretiella rapae(McIntosh).

  6. Genome sequence of the pea aphid Acyrthosiphon pisum

    DEFF Research Database (Denmark)

    Richards, S.; Gibbs, R. A.; Gerardo, N. M.;

    2010-01-01

    Aphids are important agricultural pests and also biological models for studies of insect-plant interactions, symbiosis, virus vectoring, and the developmental causes of extreme phenotypic plasticity. Here we present the 464 Mb draft genome assembly of the pea aphid Acyrthosiphon pisum. This first...... published whole genome sequence of a basal hemimetabolous insect provides an outgroup to the multiple published genomes of holometabolous insects. Pea aphids are host-plant specialists, they can reproduce both sexually and asexually, and they have coevolved with an obligate bacterial symbiont. Here we...... include genes involved in chromatin modification, miRNA synthesis, and sugar transport. Gene losses include genes central to the IMD immune pathway, selenoprotein utilization, purine salvage, and the entire urea cycle. The pea aphid genome reveals that only a limited number of genes have been acquired...

  7. Smells like aphids: orchid flowers mimic aphid alarm pheromones to attract hoverflies for pollination.

    Science.gov (United States)

    Stökl, Johannes; Brodmann, Jennifer; Dafni, Amots; Ayasse, Manfred; Hansson, Bill S

    2011-04-22

    Most insects are dependent on chemical communication for activities such as mate finding or host location. Several plants, and especially orchids, mimic insect semiochemicals to attract insects for unrewarded pollination. Here, we present a new case of pheromone mimicry found in the terrestrial orchid Epipactis veratrifolia. Flowers are visited and pollinated by several species of aphidophagous hoverflies, the females of which also often lay eggs in the flowers. The oviposition behaviour of these hoverflies is mainly guided by aphid-derived kairomones. We show that the flowers produce α- and β-pinene, β-myrcene and β-phellandrene, and that these compounds attract and induce oviposition behaviour in female hoverflies. This floral odour profile is remarkably similar to the alarm pheromone released by several aphid species, such as Megoura viciae. We therefore suggest that E. veratrifolia mimics aphid alarm pheromones to attract hoverflies for pollination; this is the first time, to our knowledge, that such a case of mimicry has been demonstrated.

  8. Smells like aphids: orchid flowers mimic aphid alarm pheromones to attract hoverflies for pollination

    Science.gov (United States)

    Stökl, Johannes; Brodmann, Jennifer; Dafni, Amots; Ayasse, Manfred; Hansson, Bill S.

    2011-01-01

    Most insects are dependent on chemical communication for activities such as mate finding or host location. Several plants, and especially orchids, mimic insect semiochemicals to attract insects for unrewarded pollination. Here, we present a new case of pheromone mimicry found in the terrestrial orchid Epipactis veratrifolia. Flowers are visited and pollinated by several species of aphidophagous hoverflies, the females of which also often lay eggs in the flowers. The oviposition behaviour of these hoverflies is mainly guided by aphid-derived kairomones. We show that the flowers produce α- and β-pinene, β-myrcene and β-phellandrene, and that these compounds attract and induce oviposition behaviour in female hoverflies. This floral odour profile is remarkably similar to the alarm pheromone released by several aphid species, such as Megoura viciae. We therefore suggest that E. veratrifolia mimics aphid alarm pheromones to attract hoverflies for pollination; this is the first time, to our knowledge, that such a case of mimicry has been demonstrated. PMID:20943694

  9. Pyridine derivatives as insecticides. Part 1: synthesis and toxicity of some pyridine derivatives against cowpea aphid, Aphis craccivora Koch (Homoptera: Aphididae).

    Science.gov (United States)

    Bakhite, Etify A; Abd-Ella, Aly A; El-Sayed, Mohamed E A; Abdel-Raheem, Shaban A A

    2014-10-15

    Five pyridine derivatives, namely, N-morpholinium 7,7-dimethyl-3-cyano-4-(4'-nitrophenyl)-5-oxo-1,4,5,6,7,8-hexahydroquinoline-2-thiolate (1), sodium 5-acetyl-3-amino-4-(4'-methoxyphenyl)-6-methylthieno[2,3-b] pyridine-2-carboxylate (2), piperidinium 3,5-dicyano-2-oxo-4-spirocyclopentane-1,2,3,4-tetrahydropyridine-6-thiolate (3), piperidinium 5-acetyl-3-cyano-4-(4'-methoxyphenyl)-6-methylpyridine-2-thiolate (4), and piperidinium 5-acetyl-4-(4'-chlorophenyl)-3-cyano-6-methyl-pyridine-2-thiolate (5) were prepared in pure state and subjected to the title study. The bioassay results indicated that the insecticidal activity of compound 1 is about 4-fold that of acetamiprid insecticide. The rest of the tested compounds possess moderate to strong aphidicidal activities.

  10. Mulches reduce aphid-borne viruses and whiteflies in cantaloupe

    OpenAIRE

    Summers, Charles G.; Mitchell, Jeffrey P.; Stapleton, James J.

    2005-01-01

    We compared reflective plastic and wheat straw mulches with conventional bare soil for managing aphid-borne virus diseases and silverleaf whitefly in cantaloupe. The occurrence of aphid-borne virus diseases was significantly reduced with both mulches as opposed to bare soil, and reflective plastic performed better than wheat straw. Silverleaf whitefly numbers, both adults and nymphs, were reduced equally by plastic mulch and wheat straw, and were significantly lower than with bare soil. Refle...

  11. Biological control of tortricids and aphids in strawberries

    DEFF Research Database (Denmark)

    Sigsgaard, Lene; Enkegaard, Annie; Eilenberg, Jørgen;

    Cropping practice and biological control can contribute to reduced pesticide use in strawberries. Organic strawberries are less attacked by strawberry tortricid and buckwheat flower strips can augment its natural enemies. Against shallot aphid the two-spot ladybird is promising.......Cropping practice and biological control can contribute to reduced pesticide use in strawberries. Organic strawberries are less attacked by strawberry tortricid and buckwheat flower strips can augment its natural enemies. Against shallot aphid the two-spot ladybird is promising....

  12. Effect of the inherent variation in the mineral concentration of alfalfa cultivars on aphid populations Efeito da variação inata da concentração de minerais em cultivares de alfafa (Medicago sativa em população de afídeos (Hemiptera: Aphididae

    Directory of Open Access Journals (Sweden)

    Alexandre de Almeida e Silva

    2005-01-01

    Full Text Available Plants have inherent variability of mineral content which affects their physiology and consequently the herbivorous insects feeding on them. Besides, insects need considerable amounts of potassium, phosphorus and magnesium in their diets, whereas little calcium, sodium and chloride are required. In this study, the inherent variation on mineral (Ca, S, Mg, N, P, K and also C:N ratio concentrations and aphid (Acyrthosiphon spp., Therioaphis maculata, Aphis craccivora populations on three alfalfa (Medicago sativa cultivars (P3; Crioula, the most widely cultivated in Brazil, and CUF 101, an aphid-resistant were studied between September/1997 and August/1998. A significant variation on mineral concentrations and aphid populations was observed among different sampling times and cultivars. The correlations between C:N ratio, Mg, N, P and S concentrations and aphid density variation suggest that the mineral status affects aphid population dynamics under field conditions.As plantas têm variação inata do conteúdo de minerais e seu estado nutricional afeta sua fisiologia cloretos. A variação inata na concentração de minerais (Ca, S, Mg, N, P, K e também a razão C:N e na população de afídeos (Acyrthosiphon spp., Therioaphis maculata, Aphis craccivora em três cultivares de alfafa (M. sativa - P3; Crioula, as mais cultivadas no Brasil, e CUF 101, resistente a afídeos - foi estudada entre setembro/1997 a agosto/1998 neste trabalho. A concentração de minerais e as populações de pulgões variaram significativamente entre os diferentes períodos de coleta e cultivares. As correlações encontradas entre as concentrações de Mg, N, P, S e a razão C:N e a variação no número de pulgões sugerem que os minerais da planta afetam a dinâmica populacional dos pulgões em campo.

  13. Development and Fecundity of Aphis Gossypii Glover (Homoptera: Aphididae) on Three Malvaceae Hosts

    OpenAIRE

    Serdar SATAR; KERSTING, Ulrich; UYGUN, Nedim

    1999-01-01

    Aphis gossypii Glover (Homoptera, Aphididae) obtained from cotton fields near Adana in the east Mediterranean region of Turkey were colonized on Gossypium hirsutumL. 'Çukurova 1518' in a climatic room. The effect of host transfer from cotton to common mallow, Malva sylvestris L., and okra, Abelmoschus esculentus (L.) Moench 'Bamya 501', on performance of A. gossypii was studied at constant 25 ± 1°C, 60 ± 5 % relative humidity and 16 h of artificial light (5000 l...

  14. Development and Fecundity of Aphis Gossypii Glover (Homoptera: Aphididae) on Three Malvaceae Hosts

    OpenAIRE

    Serdar SATAR; KERSTING, Ulrich; UYGUN, Nedim

    2014-01-01

    Aphis gossypii Glover (Homoptera, Aphididae) obtained from cotton fields near Adana in the east Mediterranean region of Turkey were colonized on Gossypium hirsutumL. 'Çukurova 1518' in a climatic room. The effect of host transfer from cotton to common mallow, Malva sylvestris L., and okra, Abelmoschus esculentus (L.) Moench 'Bamya 501', on performance of A. gossypii was studied at constant 25 ± 1°C, 60 ± 5 % relative humidity and 16 h of artifici...

  15. Preparing soft-bodied arthropods for microscope examination: Aphids (Insecta: Hemiptera: Aphididae)

    Science.gov (United States)

    Proper identification of aphids (Hemiptera: Aphididae) require preparation of the specimen on a microscope slide. This training video provides visual instruction on how to prepare aphid specimens on microscope slides for examination and indentification. Steps ranging from collection, specimen clear...

  16. Autumn leaf colouration: a new hypothesis involving plant-ant mutualism via aphids

    Science.gov (United States)

    Yamazaki, Kazuo

    2008-07-01

    Several recent hypotheses on the adaptive significance of autumn leaf colours have focused on specialist aphids. However, these hypotheses have overlooked several factors: the preferential investment by healthy vigorous trees in growth rather than defence against herbivores, variation among aphid species in their responses to bright autumn leaves and plant defences and the occurrence of tritrophic interactions in tree crowns. I incorporate these factors into a hypothesis that autumn leaf colours signal tree quality to myrmecophilous specialist aphids, with the aphids, in turn, attracting aphid-tending ants during the following spring, and the ants defending the trees from other aphids and herbivores. Therefore, bright autumn leaves may have adaptive significance, attracting myrmecophilous specialist aphids and their attending ants and, thus, reducing herbivory and competition among aphids.

  17. Agronomy of strip intercropping broccoli with alyssum for biological control of aphids

    Science.gov (United States)

    Organic broccoli growers in California typically control aphids by intercropping broccoli with strips of alyssum (Lobularia maritima (L.) Desv.) which attracts hoverflies (Diptera: Syrphidae) that are important predators of aphids. A three year study with transplanted organic broccoli in Salinas, ...

  18. Aphid Genotype Determines Intensity of Ant Attendance: Do Endosymbionts and Honeydew Composition Matter?

    National Research Council Canada - National Science Library

    N. Katayama; T. Tsuchida; M. K. Hojo; T. Ohgushi

    2013-01-01

    ABSTRACT Ant—aphid interactions are well-studied mutualisms, but surprisingly, the intraspecific variation in the degree of ant attendance of aphids has been less appreciated than interspecific variation...

  19. Transcriptomic comparison of thiamethoxam-resistance adaptation in resistant and susceptible strains of Aphis gossypii Glover.

    Science.gov (United States)

    Pan, Yiou; Peng, Tianfei; Gao, Xiwu; Zhang, Lei; Yang, Chen; Xi, Jinghui; Xin, Xuecheng; Bi, Rui; Shang, Qingli

    2015-03-01

    A thiamethoxam-resistant strain of cotton aphid (ThR) strain displayed a 19.35-fold greater resistance to thiamethoxam compared to a susceptible cotton aphid (SS) strain. Solexa sequencing technology was used to investigate differentially expressed genes (DEGs) in cotton aphids in the context of thiamethoxam resistance. A total of 22,569,311 and 21,317,732 clean reads were obtained from the ThR and SS transcriptomes, respectively, and assembled into 35,222 non-redundant (Nr) consensus sequences. The expression of 620 unigenes changed significantly in the ThR libraries compared to the SS strain; 349 genes were up-regulated, and 271 genes were down-regulated (P≤0.001). Expression levels of ribosomal proteins, ATP synthase, cytochrome c oxidase, ecdysteroid UDP-glucosyltransferase and esterase were up-regulated significantly in the ThR strain compared to the SS strain. The genes of cuticle proteins, salivary proteins, and fibroin heavy chain decreased dramatically. One nicotinic acetylcholine receptor (nAChR) α subunit was down-regulated in the ThR strain. The expression levels of 10 differentially expressed unigenes were confirmed using real-time RT-PCR, and the observed trends in gene expression matched the Solexa expression profiles. Specific single-nucleotide polymorphisms (SNPs) in nAChRs that cause amino acid substitution were found from the ThR and SS stains respectively. These data illustrate that genetic changes in nAChR genes and up-regulated ribosomal proteins, ecdysteroid UDP-glucosyltransferase, cytochrome c oxidase, esterase and peroxidase may confer the tolerance of resistant cotton aphids to thiamethoxam.

  20. New data on aphid fauna (Hemiptera, Aphididae) in Algeria.

    Science.gov (United States)

    Laamari, Malik; d'Acier, Armelle Coeur; Jousselin, Emmanuelle

    2013-01-01

    A survey of aphids was carried out during the period 2008-2011 in different regions of Algeria by collecting and identifying aphids and their host plants. Aphids were collected from 46 host plants. Forty-six species were reported including thirty-six species which were recorded for the first time in this country and thirty species which were recorded for the first time in the Maghreb (North Africa). This study extends the number of known Algerian aphid to 156 species.

  1. Irradiated cocoa beans

    Energy Technology Data Exchange (ETDEWEB)

    Ashby, R.; Tesh, J.M.

    1982-11-01

    Groups of 40 male and 40 female CD rats were fed powdered rodent diet containing 25% (w/w) of either non-irradiated, irradiated or fumigated cocoa beans. The diets were supplemented with certain essential dietary constituents designed to satisfy normal nutritional requirements. An additional 40 male and 40 female rats received basal rodent diet alone (ground) and acted as an untreated control. After 70 days of treatment, 15 male and 15 female rats from each group were used to assess reproductive function of the F/sub 0/ animals and growth and development of the F/sub 1/ offspring up to weaning; the remaining animals were killed after 91 days of treatment.

  2. Ethylene production and peroxidase activity in aphid-infested barley.

    Science.gov (United States)

    Argandoña, V H; Chaman, M; Cardemil, L; Muñoz, O; Zúñiga, G E; Corcuera, L J

    2001-01-01

    The purpose of this work was to investigate whether ethylene is involved in the oxidative and defensive responses of barley to the aphids Schizaphis graminum (biotype C) and Rhopalophum padi. The effect of aphid infestation on ethylene production was measured in two barley cultivars (Frontera and Aramir) that differ in their susceptibility to aphids. Ethylene evolution was higher in plants infested for 16 hr than in plants infested for 4 hr in both cultivars. Under aphid infestation, the production of ethylene was higher in cv. Frontera than in Aramir, the more aphid susceptible cultivar. Ethylene production also increases with the degree of infestation. Maximum ethylene evolution was detected after 16 hr when plants were infested with 10 or more aphids. Comparing the two species of aphids, Schizaphis graminum induced more ethylene evolution than Rhopalosiphum padi. Infestation with S. graminum increased hydrogen peroxide content and total soluble peroxidase activity in cv. Frontera, with a maximum level of H2O2 observed after 20 min of infestation and the maximum in soluble peroxidase activity after 30 min of infestation. When noninfested barley seedlings from cv. Frontera were exposed to ethylene, an increase in hydrogen peroxide and in total peroxidase activity was detected at levels similar to those of infested plants from cv. Frontera. When noninfested plants were treated with 40 ppm of ethylene, the maximum levels of H2O2 and soluble peroxidase activity were at 10 and 40 min, respectively. Ethylene also increased the activity of both cell-wall-bound peroxidases types (ionically and covalently bound), comparable with infestation. These results suggest that ethylene is involved in the oxidative responses of barley plants induced by infestation.

  3. Cereal aphid colony turnover and persistence in winter wheat.

    Directory of Open Access Journals (Sweden)

    Linton Winder

    Full Text Available An understanding of spatial and temporal processes in agricultural ecosystems provides a basis for rational decision-making with regards to the management and husbandry of crops, supporting the implementation of integrated farming strategies. In this study we investigated the spatial and temporal distribution of aphid pests (Sitobion avenae and Metopolophium dirhodum within winter wheat fields. Using an intensive sampling programme we investigated distributions at both the small (single shoot and large (field scales. Within two fields, a grid with 82 locations was established (area 120 m by 168 m. At each location, 25 shoots were individually marked and aphid counts by observation conducted on 21 and 22 occasions as the crop matured, resulting in 43,050 and 45,100 counts being conducted in the two fields respectively. We quantified field scale spatial distributions, demonstrating that spatial pattern generally emerged, with temporal stability being both species- and field- dependent. We then measured turnover of colonies at the small (individual shoot and large (field scales by comparing consecutive pairs of sampling occasions. Four turnover categories were defined: Empty (no aphids recorded on either occasion; Colonised (aphids recorded on the second occasion but not the first; Extinction (aphids recorded on the first occasion but not the second; Stable (aphids recorded on both occasions. At the field scale, population stability soon established, but, at the small scale there was a consistently high proportion of unoccupied shoots with considerable colonisation and extinction and low stability. The redistribution of aphids within the crop at the local scale is a vulnerability which could be used to disrupt population development--by mediating exposure to ground-active natural enemies and by incurring a metabolic cost caused by the physiological demands to re-establish on a nearby host plant.

  4. National Plant Diagnostic Network, Taxonomic training videos: Aphids under the microscope - overview

    Science.gov (United States)

    Training is a critical part of aphid (Hemiptera: Aphididae) identification. This training video provides provides an overview of general aphid morphology by using a compound microscope. The narrator discusses and highlights structures on the aphid that are important to make a species identification....

  5. Effects of organic fertilizers on the growth and yield of bush bean, winged bean and yard long bean

    Directory of Open Access Journals (Sweden)

    Mohammad Aminul Islam

    Full Text Available ABSTRACT VC (20%, TC (20% and N:P:K fertilizer (farmer's practice were used to determine the growth and yield attributes of bush bean (Phaseolus vulgaris, winged bean (Psophocarpus tetragonolobus and yard long bean (Vigna unguiculata. Plants grown with VC (20% produced the highest fresh biomass for bush bean (527.55 g m-2, winged bean (1168.61 g m-2 and yard long bean (409.84 g m-2. In all the tested legumes the highest pod weight, pod number, pod dry weight and pod length were found in the VC (20% treatment. Photosynthetic rates in the three legumes peaked at pod formation stage in all treatments, with the highest photosynthetic rate observed in winged bean (56.17 µmol m-2s-1 grown with VC (20%. The highest yield for bush bean (2.98 ton ha-1, winged bean (7.28 ton ha-1 and yard long bean (2.22 ton ha-1 were also found in VC (20% treatment. Furthermore, protein content was highest in bush bean (26.50 g/100g, followed by yard long bean (24.74 g/100g and winged bean (22.04 g/100g, under VC (20% treatment. It can be concluded that legumes grown with VC (20% produced the highest yield and yield attributes.

  6. Aphids (Homoptera, Aphidodea inhabiting the shrubs of Pinus mugo Turra in the green area of Lublin. Part II. Domination and frequency of aphids, their natural enemies and the injuries caused by aphids

    Directory of Open Access Journals (Sweden)

    Aneta Sławińska

    2012-12-01

    Full Text Available Observations were conducted in the years 1999-2001 on the shrubs Pinus mugo Turra growing in the green areas of Lublin in two sites (street and park. The purpose of the studies was to establish the domination and frequency of aphids, their effect on the decorative character of shrubs and the occurrence of the aphidophagous arthropods in the aphid colonies inhabiting mountain pine. It was found out that Schizolachnus pineti F. was the dominating species in the street site (A, while Cinara pini L. dominated in the park site (B. The decorative character of shrubs was clearly lowered only by aphids S. pineti. Predatory arthropods occurred in aphid colonies inhabiting the shrubs P. mugo. Their population in both sites was low, that is why they probably had little influence on limiting the aphid population. Parasitic Hymenoptera of I and II degrees obtained from a culture of aphid mummies were more numerous in the street site.

  7. Breeding Beans with Bruchid and Multiple Virus Resistance

    Science.gov (United States)

    Bean common mosaic virus (BCMV) and bean common mosaic necrosis virus (BCMNV) are worldwide threats to dry bean (Phaseolus vulgaris L.) production. Beans planted in the lowlands of Central America and the Caribbean also need resistance to Bean golden yellow mosaic virus (BGYMV). The common bean weev...

  8. 9 CFR 319.310 - Lima beans with ham in sauce, beans with ham in sauce, beans with bacon in sauce, and similar...

    Science.gov (United States)

    2010-01-01

    ... with ham in sauce, beans with bacon in sauce, and similar products. 319.310 Section 319.310 Animals and....310 Lima beans with ham in sauce, beans with ham in sauce, beans with bacon in sauce, and similar products. “Lima Beans with Ham in Sauce,” “Beans with Ham in Sauce,” “Beans with Bacon in Sauce,”...

  9. 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

  10. Mechanisms regulating caste differentiation in an aphid social system.

    Science.gov (United States)

    Shibao, Harunobu; Kutsukake, Mayako; Matsuyama, Shigeru; Fukatsu, Takema; Shimada, Masakazu

    2010-01-01

    For evolution and maintenance of the social systems of insect colonies, caste production should be controlled in response to external cues so that caste ratio in the colony is kept at an optimal range. Recent developments using artificial diet rearing techniques have revealed an underlying mechanism for adaptive control of caste production in a social aphid, Tuberaphis styraci, which has a sterile soldier caste in the 2(nd) instar. Aphid density was the proximate cue that acts on 1(st) instar nymphs and embryos to induce soldier differentiation. The final determination of soldier differentiation occurred postnatally, probably at a late 1(st) instar stage. Direct contact stimuli from live non-soldier aphids mediated the density effect. While coexisting non-soldiers facilitated soldier differentiation in 1(st) instar nymphs, coexisting soldiers acted to suppress such differentiation. These results suggest that caste production in aphid colonies is controlled by positive and negative feedback mechanisms consisting of density-dependent induction and suppression of soldier differentiation. Here, we demonstrate the mechanisms that coordinate aphid society, and provide a striking case of clonal superorganism system where simple responses of colony members to local extrinsic stimuli are integrated into a highly organized regulation of the whole colony.

  11. 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.

  12. 多食性瓢虫捕食5种蚜虫的统计学比较:实验室研究%COMPARATIVE DEMOGRAPHICS OF A GENERALIST PREDATORY LADYBIRD ON FIVE APHID PREY:A LABORATORY STUDY

    Institute of Scientific and Technical Information of China (English)

    Omkar; Ahmad Pervez

    2004-01-01

    Prey driven demographic parameters of an aphidophagous ladybird, Propylea dissecta (Mulsant) were studied in attempt to answer how ladybird overcomes the problem of seasonally fluctuating food base. The ladybird reared for five generations in laboratory derived differential nutrition from five food sources (i.e. aphid species, Rhopalosiphum maidis (Fitch), Aphis craccivora Koch, Aphis gossypii Glover, Uroleucon compositae (Theobald) and Lipaphis erysimi (Kalt.)). The order of relative prey suitability was A. gossypii, A. craccivora, R. maidis, U. compositae and L.erysimi. Neonates suffered maximum mortality followed by eggs. Estimates of net reproductive rate,intrinsic rate of increase and finite rate of increase were highest (407.18, 0.2274 day-1, 1.2553 day-1) on A. gossypii and lowest (176.02, 0.1533 day-i, 1.1657 day-1) on L. erysimi. Generation time was shortest (26.43 days) on A. gossypii and longest (33.73 days) on L. erysimi. The present study thus,provides an explanation to the high incidence of P. dissecta on A. gossypii, as it experienced high intrinsic rate of increase and optimal values for related demographic parameters.%通过食蚜瓢虫Propylea dissecta(Mulsant)的捕食统计学参数的比较,尝试回答瓢虫是如何克服食物基础季节性的变动问题.在实验室中饲养五世代的瓢虫从五种蚜虫(Rhopalosiphum maidis(Fitch),Aphis craccivora Kock,Aphis gossypii Glover,Uroleucon compositae(Theobald)和Lipaphis erysimi(Kalt))为食物来源获得营养.相对适合的猎物次序是A.gossypii,A.craccivora,R.maidis,U.compositae和L.erysimi.新生幼虫的死亡率最高,其次是卵.统计表明,净生殖率、内懔增长率和有限增长率为(407.18,0.2274天-1,1.2553天-1)最高的在A.gossypii和最低的(176.02,0.1533天-1,1.1657天-1)在L.erysimi,一个世代时间最短的26.43天是捕食A.gossypii;而最长的33.73天为捕食L.erysimi.本研究为P.dissecta捕食A.gossypii高发生提供一种解释,因为它经历了

  13. Biological and Cultural Control of Olive Fruit Fly in California---Utilization of Parasitoids from USDA-APHIS-PPQ, Guatemala

    Science.gov (United States)

    The parasitoid Psytallia cf. concolor (Szépligeti) was reared on sterile Mediterranean fruit fly larvae at the USDA-APHIS-PPQ, Petapa Quarantine Laboratory in Guatemala and shipped to the USDA-ARS, Parlier, for wide-spread release and biological control of olive fruit fly in California. As many as 3...

  14. 9 CFR 72.8 - Interstate movement of cattle from free premises upon inspection and certification by APHIS...

    Science.gov (United States)

    2010-01-01

    ... TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS TEXAS (SPLENETIC) FEVER IN CATTLE § 72.8... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Interstate movement of cattle from free premises upon inspection and certification by APHIS inspector. 72.8 Section 72.8 Animals...

  15. Virulent Diuraphis noxia Aphids Over-Express Calcium Signaling Proteins to Overcome Defenses of Aphid-Resistant Wheat Plants.

    Science.gov (United States)

    Sinha, Deepak K; Chandran, Predeesh; Timm, Alicia E; Aguirre-Rojas, Lina; Smith, C Michael

    2016-01-01

    The Russian wheat aphid, Diuraphis noxia, an invasive phytotoxic pest of wheat, Triticum aestivum, and barley, Hordeum vulgare, causes huge economic losses in Africa, South America, and North America. Most acceptable and ecologically beneficial aphid management strategies include selection and breeding of D. noxia-resistant varieties, and numerous D. noxia resistance genes have been identified in T. aestivum and H. vulgare. North American D. noxia biotype 1 is avirulent to T. aestivum varieties possessing Dn4 or Dn7 genes, while biotype 2 is virulent to Dn4 and avirulent to Dn7. The current investigation utilized next-generation RNAseq technology to reveal that biotype 2 over expresses proteins involved in calcium signaling, which activates phosphoinositide (PI) metabolism. Calcium signaling proteins comprised 36% of all transcripts identified in the two D. noxia biotypes. Depending on plant resistance gene-aphid biotype interaction, additional transcript groups included those involved in tissue growth; defense and stress response; zinc ion and related cofactor binding; and apoptosis. Activation of enzymes involved in PI metabolism by D. noxia biotype 2 aphids allows depletion of plant calcium that normally blocks aphid feeding sites in phloem sieve elements and enables successful, continuous feeding on plants resistant to avirulent biotype 1. Inhibition of the key enzyme phospholipase C significantly reduced biotype 2 salivation into phloem and phloem sap ingestion.

  16. Stem nematode counteracts plant resistance of aphids in alfalfa, Medicago sativa.

    Science.gov (United States)

    Ramirez, Ricardo A; Spears, Lori R

    2014-10-01

    Plants are exploited by a diverse community of insect herbivores and phytopathogens that interact indirectly through plant-mediated interactions. Generally, plants are thought to respond to insects and pathogens through different defensive signaling pathways. As plants are selected for resistance to one phytophagous organism type (insect vs. pathogen) in managed systems, it is not clear how this selection may affect community interactions. This study examined the effect of nematode-resistant varieties on aphid (Acyrthosiphon pisum) suppression, and then determined how infection by the stem nematode, Ditylenchus dipsaci, mediated ecological effects on aphids and on plant defense proteins. Four alfalfa (Medicago sativa) varieties were selected with resistance to nematodes only (+,-), aphids only (-,+), nematodes and aphids (+,+), and susceptibility to nematodes and aphids (-,-). Field and greenhouse experiments were conducted to isolate the effect of nematode infection and aphid abundance on each variety. We found that varieties resistant to nematode, regardless of aphid resistance, had the lowest aphid counts, suggesting possible cross-resistance. Aphid abundance, however, increased when plants were exposed to nematodes. Resistant varieties were associated with elevated saponins but these compounds were not affected by insect or pathogen feeding. Concentrations of peroxidases and trypsin inhibitors, however, were increased in nematode resistant varieties when exposed to nematodes and aphids, respectively. The patterns of plant defense were variable, and a combination of resistance traits and changes in nutrient availability may drive positive interactions between nematodes and aphids aboveground.

  17. Formulation of the endophytic fungus Cladosporium oxysporum Berk.

    Directory of Open Access Journals (Sweden)

    Bensaci Oussama Ali

    2015-01-01

    Full Text Available Two formulations containing culture filtrates and conidial suspensions of the endophytic fungus Cladosporium oxysporum Berk. & M.A. Curtis, isolated previously from stems of Euphorbia bupleuroides subsp. luteola (Kralik Maire, were experimentally tested for their aphicid activity against the black bean aphid Aphis fabae Scop. found in Algeria. It was shown that invert emulsions are more effective against aphids, than using aqueous suspensions. This was especially true for formulations containing culture filtrates. The relatively insignificant mortalities obtained by formulations containing conidial suspensions indicated a low infectious potential towards the aphids. The proteolytic activity seemed to be more important than the chitinolytic activity of the fungus against the black bean aphid A. fabae

  18. NetBeans IDE 8 cookbook

    CERN Document Server

    Salter, David

    2014-01-01

    If you're a Java developer of any level using NetBeans and want to learn how to get the most out of NetBeans, then this book is for you. Learning how to utilize NetBeans will provide a firm foundation for your Java application development.

  19. Chlorotic mottle of bean (Phaseolus vulgaris L.)

    NARCIS (Netherlands)

    Jayasinghe, W.U.

    1982-01-01

    For the past years there have been outbreaks of a disease of bean ( Phaseolus vulgaris L.) in Colombia called bean chlorotic mottle. The etiology of bean chlorotic mottle was not known, but the disease was generally believed to be incited by the same whitefly-transmitted virus that causes variegatio

  20. Chlorotic mottle of bean (Phaseolus vulgaris L.)

    NARCIS (Netherlands)

    Jayasinghe, W.U.

    1982-01-01

    For the past years there have been outbreaks of a disease of bean ( Phaseolus vulgaris L.) in Colombia called bean chlorotic mottle. The etiology of bean chlorotic mottle was not known, but the disease was generally believed to be incited by the same whitefly-transmitted virus

  1. Comparison of Relative Bias, Precision, and Efficiency of Sampling Methods for Natural Enemies of Soybean Aphid (Hemiptera: Aphididae).

    Science.gov (United States)

    Bannerman, J A; Costamagna, A C; McCornack, B P; Ragsdale, D W

    2015-06-01

    Generalist natural enemies play an important role in controlling soybean aphid, Aphis glycines (Hemiptera: Aphididae), in North America. Several sampling methods are used to monitor natural enemy populations in soybean, but there has been little work investigating their relative bias, precision, and efficiency. We compare five sampling methods: quadrats, whole-plant counts, sweep-netting, walking transects, and yellow sticky cards to determine the most practical methods for sampling the three most prominent species, which included Harmonia axyridis (Pallas), Coccinella septempunctata L. (Coleoptera: Coccinellidae), and Orius insidiosus (Say) (Hemiptera: Anthocoridae). We show an important time by sampling method interaction indicated by diverging community similarities within and between sampling methods as the growing season progressed. Similarly, correlations between sampling methods for the three most abundant species over multiple time periods indicated differences in relative bias between sampling methods and suggests that bias is not consistent throughout the growing season, particularly for sticky cards and whole-plant samples. Furthermore, we show that sticky cards produce strongly biased capture rates relative to the other four sampling methods. Precision and efficiency differed between sampling methods and sticky cards produced the most precise (but highly biased) results for adult natural enemies, while walking transects and whole-plant counts were the most efficient methods for detecting coccinellids and O. insidiosus, respectively. Based on bias, precision, and efficiency considerations, the most practical sampling methods for monitoring in soybean include walking transects for coccinellid detection and whole-plant counts for detection of small predators like O. insidiosus. Sweep-netting and quadrat samples are also useful for some applications, when efficiency is not paramount.

  2. The NIa-Pro protein of Turnip mosaic virus improves growth and reproduction of the aphid vector, Myzus persicae (green peach aphid).

    Science.gov (United States)

    Casteel, Clare L; Yang, Chunling; Nanduri, Ananya C; De Jong, Hannah N; Whitham, Steven A; Jander, Georg

    2014-02-01

    Many plant viruses depend on aphids and other phloem-feeding insects for transmission within and among host plants. Thus, viruses may promote their own transmission by manipulating plant physiology to attract aphids and increase aphid reproduction. Consistent with this hypothesis, Myzus persicae (green peach aphids) prefer to settle on Nicotiana benthamiana infected with Turnip mosaic virus (TuMV) and fecundity on virus-infected N. benthamiana and Arabidopsis thaliana (Arabidopsis) is higher than on uninfected controls. TuMV infection suppresses callose deposition, an important plant defense, and increases the amount of free amino acids, the major source of nitrogen for aphids. To investigate the underlying molecular mechanisms of this phenomenon, 10 TuMV genes were over-expressed in plants to determine their effects on aphid reproduction. Production of a single TuMV protein, nuclear inclusion a-protease domain (NIa-Pro), increased M. persicae reproduction on both N. benthamiana and Arabidopsis. Similar to the effects that are observed during TuMV infection, NIa-Pro expression alone increased aphid arrestment, suppressed callose deposition and increased the abundance of free amino acids. Together, these results suggest a function for the TuMV NIa-Pro protein in manipulating the physiology of host plants. By attracting aphid vectors and promoting their reproduction, TuMV may influence plant-aphid interactions to promote its own transmission. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

  3. Orange oil effect in the control of fennel aphid

    OpenAIRE

    Ivanildo Cavalcanti de Albuquerque; Luciano de Medeiros Pereira Brito; Carlos Henrique de Brito; Edson Batista Lopes; Jacinto de Luna Batista

    2009-01-01

    In the properties where fennel is grown, in the states of Bahia, Sergipe, Pernambuco and Paraiba, at the Northeast of Brazil, a high rate of usage of pesticides in the crop, aiming to control the aphid Hyadaphis foeniculi. The purpose of this study was to evaluate the effect of orange oil Prev-Am (sodium tetraborohydrate decahydrate), in the control of H. foeniculi aphid of the fennel crop. The trial was conducted in a fennel field located in Lagoa Seca Experimental Station, belonging to the ...

  4. The transcriptome of common bean: nodules to beans

    Science.gov (United States)

    Phaseolus vulgaris (common bean) is one of the most important grain legumes for direct human consumption. It comprises 50% of the grain legumes consumed worldwide and is important as a primary source of dietary protein in developing countries. We performed next generation sequencing (RNAseq) on five...

  5. 小麦和大豆蚜虫中内共生菌Wolbachia的感染检测和系统发育分析%Detection and phylogenetic analysis of Wolbachia in wheat and soybean aphids in China

    Institute of Scientific and Technical Information of China (English)

    李彤; 武予清; 肖金花; 段云; 蒋月丽; 苗进; 巩中军

    2013-01-01

    Wolbachia is a group of intracellular symbionts ubiquitous in arthropods. To investigate the Wolbachia infection in Chinese aphids, we amplified the wsp gene of Wolbachia in different geographical populations of three wheat aphids ( Sitobion miscanthi, Schizaphis graminum and Rhopalosiphum padi) and one soybean aphid ( Aphis glycines) in this study. The results showed that Wolbachia was not detected in the three wheat aphids. In A. glycines, Wolbachia was only detected in two geographical populations of Beijing and Hangzhou, with the infection rates of 95. 8% and 22. 9% , respectively. Moreover, the sequenced samples were infected with single Wolbachia strain. The Blastn search results showed that wsp gene sequences are similar among Wolbachia strains isolated from A. glycines and from some distantly related host insect species. The wsp gene phylogeny revealed that Wolbachia strains isolated from A. glycines belong to Wolbachia B supergroup, CauB group. This study provides the data for further investigation on host range and strain diversity of Wolbachia in Chinese aphid species.%Wolbachia是一类在节肢动物中广泛感染的胞内共生菌.为了了解其在我国蚜虫中的感染情况,本研究通过扩增wsp基因片段对采集自我国多个地区的3种小麦蚜虫(荻草谷网蚜Sitobion miscanthi、麦二叉蚜Schizaphisgraminum和禾谷缢管蚜Rhopalosiphum padi)和1种大豆蚜虫(大豆蚜Aphis glycines)样品进行了内共生菌Wolbachia的感染检测.结果显示:3种小麦蚜虫中均未检测出Wolabchia.大豆蚜也仅在采集自北京和杭州的种群中发现了Wolbachia的感染,感染率分别为95.8%和22.9%,并且所检测的个体均为单株系感染.wsp基因序列的比对分析显示,大豆蚜感染的Wolbachia株系与多个亲缘关系较远的昆虫物种中所感染的Wolbachia株系间具有高度一致的基因序列.wsp基因序列构建的系统发育关系和序列一致性均表明大豆蚜感染的Wolbachia株

  6. High susceptibility of Bt maize to aphids enhances the performance of parasitoids of lepidopteran pests.

    Directory of Open Access Journals (Sweden)

    Cristina A Faria

    Full Text Available Concerns about possible undesired environmental effects of transgenic crops have prompted numerous evaluations of such crops. So-called Bt crops receive particular attention because they carry bacteria-derived genes coding for insecticidal proteins that might negatively affect non-target arthropods. Here we show a remarkable positive effect of Bt maize on the performance of the corn leaf aphid Rhopalosiphum maidis, which in turn enhanced the performance of parasitic wasps that feed on aphid honeydew. Within five out of six pairs that were evaluated, transgenic maize lines were significantly more susceptible to aphids than their near-isogenic equivalents, with the remaining pair being equally susceptible. The aphids feed from the phloem sieve element content and analyses of this sap in selected maize lines revealed marginally, but significantly higher amino acid levels in Bt maize, which might partially explain the observed increased aphid performance. Larger colony densities of aphids on Bt plants resulted in an increased production of honeydew that can be used as food by beneficial insects. Indeed, Cotesia marginiventris, a parasitoid of lepidopteran pests, lived longer and parasitized more pest caterpillars in the presence of aphid-infested Bt maize than in the presence of aphid-infested isogenic maize. Hence, depending on aphid pest thresholds, the observed increased susceptibility of Bt maize to aphids may be either a welcome or an undesirable side effect.

  7. Application of plant growth regulators mitigates chlorotic foliar injury by the black pecan aphid (Hemiptera: Aphididae).

    Science.gov (United States)

    Cottrell, Ted E; Wood, Bruce W; Ni, Xinzhi

    2010-11-01

    Black pecan aphid, Melanocallis caryaefoliae (Davis) (Hemiptera: Aphididae), feeding elicits localized chlorotic injury to pecan foliage [Carya illinoinensis (Wangenh.) K Koch] and apparent acceleration of leaf senescence and defoliation. The ability of certain plant growth regulators (PGRs) (forchlorfenuron, gibberellic acid and aviglycine) to prevent M. caryaefoliae from triggering pecan leaf chlorosis and senescence-like processes was evaluated on two dates in both 2006 and 2007. Treatments were applied to orchard foliage and used in laboratory leaf-disc bioassays to assess possible reduction in aphid-elicited chlorosis and concomitant effects on aphid mortality and development. Foliage pretreated with forchlorfenuron + gibberellic acid prior to being challenged with aphids resulted in significantly less aphid-elicited chlorosis than did control or aviglycine-treated leaf discs. No PGR affected aphid mortality; however, development time was increased by forchlorfenuron + gibberellic acid in 2006 and by aviglycine + gibberellic acid on one date in 2007. Certain PGRs possess the potential for usage on pecan to protect foliar canopies from M. caryaefoliae via changes in the susceptibility of the host leaf to senescence-like factors being introduced by feeding aphids. This protective effect on host foliage and the associated suppressive effect on development of feeding aphids might also be relevant to pest management programs on other aphid-crop systems in which aphid-elicited chlorosis and senescence-like processes can limit profitability. Published 2010 by John Wiley & Sons, Ltd.

  8. Behavioral evidence for local reduction of aphid-induced resistance

    NARCIS (Netherlands)

    Prado, E.; Tjallingii, W.F.

    2007-01-01

    Twenty-five aphids of three different species, Brevicoryne brassicae L, Myzus persicae Schulzer, and Rhopalosiphum padi L(Hemiptera: Aphididae) were each allowed to infest leaves of a young plant of their respective host plant species for 4 days, except that the oldest expanded leaf (the `systemic¿

  9. Suitability of an artificial diet for rape aphid, Brevicoryne brassicae ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-09-15

    Sep 15, 2009 ... good index for study on insect dynamic. In this experiment a .... The age-specific survival of the rape aphid on leaf discs and artificial diet were fitted in .... Each of these com- ponents is responsible for a vital action in the insect.

  10. Clytostoma callistegioides (Bignoniaceae) wax extract with activity on aphid settling.

    Science.gov (United States)

    Castillo, Lucía; Díaz, Martina; González-Coloma, Azucena; González, Andrés; Alonso-Paz, Eduardo; Bassagoda, María Julia; Rossini, Carmen

    2010-12-01

    A bioassay-guided fractionation of leaf extracts from Clytostoma callistegioides (Cham.) Bureau ex Griseb. (Bignoniaceae) led to isolation of a natural mixture of four fatty acids with anti-insect activity against aphids. The compounds were identified by GC-MS as palmitic, stearic, linoleic and linolenic acids and quantified as their methyl esters. The anti-aphid activity of the natural mixture was traced to linolenic and linoleic acids, as shown by the settling inhibition activity of synthetic samples. Interestingly, the saturated acids (palmitic and stearic) tested alone stimulated settling on one of the tested aphids (Myzus persicae), but not on the other tested species (Rhopalosiphum padi). Although ubiquitous, none of these free acids have been previously reported in this Bignoniaceae species. The leaf surface chemistry, which is likely involved in modulating aphid settling behavior, was further investigated for the occurrence of lipophilic substances by histochemical staining. Short, stalked glandular trichomes, previously undescribed for this species, stained with osmium tetroxide and Sudan III, suggesting that the secretion of the defensive acids is related to these surface trichomes. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Elevated Carbon Dioxide Concentration Reduces Alarm Signaling in Aphids.

    Science.gov (United States)

    Boullis, Antoine; Fassotte, Bérénice; Sarles, Landry; Lognay, Georges; Heuskin, Stéphanie; Vanderplanck, Maryse; Bartram, Stefan; Haubruge, Eric; Francis, Frédéric; Verheggen, François J

    2017-02-01

    Insects often rely on olfaction to communicate with conspecifics. While the chemical language of insects has been deciphered in recent decades, few studies have assessed how changes in atmospheric greenhouse gas concentrations might impact pheromonal communication in insects. Here, we hypothesize that changes in the concentration of atmospheric carbon dioxide affect the whole dynamics of alarm signaling in aphids, including: (1) the production of the active compound (E)-β-farnesene (Eβf), (2) emission behavior when under attack, (3) perception by the olfactory apparatus, and (4) the escape response. We reared two strains of the pea aphid, Acyrthosiphon pisum, under ambient and elevated CO2 concentrations over several generations. We found that an increase in CO2 concentration reduced the production (i.e., individual content) and emission (released under predation events) of Eβf. While no difference in Eβf neuronal perception was observed, we found that an increase in CO2 strongly reduced the escape behavior expressed by an aphid colony following exposure to natural doses of alarm pheromone. In conclusion, our results confirm that changes to greenhouse gases impact chemical communication in the pea aphid, and could potentially have a cascade effect on interactions with higher trophic levels.

  12. Molecular characterization of aphid resistance in black raspberry germplasm

    Science.gov (United States)

    Black raspberry is a minor but lucrative crop with most of the acreage in the U.S. found in Oregon. Rapid decline of plantings results from virus infection vectored by the North American large raspberry aphid and is the most limiting factor for growing black raspberry. Existing cultivars are suscept...

  13. Aphids acquired symbiotic genes via lateral gene transfer

    Directory of Open Access Journals (Sweden)

    Nakabachi Atsushi

    2009-03-01

    Full Text Available Abstract Background Aphids possess bacteriocytes, which are cells specifically differentiated to harbour the obligate mutualist Buchnera aphidicola (γ-Proteobacteria. Buchnera has lost many of the genes that appear to be essential for bacterial life. From the bacteriocyte of the pea aphid Acyrthosiphon pisum, we previously identified two clusters of expressed sequence tags that display similarity only to bacterial genes. Southern blot analysis demonstrated that they are encoded in the aphid genome. In this study, in order to assess the possibility of lateral gene transfer, we determined the full-length sequences of these transcripts, and performed detailed structural and phylogenetic analyses. We further examined their expression levels in the bacteriocyte using real-time quantitative RT-PCR. Results Sequence similarity searches demonstrated that these fully sequenced transcripts are significantly similar to the bacterial genes ldcA (product, LD-carboxypeptidase and rlpA (product, rare lipoprotein A, respectively. Buchnera lacks these genes, whereas many other bacteria, including Escherichia coli, a close relative of Buchnera, possess both ldcA and rlpA. Molecular phylogenetic analysis clearly demonstrated that the aphid ldcA was derived from a rickettsial bacterium closely related to the extant Wolbachia spp. (α-Proteobacteria, Rickettsiales, which are intracellular symbionts of various lineages of arthropods. The evolutionary origin of rlpA was not fully resolved, but it was clearly demonstrated that its double-ψ β-barrel domain is of bacterial origin. Real-time quantitative RT-PCR demonstrated that ldcA and rlpA are expressed 11.6 and 154-fold higher in the bacteriocyte than in the whole body, respectively. LdcA is an enzyme required for recycling murein (peptidoglycan, which is a component of the bacterial cell wall. As Buchnera possesses a cell wall composed of murein but lacks ldcA, a high level of expression of the aphid ldcA in the

  14. Angus McBean - Portraits

    NARCIS (Netherlands)

    Pepper, T.

    2007-01-01

    Angus McBean (1904-90) was one of the most extraordinary British photographers of the twentieth century. In a career that spanned the start of the Second World War through the birth of the 'Swinging Sixties' to the 1980s, he became the most prominent theatre photographer of his generation and, along

  15. High throughput phenotyping for aphid resistance in large plant collections

    Directory of Open Access Journals (Sweden)

    Chen Xi

    2012-08-01

    Full Text Available Abstract Background Phloem-feeding insects are among the most devastating pests worldwide. They not only cause damage by feeding from the phloem, thereby depleting the plant from photo-assimilates, but also by vectoring viruses. Until now, the main way to prevent such problems is the frequent use of insecticides. Applying resistant varieties would be a more environmental friendly and sustainable solution. For this, resistant sources need to be identified first. Up to now there were no methods suitable for high throughput phenotyping of plant germplasm to identify sources of resistance towards phloem-feeding insects. Results In this paper we present a high throughput screening system to identify plants with an increased resistance against aphids. Its versatility is demonstrated using an Arabidopsis thaliana activation tag mutant line collection. This system consists of the green peach aphid Myzus persicae (Sulzer and the circulative virus Turnip yellows virus (TuYV. In an initial screening, with one plant representing one mutant line, 13 virus-free mutant lines were identified by ELISA. Using seeds produced from these lines, the putative candidates were re-evaluated and characterized, resulting in nine lines with increased resistance towards the aphid. Conclusions This M. persicae-TuYV screening system is an efficient, reliable and quick procedure to identify among thousands of mutated lines those resistant to aphids. In our study, nine mutant lines with increased resistance against the aphid were selected among 5160 mutant lines in just 5 months by one person. The system can be extended to other phloem-feeding insects and circulative viruses to identify insect resistant sources from several collections, including for example genebanks and artificially prepared mutant collections.

  16. Gene expression analysis of parthenogenetic embryonic development of the pea aphid, Acyrthosiphon pisum, suggests that aphid parthenogenesis evolved from meiotic oogenesis.

    Directory of Open Access Journals (Sweden)

    Dayalan G Srinivasan

    Full Text Available Aphids exhibit a form of phenotypic plasticity, called polyphenism, in which genetically identical females reproduce sexually during one part of the life cycle and asexually (via parthenogenesis during the remainder of the life cycle. The molecular basis for aphid parthenogenesis is unknown. Cytological observations of aphid parthenogenesis suggest that asexual oogenesis evolved either through a modification of meiosis or from a mitotic process. As a test of these alternatives, we assessed the expression levels and expression patterns of canonical meiotic recombination and germline genes in the sexual and asexual ovaries of the pea aphid, Acyrthosiphon pisum. We observed expression of all meiosis genes in similar patterns in asexual and sexual ovaries, with the exception that some genes encoding Argonaute-family members were not expressed in sexual ovaries. In addition, we observed that asexual aphid tissues accumulated unspliced transcripts of Spo11, whereas sexual aphid tissues accumulated primarily spliced transcripts. In situ hybridization revealed Spo11 transcript in sexual germ cells and undetectable levels of Spo11 transcript in asexual germ cells. We also found that an obligately asexual strain of pea aphid produced little spliced Spo11 transcript. Together, these results suggest that parthenogenetic oogenesis evolved from a meiosis-like, and not a mitosis-like, process and that the aphid reproductive polyphenism may involve a modification of Spo11 gene activity.

  17. Transcriptomic responses of the aphid Myzus persicae nicotianae Blackman (Hemiptera: Aphididae to insecticides: Analyses in the single Chilean clone of the tobacco aphid

    Directory of Open Access Journals (Sweden)

    Marco Cabrera-Brandt

    2014-04-01

    Full Text Available The tobacco aphid Myzus persicae nicotianae Blackman is a subspecies of the highly polyphagous and agricultural pest Myzus persicae (Sulzer. For its control, insecticide applications are widely used, but resistance to numerous molecules has been reported, displaying at least three insecticide resistance mechanisms, including: (i elevated carboxylesterases (E-Carb, (ii modification of the acetylcholinesterase (MACE, and (iii kdr and super-kdr insensitivity mutations. In Chile, populations of the tobacco aphid are characterized by the presence of a single predominant clone, which is also present in high proportions in other countries of the Americas. This aphid clone exhibits low levels of carboxylesterase activity and is kdr susceptible, but the MACE mechanism of insecticide resistance has not been studied. In order to characterize the tobacco aphid in terms of the MACE mechanism and to identify a preliminary group of aphid genes putatively involved in insecticide resistance, a cDNA microarray was used to study the transcriptomic responses when aphids are sprayed with a carbamate insecticide. The single Chilean clone of the tobacco aphid was characterized as MACE susceptible, but we found 38 transcripts significantly regulated by insecticide exposure (13 up- and 25 down-regulated genes. The expression of six of them was validated by qRT-PCR experiments at several time points (6, 12, 18, 24, 30, 36, and 42 h after insecticide application. This mutational and transcriptomic characterization of the tobacco aphid responding to insecticide spray opens new hypotheses in the understanding of the molecular mechanisms underlying insecticide resistance.

  18. Protein Quality of Irradiated Brazilian Beans

    Energy Technology Data Exchange (ETDEWEB)

    Delincee, Henry; Villavicencio, Anna-Lucia C.H.; Mancini-Filho, Jorge

    1998-06-01

    Beans are a major source of dietary protein in Brazil. However, high losses due to insect infestation occur after each harvest. To combat these losses, radiation processing of beans offers promise as an alternative to chemical treatment, provided the nutritional quality of beans is not impaired by the radiation treatment. Conflicting results have been published about the effect of radiation on the biological value of legume proteins. Therefore, two varieties of Brazilian beans were studied: 1) Phaseolus vulgaris L., var. carioca and 2) Vigna unguiculata (L.) Walp, var. macacar. The beans were irradiated with doses of 0, 0.5, 1.0, 2.5, 5.0 and 10 kGy. Since irradiated beans will be consumed after appropriate storage, the beans under study were stored for 6 months at ambient temperature. Protein quality was measured by a biological assay employing the nitrogen balance approach in weanling rats. The animals were fed with optimally cooked beans, which were the only source of protein ({approx}10%). Nitrogen contents of legumes, diets, animal urine and faeces were determined by Kjeldahl analysis. The indices for apparent protein quality: net protein utilisation, digestibility and biological value were not influenced by irradiation. Thus, radiation treatment of Brazilian beans offers considerable promise as an effective insect disinfestation process, without impairing the biological quality of the valuable bean protein.

  19. Protein Quality of Irradiated Brazilian Beans

    Science.gov (United States)

    Delincée, Henry; Villavicencio, Anna-Lucia C. H.; Mancini-Filho, Jorge

    1998-06-01

    Beans are a major source of dietary protein in Brazil. However, high losses due to insect infestation occur after each harvest. To combat these losses, radiation processing of beans offers promise as an alternative to chemical treatment, provided the nutritional quality of beans is not impaired by the radiation treatment. Conflicting results have been published about the effect of radiation on the biological value of legume proteins. Therefore, two varieties of Brazilian beans were studied: 1) Phaseolus vulgaris L., var. carioca and 2) Vigna unguiculata (L.) Walp, var. macaçar. The beans were irradiated with doses of 0, 0.5, 1.0, 2.5, 5.0 and 10 kGy. Since irradiated beans will be consumed after appropriate storage, the beans under study were stored for 6 months at ambient temperature. Protein quality was measured by a biological assay employing the nitrogen balance approach in weanling rats. The animals were fed with optimally cooked beans, which were the only source of protein (˜10%). Nitrogen contents of legumes, diets, animal urine and faeces were determined by Kjeldahl analysis. The indices for apparent protein quality: net protein utilisation, digestibility and biological value were not influenced by irradiation. Thus, radiation treatment of Brazilian beans offers considerable promise as an effective insect disinfection process, without impairing the biological quality of the valuable bean protein.

  20. Spirotetramat resistance adaption analysis of Aphis gossypii Glover by transcriptomic survey.

    Science.gov (United States)

    Pan, Yiou; Yang, Chen; Gao, Xiwu; Peng, Tianfei; Bi, Rui; Xi, Jinghui; Xin, Xuecheng; Zhu, E; Wu, Yongqiang; Shang, Qingli

    2015-10-01

    A resistant strain of the cotton aphid (SR) developed 441.26-fold and 11.97-fold resistance to spirotetramat for adult aphids and nymphs, respectively, compared with the susceptible (SS) strain. Solexa sequencing technology was employed to identify differentially expressed genes (DEGs) in the spirotetramat-resistant cotton aphid. Respective totals of 22,430,522 and 21,317,732 clean reads were obtained from SR and SS cDNA libraries and assembled into 35,222 non-redundant (Nr) consensus sequences. A total of 14,913, 9,220, 7,922, 4,314 and 4,686 sequences were annotated using Nr, Swiss-Prot, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Clusters of Orthologous Groups (COG), respectively. Compared with the SS strain, the SR strain had 1287 significantly changed unigenes, of which 130 genes were up-regulated and 1157 genes were down-regulated (P ≤ 0.001). Among these genes, 440 unigenes were annotated, consisting of 114 up-regulated and 326 down-regulated genes. The expression levels of heat shock protein 70 (Hsp70) and UDP-glucuronosyltransferase were significantly up-regulated in the SR strain compared to the SS strain. The genes encoding cuticle proteins, salivary glue protein, fibroin heavy chain, energy ATP synthase, and cytochrome c oxidase were dramatically decreased. Among the DEGs, cytochrome P450 6A2 (c20965.graph_c0) was the only P450 gene up-regulated in the SR strain. The expression levels of 10 DEGs were confirmed by real-time qPCR, and the trends in gene expression observed by qPCR matched those of the Solexa expression profiles. The acetyl-CoA carboxylase (ACC) genes in the SR and SS libraries both contain four single nucleotide polymorphisms (SNPs), with three common SNPs: 1227 (C/T), 1811 (A/T: F/Y) and 3759 (C/T); however, 7540 (A/T) and 108 (G/A) occurred solely in the SS and SR strains, respectively. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Changes in the Russian Wheat Aphid (Hemiptera: Aphididae) Biotype Complex in South Africa.

    Science.gov (United States)

    Jankielsohn, Astrid

    2016-04-01

    Russian wheat aphid Diuraphis noxia (Kurdjumov) has spread from its native area in central Asia to all the major wheat-producing countries in the world to become an international wheat pest. Because the Russian wheat aphid is a serious threat to the wheat industry in South Africa, it is important to investigate the key factors involved in the distribution of Russian wheat aphid biotypes and in the changes of the Russian wheat aphid biotype complex in South Africa. There are currently four known Russian wheat aphid biotypes occurring in South Africa. Russian wheat aphid samples were collected from 2011 to 2014 during the wheat-growing season in spring and summer and these samples were screened to determine the biotype status. RWASA1 occurred predominantly in the Western Cape, while RWASA2 and RWASA3 occurred predominantly in the Eastern Free State. Following the first record of RWASA4 in 2011, this biotype was restricted to the Eastern Free State. The surveys suggest that the Russian wheat aphid bioype complex was more diverse in the Eastern Free State than in the other wheat production areas. There was also a shift in Russian wheat aphid biotype composition over time. The Russian wheat aphid biotype complex is dynamic, influenced by environmental factors such as host plants, altitude, and climate, and it can change and diversify over time causing fluctuation in populations over sites and years. This dynamic nature of the Russian wheat aphid will continue to challenge the development of Russian wheat aphid-resistant wheat cultivars in South Africa, and the continued monitoring of the biotypic and genetic structure, to determine genetic relatedness and variation in different biotypes, of Russian wheat aphid populations is important for protecting wheat.

  2. Microorganism-associated semiochemicals reduce the size of aphid populations in potato fields

    OpenAIRE

    Alabi, Taofic; Brostaux, Yves; Grigorescu, Alina; Fischer, Christophe; Thonart, Philippe; Lognay, Georges; Haubruge, Eric; Francis, Frédéric; Verheggen, François

    2014-01-01

    The chemical cues released by many insect species, including agricultural pests, are used by predators and parasitoids to locate their prey or host. For instance, aphids excrete honeydew, which contains bacteria that produce semiochemicals. Ladybeetles and hoverflies use these semiochemicals to locate the colonies of prey aphid species. One bacterium (Staphylococcus sciuri) has been identified in the honeydew of the pea aphid, Acyrthosiphon pisum. This bacterium is responsible for the product...

  3. Aphids (Homoptera, Aphidodea inhabiting the trees Crataegus x media Bechst. in the urban green area. Part II. Domination and frequency of aphids, their enemies and the damage caused by aphids

    Directory of Open Access Journals (Sweden)

    Aneta Sławińska

    2013-12-01

    Full Text Available The studies were conducted in Lublin in the years 1999-2001 in two sites (street and park ones on the trees Crataegus x inedia Bechst. The purpose was to determine the domination and frequency of particular aphid species, their effect on the decorative character of plants as well as the occurrence of the aphidophagous in aphid colonies. It was found out that A. pomi was the dominating species in both sites. The decorative character of the studied trees was lowered by aphids A. pomi and aphids from the genus Dysaphis. Aphids from the genus Dysaphis also caused changes in the chemical composition of the injured plant parts. The presence of predatory arthropods was observed in aphid colonies occurring on hawthorn. The most numerous of these were the larvae of Syrphidae and Coccinellidae. The culture of parasitized aphids gave numerous flights of parasitoids and hyperparasitoids. Greater number of both predators and parasitoids of I and II grades were observed in the street site as compared to the park site.

  4. Lipase Activity in Fermented Oil Seeds of Africa Locust Bean ...

    African Journals Online (AJOL)

    acer

    Castor Seeds (Ricinu Communis) and African Oil Bean (Pentaclethra Macrophylla). A.A. Liman*, P. ... The peak lipase activity for fermented Africa locust bean, Castor seed, and African oil bean were ..... fermented vegetable proteins. World.

  5. New data on aphid fauna (Hemiptera, Aphididae) in Algeria

    Science.gov (United States)

    Laamari, Malik; d’Acier, Armelle Coeur; Jousselin, Emmanuelle

    2013-01-01

    Abstract A survey of aphids was carried out during the period 2008-2011 in different regions of Algeria by collecting and identifying aphids and their host plants. Aphids were collected from 46 host plants. Forty-six species were reported including thirty-six species which were recorded for the first time in this country and thirty species which were recorded for the first time in the Maghreb (North Africa). This study extends the number of known Algerian aphid to 156 species. PMID:24039520

  6. A Secreted MIF Cytokine Enables Aphid Feeding and Represses Plant Immune Responses.

    Science.gov (United States)

    Naessens, Elodie; Dubreuil, Géraldine; Giordanengo, Philippe; Baron, Olga Lucia; Minet-Kebdani, Naïma; Keller, Harald; Coustau, Christine

    2015-07-20

    Aphids attack virtually all plant species and cause serious crop damages in agriculture. Despite their dramatic impact on food production, little is known about the molecular processes that allow aphids to exploit their host plants. To date, few aphid salivary proteins have been identified that are essential for aphid feeding, and their nature and function remain largely unknown. Here, we show that a macrophage migration inhibitory factor (MIF) is secreted in aphid saliva. In vertebrates, MIFs are important pro-inflammatory cytokines regulating immune responses. MIF proteins are also secreted by parasites of vertebrates, including nematodes, ticks, and protozoa, and participate in the modulation of host immune responses. The finding that a plant parasite secretes a MIF protein prompted us to question the role of the cytokine in the plant-aphid interaction. We show here that expression of MIF genes is crucial for aphid survival, fecundity, and feeding on a host plant. The ectopic expression of aphid MIFs in leaf tissues inhibits major plant immune responses, such as the expression of defense-related genes, callose deposition, and hypersensitive cell death. Functional complementation analyses in vivo allowed demonstrating that MIF1 is the member of the MIF protein family that allows aphids to exploit their host plants. To our knowledge, this is the first report of a cytokine that is secreted by a parasite to modulate plant immune responses. Our findings suggest a so-far unsuspected conservation of infection strategies among parasites of animal and plant species.

  7. Ethylene contributes to potato aphid susceptibility in a compatible tomato host.

    Science.gov (United States)

    Mantelin, Sophie; Bhattarai, Kishor K; Kaloshian, Isgouhi

    2009-01-01

    Resistance to potato aphid (Macrosiphum euphorbiae) in tomato (Solanum lycopersicum) is conferred by Mi-1. Early during both compatible and incompatible interactions, potato aphid feeding induces the expression of ethylene (ET) biosynthetic genes. Here, we used genetic and pharmacologic approaches to investigate the role of ET signaling in basal defense and Mi-1-mediated resistance to potato aphid in tomato. The effect of potato aphid infestation on ET biosynthesis in susceptible and resistant plants was assessed. Aphid bioassays were performed using plants impaired in ET biosynthesis or perception using virus-induced gene silencing, the Never ripe (Nr) mutant, and 1-methylcyclopropene (MCP) treatment. A burst of ET was observed after aphid feeding in both resistant and susceptible plants, correlated with an increase in the expression of ET biosynthetic genes. However, impairing ET signaling or biosynthesis did not compromise Mi-1-mediated resistance but it did decrease susceptibility to potato aphid in a compatible host. ET may not play a significant role in Mi-1-mediated resistance to potato aphids in tomato but modulates the host basal defense, enhancing its susceptibility to the aphid.

  8. Anticipatory and reactive crouching of pea aphids in response to environmental perturbations.

    Science.gov (United States)

    Ben-Ari, Matan; Talal, Stav; Inbar, Moshe

    2014-10-01

    Animals use different strategies to deal with changing environmental conditions. While standing and feeding on their host plant, aphids (Hemiptera: Aphididae) may be exposed to detrimental environmental perturbations, such as strong winds. If aphids are forcibly blown off the plant and spend time on the ground, they will face additional dangers by both ground-dwelling predators and detrimental soil temperature. It is therefore adaptive for aphids to behave in a way that lowers the risk of being removed from the plant. We observed that pea aphids (Acyrthosiphon pisum (Harris)) display a specific crouched body posture, previously undescribed, which reduces their chance of being carried off from the plant by sudden winds. We exposed aphids in the laboratory to different cues indicative of a windy environment: wind, plant vibration, and visual stimuli. We found that aphids crouch in two situations: 1) reactively, when they are being pulled by a continuous gust of wind threatening to dislodge them. 2) Anticipatorily, when environmental cues, such as plant vibration or continuous movement near their host plant, may signify that sudden wind gusts are expected. Crouching aphids were less likely to be dislodged by a sudden air stream or plant vibration than were aphids that did not crouch. Crouching thus improves the aphids' chances of remaining on their host plant under unfavorable environmental conditions.

  9. Heterodera schachtii nematodes interfere with aphid-plant relations on Brassica oleracea.

    Science.gov (United States)

    Hol, W H Gera; De Boer, Wietse; Termorshuizen, Aad J; Meyer, Katrin M; Schneider, Johannes H M; Van Der Putten, Wim H; Van Dam, Nicole M

    2013-09-01

    Aboveground and belowground herbivore species modify plant defense responses differently. Simultaneous attack can lead to non-additive effects on primary and secondary metabolite composition in roots and shoots. We previously found that aphid (Brevicoryne brassicae) population growth on Brassica oleracea was reduced on plants that were infested with nematodes (Heterodera schachtii) prior (4 weeks) to aphid infestation. Here, we examined how infection with root-feeding nematodes affected primary and secondary metabolites in the host plant and whether this could explain the increase in aphid doubling time from 3.8 to 6.7 days. We hypothesized that the effects of herbivores on plant metabolites would depend on the presence of the other herbivore and that nematode-induced changes in primary metabolites would correlate with reduced aphid performance. Total glucosinolate concentration in the leaves was not affected by nematode presence, but the composition of glucosinolates shifted, as gluconapin concentrations were reduced, while gluconapoleiferin concentrations increased in plants exposed to nematodes. Aphid presence increased 4-methoxyglucobrassicin concentrations in leaves, which correlated positively with the number of aphids per plant. Nematodes decreased amino acid and sugar concentrations in the phloem. Aphid population doubling time correlated negatively with amino acids and glucosinolate levels in leaves, whereas these correlations were non-significant when nematodes were present. In conclusion, the effects of an herbivore on plant metabolites were independent of the presence of another herbivore. Nematode presence reduced aphid population growth and disturbed feeding relations between plants and aphids.

  10. EFFICACY OF IMIDACLOPRID (CONFIDOR 200 SL AGAINST APHIDS INFESTING WHEAT CROP

    Directory of Open Access Journals (Sweden)

    N Joshi

    2010-02-01

    Full Text Available Imidacloprid (Confidor 200 SL was evaluated either alone or with a fungicide (Tilt 0.01% against wheat aphids. There were seven different treatments, including an untreated control. All the treatments were replicated three times in a similar field environment. Population of wheat aphids was recorded on randomly selected five plants in each plot at different intervals, both before and after the spraying. Confidor 200 SL @ 400 ml/ha treatment was found most effective against wheat aphids. However, mixing of Confidor 200 SL @ 100 ml/ha with Tilt @ 0.01 %, was found significantly least effective for wheat aphids control.

  11. Ecological effects of aphid abundance, genotypic variation, and contemporary evolution on plants.

    Science.gov (United States)

    Turley, Nash E; Johnson, Marc T J

    2015-07-01

    Genetic variation and contemporary evolution within populations can shape the strength and nature of species interactions, but the relative importance of these forces compared to other ecological factors is unclear. We conducted a field experiment testing the effects of genotypic variation, abundance, and presence/absence of green peach aphids (Myzus persicae) on the growth, leaf nitrogen, and carbon of two plant species (Brassica napus and Solanum nigrum). Aphid genotype affected B. napus but not S. nigrum biomass explaining 20 and 7% of the total variation, respectively. Averaging across both plant species, the presence/absence of aphids had a 1.6× larger effect size (Cohen's d) than aphid genotype, and aphid abundance had the strongest negative effects on plant biomass explaining 29% of the total variation. On B. napus, aphid genotypes had different effects on leaf nitrogen depending on their abundance. Aphids did not influence leaf nitrogen in S. nigrum nor leaf carbon in either species. We conducted a second experiment in the field to test whether contemporary evolution could affect plant performance. Aphid populations evolved in as little as five generations, but the rate and direction of this evolution did not consistently vary between plant species. On one host species (B. napus), faster evolving populations had greater negative effects on host plant biomass, with aphid evolutionary rate explaining 23% of the variation in host plant biomass. Together, these results show that genetic variation and evolution in an insect herbivore can play important roles in shaping host plant ecology.

  12. Modification of Non-Vector Aphid Feeding Behavior on Virus-Infected Host Plant

    OpenAIRE

    Hu, Zuqing; Zhao, Huiyan; Thieme, Thomas

    2013-01-01

    Virus-infected host plants can have positive, neutral or negative effects on vector aphids. Even though the proportion of non-vector aphids associated with a plant far exceeds that of vector species, little is known about the effect of virus-infected plants on non-vector aphids. In the present study, the English grain aphid Sitobion avenae (Fabricius) (Hemiptera: Aphididae), a non-vector of Wheat dwarf virus (WDV) and Cereal yellow dwarf virus-RPV (CYDV-RPV), was monitored on, virus-infected,...

  13. Modification of non-vector aphid feeding behavior on virus-infected host plant.

    Science.gov (United States)

    Hu, Zuqing; Zhao, Huiyan; Thieme, Thomas

    2013-01-01

    Virus-infected host plants can have positive, neutral or negative effects on vector aphids. Even though the proportion of non-vector aphids associated with a plant far exceeds that of vector species, little is known about the effect of virus-infected plants on non-vector aphids. In the present study, the English grain aphid Sitobion avenae (Fabricius) (Hemiptera: Aphididae), a non-vector of Wheat dwarf virus (WDV) and Cereal yellow dwarf virus-RPV (CYDV-RPV), was monitored on, virus-infected, virus-free and leafhopper/aphid-infested, and virus- and insect-free (control) barley, Hordeum vulgare L. (Poales: Poaceae), plants. Electrical penetration graph recordings were performed. Compared with the control plants, S. avenae on infected plants exhibited reduced non-probing and pathway phase, and increased phloem sap ingestion phase, and more aphids reached sustained phloem ingestion. However, the electrical penetration graph parameters described above showed no significant differences in aphid feeding behavior on virus-free and vector pre-infested plants and the control barley plants during S. avenae feeding. The results suggest that WDV/CYDV-RPV-infected host plants positively affected the feeding behavior of the non-vector aphid S. avenae. Based on these results, the reasons and trends among the virus-infected host plants' effects on the feeding behavior of non-vector aphids are discussed.

  14. An exponential growth model with decreasing r captures bottom-up effects on the population growth of Aphis glycines Matsumura (Hemiptera: Aphididae)

    NARCIS (Netherlands)

    Costamagna, A.C.; Werf, van der W.; Bianchi, F.J.J.A.; Landis, D.A.

    2007-01-01

    1 There is ample evidence that the life history and population dynamics of aphids are closely linked to plant phenology. Based on life table studies, it has been proposed that the growth of aphid populations could be modeled with an exponential growth model, with r decreasing linearly with time. Thi

  15. NDVI to Detect Sugarcane Aphid Injury to Grain Sorghum.

    Science.gov (United States)

    Elliott, N C; Backoulou, G F; Brewer, M J; Giles, K L

    2015-06-01

    Multispectral remote sensing has potential to provide quick and inexpensive information on sugarcane aphid, Melanaphis sacchari (Zehntner), pest status in sorghum fields. We describe a study conducted to determine if injury caused by sugarcane aphid to sorghum plants in fields of grain sorghum could be detected using multispectral remote sensing from a fixed wing aircraft. A study was conducted in commercial grain sorghum fields in the Texas Gulf Coast region in June 2014. Twenty-six commercial grain sorghum fields were selected and rated for the level of injury to sorghum plants in the field caused by sugarcane aphid. Plant growth stage ranged from 5.0 (watery ripe) to 7.0 (hard dough) among fields; and plant injury rating from sugarcane aphid ranged from 1.0 (little or no injury) to 4.0 (>40% of plants displaying injury) among fields. The normalized differenced vegetation index (NDVI) is calculated from light reflectance in the red and near-infrared wavelength bands in multispectral imagery and is a common index of plant stress. High NDVI indicates low levels of stress and low NDVI indicates high stress. NDVI ranged from -0.07 to 0.26 among fields. The correlation between NDVI and plant injury rating was negative and significant, as was the correlation between NDVI and plant growth stage. The negative correlation of NDVI with injury rating indicated that plant stress increased with increasing plant injury. Reduced NDVI with increasing plant growth probably resulted from reduced photosynthetic activity in more mature plants. The correlation between plant injury rating and plant growth stage was positive and significant indicating that plant injury from sugarcane aphid increased as plants matured. The partial correlation of NDVI with plant injury rating was negative and significant indicating that NDVI decreased with increasing plant injury after adjusting for its association with plant growth stage. We demonstrated that remotely sensed imagery acquired from grain

  16. Successful introgression of abiotic stress tolerance from wild tepary bean to common bean

    Science.gov (United States)

    Common bean (Phaseolus vulgaris L.) production is severely limited due to abiotic stresses, including drought and sub-zero temperatures. Tepary bean (Phaseolus acutifolius Gray), a relative of common bean, has demonstrated tolerance to these stresses. Preliminary studies screening tepary accessions ...

  17. Kinetics model development of cocoa bean fermentation

    Science.gov (United States)

    Kresnowati, M. T. A. P.; Gunawan, Agus Yodi; Muliyadini, Winny

    2015-12-01

    Although Indonesia is one of the biggest cocoa beans producers in the world, Indonesian cocoa beans are oftenly of low quality and thereby frequently priced low in the world market. In order to improve the quality, adequate post-harvest cocoa processing techniques are required. Fermentation is the vital stage in series of cocoa beans post harvest processing which could improve the quality of cocoa beans, in particular taste, aroma, and colours. During the fermentation process, combination of microbes grow producing metabolites that serve as the precursors for cocoa beans flavour. Microbial composition and thereby their activities will affect the fermentation performance and influence the properties of cocoa beans. The correlation could be reviewed using a kinetic model that includes unstructured microbial growth, substrate utilization and metabolic product formation. The developed kinetic model could be further used to design cocoa bean fermentation process to meet the expected quality. Further the development of kinetic model of cocoa bean fermentation also serve as a good case study of mixed culture solid state fermentation, that has rarely been studied. This paper presents the development of a kinetic model for solid-state cocoa beans fermentation using an empirical approach. Series of lab scale cocoa bean fermentations, either natural fermentations without starter addition or fermentations with mixed yeast and lactic acid bacteria starter addition, were used for model parameters estimation. The results showed that cocoa beans fermentation can be modelled mathematically and the best model included substrate utilization, microbial growth, metabolites production and its transport. Although the developed model still can not explain the dynamics in microbial population, this model can sufficiently explained the observed changes in sugar concentration as well as metabolic products in the cocoa bean pulp.

  18. Transaction costs in beans market in Brazil

    Directory of Open Access Journals (Sweden)

    Paulo Eterno Venâncio Assunção

    2015-05-01

    Full Text Available This paper aimed to evaluate the presence of transaction costs in the beans market in Brazil. Therefore, threshold autoregressive (TAR models were used to check co-integration and the existence of transaction costs in the Brazilian beans market. The results confirmed the presence of transaction costs in the beans market, which are mainly related to the freight component of production, since the markets are often far away from the producing regions.

  19. A laboratory and field condition comparison of life table parameters of Aphis gossypii Glover (Hemiptera: Aphididae

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    Hosseini-Tabesh Behnaz

    2015-01-01

    Full Text Available Life table studies are essential tools for understanding population dynamics. The life table parameters of Aphis gossypii Glover (Hemiptera: Aphididae feeding on the host plant, Hibiscus syriacus L. were studied under laboratory (25±1°C and relative humidity of 65±5% and a photoperiod of 16L : 8D h and field conditions (23-43°C, and relative humidity of 27-95%. The data were analysed using the age-stage, two-sex life table theory. The life table studies were started with 50 and 40 nymphs in laboratory and field conditions, respectively. Under laboratory conditions, A. gossypii reared on H. syriacus had a higher survival rate, fecundity, and longevity than those reared under field conditions. When reared under field conditions, A. gossypii had a longer nymphal developmental time, shorter adult longevity, and lower fecundity than those reared under laboratory conditions. The intrinsic rate of increase (r, net reproductive rate (R0, and the finite rate of increase (λ under laboratory conditions, were higher than those obtained under field conditions. Nevertheless, there were no significant differences in the mean generation time T (days between field and laboratory conditions. In the present study, the results clearly showed that life table parameters of A. gossypii were significantly different under field and laboratory conditions. These results could help us to understand the A. gossypii population dynamics under field conditions. The results could also help us make better management decisions for economically important crops

  20. Proteomic analysis of secreted saliva from Russian wheat aphid (Diuraphis noxia Kurd.) biotypes that differ in virulence to wheat

    Science.gov (United States)

    Diuraphis noxia, Russian Wheat Aphid (RWA), biotypes are classified by their differential virulence to wheat varieties containing resistance genes. RWA salivary proteins, unlike those of most aphid species, cause foliar damage and physiological alterations in plants. A comparative proteomic analys...

  1. Genomic evidence for complementary purine metabolism in the pea aphid, Acyrthosiphon pisum, and its symbiotic bacterium Buchnera aphidicola.

    Science.gov (United States)

    Ramsey, J S; MacDonald, S J; Jander, G; Nakabachi, A; Thomas, G H; Douglas, A E

    2010-03-01

    The purine salvage pathway recycles purines to nucleotides, promoting efficient utilization of purine nucleotides. Exceptionally among animals with completely sequenced genomes, the pea aphid lacks key purine recycling genes that code for purine nucleoside phosphorylase and adenosine deaminase, indicating that the aphid can neither metabolize nucleosides to the corresponding purines, nor adenosine to inosine. Purine metabolism genes in the symbiotic bacterium Buchnera complement aphid genes, and Buchnera can meet its nucleotide requirement from aphid-derived guanosine. Buchnera demand for nucleosides may have relaxed the selection for purine recycling in the aphid, leading to the loss of key aphid purine salvage genes. Further, the coupled purine metabolism of aphid and Buchnera could contribute to the dependence of the pea aphid on this symbiosis.

  2. Yeasts are essential for cocoa bean fermentation.

    Science.gov (United States)

    Ho, Van Thi Thuy; Zhao, Jian; Fleet, Graham

    2014-03-17

    Cocoa beans (Theobroma cacao) are the major raw material for chocolate production and fermentation of the beans is essential for the development of chocolate flavor precursors. In this study, a novel approach was used to determine the role of yeasts in cocoa fermentation and their contribution to chocolate quality. Cocoa bean fermentations were conducted with the addition of 200ppm Natamycin to inhibit the growth of yeasts, and the resultant microbial ecology and metabolism, bean chemistry and chocolate quality were compared with those of normal (control) fermentations. The yeasts Hanseniaspora guilliermondii, Pichia kudriavzevii and Kluyveromyces marxianus, the lactic acid bacteria Lactobacillus plantarum and Lactobacillus fermentum and the acetic acid bacteria Acetobacter pasteurianus and Gluconobacter frateurii were the major species found in the control fermentation. In fermentations with the presence of Natamycin, the same bacterial species grew but yeast growth was inhibited. Physical and chemical analyses showed that beans fermented without yeasts had increased shell content, lower production of ethanol, higher alcohols and esters throughout fermentation and lesser presence of pyrazines in the roasted product. Quality tests revealed that beans fermented without yeasts were purplish-violet in color and not fully brown, and chocolate prepared from these beans tasted more acid and lacked characteristic chocolate flavor. Beans fermented with yeast growth were fully brown in color and gave chocolate with typical characters which were clearly preferred by sensory panels. Our findings demonstrate that yeast growth and activity were essential for cocoa bean fermentation and the development of chocolate characteristics.

  3. Effects of Entomopathogenic Nematodes on the Development of Root-knot Nematode and Aphid, and on the Parasitism of Aphid Parasitoid in Tobacco

    Directory of Open Access Journals (Sweden)

    WANG Yu-kun

    2017-05-01

    Full Text Available Entomopathogenic nematodes(EPN which is recognized as a kind of potential biological control material have been paid more and more attention in recent years. In the present study, we selected tobacco(Nicotiana tabacum as the object to study the effects of EPN (Steinernema carpocapsae and Heterorhabditis bacteriophoraon the development of root-knot nematodes and aphid (Myzus persicae, and on the parasitism of aphid parasitoid (Aphidius gifuensis in tobacco. The results showed that (1Under the condition of the artificial removal of aphids, the number of egg per plant was significantly lower under the EPN treatments than control treatment(PS. carpocapsae treatment than the other treatments(PH. bacteriophora cadaver treatment were 89.6 individual·plant-1 and 0.996 g·plant-1, 99.8 individual·plant-1 and 3.258 g·plant-1, 76.6 individual·plant-1 and 1.643 g·plant-1, respectively, indicating that EPN treatment could decrease the number of aphids per mass; (3On the first three observation dates, the number of aphid mummies was significantly lower under S. carpocapsae cadaver treatment than H. bacteriophora cadaver treatment. The results indicated that EPN treatments in tobacco could affect the development of root-knot nematode, and had impact on the development of aphids and the activities of aphid parasitoid by "bottom-up" approach, and these effects were affected by the species of EPN.

  4. Host Selection of the giant willow aphid (Tuberolachnus salignus)

    OpenAIRE

    Aradottir, G; Karp, A.; Hanley, SJ; Woodcock, C; Dewhirst, S.; Collins, CM; Leather, SR; Harrington, R.

    2009-01-01

    The giant willow aphid [Tuberolachnus salignus (Gmelin)] has recently become noteworthy as a potential pest species due to the increased uptake of willow, its host-plant, for use in growing biomass for energy production. In this paper we describe host selection studies of T. salignus on short rotation coppice (SRC) willow varieties in laboratory bioassays and field experiments. In laboratory olfactometry tests, T. salignus was significantly attracted to certain SRC willow varieties, but not t...

  5. Masculinization of the x chromosome in the pea aphid.

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    Julie Jaquiéry

    Full Text Available Evolutionary theory predicts that sexually antagonistic mutations accumulate differentially on the X chromosome and autosomes in species with an XY sex-determination system, with effects (masculinization or feminization of the X depending on the dominance of mutations. Organisms with alternative modes of inheritance of sex chromosomes offer interesting opportunities for studying sexual conflicts and their resolution, because expectations for the preferred genomic location of sexually antagonistic alleles may differ from standard systems. Aphids display an XX/X0 system and combine an unusual inheritance of the X chromosome with the alternation of sexual and asexual reproduction. In this study, we first investigated theoretically the accumulation of sexually antagonistic mutations on the aphid X chromosome. Our results show that i the X is always more favourable to the spread of male-beneficial alleles than autosomes, and should thus be enriched in sexually antagonistic alleles beneficial for males, ii sexually antagonistic mutations beneficial for asexual females accumulate preferentially on autosomes, iii in contrast to predictions for standard systems, these qualitative results are not affected by the dominance of mutations. Under the assumption that sex-biased gene expression evolves to solve conflicts raised by the spread of sexually antagonistic alleles, one expects that male-biased genes should be enriched on the X while asexual female-biased genes should be enriched on autosomes. Using gene expression data (RNA-Seq in males, sexual females and asexual females of the pea aphid, we confirm these theoretical predictions. Although other mechanisms than the resolution of sexual antagonism may lead to sex-biased gene expression, we argue that they could hardly explain the observed difference between X and autosomes. On top of reporting a strong masculinization of the aphid X chromosome, our study highlights the relevance of organisms displaying

  6. Orange oil effect in the control of fennel aphid

    Directory of Open Access Journals (Sweden)

    Ivanildo Cavalcanti de Albuquerque

    2009-08-01

    Full Text Available In the properties where fennel is grown, in the states of Bahia, Sergipe, Pernambuco and Paraiba, at the Northeast of Brazil, a high rate of usage of pesticides in the crop, aiming to control the aphid Hyadaphis foeniculi. The purpose of this study was to evaluate the effect of orange oil Prev-Am (sodium tetraborohydrate decahydrate, in the control of H. foeniculi aphid of the fennel crop. The trial was conducted in a fennel field located in Lagoa Seca Experimental Station, belonging to the EMEPA-PB. Forty-eight hours after the product has been sprayed, one flower of the umbel was collected and removed her aphids, which were placed in a "petri" plate from 9cm in diameter. As a following step, the insects were counted as part of two groups, considering the number of insects dead and alive, being tabulated for later analysis. The data were subjected to analysis of variance, using the experimental design of randomized blocks composed of six treatments (doses of 0.3, 0.4, 0.5, 0.6, 0.7% of orange oil (Prev-am and pure water as check, with five repetitions. The data were submitted to the regression analysis. The orange oil (Prev-am controls effectively H. foeniculi at the concentration of 0.3%, increasing the control up to concentrations of 0.6 and 0.7%. The product does not kill ladybugs (Cycloneda sanguinea and can be used in programs for integrated pest management.Keywords: Foeniculum vulgare, aphid, vegetable oil, ladybug, umbel.

  7. Estimating ancestral geographical distributions: a Gondwanan origin for aphid parasitoids?

    OpenAIRE

    Belshaw, R; Dowton, M; Quicke, D L; Austin, A. D.

    2000-01-01

    We tested the published hypothesis of a Gondwanan origin for the overwhelmingly northern hemisphere aphid parasitoids (Aphidiinae) as follows: (i) finding their sister group by a phylogenetic analysis of the entire Braconidae (Insecta: Hymenopterai using sequence data from approximately 500 bp fragments of both the nuclear 28S (D2 region) and mitochondrial 16S rDNA genes, (ii) using this sister-group relationship and the more informative 28S D2 gene to estimate the phylogeny of the Aphidiinae...

  8. The Process of Aphid Egg-Laying and the Little Known Role of the Coccinellidae in Aphid Egg Destruction in Poland – Preliminary Results

    Directory of Open Access Journals (Sweden)

    Lubiarz Magdalena

    2014-07-01

    Full Text Available No detailed studies have been conducted in Poland with regard to aphid eggs or egg survival in particular. So far, no studies have been conducted concerning the role of ladybird beetles in reducing the number of aphid eggs in spring, before the development of leaves, and in autumn, after the leaves have been shed. At these times, other developmental stages of aphids are unavailable as food for the ladybirds. The paper presents the preliminary results of a three-year study on the process of aphid egg-laying (especially Chaetosiphon tetrarhodum, Macrosiphum rosae, Metopolophium dirhodum, and Maculolachnus submacula. The paper also deals with the little known role of ladybirds in aphid egg destruction. Research was conducted in Otrębusy (Western Mazovia, Poland, in the years 2008-2010, on the rugosa rose and on the dog rose. In the years 2011-2013, in Otrębusy, the occurrence of M. submacula was also observed on the ornamental grandiflora rose. Furthermore, in the years 2003-2004, observations were conducted on the pedunculate oak in Polesie National Park and in the town of Puławy (Lublin Region, Poland. The observations which took place in Puławy focused on egglaying of aphids representing the genera Phylloxera and Lachnus. The study investigated aphid oviposition sites. Data was collected on the number of aphid eggs noted on the studied plants. The study also showed, that sometimes winter eggs of aphids could provide nutrition for ladybirds. This was especially true in autumn when ladybird beetles were preparing for hibernation.

  9. Pea aphid promotes amino acid metabolism both in Medicago truncatula and bacteriocytes to favor aphid population growth under elevated CO2.

    Science.gov (United States)

    Guo, Huijuan; Sun, Yucheng; Li, Yuefei; Tong, Bin; Harris, Marvin; Zhu-Salzman, Keyan; Ge, Feng

    2013-10-01

    Rising atmospheric CO(2) levels can dilute the nitrogen (N) resource in plant tissue, which is disadvantageous to many herbivorous insects. Aphids appear to be an exception that warrants further study. The effects of elevated CO(2) (750 ppm vs. 390 ppm) were evaluated on N assimilation and transamination by two Medicago truncatula genotypes, a N-fixing-deficient mutant (dnf1) and its wild-type control (Jemalong), with and without pea aphid (Acyrthosiphon pisum) infestation. Elevated CO(2) increased population abundance and feeding efficiency of aphids fed on Jemalong, but reduced those on dnf1. Without aphid infestation, elevated CO(2) increased photosynthetic rate, chlorophyll content, nodule number, biomass, and pod number for Jemalong, but only increased pod number and chlorophyll content for dnf1. Furthermore, aphid infested Jemalong plants had enhanced activities of N assimilation-related enzymes (glutamine synthetase, Glutamate synthase) and transamination-related enzymes (glutamate oxalate transaminase, glutamine phenylpyruvate transaminase), which presumably increased amino acid concentration in leaves and phloem sap under elevated CO(2). In contrast, aphid infested dnf1 plants had decreased activities of N assimilation-related enzymes and transmination-related enzymes and amino acid concentrations under elevated CO(2). Furthermore, elevated CO(2) up-regulated expression of genes relevant to amino acid metabolism in bacteriocytes of aphids associated with Jemalong, but down-regulated those associated with dnf1. Our results suggest that pea aphids actively elicit host responses that promote amino acid metabolism in both the host plant and in its bacteriocytes to favor the population growth of the aphid under elevated CO(2).

  10. Aphid Infestation Increases Fusarium langsethiae and T-2 and HT-2 Mycotoxins in Wheat.

    Science.gov (United States)

    Drakulic, Jassy; Ajigboye, Olubukola; Swarup, Ranjan; Bruce, Toby; Ray, Rumiana V

    2016-11-15

    Fusarium langsethiae is a fungal pathogen of cereal crops that is an increasing problem in northern Europe, but much of its epidemiology is poorly understood. The species produces the mycotoxins T-2 and HT-2, which are highly toxic. It was hypothesized that grain aphids, Sitobion avenae, may transmit F. langsethiae inoculum between wheat plants, and a series of transmission experiments and volatile chemical analyses was performed to test this. Manual translocation of aphids from inoculated to uninfected hosts resulted in pathogen DNA accumulation in hosts. However, the free movement of wingless aphids from infected to healthy plants did not. The addition of winged aphids reared on F. langsethiae-inoculated wheat seedlings to wheat plants also did not achieve successful pathogen transfer. While our data suggested that aphid transmission of the pathogen was not very efficient, we observed an increase in disease when aphids were present. After seedling inoculation, an increase in pathogen DNA accumulation in seedling leaves was observed upon treatment with aphids. Furthermore, the presence of aphids on wheat plants with F. langsethiae-inoculated ears not only led to a rise in the amount of F. langsethiae DNA in infected grain but also to an increase in the concentrations of T-2 and HT-2 toxins, with more than 3-fold higher toxin levels than diseased plants without aphids. This work highlights that aphids increase the susceptibility of wheat host plants to F. langsethiae and that aphid infestation is a risk factor for accumulating increased levels of T-2 and HT-2 in wheat products.

  11. Wild Solanum resistance to aphids: antixenosis or antibiosis?

    Science.gov (United States)

    Le Roux, Vincent; Dugravot, Sébastien; Campan, Erick; Dubois, Françoise; Vincent, Charles; Giordanengo, Philippe

    2008-04-01

    The type (antixenosis or antibiosis) of resistance against the aphids Myzus persicae (Sulzer) and Macrosiphum euphorbiae (Thomas) was characterized for the wild tuber-bearing potatoes, Solanum chomatophilum Bitter and Solanum stoloniferum Schltdl. & Bouché through behavioral (olfactometry and electrical penetration graph) and physiological studies. In dual-choice assays, only S. stoloniferum exerted attraction to M. euphorbiae. This ruled out the possibility that plant volatiles of S. chomatophilum and S. stoloniferum may contribute to the high resistance expressed. In electrical penetration graph experiments, aphids feeding on S. stoloniferum showed increased salivation phases, whereas phloem ingestion was drastically reduced for both aphid species. Because reaching phloem elements was not delayed in both species, the resistance mechanism was phloem-located. The antixenosis exhibited by S. stoloniferum was similar on young and mature leaves. S. chomatophilum also showed phloem-located antixenosis against M. persicae. In contrast, M. euphorbiae had no difficulty to reach S. chomatophilum phloem tissues and to ingest sap. S. chomatophilum resistance against M. euphorbiae was antibiosis and only expressed in mature leaves, where a complete nymphal mortality was observed.

  12. Gene knockdown by RNAi in the pea aphid Acyrthosiphon pisum

    Directory of Open Access Journals (Sweden)

    Rispe Claude

    2007-09-01

    Full Text Available Abstract Background RNA interference (RNAi is a powerful method to inhibit gene expression in a sequence specific manner. Results Here, we described the development of RNAi by micro-injection of double-stranded RNA (dsRNA in the pea aphid Acyrthosiphon pisum. Injection of dsRNA into whole aphid body induced the silencing of two marker genes with different expression patterns: the ubiquitously expressed Ap-crt genes encoding a calreticulin and the gut specific Ap-cath-L gene encoding a cathepsin-L. Time-course analysis of the silencing showed similar temporal patterns for both genes: inhibition started at 1 day after injection, reached its maximum at 5 days and stopped at 7 days. A comparable 40% decrease of gene expression was observed for Ap-crt and Ap-cath-L. Conclusion The pea aphid is the first Hemipteran insect for which genome sequence will be available soon. The gene knockdown technique developed in this study will be an essential post-genomic tool for further investigations in aphidology.

  13. Aphid infestation affecting the biogeochemistry of European beech saplings

    Science.gov (United States)

    Michalzik, B.; Levia, D. F., Jr.; Bischoff, S.; Näthe, K.

    2014-12-01

    Mass outbreaks of herbivore insects are known to perturb the functional properties of forests. However, it is less clear how endemic to moderate aboveground herbivory affects the vertical flow of nutrients from tree canopies to the soil. Here, we report on the effects of low to moderate infestation levels of the woolly beech aphid (Phyllaphis fagi L.) on the nutrient dynamics and hydrology of European beech (Fagus sylvatica L.). In a potted sapling experiment, we followed the vertical dynamics of nutrients via throughfall (TF), stemflow (SF) and litter leachates (LL) collected over ten weeks underneath infested and uninfested control trees. Aphid infestation amplifies the fluxes of K+, Mn2+ and particulate nitrogen (0.45μm factor of up to 200 compared to TF.Imaging of leaf surfaces by scanning electron microscopy exhibited notable differences of the surface morphology and microbiology of control, lightly infested, and heavily infested leaves. This observation might point to an aphid-mediated alteration of the phyllosphere ecology triggering the microbial uptake of NH4-N and SO4-S and its transformation to particulate N by magnified biomass growth of the phyllosphere microflora, consequently changing the chemical partitioning and temporal availability of nitrogen.

  14. Impact of aphid alarm pheromone release on virus transmission efficiency: When pest control strategy could induce higher virus dispersion.

    Science.gov (United States)

    Lin, Fang-Jing; Bosquée, Emilie; Liu, Ying-Jie; Chen, Ju-Lian; Yong, Liu; Francis, Frédéric

    2016-09-01

    Aphids cause serious damages to crops not only by tacking sap but also by transmitting numerous viruses. To develop biological control, the aphid alarm pheromone, namely E-β-farnesene (EβF), has been demonstrated to be efficient to repel aphids and as attract beneficials, making it a potential tool to control aphid pests. Considering aphids also as virus vectors, changes of their behavior could also interfere with the virus acquisition and transmission process. Here, a combination of two aphid species and two potato virus models were selected to test the influence of EβF release on aphid and virus dispersion under laboratory conditions. EβF release was found to significantly decrease the population of Myzus persicae and Macrosiphum euphorbiae around the infochemical releaser but simultaneously also increasing the dispersal of Potato Virus Y (PVY). At the opposite, no significant difference for Potato Leaf Roll Virus (PLRV) transmission efficiency was observed with similar aphid alarm pheromone releases for none of the aphid species. These results provide some support to carefully consider infochemical releasers not only for push-pull strategy and pest control but also to include viral disease in a the plant protection to aphids as they are also efficient virus vectors. Impact of aphid kinds and transmission mechanisms will be discussed according to the large variation found between persistent and non persistent potato viruses and interactions with aphids and related infochemicals.

  15. Tangible benefits of the pea aphid genome sequencing in proteomics research: enhancements in protein identification, data incorporation, and evaluation criteria

    Science.gov (United States)

    The pea aphid, Acyrthosiphon pisum, is an important agricultural pest and a model system for numerous aspects of aphid biology, including sexual and asexual reproduction, bacterial endosymbiosis, insecticide resistance, and the evolution of aphid and plant host interactions. Recently, its complete ...

  16. Integrating and Processing XML Documents with JavaBeans Components

    Directory of Open Access Journals (Sweden)

    Yin-Wah Chiou

    2003-02-01

    Full Text Available The eXtensible Markup Language (XML and JavaBeans component model have gained wide popularity in the Object Web computing. This paper explores how JavaBeans components can be used to integrate and process the XML documents. It covers Bean Markup Language (BML, XML BeanMaker, XML Bean Suite, and Xbeans. The most powerful JavaBeans connection language is BML, which represents an integration of XML and JavaBeans components to provide a mechanism for implementing active content. XML BeanMaker is used to generate JavaBeans from XML DTD files. XML Bean Suite is a toolkit of JavaBeans components to provide a comprehensive set of functionality to manipulate XML content. The Xbean is a powerful paradigm to process XML-based distributed applications.

  17. Quality of different aphids as hosts of the parasitoid Lysiphlebus testaceipes (Cresson) (Hymenoptera: Braconidae, Aphidiinae); Qualidade de diferentes especies de pulgoes como hospedeiros do parasitoide Lysiphlebus testaceipes (Cresson) (Hymenoptera: Braconidae, Aphidiinae)

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Robson J.; Bueno, Vanda H.P. [Universidade Federal de Lavras, MG (Brazil). Dept. de Entomologia]. E-mail: vhpbueno@ufla.br; Sampaio, Marcus V.[Universidade Federal de Uberlandia (UFU), MG (Brazil). Inst. de Ciencias Agrarias]. E-mail: mvsampaio@iciag.ufu.br

    2008-03-15

    Lysiphlebus testaceipes (Cresson) has a broad aphid host range; however the quality of these preys may interfere in its biological feature. This study aimed to evaluate the quality of three Macrosiphini, Brevicoryne brassicae (L.), Lipaphis erysimi (Kaltenbach) and Myzus persicae (Sulzer), and three Aphidini Schizaphis graminum (Rondani) Rhopalosiphum maidis (Fitch) and Aphis gossypii Glover as hosts to L. testaceipes and to determine the relation possible of host preference, of size and quality of the host. The tests were carried out in climatic chamber at 25 {+-} 1 deg C, RH 70 {+-} 10% and 12h photophase. The parasitoid did not oviposite in B. brassicae and L. erysimi, while the other species were nutritionally suitable to the parasitoid. L. testaceipes showed preference for aphids from tribe Aphidini and these hosts presented better quality to the parasitoid when compared to Macrosiphini. Interactions among size, preference and quality between the Aphidini were found. L. testaceipes showed preference (parasitism rate 76.7%) for R. maidis, the bigger host (hind tibia with 0.281 mm). This host provided bigger size (hind tibia with 0.49 mm) and higher emergence rate (95.6%) to the parasitoid when compared to A. gossypii (parasitism rate of 55.7%). Also the smaller host A. gossypii (0.266 mm) provided smaller size hind tibia (0.45 mm) and higher mortality of the parasitoid (emergence rate 72.1%). However, the development time was shorter and the longevity was higher in A. gossypii (6.3 and 5.4 days, respectively) when compared to the host R. maidis (6.7 and 3.8 days, respectively), and not been related to host size. (author)

  18. Performance of the Bean-protein Fiber

    Institute of Scientific and Technical Information of China (English)

    韩光亭; 杜宁; 孙亚宁

    2003-01-01

    The methods in testing the bean-protein fiber and the standards used were simply introduced. The fiber's mechanical and chemical performances were further analyzed. And the correlative performance of the bean-protein fibers and other natural fibers have been compared, then full knowledge of the fiber's performance was concluded.

  19. Nutritional and health benefits of dried beans.

    Science.gov (United States)

    Messina, Virginia

    2014-07-01

    Dried beans (often referred to as grain legumes) may contribute to some of the health benefits associated with plant-based diets. Beans are rich in a number of important micronutrients, including potassium, magnesium, folate, iron, and zinc, and are important sources of protein in vegetarian diets. In particular, they are among the only plant foods that provide significant amounts of the indispensable amino acid lysine. Commonly consumed dried beans are also rich in total and soluble fiber as well as in resistant starch, all of which contribute to the low glycemic index of these foods. They also provide ample amounts of polyphenols, many of which are potent antioxidants. Intervention and prospective research suggests that diets that include beans reduce low-density lipoprotein cholesterol, favorably affect risk factors for metabolic syndrome, and reduce risk of ischemic heart disease and diabetes. The relatively low bean intakes of North Americans and northern Europeans can be attributed to a negative culinary image as well as to intestinal discomfort attributable to the oligosaccharide content of beans. Cooking practices such as sprouting beans, soaking and discarding soaking water before cooking, and cooking in water with a more alkaline pH can reduce oligosaccharide content. Promotional efforts are needed to increase bean intake.

  20. Registration of ‘Samurai’ Otebo Bean

    Science.gov (United States)

    ‘Samurai’ otebo bean (Phaseolus vulgaris L.) (Reg. no. CV- , PI ), developed by Michigan State University AgBioResearch was released in 2015 as an upright, full-season cultivar with virus [caused by Bean common mosaic virus (BCMV)] resistance and high-yield potential. Samurai was developed using ped...

  1. Mung Bean: Technological and Nutritional Potential

    NARCIS (Netherlands)

    Dahiya, P.K.; Linnemann, A.R.; Boekel, van M.A.J.S.; Khetarpaul, N.; Grewal, R.B.; Nout, M.J.R.

    2015-01-01

    Mung bean (Vigna radiata (L.) R.Wilczek) has been intensively researched; scattered data are available on various properties. Data on physical, chemical, food processing, and nutritional properties were collected for whole mung bean grains and reviewed to assess the crop’s potential as food and to s

  2. Weed management strategies for castor bean crops

    Directory of Open Access Journals (Sweden)

    Augusto Guerreiro Fontoura Costa

    2014-04-01

    Full Text Available Castor bean crops are agriculturally relevant due to the quality and versatility of their oil, both for the chemical industry and for biodiesel production. Proper weed management is important for both the cultivation and the yield of castor bean crops; therefore, the intention of the present work is to review pertinent information regarding weed management, including the studies regarding weed interference periods, chemical controls for use in different crop production systems and herbicide selectivity, for castor bean crops. Weed science research for castor bean crops is scarce. One of the main weed management challenges for castor bean crops is the absence of herbicides registered with the Ministry of Agriculture, Livestock and Food Supply (MALFS. Research for viable herbicides for weed control in castor bean crops should be directed by research and/or rural extension institutions, associations and farmers cooperatives, as well as by manufactures, for the registration of these selective herbicides, which would be primarily used to control eudicotyledons in castor bean crops. New studies involving the integration of weed control methods in castor bean also may increase the efficiency of weed management, for both small farmers using traditional crop methods in the Brazilian Northeast region, as well as for areas with the potential for large scale production, using conservation tillage systems, such as the no-tillage crop production system.

  3. (E)-β-farnesene synthase genes affect aphid (Myzus persicae) infestation in tobacco (Nicotiana tabacum).

    Science.gov (United States)

    Yu, Xiudao; Jones, Huw D; Ma, Youzhi; Wang, Genping; Xu, Zhaoshi; Zhang, Baoming; Zhang, Yongjun; Ren, Guangwei; Pickett, John A; Xia, Lanqin

    2012-03-01

    Aphids are major agricultural pests which cause significant yield losses of the crop plants each year. (E)-β-farnesene (EβF) is the alarm pheromone involved in the chemical communication between aphids and particularly in the avoidance of predation. In the present study, two EβF synthase genes were isolated from sweet wormwood and designated as AaβFS1 and AaβFS2, respectively. Overexpression of AaβFS1 or AaβFS2 in tobacco plants resulted in the emission of EβF ranging from 1.55 to 4.65 ng/day/g fresh tissues. Tritrophic interactions involving the peach aphids (Myzus persicae), predatory lacewings (Chrysopa septempunctata) demonstrated that the transgenic tobacco expressing AaβFS1 and AaβFS2 could repel peach aphids, but not as strongly as expected. However, AaβFS1 and AaβFS2 lines exhibited strong and statistically significant attraction to lacewings. Further experiments combining aphids and lacewing larvae in an octagon arrangement showed transgenic tobacco plants could repel aphids and attract lacewing larvae, thus minimizing aphid infestation. Therefore, we demonstrated a potentially valuable strategy of using EβF synthase genes from sweet wormwood for aphid control in tobacco or other economic important crops in an environmentally benign way.

  4. National Plant Diagnostic Network, Taxonomic training videos: Aphids under the microscope - Cerataphis brasiliensis

    Science.gov (United States)

    Training is a critical part of aphid (Hemiptera: Aphididae) identification. This video provides provides training to identify the palm aphid, Cerataphis brasiliensis, using a compound microscope and an electronic identification key called “LUCID.” The video demonstrates key morphological structures...

  5. National Plant Diagnostic Network, Taxonomic training videos: Aphids under the microscope - Myzus persicae

    Science.gov (United States)

    Training is a critical part of aphid (Hemiptera: Aphididae) identification. This video provides provides training to identify the green peach aphid, Myzus persicae, using a compound microscope and an electronic identification key called “LUCID.” The video demonstrates key morphological structures t...

  6. Effects of single and combined heavy metals and their chelators on aphid performance and preferences.

    Science.gov (United States)

    Stolpe, Clemens; Müller, Caroline

    2016-12-01

    When present at elevated levels in the environment, heavy metals are toxic for most organisms. However, so-called hyperaccumulator plants tolerate heavy metals and use chelators for their internal long-distance transport. Thus, phloem-sucking insects may come in contact with the chelated metals. In the present study, the effects of individual and combined heavy metals, zinc (Zn) and cadmium (Cd), as well as of common chelators, nicotianamine and phytochelatin, were investigated on the performance, preferences, and metal accumulation of the generalist aphid Myzus persicae, using artificial diets. Added Zn increased aphid growth, whereas Cd reduced the survival of aphids. Chelators had neither protective nor negative effects on aphids. The combination of the 2 heavy metals in chelated or nonchelated form caused a potentiation effect that led to an extinction of the aphids within less than 2 wk, before they could reproduce. Both Cd and Zn accumulated in the aphids, indicating a possible biomagnification. In choice assays, aphids preferred diets amended with Zn with or without nicotianamine compared to a control diet. In contrast, a Cd-containing diet led to neither attraction nor aversion. The present study provides insight into how mixtures of heavy metals and their chelators influence the life history of a generalist aphid. The results have implications for the use of phytoremediation to remove heavy metals from contaminated soils. Environ Toxicol Chem 2016;35:3023-3030. © 2016 SETAC. © 2016 SETAC.

  7. The molecular basis of the interactions between luteoviruses and their aphid vectors

    NARCIS (Netherlands)

    Hogenhout, S.A.

    1999-01-01

    Luteoviruses essentially replicate in the phloem tissue and are transmitted from plant to plant by aphids in a circulative, persistent manner. Virus particles are acquired when aphids feed on phloem sap. Particles are then transported from the midgut or hindgut into the haemolymph and from

  8. Selection by phage display of a mustard chymotrypsin inhibitor toxic to pea aphid.

    NARCIS (Netherlands)

    Ceci, L.R.; Volpicella, M.; Conti, S.; Gallerani, R.; Beekwilder, M.J.; Jongsma, M.A.

    2003-01-01

    The mustard trypsin inhibitor, MTI-2, is a potent inhibitor of trypsin with no activity towards chymotrypsin. MTI-2 is toxic for lepidopteran insects, but has low activity against aphids. In an attempt to improve the activity of the inhibitor towards aphids, a library of inhibitor variants was const

  9. The molecular basis of the interactions between luteoviruses and their aphid vectors

    NARCIS (Netherlands)

    Hogenhout, S.A.

    1999-01-01

    Luteoviruses essentially replicate in the phloem tissue and are transmitted from plant to plant by aphids in a circulative, persistent manner. Virus particles are acquired when aphids feed on phloem sap. Particles are then transported from the midgut or hindgut into the haemolymph and from the haemo

  10. Risk to native Uroleucon aphids (Hemiptera: Aphididae) from non-native lady beetles (Coleoptera: Coccinellidae)

    Science.gov (United States)

    Aphids in the genus Uroleucon Mordvilko (Hemiptera: Aphididae) are native herbivores that feed on goldenrod (Solidago spp.) and other Asteraceae in North America. The aphids are potential prey for a wide variety of natural enemies, including native and non-native species of lady beetles (Coleoptera...

  11. UAS-derived crop height and NDVI metrics for sorghum yield and aphid stress assessment

    Science.gov (United States)

    A small, fixed-wing UAS was used to survey a replicated small plot field experiment designed to estimate sorghum damage caused by an invasive aphid. Plant stress varied among 40 plots through manipulation of aphid densities. Equipped with a consumer-grade near-infrared camera, the UAS was flown on...

  12. Sugarcane aphid (Homoptera: Aphididae): A new pest on sorghum in North America

    Science.gov (United States)

    In 2013 the sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae), a new invasive pest of sorghum in North America, was confirmed on sorghum in four states and 38 counties in the U.S. In 2015, the aphid was reported on sorghum in 17 states and over 400 counties as well as all sorgh...

  13. Screening of sorghum lines for resistance against sugarcane aphid, Melanaphis sacchari (Zehnter)

    Science.gov (United States)

    The sugarcane aphid Melanaphis sacchari (Zehnter) has emerged as the most significant threat to sorghum (Sorghum bicolor (L.) Moench) production in the United States. Since 2013, discovery of aphid resistant germplasm has been a priority all stakeholders involved. We screened twenty three differen...

  14. Utilization of ladybird beetles to curb aphids in strawberry high tunnels: preliminary results

    Science.gov (United States)

    Native and exotic aphid species continue to pose a threat to the successful cultivation of small fruits in greenhouses, glasshouses, and high tunnels throughout the World. There is considerable interest in using biological controls (predators and parasitoids) to manage aphids in lieu of synthetic in...

  15. First report on the entomopathogenic genus Neozygites (Entomophthoromycota) and Neozygites osornensis on aphids in Brazil

    Science.gov (United States)

    The genus Neozygites has been known in Brazil until now only on mites, and this is its first report on aphids in Brazil. Tree-dwelling aphids (Cinara sp.) on a cypress tree were regularly monitored for entomopathogenic fungi in the city of Terezópolis de Goiás in Central Brazil between July 2014 and...

  16. Towards efficient multi-scale methods for monitoring sugarcane aphid infestations in sorghum

    Science.gov (United States)

    We discuss approaches and issues involved with developing optimal monitoring methods for sugarcane aphid infestations (SCA) in grain sorghum. We discuss development of sequential sampling methods that allow for estimation of the number of aphids per sample unit, and statistical decision making rela...

  17. Inheritance patterns of secondary symbionts during sexual reproduction of pea aphid biotypes.

    Science.gov (United States)

    Peccoud, Jean; Bonhomme, Joël; Mahéo, Frédérique; de la Huerta, Manon; Cosson, Olivier; Simon, Jean-Christophe

    2014-06-01

    Herbivorous insects frequently harbor bacterial symbionts that affect their ecology and evolution. Aphids host the obligatory endosymbiont Buchnera, which is required for reproduction, together with facultative symbionts whose frequencies vary across aphid populations. These maternally transmitted secondary symbionts have been particularly studied in the pea aphid, Acyrthosiphon pisum, which harbors at least 8 distinct bacterial species (not counting Buchnera) having environmentally dependent effects on host fitness. In particular, these symbiont species are associated with pea aphid populations feeding on specific plants. Although they are maternally inherited, these bacteria are occasionally transferred across insect lineages. One mechanism of such nonmaternal transfer is paternal transmission to the progeny during sexual reproduction. To date, transmission of secondary symbionts during sexual reproduction of aphids has been investigated in only a handful of aphid lineages and 3 symbiont species. To better characterize this process, we investigated inheritance patterns of 7 symbiont species during sexual reproduction of pea aphids through a crossing experiment involving 49 clones belonging to 9 host-specialized biotypes, and 117 crosses. Symbiont species in the progeny were detected with diagnostic qualitative PCR at the fundatrix stage hatching from eggs and in later parthenogenetic generations. We found no confirmed case of paternal transmission of symbionts to the progeny, and we observed that maternal transmission of a particular symbiont species (Serratia symbiotica) was quite inefficient. We discuss these observations in respect to the ecology of the pea aphid.

  18. Bottom-up effects of plant genotype on aphids, ants, and predators.

    Science.gov (United States)

    Johnson, Marc T J

    2008-01-01

    Theory predicts that bottom-up ecological forces can affect community dynamics, but whether this extends to the effects of heritable plant variation on tritrophic communities is poorly understood. In a field experiment, I contrasted the effects of plant genotype (28 genotypes; 1064 plants), aphid density, and the presence/absence of mutualistic ants in affecting the per capita population growth of a specialist aphid herbivore, as well as the effects of plant genotype on the third trophic level. Plant genotype strongly affected aphid population growth rate, explaining 29% of the total variation in growth rate, whereas aphid density and ant-aphid interactions explained substantially less variation (Plant genotype also had direct and indirect effects on the third trophic level, affecting the abundance of aphid-tending ants and the richness of predators. Multiple regression identified several heritable plant traits that explained 49% of the variation in aphid growth rate and 30% of the variation in ant abundance among plant genotypes. These bottom-up effects of plant genotype on tritrophic interactions were independent of the effects of either initial aphid density or the presence/absence of mutualistic ants. This study shows that plant genotype can be one of the most important ecological factors shaping tritrophic communities.

  19. The Effects of Aphid Traits on Parasitoid Host Use and Specialist Advantage.

    Directory of Open Access Journals (Sweden)

    Vesna Gagic

    Full Text Available Specialization is a central concept in ecology and one of the fundamental properties of parasitoids. Highly specialized parasitoids tend to be more efficient in host-use compared to generalized parasitoids, presumably owing to the trade-off between host range and host-use efficiency. However, it remains unknown how parasitoid host specificity and host-use depends on host traits related to susceptibility to parasitoid attack. To address this question, we used data from a 13-year survey of interactions among 142 aphid and 75 parasitoid species in nine European countries. We found that only aphid traits related to local resource characteristics seem to influence the trade-off between host-range and efficiency: more specialized parasitoids had an apparent advantage (higher abundance on shared hosts on aphids with sparse colonies, ant-attendance and without concealment, and this was more evident when host relatedness was included in calculation of parasitoid specificity. More traits influenced average assemblage specialization, which was highest in aphids that are monophagous, monoecious, large, highly mobile (easily drop from a plant, without myrmecophily, habitat specialists, inhabit non-agricultural habitats and have sparse colonies. Differences in aphid wax production did not influence parasitoid host specificity and host-use. Our study is the first step in identifying host traits important for aphid parasitoid host specificity and host-use and improves our understanding of bottom-up effects of aphid traits on aphid-parasitoid food web structure.

  20. High levels of exotic armored scales on imported avocados raise concerns regarding USDA-APHIS' phytosanitary risk assessment.

    Science.gov (United States)

    Morse, J G; Rugman-Jones, P F; Watson, G W; Robinson, L J; Bi, J L; Stouthamer, R

    2009-06-01

    Between 1914 and 2007, a quarantine protected California avocado, Persea americana Mill., groves from pests that might be introduced into the state along with fresh, imported avocados. Soon after Mexican avocados were first allowed entry on 1 February 2007, live specimens of several species of armored scales (Hemiptera: Diaspididae) not believed to be present in California were detected on 'Hass' avocados entering the state from Mexico. Initially, the California Department of Food and Agriculture (CDFA) prevented avocados infested with these scales from entering the state or required that they be fumigated with an approved treatment such as methyl bromide. After a Science Advisory Panel meeting in May 2007, U.S. Department of Agriculture-Animal and Plant Health Inspection Service (USDA-APHIS) reaffirmed its position that armored scales on shipments of fruit for consumption (including avocados) pose a "low risk" for pest establishment. In compliance with APHIS protocols, as of 18 July 2007, CDFA altered its policy to allow shipments of scale-infested avocados into the state without treatment. Here, we report on sampling Mexican avocados over an 8-mo period, September 2007-April 2008. An estimated 67 million Mexican Hass avocados entered California over this period. Based on samples from 140 trucks containing approximately 15.6% of this volume of fruit, we estimate that approximately 47.6 million live, sessile armored scales and an additional 20.1 million live eggs and crawlers were imported. We found eight probable species of armored scales in the samples, seven of these are not believed to occur in California; 89.3% of the live scales were Abgrallaspis aguacatae Evans, Watson and Miller, a recently described species. In contrast to the USDA-APHIS opinion, we believe the volume of shipments and levels of live scales they contain present a significant risk to California's US$300 million avocado industry and to other crops that might become infested by one or more of

  1. Effects of botanical insecticides on the instantaneous population growth rate of Aphis gossypii Glover (Hemiptera: Aphididae) in cotton

    OpenAIRE

    Andrade, Lígia Helena de; Oliveira, José Vargas de; Breda, Mariana Oliveira; Marques,Edmilson Jacinto; Lima,Iracilda Maria de Moura

    2012-01-01

    Botanical insecticides have been studied aiming the alternative pest control. The present study investigated the effects of these insecticides on the instantaneous population growth rate (ri) of Aphis gossypii. Botanical insecticides were tested in the following concentrations: Compostonat®, Rotenat-CE® and Neempro (0, 0.50, 0.75, 1.00, 1.25, 1.50 and 1.75%); Natuneem® and Neemseto® (0, 0.25, 0.50, 0.75 and 1.00%) and essential oils of Foeniculum vulgare Mill., Cymbopogom winterianus (L.), Ch...

  2. Enterprise JavaBeans 31

    CERN Document Server

    Rubinger, Andrew

    2010-01-01

    Learn how to code, package, deploy, and test functional Enterprise JavaBeans with the latest edition of this bestselling guide. Written by the developers of JBoss EJB 3.1, this book not only brings you up to speed on each component type and container service in this implementation, it also provides a workbook with several hands-on examples to help you gain immediate experience with these components. With version 3.1, EJB's server-side component model for building distributed business applications is simpler than ever. But it's still a complex technology that requires study and lots of practi

  3. 21 CFR 184.1343 - Locust (carob) bean gum.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Locust (carob) bean gum. 184.1343 Section 184.1343... Listing of Specific Substances Affirmed as GRAS § 184.1343 Locust (carob) bean gum. (a) Locust (carob) bean gum is primarily the macerated endosperm of the seed of the locust (carob) bean tree,...

  4. Development, release and dissemination of "Sankara" black bean in Haiti

    Science.gov (United States)

    Common bean (Phaseolus vulgaris L.) production in the Caribbean is threatened by Bean Golden Yellow Mosaic Virus (BGYMV), Bean Common Mosaic Virus (BCMV) and Bean Common Mosaic Necrosis Virus (BCMNV). The University of Puerto Rico, the University of Nebraska, the USDA-ARS, Zamorano and the National ...

  5. Breeding black beans for Haiti with multiple virus resistance

    Science.gov (United States)

    Black bean production in the lowlands of Central America and the Caribbean is threatened by Bean golden yellow mosaic virus (BGYMV) and Bean common mosaic necrosis virus (BCMNV). Therefore, the objective of this research was to develop, test and release tropically-adapted black bean lines with resis...

  6. Early-season predation on aphids by winter-active spiders in apple orchards revealed by diagnostic PCR.

    Science.gov (United States)

    Boreau de Roincé, C; Lavigne, C; Mandrin, J-F; Rollard, C; Symondson, W O C

    2013-04-01

    Aphids are major pests in apple orchards, debilitating the crop and spreading disease. We investigated whether early-season predation by canopy spiders may be effectively controlling aphid numbers in three organic orchards. For this purpose, we monitored the aphid population dynamics from the winter eggs to colony stages and compared this to spider abundances and rates of predation on aphids detected by diagnostic polymerase chain reaction. For the latter, we applied existing general aphid primers. We found that spiders ate colony fundatrices and that aphid numbers were negatively related to spider abundance. Spiders were the main active predators within the orchards when the first colony fundatrices were present, indicating their importance in the early control of aphid populations.

  7. 抗吡虫啉棉蚜对其他新烟碱类药剂的交互抗性及相关酶的活性变化%Cross-resistance of the imidacloprid-resistant population of Aphis gossypii Glover (Homoptera: Aphididae ) to other neonicotinoid insecticides and changes in activities of related enzymes

    Institute of Scientific and Technical Information of China (English)

    史晓斌; 石绪根; 王红艳; 夏晓明; 王开运

    2011-01-01

    In order to clarify the cross-resistance and the change in related enzymes of the imidacloprid-resistant population of Aphis gossypii to other neonicotinoid insecticides, the bioassay method was used to determine the cross-resistance of different resistant populations of imidacloprid-resistant A. Gossypii to dinotefuran and nitenpyram, and the synergism of three detoxification enzyme inhibitors to imidacloprid and other two neonicotinoid insecticides using cotton aphids of the imidacloprid-resistant population selected in the laboratory, the Xiajin resistant population in the field in Shandong and the susceptible population. The activities of detoxification enzymes and AChE of three populations of cotton aphid and the inhibition effect of insecticides were determined through biochemical analysis. The results showed that the imidacloprid-resistant population and the Xiajin resistant population exhibited no cross-resistance to dinotefuran, but showed 5. 28-fold and 4. 89-fold cross-resistance to nitenpyram, respectively. Dinotefuran could significantly inhibit the activities of CarE, GST and AChE of the imidacloprid-resistant cotton aphid. Nitenpyram showed little effect on the activities of CarE, GST and AChE of the imidacloprid-resistant cotton aphid. Carboxylesterase inhibitor TPP and mixed-functional oxidase inhibitor PBO had obvious synergism to imidacloprid and nitenpyram, while had little synergism to dinotefuran. Glutathione-S-transferase inhibitor DEM showed no obvious synergism to the three insecticides. Dinotefuran and nitenpyram could inhibit the activities of detoxification enzymes and AChE of the imidacloprid-resistant conton aphid, with dinotefuran showing significant effect. The results demonstrate the great application value of dinotefuran in control of the imidacloprid-resistant cotton aphid, and its structure can provide a reference to the development of neonicotinoid insecticides in the future.%为明确抗吡虫啉棉蚜Aphis gossypii对其他

  8. A trio of viral proteins tunes aphid-plant interactions in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Jack H Westwood

    Full Text Available BACKGROUND: Virus-induced deterrence to aphid feeding is believed to promote plant virus transmission by encouraging migration of virus-bearing insects away from infected plants. We investigated the effects of infection by an aphid-transmitted virus, cucumber mosaic virus (CMV, on the interaction of Arabidopsis thaliana, one of the natural hosts for CMV, with Myzus persicae (common names: 'peach-potato aphid', 'green peach aphid'. METHODOLOGY/PRINCIPAL FINDINGS: Infection of Arabidopsis (ecotype Col-0 with CMV strain Fny (Fny-CMV induced biosynthesis of the aphid feeding-deterrent 4-methoxy-indol-3-yl-methylglucosinolate (4MI3M. 4MI3M inhibited phloem ingestion by aphids and consequently discouraged aphid settling. The CMV 2b protein is a suppressor of antiviral RNA silencing, which has previously been implicated in altering plant-aphid interactions. Its presence in infected hosts enhances the accumulation of CMV and the other four viral proteins. Another viral gene product, the 2a protein (an RNA-dependent RNA polymerase, triggers defensive signaling, leading to increased 4MI3M accumulation. The 2b protein can inhibit ARGONAUTE1 (AGO1, a host factor that both positively-regulates 4MI3M biosynthesis and negatively-regulates accumulation of substance(s toxic to aphids. However, the 1a replicase protein moderated 2b-mediated inhibition of AGO1, ensuring that aphids were deterred from feeding but not poisoned. The LS strain of CMV did not induce feeding deterrence in Arabidopsis ecotype Col-0. CONCLUSIONS/SIGNIFICANCE: Inhibition of AGO1 by the 2b protein could act as a booby trap since this will trigger antibiosis against aphids. However, for Fny-CMV the interplay of three viral proteins (1a, 2a and 2b appears to balance the need of the virus to inhibit antiviral silencing, while inducing a mild resistance (antixenosis that is thought to promote transmission. The strain-specific effects of CMV on Arabidopsis-aphid interactions, and differences

  9. Reflective Polyethylene Mulch Reduces Mexican Bean Beetle (Coleoptera: Coccinellidae) Densities and Damage in Snap Beans.

    Science.gov (United States)

    Nottingham, L B; Kuhar, T P

    2016-08-01

    Mexican bean beetle, Epilachna varivestis Mulsant, is a serious pest of snap beans, Phaseolus vulgaris L., in the eastern United States. These beetles are intolerant to direct sunlight, explaining why individuals are typically found on the undersides of leaves and in the lower portion of the plant canopy. We hypothesized that snap beans grown on reflective, agricultural polyethylene (plastic mulch) would have fewer Mexican bean beetles and less injury than those grown on black plastic or bare soil. In 2014 and 2015, beans were seeded into beds of metallized, white, and black plastic, and bare soil, in field plots near Blacksburg, VA. Mexican bean beetle density, feeding injury, predatory arthropods, and snap bean yield were sampled. Reflected light intensity, temperature, and humidity were monitored using data loggers. Pyranometer readings showed that reflected light intensity was highest over metallized plastic and second highest over white plastic; black plastic and bare soil were similarly low. Temperature and humidity were unaffected by treatments. Significant reductions in Mexican bean beetle densities and feeding injury were observed in both metallized and white plastic plots compared to black plastic and bare soil, with metallized plastic having the fewest Mexican bean beetle life stages and injury. Predatory arthropod densities were not reduced by reflective plastic. Metallized plots produced the highest yields, followed by white. The results of this study suggest that growing snap beans on reflective plastic mulch can suppress the incidence and damage of Mexican bean beetle, and increase yield in snap beans. © 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.

  10. Estimating ancestral geographical distributions: a Gondwanan origin for aphid parasitoids?

    Science.gov (United States)

    Belshaw, R; Dowton, M; Quicke, D L; Austin, A D

    2000-01-01

    We tested the published hypothesis of a Gondwanan origin for the overwhelmingly northern hemisphere aphid parasitoids (Aphidiinae) as follows: (i) finding their sister group by a phylogenetic analysis of the entire Braconidae (Insecta: Hymenopterai using sequence data from approximately 500 bp fragments of both the nuclear 28S (D2 region) and mitochondrial 16S rDNA genes, (ii) using this sister-group relationship and the more informative 28S D2 gene to estimate the phylogeny of the Aphidiinae and (iii) estimating the ancestral distribution for the Aphidiinae using maximum-likelihood and maximum-parsimony methods. Both methods indicated a Gondwanan origin. PMID:10737407

  11. Aphids of the genus Diuraphis caught by Johnson suction trap in Poznań, Poland

    Directory of Open Access Journals (Sweden)

    Strażyński Przemysław

    2016-12-01

    Full Text Available In 1973-2011 in Poznań, aphid catches were carried out using Johnson’s suction trap. Since then the suction trap located at the Institute of Plant Protection - National Research Institute in Poznań has continuously recorded the daily and seasonal dynamics of aphid flights. The collected results has been used to establish one of the largest databases of this type in Europe. The data also allow tracking changes in aphid biodiversity under the changing climatic conditions. Three aphid species of Diuraphis spp. were identified: D. muehlei (Börner, 1950 - in 1974, D. bromicola (Hille Ris Lambers, 1959 - in 1988, D. noxia (Kurdjumov, 1913 - in 2003 as a result of systematic and long-term aphid collections. The occurrence of D. noxia presents a particular risk to cereal crops in Poland. This expansive aphid species that originates from Asia and the Mediterranean is a vector of Barley yellow dwarf viruses (BYDV, and has become one of the most important pest of wheat and barley in the world. Changes in climatic conditions that have been observed in recent years in Poland such as hot summer, long and warm autumn, mild winter seem to be optimal for occurrence and development of aphid species from warmer parts of Europe.

  12. Indirect effect of a transgenic wheat on aphids through enhanced powdery mildew resistance.

    Directory of Open Access Journals (Sweden)

    Simone von Burg

    Full Text Available In agricultural ecosystems, arthropod herbivores and fungal pathogens are likely to colonise the same plant and may therefore affect each other directly or indirectly. The fungus that causes powdery mildew (Blumeria graminis tritici and cereal aphids are important pests of wheat but interactions between them have seldom been investigated. We studied the effects of powdery mildew of wheat on two cereal aphid species, Metopolophium dirhodum and Rhopalosiphum padi. We hypothesized that aphid number and size will be smaller on powdery mildew-infected plants than on non-infected plants. In a first experiment we used six commercially available wheat varieties whereas in the second experiment we used a genetically modified (GM mildew-resistant wheat line and its non-transgenic sister line. Because the two lines differed only in the presence of the transgene and in powdery mildew resistance, experiment 2 avoided the confounding effect of variety. In both experiments, the number of M. dirhodum but not of R. padi was reduced by powdery mildew infection. Transgenic mildew-resistant lines therefore harboured bigger aphid populations than the non-transgenic lines. For both aphid species individual size was mostly influenced by aphid number. Our results indicate that plants that are protected from a particular pest (powdery mildew became more favourable for another pest (aphids.

  13. Indirect effect of a transgenic wheat on aphids through enhanced powdery mildew resistance.

    Science.gov (United States)

    von Burg, Simone; Álvarez-Alfageme, Fernando; Romeis, Jörg

    2012-01-01

    In agricultural ecosystems, arthropod herbivores and fungal pathogens are likely to colonise the same plant and may therefore affect each other directly or indirectly. The fungus that causes powdery mildew (Blumeria graminis tritici) and cereal aphids are important pests of wheat but interactions between them have seldom been investigated. We studied the effects of powdery mildew of wheat on two cereal aphid species, Metopolophium dirhodum and Rhopalosiphum padi. We hypothesized that aphid number and size will be smaller on powdery mildew-infected plants than on non-infected plants. In a first experiment we used six commercially available wheat varieties whereas in the second experiment we used a genetically modified (GM) mildew-resistant wheat line and its non-transgenic sister line. Because the two lines differed only in the presence of the transgene and in powdery mildew resistance, experiment 2 avoided the confounding effect of variety. In both experiments, the number of M. dirhodum but not of R. padi was reduced by powdery mildew infection. Transgenic mildew-resistant lines therefore harboured bigger aphid populations than the non-transgenic lines. For both aphid species individual size was mostly influenced by aphid number. Our results indicate that plants that are protected from a particular pest (powdery mildew) became more favourable for another pest (aphids).

  14. Differential expression of superoxide dismutase genes in aphid-stressed maize (Zea mays L.) seedlings.

    Science.gov (United States)

    Sytykiewicz, Hubert

    2014-01-01

    The aim of this study was to compare the expression patterns of superoxide dismutase genes (sod2, sod3.4, sod9 and sodB) in seedling leaves of the Zea mays L. Tasty Sweet (susceptible) and Ambrozja (relatively resistant) cultivars infested with one of two hemipteran species, namely monophagous Sitobion avenae F. (grain aphid) or oligophagous Rhopalosiphum padi L. (bird cherry-oat aphid). Secondarily, aphid-elicited alternations in the antioxidative capacity towards DPPH (1,1-diphenyl-2-picrylhydrazyl) radical in insect-stressed plants were evaluated. Comprehensive comparison of expression profiles of the four sod genes showed that both insect species evoked significant upregulation of three genes sod2, sod3.4 and sod9). However, aphid infestation affected non-significant fluctuations in expression of sodB gene in seedlings of both maize genotypes. The highest levels of transcript accumulation occurred at 8 h (sod2 and sod3.4) or 24 h (sod9) post-infestation, and aphid-induced changes in the expression of sod genes were more dramatic in the Ambrozja cultivar than in the Tasty Sweet variety. Furthermore, bird cherry-oat aphid colonization had a more substantial impact on levels of DPPH radical scavenging activity in infested host seedlings than grain aphid colonization. Additionally, Ambrozja plants infested by either hemipteran species showed markedly lower antioxidative capacity compared with attacked Tasty Sweet plants.

  15. Differential expression of superoxide dismutase genes in aphid-stressed maize (Zea mays L. seedlings.

    Directory of Open Access Journals (Sweden)

    Hubert Sytykiewicz

    Full Text Available The aim of this study was to compare the expression patterns of superoxide dismutase genes (sod2, sod3.4, sod9 and sodB in seedling leaves of the Zea mays L. Tasty Sweet (susceptible and Ambrozja (relatively resistant cultivars infested with one of two hemipteran species, namely monophagous Sitobion avenae F. (grain aphid or oligophagous Rhopalosiphum padi L. (bird cherry-oat aphid. Secondarily, aphid-elicited alternations in the antioxidative capacity towards DPPH (1,1-diphenyl-2-picrylhydrazyl radical in insect-stressed plants were evaluated. Comprehensive comparison of expression profiles of the four sod genes showed that both insect species evoked significant upregulation of three genes sod2, sod3.4 and sod9. However, aphid infestation affected non-significant fluctuations in expression of sodB gene in seedlings of both maize genotypes. The highest levels of transcript accumulation occurred at 8 h (sod2 and sod3.4 or 24 h (sod9 post-infestation, and aphid-induced changes in the expression of sod genes were more dramatic in the Ambrozja cultivar than in the Tasty Sweet variety. Furthermore, bird cherry-oat aphid colonization had a more substantial impact on levels of DPPH radical scavenging activity in infested host seedlings than grain aphid colonization. Additionally, Ambrozja plants infested by either hemipteran species showed markedly lower antioxidative capacity compared with attacked Tasty Sweet plants.

  16. Soil pathogen-aphid interactions under differences in soil organic matter and mineral fertilizer

    Science.gov (United States)

    Marini, Lorenzo; Biere, Arjen; van Agtmaal, Maaike; Tyc, Olaf; Kos, Martine; Kleijn, David; van der Putten, Wim H.

    2017-01-01

    There is increasing evidence showing that microbes can influence plant-insect interactions. In addition, various studies have shown that aboveground pathogens can alter the interactions between plants and insects. However, little is known about the role of soil-borne pathogens in plant-insect interactions. It is also not known how environmental conditions, that steer the performance of soil-borne pathogens, might influence these microbe-plant-insect interactions. Here, we studied effects of the soil-borne pathogen Rhizoctonia solani on aphids (Sitobion avenae) using wheat (Triticum aestivum) as a host. In a greenhouse experiment, we tested how different levels of soil organic matter (SOM) and fertilizer addition influence the interactions between plants and aphids. To examine the influence of the existing soil microbiome on the pathogen effects, we used both unsterilized field soil and sterilized field soil. In unsterilized soil with low SOM content, R. solani addition had a negative effect on aphid biomass, whereas it enhanced aphid biomass in soil with high SOM content. In sterilized soil, however, aphid biomass was enhanced by R. solani addition and by high SOM content. Plant biomass was enhanced by fertilizer addition, but only when SOM content was low, or in the absence of R. solani. We conclude that belowground pathogens influence aphid performance and that the effect of soil pathogens on aphids can be more positive in the absence of a soil microbiome. This implies that experiments studying the effect of pathogens under sterile conditions might not represent realistic interactions. Moreover, pathogen-plant-aphid interactions can be more positive for aphids under high SOM conditions. We recommend that soil conditions should be taken into account in the study of microbe-plant-insect interactions. PMID:28817594

  17. Widespread infection and diverse infection patterns of Wolbachia in Chinese aphids.

    Science.gov (United States)

    Wang, Zhe; Su, Xiao-Min; Wen, Juan; Jiang, Li-Yun; Qiao, Ge-Xia

    2014-06-01

    Wolbachia are intracellular symbionts that infect a wide range of arthropods and filarial nematodes. Aphids are engaged in diverse and complex relationships with their endosymbionts. Four supergroups (A, B, M and N) of Wolbachia were previously detected in aphids and supergroups M and N were only found in aphids. In this study, we detected and described Wolbachia infections in natural populations of aphids in China. Three supergroups (A, B and M) were found in the examined aphid species. Supergroup M was preponderant, whereas supergroups A and B were only detected in certain species. Supergroup N was not found in this study. There were four infection patterns of Wolbachia in aphids, namely, infection with supergroup M alone, co-infection with supergroups A and M, co-infection with supergroups B and M, and co-infection with supergroups A, B and M. The pattern of infection only with supergroup M was universal and was found in all evaluated subfamilies. Only two subfamilies, Aphidinae and Lachninae, manifested to present all four infection patterns. Three patterns were observed in Calaphidinae (M, A&M, B&M) and Eriosomatinae (M, B&M, A&B&M). Two patterns were observed in the Anoeciinae (M, A&M) and Greenideinae (M, B&M), and only one pattern (M) was observed in the remaining families and/or subfamilies of Aphidoidea. These results indicated that Wolbachia infections in Chinese aphids are widespread. Phylogenetic analyses suggest that Wolbachia supergroup M spread rapidly and recently among all host species of aphids in China. Reasons for this spread and its mechanisms are discussed along with the possible effects of Wolbachia on their aphid hosts.

  18. Characterisation and cross-amplification of polymorphic microsatellite loci in ant-associated root-aphids

    DEFF Research Database (Denmark)

    Ivens, A.B.F.; Kronauer, Daniel Jan Christoph; Boomsma, J.J.

    2011-01-01

    Twenty-six polymorphic microsatellite loci were developed for four species of ant-associated root-aphids: Geoica utricularia, Forda marginata, Tetraneura ulmi and Anoecia corni. We found up to 9 alleles per locus, with an average of 4.8. We also report polymorphic cross-amplification of eleven...... of these markers between different pairs of study species. Furthermore, we tested previously published aphid microsatellites and found one locus developed for Pemphigus bursarius to be polymorphic in G. utricularia. These microsatellite markers will be useful to study the population structure of aphids associated...

  19. Biological and Cultural Control of Olive Fruit Fly in California---Utilization of Parasitoids from USDA-APHIS-PPQ, Guatemala and Cultural Control Methods

    Science.gov (United States)

    The parasitoid Psytallia humilis = P. cf. concolor (Szépligeti) was reared on sterile Mediterranean fruit fly, Ceratitis capitata (Wiedemann), larvae at the USDA, APHIS, PPQ, Moscamed biological control laboratory in San Miguel Petapa, Guatemala and shipped to the USDA, ARS, Parlier, for biological ...

  20. Market strategies for Central American dry beans.

    OpenAIRE

    Mertínez, Lourdes; Bernsten, Richard; Zamora, Miguel

    2004-01-01

    In the past few years, the dry bean sub-sector in CentralAmerica has witnessed many dynamic changes. Unless wefind ways to increase the competitiveness of the regionalbean sub-sector, Central American countries will likelyexperience significant negative social and economic impacts,especially since these countries are facing the challenge ofadjusting to new open markets, such as the Central AmericanFree Trade Agreement (CAFTA). Bean traders, retailers, andknowledgeable government official in C...

  1. [UV-induced DNA mutation of peach aphid].

    Science.gov (United States)

    Du, Erxia; Guo, Jianwen; Zhao, Huiyan

    2006-07-01

    By using PCR technique and microsatellite marks, this paper studied the DNA polymorphism of peach aphid (Myzus persicae) under UV-radiation. The fragments of three primers were amplified, and the gene diversity and the rate of loci polymorphisms of their genomic DNA, which could reflect the damage degree of DNA after UV-radiation, were measured. The results revealed that after treated with different radiation intensity (15, 30, 45 W) and duration (2, 4, 6 h) , the UV-induced DNA mutations were genetic and could be delivered to F2 generation. The mutations depended on the interaction of radiation intensity and duration. Variance analysis on the gene diversity and the rate of loci polymorphisms showed that there existed a significant difference between UV-treated and control groups, except the rate of loci polymorphisms under 2 h radiation. The average value of the control was higher than that of 2 h radiation treatment. According to the cluster analysis of the genetic distance, the aphids were divided into three groups, i. e., control group, 2 h (15, 30 W) treatment group, and the other, which was consistent with the result of variance analysis.

  2. Testing of Toxicity to Broadbean Aphids by Two Chloronicotinyl Insecticides with Different Treatment Methods%2种氯化烟碱类杀虫剂不同处理方法对蚕豆蚜的毒力测定研究

    Institute of Scientific and Technical Information of China (English)

    斯哲人; 王在林; 姚安庆

    2015-01-01

    为了明确杀虫剂毒力与其测定方法间的关系,选取蚕豆蚜为试验对象分别采用浸渍法、离体喷雾法和连续浸液法测定噻虫嗪和呋虫胺的毒力.结果表明,噻虫嗪浸渍法和连续浸液法对蚕豆蚜的毒力显著高于离体喷雾法;呋虫胺浸渍法对蚕豆蚜的毒力显著高于离体喷雾法和连续浸液法.由此可知,同种药剂不同测定方法与其毒力的表达结果具有显著的相关性.%In order to clarify the relationship between the toxicity of insecticides and its determination method, the paper selected the aphid virulence as experimental objects using the immersion, isolated spray method and continuous infusion method for the determination of thiamethoxam and dinotefuran.Results showed that the virulence of thiamethoxam impregnation method and continuous immersion method of broad bean aphid was significantly higher than that in vitro spray method.Virulence dinotefuran impregnation on the broad bean aphid was significantly higher than that in vitro spray method and continuous immersion method.Therefore, the same medicament different vulence methods and expression of pesticide toxicity results had significant correlation.

  3. The impact of clonal mixing on the evolution of social behaviour in aphids.

    Science.gov (United States)

    Bryden, John; Jansen, Vincent A A

    2010-06-07

    Reports of substantial clonal mixing measured in social aphid colonies seem, on the face of it, to rule out population structure as an explanation of this enigmatic insect's social behaviour. To clarify how selection operates in aphids, and to disentangle direct and indirect fitness components, we present a model of the life cycle of a typical colony-dwelling aphid. The model incorporates ecological factors and includes a trade-off between investing in social behaviour and investing in reproduction. Our focus on inclusive fitness contrasts with previous approaches that optimize colony output. Through deriving a variant of Hamilton's rule, we show that a simple relationship can be established between the patch-carrying capacity and immigration rates into patches. Our results indicate that the levels of clonal mixing reported are not inconsistent with social behaviour. We discuss our model in terms of the evolutionary origins of social behaviour in aphids.

  4. Natural enemies of woolly apple aphid (Hemiptera: Aphididae) in Washington State.

    Science.gov (United States)

    Gontijo, Lessando M; Cockfield, Stephen D; Beers, Elizabeth H

    2012-12-01

    Woolly apple aphid, Eriosoma lanigerum (Hausmann), has become a pest of increasing importance in Washington apple orchards in the past decade. The increase in aphid outbreaks appears to be associated with changes in pesticide programs and disruption of biological control. We sampled woolly apple aphid colonies in central Washington apple orchards for natural enemies of this pest from 2006 to 2008. The most common predators encountered were Syrphidae (Syrphus opinator Osten Sacken, Eupeodes fumipennis Thomson, and Eupeodes americanus Wiedemann); Chrysopidae (Chrysopa nigricornis Burmeister); and Coccinellidae (Coccinella transversoguttata Brown and Hippodamia convergens Guérin-Méneville). The specialist syrphid Heringia calcarata Loew was recorded for the first time occurring in Washington apple orchards. The only parasitoid found in aerial colonies of woolly apple aphid was Aphelinus mali Haldeman; root colonies, however, were not parasitized. Identification of important natural enemies provides a better basis for conservation biological control of this pest.

  5. Foraging behaviour at the fourth tropic level: a comparative study of host location in aphid hyperparasitoids

    NARCIS (Netherlands)

    Buitenhuis, R.; Vet, L.E.M.; Boivin, G.; Brodeur, J.

    2005-01-01

    In studies of foraging behaviour in a multitrophic context, the fourth trophic level has generally been ignored. We used four aphid hyperparasitoid species: Dendrocerus carpenteri (Curtis) (Hymenoptera: Megaspilidae), Asaphes suspensus Walker (Hymenoptera: Pteromalidae), Alloxysta victrix (Westwood)

  6. Foraging behaviour at the fourth tropic level: a comparative study of host location in aphid hyperparasitoids

    NARCIS (Netherlands)

    Buitenhuis, R.; Vet, L.E.M.; Boivin, G.; Brodeur, J.

    2005-01-01

    In studies of foraging behaviour in a multitrophic context, the fourth trophic level has generally been ignored. We used four aphid hyperparasitoid species: Dendrocerus carpenteri (Curtis) (Hymenoptera: Megaspilidae), Asaphes suspensus Walker (Hymenoptera: Pteromalidae), Alloxysta victrix (Westwood)

  7. Foraging behaviour at the fourth trophic level: a comparative study of host location in aphid hyperparasitoids

    NARCIS (Netherlands)

    Buitenhuis, R.; Vet, L.E.M.; Boivin, G.; Brodeur, J.

    2005-01-01

    In studies of foraging behaviour in a multitrophic context, the fourth trophic level has generally been ignored. We used four aphid hyperparasitoid species: Dendrocerus carpenteri (Curtis) (Hymenoptera: Megaspilidae), Asaphes suspensus Walker (Hymenoptera: Pteromalidae), Alloxysta victrix (Westwood)

  8. First survey on ecological host range of aphid pathogenic fungi (Phylum Entomophthoromycota) in Tunisia

    DEFF Research Database (Denmark)

    Ben Fekih, Ibtissem; Boukhris-Bouhachem, Sonia; Allagui, Mohamed Bechir;

    2015-01-01

    sites belonging to three different bioclimatic zones. Four pathogens from the phylum Entomophthoromycota were found to occur naturally in Tunisian ecosystems: Pandora neoaphidis (Entomophthorales: Entomophthoraceae), Entomophthora planchoniana (Entomophthorales: Entomophthoraceae), Conidiobolus obscurus...... (Entomophthorales: Ancylistaceae) and Neozygites fresenii (Neozygitales: Neozygitaceae). The occurrence of entomophthoralean fungi depended on the sampling area, the bioclimatic zone, and aphid species. P. neoaphidis and E. planchoniana were the predominant pathogens infecting a wide range of aphid species whereas...

  9. Resistance of Wild Solanum Accessions to Aphids and Other Potato Pests in Quebec Field Conditions

    OpenAIRE

    Fréchette, B.; Bejan, M.; Lucas, É.; Giordanengo, P.; Vincent, C

    2010-01-01

    Two experiments were done to determine the susceptibility of six wild potato accessions to the aphids Macrosiphum euphorbiae (Thomas) (Hemiptera: Aphididae) and Myzus persicae (Sulzer). Densities of aphid colonies were compared between caged Solanum pinnatisectum Dunal (Solanales: Solanaceae), S. polyadenium Greenmam, S. tarijense Hawkes, S. infundibuliforme Philippi, S. oplocense Hawkes, and S. stoloniferum Schlechted and Bouché, and the commercially cultivated potato plant S. tuberosum L. c...

  10. Water stress and aphid feeding differentially influence metabolite composition in Arabidopsis thaliana (L..

    Directory of Open Access Journals (Sweden)

    Inga Mewis

    Full Text Available Little is known about how drought stress influences plant secondary metabolite accumulation and how this affects plant defense against different aphids. We therefore cultivated Arabidopsis thaliana (L. plants under well-watered, drought, and water-logged conditions. Two aphid species were selected for this study: the generalist Myzus persicae (Sulzer and the crucifer specialist Brevicoryne brassicae (L.. Metabolite concentrations in the phloem sap, which influence aphid growth, changed particularly under drought stress. Levels of sucrose and several amino acids, such as glutamic acid, proline, isoleucine, and lysine increased, while concentrations of 4-methoxyindol-3-ylmethyl glucosinolate decreased. M. persicae population growth was highest on plants under drought stress conditions. However, B. brassicae did not profit from improved phloem sap quality under drought stress and performed equally in all water treatments. Water stress and aphids generally had an opposite effect on the accumulation of secondary metabolites in the plant rosettes. Drought stress and water-logging led to increased aliphatic glucosinolate and flavonoid levels. Conversely, aphid feeding, especially of M. persicae, reduced levels of flavonoids and glucosinolates in the plants. Correspondingly, transcript levels of aliphatic biosynthetic genes decreased after feeding of both aphid species. Contrary to M. persicae, drought stress did not promote population growth of B. brassicae on these plants. The specialist aphid induced expression of CYP79B2, CYP79B3, and PAD3 with corresponding accumulation of indolyl glucosinolates and camalexin. This was distinct from M. persicae, which did not elicit similarly strong camalexin accumulation, which led to the hypothesis of a specific defense adaptations against the specialist aphid.

  11. The cellular immune response of the pea aphid to foreign intrusion and symbiotic challenge.

    Directory of Open Access Journals (Sweden)

    Antonin Schmitz

    Full Text Available Recent studies suggest that the pea aphid (Acyrthosiphon pisum has low immune defenses. However, its immune components are largely undescribed, and notably, extensive characterization of circulating cells has been missing. Here, we report characterization of five cell categories in hemolymph of adults of the LL01 pea aphid clone, devoid of secondary symbionts (SS: prohemocytes, plasmatocytes, granulocytes, spherulocytes and wax cells. Circulating lipid-filed wax cells are rare; they otherwise localize at the basis of the cornicles. Spherulocytes, that are likely sub-cuticular sessile cells, are involved in the coagulation process. Prohemocytes have features of precursor cells. Plasmatocytes and granulocytes, the only adherent cells, can form a layer in vivo around inserted foreign objects and phagocytize latex beads or Escherichia coli bacteria injected into aphid hemolymph. Using digital image analysis, we estimated that the hemolymph from one LL01 aphid contains about 600 adherent cells, 35% being granulocytes. Among aphid YR2 lines differing only in their SS content, similar results to LL01 were observed for YR2-Amp (without SS and YR2-Ss (with Serratia symbiotica, while YR2-Hd (with Hamiltonella defensa and YR2(Ri (with Regiella insecticola had strikingly lower adherent hemocyte numbers and granulocyte proportions. The effect of the presence of SS on A. pisum cellular immunity is thus symbiont-dependent. Interestingly, Buchnera aphidicola (the aphid primary symbiont and all SS, whether naturally present, released during hemolymph collection, or artificially injected, were internalized by adherent hemocytes. Inside hemocytes, SS were observed in phagocytic vesicles, most often in phagolysosomes. Our results thus raise the question whether aphid symbionts in hemolymph are taken up and destroyed by hemocytes, or actively promote their own internalization, for instance as a way of being transmitted to the next generation. Altogether, we

  12. Foliar aphid feeding recruits rhizosphere bacteria and primes plant immunity against pathogenic and non-pathogenic bacteria in pepper.

    Science.gov (United States)

    Lee, Boyoung; Lee, Soohyun; Ryu, Choong-Min

    2012-07-01

    Plants modulate defence signalling networks in response to different biotic stresses. The present study evaluated the effect of a phloem-sucking aphid on plant defence mechanisms in pepper (Capsicum annuum) during subsequent pathogen attacks on leaves and rhizosphere bacteria on roots. Plants were pretreated with aphids and/or the chemical trigger benzothiadiazol (BTH) 7 d before being challenged with two pathogenic bacteria, Xanthomonas axonopodis pv. vesicatoria (Xav) as a compatible pathogen and X. axonopodis pv. glycines (Xag) as an incompatible (non-host) pathogen. Disease severity was noticeably lower in aphid- and BTH + aphid-treated plants than in controls. Although treatment with BTH or aphids alone did not affect the hypersensitive response (HR) against Xag strain 8ra, the combination treatment had a synergistic effect on the HR. The aphid population was reduced by BTH pretreatment and by combination treatment with BTH and bacterial pathogens in a synergistic manner. Analysis of the expression of the defence-related genes Capsicum annum pathogenesis-related gene 9 (CaPR9), chitinase 2 (CaCHI2), SAR8·2 and Lipoxygenase1 (CaLOX1) revealed that aphid infestation resulted in the priming of the systemic defence responses against compatible and incompatible pathogens. Conversely, pre-challenge with the compatible pathogen Xav on pepper leaves significantly reduced aphid numbers. Aphid infestation increased the population of the beneficial Bacillus subtilis GB03 but reduced that of the pathogenic Ralstonia solanacearum SL1931. The expression of defence-related genes in the root and leaf after aphid feeding indicated that the above-ground aphid infestation elicited salicylic acid and jasmonic acid signalling throughout the whole plant. The findings of this study show that aphid feeding elicits plant resistance responses and attracts beneficial bacterial populations to help the plant cope with subsequent pathogen attacks.

  13. High-throughput phenotyping of plant resistance to aphids by automated video tracking.

    Science.gov (United States)

    Kloth, Karen J; Ten Broeke, Cindy Jm; Thoen, Manus Pm; Hanhart-van den Brink, Marianne; Wiegers, Gerrie L; Krips, Olga E; Noldus, Lucas Pjj; Dicke, Marcel; Jongsma, Maarten A

    2015-01-01

    Piercing-sucking insects are major vectors of plant viruses causing significant yield losses in crops. Functional genomics of plant resistance to these insects would greatly benefit from the availability of high-throughput, quantitative phenotyping methods. We have developed an automated video tracking platform that quantifies aphid feeding behaviour on leaf discs to assess the level of plant resistance. Through the analysis of aphid movement, the start and duration of plant penetrations by aphids were estimated. As a case study, video tracking confirmed the near-complete resistance of lettuce cultivar 'Corbana' against Nasonovia ribisnigri (Mosely), biotype Nr:0, and revealed quantitative resistance in Arabidopsis accession Co-2 against Myzus persicae (Sulzer). The video tracking platform was benchmarked against Electrical Penetration Graph (EPG) recordings and aphid population development assays. The use of leaf discs instead of intact plants reduced the intensity of the resistance effect in video tracking, but sufficiently replicated experiments resulted in similar conclusions as EPG recordings and aphid population assays. One video tracking platform could screen 100 samples in parallel. Automated video tracking can be used to screen large plant populations for resistance to aphids and other piercing-sucking insects.

  14. Expression profiling of selected glutathione transferase genes in Zea mays (L.) seedlings infested with cereal aphids.

    Science.gov (United States)

    Sytykiewicz, Hubert; Chrzanowski, Grzegorz; Czerniewicz, Paweł; Sprawka, Iwona; Łukasik, Iwona; Goławska, Sylwia; Sempruch, Cezary

    2014-01-01

    The purpose of this report was to evaluate the expression patterns of selected glutathione transferase genes (gst1, gst18, gst23 and gst24) in the tissues of two maize (Zea mays L.) varieties (relatively resistant Ambrozja and susceptible Tasty Sweet) that were colonized with oligophagous bird cherry-oat aphid (Rhopalosiphum padi L.) or monophagous grain aphid (Sitobion avenae L.). Simultaneously, insect-triggered generation of superoxide anion radicals (O2•-) in infested Z. mays plants was monitored. Quantified parameters were measured at 1, 2, 4, 8, 24, 48 and 72 h post-initial aphid infestation (hpi) in relation to the non-infested control seedlings. Significant increases in gst transcript amounts were recorded in aphid-stressed plants in comparison to the control seedlings. Maximal enhancement in the expression of the gst genes in aphid-attacked maize plants was found at 8 hpi (gst23) or 24 hpi (gst1, gst18 and gst24) compared to the control. Investigated Z. mays cultivars formed excessive superoxide anion radicals in response to insect treatments, and the highest overproduction of O2•- was noted 4 or 8 h after infestation, depending on the aphid treatment and maize genotype. Importantly, the Ambrozja variety could be characterized as having more profound increments in the levels of gst transcript abundance and O2•- generation in comparison with the Tasty Sweet genotype.

  15. Java EE 7 development with NetBeans 8

    CERN Document Server

    Heffelfinger, David R

    2015-01-01

    The book is aimed at Java developers who wish to develop Java EE applications while taking advantage of NetBeans functionality to automate repetitive tasks. Familiarity with NetBeans or Java EE is not assumed.

  16. factors influencing smallholder farmers' bean production and supply ...

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    marketing has the potential for raising incomes of the farming households. In the country, bean ... Constraints that affect quantities of beans marketed by farmers include levels of production and .... A multi-stage stratified sampling procedure ...

  17. Potency of Traditional Insecticide Materials against Stored Bean ...

    African Journals Online (AJOL)

    Potency of Traditional Insecticide Materials against Stored Bean Weevil, ... AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING AJOL ... apply traditional insecticide materials in the protection of bean from insect pests.

  18. Small Scale Farmers' Knowledge on Grain Losses from Bean ...

    African Journals Online (AJOL)

    Bruchid, Pesticides Safe Use and Implication on Food .... whether bean bruchids is major pest, how much damage it causes, knowledge of .... The dry bean stored in inadequate environment deteriorates so easily especially in areas where.

  19. Registration of AO-1012-29-3-3A red kidney bean germplasm line with bean weevil, BCMV and BCMNV resistance

    Science.gov (United States)

    Bean common mosaic virus (BCMV) and bean common mosaic necrosis virus (BCMNV) are important seed-borne diseases of dry bean (Phaseolus vulgaris L.) in the Americas and Africa. The bean weevil (Acanthoscelides obtectus Say) is an aggressive post-harvest pest of the common bean. The development of bea...

  20. Alternaria toxin-induced resistance against rose aphids and olfactory response of aphids to toxin-induced volatiles of rose plants

    Institute of Scientific and Technical Information of China (English)

    Fa-zhong YANG; Li LI; Bin YANG

    2012-01-01

    The search for active toxins for managing weeds or plant diseases is believed to be a promising avenue of investigation.However,the effects of Alternaria toxins on insects have just begun to be investigated.Bioactivities of toxins from four strains of Alternaria alternata on Rosa chinensis and rose aphid Macrosiphum rosivorum were tested in the present study.At a concentration of 50.0 μg/ml,the crude extract (toxin) of strain 7484 was found not to be harmful to rose plants with excised leaf-puncture method (P≥0.079),and rose plants showed enhanced resistance to rose aphids when this Alternaria toxin was sprayed on the plants (P≤0.001).However,this toxin caused no detrimental effects on aphids in insecticidal bioassay at a concentration of 10.0 to 160.0 μg/ml (P≥0.096).Therefore,the Alternaria toxin had significantly induced the resistance of rose plants against rose aphids,demonstrating that the resistance mechanism triggered by the Altemaria toxin in the rose plant may also be used by the plant to defend itself against insects.Further bioassays aimed to discover the olfactory responses of aphids to the toxin-induced volatiles of host plants.The aphids were significantly more attracted to both volatiles emitted and collected from control rose plants than to both volatiles emitted and collected from the toxin-treated rose plants (P≤0.014).This result showed that the toxin-induced resistance related to the volatile changes of host plants.

  1. Characterization of the natural enemy community attacking cotton aphid in the Bt cotton ecosystem in Northern China.

    Science.gov (United States)

    Ali, Abid; Desneux, Nicolas; Lu, Yanhui; Liu, Bing; Wu, Kongming

    2016-04-14

    Planting Bt cotton in China since 1997 has led to important changes in the natural enemy communities occurring in cotton, however their specific effect on suppressing the cotton aphids (being notorious in conventional cotton ecosystem) has not been fully documented yet. We observed strong evidence for top-down control of the aphid population, e.g. the control efficiency of natural enemies on cotton aphid increased significantly in open field cages compared to exclusion cages, accounted for 60.2, 87.2 and 76.7% in 2011, 2012 and 2013 season, respectively. The cotton aphid populations peaked in early June to late July (early and middle growth stages) in open field cotton survey from 2011 to 2013. The population densities of cotton aphids and natural enemies were highest on middle growth stage while lowest densities were recorded on late stage for aphids and on early plant stage for natural enemies. Aphid parasitoids (Trioxys spp., Aphidius gifuensis), coccinellids and spiders were key natural enemies of cotton aphid. Briefly, natural enemies can suppress aphid population increase from early to middle plant growth stages by providing biocontrol services in Chinese Bt cotton.

  2. Hoverfly preference for high honeydew amounts creates enemy-free space for aphids colonizing novel host plants.

    Science.gov (United States)

    Vosteen, Ilka; Gershenzon, Jonathan; Kunert, Grit

    2016-09-01

    The existence of an enemy-free space can play an important role in aphid host race formation processes, but little is known about the mechanisms that create an area of low predation pressure on particular host plants. In this paper, we identify a mechanism generating lower predation pressure that promotes the maintenance of the different host races of the pea aphid (Acyrthosiphon pisum) complex, a well-studied model for ecological speciation. The pea aphid consists of at least 15 genetically distinct host races which are native to specific host plants of the legume family, but can all develop on the universal host plant Vicia faba. Previous work showed that hoverfly (Episyrphus balteatus) oviposition preferences contribute to the enemy-free space that helps to maintain the different pea aphid host races, and that higher amounts of honeydew are more attractive to ovipositing hoverflies. Here we demonstrated that aphid honeydew is produced in large amounts when aphid reproduction rate was highest, and is an important oviposition cue for hoverflies under field conditions. However, on less suitable host plants, where honeydew production is reduced, pea aphids enjoy lower predation rates. A reduction in enemy pressure can mitigate the performance disadvantages of aphids colonizing a novel host and probably plays an important role in pea aphid host race formation.

  3. The effect of plant inbreeding and stoichiometry on interactions with herbivores in nature: Echinacea angustifolia and its specialist aphid.

    Directory of Open Access Journals (Sweden)

    Caroline E Ridley

    Full Text Available Fragmentation of once widespread communities may alter interspecific interactions by changing genetic composition of interacting populations as well as their abundances and spatial distributions. In a long-term study of a fragmented population of Echinacea angustifolia, a perennial plant native to the North American prairie, we investigated influences on its interaction with a specialist aphid and tending ants. We grew plant progeny of sib-matings (I, and of random pairings within (W and between (B seven remnants in a common field within 8 km of the source remnants. During the fifth growing season, we determined each plant's burden of aphids and ants, as well as its size and foliar elemental composition (C, N, P. We also assayed composition (C, N of aphids and ants. Early in the season, progeny from genotypic classes B and I were twice as likely to harbor aphids, and in greater abundance, than genotypic class W; aphid loads were inversely related to foliar concentration of P and positively related to leaf N and plant size. At the end of the season, aphid loads were indistinguishable among genotypic classes. Ant abundance tracked aphid abundance throughout the season but showed no direct relationship with plant traits. Through its potential to alter the genotypic composition of remnant populations of Echinacea, fragmentation can increase Echinacea's susceptibility to herbivory by its specialist aphid and, in turn, perturb the abundance and distribution of aphids.

  4. Effects of Wildflower Strips and an Adjacent Forest on Aphids and Their Natural Enemies in a Pea Field

    Directory of Open Access Journals (Sweden)

    Séverin Hatt

    2017-09-01

    Full Text Available Landscape diversification is a key element for the development of sustainable agriculture. This study explores whether the implementation of habitats for pest natural enemies enhances conservation biological control in an adjacent field. In the present study conducted in Gembloux (Belgium in 2016, the effect of two different habitats (wildflower strips and a forest and aphid abundance on the density of aphid natural enemies, mummified aphids and parasitism on pea plants was assessed through visual observations. The effect of the habitats on aphids was also evaluated. The habitats but not aphid density significantly affected hoverfly larvae, which were more abundant adjacent to wildflower strips than to the forest. The contrary was observed for ladybeetle adults, which were positively related with aphids but not affected by the adjacent habitats. The abundance of mummies and the parasitism rate were significantly affected by both the habitats and aphid density. They were both significantly enhanced adjacent to wildflower strips compared to the forest, but the total parasitism rate was low (<1%, questioning whether parasitoids could significantly control aphids on the pea crop. As for the aphids, their abundance was not significantly affected by the adjacent habitats. These results are discussed with respect to the potential of these habitats to provide overwintering sites and food resources for natural enemies, and thereby enhance conservation biological control.

  5. Effect of cooking methods on selected physicochemical and nutritional properties of barlotto bean, chickpea, faba bean, and white kidney bean.

    Science.gov (United States)

    Güzel, Demet; Sayar, Sedat

    2012-02-01

    The effects of atmospheric pressure cooking (APC) and high-pressure cooking (HPC) on the physicochemical and nutritional properties of barlotto bean, chickpea, faba bean, and white kidney bean were investigated. The hardness of the legumes cooked by APC or HPC were not statistically different (P > 0.05). APC resulted in higher percentage of seed coat splits than HPC. Both cooking methods decreased Hunter "L" value significantly (P < 0.05). The "a" and "b" values of dark-colored seeds decreased after cooking, while these values tended to increase for the light-colored seeds. The total amounts of solid lost from legume seeds were higher after HPC compared with APC. Rapidly digestible starch (RDS) percentages increased considerably after both cooking methods. High pressure cooked legumes resulted in higher levels of resistant starch (RS) but lower levels of slowly digestible starch (SDS) than the atmospheric pressure cooked legumes.

  6. An annotated checklist of the Aphids (Hemiptera: Aphidomorpha of Poland

    Directory of Open Access Journals (Sweden)

    Wojciechowski Wacław

    2015-12-01

    Full Text Available The paper presents a comprehensive compilation of 764 taxa (species and subspecies, distributed over 167 genera, belonging to 17 subfamilies, three families and three superfamilies of Aphidomorpha recorded to date from Poland. The systematic positions of 19 taxa have been revised in accordance with recent changes in nomenclature. The presence in the Polish aphidofauna of Drepanosiphum oregonensis and Coloradoa huculaki, previously included without any distribution data in checklists of Polish aphids, has been confirmed. One species Sitobion (Sitobion alopecuri is recognized as being new to Poland. At least 44 species (6% of local fauna of Aphidomorpha are alien to Poland; among them 11 species collected from plants imported or cultivated in indoor conditions are listed.

  7. Blanching of green bean (Phaseolus vulgaris).

    Science.gov (United States)

    Kaack, K

    1994-12-01

    Experiments with one and two steps blanching of green beans have been carried out. Inactivation of the peroxydase requires more heating than inactivation of the enzymes which gives rise to off flavour from aldehydes. When blanching for about one minute to inactivate lipoxygenase, aldehyde formation of flavour ceases. The content of vitamin C decreases during blanching according to a first order reaction. Since considerable loss of vitamin C occurs during blanching, the treatment time should be reduced to a minimum. During preblanching at 65-75 degrees C and final blanching, chlorophyll is degraded to pheophytin and the surface colour expressed by the Hunter-values (-a/b) increases with time which means that the colour of the beans changes from green to yellow. The firmness of beans, which was measured by use of a tenderometer, decreases during blanching according to a first order reaction with 40 kcal/mole activation energy. Preblanching at 65-75 degrees C increases the firmness of the beans linearly with treatment time. This increase in firmness is stable after final blanching at 95 degrees C and even after thawing of frozen beans.

  8. Outbreaks of Chrysodeixis includens (Walker (Lepidoptera: Noctuidae in common bean and castor bean in São Paulo State, Brazil

    Directory of Open Access Journals (Sweden)

    Edson Luiz Lopes Baldin

    2014-12-01

    Full Text Available Since 2009, increasing populations of Chrysodeixis includens (Walker (Lepidoptera: Noctuidae have been observed in cultivated common bean (Phaseolus vulgaris L. and castor bean (Ricinus communis L. at the Lageado Experimental Farm, belonging to the FCA/UNESP, Botucatu, São Paulo State, Brazil. Defoliations around 80% and 50% were observed in the common bean cv. Pérola and castor bean cv. IAC-2028, respectively. Samples of individuals (caterpillars and pupae were collected in the field, and kept in laboratory until adult emergence aiming to confirm the species. These are new observations for common bean in São Paulo State and, in the case of castor bean, unpublished in Brazil. It suggests that C. includens has adapted to attack other agricultural crops, demanding attention of common bean and castor bean producers.

  9. New bean seeds and the struggle for their dissemination

    NARCIS (Netherlands)

    Almekinders, C.J.M.; Aguilar, E.; Herrera, R.

    2007-01-01

    The northern region of Nicaragua has always been an important bean and maize producing area. But a widespread presence of the Golden Mosaic Virus made it impossible to grow beans in the last years. A Participatory Plant Breeding programme started in 1999, aiming to develop new bean varieties that

  10. Effect of hydrocolloids on functional properties of navy bean starch

    Science.gov (United States)

    The effects of hydrocolloid replacement on the pasting properties of navy bean starch and on the properties of navy bean starch gels were studied. Navy bean starch was isolated, and blends were prepared with beta-glucan, guar gum, pectin and xanthan gum solutions. The total solids concentration was ...

  11. Effects of fermented soya bean on digestion, absorption and diarrhoea

    NARCIS (Netherlands)

    Kiers, J.L.

    2001-01-01

    For many centuries Asian people have consumed soya beans in various forms of traditional fermented soya bean foods. Major desirable aspects of fermented soya bean foods are their attractive flavour and texture, certain nutritional properties, and possible health promoting effects. This study describ

  12. 9 CFR 319.301 - Chili con carne with beans.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Chili con carne with beans. 319.301 Section 319.301 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... Dehydrated Meat Food Products § 319.301 Chili con carne with beans. Chili con carne with beans shall...

  13. New bean seeds and the struggle for their dissemination

    NARCIS (Netherlands)

    Almekinders, C.J.M.; Aguilar, E.; Herrera, R.

    2007-01-01

    The northern region of Nicaragua has always been an important bean and maize producing area. But a widespread presence of the Golden Mosaic Virus made it impossible to grow beans in the last years. A Participatory Plant Breeding programme started in 1999, aiming to develop new bean varieties that wo

  14. Effects of fermented soya bean on digestion, absorption and diarrhoea

    NARCIS (Netherlands)

    Kiers, J.L.

    2001-01-01

    For many centuries Asian people have consumed soya beans in various forms of traditional fermented soya bean foods. Major desirable aspects of fermented soya bean foods are their attractive flavour and texture, certain nutritional properties, and possible health promoting effects. This

  15. Evaluation of the reaction oof interspecific hybrids of common bean and tepary bean to Bradyrhizobium y Rhizobium

    Science.gov (United States)

    Interspecific hybrids between common bean, Phaseolus vulgaris L., and tepary bean, Phaseolus acutifolius A. Gray, have the potential to increase bean production in regions where rainfall is limited. In 2014, an experiment was initiated using a split-plot design. The treatments included inoculation, ...

  16. 76 FR 16700 - Importation of French Beans and Runner Beans From the Republic of Kenya Into the United States

    Science.gov (United States)

    2011-03-25

    ... individual beans. We would require the beans to be inspected by the Kenyan NPPO and found to be free of..., primarily to the European Union (EU). The EU provides a well-established market and it is unlikely that there would be a large diversion of French bean exports by Kenya from this market to the United...

  17. Impacto do algodoeiro Bt na dinâmica populacional do pulgão-do-algodoeiro em casa de vegetação Impact of Bt cotton on the population dynamics of the cotton aphid in greenhouse

    Directory of Open Access Journals (Sweden)

    Edison Ryoiti Sujii

    2008-10-01

    Full Text Available O objetivo deste trabalho foi desenvolver um protocolo experimental para avaliar o impacto do algodoeiro Bt na bionomia e na escolha de plantas para colonização pelo pulgão-do-algodoeiro (Aphis gossypii. A bionomia do pulgão foi avaliada em casa de vegetação com insetos criados em gaiolas individuais com plantas de algodão Bt, da variedade DP 404 BG (Bollgard, ou sua isolinha não transformada DP 4049. Gaiolas contendo vasos com plantas de algodoeiro Bt e não-Bt foram usadas como arena de escolha, para a avaliação de preferência de adultos alados. O período pré-reprodutivo e reprodutivo, a longevidade, a curva de sobrevivência, a produção de prole total e diária por fêmea e a curva acumulada de produção de prole da população não apresentaram diferenças significativas. Não foi observada diferença na escolha de plantas para colonização por indivíduos alados, o que indica taxas equivalentes de colonização nas populações iniciais. O algodoeiro Bt não afeta a dinâmica populacional de A. gossypii e não aumenta seu potencial de risco como praga.The objective of this work was to develop an experimental protocol to assess the impact of Bt cotton on bionomics and on plant choice for Aphis gossypii colonization. The bionomics of the cotton aphid was assessed in greenhouse with insects reared in individual cages containing Bt cotton plants of the variety DP 404 BG (Bollgard or its nontransformed isoline DP 4049. Cages with Bt cotton and non-Bt cotton were used as choosing arena for evaluation of winged adults preference. There was no significant difference for pre-reproduction period (immature phase, reproduction period, longevity, survivorship curve total and daily production of offspring by female, and curve of accumulated production of offspring by the population. There was no preference of colonization for any plant by winged adults, which indicates equivalent rates of colonization of the initial populations. Bt

  18. CO2浓度变化下蚜茧蜂胁迫作用对多世代棉蚜适合度的影响%Response of three successive generations of aphids to stress from Lysiphlebia japonica Ashmead under ambient CO2 and elevated CO2

    Institute of Scientific and Technical Information of China (English)

    李姣; 龙大彬; 肖铁光

    2013-01-01

    The effects of two levels of CO2 (375 μL/L VS 750 μL/L) on the cotton-Aphis gossypii-Lysiphlebiajaponica system were studied using OTCs.We evaluated the influence of direct and indirect stress from L.japonica on the fitness response of aphids to changing CO2 for three successive generations.We wished to show whether CO2 levels,generation and L.japonica-stress markedly determined the fecundity,net reproduction,mean generation time and intrinsic rate of increase in cotton aphids,and whether interactions between these variables also had a notable impact on the fecundity,net reproduction,and intrinsic rate of increase of aphids.Our results suggest that the stress induced by exposure to caged L.japonica had greater impact on the fitness and population dynamics of successive generations of A.gossypii under elevated CO2,resulting in a lower aphid-population.%本文以蚜茧蜂Lysiphlebia japonica Ashmead与棉蚜Aphis gossypii Glover系统为研究对象,以内禀增长率rm作为适合度指标,通过开顶式动态CO2气室(OTC),重点比较了目前大气CO2浓度与未来加倍的大气CO2浓度下(375 μL/L VS 750 μL/L)直接放入蚜茧蜂、笼罩间接放入蚜茧蜂的胁迫作用对不同世代和3个连续世代棉蚜适合度的影响.结果表明:CO2浓度变化、世代之间、寄生胁迫方式对棉蚜净繁殖率R0、平均世代时间T和内禀增长率rm均存在着极显著的影响;CO2浓度变化和寄生胁迫方式之间、CO2浓度变化和棉蚜发生世代之间的交互作用对棉蚜净繁殖率R0和内禀增长率rm也存在着极显著的影响.结果提示:大气CO2浓度将通过影响寄生蜂的间接干扰作用,从而影响棉蚜的适合度和种群动态,使棉蚜种群有下降的趋势.

  19. Pest control of aphids depends on landscape complexity and natural enemy interactions

    Directory of Open Access Journals (Sweden)

    Emily A. Martin

    2015-07-01

    Full Text Available Aphids are a major concern in agricultural crops worldwide, and control by natural enemies is an essential component of the ecological intensification of agriculture. Although the complexity of agricultural landscapes is known to influence natural enemies of pests, few studies have measured the degree of pest control by different enemy guilds across gradients in landscape complexity. Here, we use multiple natural-enemy exclosures replicated in 18 fields across a gradient in landscape complexity to investigate (1 the strength of natural pest control across landscapes, measured as the difference between pest pressure in the presence and in the absence of natural enemies; (2 the differential contributions of natural enemy guilds to pest control, and the nature of their interactions across landscapes. We show that natural pest control of aphids increased up to six-fold from simple to complex landscapes. In the absence of pest control, aphid population growth was higher in complex than simple landscapes, but was reduced by natural enemies to similar growth rates across all landscapes. The effects of enemy guilds were landscape-dependent. Particularly in complex landscapes, total pest control was supplied by the combined contribution of flying insects and ground-dwellers. Birds had little overall impact on aphid control. Despite evidence for intraguild predation of flying insects by ground-dwellers and birds, the overall effect of enemy guilds on aphid control was complementary. Understanding pest control services at large spatial scales is critical to increase the success of ecological intensification schemes. Our results suggest that, where aphids are the main pest of concern, interactions between natural enemies are largely complementary and lead to a strongly positive effect of landscape complexity on pest control. Increasing the availability of seminatural habitats in agricultural landscapes may thus benefit not only natural enemies, but also the

  20. Pest control of aphids depends on landscape complexity and natural enemy interactions.

    Science.gov (United States)

    Martin, Emily A; Reineking, Björn; Seo, Bumsuk; Steffan-Dewenter, Ingolf

    2015-01-01

    Aphids are a major concern in agricultural crops worldwide, and control by natural enemies is an essential component of the ecological intensification of agriculture. Although the complexity of agricultural landscapes is known to influence natural enemies of pests, few studies have measured the degree of pest control by different enemy guilds across gradients in landscape complexity. Here, we use multiple natural-enemy exclosures replicated in 18 fields across a gradient in landscape complexity to investigate (1) the strength of natural pest control across landscapes, measured as the difference between pest pressure in the presence and in the absence of natural enemies; (2) the differential contributions of natural enemy guilds to pest control, and the nature of their interactions across landscapes. We show that natural pest control of aphids increased up to six-fold from simple to complex landscapes. In the absence of pest control, aphid population growth was higher in complex than simple landscapes, but was reduced by natural enemies to similar growth rates across all landscapes. The effects of enemy guilds were landscape-dependent. Particularly in complex landscapes, total pest control was supplied by the combined contribution of flying insects and ground-dwellers. Birds had little overall impact on aphid control. Despite evidence for intraguild predation of flying insects by ground-dwellers and birds, the overall effect of enemy guilds on aphid control was complementary. Understanding pest control services at large spatial scales is critical to increase the success of ecological intensification schemes. Our results suggest that, where aphids are the main pest of concern, interactions between natural enemies are largely complementary and lead to a strongly positive effect of landscape complexity on pest control. Increasing the availability of seminatural habitats in agricultural landscapes may thus benefit not only natural enemies, but also the effectiveness of

  1. [Obtainment of transgenic wheat with the insecticidal lectin from snowdrop (Galanthus nivalis agglutinin; GNA) gene and analysis of resistance to aphid].

    Science.gov (United States)

    Liang, Hui; Zhu, Yin-Feng; Zhu, Zhen; Sun, Dong-Fa; Jia, Xu

    2004-02-01

    Snowdrop lectin (Galanthus nivalis agglutinin; GNA) is toxic to sap sucking injurious insects of Homopteran. A new gna gene has been transferred into common spring wheat Zhong60634 and winter wheat Yumai66 with high yield by using the biolistic transformation method. Transgenic wheat plants have been obtained in both of the two varieties. Two transgenic plants (T0) have been obtained from the bombarded 535 immature embryos of Zhong60634. Bioassay results show that the development of aphid could be slowed down and the survival rate of young aphid could be reduced by gna gene. Seventeen transgenic plants (T0) were obtained from the bombarded 4636 immature embryos of Yumai66. Twenty plantlets with good resistance to Rhopalosiphum padi and Macrosiphum avenae, which are mainly aphid in north wheat area, were identified from the transgenic plants of T1 generation that came from 8 T0 transgenic plants with good resistance to aphid. The anti-aphid bioassay shows that resistance to the different grain aphid is not the same in transgenic wheat plants. To Rhopalosiphum padi, the rate of survival aphid 8 days after exposing transgenic plants to aphids is significantly lower than that of nontransgenic plants. To Macrosiphum avenae, growth speed of aphids is slowed down but not killed. At the same time, the death rate of young aphids is increased. Anyway, feeding of the two kinds of aphids has been controlled in a certain degree by gna gene when aphids can free to move in plants.

  2. First report of Pandora neoaphidis resting spore formation in vivo in aphid hosts

    DEFF Research Database (Denmark)

    Clara Scorsetti, Ana; Jensen, Annette Bruun; Lopez Lastra, Claudia

    2012-01-01

    The entomopathogenic fungus Pandora neoaphidis is a recognized pathogen of aphids, causes natural epizootics in aphid populations, and interacts and competes with aphid predators and parasitoids. Survival of entomophthoralean fungi in periods of unsuitable weather conditions or lack of appropriat...... is the first gene-based confirmation from either infected hosts or cultures that P. neoaphidis is able to produce resting spores....

  3. Mapping snap bean (Phaseolus vulgaris L.) pod and color traits, in a dry bean x snap bean recombinant inbred population

    Science.gov (United States)

    Snap bean (Phaseolus vulgaris) breeding programs are tasked with developing varieties that meet the standards of the vegetable processing industry and ultimately that of the consumer; all the while matching or exceeding the field performance of existing varieties. While traditional breeding methods ...

  4. Complete genome sequence of bean leaf crumple virus, a novel begomovirus infecting common bean in Colombia.

    Science.gov (United States)

    Carvajal-Yepes, Monica; Zambrano, Leidy; Bueno, Juan M; Raatz, Bodo; Cuellar, Wilmer J

    2017-02-10

    A copy of the complete genome of a novel bipartite begomovirus infecting common bean (Phaseolus vulgaris L.) in Colombia was obtained by rolling-circle amplification (RCA), cloned, and sequenced. The virus is associated with leaf crumple symptoms and significant yield losses in Andean and Mesoamerican beans. Such symptoms have been reported increasingly in Colombia since at least 2002, and we detected the virus in leaf material collected since 2008. Sequence analysis showed that the virus is a member of a distinct species, sharing 81% and 76% nucleotide (nt) sequence identity (in DNA-A and DNA-B, respectively) to other begomoviruses infecting common bean in the Americas. The data obtained support the taxonomic status of this virus (putatively named 'bean leaf crumple virus', BLCrV) as a member of a novel species in the genus Begomovirus.

  5. Preference and performance of the hyperparasitoid Syrphophagus aphidivorus (Hymenoptera: Encyrtidae): fitness consequences of selecting hosts in live aphids or aphid mummies

    NARCIS (Netherlands)

    Buitenhuis, R.; Boivin, G.; Vet, L.E.M.; Brodeur, J.

    2004-01-01

    1. Theoretical models predict that ovipositional decisions of parasitoid females should lead to the selection of the most profitable host for parasitoid development. Most parasitoid species have evolved specific adaptations to exploit a single host stage. However, females of the aphid

  6. Management of the broad bean weevil (Bruchus rufimanus Boh.) in faba bean (Vicia faba L.)

    OpenAIRE

    Roubinet, Eve

    2016-01-01

    Summary Bruchus rufimanus Boh. is a common pest on faba beans (Vicia faba L.) all over Europe and worldwide. The area of faba bean production is increasing in Sweden and in Europe, partly encouraged by the CAP subsidies for legume crops and diversified crop rotations. At the same time, number of the insecticides commonly used against B. rufimanus have been removed from the market as pollinators risk to be harmed as the treatment timing corresponds to crop flowering. In Sweden, only one ins...

  7. 七星瓢虫对刺槐蚜和绣线菊蚜的功能反应%Functional Responses of Ladybirds (Coccinella Septempunctata L. ) to the Aphids:Aphis robiniae macchiati and a citricola vander goot

    Institute of Scientific and Technical Information of China (English)

    王进忠; 王熠; 孙淑玲

    1999-01-01

    试验研究了七星瓢虫对刺槐蚜和绣线菊蚜的捕食功能反应.捕食者与猎物的功能反应均属于HollingⅡ型,经X2测验,其理论值与观察值很接近,说明模拟后的各方程可用来描述瓢虫的功能反应.七星瓢虫对刺槐蚜和绣线菊蚜的理论最大捕食量,三、四龄幼虫明显大于一、二龄幼虫.而且七星瓢虫对不同蚜虫的捕食量有一定的差异.

  8. Using multispectral imagery to compare the spatial pattern of injury to wheat caused by Russian wheat aphid and greenbug

    Science.gov (United States)

    The Russian wheat aphid, Diuraphis noxia (Mordvilko), and greenbug, Schizaphis graminum (Rondani), are important aphid pests of wheat. Outbreaks of both pests in commercial wheat fields occur almost every year in the Great Plains of the United States. Infestations of both pests in wheat fields are...

  9. 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,...

  10. Resistance to a new biotype of the lettuce aphid Nasonovia ribisnigri in Lactuca virosa accession IVT280

    NARCIS (Netherlands)

    Broeke, ten C.J.M.; Dicke, M.; Loon, van J.J.A.

    2013-01-01

    Host plant resistance is an effective protection strategy to control aphids in many crops. However, the evolution of insensitive aphid biotypes necessitates the search for new resistance sources. Wild relatives of crop plants can be important sources for resistance genes to be introgressed into new

  11. Resistance to a new biotype of the lettuce aphid Nasonovia ribisnigri in Lactuca virosa accession IVT280

    NARCIS (Netherlands)

    Broeke, ten C.J.M.; Dicke, M.; Loon, van J.J.A.

    2013-01-01

    Host plant resistance is an effective protection strategy to control aphids in many crops. However, the evolution of insensitive aphid biotypes necessitates the search for new resistance sources. Wild relatives of crop plants can be important sources for resistance genes to be introgressed into new

  12. An update to the adventive aphids (Hemiptera: Aphidoidea) of America north of Mexico, with notes on intercepted species

    Science.gov (United States)

    An update to the list of adventive aphids in North America north of Mexico is provided , including the location and date of first discovery, biogeographic origin, and economically important North American hosts for 24 previously unrecorded species. Additionally, we discuss aphids intercepted at Uni...

  13. Assessment of fennel aphids (Hemiptera: Aphididae) and their predators in fennel intercropped with cotton with colored fibers.

    Science.gov (United States)

    Ramalho, F S; Fernandes, F S; Nascimento, A R B; Nascimento Júnior, J L; Malaquias, J B; Silva, C A D

    2012-02-01

    The fennel aphid, Hyadaphis foeniculi (Passerini) (Hemiptera: Aphididae) is a major pest of fennel, Foeniculum vulgare Miller in northeast region of Brazil. We hypothesize that intercropping can be used as an alternative pest management strategy to reduce aphid yield loss in fennel. Thus, we investigated the severity of fennel plant damage in relation to infestation by the fennel aphid and predation by Cycloneda sanguinea (L.) (Coleoptera: Coccinellidae) (spotless lady beetle), green lacewing, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae), and Scymnus spp. (Coleoptera: Coccinellidae) in sole fennel plots and plots of fennel intercropped with cotton with colored fibers. The fennel aphid populations in nontreated plots were significantly larger in sole fennel plots than in intercropped plots. The highest densities of C. sanguinea, green lacewings and Scymnus spp., associated with the suppression of fennel aphid populations was found in fennel in the intercropping systems. Fennel aphids reduced the fennel seed yield by 80% in the sole fennel plots compared with approximately 30% for all intercropping systems. The results obtained in this research are of practical significance for designing appropriate strategies for fennel aphid control in fennel-cotton intercropping systems. In summary, intercropping fennel with cotton with colored fibers apparently promoted biocontrol of fennel aphid in fennel.

  14. Genetic population structure of sugarcane aphid, Melanaphis sacchari, in sorghum, sugarcane, and Johnsongrass in the continental USA

    Science.gov (United States)

    In 2013, an outbreak of Melanaphis sacchari, the sugarcane aphid, was reported in sorghum in Texas. Although this aphid has been reported in the continental U.S. since the 1920s, its occurrence was limited to Florida and Louisiana sugarcane. In just two years M. sacchari has been reported in almos...

  15. Invertebrate communities in spring wheat and the identification of cereal aphid predators through molecular gut content analysis

    Science.gov (United States)

    Cereal aphid complexes are responsible for reducing wheat production worldwide; however, management against these species is rare in North America. Generalist predators may contribute to reducing cereal aphid numbers and preventing significant damage to crops. A two-year survey identifying the arth...

  16. Modulation of legume defense signaling pathways by native and non-native pea aphid clones

    Directory of Open Access Journals (Sweden)

    Carlos Sanchez-Arcos

    2016-12-01

    Full Text Available The pea aphid (Acyrthosiphon pisum is a complex of at least 15 genetically different host races that are native to specific legume plants, but can all develop on the universal host plant Vicia faba. Despite much research it is still unclear why pea aphid host races (biotypes are able to colonize their native hosts while other host races are not. All aphids penetrate the plant and salivate into plant cells when they test plant suitability. Thus plants might react differently to the various pea aphid host races. To find out whether legume species vary in their defense responses to different pea aphid host races, we measured the amounts of salicylic acid (SA, the jasmonic acid-isoleucine conjugate (JA-Ile, other jasmonate precursors and derivatives, and abscisic acid (ABA in four different species (Medicago sativa, Trifolium pratense, Pisum sativum, V. faba after infestation by native and non-native pea aphid clones of various host races. Additionally, we assessed the performance of the clones on the four plant species. On M. sativa and T. pratense, non-native clones that were barely able to survive or reproduce, triggered a strong SA and JA-Ile response, whereas infestation with native clones led to lower levels of both phytohormones. On P. sativum, non-native clones, which survived or reproduced to a certain extent, induced fluctuating SA and JA-Ile levels, whereas the native clone triggered only a weak SA and JA-Ile response. On the universal host V. faba all aphid clones triggered only low SA levels initially, but induced clone-specific patterns of SA and JA-Ile later on. The levels of the active JA-Ile conjugate and of the other JA-pathway metabolites measured showed in many cases similar patterns, suggesting that the reduction in JA signaling was due to an effect upstream of OPDA. ABA levels were downregulated in all aphid clone-plant combinations and were therefore probably not decisive factors for aphid-plant compatibility. Our results

  17. Effect of Different Aphid I noculation Methods on Aphid Reproduction%不同接蚜方式对烟蚜繁殖效果的影响

    Institute of Scientific and Technical Information of China (English)

    范才银; 张卓; 颜勋锐; 李天艺; 李建华; 黄景崇; 罗井清; 唐海峰; 詹良; 何永秋; 曾惠宇; 安然; 刘亮; 杨会超

    2016-01-01

    利用盆栽成株法、漂浮盘育苗法两种繁蚜方法,研究了挑接法、抹接法、碎片法3种接蚜方式对烟蚜繁蚜效果的影响。结果表明:盆栽成株法繁蚜3种接蚜方式繁蚜速度(繁蚜量)表现为抹接法>碎片法>挑接法;漂浮盘育苗法繁蚜以碎片法接蚜繁蚜效率最好,其次是挑接法,抹接法效果最差。在相同的繁蚜时间里,采用成株法繁蚜的繁蚜量是漂浮盘育苗法的7.85~18.6倍。%The effects of different aphid Inoculation methods on aphid reproduction were studied with planting of potted plant and floating tray seeding methods. The result showed that:when potted planting method was used,the velocity (a-mount)of aphid reproduction was the highest with picking up method,that of wiping off method was the second,and that of fragment method was the third. When floating tray seeding method was used,the velocity (amount)of aphid reproduction was the highest with fragment method,that of picking up method was the second,and that of wiping off method was the third. During the same time of aphid reproduction,the amount of planting of potted plant was 7. 85 -18. 6 times more than that of floating tray seeding method.

  18. Competition for Aphid Prey between Different Lady Beetle Species in a Laboratory Arena

    Directory of Open Access Journals (Sweden)

    Christy Leppanen

    2012-01-01

    Full Text Available Direct competition for aphid prey (Hemiptera: Aphididae was evaluated between and among several lady beetle species (Coleoptera: Coccinellidae. The behavior of three native (Coccinella trifasciata, Coleomegilla maculata, and Hippodamia convergens and four nonnative (Coccinella septempunctata, Harmonia axyridis, Hippodamia variegata, and Propylea quatuordecimpunctata lady beetles was observed in laboratory arenas. The beetles were kept alone, paired with conspecifics or paired with heterospecifics, and presented with potato aphids (Macrosiphum euphorbiae. Harmonia axyridis was the most successful aphid predator in our study, being able to find aphids more quickly and consume more of them compared to most other lady beetle species. It was also by far the most aggressive of the tested species. Coccinella septempunctata, C. trifasciata, and C. maculata generally followed H. axyridis in aphid consumption. Prey discovery, consumption, and aggressive behaviors were dependent on which species were present in the arena. Except for the generally superior H. axyridis, there was no obvious dominance hierarchy among the other tested species and no dichotomy between the native and non-native species. Asymmetric interactions between lady beetle species may affect their abilities to coexist in the same habitat.

  19. Volatiles from Plants Induced by Multiple Aphid Attacks Promote Conidial Performance of Lecanicillium lecanii

    Science.gov (United States)

    Avery, Pasco Bruce; Qasim, Muhammad; Fang, Dalin; Wang, Liande

    2016-01-01

    Herbivore-induced plant volatiles (HIPVs) are clues that help predatory insects search for food. The hypothesis that entomopathogenic fungi, which protect plants, benefit from the release of HIPVs was tested. The plant Arabidopsis thaliana was used as the source of HIPVs. The insect herbivore Lipaphis erysimi (Kaltenbach) was used as the inducer, and the fungal pathogen of the aphid Lecanicillium lecanii was exposed to HIPVs to test our hypothesis. When exposed to aphid-induced A. thaliana volatiles, the mortality of aphids pre-treated with a conidial suspension of L. lecanii, the conidial germination and the appressorial formation were significantly increased compared with the control. The decan-3-ol and 4-methylpentyl isothiocyanate that were detected in the headspace seemed to have positive and negative affection, respectively. Moreover, HIPVs generated from groups of eight aphids per plant promoted significantly increased conidial germination and appressorial formation compared with HIPVs from groups of one, two and four aphids per plant. Our results demonstrated that the pathogenicity of the entomopathogenic fungus L. lecanii was enhanced when exposed to HIPVs and that the HIPVs were affected by the number of insect herbivores that induced them. PMID:26999795

  20. Unravelling mycorrhiza-induced wheat susceptibility to the English grain aphid Sitobion avenae

    Science.gov (United States)

    Simon, Amma L.; Wellham, Peter A. D.; Aradottir, Gudbjorg I.; Gange, Alan C.

    2017-04-01

    Arbuscular mycorrhizal (AM) fungi are root symbionts that can increase or decrease aphid growth rates and reproduction, but the reason by which this happens is unknown. To investigate the underlying mechanisms of this interaction, we examined the effect of AM fungi on the English Grain aphid (Sitobion avenae) development, reproduction, attraction, settlement and feeding behaviour on two naturally susceptible varieties Triticum aestivum (L.) variety Solstice and T. monococcum MDR037, and two naturally resistant lines, T. monococcum MDR045 and MDR049. Mycorrhizal colonisation increased the attractiveness of T. aestivum var. Solstice to aphids, but there was no effect on aphid development on this variety. Using the Electrical Penetration Graph (EPG) technique, we found that mycorrhizal colonisation increased aphid phloem feeding on T. monococcum MDR037 and MDR045, colonisation also increased growth rate and reproductive success of S. avenae on these varieties. Mycorrhizas increased vascular bundle size, demonstrating that these fungi can influence plant anatomy. We discuss if and how this could be related to an enhanced success rate in phloem feeding in two varieties. Overall, we present and discuss how mycorrhizal fungi can affect the feeding behaviour of S. avenae in wheat, inducing susceptibility in a resistant variety.

  1. Annotated expressed sequence tags and xenobiotic detoxification in the aphid Myzus persicae (Sulzer)

    Institute of Scientific and Technical Information of China (English)

    C.C. FIGUEROA; N. PRUNIER-LETERME; C. RISPE; F. SEPULVEDA; E. FUENTES-CONTRERAS; B. SABATER-MUNOZ; J.-C. SIMON; D. TAGU

    2007-01-01

    Aphids (Hemiptera: Aphididae) are phytophagous insects that are importantagricultural pests. The enormous negative economic impacts caused by aphids worldwide arewell known, and are mostly due to their high multiplication rate and the transmission ofphytopathogenic viruses. Aphid management strategies mainly involve chemical treatmentswhich are pollutants and are increasingly inefficient, since aphids have developed multipleinsecticide-resistant mechanisms. Among the most economically important species is thegreen peach aphid Myzuspersicae Sulzer (Aphididae: Macrosiphini), which is able to colonizea wide range of host plants belonging to many different families, and transmits numerous plantviruses. Because of its large prevalence, M. persicae has been the target of massive insecticidetreatments; consequently, it has evolved several insecticide-resistant mechanisms. In thiswork, a collection of expressed genes from M. persicae is presented in order to identify putativegenes involved in xenobiotic detoxification. After cDNA cloning and sequencing, 959expressed sequence tags (EST) were annotated. Most sequences matched known genescorresponded to metabolism proteins (26%), ribosomal proteins (23%) and structural proteins(8%). Among them, several sequences corresponded to proteins putatively involved in sensing,degradation or detoxification of plant xenobiotic products.

  2. Distribution, host plants and natural enemies of sugar beet root aphid (Pemphigus fuscicornis In Slovakia

    Directory of Open Access Journals (Sweden)

    Tóth Peter

    2006-01-01

    Full Text Available During 2003-2004, field surveys were realized to observe the distribution of sugar beet aphid, Pemphigus fuscicornis (K o c h (Sternorrhyncha Pemphigidae in southwestern Slovakia. The research was carried out at 60 different localities with altitudes 112-220 m a. s. l. Sugar beet root aphid was recorded at 30 localities. The aphid was recorded in Slovakia for the first time, but its occurrence was predicted and symptoms and harmfulness overlooked by now. The presence of P. fuscicornis was investigated on roots of various plants from Chenopodiaceae. The most important host plants were various species of lambsquarters (above all Chenopodium album. Furthermore sugar beet (Beta vulgaris provar. altissima, red beet (B. vulgaris provar. conditiva and oraches (Atriplex spp act as host plants. Infestation of sugar beet by P. fuscicornis never exceeded 5% at single locality in Slovakia. Dry and warm weather create presumptions for strong harmfulness. In Slovakia, Chenopodium album is a very important indicator of sugar beet aphid presence allowing evaluation of control requirements. During the study, the larvae of Thaumatomyia glabra (Diptera: Chloropidae were detected as important natural enemies of sugar beet aphid. The species occurred at each location evaluated.

  3. Biological Control of Aphid Using Fungal Culture and Culture Filtrates of Beauveria bassiana.

    Science.gov (United States)

    Kim, Jeong Jun; Jeong, Gayoung; Han, Ji Hee; Lee, Sangyeob

    2013-12-01

    Aphids are one of the most destructive pests in crop production such as pepper, cucumber, and eggplants. The importance of entomopathogenic fungi as alternative pest control agents is increasing. Conidia of entomopathogenic fungi are influenced by environmental conditions, such as temperature and relative humidity, and cause slow and fluctuating mortality. These factors have prevented wider application and use of biocontrol agents. For investigation of means of mitigation of such problems, we conducted bioassays with 47 fungal culture filtrates in order to evaluate the potential of secondary metabolites produced by entomopathogenic fungi for use in aphid control. Among 47 culture filtrates cultured potato dextrose broth, filtrate of Beauveria bassiana Bb08 showed the highest mortality (78%) against green peach aphid three days after treatments. Filtrate of Bb08 cultured in Adamek's medium showed higher toxicity as 100% to third instar nymphs of the aphid compared with seven other filtrates cultured in different broths amended with colloidal chitin or oil. The culture filtrates and fungal cultures from media amended with colloidal chitin or oil had lower control efficacies than filtrates without these additives in three different media. These results indicate that the fungal culture fluid or culture filtrate of B. bassiana Bb08 cultured in Adamek's medium has potential for development as a mycopesticide for aphid control.

  4. Transcriptomic and proteomic analyses of seasonal photoperiodism in the pea aphid

    Directory of Open Access Journals (Sweden)

    Gauthier J-P

    2009-09-01

    Full Text Available Abstract Background Aphid adaptation to harsh winter conditions is illustrated by an alternation of their reproductive mode. Aphids detect photoperiod shortening by sensing the length of the night and switch from viviparous parthenogenesis in spring and summer, to oviparous sexual reproduction in autumn. The photoperiodic signal is transduced from the head to the reproductive tract to change the fate of the future oocytes from mitotic diploid embryogenesis to haploid formation of gametes. This process takes place in three consecutive generations due to viviparous parthenogenesis. To understand the molecular basis of the switch in the reproductive mode, transcriptomic and proteomic approaches were used to detect significantly regulated transcripts and polypeptides in the heads of the pea aphid Acyrthosiphon pisum. Results The transcriptomic profiles of the heads of the first generation were slightly affected by photoperiod shortening. This suggests that trans-generation signalling between the grand-mothers and the viviparous embryos they contain is not essential. By analogy, many of the genes and some of the proteins regulated in the heads of the second generation are implicated in visual functions, photoreception and cuticle structure. The modification of the cuticle could be accompanied by a down-regulation of the N-β-alanyldopamine pathway and desclerotization. In Drosophila, modification of the insulin pathway could cause a decrease of juvenile hormones in short-day reared aphids. Conclusion This work led to the construction of hypotheses for photoperiodic regulation of the switch of the reproductive mode in aphids.

  5. Synthesis of a jojoba bean disaccharide.

    Science.gov (United States)

    Kornienko, A; Marnera, G; d'Alarcao, M

    1998-08-01

    A synthesis of the disaccharide recently isolated from jojoba beans, 2-O-alpha-D-galactopyranosyl-D-chiro-inositol, has been achieved. The suitably protected chiro-inositol unit was prepared by an enantiospecific synthesis from L-xylose utilizing SmI2-mediated pinacol coupling as a key step.

  6. Phenotyping common beans for adaptation to drought

    Directory of Open Access Journals (Sweden)

    Stephen eBeebe

    2013-03-01

    Full Text Available Common beans (Phaseolus vulgaris L. originated in the New World and are the grain legume of greatest production for direct human consumption. Common bean production is subject to frequent droughts in highland Mexico, in the Pacific coast of Central America, in northeast Brazil, and in eastern and southern Africa from Ethiopia to South Africa. This article reviews efforts to improve common bean for drought tolerance, referring to genetic diversity for drought response, the physiology of of drought tolerance mechanisms, and breeding strategies. Different races of common bean respond differently to drought, with race Durango of highland Mexico being a major source of genes. Sister species of P. vulgaris likewise have unique traits, especially P. acutifolius which is well adapted to dryland conditions. Diverse sources of tolerance may have different mechanisms of plant response, implying the need for different methods of phenotyping to recognize the relevant traits. Practical considerations of field management are discussed including: trial planning; water management; and field preparation.

  7. PROCESSING AND UTILIZATION OF AFRICAN LOCUST BEAN ...

    African Journals Online (AJOL)

    User

    Based on the results of the study it can be concluded that locust bean processing is a .... quality if no chemical substances such as wood ash additives as preservatives are added as processing catalysts ..... Plant Food 25. Pp. 245-250. Okafor ...

  8. BEANS GROWN IN AN INTERCROPPING SYSTEM

    African Journals Online (AJOL)

    2002-10-10

    Oct 10, 2002 ... EFFECT OF PLANT POPULATION ON YIELD OF MAI-ZE AND CLIMBING. BEANS GROWN IN .... maize are planted at high and low plant densities, respectively ..... performance of the system be initiated in future. For a relay ...

  9. Epidemiology of bean rust in Ethiopia

    NARCIS (Netherlands)

    Habtu, A.

    1994-01-01

    Field and greenhouse experiments were conducted to study the epidemiology of rust ( Uromyces appendiculatus ) on beans ( Phaseolus vulgaris L.) in Ethiopia. The experiments were conducted under low input conditions reflecting

  10. Phytoalexin Induction in French Bean 1

    Science.gov (United States)

    Dixon, Richard A.; Dey, Prakash M.; Lawton, Michael A.; Lamb, Christopher J.

    1983-01-01

    Treatment of hypocotyl sections or cell suspension cultures of dwarf French bean (Phaseolus vulgaris L.) with an abiotic elicitor (denatured ribonuclease A) resulted in increased extractable activity of the enzyme l-phenylalanine ammonia-lyase. This induction could be transmitted from treated cells through a dialysis membrane to cells which were not in direct contact with the elicitor. In hypocotyl sections, induction of isoflavonoid phytoalexin accumulation was also transmitted across a dialysis membrane, although levels of insoluble, lignin-like phenolic material remained unchanged in elicitor-treated and control sections. In bean cell suspension cultures, the induction of phenylalanine ammonia-lyase in cells separated from ribonuclease-treated cells by a dialysis membrane was also accompanied by increases in the activities of chalcone synthase and chalcone isomerase, two enzymes previously implicated in the phytoalexin defense response. Such intercellular transmission of elicitation did not occur in experiments with cells treated with a biotic elicitor preparation heat-released from the cell walls of the bean pathogen Colletotrichum lindemuthianum. The results confirm and extend previous suggestions that a low molecular weight, diffusible factor of host plant origin is involved (in French bean) in the intercellular transmission of the elicitation response to abiotic elicitors. PMID:16662813

  11. Seed coat darkening in Cowpea bean

    Science.gov (United States)

    Seed coat of cowpea bean (Vigna unguiculata L. Walp) slowly browns to a darker color during storage. High temperature and humidity during storage might contribute to this color change. Variation in browning rate among seeds in a lot leads to a mixture of seed colors creating an unacceptable product...

  12. Common bean and cowpea improvement in Angola

    Science.gov (United States)

    During 2014 and 2015, the Instituto de Investigação Agronómica (IIA) evaluated the performance of common bean (Phaselolus vulgaris L.) breeding lines and improved cowpea (Vigna unguiculata L. Walp.) varieties. The field experiments were planted in the lowlands at Mazozo and in the highlands at Chian...

  13. Castor bean response to zinc fertilization

    Energy Technology Data Exchange (ETDEWEB)

    Chaves, Lucia Helena Garofalo; Cunha, Tassio Henrique Cavalcanti da Silva; Lima, Vinicius Mota; Cabral, Paulo Cesar Pinto; Barros Junior, Genival; Lacerda, Rogerio Dantas de [Universidade Federal de Campina Grande (UAEAg/UFCG), PB (Brazil). Unidade Academica de Engenharia Agricola

    2008-07-01

    Zinc is a trace element and it is absolutely essential for the normal healthy growth of plants. This element plays a part of several enzyme systems and other metabolic functions in the plants. Castor beans (Ricinus communis L.) crop is raising attention as an alternative crop for oil and biodiesel production. Despite the mineral fertilization is an important factor for increasing castor beans yield, few researches has been made on this issue, mainly on the use of zinc. In order to evaluate the effects of zinc on growth of this plant an experiment was carried out in a greenhouse, in Campina Grande, Paraiba State, Brazil, from July to December 2007. The substrate for the pot plants was a 6 mm-sieved surface soil (Neossolo Quartzarenico). The experimental design was a completely randomized with three replications. The treatments were composed of five levels of Zn (0; 2; 4; 6 and 8 mg dm{sup -3}), which were applied at the time of planting. One plant of castor bean, cultivar BRS 188 - Paraguacu, was grown per pot after thinning and was irrigated whenever necessary. Data on plant height, number and length of leaves and stem diameter were measured at 21, 34, 77 and 103 days after planting. Under conditions that the experiment was carried out the results showed that the Zn levels used, did not affect the castor bean plants growth. (author)

  14. Registration of ‘Zenith' black bean

    Science.gov (United States)

    ‘Zenith’ black bean (Phaseolus vulgaris L.) (Reg. no. CV- , PI -), developed by Michigan State University AgBioResearch was released in 2014 as an upright, full-season cultivar with anthracnose [caused by Colletotrichum lindemuthianum (Sacc. et Magnus) Lams.-Scrib] resistance and excellent canning q...

  15. 防治绿色食品西瓜蚜虫的药剂筛选试验研究%Screening of Pesticides for Controlling Green Pharmaceutical Watermelon Aphids

    Institute of Scientific and Technical Information of China (English)

    谈振兰; 王晓栋

    2011-01-01

    The efficacy of 3 different types and 6 different kinds of insecticides were evaluated against aphids in watermelon field, and carried on the variance analysis by using new multiple range method, it screened the best insecticides against the aphids in watermelon field. The results showed that 6 kinds of tested insecticides including 1% matrine SL, 0.32% azadirachtin EC, 20% acetamiprid Hong Ding WP, 5% hypertonic imidacloprid EC, 2.5% efficient cyhalothrin AS and 48% chlorpyrifos EC could be used, 20% acetamiprid Hong Ding WP was optimal for comprehensive efficacy, 48% chlorpyrifos EC was worst for efficacy, the efficacy of different types of insecticides showed different features, people should choose flexibly suitable varieties of pesticides according to role of the characteristics of various pesticides and occurrence of aphis in production.%通过3个不同类型6种不同药剂对瓜蚜的防效试验,并采用新复极差法进行统计分析,筛选出防治西瓜蚜虫的最佳药剂.结果表明:1%苦参碱可溶性液剂、0.32%印楝素乳油、20%红鼎啶虫脒可湿性粉荆、5%高渗吡虫啉乳油、2.5%高效氯氟氰菊酯水剂和48%毒死蜱乳油等6种供试药剂均可使用,20%红鼎啶虫脒可湿性粉剂综合防效最理想,48%毒死蜱乳油防效最差,不同类型药剂防效显示出不同特征,生产中应根据各种农药的作用特点以及瓜蚜的发生情况灵活选用适宜的农药品种.

  16. Transcriptome Analysis of Green Peach Aphid (Myzus persicae): Insight into Developmental Regulation and Inter-Species Divergence

    Science.gov (United States)

    Ji, Rui; Wang, Yujun; Cheng, Yanbin; Zhang, Meiping; Zhang, Hong-Bin; Zhu, Li; Fang, Jichao; Zhu-Salzman, Keyan

    2016-01-01

    Green peach aphid (Myzus persicae) and pea aphid (Acyrthosiphon pisum) are two phylogenetically closely related agricultural pests. While pea aphid is restricted to Fabaceae, green peach aphid feeds on hundreds of plant species from more than 40 families. Transcriptome comparison could shed light on the genetic factors underlying the difference in host range between the two species. Furthermore, a large scale study contrasting gene expression between immature nymphs and fully developed adult aphids would fill a previous knowledge gap. Here, we obtained transcriptomic sequences of green peach aphid nymphs and adults, respectively, using Illumina sequencing technology. A total of 2244 genes were found to be differentially expressed between the two developmental stages, many of which were associated with detoxification, hormone production, cuticle formation, metabolism, food digestion, and absorption. When searched against publically available pea aphid mRNA sequences, 13,752 unigenes were found to have no homologous counterparts. Interestingly, many of these unigenes that could be annotated in other databases were involved in the “xenobiotics biodegradation and metabolism” pathway, suggesting the two aphids differ in their adaptation to secondary metabolites of host plants. Conversely, 3989 orthologous gene pairs between the two species were subjected to calculations of synonymous and nonsynonymous substitutions, and 148 of the genes potentially evolved in response to positive selection. Some of these genes were predicted to be associated with insect-plant interactions. Our study has revealed certain molecular events related to aphid development, and provided some insight into biological variations in two aphid species, possibly as a result of host plant adaptation.

  17. Transcriptome analysis of green peach aphid (Myzus persicae: Insight into developmental regulation and inter-species divergence

    Directory of Open Access Journals (Sweden)

    Rui Ji

    2016-10-01

    Full Text Available Green peach aphid (Myzus persicae and pea aphid (Acyrthosiphon pisum are two phylogenetically closely related agricultural pests. While pea aphid is restricted to Fabaceae, green peach aphid feeds on hundreds of plant species from more than 40 families. Transcriptome comparison could shed light on the genetic factors underlying the difference in host range between the two species. Furthermore, a large scale study contrasting gene expression between immature nymphs and fully developed adult aphids would fill a previous knowledge gap. Here, we obtained transcriptomic sequences of green peach aphid nymphs and adults, respectively, using Illumina sequencing technology. A total of 2,244 genes were found to be differentially expressed between the two developmental stages, many of which were associated with detoxification, hormone production, cuticle formation, metabolism, food digestion and absorption. When searched against publically available pea aphid mRNA sequences, 13,752 unigenes were found to have no homologous counterparts. Interestingly, many of these unigenes that could be annotated in other databases were involved in the xenobiotics biodegradation and metabolism pathway, suggesting the two aphids differ in their adaptation to secondary metabolites of host plants. Conversely, 3,989 orthologous gene pairs between the two species were subjected to calculations of synonymous and nonsynonymous substitutions, and 148 of the genes potentially evolved in response to positive selection. Some of these genes were predicted to be associated with insect-plant interactions. Our study has revealed certain molecular events related to aphid development, and provided some insight into biological variations in two aphid species, possibly as a result of host plant adaptation.

  18. Core RNAi Machinery and Sid1, a Component for Systemic RNAi, in the Hemipteran Insect, Aphis glycines

    Directory of Open Access Journals (Sweden)

    Raman Bansal

    2013-02-01

    Full Text Available RNA interference (RNAi offers a novel tool to manage hemipteran pests. For the success of RNAi based pest control in the field, a robust and systemic RNAi response is a prerequisite. We identified and characterized major genes of the RNAi machinery, Dicer2 (Dcr2, Argonaute2 (Ago2, and R2d2 in Aphis glycines, a serious pest of soybean. The A. glycines genome encodes for at least one copy of Dcr2, R2d2 and Ago2. Comparative and molecular evolution analyses (dN/dS showed that domain regions of encoded proteins are highly conserved, whereas linker (non-domain regions are diversified. Sequence homology and phylogenetic analyses suggested that the RNAi machinery of A. glycines is more similar to that of Tribolium casteneum as compared to that of Drosophila melanogaster. We also characterized Sid1, a major gene implicated in the systemic response for RNAi-mediated gene knockdown. Through qPCR, Dcr2, R2d2, Ago2, and Sid1 were found to be expressed at similar levels in various tissues, but higher expression of Dcr2, R2d2, and Ago2 was seen in first and second instars. Characterization of RNAi pathway and Sid1 in A. glycines will provide the foundation of future work for controlling one of the most important insect pests of soybean in North America.

  19. Core RNAi Machinery and Sid1, a Component for Systemic RNAi, in the Hemipteran Insect, Aphis glycines.

    Science.gov (United States)

    Bansal, Raman; Michel, Andy P

    2013-02-08

    RNA interference (RNAi) offers a novel tool to manage hemipteran pests. For the success of RNAi based pest control in the field, a robust and systemic RNAi response is a prerequisite. We identified and characterized major genes of the RNAi machinery, Dicer2 (Dcr2), Argonaute2 (Ago2), and R2d2 in Aphis glycines, a serious pest of soybean. The A. glycines genome encodes for at least one copy of Dcr2, R2d2 and Ago2. Comparative and molecular evolution analyses (dN/dS) showed that domain regions of encoded proteins are highly conserved, whereas linker (non-domain) regions are diversified. Sequence homology and phylogenetic analyses suggested that the RNAi machinery of A. glycines is more similar to that of Tribolium casteneum as compared to that of Drosophila melanogaster. We also characterized Sid1, a major gene implicated in the systemic response for RNAi-mediated gene knockdown. Through qPCR, Dcr2, R2d2, Ago2, and Sid1 were found to be expressed at similar levels in various tissues, but higher expression of Dcr2, R2d2, and Ago2 was seen in first and second instars. Characterization of RNAi pathway and Sid1 in A. glycines will provide the foundation of future work for controlling one of the most important insect pests of soybean in North America.

  20. Zinc supplementation, production and quality of coffee beans

    Directory of Open Access Journals (Sweden)

    Herminia Emilia Prieto Martinez

    2013-04-01

    Full Text Available Besides its importance in the coffee tree nutrition, there is almost no information relating zinc nutrition and bean quality. This work evaluated the effect of zinc on the coffee yield and bean quality. The experiment was conducted with Coffea arabica L. in "Zona da Mata" region, Minas Gerais, Brazil. Twelve plots were established at random with 4 competitive plants each. Treatments included plants supplemented with zinc (eight plots and control without zinc supplementation (four plots. Plants were subjected to two treatments: zinc supplementation and control. Yield, number of defective beans, beans attacked by berry borers, bean size, cup quality, beans zinc concentration, potassium leaching, electrical conductivity, color index, total tritable acidity, pH, chlorogenic acids contents and ferric-reducing antioxidant activity of beans were evaluated. Zinc positively affected quality of coffee beans, which presented lower percentage of medium and small beans, lower berry borer incidence, lower potassium leaching and electrical conductivity, higher contents of zinc and chlorogenic acids and higher antioxidant activity in comparison with control beans.

  1. Weather, cultivar and density-dependent processes influence on aphid in alfalfa Influência do clima, da cultivar e de processos dependentes da densidade sobre afídeos em alfafa

    Directory of Open Access Journals (Sweden)

    Alexandre de Almeida e Silva

    2007-01-01

    Full Text Available It is important to understand the effects of weather, insect density and plant cultivar on insect abundance to predict and prevent crop production loss. The present work investigated the influence of such factors on aphid in alfalfa during one year (short term. Data was collected from September/1997 to August/1998 at Canchin Farm (CCPSE-EMBRAPA, São Carlos, State of São Paulo, Brazil. Weather conditions had, in general, little effect on the variation of aphid populations, but Therioaphis maculata abundance was negatively correlated to humidity. Moreover, high maximum temperatures and low levels of rainfall possible favored T. maculata high abundance on Crioula and P3 cultivars. Therefore, appropriate management of this species is required during hot and dry periods. Population variation of Acyrthosiphon spp., T. maculata and Aphis craccivora seems to be regulated by density dependent processes. Resistant cultivar CUF 101 had a lower abundance of T. maculata and A. craccivora and a narrower population variation than the other cultivars and may reduce their abundance on field. Long-term studies on population dynamics including the effect of climatic conditions and density-dependent factors on plant quality will contribute to pest management in alfalfa fields.É importante entender os efeitos do clima, da densidade dos insetos e da cultivar sobre a abundância de insetos para se predizer e prevenir perdas na produção das culturas. O objetivo do presente trabalho foi analisar a influência desses fatores sobre afídeos em alfafa no período de um ano. Os dados foram coletados de setembro/1997 a agosto/1998 na Fazenda Canchin (CPPSE-EMBRAPA, São Carlos, São Paulo, Brasil. As condições climáticas, em geral, tiveram pequeno efeito sobre a variação populacional dos afídeos, mas a abundância de Therioaphis maculata esteve negativamente correlacionada à umidade. Além disso, as altas temperaturas máximas e os baixos níveis de precipita

  2. Identification of aphid salivary proteins: a proteomic investigation of Myzus persicae.

    Science.gov (United States)

    Harmel, N; Létocart, E; Cherqui, A; Giordanengo, P; Mazzucchelli, G; Guillonneau, F; De Pauw, E; Haubruge, E; Francis, F

    2008-04-01

    The role of insect saliva in the first contact between an insect and a plant is crucial during feeding. Some elicitors, particularly in insect regurgitants, have been identified as inducing plant defence reactions. Here, we focused on the salivary proteome of the green peach aphid, Myzus persicae. Proteins were either directly in-solution digested or were separated by 2D SDS-PAGE before trypsin digestion. Resulting peptides were then identified by mass spectrometry coupled with database investigations. A homemade database was constituted of expressed sequence tags from the pea aphid Acyrtosiphon pisum and M. persicae. The databases were used to identify proteins related to M. persicae with a nonsequenced genome. This procedure enabled us to discover glucose oxidase, glucose dehydrogenase, NADH dehydrogenase, alpha-glucosidase and alpha-amylase in M. persicae saliva. The presence of these enzymes is discussed in terms of plant-aphid interactions.

  3. Wheat Nitrogen Fertilisation Effects on the Performance of the Cereal Aphid Metopolophium dirhodum

    Directory of Open Access Journals (Sweden)

    Alan F. J. Gash

    2012-02-01

    Full Text Available The effects of five rates of nitrogen fertiliser applications on the performance of the cereal aphid Metopolophium dirhodum on winter wheat, within the range of rates recommended for UK crops, were investigated over two seasons in field-grown crops and also on plants grown in the glasshouse. Longevity was unaffected by the level of fertilisation, but aphid intrinsic rate of increase and fecundity increased with each level applied. In the second field season, when a higher upper limit was used, many of these increases were significant. A previously unreported finding for this species was that there was a significant decrease in fecundity for the highest rate of fertilisation. Results for the glasshouse-reared aphids followed a similar pattern to those in the field, and overall they underline recent reports in the literature of the negative effects of high nutrient concentrations on the performance of herbivorous insects. The underlying reasons for these are discussed.

  4. Host Plant Volatiles and the Sexual Reproduction of the Potato Aphid, Macrosiphum euphorbiae

    Directory of Open Access Journals (Sweden)

    Jessica Hurley

    2014-10-01

    Full Text Available In late summer, heteroecious aphids, such as the potato aphid, Macrosiphum euphorbiae, move from their secondary summer host plants to primary host plants, where the sexual oviparae mate and lay diapausing eggs. We tested the hypothesis that volatiles of the primary host, Rosa rugosa, would attract the gynoparae, the parthenogenetic alate morph that produce oviparae, as well as the alate males foraging for suitable mates. In wind tunnel assays, both gynoparae and males oriented towards and reached rose cuttings significantly more often than other odour sources, including potato, a major secondary host. The response of males was as high to rose cuttings alone as to potato with a calling virgin oviparous female. These findings are discussed within the seasonal ecology of host alternating aphids.

  5. Trophic interactions between rhizosphere bacteria and bacterial feeders influenced by phosphate and aphids in barley

    DEFF Research Database (Denmark)

    Strandmark, Lisa Bjørnlund; Mørk, Søren; Madsen, Mette Vestergård;

    2006-01-01

    The aim was to study the effects of P fertilization and leaf aphid attack on the trophic interactions of bacteria and bacterial feeders in the rhizospheres of barley plants. The density of protozoa peaked in the rhizospheres of plants fertilized with N and P, whereas nematodes peaked in the rhizo......The aim was to study the effects of P fertilization and leaf aphid attack on the trophic interactions of bacteria and bacterial feeders in the rhizospheres of barley plants. The density of protozoa peaked in the rhizospheres of plants fertilized with N and P, whereas nematodes peaked...... in the rhizospheres of plants to which only N had been added. Fingerprinting of bacterial communities by length heterogeneity polymerase chain reaction revealed differences in community structure between NP rhizospheres and N rhizospheres as well as aphid-related differences within N rhizospheres. Specifically, a...

  6. Methylxanthine and catechin content of fresh and fermented cocoa beans, dried cocoa beans, and cocoa liquor

    Directory of Open Access Journals (Sweden)

    Pedro P. Peláez

    2016-01-01

    Full Text Available The theobromine and catechin content can affect the quality of cocoa liquor and is influenced by cacao variety, production area (PA, and fermentation, as well as the method of drying beans (FDB and cocoa liquor production (CLP. This study examined variationsin methylxanthine and catechin levels in fresh and fermented cocoa beans, dried cocoa grains, and in cocoa liquor from Trinitario, Criollo, and Forastero cacao varieties. A total of 123 cocoa bean samples from three Peruvian PAs at different altitudes, Tingo María (TM, San Alejandro (SA, and Curimana (CU, were evaluated. The theobromine (Tb and caffeine (Cf contents in fresh cocoa beans were affected by both cocoa type and PA. The caffeine content was higher in Trinitario cacao than in Criollo and Forastero varieties (p ≤ 0.05. The Tb and CF contents decreased in dry cocoa grain and was affected by FDB (p ≤ 0.05 (1.449 ± 0.004 to 1.140 ± 0.010 and 0.410 ± 0.03 to 0.165 ± 0.02 g Tb and C, respectively, per 100 g dry weight. Cocoa beans from Tingo María, which has thehighest altitude, had higher Tb and CF contents than those from other PAs. The catechin (C and epicatechin (EC contents were affected by the FDB and CLP, and were highestin fresh cocoa beans from the Tingo María area (range: 0.065 ± 0.01 to 0.020 ± 0.00 g C/100 g. The C and EC contents decreased during FDB and CLP (0.001 g C/100 g of cocoa liquor. Taken together, these results show that higher concentrations of Tb, Cf, C,and EC are present in fresh cocoa beans. Moreover, the cocoa variety influenced cocoa liquor quality. Overall, cocoa from the Tingo María PA had the most desirable chemical composition.

  7. Polyphyly of the extinct family Oviparosiphidae and its implications for inferring aphid evolution (Hemiptera, Sternorrhyncha).

    Science.gov (United States)

    Żyła, Dagmara; Homan, Agnieszka; Wegierek, Piotr

    2017-01-01

    Aphidoidea, the so-called "true aphids" are one of the most challenging groups in terms of solving the phylogenetic relationships. Morphology-based analyses were strongly affected by widespread homoplasy, while the molecular-based attempts struggled with the lack of sufficient phylogenetic signal. Despite significant improvements, the higher classification still remains unresolved and rather controversial. However, the use of the fossil record, one of the most valuable sources of information, was mainly limited to calibration of a phylogenetic tree, without a direct inclusion into the analysis. The extinct family Oviparosiphidae has long been considered as the common ancestor of all recent Aphidoidea and it was used as a calibration point in several analyses, but it has been never analyzed in a phylogenetic context. The family has been treated as a monophyletic group purely based on the simultaneous presence of two abdominal structures, ovipositor and siphunculi. However, it has been shown recently that at least one more extinct lineage, present at the same time, was characterized by the same features. For these reasons, we performed a maximum parsimony analysis using morphological data for extinct aphid taxa to prove the monophyly of Oviparosiphidae. Our analysis shows that the presumed ancestor lineage of recent aphids is a polyphyletic group. Our results support the hypothesis of an early Mesozoic rapid radiation of aphids, which led to several different lineages characterized by both ovipositor and siphunculi. The results indicate the necessity of examining the other extinct families, and shows that the diversity of aphids before the Cretaceous Terrestrial Revolution (KTR) was higher than expected. Even though there is not enough data to perform a formal analysis, fossils seem to suggest a significant impact of the KTR on aphid diversification. Additionally, we have made a redescription of two genera and description of a new species, Vitimaphis subridens sp

  8. Aphid thermal tolerance is governed by a point mutation in bacterial symbionts.

    Directory of Open Access Journals (Sweden)

    Helen E Dunbar

    2007-05-01

    Full Text Available Symbiosis is a ubiquitous phenomenon generating biological complexity, affecting adaptation, and expanding ecological capabilities. However, symbionts, which can be subject to genetic limitations such as clonality and genomic degradation, also impose constraints on hosts. A model of obligate symbiosis is that between aphids and the bacterium Buchnera aphidicola, which supplies essential nutrients. We report a mutation in Buchnera of the aphid Acyrthosiphon pisum that recurs in laboratory lines and occurs in field populations. This single nucleotide deletion affects a homopolymeric run within the heat-shock transcriptional promoter for ibpA, encoding a small heat-shock protein. This Buchnera mutation virtually eliminates the transcriptional response of ibpA to heat stress and lowers its expression even at cool or moderate temperatures. Furthermore, this symbiont mutation dramatically affects host fitness in a manner dependent on thermal environment. Following a short heat exposure as juveniles, aphids bearing short-allele symbionts produced few or no progeny and contained almost no Buchnera, in contrast to aphids bearing symbionts without the deletion. Conversely, under constant cool conditions, aphids containing symbionts with the short allele reproduced earlier and maintained higher reproductive rates. The short allele has appreciable frequencies in field populations (up to 20%, further supporting the view that lowering of ibpA expression improves host fitness under some conditions. This recurring Buchnera mutation governs thermal tolerance of aphid hosts. Other cases in which symbiont microevolution has a major effect on host ecological tolerance are likely to be widespread because of the high mutation rates of symbiotic bacteria and their crucial roles in host metabolism and development.

  9. Natural enemies act faster than endophytic fungi in population control of cereal aphids.

    Science.gov (United States)

    Härri, Simone A; Krauss, Jochen; Müller, Christine B

    2008-05-01

    1. Fast-growing populations of phytophagous insects can be limited by the presence of natural enemies and by alkaloids that are produced by symbiotic associations of many temperate grass species with endophytic fungi. It is unclear if and how acquired plant defences derived from endophytic fungi interact with natural enemies to affect phytophagous insect populations. 2. To assess the relative importance of endophytic fungi compared to that of natural enemies on the population dynamics of phytophagous insects, we carried out a fully factorial field experiment, in which the presence of natural enemies and the presence of endophytic fungi were manipulated simultaneously. Target colonies of aphids were monitored for 8 weeks starting from their natural appearance in the field to the end of the aphid season. 3. We show that on Lolium perenne increased natural enemy densities reduced the individual numbers of two common cereal aphids, Rhopalosiphum padi and Metopolophium festucae. 4. The presence of the endophytic fungi Neotyphodium lolii reduced the number of M. festucae but did not affect the number of R. padi. The reduction in R. padi numbers by predators and parasitoids was not influenced by the presence of endophytes. For adult M. festucae, however, the negative effects of natural enemies were significant only in the absence of endophytes. 5. Over the duration of the experiment, the effect of natural enemies on aphid colony growth was much stronger than the effect of the endophytic fungi N. lolii, presumably because predator and parasitoid action on aphid colonies is much faster than any effects of endophytes. 6. Our results demonstrate that with simultaneous action of acquired endosymbionts and natural enemies, both factors can control aphid colony growth but they generally act independently of each other.

  10. Increased Susceptibility to Aphids of Flowering Wheat Plants Exposed to Low Temperatures.

    Science.gov (United States)

    Lacoste, C; Nansen, C; Thompson, S; Moir-Barnetson, L; Mian, A; McNee, M; Flower, K C

    2015-06-01

    Frost is known to directly affect flowering wheat plants (Triticum aestivum L.) and lead to reduced grain yield. Additionally, it may increase wheat susceptibility to economically important pests, such as aphids (Hemiptera: Aphididae). Wheat plants at flowering stage were exposed to one of the three temperature treatments: ambient (11-12°C), 0°C, and -3°C for 60 min. Preference (3-choice) and performance (no-choice) bioassays with aphids (Rhopalosiphum padi L.) were conducted 1, 3, 6, and 12 d after temperature treatments to assess effects of temperature-induced stress over time. As an initial feasibility study of using remote sensing technologies to detect frost-induced stress in flowering wheat plants, hyperspectral imaging data were acquired from wheat plants used in preference bioassays. Element analysis of wheat plants was included to determine the effect of temperature-induced stress on the nutritional composition of flowering wheat plants. The results from this study support the following cause-effect scenario: a 60-min exposure to low temperatures caused a significant decrease in potassium and copper content of wheat plants 6 d after temperature exposure, and it coincided with a marked increase in preference by aphids of wheat plants. The preference exhibited by aphids correlated positively with performance of aphids, so the preference-performance hypothesis was confirmed and possibly driven by potassium and copper content of wheat plants. In addition, we demonstrated that hyperspectral imaging data can be used to detect frost-induced susceptibility to aphid infestation in flowering wheat plants. These findings justify further research into airborne remote sensing of frost-induced stress and the possible secondary effects on crop susceptibility to arthropod pests.

  11. Role of terpenes from aphid-infested potato on searching and oviposition behavior of Episyrphus balteatus

    Institute of Scientific and Technical Information of China (English)

    NICOLAS HARMEL; RAKI ALMOHAMAD; MARIE-LAURE FAUCONNIER; PATRICK DU JARDIN; FRANCO IS VERHEGGEN; MICHEL MARLIER; ERIC HAUBRUGE; FR(E)D(E)RIC FRANCIS

    2007-01-01

    To cope with pathogen and insect attacks, plants develop different mechanismsof defence, in both direct (physical and chemical) and indirect ways (attractive volatiles toentomophagous beneficials). Plants are then able to express traits that facilitate "top-down"control of pests by attracting herbivore predators. Here we investigate the indirect defencemechanism of potato plants by analyzing the volatile patterns of both healthy and aphidinfested plants. Important changes in the emitted terpene pattern by the Myzus persicaeinfested host plant were observed. Using Solid Phase MicroExtraction (SPME) and GC-MS,the (E)-β-farnesene (EBF) appeared to be emitted by aphid-infested potato and not byhealthy plants. To assess the infochemical role of these volatile releases after aphid damageon the aphidophagous predators Episyrphus balteatus, the hoverfly foraging behavior wasassessed using the Observer 5.0 software (Noldus, Wageningen, The Netherlands). Aphidfree potato plants were also used as a control volatile source in the predator behavioral study.While aphid-infested plants induced efficient searching and acceptation behaviors leadingto egg-laying, no kairomonal effect of healthy potato plants was observed, leading to longerimmobility durations and shorter searching periods in the net cage. High oviposition rate ofE. balteatus was observed when aphid-infested potato was used (mean of 48.9 eggs perlaying and per female). On the other hand, no egg was produced by the hoverfly on healthyaphid-free plants. The E. balteatus foraging and reproductive behaviors according to thevolatile emission from aphid-infested plants are discussed in relation to the potential use ofactive infochemical molecules in integrated aphid pest management.

  12. 转Bt基因抗虫棉对棉蚜个体生长发育和繁殖能力的影响%Effects of Transgenic Bt gene Cotton on the Development and Reproduction of Individuals Cotton Aphids

    Institute of Scientific and Technical Information of China (English)

    李海强; 王冬梅; 徐遥; 张永军; 丁瑞丰; 李号宾; 汪飞; 阿克旦·吾外士; 刘建

    2011-01-01

    [目的]研究转Bt基因抗虫棉对棉蚜的个体生长发育及繁殖能力的影响.[方法]在室内研究转Bt基因棉(处理)和常规棉(对照)对棉蚜个体生长发育及繁殖能力的影响.[结果]转Bt基因抗棉铃虫棉对棉蚜发育速度、成蚜寿命、4龄若蚜体重、成蚜繁殖力无明显影响.[结论]取食转Bt基因棉花对棉蚜个体生长发育没有负面影响,转Bt基因棉花对棉蚜生长发育和繁殖是安全的.为转Bt基因抗虫棉对棉蚜的生态安全性评价提供相关依据.%[Objective] The purpose of this study was to discuss effects of transgenic Bt gene cotton on the development and reproduction of individuals cotton Aphuids. [Method] The preliminary effects of transgenic cotton on Aphis were measured in laboratory with the method of life - table. [Result]The result showed that the effect on the development speed , adult life - span. 4 duration avoirdupois, and adult reproduction of Aphids were not significant. [ Conclusion] The correlative evidence had been built on transgenic Bt gene cotton ecoloey safety evaluation .

  13. Field Efficacy Test of Some Kinds of Insecticide on Soybean Aphid and Influence to Natural Enemy%几种杀虫剂防治大豆蚜效果及对天敌的影响

    Institute of Scientific and Technical Information of China (English)

    陈彦; 王兴亚; 徐蕾; 赵彤华; 许国庆

    2011-01-01

    [Aims] The effective insecticides were selected to control soybean aphid(Aphis glycines) by field trials. [Results] Matrine and pyrethrin showed better rapid and durable effect, after treatment, the control effect was the highest after 2 days, the control effect was above 94% after 10 days. Imidacloprid and abamectin showed certain rapid effect and durable effect. Pirimicarb has poor rapid effect and durable effect and its highest control effect was only 72% after 10 days after treatment. [Conclusions] Matrine is a suitable insecticide for application and popularization of controlling A. Glycines in field with little effect on natural enemies.%[目的]通过田间药效试验从目前使用的杀蚜剂中筛选出对大豆蚜防效较好、对天敌杀伤力小的生物药剂.[结果]试验表明:苦参碱、除虫菊素具有良好的速效性和持效性,药后2d的防效最高,药后10d的防效为94%以上;吡虫啉、阿维菌素的速效性和持效性次之;抗蚜威的速效性和持效性差;药后10d防效最低,为72%.[结论]5种试验药剂中,苦参碱对天敌影响小,是防治大豆蚜的良好生物农药.

  14. Macrosiphoniella remaudierei, a new species of aphid on Helichrysum in Iran (Hemiptera, Aphididae)

    Science.gov (United States)

    Barbagallo, Sebastiano; Nieto Nafría, Juan M.

    2016-01-01

    Abstract A new species of aphid, belonging to the genus Macrosiphoniella Del Guercio, 1911, is described using three samples collected in Iran on Helichrysum armenium (Asteraceae, Inuleae) by the late Prof. G. Remaudière. Both apterous and alate viviparous females of the new taxon, Macrosiphoniella remaudierei sp. n., are described and compared to corresponding morphs of the closely allied Macrosiphoniella aetnensis and to other congeneric aphid species on Helichrysum in the Palaearctic region. Type specimens are now stored in the Muséum national d’Histoire naturelle in Paris. PMID:28138287

  15. Bacterial genes in the aphid genome: absence of functional gene transfer from Buchnera to its host.

    Directory of Open Access Journals (Sweden)

    Naruo Nikoh

    2010-02-01

    Full Text Available Genome reduction is typical of obligate symbionts. In cellular organelles, this reduction partly reflects transfer of ancestral bacterial genes to the host genome, but little is known about gene transfer in other obligate symbioses. Aphids harbor anciently acquired obligate mutualists, Buchnera aphidicola (Gammaproteobacteria, which have highly reduced genomes (420-650 kb, raising the possibility of gene transfer from ancestral Buchnera to the aphid genome. In addition, aphids often harbor other bacteria that also are potential sources of transferred genes. Previous limited sampling of genes expressed in bacteriocytes, the specialized cells that harbor Buchnera, revealed that aphids acquired at least two genes from bacteria. The newly sequenced genome of the pea aphid, Acyrthosiphon pisum, presents the first opportunity for a complete inventory of genes transferred from bacteria to the host genome in the context of an ancient obligate symbiosis. Computational screening of the entire A. pisum genome, followed by phylogenetic and experimental analyses, provided strong support for the transfer of 12 genes or gene fragments from bacteria to the aphid genome: three LD-carboxypeptidases (LdcA1, LdcA2,psiLdcA, five rare lipoprotein As (RlpA1-5, N-acetylmuramoyl-L-alanine amidase (AmiD, 1,4-beta-N-acetylmuramidase (bLys, DNA polymerase III alpha chain (psiDnaE, and ATP synthase delta chain (psiAtpH. Buchnera was the apparent source of two highly truncated pseudogenes (psiDnaE and psiAtpH. Most other transferred genes were closely related to genes from relatives of Wolbachia (Alphaproteobacteria. At least eight of the transferred genes (LdcA1, AmiD, RlpA1-5, bLys appear to be functional, and expression of seven (LdcA1, AmiD, RlpA1-5 are highly upregulated in bacteriocytes. The LdcAs and RlpAs appear to have been duplicated after transfer. Our results excluded the hypothesis that genome reduction in Buchnera has been accompanied by gene transfer to the

  16. Macrosiphoniella remaudierei, a new species of aphid on Helichrysum in Iran (Hemiptera, Aphididae

    Directory of Open Access Journals (Sweden)

    Sebastiano Barbagallo

    2017-01-01

    Full Text Available A new species of aphid, belonging to the genus Macrosiphoniella Del Guercio, 1911, is described using three samples collected in Iran on Helichrysum armenium (Asteraceae, Inuleae by the late Prof. G. Remaudière. Both apterous and alate viviparous females of the new taxon, M. remaudierei sp. n., are described and compared to corresponding morphs of the closely allied M. aetnensis and to other congeneric aphid species on Helichrysum in the Palaearctic region. Type specimens are now stored in the Muséum national d’Histoire naturelle in Paris.

  17. Comparative analysis of Solanum stoloniferum responses to probing by the green peach aphid Myzus persicae and the potato aphid Macrosiphum euphorbiae

    Institute of Scientific and Technical Information of China (English)

    Adriana E.Alvarez; Viviana G.Broglia; Anahí M.Alberti D'Amato; Doret Wouters; Edwin van der Vossen; Elisa Garzo; W.Fred Tjallingii

    2013-01-01

    Plants protect themselves against aphid attacks by species-specific defense mechanisms.Previously,we have shown that Solanum stoloniferum Schlechtd has resistance factors to Myzus persicae Sulzer (Homoptera:Aphididae) at the epidermal/mesophyll level that are not effective against Macrosiphum euphorbiae Thomas (Homoptera:Aphididae).Here,we compare the nymphal mortality,the pre-reproductive development time,and the probing behavior of M.persicae and M.euphorbiae on S.stoloniferum and Solanum tuberosum L.Furthermore,we analyze the changes in gene expression in S.stoloniferum 96 hours post infestation by either aphid species.Although the M.euphorbiae probing behavior shows that aphids encounter more probing constrains on phloem activities-longer probing and salivation time-on S.stoloniferum than on S.tuberosum,the aphids succeeded in reaching a sustained ingestion of phloem sap on both plants.Probing by M.persicae on S.stoloniferum plants resulted in limited feeding only.Survival of M.euphorbiae and M.persicae was affected on young leaves,but not on senescent leaves of S.stoloniferum.Infestation by M.euphorbiae changed the expression of more genes than M.persicae did.At the systemic level both aphids elicited a weak response.Infestation of S.stoloniferum plants with a large number ofM.persicae induced morphological changes in the leaves,leading to the development of pustules that were caused by disrupted vascular parenchyma and surrounding tissue.In contrast,an infestation by M.euphorbiae had no morphological effects.Both plant species can be regarded as good host for M.euphorbiae,whereas only S.tuberosum is a good host for Mo persicae and S.stoloniferum is not.Infestation of S.stoloniferum by M.persicae or M.euphorbiae changed the expression of a set of plant genes specific for each of the aphids as well as a set of common genes.

  18. Ion beam analysis of ground coffee and roasted coffee beans

    Science.gov (United States)

    Debastiani, R.; dos Santos, C. E. I.; Yoneama, M. L.; Amaral, L.; Dias, J. F.

    2014-01-01

    The way that coffee is prepared (using roasted ground coffee or roasted coffee beans) may influence the quality of beverage. Therefore, the aim of this work is to use ion beam techniques to perform a full elemental analysis of packed roasted ground coffee and packed roasted coffee beans, as well as green coffee beans. The samples were analyzed by PIXE (particle-induced X-ray emission). Light elements were measured through RBS (Rutherford backscattering spectrometry) experiments. Micro-PIXE experiments were carried out in order to check the elemental distribution in the roasted and green coffee beans. In general, the elements found in ground coffee were Mg, P, S, Cl, K, Ca, Ti, Mn, Fe, Cu, Zn, Rb and Sr. A comparison between ground coffee and grinded roasted beans shows significant differences for several elements. Elemental maps reveal that P and K are correlated and practically homogeneously distributed over the beans.

  19. Dynamics of Cocoa Bean Pulp Degradation during Cocoa Bean Fermentation: Effects of Yeast Starter Culture Addition

    Directory of Open Access Journals (Sweden)

    Laras Cempaka

    2014-07-01

    Full Text Available Fermentation is a crucial step in the post-harvest processing of cocoa beans. This process comprises mixed culture microbial activities on the cocoa bean pulp, producing metabolites that act as important precursors for cocoa flavour development. Variations in the microbial population dynamics during the fermentation process may induce changes in the overall process. Thus, the introduction of a specific microbial starter culture may improve the quality of the fermentation. This article discusses the effects ofthe addition of Saccharomyces cerevisae var. Chevalieri starter culture on cocoa bean fermentation. The dynamics in the yeast concentration, sugary pulp compounds and metabolic products were measured during fermentation. The alterations in the dynamic metabolite profile were significant, although only a slight difference was observed in the yeast population. A higher fermentation index was measured for the cocoa bean fermentation with yeast starter culture, 1.13 compared to 0.84. In conclusion, this method can potentially be applied to shorten the cocoa bean fermentation time.

  20. Dynamic transcriptome profiling of Bean Common Mosaic Virus (BCMV) infection in Common Bean (Phaseolus vulgaris L.).

    Science.gov (United States)

    Martin, Kathleen; Singh, Jugpreet; Hill, John H; Whitham, Steven A; Cannon, Steven B

    2016-08-11

    Bean common mosaic virus (BCMV) is widespread, with Phaseolus species as the primary host plants. Numerous BCMV strains have been identified on the basis of a panel of bean varieties that distinguish the pathogenicity types with respect to the viral strains. The molecular responses in Phaseolus to BCMV infection have not yet been well characterized. We report the transcriptional responses of a widely susceptible variety of common bean (Phaseolus vulgaris L., cultivar 'Stringless green refugee') to two BCMV strains, in a time-course experiment. We also report the genome sequence of a previously unreported BCMV strain. The interaction with the known strain NL1-Iowa causes moderate symptoms and large transcriptional responses, and the newly identified strain (Strain 2 or S2) causes severe symptoms and moderate transcriptional responses. The transcriptional profiles of host plants infected with the two isolates are distinct, and involve numerous differences in splice forms in particular genes, and pathway specific expression patterns. We identified differential host transcriptome response after infection of two different strains of Bean common mosaic virus (BCMV) in common bean (Phaseolus vulgaris L.). Virus infection initiated a suite of changes in gene expression level and patterns in the host plants. Pathways related to defense, gene regulation, metabolic processes, photosynthesis were specifically altered after virus infection. Results presented in this study can increase the understanding of host-pathogen interactions and provide resources for further investigations of the biological mechanisms in BCMV infection and defense.