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Sample records for weevil sitophilus oryzae

  1. Polygalacturonase from Sitophilus oryzae: Possible horizontal transfer of a pectinase gene from fungi to weevils

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    Zhicheng Shen

    2003-08-01

    Full Text Available Endo-polygalacturonase, one of the group of enzymes known collectively as pectinases, is widely distributed in bacteria, plants and fungi. The enzyme has also been found in several weevil species and a few other insects, such as aphids, but not in Drosophila melanogaster, Anopheles gambiae, or Caenorhabditis elegans or, as far as is known, in any more primitive animal species. What, then, is the genetic origin of the polygalacturonases in weevils? Since some weevil species harbor symbiotic microorganisms, it has been suggested, reasonably, that the symbionts' genomes of both aphids and weevils, rather than the insects' genomes, could encode polygalacturonase. We report here the cloning of a cDNA that encodes endo-polygalacturonase in the rice weevil, Sitophilus oryzae (L., and investigations based on the cloned cDNA. Our results, which include analysis of genes in antibiotic-treated rice weevils, indicate that the enzyme is, in fact, encoded by the insect genome. Given the apparent absence of the gene in much of the rest of the animal kingdom, it is therefore likely that the rice weevil polygalacturonase gene was incorporated into the weevil's genome by horizontal transfer, possibly from a fungus.

  2. Genetics of resistance to stored grain weevil (Sitophilus oryzae L. in maize

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    Rajkumar Zunjare

    2015-12-01

    Full Text Available Stored grain weevil (Sitophilus oryzae has emerged as important storage grain pest of maize, causing substantial economic losses. Owing to high costs and environmental hazards of pesticides, host plant resistance holds promise for effective control of weevils. In the present study, a set of experimental maize hybrids generated using line × tester mating design were evaluated against S. oryzae. Significant variation for grain weight loss (GWL (6.0–49.1%, number of insect progeny emerged (NIP (17.8–203.3, grain hardness (GH (263.1–495.4 N, and pericarp thickness (PT (60.3–161.0 μm was observed. Strong positive association was observed between GWL and NIP. GH and PT did not show any correlation with GWL and NIP. Additive and non-additive gene actions were important for both GWL and NIP. Promising inbreds and experimental crosses identified can be effectively utilized in the resistance breeding programme. In majority of promising crosses having desirable SCA effects, one of the parents had desirable GCA effects, indicating that selection of inbred parents based on per se performance for generating resistant crosses may be possible. The commercial hybrid checks were highly susceptible compared to experimental hybrids. The inbreds and experimental hybrids identified hold promise in developing weevil resistant maize cultivars offering sustainable solution to management of weevils in maize.

  3. Genetic Conservation of Phosphine Resistance in the Rice Weevil Sitophilus oryzae (L.).

    Science.gov (United States)

    Nguyen, Tam T; Collins, Patrick J; Duong, Tu M; Schlipalius, David I; Ebert, Paul R

    2016-05-01

    High levels of resistance to phosphine in the rice weevil Sitophilus oryzae have been detected in Asian countries including China and Vietnam, however there is limited knowledge of the genetic mechanism of resistance in these strains. We find that the genetic basis of strong phosphine resistance is conserved between strains of S. oryzae from China, Vietnam, and Australia. Each of 4 strongly resistant strains has an identical amino acid variant in the encoded dihydrolipoamide dehydrogenase (DLD) enzyme that was previously identified as a resistance factor in Rhyzopertha dominica and Tribolium castaneum. The unique amino acid substitution, Asparagine > Threonine (N505T) of all strongly resistant S. oryzae corresponds to the position of an Asparagine > Histidine variant (N506H) that was previously reported in strongly resistant R. dominica. Progeny (F16 and F18) from 2 independent crosses showed absolute linkage of N505T to the strong resistance phenotype, indicating that if N505T was not itself the resistance variant that it resided within 1 or 2 genes of the resistance factor. Non-complementation between the strains confirmed the shared genetic basis of strong resistance, which was supported by the very similar level of resistance between the strains, with LC50 values ranging from 0.20 to 0.36 mg L(-1) for a 48-h exposure at 25 °C. Thus, the mechanism of high-level resistance to phosphine is strongly conserved between R. dominica, T. castaneum and S. oryzae. A fitness cost associated with strongly resistant allele was observed in segregating populations in the absence of selection.

  4. Fumigant Toxicity of Lamiaceae Plant Essential Oils and Blends of Their Constituents against Adult Rice Weevil Sitophilus oryzae

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    Sung-Woong Kim

    2016-03-01

    Full Text Available To find a new and safe alternative to conventional insecticides, we evaluated the fumigant toxicity of eight Lamiaceae essential oils and their constituents against the adult rice weevil Sitophilus oryzae. Of the eight species tested, hyssop (Hyssopus offcinalis, majoram (Origanum majorana, and Thymus zygis essential oils showed strong fumigant toxicity against S. oryzae adults at 25 mg/L air concentration. Constituents of active essential oils were analyzed by gas chromatography coupled to flame ionization detector (FID and gas chromatography-mass spectrometry. A total of 13, 15, and 17 compounds were identified from hyssop, majoram, and Thymus zygis essential oils, respectively. Pinocamphone and isopinocamphone were isolated by open column chromatography. Among the test compounds, pinocamphone and isopinocamphone showed the strongest fumigant toxicity against S. oryzae. Sabinene hydrate, linalool, α-terpineol, and terpinen-4-ol exhibited 100% fumigant toxicity against S. oryzae at 3.9 mg/L air concentration. The measured toxicity of the artificial blends of the constituents identified in hyssop, majoram, and Thymus zygis oils indicated that isopinocamphone, terpine-4-ol, and linalool were major contributors to the fumigant toxicity of the artificial blend, respectively.

  5. Fumigant Toxicity of Lamiaceae Plant Essential Oils and Blends of Their Constituents against Adult Rice Weevil Sitophilus oryzae.

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    Kim, Sung-Woong; Lee, Hyo-Rim; Jang, Myeong-Jin; Jung, Chan-Sik; Park, Il-Kwon

    2016-03-16

    To find a new and safe alternative to conventional insecticides, we evaluated the fumigant toxicity of eight Lamiaceae essential oils and their constituents against the adult rice weevil Sitophilus oryzae. Of the eight species tested, hyssop (Hyssopus offcinalis), majoram (Origanum majorana), and Thymus zygis essential oils showed strong fumigant toxicity against S. oryzae adults at 25 mg/L air concentration. Constituents of active essential oils were analyzed by gas chromatography coupled to flame ionization detector (FID) and gas chromatography-mass spectrometry. A total of 13, 15, and 17 compounds were identified from hyssop, majoram, and Thymus zygis essential oils, respectively. Pinocamphone and isopinocamphone were isolated by open column chromatography. Among the test compounds, pinocamphone and isopinocamphone showed the strongest fumigant toxicity against S. oryzae. Sabinene hydrate, linalool, α-terpineol, and terpinen-4-ol exhibited 100% fumigant toxicity against S. oryzae at 3.9 mg/L air concentration. The measured toxicity of the artificial blends of the constituents identified in hyssop, majoram, and Thymus zygis oils indicated that isopinocamphone, terpine-4-ol, and linalool were major contributors to the fumigant toxicity of the artificial blend, respectively.

  6. Toxicity of lemon grass Cymbopogon citratus powder and methanol extract against rice weevil Sitophilus oryzae (Coleoptera: Curculionidae

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    Martin Osaigbokan Uwamose

    2017-03-01

    Full Text Available Objective: To evaluate the toxicity potential of lemon grass [Cymbopogon citratus (C. citratus] products against adult rice weevil, Sitophilus oryzae. Methods: Lemon grass (C. citratus leaves were sundried for 7 days, pulverized and sieved using 0.5 mm mesh size to obtain fine powders. About 500 g of the powder were dissolved in 1000 mL of 90% methanol to produce the extract. The powder and extract were used for the bioassay. The powder was tested at 1.0, 1.5, 2.0 and 2.5 g/10 g rice grains, respectively. The toxic potential of the extract of concentration of 1.0, 1.5, 2.0, and 2.5 mg/mL were evaluated using the filter paper method. The experiment was setup on a completely randomized design using three replicates per treatment. Results: The results indicated significant difference (F = 7.450; df = 3.15; P < 0.05 in mean percentage mortality after 24, 48, 72, and 96 h exposure with the powder compared with the control. Significantly (F = 5.519; df = 3.15; P < 0.05 higher percentage adult mortality was also observed in the extract after 24, 48, 72, and 96 h exposure compared with the control. The LC50 value of the powder was 4.91 g/10 g of rice while the LT50 was 160.51 h. The LC50 value of the extract was 2.16 mg/20 mL of methanol with an LT50 of 75.10 h. The methanol extract of C. citratus showed the highest mortality compared to the powder which was less toxic. Conclusions: The study showed that C. citratus products are promising insecticides and can be used effectively in the management of Sitophilus oryzae in storage..

  7. Genetic variability among exotic and indigenous maize inbreds for resistance to stored grain weevil (Sitophilus oryzae L. infestation

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    Rajkumar Zunjare

    2016-12-01

    Full Text Available Sitophilus oryzae is one of the most important stored grain pests of maize causing substantial losses. Owing to high cost, environmental and health hazards, chemical control does not provide an acceptable solution. Host plant resistance offers sustainable and cost-effective way to reduce the losses. A set of 162 diverse inbreds were evaluated to assess their responses to infestation of S. oryzae. Significant variation for (1 grain weight loss (GWL (4.19–42.32%, (2 emergence of insect progeny (5.67–75.67, (3 germination of infested seeds (GIS (0.00–81.33%, (4 pericarp thickness (PT of the grain (47.32–194.83 μm and (5 grain hardness (GH (113.00–1,171.67 Newton was observed among inbreds. GWL and emergence of insect progeny were positively correlated, while GIS was negatively correlated with both. PT and GH did not show any association with other characters. CML442 and CM394 earlier reported to be promising against S. zeamais, were also identified as resistant to S. oryzae. SKV21, Pant109, Pant124, MGB1, CML207 and LM13 were identified as resistant inbreds. These inbreds can potentially serve as valuable donors in the resistance breeding programme. The resistant inbreds can also be crossed with diverse susceptible inbreds to generate mapping populations for identifying QTLs conferring resistance to S. oryzae.

  8. Basil oil fumigation increases radiation sensitivity in adult Sitophilus oryzae (Coleoptera: Curculionidae).

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    The biological activity of basil (Ocimum basilicum L.) oil was tested against the stored product pest rice weevil, Sitophilus oryzae(L.). Adult weevils were exposed to seven different concentrations of basil oil ranging from 0.12 µl/ml-0.60 µl/ml in Petri dishes and mortality was assessed at 3,4 and...

  9. Biological Activity of Essential Oils from Leaves and Fruits of Pepper Tree (Schinus molle L. to Control Rice Weevil (Sitophilus oryzae L. Bioactividad de aceites esenciales de hojas y frutos del aguaribay (Schinus molle L. en el gorgojo del arroz (Sitophilus oryzae L.

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    Verónica Benzi

    2009-06-01

    Full Text Available Rice weevil (Sitophilus oryzae L. is a primary insect pest of stored grain. The development of resistance resulted in the application of synthetic insecticides. In recent years many plant essential oils have provided potential alternatives to currently used insect control agents. The Brazilian pepper tree (Schinus molle L. var. areira (L. DC. (Anacardiaceae has different biological properties such as insecticidal activity. In this study, repellent, fumigant activity, nutritional indices, and feeding deterrent action were evaluated on S. oryzae adults. Filter paper impregnation was used to test fumigant toxicity, whereas treated whole wheat was used to evaluate repellent activity and a flour disk bioassay was done to evaluate feeding deterrent action and nutritional index alteration. Leaf essential oils showed repellent effects at both concentrations (0.04 and 0.4% w/w, while fruit essential oils lacked repellent activity. Both plant oils altered nutritional indices. Fruit essential oils had a strong feeding deterrent action (62% while leaves had a slight effect (40.6%. With respect to fumigant activity, neither of the essential oils was found to be toxic.El gorgojo del arroz (Sitophilus oryzae. L. es un insecto-plaga de infestación primaria de granos. El uso de insecticidas sintéticos ha desarrollado fenómenos de resistencia. En los últimos años los aceites esenciales se presentan como una alternativa en el control de insectos-plaga. El aguaribay (Schinus molle L. var. areira (L. DC. (Anacardiaceae es una planta con diferentes propiedades biológicas entre las que se destacan el uso como insecticida. El objetivo de este estudio fue evaluar la actividad fumigante, repelente, los índices nutricionales y la actividad antialimentaria de los aceites esenciales de hojas y frutos de S. molle var. areira en adultos de S. oryzae. Para la actividad fumigante se utilizó la técnica de impregnación de papeles de filtro; para la actividad repelente

  10. Cloning, expression, and purification of insect (Sitophilus oryzae) alpha-amylase, able to digest granular starch, in Yarrowia lipolytica host

    OpenAIRE

    2014-01-01

    Raw-starch-digesting enzymes (RSDE) are of major importance for industrial applications, as their usage greatly simplifies the starch processing pipeline. To date, only microbial RSDE have gained considerable attention, since only microbial production of enzymes meets industrial demands. In this study, α-amylase from rice weevil (Sitophilus oryzae), the major rice pest, was cloned and expressed in Yarrowia lipolytica Po1g strain. The enzyme was secreted into the culture medium, and the peak a...

  11. Toxic effects of essential plant oils in adult Sitophilus oryzae (Linnaeus (Coleoptera, Curculionidae

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    Andréa Roveré Franz

    2011-03-01

    Full Text Available Toxic effects of essential plant oils in adult Sitophilus oryzae (Linnaeus (Coleoptera, Curculionidae. Stored grains are subject to losses in quality nutritional value and in sanitation from the time they are stored to the time they are consumed. Botanical insecticides may offer an alternative solution for pest control. The objective was to test the insecticidal properties of the essential oils of Cymbopogon citratus (leaf, Zingiber officinale (root and Mentha sp. (leaf. The efficacy of these oils was tested to control the rice weevil, S. oryzae, using hydrodistillation. Chemical analysis of the essential oils was carried out by gas chromatography. Major components of C. citratus were geranial (48% and neral (31%, of Z. officinale were α-zingibereno (13%, geranial (16%, neral (10% and α-farneseno (5% and of Mentha sp. was menthol (92%. Bioassays were carried out by fumigation and topical application. In topical application assays, the essential oil of C. citratus had greater toxicity (LC50 0.027 µL mL-1 and shorter exposure time than the oils of the other two plants. After 24 h and 48 h, 70% and 100% mortality of S. oryzae occurred, respectively. In fumigation assays, essential oil of Z. officinale had a lower LC50 (1.18 µL cm-2 and 70% mortality after 24 h exposure. Therefore, we recommend the use of essential oils of C. citratus and Z. officinale to control the rice weevil S. oryzae.

  12. On automatic bioacoustic detection of pests: the cases of Rhynchophorus ferrugineus and Sitophilus oryzae.

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    Potamitis, Ilyas; Ganchev, Todor; Kontodimas, Dimitris

    2009-08-01

    The present work reports research efforts toward development and evaluation of a unified framework for automatic bioacoustic recognition of specific insect pests. Our approach is based on capturing and automatically recognizing the acoustic emission resulting from typical behaviors, e.g., locomotion and feeding, of the target pests. After acquisition the signals are amplified, filtered, parameterized, and classified by advanced machine learning methods on a portable computer. Specifically, we investigate an advanced signal parameterization scheme that relies on variable size signal segmentation. The feature vector computed for each segment of the signal is composed of the dominant harmonic, which carry information about the periodicity of the signal, and the cepstral coefficients, which carry information about the relative distribution of energy among the different spectral sub-bands. This parameterization offers a reliable representation of both the acoustic emissions of the pests of interest and the interferences from the environment. We illustrate the practical significance of our methodology on two specific cases: 1) a devastating pest for palm plantations, namely, Rhynchophorus ferrugineus Olivier and 2) a pest that attacks warehouse stored rice (Oryza sativa L.), the rice weevil, Sitophilus oryzae (L.) (both Coleoptera: Curculionidae, Dryophorinae). These pests are known in many countries around the world and contribute for significant economical loss. The proposed approach led to detection results in real field trials, reaching 99.1% on real-field recordings of R. ferrugineus and 100% for S. oryzae.

  13. Pleiotropic impact of endosymbiont load and co-occurrence in the maize weevil Sitophilus zeamais.

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    Gislaine A Carvalho

    Full Text Available Individual traits vary among and within populations, and the co-occurrence of different endosymbiont species within a host may take place under varying endosymbiont loads in each individual host. This makes the recognition of the potential impact of such endosymbiont associations in insect species difficult, particularly in insect pest species. The maize weevil, Sitophilus zeamais Motsch. (Coleoptera: Curculionidae, a key pest species of stored cereal grains, exhibits associations with two endosymbiotic bacteria: the obligatory endosymbiont SZPE ("Sitophilus zeamais Primary Endosymbiont" and the facultative endosymbiont Wolbachia. The impact of the lack of SZPE in maize weevil physiology is the impairment of nutrient acquisition and energy metabolism, while Wolbachia is an important factor in reproductive incompatibility. However, the role of endosymbiont load and co-occurrence in insect behavior, grain consumption, body mass and subsequent reproductive factors has not yet been explored. Here we report on the impacts of co-occurrence and varying endosymbiont loads achieved via thermal treatment and antibiotic provision via ingested water in the maize weevil. SZPE exhibited strong effects on respiration rate, grain consumption and weevil body mass, with observed effects on weevil behavior, particularly flight activity, and potential consequences for the management of this pest species. Wolbachia directly favored weevil fertility and exhibited only mild indirect effects, usually enhancing the SZPE effect. SZPE suppression delayed weevil emergence, which reduced the insect population growth rate, and the thermal inactivation of both symbionts prevented insect reproduction. Such findings are likely important for strain divergences reported in the maize weevil and their control, aspects still deserving future attention.

  14. Effet comparé des huiles essentielles de quatre espèces végétales contre la bruche du niébé (Callosobruchus maculatus Fab. et le charançon du riz (Sitophilus oryzae L

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    Gakuru, S.

    1995-01-01

    Full Text Available Compared Effect of Four Plant Essential Oils against Cowpea Weevil Callosobruchus maculatus Fab. and Rice Weevil Sitophilus oryzae L. The aim of this paper is to compare the essential oil effects of Eucalyptus tereticornis Sm., Eucalyptus citriodora Hook, Citrus sinensis (L. Obs. and Ocimum basilicum L. against the cowpea weevil (Callosobruchus maculatus Fab. and the rice weevil (Sitophilus oryzae L. The experiments were conducted in laboratory, in Petri dishes. As nutritive support, we used cowpea and maize grains for respectively C. maculatus and S. oryzae. The Petri dish bottom had a filter paper impregnated with a desired essential oil quantity. The obtained results showed that the tested essential oils were not efficient against S. oryzae. On the other hand, the essential oils of E. citriodora and O. basilicum were very efficient against C. maculatus. The respective LD 50 was 1.26 ml and 1.49 ml in acetone dilution of 2 %.

  15. Resistance of maize varieties to the maize weevil Sitophilus zeamais

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-02

    Nov 2, 2009 ... as an increasingly important problem in Africa (Markham et al., 1994). Cheap and ... Removal of parent weevils and placement on a fresh seed medium ..... stored maize. An M.Sc. Thesis presented to the School of Graduate.

  16. Biotoxic efficacy of two horticultural plants against infestation of Sitophilus oryzae on stored maize

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    Mercy Olayinka ONI

    2016-06-01

    Full Text Available Since botanicals still remained the most promising tool that could obviate the use of chemical insecticides, this study investigated the biotoxic effect of Acacia auriculiformis and Acalypha goddsefiana powder and oil against Sitophilus oryzae. The powder of the plants were tested at 0.0g (control, 0.1, 0.2, 0.4, 0.6, 0.8, 1.0 and 2.0g dosages while their extracts were prepared at 1, 2, 3, 4 and 5% concentrations per 20g of maize seeds. Solvent control was also prepared for the oil extracts bioassay. Mortality, adult emergence, % inhibition rate and % weight loss were observed. LD50 and LC50 of the powders and oils of the two botanicals were calculated at 48 hours of application. The powders of both plants achieved complete weevil mortality within 72h of application at 2.0g and their effect was significantly (p<0.05 different from other dosages except 1.0g dosage. Also, the extracts of both plant achieved 100% insect mortality within 48h hours of application at 5%. However the powder and oil of A. auriculiformis appeared more effective than that of A. goddsefiana in term of mortality as reflected by their lethal dosage and concentration. However, A. goddsefiana powder and extract appeared more effective than that of A. auriculiformis in term of protectability as they greatly reduced the emergence of the adult weevil and their ability to cause weight loss of the maize grains. Only the higher dosages and concentrations of the plants were able to achieve 100% inhibition rate.

  17. Influence of growing location and cultivar on Rhyzopertha dominica (Coleoptera: Bostrichidae) and Sitophilus oryzae (Coleoptera: Curculionidae) infestation of rough rice

    Institute of Scientific and Technical Information of China (English)

    FRANK H. ARTHUR; RUSTY C. BAUTISTA; TERRENCE J. SIEBENMORGEN

    2007-01-01

    Long-grain rice cultivars Cocodrie, Wells, and XP 723 grown in three locations (Hazen, MO; Essex and Newport, AR, USA), and medium-grain rice cultivars Bengal and XP 713 grown in two locations (Jonesboro and Lodge Corner, AR, USA), were harvested and assayed for susceptibility to Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae), the lesser grain borer, and Sitophilus oryzae (L.) (Coleoptera: Curculionidae), the rice weevil, on rice held at 27℃ 57% and 75% relative humidity (RH).Separate samples from the same harvest lots were also analyzed for the physical characteristics of brown rice yield, percentage whole kernels and kernel thickness. Progeny production and feeding damage of R. dominica were significantly different among long-grain cultivars within two of the three locations (P < 0.05), but not for location or RH (P ≥ 0.05), while progeny production of S. oryzae was different among cultivars, location, and RH (P < 0.05). On medium-grain rice, both cultivar and location were significant for progeny production of R. dominica, but not RH, while cultivar and RH were significant for progeny production of S. oryzae, but not location. On both rice types, feeding damage of R. dominica followed the same trends and was always strongly positively correlated with progeny production (P < 0.05), but for S. oryzae there were several instances in which progeny production was not correlated with feeding damage (P ≥ 0.05). Physical characteristics of both rice types were statistically significant (P < 0.01) but actual numerical differences were extremely small, and were generally not correlated with progeny production of either species. Results indicate that the location in which a particular rice cultivar is grown, along with its characteristics, could affect susceptibility of the rice to R. dominica and S. oryzae.

  18. Composition of essential oil of Chinese Chenopodium ambrosioides and insecticidal activity against maize weevil, Sitophilus zeamais.

    Science.gov (United States)

    Chu, Sha Sha; Feng Hu, Jin; Liu, Zhi Long

    2011-06-01

    In a screening programme for new agrochemicals from Chinese medicinal herbs, Chenopodium ambrosioides L. was found to possess strong fumigant activity against the maize weevil Sitophilus zeamais (Motsch.). Essential oil of C. ambrosioides was obtained by hydrodistillation, and the constituents were determined by GC-MS analysis. The active compounds were isolated and identified by bioassay-directed fractionation. Five active compounds [(Z)-ascaridole, 2-carene, ρ-cymene, isoascaridole and α-terpinene] were isolated and identified from the essential oil from Chinese C. ambrosioides. The LC₅₀ values (fumigation) of the crude essential oils and the active compound (Z)-ascaridole against S. zeamais adults were 3.08 and 0.84 mg L⁻¹ air respectively. The LD₅₀ values (contact toxicity) of the crude essential oil and (Z)-ascaridole against S. zeamais adults were 2.12 and 0.86 µg g⁻¹ body weight respectively. The findings suggested that the essential oil of Chenopodium ambrosioides and its main active constituent, (Z)-ascaridole, may be explored as a natural potential fumigant. Copyright © 2011 Society of Chemical Industry.

  19. Does cypermethrin affect enzyme activity, respiration rate and walking behavior of the maize weevil (Sitophilus zeamais)?

    Institute of Scientific and Technical Information of China (English)

    Ronnie Von Santos Veloso; Eliseu José G.Pereira; Raul Narciso C.Guedes; Maria Goreti A.Oliveira

    2013-01-01

    Insecticides cause a range of sub-lethal effects on targeted insects,which are frequently detrimental to them.However,targeted insects are able to cope with insecticides within sub-lethal ranges,which vary with their susceptibility.Here we assessed the response of three strains of the maize weevil Sitophilus zeamais Motschulsky (Coleoptera:Curculionidae) to sub-lethal exposure to the pyrethoid insecticide cypermethrin.We expected enzyme induction associated with cypermethrin resistance since it would aid the resistant insects in surviving such exposure.Lower respiration rate and lower activity were also expected in insecticide-resistant insects since these traits are also likely to favor survivorship under insecticide exposure.Curiously though,cypermethrin did not affect activity of digestive and energy metabolism enzymes,and even reduced the activity of some enzymes (particularly for cellulase and cysteine-proteinase activity in this case).There was strain variation in response,which may be (partially) related to insecticide resistance in some strains.Sub-lethal exposure to cypermethrin depressed proteolytic and mainly cellulolytic activity in the exposed insects,which is likely to impair their fitness.However,such exposure did not affect respiration rate and walking behavior of the insects (except for the susceptible strain where walking activity was reduced).Walking activity varies with strain and may minimize insecticide exposure,which should be a concern,particularly if associated with (physiological) insecticide resistance.

  20. Life History of the Tamarind Weevil, Sitophilus linearis (Herbst (Coleoptera: Curculionidae, on Tamarind Seed

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    James Adebayo Ojo

    2015-01-01

    Full Text Available The tamarind weevil, Sitophilus linearis Herbst (Coleoptera: Curculionidae, is an important pest of tamarind and other Caesalpinioideae. Investigating its life history is important in the implementation of management strategy. Its life history was monitored daily to understand its developmental biology on tamarind seed following standard procedures under laboratory conditions of 24–30°C temperature, 60–70% relative humidity, and 12L : 12D photoperiod. The egg incubation period lasted 3.17 ± 0.07 days. A mated female of S. linearis laid an average of 165 ± 5.78 eggs during an oviposition period of 86.8 ± 2.47 days. There were four larval instars, with a total larval developmental period of 16 days. The pupal period lasted 8 days, and adult lived 108.5 ± 3.61 days. The overall growth ratio for the four instars was 1.33. There was a regular relationship and significant correlation (r=0.94 between the stages of larval development and head capsule width.

  1. Does cypermethrin affect enzyme activity, respiration rate and walking behavior of the maize weevil (Sitophilus zeamais)?

    Science.gov (United States)

    Von Santos Veloso, Ronnie; Pereira, Eliseu José G; Guedes, Raul Narciso C; Oliveira, Maria Goreti A

    2013-06-01

    Insecticides cause a range of sub-lethal effects on targeted insects, which are frequently detrimental to them. However, targeted insects are able to cope with insecticides within sub-lethal ranges, which vary with their susceptibility. Here we assessed the response of three strains of the maize weevil Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) to sub-lethal exposure to the pyrethoid insecticide cypermethrin. We expected enzyme induction associated with cypermethrin resistance since it would aid the resistant insects in surviving such exposure. Lower respiration rate and lower activity were also expected in insecticide-resistant insects since these traits are also likely to favor survivorship under insecticide exposure. Curiously though, cypermethrin did not affect activity of digestive and energy metabolism enzymes, and even reduced the activity of some enzymes (particularly for cellulase and cysteine-proteinase activity in this case). There was strain variation in response, which may be (partially) related to insecticide resistance in some strains. Sub-lethal exposure to cypermethrin depressed proteolytic and mainly cellulolytic activity in the exposed insects, which is likely to impair their fitness. However, such exposure did not affect respiration rate and walking behavior of the insects (except for the susceptible strain where walking activity was reduced). Walking activity varies with strain and may minimize insecticide exposure, which should be a concern, particularly if associated with (physiological) insecticide resistance.

  2. Cloning, expression, and purification of insect (Sitophilus oryzae) alpha-amylase, able to digest granular starch, in Yarrowia lipolytica host.

    Science.gov (United States)

    Celińska, Ewelina; Białas, Wojciech; Borkowska, Monika; Grajek, Włodzimierz

    2015-03-01

    Raw-starch-digesting enzymes (RSDE) are of major importance for industrial applications, as their usage greatly simplifies the starch processing pipeline. To date, only microbial RSDE have gained considerable attention, since only microbial production of enzymes meets industrial demands. In this study, α-amylase from rice weevil (Sitophilus oryzae), the major rice pest, was cloned and expressed in Yarrowia lipolytica Po1g strain. The enzyme was secreted into the culture medium, and the peak activity (81 AU/L) was reached after only 29 h of culturing in 5-L bioreactors. Through simple purification procedure of ammonium sulfate precipitation and affinity chromatography, it was possible to purify the enzyme to apparent homogeneity (25-fold purification factor, at 5 % yield). The optimal conditions for the α-amylase activity were pH 5.0 and a temperature of 40 °C. The α-amylase studied here did not show any obligate requirement for Ca(2+) ions. The recombinant α-amylase appeared to efficiently digest granular starch from pea, amaranth, waxy corn, and waxy rice.

  3. Tithonia diversifolia, Moringa oleifera and Piper auritum: Alternatives for the control of Sitophilus oryzae

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    Leticia Jiménez Álvarez

    2016-07-01

    Full Text Available With the objective to determine the effect exerted by vegetable powders of Tithonia diversifolia (Hemsl A. Gray, Moringa oleifera (Lam y Piper auritum Kunth on Sitophilus oryzae L., this experiment was performed. In the execution, adult insects were taken to evaluate the increase of them. Petri dishes of 9 cm with 10 insects were used inside additionally 5 g of rice (Oryza sativa L. and 0.4 g of powder was added botanical species (T. diversifolia, M. oleifera, P. auritum previously dried at 40 0C for 72 hours and finely ground. At 40 days the test mounted, the number of insects present per plate was counted, and after testing, Z Multiple Comparison was performed using the software Stadistix. The results allowed us to conclude that these plant species are a viable alternative for the control of S. oryzae.

  4. ALIMENTARY PREFERENCE OF SITOPHILUS ORYZAE (COLEOPTERA: CURCULIONIDAE TO BRANDS OF COMMERCIAL RICE FROM PERU

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    Velez-Azañero, Armando

    2013-07-01

    Full Text Available Between February and April 2012 were evaluated the feeding preferences of S. oryzae on four brands of commercial rice from Peru: criollo rendidor®, Chulucanas®, Costeño® and Samán®. It was found that the "rice weevil" showed a food preference for costeño brand. However, oviposition levels were variable, with a larger population of adults in the Saman® brand.

  5. Rice weevil response to basil oil fumigation

    Science.gov (United States)

    Basil oil, Ocimum basilicum L., is a volatile plant essential oil that is known to have insecticidal activity against stored product pests such as rice weevil, Sitophilus oryzae (L.). Basil oil was diluted in acetone and applied to a sponge held inside a tea strainer for fumigations in containers wi...

  6. Insecticidal effect of three diatomaceous earth formulations against adults of Sitophilus oryzae (Coleoptera: Curculionidae) and Tribolium confusum (Coleoptera: Tenebrionidae) on oat, rye, and triticale.

    Science.gov (United States)

    Athanassiou, Christos G; Kavallieratos, Nickolas G; Andris, Nickolas S

    2004-12-01

    Bioassays were conducted in the laboratory to assess the effect of the diatomaceous earth (DE) formulations Insecto, SilicoSec, and PyriSec, on stored oat, rye, and triticale, against adults of the rice weevil, Sitophilus oryzae (L.), and the confused flour beetle, Tribolium confusum Jacquelin du Val. The DEs were tested at three dose rates, 0.75, 1, and 1.5 g of DE/kg of grain. Adults of the two aforementioned species were exposed to all combinations of grain-formulation-dose rate, at 26 degrees C and 60% RH. Mortality in DE-treated commodities was recorded after 24 h, 48 h, 7 d, and 14 d of exposure for S. oryzae and T. confusum and after 21 d for T. confusum. In S. oryzae, adult mortality was almost 100% after 7 d of exposure in all three grains examined. The mortality of T. confusum adults in DE-treated grains did not reach 100%, even after 21 d of exposure. Generally, the application of DE in rye caused higher adult mortality of T. confusum than in the other two products. All three dose rates tested provided the same mortality level of S. oryzae adults after 7 d of exposure. In contrast, 1.5 g of DE resulted in significant higher adult mortality of T. confusum, in comparison with the other dose rates, even after 21 d of exposure. All formulations were equally effective after 7 d of exposure against S. oryzae, but at 48 h of exposure, PyriSec caused significantly higher mortality than the other two formulations. For both species, progeny production in the treated grains was significantly reduced in comparison with the untreated grains, whereas significant differences were noted among commodities, formulations, and dose rates. No progeny were recorded in the treated rye for either species or in the treated triticale for S. oryzae.

  7. Contact toxicity of deltamethrin against Tribolium castaneum (Coleoptera: Tenebrionidae), Sitophilus oryzae (Coleoptera: Curculionidae), and Rhyzopertha dominica (Coleoptera: Bostrichidae) adults

    Science.gov (United States)

    This study was conducted to evaluate deltamethrin-incorporated ZeroFly® Storage Bags for efficacy against stored-product insect pests. We evaluated response to deltamethrin concentrations for adults of three stored-product insects, Tribolium castaneum (Herbst), Sitophilus oryzae (L.), and Rhyzoperth...

  8. High toxicity and specificity of the saponin 3-GlcA-28-AraRhaxyl-medicagenate, from Medicago truncatula seeds, for Sitophilus oryzae

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    Da Silva Pedro

    2012-07-01

    Full Text Available Abstract Background Because of the increasingly concern of consumers and public policy about problems for environment and for public health due to chemical pesticides, the search for molecules more safe is currently of great importance. Particularly, plants are able to fight the pathogens as insects, bacteria or fungi; so that plants could represent a valuable source of new molecules. Results It was observed that Medicago truncatula seed flour displayed a strong toxic activity towards the adults of the rice weevil Sitophilus oryzae (Coleoptera, a major pest of stored cereals. The molecule responsible for toxicity was purified, by solvent extraction and HPLC, and identified as a saponin, namely 3-GlcA-28-AraRhaxyl-medicagenate. Saponins are detergents, and the CMC of this molecule was found to be 0.65 mg per mL. Neither the worm Caenorhabditis elegans nor the bacteria E. coli were found to be sensitive to this saponin, but growth of the yeast Saccharomyces cerevisiae was inhibited at concentrations higher than 100 μg per mL. The purified molecule is toxic for the adults of the rice weevils at concentrations down to 100 μg per g of food, but this does not apply to the others insects tested, including the coleopteran Tribolium castaneum and the Sf9 insect cultured cells. Conclusions This specificity for the weevil led us to investigate this saponin potential for pest control and to propose the hypothesis that this saponin has a specific mode of action, rather than acting via its non-specific detergent properties.

  9. Inheritance and Characterization of Strong Resistance to Phosphine in Sitophilus oryzae (L.)

    Science.gov (United States)

    Nguyen, Tam T.; Collins, Patrick J.; Ebert, Paul R.

    2015-01-01

    Sitophilus oryzae (Linnaeus) is a major pest of stored grain across Southeast Asia and is of increasing concern in other regions due to the advent of strong resistance to phosphine, the fumigant used to protect stored grain from pest insects. We investigated the inheritance of genes controlling resistance to phosphine in a strongly resistant S. oryzae strain (NNSO7525) collected in Australia and find that the trait is autosomally inherited and incompletely recessive with a degree of dominance of -0.66. The strongly resistant strain has an LC50 52 times greater than a susceptible reference strain (LS2) and 9 times greater than a weakly resistant strain (QSO335). Analysis of F2 and backcross progeny indicates that two or more genes are responsible for strong resistance, and that one of these genes, designated So_rph1, not only contributes to strong resistance, but is also responsible for the weak resistance phenotype of strain QSO335. These results demonstrate that the genetic mechanism of phosphine resistance in S. oryzae is similar to that of other stored product insect pests. A unique observation is that a subset of the progeny of an F1 backcross generation are more strongly resistant to phosphine than the parental strongly resistant strain, which may be caused by multiple alleles of one of the resistance genes. PMID:25886629

  10. Inheritance and characterization of strong resistance to phosphine in Sitophilus oryzae (L..

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    Tam T Nguyen

    Full Text Available Sitophilus oryzae (Linnaeus is a major pest of stored grain across Southeast Asia and is of increasing concern in other regions due to the advent of strong resistance to phosphine, the fumigant used to protect stored grain from pest insects. We investigated the inheritance of genes controlling resistance to phosphine in a strongly resistant S. oryzae strain (NNSO7525 collected in Australia and find that the trait is autosomally inherited and incompletely recessive with a degree of dominance of -0.66. The strongly resistant strain has an LC50 52 times greater than a susceptible reference strain (LS2 and 9 times greater than a weakly resistant strain (QSO335. Analysis of F2 and backcross progeny indicates that two or more genes are responsible for strong resistance, and that one of these genes, designated So_rph1, not only contributes to strong resistance, but is also responsible for the weak resistance phenotype of strain QSO335. These results demonstrate that the genetic mechanism of phosphine resistance in S. oryzae is similar to that of other stored product insect pests. A unique observation is that a subset of the progeny of an F1 backcross generation are more strongly resistant to phosphine than the parental strongly resistant strain, which may be caused by multiple alleles of one of the resistance genes.

  11. Inheritance and characterization of strong resistance to phosphine in Sitophilus oryzae (L.).

    Science.gov (United States)

    Nguyen, Tam T; Collins, Patrick J; Ebert, Paul R

    2015-01-01

    Sitophilus oryzae (Linnaeus) is a major pest of stored grain across Southeast Asia and is of increasing concern in other regions due to the advent of strong resistance to phosphine, the fumigant used to protect stored grain from pest insects. We investigated the inheritance of genes controlling resistance to phosphine in a strongly resistant S. oryzae strain (NNSO7525) collected in Australia and find that the trait is autosomally inherited and incompletely recessive with a degree of dominance of -0.66. The strongly resistant strain has an LC50 52 times greater than a susceptible reference strain (LS2) and 9 times greater than a weakly resistant strain (QSO335). Analysis of F2 and backcross progeny indicates that two or more genes are responsible for strong resistance, and that one of these genes, designated So_rph1, not only contributes to strong resistance, but is also responsible for the weak resistance phenotype of strain QSO335. These results demonstrate that the genetic mechanism of phosphine resistance in S. oryzae is similar to that of other stored product insect pests. A unique observation is that a subset of the progeny of an F1 backcross generation are more strongly resistant to phosphine than the parental strongly resistant strain, which may be caused by multiple alleles of one of the resistance genes.

  12. Efficacy of soft-electron (low-energy electron) treatment for disinfestation of brown rice containing different ages of the maize weevil, Sitophilus zeamais Motschulsky

    Science.gov (United States)

    Imamura, Taro; Todoriki, Setsuko; Miyanoshita, Akihiro; Horigane, Akemi K.; Yoshida, Mitsuru; Hayashi, Toru

    2009-07-01

    Soft electrons (low-energy electrons) have been reported to effectively disinfest grains contaminated with stored-product insects. In this study, brown rice grains infested with different ages of the maize weevil, Sitophilus zeamais Motschulsky, were exposed to soft electrons. Soft electrons at an acceleration voltage of 170 kV effectively inactivated eggs, old larvae and pupae of the maize weevil, but could not completely inactivate young larvae. The locations of young larvae in rice grains were specified by magnetic resonance microimaging. Most of the larvae resided at the periphery of the grains while only a few at the center, which were assumed to get out of inactivation. This indicated that soft electrons with low penetration capacity could reach the most of weevil larvae in grains. Combination of soft-electron treatment and short time-low-dose phosphine fumigation achieved high mortality rate of S. zeamais.

  13. Efficacy of soft-electron (low-energy electron) treatment for disinfestation of brown rice containing different ages of the maize weevil, Sitophilus zeamais Motschulsky

    Energy Technology Data Exchange (ETDEWEB)

    Imamura, Taro [National Food Research Institute, NARO Kannondai, Tsukuba, Ibaraki 305-8642 (Japan)], E-mail: taroi@affrc.go.jp; Todoriki, Setsuko; Miyanoshita, Akihiro; Horigane, Akemi K.; Yoshida, Mitsuru; Hayashi, Toru [National Food Research Institute, NARO Kannondai, Tsukuba, Ibaraki 305-8642 (Japan)

    2009-07-15

    Soft electrons (low-energy electrons) have been reported to effectively disinfest grains contaminated with stored-product insects. In this study, brown rice grains infested with different ages of the maize weevil, Sitophilus zeamais Motschulsky, were exposed to soft electrons. Soft electrons at an acceleration voltage of 170 kV effectively inactivated eggs, old larvae and pupae of the maize weevil, but could not completely inactivate young larvae. The locations of young larvae in rice grains were specified by magnetic resonance microimaging. Most of the larvae resided at the periphery of the grains while only a few at the center, which were assumed to get out of inactivation. This indicated that soft electrons with low penetration capacity could reach the most of weevil larvae in grains. Combination of soft-electron treatment and short time-low-dose phosphine fumigation achieved high mortality rate of S. zeamais.

  14. Effect of hypoxia on phosphine resistance of sitophilus oryzae(linné) and rhizopertha dominica(fabricius)%低氧对 PH3抗性米象和谷蠹的控制作用研究

    Institute of Scientific and Technical Information of China (English)

    张涛; 田琳; 伍祎; 汪中明; 贺培欢; 郑丹; 曹阳

    2016-01-01

    针对米象 Sitophilus oryzae(Linné)和谷蠹 Rhizopertha dominica(Fabricius)等主要储粮害虫对PH3抗性越来越高,单一使用 PH3防治难度加大等问题,对2%和5%氧浓度环境控制不同 PH3抗性米象和谷蠹成虫及 F1代的效果进行了实验室验证。结果表明:氧气浓度为2%时,PH3抗性的米象和谷蠹成虫在6 d 内全部死亡,无 F1代出现;氧气浓度为5%时,28 d 后 PH3抗性米象和谷蠹成虫的死亡率小于50%,抗性谷蠹和米象均无 F1代出现。%Phosphine resistance of main stored grain insects such as Rhizopertha dominica(Fabricius)and Sitophilus oryzae(Linné)increased and ,controlling insects by only PH3 was more difficulty than ever. Low oxygen concentrations were used to control lesser grain borer and rice weevil and offspring with differ-ent resistance level to phosphine.The results showed that lesser grain borer and rice weevil adult can be all killed in 2 % oxygen concentrations within 6 days,without offspring,lesser grain borer and rice wee-vil adult can be killed less than 50 % in 5 % oxygen concentrations after 28 days,without offspring.

  15. Phytochemical study and insecticidal activity of Mentha pulegium L. oils from Morocco against Sitophilus Oryzae

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    Touria Zair

    2013-11-01

    Full Text Available There is a growing interest of industry to replace synthetic chemicals by natural products with bioactive properties from plant origin. The aim of this study was to validate the therapeutic properties of Mentha pulegium L. by conducting a phytochemical study, to determine the chemical composition of its essential oils (EO and evaluate its insecticidal activity against stored cereals pests. Leaves and flowers of M. pulegium L. were collected from three regions of the Moroccan Middle Atlas. Phytochemical tests on pennyroyal aerial parts revealed the presence of gallic tannins, flavonoids, alkaloids, sterols and triterpenes and saponins. The chemical composition of essential oils was analyzed by gas chromatography coupled with mass spectrometry. The main components were pulegone and piperitenone. The EO from Khénifra is dominated by pulegone (81.46%, and those from Azrou and M'rirt are rich both in pulegone (68.86 and 71.97% and piperitenone (24.79% and 26.04% respectively. Pennyroyal oil has showed an important fumigant effect against Sitophilus oryzae (L. adults. This effect is influenced by the tested doses and exposure periods. The potential of this plant to be used to control stored product insects was discussed.

  16. Physico-chemical and sensorial characteristics of rice (Oryza sativa L.) irradiated and the effect in Sitophilus oryzae L. development;Caracteristicas fisico-quimicas e sensoriais do arroz (Oryza sativa L.) irradiado e o efeito no desenvolvimento de Sitophilus oryzae L.

    Energy Technology Data Exchange (ETDEWEB)

    Zanao, Cintia Fernanda Pedroso

    2007-07-01

    Rice is exposed to injuries especially due to the attack of insects, which represent great qualitative and quantitative losses. The aim of the present research was to verify the viability of the gamma irradiation as rice (Oryza sativa L.) conservation method; its efficiency in the control of an important pest for stored grains Sitophilus oryzae L. and the effects that irradiation may present in irradiated grains in relation to the sensory aspect and starch alterations. Samples were composed of polished rice and the gamma irradiation dosages used were 0.5; 1.0; 3.0; and 5.0 kGy, and kept at room temperature. Analyses of the grain breakage percentages during processing and the longevity and reproduction of the rice weevil were performed. Analyses of the centesimal composition, phytic acid, apparent amylose content and starch paste properties were also conducted, as well as analyses of the rice color (instrumental) and acceptability (hedonic test), aimed at the determination of the raw and cooked rice sensory quality. It was verified that the gamma irradiation did not change the grain breakage percentage significantly and caused a negative effect on the insect development. Irradiation did not change the centesimal composition significantly. No significant values of phytic acid were found because during rice processing, the outer part (bran) containing 85-92% of total phytates was removed. Values from 17.33 to 18.44% for the apparent amylose content were found, and irradiation did not affect the rice starch amylose content significantly. The paste properties results were significantly changed, where reduction on the paste temperature, decrease on the time for the occurrence of the peak viscosity, reduction on the final viscosity values were observed. The retrogradation tendency became less intense in starches with increasing irradiation dosages. Statistical differences (p<0.05) were detected in the sensory aspect between irradiated and non-irradiated samples, and the

  17. Locomotory and physiological responses induced by clove and cinnamon essential oils in the maize weevil Sitophilus zeamais.

    Science.gov (United States)

    Gonzales Correa, Yenis Del Carmen; Faroni, Lêda R A; Haddi, Khalid; Oliveira, Eugênio E; Pereira, Eliseu José G

    2015-11-01

    Plant essential oils have been suggested as a suitable alternative for controlling stored pests worldwide. However, very little is known about the physiological or behavioral responses induced by these compounds in insect populations that are resistant to traditional insecticides. Thus, this investigation evaluated the toxicity (including the impacts on population growth) as well as the locomotory and respiratory responses induced by clove, Syzygium aromaticum L., and cinnamon, Cinnamomum zeylanicum L., essential oils in Brazilian populations of the maize weevil Sitophilus zeamais. We used populations that are resistant to phosphine and pyrethroids (PyPhR), only resistant to pyrethroids (PyR1 and PyR2) or susceptible to both insecticide types (SUS). The PyPhR population was more tolerant to cinnamon essential oil, and its population growth rate was less affected by both oil types. Insects from this population reduced their respiratory rates (i.e., CO2 production) after being exposed to both oil types and avoided (in free choice-experiments) or reduced their mobility on essential oil-treated surfaces. The PyR1 and PyR2 populations reduced their respiratory rates, avoided (without changing their locomotory behavior in no-choice experiments) essential oil-treated surfaces and their population growth rates were severely affected by both oil types. Individuals from SUS population increased their mobility on surfaces that were treated with both oil types and showed the highest levels of susceptibility to these oils. Our findings indicate that S. zeamais populations that are resistant to traditional insecticides might have distinct but possibly overlapping mechanisms to mitigate the actions of essential oils and traditional insecticides.

  18. Periodic Physical Disturbance: An Alternative Method for Controlling Sitophilus zeamais (Maize Weevil Infestation

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    Rashid Suleiman

    2016-09-01

    Full Text Available Sitophilus zeamais Motschulsky is the most important insect pest of stored maize in tropical regions. The objective of this study was to determine the practicality of periodic physical disturbance on S. zeamais mortality and its adoption by smallholder farmers in developing countries. In this experiment, treatments and control were arranged in a randomized block design with three replications and three storage times in three regions of Tanzania. Region was used as the blocking variable. A total of 108 clean 20-L plastic containers were each loaded with 10 kg of fresh white dent corn and 0.50 kg of maize infested with S. zeamais. For the treatment, containers were disturbed twice a day, whereas for the controls the containers were not disturbed until the end of storage. The overall mortality rate (% after 30, 60, and 90 days of storage were 88%, 96%, and 98%, respectively. A statistically significant difference (p < 0.05 was observed for the number of live S. zeamais between the control and experimental treatments. Additionally, the number of live S. zeamais in the treatment significantly decreased as storage time increased. This study shows the potential of a feasible, simple, affordable, and effective method of protecting maize grain for small-holder farmers in developing countries without using chemicals.

  19. Evaluation of the entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae, and Isaria fumosorosea for control of Sitophilus oryzae.

    Science.gov (United States)

    Kavallieratos, Nickolas G; Athanassiou, Christos G; Aountala, Maria M; Kontodimas, Demetrius C

    2014-01-01

    The entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae, and Isaria fumosorosea were tested against the stored-grain pest Sitophilus oryzae. The fungi were isolated from the soil (from three locations in Attica, Greece: B. bassiana from Tatoion, M. anisopliae from Marathon, and I. fumosorosea from Aghios Stefanos) using larvae of Galleria mellonella as bait. Suspensions of 2.11 × 10(7) and 2.11 × 10(8), 1.77 × 10(7) and 1.77 × 10(8), and 1.81 × 10(7) and 1.81 × 10(8) conidia per ml of B. bassiana, M. anisopliae, and I. fumosorosea, respectively, were applied by three treatments: (i) sprayed on food and set in petri dishes with adults of S. oryzae, (ii) sprayed on adults of S. oryzae and set in petri dishes without food, and (iii) sprayed on adults of S. oryzae and set in petri dishes with food. The observed mortality of S. oryzae adults during the overall exposure period for the lowest, as well as for the highest, concentrations of B. bassiana, M. anisopliae, and I. fumosorosea ranged from 0 to 100%. Concentration was, in most of the cases tested, a critical parameter that determined the "speed of kill" of the exposed insect species for B. bassiana and M. anisopliae. Conversely, concentration was not that critical for I. fumosorosea, and survival was high in some of the combinations tested, even after 14 days of exposure. Both in the highest and the lowest concentrations of fungi, the mortality of S. oryzae adults was higher when the fungi were applied on adults than when they were applied on food. Higher mortality was observed when food was absent than when food was present, in most of the cases tested. The high efficacy levels recorded in the current study indicate that the tested fungi could be effective biocontrol agents against S. oryzae.

  20. AVALIAÇÃO DE RESISTÊNCIA EM VARIEDADES DE ARROZ (Oryza sativa L. AO ATAQUE DO Sitophilus oryzae LINNAEUS, 1763 (COLEOPTERA: CURCULIONIDAE

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    SOUSA, Joseane Rodrigues

    2010-04-01

    Full Text Available The resistance of rice varieties to the attack of Sitophilus oryzae Linnaeus, 1763 (Coleoptera: Curculionidae was evaluated in an experiment conducted in the laboratory of the Universidade Estadual do Maranhão, in a randomized completely design with 19 treatments in six replications. The varieties used in this study were from field experiment conducted in Miranda do Norte, MA between the months of january to may 2006. We evaluated the emerged insects total at 35 and 60 days after harvest and at 35 days was determined thepercentage of grains with defects in the skin. The results showed that the varieties Nenenzinho and Branco Tardão were, respectively, in the two storage periods (35 and 60 days after harvest the most resistant to attack by S. oryzae as the variety Branco Tardão was the most susceptible in both storage of periods.A resistência de variedades de arroz ao ataque do Sitophilus oryzae, Linnaeus, 1763 (Coleoptera: Curculionidae foi avaliada em experimento conduzido em laboratório na Universidade Estadual do Maranhão, em delineamento experimental inteiramente casualizado com 19 tratamentos em seis repetições. As variedades utilizadas nesta pesquisa foram provenientes de experimento conduzido em campo no município de Miranda do Norte, MA entre os meses de janeiro a maio de 2006. Foram avaliados o total de insetos emergidos aos 35 e 60dias após a colheita e aos 35 dias foi determinado o percentual de grãos com defeitos na casca. Os resultados evidenciaram que as variedades Agulha e Nenenzinho foram, respectivamente, nos dois períodos de armazenamento (35 e 60 dias após a colheita as mais resistentes ao ataque de S. oryzae enquanto a variedade Branco Tardão foi a mais suscetível nos dois períodos de armazenamento.

  1. Competition of three species of Sitophilus on rice and maize

    Science.gov (United States)

    Athanassiou, Christos G.; Kavallieratos, Nickolas G.; Campbell, James F.

    2017-01-01

    Laboratory tests were carried out in order to examine competition among three congeneric species on rice and maize: the granary weevil, Sitophilus granarius, the rice weevil, Sitophilus oryzae and the maize weevil, Sitophilus zeamais. For this purpose, a total of 30 adults were placed in vials that contained 50 g or either rice or maize: 30 adults of S. granarius, 30 adults of S. oryzae, 30 adults of S. zeamais, 15 adults of S. granarius+15 adults of S. oryzae, 15 adults of S. granarius+15 adults of S. zeamais, 15 adults of S. oryzae +15 adults of S. zeamais, and 10 adults of S. granarius+10 adults of S. oryzae+10 adults of S. zeamais. After 62 days at 30°C and 65% relative humidity the number of individuals of each species were counted. Insect damaged kernels (IDK), weight of frass and grain weight were measured. When each species was alone, S. granarius had the lowest numbers of adults in both grains, which did not exceed 34 adults/vial, and S. oryzae numbers were always higher than other species. For S. oryzae and S. zeamais, the numbers of adults were considerably higher on rice than on maize. On rice, S. oryzae numbers ranged between 281 and 563 adults per vial, while for S. zeamais between 137 and 372 adults per vial. At the same time, for both species on maize, adult numbers did not exceed 54 adults per vial. The number of S. oryzae adults were constantly higher than the other species in all combinations tested. Moreover, for rice, IDK in the vials that contained S. oryzae, either alone or in combination with other species, was higher than all the other combinations. Similarly, grain weight was lower in the vials that contained S. oryzae compared to the other species combinations. In general, for S. oryzae and S. zeamais progeny production was increased with the increase of the number of the initial adults that had been placed inside the vials. At the same time, progeny production of all three species was not affected by the presence of another species

  2. Effect of ozone on respiration of adult Sitophilus oryzae (L.), Tribolium castaneum (Herbst) and Rhyzopertha dominica (F.).

    Science.gov (United States)

    Lu, Baoqian; Ren, Yonglin; Du, Yu-zhou; Fu, Yueguan; Gu, Jie

    2009-10-01

    The effect of ozone on the respiration of three species of adult stored-product Coleoptera was tested in an air-tight flask. Sitophilus oryzae (L.), Rhyzopertha dominica (F.) and Tribolium castaneum (Herbst) adults were exposed to atmosphere containing 0.1, 0.2 or 0.4microg/ml initial ozone at 23-25 degrees C and 50% r.h. Carbon dioxide (CO(2)) production reflected the respiration rates of insects and was determined with a gas chromatograph (GC). The experiments showed that the effects of ozone on respiration had two distinct phases. Phase 1 involved a lower respiration rate of the adult stored-product Coleoptera under ozone atmosphere and reflected the need for insects to reduce ozone toxicity. After 1h, CO(2) production of S. oryzae was 3.19, 2.63, 2.27 and 1.99microl/mg for the ozone concentration of 0, 0.1, 0.2 and 0.4microg/ml, respectively. The results also showed that there were decreases in the rate of respiration in R. dominica and T. castaneum with an increase in ozone concentration. During phase 2, respiration of S. oryzae, R. dominica, and T. castaneum adults treated with ozone increased as the ozone degraded to oxygen. After 7h, the effect of ozone on CO(2) production, relative to the control, changed from a decrease to an increase. The findings in relation to control strategies were discussed.

  3. Actividad biológica de extractos crudos de Larrea divaricata Cav. y Capparis atamisquea Kuntze sobre Sitophilus oryzae (L. Biological activity of crude extracts of Larrea divaricata Cav. and Capparis atamisquea Kuntze on Sitophilus oryzae (L.

    Directory of Open Access Journals (Sweden)

    A.I. Viglianco

    2006-12-01

    Full Text Available Se evaluaron las propiedades repelentes y antialimentarias de extractos crudos de dos plantas difundidas en la provincia de Córdoba (Argentina, jarilla (Larrea divaricata Cav. y atamisqui (Capparis atamisquea Kuntze., sobre Sitophilus oryzae (L.. Se estudiaron los extractos crudos en etanol, cloroformo y hexano de ambas especies. Para cada extracto se determino el coeficiente de disuasión total. Para las pruebas de repelencia se utilizaron papeles de filtro separados en dos mitades iguales; se determinaron los porcentajes de repelencia de cada extracto. Se observó mayor efecto antialimentario de los extractos de atamisqui con respecto a los de jarilla, y de los de hojas o tallos sobre los de frutos. El extracto de mayor efecto antialimentario fue el etanólico de tallos de atamisqui (clase ++++ seguido por los extractos etanólico y clorofórmico de hojas de esta especie (clase +++. Se observó un moderado efecto de repelencia de los extractos de jarilla y atamisqui sobre S. oryzae, destacándose el de hojas de atamisqui en hexano como el de mayor efecto de repelencia (clase IV. El extracto clorofórmico de hojas de atamisqui, los tres de hoja de jarilla y los clorofórmicos de tallos y frutos de jarilla presentaron efecto de repelencia (clase III.Repellent and antifeedant properties of crude extracts of two plants widely distributed in the province of Córdoba (Argentina, jarilla (Larrea divaricata Cav. and atamisqui (Capparis atamisquea Kuntze on Sitophilus oryzae were studied. Crude extracts in ethanol, chloroform and hexane of both species were evaluated. The Total Deterrence Coefficient for each extract was determined. Repellence tests were conducted using filter paper separated in halves. Repellence percentages were determined for each extract. A greater antifeedant effect was observed in the atamisqui extracts than in the jarilla ones; the effect was also greater in extracts of leaves or twigs than in extracts of fruits. The extracts

  4. Comparative toxicity and micronuclei formation in Tribolium castaneum, Callosobruchus maculatus and Sitophilus oryzae exposed to high doses of gamma radiation.

    Science.gov (United States)

    Ahmadi, Mehrdad; Mozdarani, Hossein; Abd-Alla, Adly M M

    2015-07-01

    The effects of gamma radiation on mortality and micronucleus formation in Tribolium castaneum Herbst, Callosobruchus maculatus (F.) and Sitophilus oryzae (L.) genital cells were evaluated. Two groups of healthy and active adult insects 1-3 and 8-10 days old were irradiated with various doses (50-200 Gy) gamma ray. Seven days post-irradiation; mortality rates and micronucleus formation were assessed in genital cells of the irradiated insects. The results show that with increasing gamma doses, the mortality rate of each species increased and T. castaneum and S. oryzae showed the low and high sensitivity respectively. It was shown that the micronucleus appearance in the tested insects had correlation with amount and intensity of radiation doses. Moreover our results indicate different levels in the genotoxicity of gamma radiation among the insects' genital cells under study. The frequency of micronuclei in genital cells of 1-3 days old insects exposed to 50 and 200 Gy were 12.6 and 38.8 Mn/1000 cells in T. castaneum, 20.8 and 46.8 Mn/1000 cells in C. maculatus and 16.8 and 57.2 Mn/1000 cells in S. oryzae respectively. A high sensitivity of the genital cells to irradiation exposure was seen in S. oryzae correlated with its high mortality rate compared with the other two species. These results might be indicative of inflicting chromosomal damage expressed as micronucleus in high mortality rates observed in the pest population; an indication of genotoxic effects of radiation on the studied species.

  5. Susceptibility of Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) and Sitophilus oryzae (L.) (Coleoptera: Curculionidae) to Spinosad (Tracer®) as a Eco-friendly Biopesticide

    OpenAIRE

    Reza Sadeghi; Asgar Ebadollahi

    2015-01-01

    Rhyzopertha dominica (F.) and Sitophilus oryzae (L.) are internal feeder of various stored grains and introducted as major stored product insect pests. Due to the resistance by insect pests and negative effects of synthetic pesticides to the environment, it is necessary to use novel and suitable compounds in insect pest’s management. Spinosad is a bio-insecticide that is derived from fermentation of a bacterium Saccharopolyspora spinosa Mertz and Yao. In the present study, the toxicity of Tra...

  6. Insecticidal Effect of Fruit Extracts from Xylopia aethiopica and Dennettia tripetala (Annonaceae against Sitophilus oryzae (Coleoptera: Curculionidae Efecto Insecticida de Extractos de Fruta de Xylopia aethiopica y Dennettia tripetala (Annonaceae contra Sitophilus oryzae (Coleoptera: Curculionidae

    Directory of Open Access Journals (Sweden)

    Donald A . Ukeh

    2012-06-01

    Full Text Available The insecticidal and repellent activities of fruit extracts of Xylopia aethiopica (Dunal A. Rich. and Dennettia tripetala (Baker f. G.E. Schatz belonging to the family Annonaceae was studied against Sitophilus oryzae (L., an economic, primary post-harvest pest of rice, and other cereal products. Infested rice grains (100 g treated with 1, 2, 3, 4, and 5% (w/w powders of both plants were evaluated for toxicity against S. oryzae every 24 h for 3 d, and during Fi progeny emergence. The essential oils of both plants were also applied at 0.5, 1, 1.5 and 2 mg cm-2 filter paper in Petri dishes for toxicity bioassays at 24 h exposure. Repellence bioassay with 10 μL solution of essential oils on filter paper was performed in a Y-Tube airflow olfactometer. Results indicate that powders of both plants significantly (P La actividad insecticida y repelente de los extractos frutales de Xylopia aethiopica (Dunal A. Rich. y Dennettia tripetala (Baker f. G.E. Schatz pertenecientes a la familia Annonaceae fueron evaluados contra Sitophilus oryzae (L., plaga primaria de importancia económica en poscosecha de arroz y otros cereales. Granos de arroz (100 g infestados tratados con polvos de ambas plantas al 1, 2, 3, 4, y 5% (p/p fueron evaluados para la toxicidad contra S. oryzae cada 24 h por 3 d y durante la emergencia de la progenie F1. Los aceites esenciales de ambas plantas también fueron aplicados en papel filtro a 0,5; 1; 1,5 y 2 mg cm-2 en cajas de Petri para bioensayos de toxicidad con exposición de 24 h. Bioensayos de repelencia con 10 μL de solución de los aceites esenciales impregnados en papel filtro fueron realizados en un olfatómetro de flujo de aire Y-Tube. Los resultados indican que los polvos de ambas plantas causan una mortalidad significativa de estos insectos (P < 0,001 y una reducción en la emergencia de la progenie F1 con relación al control. Los aceites esenciales también mostraron un efecto adulticida significativo (P < 0,001 despu

  7. Characterization and selection of Bacillus thuringiensis isolates effective against Sitophilus oryzae Caracterização e seleção de isolados de Bacillus thuringiensis efetivos contra Sitophilus oryzae

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    Najara da Silva

    2010-08-01

    Full Text Available The entomopathogenic bacterium Bacillus thuringiensis is a control agent with toxic and environmental characteristics that allows the control of pest insects according to the Integrate Pest Management (IPM precepts. In order to find new strains, potentially toxic to Sitophilus oryzae L. 1763 (Coleoptera: Curculinidae, 1.073 strains of B. thuringiensis from parts of Brazil were used. Genetic material was extracted with InstaGene Matrix kit, used for the amplification of sequences in Polymerase chain reaction (PCR, and viewed in 1.5% agarose gel. The gene cry35Ba class was represented by 60 B. thuringiensis isolates (5.6%, which were then subjected to bioassays with S. oryzae larvae. Among the isolates studied, four caused more than 50% mortality in pathogenicity tests, and the isolates 544 and 622 were the most virulent, as determined by CL50 estimates. The four toxic isolates had spherical, bi-pyramidal and cuboid crystals, and a 44-kDa protein was found in sodium dodecyl sulphate - polyacrylamide gel electrophoresis (SDS-PAGE, which coded for the product of cry35Ba genes. These data demonstrate the potential of B. thuringiensis for the management of S. oryzae larvae.A bactéria entomopatogênica Bacillus thuringiensis (Bt é um agente de controle com características tóxicas e ambientais que permitem o controle de insetos-praga de acordo com as premissas do Manejo integrado de pragas (MIP. Com o objetivo de buscar novas linhagens potencialmente tóxicas para Sitophilus oryzae L. 1763 (Coleoptera: Curculinidae, caracterizaram-se molecularmente 1,073 isolados de B. thuringiensis de regiões do Brasil. O material genético foi extraído através do kit InstaGene Matrix, utilizado para a amplificação das seqüências através da técnica de Polymerase chain reaction PCR, sendo os resultados visualizados em gel de agarose 1,5%. A classe do gene cry35Ba foi representada por 60 isolados (5,6% de Bt, os quais foram submetidos a bioensaio com larvas

  8. Cytogenetic analyses using C-banding and DAPI/CMA3 staining of four populations of the maize weevil Sitophilus zeamais Motschulsky, 1855 (Coleoptera, Curculionidae

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    Alexandra A. da Silva

    2015-03-01

    Full Text Available Cytogenetic data avalaible for the maize weevil Sitophilus zeamais Motschulsky, 1855 (Coleoptera: Curculionidae, one of the most destructive pests of stored cereal grains, are controversial. Earlier studies focused on single populations and emphasized chromosome number and sex determination system. In this paper, the karyotypes of four populations of S. zeamais were characterized by conventional staining, C-banding and sequential staining with the fluorochromes chromomycin-A3/4-6-diamidino-2-phenylindole (CMA3/DAPI. The analyses of metaphases obtained from the cerebral ganglia of last instar larvae and the testes of adults showed that the species had 2n = 22 chromosomes, with 10 autosomal pairs and a sex chromosome pair (XX in females and Xyp in males. Chromosome number, however, ranged from 2n = 22 to 26 due to the presence of 0–4 supernumerary chromosomes in individuals from the populations of Viçosa, Unai and Porto Alegre. With the exception of the Y chromosome, which was dot-like, all other chromosomes of this species were metacentric, including the supernumeraries. The heterochromatin was present in the centromeric regions of all autosomes and in the centromere of the X chromosome. The B chromosomes were partially or totally heterochromatic, and the Y chromosome was euchromatic. The heterochromatic regions were labeled with C-banding and DAPI, which showed that they were rich in AT base pairs.

  9. Efeito da irradiação gama nas características físico-químicas e sensoriais do arroz (Oryza sativa L. e no desenvolvimento de Sitophilus oryzae L. Effect of gamma irradiation on physico-chemical and sensorial characteristics of rice (Oryza sativa L. and on the development of Sitophilus oryzae L.

    Directory of Open Access Journals (Sweden)

    Cíntia Fernanda Pedroso Zanão

    2009-03-01

    Full Text Available A pesquisa teve como objetivo verificar a viabilidade da radiação gama como método de conservação do arroz polido (Oryza sativa L.. As amostras foram irradiadas com doses 0,5; 1,0; 3,0; e 5,0 kGy. Foram realizadas análises da quebra do grão no beneficiamento, da longevidade e reprodução do Sitophilus oryzae L., a composição centesimal, o conteúdo de amilose aparente e propriedades de pasta dos amidos, e análises para cor (instrumental e análise sensorial do arroz cru e cozido. Foi utilizado teste de Tukey (p The objective of this research was to verify the viability of the gamma radiation as polished rice (Oryza sativa L. conservation method. The samples were irradiated with doses of 0.5; 1.0; 3.0; and 5.0 kGy. Analysis of the grain breakage during the enriching process, longevity and reproduction of the Sitophilus oryzae L., centesimal composition, apparent amylose content, starch paste properties, color (instrumental, and the sensorial evaluation of raw and cooked rice were performed. It was verified that the irradiation did not change the percentage of grain breakage during the enrichment process, and it caused a negative effect on the development of insects. The irradiation did not change significantly the centesimal composition and the apparent amylase content. The Tukey test (p < 0.05 was conducted to verify the differences between the treatments. Gamma irradiation affected the pasting properties of the rice flour. Pasting parameters as temperature, peak, final viscosity, and setback values showed decreasing values with irradiation doses. Differences were detected in the sensorial aspect among the samples, and the sample irradiated with the dose of 1.0 kGy presented greater averages. Regarding the instrumental color parameter, it was observed the difference in the values b* indicating that the rice changed the white color for yellowish with the increase in the irradiation dose. The irradiation dose of 1.0 kGy proved the best

  10. Effect of gamma irradiation on physico-chemical and sensorial characteristics of rice (Oryza sativa L.) and on the development of Sitophilus oryzae L; Efeito da irradiacao gama nas caracteristicas fisico-quimicas e sensoriais do arroz (Oryza sativa L.) e no desenvolvimento de Sitophilus oryzae L

    Energy Technology Data Exchange (ETDEWEB)

    Zanao, Cintia Fernanda Pedroso; Canniatti-Brazaca, Solange Guidolin; Sarmento, Silene Bruder Silveira [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Dept. de Agroindustria, Alimentos e Nutricao], e-mail: sgcbrazaca@esalq.usp.br, e-mail: cpedroso@claretianas.com.br, e-mail: sbssarme@esalq.usp.br; Arthur, Valter [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). Lab. de Irradiacao de Alimentos e Radioentomologia], e-mail: arthur@cena.usp.br

    2009-01-15

    The objective of this research was to verify the viability of the gamma radiation as polished rice (Oryza sativa L.) conservation method. The samples were irradiated with doses of 0.5; 1.0; 3.0; and 5.0 kGy. Analysis of the grain breakage during the enriching process, longevity and reproduction of the Sitophilus oryzae L., centesimal composition, apparent amylose content, starch paste properties, color (instrumental), and the sensorial evaluation of raw and cooked rice were performed. It was verified that the irradiation did not change the percentage of grain breakage during the enrichment process, and it caused a negative effect on the development of insects. The irradiation did not change significantly the centesimal composition and the apparent amylase content. The Tukey test (p {<=} 0.05) was conducted to verify the differences between the treatments. Gamma irradiation affected the pasting properties of the rice flour. Pasting parameters as temperature, peak, final viscosity, and setback values showed decreasing values with irradiation doses. Differences were detected in the sensorial aspect among the samples, and the sample irradiated with the dose of 1.0 kGy presented greater averages. Regarding the instrumental color parameter, it was observed the difference in the values b{sup *} indicating that the rice changed the white color for yellowish with the increase in the irradiation dose. The irradiation dose of 1.0 kGy proved the best to meet the objectives of this study. (author)

  11. Effect of two azadirachtin formulations against adults of Sitophilus oryzae and Tribolium confusum on different grain commodities.

    Science.gov (United States)

    Kavallieratos, Nickolas G; Athanassiou, Christos G; Saitanis, Constantin J; Kontodimas, Demetrius C; Roussos, Alexander N; Tsoutsa, Maria S; Anastassopoulou, Urania A

    2007-07-01

    The insecticidal effect of two azadirachtin-based insecticides, NeemAzal-T/S and Oikos 32 EC, was examined against adults of the grain beetles Sitophilus oryzae and Tribolium confusum on wheat and maize under different temperature and humidity regimes. The insecticides were applied at three dosages, equivalent to 50, 100, and 200 mg of active ingredient per kg of grain. Adults of the above species were exposed to the treated grains at 20, 25, and 30 degrees C and two relative humidity levels (55 and 75%), and mortality was assessed after 14 days of exposure. All adults were then removed, and the treated substrate remained under the same conditions for 45 more days. After this period, the grains were checked for progeny production. In both species and both commodities, mortality increased with insecticide dosage. For many dosage-formulation combinations, mortality increased with temperature at 55% relative humidity but the reverse was observed at 75% relative humidity. Comparing the two formulations, NeemAzal-T/S was more effective than Oikos 32 EC at all the combinations tested. NeemAzal-T/S was more effective at high relative humidity, but the efficacy of Oikos 32 EC was not much affected by the relative humidity. Survival was high, even at the higher dosages, in some of the temperature-humidity combinations. Progeny production of S. oryzae in the treated grains was considerably higher than that of T. confusum. The results of the present study indicate that further dosage increases and longer exposure times are needed to obtain a complete (100%) adult mortality in all combinations tested. However, the feasibility of using higher azadirachtin dosages (>200 mg/kg grain) is questionable for cost reasons. Consequently, the use of these substances is not comparable to the use of traditional grain protectants, which are usually used at dosages of <5 mg/kg grain. Although azadirachtin-based insecticides can be used with success for protection of stored grain, our study

  12. Partial purification and characterization of trypsin-like proteinases from insecticide-resistant and -susceptible strains of the maize weevil, Sitophilus zeamais.

    Science.gov (United States)

    Silva, L B; Reis, A P; Pereira, E J G; Oliveira, M G A; Guedes, R N C

    2010-01-01

    Serine proteinases from three strains of Sitophilus zeamais (Coleoptera: Curculionidae), one susceptible and two resistant to insecticides--one exhibiting fitness cost (resistant cost strain) and the other lacking it (resistant no-cost strain), were partially purified using an aprotinin-agarose affinity column providing purification factors ranging from 36.5 to 51.2%, with yields between 10 and 15% and activity between 529 and 875 microM/min/mg protein with the substrate N-alpha-benzoyl-L-Arg-p-nitroanilide (L-BApNA). SDS-PAGE of the purified fraction revealed a 56,000 Da molecular mass band in all strains and a 70,000 Da band more visible in the resistant no-cost strain. The purified proteinases from all strains were inhibited by phenylmethyl sulphonyl fluoride (PMSF), N-alpha-tosyl-L-lysine chloromethyl ketone (TLCK), aprotinin, benzamidine and soybean trypsin inhibitor (SBTI) characterizing them as trypsin-like serine proteinases. Trypsin-like proteinases from the resistant strains exhibited higher affinity for L-BApNA. The resistant no-cost strain exhibited V(max)-values 1.5- and 1.7-fold higher than the susceptible and resistance cost strains, respectively. A similar trend was also observed when using N-alpha-p-tosyl-L-Arg methyl ester (L-TAME) as substrate. These results provide support to the hypothesis that the enhanced serine proteinase activity may be playing a role in mitigating physiological costs associated with the maintenance of insecticide resistance mechanisms in some maize weevil strains.

  13. Susceptibility of Rhyzopertha dominica (F. (Coleoptera: Bostrichidae and Sitophilus oryzae (L. (Coleoptera: Curculionidae to Spinosad (Tracer® as a Eco-friendly Biopesticide

    Directory of Open Access Journals (Sweden)

    Reza Sadeghi

    2015-06-01

    Full Text Available Rhyzopertha dominica (F. and Sitophilus oryzae (L. are internal feeder of various stored grains and introducted as major stored product insect pests. Due to the resistance by insect pests and negative effects of synthetic pesticides to the environment, it is necessary to use novel and suitable compounds in insect pest’s management. Spinosad is a bio-insecticide that is derived from fermentation of a bacterium Saccharopolyspora spinosa Mertz and Yao. In the present study, the toxicity of Tracer® as a spinosad based insecticidise was evaluated against R. dominica and S. oryzae. Insect species were kept in stored-products insects rearing room in Agriculture Faculty of Tehran University at 27 ± 2ºC, 65 ± 5% relative humidity. Adult insects were exposed to different concentrations of Tracer® by oral trials for 10 and 20 days exposure periods. The mortality data were subjected to probit analysis using SPSS software to estimate LC (lethal concentration values and their related information. Tracer® showed strong toxicity against the adults of R. dominica and S. oryzae. Maximum mortality was occurred in the concentration of 250 and 80 ppm after 20 days exposure for R. dominica and S. oryzae, respectively. Direct relationship between mortality of insects with concentration and exposure period was found. Probit analysis displayed R. dominica (10-days LC50 = 49.89 ppm was more susceptible than S. oryzae (10-days LC50 = 50.75 ppm to Tracer®. Results of present study stimulated the utilization of Tracer® as an eco-friendly and safe agent for insect pests’ management.

  14. External and internal structure of weevils (Insecta: Coleoptera) investigated with phase-contrast X-ray imaging

    Science.gov (United States)

    Hönnicke, M. G.; Cusatis, C.; Rigon, L.; Menk, R.-H.; Arfelli, F.; Foerster, L. A.; Rosado-Neto, G. H.

    2010-08-01

    Weevils (Coleoptera: Curculionidae) are identified by the external structure (dorsal, ventral and lateral features) and also by internal structure. The genitalia can be used to distinguish the sex and to identify the insects when the external structure appears identical. For this purpose, a destructive dissecting microscopy procedure is usually employed. In this paper, phase contrast X-ray imaging (radiography and tomography) is employed to investigate the internal structure (genitalia) of two entire species of weevils that presents very similar external structures ( Sitophilus oryzae and Sitophilus zeamais). The detection of features, which looks like the genital structure, shows that such non-destructive technique could be used as an alternative method for identification of insects. This method is especially useful in examining the internal features of precious species from museum collections, as already described in the recent literature.

  15. External and internal structure of weevils (Insecta: Coleoptera) investigated with phase-contrast X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Hoennicke, M.G., E-mail: mhonnicke@bnl.go [NSLS II, Brookhaven National Laboratory, Upton, NY (United States); Cusatis, C. [LORXI, Departamento de Fisica-UFPR, Curitiba (Brazil); Rigon, L. [Instituto Nazionale di Fisica Nucleare, Trieste (Italy); Menk, R.-H. [Sincrotrone Trieste SCPa, Basovizza, Trieste (Italy); Arfelli, F. [Instituto Nazionale di Fisica Nucleare, Trieste (Italy); Dipartamento di Fisica-Universita di Trieste, Trieste (Italy); Foerster, L.A.; Rosado-Neto, G.H. [Departamento de Zoologia-UFPR, Curitiba (Brazil)

    2010-08-21

    Weevils (Coleoptera: Curculionidae) are identified by the external structure (dorsal, ventral and lateral features) and also by internal structure. The genitalia can be used to distinguish the sex and to identify the insects when the external structure appears identical. For this purpose, a destructive dissecting microscopy procedure is usually employed. In this paper, phase contrast X-ray imaging (radiography and tomography) is employed to investigate the internal structure (genitalia) of two entire species of weevils that presents very similar external structures (Sitophilus oryzae and Sitophilus zeamais). The detection of features, which looks like the genital structure, shows that such non-destructive technique could be used as an alternative method for identification of insects. This method is especially useful in examining the internal features of precious species from museum collections, as already described in the recent literature.

  16. Susceptibility of Two Sitophilus species (Coleoptera: Curculionidae to Essential Oils from Foeniculum vulgare and Satureja hortensis

    Directory of Open Access Journals (Sweden)

    Asgar Ebadollahi

    2011-12-01

    Full Text Available This study was conducted to determine the insecticidal activity of essential oils from Fennel, Foeniculum vulgare (Apiaceae, and Summer savory, Satureja hortensis (Lamiaceae, against two stored-product insects. Essential oils from two species of plants were obtained by Clevenger-type water distillation and their fumigant toxicities were tested against adults of the wheat weevil, Sitophilus granarius and rice weevil, Sitophilus oryzae (Curculionidae. The mortality was determined after 24 and 48 hrs from beginning of exposure. LC50 values of each essential oil were estimated for each insect species. Fumigation bioassays revealed that essential oils from two plants had strong insecticidal activity on experimental insects. LC50 values indicated that S. granarius was more susceptible than S. oryzae to essential oils at the exposure time 24 and 48 hrs. The mortality effect of S. hortensis oil was lower than F. vulgare oil. The LC50 values decreased with the duration of exposure to the essential oil concentrations. In all case, responses varied according to plant material, concentration, and exposure time. These results indicated that essential oils from S. hortensis and F. vulgare could be applicable to the management of stored product insects to decrease ecologically detrimental effects of utilization synthetic insecticides.

  17. Insecticidal efficacy of silica gel with Juniperus oxycedrus ssp. oxycedrus (Pinales: Cupressaceae) essential oil against Sitophilus oryzae (Coleoptera: Curculionidae) and Tribolium confusum (Coleoptera: Tenebrionidae).

    Science.gov (United States)

    Athanassiou, Christos G; Kavallieratos, Nickolas C; Evergetis, Epameinondas; Katsoula, Anna-Maria; Haroutounian, Serkos A

    2013-08-01

    Laboratory bioassays were carried out to evaluate the effect of silica gel enhanced with the essential oil (EO) of Juniperus oxycedrus L. ssp. oxycedrus (Pinales: Cupressaceae) (derived from berry specimens from Greece) against adults of Sitophilus oryzae (L.) (Coleoptera: Curculionidae) and Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae). For that purpose, a dry mixture consisting of 500 mg of silica gel that had absorbed 2.18 mg of EO (total weight: 502.18 mg) was tested at three doses; 0.125, 0.250, and 0.5 g/kg of wheat, corresponding to 125, 250, and 500 ppm, respectively, and silica gel alone at 0.5 g/kg of wheat corresponding to 500 ppm, at different exposure intervals (24 and 48 h and 7 and 14 d for S. oryzae; 24 and 48 h and 7, 14, and 21 d for T. confusum). The chemical content of the specific EO was determined by gas chromatography (GC)-mass spectrometry (MS) analyses indicating the presence of 31 constituents with myrcene and germacrene-D being the predominant compounds. The bioactivity results for S. oryzae indicated that 48 h of exposure in wheat resulted in an 82% mortality for treatment with 500 ppm of the enhanced silica gel. For 7 d of exposure, 100 and 98% of S. oryzae adults died when they were treated with 500 and 250 ppm of enhanced silica gel, respectively. At 14 d of exposure, all adults died both at 250 and 500 ppm of enhanced silica gel. At 48 h, 7 and 14 d of exposure significantly less S. oryzae adults died in wheat treated with silica gel alone than at 250 or 500 ppm of enhanced silica gel. In the case of T. confusum, at 7 d of exposure, mortality in wheat treated with silica gel only was significantly higher in comparison to the other treatments. At the 14 d of exposure mortality in wheat treated with 500 ppm of silica gel alone was significantly higher than 125 and 250 ppm of the enhanced silica gel. Similar trends were also noted at 21 d of exposure, indicating that there is no enhancement effect from the addition of

  18. Avaliação de inseticidas no controle de Sitophilus oryzae (Linnaeus (Coleoptera, Curculionidae e Rhyzopertha dominica (Fabricius (Coleoptera, Bostrichidae em trigo armazenado Efficacy of insecticides to control Sitophilus oryzae (Linnaeus (Coleoptera, Curculionidae and Rhyzopertha dominica (Fabricius (Coleoptera, Bostrichidae in stored wheat

    Directory of Open Access Journals (Sweden)

    Rui S. Furiatti

    1999-03-01

    Full Text Available The efficiency of insecticides against Sitophilus oryzae (Linnaeus, 1763 (Coleoptera, Curculionidae and Rhyzopertha dominica (Fabricius, 1792 (Coleoptera, Bostrichidae was determined exposing them to treated wheat in laboratory. Each plot, which was composed by 1.2 kg of wheat grain, was treated with 5 ml of the concentration/kg of wheat using a propelling air atomizer. Fifteen days after treatment 50 g samples of the grain were taken, from each plot, placed in plastic jars into which 10 adult insects of each species were released. This was repeated every 30 days until 165 days after treatment. The number of dead insects was counted 15 days after each infestation thus the evaluations were made at 30, 60, 90, 120, 150 and 180 days after the insecticide application. Esfenvalerate+fenitrothion+pyperonil butoxide (0,375+7,5+3,0 and 0,5+10,0+4,0 g a.i./t, fenitrothion+esfen-valerate (7,5+0,375 and 10,0+0,375 g a.i./t, fenitrothion+synergised deltamethrin (7,5+0,375 g a.i./t and fenitrothion (7,5 g a.i./t were effective against Sitophilus oryzae until 180 days after treatment. Esfenvalerate+fenitrothion+pyperonil butoxide (0,5+10,0+4,0 g a.i./t, fenitrothion+esfenvalerate (7,5+0,375 and 10,0+0,375 g a.i./t, fenitrothion+synergised deltamethrin (7,5+0,375 g a.i./t were effective against R. dominica until 180 days after treatment. Synergised deltamethrin (0,375 g a.i./t was effective against S. oryzae until 150 days and against R. dominica until 120 days after treatment. Esfenvalerate (0,5 g a.i./t was ineffective against S. oryzae and effective until 60 days after treatment against R. dominica. Fenitrothion (7,5 g a.i./t was ineffective against R. dominica. The use of mixtures of organophosphorus plus pyrethroids were more effective against S. oryzae and R. dominica when compared with these insecticides used alone.

  19. Efficacité des huiles essentielles d'Eucalyptus camaldulensis et de Cymbopogon citratus dans la protection des stocks de riz contre Sitophilus oryzae (Coleoptera: Curculionidae) et Sitotroga cerealella (Lepidoptera: Gelechiidae)

    OpenAIRE

    Togola, A.; Silvie, Pierre; Seck, P.A.; Menozzi, P.; Nwilene, F. E.; Glitho, I.A.; Chougourou, D.

    2014-01-01

    L'augmentation de la production rizicole en Afrique Subsaharienne et la recrudescence conséquente des ravageurs de stocks tels que Sitophilus oryzae et Sitotroga cerealella nécessitent des actions d'accompagnement de la recherche afin de préserver la qualité et la quantité des récoltes entreposées. Les méthodes de lutte les plus largement utilisées en milieu paysan dans le cadre de la protection des stocks sont les méthodes chimiques. Il apparaît nécessaire de développer de nouvelles mesures ...

  20. Research on the Repelling Action of Rhizoma Galangae Extracts on Sitophilus Oryzae Ephebic%高良姜提取物对米象成虫的驱避作用研究

    Institute of Scientific and Technical Information of China (English)

    肖雅斌; 石运庆; 于航; 王祺; 刘洋

    2012-01-01

    Rhizoma galangae extracts were obtained using soxhlet extraction method. Control method was adopted to study its repelling action on sitophilus oryzae ephebic. The experiment results show that rhizoma galangae extracts have a strong repelling action on sitophilus oryzae ephebic with a repelling rate of 77% which belongs to Ⅳ level. The ideal repelling time is 36--48 h with a repelling rate of 85%, or of Ⅴ level. In a word, rhizoma galangae is a relatively ideal botanic pesticide.%利用索氏提取法提取高良姜植物提取物后,采用对照方法,探讨其对米象成虫的驱避作用。试验结果表明:高良姜植物提取物对米象成虫的驱避作用较强,驱避率达77%以上,属于Ⅳ级水平;最理想的驱避时间是36—48h,驱避率在85%以上,可达Ⅴ级水平。总体来说,高良姜是相对理想的植物源农药。

  1. Resposta de Sitophilus oryzae (L., Cryptolestes ferrugineus (Stephens e Oryzaephilus surinamensis (L. a diferentes concentrações de terra de diatomácea em trigo armazenado a granel Response of Sitophilus oryzae (L., Cryptolestes ferrugineus (Stephens and Oryzaephilus surinamensis (L. to different concentrations of diatomaceous earth in bulk stored wheat

    Directory of Open Access Journals (Sweden)

    Airton Rodrigues Pinto Júnior

    2008-11-01

    Full Text Available Formulações de terra de diatomácea de diferentes origens apresentam variação em toxicidade e em características físicas que afetam sua eficácia. Da mesma forma, diferentes espécies de insetos variam quanto a sua suscetibilidade ao produto. Adultos de Sitophilus oryzae (L., Cryptolestes ferrugineus (Stephens e Oryzaephilus surinamensis (L. foram expostos a concentrações de 250, 500, 750, 1000 e 1250g t-1 de uma formulação de terra de diatomácea de origem brasileira (Keepdry®, em trigo armazenado, por diferentes períodos de exposição. Os grãos tratados com as diferentes concentrações foram colocados em frascos, com quatro repetições de 100g de grãos por tratamento, e infestados com os insetos. Os frascos foram mantidos em câmara climatizada a 25°C e 65% UR, avaliando-se a mortalidade periodicamente. O número de insetos mortos por parcela foi submetido à análise de variância e as diferenças entre as médias discriminadas pelo teste de Tukey a 5%. A mortalidade das três espécies foi diretamente relacionada à concentração e ao tempo de exposição, sendo que os melhores resultados foram obtidos com concentrações acima de 500g t-1. A espécie S. oryzae atingiu 100% de mortalidade somente no 14° dia de exposição, na concentração de 750g t-1. C. ferrugineus foi a espécie mais suscetível ao tratamento com a terra de diatomácea, com 100% de mortalidade a 500g t-1 já no 4° dia. Conclui-se que a terra de diatomácea utilizada apresenta um nível de controle satisfatório, e pode ser utilizada em programas de manejo de insetos, em trigo armazenado.Formulations of diatomaceous earth from different sources show variation in toxicity and in certain physical characteristics which can affect product efficacy. Also, different insect species show variation in their susceptibility to the product. Adults of Sitophilus oryzae (L., Cryptolestes ferrugineus (Stephens and Oryzaephilus surinamensis (L. were exposed to wheat

  2. Microwave radiation effects on the different stages of Sitophilus oryzae (Linne, 1763) (Coleoptera, Curculionidae) evolutive cycle in rice, focusing its control

    Energy Technology Data Exchange (ETDEWEB)

    Franco, Jose G.; Franco, Suely S.H., E-mail: gilmita@uol.com.br, E-mail: zegilmar60@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Franco, Caio H.; Arthur, Paula B.; Arthur, Valter, E-mail: caiohaddadfranco@lnbio.cnpem.com.br, E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). Lab. de Radiobiologia e Ambiente

    2013-07-01

    As insects increase in radio tolerance as they develop and usually several developmental stages of pest may present in grain shipped commodity, it is important to know the microwave radiation susceptibility of stages of the target insect before the establishment of microwave radiation quarantine treatments. The current research had the aim to evaluate the microwave radiation effects on several phases of the rice weevil evolution cycle (S.oryzae), focusing its control. This specie is considered as on of the most serious worldwide pests for stored grains. The tests have been done in glass vials with 250 grams of whole grain (brown) rice and the irradiation was done in a 2,450 MHz commercial microwave oven, model Carousel II (potency of 800W). It was determined the exposure time needed to each phase control for the insect evolutive cycle, concluding that the immature phases (larvae and pupae), contained inside the rice, are more sensitive, requiring only 100 seconds to obtain 100% control while the egg phase requires a longer exposure (130 seconds). Referring to the grown phase, the time required to attain the lethal dose was 160 seconds. All the exposure time have been irradiated with a low potency (240 W). It also displayed that to greater quantities of rice (1.0 kg), with egg presence and forming a 2.0-centimeter layer on the microwave plate surface, it required an exposure time of 180 seconds. Therefore, in a more effective way, we can recommend these 180 seconds exposure time to the control of all phases concerning the insect evolutive cycle. (author)

  3. Interspecific competition between Sitophilus zeamais and Sitotroga cerealella in a patchy environment

    DEFF Research Database (Denmark)

    Larsen, Marie Nykjær; Nachman, Gösta; Skovgård, Henrik

    2005-01-01

    The maize weevil, Sitophilus zeamais (Motchulsky) (Coleoptera: Curculionidae), and the Angoumois grain moth, Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae), are important insect pests of stored products. The coexistence in nature of the two species on maize has been difficult to explain...

  4. Genotypic variation for maize weevil resistance in eastern and ...

    African Journals Online (AJOL)

    ACSS

    ... Resources Research Institute, National Agricultural Research Organization, ... resistance and grain yield, suggesting that breeding for maize weevil resistance can be achieved without compromising grain yield. Key words: Sitophilus zeamais, weevil resistance, Zea mays ..... might be manifested as a result of changes.

  5. TOXICITY ASSAY OF BASSA AND MALATHION TO SITOPHILUS ORYZAE AND TRIBOLIUM CASTANEUM%巴沙和马拉硫磷对两种储粮害虫成虫的毒力测定

    Institute of Scientific and Technical Information of China (English)

    罗来凌; 刘伟强; 田世尧; 杨森辉; 赖志勇

    2002-01-01

    用97%巴沙和45%马拉硫磷乳油对米象(Sitophilus oryzae)和赤拟谷盗(Triboli-um castaneum)作毒力测定.根据结果求出巴沙和马拉硫磷处理米象成虫72小时毒力回归方程:巴沙为y=2.3960x-0.1760(r=0.9970),马拉硫磷为y=2.5642x-1.0915(r=0.9858);巴沙LG5o为144.6299mg/L(95%置信区间127.7332~161.5266mg/L),马拉硫磷LC50为237.4535mg/L(95%置信区间206.2068~268.7003mg/L).结果表明巴沙对供试米象的毒力比马拉硫磷大得多,但巴沙和马拉硫磷对供试赤拟谷盗的毒力均很小.

  6. A new light on the evolution and propagation of prehistoric grain pests: the world's oldest maize weevils found in Jomon Potteries, Japan.

    Directory of Open Access Journals (Sweden)

    Hiroki Obata

    Full Text Available Three Sitophilus species (S. granarius L., S. oryzae L., and S. zeamais Mots. are closely related based on DNA analysis of their endosymbionts. All are seed parasites of cereal crops and important economic pest species in stored grain. The Sitophilus species that currently exist, including these three species, are generally believed to be endemic to Asia's forested areas, suggesting that the first infestations of stored grain must have taken place near the forested mountains of southwestern Asia. Previous archaeological data and historical records suggest that the three species may have been diffused by the spread of Neolithic agriculture, but this hypothesis has only been established for granary weevils in European and southwestern Asian archaeological records. There was little archeological evidence for grain pests in East Asia before the discovery of maize weevil impressions in Jomon pottery in 2004 using the "impression replica" method. Our research on Jomon agriculture based on seed and insect impressions in pottery continued to seek additional evidence. In 2010, we discovered older weevil impressions in Jomon pottery dating to ca. 10 500 BP. These specimens are the oldest harmful insects in the world discovered at archaeological sites. Our results provide evidence of harmful insects living in the villages from the Earliest Jomon, when no cereals were cultivated. This suggests we must reconsider previous scenarios for the evolution and propagation of grain pest weevils, especially in eastern Asia. Although details of their biology or the foods they infested remain unclear, we hope future interdisciplinary collaborations among geneticists, entomologists, and archaeologists will provide the missing details.

  7. Flight capacity of Sitophilus zeamais Motschulsky in relation to gender and temperature

    Science.gov (United States)

    The maize weevil, Sitophilus zeamais, is a major pest of stored products worldwide. In this research, we evaluated the flight performance of S. zeamais under various temperatures using a 26-channel computer-monitored flight-mill system to estimate total flight distance (TFD), total flight duration (...

  8. LETHAL EFFECTS OF MICROWAVE TREATMENT ON Sitophilus oryzae Linnaeus AND GERMINATION RATE OF WHEAT%微波处理对米象致死效果及小麦发芽率的影响

    Institute of Scientific and Technical Information of China (English)

    王殿轩; 刘炎; 曹阳; 李淑荣; 李光涛; 高美须

    2011-01-01

    The effects of microwave treatment on mortality of all stages of Sitophilus oryzae Linnaeus were studied after the pests were treated at the microwave power of 160, 320,480, 640 and 800W for 5, 10, 15, 20 and 25s, respectively.Meanwhile, the adult in the wheat were treated at 160, 320,480,640 and 800W for 20s, and 800W for 5, 10, 15, 20 and 25s.And wheat germination rate was also evaluated.Results showed that the susceptibility from high to low of the pest to microwave treatment was eggs, larvae, pupae and the adult.While the adults were treated at 800W for 25s,instant mortality reached 100%.The germination rate of wheat was reduced significantly after microwave treatment.%以米象为试虫,采用G80F20CN2L-B8(SO)型平板微波炉分别以160、320、480、640和800W微波功率处理不同虫态米象5、10、15、20、25和30s,研究米象致死情况;另外以上述微波功率处理20s,及800W分别处理5、10、15、20和25s,测定混合于小麦中米象成虫的致死情况.同时考察微波对小麦发芽率的影响.结果表明,米象不同虫态对微波处理的敏感性由小到大依次为成虫、蛹、幼虫和卵,800W处理25s可立即完全致死米象成虫;微波处理后小麦的发芽率显著降低.故微波辐照技术不适合种子粮的杀虫处理,但可应用于储粮杀虫.

  9. Bioactivities of extracts from 21 species of plants against maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae)%21种植物提取物对玉米象的生物活性

    Institute of Scientific and Technical Information of China (English)

    姚英娟; 薛东; 杨长举

    2005-01-01

    为了筛选对粮库安全的植物源杀虫剂,研究了21种植物的4种溶剂(无水乙醇、丙酮、乙酸乙酯和石油醚)提取物对玉米象Sitophilus zeamais Motschulsky的驱避和触杀作用.结果表明,高良姜Alpinia officinarum石油醚提取物、黄姜Curcuma longa丙酮提取物和山鸡椒Litsea cubeba石油醚提取物对玉米象成虫的驱避作用显著,处理60 h平均驱避等级均达到Ⅴ级,平均驱避率分别为80.02%、80.60%和81.70%.在21种植物中,石菖蒲Acorus gramineus和巴豆Croton tiglium的4种溶剂提取物均对玉米象成虫的触杀作用明显,7.86 mg/cm2的剂量处理4天后的校正死亡率均达到90%以上.

  10. 近红外高光谱成像技术检测粮仓米象活虫%Detection of live Sitophilus oryzae (L.) in stored wheat by near-infrared hyperspectral imaging

    Institute of Scientific and Technical Information of China (English)

    张红涛; 毛罕平; 韩绿化

    2012-01-01

    为了准确地统计出仓储害虫的密度,需对储粮活虫和死虫进行有效地判别.该文研究开发一个900~1 700 nm的近红外高光谱成像系统来检测仓储小麦活虫.用液氮低温猝死法杀死米象,在其死亡后0~7 d进行高光谱图像采集.随着粮虫死亡时间的延长,粮虫相对光谱反射率逐渐增大,到死后第5天时粮虫的光谱曲线基本趋于稳定.应用相邻波长指数法对1 320~1 680 nm之间的110个波长的高光谱图像进行分析,提取出最优波长为1 417.2 nm.提出双区域连通阈值面积比的区域生长法粮虫活虫判别方法,即当粮虫的双区域连通阈值面积比大于0.5时,应判别为活虫.结果表明,自粮虫死亡后的第2.0天开始,储粮活虫与死虫的训练样本和检验样本全部被正确识别,为实现储粮活虫的计算机视觉实时检测与分类提供依据.%It is necessary to distinguish between the live and the dead insects effectively for counting the density of the storage insects accurately. A 900-1700nm near-infrared hyperspectral imaging system was developed to detect live insects in stored wheat. The Sitophilus oryzae was killed by using low-temperature sudden death method with liquid nitrogen,and then the hyperspectral images were acquired over the period of time 0-7 day after the death of insects. The relative spectral reflectance of the insects increased gradually with the duration of the death time. Then the spectral curve of the insects became stable on the fifth day after the death. 110 hyperspectral images whose wavelength was from 1320 to 1680 nm were analyzed by the neighbor wavelength index,and the optimal characteristic wavelength to distinguish the live and the dead was 1417.2 nm. The region-growing method for identifying the live insects was proposed based on the area ratio of the two thresholds for connecting regions. And the insect should be judged to be alive if the area ratio was higher than 0.5. The results

  11. SPATHODEA CAMPANULATA (BIGNONIACEAE EXTRACTS BIOACTIVITY AGAINST SITOPHILUS ZEAMAIS (COLEOPTERA: CURCULIONIDAE

    Directory of Open Access Journals (Sweden)

    T. M. Pascutti

    2016-11-01

    Full Text Available The insect attack is one of the main factors responsible for the loss of corn grain stored after harvest, thus sustainable strategies such as natural extracts can be used as cheap methods of control. This study evaluated the effects caused by Spathodea campanulata nectar extracts on the maize weevil Sitophilus zeamais to the preference test and mortality was used completely randomized design with 10 replications and treatments solutions of 0, 5, 10, 30 to 50% nectar under study. He noted that the preference index was lower in the first 3 hours of evaluation and the highest concentration of extract (50%, resulting in a possible repellent effect, but with the potential loss in subsequent evaluations. Already mortality was increased from the concentration of 30%, but the number of dead insects was low, indicating low efficiency. However, the percentage of perforated grains was reduced at the highest concentration and decreasing interfering insect feeding.

  12. 米象成虫触角感器及其取食偏好性%Ultrastructure of antennal sensilla and host preference of adult rice weevil

    Institute of Scientific and Technical Information of China (English)

    林喜建; 黄蓬英; 刘馨怡; 陈伟军; 陈思涵; 蔡立君

    2016-01-01

    米象Sitophilus oryzae (L.)是重要的储粮害虫,如何有效防控仍是世界性的研究难题.应用扫描电镜研究了米象成虫触角感器的超微结构,证实了米象触角上仅分布3种感器,分别为毛形感器、刺形感器及锥形感器;采用嗅觉行为仪测定了米象对5种粮食的取食偏好性,结果表明:粮食对米象的引诱由强至弱依次为:燕麦>湖北丁优大米>黑米>莲子>薏米;同时观察了5种粮食对米象F1代种群生长发育的影响,发现在莲子中米象F1代发育历期最长,米象F1代种群数量在供试粮食中由多到少依次为:黑米>燕麦>薏米>湖北丁优大米>莲子.研究其触角感器与取食偏好可为探索米象防治新途径提供理论依据.%Rice weevil, Sitophilus oryzae ( L.) is one of the most destructive pests to stored products. To develop an effective S.oryzae management, ultrastructure of antennal sensilla of adult rice weevil was investigated by scanning electronic microscopy (SEM), and followed by observation on behavioral responses of adult S.oryzae to five common types of grain by Y-tube olfactometer and influences of feed on population development. Antennal sensilla observations were in accordance with previous study that there were only three types of antennal sensilla, including sensilla trichodea, sensilla basiconica and sensilla chaetica in S.oryzae. Oat was significantly more attractive to adult S.oryzae than other types of grain, which was followed by Hubei Dingyou rice, black rice, lotus seed and pearl barley in a descending order. S.oryzae F1 generation needed the longest time for developmental period in lotus seed. Furthermore, population of F1 generation varied among different types of grain, with the largest population in black rice, followed by in oat, pearl barley, Hubei Dingyou rice and lotus seed in a descending order. The findings were attributed to the development of comprehensive pest prevention and management.

  13. as Sitophilus zeamais (Coleoptera: Curculionidae)

    African Journals Online (AJOL)

    STORAGESEVER

    2008-10-20

    Oct 20, 2008 ... myrcene (3.1%). The results provide a scientific rationale for the use of the plant in post-harvest .... Effect of essential oil on maize damage by the weevil. Damage ... Time. 0. 100. %. EF19406B Sb (65,0.10 ). Scan EI+. TIC. 6.35e6. 11. 2. 3. 45. 6 .... Third World Organization for Women in Science. (TWOWS) ...

  14. Micromorphology of the elytral cuticle of beetles, with an emphasis on weevils (Coleoptera: Curculionoidea).

    Science.gov (United States)

    van de Kamp, Thomas; Riedel, Alexander; Greven, Hartmut

    2016-01-01

    The elytral cuticle of 40 beetle species, comprising 14 weevils (Curculionoidea) and 26 representatives of other taxa, is examined. All weevils and 18 other species have an endocuticle with prominent macrofibers, which corresponds to a modified pseudo-orthogonal cuticle. Angles between successive layers of macrofibers range between 30° and 90°, but are constantly less than 60° in weevils. In all Curculionoidea, as well as in one buprestid and one erotylid species exo- and endocuticle are densely interlocked. In the weevil Sitophilus granarius, transmission electron microscopy revealed vertical microfibrils extending from the exocuticle between the macrofibers of the underlaying endocuticle. Vertical microfibrils connecting successive macrofiber layers of the endocuticle were observed in S. granarius and Trigonopterus nasutus. Distinct cuticular characters are traced on a beetle phylogeny: the angles between unidirectional endocuticle layers; the presence and the shape of endocuticular macrofibers; and the interlocking of exo- and endocuticle. While character traits seem to be more or less randomly distributed among Coleoptera, the Curculionoidea have a uniform groundplan: The "weevil-specific" combination of characters includes 1) interlocking of exo- and endocuticle, 2) an endocuticle with distinct ovoid macrofibers embedded in a matrix and 3) comparatively small angles between successive endocuticular layers. Thus, phylogenetic constraints appear equally important to functional factors in the construction of the weevil elytron.

  15. Ozone toxicity and walking response of populations of Sitophilus zeamais (Coleoptera: Curculionidae).

    Science.gov (United States)

    Sousa, A H; Faroni, L R A; Silva, G N; Guedes, R N C

    2012-12-01

    Ozone is a recognized alternative to the fumigants methyl bromide and phosphine for the control of stored product insects. However, as with fumigants in general, the potential sublethal effects of ozone on targeted insect species may compromise its efficacy and has yet to be investigated. Here, we determined ozone toxicity of 30 field-collected populations of the maize weevil, Sitophilus zeamais (Coleoptera: Curculionidae), and assessed the walking response of adult insects from these populations to sublethal ozone exposure. Time-mortality toxicity to ozone at 50 ppm concentration in a continuous 2 liter/min flow indicated uniform susceptibility among the populations studied without any indication of ozone resistance (toxicity ratios [at LT50] > two-fold). In contrast, there was significant variation in walking activity among the maize weevil populations, which was not correlated with ozone susceptibility. This was not surprising because of the relatively uniform susceptibility to ozone among the maize weevil populations. Respiration rate affected ozone toxicity but not walking activity, whereas body mass was negatively correlated with walking activity but was not correlated with ozone toxicity. Based on our data, lower respiration rates may potentially lead to reduced ozone uptake whereas larger body mass limits walking activity. Ozone seems a promising alternative fumigant with low short-term risk of resistance development because of the high susceptibility and low variability of response to this compound. Furthermore, ozone reduces walking activity of S. zeamais that implies it likely reduces the chances of insects escaping exposure at the early stages of fumigation.

  16. 九种植物精油对玉米象成虫的熏蒸作用比较%Comparison of Fumigation Activities of 9 Kinds of Essential Oils against the Adults of Maize Weevil,Sitophilus zeamaise Motschulsky (Coleoptera:Curculionidae)

    Institute of Scientific and Technical Information of China (English)

    邓永学; 王进军; 鞠云美; 张海燕

    2004-01-01

    采用广口瓶密闭方法,测定红桔油Citrus tangerina、柠檬叶油Citrus limonum、红河橙油Citrus hongheensis、山苍子油Litsea cubeba、留兰香油Mentha spicata、松节油Pinus tabulaeformis、黄樟油Cinnamonum camphora、互叶白千层油Melaleuca alternifolia、蓝桉叶油Eucalyptus globulus等9种植物精油,在熏杀浓度为16 μL/L、熏蒸时间为24、36、48及60 h条件下,对玉米象Sitophilus zeamais成虫的熏蒸活性.结果表明:黄樟油、互叶白千层油、柠檬叶油、留兰香油及松节油的熏杀效果较好,尤以黄樟油的效果最佳.黄樟油在12、24、36、48和60 h不同熏蒸时间下的LC50值分别为31.43、11.26、6.16、2.72和1.11 μL/L.可考虑将黄樟油作为磷化氢及溴甲烷的替代药物用于控制玉米象的危害.

  17. Toxicity of Rhododendron anthopogonoides Essential Oil and Its Constituent Compounds towards Sitophilus zeamais

    Directory of Open Access Journals (Sweden)

    Qi Zhi Liu

    2011-08-01

    Full Text Available The screening of several Chinese medicinal plants for insecticidal principles showed that essential oil of Rhododendron anthopogonoides flowering aerial parts possessed significant toxicity against maize weevils, Sitophilus zeamais. A total of 37 components were identified in the essential oil and the main constituents of the essential oil were 4-phenyl-2-butanone (27.22%, nerolidol (8.08%, 1,4-cineole (7.85%, caryophyllene (7.63% and γ-elemene (6.10%, followed by α-farnesene (4.40% and spathulenol (4.19%. Repeated bioactivity-directed chromatographic separation on silica gel columns led us to isolate three compounds, namely 4-phenyl-2-butanone, 1,4-cineole, and nerolidol. 4-Phenyl-2-butanone shows pronounced contact toxicity against S. zeamais (LD50 = 6.98 mg/adult and was more toxic than either 1,4-cineole or nerolidol (LD50 = 50.86 mg/adult and 29.30 mg/adult, respectively against the maize weevils, while the crude essential oil had a LD50 value of 11.67 mg/adult. 4-Phenyl-2-butanone and 1,4-cineole also possessed strong fumigant toxicity against the adults of S. zeamais (LC50 = 3.80 mg/L and 21.43 mg/L while the crude essential oil had a LC50 value of 9.66 mg/L.

  18. Do rice water weevils and rice stem borers compete when sharing a host plant?

    Institute of Scientific and Technical Information of China (English)

    Sheng-wei SHI; Yan HE; Xiang-hua JI; Ming-xing JIANG; Jia-an CHENG

    2008-01-01

    The rice water weevil (RWW) Lissorhoptrus oryzophilus Knsehel (Coleoptera: Curculionidae) is an invasive insect pest office Oryza sativa L. in China. Little is known about the interactions of this weevil with indigenous herbivores. In the present study, adult feeding and population density of the weevil, injury level of striped stem borer Chilo suppressalis (Walker) (Lepi-doptera: Pyralidae) and pink stem borer Sesamia inferens (Walker) (Lepidoptera: Noctuidae) to rice, as well as growth status of their host plants were surveyed in a rice field located in Southeastern Zhejiang, China, in 2004 with the objective to discover interspecific interactions on the rice. At tillering stage, both adult feeding of the weevil and injury of the stem borers tended to occur on larger tillers (bearing 5 leaves) compared with small tillers (bearing 24 leaves), but the insects showed no evident competition with each other. At booting stage, the stem borers caused more withering/dead hearts and the weevil reached a higher density on the plants which had more productive tillers and larger root system; the number of weevils per tiller correlated nega-tively with the percentage of withering/dead hearts of plants in a hill. These observations indicate that interspecific interactions exist between the rice water weevil and the rice stem borers with negative relations occurring at booting or earlier developmental stages of rice.

  19. Fumigant toxicity of essential oils from Achillea millefolium (asteraceae) and Prangos ferulacea (Apiaceae) against Sitophilus granarius and S. oryzea (col.: Curculionidae)

    Science.gov (United States)

    Şimşek, Şeyda; Pekbey, Gamze; Yaman, Cennet

    2016-04-01

    In the present study, experiments were conducted to investigate fumigant toxicity of the essential oil from Achillea millefolium (Asteraceae) and Prangos ferulacea (Apiaceae) plants for adult grain weevil (Sitophilus granarius) and rice weevil (S. oryzea) in vitro conditions. The essential oils were isolated with the water distillation method by Neo-Clevenger apparatus. During the study 10% (v/v) doses of oils in 20 cc of compressed rubber-capped glass tubes were used. After 24 hours mortality rates of the essential oils were compared. For S. granarius the toxicity of A. millefolium (98.85%) was observed to be more effective than P. ferulace (28.73%). Similarly for S. oryzea, A. millefolium (100 %) was found much more toxic than P. ferulace (9.82%). At the results of the study the essential oil of the A. millefolium has been determined as a promising insecticidal component against both pests.

  20. the efficacy of xylopia aethiopica and piper guinense seeds powder ...

    African Journals Online (AJOL)

    Sammy

    Insect pests damage to stored grains results in major economic losses and in Africa ... grain loss caused by storage pest such as the Rice weevils Sitophilus oryzae ... of these are serious problems of toxic residues, health and environmental.

  1. Chemical Composition and Toxicity against Sitophilus zeamais and Tribolium castaneum of the Essential Oil of Murraya exotica Aerial Parts

    Directory of Open Access Journals (Sweden)

    Zhi Long Liu

    2010-08-01

    Full Text Available In our screening program for new agrochemicals from Chinese medicinal herbs, Murraya exotica was found to possess insecticidal activity against the maize weevil, Sitophilus zeamais and red flour beetle, Tribolium castaneum. The essential oil of aerial parts of M. exotica was obtained by hydrodistillation and investigated by GC and GC-MS. The main components of M. exotica essential oil were spathulenol (17.7%, a-pinene (13.3%, caryophyllene oxide (8.6%, and a-caryophyllene (7.3%. Essential oil of M. exotica possessed fumigant toxicity against S. zeamais and T. castaneum adults with LC50 values of 8.29 and 6.84 mg/L, respectively. The essential oils also show contact toxicity against S. zeamais and T. castaneum adults with LD50 values of 11.41 and 20.94 mg/adult, respectively.

  2. EFFECTS OF ELECTRONIC BEAM IRRADIATION ON PHOSPHINE RESISTANT AND SUSCEPTIBLE OF SITOPHILUS ORYZAE LINNAEUS AND COOKING QUALITY OF RICE%电子束辐照防治不同品系米象成虫及对大米蒸煮品质的影响

    Institute of Scientific and Technical Information of China (English)

    李湘; 董威杰; 崔龙; 陈云堂; 郭东权; 范家霖; 张建伟; 杨保安; 鲁玉杰; 王争艳; 商飞飞; 许勃

    2014-01-01

    In view of phosphine resistance problem of the insects in stored grain , the irradiation biological effects of 0~1000 Gy electronic beam on phosphine resistant and susceptible of Sitophilus oryz ae Linnaeus were studied , the irradiation susceptibilities of the two strains were compared , and the irradiation effects of 0~5000 Gy electronic beam on the cooking quality of rice were studied . The results showed that the lethal rules of tw o strains w ere similar . T he irradiation susceptibilities of strains w ere different , but the differ‐ence between the two strains was not significant . The cooking quality was changed significantely by irradi‐ation . With the dose increasing , gel consistency raised while water absorption , swelling degree and the sensory score of cooking quality reduced . The cooked rice browned at 5000 Gy dose level . Thus , 100~3000 Gy irradiation could be considered as a suitable dose for control on the development of Sitophilus oryz ae Linnaeus in stored rice .%针对储粮害虫的磷化氢抗性问题,采用电子加速器对磷化氢抗性品系和敏感品系米象成虫及大米进行辐照处理,研究了0~1000 G y的电子束辐照对两品系米象的致死效应,分析了二者对辐照的敏感性,并研究了0~5000 G y剂量辐照下大米的蒸煮品质。结果表明,电子束处理对两品系米象的致死规律大致相同,二者对电子束的敏感性存在差异,但差异不显著。电子束辐照对大米的蒸煮品质影响显著,随辐照剂量的升高,大米的胶稠度升高,吸水率、膨胀率和感官评分降低,5000 G y时蒸煮米饭出现明显的褐变。因此,100 G y~3000 G y的剂量可以作为电子束辐照防治不同品系米象的适宜剂量。

  3. Insecticidal activity of Laurelia sempervirens (Ruiz & Pav. Tul. essential oil against Sitophilus zeamais Motschulsky

    Directory of Open Access Journals (Sweden)

    Cristian Torres

    2014-12-01

    Full Text Available The maize weevil Sitophilus zeamais Motschulsky is a worldwide key pest of stored products. Usually contact insecticides or fumigants are used against it, but problems as toxic residues, human intoxications, and resistance have triggered the search for alternative control methods as the use of essential oils. The objective of this research was to assess under laboratory conditions, the insecticidal properties of Laurelia sempervirens (Ruiz & Pav. Tul. essential oil against S. zeamais. In contact toxicity bioassay assessed treatments were 0 (control, 1.25, 2.5, 5.0, 10, 20, and 40 mL essential oil kg-1 grain and 0 (control, 25, 50, 75, 100, 125, 150, and 175 μL essential oil L-1 air in fumigant toxicity tests. The highest toxicity by contact activity was reached by concentrations higher than 10 mL essential oil kg-1 grain (100% mortality. The same treatments totally inhibit F1. The dose of 175 μL essential oil L-1 air showed a significant toxicity by fumigant activity causing 72.5% of dead insects. The other treatments did not surpass 5% mortality. In offspring effect (F1 bioassay, all treatments had an insect emergence significantly lower than the control but concentrations equal or higher than 10 mL essential oil kg-1 grain prevented the emergence of F1 during the 7 wk of bioassay. The residual effect of contact toxicity remained by 15 d. The treatments based on essential oil lead to a weight grain loss lower than control and germination was not affected. All assessed treatments showed repellent effect. The essential oil of L. sempervirens has promissory perspectives to maize weevil control.

  4. Toxicity of Boldo Peumus boldus Molina for Sitophilus zeamais Motschulsky and Tribolium castaneum Herbst Toxicidad del Boldo, Peumus boldus Molina, sobre Sitophilus zeamais Motschulsky y Tribolium castaneum Herbst

    Directory of Open Access Journals (Sweden)

    Margarita Ortiz U

    2012-09-01

    Full Text Available The maize weevil (Sitophilus zeamais Motschulsky and the red flour beetle (Tribolium castaneum Herbst are two key pests of stored-grain products worldwide. The insecticidal activity of boldo (Peumus boldus Molina powder, liquid ethanolic and hexanic extracts against S. zeamais and T. castaneum were evaluated under laboratory conditions. The evaluated variables were mortality, emergence of adult insects (F1, and grain weight loss. The experimental design was completely randomized. The mortality in S. zeamais was 100% even at the lowest powder concentration (0.5% w/w, whereas emergence of F1 adult insects was 0% and grain weight loss was El gorgojo del maíz (Sitophilus zeamais Motschulsky y el gorgojo castaño de la harina (Tribolium castaneum Herbst son plagas primarias de productos almacenados a nivel mundial. Se evaluó en laboratorio la actividad insecticida de polvo y extractos líquidos etanólicos y hexánicos del boldo (Peumus boldus Molina sobre S. zeamais y T. castaneum. Las variables evaluadas fueron mortalidad y emergencia de insectos adultos (F1 y pérdida de peso de los granos con un diseño experimental completamente al azar. La mortalidad en S. zeamais fue 100%, incluso con la concentración menor (0,5% p/p mientras que la emergencia de insectos adultos y la pérdida de peso de granos de maíz fue < 0,08%. Para T. castaneum sólo las concentraciones de 8 y 16% p/p de polvo causaron una mortalidad de 100%. Los extractos en agua, etanol, y hexano tuvieron un efecto insecticida de 100% en S. zeamais, mientras que en T. castaneum sólo el extracto en etanol alcanzó este valor. Por lo tanto, el polvo y los extractos evaluados de P. boldus presentan actividad insecticida contra S. zeamais y T. castaneum y son promisorios para utilizarse contra éstas y otras plagas de granos almacenados.

  5. Insecticidal Activity of Peumus boldus Molina Essential Oil against Sitophilus zeamais Motschulsky Actividad Insecticida del Aceite Esencial de Peumus boldus Molina sobre Sitophilus zeamais Motschulsky

    Directory of Open Access Journals (Sweden)

    Jessica Betancur R

    2010-09-01

    Full Text Available In stored grains, the main agents diminishing production are insects, which can produce losses between 20% and 80% before harvest or under storage. The insecticidal properties of the essential oil of fresh leaves of Peumus boldus Molina against maize weevil (Sitophilus zeamais Motschulsky adults were determined under laboratory conditions. The highest mortality (100% was achieved at 4% concentration by contact with a treated glass surface. The same concentration in impregnated corn (Zea mays L. grain, resulted in 98.7% mortality. Mortality by fumigant action at 6 h was 100% with 35 µL oil in 0.15 L (air volume. Concentrations 1, 2 and 4% of essential oil produced 0% F1 adult emergence. At 10 d of residual effect, the 4% concentration reached 63.7% mortality. All treatments were repellent to adults of S. zeamais and corn grain germination was not affected by any treatment.Los principales agentes que disminuyen la producción en los granos almacenados son los insectos, antes de la cosecha y en el almacenamiento pueden causar pérdidas de 20 a 80%. Se evaluaron las propiedades insecticidas del aceite esencial de hojas frescas de Peumus boldus Molina para el control de adultos de gorgojo del maíz (Sitophilus zeamais Motschulsky en laboratorio. La mayor mortalidad (100% por contacto con una superficie de vidrio tratada se obtuvo con la concentración de 4%. Esta misma concentración produjo 98,7% de mortalidad en exposición a grano de maíz (Zea mays L. tratado. El efecto fumigante a las 6 h de exposición fue 100% con 35 µL de aceite en 0,15 L (volumen de aire. Con las concentraciones de 1, 2 y 4% de aceite esencial, el porcentaje de emergencia de la F1 fue 0%. A los 10 d de efecto residual se alcanzó 63,7% de mortalidad con la concentración de 4%. Todos los tratamientos fueron repelentes para adultos de S. zeamais y ningún tratamiento afectó la germinación de los granos.

  6. Development and Life History of Sitophilus zeamais (Coleoptera: Curculionidae on Cereal Crops

    Directory of Open Access Journals (Sweden)

    James Adebayo Ojo

    2016-01-01

    Full Text Available The maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae, is one of the most destructive pests of stored cereals. Knowledge of the life history and biology is important to the development of an integrated pest management program. Investigation was carried out on developmental biology of S. zeamais on four main cereal crops, maize, rice, sorghum, and millet, under laboratory conditions. Egg incubation, oviposition periods, and larval instar development were not different significantly among the food hosts. Number of eggs laid varied significantly among the cereal grains; mean fecundity was highest on maize (67.2±3.16 and lowest on millet (53.8±0.17. Number of immature (larva and pupa and adult stages varied significantly among the cereal grains. There exist four larval instars with a varied mean head capsule width, with a mean total instar larval developmental period of 23.1, 22.2, 22.2, and 21.6 d on maize, rice, sorghum, and millet, respectively. There was linear relationship and significant correlation between the stages of larval development and head capsule width. The mean developmental period from egg to adult varied, being highest on maize (34.7 d and lowest on sorghum (33.5 d.

  7. Insecticidal activity of powder and essential oil of Cryptocarya alba (Molina Looser against Sitophilus zeamais Motschulsky

    Directory of Open Access Journals (Sweden)

    Juan J Pinto

    2016-03-01

    Full Text Available Cereals constitute a relevant part of human and domestic animal diet. Under storage conditions, one of the most significant problems of these crops is insect pests as the maize weevil (Sitophilus zeamais Motschulsky. This insect species is usually controlled by means of synthetic insecticides but problems as toxic residues and resistance has led to the search for more friendly control alternatives such as botanical insecticides. The aim of this research was to evaluate, under laboratory conditions, the insecticidal properties of the powder and the essential oil of peumo (Cryptocarya alba [Molina] Looser; Lauraceae leaves against S. zeamais. The variables assessed were toxicity by contact and fumigant activity, adult emergence (F1, repellent effect, and impact on wheat (Triticum aestivum L. seed germination. A completely randomized design was used with five treatments and 10 replicates. The higher mortality levels were obtained at 80 g powder kg-1 grain and 40 mL essential oil kg-1 grain of C. alba; in both cases, the mortality of adult S. zeamais surpassed 80%. The emergence of adults S. zeamais (F1 was reduced by 100% at 80 g powder kg-1 grain and 40 mL essential oil kg-1 grain. Germination of wheat seeds treated with C. alba powder and essential oil was not affected. Both, the powder and the oil treatments showed repellent effect, but not fumigant activity.

  8. The influence of package and gamma radiation in the quarantine treatment of Sitophilus Orizae in rice

    Energy Technology Data Exchange (ETDEWEB)

    Modolo, Debora M.; Oliveira, Ana Claudia S.; Silva, Lucia C.A.S.; Arthur, Valter; Harder, Marcia N.C.; Arthur, Paula B.; Lima, Roberta B., E-mail: arthur@cena.usp.b [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). Dept. de Radiobiologia e Ambiente

    2009-07-01

    There are a variety of insect and pests that damage stored grains, therefore, the need for better conservation with advanced technology, high efficiency, absence of side effects, irradiation has been used as an alternative method to control these insects, being completely the opposite the chemical treatment, which leaves waste and is not always efficient enough. This study has the objective to use the gamma radiation from Cobalt-60 for the control of Sitophilus oryzae, in plastic package with previously infested rice and artificially reinfested. In this research was used 3 types of samples: 'Prato Fino' rice's package, crystal sugar's package and 'Namorado' rice's package. It were packages (bags) of 10x5cm for each type of sample, containing holes for gases exchange. Each pack contained 20g of wholemeal rice and 10 adult insects of the species S. oryzae. The samples were irradiated with dose of 1 kGy to make disinfestations under a dose rate of 0.560 Gy/hour and more the non-irradiated sample (control). After irradiation the bags were placed in a glass bottle with the volume of 3 liters and it were added 300 adult insects in the same bottle to induce reinfestation. This container was closed and after 60 days was calculated the number of living and dead insects existing in each package. The experiment was developed in a room with temperature 25 +- 5 deg C and relative humidity of 60 +- 5%. With the results obtained, it was concluded that the packages containing holes for gases exchange from inside to outside of the package showed more ease of penetration of insects, while the two packages without holes prevented the reinfestation of insects. The dose of 1 kGy was sufficient to induce disinfestations of rice. (author)

  9. Bioactivity of Peumus boldus Molina, Laurelia sempervirens (Ruiz & Pav. Tul. and Laureliopsis philippiana (Looser Schodde (Monimiacea essential oils against Sitophilus zeamais Motschulsky

    Directory of Open Access Journals (Sweden)

    Carmen Herrera-Rodríguez

    2015-09-01

    Full Text Available The maize weevil (Sitophilus zeamais Motschulsky is one of most important pest of stored seeds worldwide, but its current control method is based on the use of synthetic insecticides, usually leading to undesirable problems such as insecticide residues on treated food, human intoxications, and insect resistance development. Therefore the search of friendly alternative methods is required. The aim of this study was to assess, under laboratory conditions, the insecticidal properties of Peumus boldus Molina, Laurelia sempervirens (Ruiz & Pav. Tul., and Laureliopsis philippiana (Looser Schodde essential oils against S. zeamais. The phytochemical analysis of the three essential oils showed 1,8-cineole, safrole and methyleugenol as the common components; all of them documented with insecticidal activity from essential oils from other plant species. The highest toxicity (100% mortality of these three oils acting as a contact insecticide was observed at 24 h exposure at 4% concentration. The estimated LC50 values for P. boldus, L. sempervirens, and L. philippiana were 0.37, 1.02, and 0.28 μL g-1, respectively. Peumus boldus exhibited the highest fumigant activity with 100% adult mortality at 30 μL oil L-1 air. At ≥ 0.5% (v/w concentration, all essential oils showed repellent activity. These three essential oils showed a promissory insecticidal activity against the maize weevil.

  10. Toxicidade de óleos essenciais de Piper aduncum e Piper hispidinervum em Sitophilus zeamais Toxicity of essential oils of Piper aduncum and Piper hispidinervum against Sitophilus zeamais

    Directory of Open Access Journals (Sweden)

    Joelma Lima Vidal Estrela

    2006-02-01

    Full Text Available Óleos essenciais de Piper aduncum L. e Piper hispidinervum C.DC. (Piperaceae foram avaliados quanto ao efeito inseticida em Sitophilus zeamais Motsch. por ação de contato, fumigação e tópica. Na determinação da DL50 e CL50, foi utilizada a análise de Probit. Médias porcentuais de mortalidade dos insetos foram comparadas por meio da análise de regressão linear e superposição das barras do erro padrão. S. zeamais foi mais suscetível ao efeito de contato do óleo de P. hispidinervum em relação ao de P. aduncum, obtendo-se CL50 de 0,51 e 2,87 mL cm- 2 de óleo, respectivamente. Mortalidade próxima a 100% foi obtida nas concentrações de 20 e 30% do óleo de P. hispidinervum. Quanto ao efeito fumigante, a susceptibilidade foi maior no óleo de P. aduncum do que no de P. hispidinervum. Houve diferença significativa entre os óleos somente nas concentrações de 0,1 e 1,0. A DL50 foi semelhante nos dois óleos essenciais por aplicação tópica. No entanto, a mortalidade foi maior com P. aduncum. Óleos essenciais de P. aduncum e P. hispidinervum possuem efeito inseticida em S. zeamais, mas as respostas dependem da concentração e do método de exposição a que o inseto seja submetido.Essential oils of Piper aduncum L. and Piper hispidinervum C. DC. (Piperaceae were tested against Sitophilus zeamais Motsch. Contact, fumigant toxicity and topical effect were tested. Probit analysis was employed in evaluating the LC50 and LD50 response. Linear regression analysis and superposition of the bars (means error standard were used for comparison of means percentage mortality. S. zeamais was more susceptible to the contact toxicity of the P. hispidinervum oil than P. aduncum oil with LC50 values of 0.51 and 2.87 mL cm-2 of the oil, respectively. The mortality rate was nearly 100% at P. hispidinervum oil concentrations of 20 and 30%. With respect to the fumigant action, the weevil was more susceptible to the P. aduncum oil than to P

  11. Bioactivity of Tepa (Laureliopsis philippiana (Looser Shodde Powder to Sitophilus zeamais Motschulsky Control in Laboratory Bioactividad del Polvo de Tepa (Laureliopsis philippiana (Looser Shodde para el Control de Sitophilus zeamais Motschulsky en Laboratorio

    Directory of Open Access Journals (Sweden)

    Ana Ortiz U

    2012-03-01

    Full Text Available The maize weevil (Sitophilus zeamais Motschulsky is one of the most widespread pests and causes heavy losses of stored grain throughout the world. Control of this insect is primarily dependent upon continued applications of organophosphorus and pyrethroid insecticides and fumigants as phosphine but the increasing problems with current insecticides drive the need for research and to develop new control methods. The insecticidal effect of leaf powder of tepa, Laureliopsis philippiana (Looser Shodde, was evaluated against maize weevil under laboratory conditions. The parameters evaluated were adult mortality and emergence, grain weight loss and germination, and residual, repellent and fumigant effect. The highest levels of insect mortality were registered with treatments at 1, 2, and 4%, with values from 94.7 to 100%. Also, it was obtained 0% of adult insect emergence with these concentrations. In all treatments grain weight was less than 5.8 g. Seed germination was not affected. The powder of L. philippiana exhibited repellent effect in all concentrations and did not show fumigant effect. Insecticidal effect of powder remained for 14 d. Finally, we concluded that powder of L. philippiana has great potential for controlling S. zeamais.El gorgojo del maíz (Sitophilus zeamais Motschulsky es una de las plagas que provoca pérdidas a los granos almacenados más importantes a nivel mundial. El control de esta especie se realiza fundamentalmente con aplicaciones continuas de insecticidas organofosforados y piretroides y fumigantes como fosfuro de aluminio, pero problemas con éstos han hecho necesaria la busqueda y desarrollo de nuevos métodos de control. Se evaluó el efecto insecticida del polvo de hojas de tepa, Laureliopsis philippiana (Looser Shodde, sobre el gorgojo del maíz en condiciones de laboratorio. Los parámetros evaluados fueron mortalidad y emergencia de insectos adultos, pérdida de peso y germinación de los granos, además de

  12. Edge effect on weevils and spiders

    OpenAIRE

    Horváth, R.; Magura, T.; Péter, G.; B. Tóthmérész

    2002-01-01

    The edge effect on weevils and spiders was tested along oak forest – meadow transects using sweep-net samples at the Síkfökút Project in Hungary. For spiders the species richness was significantly higher in the forest edge than either in the meadow or the forest interior. For weevils the species richness of the forest edge was higher than that of the meadow, but the difference was not statistically significant whereas the species richness of the forest...

  13. Palm Weevil Pheromones - Discovery and Use.

    Science.gov (United States)

    Oehlschlager, A C

    2016-07-01

    Male-produced aggregation pheromones of seven major pest species of weevils in the subfamily Rhynchophorinae have been identified as a closely related set of methyl-branched secondary alcohols. Although the weevils produce only one stereoisomer of these alcohols, no instances of isomeric inhibition have been observed, enabling stereoisomeric mixtures to be used in traps. Addition of fermenting plant material to traps synergizes attraction of weevils to the pheromones. The weevils are large, have long life cycles, and are strong fliers. These characteristics make mass trapping a suitable tactic to add to existing management strategies. When coupled with good phytosanitary practices, mass trapping of Rhynchophorus palmarum at 1 trap/5-ha significantly lowered the incidence of red ring nematode infection vectored by the weevil in commercial oil palm plantations in the Americas. Similarly, trap densities of 1-10 traps/ha have significantly lowered R. ferrugineus infestation of date palm throughout the Middle East. Although management of R. ferrugineus in urban areas is more problematic, trapping is an integral part of most programs aimed at protection of ornamental Canary palms in Europe. Overall, semiochemically-based management of these large weevils is now a mature and usually economically feasible control technology.

  14. A screening method for banana weevil (Cosmopolites sordidus ...

    African Journals Online (AJOL)

    EJIRO

    2010-07-26

    Jul 26, 2010 ... sordidus Germar) resistance using reference genotypes ... experiments to assess weevil resistance/susceptibility. ..... change into adults. ... management for the banana weevil, Cosmopolites sordidus (Germar) ... Pest Manage.

  15. Mating behavior and reproductive output in insecticide-resistant and -susceptible strains of the maize weevil (Sitophilus zeamais)

    Science.gov (United States)

    Insecticide resistance is the most broadly recognized and well studied ecological problem resulting from intensive insecticide use, which also provides useful evolutionary models of newly adapted phenotypes to changing environments. Two common assumptions in such population-oriented models are the e...

  16. Efficiency of deltamethrin dust (k-obiol to control corn weevils sitophilus oryzaeand pagiocerus trontalisin the corn growing area of Caqueza, Cundinamarca Eficiencia de la Deltrametrina en polvo (K-Obiol en el control de los gorgojos del maíz Sítophílus oryzae (L. y Pagíocerus frontalís (F. en la zona maicera de Caqueza (Cundinamarca

    Directory of Open Access Journals (Sweden)

    Aldana A. Héctor M.

    1994-06-01

    Full Text Available To a larqe. extent, staple food production in developing countries is in the hands of smallholder peasants, who take important losses from crop pests in the field and at postharvest. This work was carried out to compare the efficacy of deltamethrine (K-Obiol, lindane (Gorgoricida and chlorpiriphos.En los países en proceso de desarrollo, la producción de granos de cereales y de leguminosas está, principalmente en manos, de los pequeños agricultores, quienes tienen que soportar importantes pérdidas económicas, tanto en precosecha, como en poscosecha. El presente trabajo se realizó en 1990 en la vereda Girón de Resguardo del municipio de Cáqueza (Cundinamarca a alturas sobre el nivel del mar comprendidas entre 1690 y 1780 metros, con
    temperaturas ambientales entre 19 C y 29 C y humedad relativa promedia de 72%. En el lugar del ensayo, los agricultores minifundistas almacenan buena parte del maíz que producen (Blanco harinoso Moya 1, el cual es atacado en forma severa por los gorgojos S. Olyzae (L y P. frontalis
    (F, insectos-plaga sobre los cuales, con esta
    investigación, se pretendió controlarlos con Deltametrina en comparación con insecticidas que tradicionalmente se han usado en la zona. Se compararon las respectivas eficacias insecticidas de la Deltametrina (K-OBIOL, 2P, del lindano
    (GORGORICIDA 1 P Y del Clorpirifos (LORSBAN 2,5P, cada uno en dosis de 500 g de producto comercial por tonelada de grano, aplicados en ensayos separados tanto sobre maíz desgranado como sobre maíz con capacho entrojado, en capas de 25 cm de espesor. La evaluación se hizo mediante el conteo del número de adultos vivos y muertos de las dos especies de gorgojos, así como del daño en muestras tomadas al azar mensualmente hasta los 150 días de almacenamiento. Los resultedos mostraron que, tanto sobre maíz desgranado, como sobre maíz con capacho, la Deltametrina (K-OBIOL 2P ejerce un buen control sobre las dos especies de insectos antes citadas. Los insecticidas Lindano y Clorpirifos dieron, también, buen control, pero contra los insectos-plaga del maíz almacenado no es aconsejable por el alto riesgo que corre con su uso.

  17. Efficiency of inert mineral dusts in the control of corn weevil

    Directory of Open Access Journals (Sweden)

    Carlos F. Jairoce

    2016-02-01

    Full Text Available ABSTRACT Corn weevil (Sitophilus zeamais may cause great losses in the crop and in stored corn grains. This insect is controlled with the use of chemical insecticides, which may cause serious damage to human health. One alternative of control is the use of inert dusts. The objective of this study was to evaluate the efficiency of inert dusts in the control of S. zeamais under laboratory conditions. The experiment was conducted in 2014, in a completely randomized design, and the treatments consisted of basalt dust with three different granulometries (A, B and C and diatomaceous earth, each of which at the doses of 2 and 4 kg t-1 and a control (no application. Each treatment had four replicates, and the sample unit consisted of 20 g of corn grains infected with 10 adults of S. zeamais kept in temperature-controlled chamber at 25 °C, 70% RH and photophase of 12 h. The dust efficiency was calculated using the equation of Abbott. The mortality rate was higher with the use of diatomaceous earth, reaching 100% after 5 days of exposure and the percentage of control for basalt dusts, 29 days after treatment, was above 80%.

  18. Effect of vacuum storage on shelf life of a grain protector based on Peumus boldus Molina foliage powder and lime against Sitophilus zeamais Motschulsk

    Directory of Open Access Journals (Sweden)

    Paulina Rivera

    2014-03-01

    Full Text Available The maize weevil (Sitophilus zeamais Motschulsky, Coleoptera: Curculionidae is a key pest of stored grain maize. As an ecological pest control alternative, the use of botanical insecticides, such as powder from boldus (Peumus boldus Molina foliage singly or mixed with lime, has been evaluated. Unfortunately, its shelf life is very short and does not exceed 15 d. The effectiveness of vacuum storage on insecticidal properties of a natural grain protector produced with boldus powder:lime at proportions of 50:50 and 60:40 against adults of S. zeamais was assessed under laboratory conditions. Treatments were evaluated at 1% and 2% (w/w for 150 d of storage. All treatments based on boldus powder kept the level of mortality by contact activity over 80% at 150 d of storage. The highest toxicity, as a fumigant, was observed in treatments 50:50 at 2% and 60:40 at 1% and 2% with mortality over 60%. The grain weight loss was less than 1% and seed germination was not affected. With the exception of 0:100 at 2% without vacuum storage, all treatments were repellent to S. zeamais. Vacuum storage extended shelf life of the grain protector for 150 d.

  19. Determination of degree of infestation of triticale seed using NIR spectroscopy

    Science.gov (United States)

    Insect infestation of seeds of the triticale hybrid, Triticosecale, causes extraordinary storage losses as a consequence of vulnerability of triticale seed to insect infestation and its soft coat. Rice weevil, Sitophilus oryzae (L.), is a common insect that causes infestation in Florida, which was t...

  20. Edge effect on weevils and spiders

    Directory of Open Access Journals (Sweden)

    R. Horváth

    2002-05-01

    Full Text Available The edge effect on weevils and spiders was tested along oak forest – meadow transects using sweep-net samples at the Síkfökút Project in Hungary. For spiders the species richness was significantly higher in the forest edge than either in the meadow or the forest interior. For weevils the species richness of the forest edge was higher than that of the meadow, but the difference was not statistically significant whereas the species richness of the forest interior was significantly lower than that of the forest edge and the meadow. The composition of the spider assemblage of the edge was more similar to the forest, while the composition of weevils in the edge was more similar to the meadow. Our results based on two invertebrate groups operating on different trophic levels suggest that there is a significant edge effect for the studied taxa resulting in higher species richness in the edge.

  1. Biology of the African sweetpotato weevil species

    NARCIS (Netherlands)

    Smit, N.E.J.M.; Huis, van A.

    1999-01-01

    The biology of two African sweetpotato weevil species, Cylas pitncticollis and C. bninnens (Fabricius) (Coleoptera: Apionidae), was studied in laboratory experiments carried out at 27 ±1°C, 45 ±5% RH, and a 12 h photophase. Cylns pinicticollis females lived longer than C. brunneus (141 ±10 and 92

  2. Three Boll Weevil Diapause Myths in Perspective

    Science.gov (United States)

    The boll weevil, Anthonmus grandis grandis Boheman (Coleoptera: Curculionidae), originated in Mesoamerica but its contemporary distribution extends from the United States Cotton Belt to Argentina, throughout which it is a serious pest of cotton, Gossypium hirsutum L. While research on the boll weev...

  3. Insecticidal Properties of Peumus boldus Molina Powder Used Alone and Mixed with Lime Against Sitophilus zeamais Motschulsky (Coleopter: Curculionidae Propiedades Insecticidas del Polvo de Peumus boldus Molina Solo y en Mezcla con Cal contra Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae

    Directory of Open Access Journals (Sweden)

    Gabriel Bustos-Figueroa

    2009-09-01

    Full Text Available The insecticidal properties of boldus (Peumus boldus Molina powder used alone and mixed with lime against adults of maize weevil (Sitophilus zeamais Motschulsky were evaluated under laboratory conditions. Additionally, aeration effects (presence or absence and temperature (room temperature vs. 3 ºC on insecticidal properties were studied over time. A mortality rate of 100% was observed at 20 g kg-1 (w/w of P. boldus powder when used alone and mixed with lime in proportions of 50:50, 60:40, and 80:20. The 50% lethal concentration (LC50 for all treatments was Se evaluaron las propiedades insecticidas del polvo de boldo (Peumus boldus Molina, solo y en mezcla con cal, bajo condiciones de laboratorio. Adicionalmente, se evaluó el efecto de la aeración (presencia vs. ausencia y de la temperatura (temperatura ambiente vs. 3 ºC sobre la mortalidad y emergencia de adultos de la F1. La concentración de 20 g kg-1 (p/p del polvo de boldo ya sea solo o en combinación con cal en las proporciones de 50:50, 60:40 y 80:20 mostraron 100% de mortalidad. La concentración letal 50% (CL50, en todos los tratamientos fue menor a 5 g kg-1 (p/p mientras que la CL90 no superó 11 g kg-1 (p/p. La mezcla del polvo con los granos de maíz tanto solo como en mezcla con cal no afectó la germinación. La temperatura y la aeración no afectaron la mortalidad de los adultos parentales ni la emergencia de adultos de la F1. Cuando se mezcló el maíz con el polvo de boldo molido 24 h antes de la infestación con adultos, la mortalidad de los adultos parentales y la emergencia de adultos de la F1 fue de 100 y de 0%, respectivamente. Los resultados no fueron satisfactorios cuando el polvo de boldo almacenado durante 30, 60 y 90 d fue mezclado con el maíz infestado. La toxicidad del follaje de boldo es alta 24 h después de pulverizarse; si el tiempo es mayor, la toxicidad declina significativamente.

  4. Comportamento em populações de Sitophilus zeamais resistentes a inseticidas

    OpenAIRE

    Guedes, Nelsa Maria Pinho

    2008-01-01

    O principal método de controle contra o caruncho-do-milho em clima tropical é o uso de inseticidas, particularmente piretróides, devido à falta de métodos alternativos de controle. Custos adaptativos associados à resistência a inseticidas foram observados em linhagens de Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae). Linhagens de Sitophilus zeamais susceptíveis e resistentes a piretróides foram usadas para avaliar o processo comportamental e o resultado da competição larval dentr...

  5. Genome evolution of Oryza

    Directory of Open Access Journals (Sweden)

    Tieyan Liu

    2014-01-01

    Full Text Available The genus Oryza is composed of approximately 24 species. Wild species of Oryza contain a largely untapped resource of agronomically important genes. As an increasing number of genomes of wild rice species have been or will be sequenced, Oryza is becoming a model system for plant comparative, functional and evolutionary genomics studies. Comparative analyses of large genomic regions and whole-genome sequences have revealed molecular mechanisms involved in genome size variation, gene movement, genome evolution of polyploids, transition of euchromatin to heterochromatin and centromere evolution in the genus Oryza. Transposon activity and removal of transposable elements by unequal recombination or illegitimate recombination are two important factors contributing to expansion or contraction of Oryza genomes. Double-strand break repair mediated gene movement, especially non-homologous end joining, is an important source of non-colinear genes. Transition of euchromatin to heterochromatin is accompanied by transposable element amplification, segmental and tandem duplication of genic segments, and acquisition of heterochromatic genes from other genomic locations. Comparative analyses of multiple genomes dramatically improve the precision and sensitivity of evolutionary inference than single-genome analyses can provide. Further investigations on the impact of structural variation, lineage-specific genes and evolution of agriculturally important genes on phenotype diversity and adaptation in the genus Oryza should facilitate molecular breeding and genetic improvement of rice.

  6. Components and Insecticidal Activity against the Maize Weevils of Zanthoxylum schinifolium Fruits and Leaves

    Directory of Open Access Journals (Sweden)

    Shu Shan Du

    2011-04-01

    Full Text Available In our screening program for new agrochemicals from Chinese medicinal herbs and wild plants, Zanthoxylum schinifolium essential oils were found to possess strong insecticidal activity against the maize weevil Sitophilus zeamais. The essential oils of Z. schinifolium fruits and leaves were extracted via hydrodistillation and investigated by GC and GC-MS. Estragole (69.52% was the major compound of the essential oil of fresh fruits, followed by linalool (8.63% and limonene (4.34% and 94.33% of the total components were monoterpenoids. The main components of the essential oil of fresh leaves were linalool (12.94%, ar-tumerone (8.95%, limonene (6.45% and elixene (5.43% and only 50.62% were monoterpenoids. However, the essential oil from purchased fruits contained linalool (33.42%, limonene (13.66% and sabinene (5.72%, followed by estragole (4.67%, nerol (4.56% and 4-terpineol (4.27%. Estragole, linalool and sabinene were separated and purified by silica gel column chromatography and preparative thin layer chromatography, and further identified by means of physicochemical and spectrometric analysis. The essential oil from the fresh fruits (LD50 = 15.93 μg/adult possessed two times more toxicity to the insects compared with that of fresh leaves (LD50 = 35.31 μg/adult. Estragole, linalool and sabinene exhibited contact activity against S. zeamais with LD50 values of 17.63, 13.90 and 23.98 μg/adult, respectively. The essential oils of Z. schinifolium possessed strong fumigant toxicity against S. zeamais adults with LC50 values of 13.19 mg/L (fresh fruits, 24.04 mg/L (fresh leaves and 17.63 mg/L (purchased fruits. Estragole, linalool and sabinene also exhibited strong fumigant toxicity against the maize weevils with LC50 values of 14.10, 10.46 and 9.12 mg/L, respectively.

  7. Expression of Heat Shock Protein Genes in Different Developmental Stages and After Temperature Stress in the Maize Weevil (Coleoptera: Curculionidae).

    Science.gov (United States)

    Tungjitwitayakul, Jatuporn; Tatun, Nujira; Vajarasathira, Boongeua; Sakurai, Sho

    2015-06-01

    The maize weevil, Sitophilus zeamais Motschulsky, is a major pest of rice and other postharvest grain stocks in tropical countries. Heating and cooling treatments have been adopted to control this pest. Because heat shock protein (hsp) genes respond to temperature stress, we examined the association of hsp genes with development and thermal stress in S. zeamais. The temperature response of the insect to heat and cold treatments was assessed at four developmental stages: egg, larva, pupa, and adult. LT50 values at high temperatures were similar among the four developmental stages, while adults were the most tolerant to low temperatures, and eggs, larvae, and pupae exhibited similar LT50 values. Expression levels of three hsps--Szhsp70, Szhsc70, and Szhsp90--fluctuated substantially throughout the four stages at a rearing temperature of 28°C. Heat shock and cold shock increased the expression of all three hsps, and the highest upregulation was observed at 40°C, although the intensity of upregulation varied among the three genes: strongly in Szhsp70, moderately in Szhsp90, and slightly in Szhsc70. Basal expression of the three hsps at 28°C and gene responses to heat and cold shock also varied significantly at the tissue level.

  8. Identification of the Weevil immune genes and their expression in the bacteriome tissue

    Directory of Open Access Journals (Sweden)

    Moya Andrés

    2008-10-01

    Full Text Available Abstract Background Persistent infections with mutualistic intracellular bacteria (endosymbionts are well represented in insects and are considered to be a driving force in evolution. However, while pathogenic relationships have been well studied over the last decades very little is known about the recognition of the endosymbionts by the host immune system and the mechanism that limits their infection to the bacteria-bearing host tissue (the bacteriome. Results To study bacteriome immune specificity, we first identified immune-relevant genes of the weevil Sitophilus zeamais by using suppressive subtractive hybridization (SSH and then analyzed their full-length coding sequences obtained by RACE-PCR experiments. We then measured immune gene expression in the bacteriome, and in the aposymbiotic larvae following S. zeamais primary endosymbiont (SZPE injection into the hemolymph, in order to consider the questions of bacteriome immune specificity and the insect humoral response to symbionts. We show that larval challenge with the endosymbiont results in a significant induction of antibacterial peptide genes, providing evidence that, outside the bacteriome, SZPE are recognized as microbial intruders by the host. In the bacteriome, gene expression analysis shows the overexpression of one antibacterial peptide from the coleoptericin family and, intriguingly, homologs to genes described as immune modulators (that is, PGRP-LB, Tollip were also shown to be highly expressed in the bacteriome. Conclusion The current data provide the first description of immune gene expression in the insect bacteriome. Compared with the insect humoral response to SZPE, the bacteriome expresses few genes among those investigated in this work. This local immune gene expression may help to maintain the endosymbiont in the bacteriome and prevent its invasion into insect tissues. Further investigations of the coleoptericin, the PGRP and the Tollip genes should elucidate the role

  9. Field attraction of the vine weevil Otiorhynchus sulcatus to Kairomones

    NARCIS (Netherlands)

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

    2012-01-01

    Root weevils in the genus Otiorhynchus are cited as one of the most important pests in the major nursery and small fruit production areas throughout the United States, western Canada, and northern Europe. A major problem in combating weevil attack is monitoring and timing of control measures. Becaus

  10. PENGARUH RHIZOPUS ORYZAE DAN ASPERGILLUS ORYZAE TERHADAP KUALITAS KECAP

    Directory of Open Access Journals (Sweden)

    Dewi Sabita Slamet

    2012-11-01

    Full Text Available Telah diteliti pengganti fermentasi mikroorganisme Aspergillus oryzae Rhyzopus oryzae dan campuran Aspergillus dan Rhyzopus oryzae, dengan perendaman dalam larutan garam 20% dalam waktu yang berbeda terhadap kualitas kecap.Lamanya perendaman dalam larutan garam 20% yang berbeda menghasilkan kadar protein kecap yang berbeda. Aspergillus oryzae lebih baik dalam menghasilkan enzima protease dari pada Rhyzopus oryzae.Uji organoleptik menunjukkan perbedaan tidak bermakna dalam hal rasa maupun aroma antar kecap yang dibuat dengan strain jamur yang berlainan serta waktu perendaman yang berbeda. Untuk membuat kecap, sebaiknya dilakukan perendaman dalam larutan garam 20% selama 14 hari.

  11. Rice (Oryza) hemoglobins

    Science.gov (United States)

    Hemoglobins (Hbs) corresponding to non-symbiotic (nsHb) and truncated (tHb) Hbs have been identified in rice (Oryza). This review discusses the major findings from the current studies on rice Hbs. At the molecular level, a family of the nshb genes, consisting of hb1, hb2, hb3, hb4 and hb5, and a sin...

  12. Pepper weevil attraction to volatiles from host and nonhost plants.

    Science.gov (United States)

    Addesso, Karla M; McAuslane, Heather J

    2009-02-01

    The location of wild and cultivated host plants by pepper weevil (Anthonomus eugenii Cano) may be aided by visual cues, the male-produced aggregation pheromone, herbivore-induced, or constitutive host plant volatiles. The attractiveness of constitutive plant volatiles to pioneer weevils is important in understanding, and perhaps controlling, dispersal of this insect between wild and cultivated hosts. Ten-day-old male and 2- and 10-day-old female weevils were tested in short-range Y-tube assays. Ten-day-old male and female weevils were attracted to the volatiles released by whole plants of three known oviposition hosts, 'Jalapeno' pepper, American black nightshade, and eggplant, as well as tomato, a congener, which supports feeding but not oviposition. Two-day-old females were attracted to all plants tested, including lima bean, an unrelated, nonhost plant. Fruit volatiles from all three hosts and flower volatiles from nightshade and eggplant were also attractive. In choice tests, weevils showed different preferences for the oviposition hosts, depending on age and sex. Upwind response of 10-day-old male and female weevils to host plant volatiles was also tested in long-range wind tunnel assays. Weevils responded to pepper, nightshade, and eggplant volatiles by moving upwind. There was no difference in the observed upwind response of the weevils to the three host plants under no-choice conditions. Reproductively mature pepper weevils can detect, orient to, and discriminate between the volatile plumes of host plants in the absence of visual cues, conspecific feeding damage, or the presence of their aggregation pheromone.

  13. Fossil history of Mesozoic weevils (Coleoptera:Curculionoidea)

    Institute of Scientific and Technical Information of China (English)

    Andrei A.Legalov

    2012-01-01

    The first synopsis of Mesozoic weevils (Curculionoidea: Coleoptera) is presented.Changes of family,genera and species abundance during the Mesozoic revealed three distributional patterns.The Jurassic (Karatau) fauna was dominated by the Nemonychidae.During the Early Cretaceous (beginning at the Jurassic/Cretaceous border),the Ithyceridae was the prevalent group with a significant role played by the Nemonychidae.In the Late Cretaceous (Cenomanian and Turonian),the major groups were the Curculionidae and Brentidae.Obviously,the change of weevil fauna during this period was due to the expansion of the angiosperms,which provided multiple niches in their vegetative and reproductive organs for weevil development.

  14. Fumigant toxicity of five essential oils rich in ketones against Sitophilus zeamais (Motschulsky)

    OpenAIRE

    Herrera, J. M.; M.P Zunino; Y Massuh; R.P Pizzollito; J.S Dambolena; N.A Gañan; Zygadlo, J. A.

    2014-01-01

    Essential oils (EOs) and individual compounds act as fumigants against insects found in stored products. In fumigant assays, Sitophilus zeamais Motschulsky adults were treated with essential oils derived from Aphyllocladus decussatus Hieron, Aloysia polystachya Griseb, Minthostachys verticillata Griseb Epling and Tagetes minuta L , which are rich in ketones and their major components: a- thujone, R-carvone, S-carvone, (-) menthone, R (+) pulegone and E-Z- ocimenone. M. verticillata oil was th...

  15. Effects of potassium deficiency, drought and weevils on banana ...

    African Journals Online (AJOL)

    Mo

    This paper reports results from a 6-year long-term fertilizer X banana weevil trial for highland banana in ... Soil and foliar analyses, and visual observations (i.e. yellowing of leaves) ... organic amendments, causing further soil fertility decline.

  16. An Insight into Sweet Potato Weevils Management: A Review

    Directory of Open Access Journals (Sweden)

    Seow-Mun Hue

    2015-01-01

    Full Text Available Sweet potato is an important food crop that is grown widely in tropical and subtropical regions. Sweet potato weevil is the most disastrous pest affecting sweet potato plantations, causing millions of dollars losses annually. An effective integrated pest management (IPM method will help to prevent economic losses, and it is crucial to understand the factors that contribute to weevil infestation and strategies that are available to overcome them. This review summarizes the (1 mechanisms of action of weevil on sweet potato and (2 contributing factors in weevil infestation, followed by (3 discussion on current IPM practices used in the different regions, including intercropping, entomopathogenic fungi and bacteria, sex pheromones, and pesticides. Lastly, it also focuses on (4 applications of advanced biotechnology and genomics strategies towards reducing weevil’s infestation in sweet potato plantation.

  17. Methods for assessing infestations of sunflower stem weevil (Coleoptera: Curculionidae) in sunflower stems

    Science.gov (United States)

    The sunflower stem weevil, Cylindrocopturus adspersus LeConte (Coleoptera: Curculionidae), reduces sunflower, Helianthus annuus L. (Asteraceae), yields by spreading pathogens, damaging vascular tissues, and promoting lodging of sunflower plants. To assess weevil populations for host plant resistanc...

  18. How Far Can the Red Palm Weevil (Coleoptera: Curculionidae) Fly?: Computerized Flight Mill Studies With Field-Captured Weevils.

    Science.gov (United States)

    Hoddle, M S; Hoddle, C D; Faleiro, J R; El-Shafie, H A F; Jeske, D R; Sallam, A A

    2015-12-01

    Adult Rhynchophorus ferrugineus (Olivier) captured in pheromone-baited traps in commercial date palm orchards in the Al Ahsaa Directorate, Kingdom of Saudi Arabia, were used in computerized flight mill studies to determine the flight characteristics of this highly invasive and destructive palm pest. Flight mill studies were run at three different time periods, winter (December), spring (March), and summer (May). Of the 192 weevils tethered to flight mills ∼30% failed to fly > 1 km. Of those weevils flying > 1 km (n = 139), 55% flew > 10 km, and of these flyers 5% flew > 50 km in 24 h. Flying weevils exhibited an average weight loss of 20-30% and nonflying control weevils lost ∼9-13% body weight in 24 h. Male and female weevils flying in summer (average laboratory temperature was ∼27°C) flew the longest average distances (∼25-35 km), exhibited highest weight reductions (∼30%), and greatest mortality rates (∼80%). Consequently, time of year not weevil sex or color morph had a consistent and significant effect on flight activity, weight loss, and survivorship rates. Flight activity was predominantly diurnal commencing around 5:00 a.m. and peaking between 9-11:00 a.m. before tapering off. The distribution of flight distances combined across season and sex was mesokurtic (i.e., normally distributed).

  19. Molecular diagnostic for boll weevil (Coleoptera: Curculionidae) based on amplification of three species-specific microsatellites.

    Science.gov (United States)

    Kim, Kyung Seok; Szendrei, Zsofia; Rodriguez-Saona, Cesar; Mulder, Phillip G; Sappington, Thomas W

    2009-04-01

    The boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), is a serious pest of cultivated cotton, Gossypium hirsutum L., in the Americas, and reinfestation of zones from which they have been eradicated is of perpetual concern. Extensive arrays of pheromone traps monitor for reintroductions, but occasionally the traps collect nontarget weevils that can be misidentified by scouts. For example, the congeneric pepper weevil, Anthonomus eugenii Cano, and other superficially similar weevils are attracted to components of the boll weevil lure or trap color. Although morphologically distinguishable by trained personnel, the potential for misidentification is compounded when captured weevils are dismembered or partially consumed by ants or ground beetles that sometimes feed on them in the traps. Because misidentification can have expensive consequences, a molecular diagnostic tool would be of great value to eradication managers. We demonstrate that a cocktail of three primer pairs in a single polymerase chain reaction (PCR) amplify species-specific microsatellites that unambiguously distinguish the boll weevil from three other weevil species tested, including pepper weevil; cranberry weevil, Anthonomus eugenii musculus Say; and pecan weevil, Curculio caryae Horn. However, it does not distinguish the boll weevil from the subspecific "thurberia" weevil. A universal internal transcribed spacer primer pair included in the cocktail cross-amplifies DNA from all species, serving as a positive control. Furthermore, the diagnostic primers amplified the target microsatellites from various boll weevil adult body parts, indicating that the PCR technology using the primer cocktail is sensitive enough to positively identify a boll weevil even when the body is partly degraded.

  20. Penicillium expansum volatiles reduce pine weevil attraction to host plants.

    Science.gov (United States)

    Azeem, Muhammad; Rajarao, Gunaratna Kuttuva; Nordenhem, Henrik; Nordlander, Göran; Borg-Karlson, Anna Karin

    2013-01-01

    The pine weevil Hylobius abietis (L.) is a severe pest of conifer seedlings in reforested areas of Europe and Asia. To identify minimally toxic and ecologically sustainable compounds for protecting newly planted seedlings, we evaluated the volatile metabolites produced by microbes isolated from H. abietis feces and frass. Female weevils deposit feces and chew bark at oviposition sites, presumably thus protecting eggs from feeding conspecifics. We hypothesize that microbes present in feces/frass are responsible for producing compounds that deter weevils. Here, we describe the isolation of a fungus from feces and frass of H. abietis and the biological activity of its volatile metabolites. The fungus was identified by morphological and molecular methods as Penicillium expansum Link ex. Thom. It was cultured on sterilized H. abietis frass medium in glass flasks, and volatiles were collected by SPME and analyzed by GC-MS. The major volatiles of the fungus were styrene and 3-methylanisole. The nutrient conditions for maximum production of styrene and 3-methylanisole were examined. Large quantities of styrene were produced when the fungus was cultured on grated pine bark with yeast extract. In a multi-choice arena test, styrene significantly reduced male and female pine weevils' attraction to cut pieces of Scots pine twigs, whereas 3-methylanisole only reduced male weevil attraction to pine twigs. These studies suggest that metabolites produced by microbes may be useful as compounds for controlling insects, and could serve as sustainable alternatives to synthetic insecticides.

  1. Insecticidal Activity of Melaleuca alternifolia Essential Oil and RNA-Seq Analysis of Sitophilus zeamais Transcriptome in Response to Oil Fumigation

    Science.gov (United States)

    Liao, Min; Xiao, Jin-Jing; Zhou, Li-Jun; Liu, Yang; Wu, Xiang-Wei; Hua, Ri-Mao; Wang, Gui-Rong; Cao, Hai-Qun

    2016-01-01

    Background The cereal weevil, Sitophilus zeamais is one of the most destructive pests of stored cereals worldwide. Frequent use of fumigants for managing stored-product insects has led to the development of resistance in insects. Essential oils from aromatic plants including the tea oil plant, Melaleuca alternifolia may provide environmentally friendly alternatives to currently used pest control agents. However, little is known about molecular events involved in stored-product insects in response to plant essential oil fumigation. Results M. alternifolia essential oil was shown to possess the fumigant toxicity against S. zeamais. The constituent, terpinen-4-ol was the most effective compound for fumigant toxicity. M. alternifolia essential oil significantly inhibited the activity of three enzymes in S. zeamais, including two detoxifying enzymes, glutathione S-transferase (GST), and carboxylesterase (CarE), as well as a nerve conduction enzyme, acetylcholinesterase (AChE). Comparative transcriptome analysis of S. zeamais through RNA-Seq identified a total of 3,562 differentially expressed genes (DEGs), of which 2,836 and 726 were up-regulated and down-regulated in response to M. alternifolia essential oil fumigation, respectively. Based on gene ontology (GO) analysis, the majority of DEGs were involved in insecticide detoxification and mitochondrial function. Furthermore, an abundance of DEGs mapped into the metabolism pathway in the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database were associated with respiration and metabolism of xenobiotics, including cytochrome P450s, CarEs, GSTs, and ATP-binding cassette transporters (ABC transporters). Some DEGs mapped into the proteasome and phagosome pathway were found to be significantly enriched. These results led us to propose a model of insecticide action that M. alternifolia essential oil likely directly affects the hydrogen carrier to block the electron flow and interfere energy synthesis in

  2. Variación anual de las propiedades insecticidas de Peumus boldus sobre Sitophilus zeamais

    OpenAIRE

    Felipe Pérez; Gonzalo Silva; Maritza Tapia; Ruperto Hepp

    2007-01-01

    El objetivo del presente trabajo fue determinar la variación anual en las propiedades insecticidas de Peumus boldus Molina, en el control de Sitophilus zeamais Motschulsky, bajo condiciones de laboratorio. El polvo de hojas de P. boldus se evaluó durante 12 meses, en concentraciones de 0,5, 1 y 2% (p/p). Se evaluaron 36 tratamientos con tres repeticiones, en un diseño experimental completamente al azar, con un arreglo factorial. Se determinó el porcentaje de mortalidad y emergencia de insecto...

  3. Variación anual de las propiedades insecticidas de Peumus boldus sobre Sitophilus zeamais

    OpenAIRE

    Pérez, F.; Silva, G.; De Tapia, M; Hepp, R

    2008-01-01

    El objetivo del presente trabajo fue determinar la variación anual en las propiedades insecticidas de Peumus boldus Molina, en el control de Sitophilus zeamais Motschulsky, bajo condiciones de laboratorio. El polvo de hojas de P. boldus se evaluó durante 12 meses, en concentraciones de 0,5, 1 y 2% (p/p). Se evaluaron 36 tratamientos con tres repeticiones, en un diseño experimental completamente al azar, con un arreglo factorial. Se determinó el porcentaje de mortalidad y emergencia de insecto...

  4. Infectivity of Steinernema carpocapsae and S. feltiae to larvae and adults of the hazelnut weevil, Curculio nucum: Differential virulence and entry routes

    Science.gov (United States)

    The hazel nut weevil, Curculio nucum, is a major pest of hazel nuts, particularly in Europe; hazel nut weevil is also closely related to other nut-attacking weevils such as pecan weevil (Curculio caryae). In this study, the basis for differential susceptibility of the hazelnut weevil (to entomopatho...

  5. Genomic affinity between Oryza sativa and Oryza brachyantha as ...

    African Journals Online (AJOL)

    USER

    2010-05-24

    May 24, 2010 ... brachyantha as revealed by in situ hybridization and ... Department of Genetics, Hazara University, Garden Campus Mansehra, Pakistan. Accepted 26 April ..... Oryza complex identified on the basis of molecular divergence.

  6. Atividade inseticida do óleo essencial de Tanaecium nocturnum (Barb. Rodr. Bur. & K. Shum (Bignoneaceae sobre Sitophilus zeamais Motsch. (Coleoptera: Curculionidae Insecticide activity of the essencial oil Tanaecium nocturnum (Barb. Rodr. Bur. & K. Shum (Bignoneaceae on Sitophilus zeamais Motsch. (Coleoptera: Curculionidae

    Directory of Open Access Journals (Sweden)

    Murilo Fazolin

    2007-01-01

    Full Text Available O óleo essencial extraído de folhas frescas de Tanaecium nocturnum (Barb. Rodr. Bur.& K. Shum por destilação de arraste a vapor foi avaliado quanto à toxicidade a Sitophilus zeamais Motsch., principal praga do milho armazenado. Papel de filtro e grãos de milho foram impregnados pelo óleo para se avaliar o efeito por via de contato (papel-filtro e fumigação, respectivamente. Para avaliação do efeito da aplicação tópica 0,5 µl das diferentes concentrações do óleo foram aplicadas em adultos do inseto. A partir de uma ampla faixa de concentrações, foram determinadas as mais promissoras para os bioensaios definitivos. Na determinação das dose/concentrações-letais (DL50 e CL50 foi utilizada a análise de Probit, realizando-se também, uma análise de regressão linear conjunta de todos os dados de mortalidade. O óleo de T. nocturnum foi considerado tóxico para S. zeamais baseado nos seguintes valores: CL50 de 14,1 ng.cm-2 e CL50 de 1.321,6 ng.g-1 de grãos para os efeitos de contacto (papel-filtro e fumigação, respectivamente, e DL50 de 14,7 µg.mg-1 de inseto para efeito tópico. Porcentagens de mortalidade próximas a 100 % foram obtidas nas concentrações de: 2 e 5 % (m/v (contato, 3 4, e 5 % (m/v (fumigação e 10 % (m/v para o efeito de aplicação tópica. O presente estudo mostrou que o ácido cianídrico, liberado do óleo essencial de T. nocturnum por hidrólise, pode ter atividade inseticida para S. zeamais e que concentrações acima de 4 % (m/v são promissoras no controle do inseto.Insecticidal activities of Tanaecium nocturnum (Barb. Rodr. Bur. & K. Shum (Bignoneaceae essential oil against Sitophilus zeamais Motsch. (Coleoptera: Curculionidae. The essential oil extracted from fresh leaves of the Tanaecium nocturnum (Barb. Rodr. Bur.& K. Shum by steam distillation, was tested against maize weevil Sitophilus zeamais Motsch.. Filter paper and maize grains impregnation was employed, for contact and fumigant

  7. Assessment of genetic diversity of Xanthomonas oryzae pv. oryzae

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@Bacterial blight of rice, caused by Xanthomonas oryzae pv. Oryzae(Xoo. ), is one of the major rice diseases in China. Making clear the shift of genetic diversity of the pathogen will provide important information for rice breeding. Strains collected from 11 provinces located in Southern region of the Changjiang River in China were assessed by using inoculation method and IS-PCR(Insertion Sequence-Based Polymerase Chain Reaction) analysis.

  8. Control Sitophilus zeamais (Coleoptera: Curculionidae in Maize (Zea mays L. treated with diatomaceous eart Coltrol de Sitophilus zeamais (Coleoptera: Curculionidae en maíz (Zea mays L. tratados con tierra de diatomeas Controle de Sitophilus zeamais (Coleoptera: Curculionidae em milho (Zea mays L. tratado com terra de diatomácea

    Directory of Open Access Journals (Sweden)

    Juliana Neitzke

    2010-04-01

    Full Text Available

    Maize (Zea mays L. is one of the most important cereals grown worldwide. As the product is sold fresh, the major concern is to maintain the quality of the grain, but its storage is difficult due to wide range of pests that can attack, reducing the quality. The objective of this study was to evaluate the effect of diatomaceous earth in the mortality of maize weevil Sitophilus zeamais in maize grains stored in different dosages and check the exposure time of each treatment. The experimental design was completely randomized with six treatments and five replications. The treatments consisted of increasing doses of diatomaceus eart (DE, in the proportion of zero, 50, 100, 150, 200, 250 g of DE t-1, all packed in plastic cups of 250 mL. In each plastic cup it was released 20 insects of S. zeamais and they were closed with fabric nylon fine mesh for aeration. The evaluation of insect mortality were performed at 3, 6 and 9 days after infestation (DAI, by counting the living and dead insects in the trays and the possible re-infestation. Treatment with diatomaceous earth in maize (Zea mays at a dosage of 250 g t-1 provided better control of S. zeamais.

    O milho (Zea mays L. é um dos cereais mais importantes cultivados no mundo todo. Como o produto é vendido “in natura”, a grande preocupação é manter a qualidade do grão, mas o seu armazenamento é dificultado devido à grande gama de pragas que podem atacar, diminuindo a qualidade. O objetivo deste trabalho foi avaliar o efeito da terra de diatomácea na mortalidade do gorgulho de milho Sitophilus zeamais em grãos armazenados de milho em diferentes dosagens e verificar o tempo de exposição de cada tratamento. O delineamento experimental foi inteiramente casualizado, com seis tratamentos e cinco repetições. Os tratamentos consistiram em doses crescentes de pó inerte terra de diatom

  9. Variación anual de las propiedades insecticidas de Peumus boldus sobre Sitophilus zeamais Annual variation of insecticide properties of Peumus boldus on Sitophilus zeamais

    Directory of Open Access Journals (Sweden)

    Felipe Pérez

    2007-05-01

    Full Text Available El objetivo del presente trabajo fue determinar la variación anual en las propiedades insecticidas de Peumus boldus Molina, en el control de Sitophilus zeamais Motschulsky, bajo condiciones de laboratorio. El polvo de hojas de P. boldus se evaluó durante 12 meses, en concentraciones de 0,5, 1 y 2% (p/p. Se evaluaron 36 tratamientos con tres repeticiones, en un diseño experimental completamente al azar, con un arreglo factorial. Se determinó el porcentaje de mortalidad y emergencia de insectos adultos e inmaduros y pérdida de peso y germinación del grano. La mayor mortalidad se obtuvo en los meses de agosto y septiembre de 2003, para las tres concentraciones con un 100%, mientras que la menor fue en mayo de 2003, cuando solo la concentración de 2% fue próxima a 100% de mortalidad. La menor emergencia de insectos adultos y pérdida de peso se obtuvieron en los mismos tratamientos. El efecto sobre estados inmaduros fue menor que contra adultos, y la germinación de los granos de maíz fue afectada por los polvos de P. boldus. Las propiedades insecticidas del polvo de hojas de P. boldus no son estables durante el año, Mayo es el mes con la menor eficacia insecticida, y la germinación de las semillas se ve afectada por el polvo.The objective of this work was to determine the annual variation of Peumus boldus Molina insecticidal properties for the control of Sitophilus zeamais Motschulsky, under laboratory conditions. The powder of P. boldus leaves was evaluated, during 12 months, in 0.5, 1, and 2% (w/w concentrations. Thirty-six treatments, with three replications, were evaluated in a completely randomized experimental design, with a factorial arrangement. Evaluations were made for adult and immature insect percentage mortality and emergence, grain weight loss and seed germination. The greatest mortality was obtained in August and September 2003, in the three concentrations with 100%, and the lowest mortality was registered in May 2003

  10. Green light synergistically enhances male sweetpotato weevil sex pheromone response

    Science.gov (United States)

    Sweetpotato, Ipomoea batatas (L.) Lamarck, commercially grown in over 100 countries, is the 7th most important staple crop in the world. Sweetpotato weevil is a major pest of sweetpotato in most areas of cultivation, the feeding of which induces production in the sweetpotato root of extremely bitter...

  11. Thousand cankers disease: Geosmithia morbida spores isolated from a weevil

    Science.gov (United States)

    Michele Warmund; Jerry. Van Sambeek

    2014-01-01

    Recently, Geosmithia morbida, the canker-causing fungus associated with thousand cankers disease, was isolated from Stenomimus pallidus weevils found on two stressed black walnut trees in Yellowwood State Forest near Nashville, Indiana. This is the first report of Geosmithia fungus occurring on an insect other than the walnut twig beetle (Pityophthorus juglandis)....

  12. Cultural control of banana weevils in Ntungamo, southwestern Uganda

    NARCIS (Netherlands)

    Okech, S.H.; Gold, C.S.; Bagamba, F.; Masanza, M.; Tushemereirwe, W.; Ssennyonga, J.

    2005-01-01

    The International Institute of Tropical Agriculture and the Uganda National Banana Research Programme tested and evaluated selected cultural management options for the banana weevil through on-farm farmer participatory research in Ntungamo district, Uganda between 1996 and 003. A farmer adoption stu

  13. Control damage by seedling debarking weevil. Technical note No. 271

    Energy Technology Data Exchange (ETDEWEB)

    Eidt, D.C.; Weaver, C.A.A.

    1993-01-01

    Technical note describing a method of controlling the damage to seedlings by the seedling debarking weevil by using nematodes. Information is given on the damage involved, the nematodes to be used, treatment methods, planting procedures, benefits and costs, and results of earlier trials.

  14. Effect of radio frequency treatments on cowpea weevil adults

    Science.gov (United States)

    Dried pulses (chickpeas, lentils and dried peas) are valuable export commodities in the US Pacific Northwest. Postharvest infestation by stored product insect pests such as the cowpea weevil may cause importing countries to require phytosanitary treatments before shipment. Typically, chemical fumiga...

  15. OryzaGenome: Genome Diversity Database of Wild Oryza Species

    KAUST Repository

    Ohyanagi, Hajime

    2015-11-18

    The species in the genus Oryza, encompassing nine genome types and 23 species, are a rich genetic resource and may have applications in deeper genomic analyses aiming to understand the evolution of plant genomes. With the advancement of next-generation sequencing (NGS) technology, a flood of Oryza species reference genomes and genomic variation information has become available in recent years. This genomic information, combined with the comprehensive phenotypic information that we are accumulating in our Oryzabase, can serve as an excellent genotype-phenotype association resource for analyzing rice functional and structural evolution, and the associated diversity of the Oryza genus. Here we integrate our previous and future phenotypic/habitat information and newly determined genotype information into a united repository, named OryzaGenome, providing the variant information with hyperlinks to Oryzabase. The current version of OryzaGenome includes genotype information of 446 O. rufipogon accessions derived by imputation and of 17 accessions derived by imputation-free deep sequencing. Two variant viewers are implemented: SNP Viewer as a conventional genome browser interface and Variant Table as a textbased browser for precise inspection of each variant one by one. Portable VCF (variant call format) file or tabdelimited file download is also available. Following these SNP (single nucleotide polymorphism) data, reference pseudomolecules/ scaffolds/contigs and genome-wide variation information for almost all of the closely and distantly related wild Oryza species from the NIG Wild Rice Collection will be available in future releases. All of the resources can be accessed through http://viewer.shigen.info/oryzagenome/.

  16. OryzaGenome: Genome Diversity Database of Wild Oryza Species.

    Science.gov (United States)

    Ohyanagi, Hajime; Ebata, Toshinobu; Huang, Xuehui; Gong, Hao; Fujita, Masahiro; Mochizuki, Takako; Toyoda, Atsushi; Fujiyama, Asao; Kaminuma, Eli; Nakamura, Yasukazu; Feng, Qi; Wang, Zi-Xuan; Han, Bin; Kurata, Nori

    2016-01-01

    The species in the genus Oryza, encompassing nine genome types and 23 species, are a rich genetic resource and may have applications in deeper genomic analyses aiming to understand the evolution of plant genomes. With the advancement of next-generation sequencing (NGS) technology, a flood of Oryza species reference genomes and genomic variation information has become available in recent years. This genomic information, combined with the comprehensive phenotypic information that we are accumulating in our Oryzabase, can serve as an excellent genotype-phenotype association resource for analyzing rice functional and structural evolution, and the associated diversity of the Oryza genus. Here we integrate our previous and future phenotypic/habitat information and newly determined genotype information into a united repository, named OryzaGenome, providing the variant information with hyperlinks to Oryzabase. The current version of OryzaGenome includes genotype information of 446 O. rufipogon accessions derived by imputation and of 17 accessions derived by imputation-free deep sequencing. Two variant viewers are implemented: SNP Viewer as a conventional genome browser interface and Variant Table as a text-based browser for precise inspection of each variant one by one. Portable VCF (variant call format) file or tab-delimited file download is also available. Following these SNP (single nucleotide polymorphism) data, reference pseudomolecules/scaffolds/contigs and genome-wide variation information for almost all of the closely and distantly related wild Oryza species from the NIG Wild Rice Collection will be available in future releases. All of the resources can be accessed through http://viewer.shigen.info/oryzagenome/.

  17. The interaction of the bioinsecticide PA1b (Pea Albumin 1 subunit b) with the insect V-ATPase triggers apoptosis.

    Science.gov (United States)

    Eyraud, Vanessa; Balmand, Séverine; Karaki, Lamis; Rahioui, Isabelle; Sivignon, Catherine; Delmas, Agnès F; Royer, Corinne; Rahbé, Yvan; Da Silva, Pedro; Gressent, Frédéric

    2017-07-07

    PA1b (Pea Albumin 1, subunit b) peptide is an entomotoxin, extracted from Legume seeds, with a lethal activity towards several insect pests, such as mosquitoes, some aphids and cereal weevils. This toxin acts by binding to the subunits c and e of the plasma membrane H(+)-ATPase (V-ATPase) in the insect midgut. In this study, two cereal weevils, the sensitive Sitophilus oryzae strain WAA42, the resistance Sitophilus oryzae strain ISOR3 and the insensitive red flour beetle Tribolium castaneum, were used in biochemical and histological experiments to demonstrate that a PA1b/V-ATPase interaction triggers the apoptosis mechanism, resulting in insect death. Upon intoxication with PA1b, apoptotic bodies are formed in the cells of the insect midgut. In addition, caspase-3 enzyme activity occurs in the midgut of sensitive weevils after intoxication with active PA1b, but not in the midgut of resistant weevils. These biochemical data were confirmed by immuno-histochemical detection of the caspase-3 active form in the midgut of sensitive weevils. Immuno-labelling experiments also revealed that the caspase-3 active form and V-ATPase are close-localized in the insect midgut. The results concerning this unique peptidic V-ATPase inhibitor pave the way for the utilization of PA1b as a promising, more selective and eco-friendly insecticide.

  18. Molecular cloning and expression analysis of cytochrome c oxidase subunit II from Sitophilus zeamais.

    Science.gov (United States)

    Hou, Chang-Liang; Wang, Jing-Bo; Wu, Hua; Liu, Jia-Yu; Ma, Zhi-Qing; Feng, Jun-Tao; Zhang, Xing

    2016-09-30

    Cytochrome c oxidase subunit II (COX II) containing a dual core CuA active site is one of the core subunits of mitochondrial Cytochrome c oxidase (Cco), which plays a significant role in the physiological process. In this report, the full-length cDNA of COXII gene was cloned from Sitophilus zeamais, which had an open reading frame (ORF) of 684 bp encoding 227 amino acids residues. The predicted COXII protein had a molecular mass of 26.2 kDa with pI value of 6.37. multiple sequence alignment and phylogenetic analysis indicated that Sitophilus zeamais COXII had high sequence identity with the COXII of other insect species. The gene was subcloned into the expression vector pET-32a, and induced by isopropyl β-d-thiogalactopyranoside (IPTG) in E. coli Transetta (DE3) expression system. Finally the recombinant COXII with 6-His tag was purified using affinity chromatography with Ni(2+)-NTA agarose. Western Blotting (WB) showed the recombinant protein was about 44 kD, and the concentration of fusion protein was 50 μg/mL. UV-spectrophotometer and infrared spectrometer analysis showed that recombinant COXII could catalyze the oxidation of substrate Cytochrome C (Cyt c), and influenced by allyl isothiocyanate (AITC). By using molecular docking method, It was found that a sulfur atom of AITC structure could form a length of 2.9 Å hydrogen bond with Leu-31. These results suggested that tag-free COXII was functional and one of the action sites of AITC, which will be helpful to carry out a point mutation in binding sites for the future research.

  19. The use of aggregation pheromone to enhance dissemination of Beauveria bassiana for the control of the banana weevil in Uganda

    NARCIS (Netherlands)

    Tinzaara, W.; Gold, C.S.; Dicke, M.; Huis, van A.; Nankinga, C.M.; Kagezi, G.H.; Ragama, P.E.

    2007-01-01

    Candidate strains of Beauveria bassiana were identified for use in integrated pest management of the banana weevil Cosmopolites sordidus. Horizontal field transmission of B. bassiana between banana weevils using different delivery systems, including aggregation pheromones, was investigated. We obser

  20. Distribution of arthropods in rice grains in Malaysia

    Institute of Scientific and Technical Information of China (English)

    Mariana A; Ho TM; Lau TY; Heah SK; Wong AL

    2009-01-01

    Objective:To determine distribution of arthropods in rice grains obtained from different sources.Methods:Rice samples were randomly collected from public in urban areas,farmers in rice field areas,aborigines in un-developed areas and retailers in commercial premises.Random samples of rice were taken out from each sam-ple for isolation of arthropods using a modified Berlese Tullgren Funnel Method.Mites were mounted prior to i-dentification;weevils were directly identified.Results:Samples of rice from retailers in commercial premises had the highest infestation by arthropods followed by samples from urbanites,aborigines and rice farmers.Two species of weevils,Sitophilus oryzae(S.oryzae)and Sitophilus granarius(S.granarius),were found.Samples from commercial premises had the least percentage of weevils compared to those collected from domestic premi-ses.Depending on the source of samples,densities of S.granarius and S.oryzae ranges from 1 1 -1 03 weevils? kg and 7-80 weevils?kg,respectively.Important species of mites in stored rice identified were mainly members of the families Cheyletidae,Echimyopodidae,Pyroglyphidae,Saproglyphidae and Tenuipalpidae.Among the species of mites identified were Austroglycyphagus malaysiensis,Cheyletus fortis,Cheyletus malaccensis,Der-matophagoides pteronyssinus,Grammolichus malukuensis and Suidasia pontifica.Average density of most of the mites was less than 40 mites?kg of rice grains.In this study,the highest number of mites in rice samples was recovered from commercial premises,followed by samples from urbanites.Samples from farmers and aborigines contained lesser mites.Conclusion:This study demonstrated the presence of 3 allergenic mite species in rice, i.e A.malaysiensis,D.pteronyssinus and S.pontifica.Weevils,S.oryzae and S.granarius that are known to be allergenic,were also found.

  1. Phenylphenalenones Accumulate in Plant Tissues of Two Banana Cultivars in Response to Herbivory by the Banana Weevil and Banana Stem Weevil

    Science.gov (United States)

    Hölscher, Dirk; Buerkert, Andreas; Schneider, Bernd

    2016-01-01

    Phenylphenalenone-type compounds accumulated in the tissues of two banana cultivars—Musa acuminata cv. “Grande Naine” (AAA) and Musa acuminata × balbisiana Colla cv. “Bluggoe” (ABB)—when these were fed on by the banana weevil (Cosmopolites sordidus (Germ.) (Coleoptera: Curculionidae)) and the banana stem weevil (Odoiporus longicollis (Oliver) (Coleoptera: Curculionidae)). The chemical constituents of the banana material were separated by means of chromatographic techniques and identified by NMR spectroscopy. One new compound, 2-methoxy-4-phenylphenalen-1-one, was found exclusively in the corm material of “Bluggoe” that had been fed on by the weevils. PMID:27571112

  2. Effect of drying conditions on triticale seed germination and weevil infestation

    Science.gov (United States)

    The combination of high protein content and a soft seed coat makes triticale vulnerable to attack by weevils. Drying triticale grain to moisture contents safe for storage can prevent infestation by weevils, but if grain is being stored for seed, high drying temperatures can affect seed germination. ...

  3. Captures of boll weevils (Coleoptera: Curculionidae) in relation to trap distance from cotton fields

    Science.gov (United States)

    Once populations of the boll weevil (Anthonomus grandis grandis Boheman) are suppressed, eradication programs rely on pheromone trap-based monitoring for timely detection of weevil populations in cotton (Gossypium spp.). Delayed detection may increase the costs of remedial treatments, and permit rep...

  4. Attraction of dispersing boll weevils from surrounding habitats relative to simulated pheromone diffusion from traps

    Science.gov (United States)

    The ability to detect populations of boll weevils, Anthonomus grandis (Boheman), with pheromone traps has contributed significantly in progress toward eradication of the boll weevil. However, new information is needed to aid in the interpretation of trap captures, such as identification of habitats...

  5. Attraction of milkweed stem weevils, Rhyssomatus spp. (Coleoptera: Curculiondae), to grandlure

    Science.gov (United States)

    A trapping study was initiated in the spring of 2010 to compare the attraction of boll weevils to standard grandlure (synthesized boll weevil pheromone) and a new experimental formulation of grandlure. Both formulations contained the same four pheromone components, but differed in the proportion of...

  6. Roles of host plants in boll weevil range expansion beyond tropical Mesoamerica

    Science.gov (United States)

    New findings on boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), biology and ecology have had repercussions on the current level of understanding about short- and long-range boll weevil dispersal, and range expansion from its original tropical Mesoamerican habitat. The w...

  7. Effect of mulching on banana weevil movement relative to pheromone traps

    NARCIS (Netherlands)

    Tinzaara, W.; Gold, C.S.; Dicke, M.; Huis, van A.; Ragama, P.E.

    2008-01-01

    Banana weevil (Cosmopolites sordidus) is a major pest in East Africa causing yield losses of up to 14 metric tonnes per hectare annually. A study was conducted in Uganda to determine the effect of mulching on banana (Musa spp. L.) weevil, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae), m

  8. Forensic pollen geolocation techniques used to identify the origin of boll weevil reinfestation

    Science.gov (United States)

    The boll weevil, Anthonomus grandis, entered the United States of America in the early 20th century and became a major pest in cotton, Gossypium spp. Shortly after the passage of Tropical Storm Erin on 16 August 2007 through the South Texas/Winter Garden boll weevil eradication zone, over 150 boll ...

  9. Controlling pecan weevil with beneficial fungi: the impact of fungal species and fertilizer regimes

    Science.gov (United States)

    The pecan weevil, Curculio caryae (Horn), is a key pest of pecan. Prior research indicated the potential for using entomopathogenic fungi to suppress pecan weevil in the soil. We compared the efficacy of two fungal species, Beauveria bassiana (GHA strain) and Metarhizium brunneum (F52), in their a...

  10. Molecular systematics and evolution in an African cycad-weevil interaction: Amorphocerini (Coleoptera: Curculionidae: Molytinae) weevils on Encephalartos.

    Science.gov (United States)

    Downie, D A; Donaldson, J S; Oberprieler, R G

    2008-04-01

    Weevils in the tribe Amorphocerini have been implicated in pollination of Encephalartos species in southern Africa. The services they render these plants and the unique attributes of the cycad-weevil interaction make them important from both conservation and evolutionary standpoints. Oberprieler [Oberprieler, R.G., 1996. Systematics and evolution of the tribe Amorphocerini, with a review of the cycad weevils of the world. Ph.D. dissertation, University of the Free State, Bloemfontein, South Africa], using morphological characters, proposed a tentative hypothesis of relationships among the Amorphocerini which is tested here using DNA sequence data. Sequences from one mitochondrial and three nuclear genes were used to infer phylogenetic relationships, levels of sequence divergence, evolution of host associations, and patterns of speciation in this tribe. The results are reasonably consistent with the morphological hypothesis of relationships and species concepts, though important differences are observed, particularly in relationships among a Porthetes hispidus Boheman species group, which is indicated to have experienced recent divergences. In general, low levels of sequence divergence among species within two of the three genera indicate a recent radiation of this tribe onto African cycads, thus while cycad-insect interactions have often been considered ancient this may not be the case for some extant interactions. A complex pattern of host shifts onto both closely related and more distantly related hosts is suggested.

  11. A model for long-distance dispersal of boll weevils (Coleoptera: Curculionidae)

    Science.gov (United States)

    Westbrook, John K.; Eyster, Ritchie S.; Allen, Charles T.

    2011-07-01

    The boll weevil, Anthonomus grandis (Boheman), has been a major insect pest of cotton production in the US, accounting for yield losses and control costs on the order of several billion US dollars since the introduction of the pest in 1892. Boll weevil eradication programs have eliminated reproducing populations in nearly 94%, and progressed toward eradication within the remaining 6%, of cotton production areas. However, the ability of weevils to disperse and reinfest eradicated zones threatens to undermine the previous investment toward eradication of this pest. In this study, the HYSPLIT atmospheric dispersion model was used to simulate daily wind-aided dispersal of weevils from the Lower Rio Grande Valley (LRGV) of southern Texas and northeastern Mexico. Simulated weevil dispersal was compared with weekly capture of weevils in pheromone traps along highway trap lines between the LRGV and the South Texas / Winter Garden zone of the Texas Boll Weevil Eradication Program. A logistic regression model was fit to the probability of capturing at least one weevil in individual pheromone traps relative to specific values of simulated weevil dispersal, which resulted in 60.4% concordance, 21.3% discordance, and 18.3% ties in estimating captures and non-captures. During the first full year of active eradication with widespread insecticide applications in 2006, the dispersal model accurately estimated 71.8%, erroneously estimated 12.5%, and tied 15.7% of capture and non-capture events. Model simulations provide a temporal risk assessment over large areas of weevil reinfestation resulting from dispersal by prevailing winds. Eradication program managers can use the model risk assessment information to effectively schedule and target enhanced trapping, crop scouting, and insecticide applications.

  12. Essential oil of Cinnamodendron dinisii Schwanke for the control of Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae

    Directory of Open Access Journals (Sweden)

    F. VEDOVATTO

    2015-01-01

    Full Text Available ABSTRACT The use of natural compounds is a less aggressive alternative for the control of insects in stored grains, in relation to synthetic chemical agents. Plants with insecticidal properties can be used as a source of these compounds to the direct application in pest control. In this work, the essential oil of Cinnamodendron dinisii was chemically characterized and tested regarding its insecticidal and repellent effect on the control of Sitophilus zeamais in stored grains. The essential oil was obtained by hydrodistillation and analyzed by gas chromatography–mass spectrometry (GC-MS. The insecticidal potential was evaluated through the maintenance of the insects during 24 hours in contact with several doses of the oil, in the absence of feed substrate. The Bioassays of repellency were conducted with lethal doses (LD5, LD25, LD50 and LD95 obtained from insecticidal bioassay. In order to compare the treatments, the preference index (PI was used. The essential oil of C. dinisii had insecticidal activity against S. zeamais, causing a linear and crescent mortality with LD of 0.04, 0.17, 0.34 and 0.63 µL/cm2, respectively. The repellency ranged from 55.4% to 85.2%, using the LD values previously mentioned. The DL5 was neutral regarding repellence (PI index -0,09, but from DL25 on, the PI index was between -0.1 and -1.0, indicating repellence activity.

  13. Bioactivity of diatomaceous earth to Sitophilus zeamais (Coleoptera: Curculionidae in different application conditions

    Directory of Open Access Journals (Sweden)

    Adalberto H. Sousa

    2013-09-01

    Full Text Available The objective of this study was to evaluate the insecticidal activity of diatomaceous earth (DE at different ambient temperatures on adult Sitophilus zeamais and progeny, using different doses and exposure periods. The experiments were performed in Petri dishes containing 40 g of the whole corn kernel, treated with DE at doses of 0, 0.25, 0.5 and 1.0 kg Mg-1. Each dish was infested with 25 S. zeamais adults and kept at climatic chambers under temperatures of 20, 25, 30, 35 and 40 ºC. The insect mortality was recorded after six and 15 days from the beginning of the bioassays. The grains evaluated at 15 days were separated from insects and kept in the dishes for another 75 days under the same temperature conditions. After this period the effect of ambient temperature and of diatomaceous earth doses on the emergence of S. zeamais in the F1 generation was evaluated. It was found that the mortality of S. zeamais increased with the higher dose and temperature during the exposure period of six and 15 days. The number of insects emerged reduced with increasing temperature in these two exposure periods. The increase of temperature and exposure period favored the efficacy of DE in lower doses for control of S. zeamais.

  14. EFEITO RESIDUAL DE INSETICIDAS NATURAIS NO CONTROLE DE SITOPHILUS ZEAMAIS MOTS. EM MILHO ARMAZENADO

    Directory of Open Access Journals (Sweden)

    Rodrigo Leandro Braga de Castro Coitinho

    2006-01-01

    Full Text Available The residual effect of natural insecticides was evaluated on adults of Sitophilus zeamais Mots. (Coleoptera: Curculionidae on stored corn grains. Clove (Syzygium aromaticum L., white pepper (Piper nigrum L., neem (Azadirachta indica A. Juss and silica dioxide powders were tested as well as neem, eucalyptus (Eucaliptus globulus Labill and Eucaliptus citriodora Hook., eugenol, andiroba (Carapa guianensis Aubl., rosemary (Lippia gracillis HBK., cedar (Cedrela fissilis Vell. and pequi (Caryocar brasiliense Camb. oils. Powders were tested at concentration of 1kg/t in 50g-corn-plot and the oils at dosage of 50¿L in 20g-corn-plot. The plots infestation was accomplished using 20 and 8 adults (males and females of S. zeamais being 0 to 15 days old, respectively, in the experiments with powders and oils. Silica dioxide caused 46.7, 38.3 and 37.5% of mortality, respectively, in the initial (soon after the treatment with the powders or oils and at 60 and 120 days of storage periods, but the mortality induced by the other powders was inexpressive. In the three studied storage periods, silica dioxide was the more efficient in reducing adults emergency. At the initial storage period, all the oils caused mortality above 79%, however, after 60 and 120 days, mortality was lower than 2.5%. The adult emergency increased as stored period increased, although at 120 days the best performance was obtained using neem, followed by andiroba, cedar, rosemary and E. globulus oils.

  15. Fumigant toxicity of five essential oils rich in ketones against Sitophilus zeamais (Motschulsky

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    J.M Herrera

    2014-06-01

    Full Text Available Essential oils (EOs and individual compounds act as fumigants against insects found in stored products. In fumigant assays, Sitophilus zeamais Motschulsky adults were treated with essential oils derived from Aphyllocladus decussatus Hieron, Aloysia polystachya Griseb, Minthostachys verticillata Griseb Epling and Tagetes minuta L , which are rich in ketones and their major components: a- thujone, R-carvone, S-carvone, (- menthone, R (+ pulegone and E-Z- ocimenone. M. verticillata oil was the most toxic ( LC50: 116.6 µl /L air characterized by a high percentage of menthone (40.1% and pulegone (43.7%. All ketones showed insecticidal activity against S. zeamais. However, pulegone (LC50: 11.8 µl/L air, R- carvone (LC50: 17.5 µl/L air, S-carvone (LC50: 28.1 µl/L air and E-Z-ocimenone (LC50: 42.3 µl/L air were the most toxic. These ketones are a,b-unsaturated carbonyl. This feature could play a fundamental role in the increase of insecticidal activity against S. zeamais.

  16. Pimenta pseudocaryophyllus Derivatives: Extraction Methods and Bioactivity Against Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae).

    Science.gov (United States)

    Ribeiro, L P; Ansante, T F; Niculau, E S; Pavarini, R; Silva, M F G F; Seffrin, R C; Vendramim, J D

    2015-12-01

    Plant-based insecticides can play an important role in integrated insect pest management (IPM), especially in protecting stored grains. The aim of this study was to evaluate the bioactivity of derivatives (powder, ethanolic extract, and essential oil (EO)) from the leaves of Pimenta pseudocaryophyllus (Myrtaceae), a Brazilian native species, against Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), the main insect pest of stored corn. The powder and essential oil prepared from leaves showed a repellent effect. Moreover, the EO exhibited promising insecticidal activity through residual contact (LC50 = 1522 mg kg(-1)) and significantly decreased the F 1 progeny and the percentage of damaged grains. However, the essential oil obtained from P. pseudocaryophyllus leaves did not result in significant mortality of S. zeamais adults after 72 h of exposure by fumigation in concentrations up to 400 μL L(-1) of air. Based on GC-MS analysis, 20 compounds were identified in the essential oil of P. pseudocaryophyllus leaves, being chavibetol (38.14%), methyl eugenol (11.35%), and terpinolene (9.17%) as the major constituents. Essential oil from P. pseudocaryophyllus leaves is an interesting source of compounds with grain-protectant properties and should be analyzed in future studies aiming to develop new bioinsecticides to use in the IPM of stored grains.

  17. Toxicity of some essential oils and plant extracts against Sitophilus oryzea, Aconthocelides obtectus and Rhizoperta dominica

    Science.gov (United States)

    Şimşek, Şeyda; Yaman, Cennet; Yarımoǧlu, Berkan; Yılmaz, Ayşegül

    2017-04-01

    In the present study, experiments were conducted to investigate fumigant toxicity of the essential oil from Myrtus sp plants for adult Aconthocelides obtectus, Sitophilus oryzea and Rhizoperta dominica in vitro conditions. The essential oils were isolated with the water distillation method by Neo-Clevenger apparatus. During the study 10% (v/v) doses of oils in 20 cc of compressed rubber-capped glass tubes were used. After 24 hours mortality rates of the essential oil were compared. Myrtus sp essential oil showed the highest fumigant toxicity on A. obtectus (46.66%). The lowest fumigant toxicity on S. oryzea (8.88%). The contact toxicity plant extracts (Prangos ferulacea, Alkanna orientalis, Myrtus communis) were tested against S. oryzea under laboratory conditions. Single dose contact toxicity effects of plant extracts were tested on S. oryzea adults via applying 1 µl extract suspension (10% w/v) to individual insect. The greatest contact toxicity to S. oryzea adults was observed with M. communis (43.33%) and A. orientalis (41.11%) extracts. P. ferulacea (34.44%) extracts produced moderate toxicity to S. oryzea adults.

  18. Tri-party underground symbiosis between a weevil, bacteria and a desert plant.

    Science.gov (United States)

    Shelef, Oren; Helman, Yael; Friedman, Ariel-Leib-Leonid; Behar, Adi; Rachmilevitch, Shimon

    2013-01-01

    Inhabitants of arid ecosystems face severe nitrogen and water limitations. Inventive adaptations by organisms occupying such habitats are essential for survival. This study describes a tri-party symbiotic interaction between a plant (Salsola inermis), a beetle (Conorhynchus pistor), and a bacterium (Klebsiella pneumonia). The weevil survives by living within a mud structure affixed to the plant roots, thus benefiting from increased carbon and water, and refuge from predators and parasites. Active nitrogen-fixing bacteria harbored within the weevil's gut mediate this interaction, by supplying nitrogen to the system, which eventually promotes seed development. We studied the correlation between the weevil's existence and (i) root carbon and nitrogen content, (ii) soil water content and (iii) seed weight. Roots hosting weevils contained more nitrogen, heavier seeds and less carbon. In addition, water content was higher around the roots than in open spaces a short distance from the plant stem. Bacterial studies and nitrogen-fixation analyses, including molecular and chemical assays, indicated atmospheric nitrogen fixation in the larval stage and identified the bacterium. The coexistence of weevil and bacterial behavior coinciding with the plant's life cycle was revealed here by a long period of field observations. Out of over 60,000 known weevils, this is the only report of a weevil living most of its life underground without harming plants. The unique tri-party interaction described herein shows the important ecological role of desert plant roots and provides an example of a sustainable consortium of living organisms coping with the challenging desert environment.

  19. Isolation and characterization of bacteria from midgut of the rice water weevil (Coleoptera: Curculionidae).

    Science.gov (United States)

    Lu, Fang; Kang, Xiaoying; Jiang, Cong; Lou, Binggan; Jiang, Mingxing; Way, Michael O

    2013-10-01

    Gut bacteria are known to play important and often essential roles in the biology of insects. Theoretically, they can be genetically manipulated, then reintroduced into insects to negatively modify specific biological features. The weevil superfamily Curculionoidea is one of the most species-rich and successful animal groups on earth, but currently the overall knowledge of the bacterial communities in weevils and their associations with hosts is still limited. In this study, we isolated and characterized the bacteria in the midgut of an invasive weevil, Lissorhoptrus oryzophilus Kuschel, by culturing methods. Female adults of this weevil were collected from four different geographic regions of the United States and mainland China. Sequencing of the bacterial 16S rRNA amplicons demonstrated that the major culturable gut bacteria of rice water weevil are γ-proteobacteria and Bacilli. The gut bacterial composition differs among regions, with many of the bacteria isolated from only a single region while several were detected from more than one region. Overall, the diversity of gut bacteria in rice water weevil is relatively low. The possible origins of certain bacteria are discussed in relation to the weevil, rice plant, and bacteria.

  20. Influence of tillage on adult and immature pea leaf weevil (Coleoptera: Curculionidae) densities in pea.

    Science.gov (United States)

    Hanavan, Ryan P; Bosque-Pérez, Nilsa A; Schotzko, Dennis J; Eigenbrode, Sanford D

    2010-06-01

    The pea leaf weevil, Sitona lineatus (L.) (Coleoptera: Curculionidae), has been a major pest of pea, Pisum sativum L., in eastern Washington and northern Idaho since its introduction to the region in the early 1970s. Eggs are deposited in the spring on the soil surface and first instars hatch and move to pea root nodules, where larvae feed before they pupate and adults emerge in mid- to late summer. No-tillage practices are known to reduce pea leaf weevil colonization in pea, but the effects of tillage on larval densities and subsequent adult emergence have not been examined. During 2005, 2006, and 2007, we compared densities of colonizing adult and immature pea leaf weevils on pea plots grown using conventional tillage and no-tillage. In 2005 and 2006, emergence of adult pea leaf weevil was monitored in the same plots. Densities of colonizing adult and immature pea leaf weevil were significantly higher in conventional tillage plots. Larvae in conventional tillage were further along in development than larvae in no-tillage plots during June and July. Densities of emerging adult pea leaf weevil were significantly greater from conventional tillage than no-tillage plots. Based on densities of colonizing and subsequent emerging adults, survival of weevils from egg through adult was greater in conventional tillage plots. Soils under no-tillage are cooler, resulting in later emergence of the pea crop and delayed root nodule development, possibly affecting the ability of first-instar pea leaf weevil to locate host plant roots. Our results indicate no-tillage fields are less suitable for pea leaf weevil colonization and survival than conventional tillage fields.

  1. Iridovirus infection of cell cultures from the Diaprepes root weevil, Diaprepes abbreviatus

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    W.B. Hunter

    2003-12-01

    Full Text Available We here report the development and viral infection of a Diaprepes root weevil cell culture. Embryonic tissues of the root weevil were used to establish cell cultures for use in screening viral pathogens as potential biological control agents. Tissues were seeded into a prepared solution of insect medium and kept at a temperature of 24°C. The cell culture had primarily fibroblast-like morphology with some epithelial monolayers. Root weevil cells were successfully infected in vitro with a known insect virus, Invertebrate Iridescent Virus 6. Potential uses of insect cell cultures and insect viruses are discussed.

  2. [Biological characteristics of the egg phase of citrus root weevils].

    Science.gov (United States)

    Guedes, Jerson V C; Parra, José R P

    2007-01-01

    The goal of this work was to study some characteristics of the egg phase of three species of citrus root weevils. The insects were collected from citrus plants in Itapetininga, SP, and brought to the Laboratório de Biologia de Insetos of ESALQ/USP, in Piracicaba, SP, where the species Naupactus cervinus (Boheman), Naupactus versatilis (Hustache) and Parapantomorus fluctuosus (Boheman) were kept. Duration and viability of the egg phase were evaluated, and the lower temperature threshold and thermal constant (K) were calculated for these species. The species of citrus root weevils showed different duration of egg phases. The egg phase ranged from 40.4 to 13.8 N. cervinus, from 38.7 to 20.0 days for N. versatilis, and from 35.0 to 13.8 days for P. fluctuosus, depending upon temperature. The temperature thresholds of this stage were 8.1, 8.3, and 9.9 masculineC at thermal constant was 385.7, 397.7 and 294.1 degree-days, for N. cervinus, N. versatilis and P. fluctuosus respectively. The duration of the egg phases of N. cervinus and N. versatilis were similar at the same temperatures and P. fluctuosus had a faster development than Naupactus spp. in all temperatures tested.

  3. Quarantine treatment for Sitophilus zeamais (Coleoptera: Curculionidae) through gamma radiation from Cobalt-60

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Amanda Cristina Oliveira, E-mail: amandaramos@usp.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Potenza, Marcos Roberto, E-mail: potenza@biologico.sp.gov.b [Instituto Biologico de Sao Paulo, Sao Paulo, SP (Brazil). Centro de Pesquisa e Desenvolvimento de Sanidade Vegetal; Arthur, Valter, E-mail: varthur@cena.usp.b [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

    2009-07-01

    Pests like beetles, moths, fungus and mites normally attack stored products such as grains, spices, flours, brans and tobacco in bale. Among these pests the Sitophilus zeamais is one of the most important pests due its elevated potential of reproduction, infesting a great number of products, inducing great damages. This work had as objective to determine the efficacy of gamma radiation from Cobalt-60 as quarantine treatment for S. zeamais. The insects used in this experiment were reared in maize grains, at the Laboratorio de Artropodes of the Instituto Biologico/SP, on climatic room with 27 +- 2 deg C of temperature and relative humidity of 70 +- 5%. Samples containing 25 adult insects were put in acrylic recipients measuring 2.8cm x 2.8cm. Each treatment had four repetitions, in a total of 100 insects for treatment. They were irradiated with growing doses of gamma radiation: 0 (control); 0,25; 0,5; 0,75; 1,0; 1,25; 1,5; 1,75; 2,0; 2,25 2,5; 2,75; 3,0; 3,5 e 4,0 kGy, in a experimental irradiator of Cobalt-60, model Gammacell-220, located at the Centro de Tecnologia da Radiacoes - CTR of the Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN/SP. After irradiation, the samples were transferred to plastic recipients measuring 3,5cm x 10cm, with perforated lids (to allow gaseous exchanges). After the irradiation the samples were kept in climatic room (27 +- 2 deg C and 70 +- 5%). The mortality of insects was evaluated 1 hour after the irradiation and also on the next 7 days. By the results obtained we can conclude that was the dose of 2.75 kGy that induced the immediate mortality for adult insects of the specie S. zeamais. (author)

  4. HOJAS DE CHAN (Hyptis suaveolens PARA EL CONTROL DE Sitophilus zeamais Y Zabrotes subfasciatus

    Directory of Open Access Journals (Sweden)

    Modesto Armando G\\u00F3mez-Peralta

    2009-01-01

    Full Text Available Con el obje­tivo de evaluar el efecto de la hoja de chan sobre Sitophilus zeamais y Zabrotes subfasciatus en granos almacenados de maíz y fri­jol respectivamente, se estableció un ensayo en condiciones controladas en el año 2007, entre los meses de mayo a setiembre, en la ciudad de León, Nicaragua, a 129 msnm y una temperatura promedio de 29 °C. Se emplearon semillas de frijol de la variedad DOR 364 y semillas de maíz de la variedad NB - 6. Las hojas de chan del estrato medio de las plantas hacia el estrato superior y de tamaño similar, se colectaron antes de la floración se secaron por tres días en un secador solar y luego fueron pulverizadas. Las unidades experimentales consistieron de frascos de plástico de 172,2 g de capacidad, y dimensiones de 7,5 cm de diámetro por 8 cm de alto, a los que se adicionaron 100 g de maíz o 100 g de frijol. Los tratamientos consistieron en la adición del polvo de hoja seca de chan entre las semillas en seis dosis: 0, 5, 10, 15, 20 y 25 gramos por 100 de semilla. Luego se adicionaron 20 adultos seleccionados al azar y sin sexar. Las variables medidas en frijol y maíz fueron: número de insectos muertos; número de granos picados; número de adultos mergidos de los granos y peso del los granos. El polvo de las hojas de chan sólo tuvo efecto en la mortalidad de S. zeamays.

  5. Atividade insetistática de óleo essencial de Pothomorphe umbellata sobre Sitophilus zeamais

    Directory of Open Access Journals (Sweden)

    Carolina F. Pauliquevis

    2015-12-01

    Full Text Available RESUMO Sitophilus zeamais (Motschulsky, 1885 (Coleoptera: Curculionidae é um dos principais insetos que atacam e comprometem severamente a qualidade de grãos armazenados cujo controle é feito através de inseticidas químicos que nem sempre são eficazes, ocasionam a seleção de insetos resistentes, eliminam populações de inimigos naturais, deixam resíduos nos alimentos e contaminam o meio ambiente. Na tentativa de minimizar o problema com a possibilidade de uma alternativa agroecológica, pesquisas com óleos essenciais têm-se mostrado promissoras. Neste contexto, o objetivo da pesquisa foi identificar o potencial insetistático do óleo essencial da pariparoba no controle do gorgulho-do-milho para o que foram realizados bioensaios para verificar o efeito fumigante, exposição em superfície de contato e repelência. Houve efeito fumigante, os valores da CL50 e CL99 para as 24 h de confinamento dos insetos foram, respectivamente, 0,95 e 6,73 µL g-1. Os valores da CL50 e CL99 para as 24 h de exposição em superfície de contato foram, respectivamente, 0,34 e 4,91 µL cm-2; a repelência ocorreu na primeira hora; desta forma, o óleo essencial de Pothomorphe umbellata apresenta efeito insetistático para o controle de S. zeamais.

  6. Combining larval parasitoids and an entomopathogenicfungus for biological control of Sitophilus granarius (Coleoptera: Curculionidae) in stored grain

    DEFF Research Database (Denmark)

    Hansen, Lise Stengaard; Steenberg, Tove

    2006-01-01

    The potential of combining different natural enemies for biological control of Sitophilus granarius (L.) in grain was investigated in a laboratory study. We compared the effect of two species of larval parasitoids, Lariophagus distinguendus Förster and Anisoptermalus calandrae (Howard), alone or ...

  7. Frequency and time pattern differences in acoustic signals produced by Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) and Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae) in stored maize

    Science.gov (United States)

    The acoustic signals emitted by the last stage larval instars and adults of Prostephanus truncatus and Sitophilus zeamais in stored maize were investigated. Analyses were performed to identify brief, 1-10-ms broadband sound impulses of five different frequency patterns produced by larvae and adults,...

  8. Behavioral and Reproductive Response of White Pine Weevil (Pissodes strobi to Resistant and Susceptible Sitka Spruce (Picea sitchensis

    Directory of Open Access Journals (Sweden)

    Jeanne A. Robert

    2010-08-01

    Full Text Available White pine weevil (Pissodes strobi, Peck. is a native forest insect pest in the Pacific Northwest of North America that attacks species of spruce (Picea spp. and pine (Pinus spp.. Young Sitka spruce [Picea sitchensis (Bong. Carr.] trees are particularly susceptible to weevil attack. Pockets of naturally occurring Sitka spruce resistance have been identified in high weevil hazard areas in coastal British Columbia. In this study, we characterize behavioral, physiological and reproductive responses of weevils to an extremely resistant Sitka spruce genotype (H898 in comparison to a highly susceptible genotype (Q903. The experiments relied on a large number of three-year-old clonally propagated trees and were therefore restricted to two contrasting Sitka spruce genotypes. When exposed to resistant trees, both male and female weevils were deterred during host selection and mating, females showed delayed or reduced ovary development, and successful reproduction of weevils was prevented on resistant trees.

  9. Polyploid evolution in Oryza officinalis complex of the genus Oryza

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    Li Changbao

    2009-10-01

    Full Text Available Abstract Background Polyploidization is a prominent process in plant evolution, whereas the mechanism and tempo-spatial process remained poorly understood. Oryza officinalis complex, a polyploid complex in the genus Oryza, could exemplify the issues not only for it covering a variety of ploidy levels, but also for the pantropical geographic pattern of its polyploids in Asia, Africa, Australia and Americas, in which a pivotal genome, the C-genome, witnessed all the polyploidization process. Results Tracing the C-genome evolutionary history in Oryza officinalis complex, this study revealed the genomic relationships, polyploid forming and diverging times, and diploidization process, based on phylogeny, molecular-clock analyses and fluorescent in situ hybridization using genome-specific probes. Results showed that C-genome split with B-genome at ca. 4.8 Mya, followed by a series of speciation of C-genome diploids (ca. 1.8-0.9 Mya, which then partook in successive polyploidization events, forming CCDD tetraploids in ca. 0.9 Mya, and stepwise forming BBCC tetraploids between ca. 0.3-0.6 Mya. Inter-genomic translocations between B- and C-genomes were identified in BBCC tetraploid, O. punctata. Distinct FISH (fluorescent in situ hybridization patterns among three CCDD species were visualized by C-genome-specific probes. B-genome was modified before forming the BBCC tetraploid, O. malampuzhaensis. Conclusion C-genome, shared by all polyploid species in the complex, had experienced different evolutionary history particularly after polyploidization, e.g., inter-genomic exchange in BBCC and genomic invasion in CCDD tetraploids. It diverged from B-genome at 4.8 Mya, then participated in the tetraploid formation spanning from 0.9 to 0.3 Mya, and spread into tropics of the disjunct continents by transcontinentally long-distance dispersal, instead of vicariance, as proposed by this study, given that the continental splitting was much earlier than the C

  10. Control of Cowpea Weevil, Callosobruchus Maculatus (F.) (Coleoptera: Bruchidae), Using Natural Plant Products

    OpenAIRE

    Bamphitlhi Tiroesele; Kesegofetse Thomas; Seipati Seketeme

    2014-01-01

    A laboratory study was conducted to investigate the effects of natural products on the reproduction and damage of Callosobruchus maculatus, the cowpea weevil, on cowpea seeds at Botswana College of Agriculture in Gaborone, Botswana. The cowpea variety Blackeye was used in the study. Fifty grams of each plant product (garlic, peppermint and chilies) was added to 500 g of the cowpea seeds. Findings of this experiment revealed that chilies and garlic had negative effects on cowpea weevils for al...

  11. Insect monitoring and the spatial distribution of Sitophilus spp. (Coleoptera: Curculionidae in a grain processing and storage unit= Monitoramento de insetos e distribuição espacial de Sitophilus spp. (Coleoptera: Curculionidae em unidade de beneficiamento e armazenamento de grãos

    Directory of Open Access Journals (Sweden)

    Luiz Fernandes Silva Dionisio

    2016-10-01

    Full Text Available The aim of this study was to identify the main species of insects in stored grain, as well as determine the spatial distribution pattern of Sitophilus spp. in a grain processing and storage structure. The study was carried out in a grain storage and processing unit in Boa Vista, in the State of Roraima, where 20 samples were taken from July 2013 to May 2014. To collect the insects, traps with food capsules as bait were used distributed around the storage unit, with 8 traps placed on the floor of the external area, along the walls of the silo, and 12 traps placed inside, along the drying and bagging areas and hopper. The insects were collected monthly, the bait being removed from the traps and taken to the Plant Protection Laboratory at the Centre for Agricultural Sciences-CCA of UFRR, for counting and identification of the insects. Analysis of variability and spatial dependence was carried out using geostatistical procedures based on techniques of spatial modelling by semivariogram. Kriging maps were generated from count data of adult Sitophilus spp. in the traps. In eleven months, 60,913 insects were collected. The most representative species were Oryzaephilus surinamensis (29.3%, Rhyzopertha dominica (28%, Sitophilus spp. (17% and Cryptolestes spp. (15.7%. The spatial distribution of Sitophilus spp. is aggregated with spatial dependence described by a spherical model. The greatest infestation of Sitophilus spp. was seen in areas near the storage silos. To develop safe methods of sampling Sitophilus spp., placing a trap every 21 m is recommended. = O objetivo deste trabalho foi identificar as principais espécies de insetos de grãos armazenados, bem como determinar o padrão de distribuição espacial de Sitophilus spp. em estrutura de beneficiamento e armazenamento de grãos. O estudo foi realizado em uma unidade de armazenamento e beneficiamento de grãos no município de Boa Vista/RR, onde foram realizadas 20 amostragens no período de

  12. Aggregation pheromone for the pepper weevil,Anthonomus eugenii cano (Coleoptera: Curculionidae): Identification and field activity.

    Science.gov (United States)

    Eller, F J; Bartelt, R J; Shasha, B S; Schuster, D J; Riley, D G; Stansly, P A; Mueller, T F; Shuler, K D; Johnson, B; Davis, J H; Sutherland, C A

    1994-07-01

    This study describes the identification of an aggregation pheromone for the pepper weevil,Anthonomus eugenii and field trials of a synthetic pheromone blend. Volatile collections and gas chromatography revealed the presence of six male-specific compounds. These compounds were identified using chromatographic and spectral techniques as: (Z)-2-(3,3-dimethylcyclohexylidene)ethanol, (E)-2-(3,3-dimethylcyclohexylidene)ethanol, (Z)-(3,3-dimethylcyclohexylidene)acetaldehyde, (E)-(3,3-dimethylcyclohexylidene)acetaldehyde, (E)-3,7-dimethyl-2,6-octadienoic acid (geranic acid), and (E)-3,7-dimethyl-2,6-octadien-1-ol (geraniol). The emission rates of these compounds from feeding males were determined to be about: 7.2, 4.8, 0.45, 0.30, 2.0, and 0.30µg/male/day, respectively. Sticky traps baited with a synthetic blend of these compounds captured more pepper weevils (both sexes) than did unbaited control traps or pheromone-baited boll weevil traps. Commercial and laboratory formulations of the synthetic pheromone were both attractive. However, the commercial formulation did not release geranic acid properly, and geranic acid is necessary for full activity. The pheromones of the pepper weevil and the boll weevil are compared. Improvements for increasing trap efficiency and possible uses for the pepper weevil pheromone are discussed. A convenient method for purifying geranic acid is also described.

  13. Survival and preference of cotton boll weevil adults for alternative food sources

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    M. Pimenta

    Full Text Available Abstract Plants that have potential as alternative food source (floral nectar, pollen and plant tissues to the boll weevil during the intercropping season were evaluated considering the prevalent conditions of Cerrado in the Central Brazil. Initially, we tested the nutritional adequacy for the survival of the insect of flower resource (pollen and nectar provided by eight plant species (fennel, mexican sunflower, castor bean, okra, hibiscus, sorghum, pigeonpea and sunn hemp. Subsequently, we tested if the resources provided by the selected plants continued to be exploited by the boll weevil in the presence of cotton plant, its main food source average longevity of boll weevil adults was significantly longer when they were fed on hibiscus’ flowers (166.6 ± 74.4 and okra flowers (34.7 ± 28.9 than when they fed on flowers of other six species. Subsequently, the preference of the boll weevil in the use of resources was compared between okra or hibiscus and cotton plants, in dual choice experiments. Boll weevils preferred plants of the three species in the reproductive stages than those in vegetative stages. Although the cotton plant in the reproductive stage was the most preferred plant of all, boll weevils preferred flowering okra and hibiscus than cotton at the vegetative stage.

  14. ENHANCED TOXICITY OF CARBON DIOXICE TO ETHYL FORMATE FUMIGANTING ON ADULTS OF SITOPHILUS ORYZAE(LINNAEUS)AND TRIBOLIUM CASTANEUM(HERBST)%二氧化碳对甲酸乙酯熏蒸米象和赤拟谷盗的毒力增效作用

    Institute of Scientific and Technical Information of China (English)

    王殿轩; 郜智贤; 国娜; 严晓平; 储昭兵

    2009-01-01

    在(28±2)℃、70%±5%相对湿度条件下,设定约1%、3%、5%、7%的二氧化碳浓度环境,参照FAO推荐的害虫抗性测定方法,测定了甲酸乙酯对米象Sitophilus oryzae (Linnaeus)和赤拟谷盗Tribolium castaneum(Herbst)的毒力.结果表明:1%的二氧化碳浓度即对甲酸乙酯有一定增效作用,3%~7%的二氧化碳浓度明显增加甲酸乙酯对害虫的毒力.不管是甲酸乙酯单剂熏蒸,还是在不同二氧化碳浓度下,赤拟谷盗对甲酸乙酯的耐受力均大于米象.

  15. Controle de Sitophilus zeamais Mots. através de diferentes concentrações de CO2 e O2 Control of Sitophilus zeamais Mots with different concentrations of CO2 and O2

    Directory of Open Access Journals (Sweden)

    Jerson Vanderlei Carús Guedes

    1996-08-01

    Full Text Available Instalou-se um experimento com objetivo de avaliar o efeito de diferentes concentrações dos gases: CO2 e O2 balanceado com N, no controle de Sitophilus zeamais. Utilizou-se parcelas subdivididas no tempo com parcela principal distribuída segundo o delineamento inteiramente casualizado com quatro repetições. A unidade experimental constou de um vidro com volume de cinco litros, onde estavam acondicionados 0,15 kg de milho desinfestado e 200 insetos adultos não sexados. Foram avaliadas oito concentrações de gases (tratamentos: 0,03% de CO2 e 21% de O2 (testemunha, 10% de CO2 e 16% de O2, 15% CO2 e 16% O2, 20% CO2 e 16% O2, 0% CO2 e 5% O2, 0% CO2 e 1% O2, 75% CO2 e 5% O2, e 12% CO2 e 8% O2. Os resultados demonstraram que 20% de CO2 controla totalmente os insetos em cinco dias. Tratamento com 15% de CO2 associado com 5% de O2, controla a totalidade dos insetos após dez dias. Concentração de 1% O2, sem adição de CO2, também controla 100% da população de Sitophilus zeamais. após 15 dias.This experiment was carried out aiming to evaluate the effect of different CO2 and 0(2 concentrations on the contral of Sitophilus zeamais. The experimental design was a split-plot in time, with the main plot distribucted in a completly randomized design, with four replications. The plot was consisted of a 5-liter glass chamber, in which 0.15 kg of desinfected maize with 200 unsexed adults insects. Eight gas concentrations were avaluated: 0.03% of CO2 and 21% of O2 (control, 10% of CO2 and 16% of O2, 15% of CO2 and 16% of O2, 20% of CO2 and 16% of O2, 0% of CO2 and 5% of O2, 0% of CO2 and 1% of O2, 15% of CO2 and 5% of O2 and 12% of CO2 and 8% of O2. Results demonstrated that 20% of CO2 controlled the insects in five days. Treatment with 15% of CO2 and 5% of 0(2 controlled 100% of insects in 10 days and 0% of CO2 and 1% of O2 controlled in 15 days.

  16. Molecular detection of Xanthomonas oryzae pv.oryzae, Xanthomonas oryzae pv. oryzicola, and Burkholderia glumae in infected rice seeds and leaves

    Institute of Scientific and Technical Information of China (English)

    Wen; Lu; Luqi; Pan; Haijun; Zhao; Yulin; Jia; Yanli; Wang; Xiaoping; Yu; Xueyan; Wang

    2014-01-01

    The polymerase chain reaction(PCR) is particularly useful for plant pathogen detection. In the present study, multiplex PCR and SYBR Green real-time PCR were developed to facilitate the simultaneous detection of three important rice pathogens, Xanthomonas oryzae pv.oryzae, X. oryzae pv. oryzicola, and Burkholderia glumae. The unique PCR primer sets were designed from portions of a putative glycosyltransferase gene of X. oryzae pv. oryzae, an Avr Rxo gene of X. oryzae pv. oryzicola, and an internal transcribed spacer(ITS) sequence of B. glumae. Using a multiplex PCR assay, X. oryzae pv. oryzae, X. oryzae pv. oryzicola, and B. glumae were detected in one PCR reaction that contained the newly developed primer set mix. Using SYBR Green real-time PCR assays, X. oryzae pv. oryzae, X. oryzae pv. oryzicola, and B. glumae were detected at 1, 1, and 10 fg μL-1, respectively. These newly designed molecular assays are sensitive and could be reliable tools for pathogen detection and disease forecasting.

  17. Toxigenic Aspergillus and Penicillium isolates from weevil-damaged chestnuts.

    Science.gov (United States)

    Wells, J M; Payne, J A

    1975-10-01

    Aspergillus and Penicillium were among the most common genera of fungi isolated on malt-salt agar from weevil-damaged Chinese chestnut kernels (16.8 and 40.7% occurrence, respectively). Chloroform extracts of 21 of 50 Aspergillus isolates and 18 of 50 representative Penicillium isolates, grown for 4 weeks at 21.1 C on artificial medium, were toxic to day-old cockerels. Tweleve of the toxic Aspergillus isolates were identified as A. wentii, eight as A. flavus, and one as A. flavus var. columnaris. Nine of the toxic Penicillium isolates were identified as P. terrestre, three as P. steckii, two each as P. citrinum and P. funiculosum, and one each as P. herquei (Series) and P. roqueforti (Series). Acute diarrhea was associated with the toxicity of A. wentii and muscular tremors with the toxicity of P. terrestre, one isolate of P. steckii, and one of P. funiculosum.

  18. Bioatividade de diversos pós de origem vegetal em relação A Sitophilus zeamais Mots. (Coleoptera: Curculionidae Bioactivity of powders from some plants on Sitophilus zeamais Mots. (Coleoptera: Curculionidae

    Directory of Open Access Journals (Sweden)

    Sérgio de Oliveira Procópio

    2003-12-01

    Full Text Available Foram avaliadas, em condições de laboratório, a repelência, sobrevivência e emergência de adultos de Sitophilus zeamais em grãos de milho tratados com pós de Azadirachta indica A. Juss (frutos, Capsicum frutescens L. (frutos e folhas, separadamente, Chenopodium ambrosioides L. (folhas, flores e frutos, conjuntamente, Eucalyptus citriodora Hook (folhas, Melia azedarach Blanco (folhas e Ricinus communis L. (folhas. As plantas que provocaram repelência foram E. citriodora e C. frutescens (folhas, com efeito mais pronunciado na primeira espécie. A única planta que afetou a sobrevivência da praga foi C. ambrosioides, que provocou mortalidade total dos insetos infestantes e nenhuma emergência de adultos. Para essa planta, foi também determinado o limiar de atividade inseticida, constatando-se que a dosagem mínima necessária para controle total da população dos insetos foi de 0,1645 g/ 20 g de milho.The repellency, reproduction and survival of Sitophilus zeamais were evaluated under laboratory conditions with maize grains treated with powders obtained from fruits of Azadirachta indica A. Juss, leaves and fruits of Capsicum frutescens L., leaves of Eucalyptus citriodora Hook, Melia azedarach Blanco, Capsicum frutescens and Ricinus communis L., and a mixture of leaves, flowers and fruits of Chenopodium ambrosioides L.. The most repellent plant species were E. citriodora and C. frutescens (leaves. The only treatment that showed significant effect on survival and reproduction of S. zeamais was C. ambrosioides which caused 100% mortality and avoided the emergency of adults. The insecticide activity threshold was determined for this plant species and the minimal dosage for total control of this insect was 0.1645 g of powder per 20 g of maize.

  19. Tri-party underground symbiosis between a weevil, bacteria and a desert plant.

    Directory of Open Access Journals (Sweden)

    Oren Shelef

    Full Text Available Inhabitants of arid ecosystems face severe nitrogen and water limitations. Inventive adaptations by organisms occupying such habitats are essential for survival. This study describes a tri-party symbiotic interaction between a plant (Salsola inermis, a beetle (Conorhynchus pistor, and a bacterium (Klebsiella pneumonia. The weevil survives by living within a mud structure affixed to the plant roots, thus benefiting from increased carbon and water, and refuge from predators and parasites. Active nitrogen-fixing bacteria harbored within the weevil's gut mediate this interaction, by supplying nitrogen to the system, which eventually promotes seed development. We studied the correlation between the weevil's existence and (i root carbon and nitrogen content, (ii soil water content and (iii seed weight. Roots hosting weevils contained more nitrogen, heavier seeds and less carbon. In addition, water content was higher around the roots than in open spaces a short distance from the plant stem. Bacterial studies and nitrogen-fixation analyses, including molecular and chemical assays, indicated atmospheric nitrogen fixation in the larval stage and identified the bacterium. The coexistence of weevil and bacterial behavior coinciding with the plant's life cycle was revealed here by a long period of field observations. Out of over 60,000 known weevils, this is the only report of a weevil living most of its life underground without harming plants. The unique tri-party interaction described herein shows the important ecological role of desert plant roots and provides an example of a sustainable consortium of living organisms coping with the challenging desert environment.

  20. Circadian rhythms of feeding, oviposition, and emergence of the boll weevil (Coleoptera: Curculionidae)

    Institute of Scientific and Technical Information of China (English)

    SHOIL M.GREENBERG; J.SCOTT ARMSTRONG; MAMOUDOU S(E)TAMOU; THOMAS W.SAPPINGTON; RANDY J.COLEMAN; TONG-XIAN LIU

    2006-01-01

    Circadian rhythm of feeding,oviposition,and emergence of boll weevil adults were determined at five different photophases (24,14,12,10,and 0 hours) and a constant 27℃ temperature,65% RH in the laboratory. Squares from Petri dishes,where they were exposed to boll weevil females,were removed and examined for feeding and oviposition punctures every 4 hours during daylight (0700-1900 h) and every 12 h at night (1900-0700 h) over eight consecutive days. Cohorts of randomly selected egg-punctured squares were sampled from ovipositing females at 0700,1100,1500,and 1900 during 24 hours and under different photophase treatments,and maintained in Petri dishes at 27 ± 1℃,65% RH.Dishes were observed twice daily (1900 and 0700 h) for adults emerging at day or night.Circadian rhythm of oviposition was not affected by the length of the photophase. The boll weevil has round-the-clock circadian rhythm of oviposition,with a daytime preference. We observed that 82.4%-86.0% of the boll weevil eggs were deposited between 0700 and 1900 h,and 14.0%-17.6% between 1900 and 0700 h during a 24-h period. Feeding of boll weevil females in photoperiods 24:0 h (complete light) and 0:24 h (complete darkness) did not significantly change between 0700-1900 h versus 1900-0700 h,while the daily cycle of light and darkness in other photoperiods significantly increased the feeding punctures from 0700-1900 compared with 1900-0700 h. The circadian rhythm of emergence depended significantly on the time of oviposition and the length of the photophase. Investigation of boll weevil circadian rhythm provides a better understanding of boll weevil ecology and reveals potential weak links for improving control technologies targeting their reproductive strategies.

  1. Leptographium bhutanense sp. nov., associated with the root collar weevil Hylobitelus chenkupdorjii on Pinus wallichiana in Bhutan

    NARCIS (Netherlands)

    Zhou, X.D.; Jacobs, K.; Kirisits, T.; Chhetri, D.B.; Wingfield, M.J.

    2008-01-01

    Leptographium spp. are commonly associated with bark beetles and weevils (Coleoptera: Curculionidae), and some are important tree pathogens. In a recent survey of diseases and insect pests of conifer trees in Bhutan, the root collar weevil, Hylobitelus chenkupdorjii was found girdling young Himalaya

  2. Effects of two pheromone trap densities against banana weevil Cosmopolites sordidus, populations and their impact on plant damage in Uganda

    NARCIS (Netherlands)

    Tinzaara, W.; Gold, C.S.; Kagezi, G.H.; Dicke, M.; Huis, van A.; Nankinga, C.; Tushemereirwe, W.; Ragama, P.E.

    2005-01-01

    An on-farm study to evaluate the effect of pheromone trap density on the population of the banana weevil, Cosmopolites sordidus (Germar) (Col., Curculionidae) was conducted in Masaka district, Uganda. The pheromone used was Cosmolure+, a commercially available weevil aggregation pheromone. Forty-two

  3. Leptographium bhutanense sp. nov., associated with the root collar weevil Hylobitelus chenkupdorjii on Pinus wallichiana in Bhutan

    NARCIS (Netherlands)

    Zhou, X.D.; Jacobs, K.; Kirisits, T.; Chhetri, D.B.; Wingfield, M.J.

    2008-01-01

    Leptographium spp. are commonly associated with bark beetles and weevils (Coleoptera: Curculionidae), and some are important tree pathogens. In a recent survey of diseases and insect pests of conifer trees in Bhutan, the root collar weevil, Hylobitelus chenkupdorjii was found girdling young Himalaya

  4. Sublethal effects of malathion on boll weevil (Coleoptera:Curculionidae) fecundity when maintained on cotton squares or artificial diet

    Institute of Scientific and Technical Information of China (English)

    JOHN SCOTT ARMSTRONG; ALLAN T. SHOWLER; MAMOUDOU SETAMOU; SHOIL GREENBERG

    2006-01-01

    Mated 3-day-old female boll weevils, Anthonomus grandis grandis Boheman,reared from field-infested cotton (Gossypium hirsutum L.) squares were topically treated with an estimated LD50 of malathion (2μg) to assess its effects on fecundity, oviposition, and body fat condition. Two different food sources, cotton squares and artificial diet, were assessed in malathion-treated and nontreated (control) weevils. The LD50 caused ≈ 50%mortality in the square-fed malathion treatment, but the artificial diet-fed malathion-treated weevils were less susceptible. LD50 survivors fed on the squares produced ≥ 9 times more chorionated eggs in the ovaries and oviposited≥ 19-fold more than survivors fed artificial diet, regardless of the malathion treatment. Boll weevils that survived a 2μg LD50 malathion and also fed squares were ≈ 4.5-fold leaner than diet-fed weevils. Our findings demonstrate that non-resistant boll weevils surviving a sublethal dose of malathion will reproduce without any delay or significant loss in fecundity, and the food source for which boll weevils are maintained when conducting these assays will directly affect the results. The significance of these findings and how they are related to the final stages of eradicating the boll weevil from the US are discussed.

  5. Factors Affecting Pheromone Production by the Pepper Weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae and Collection Efficiency

    Directory of Open Access Journals (Sweden)

    Fred J. Eller

    2014-11-01

    Full Text Available Several factors affecting pheromone production by male pepper weevils, Anthonomus eugenii Cano (Coleoptera: Curculionidae as well as collection efficiency were investigated. Factors studied included: porous polymer adsorbents (Tenax versus Super Q, male age, time of day, male density, and male diet. Super Q was found to be a superior adsorbent for the male-produced alcohols and geranic acid as well as the plant-produced E-β-ocimene. Pheromone production increased with male age up to about age 15 days old and then tapered off. Male pepper weevils produced the highest amount of pheromone between noon and 2 pm (i.e., 4 to 6 h after “lights on” and were producing ca. 800 ng/h during this period. Thereafter, pheromone production decreased and was extremely low during the scotophase (i.e., ca. 12 ng/h. Male pepper weevil density had a significant effect on both release rate and pheromone composition. Pheromone production on a per male basis was highest for individual males and the percentage of geranic acid in the blend was lowest for individual males. Male pepper weevils produced only extremely low amounts of pheromone when feeding on artificial diet; however, they produced very high amounts when on fresh peppers. Together, this information will be useful in designing better attractant lures for pepper weevils.

  6. Artificial substrates for oviposition and larval development of the pepper weevil (Coleoptera: Curculionidae).

    Science.gov (United States)

    Addesso, K M; McAuslane, H J; Stansly, P A; Slansky, F; Schuster, D J

    2009-02-01

    The pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae), is a major pest of cultivated peppers (Capsicum spp.) and other cultivated and wild species within the family Solanaceae. Laboratory study of this insect, as well as its biological control agents, will be greatly facilitated by an artificial rearing system that does not rely on pepper fruit. An egg collection method and amendments to a standard larval diet were investigated for use in the rearing of this weevil. Spherical sachets made of Parafilm or netting enclosing leaves of pepper, American black nightshade, eggplant, tomato, potato, and jasmine tobacco induced oviposition. Tomato, potato, and jasmine tobacco leaves were accepted despite the fact that these are not oviposition hosts for pepper weevils in the wild. A standard larval diet formula was modified in an attempt to improve egg hatch, larval survival, developmental time, and adult mass. The diet formula was modified with the addition of freeze-dried jalapeño pepper powder, an additional lipid source, alternate protein sources, and the removal of methyl paraben. None of the aforementioned treatments resulted in a significant improvement over the standard diet. Egg hatch was greater when eggs were incubated on moist paper towels rather than in diet; thus, placement of neonates rather than eggs into diet improved production of adults. Suggestions for more efficient rearing of weevils on the currently available diet and future directions for the development of an artificial rearing system for pepper weevil are discussed.

  7. Factors Affecting Pheromone Production by the Pepper Weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae) and Collection Efficiency.

    Science.gov (United States)

    Eller, Fred J; Palmquist, Debra E

    2014-11-18

    Several factors affecting pheromone production by male pepper weevils, Anthonomus eugenii Cano (Coleoptera: Curculionidae) as well as collection efficiency were investigated. Factors studied included: porous polymer adsorbents (Tenax versus Super Q), male age, time of day, male density, and male diet. Super Q was found to be a superior adsorbent for the male-produced alcohols and geranic acid as well as the plant-produced E-β-ocimene. Pheromone production increased with male age up to about age 15 days old and then tapered off. Male pepper weevils produced the highest amount of pheromone between noon and 2 pm (i.e., 4 to 6 h after "lights on") and were producing ca. 800 ng/h during this period. Thereafter, pheromone production decreased and was extremely low during the scotophase (i.e., ca. 12 ng/h). Male pepper weevil density had a significant effect on both release rate and pheromone composition. Pheromone production on a per male basis was highest for individual males and the percentage of geranic acid in the blend was lowest for individual males. Male pepper weevils produced only extremely low amounts of pheromone when feeding on artificial diet; however, they produced very high amounts when on fresh peppers. Together, this information will be useful in designing better attractant lures for pepper weevils.

  8. Mutualistic interaction between a weevil and a rust fungus, two parasites of the weed Cirsium arvense.

    Science.gov (United States)

    Friedli, Jürg; Bacher, Sven

    2001-12-01

    We present a mutualism between a stem-boring weevil, Apion onopordi Kirby (Coleoptera: Apionidae), and a rust fungus, Puccinia punctiformis (Str.) Röhl. (Uredinales), both parasites of the creeping thistle, Cirsium arvense (L.) Scop. (Asteraceae). Females, but not males, of A. onopordi induced systemic rust infections of thistle shoots in the season after they were attacked by the weevil, indicating that insect oviposition is a crucial stage in pathogen transmission. Adult weevils emerged from systemically infected thistle shoots were heavier than weevils from healthy C. arvense shoots. Heavier females had a higher fecundity and laid larger eggs. The weevil preferred to deposit eggs in systemically rust-infected over healthy thistle shoots, which seemed to be a sub-optimal host. This is to our knowledge the first report of a mutualistic interaction between an herbivorous insect and a biotrophic plant pathogen. The mechanism responsible for the advantage of rust-infected shoots for A. onopordi causes a different outcome in other thistle herbivores, and therefore can not be explained by a general enhancement of nutritional quality in rust-infected tissue. This mutualism likely has evolved from a competitive relationship. Unlike other thistle herbivores A. onopordi seems to be better suited as mutualist for P. punctiformis because of its small impact on the host plant and its feeding niche on plant parts not directly associated with pathogen reproduction.

  9. Have stump piles any effect on the pine weevil (Hylobius abietis L. incidence and seedling damage?

    Directory of Open Access Journals (Sweden)

    Abul Rahman

    2015-01-01

    Full Text Available Tree stumps are being increasingly used for bioenergy purposes, which may have significant effects on pine weevil (Hylobius abietis L. populations and the level of damage they can cause to seedlings. Pine weevils are attracted by the smell of fresh stumps in clear-cut areas, and have been shown to cause serious damage to planted coniferous seedlings in European forests. This study was conducted to measure the incidence of pine weevil and damage caused to Norway spruce (Picea abies seedlings in a field experiment including single stump pile plots (SSP, multiple stump pile plots (MSP and control plots in North Karelia, Finland. Pine weevils were significantly more abundant in MSP stump plots (22% higher than in SSP plots, and are 23% more abundant compared to the control plots. The extent of seedling damage was significantly lower in the SSP (by 67% and MSP plots (by 58% than in the controls. Seedlings damage increased significantly with the distance from the stump pile. Stump harvesting practices should be updated and, in particular, multiple stump piles should be avoided in the clearcut area. However, future studies will be required to explore the environmental and physical factors in the stump-removal area influencing pine weevil abundance.

  10. 21 CFR 173.130 - Carbohydrase derived from Rhizopus oryzae.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Carbohydrase derived from Rhizopus oryzae. 173.130... HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.130 Carbohydrase derived from Rhizopus oryzae. Carbohydrase from Rhizopus oryzae may be safely used in the production of dextrose from starch...

  11. Evaluation of the dust and methanol extracts of Garcinia kolae for the control of Callosobruchus maculatus (F.) and Sitophilus zeamais (Mots)

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Insecticidal effects of different doses of the dust and methanol extracts ofGarcinia kolae on Callosobruchus maculatus and Sitophilus zeamais were tested. The dust had no significant effect on the two insects; none of them died even at 3 d after treatment. The methanol extracts, however, had rapid lethal effects on both C. maculatus and S. zeamais. The mortality of C.maculatus by the lowest concentration of methanol extracts ranged from 95%~100% whereas in S. zeamais, the mortality ranged from 87.5%~100% and 70% ~100% in concentrations of 1 g extract+3 ml methanol and 1 g extract+5 ml methanol, respectively,from 24 to 48 h. The least concentration of 1 g extract+15 ml methanol had no significant lethal effect on Sitophilus zeamais.

  12. Eficácia da mistura dióxido de carbono-fosfina no controle de Sitophilus zeamais em função do período de exposição Effectiveness of the mixture dioxide of carbon-phosphine in the control of Sitophilus zeamais as a function of the exposure period

    Directory of Open Access Journals (Sweden)

    Enilce Maria Coelho

    2000-01-01

    Full Text Available Este trabalho teve por objetivo avaliar o efeito da atmosfera modificada (100% CO2 associada a doses de fosfina no controle de Sitophilus zeamais (Motschulsky. Concluiu-se que: o aumento do período de exposição resultou no aumento da eficácia dos tratamentos; as pupas de S. zeamais foram mais tolerantes aos tratamentos, enquanto os ovos e as larvas de primeiro ínstar foram mais sensíveis e que a concentração de 0,75 g m-3 de fosfina, associada à atmosfera contendo 100% de CO2, no período de 120 h de exposição, é a mínima necessária para o controle efetivo de todas as fases de desenvolvimento do S. zeamais.The objective of this work was to evaluate the effect of a modified atmosphere (100% of CO2 associated with three phosphine concentrations (0.25, 0.50, and 0.75 g m-3, on the control of different stages of development of the insect Sitophilus zeamais (Motschulsky. It was concluded that, in general, (1 an increase in the exposure period caused an increase in the effectiveness of both the treatments with atmosphere containing 100% of CO2 and atmosphere with ambient air, associated to the phosphine, for all development stages of Sitophilus zeamais; (2 the pupae of Sitophilus zeamais were the ones with the highest tolerance to the treatments used for control, while the eggs and larvae from the first instar were the ones with lesser tolerance; (4 the concentration of 0.75 g m-3 of phosphine associated to the atmosphere containing 100% of CO2, for the exposure period of 120 h, was the minimum necessary to effectively control all development stages of Sitophilus zeamais.

  13. Estimation of the population density of the sweetpotato weevils on the Mariana Islands

    Directory of Open Access Journals (Sweden)

    Gadi V.P. Reddy

    2012-05-01

    Full Text Available The sweetpotato Ipomoea batatas L. (Convolvulaceae has been one of the most important foods for Pacific islanders for centuries. However, the yield levels have been declining in the recent past due to the presence of sweetpotato weevils Cylas formicarius (Fabricius (Coleoptera, Brentidae, Euscepes postfasciatus (Fairmaire and Daealus tuberosus (Zimmer man (Coleoptera, Curculionidae. Therefore, urgent management or eradication methods are sought in the Mariana Islands (Guam, Rota, Saipan, and Tinian. However, the management or eradication of these weevil pests requires accurate assessments of the target pest density. Currently, no advice is provided to growers on the best method for sampling sweetpotato for weevil pests, although pheromone-based traps or chemicals are being used. This study defines the results of field counts designed to adjust relative sampling techniques for three sweetpotato weevil pests by inspecting plants visually and at random in the field with an absolute measure of population density. Significant relationships were detected between the relative four sampling sites between the three weevil pests. In the dry and wet season, 90% and 35.5%, respectively, of population density of C. formicarius was noticed in Rota. This density of the population levels of this species is significantly lower in Saipan, Guam and Tinian. No incidence of E. postfasciatus and D. tuberosus was observed on Guam. However, E. postfasciatus is identified as the second most destructive pest in Rota, Tinian and Saipan in both the dry and wet seasons. Likewise, D. tuberosus is the third major pest as the recorded population density ranged from 12.5% to 2.5%. Also, it is evident from the sampling study that the population densities of all three weevils are significantly higher in the dry season than the wet season.

  14. Threat to Cedar, Cedrela odorata, Plantations in Vietnam by the Weevil, Aclees sp.

    OpenAIRE

    Thu, Pham Quang; Quang, Dao Ngoc; Dell, Bernard

    2010-01-01

    The recent decline and death of young cedar, Cedrela odorata L. (Sapindales: Meliaceae), plantations in Vietnam is caused by Aclees sp. (Coleoptera: Curculionidae), a wood-boring brown weevil. A field study was undertaken in three-year-old plantations in two districts in Thanh Hoa province in August 2008. Trees were heavily impacted by the weevil, Aclees; the infestation level (P) ranged from 80 to 100% and the average damage index (R) ranged from 1.8 to 2.8. Observations over one year enable...

  15. Survival of boll weevil (Coleoptera: Curculionidae)adults after feeding on pollens from various sources

    Institute of Scientific and Technical Information of China (English)

    SHOIL M. GREENBERG; GRETCHEN D. JONES; FRANK EISCHEN; RANDY J.COLEMAN; JOHN J. ADAMCZYK, JR; TONG-XIAN LIU; MAMOUDOU SETAMOU

    2007-01-01

    The survival of overwintering boll weevil, Anthonomus grandis grandis (Boheman),adults on non-cotton hosts in the Lower Rio Grande Valley (LRGV) of Texas was examined from 2001 to 2006. The success of the Boll Weevil Eradication Program, which was reintroduced into the LRGV in 2005, depends on controlling overwintering boll weevil populations. Laboratory studies were conducted using boll weevil adults that were captured in pheromone traps from September through March. The number of adults captured per trap declined significantly in the field from fall to the beginning of spring (3.5-7.0-fold). The proportion of trapped males and females did not differ significantly. The mean weight of boll weevil adults captured in September was 13.3 mg, while those of captured adults from November to February were significantly lower and ranged from 6.7 to 7.8 mg. Our results show that boll weevil adults can feed on different plant pollens. The highest longevity occurred when adults were fed almond pollen or mixed pollens (72.6 days and 69.2 days, respectively)and the lowest when they fed on citrus pollen or a non-food source (9.7 days or 7.4 days,respectively). The highest adult survival occurred on almond and mixed pollens [88.0%-97.6% after 1st feeding period (10 days), 78.0%-90.8% after 3rd feeding period (10 days), 55.0%-83.6% after 5th feeding period (10 days), and 15.2%-32.4% after 10th feeding period (10days)]. The lowest adult survival occurred on citrus pollen [52.0%-56.0% after 1st feeding period (10 days), 13.3% after 3rd and 5th feeding periods (10 days), and 0 after 6th feeding period (10 days)]. Pollen feeding is not a behavior restricted to adult boll weevils of a specific sex or physiological state. Understanding how boll weevil adults survive in the absence of cotton is important to ensure ultimate success of eradicating this pest in the subtropics.

  16. Root weevils of artificial forests in Ukraine steppe area (Coleoptera: Curculionidae: Cleonini

    Directory of Open Access Journals (Sweden)

    Volovnik S. V.

    2012-06-01

    Full Text Available Seven species of root weevils (Cleonini: were found in man-made forests in the steppe of Ukraine. They are Asproparthenis punctiventris, Bothynoderes affinis, Bothynoderes declivis, Cleonis pigra, Cyphocleonus dealbatus, Pachycerus segnis, Temnorhinus strabus. All these species were registered in open habitats, namely forest borders, glades, sides of the roads, slopes, and connected with plants from Asteraceae, Chenopodiacea, Boraginaceae. If beet plantations situated near artificial forests then A. punctiventris, B. affinis, B. declivis could damage them in case of mass reproduction. C.dealbatus is a potential pest of the ornamental camoniles. Literary data as to real damage caused to artificial forests by root weevils need to be proved.

  17. OsSERK1 regulates rice development but not immunity to Xanthomonas oryzae pv. oryzae or Magnaporthe oryzae

    Institute of Scientific and Technical Information of China (English)

    Shimin Zuo; and Pamela C Ronald; Xiaogang Zhou; Mawsheng Chen; Shilu Zhang; Benjamin Schwessinger; Deling Ruan; Can Yuan; Jing Wang; Xuewei Chen

    2014-01-01

    Somatic embryogenesis receptor kinase (SERK) proteins play pivotal roles in regulation of plant development and immunity. The rice genome contains two SERK genes, OsSerk1 and OsSerk2. We previously demonstrated that OsSerk2 is required for rice Xa21‐mediated resistance to Xanthomonas oryzae pv. oryzae (Xoo) and for normal development. Here we report the molecular characterization of OsSerk1. Overexpres-sion of OsSerk1 results in a semi‐dwarf phenotype whereas silencing of OsSerk1 results in a reduced angle of the lamina joint. OsSerk1 is not required for rice resistance to Xoo or Magnaporthe oryzae. Overexpression of OsSerk1 in OsSerk2‐silenced lines complements phenotypes associated with brassinosteroid (BR) signaling defects, but not the disease resistance phenotype mediated by Xa21. In yeast, OsSERK1 interacts with itself forming homodimers, and also interacts with the kinase domains of OsSERK2 and BRI1, respectively. OsSERK1 is a functional protein kinase capable of auto‐phosphorylation in vitro. We conclude that, whereas OsSERK2 regulates both rice development and immunity, OsSERK1 functions in rice development but not immunity to Xoo and M. oryzae.

  18. Control de Sitophilus zeamais con polvos vegetales de tres especies del género Chenopodium Control of Sitophilus zeamais with vegetable powders of three species of Chenopodium genus

    Directory of Open Access Journals (Sweden)

    Gonzalo Ivan Silva-Aguayo

    2005-10-01

    Full Text Available Se evaluaron polvos vegetales de Chenopodium ambrosioides L., Chenopodium album L. y Chenopodium quinoa Willd. para el control de Sitophilus zeamais Motschulsky, bajo condiciones de laboratorio. Los parámetros evaluados fueron mortalidad y emergencia de insectos adultos, pérdida de peso y germinación de los granos, efecto ovicida y larvicida, fumigación, repelencia y residualidad de los polvos. El diseño experimental fue completamente al azar, con un arreglo factorial y tres repeticiones. La mayor mortalidad de insectos se obtuvo con los polvos de la inflorescencia y la mezcla de hojas y tallos de Chenopodium ambrosioides L., al 2% (p/p con valores de 69,4% y 67,9% respectivamente. La menor emergencia de adultos se obtuvo con los mismos tratamientos. La pérdida de peso de granos, en todos los tratamientos de C. ambrosioides, no superó el 3%. Para el tratamiento inflorescencia de C. ambrosioides al 2% (p/p, la residualidad de los polvos se mantuvo hasta los 15 días, con una mortalidad de 98,3%. Esta misma especie presentó una mortalidad de huevos y larvas de 100%, además de presentar un efecto fumigante con una mortalidad de adultos de 100%, en todos los tratamientos evaluados. El polvo de C. ambrosioides es repelente para S. zeamais.Powders of Chenopodium ambrosioides L., Chenopodium album L. and Chenopodium quinoa Willd. were evaluated under laboratory conditions for Sitophilus zeamais Motschulsky control. Evaluated parameters were insect mortality and adult emergence, grain weight loss, grain germination and the following effects of powders: ovicide and larvicide, fumigant, repellent and residual. A completely randomized experimental design with factorial arrangement and three replicates was used. The highest levels of insect mortality were obtained with the powders of Chenopodium ambrosioides L. inflorescence and the mixture of leaves and stems at 2% (w/w, with values of 69.4% and 67.9% respectively. Best emergence reductions were

  19. Population density of oil palm pollinator weevil Elaeidobius kamerunicus based on seasonal effect and age of oil palm

    Science.gov (United States)

    Daud, Syarifah Nadiah Syed Mat; Ghani, Idris Abd.

    2016-11-01

    The pollinating weevil, Elaedobius kamerunicus (EK) has been known to be the most efficient insect pollinator of oil palm, and has successfully improved the oil palm pollination and increased the yield. Its introduction has greatly reduced the need for assisted pollination. The purpose of this study was to identify the population density of oil palm pollinator weevil EK using the concept of pollinator force and to relate the population density with the seasonal effect and the age of oil palm at Lekir Oil Palm Plantation Batu 14, Perak, Peninsular Malaysia. The pollinator force of the weevil was sustained at a range between 3095.2 to 19126.1 weevils per ha. The overall mean of weevil per spikelet shows that the range of weevil was between 13.51 and 54.06 per spikelet. There was no correlation between rainfall and population density of EK. However, positive correlation was obtained between weevil density and the number of anthesising female inflorescence of oil palm (r= 0.938, ppollinator force per spikelete and the Fresh fruit Bunch (FFB), fruit set or fruit to bunch ratio.

  20. EXTRATO AQUOSO DE FOLHAS DE Azadirachta indica A. Juss NO CONTROLE DE Sitophilus zeamais Mots. (COLEOPTERA: CURCULIONIDAE EM MILHO ARMAZENADO

    Directory of Open Access Journals (Sweden)

    Marcelo Toller Borsonaro

    2013-05-01

    Full Text Available The present work had as objective to test different dosages of aqueous extract of leaves of neem(Azadirachta indica as natural alternative and of easy application in the control of Sitophilus zeamais in grains of corn, seeing it is one of main stored corn pests. Were evaluated the following concentrations: 10%, 20%, 30% and witness. They were applied directly on the mass of grains and the insects with a pressurized pulverizer model Guarany PCP-1P in the dosage of 0,56 mL for dish. The treatments did not present significant difference as the reduction of weight of grains, but there was significant difference in relation to the population control. As for this parameter, the aqueous extract of leaves of neem in concentration 30,3%, can be considered an alternative treatment against S. zeamais in stored corn grains.O presente trabalho teve como objetivo testar diferentes dosagens de extrato aquoso de folhas de Nim (Azadirachta indica A Juss como alternativa natural e de fácil aplicação no controle de Sitophilus zeamais Mots.(Coleoptera: Curculionidae em grãos de milho (Zea mays L., visto que esta é uma das principais pragas do milhoarmazenado. Avaliaram-se as seguintes concentrações: 10%, 20%, 30,3%, além do tratamento testemunha. Foram aplicados diretamente sobre a massa de grãos e sobre os insetos com um pulverizador pressurizado modelo Guarany PCP-1P na dosagem de 0,56 mL por placa. Os tratamentos não apresentaram diferença significativa quanto à redução de peso de grãos, mas houve diferença significativa em relação ao controle populacional. Quanto a este parâmetro, o extrato aquoso de folhas de Nim na concentração 30,3%, pode ser considerado um tratamento alternativo no controle de S. zeamais em grãos de milho armazenado.

  1. A Reliable Identification System for Red Palm Weevil

    Directory of Open Access Journals (Sweden)

    Saleh Mufleh Al-Saqer

    2012-01-01

    Full Text Available Problem statement: Red Palm Weevil (RPW is a widely found pest among palm trees and is known to cause significant losses every year to palm growers. Existing identification techniques for RPW comprise of using traps with pheromones to detect these pests. However, these traditional methods are labor-intensive, expensive to implement and unreliable for early detection of RPW infestation. Early detection of these pests would provide the best opportunity to eradicate them and minimize the potential losses of palm trees. Approach: In this study, a reliable identification system is developed to identify RPW by using only a small number of image descriptors in combination with neural network models. The neural networks were developed by using between three to nine image descriptors as inputs and a large database of insects’ images was used for training. Three different training ratios ranging from 25-75% were used and the network was trained by two different algorithms. Further, several scenarios were formulated to test the efficacy and reliability of the newly developed identification system. Results: The results indicate that the identification system developed in this study is capable of 100% recognition of RPW and 93% recognition of other insects in the database by taking as input only three easily-calculable image descriptors. Further, the average training times for these networks was 13 sec and the testing time for a single image was only 0.015 sec. Conclusion: The new system developed in this study provided reliable identification for RPW and was found to be up to 14 times faster in training and three times faster in testing of insects’ images.

  2. Field efficacy against the hazelnut weevil, Curculio nucum and short-term persistence of entomopathogenic nematodes

    Directory of Open Access Journals (Sweden)

    L. Batalla-Carrera

    2013-11-01

    Full Text Available The hazelnut weevil, Curculio nucum L. (Coleoptera: Curculionidae is a pest affecting hazelnut orchards in Europe, with an important economical repercussion. Its potential control, short-term field persistence and the vertical distribution of native entomopathogenic nematode strains were tested in Muntanyes de Prades, Tarragona (NE Iberian Peninsula over two consecutive years. Steinernema feltiae strain D114, Steinernema sp. strain D122 and Heterorhabditis bacteriophora strain DG46 were used in summer and spring applications at a dosage of 5·105 IJs m-2. The three nematode species reduced the hazelnut weevil population, ranging from 32% to 88% efficacy, without significant differences in efficacy or between the two applications. Persistence evaluation was carried out during 9 weeks for S. feltiae (D114, Steinernema sp. (D122 and H. bacteriophora (DG46 and showed all species capable of lasting for this period. Nematodes and larval vertical distribution was assessed. Most of the hazelnut weevil stayed within the first 25 cm although some were found as deep as 40 cm. Entomopathogenic nematodes were found along all 40 cm depth. This study proves the suitability of entomopathogenic nematodes to control the hazelnut weevil.

  3. Green Light Synergistally Enhances Male Sweetpotato Weevil Response to Sex Pheromone

    Science.gov (United States)

    McQuate, Grant T.

    2014-01-01

    Sweetpotato, commercially grown in over 100 countries, is one of the ten most important staple crops in the world. Sweetpotato weevil is a major pest of sweetpotato in most areas of cultivation, the feeding of which induces production in the sweetpotato root of extremely bitter tasting and toxic sesquiterpenes which can render the sweetpotato unfit for consumption. A significant step towards improved management of this weevil species was the identification of a female-produced sex pheromone [(Z)-3-dodecenyl (E)-2-butenoate] to which males are highly attracted. Reported here are results of research that documents a nearly 5-fold increase in male sweetpotato weevil catch in traps baited with this pheromone and a green light provided by a solar-powered, light-emitting diode (LED). The combination of olfactory and night-visible visual cues significantly enhanced trap effectiveness for this nighttime-active insect species. These results provide promise for improved sweetpotato weevil detection and suppression in mass trapping programs. PMID:24675727

  4. Assessing the role of generalist predators in the biological control of alfalfa weevil (Coleoptera: Curculionidae)

    Science.gov (United States)

    The alfalfa weevil, Hypera postica (Gyllenhal), is a major and longstanding economic pest of alfalfa throughout much of the United States. While work on biological control of this species has disproportionately focused on introduced parasitoids, generalist predators are also considered potentially i...

  5. Relationship of black vine weevil egg density and damage to two cranberry cultivars

    Science.gov (United States)

    Field and laboratory trials compared Metarhizium anisopliae and Steinernema kraussei to imidacloprid for black vine weevil (BVW), Otiorhynchus sulcatus, larval control in cranberry. Two field sites were treated in fall of 2009 and soil samples collected during 2009 and 2010 to assess treatment effic...

  6. Host plant preference and performance of the vine weevil Otiorhynchus sulcatus

    NARCIS (Netherlands)

    Tol, van R.W.H.M.; Dijk, van N.; Sabelis, M.W.

    2004-01-01

    1. The relationship between reproductive performance and preference for potential host plants of the vine weevil is investigated, as shown in tests on contact (or feeding) preference, presented herein, and tests on olfactory preference, published elsewhere. 2. Assessment of reproductive performance

  7. Continued pheromone release by boll weevils (Coleoptera: curculionidae) following host removal

    Science.gov (United States)

    Pheromone traps are a key component of management and eradication programs directed against the boll weevil, Anthonomus grandis (Boheman), but trap data remain difficult to interpret because of the day-to-day variability in captures. Our prior observations suggested a substantial proportion of boll...

  8. Host plant odours enhance the responses of adult banana weevil to the synthetic aggregation pheromone Cosmolure+

    NARCIS (Netherlands)

    Tinzaara, W.; Gold, C.S.; Dicke, M.; Huis, van A.; Ragama, P.E.

    2007-01-01

    Attraction of adult banana weevil, Cosmopolites sordidus to volatiles from banana pseudostem tissue and the synthetic pheromone Cosmolure+ presented singly or in combination, was studied in the laboratory and in the field. Olfactometric studies in the laboratory showed that 50 g of fermented banana

  9. Phylogeography of specialist weevil Trichobaris soror: a seed predator of Datura stramonium.

    Science.gov (United States)

    De-la-Mora, Marisol; Piñero, Daniel; Núñez-Farfán, Juan

    2015-12-01

    Can the genetic structure of a specialist weevil be explained by the geological history of their distribution zone? We analyze the genetic variation of the weevil Trichobaris soror, a specialist seed predator of Datura stramonium, in order to address this question. For the phylogeographic analysis we used the COI gene, and assessed species identity in weevil populations through geometric morphometric approach. In total, we found 53 haplotypes in 413 samples, whose genetic variation supports the formation of three groups: (1) the Transmexican Volcanic Belt (TVB group), (2) the Sierra Madre Sur (SMS group) and (3) the Balsas Basin (BB group). The morphometric analysis suggests that BB group is probably not T. soror. Our results have two implications: first, the phylogeographic pattern of T. soror is explained by both the formation of the geological provinces where it is currently distributed and the coevolution with its host plant, because the TVB and SMS groups could be separated due to the discontinuity of altitude between the geological provinces, but the recent population expansion of TVB group and the high frequency of only one haplotype can be due to specialization to the host plant. Second, we report a new record of a different species of weevil in BB group parasitizing D. stramonium fruits.

  10. Using molecular genetics to identify immature specimens of the weevil Ceratapion basicorne (Coleoptera, Apionidae)

    Science.gov (United States)

    A field experiment was conducted to evaluate host plant specificity of the yellow starthistle rosette weevil, Ceratapion basicorne. Larvae infesting plants were preserved in 99% ethanol. Adult specimens of C. basicorne and four closely related species were identified using conventional morphologic...

  11. Effect of Hexaflumuron on gustation and reproduction of adult boll weevil

    Science.gov (United States)

    The efficacy of hexaflumuron was evaluated in the laboratory against boll weevil, Anthonomus grandis grandis Boheman, captured in pheromone-baited traps for gustatory response and reproduction of the insect. Hexaflumuron is an insect growth regulator which inhibits chitin synthesis and disrupts inse...

  12. Metapopulation structure of a seed-predator weevil and its host plant in arms race coevolution.

    Science.gov (United States)

    Toju, Hirokazu; Ueno, Saneyoshi; Taniguchi, Fumiya; Sota, Teiji

    2011-06-01

    Although the importance of gene flow in the geographic structuring of host-parasite interactions has been well discussed, little is known about how dispersal drives the spatial dynamics of other types of coevolutionary interactions in nature. We evaluated the roles of gene flow in the geographically structured processes of a predator-prey arms race involving a seed-predatory weevil with a long mouthpart and its host camellia plant with a thick fruit coat. Molecular genetic analyses showed that both weevil and camellia populations were structured at a spatial scale of several kilometers. Importantly, the spatial pattern of the migration of weevils, but not that of camellias, imposed significant effects on the geographic configuration of the levels of coevolutionary escalation. This result suggests that even if migration is limited in one species (camellia), local coevolution with the other species that migrates between neighboring localities (weevil) can reduce the interpopulation difference in the local adaptive optima of the former species. Thus, gene flow of a species potentially homogenizes the local biological environments provided by the species and thereby promotes the evolutionary convergence of its coevolving counterparts. Consequently, by focusing on coevolutionary interactions in natural communities, "indirect" effects of gene flow on the adaptive divergence of organisms could be identified.

  13. Attractant compositions for weevils of the genus Otiorhynchus and uses thereof

    NARCIS (Netherlands)

    Bruck, D.J.; Tol, van R.W.H.M.; Griepink, F.C.

    2011-01-01

    The present invention relates to formulations of volatile organic compounds having effects on Otiorhynchus weevils e.g., Otiorhynchus sulcatus. In some embodiments, volatile organic compounds selected from (E)-2-hexenol, (Z)-2-pentenol, methyl eugenol and a combination thereof are effective for attr

  14. Effects of combining microbial and chemical insecticides on mortality of the Pecan Weevil (Coleoptera: Curculionidae).

    Science.gov (United States)

    Shapiro-Ilan, David I; Cottrell, Ted E; Wood, Bruce W

    2011-02-01

    The pecan weevil, Curculio caryae (Horn), is a key pest of pecan [Carya illinoinensis (Wangenh.) K. Koch]. Current control recommendations are based on chemical insecticide applications. Microbial control agents such as the entomopathogenic nematode, Steinernema carpocapsae (Weiser) and the fungus Beauveria bassiana (Balsamo) Vuillemin occur naturally in southeastern U.S. pecan orchards and have shown promise as alternative control agents for C. caryjae. Conceivably, the chemical and microbial agents occur simultaneously within pecan orchards or might be applied concurrently. The objective of this study was to determine the interactions between two chemical insecticides that are used in commercial C. caryae control (i.e., carbaryl and cypermethrin applied below field rates) and the microbial agents B. bassiana and S. carpocapsae. In laboratory experiments, pecan weevil larval or adult mortality was assessed after application of microbial or chemical treatments applied singly or in combination (microbial + chemical agent). The nature of interactions (antagonism, additivity, or synergy) in terms of weevil mortality was evaluated over 9 d (larvae) or 5 d (adults). Results for B. bassiana indicated synergistic activity with carbaryl and antagonism with cypermethrin in C. caryae larvae and adults. For S. carpocapsae, synergy was detected with both chemicals in C. caryae larvae, but only additive effects were detected in adult weevils. Our results indicate that the chemical-microbial combinations tested are compatible with the exception of B. bassiana and cypermethrin. In addition, combinations that exhibited synergistic interactions may provide enhanced C. caryae control in commercial field applications; thus, their potential merits further exploration.

  15. New initiatives for managment of red palm weevil threats to historical Arabian date palms

    Science.gov (United States)

    The date palm is an important part of the religious, cultural, and economic heritage of the Arabian Peninsula. This heritage is threatened by the recent invasion of the red palm weevil(RPW) from Southeast Asia. In Saudi Arabia, a national campaign for control of RPW by containment/destruction of inf...

  16. Effects of covering highland banana stumps with soil on banana weevil Cosmopolites sordidus (Coleoptera: Curculionidae) oviposition

    NARCIS (Netherlands)

    Masanza, M.; Gold, C.S.; Huis, van A.; Ragama, P.E.

    2005-01-01

    The effect of covering post-harvest banana stumps with soil on banana weevil Cosmopolites sordidus (Germar) oviposition levels was investigated at three locations, Sendusu, Kawanda Agricultural Research Institute (KARI) and Ntungamo district of southwestern Uganda. In the first experiment ovipositio

  17. Olfactory responses of banana weevil predators to volatiles from banana pseudostem tissue and synthetic pheromone

    NARCIS (Netherlands)

    Tinzaara, W.; Gold, C.S.; Dicke, M.; Huis, van A.

    2005-01-01

    As a response to attack by herbivores, plants can emit a variety of volatile substances that attract natural enemies of these insect pests. Predators of the banana weevil, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) such as Dactylosternum abdominale (Coleoptera: Hydrophilidae) and Phe

  18. Mango seed weevil (Coleoptera: Curculionidae) and premature fruit drop in mangoes.

    Science.gov (United States)

    Follett, Peter A

    2002-04-01

    The effect of infestations of mango seed weevil, Sternochetus mangiferae (F.), on premature fruit drop of mangoes was investigated. Mango fruits ('Haden') of equal size were collected both off the ground and from the tree at four times during the season (June-August). If weevil-infested fruit were more prone to dropping than uninfested fruit, the prediction was that a higher infestation rate would be found in fruit on the ground compared with fruit on the tree. Average fruit weight was used as an indicator of fruit maturity. The seed infestation rate was significantly higher in fruit collected off the ground compared with fruit collected from the tree in 38 g and 79 g (early-season) fruit but not significantly different in 207 g (midseason) and 281 g (late season) fruit. The age distribution of weevils and the number of insects in infested fruits were similar for ground and tree fruits on all dates. Results suggest that mango seed weevil infestation can increase fruit drop during early fruit development.

  19. Effect of crop sanitation on banana weevil Cosmopolites sordidus (Germar) populations and associated damage

    NARCIS (Netherlands)

    Masanza, M.

    2003-01-01

    The banana weevil, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) is a serious pest of bananas. However, its ecology is not well elucidated especially in East Africa where plantations are up to 50 years old and are under various management and cropping systems. No single satisfa

  20. Genome sequence and rapid evolution of the rice pathogen Xanthomonas oryzae pv. oryzae PXO99A

    Directory of Open Access Journals (Sweden)

    Szurek Boris

    2008-05-01

    Full Text Available Abstract Background Xanthomonas oryzae pv. oryzae causes bacterial blight of rice (Oryza sativa L., a major disease that constrains production of this staple crop in many parts of the world. We report here on the complete genome sequence of strain PXO99A and its comparison to two previously sequenced strains, KACC10331 and MAFF311018, which are highly similar to one another. Results The PXO99A genome is a single circular chromosome of 5,240,075 bp, considerably longer than the genomes of the other strains (4,941,439 bp and 4,940,217 bp, respectively, and it contains 5083 protein-coding genes, including 87 not found in KACC10331 or MAFF311018. PXO99A contains a greater number of virulence-associated transcription activator-like effector genes and has at least ten major chromosomal rearrangements relative to KACC10331 and MAFF311018. PXO99A contains numerous copies of diverse insertion sequence elements, members of which are associated with 7 out of 10 of the major rearrangements. A rapidly-evolving CRISPR (clustered regularly interspersed short palindromic repeats region contains evidence of dozens of phage infections unique to the PXO99A lineage. PXO99A also contains a unique, near-perfect tandem repeat of 212 kilobases close to the replication terminus. Conclusion Our results provide striking evidence of genome plasticity and rapid evolution within Xanthomonas oryzae pv. oryzae. The comparisons point to sources of genomic variation and candidates for strain-specific adaptations of this pathogen that help to explain the extraordinary diversity of Xanthomonas oryzae pv. oryzae genotypes and races that have been isolated from around the world.

  1. Contact and fumigant toxicities of calamusenone isolated from Acorus gramineus rhizome against adults of Sitophilus zeamais and Rhizopertha dominica

    Institute of Scientific and Technical Information of China (English)

    Yan-Zhang Huang; Hong-Xia Hua; Shi-Guang Li; Chang-Ju Yang

    2011-01-01

    Calamusenone [3,8-dimethyl-5-(l-methylethylidene)- 1,2,3,4,5,6,7,8-octa-hydroazulene-6-one, C15H220] from Acorus gramineus Soland rhizome was tested in the laboratory for its insecticidal activities against adults of Sitophilus zeamais Motsch. and Rhizopertha dominica (Fab.), using dry film contact and fumigation methods. Responses varied with insect species, dosage and exposure time. In the dry film contact experiment, the highest insecticidal effects of calamusenone against S. zeamais and R. dominica adults were produced at 170.32 μg/cm2 after treatment for 72 h, with 96.2% and 98.7% mortalities, respectively. The median lethal concentration (LC50) (72 h) values of calamusenone against S. zeamais and R. dominica adults were 67.00 μg/cm2 and 77.30 μg/cm2, respectively. As a potential fumigant, calamusenone showed moderate insecticidal effect on the adults of S. zeamais and R. dominica in fumigation experiment, with their LC50 (120 h) values of 125.7μzL/L and 93.64μL/L respectively. Calamusenone isolated from A. gramineus rhizome showed promise as a novel pesticide candidate for stored-product pest control.

  2. The Efficacy of Bacillus thuringiensis spp. galleriae Against Rice Water Weevil (Coleoptera: Curculionidae) for Integrated Pest Management in California Rice.

    Science.gov (United States)

    Aghaee, Mohammad-Amir; Godfrey, Larry D

    2015-02-01

    Rice water weevil (Lissorhoptrus oryzophilus Kushel) is the most damaging insect pest of rice in the United States. Larval feeding on the roots stunt growth and reduce yield. Current pest management against the weevil in California relies heavily on pyrethroids that can be damaging to aquatic food webs. Examination of an environmentally friendly alternative biopesticide based on Bacillus thuringiensis spp. galleriae chemistry against rice water weevil larvae showed moderate levels of activity in pilot studies. We further examined the performance of different formulations of Bt.galleriae against the leading insecticide used in California rice, λ-cyhalothrin. The granular formulation performed as well as the λ-cyhalothrin in use in California in some of our greenhouse and field studies. This is the first reported use of B. thuringiensis spp. galleriae against rice water weevil.

  3. A synopsis of the orchid weevil genus Orchidophilus Buchanan (Curculionidae, Baridinae), with taxonomic rectifications and description of one new species

    Science.gov (United States)

    Six species of the weevil genus Orchidophilus Buchanan are recognized: O. epidendri (Murray) comb. n. (=Acythopeus genuinus Pascoe syn. n., =Baris orchivora Blackburn syn. n., =Apotomorhinus orchidearum Kolbe syn. n.), O. aterrimus (Waterhouse), O. eburifer (Pascoe) comb. n. (=Acythopeus gilvonotatu...

  4. Susceptibility of pepper weevil (anthonomus eugenii cano) (coleoptera: curculionidae) to seven insecticides in rural areas of Baja California Sur, Mexico

    OpenAIRE

    Rosalía Servín Villegas; José. L. García Hernández; Armando Tejas Romero; José L. Martínez Carrillo; M. A. Toapanta

    2008-01-01

    The susceptibility of the pepper weevil (Anthonomus eugenii), collected from Baja California Sur, Mexico, to seven insecticides was determined. Acontact, residual exposition method was used to obtain the lethal concentrations fifty (LC50) and the diagnostic concentration (LC95) of organophosphates (OF), carbamates (CA), pyrethroids (PIR), and organochlorine (OC) insecticides used to control pepper weevils from two agricultural areas (Los Planes and Todos Santos) in Southern Baja California Pe...

  5. Growth deficiency of a Xanthomonas oryzae pv. oryzae fur mutant in rice leaves is rescued by ascorbic acid supplementation.

    Science.gov (United States)

    Subramoni, Sujatha; Sonti, Ramesh V

    2005-07-01

    Xanthomonas oryzae pv. oryzae causes bacterial leaf blight, a serious disease of rice. A mutation was isolated in the ferric uptake regulator (fur) gene of X. oryzae pv. oryzae and it was shown to result in the production of siderophores in a constitutive manner. The fur mutant is hypersensitive to the metallo-antibiotic streptonigrin, a phenotype that is indicative of intracellular free-iron overload, and also exhibits a slow growth phenotype on rich medium. The fur mutant is virulence deficient, hypersensitive to hydrogen peroxide, and exhibits reduced catalase activity. Exogenous supplementation with ascorbic acid (an antioxidant) rescues the growth deficiency of the fur mutant in rice leaves. The virulence deficiency of the X. oryzae pv. oryzae fur mutant is proposed to be due, at least in part, to an impaired ability to cope with the oxidative stress conditions that are encountered during infection.

  6. [Invasive maxilar sinusitis by Rhizopus oryzae].

    Science.gov (United States)

    Perea, S; del Palacio, A; Gil, R; de la Serna, J; Mata, R; Arribi, A

    1997-12-01

    We herein present a diabetic with non Hodgkin lymphoma patient that had been treated with steroids and developed fungal invasive sinusitis. The patient had intensive facial pain that did not respond to antibiotics and on clinical inspection had a necrotic lesion on right nasal area. A smear and biopsy tissue showed broad non septate hyphae and on cultures Rhizopus oryzae was isolated. There was an unfavorable outcome, and the patient died even though liposomal Amphotericin B was administered and surgical treatment was performed.

  7. Study on seed germination of Oryza rufipogon

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Oryza rufipogon, distributed in tropical and subtropical regions is an important germplasm for rice breeding. Dongxiang (28°14′N, 116°36′E) is the northernmost area of this species recorded in the world, and Chaling (26°50′N, 113°40′E) is near to the northern range limit. Seed dormancy commonly exists in O. rufipogon seeds.

  8. Comparative Analysis on Genomes from Oryza alta and Oryza latifolia by C0t-1 DNA

    Institute of Scientific and Technical Information of China (English)

    WANG De-bin; WANG Yang; WU Qi; ZHAO Hou-ming; LI Gang; QIN Rui; WANG Chun-tai; LIU Hong

    2010-01-01

    In order to reveal the origin and evolutionary relationship between two CCDD genome species, Oryza alta and Oryza latifolia, fluorescence in situ hybridization (FISH) was adopted to analyze the genomes of the two species with C0t-1 DNA from O. alta as a probe. Karyotype was also comparatively analyzed between O. alta and O. latifolia based on their similar band patterns of the hybridization signals. There were a high homology and close relationship between O. alta and O. latifolia, however, the distinction between the hybridization signals was also clear. C0t-1 DNA was proved to be species- and genome type-specific. It is suggested that C0t-1 DNA-FISH could be more efficient to analyze the genomic relationship between different species. According to the comparative analysis of highly and moderately repetitive DNA sequences between the two allotetraploidy species, O. alta and O. latifolia, the possible origin and evolutionary mechanism of allotetraploidy of Oryza were discussed.

  9. Efeito do óleo essencial de Tagetes patula L. (Asteraceae sobre Sitophilus zeamais Motschulsky (Coleoptera, Curculionidae Efeito do óleo essencial de Tagetes patula L. (Asteraceae sobre Sitophilus zeamais Motschulsky (Coleoptera, Curculionidae

    Directory of Open Access Journals (Sweden)

    Rozane Maria Restello

    2009-06-01

    Full Text Available Resistência de pragas a inseticidas, danos ao ambiente em função da poluição do solo e de recursos hídricos vem sendo observados pelo uso de inseticidas químicos no controle de pragas em grãos armazenados. Com o intuito de minimizar estes problemas, estão sendo estudadas alternativas como o uso de inseticidas botânicos. Este trabalho foi realizado com o objetivo de avaliar o efeito do óleo essencial de Tagetes patula L. sobre, Sitophilus zeamais Motschulsky, 1855 em milho sob condições de laboratório. O óleo essencial de T. patula foi obtido através de arraste a vapor com aparelho clevenger. A caracterização química dos compostos encontrados no óleo essencial de T. patula foi realizada através de cromatografia gasosa acoplado a espectrometria de massas, sendo observados: limoneno (37,05%, terpinoleno (32,61%, piperitone (14,40%, eofitadieno (5,91%, sabineno (2,88%, trans-ocimeno (2,02%, beta-cariofileno (1,98%, farnesol (1,84% e alfa-pineno (1,30%. Os insetos utilizados nos bioensaios foram mantidos em temperatura e umidade relativa controlada. Foram avaliados os efeitos do óleo essencial de T. patula sobre o comportamento (atratividade e/ou repelência e atividade inseticida sobre adultos de S. zeamais através de dois bioensaios. Pelos resultados pode-se observar o efeito repelente e inseticida do óleo essencial de T. patula sobre S. zeamais, na concentração de 10 µL (pCountless problems due to the use of chemical insecticides for the control of pests in stored grains have been observed. In order to minimize these problems, alternative measures have been developed, including the use of botanical insecticides. This work was carried out with the objective of evaluating the effect of the essential oil of Tagetes patula L. on, Sitophilus zeamais (Mots., 1855 in corn kernels in laboratory conditions. The T. patula essential oil was obtained through hidrodestilation with the Clevenger device. The chemical characterization

  10. Búsqueda de plantas con propiedades insecticidas para el control de Sitophilus zeamais en maíz almacenado Search for plants with insecticidal properties for Sitophilus zeamais control in stored corn

    Directory of Open Access Journals (Sweden)

    Gonzalo Silva

    2005-01-01

    Full Text Available Se evaluaron, bajo condiciones de laboratorio, 23 plantas en polvo para el control de Sitophilus zeamais Mots. en maíz almacenado. En una primera etapa se evaluaron todos los polvos a una concentración del 1,0% (p/p. Posteriormente aquellos polvos con mejores resultados fueron probados en concentraciones del 0,1, 0,5, 1,0 y 2,0% en granos de maíz infestados con los insectos a las 24 horas, 30, 60 y 90 días. Se evaluaron 63 tratamientos distribuidos en un diseño experimental completamente al azar y el ensayo se repitió tres veces. En la primera etapa, la mayor mortalidad de insectos se obtuvo con Chenopodium ambrosioides L. y Peumus boldus Mol. con 65,8% y 99,3%, respectivamente. Estos tratamientos también propiciaron la menor emergencia de adultos, mientras que la pérdida de peso de los granos no superó el 13,0%. En las evaluaciones a diferentes concentraciones mostraron una mayor mortalidad y menor emergencia a concentraciones del 1,0% y 2,0% (p/p, obteniéndose para C. ambrosioides una mortalidad del 90,3% y 90,1% y para P. boldus 97,1% y 98,8%, respectivamente. La residualidad se mantuvo sólo en el tratamiento de 24 horas.Twenty three powdered plants were evaluated under laboratory conditions against Sitophilus zeamais Mots. on stored corn. In the first part of the work all plants were evaluated at a concentration of 1.0% (w/w. Furthermore the powders with best results were evaluated at concentrations of 0.1, 0.5, 1.0 and 2.0% on corn grains infested with insects during 24 hours, 30, 60 and 90 days. Sixty three treatments in a completely randomized experimental design were evaluated and the study was replicated three times. In the first stage the highest level of insect mortality was exhibited with Chenopodium ambrosioides L. and Peumus boldus Mol. at 1.0% concentration (w/w, with values of 65.8% and 99.3%, respectively. The highest insect emergence reductions were obtained with the same treatments and the grain weight was reduced

  11. Bioconversion of Capsaicin by Aspergillus oryzae.

    Science.gov (United States)

    Lee, Minji; Cho, Jeong-Yong; Lee, Yu Geon; Lee, Hyoung Jae; Lim, Seong-Il; Park, So-Lim; Moon, Jae-Hak

    2015-07-08

    This study identified metabolites of capsaicin bioconverted by Aspergillus oryzae, which is generally used for mass production of gochujang prepared by fermenting red pepper powder in Korea. A. oryzae was incubated with capsaicin in potato dextrose broth. Capsaicin decreased depending on the incubation period, but new metabolites increased. Five capsaicin metabolites purified from the ethyl acetate fraction of the capsaicin culture were identified as N-vanillylcarbamoylbutyric acid, N-vanillyl-9-hydroxy-8-methyloctanamide, ω-hydroxycapsaicin, 8-methyl-N-vanillylcarbamoyl-6(E)-octenoic acid, and 2-methyl-N-vanillylcarbamoyl-6(Z)-octenoic acid by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The capsaicin metabolites in gochujang were confirmed and quantitated by selective multiple reaction monitoring detection after liquid chromatography electrospray ionization MS using the isolated compounds as external standards. On the basis of the structures of the capsaicin metabolites, it is proposed that capsaicin metabolites were converted by A. oryzae by ω-hydroxylation, alcohol oxidation, hydrogenation, isomerization, and α- and/or β-oxidation.

  12. Mella (Olax zeylanica Leaves as an Eco-friendly Repellent for Storage Insect Pest Management

    Directory of Open Access Journals (Sweden)

    H. S. D. Fernando

    2013-04-01

    Full Text Available Among the cereals, rice is the most important staple food supplying energy requirements for mostof the worlds’ population. However during storage a loss of about 10-20% rice grains occurs due to storedgrain pests. Repellents are considered as the best source of protection against insect attack upon storedproducts as they have potential for the exclusion of stored product pests from grain, and therebypreventing insect feeding and oviposition on food materials. Various plant materials have been utilizedeffectively through time as safe and ecofriendly insect pest control measures due to their repellentactivity. The aim of the present study was to investigate the potential of powdered leaves and leaf extractsof Olax zeylanica as repellents against the rice weevil, Sitophilus oryzae. All the experiments were carriedout under laboratory conditions using 1-7 day old unsexed adults. Four different doses (1.0g, 3.0g, 5.0gand 7.0g.of powdered leaves were tested for fumigant repellency in a dual-choice bio-assay apparatus.Repellent action of leaf extracts was evaluated by means of an area preference test using methanol,ethanol and n- hexane as solvents. Repellent effect of powdered leaves against the adult rice weevils wasfound to be significantly high (P< 0.05 at all doses. The highest repellent effect was produced by 7.0g ofleaf powder resulting in repellency of 97%, while the lowest dose (1.0g also elicited more than 50%repellency in weevils indicating a very strong repellent action of the powdered leaves. In comparison,methanol extract of leaves produced the highest repellent effect (96% on weevils whereas n-hexaneextract elicited the lowest. Nevertheless, at higher concentrations all three extracts produced more or lesssignificantly similar repellent effect on the weevils. The findings of the present study suggest that certainactive materials of Olax zeylanica leaves have potential to act as a grain protectant and may be exploitedfor the control of

  13. Components of male aggregation pheromone of strawberry blossom weevil, Anthonomus rubi herbst. (Coleoptera:Curculionidae).

    Science.gov (United States)

    Innocenzi, P J; Hall, D R; Cross, J V

    2001-06-01

    The strawberry blossom weevil, Anthonomus rubi, is a major pest of strawberries in the United Kingdom and continental Europe. As part of a project to develop noninsecticidal control methods, the pheromone system of this species was investigated. Comparison of volatiles produced by field-collected, overwintering individuals of each sex led to identification of three male-specific compounds--(Z)-2-(3,3-dimethylcyclohexylidene)ethanol, (cis)-1-methyl-2-(1-methylethenyl)cyclobutaneethanol, and 2-(1-methylethenyl)-5-methyl-4-hexen-1-ol (lavandulol)--in amounts of 6.1, 1.2, and 0.82 microg/day/ male. The first two compounds are components of the aggregation pheromone of the boll weevil, Anthonomus grandis, grandlure II and grandlure I, respectively. Grandlure I was the (1R,2S)-(+) enantiomer and lavandulol was a single enantiomer, although the absolute configuration was not determined. Trace amounts of the other two grandlure components (Z)-(3,3-dimethylcyclohexylidene)acetaldehyde (grandlure III) and (E)-(3,3-dimethylcyclohexylidene)acetaldehyde (grandlure IV) were also detected. (E,E)-1-(1-Methylethyl)-4-methylene-8-methyl-2,7-cyclo-decadiene (germacrene-D), a known volatile from strawberry plants, Fragaria ananassa, was collected in increased amounts in the presence of pheromone-producing weevils. Male weevils only produced pheromone on F. ananassa and not on scented mayweed, Matracaria recutita, or cow parsley, Anthriscus sylvestris, although these are known food sources. In field trials using various combinations of synthetic grandlures I, II, III, and IV and lavandulol, significantly more weevils were caught in traps baited with blends containing grandlure I and II and lavandulol than in those baited with blends without lavandulol or unbaited controls. Addition of grandlure III and IV had no significant effect on attractiveness. Horizontal sticky traps were found to be more effective than vertical sticky traps or standard boll weevil traps. In mid-season females

  14. Persistência de óleos essenciais em milho armazenado, submetido à infestação de gorgulho do milho Persistence of essential oils in stored maize submitted to infestation of maize weevil

    Directory of Open Access Journals (Sweden)

    Rodrigo Leandro Braga de Castro Coitinho

    2010-07-01

    Full Text Available Os óleos essenciais e os compostos constituintes têm sido pesquisados quanto a sua atividade inseticida contra pragas de grãos armazenados. Neste trabalho, avaliou-se a persistência de óleos essenciais em milho armazenado, submetido à infestação do gorgulho do milho, Sitophilus zeamais Mots. (Coleoptera: Curculionidae. A persistência dos óleos e do eugenol foi avaliada no período inicial (logo após a impregnação e aos 30, 60, 90 e 120 dias de armazenamento. As mortalidades de S. zeamais, no período inicial, variaram entre 93,8 (Piper hispidinervum, Melaleuca leucadendron e eugenol e 100% (Eugenia uniflora, frutos verdes de Schinus terebinthifolius e Piper marginatum. A partir dos 30 dias, as mortalidades, de modo geral, decresceram, com exceção de P. marginatum (92,2%, que alcançou 53,1% de mortalidade aos 120 dias de armazenamento. De acordo com as equações de regressão ajustadas para o número de S. zeamais emergidos em todo o período de armazenamento, apenas não houve significância para os óleos de S. terebinthifolius, P. marginatum e testemunha. Em relação à média geral, o óleo de P. marginatum foi o mais persistente, proporcionando emergência de apenas 0,30 insetos, diferindo dos óleos restantes, do eugenol e da testemunha. Os demais tratamentos só diferiram em relação à testemunha.The essential oils and constituent compounds have been studied for their insecticidal activity against stored grain pests. In this research, persistence of the essential oils in stored maize subject to infestation by maize weevil, Sitophilus zeamais Mots. (Coleoptera: Curculionidae were evaluated. Persistence of oils and eugenol were evaluated in the initial period (after impregnation and at 30, 60, 90 and 120 days of storage. Mortalities of S. zeamais in the initial period ranged between 93.8 (Piper hispidinervum, Melaleuca leucadendron and eugenol to 100% (Eugenia uniflora, green fruits of Schinus terebinthifolius and Piper

  15. Partial purification and characterization of {alpha}-amylases from one insecticide-resistant population of Sitophilus zeamais

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, K.V.; Oliveira, M.G.A.; Paixao, G.P.; Visotto, L.E. [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Bioquimica e Biologia Molecular; Veloso, R.V.S.; Marinho, J.S.; Guedes, R.N.C. [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Biologia Animal; Oliveira, J.A. [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Quimica

    2008-07-01

    Full text: {alpha}-Amylases (EC 3.2.1.1) constitute a family of endo-amylases that catalyze the hydrolysis of a-D- (1,4)-glucan linkages in st ach components and various other related carbohydrates. They play a central role in carbohydrate metabolism of animals, plants and microorganisms. Many insects, especially those that feed on grain products during larval and/or adult life, depend on their amylases for survival. This is particularly true for the Sitophilus zeamais Motschulsky, a cosmopolitan pest of stored products. It is mainly controlled by insecticides. Amylases from adults of S.zeamais insecticide-resistant were purified by using a sequential procedure of glycogen-complex precipitation and ion exchange chromatography. Specific activity increased from 58,0454 AU/dL/mg protein in the crude homogenate to 2558,8720 AU/dL/mg protein in the final purified sample. Amylase unit (AU/dL) refers to the amount of amylase that hydrolysis 10 mg starch in 30 min at 37 deg C. The purified amylase ran as a single protein band on SDS-PAGE. From a plot of log molecular weight against relative mobility in 10% acrylamide gel, molecular weight was estimated to be 56 kDa. The enzyme had a K{sub m} of 0,2243 g/L for soluble starch and was most active at ph 5,0. The temperature of major activity was 40 deg C. The activity of enzyme was unaffected by presence or absence of Cl{sup -} and Ca{sup 2+}.

  16. Evidence of contact pheromone use in mating behavior of the raspberry weevil (Coleoptera: Curculionidae).

    Science.gov (United States)

    Mutis, Ana; Parra, Leonardo; Palma, Rubén; Pardo, Fernando; Perich, Fernando; Quiroz, Andrés

    2009-02-01

    Numerous studies of insect species have shown that a subset of female cuticular hydrocarbons is used as short-range or contact pheromones. Here, we studied the possible use of contact pheromones in the mating behavior of the weevil Aegorhinus superciliosus, a native species of Chile. Males mounted females only after antennal contact with the female's cuticle, and only 33% of the males attempted to mate with dead females washed with solvent. When a glass rod (dummy) was coated with female cuticular extracts, males exhibited behaviors similar to those observed with females. A preliminary gas chromatography-mass spectrometry (GC-MS) analysis of cuticular extracts indicated that males and females share a series of aliphatic hydrocarbons but that the relative abundance of some of these compounds differ between the sexes. These results suggest that cuticular lipids mediate mating behavior of the raspberry weevil and provide the first evidence of contact pheromones in curculionids.

  17. Elemental stoichiometry and compositions of weevil larvae and two acorn hosts under natural phosphorus variation.

    Science.gov (United States)

    Ji, Huawei; Du, Baoming; Liu, Chunjiang

    2017-04-05

    To understand how different trophic organisms in a parasite food chain adapt to the differences in soil nutrient conditions, we investigated stoichiometric variation and homeostasis of multiple elements in two acorn trees, Quercus variabilis and Quercus acutissima, and their parasite weevil larvae (Curculio davidi Fairmaire) at phosphorus (P)-deficient and P-rich sites in subtropical China where P-rich ores are scattered among dominant P-deficient soils. Results showed that elemental stoichiometry and compositions of both acorns and weevil larvae differed significantly between P-deficient and P-rich sites (p stoichiometry and compositions (p stoichiometry and composition and physiological regulations of nutritional needs in organisms and provide possible stoichiometric responses of both plants and animals to P loading, a worldwide issue from excess release of P into the environment.

  18. Elemental stoichiometry and compositions of weevil larvae and two acorn hosts under natural phosphorus variation

    Science.gov (United States)

    Ji, Huawei; Du, Baoming; Liu, Chunjiang

    2017-04-01

    To understand how different trophic organisms in a parasite food chain adapt to the differences in soil nutrient conditions, we investigated stoichiometric variation and homeostasis of multiple elements in two acorn trees, Quercus variabilis and Quercus acutissima, and their parasite weevil larvae (Curculio davidi Fairmaire) at phosphorus (P)-deficient and P-rich sites in subtropical China where P-rich ores are scattered among dominant P-deficient soils. Results showed that elemental stoichiometry and compositions of both acorns and weevil larvae differed significantly between P-deficient and P-rich sites (p plants and animals to P loading, a worldwide issue from excess release of P into the environment.

  19. Genetic variation in avocado stem weevils Copturus aguacatae (Coleoptera: Curculionidae) in Mexico.

    Science.gov (United States)

    Engstrand, Rachel C; Cibrián Tovar, Juan; Cibrián-Jaramillo, Angélica; Kolokotronis, Sergios-Orestis

    2010-12-01

    The avocado stem weevil Copturus aguacatae is an important pest in avocado plantations. Its presence hinders the production and marketing of avocado in Mexico, the largest avocado producer worldwide. Biological control through pheromone synthesis, a strategy favored over chemical control in crops, is currently limited by difficult field identification of this species. Using DNA barcoding, we examine the patterns of genetic variation of C. aguacatae in avocado trees in Mexico to help facilitate its identification and biological control. We show that there is one single species of avocado stem weevil throughout the sampled sites in Mexico. Overall, haplotype diversity is high, with Oaxaca forming one distinct group and all other sampled populations are admixed irrespective of geographic origin. The results suggest that high gene flow is maintained in this species and that a global strategy for biocontrol can be designed and implemented throughout the sampled range.

  20. Survival and development of a stored-product pest, Sitophilus zeamais (Coleoptera: Curculionidae), and its natural enemy, the parasitoid Lariophagus distinguendus (Hymenoptera. Pteromalidae), on transgenic Bt maize

    DEFF Research Database (Denmark)

    Hansen, Lise S.; Lövei, Gabor L; Székács, András

    2013-01-01

    Background The effect of transgenic maize (Zea mays L.) containing a lepidopteran-specific Bt toxin on a stored-product pest, Sitophilus zeamais Motschulsky, and its parasitoid, Lariophagus distinguendus Förster, was examined in the laboratory to test the impact of transgenic maize on stored...

  1. Survival and development of a stored-product pest, Sitophilus zeamais (Coleoptera: Curculionidae), and its natural enemy, the parasitoid Lariophagus distinguendus (Hymenoptera. Pteromalidae), on transgenic Bt maize

    DEFF Research Database (Denmark)

    Hansen, Lise S.; Lövei, Gabor L; Székács, András

    2013-01-01

    Background The effect of transgenic maize (Zea mays L.) containing a lepidopteran-specific Bt toxin on a stored-product pest, Sitophilus zeamais Motschulsky, and its parasitoid, Lariophagus distinguendus Förster, was examined in the laboratory to test the impact of transgenic maize on stored...

  2. A new fossil weevil (Coleoptera, Curculionoidea, Belidae) from the Yixian Formation of western Liaoning, China

    Institute of Scientific and Technical Information of China (English)

    LIU Ming; REN Dong; SHIH Chungkun

    2006-01-01

    This paper reports a new genus and a new species Microprobelus liuae gen. et sp. nov. referred to the family Belidae.This fossil was collected from the Late Jurassic Yixian Formation of western Liaoning, China. Detailed description and illustration of the specimen along with a brief review of fossil belids are given. And the age of the Yixian Formation and the early diversification of the weevils are discussed.

  3. Ethyl Formate: A Potential Disinfestation Treatment for Eucalyptus Weevil (Gonipterus platensis) (Coleoptera: Curculionidae) in Apples.

    Science.gov (United States)

    Agarwal, Manjree; Ren, Yonglin; Newman, James; Learmonth, Stewart

    2015-12-01

    Export of Pink Lady apples from Australia has been significantly affected by infestations of adult eucalyptus weevils (Gonipterus platensis Marelli). These weevils cling tenaciously to the pedicel of apple fruit when selecting overwintering sites. As a result, apples infested with live G. platensis adults lead to rejection for export. Since the Montreal Protocol restricted use of methyl bromide as postharvest treatment, it was necessary to consider alternative safer fumigants for disinfestation of eucalyptus weevil. Laboratory experiments were conducted using concentrations of 5, 10, 15, 20, 25, 30, 40, and 80 mg/liter of ethyl formate. Complete control (100% mortality) was achieved at 25-30 mg/liter of ethyl formate at 22-24°C for 24-h exposure without apples. However, with 90-95% of the volume full of apples, complete control was achieved at 40 mg/liter of ethyl formate at 22-24°C for 24-h exposure. No phytotoxicity was observed and after one day aeration, residue of ethyl formate declined to natural levels (0.05-0.2 mg/kg). Five ethyl formate field trials were conducted in cool storages (capacity from 250-900 tons) and 100% kill of eucalyptus weevils were achieved at 50-55 mg/liter at 7-10°C for 24 h. Ethyl formate has great potential for preshipment treatment of apples. Its use is considerably cheaper and safer than already existing fumigants like methyl bromide and phosphine.

  4. Olfactory cues are subordinate to visual stimuli in a neotropical generalist weevil.

    Directory of Open Access Journals (Sweden)

    Fernando Otálora-Luna

    Full Text Available The tropical root weevil Diaprepes abbreviatus is a major pest of multiple crops in the Caribbean Islands and has become a serious constraint to citrus production in the United States. Recent work has identified host and conspecific volatiles that mediate host- and mate-finding by D. abbreviatus. The interaction of light, color, and odors has not been studied in this species. The responses of male and female D. abbreviatus to narrow bandwidths of visible light emitted by LEDs offered alone and in combination with olfactory stimuli were studied in a specially-designed multiple choice arena combined with a locomotion compensator. Weevils were more attracted to wavelengths close to green and yellow compared with blue or ultraviolet, but preferred red and darkness over green. Additionally, dim green light was preferred over brighter green. Adult weevils were also attracted to the odor of its citrus host + conspecifics. However, the attractiveness of citrus + conspecific odors disappeared in the presence of a green light. Photic stimulation induced males but not females to increase their speed. In the presence of light emitted by LEDs, turning speed decreased and path straightness increased, indicating that weevils tended to walk less tortuously. Diaprepes abbreviatus showed a hierarchy between chemo- and photo-taxis in the series of experiments presented herein, where the presence of the green light abolished upwind anemotaxis elicited by the pheromone + host plant odor. Insight into the strong responses to visual stimuli of chemically stimulated insects may be provided when the amount of information supplied by vision and olfaction is compared, as the information transmission capacity of compound eyes is estimated to be several orders of magnitude higher compared with the olfactory system. Subordination of olfactory responses by photic stimuli should be considered in the design of strategies aimed at management of such insects.

  5. Acorn fall and weeviling in a northern red oak seedling orchard

    Science.gov (United States)

    Daniel R. Miller; Scott E. Schlarbaum

    2005-01-01

    In 2000, we determined levels of damage by acorn weevils (Curculio spp.) and patterns of acorn fall in a northern red oak (Quercus rubra L.) seedling orchard in eastern Tennessee. The mean (±SE) production of acorns among 43 selected trees was 5,930 ± 586 acorns per tree with a maximum production level of 16,969 acorns for one tree...

  6. Factors Affecting Pheromone Production by the Pepper Weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae) and Collection Efficiency

    OpenAIRE

    Eller, Fred J.; Palmquist, Debra E.

    2014-01-01

    Several factors affecting pheromone production by male pepper weevils, Anthonomus eugenii Cano (Coleoptera: Curculionidae) as well as collection efficiency were investigated. Factors studied included: porous polymer adsorbents (Tenax versus Super Q), male age, time of day, male density, and male diet. Super Q was found to be a superior adsorbent for the male-produced alcohols and geranic acid as well as the plant-produced E-β-ocimene. Pheromone production increased with male age up to about ...

  7. Factors Affecting Pheromone Production by the Pepper Weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae) and Collection Efficiency

    OpenAIRE

    Eller, Fred; Palmquist,Debra

    2014-01-01

    Several factors affecting pheromone production by male pepper weevils, Anthonomus eugenii Cano (Coleoptera: Curculionidae) as well as collection efficiency were investigated. Factors studied included: porous polymer adsorbents (Tenax versus Super Q), male age, time of day, male density, and male diet. Super Q was found to be a superior adsorbent for the male-produced alcohols and geranic acid as well as the plant-produced E-β-ocimene. Pheromone production increased with male age up to about a...

  8. Factors Affecting Pheromone Production by the Pepper Weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae) and Collection Efficiency

    OpenAIRE

    Eller, Fred J.; Debra E. Palmquist

    2014-01-01

    Several factors affecting pheromone production by male pepper weevils, Anthonomus eugenii Cano (Coleoptera: Curculionidae) as well as collection efficiency were investigated. Factors studied included: porous polymer adsorbents (Tenax versus Super Q), male age, time of day, male density, and male diet. Super Q was found to be a superior adsorbent for the male-produced alcohols and geranic acid as well as the plant-produced E-β-ocimene. Pheromone production increased with male age up to about ...

  9. Toxicity to cotton boll weevil Anthonomus grandis of a trypsin inhibitor from chickpea seeds.

    Science.gov (United States)

    de P G Gomes, Angélica; Dias, Simoni C; Bloch, Carlos; Melo, Francislete R; Furtado, José R; Monnerat, Rose G; Grossi-de-Sá, Maria F; Franco, Octávio L

    2005-02-01

    Cotton (Gossypium hirsutum L.) is an important agricultural commodity, which is attacked by several pests such as the cotton boll weevil Anthonomus grandis. Adult A. grandis feed on fruits and leaf petioles, reducing drastically the crop production. The predominance of boll weevil digestive serine proteinases has motivated inhibitor screenings in order to discover new ones with the capability to reduce the digestion process. The present study describes a novel proteinase inhibitor from chickpea seeds (Cicer arietinum L.) and its effects against A. grandis. This inhibitor, named CaTI, was purified by using affinity Red-Sepharose Cl-6B chromatography, followed by reversed-phase HPLC (Vydac C18-TP). SDS-PAGE and MALDI-TOF analyses, showed a unique monomeric protein with a mass of 12,877 Da. Purified CaTI showed significant inhibitory activity against larval cotton boll weevil serine proteinases (78%) and against bovine pancreatic trypsin (73%), when analyzed by fluorimetric assays. Although the molecular mass of CaTI corresponded to alpha-amylase/trypsin bifunctional inhibitors masses, no inhibitory activity against insect and mammalian alpha-amylases was observed. In order to observe CaTI in vivo effects, an inhibitor rich fraction was added to an artificial diet at different concentrations. At 1.5% (w/w), CaTI caused severe development delay, several deformities and a mortality rate of approximately 45%. These results suggested that CaTI could be useful in the production of transgenic cotton plants with enhanced resistance toward cotton boll weevil.

  10. Biochemical properties of digestive carbohydrases from the sugar beet weevil, Lixus incanescens (Coleoptera: Curculionidae

    Directory of Open Access Journals (Sweden)

    Seyed Mohammad Ahsaei

    2013-09-01

    Full Text Available The sugar beet weevil, Lixus incanescens B., is one of the most important pests of sugar beet plant in Iran. The petioles and leaves of sugar beet are attacked by larvae and adults of the sugar beet weevil. Chemical application is currently used for controlling the pest. Digestion in the alimentary canal of the sugar beet weevil is facilitated by some carbohydrases. Results of the in vitro studies indicated the presence of alpha-amylase, beta-glucosidase and beta-galactosidase in the digestive tract of the pest. Highest activities of alpha-amylase, beta-glucosidase and beta-galactosidase were at pH 5, pH 5 and pH 4, respectively. No significant alpha-glucosidase and alpha-galactosidase activity was detected in the pest's digestive system. Optimum temperatures for alpha-amylase, beta-glucosidase and beta-galactosidase activity were determined at 45, 50 and 40 oC, respectively. alpha-amylase was more stable under acidic condition (pH 4 to pH 6 than under highly acidic and alkaline condition. Na+ and K+ increased alpha-amylase activity, but sodium dodecyl sulfate significantly decreased amylase activity. Also, the activity of alpha-amylase was inhibited by the other compounds such as MgCl2, CaCl2 and EDTA. Zymogram analysis using native-PAGE revealed one band of alpha-amylase activity in Lixus incanescens. High activity of carbohydrases in the digestive system of adults was determined and further researches are needed to be applied to design new strategies for controlling the sugar beet weevil based on natural carbohydrase inhibitors.

  11. New Approach of Beauveria bassiana to Control the Red Palm Weevil (Coleoptera: Curculionidae) by Trapping Technique.

    Science.gov (United States)

    Hajjar, M J; Ajlan, A M; Al-Ahmad, M H

    2015-04-01

    This work is the first study to investigate the efficacy of the commercial formulation of Beauveria bassiana (Broadband) to control adults of red palm weevil (Rhynchophorus ferrugineus (Olivier)). This fungus could be applied as one of the biological tactics in controlling red palm weevil. Bioassay experiments for medium lethal concentrate and medium time to cause death of 50% of red palm weevil adults were carried out. The result showed that the LC50 of B. bassiana (Broadband) was 2.19×10(7) and 2.76×10(6) spores/ml at 9 and 23 d of treatment, respectively. The LT50 was 13.95 and 4.15 d for concentration of 1×10(7) and 1×10(8) spores/ml, respectively, whereas 1×10(9) spores/ml caused 100% mortality after 24 h. Additionally, a red palm weevil pheromone trap was designed to attract the adults to be contaminated with spores of Broadband, which was applied to the sackcloth fabric that coated the internal surfaces of the bucket trap. The mating behavior was studied to determine direct and indirect infection of the spores from male to female and vice versa. The results showed a high efficacy of Broadband suspension at 1×10(9) spores/ml; 40 ml of suspension at this concentration treated to cloth in a trap caused death of contaminated adults with B. bassiana spores directly and indirectly. The 100% mortality was obtained even after 13 d of traps treatment with 40 ml of the suspension at 1×10(9) spores/ml.

  12. Reproductive potential of field-collected overwintering boll weevils (Coleoptera" Curculionidae) fed on pollen in the laboratory

    Institute of Scientific and Technical Information of China (English)

    S.M.Greenberg; G.D.Jones; J.J.Adamczyk, Jr.; F.Eischen; J.S.Armstrong; R.J.Coleman; M.Sétamou; Tong-Xian Liu

    2009-01-01

    The reproductive potential of overwintering boll weevil, Anthonomus grandis grandis (Bobeman), females collected from pheromone traps in September, November and January, fed for 1, 3, and 5 weeks on plant pollens, and then provided cotton squares, was determined in the laboratory at 27 ± 1℃, 65% RH, and a photoperiod 13 : 11 (L : D) h.Duration of pollen feeding by overwintering boll weevils did not significantly influence egg and feeding punctures, or puncture ratios (egg to total punctures) for any of the three months of parent weevil collections when provided cotton squares on a daily basis.However, punctures and puncture ratios are significantly different when comparing mean data between months of boll weevil collections. When boll weevils were provided with cotton squares daily, the pre-ovipositional periods of female parents captured in September, November and January were 5, 9 and 14 days, respectively. The rate of eggs by females was significantly lower during November and January than September. Female parents collected in September produced a significantly higher percentage of eggs yielding adult progeny than those collected in November and January. Life table parameters indicated that net reproductive rate (R_o) of boll weevil females collected in September was 1.2-fold higher than those collected in November and 10.7-fold higher than those collected in January. Except for testes size, no differences in male reproductive parameters were observed during the cotton-free period compared with males captured during mid-cotton (June). The number of oocytes in the ovarioles and the number of oocytes containing yolk were significantly lower during September, November and January compared with June. The reproductive potential of overwintering boll weevil females collected in different months is an important consideration in determining the success of any control strategy.

  13. THE USE OF GRIGNARD REAGENT IN PHEROMONE SYNTHESIS FOR PALM WEEVIL (Rhynchorus, Sp

    Directory of Open Access Journals (Sweden)

    Warsito Warsito

    2010-06-01

    Full Text Available In an integrated controlling system of palm weevil, using of synthetic feromoid is strickly needed. The research is aimed to synthesize pheromone which secreted by the weevil, e.g. 4-methyl-5-nonanol (R. ferrugineus and 3-methyl-4-octanol (R. schach through Grignard reagent which formed in situ. The synthesis was proceded by retrosynthesis to determine the precursor, valeraldehyde. The precursor was reacted with Grignard reagent of sec-amyl magnesium bromide (R. ferrugenieus and sec-butyl magnesium bromide (R. shach which made in situ. Characterization of the synthetic molecular pheromone was performed by Gas Chromatography-mass spectroscopy and Fourier Transformed Infra Red. The bioassay of the molecule was carried out by olfactometer. The result showed that the conversion of the reactions were 51.28% (4-methyl-5-nonanol and 85.90% (3-methyl-4-octanol. The character of physico-chemical and bioactivity of the synthetic pheromone are identic with natural pheromones.   Keywords: palm weevil, pheromone, grignard reagent

  14. Classification of weevils as a data-driven science: leaving opinion behind

    Directory of Open Access Journals (Sweden)

    Bjarte Jordal

    2014-09-01

    Full Text Available Data and explicit taxonomic ranking criteria, which minimize taxonomic change, provide a scientific approach to modern taxonomy and classification. However, traditional practices of opinion-based taxonomy (i.e., mid-20th century evolutionary systematics, which lack explicit ranking and naming criteria, are still in practice despite phylogenetic evidence. This paper discusses a recent proposed reclassification of weevils that elevates bark and ambrosia beetles (Scolytinae and Platypodinae to the ranks of Family. We demonstrate that the proposed reclassification 1 is not supported by an evolutionary systematic justification because the apparently unique morphology of bark and ambrosia beetles is shared with other unrelated wood-boring weevil taxa; 2 introduces obvious paraphyly in weevil classification and hence violates good practices on maintaining an economy of taxonomic change; 3 is not supported by other taxonomic naming criteria, such as time banding. We recommend the abandonment of traditional practices of an opinion-based taxonomy, especially in light of available data and resulting phylogenies.

  15. Effects of the Diet on the Microbiota of the Red Palm Weevil (Coleoptera: Dryophthoridae)

    KAUST Repository

    Montagna, Matteo

    2015-01-30

    Rhynchophorus ferrugineus, also known as the red palm weevil, is regarded as the major pest of palm trees. Although studies of the microbiota associated with this species have been performed in recent years, little attention has been dedicated to the influence of the diet in shaping the host bacterial community. Here, we investigated the influence of food sources (i.e. palm tissues vs apple based substrate) on the microbial diversity associated with RPW, which was compared with the microbiota associated with wild individuals of the sister species Rhynchophorus vulneratus. The bacterial characterization was performed using a culture independent approach, i.e. the 16S rRNA pyrotag, and a culture dependent approach for a subset of the samples, in order to obtain bacterial isolates from RPW tissues. The bacterial community appeared significantly influenced by diet. Proteobacteria resulted to be the most abundant clade and was present in all the specimens of the three examined weevil groups. Within Proteobacteria, Enterobacteriaceae were identified in all the organs analysed, including hemolymph and reproductive organs. The apple-fed RPWs and the wild R. vulneratus showed a second dominant taxon within Firmicutes that was scarcely present in the microbiota associated with palm-fed RPWs. A comparative analysis on the bacteria associated with the palm tissues highlighted that 12 bacterial genera out of the 13 identified in the plant tissues were also present in weevils, thus indicating that palm tissues may present a source for bacterial acquisition.

  16. Effects of the Diet on the Microbiota of the Red Palm Weevil (Coleoptera: Dryophthoridae)

    Science.gov (United States)

    Montagna, Matteo; Chouaia, Bessem; Mazza, Giuseppe; Prosdocimi, Erica Maria; Crotti, Elena; Mereghetti, Valeria; Vacchini, Violetta; Giorgi, Annamaria; De Biase, Alessio; Longo, Santi; Cervo, Rita; Lozzia, Giuseppe Carlo; Alma, Alberto; Bandi, Claudio; Daffonchio, Daniele

    2015-01-01

    Rhynchophorus ferrugineus, also known as the red palm weevil, is regarded as the major pest of palm trees. Although studies of the microbiota associated with this species have been performed in recent years, little attention has been dedicated to the influence of the diet in shaping the host bacterial community. Here, we investigated the influence of food sources (i.e. palm tissues vs apple based substrate) on the microbial diversity associated with RPW, which was compared with the microbiota associated with wild individuals of the sister species Rhynchophorus vulneratus. The bacterial characterization was performed using a culture independent approach, i.e. the 16S rRNA pyrotag, and a culture dependent approach for a subset of the samples, in order to obtain bacterial isolates from RPW tissues. The bacterial community appeared significantly influenced by diet. Proteobacteria resulted to be the most abundant clade and was present in all the specimens of the three examined weevil groups. Within Proteobacteria, Enterobacteriaceae were identified in all the organs analysed, including hemolymph and reproductive organs. The apple-fed RPWs and the wild R. vulneratus showed a second dominant taxon within Firmicutes that was scarcely present in the microbiota associated with palm-fed RPWs. A comparative analysis on the bacteria associated with the palm tissues highlighted that 12 bacterial genera out of the 13 identified in the plant tissues were also present in weevils, thus indicating that palm tissues may present a source for bacterial acquisition. PMID:25635833

  17. Using an Electronic Nose to Rapidly Assess Grandlure Content in Boll Weevil Pheromone Lures

    Institute of Scientific and Technical Information of China (English)

    Charles P.-C. Suh; Ningye Ding; Yubin Lan

    2011-01-01

    Samples of pheromone lures used in boll weevil,Anthonomus grandis (Boheman),eradication programs are routinely analyzed by Gas Chromatography (GC) to ensure lures are adequately dosed with grandlure,the synthetic aggregation pheromone produced by male weevils.However,preparation of GC samples is tedious,time consuming,and requires a moderate level of experience.We examined the use of a commercially-available electronic nose (e-nose) for rapidly assessing the grandlure contents of lures.The e-nose was trained to recognize headspace collections of grandlure emitted from new lures and after lures were aged under field conditions for 4 d,7 d,10 d,and 14 d.Based on cross-validation of the training set,the e-nose was 82%accurate in discriminating among the different age classes of lures.Upon sampling headspace collections of pheromone from a different set of field-aged lures,the e-nose was <50% accurate in discriminating 4 d,7 d,and 10 d aged lures from the other ageclasses of lures.However,the e-nose identified new and 14 d aged lure samples with 100% accuracy.In light of these findings,e-nose technology shows considerable promise as an alternative approach for rapidly assessing the initial grandlure contents of lures used in boll weevil eradication programs.

  18. Greenhouse studies of thiamethoxam effects on pea leaf weevil, Sitona lineatus.

    Science.gov (United States)

    Cárcamo, Héctor; Herle, Carolyn; Hervet, Vincent

    2012-01-01

    The pea leaf weevil, Sitona lineatus L. (Coleoptera: Curculionidae), has recently emerged as an important pest of field peas in the Canadian prairies. Systemic seed-coated insecticides may provide a tool for the integrated pest management of this pest. Therefore, several controlled assays were performed in order to determine effects of a recently registered neonicotinoid, (thiamethoxam) on S. lineatus damage to foliage, weevil mortality, fertility, egg viability, larval mortality, and root nodule damage. Foliage damage was reduced by thiamethoxam relative to untreated controls during the seedling stage (2(nd)-5(th) nodes), but weevil adult mortality was only 15-30%. Fertility was reduced substantially through an extra seven-day delay in the preoviposition period and reduced egg-laying rate during the first 20 days of the study (92% lower than controls). Overall egg viability was lower in females fed foliage grown from thiamethoxamtreated seeds. Larval survivorship and nodule damage were also lower, but only when eggs were added to treated plants at the 2(nd) node stage. When eggs were added late, at the 5th node stage, thiamethoxam had no effect on larval survivorship or nodule damage. The results of this study led to the conclusion that seed treatments such as thiamethoxam have potential to be used as tools that will aid in the integrated pest management of S. lineatus, especially in combination with other methods such as biocontrol and trap crops.

  19. Genetical genomics identifies the genetic architecture for growth and weevil resistance in spruce.

    Science.gov (United States)

    Porth, Ilga; White, Richard; Jaquish, Barry; Alfaro, René; Ritland, Carol; Ritland, Kermit

    2012-01-01

    In plants, relationships between resistance to herbivorous insect pests and growth are typically controlled by complex interactions between genetically correlated traits. These relationships often result in tradeoffs in phenotypic expression. In this study we used genetical genomics to elucidate genetic relationships between tree growth and resistance to white pine terminal weevil (Pissodes strobi Peck.) in a pedigree population of interior spruce (Picea glauca, P. engelmannii and their hybrids) that was growing at Vernon, B.C. and segregating for weevil resistance. Genetical genomics uses genetic perturbations caused by allelic segregation in pedigrees to co-locate quantitative trait loci (QTLs) for gene expression and quantitative traits. Bark tissue of apical leaders from 188 trees was assayed for gene expression using a 21.8K spruce EST-spotted microarray; the same individuals were genotyped for 384 SNP markers for the genetic map. Many of the expression QTLs (eQTL) co-localized with resistance trait QTLs. For a composite resistance phenotype of six attack and oviposition traits, 149 positional candidate genes were identified. Resistance and growth QTLs also overlapped with eQTL hotspots along the genome suggesting that: 1) genetic pleiotropy of resistance and growth traits in interior spruce was substantial, and 2) master regulatory genes were important for weevil resistance in spruce. These results will enable future work on functional genetic studies of insect resistance in spruce, and provide valuable information about candidate genes for genetic improvement of spruce.

  20. Genetical genomics identifies the genetic architecture for growth and weevil resistance in spruce.

    Directory of Open Access Journals (Sweden)

    Ilga Porth

    Full Text Available In plants, relationships between resistance to herbivorous insect pests and growth are typically controlled by complex interactions between genetically correlated traits. These relationships often result in tradeoffs in phenotypic expression. In this study we used genetical genomics to elucidate genetic relationships between tree growth and resistance to white pine terminal weevil (Pissodes strobi Peck. in a pedigree population of interior spruce (Picea glauca, P. engelmannii and their hybrids that was growing at Vernon, B.C. and segregating for weevil resistance. Genetical genomics uses genetic perturbations caused by allelic segregation in pedigrees to co-locate quantitative trait loci (QTLs for gene expression and quantitative traits. Bark tissue of apical leaders from 188 trees was assayed for gene expression using a 21.8K spruce EST-spotted microarray; the same individuals were genotyped for 384 SNP markers for the genetic map. Many of the expression QTLs (eQTL co-localized with resistance trait QTLs. For a composite resistance phenotype of six attack and oviposition traits, 149 positional candidate genes were identified. Resistance and growth QTLs also overlapped with eQTL hotspots along the genome suggesting that: 1 genetic pleiotropy of resistance and growth traits in interior spruce was substantial, and 2 master regulatory genes were important for weevil resistance in spruce. These results will enable future work on functional genetic studies of insect resistance in spruce, and provide valuable information about candidate genes for genetic improvement of spruce.

  1. EFFECT OF FENNEL WATER EXTRACTS ON REDUCTION OF FEEDING OF PEA LEAF WEEVIL

    Directory of Open Access Journals (Sweden)

    Barbara Biniaś

    2016-11-01

    Full Text Available The objective of the study was to examine the effect of aqueous extracts from fennel (Foeniculum vulgare Mill. seeds at 2%, 5%, 10% and 20% concentrations on the feeding of peal leaf weevil (Sitona lineatus L. on broad bean (Vicia faba L.. The experiment was conducted in the laboratory, in six replicates. Feeding intensity assessment was conducted by dipping leaves of broad bean in respective solutions of the extracts and determining the area of broad bean leaves, eaten by pea leaf weevil beetle in the 12 hour intervals. In addition, absolute deterrence index and palatability index were calculated. As a result of the observation no significant limiting effect of fennel seed aqueous extracts on the feeding of the pea leaf weevil females was shown. All of the used fennel extracts had inhibitory effect on the feeding of male S. linetaus and the strongest effect of extracts was observed in the first 36 hours of the experiment. The high values of the palatability index (particularly for the females with relatively low absolute deterrence index, indicate limited possibilities of the use of aqueous extracts from fennel seeds for the protection against the feeding of the beetles from the genus Sitona.

  2. Effect of mango weevil (Coleoptera: Curculionidae) damage on mango seed viability in Hawaii.

    Science.gov (United States)

    Follett, P A; Gabbard, Z

    2000-08-01

    The mango weevil, Cryptorhynchus (= Sternochetus) mangiferae (F.), is a federally quarantined pest that prevents shipment of mangos from Hawaii into the continental United States. Although this monophagous weevil allegedly causes reduced seed germination, damage to the fruit pulp, and premature fruit drop in mangos, there are few studies examining these potential sources of crop loss. We conducted studies to assess the effect of mango weevil infestation on seed viability while making observations on the frequency of pulp feeding. Naturally infested seeds from mature fruit were planted in pots and scored for successful germination. Germination rates for infested seeds were equal to those of uninfested control seeds in a polyembryonic cultivar ('Common'), whereas germination was significantly reduced for infested seeds of a monoembryonic cultivar ('Haden') compared with uninfested control seeds but germination of infested seeds was still > 70%. To assess seed tolerance of damage, seeds were artificially damaged by cutting away 25, 50, or 75% of the cotyledon before planting and scored for germination. None of the damage treatments was significantly different from the undamaged controls, indicating that mango seeds can withstand substantial damage and still germinate successfully. Over the 2-yr period we conducted experiments, only four of 3,602 mango fruits (0.11%) showed evidence of direct feeding damage to the pulp. Results suggest that C. mangiferae is a less serious pest of mangos than previously thought.

  3. Xanthomonas oryzae pv oryzae the Causal Agent of Bacterial Leaf Blight of rice: Isolation, Characterization, and Study of Transposon Mutagenesis

    Directory of Open Access Journals (Sweden)

    Abdjad Asih Nawangsih

    2011-04-01

    Full Text Available Xanthomonas oryzae pv oryzae the Causal Agent of Bacterial Leaf Blight of rice: Isolation, Characterization, and Study of Transposon Mutagenesis. X. oryzae pv. oryzae (Xoo causes bacterial leaf blight (BLB of rice (Oryza sativa L., a major disease that constrains production of the staple crop in many countries of the world. Identification of X. oryzae pv. oryzae (Xoo was conducted based on the disease symptoms, pathogenicity, morphological, physiological, and genetic characteristics of bacterial cultures isolated from the infected plants. Fifty bacterial isolates predicted as Xoo have been successfully isolated. They are aerobic, rod shaped, and Gram negative bacteria. The isolates were evaluated for their hypersensitivity in tobacco and pathogenicity in rice plant. Fifty isolates induced hypersensitive reaction in tobacco and showed pathogenicity symptom in rice in different length. Based on physiological test, hypersensitivity and pathogenicity reactions, three bacterial isolates strongly predicted as Xoo, i.e. STG21, STG42, and STG46, were non indole formation, non pigment fluorescent, hydrolyzed casein, catalase activity positive, but negative oxidase. Partial sequencing of 16S rRNA genes of STG21 and STG42 showed 80% and 82% homology with X. oryzae, respectively, while STG46 showed 84% homology with X. campestris. Mini-Tn5 transposon mutagenesis of STG21 generated one of the mutants (M5 lossed it’s ability to induce hypersensitive reaction in tobacco plant and deficient in pathogenicity on rice. The lesion length of rice leaf caused by the mutant M5 decreased up to 80%.

  4. Genetic Profiling to Determine Potential Origins of Boll Weevils (Coleoptera: Curculionidae) Captured in a Texas Eradication Zone: Endemicity, Immigration, or Sabotage

    Science.gov (United States)

    Five specimens of adult boll weevil, Anthonomus grandis, were captured nearly simultaneously in pheromone traps clustered near Lubbock, TX, in the Southern High Plains/Caprock eradication zone in late summer 2006. No boll weevils had been captured in this zone or neighboring zones to the north earl...

  5. Boll weevil (Coleoptera: Curculionidae) response to and volitilization rates of grandlure when combined with varying doses of eugenol in the extended-life pheromone lure

    Science.gov (United States)

    Boll weevil extended-life pheromone lures, impregnated with 25 mg grandlure and 30 mg eugenol, are replacing standard pheromone lures (10 mg grandlure) in boll weevil eradication programs, to increase the changing interval from 2 weeks, to 3 or 4 weeks, which reduces labor and material costs. The a...

  6. Molecular and morphological tools to distinguish Scyphophorus acupunctatus Gyllenhal, 1838: a new weevil pest of the endangered Eggers Agave from St Croix, US Virgin Islands

    Science.gov (United States)

    The Agave Snout Weevil (ASW) or Sisal Weevil, Scyphophorus acupunctatus Gyllenhal, is one of the most destructive pests of agave plants, capable of destroying up to 70% of commercial crops, costing millions of dollars in damage to global industries including tequila, mezcal, perfume, henequen, nardo...

  7. Acquired resistance in a weevil to its parasitoid influenced by host plants

    Directory of Open Access Journals (Sweden)

    Stephen Latham Goldson

    2016-08-01

    Full Text Available Field parasitism rates of the Argentine stem weevil Listronotus bonariensis (Kuschel (Coleoptera: Curculionidae by Microctonus hyperodae Loan (Hymenoptera: Braconidae are known to vary according to different host Lolium species that also differ in ploidy. To further investigate this, a laboratory study was conducted to examine parasitism rates on tetraploid Italian L. multiflorum, diploid L. perenne and diploid hybrid L. perenne × L. multiflorum; none of which were infected by Epichloë endophyte. At the same time, the opportunity was taken to compare the results of this study with observations made during extensive laboratory-based research and parasitoid-rearing in the 1990s using the same host plant species. This made it possible to determine whether there has been any change in weevil susceptibility to the parasitoid over a 20 year period in the presence of the tetraploid Italian, diploid perennial and hybrid host grasses that were common to both experiments.The incidence of parasitism in cages, in the presence of these three grasses mirrored what has recently been observed in the field. When caged, weevil parasitism rates in the presence of a tetraploid Italian ryegrass host were significantly higher (75% than rates that occurred in the presence of either the diploid perennial (46% or the diploid hybrid (52% grass, which were not significantly different from each other. This is very different to laboratory parasitism rates in the 1990s when in the presence of both of the latter grasses high rates of parasitism (c. 75% were recorded. These high rates are typical of those still found in both field and caged tetraploid Italian grasses. In contrast, the abrupt decline in weevil parasitism rates points to the possibility of evolved resistance by the weevil to the parasitoid in the diploid and hybrid grasses, but not so in the tetraploid. The orientation of plants in the laboratory cages had no significant effect on parasitism rates under any

  8. Influence of Rice Seeding Rate on Efficacies of Neonicotinoid and Anthranilic Diamide Seed Treatments against Rice Water Weevil

    Directory of Open Access Journals (Sweden)

    Jason Hamm

    2014-12-01

    Full Text Available Rice in the U.S. is frequently seeded at low rates and treated before sowing with neonicotinoid or anthranilic diamide insecticides to target the rice water weevil. A previous study of the influence of seeding rate on rice water weevil densities showed an inverse relationship between seeding rates and immature weevil densities. This study investigated interactive effects of seeding rate and seed treatment on weevil densities and rice yields; in particular, experiments were designed to determine whether seed treatments were less effective at low seeding rates. Four experiments were conducted over three years by varying seeding rates of rice treated at constant per seed rates of insecticide. Larval suppression by chlorantraniliprole was superior to thiamethoxam or clothianidin, and infestations at low seeding rates were up to 47% higher than at high seeding rates. Little evidence was found for the hypothesis that seed treatments are less effective at low seeding rates; in only one of four experiments was the reduction in weevil densities by thiamethoxam greater at high than at low seeding rates. However, suppression of larvae by neonicotinoid seed treatments in plots seeded at low rates was generally poor, and caution must be exercised when using the neonicotioids at low seeding rates.

  9. Fine-scale local adaptation of weevil mouthpart length and camellia pericarp thickness: altitudinal gradient of a putative arms race.

    Science.gov (United States)

    Toju, Hirokazu

    2008-05-01

    Although coevolutionary theory predicts that evolutionary interactions between species are spatially hierarchical, few studies have examined coevolutionary processes at multiple spatial scales. In an antagonistic system involving a plant, the Japanese camellia (Camellia japonica), and its obligate seed predator, the camellia weevil (Curculio camelliae), I elucidated the local adaptation of a camellia defensive armament (pericarp thickness) and a weevil offensive armament (rostrum length) within Yakushima Island (ca. 30 km in diameter), compared to a larger-scale variation in those traits throughout Japan reported in previous studies. Results showed that camellia pericarp thickness and weevil rostrum length vary remarkably within several kilometers on this island. In addition, geographic variation in each camellia and weevil armament was best explained by the armament size of the sympatric participant than by abiotic environmental heterogeneity. However, I also found that camellia pericarp thickness significantly decreased in cool-temperate (i.e., highland) areas, suggesting the contributions of climate on the spatial structuring of the weevil-camellia interaction. Interestingly, relatively thin pericarps occurred not only in the highlands but also in some low-altitude areas, indicating that other factors such as nonrandom or asymmetric gene flow play important roles in the metapopulation processes of interspecific interactions at small spatial scales.

  10. Controle de Sitophilus zeamais Mots., 1855 (Coleoptera: Curculionidae com inseticidas empregados em frutíferas temperadas

    Directory of Open Access Journals (Sweden)

    Faria João Luiz

    2005-01-01

    Full Text Available O gorgulho do milho Sitophilus zeamais Mots. tem sido relatado com freqüência atacando frutíferas temperadas em condições de campo, com destaque para o pessegueiro em Pelotas, RS, macieira em Fraiburgo, SC e videira na Serra Gaúcha, RS. Este trabalho avaliou, em laboratório, o efeito dos inseticidas deltametrina (Decis 25 CE, 40mL 100L-1, dimetoato (Dimetoato 400 CE, 150mL 100L-1, triclorfon (Dipterex 500 SNAqC, 300mL 100L-1, fosmet (Imidan 500 PM, 200g 100L-1, fention (Lebaycid 500 CE, 100mL 100L-1, clorpirifós (Lorsban 480 BR, 150mL 100L-1, malation (Malation 1000, 200mL 100L-1, carbaril (Sevin 480 SC, 360mL 100L-1, fenitrotion (Sumithion 500 CE, 150mL 100L-1 e metidation (Supracid 400 CE, 100mL 100L-1 atualmente empregados no controle de pragas em frutíferas temperadas e os novos inseticidas tiametoxam (Actara 250 WG, 15 e 30g 100L-1, benzoato de emamectina (Proclaim 5 SG, 10 e 20g 100L-1, imidacloprid (Provado 200 SC, 30 e 60mL 100L-1, spinosad (Tracer 480 CE, 10 e 20mL 100L-1 e etofenprox (Trebon 100 SC, 100 e 150mL 100L-1. No primeiro experimento, frutos de maçã foram mergulhados na calda inseticida por 10 segundos e oferecidos a adultos de S. zeamais sp (contato residual e, no segundo, os produtos foram aplicados diretamente sobre os insetos (contato direto em torre de pulverização. Os inseticidas triclorfon (150g 100L-1, fention (50g 100L-1, clorpirifós (72g 100L-1, malation (200g 100L-1, metidation (40g 100L-1 e tiametoxam (3,75 e 7,5g 100L-1 foram eficientes no controle do gorgulho do milho, via contato residual, enquanto fention (50g 100L-1, clorpirifós (72g 100L-1, malation (200g 100L-1, fenitrotion (75g 100L-1 e metidation (40g 100L-1 foram eficientes via contato direto.

  11. Effects of tillage practices on pea leaf weevil (Sitona lineatus L., Coleoptera: Curculionidae) biology and crop damage: a farm-scale study in the US Pacific Northwest.

    Science.gov (United States)

    Hanavan, R P; Bosque-Pérez, N A

    2012-12-01

    The pea leaf weevil, Sitona lineatus L., is periodically a significant pest of pea, Pisum sativum L., in the Palouse region of northern Idaho and eastern Washington, USA. Previous on-station research demonstrated significantly greater adult pea leaf weevil colonization, immature survival, adult emergence and plant damage in conventional-tillage compared to no-tillage plots of pea. In experiments conducted during the 2006 and 2007 growing seasons, aerial and ground adult pea leaf weevil colonization of large-scale commercial pea fields under different tillage regimes in northern Idaho and eastern Washington was examined for the first time. Initial pea leaf weevil feeding damage, immature weevil densities and subsequent adult emergence from the fields were also assessed. During both years, significantly more adult pea leaf weevils were captured in conventional-tillage than in no-tillage fields during the crop establishment period in May. No-tillage soils remained wet longer in the spring and could not be planted by growers until later than conventional-tillage fields. Pea planted under conventional-tillage emerged earlier and had significantly greater feeding damage by the pea leaf weevil than no-tillage pea. Significantly, greater immature pea leaf weevil densities and subsequent adult emergence were observed in conventional-tillage than in no-tillage pea fields. Delayed development of root nodules in the cooler, moister conditions of no-tillage pea fields likely resulted in escape from attack and injury during the critical growth stages that ultimately influence yield. Results indicate that large-scale commercial no-tillage pea fields are less suitable for colonization and survival of the pea leaf weevil and suffer less weevil damage than fields under conventional tillage.

  12. Effector Diversification Contributes to Xanthomonas oryzae pv. oryzae Phenotypic Adaptation in a Semi-Isolated Environment

    Science.gov (United States)

    Quibod, Ian Lorenzo; Perez-Quintero, Alvaro; Booher, Nicholas J.; Dossa, Gerbert S.; Grande, Genelou; Szurek, Boris; Vera Cruz, Casiana; Bogdanove, Adam J.; Oliva, Ricardo

    2016-01-01

    Understanding the processes that shaped contemporary pathogen populations in agricultural landscapes is quite important to define appropriate management strategies and to support crop improvement efforts. Here, we took advantage of an historical record to examine the adaptation pathway of the rice pathogen Xanthomonas oryzae pv. oryzae (Xoo) in a semi-isolated environment represented in the Philippine archipelago. By comparing genomes of key Xoo groups we showed that modern populations derived from three Asian lineages. We also showed that diversification of virulence factors occurred within each lineage, most likely driven by host adaptation, and it was essential to shape contemporary pathogen races. This finding is particularly important because it expands our understanding of pathogen adaptation to modern agriculture. PMID:27667260

  13. The Potential of Streptomyces as Biocontrol Agents against the Rice Blast Fungus, Magnaporthe oryzae (Pyricularia oryzae)

    Science.gov (United States)

    Law, Jodi Woan-Fei; Ser, Hooi-Leng; Khan, Tahir M.; Chuah, Lay-Hong; Pusparajah, Priyia; Chan, Kok-Gan; Goh, Bey-Hing; Lee, Learn-Han

    2017-01-01

    Rice is a staple food source for more than three billion people worldwide. However, rice is vulnerable to diseases, the most destructive among them being rice blast, which is caused by the fungus Magnaporthe oryzae (anamorph Pyricularia oryzae). This fungus attacks rice plants at all stages of development, causing annual losses of approximately 10–30% in various rice producing regions. Synthetic fungicides are often able to effectively control plant diseases, but some fungicides result in serious environmental and health problems. Therefore, there is growing interest in discovering and developing new, improved fungicides based on natural products as well as introducing alternative measures such as biocontrol agents to manage plant diseases. Streptomyces bacteria appear to be promising biocontrol agents against a wide range of phytopathogenic fungi, which is not surprising given their ability to produce various bioactive compounds. This review provides insight into the biocontrol potential of Streptomyces against the rice blast fungus, M. oryzae. The ability of various Streptomyces spp. to act as biocontrol agents of rice blast disease has been studied by researchers under both laboratory and greenhouse/growth chamber conditions. Laboratory studies have shown that Streptomyces exhibit inhibitory activity against M. oryzae. In greenhouse studies, infected rice seedlings treated with Streptomyces resulted in up to 88.3% disease reduction of rice blast. Studies clearly show that Streptomyces spp. have the potential to be used as highly effective biocontrol agents against rice blast disease; however, the efficacy of any biocontrol agent may be affected by several factors including environmental conditions and methods of application. In order to fully exploit their potential, further studies on the isolation, formulation and application methods of Streptomyces along with field experiments are required to establish them as effective biocontrol agents. PMID:28144236

  14. The Potential of Streptomyces as Biocontrol Agents against the Rice Blast Fungus, Magnaporthe oryzae (Pyricularia oryzae).

    Science.gov (United States)

    Law, Jodi Woan-Fei; Ser, Hooi-Leng; Khan, Tahir M; Chuah, Lay-Hong; Pusparajah, Priyia; Chan, Kok-Gan; Goh, Bey-Hing; Lee, Learn-Han

    2017-01-01

    Rice is a staple food source for more than three billion people worldwide. However, rice is vulnerable to diseases, the most destructive among them being rice blast, which is caused by the fungus Magnaporthe oryzae (anamorph Pyricularia oryzae). This fungus attacks rice plants at all stages of development, causing annual losses of approximately 10-30% in various rice producing regions. Synthetic fungicides are often able to effectively control plant diseases, but some fungicides result in serious environmental and health problems. Therefore, there is growing interest in discovering and developing new, improved fungicides based on natural products as well as introducing alternative measures such as biocontrol agents to manage plant diseases. Streptomyces bacteria appear to be promising biocontrol agents against a wide range of phytopathogenic fungi, which is not surprising given their ability to produce various bioactive compounds. This review provides insight into the biocontrol potential of Streptomyces against the rice blast fungus, M. oryzae. The ability of various Streptomyces spp. to act as biocontrol agents of rice blast disease has been studied by researchers under both laboratory and greenhouse/growth chamber conditions. Laboratory studies have shown that Streptomyces exhibit inhibitory activity against M. oryzae. In greenhouse studies, infected rice seedlings treated with Streptomyces resulted in up to 88.3% disease reduction of rice blast. Studies clearly show that Streptomyces spp. have the potential to be used as highly effective biocontrol agents against rice blast disease; however, the efficacy of any biocontrol agent may be affected by several factors including environmental conditions and methods of application. In order to fully exploit their potential, further studies on the isolation, formulation and application methods of Streptomyces along with field experiments are required to establish them as effective biocontrol agents.

  15. Field Abundance Patterns and Odor-Mediated Host Choice by Clover Seed Weevils, Apion fulvipes and Apion trifolii (Coleoptera: Apionidae).

    Science.gov (United States)

    Nyabuga, Franklin N; Carrasco, David; Ranåker, Lynn; Andersson, Martin N; Birgersson, Göran; Larsson, Mattias C; Lundin, Ola; Rundlöf, Maj; Svensson, Glenn P; Anderbrant, Olle; Lankinen, Åsa

    2015-04-01

    The clover seed weevils Apion fulvipes Geoffroy, 1785 and Apion trifolii L., 1768 (Coleoptera: Apionidae) cause major losses to seed production of white clover (Trifolium repens L.) and red clover (Trifolium pratense L.), respectively. Clover is important as animal forage and an alternative to inorganic fertilizers. Because clover is mainly pollinated by bees, the use of insecticides in management of these weevils is discouraged. To gain basic knowledge for development of alternative management strategies, we investigated weevil field abundance over two growing seasons, as well as feeding and olfactory host preferences by A. fulvipes and A. trifolii. Field trap catches in southern Sweden revealed that white clover was dominated by A. fulvipes and red clover by A. trifolii. For both weevil species, female catches were positively correlated to the number of clover buds and flowers in the field. In feeding and olfactory bioassays, females of A. fulvipes and A. trifolii showed a preference for T. repens and T. pratense, respectively. However, the feeding preference was lost when the antennae were removed, indicating a significant role of olfaction in host choice. Male weevils of both species did not show clear olfactory or feeding preferences for host plant species. The field study and laboratory bioassays demonstrate that, at least for female weevils, olfaction is important for selection of host plants. We discuss these novel results in the context of managing these important pests of clover by exploiting olfaction and behavioral attraction to host plant volatiles. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Action of Multiple Cell Wall-Degrading Enzymes Is Required for Elicitation of Innate Immune Responses During Xanthomonas oryzae pv. oryzae Infection in Rice.

    Science.gov (United States)

    Tayi, Lavanya; Maku, Roshan; Patel, Hitendra Kumar; Sonti, Ramesh V

    2016-08-01

    Xanthomonas oryzae pv. oryzae secretes a number of plant cell wall-degrading enzymes (CWDEs) whose purified preparations induce defense responses in rice. These defense responses are suppressed by X. oryzae pv. oryzae using type 3 secretion system (T3SS) effectors and a type 3 secretion system mutant (T3SS(-)) of X. oryzae pv. oryzae is an inducer of rice defense responses. We assessed the role of individual CWDEs in induction of rice defense responses during infection, by mutating them in the genetic background of a T3SS(-). We mutated the genes for five different plant CWDEs secreted by X. oryzae pv. oryzae, including two cellulases (clsA and cbsA), one xylanase (xyn), one pectinase (pglA), and an esterase (lipA), singly in a T3SS(-) background. We have demonstrated that, as compared with a T3SS(-) of X. oryzae pv. oryzae, a cbsA(-)T3SS(-), a clsA(-)T3SS(-), and a xyn(-)T3SS(-) are deficient in induction of rice immune responses such as callose deposits and programmed cell death. In comparison, a lipA(-) T3SS(-) and a pglA(-)T3SS(-) is as efficient in induction of host defense responses as a T3SS(-). Overall, these results indicate that the collective action of X. oryzae pv. oryzae-secreted ClsA, CbsA, and Xyn proteins is required for induction of rice defense responses during infection.

  17. Screening of gamma radiation-induced pathogen resistance rice lines against Xanthomonas oryzae pv. oryzae

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Chan Ju; Lee, Ha Yeon; Kim, Woong Bom; Ahmad, Raza; Moon, Jae Sun; Kwon, Suk Yoon [Korea Research Institute of Beoscience and Biotechnology, Daejeon (Korea, Republic of); Kim, Dong Sub [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2010-09-15

    Bacterial blight is one of the most serious diseases of rice (Oryza sativa L.), and it has been known that Xanthomonas oryzae pv. oryzae (Xoo) causes this disease symptom. To develop resistance rice cultivars against Xoo, 3,000 lines of M{sub 3}, which were irradiated with gamma ray, were tested by 'scissor-dip method' primarily, and 191 putative resistant lines were selected. In M{sub 4} generation, these lines were screened again with various ways such as measuring of symptom of bacterial blight in leaf, number of tiller, fresh weight, and phenotypic segregation ratio in next generation. Finally, six resistance lines were selected. RT-PCR analysis revealed that these lines displayed high level of R-genes such as Xa21, Pi36, and Pi-ta. These results indicate that mutations by gamma ray cause disruptions of regulatory signal transduction systems of these R-genes. Furthermore, these selected mutants could be useful for the development of rice cultivar resistant to Xoo.

  18. Suitability of five species of stored-product insects as hosts for development and reproduction of the parasitoid Anisopteromalus calandrae (Hymenoptera: Pteromalidae).

    Science.gov (United States)

    Ghimire, Mukti N; Phillips, Thomas W

    2007-10-01

    We investigated the ability of two populations of Anisopteromalus calandrae (Hymenoptera: Pteromalidae), to parasitize and develop on late instars of five different stored-product insects that typically complete their development inside seeds of grain or legume species or other dry commodity. The host species were the cigarette beetle, Lasioderma serricorne (F.); cowpea weevil, Callosobruchus maculatus (F.); rice weevil, Sitophilus oryzae (L.); lesser grain borer, Rhyzopertha dominica (F.); and Angoumois grain moth, Sitotroga cerealella (Olivier). Experiments were conducted in the laboratory in a no-choice design by using petri dishes (15 by 100 mm) as experimental arenas with 20 host larvae. A. calandrae females from populations originating in Georgia (GA) and Oklahoma (OK) were introduced singly into experimental arenas and allowed to sting and oviposit for 24 h. Parasitism by the OK population was greater than that for the GA population across all hosts. However, no or very low parasitism was found on Angoumois grain moth for either population in this experiment. The highest number of parasitoid progeny was recorded on cowpea weevil (15.9) followed by rice weevil (11.5) and cigarette beetle (10.8) for the OK population. A similar trend was observed in the GA population. The highest proportion of female progeny was produced on cowpea weevil (73.0%) by the OK population. Conversely, a higher proportion of female progeny was produced on rice weevil (64.6%) by the GA population than produced by the OK population. Parasitoid adults were significantly larger and heavier when they developed on cowpea weevil irrespective of parasitoid population. The possible application of these results for biological control of stored-product insects is discussed.

  19. Screening of extracts of leaves and stems of Psychotria spp. (Rubiaceae) against Sitophilus zeamais (Coleoptera: Curculionidae) and Spodoptera frugiperda (Lepidoptera: Noctuidae) for maize protection.

    Science.gov (United States)

    Tavares, Wagner de Souza; Grazziotti, Geisel Hudson; de Souza Júnior, Amauri Alves; de Sousa Freitas, Silvia; Consolaro, Hélder Nagai; Ribeiro, Paulo Eduardo de Aquino; Zanuncio, José Cola

    2013-11-01

    Sitophilus zeamais (Coleoptera: Curculionidae) and Spodoptera frugiperda (Lepidoptera: Noctuidae) are important economic pests of corn, Zea mays (Poaceae). Psychotria spp. (Rubiaceae) plants are rich in secondary metabolites that could be toxic against such pests. We have screened extracts from four species of Psychotria abundant in the Cerrado (Savannah-type) biome of Brazil for the toxicity to two insects. We found that extracts from leaves and stems had significant effects on the hatching rate, parameters of caterpillar body (weight and length and width of head capsule), repellency, and mortality of these two pests, although the effects varied according to the Psychotria species and plant source (stem or leaf). Extracts of the stems of Psychotria hoffmannseggiana and of Psychotria capitata were more toxic to S. zeamais and the stems of Psychotria goyazensis to S. frugiperda; therefore, such extracts could have the potential for use in integrated pest management schemes.

  20. Bioactivities of extracts from Croton tiglium against Sitophilus zeamais%巴豆提取物对玉米象的生物活性

    Institute of Scientific and Technical Information of China (English)

    姚英娟; 薛东; 杨长举; 谢令德; 舒在习

    2006-01-01

    研究了巴豆(Croton tiglum L.)4种溶剂提取物对玉米象Sitopilus zeamais(Motschulsky)成虫的驱避作用和触杀作用.结果表明:巴豆的4种溶剂提取物对玉米象Sitophilus zeamais(Mostchulsky)成虫均有很好的触杀作用,7.86 mg/cm2的浓度处理后,4 d后的校正死亡率均达到100%.巴豆的4种溶剂提取物对玉米象成虫没有明显的驱避作用.

  1. Radiation effects evaluation for electrons sheaf in packages resistance in a Lasioderma serricorne, Plodia interpunctella and Sitophilus zeamais; Avaliacao dos efeitos da radiacao por feixe de eletrons na resistencia de embalagens a Lasioderma serricorne, Plodia interpunctella e Sitophilus zeamais

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Juliana Nazare

    2011-07-01

    The plagues of stored products consist of a man problem, depreciating products and causing economical damages. Among these curses we have Lasioderma serricorne (F. 1792), Sitophilus zeamais (M. 1855) and Plodia interpunctella (H. 1813) known by infesting stored products as: grains, brans, flours, coffee, tobacco, dried fruits and spices. These curses perforate and penetrate the packages, ovipositing over the substratum. In this context the package plays a fundamental part, preventing the contact and curses' proliferation in the packed product. So, to protect the packed product and to prolong its shelf life, the package should have good mechanical resistance to tension and perforation, good sealing, good barrier properties and should not transfer odors nor strange flavors to the packed product. The ionizing radiation can cause structural changes in polymer packages, these changes are caused by the scission processes and reticulation of the polymers chains. These are concurrent processes and the predominance of one over the other depends on the chemical structure of the polymer, the irradiation conditions and specific factors of the material that will absorb the energy. This work had the objective to evaluate the changes in mechanical properties of package structures used to store granola, cereal bar and pasta, as well as its resistance to perforation by L. serricorne, P. interpunctella and S. zeamais, when submitted to electrons sheaf radiation. In this methodology were used five structures of commercially utilized packages to store granola, cereal bar and pasta composed by (Polypropylene bi-oriented metallic/Polypropylene bi-oriented coextruded - BOPPmet/BOPP 50 {mu}m), (Polypropylene bi-oriented/Polypropylene - BOPP/PP 50 {mu}m), Poli (ethylene terephthalate) metallic/Polypropylene bi-oriented coextruded - PETmet/BOPP 32 {mu}m), Poli (ethylene terephthalate) /Polypropylene - PET/PP1 72 {mu}m), Poli (ethylene terephthalate)/Polypropylene - PET/PP2 32 {mu

  2. Evaluation of irradiated essential oils to control of Sitophilus zeamais Mots. (Coleoptera: Curculionidae) and Blatella germanica (L.) (Dictyopera: Blattellidae); Avaliacao de produtos naturais irradiados para o controle de Sitophilus zeamais Mots. (Coleoptera: Curculionidae) e Blatella germanica (L.) (Dictyopera: Blattellidae)

    Energy Technology Data Exchange (ETDEWEB)

    Potenza, Marcos Roberto

    2004-07-01

    This work aimed to evaluate the effect of irradiated essential oils of Eucalyptus citriodora, Eucalyptus globulus, Pinus sp., Azadirachta indica, Cymbopogon nardus, Cupressus sempervirens, Cymbopogons citratus and Juniperus communis and aqueous, hexanic and ethanolic irradiated extracts of Solanum paniculatum, Dahlia pinnata, Lycopersicon esculentum, Nephrolepis pectinata, Ruta graveolens, Ficus elastica, Lavandula angustifolia, Rhododendron simsii, Agave angustifolia, Ocimum basilicum, Allamanda cathartica, Dieffenbachia brasiliensis, Pennisetum purpureum, Annona squamosa, Coffea arabica and Hibiscus rosa-sinensis, in order to identify new substances to integrated pest management (IPM) and to observe possible effects of gamma radiation about extracts and essential oils efficiency such as increase, reduction, activation and inactivation of the same to the pest control. It evaluated the effect of contact on Sitophilus zeamais and by ingestion in Blattella germanica. To irradiation was used an experimental irradiator of Cobalt-60, type Gammacell 220. The essential oils were submitted increasing doses of gamma radiation: 2.5; 5.0; 7.5 and 10.0 kGy. The bioassay with B. germanica demonstrated efficiency between 22.0 e 30.0% and between 30.0 and 42.0%, respectively, to irradiated essential oils of E. citriodora and E. globulus and they demonstrated too repellency to the nymphs. The gamma radiation used promoted changes in essential oils of E. citriodora e E. globulus that they began to show efficiency on B. germanica nymphs besides a significant reduction of repellency. Essential oils of Pinus sp., A. indica, C. sempervirens and J. communis did not display efficiency. The essential oils of C. nardus, and C. citratus had low efficiency. The gamma radiation increased the efficiency of ethanolic extract of D. Pinnata with dose of 7.5 kGy, showing 48.0% of efficiency on B. germanica nymphs. The gamma radiation showed adverse effect on the aqueous extract of R. Graveolens

  3. The occurrence of arthropods in processed rice products in Malaysia

    Institute of Scientific and Technical Information of China (English)

    Mariana A; Heah SK; Wong AL; Ho TM

    2010-01-01

    Objective:To determine distribution of arthropods in processed rice products such as rice flour and rice cereal-based infant food. Methods: Random samples of rice flour and rice cereal-based infant food purchased from commercial outlets were examined for the presence of arthropods using a modified Berlese Tullgren Funnel Method. Mites were mounted prior to identification and weevils were directly identified. Results: For non-expired products, infestation was found in 6.7%of rice flour and none was found in rice cereal-based infant food samples. The arthropods found in the flour samples were Cheyletus spp., Suidasia pontifica (S. pontifica), Tarsonemus spp., Tyrophagus putrescentiae (T. putrescentiae), Sitophilus granarius (S. granarius) and Sitophilus oryzae (S. oryzae). Others which cannot be identified were Oribatid and Prostigmatid mites. The most common mites in rice flour were Tarsonemus spp. (69.1%), followed by S. pontifica (18.2%). For expired products, only one sample of rice cereal-based infant food was infested and the infestation was by mites of the family Tydeidae. Conclusions:This study demonstrates the presence of 4 allergenic species of S. pontifica, T. putrescentiae, S. granarius and S. oryzae in rice flour. These arthropods can contribute to the incidence of anaphylaxis upon consumption by atopic individuals. There was no infestation of arthropods in rice cereal-based infant food surveyed except for an expired product in a moderate rusty tin container.

  4. RAPD and mitochondrial DNA analysis of the soybean stalk weevil, Sternechus subsignatus (Coleoptera: Curculionidae).

    Science.gov (United States)

    Sosa-Gomez, D R; Coronel, N; Binneck, E; Zucchi, M I; Rosado-Neto, G

    2008-10-01

    Sternechus subsignatus Boheman (Curculionidae: Sternechini) is one of the primary Curculionidae species that reduces soybean yield in Brazil. Initially, outbreaks were reported in southern Brazil in 1973; but, more recent, outbreaks were reported in Bahia (summer 1997-1998) and Maranhão (summer 2003-2004), two states in northeastern Brazil. A putative related species, S. pinguis (Fabricius), was first detected in Salta Province, Argentina. The objective of this study was to evaluate intraspecific molecular polymorphisms of geographically distinct Sternechus populations. Randomly amplified polymorphic DNA (RAPD) profiles and partial mitochondrial cytochrome B (CytB) gene sequences were used to determine whether individual soybean stalk weevils were one of two different species and to infer pest invasion pattern. Putative S. pinguis and S. subsignatus populations were collected in San Agustin (Cruz Alta, Tucumán Province, Argentina) and different sampling sites in the Brazilian states of Paraná, Bahia and Maranhão. Polymorphic bands were obtained by RAPD and analyzed by Dice coefficients. Populations from southern Brazil were more closely related genetically to an Argentinean group than the populations sampled in northeastern Brazil. The Londrina Co., Brazil population displayed the highest intra-population genetic similarity. Most of the soybean stalk weevils collected from San Agustin, Tucumán, Argentina were divergent from those collected in Brazil. Sequencing and parsimony analysis of CytB did not differentiate specimens collected in Argentina and Brazil. Thus, our data show that soybean stalk weevil outbreaks and population increases in northeastern Brazil involved local genotypes.

  5. The age and phylogeny of wood boring weevils and the origin of subsociality.

    Science.gov (United States)

    Jordal, Bjarte H; Sequeira, Andrea S; Cognato, Anthony I

    2011-06-01

    A large proportion of the hyperdiverse weevils are wood boring and many of these taxa have subsocial family structures. The origin and relationship between certain wood boring weevil taxa has been problematic to solve and hypotheses on their phylogenies change substantially between different studies. We aimed at testing the phylogenetic position and monophyly of the most prominent wood boring taxa Scolytinae, Platypodinae and Cossoninae, including a range of weevil outgroups with either the herbivorous or wood boring habit. Many putatively intergrading taxa were included in a broad phylogenetic analysis for the first time in this study, such as Schedlarius, Mecopelmus, Coptonotus, Dactylipalpus, Coptocorynus and allied Araucariini taxa, Dobionus, Psepholax, Amorphocerus-Porthetes, and some peculiar wood boring Conoderini with bark beetle behaviour. Data analyses were based on 128 morphological characters, rDNA nucleotides from the D2-D3 segment of 28S, and nucleotides and amino acids from the protein encoding gene fragments of CAD, ArgK, EF-1α and COI. Although the results varied for some of the groups between various data sets and analyses, one may conclude the following from this study: Scolytinae and Platypodinae are likely sister lineages most closely related to Coptonotus; Cossoninae is monophyletic (including Araucariini) and more distantly related to Scolytinae; Amorphocerini is not part of Cossoninae and Psepholax may belong to Cryptorhynchini. Likelihood estimation of ancestral state reconstruction of subsociality indicated five or six origins as a conservative estimate. Overall the phylogenetic results were quite dependent on morphological data and we conclude that more genetic loci must be sampled to improve phylogenetic resolution. However, some results such as the derived position of Scolytinae were consistent between morphological and molecular data. A revised time estimation of the origin of Curculionidae and various subfamily groups were made using

  6. Chitinolitic activity in proteic extracts of Bacillus thuringiensis toxic to boll weevil (Anthonomus grandis)

    Energy Technology Data Exchange (ETDEWEB)

    Silva, T.S; Rocha, T.L. [EMBRAPA Recursos Geneticos e Biotecnologia, DF (Brazil); Vasconcelos, E.A.R [Universidade de Brasilia (UnB), DF (Brazil); Grossi-de-Sa, M.F. [Universidade Catolica de Brasilia, DF (Brazil)

    2008-07-01

    Full text: Bacillus thuringiensis (Bt) is a spore forming bacteria, which produces Cry proteins toxic towards several insect orders. Bt S 811 strain produces at least three Cry toxins: Cry1Ab, Cry1Ia12, and Cry8, and shown toxicity to insects from Coleoptera order. In order to characterize the production of theses toxins, and check its activity against Boll weevil larvae, proteic extracts from Bt cells and supernatant proteins from the bacterial culture, were obtained at different stages of cell cycle; 8, 16, 24, and 32 hours after inoculation (HAI). Proteins from 32 HAI of the supernatant, and 8 HAI of the cellular fractions, shown highest activity towards the Boll weevil larvae. Western blotting assays using anti-Cry8 and anti-Cry1I were carried out to analyse these toxins in the Bt proteic extracts. The existence of a Cry8 was detected at 8 HAI in the cellular fraction, what allow associate this molecule with the toxicity of this fraction. However, toxicity observed at 32 HAI in the supernatant fraction, was not possible to be associated with Cry8 or Cry1Ia toxins, indicating that there are another protein(s) responsible for the toxicity. A protein homo log to Cry1Ab was identified by 'Peptide Mass Fingerprint' at 32 HAI of the supernatant fraction and a chitin binding protein was identified by 2DE/MS/MS in this same stage and chitinolitic activity was also observed by enzymatic assay. All our data suggest a possible synergism between Cry toxins and a chitinase in the activity of this strain towards Boll weevil.

  7. Deleterious effects of plant cystatins against the banana weevil Cosmopolites sordidus.

    Science.gov (United States)

    Kiggundu, Andrew; Muchwezi, Josephine; Van der Vyver, Christell; Viljoen, Altus; Vorster, Juan; Schlüter, Urte; Kunert, Karl; Michaud, Dominique

    2010-02-01

    The general potential of plant cystatins for the development of insect-resistant transgenic plants still remains to be established given the natural ability of several insects to compensate for the loss of digestive cysteine protease activities. Here we assessed the potential of cystatins for the development of banana lines resistant to the banana weevil Cosmopolites sordidus, a major pest of banana and plantain in Africa. Protease inhibitory assays were conducted with protein and methylcoumarin (MCA) peptide substrates to measure the inhibitory efficiency of different cystatins in vitro, followed by a diet assay with cystatin-infiltrated banana stem disks to monitor the impact of two plant cystatins, oryzacystatin I (OC-I, or OsCYS1) and papaya cystatin (CpCYS1), on the overall growth rate of weevil larvae. As observed earlier for other Coleoptera, banana weevils produce a variety of proteases for dietary protein digestion, including in particular Z-Phe-Arg-MCA-hydrolyzing (cathepsin L-like) and Z-Arg-Arg-MCA-hydrolyzing (cathepsin B-like) proteases active in mildly acidic conditions. Both enzyme populations were sensitive to the cysteine protease inhibitor E-64 and to different plant cystatins including OsCYS1. In line with the broad inhibitory effects of cystatins, OsCYS1 and CpCYS1 caused an important growth delay in young larvae developing for 10 days in cystatin-infiltrated banana stem disks. These promising results, which illustrate the susceptibility of C. sordidus to plant cystatins, are discussed in the light of recent hypotheses suggesting a key role for cathepsin B-like enzymes as a determinant for resistance or susceptibility to plant cystatins in Coleoptera.

  8. Pigment and Virulence Deficiencies Associated with Mutations in the aroE Gene of Xanthomonas oryzae pv. oryzae

    OpenAIRE

    2001-01-01

    Xanthomonadins are yellow, membrane-bound pigments produced by members of the genus Xanthomonas. We identified an ethyl methanesulfonate-induced Xanthomonas oryzae pv. oryzae mutant (BXO65) that is deficient for xanthomonadin production and virulence on rice, as well as auxotrophic for aromatic amino acids (Pig− Vir− Aro−). Reversion analysis indicated that these multiple phenotypes are due to a single mutation. A genomic library of the wild-type strain was used to isolate a 7.0-kb clone that...

  9. Crystallization and preliminary crystallographic studies of LipA, a secretory lipase/esterase from Xanthomonas oryzae pv. oryzae

    Energy Technology Data Exchange (ETDEWEB)

    Aparna, Gudlur; Chatterjee, Avradip; Jha, Gopaljee; Sonti, Ramesh V.; Sankaranarayanan, Rajan, E-mail: sankar@ccmb.res.in [Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007 (India)

    2007-08-01

    The crystallization and preliminary crystallographic studies of LipA, a lipase/esterase secreted by X. oryzae pv. oryzae during its infection of rice plants, are reported. Xanthomonas oryzae pv. oryzae is the causal agent of bacterial leaf blight, a serious disease of rice. Several enzymes that are secreted through the type II secretion system of this bacterium play an important role in the plant–microbe interaction, being important for virulence and also being able to induce potent host defence responses. One of these enzymes is a secretory lipase/esterase, LipA, which shows a very weak homology to other bacterial lipases and gives a positive tributyrin plate assay. In this study, LipA was purified from the culture supernatant of an overexpressing clone of X. oryzae pv. oryzae and two types of crystals belonging to space group C2 but with two different unit-cell parameters were obtained using the hanging-drop vapour-diffusion method. Type I crystals diffract to a maximum resolution of 1.89 Å and have unit-cell parameters a = 93.1, b = 62.3, c = 66.1 Å, β = 90.8°. Type II crystals have unit-cell parameters a = 103.6, b = 54.6, c = 66.3 Å, β = 92.6° and diffract to 1.86 Å. Solvent-content analysis shows one monomer in the asymmetric unit in both the crystal forms.

  10. Identification and molecular characterization of twin-arginine translocation system (Tat) in Xanthomonas oryzae pv. oryzae strain PXO99.

    Science.gov (United States)

    Chen, Lei; Hu, Baishi; Qian, Guoliang; Wang, Chen; Yang, Wanfeng; Han, Zhicheng; Liu, Fengquan

    2009-02-01

    Xanthomonas oryzae pv. oryzae causes bacterial leaf blight, one of the most widespread and destructive bacterial diseases in rice. This study identified and characterized the contribution of the twin-arginine translocation (Tat) pathway to motility, chemotaxis, extracellular polysaccharide (EPS) production and virulence in X. oryzae pv. oryzae strain PXO99. The tatC disruption mutant (strain TCM) of strain PXO99 were generated, and confirmed both by PCR and Southern blotting. Strain PXO99 cells were highly motile in NYGB 0.3% soft agar plate. In contrast, the tatC mutation impaired motility. Furthermore, strain TCM cells lacked detectable flagella and exhibited almost no chemotaxis toward glucose under aerobic conditions, indicating that the Tat secretion pathway contributed to flagellar biogenesis and chemotactic responses. It was also observed that strain TCM exhibited a reductive production of extracellular polysaccharide (EPS) and a significant reduction of virulence on rice plants when compared with the wild type PXO99. However, the tatC mutation in strain PXO99 did not affect growth rate and the ability to induce hypersensitive response (HR) in nonhost tobacco (Nicotiana tabacum L. cv. Samsun). Our findings indicated that the Tat system of X. oryzae pv. oryzae played an important role in the pathogen's virulence.

  11. Electroantennographic and behavioral responses of adults of raspberry weevil Aegorhinus superciliosus (Coleoptera: Curculionidae) to odors released from conspecific females.

    Science.gov (United States)

    Mutis, Ana; Parra, Leonardo; Manosalva, Loreto; Palma, Rubén; Candia, Oscar; Lizama, Marcelo; Pardo, Fernando; Perich, Fernando; Quiroz, Andrés

    2010-08-01

    The raspberry weevil, Aegorhinus superciliosus (Guérin) (Coleoptera: Curculionidae), is the most important pest in blueberry and raspberry fields in the south of Chile. In this study, we investigated the electroantennographic and behavioral responses of A. superciliosus to semiochemicals released from conspecific individual adults, with particular attention to male attraction to females. Odors released from females significantly attracted males in a Y-tube olfactometer. Gas chromatographic and mass spectral analysis of female volatile extracts revealed the presence of limonene and α-pinene. Electroantennogram recordings from both sexes indicated that males of A. superciliosus possess olfactory sensitivity for the R isomer of limonene and α-pinene, whereas females only perceived R-limonene. Behavioral assays using synthetic compounds showed that only R-limonene elicited an attraction response from male weevils. Field experiments confirmed the laboratory results, showing that R-limonene was attractive to weevils. This is the first report of intraspecific chemical communication in this weevil. We discuss the origin of these compounds, their possible role in the sexual behavior of this species, and their potential use in a pest control strategy.

  12. Evidence for the presence of a female produced sex pheromone in the banana weevil, Cosmopolites sordidus Germar (Coleoptera: Curculionidae)

    Science.gov (United States)

    Behavior-modifying chemicals such as pheromones and kairomones have great potential in pest management. Studies reported here investigated chemical cues involved in mating and aggregation behavior of banana weevil, Cosmopolites sordidus, a major insect pest of banana in every country where bananas a...

  13. Distribution, timing of attack, and oviposition of the banana weevil, Cosmopolites sordidus, on banana crop residues in Uganda

    NARCIS (Netherlands)

    Masanza, M.; Gold, C.S.; Huis, van A.

    2005-01-01

    Crop sanitation (removal and chopping of residue corms and pseudostems following plant harvest) has been recommended as a 'best bet' means of reducing banana weevil, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae), populations. However, it has been unclear when such practices should be ca

  14. The life history and immature stages of the weevil Anthonomus monostigma Champion (Coleoptera: Curculiondidae) on Miconia calvescens DC (Melastomataceae)

    Science.gov (United States)

    Eduardo Chacón-Madrigal; M.Tracy Johnson; Paul. Hanson

    2012-01-01

    We describe and illustrate the life history and immature stages of Anthonomus monostigma Champion (Curculionidae: Curculioninae: Anthonomini). This weevil is a fruit borer in Miconia calvescens DC (Melastomataceae), a Neotropical tree that is invasive in Pacific islands. The larva has three instars, and development from egg to...

  15. Effects of crop sanitation on banana weevil, Cosmopolites sordidus (Germar) (Coleoptera : Curculionidae), populations and crop damage in Uganda

    NARCIS (Netherlands)

    Masanza, M.; Gold, C.S.; Huis, van A.; Ragama, P.E.

    2006-01-01

    Crop sanitation, i.e. destruction of crop residues, has been hypothesized to lower banana weevil damage by removing adult refuges and breeding sites. Although it has been widely recommended to farmers, limited data are available to demonstrate the efficacy of this method. The effects of crop sanitat

  16. Enhancing dissemination of Beauveria bassiana with host plant base incision trapfor the management of the banana weevil Cosmopolites sordidus

    NARCIS (Netherlands)

    Tinzaara, W.; Emudong, P.; Nankinga, C.; Tushemereirwe, W.; Kagezi, G.H.; Gold, C.S.; Dicke, M.; Huis, van A.; Karamura, E.

    2015-01-01

    The banana weevil, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) is an important pest of highland banana in East and central Africa. It causes yield loss of up to 100% in heavily infested fields. Studies were carried out in Uganda to evaluate the efficacy of the the plant base incision

  17. Effects of entomopathogenic fungus species, and impact of fertilizers, on biological control of pecan weevil (Coleoptera: Curculionidae)

    Science.gov (United States)

    The pecan weevil, Curculio caryae (Horn), is a key pest of pecan. Prior research indicated potential to use Hypocreales fungi for suppression of C. caryae. In this study, we first compared the efficacy of two fungal spp. Beauveria bassiana (GHA strain) and Metarhizium brunneum (F52) in ability to ...

  18. Reaction of Leaf Weevil Phyllobius arborator (Coleoptera: Curculionidae) to Manganese Content in Diet.

    Science.gov (United States)

    Martinek, P; Kula, E; Hedbávný, J

    2017-02-01

    Reaction of leaf weevil (Phyllobius arborator (Herbst)) to increased concentration of manganese in diet was investigated in laboratory rearing with controlled temperature, humidity, and light conditions. Food for leaf weevils in rearing (leaves of birch Betula pendula Roth) was contaminated by soaking the leaves in solutions of MnCl2.4H2O with graded concentration of manganese. Direct influence of food was characterized by the consumed amount of leaves, period of feeding, and weight of P. arborator adults. At the same time, the levels of manganese in unconsumed food, excrement, and bodies of adults were determined.Even very high content of manganese in food did not cause significantly different reaction of P. arborator adults in comparison to individuals in control treatment. No significant difference in the quantity of the consumed food, weight of adults, and duration of their feeding period was found between the treatments within the experiment. The content of manganese found in food, excrement, and adult beetles indicate that P. arborator avoided manganese intoxication through food by both-voiding manganese through the feces and sequestering it at relatively high concentrations in unspecified parts of their body. © 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.

  19. Experimental and numerical evaluations on palm microwave heating for Red Palm Weevil pest control

    Science.gov (United States)

    Massa, Rita; Panariello, Gaetano; Pinchera, Daniele; Schettino, Fulvio; Caprio, Emilio; Griffo, Raffaele; Migliore, Marco Donald

    2017-01-01

    The invasive Red Palm Weevil is the major pest of palms. Several control methods have been applied, however concern is raised regarding the treatments that can cause significant environmental pollution. In this context the use of microwaves is particularly attractive. Microwave heating applications are increasingly proposed in the management of a wide range of agricultural and wood pests, exploiting the thermal death induced in the insects that have a thermal tolerance lower than that of the host matrices. This paper describes research aiming to combat the Red Palm pest using microwave heating systems. An electromagnetic-thermal model was developed to better control the temperature profile inside the palm tissues. In this process both electromagnetic and thermal parameters are involved, the latter being particularly critical depending on plant physiology. Their evaluation was carried out by fitting experimental data and the thermal model with few free parameters. The results obtained by the simplified model well match with both that of a commercial software 3D model and measurements on treated Phoenix canariensis palms with a ring microwave applicator. This work confirms that microwave heating is a promising, eco-compatible solution to fight the spread of weevil. PMID:28361964

  20. Threat to cedar, Cedrela odorata, plantations in Vietnam by the weevil, Aclees sp.

    Science.gov (United States)

    Thu, Pham Quang; Quang, Dao Ngoc; Dell, Bernard

    2010-01-01

    The recent decline and death of young cedar, Cedrela odorata L. (Sapindales: Meliaceae), plantations in Vietnam is caused by Aclees sp. (Coleoptera: Curculionidae), a wood-boring brown weevil. A field study was undertaken in three-year-old plantations in two districts in Thanh Hoa province in August 2008. Trees were heavily impacted by the weevil, Aclees; the infestation level (P) ranged from 80 to 100% and the average damage index (R) ranged from 1.8 to 2.8. Observations over one year enabled the life history to be determined. Eggs were laid (February to March, September to November) inside the bark from the base of the trunk up to 60 cm in height. Larvae formed extensive feeding tunnels in the inner bark and sap wood. Pupation occurred in feeding tunnels or pupal chambers in the sapwood. Adults emerged twice a year, February to March and August to October. It is concluded that Aclees is a threat to C. odorata plantations in tropical regions of the world, and quarantine measures should be implemented to reduce the risk of spread.

  1. Experimental and numerical evaluations on palm microwave heating for Red Palm Weevil pest control

    Science.gov (United States)

    Massa, Rita; Panariello, Gaetano; Pinchera, Daniele; Schettino, Fulvio; Caprio, Emilio; Griffo, Raffaele; Migliore, Marco Donald

    2017-03-01

    The invasive Red Palm Weevil is the major pest of palms. Several control methods have been applied, however concern is raised regarding the treatments that can cause significant environmental pollution. In this context the use of microwaves is particularly attractive. Microwave heating applications are increasingly proposed in the management of a wide range of agricultural and wood pests, exploiting the thermal death induced in the insects that have a thermal tolerance lower than that of the host matrices. This paper describes research aiming to combat the Red Palm pest using microwave heating systems. An electromagnetic-thermal model was developed to better control the temperature profile inside the palm tissues. In this process both electromagnetic and thermal parameters are involved, the latter being particularly critical depending on plant physiology. Their evaluation was carried out by fitting experimental data and the thermal model with few free parameters. The results obtained by the simplified model well match with both that of a commercial software 3D model and measurements on treated Phoenix canariensis palms with a ring microwave applicator. This work confirms that microwave heating is a promising, eco-compatible solution to fight the spread of weevil.

  2. Heterochromatic banding patterns on chromosomes of twelve weevil species (Insecta, Coleoptera, Curculionoidea: Apionidae, Curculionidae).

    Science.gov (United States)

    Holecová, Milada; Rozek, Maria; Lachowska, Dorota

    2002-01-01

    The C-banding patterns of twelve weevil species are presented. The obtained results confirm the existence of two groups of species: with a small or large amount of heterochromatin in the karyotype. The first group comprises seven species (Apionidae: Holotrichapion pisi; Curculionidae: Phyllobius urticae, Ph. pyri, Ph. maculicornis, Tanymecus palliatus, Larinodontes turbinatus, Cionus tuberculosus). In weevils with a small amount of heterochromatin, tiny grains on the nucleus in interphase are visible, afterwards in mitotic and meiotic prophase appearing as dark dots. The absence of C-bands does not indicate a lack of heterochromatin but heterochromatic regions are sometimes so small that the condensation is not visible during the cell cycle. The second group comprises five species (Otiorhynchus niger, O. morio, Polydrusus corruscus, Barypeithes chevrolati, Nedyus quadrimaculatus) which possess much larger heteropicnotic parts of chromosomes visible during all nuclear divisions. The species examined have paracentromeric C-bands on autosomes and the sex chromosome X, except for Otiorhynchus niger, which also has an intercalary bands on one pair of autososomes. All the species examined differ in the size of segments of constitutive heterochromatin. The y heterochromosome is dot-like and wholly euchromatic in all the studied species.

  3. Characterization of olfactory sensory neurons in the white clover seed weevil, Apion fulvipes (Coleoptera: Apionidae).

    Science.gov (United States)

    Andersson, Martin N; Larsson, Mattias C; Svensson, Glenn P; Birgersson, Göran; Rundlöf, Maj; Lundin, Ola; Lankinen, Åsa; Anderbrant, Olle

    2012-10-01

    Seed-eating Apion weevils (Coleoptera: Apionidae) cause large economic losses in white and red clover seed production across Europe. Monitoring and control of clover weevils would be facilitated by semiochemical-based methods. Until now, however, nothing was known about physiological or behavioral responses to semiochemicals in this insect group. Here we analyzed the antenna of the white clover (Trifolium repens L.) specialist Apion fulvipes Geoffroy with scanning electron microscopy, and used single sensillum recordings with a set of 28 host compounds to characterize 18 classes of olfactory sensory neurons (OSNs). Nine of the OSN classes responded strongly to synthetic compounds with high abundance in clover leaves, flowers, or buds. Eight classes responded only weakly to the synthetic stimuli, whereas one collective class responded exclusively to volatiles released from a crushed clover leaf. The OSNs showed a remarkable degree of specificity, responding to only one or a few chemically related compounds. In addition, we recorded a marked difference in the temporal dynamics of responses between different neurons, compounds, and doses. The identified physiologically active compounds will be screened for behavioral activity, with the ultimate goal to develop an odor-based control strategy for this pest. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. On the spatial spread of the Rice Water Weevil, Lissorhoptrus oryzophilus Kuschel (Coleoptera: Erirhinidae, in Italy

    Directory of Open Access Journals (Sweden)

    Daniela Lupi

    2010-07-01

    Full Text Available A five year study has been made to establish the spread of the rice water weevil Lissorhoptrus oryzophilus (Coleoptera: Erirhinidae in Northern Italy. Data obtained with GPS from 2005 throughout 2009 were first georeferenced with SW ArcGis® 9.2, then overlapped and compared to the map of the European environmental landscape based on the interpretation of satellite images (CORINE Land Cover map and to the hydrographic chart CT10 (Technical Regional map 10000. The analysis of the radial rate of spread per year indicates a deceleration in the expansion from 10.864 ± 6.801 km/year in 2005 to 5.318 ± 1.401 km/year in 2009. In five years the weevil has expanded its distribution in nearly all rice paddies in Lombardy and Piedmont, over an area of about 200,000 ha, which correspond to 86% of the total Italian rice area. Its expansion is thought to follow a type of stratified dispersal, due both to insect adult active dispersal and to accidental movements caused by human transportation.

  5. Adaptive divergence of scaling relationships mediates the arms race between a weevil and its host plant.

    Science.gov (United States)

    Toju, Hirokazu; Sota, Teiji

    2006-12-22

    Coevolution of exaggerated morphologies between insects and plants is a well-known but poorly understood phenomenon in evolutionary biology. In the antagonistic interaction between a seed-predatory insect, the camellia weevil (Curculio camelliae), and its host plant, Japanese camellia (Camellia japonica), we examined the evolutionary trajectory of an exaggerated offensive trait of the weevil (rostrum length) in terms of scaling relationship. Sampling throughout Japan revealed that the ratio of the rostrum length to overall body size was correlated with the ratio of the pericarp thickness to overall fruit size across the localities. We found a geographical interpopulation divergence in a parameter pertaining to the allometric equation of rostrum length (the coefficient a in y=axb, where y and x denote rostrum and body lengths, respectively), and the pattern of geographical differentiation in the allometric coefficient was closely correlated with the variation in the pericarp thickness of Japanese camellia. Our results provide a novel example of a geographically diverged scaling relationship in an insect morphology resulting from a coevolutionary arms race with its host plant.

  6. In planta gene expression analysis of Xanthomonas oryzae pathovar oryzae, African strain MAI1

    Directory of Open Access Journals (Sweden)

    Verdier Valérie

    2010-06-01

    Full Text Available Abstract Background Bacterial leaf blight causes significant yield losses in rice crops throughout Asia and Africa. Although both the Asian and African strains of the pathogen, Xanthomonas oryzae pv. oryzae (Xoo, induce similar symptoms, they are nevertheless genetically different, with the African strains being more closely related to the Asian X. oryzae pv. oryzicola (Xoc. Results Changes in gene expression of the African Xoo strain MAI1 in the susceptible rice cultivar Nipponbare were profiled, using an SSH Xoo DNA microarray. Microarray hybridization was performed comparing bacteria recovered from plant tissues at 1, 3, and 6 days after inoculation (dai with bacteria grown in vitro. A total of 710 bacterial genes were found to be differentially expressed, with 407 up-regulated and 303 down-regulated. Expression profiling indicated that less than 20% of the 710 bacterial transcripts were induced in the first 24 h after inoculation, whereas 63% were differentially expressed at 6 dai. The 710 differentially expressed genes were one-end sequenced. 535 sequences were obtained from which 147 non-redundant sequences were identified. Differentially expressed genes were related to metabolism, secretion and transport, pathogen adherence to plant tissues, plant cell-wall degradation, IS elements, and virulence. In addition, various other genes encoding proteins with unknown function or showing no similarity to other proteins were also induced. The Xoo MAI1 non-redundant set of sequences was compared against several X. oryzae genomes, revealing a specific group of genes that was present only in MAI1. Numerous IS elements were also found to be differentially expressed. Quantitative real-time PCR confirmed 86% of the identified profile on a set of 14 genes selected according to the microarray analysis. Conclusions This is the first report to compare the expression of Xoo genes in planta across different time points during infection. This work shows that

  7. Enhancing Neoplasm Expression in Field Pea (Pisum sativum via Intercropping and its Significance to Pea Weevil (Bruchus pisorum Management

    Directory of Open Access Journals (Sweden)

    Abel eTeshome

    2016-05-01

    Full Text Available Neoplasm formation, a non-meristematic tissue growth on young field pea (Pisum sativum L. pods is triggered in the absence of UV light and/or in response to oviposition by pea weevil (Bruchus pisorum L.. This trait is expressed in some genotypes (Np genotypes of P. sativum and has the capacity to obstruct pea weevil larval entry into developing seeds. In the present study, 26% of the tested accessions depicted the trait when grown under greenhouse conditions. However, UV light inhibits full expression of this trait and subsequently it is inconspicuous at the field level. In order to investigate UV light impact on the expression of neoplasm, particular Np genotypes were subjected to UV lamp light exposure in the greenhouse and sunlight at the field level. Under these different growing conditions, the highest mean percentage of neoplastic pods was in the control chamber in the greenhouse (36% whereas in single and double UV lamp chambers, the percentage dropped to 10% and 15%, respectively. Furthermore, when the same Np genotypes were grown in the field, the percentage of neoplastic pods dropped significantly (7%. In order to enhance neoplastic expression at the field level, intercropping of Np genotypes with sorghum was investigated. As result, the percentage of neoplastic pods was threefold in intercropped Np genotypes as compared to those without intercropping. Therefore, intercropping neoplastic genotypes with other crops such as sorghum and maize can facilitate neoplasm formation, which in turn can minimize the success rate of pea weevil larvae entry into developing seeds. Greenhouse artificial infestation experiments showed that pea weevil damage in neoplastic genotypes is lower in comparison to wild type genotypes. Therefore, promoting neoplastic formation under field conditions via intercropping can serve as part of an integrated pea weevil management strategy especially for small scale farming systems.

  8. The gut microbiota of the pine weevil is similar across Europe and resembles that of other conifer-feeding beetles.

    Science.gov (United States)

    Berasategui, Aileen; Axelsson, Karolin; Nordlander, Göran; Schmidt, Axel; Borg-Karlson, Anna-Karin; Gershenzon, Jonathan; Terenius, Olle; Kaltenpoth, Martin

    2016-08-01

    The pine weevil (Hylobius abietis, Coleoptera: Curculionidae) is an important pest of conifer seedlings in Europe. Despite its economic importance, little is known about the composition of its gut microbial community and the role it plays in mediating the weevil's ability to utilize conifers as a food source. Here, we characterized the gut bacterial communities of different populations of H. abietis across Europe and compared them to those of other beetles that occupy similar ecological niches. We demonstrate that the microbial community of H. abietis is similar at higher taxonomic levels (family and genus) across locations in Europe, with Wolbachia as the dominant microbe, followed by Enterobacteria and Firmicutes. Despite this similarity, we observed consistent differences between countries and locations, but not sexes. Our meta-analysis demonstrates that the gut bacterial community of the pine weevil is very similar to that of bark beetles that also exploit conifers as a food source. The Enterobacteriaceae symbionts of both host taxa are especially closely related phylogenetically. Conversely, the microbiota of H. abietis is distinct from that of closely related weevils feeding on nonconifer food sources, suggesting that the microbial community of the pine weevil is determined by the environment and may be relevant to host ecology. Furthermore, several H. abietis-associated members of the Enterobacteriaceae family are known to contain genes involved in terpenoid degradation. As such, we hypothesize that the gut microbial community is important for the utilization of conifer seedlings as a food source, either through the detoxification of plant secondary metabolites or through the supplementation of essential nutrients.

  9. Enhancing Neoplasm Expression in Field Pea (Pisum sativum) via Intercropping and Its Significance to Pea Weevil (Bruchus pisorum) Management

    Science.gov (United States)

    Teshome, Abel; Bryngelsson, Tomas; Mendesil, Esayas; Marttila, Salla; Geleta, Mulatu

    2016-01-01

    Neoplasm formation, a non-meristematic tissue growth on young field pea (Pisum sativum L.) pods is triggered in the absence of UV light and/or in response to oviposition by pea weevil (Bruchus pisorum L.). This trait is expressed in some genotypes [neoplastic (Np) genotypes] of P. sativum and has the capacity to obstruct pea weevil larval entry into developing seeds. In the present study, 26% of the tested accessions depicted the trait when grown under greenhouse conditions. However, UV light inhibits full expression of this trait and subsequently it is inconspicuous at the field level. In order to investigate UV light impact on the expression of neoplasm, particular Np genotypes were subjected to UV lamp light exposure in the greenhouse and sunlight at the field level. Under these different growing conditions, the highest mean percentage of Np pods was in the control chamber in the greenhouse (36%) whereas in single and double UV lamp chambers, the percentage dropped to 10 and 15%, respectively. Furthermore, when the same Np genotypes were grown in the field, the percentage of Np pods dropped significantly (7%). In order to enhance Np expression at the field level, intercropping of Np genotypes with sorghum was investigated. As result, the percentage of Np pods was threefold in intercropped Np genotypes as compared to those without intercropping. Therefore, intercropping Np genotypes with other crops such as sorghum and maize can facilitate neoplasm formation, which in turn can minimize the success rate of pea weevil larvae entry into developing seeds. Greenhouse artificial infestation experiments showed that pea weevil damage in Np genotypes is lower in comparison to wild type genotypes. Therefore, promoting Np formation under field conditions via intercropping can serve as part of an integrated pea weevil management strategy especially for small scale farming systems. PMID:27242855

  10. Systemic Insecticides Reduce Feeding, Survival and Fecundity of Adult Black Vine Weevils (Coleoptera: Curculionidae) on a Variety of Ornamental Nursery Crops

    Science.gov (United States)

    A series of bioassays were conducted to test the systemic activity of clothianidin, chlorantraniliprole, dinotefuran, and thiamethoxam against adult black vine weevils (Otiorhynchus sulcatus F.) on Taxus, Heuchera, Astilbe, Sedum, Euonymus, and Rhododendron grown in containers. The insecticides wer...

  11. First report of wheat blast caused by magnaporthe oryzae pathotype triticum in Bangladesh

    Science.gov (United States)

    Wheat blast or ‘brusone’, caused by the ascomycetous fungus Magnaporthe oryzae B.C. Couch (synonym Pyricularia oryzae Cavara), was first identified in 1985 in Brazil. M. oryzae is composed of a range of morphologically identical but genetically different host-specific pathotypes that are specialized...

  12. Morphological and molecular characterization of fungal pathogen, Magnaphorthe oryzae

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, Nor’Aishah, E-mail: aishahnh@ns.uitm.edu.my [Faculty of Applied Science, UniversitiTeknologi MARA (UiTM), Kuala Pilah, Negeri Sembilan (Malaysia); Rafii, Mohd Y., E-mail: mrafii@upm.edu.my [Institute of Tropical Agriculture, Universiti Putra Malaysia (UPM), Serdang, Selangor (Malaysia); Department of Crop Science, Universiti Putra Malaysia (UPM), Serdang, Selangor (Malaysia); Rahim, Harun A. [Agrotechnology & Bioscience Division, Malaysian Nuclear Agency, Bangi, Kajang, Selangor (Malaysia); Ali, Nusaibah Syd [Department of Plant Protection, Universiti Putra Malaysia (UPM), Serdang, Selangor (Malaysia); Mazlan, Norida [Department of Agriculture Technology, Universiti Putra Malaysia (UPM), Serdang, Selangor (Malaysia); Abdullah, Shamsiah [Faculty of Plantation and Agrotechnology, UniversitiTeknologi MARA (UiTM), Shah Alam, Selangor (Malaysia)

    2016-02-01

    Rice is arguably the most crucial food crops supplying quarter of calories intake. Fungal pathogen, Magnaphorthe oryzae promotes blast disease unconditionally to gramineous host including rice species. This disease spurred an outbreaks and constant threat to cereal production. Global rice yield declining almost 10-30% including Malaysia. As Magnaphorthe oryzae and its host is model in disease plant study, the rice blast pathosystem has been the subject of intense interest to overcome the importance of the disease to world agriculture. Therefore, in this study, our prime objective was to isolate samples of Magnaphorthe oryzae from diseased leaf obtained from MARDI Seberang Perai, Penang, Malaysia. Molecular identification was performed by sequences analysis from internal transcribed spacer (ITS) region of nuclear ribosomal RNA genes. Phylogenetic affiliation of the isolated samples were analyzed by comparing the ITS sequences with those deposited in the GenBank database. The sequence of the isolate demonstrated at least 99% nucleotide identity with the corresponding sequence in GenBank for Magnaphorthe oryzae. Morphological observed under microscope demonstrated that the structure of conidia followed similar characteristic as M. oryzae. Finding in this study provide useful information for breeding programs, epidemiology studies and improved disease management.

  13. Cell biology of the Koji mold Aspergillus oryzae.

    Science.gov (United States)

    Kitamoto, Katsuhiko

    2015-01-01

    Koji mold, Aspergillus oryzae, has been used for the production of sake, miso, and soy sauce for more than one thousand years in Japan. Due to the importance, A. oryzae has been designated as the national micro-organism of Japan (Koku-kin). A. oryzae has been intensively studied in the past century, with most investigations focusing on breeding techniques and developing methods for Koji making for sake brewing. However, the understanding of fundamental biology of A. oryzae remains relatively limited compared with the yeast Saccharomyces cerevisiae. Therefore, we have focused on studying the cell biology including live cell imaging of organelles, protein vesicular trafficking, autophagy, and Woronin body functions using the available genomic information. In this review, I describe essential findings of cell biology of A. oryzae obtained in our study for a quarter of century. Understanding of the basic biology will be critical for not its biotechnological application, but also for an understanding of the fundamental biology of other filamentous fungi.

  14. A reductive aminase from Aspergillus oryzae

    Science.gov (United States)

    Aleku, Godwin A.; France, Scott P.; Man, Henry; Mangas-Sanchez, Juan; Montgomery, Sarah L.; Sharma, Mahima; Leipold, Friedemann; Hussain, Shahed; Grogan, Gideon; Turner, Nicholas J.

    2017-10-01

    Reductive amination is one of the most important methods for the synthesis of chiral amines. Here we report the discovery of an NADP(H)-dependent reductive aminase from Aspergillus oryzae (AspRedAm, Uniprot code Q2TW47) that can catalyse the reductive coupling of a broad set of carbonyl compounds with a variety of primary and secondary amines with up to >98% conversion and with up to >98% enantiomeric excess. In cases where both carbonyl and amine show high reactivity, it is possible to employ a 1:1 ratio of the substrates, forming amine products with up to 94% conversion. Steady-state kinetic studies establish that the enzyme is capable of catalysing imine formation as well as reduction. Crystal structures of AspRedAm in complex with NADP(H) and also with both NADP(H) and the pharmaceutical ingredient (R)-rasagiline are reported. We also demonstrate preparative scale reductive aminations with wild-type and Q240A variant biocatalysts displaying total turnover numbers of up to 32,000 and space time yields up to 3.73 g l‑1 d‑1.

  15. A new diketopiperazine alkaloid from Aspergillus oryzae.

    Science.gov (United States)

    Shaaban, Mohamed; El-Metwally, Mohammad Magdy; Nasr, Hamdi

    2014-01-01

    Investigation of bioactive secondary metabolites from terrestrial Aspergillus oryzae sp. MMAO1 using M2 medium afforded a new diketopiperazine alkaloid, 7,9-dihydroxy-3-(1H-indol-3-ylmethyl)-8-methoxy-2,3,11,11a-tetrahydro-6H-pyrazino[1,2-b]isoquinoline-1,4-dione (1a), containing the unusual amino acid L-6,8-dihydroxy-7-methoxyphenylalanine. This was co-isolated with ditryptophenaline (2), cyclo-(Tryp,Tyr) (4), cyclo-(Pro,Val), α-cyclopiazonic acid (3), kojic acid and uridine. Re-cultivation of the fungal strain on Dox medium led to the production of bisdethio(bismethylthio)gliotoxin (5), pseurotin A (6) along with linoleic acid, α-cyclopiazonic acid (3) and kojic acid. The chemical structure of the new diketopiperazine alkaloid including the relative configuration was determined by 1D and 2D NMR spectroscopy and HR-ESI-MS spectrometry, and by comparison with the related literature. The new alkaloid (1a) showed no antimicrobial activity or cytotoxicity against brine shrimps.

  16. Population genomic insights into variation and evolution of Xanthomonas oryzae pv. oryzae

    Science.gov (United States)

    Midha, Samriti; Bansal, Kanika; Kumar, Sanjeet; Girija, Anil Madhusoodana; Mishra, Deo; Brahma, Kranthi; Laha, Gouri Sankar; Sundaram, Raman Meenakshi; Sonti, Ramesh V.; Patil, Prabhu B.

    2017-01-01

    Xanthomonas oryzae pv. oryzae ( Xoo) is a serious pathogen of rice causing bacterial leaf blight disease. Resistant varieties and breeding programs are being hampered by the emergence of highly virulent strains. Herein we report population based whole genome sequencing and analysis of 100 Xoo strains from India. Phylogenomic analysis revealed the clustering of Xoo strains from India along with other Asian strains, distinct from African and US Xo strains. The Indian Xoo population consists of a major clonal lineage and four minor but highly diverse lineages. Interestingly, the variant alleles, gene clusters and highly pathogenic strains are primarily restricted to minor lineages L-II to L-V and in particularly to lineage L-III. We could also find the association of an expanded CRISPR cassette and a highly variant LPS gene cluster with the dominant lineage. Molecular dating revealed that the major lineage, L-I is youngest and of recent origin compared to remaining minor lineages that seems to have originated much earlier in the past. Further, we were also able to identify core effector genes that may be helpful in efforts towards building durable resistance against this pathogen. PMID:28084432

  17. Cloning and expression of a IuxRhomologue from Xanthomonas oryzae pv.Oryzae

    Institute of Scientific and Technical Information of China (English)

    Liang Bin; Guo Bin; Yang Chen; Zhang Xinjun; Dai Luyuan; Yu Tengqiong; Shen Daleng

    2006-01-01

    LuxR homologues are the main components of LuxR/LuxI circuit in Quorum Sensing(QS)of Gram-negative bacteria.A luxR homologue,designated as xooR,was cloned from Ⅹ.oryzae pv.oryzae.The xooR gene is atranscription factor with 765 bp inlength,and encodes a 254-amino acid putative protein with a molecular weight and an isoelectric point of 28.3 ku and 8.72 respectively.Amino acids 15 to 171 from the N-terminus are the Autoin-bind domain of XooR whereas amino acids 191 to 245 form a helix-turn-helix(HTH)motif that serves as the DNA-binding domain.In this study,XooR was expressed as a fusion protein along with green fluorescent protein(GFP),using pET-24a-d(+),a prokaryotic expression vector.Western blot showed that the xooR gene was successfully expressed in vitro in E.coli as a XooR-GFP fusion protein with a size of 54 ku.

  18. Deciphering the Role of Tyrosine Sulfation in Xanthomonas oryzae pv. oryzae Using Shotgun Proteomic Analysis

    Directory of Open Access Journals (Sweden)

    Hye-Jee Park

    2016-06-01

    Full Text Available A bacterial tyrosine sulfotransferase, RaxST, is required for activation of rice XA21-mediated immunity, and it catalyzes sulfation of tyrosine residues of Omp1X and RaxX in Xanthomonas oryzae pv. oryzae, a causal agent of bacterial blight in rice. Although RaxST is biochemically well-characterized, biological functions of tyrosine sulfation have not been fully elucidated. We compared protein expression patterns between the wildtype and a raxST knockout mutant using shotgun proteomic analysis. Forty nine proteins displayed a more than 1.5-fold difference in their expression between the wildtype and the mutant strains. Clusters of orthologous groups analysis revealed that proteins involved in cell motility were most abundant, and phenotypic observation also showed that the twitching motility of the mutant was dramatically changed. These results indicate that tyrosine sulfation by RaxST is essential for Xoo movement, and they provide new insights into the biological roles of RaxST in cellular processes.

  19. Role of DetR in defence is critical for virulence of Xanthomonas oryzae pv. oryzae.

    Science.gov (United States)

    Nguyen, Minh-Phuong; Park, Jongchan; Cho, Man-Ho; Lee, Sang-Won

    2016-05-01

    Like other bacteria, Xanthomonas oryzae pv. oryzae (Xoo), the causal agent of bacterial leaf blight disease in rice, possesses intracellular signalling systems, known as two-component regulatory systems (TCSs), which regulate pathogenesis and biological processes. Completion of the genome sequences of three Xoo strains has facilitated the functional study of genes, including those of TCSs, but the biological functions of most Xoo TCSs have not yet been uncovered. To identify TCSs involved in Xoo pathogenesis, we generated knockout strains lacking response regulators (RRs, a cytoplasmic signalling component of the TCS) and examined the virulence of the RR knockout strains. This study presents a knockout strain (detR(-) ) lacking the PXO_04659 gene which shows dramatically reduced virulence relative to the wild-type. Our studies to elucidate detR function in Xoo pathogenesis revealed a reduction in extracellular polysaccharide (EPS), intolerance to reactive oxygen species (ROS) and deregulation of iron homeostasis in the detR(-) strain. Moreover, gene expression of regulatory factors, including other RRs and transcription factors (TFs), was altered in the absence of DetR protein, as determined by reverse transcription-polymerase chain reaction (RT-PCR) and/or real-time quantitative RT-PCR analyses. All evidence leads to the conclusion that DetR is essential for Xoo virulence through the regulation of the Xoo defence system including EPS synthesis, ROS detoxification and iron homeostasis, solely or cooperatively with other regulatory factors.

  20. Do tissue carbon and nitrogen limit population growth of weevils introduced to control waterhyacinth at a site in the Sacramento-San Joaquin Delta, California?

    OpenAIRE

    Spencer, David F.; Ksander, Gregory G.

    2004-01-01

    Waterhyacinth (Eichhornia crassipes(Mart.) Solms), is a serious problem in the Sacramento Delta. Two weevil species (Neochetina bruchi Hustache and N. eichhorniae Warner) have been introduced as biological control agents. The purpose of this study was to test the hypothesis that nitrogen (N) in the tissue of waterhyacinth was not sufficient to support weevil growth and reproduction. Because it grows better on plants with high N content and because it has a greater impact on the growth...

  1. Permanent genetic resources added to Molecular Ecology Resources Database 1 June 2012-31 July 2012.

    Science.gov (United States)

    Barat, Ashoktaru; Bravo, S P; Chandra, Suresh; Corrêa, A S; Giombini, M I; Guedes, R N C; Huailei, Ma; Lal, Kuldeep K; Liang, Lu; Matura, Rakesh; Mohindra, Vindhya; Oliveira, L O; Patangia, Ruchi; Qiyong, Liu; Sah, Rama Shankar; Singh, Akanksha; Singh, Birender Kumar; Singh, Rajeev K; Tosto, D S; Tripathi, Ratnesh K; Vinson, C C

    2012-11-01

    This article documents the addition of 96 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Clarias batrachus, Marmota himalayana, Schizothorax richardsonii, Sitophilus zeamais and Syagrus romanzoffiana. These loci were cross-tested on the following species: Clarias dussumeri, Clarias gariepinus, Heteropneustus fossilis, Sitophilus granarius and Sitophilus oryzae.

  2. Rational Practices to Manage Boll Weevils Colonization and Population Growth on Family Farms in the Semiárido Region of Brazil

    Directory of Open Access Journals (Sweden)

    Robério C. S. Neves

    2014-10-01

    Full Text Available Because boll weevil, Anthonomus grandis Boh. develops partially protected inside cotton fruiting structures, once they become established in a field, they are difficult to control, even with nearly continuous insecticide spray. During two cotton-growing seasons in the Semiárido region of Pernambuco State, Brazil, we tested the use of kaolin sprays to disrupt plant colonization through visual cue interference, combined with removal of fallen fruiting bodies to restrain boll weevil population growth after colonization. Kaolin spray under non-choice trials resulted in 2.2×, 4.4×, and 8.6× fewer weevils, oviposition and feeding punctures on kaolin-treated plants, respectively, despite demonstrating no statistical differences for colonization and population growth. Early season sprays in 2010 occurred during a period of rainfall, and hence, under our fixed spraying schedule no significant differences in boll weevil colonization were detected. In 2011, when kaolin sprays were not washed out by rain, delayed boll weevil colonization and reduction on attacked fruiting bodies were observed in eight out of 12 evaluations, and kaolin-treated plots had 2.7× fewer damaged fruiting bodies compared to untreated plots. Adoption of simple measures such as removal of fallen fruiting bodies and prompt reapplication of kaolin sprays after rainfall show promise in reducing boll weevil infestation.

  3. Bipolaris oryzae, a novel fungal opportunist causing keratitis.

    Science.gov (United States)

    Wang, Luxia; Al-Hatmi, Abdullah M S; Lai, Xuwen; Peng, Lianghong; Yang, Chuanhong; Lai, Huangwen; Li, Jianxun; Meis, Jacques F; de Hoog, G Sybren; Zhuo, Chao; Chen, Min

    2016-05-01

    We report a case of mycotic keratitis caused by Bipolaris oryzae with predisposing trauma from a foreign body. The fungus was identified by sequencing the internal transcribed spacer region, translation elongation factor 1α (TEF1) gene, and partial glyceraldehyde-3-phosphate dehydrogenase (GPDH) gene, and the species identity was confirmed on the basis of its characteristic conidial phenotype. The patient was treated with surgical intervention and antifungal agents, including intravenous fluconazole (FLC), oral itraconazole, topical 0.15% amphotericin B eye drops, and 0.5% FLC eye drops. To our knowledge, this is the first report of mycotic keratitis caused by B. oryzae worldwide.

  4. The biosynthesis, structure and gelatinization properties of starches from wild and cultivated African rice species (Oryza barthii and Oryza glaberrima).

    Science.gov (United States)

    Wang, Kai; Wambugu, Peterson W; Zhang, Bin; Wu, Alex Chi; Henry, Robert J; Gilbert, Robert G

    2015-09-20

    The molecular structure and gelatinization properties of starches from domesticated African rice (Oryza glaberrima) and its wild progenitor (Oryza barthii) are determined and comparison made with Asian domesticated rice (Oryza sativa), the commonest commercial rice. This suggests possible enzymatic processes contributing to the unique traits of the African varieties. These have similar starch structures, including smaller amylose molecules, but larger amounts of amylose chains across the whole amylose chain-length distribution, and higher amylose contents, than O. sativa. They also show a higher proportion of two- and three-lamellae spanning amylopectin branch chains (degree of polymerization 34-100) than O. sativa, which contributes to their higher gelatinization temperatures. Fitting amylopectin chain-length distribution with a biosynthesis-based mathematical model suggests that the reason for this difference might be because O. glaberrima and O. barthii have more active SSIIIa and/or less active SBEIIb enzymes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Emodin, a toxic metabolite of Aspergillus wentii isolated from weevil-damaged chestnuts.

    Science.gov (United States)

    Wells, J M; Cole, R J; Kirksey, J W

    1975-07-01

    A diarrheagenic toxin from culture extracts of Aspergillus wentii Wehmer isolated from weevil-damaged Chinese chestnuts was identified as emodin (2-methyl-4,5,7-trihydroxyanthraquinone). The orange-red, crystalline toxin (mp 255 to 257 C) showed ultraviolet absorption maxima in ethyl alcohol at 223, 250, 267, 290, and 442 nm, and infrared absorption maxima at 3,400 cm-1 (OH), 1,635, and 1,625 CM-1. Chemical shifts and coupling constants of the proton magnetic resonance spectra of the A. wentii toxin and of authentic emodin agreed. Mean lethal dose of emodin orally administered to 1-day-old DeKalb cockerels was 3.7 mg/kg.

  6. Trichobaris weevils distinguish amongst toxic host plants by sensing volatiles that do not affect larval performance.

    Science.gov (United States)

    Lee, Gisuk; Joo, Youngsung; Diezel, Celia; Lee, Eun Ju; Baldwin, Ian T; Kim, Sang-Gyu

    2016-07-01

    Herbivorous insects use plant metabolites to inform their host plant selection for oviposition. These host-selection behaviours are often consistent with the preference-performance hypothesis; females oviposit on hosts that maximize the performance of their offspring. However, the metabolites used for these oviposition choices and those responsible for differences in offspring performance remain unknown for ecologically relevant interactions. Here, we examined the host-selection behaviours of two sympatric weevils, the Datura (Trichobaris compacta) and tobacco (T. mucorea) weevils in field and glasshouse experiments with transgenic host plants specifically altered in different components of their secondary metabolism. Adult females of both species strongly preferred to feed on D. wrightii rather than on N. attenuata leaves, but T. mucorea preferred to oviposit on N. attenuata, while T. compacta oviposited only on D. wrightii. These oviposition behaviours increased offspring performance: T. compacta larvae only survived in D. wrightii stems and T. mucorea larvae survived better in N. attenuata than in D. wrightii stems. Choice assays with nicotine-free, JA-impaired, and sesquiterpene-over-produced isogenic N. attenuata plants revealed that although half of the T. compacta larvae survived in nicotine-free N. attenuata lines, nicotine did not influence the oviposition behaviours of both the nicotine-adapted and nicotine-sensitive species. JA-induced sesquiterpene volatiles are key compounds influencing T. mucorea females' oviposition choices, but these sesquiterpenes had no effect on larval performance. We conclude that adult females are able to choose the best host plant for their offspring and use chemicals different from those that influence larval performance to inform their oviposition decisions. © 2016 John Wiley & Sons Ltd.

  7. Molecular Cytogenetic Analysis of Spontaneous Interspecific Hybrid Between Oryza sativa and Oryza minuta

    Institute of Scientific and Technical Information of China (English)

    YI Chuan-deng; CHENG Xu; WANG Bei-bei; LIANG Guo-hua; GONG Zhi-yun; TANG Shu-zhu; GU Ming-hong

    2008-01-01

    Genomic in situ hybridization (GISH) is a powerful tool to characterize parental chromosomes in interspecific hybrids, including the behaviour of autosynapsis and chromosome paidng. It was used to distinguish the chromosomes of Oryza sativa from wild species in a spontaneous interspecific hybdd and to investigate the chromosome pairing at metaphase I in meiosis of the hybdd in this study. The hybrid was a triploid with 36 chromosomes according to the chromosome nurnber investigated in mitosis of root tips. During metaphase I of meiosis in the hybrid, less chromosome pairing was observed and most of the chromosomes existed as univalent. Based on GISH and FISH (Fluorescent in situ hybridization) analyses, the chromosomes of the hybrid were composed of genomes A, B and C. Thus, it was believed that the hybrid was the result of natural hybridization between cultivated rice and wild species O. minuta which was planted in experimental fields.

  8. Molecular Cytogenetic Analysis of Spontaneous Interspecific Hybrid Between Oryza sativa and Oryza minuta

    Directory of Open Access Journals (Sweden)

    Chuan-deng YI

    2008-12-01

    Full Text Available Genomic in situ hybridization (GISH is a powerful tool to characterize parental chromosomes in interspecific hybrids, including the behaviour of autosynapsis and chromosome pairing. It was used to distinguish the chromosomes of Oryza sativa from wild species in a spontaneous interspecific hybrid and to investigate the chromosome pairing at metaphase I in meiosis of the hybrid in this study. The hybrid was a triploid with 36 chromosomes according to the chromosome number investigated in mitosis of root tips. During metaphase I of meiosis in the hybrid, less chromosome pairing was observed and most of the chromosomes existed as univalent. Based on GISH and FISH (Fluorescent in situ hybridization analyses, the chromosomes of the hybrid were composed of genomes A, B and C. Thus, it was believed that the hybrid was the result of natural hybridization between cultivated rice and wild species O. minuta which was planted in experimental fields.

  9. The Lesser of Two Weevils: Molecular-Genetics of Pest Palm Weevil Populations Confirm Rhynchophorus vulneratus (Panzer 1798) as a Valid Species Distinct from R. ferrugineus (Olivier 1790), and Reveal the Global Extent of Both

    OpenAIRE

    Rugman-Jones, Paul F.; Christina D Hoddle; Mark S Hoddle; Richard Stouthamer

    2013-01-01

    The red palm weevil (RPW) is a major pest of palms. It is native to southeast Asia and Melanesia, but in recent decades has vastly expanded its range as the result of multiple accidental anthropogenic introductions into the Middle East, Mediterranean Basin, Caribbean, and U.S.A. Currently regarded as a single species, Rhynchophorus ferrugineus (Olivier), RPW displays remarkable color variation across its range, and consequently has a taxonomic history littered with new species descriptions an...

  10. Action of amorphous diatomaceous earth against different stages of the stored product pests Tribolium confusum, Tenebrio molitor, Sitophilus granarius and Plodia interpunctella.

    Science.gov (United States)

    Mewis; Ulrichs

    2001-04-01

    Environmental and human health problems associated with the use of synthetic pesticides have prompted the demand for non-polluting, biologically specific insecticides. The current study tested the use and action of diatomaceous earth against several stored product pests. Fossil Shield(R) applied to wooden plates was lethal to adult Tenebrio molitor and Tribolium confusum, but larvae of the mealworm were unaffected. Beetles died within 14 days exposure in the absence of food to a dose of 2 and 4 g/m(2), but mortality was reduced in those fed grain bran. Fossil Shield(R) was lethal to first instar larvae of Plodia interpunctella, but not lethal to older larval stages. Two-week old larvae of T. confusum were more sensitive to diatomaceous earth than P. interpunctella at the same age. Contact with diatomaceous earth caused adult Sitophilus granarius, T. molitor and T. confusum to lose weight and reduced their water content, suggesting disruption of "the water barrier". Death of stored product insects treated with diatomaceous earth decreased with increased r.h., due to reduced transpiration through the cuticle. High r.h. delays, or above 60% can prevent, the drying action of diatomaceous earth.

  11. Identification and functional characterization of small non-coding RNAs in Xanthomonas oryzae pathovar oryzae

    Directory of Open Access Journals (Sweden)

    Zhang Jie-Qiong

    2011-01-01

    Full Text Available Abstract Background Small non-coding RNAs (sRNAs are regarded as important regulators in prokaryotes and play essential roles in diverse cellular processes. Xanthomonas oryzae pathovar oryzae (Xoo is an important plant pathogenic bacterium which causes serious bacterial blight of rice. However, little is known about the number, genomic distribution and biological functions of sRNAs in Xoo. Results Here, we performed a systematic screen to identify sRNAs in the Xoo strain PXO99. A total of 850 putative non-coding RNA sequences originated from intergenic and gene antisense regions were identified by cloning, of which 63 were also identified as sRNA candidates by computational prediction, thus were considered as Xoo sRNA candidates. Northern blot hybridization confirmed the size and expression of 6 sRNA candidates and other 2 cloned small RNA sequences, which were then added to the sRNA candidate list. We further examined the expression profiles of the eight sRNAs in an hfq deletion mutant and found that two of them showed drastically decreased expression levels, and another exhibited an Hfq-dependent transcript processing pattern. Deletion mutants were obtained for seven of the Northern confirmed sRNAs, but none of them exhibited obvious phenotypes. Comparison of the proteomic differences between three of the ΔsRNA mutants and the wild-type strain by two-dimensional gel electrophoresis (2-DE analysis showed that these sRNAs are involved in multiple physiological and biochemical processes. Conclusions We experimentally verified eight sRNAs in a genome-wide screen and uncovered three Hfq-dependent sRNAs in Xoo. Proteomics analysis revealed Xoo sRNAs may take part in various metabolic processes. Taken together, this work represents the first comprehensive screen and functional analysis of sRNAs in rice pathogenic bacteria and facilitates future studies on sRNA-mediated regulatory networks in this important phytopathogen.

  12. Pathotype and genetic diversity amongst Indian isolates of Xanthomonas oryzae pv. oryzae.

    Directory of Open Access Journals (Sweden)

    Deo Mishra

    Full Text Available A number of rice resistance genes, called Xa genes, have been identified that confer resistance against various strains of Xanthomonas oryzae pv. oryzae (Xoo, the causal agent of bacterial blight. An understanding of pathotype diversity within the target pathogen population is required for identifying the Xa genes that are to be deployed for development of resistant rice cultivars. Among 1024 isolates of Xoo collected from 20 different states of India, 11 major pathotypes were distinguished based on their reaction towards ten Xa genes (Xa1, Xa3, Xa4, xa5, Xa7, xa8, Xa10, Xa11, xa13, Xa21. Isolates belonging to pathotype III showing incompatible interaction towards xa8, xa13 and Xa21 and compatible interaction towards the rest of Xa genes formed the most frequent (41% and widely distributed pathotype. The vast majority of the assayed Xoo isolates were incompatible with one or more Xa genes. Exceptionally, the isolates of pathotype XI were virulent on all Xa genes, but have restricted distribution. Considering the individual R-genes, Xa21 appeared as the most broadly effective, conferring resistance against 88 % of the isolates, followed in decreasing order by xa13 (84 %, xa8 (64 %, xa5 (30 %, Xa7 (17 % and Xa4 (14 %. Fifty isolates representing all the eleven pathotypes were analyzed by southern hybridization to determine their genetic relatedness using the IS1112 repeat element of Xoo. Isolates belonging to pathotype XI were the most divergent. The results suggest that one RFLP haplotype that is widely distributed all over India and is represented in strains from five different pathotypes might be an ancestral haplotype. A rice line with xa5, xa13 and Xa21 resistance genes is resistant to all strains, including those belonging to pathotype XI. This three gene combination appears to be the most suitable Xa gene combination to be deployed in Indian rice cultivars.

  13. Identification of genes required for nonhost resistance to Xanthomonas oryzae pv. oryzae reveals novel signaling components.

    Directory of Open Access Journals (Sweden)

    Wen Li

    Full Text Available BACKGROUND: Nonhost resistance is a generalized, durable, broad-spectrum resistance exhibited by plant species to a wide variety of microbial pathogens. Although nonhost resistance is an attractive breeding strategy, the molecular basis of this form of resistance remains unclear for many plant-microbe pathosystems, including interactions with the bacterial pathogen of rice, Xanthomonas oryzae pv. oryzae (Xoo. METHODS AND FINDINGS: Virus-induced gene silencing (VIGS and an assay to detect the hypersensitive response (HR were used to screen for genes required for nonhost resistance to Xoo in N. benthamiana. When infiltrated with Xoo strain YN-1, N. benthamiana plants exhibited a strong necrosis within 24 h and produced a large amount of H(2O(2 in the infiltrated area. Expression of HR- and defense-related genes was induced, whereas bacterial numbers dramatically decreased during necrosis. VIGS of 45 ACE (Avr/Cf-elicited genes revealed identified seven genes required for nonhost resistance to Xoo in N. benthamiana. The seven genes encoded a calreticulin protein (ACE35, an ERF transcriptional factor (ACE43, a novel Solanaceous protein (ACE80, a hydrolase (ACE117, a peroxidase (ACE175 and two proteins with unknown function (ACE95 and ACE112. The results indicate that oxidative burst and calcium-dependent signaling pathways play an important role in nonhost resistance to Xoo. VIGS analysis further revealed that ACE35, ACE80, ACE95 and ACE175, but not the other three ACE genes, interfered with the Cf-4/Avr4-dependent HR. CONCLUSIONS/SIGNIFICANCE: N. benthamiana plants inoculated with Xoo respond by rapidly eliciting an HR and nonhost resistance. The oxidative burst and other signaling pathways are pivotal in Xoo-N. benthamiana nonhost resistance, and genes involved in this response partially overlap with those involved in Cf/Avr4-dependent HR. The seven genes required for N. benthamiana-mediated resistance to Xoo provide a basis for further dissecting

  14. Leptographium bhutanense sp. nov., associated with the root collar weevil Hylobitelus chenkupdorjii on Pinus wallichiana in Bhutan.

    Science.gov (United States)

    Zhou, X D; Jacobs, K; Kirisits, T; Chhetri, D B; Wingfield, M J

    2008-12-01

    Leptographium spp. are commonly associated with bark beetles and weevils (Coleoptera: Curculionidae), and some are important tree pathogens. In a recent survey of diseases and insect pests of conifer trees in Bhutan, the root collar weevil, Hylobitelus chenkupdorjii was found girdling young Himalayan blue pine (Pinus wallichiana) trees in Central Bhutan. Intensive wood staining and a Leptographium sp. were associated with damage by this insect. The fungus was also isolated from individuals of H. chenkupdorjii. It was tentatively identified based on morphology and then compared with other Leptographium spp. using DNA sequences for three gene regions. Morphological characteristics showed that the Leptographium sp. from H. chenkupdorjii is similar to, but distinct from L. procerum and L. profanum. DNA sequence comparisons revealed that the isolates from Bhutan resided in a distinct well-supported clade and confirmed that they represent an undescribed taxon for which the name Leptographium bhutanense sp. nov. is provided.

  15. EVALUATION OF NATURAL ENEMIES IN CONTROLLING OF THE BANANA WEEVIL BORER Cosmopolites sordidus Germar IN WEST SUMATRA

    Directory of Open Access Journals (Sweden)

    Ahsol Hasyim

    2016-10-01

    Full Text Available The banana weevil, Cosmopolites sordidus Germar, is an important pest of highland banana and plantain in Africa, but it exists in low densities in presumed area of origin in Southeast Asia such as in Indonesia. This suggests a possible existence of effective co-evolved natural enemies in the origin area of Indonesia, especially West Sumatra. The objectives of this study were: (1 to evaluate banana weevil pest status at selected sites in West Sumatra, (2 to survey parasitoids and predators, and (3 to determine the control potential of the most important natural enemies. Surveys were undertaken in March 2002-August 2003 in five locations in West Sumatra, i.e., Bukittinggi, Sitiung, Pariaman, Pasaman, and Batusangkar. Five farms per site were selected randomly among all farms that contained banana stands of > 0.5 ha. Sampling for banana weevil adults and damage, and for predators was done throughout small banana stands and within a 20 m x 40 m (0.08 ha subplot on larger farms. Field-collected larvae were taken to the laboratory and reared on corm pieces (3 cm x 3 cm x 3 cm until pupation. Larvae were collected from pseudostem as well as corm residues. To estimate the abundance of non-social predators, i.e., those other than ants, 10 residues each on each farm were examined from plants that had been harvested 1-4 weeks, 5-8 weeks or 9 or more weeks before our visit to the site. Samples of the different morphospecies were saved in alcohol for later identification. The result showed that the banana weevil incidence was found to be low,  0.6-1.7 adults per trap. Plant damage indices were below 2.2%. We collected and reared 24,360 eggs and 3118 larvae, but no parasitism was detected. Phorids (Megaselia sp. and drosophilids were recovered from larval rearings, but most likely were scavengers. A complex of predators was detected, the most important of which was the histerid beetles,  Plaesius javanus Erichson. In laboratory tests, adults and larvae

  16. Kinetics of alpha-amylase secretion in Aspergillus oryzae

    DEFF Research Database (Denmark)

    Henriksen, Anne Laurence Santerre; Carlsen, Morten; Bang de, H.

    1999-01-01

    Pulse and pulse-chase experiments have been performed to study L-[S-35] methionine incorporation and protein secretion kinetics in Aspergillus oryzae. Pulse experiments confirmed the mechanism of methionine uptake reported previously for Penicillium chrysogenum (Benko et al., 1967). Pulse...

  17. The Population Structure of African Cultivated Rice Oryza glaberrima (Steud.)

    DEFF Research Database (Denmark)

    Semon, Mande; Nielsen, Rasmus; Jones, Monty P.;

    2005-01-01

    Genome-wide linkage disequilibrium (LD) was investigated for 198 accessions of Oryza glaberrima using 93 nuclear microsatellite markers. Significantly elevated levels of LD were detected, even among distantly located markers. Free recombination among loci at the population genetic level was shown...

  18. Bipolaris oryzae, a novel fungal opportunist causing keratitis

    NARCIS (Netherlands)

    Al-Hatmi, Abdullah

    2015-01-01

    We report a case of mycotic keratitis caused by Bipolaris oryzae with predisposing trauma from a foreign body. The fungus was identified by sequencing the internal transcribed spacer (ITS) region, translation elongation factor 1α (TEF1) gene and partial glyceraldehyde-3-phosphate dehydrogenase (GPDH

  19. Study on the structures of papilla of lemma in Oryza

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Structures of papilla of lemma among 23 Oryza species were investigated and classified into 6 kinds by scanning electron microscopy. The lemma surface was composed of papilla pedestals with multi-row longitudinal ordered arrangements and the papilla was inserted into pedestal. The morphology and characterization of papilla varied among species.

  20. CBS domain-containing proteins are Rhizopus oryzae ferrioxamine receptors

    Science.gov (United States)

    Background: Iron-overload patients treated with deferoxamine are uniquely susceptible to mucormycosis, because Rhizopus spp. can obtain iron from ferrioxamine (deferoxamine + Fe**3+). Previously we have identified two closely related, ferrioxamine-inducible R. oryzae genes (FOB1 and FOB2) in which ...

  1. Biofunctional constituent isolated from Citrullus colocynthis fruits and structure-activity relationships of its analogues show acaricidal and insecticidal efficacy.

    Science.gov (United States)

    Jeon, Ju-Hyun; Lee, Hoi-Seon

    2014-08-27

    The acaricidal and insecticidal potential of the active constituent isolated from Citrullus colocynthis fruits and its structurally related analogues was evaluated by performing leaf disk, contact toxicity, and fumigant toxicity bioassays against Tetranychus urticae, Sitophilus oryzae, and Sitophilus zeamais adults. The active constituent of C. colocynthis fruits was isolated by chromatographic techniques and was identified as 4-methylquinoline on the basis of spectroscopic analyses. To investigate the structure-activity relationships, 4-methylquinoline and its structural analogues were tested against mites and two insect pests. On the basis of the LC50 values, 7,8-benzoquinoline was the most effective against T. urticae. Quinoline, 8-hydroxyquinoline, 2-methylquinoline, 4-methylquinoline, 6-methylquinoline, 8-methylquinoline, and 7,8-benzoquinoline showed high insecticidal activities against S. oryzae and S. zeamais regardless of the application method. These results indicate that introduction of a functional group into the quinoline skeleton and changing the position of the group have an important influence on the acaricidal and insecticidal activities. Furthermore, 4-methylquinoline isolated from C. colocynthis fruits, along with its structural analogues, could be effective natural pesticides for managing spider mites and stored grain weevils.

  2. Pepper Weevil (Coleoptera: Curculionidae) Preferences for Specific Pepper Cultivars, Plant Parts, Fruit Colors, Fruit Sizes, and Timing

    OpenAIRE

    Dakshina R. Seal; Martin, Cliff G.

    2016-01-01

    Peppers (Capsicum spp.) are an important crop in the USA, with about 32,000 ha cultivated in 2007, which resulted in $588 million in farm revenue. The pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae), is the most troublesome insect pest of peppers in the southern United States. It is therefore urgent to find different vulnerabilities of pepper cultivars, fruit and plants parts, fruit colors and sizes, and timing to infestation by A. eugenii. Also relevant is testing whether ...

  3. Pepper Weevil (Coleoptera: Curculionidae) Preferences for Specific Pepper Cultivars, Plant Parts, Fruit Colors, Fruit Sizes, and Timing

    OpenAIRE

    Seal, Dakshina R.; Cliff G. Martin

    2016-01-01

    Peppers (Capsicum spp.) are an important crop in the USA, with about 32,000 ha cultivated in 2007, which resulted in $588 million in farm revenue. The pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae), is the most troublesome insect pest of peppers in the southern United States. It is therefore urgent to find different vulnerabilities of pepper cultivars, fruit and plants parts, fruit colors and sizes, and timing to infestation by A. eugenii. Also relevant is testing whether ...

  4. Curculio Curculis lupus: biology, behavior and morphology of immatures of the cannibal weevil Anchylorhynchus eriospathae G. G. Bondar, 1943

    Science.gov (United States)

    Bená, Daniela de Cássia; Vanin, Sergio Antonio

    2014-01-01

    Weevils are one of the largest groups of living organisms, with more than 60,000 species feeding mostly on plants. With only one exception, their described larvae are typical plant-feeders, with mouthparts adapted to chewing plant material. Here we describe the second case of a weevil with early-instar larvae adapted to killing conspecifics. We have studied the life history of Anchylorhynchus eriospathae G. G. Bondar, 1943 (Curculioninae: Derelomini sensu Caldara, Franz & Oberprieler (2014)), a species whose immatures feed internally on palm flowers and fruits. We provide detailed descriptions of all immature stages, including the extremely modified first-instar larva. Unlike other weevils and later instars, this stage exhibits a flat body with very long ventropedal lobe setae, a large and prognathous head with a gula, and falciform mandibles, each with a serrate retinaculum, that are used to fight with and eventually kill other first-instar larvae. We also provide biological notes on all stages and the results of behavioral tests that showed that larval aggression occurs only among early life stages. Finally we show that adult size is highly dependent on timing of oviposition. This specialized killer first instar probably evolved independently from the one other case known in weevils, in Revena rubiginosa (Conoderinae: Bariditae sensu Prena, Colonnelli & Hespenheide (2014)). Interestingly, both lineages inhabit the same hosts, raising the possibility that both intra- and inter-specific competition shaped those phenotypes. Given the scarcity of knowledge on early larval stages of concealed insect herbivores, it is possible that our findings represent an instance of a much broader phenomenon. Our observations also allowed us to conclude that Anchylorhynchus eriospathae and A. hatschbachi G. G. Bondar, 1943 are actually the same species, which we synonymize here by considering the latter as a junior synonym (new synonymy). PMID:25101231

  5. Effect of Light Availability on the Interaction between Maritime Pine and the Pine Weevil: Light Drives Insect Feeding Behavior But Also the Defensive Capabilities of the Host

    Directory of Open Access Journals (Sweden)

    Estefanía Suárez-Vidal

    2017-08-01

    Full Text Available Light is a major environmental factor that may determine the interaction between plants and herbivores in several ways, including top-down effects through changes in herbivore behavior and bottom-up effects mediated by alterations of plant physiology. Here we explored the relative contribution of these two regulation processes to the outcome of the interaction of pine trees with a major forest pest, the pine weevil (Hylobius abietis. We studied to what extent light availability influence insect feeding behavior and/or the ability of pines to produce induced defenses in response to herbivory. For this purpose, 3-year old Pinus pinaster plants from three contrasting populations were subjected to 6 days of experimental herbivory by the pine weevil under two levels of light availability (complete darkness or natural sunlight independently applied to the plant and to the insect in a fully factorial design. Light availability strongly affected the pine weevil feeding behavior. The pine weevil fed more and caused larger feeding scars in darkness than under natural sunlight. Besides, under the more intense levels of weevil damage (i.e., those registered with insects in darkness, light availability also affected the pine’s ability to respond to insect feeding by producing induced resin defenses. These results were consistent across the three studied populations despite they differed in weevil susceptibility and inducibility of defenses. Morocco was the most damaged population and the one that induced more defensive compounds. Overall, results indicate that light availability modulates the outcome of the pine–weevil interactions through both bottom-up and top-down regulation mechanisms.

  6. Oviposition Preference of Pea Weevil, Bruchus pisorum L. Among Host and Non-host Plants and its Implication for Pest Management.

    Science.gov (United States)

    Mendesil, Esayas; Rämert, Birgitta; Marttila, Salla; Hillbur, Ylva; Anderson, Peter

    2015-01-01

    The pea weevil, Bruchus pisorum L. is a major insect pest of field pea, Pisum sativum L. worldwide and current control practices mainly depend on the use of chemical insecticides that can cause adverse effects on environment and human health. Insecticides are also unaffordable by many small-scale farmers in developing countries, which highlights the need for investigating plant resistance traits and to develop alternative pest management strategies. The aim of this study was to determine oviposition preference of pea weevil among P. sativum genotypes with different level of resistance (Adet, 32410-1 and 235899-1) and the non-host leguminous plants wild pea (Pisum fulvum Sibth. et Sm.) and grass pea (Lathyrus sativus L.), in no-choice and dual-choice tests. Pod thickness and micromorphological traits of the pods were also examined. In the no-choice tests significantly more eggs were laid on the susceptible genotype Adet than on the other genotypes. Very few eggs were laid on P. fulvum and L. sativus. In the dual-choice experiments Adet was preferred by the females for oviposition. Furthermore, combinations of Adet with either 235899-1 or non-host plants significantly reduced the total number of eggs laid by the weevil in the dual-choice tests. Female pea weevils were also found to discriminate between host and non-host plants during oviposition. The neoplasm (Np) formation on 235899-1 pods was negatively correlated with oviposition by pea weevil. Pod wall thickness and trichomes might have influenced oviposition preference of the weevils. These results on oviposition behavior of the weevils can be used in developing alternative pest management strategies such as trap cropping using highly attractive genotype and intercropping with the non-host plants.

  7. Evaluation of the Boll Weevil Anthonomus grandis Boheman (Coleoptera: Curculionidae) suppression program in the state of Goiás, Brazil.

    Science.gov (United States)

    de Lima, I S; Degrande, P E; Miranda, J E; dos Santos, W J

    2013-02-01

    The boll weevil Anthonomus grandis Boheman (Coleoptera: Curculionidae) is the most important cotton pest in Brazil. A large-scale field-testing of a Boll Weevil Suppression Program (BWSP) was implemented to assess its technical and operational feasibility for boll weevil suppression in the state of Goiás, Brazil. The pilot plan focused on 3,608 ha of cotton during the 2006/2007 and 6,011 ha in the 2007/2008 growing seasons; the areas were divided into four inner zones with an outer buffer zone. We analyzed data on boll weevil captures using pheromone traps installed in the BWSP fields, on the detection of the first insect and the first damaged floral bud, greatest damage, and number of insecticide applications. The nonparametric Mann-Whitney U test was used to evaluate the differences between presuppression and suppression years. Fourteen pheromone-baited trapping evaluations were used to compare the weevil populations from 2006/2007 and 2007/2008 growing seasons. The BWSP regime reduced in-season boll weevil captures from 15- to 500-fold compared to presuppression levels in the preceding year. The low capture rates were related to delays in infestation and damage by weevils. The smaller population size measured by trapping and field monitoring reduced the number of required insecticide treatments. The BWSP strategy was efficient in suppressing populations of this pest and is a viable program for cotton production in subtropical and tropical regions, with long-term economic and environmental benefits.

  8. Oviposition preference of pea weevil, Bruchus pisorum L. among host and non-host plants and its implication for pest management

    Directory of Open Access Journals (Sweden)

    Esayas Mendesil eAmosa

    2016-01-01

    Full Text Available The pea weevil, Bruchus pisorum L. is a major insect pest of field pea, Pisum sativum L. worldwide and current control practices mainly depend on the use of chemical insecticides that can cause adverse effects on environment and human health. Insecticides are also unaffordable by many small-scale farmers in developing countries, which highlights the need for investigating plant resistance traits and to develop alternative pest management strategies. The aim of this study was to determine oviposition preference of pea weevil among P. sativum genotypes with different level of resistance (Adet, 32410-1 and 235899-1 and the non-host leguminous plants wild pea (Pisum fulvum Sibth. et Sm. and grass pea (Lathyrus sativus L., in no-choice and dual-choice tests. Pod thickness and micromorphological traits of the pods were also examined. In the no-choice tests significantly more eggs were laid on the susceptible genotype Adet than on the other genotypes. Very few eggs were laid on P. fulvum and L. sativus. In the dual-choice experiments Adet was preferred by the females for oviposition. Furthermore, combinations of Adet with either 235899-1 or non-host plants significantly reduced the total number of eggs laid by the weevil in the dual-choice tests. Female pea weevils were also found to discriminate between host and non-host plants during oviposition. The neoplasm (Np formation on 235899-1 pods was negatively correlated with oviposition by pea weevil. Pod wall thickness and trichomes might have influenced oviposition preference of the weevils. These results on oviposition behavior the weevils can be used in developing alternative pest management strategies such as trap cropping using highly attractive genotype and intercropping with the non-host plants.

  9. ESTUDOS NUTRICIONAIS COM ARROZ (Oryza sativa, L.

    Directory of Open Access Journals (Sweden)

    Alfredo LAM-SÁNCHEZ

    2009-07-01

    Full Text Available

    RESUMO: Estudos com arroz (Oryza sativa, L. foram realizados a fim de determinar a variabilidade do teor de proteína em coleções de cultivares e a possibilidade de utilizar as camadas periféricas do grão na alimentação humana. Foram analisadas 626 linhagens e cultivares de arroz que mostraram uma variação quanto ao teor de proteína de 4.00 a 14.31 g/100 g de amostra. Para se extrair as camadas periféricas do grão, foi desenvolvida uma máquina experimental, que removia as camadas superficiais dos grãos de arroz integral (inteiros somente com a casca removida. Verificou-se que a quantidade de proteína do grão diminui de fora para dentro. O resíduo, que era constituído de grande parte de restos de endosperma com um teor protéico menor mas incluía o embrião, que é a primeira estrutura a se deslocar de grão no beneficiamento e contém proteínas, vitaminas, sais minerais e lípides, tinha um bom valor nutritivo. Desenvolveu-se também uma fórmula para alimentação infantil a partir da mistura de leite de vaca com arroz, com composição semelhante à do leite materno, a ser utilizada sob a forma de bebida ou mingau. Formulações com 40%-20% arroz + 60%-80% leite de vaca proporcionaram valores de Coeficiente de Eficiência Protéica (2,39 e 2,38, respectivamente que não diferiam estatisticamente do valor de 2,43 obtido na fórmula com 100% de leite de vaca. Seus preços foram 59% e 65% do obtido para o leite de vaca integral. PALAVRAS-CHAVE: Arroz; qualidade do grão; proteína; camadas periféricas; misturas arroz-leite; nutrição humana.

  10. Use of the entomopathogenic nematode Heterorhabditis atacamensis CIA- NE07 in the control of banana weevil Cosmopolites sordidus in vitro

    Directory of Open Access Journals (Sweden)

    Marianela Amador

    2015-11-01

    Full Text Available Among the species of banana borers, black weevil (Cosmopolites sordidus is the most economically important pest in Costa Rica and worldwide. The control of C. sordidus in intensive production systems is mainly based on application of insecticides; therefore the search for biological alternatives, such as the use of entomopathogenic nematodes (EPN, is needed. The susceptibility of Cosmopolites sordidus to Heterorhabditis atacamensis CIANE07 was evaluated. The effect of inoculating H. atacamensis on larvae and adults of C. sordidus, in vitro and in artificially infected corms, was evaluated. Larvae inoculated with EPN had a mortality of 88% on the second day and 100% on the third day; no mortality was observed in adults. The treatments of 100, 500 and 1000 IJ.larvae-1 showed statistically significant differences from the control and theLD50 was 52 IJ.larvae-1. When the larvae were placed within the corms the LD50 increased to 375 IJ.larvae-1. The results indicate that the strain H. atacamensis CIA-NE07 is capable of locating and infecting weevil larvae within the banana corm and reach infection levels over 80%, 10 days after inoculation at doses of 1000 and 2000 IJ.larvae-1. The entomopathogenic nematodes are a viable alternative to be considered in the Integrated Pest Management programs of black weevil, in crops such us banana and plantain.

  11. Genetic variability and resistance of cultivars of cowpea [Vigna unguiculata (L.) Walp] to cowpea weevil (Callosobruchus maculatus Fabr.).

    Science.gov (United States)

    Vila Nova, M X; Leite, N G A; Houllou, L M; Medeiros, L V; Lira Neto, A C; Hsie, B S; Borges-Paluch, L R; Santos, B S; Araujo, C S F; Rocha, A A; Costa, A F

    2014-03-31

    The cowpea weevil (Callosobruchus maculatus Fabr.) is the most destructive pest of the cowpea bean; it reduces seed quality. To control this pest, resistance testing combined with genetic analysis using molecular markers has been widely applied in research. Among the markers that show reliable results, the inter-simple sequence repeats (ISSRs) (microsatellites) are noteworthy. This study was performed to evaluate the resistance of 27 cultivars of cowpea bean to cowpea weevil. We tested the resistance related to the genetic variability of these cultivars using ISSR markers. To analyze the resistance of cultivars to weevil, a completely randomized test design with 4 replicates and 27 treatments was adopted. Five pairs of the insect were placed in 30 grains per replicate. Analysis of variance showed that the number of eggs and emerged insects were significantly different in the treatments, and the means were compared by statistical tests. The analysis of the large genetic variability in all cultivars resulted in the formation of different groups. The test of resistance showed that the cultivar Inhuma was the most sensitive to both number of eggs and number of emerged adults, while the TE96-290-12-G and MNC99-537-F4 (BRS Tumucumaque) cultivars were the least sensitive to the number of eggs and the number of emerged insects, respectively.

  12. ANTAGONISTIC ACTIVITY OF SERRATIA MARCESCENS AGAINST PYRICULARIA ORYZAE

    Directory of Open Access Journals (Sweden)

    V. JAIGANESH

    2007-08-01

    Full Text Available Rice is an important crop, widely affected by quite a number of diseases that results in higher yield losses. Among the fungal diseases, blast incited by Pyricularia oryzae is a major disease. The biological method of plant disease management seems to be an alternative to chemical fungicides in managing the blast disease. A new bio control agent viz., Serratia marcescens appears to be an ideal agent for the control of P. oryzae, because it produces chitinolytic enzymes which causes degradation of the fungal cell walls, induction of plant defence reaction and certain antifungal low molecular weight molecules. A study was undertaken to investigate the effect of a new bio control agent like S. marcescens against P. oryzae. The talc based formulation of S. marcescens (@ 1.0, 1.5, 2.0 and 2.5 kg/ha was sprayed on old IR 50 rice plants in fields. Out of the six-bio protectants tested, S. marcescens was found very effective against P. oryzae under in vitro conditions. S. marcescens could be isolated from shoots as well as roots emerging from the treated seeds and the plant parts from treated seeds inhibited P. oryzae. The antagonist S. marcescens survived in the phyllosphere even 80 days after spray. The results revealed that rice blast control was achieved by spraying S. marcescens @ 1.0 kg/ha. The increasing dose of talc-based inoculum when applied on foliage increased the phyllosphere population of S. marcescens and controlled rice blast. The maximum disease control was achieved when inoculum was applied at 2.5 kg/ha.

  13. STANDARDIZING THE EXTRACTION AND EVALUATION OF ANTIMICROBIAL FRACTION FROM STREPTOMYCES SP. TC1 AGAINST XANTHOMONAS ORYZAE PV. ORYZAE

    Directory of Open Access Journals (Sweden)

    NANJUNDAN JAIVEL*, RAMASAMY RAJESH AND PONNUSAMY MARIMUTHU

    2014-08-01

    Full Text Available Streptomyces are prokaryotic microorganisms capable of producing a wide range of secondary metabolites has the capacity to fight with the competing plant pathogens and suppress the growth of them. A promising Streptomyces sp. TC1 isolate exhibited antimicrobial activity against bacterial leaf blight pathogen Xanthomonas oryzae pv. oryzae under in vitro conditions. The antimicrobial activity of TC1 culture filtrate was found to be higher at seven days of incubation. The optimized extraction of antimicrobial fractions from the culture filtrate was obtained with ethyl acetate solvent. Adjusting the pH of the culture filtrate to 3 prior to extraction process resulted in increased recovery of antimicrobial fractions. The crude antimicrobial fraction obtained from the TC1 fermentation broth exhibited a minimum inhibitory concentration value of 300 µg/ml against the test pathogen Xanthomonas oryzae pv. oryzae. The antimicrobial activity results including agar well diffusion assay and MIC experiments strongly recommend that the Streptomyces sp. TC1 can be explored for antimicrobial metabolites for bacterial blight disease control in rice.

  14. Transposable element distribution, abundance and role in genome size variation in the genus Oryza.

    Science.gov (United States)

    Zuccolo, Andrea; Sebastian, Aswathy; Talag, Jayson; Yu, Yeisoo; Kim, HyeRan; Collura, Kristi; Kudrna, Dave; Wing, Rod A

    2007-08-29

    The genus Oryza is composed of 10 distinct genome types, 6 diploid and 4 polyploid, and includes the world's most important food crop - rice (Oryza sativa [AA]). Genome size variation in the Oryza is more than 3-fold and ranges from 357 Mbp in Oryza glaberrima [AA] to 1283 Mbp in the polyploid Oryza ridleyi [HHJJ]. Because repetitive elements are known to play a significant role in genome size variation, we constructed random sheared small insert genomic libraries from 12 representative Oryza species and conducted a comprehensive study of the repetitive element composition, distribution and phylogeny in this genus. Particular attention was paid to the role played by the most important classes of transposable elements (Long Terminal Repeats Retrotransposons, Long interspersed Nuclear Elements, helitrons, DNA transposable elements) in shaping these genomes and in their contributing to genome size variation. We identified the elements primarily responsible for the most strikingly genome size variation in Oryza. We demonstrated how Long Terminal Repeat retrotransposons belonging to the same families have proliferated to very different extents in various species. We also showed that the pool of Long Terminal Repeat Retrotransposons is substantially conserved and ubiquitous throughout the Oryza and so its origin is ancient and its existence predates the speciation events that originated the genus. Finally we described the peculiar behavior of repeats in the species Oryza coarctata [HHKK] whose placement in the Oryza genus is controversial. Long Terminal Repeat retrotransposons are the major component of the Oryza genomes analyzed and, along with polyploidization, are the most important contributors to the genome size variation across the Oryza genus. Two families of Ty3-gypsy elements (RIRE2 and Atlantys) account for a significant portion of the genome size variations present in the Oryza genus.

  15. Transposable element distribution, abundance and role in genome size variation in the genus Oryza

    Directory of Open Access Journals (Sweden)

    Collura Kristi

    2007-08-01

    Full Text Available Abstract Background The genus Oryza is composed of 10 distinct genome types, 6 diploid and 4 polyploid, and includes the world's most important food crop – rice (Oryza sativa [AA]. Genome size variation in the Oryza is more than 3-fold and ranges from 357 Mbp in Oryza glaberrima [AA] to 1283 Mbp in the polyploid Oryza ridleyi [HHJJ]. Because repetitive elements are known to play a significant role in genome size variation, we constructed random sheared small insert genomic libraries from 12 representative Oryza species and conducted a comprehensive study of the repetitive element composition, distribution and phylogeny in this genus. Particular attention was paid to the role played by the most important classes of transposable elements (Long Terminal Repeats Retrotransposons, Long interspersed Nuclear Elements, helitrons, DNA transposable elements in shaping these genomes and in their contributing to genome size variation. Results We identified the elements primarily responsible for the most strikingly genome size variation in Oryza. We demonstrated how Long Terminal Repeat retrotransposons belonging to the same families have proliferated to very different extents in various species. We also showed that the pool of Long Terminal Repeat Retrotransposons is substantially conserved and ubiquitous throughout the Oryza and so its origin is ancient and its existence predates the speciation events that originated the genus. Finally we described the peculiar behavior of repeats in the species Oryza coarctata [HHKK] whose placement in the Oryza genus is controversial. Conclusion Long Terminal Repeat retrotransposons are the major component of the Oryza genomes analyzed and, along with polyploidization, are the most important contributors to the genome size variation across the Oryza genus. Two families of Ty3-gypsy elements (RIRE2 and Atlantys account for a significant portion of the genome size variations present in the Oryza genus.

  16. Molecular and Morphological Tools to Distinguish Scyphophorus acupunctatus Gyllenhal, 1838 (Curculionidae: Dryophthorinae): A New Weevil Pest of the Endangered Century Plant, Agave eggersiana from St. Croix, U.S. Virgin Islands

    Science.gov (United States)

    M. Lourdes Chamorro; Joshua Persson; Christian W. Torres-Santana; Jeff Keularts; Sonja J. Scheffer; Matthew L. Lewis

    2016-01-01

    The agave snout weevil (AGW) or sisal weevil, Scyphophorus acupunctatus Gyllenhal is here reported for the first time in St. Croix, U.S. Virgin Islands (USVI) where it threatens Agave eggersiana Trel., a USVI endemic and endangered century-plant. We provide molecular, morphological, and behavioral characters to successfully distinguish the two known Scyphophorus...

  17. Effect of different factors on the induced resistance of Xanthomonas oryzae pv. oryzae and relationship between the effect and active oxygen metabolism in rice seedling leaves

    Institute of Scientific and Technical Information of China (English)

    ZENGFuhua; WUYuexuan; LUOZemin

    1999-01-01

    We studied the relationship between the resistance to Xanthomonas oryzae pv, oryzae (XOO) and active oxygen species (AOS).Materials used were Yushuinuo (high resistant) and Zhefu 802 (high susceptible).Paraquat (PQ) specially generated superoxide anion (O2 ) and Tiron (4, 5-dihydroxy-1.3-benzenedisufonic acid).

  18. The potential for biocontrol in stored products in general, with specific attention to application of parasitoids against Sitophilus granarius in grains stores at low temperatures

    DEFF Research Database (Denmark)

    Hansen, Lise Stengård

    : This presentation will give an overview of the current state of biocontrol in stored products. An EU-funded COST Action Working Group, active during 2000-2006. evaluated the possibilities in different sectors: grain stores, mills and bakeries, pasta factories, stored nuts and dried fruit, etc. Three situations were...... identified with the greatest potential for widespread application: (1) empty room treatment against mites, beetles and moths, (2) treatment of bulk commodities against Sitophilus spp. and mites, and (3) application of egg-parasitoids against moths in packaged products. As an example, results of research...

  19. Combination Patterns of Major R Genes Determine the Level of Resistance to the M. oryzae in Rice (Oryza sativa L..

    Directory of Open Access Journals (Sweden)

    Yunyu Wu

    Full Text Available Rice blast caused by Magnaporthe oryzae is the most devastating disease of rice and poses a serious threat to world food security. In this study, the distribution and effectiveness of 18 R genes in 277 accessions were investigated based on pathogenicity assays and molecular markers. The results showed that most of the accessions exhibited some degree of resistance (resistance frequency, RF >50%. Accordingly, most of the accessions were observed to harbor two or more R genes, and the number of R genes harbored in accessions was significantly positively correlated with RF. Some R genes were demonstrated to be specifically distributed in the genomes of rice sub-species, such as Pigm, Pi9, Pi5 and Pi1, which were only detected in indica-type accessions, and Pik and Piz, which were just harbored in japonica-type accessions. By analyzing the relationship between R genes and RF using a multiple stepwise regression model, the R genes Pid3, Pi5, Pi9, Pi54, Pigm and Pit were found to show the main effects against M. oryzae in indica-type accessions, while Pita, Pb1, Pik, Pizt and Pia were indicated to exhibit the main effects against M. oryzae in japonica-type accessions. Principal component analysis (PCA and cluster analysis revealed that combination patterns of major R genes were the main factors determining the resistance of rice varieties to M. oryzae, such as 'Pi9+Pi54', 'Pid3+Pigm', 'Pi5+Pid3+Pigm', 'Pi5+Pi54+Pid3+Pigm', 'Pi5+Pid3' and 'Pi5+Pit+Pid3' in indica-type accessions and 'Pik+Pib', 'Pik+Pita', 'Pik+Pb1', 'Pizt+Pia' and 'Pizt+Pita' in japonica-type accessions, which were able to confer effective resistance against M. oryzae. The above results provide good theoretical support for the rational utilization of combinations of major R genes in developing rice cultivars with broad-spectrum resistance.

  20. Differential gene expression profiling in the developed ovaries between the parthenogenetic and bisexual female rice water weevils, Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidae)

    Institute of Scientific and Technical Information of China (English)

    YANG Pu; ZHOU WenWu; ZHANG Qin; CHENG JiaAn; ZHU ZengRong; WAY M O

    2009-01-01

    The rice water weevil, Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidee), reproduces by sex in the Southeastern United States, but reproduces by parthenogenesis in California and other in-vaded regions in Asia and Europe. The objective of this study was to create a parthenogenetic gene expression profile of the rice water weevil in order to gain a better insight into the molecular mecha-nisms of parthenogenesis in the weevil. Suppression subtractive hybridization (SSH) technique was employed for profiling differential gene expression in the developed ovary between the parthenoge-netic and bisexual female rice water weevils. A total of 70 contigs were obtained, and the BLASTX search identified putatively 28 genes with differential functions. According to the cytological process of parthenogenesis, the tubulin alpha-1 chain and signal transduction genes etc. were selected for real time quantitative RT-PCR analyses, and their possible functions related to the molecular mechanism of parthenogenesis were discussed. The tubulin alpha-1 chain and some signal transduction genes may be related to the molecular mechanisms of parthenogenesis of the rice water weevil.

  1. Alternative food sources and over wintering feeding behavior of the boll weevil, Anthonomus grandis boheman (coleoptera: curculionidae) under the tropical conditions of central Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Paulina de A.; Sujii, Edison R.; Pires, Carmen S.S.; Fontes, Eliana M.G. [EMBRAPA Recursos Geneticos e Biotecnologia (CENARGEN), Brasilia, DF (Brazil)], e-mail: paulina723@hotmail.com, e-mail: sujii@cenargen.embrapa.br, e-mail: cpires@cenargen.embrapa.br, e-mail: eliana@cenargen.embrapa.br; Diniz, Ivone R. [Universidade de Brasilia (UnB), DF (Brazil). Dept. de Zoologia], e-mail: irdiniz@unb.br; Medeiros, Maria A. de; Branco, Marina C. [EMBRAPA Hortalicas, Brasilia, DF (Brazil)], e-mail: medeiros@cnph.embrapa.br, e-mail: marina@cnph.embrapa.br; Salgado-Labouriau, Maria L. [Universidade de Brasilia (UnB), DF (Brazil). Dept. de Geologia], e-mail: mlea@unb.br

    2010-01-15

    The boll weevil causes serious damage to the cotton crop in South America. Several studies have been published on this pest, but its phenology and behavior under the tropical conditions prevailing in Brazil are not well-known. In this study the feeding behavior and main food sources of adult boll weevils throughout the year in Central Brazil was investigated. The digestive tract contents of insects captured in pheromone traps in two cotton fields and two areas of native vegetation (gallery forest and cerrado sensu stricto) were analyzed. The insect was captured all through the year only in the cerrado. It fed on pollen of 19 different plant families, on Pteridophyta and fungi spores and algae cysts. Simpson Index test showed that the cerrado provided greater diversity of pollen sources. In the beginning of the cotton cycle, the plant families used for pollen feeding were varied: in cotton area 1, the weevil fed on Poaceae (50%), Malvaceae and Smilacaceae (25% each); in cotton area 2 the pollen sources were Malvaceae (50%), Asteraceae (25%) and Fabaceae and Clusiaceae (25% each); in the cerrado they were Chenopodiaceae (67%) and Scheuchzeriaceae (33%). No weevils were collected in the gallery forest in this period. After cotton was harvested, the family Smilacaceae was predominant among the food plants exploited in all the study areas. These results help to explain the survivorship of adult boll weevil during cotton fallow season in Central Brazil and they are discussed in the context of behavioral adaptations to the prevailing tropical environmental conditions. (author)

  2. Effects of a non-native biocontrol weevil, Larinus planus, and other emerging threats on populations of the federally threatened Pitcher's thistle, Cirsium pitcheri

    Science.gov (United States)

    Havens, Kayri; Jolls, Claudia L.; Marik, Julie E.; Vitt, Pati; McEachern, A. Kathryn; Kind, Darcy

    2012-01-01

    Larinus planus Frabicius (Curculionidae), is a seed-eating weevil that was inadvertently introduced into the US and was subsequently distributed in the US and Canada for the control of noxious thistle species of rangelands. It has been detected recently in the federally threatened Pitcher's thistle (Cirsium pitcheri). We assayed weevil damage in a natural population of Pitcher's thistle at Whitefish Dunes State Park, Door County, WI and quantified the impact on fecundity. We then estimated the impact of this introduced weevil and other emerging threats on two natural, uninvaded populations of Pitcher's thistle for which we have long-term demographic data for 16 yr (Wilderness State Park, Emmet County, MI) and 23 yr (Miller High Dunes, Indiana Dunes National Lakeshore, Porter County, IN). We used transition matrices to determine growth rates and project the potential effects of weevil damage, inbreeding, goldfinch predation, and vegetative succession on Pitcher's thistle population viability. Based on our models, weevil seed predation reduced population growth rate by 10–12%, but this reduction was enough to reduce time to extinction from 24 yr to 13 yr and 8 yr to 5 yr in the MI and IN population, respectively. This impact is particularly severe, given most populations of Pitcher's thistle throughout its range hover near or below replacement. This is the first report of unanticipated ecological impacts from a biocontrol agent on natural populations of Cirsium pitcheri.

  3. Identification and characterization of integron-mediated antibiotic resistance in the phytopathogen Xanthomonas oryzae pv. oryzae.

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    Ying Xu

    Full Text Available Four streptomycin-resistant isolates of Xanthomonas oryzae pv. oryzae (YNA7-1, YNA10-2, YNA11-2, and YNA12-2 were examined via PCR amplification for the presence of class 1, class 2, and class 3 integrons and aadA1 and aadA2 genes, which confer resistance to streptomycin and spectinomycin. The class 1 integrase gene intI1 and the aminoglycoside adenylyltransferase gene aadA1 were identified in all four resistant isolates but not in 25 sensitive isolates. PCR amplifications showed that 7790-bp, 7162-bp, 7790-bp, and 7240-bp resistance integrons with transposition gene modules (tni module in 3' conserved segments existed in YNA7-1, YNA10-2, YNA11-2, and YNA12-2, respectively. Subsequent analysis of sequences indicated that the integrons of YNA7-1 and YNA11-2 carried three gene cassettes in the order |aacA3|arr3|aadA1|. The integron of YNA10-2 carried only |arr3|aadA1| gene cassettes. The integron of YNA12-2 lacked a 550-bp sequence including part of intI1 but it still carried |aacA3|arr3|aadA1| gene cassettes. The analysis of inactive mutants and complementation tests confirmed that the aacA3 gene conferred resistance to tobramycin, kanamycin, gentamicin and netilmicin; the arr3 gene conferred resistance to rifampicin; and the aadA1 gene conferred resistance to streptomycin and spectinomycin. The resistance phenotypes of the four isolates corresponded with their resistance gene cassettes, except that YNA7-1 and YNA12-2 did not show rifampicin resistance. Sequence comparison revealed that no gene cassette array in GenBank was in the same order as in the integrons of the four resistant isolates in this study and the aadA1, which was identical in the four resistant isolates, showed 99% identity with aadA1 sequences in GenBank. The result of a stability test showed that the resistance phenotype, the aadA1 gene, and the intI1 gene were completely stable in YNA7-1 and YNA12-2 but unstable in YNA10-2 and YNA11-2. To our knowledge, this is the first

  4. Predicting the Interactome of Xanthomonas oryzae pathovar oryzae for target selection and DB service

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    Yoon Kyong-Oh

    2008-01-01

    Full Text Available Abstract Background Protein-protein interactions (PPIs play key roles in various cellular functions. In addition, some critical inter-species interactions such as host-pathogen interactions and pathogenicity occur through PPIs. Phytopathogenic bacteria infect hosts through attachment to host tissue, enzyme secretion, exopolysaccharides production, toxins release, iron acquisition, and effector proteins secretion. Many such mechanisms involve some kind of protein-protein interaction in hosts. Our first aim was to predict the whole protein interaction pairs (interactome of Xanthomonas oryzae pathovar oryzae (Xoo that is an important pathogenic bacterium that causes bacterial blight (BB in rice. We developed a detection protocol to find possibly interacting proteins in its host using whole genome PPI prediction algorithms. The second aim was to build a DB server and a bioinformatic procedure for finding target proteins in Xoo for developing pesticides that block host-pathogen protein interactions within critical biochemical pathways. Description A PPI network in Xoo proteome was predicted by bioinformatics algorithms: PSIMAP, PEIMAP, and iPfam. We present the resultant species specific interaction network and host-pathogen interaction, XooNET. It is a comprehensive predicted initial PPI data for Xoo. XooNET can be used by experimentalists to pick up protein targets for blocking pathological interactions. XooNET uses most of the major types of PPI algorithms. They are: 1 Protein Structural Interactome MAP (PSIMAP, a method using structural domain of SCOP, 2 Protein Experimental Interactome MAP (PEIMAP, a common method using public resources of experimental protein interaction information such as HPRD, BIND, DIP, MINT, IntAct, and BioGrid, and 3 Domain-domain interactions, a method using Pfam domains such as iPfam. Additionally, XooNET provides information on network properties of the Xoo interactome. Conclusion XooNET is an open and free public

  5. The Xanthomonas oryzae pv. oryzae PhoPQ two-component system is required for AvrXA21 activity, hrpG expression, and virulence.

    Science.gov (United States)

    Lee, Sang-Won; Jeong, Kyu-Sik; Han, Sang-Wook; Lee, Seung-Eun; Phee, Bong-Kwan; Hahn, Tae-Ryong; Ronald, Pamela

    2008-03-01

    The rice pathogen recognition receptor, XA21, confers resistance to Xanthomonas oryzae pv. oryzae strains producing the type one system-secreted molecule, AvrXA21. X. oryzae pv. oryzae requires a regulatory two-component system (TCS) called RaxRH to regulate expression of eight rax (required for AvrXA21 activity) genes and to sense population cell density. To identify other key components in this critical regulatory circuit, we assayed proteins expressed in a raxR gene knockout strain. This survey led to the identification of the phoP gene encoding a response regulator that is up-regulated in the raxR knockout strain. Next we generated a phoP knockout strain and found it to be impaired in X. oryzae pv. oryzae virulence and no longer able to activate the response regulator HrpG (hypersensitive reaction and pathogenicity G) in response to low levels of Ca2+. The impaired virulence of the phoP knockout strain can be partially complemented by constitutive expression of hrpG, indicating that PhoP controls a key aspect of X. oryzae pv. oryzae virulence through regulation of hrpG. A gene encoding the cognate putative histidine protein kinase, phoQ, was also isolated. Growth curve analysis revealed that AvrXA21 activity is impaired in a phoQ knockout strain as reflected by enhanced growth of this strain in rice lines carrying XA21. These results suggest that the X. oryzae pv. oryzae PhoPQ TCS functions in virulence and in the production of AvrXA21 in partnership with RaxRH.

  6. EFFECTIVNESS OF PURE DIATOMACEUS EARTH AND DIFFERENT MIXTURES OF DIATOMACEUS EARTH WITH PYRETHRINS

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    Irma Kalinović

    2011-12-01

    Full Text Available This study shows results of laboratory experiments on stored soft white wheat infested with two stored pest species: rice weevil - Sitophilus oryzae (L., and red flour beetle - Tribolium castaneum (Herbst, treated with different mixtures of Diatomaceus earth (DE and pyrethrins (Diatect V, Diatect II, Bug-B-Gon, Perma-Guard D-20 , and DE without pyrethrins (Protect-It, Perma-Guard and DE from Croatia. The obtained results confirmed that the mixture of DE and pyrethrin and PBO is useful against test-insects and generated significantly higher effectiveness when compared with the results obtained with DE without pyrethrins. Due to the fact that Croatia has the sources of good DE and indigenous Dalmatian pyrethrum, it is possible to develop and produce safe, natural and ecologically acceptable Croatian insecticide by using mixture of DE and pyrethrins, for domestic market and export.

  7. Identification and field evaluation of attractants for the cranberry weevil, Anthonomus musculus Say.

    Science.gov (United States)

    Szendrei, Zsofia; Averill, Anne; Alborn, Hans; Rodriguez-Saona, Cesar

    2011-04-01

    Studies were conducted to develop an attractant for the cranberry weevil, Anthonomus musculus, a pest of blueberry and cranberry flower buds and flowers in the northeastern United States. In previous studies, we showed that cinnamyl alcohol, the most abundant blueberry floral volatile, and the green leaf volatiles (Z)-3-hexenyl acetate and hexyl acetate, emitted from both flowers and flower buds, elicit strong antennal responses from A. musculus. Here, we found that cinnamyl alcohol did not increase capture of A. musculus adults on yellow sticky traps compared with unbaited controls; however, weevils were highly attracted to traps baited with the Anthonomus eugenii Cano aggregation pheromone, indicating that these congeners share common pheromone components. To identify the A. musculus aggregation pheromone, headspace volatiles were collected from adults feeding on blueberry or cranberry flower buds and analyzed by gas chromatography-mass spectrometry. Three male-specific compounds were identified: (Z)-2-(3,3-dimethyl-cyclohexylidene) ethanol (Z grandlure II); (Z)-(3,3-dimethylcyclohexylidene) acetaldehyde (grandlure III); and (E)-(3,3- dimethylcyclohexylidene) acetaldehyde (grandlure IV). A fourth component, (E)-3,7-dimethyl-2,6-octadien-1-ol (geraniol), was emitted in similar quantities by males and females. The emission rates of these volatiles were about 2.8, 1.8, 1.3, and 0.9 ng/adult/d, respectively. Field experiments in highbush blueberry (New Jersey) and cranberry (Massachusetts) examined the attraction of A. musculus to traps baited with the male-produced compounds and geraniol presented alone and combined with (Z)-3-hexenyl acetate and hexyl acetate, and to traps baited with the pheromones of A. eugenii and A. grandis. In both states and crops, traps baited with the A. musculus male-produced compounds attracted the highest number of adults. Addition of the green leaf volatiles did not affect A. musculus attraction to its pheromone but skewed the sex ratio

  8. Insecticidal activity of 2-tridecanone against the cowpea weevil Callosobruchus maculatus (Coleoptera: Bruchidae

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    Yussef F.B. Braga

    2007-03-01

    Full Text Available The effect of 2-tridecanone vapor on the cowpea weevil (Callosobruchus maculatus development was determined. Seeds of cowpea were infested with adults and exposed to different doses of 2-tridecanone isolated from Pilocarpus microphyllus Stapf ex Holm, a plant species native from northeastern Brazil. The pure monoterpene was evaluated both undiluted as well as in the dilutions 1:10, 1:100 and 1:1,000 (v/v. The following parameters of the cowpea weevil life cycle were analyzed in response to decreasing doses of 2-tridecanone: number of eggs laid, percentage of egg hatching on seeds, percentage of adult emergence, adult weight at emergence, mean developmental time and number of adults emerged. Vapor of 2-tridecanone caused a significant (P O efeito dos vapores da 2-tridecanona sobre o caruncho do feijão-de-corda (Callosobruchus maculatus foi avaliado. Sementes de feijão-de-corda infestados com insetos adultos foram expostas a diferentes doses de 2-tridecanona isolada de Pilocarpus microphyllus, uma espécie nativa do Nordeste do Brasil. O monoterpeno puro foi utilizado nas diluições 1:10, 1:100 e 1:1000 (v/v. Os parâmetros da biologia do inseto foram analisados em função da resposta a doses decrescentes de 2-tridecanona: número de ovos postos por fêmea, percentagem de eclosão de ovos, percentagem de emergência de adultos, peso dos adultos recém-emergidos, tempo médio de desenvolvimento e número total de ovos emergidos. Diferenças significativas (P < 0.05 entre as doses de 2-tridecanona testadas foram observadas, para quatro dos seis parâmetros biológicos analisados. Os resultados obtidos indicaram que a 2-tridecanona é tóxica para C. maculatus, reduzindo significativamente (P < 0.05 o número de insetos emergidos após a infestação. Esse efeito foi causado principalmente pela significativa redução observada na eclosão dos ovos expostos ao vapor da substância.

  9. TOLERANCIA A INFESTACIÓN POR GORGOJOS (Sitophilus spp. EN GENOTIPOS DE MAÍZ COMUNES Y DE ALTA CALIDAD PROTEÍNICA

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    Artemio Palafox-Caballero

    2008-01-01

    Full Text Available Se estableció un experimento en el Campo Experimental Cotaxtla del INIFAP, en el estado de Veracruz, México, durante el ciclo primavera-verano del año 2002, con el objetivo de determinar la producción de genotipos de maíz y el daño causado por gorgojos (Sitophilus spp. Se evaluaron cinco genotipos comunes y 14 de alta calidad de proteína (QPM en un diseño estadístico de bloques al azar con dos repeticiones. Se registraron y analizaron el rendimiento de grano, la sanidad de la mazorca, el porcentaje de mazorcas con mala cobertura y el porcentaje de mazorcas dañadas por gorgojos. Esta última variable se midió durante cinco meses, en diferentes fechas de cosecha y en mazorcas almacenadas. Se detectaron diferencias signifi cativas en todas las variables excepto la sanidad de la mazorca. El rendimiento de tres genotipos fue sobresaliente: H-520 (7,93 t/ha y SINT 9 (7,11 t/ha comunes y el H-553C (7,01 t/ha de alta calidad de proteína; los tres presentaron bajo porcentaje de mazorcas con mala cobertura (menor a 5%. El daño por gorgojos fue signifi cativamente mayor conforme la cosecha se realizó más tardíamente, incrementándose de 0,19% en enero a 76,80% en mayo. Los genotipos menos afectados en el campo fueron H-519C, H-363C y VS-536, con daños inferiores a 2%. Después de cinco meses de almacenamiento, H-363C y SINT9 presentaron daños menores al 70%, mientras que el resto de los genotipos presentaron daños mayores a 90%.

  10. Characterization of interspecific hybrids and backcross progenies from a cross between Oryza minuta and Oryza sativa

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Oryza minuta, a tetraploid wild relative of cultivated rice, is an important source for the genetic improvement. Interspecific hybrids were obtained from the cross of O. sativa L. (IR24) and O. minuta (Acc. No. 101133) with 5.58% crossability, which ranged from 0.11% to 1.62% in the backcross generations. The chromosome numbers of the backcross progenies were 24 to 48. Seven yield-related traits of the parents, hybrid F1, and backcross progenies were evaluated. Simple sequence repeat markers analysis showed that the polymorphism ratio of SSR bands between IR24 and Acc. No. 101133 was 93.2%. The average donor segment number, length, donor genome size, and percentage of donor genome of 92 BC3F1 plants (2n=24) were 24.1, 17.8 cM, 438.4 cM and 26.2%, respectively. They were complex variation and uneven among the chromosomes. These introgression lines could be used to identify the favorable genes of O. minuta and provide a new platform for the genetic improvement of cultivated rice.

  11. Evaluation of resistance of corn hybrids against the attack of Sitophilus zeamais motschulsky (Coleoptera: Curculionidae in stored kernels/ Avaliação da resistência de híbridos de milho ao ataque de Sitophilus zeamais motschulsky (Coleoptera: Curculionidae no grão armazenado

    Directory of Open Access Journals (Sweden)

    Antônio Carlos Gerage

    2005-06-01

    Full Text Available Resistance of corn hybrids, cultivated or in phase of genetic improvement in Paraná, was evaluated against the attack of Sitophilus zeamais, main grain pest of corn storage. Samples of kernels of eleven hybrids of corn, IPD T1/3AC, IPD 029, IPT 4/029, AG 5011, IPS G/58, IPT 2/15, IPT 4/15, IPT T/23, IPT 5/T02, IPT 2/92 and IPT 9/13, were infested with adults of S. zeamais and maintained in BOD, at 27±1°C, 75±5% RH and 12 hours of photophase. After 30 days of infestation the following parameters of resistance were evaluated: susceptibility index, reduce of dry mass of the grains, number of emerged insects, biological cycle and adult mass. The most susceptible hybrids to the attack of S. zeamais were: IPD T1/3AC and IPD 029; while the most resistant were: IPT 4/029, AG 5011, IPS G/58, IPT 2/15 and IPT 4/15.A resistência de híbridos de milho, cultivados ou em fase de melhoramento genético no Paraná, foi avaliada com relação ao ataque de Sitophilus zeamais, principal praga de grãos armazenados de milho. Amostras de grãos de onze híbridos de milho, IPD T1/3AC, IPD 029, IPT 4/029, AG 5011, IPS G/58, IPT 2/15, IPT 4/15, IPT T/23, IPT 5/T02, IPT 2/92 e IPT 9/13, foram infestadas com adultos de S. zeamais e mantidas em BOD, a 27±1°C, 75±5% UR e 12 horas de fotofase. Após trinta dias da infestação foram avaliados os seguintes parâmetros de resistência: índice de suscetibilidade, perda de massa seca dos grãos, número de insetos emergidos, ciclo biológico e massa dos adultos. Os híbridos mais suscetíveis ao ataque de S. zeamais foram: IPD T1/3AC e IPD 029, enquanto que os mais resistentes foram: IPT 4/029, AG 5011, IPS G/58, IPT 2/15 e IPT 4/15.

  12. Effect of Preexposure to Triazoles on Susceptibility and Virulence of Rhizopus oryzae.

    Science.gov (United States)

    Bellanger, Anne-Pauline; Albert, Nathaniel D; Lewis, Russell E; Walsh, Thomas J; Kontoyiannis, Dimitrios P

    2015-12-01

    Triazole prophylaxis has become the norm in patients with hematological malignancies. Breakthrough infections caused by Mucorales during triazole prophylaxis remain a challenging problem. We found that preexposure of Rhizopus oryzae to antifungal triazoles (fluconazole, voriconazole, posaconazole, and itraconazole) did not modify the in vitro susceptibility of Rhizopus oryzae to posaconazole. In contrast, preexposure of Rhizopus to triazoles was associated with the enhanced in vitro susceptibility of R. oryzae to amphotericin B. Preexposure to posaconazole did not alter the virulence of R. oryzae in the fly model of mucormycosis.

  13. Regulation of the abundance of clover seed weevils, Apion spp. (Coleoptera: Curculionidae in a seed stand of red clover (Trifolium pratense L.

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    P. Kolařík

    2013-12-01

    Full Text Available The clover seed weevils, Apion trifolii and Protapion apricans, members of the genus Apion, are responsible for causing serious economic damage in clover. In 2010-2012, the effectiveness of some insecticides against clover seed weevils in the genus Apion were tested in red clover stands. The efficacy of different products was evaluated on the basis of analyses of specimens trapped in the herb layer of red clover using a sweep net and red clover heads sampled in individual plots. Over the course of these trials, the applications of the products tested resulted in a marked reduction in their numbers (particularly of adults and, to a lesser extent, also of larvae. The highest efficacy was observed with Biscaya 240 (A.I. thiacloprid and Mospilan 20 SP (A.I. acetamiprid. Results obtained in this study corroborated the low efficacy of the insecticide Karate Zeon Technology 5 CS against seed weevils of the genus Apion.

  14. Immobilization of Isolated Lipase From Moldy Copra (Aspergillus Oryzae

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    Seniwati Dali

    2011-01-01

    Full Text Available Enzyme immobilization is a recovery technique that has been studied in several years, using support as a media to help enzyme dissolutions to the reaction substrate. Immobilization method used in this study was adsorption method, using specific lipase from Aspergillus oryzae. Lipase was partially purified from the culture supernatant of Aspergillus oryzae. Enzyme was immobilized by adsorbed on silica gel. Studies on free and immobilized lipase systems for determination of optimum pH, optimum temperature, thermal stability and reusability were carried out. The results showed that free lipase had optimum pH 8,2 and optimum temperature 35 °C while the immobilized lipase had optimum 8,2 and optimum temperature 45 °C. The thermal stability of the immobilized lipase, relative to that of the free lipase, was markedly increased. The immobilized lipase can be reused for at least six times.

  15. Effectiveness of spinosad against seven major storedgrain insects on corn

    Institute of Scientific and Technical Information of China (English)

    FANGNENG HUANG; BHADRIRAJU SUBRAMANYAM

    2007-01-01

    In January 2005, the United States Environmental Protection Agency registered spinosad as a stored grain protectant. No referenced data on the efficacy of spinosad on corn in suppressing major stored-grain insects have been published. In this paper, we evaluated the efficacy of spinosad against seven major stored-grain insects on shelled corn in the laboratory. Insect species tested were the red flour beetle, Tribolium castaneum (Jacquelin duVal); rusty grain beetle, Cryptolestes ferrugineus (Stephens); lesser grain borer, Rhyzopertha dominica (F.); sawtoothed grain beetle, Oryzaephilus surinamensis (L.); rice weevil, Sitophilus oryzae (L.); maize weevil, Sitophilus zeamais (Motschulsky); and Indian meal moth, Plodia interpunctella (Hübner). Corn kernels were treated with spinosad at 0,0.1, 0.5, 1, and 2 active ingredient (a.i.) mg/kg for controlling the seven species. Beetle adults or P.interpunctella eggs were introduced into each container holding 100 g of untreated or insecticide-treated corn. The seven insect species survived well on the control treatment, produced 28 to 336 progeny, and caused significant kernel damage after 49 days. On spinosad-treated corn, adult mortality of C. ferrugineus, R. dominica, O. surinamensis, S. oryzae, and S. zeamais was > 98% at 1 and 2 mg/kg after 12 days. Spinosad at > 0.5 mg/kg completely suppressed egg-to-larval survival after 21 days and egg-to-adult emergence of P. interpunctella after 49 days, whereas 16% T. castaneum adults survived at 1 mg/kg after 12 days. Spinosad at 1 or 2 mg/kg provided complete or near complete suppression of progeny production and kernel damage of all species after 49 days. Our results indicate that spinosad at the current labeled rate of 1 mg/kg is effective against the seven stored-grain insect pests on corn.

  16. Characterization of Aspergillus oryzae aspartyl aminopeptidase expressed in Escherichia coli.

    Science.gov (United States)

    Watanabe, Jun; Tanaka, Hisaki; Akagawa, Takumi; Mogi, Yoshinobu; Yamazaki, Tatsuo

    2007-10-01

    To characterize aspartyl aminopeptidase from Aspergillus oryzae, the recombinant enzyme was expressed in Escherichia coli. The enzyme cleaves N-terminal acidic amino acids. About 30% activity was retained in 20% NaCl. Digestion of defatted soybean by the enzyme resulted in an increase in the glutamic acid content, suggesting that the enzyme is potentially responsible for the release of glutamic acid in soy sauce mash.

  17. Control of Three Stored−Product Beetles with Artemisia haussknechtii (Boiss (Asteraceae Essential Oil

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    Seyed Mehdi Hashemi

    2012-12-01

    Full Text Available Fumigant toxicity of the essential oil of aerial parts from Artemisia haussknechtii (Boiss (Asteraceae was investigated against the cowpea weevil Callosobruchus maculatus (Fab., the rice weevil Sitophilus oryzae (L., and the red flour beetle Tribolium castaneum (Herbst. Dry ground plants were subjected to hydro−distillation using a Clevenger−type apparatus and the chemical composition of the volatile oil was studied by gas chromatography−mass spectrometry (GC−MS. The major components of the oil were camphor (29.24%, 1, 8−cineol (27.62%, yomogi alcohol (5.23%, and camphene (4.80%. The essential oil in same concentrations was assayed against (1−7 days old adults of insect species and percentage mortality was recorded after 24, 48, and 72 h exposure times. LC50 values were varied between 19.84 and 103.59 μL L-1 air, depending on insect species and exposure time. Callosobruchus maculatus was more susceptible than other species. These results suggested that A. haussknechtii oil might have potential as a control agent against C. maculatus, S. oryzae and T. castaneum.

  18. The effects of island forest restoration on open habitat specialists: the endangered weevil Hadramphus spinipennis Broun and its host-plant Aciphylla dieffenbachii Kirk

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    Emily D. Fountain

    2015-02-01

    Full Text Available Human alteration of islands has made restoration a key part of conservation management. As islands are restored to their original state, species interactions change and some populations may be impacted. In this study we examine the coxella weevil, (Hadramphus spinipennis Broun and its host-plant Dieffenbach’s speargrass (Aciphylla dieffenbachii Kirk, which are both open habitat specialists with populations on Mangere and Rangatira Islands, Chathams, New Zealand. Both of these islands were heavily impacted by the introduction of livestock; the majority of the forest was removed and the weevil populations declined due to the palatability of their host-plant to livestock. An intensive reforestation program was established on both islands over 50 years ago but the potential impacts of this restoration project on the already endangered H. spinipennis are poorly understood. We combined genetic and population data from 1995 and 2010–2011 to determine the health and status of these species on both islands. There was some genetic variation between the weevil populations on each island but little variation within the species as a whole. The interactions between the weevil and its host-plant populations appear to remain intact on Mangere, despite forest regeneration. A decline in weevils and host-plant on Rangatira does not appear to be caused by canopy regrowth. We recommend that (1 these populations be monitored for ongoing effects of long-term reforestation, (2 the cause of the decline on Rangatira be investigated, and (3 the two populations of weevils be conserved as separate evolutionarily significant units.

  19. New Initiatives for Management of Red Palm Weevil Threats to Historical Arabian Date Palms *

    KAUST Repository

    Mukhtar, Muhammad

    2011-12-01

    The date palm is an important part of the religious, cultural, and economic heritage of the Arabian Peninsula. This heritage is threatened by the recent invasion of the red palm weevil (RPW) from Southeast Asia. In Saudi Arabia, a national campaign for control of RPW by containment/destruction of infested plants, injection and spraying of biochemical and chemical pesticide treatments in heavily infested and newly infested areas, and the use of pheromone/ kairomone traps for monitoring and reduction of RPW populations has been only partially successful in controlling its spread. New methods are needed to help manage the RPW populations. At a workshop in Riyadh in March 2010, plans were recommended to 1) devise and test new biological, chemical, and biotechnological methods to manage RPW in farms and urban palms; 2) compare the economic and logistic feasibility of acoustic and other detection methods against RPW larvae; and 3) develop biosensor indicators of RPW infestation in date palms. If these initiatives are successful, they will be of great assistance to landscape and orchard managers dealing with such a challenging pest of a highly valuable tree.

  20. Molecular phylogeny and biogeography of the weevil subfamily Platypodinae reveals evolutionarily conserved range patterns.

    Science.gov (United States)

    Jordal, Bjarte H

    2015-11-01

    Platypodinae is a peculiar weevil subfamily of species that cultivate fungi in tunnels excavated in dead wood. Their geographical distribution is generally restricted, with genera confined to a single continent or large island, which provides a useful system for biogeographical research. This study establishes the first detailed molecular phylogeny of the group, with the aim of testing hypotheses on classification, diversification, and biogeography. A phylogeny was reconstructed based on 3648 nucleotides from COI, EF-1α, CAD, ArgK, and 28S. Tree topology was well resolved and indicated a strong correlation with geography, more so than predicted by previous morphology-based classifications. Tesserocerini was paraphyletic, with Notoplatypus as the sister group to a clade consisting of three main lineages of Tesserocerini and the recently evolved Platypodini. Austroplatypus formed the sister group to all remaining Platypodini and hence confirmed its separate status from Platypus. The Indo-Australian genera of Platypodini were strikingly paraphyletic, suggesting that the taxonomy of this tribe needs careful revision. Ancestral-area reconstructions in Lagrange and S-DIVA were ambiguous for nodes roughly older than 80 Ma. More recent events were firmly assessed and involved post-Gondwanan long-distance dispersal. The Neotropics was colonized three times, all from the Afrotropical region, with the latest event less than 25 Ma that included the ancestor of all Neotropical Platypodini. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Wood digestion in Pselactus spadix Herbst--a weevil attacking marine timber structures.

    Science.gov (United States)

    Oevering, Pascal; Pitman, Andrew J; Pandey, Krishna K

    2003-04-01

    Pselactus spadix tunnels timber structures in the marine environment. Recent studies reported a cosmopolitan distribution for this weevil, which is frequently found in harbour and port areas. P. spadix feeds on timber (hardwood and softwood) in immature and adult life stages, but its digestion of wood components had not been investigated. Using dry weight analyses of tunnel walls and frass produced, P. spadix adults consumed Scots pine with soft rot decay at a rate of 1.59 +/- 0.37 mg d-1 and the digestibility of this substrate was 57.96 +/- 5.89 (i.e. for 100 mg consumed SR-pine, 58 mg was digested). Using gravimetric analysis to quantify structural wood components in tunnel walls and frass, P. spadix adults were found to digest cellulose, lignin and hemicellulose with digestibility coefficients of 82.2, 41.2 and 14.5 respectively. Fourier Transform Infrared (FTIR) spectroscopy analyses of tunnel walls and frass of adults and larvae from soft rotted pine also indicated digestion of all structural components, with larvae digesting cellulose and lignin more efficiently than adults. When FTIR was employed to analyse adult tunnel walls and frass from undecayed pine, cellulose and hemicellulose were digested, but no evidence of lignin digestion was found. This study shows that adults digest lignin when soft rot is present and suggests a symbiotic function of wood degrading microorganisms.

  2. Transcriptome analysis and systemic RNAi response in the African sweetpotato weevil (Cylas puncticollis, Coleoptera, Brentidae).

    Science.gov (United States)

    Prentice, Katterinne; Pertry, Ine; Christiaens, Olivier; Bauters, Lander; Bailey, Ana; Niblett, Chuck; Ghislain, Marc; Gheysen, Godelieve; Smagghe, Guy

    2015-01-01

    The African sweetpotato weevil (SPW) Cylas puncticollis Boheman is one of the most important constraints of sweetpotato production in Sub-Saharan Africa and yet is largely an uncharacterized insect pest. Here, we report on the transcriptome analysis of SPW generated using an Illumina platform. More than 213 million sequencing reads were obtained and assembled into 89,599 contigs. This assembly was followed by a gene ontology annotation. Subsequently, a transcriptome search showed that the necessary RNAi components relevant to the three major RNAi pathways, were found to be expressed in SPW. To address the functionality of the RNAi mechanism in this species, dsRNA was injected into second instar larvae targeting laccase2, a gene which encodes an enzyme involved in the sclerotization of insect exoskeleton. The body of treated insects showed inhibition of sclerotization, leading eventually to death. Quantitative Real Time PCR (qPCR) confirmed this phenotype to be the result of gene silencing. Together, our results provide valuable sequence data on this important insect pest and demonstrate that a functional RNAi pathway with a strong and systemic effect is present in SPW and can further be explored as a new strategy for controlling this important pest.

  3. RNA interference: a promising biopesticide strategy against the African Sweetpotato Weevil Cylas brunneus

    Science.gov (United States)

    Christiaens, Olivier; Prentice, Katterinne; Pertry, Ine; Ghislain, Marc; Bailey, Ana; Niblett, Chuck; Gheysen, Godelieve; Smagghe, Guy

    2016-01-01

    The African sweetpotato weevil Cylas brunneus is one of the most devastating pests affecting the production of sweetpotatoes, an important staple food in Sub-Saharan Africa. Current available control methods against this coleopteran pest are limited. In this study, we analyzed the potential of RNA interference as a novel crop protection strategy against this insect pest. First, the C. brunneus transcriptome was sequenced and RNAi functionality was confirmed by successfully silencing the laccase2 gene. Next, 24 potential target genes were chosen, based on their critical role in vital biological processes. A first screening via injection of gene-specific dsRNAs showed that the dsRNAs were highly toxic for C. brunneus. Injected doses of 200ng/mg body weight led to mortality rates of 90% or higher for 14 of the 24 tested genes after 14 days. The three best performing dsRNAs, targeting prosα2, rps13 and the homolog of Diabrotica virgifera snf7, were then used in further feeding trials to investigate RNAi by oral delivery. Different concentrations of dsRNAs mixed with artificial diet were tested and concentrations as low as 1 μg dsRNA/ mL diet led to significant mortality rates higher than 50%.These results proved that dsRNAs targeting essential genes show great potential to control C. brunneus. PMID:27941836

  4. Effect of mango weevil (Coleoptera: Curculionidae) damage on mango seed viability in Tanzania.

    Science.gov (United States)

    Mulungu, Loth S; Mpinga, Makala; Mwatawala, Maulid W

    2008-02-01

    Studies were conducted at the horticulture unit of Sokoine University of Agriculture, Morogoro, Tanzania, to assess the incidence and effect of mango weevil, Cryptorhynchus mangiferae (F.) (Coleoptera: Curculionidae), infestation on mango, Mangifera indica L., seed viability. Three polyembryo mango cultivars ('Sindano nyeusi', 'Sindano nyeupe', and 'Dodo') as well as three monoembryo mango cultivars ('Ex-horticulture', 'Tango', and 'Bongwa') were collected and examined for the presence of C. mangiferae. The effect of seed damage on viability was assessed for both naturally and artificially damaged seeds. However, for artificially damaged seeds, the viability was assessed by cutting away 0, 25, 50, or 75% of the cotyledon before planting. In this experiment, only monoembryo mango cultivars were used. All the examined cultivars were infested by C. mangiferae, although at varying levels. Polyembryo mango cultivars were relatively more infested than monoembryo cultivars. Bongwa and Tango were least infested, whereas Sindano nyeusi recorded the highest C. mangiferae incidence. Germination rates of damaged seeds of polyembryonic cultivars differed significantly from the uninfested control, except for Sindano nyeusi. There were no significant differences in germination percentage among the three monoembryo cultivars, and all the cultivars differed significantly from the uninfested control. The germination rates of seeds with 25% of their cotyledons removed did not differ significantly from the undamaged seeds, indicating that monoembryo cultivar seeds can withstand up to 25% damage and germinate successfully.

  5. Transcriptome Analysis of Oryza sativa Calli Under Microgravity

    Science.gov (United States)

    Jin, Jing; Chen, Haiying; Cai, Weiming

    2015-11-01

    The transcriptome of Oryza sativacalli was analyzed on board the Chinese spaceship "Shenzhou 8" to study the effects of microgravity on plant signal transduction and secondary metabolism (as one of the experiments with SIMBOX on Shenzhou 8). Calli of Oryza sativa were pre-cultured for 4 days on ground and then loaded into the stationary platform or the rotating platform of a biological incubator, called SIMBOX, to grow in space under microgravity conditions or 1g-conditions, respectively. The calli were fixed by RNAlater after grew 324 h under microgravity. After 17 days, Shenzhou 8 returned to Earth carrying SIMBOX. Oryza sativa calli were recovered, and the RNA was extracted for transcriptome analysis. After comparing 1 gspaceflight controls-inflight controls with 1 g-ground controls, 157 probe sets with different expression levels (fold change ≥2, p<0.05) were identified. When comparing spaceflight controls to 1 g-ground controls and to 1 g-inflight controls, 678 probe sets with different expression levels (fold change ≥2, p<0.05) were identified. The fact that the same 678 probe sets were identified in these two comparisons suggests that transcription was affected under microgravity conditions. MapMan analysis was used to classify 627 microgravity responsive (MR) transcripts. The MR transcripts were mainly involved in cell wall structure, the TCA cycle, primary metabolism, transcription, protein modification and degradation, hormone metabolism, calcium regulation, receptor like kinase activity and transport.

  6. Jewelry boxes contaminated by Aspergillus oryzae: an occupational health risk?

    Science.gov (United States)

    Bellanger, Anne-Pauline; Roussel, Anaïs; Millon, Laurence; Delaforge, Marcel; Reboux, Gabriel

    2012-01-01

    In 2009, 100,000 jewelry boxes, manufactured in China, were delivered to a jewelry manufacturer in Besançon, France. All the boxes were contaminated by mold. Because the workers refused to handle these jewelry boxes, the company contacted our laboratory to determine how to deal with the problem. Three choices were available: (1) decontaminate the boxes, (2) return the boxes to the Chinese manufacturer, or (3) destroy the entire shipment. Based on microscopic identification, the culture analysis was positive for A. oryzae. This could not be confirmed by molecular techniques because of the genetic proximity of A. oryzae and A. flavus. Because A. flavus can produce aflatoxins, we tested for them using mass spectrometry. Aflatoxins B1, B2, G1, G2, and M1 were not detected; however, given the specifics of this situation, we could not discard the possibility of the presence of other aflatoxins, such as P1, B3, GM2, and ethoxyaflatoxin B2. We concluded that the contamination by A. oryzae was probably due to food products. However, because of the possible presence of aflatoxins, occupational health risks could not be entirely ruled out. The decision was therefore taken to destroy all the jewelry boxes by incineration. To avoid a similar situation we propose: (1) to maintain conditions limiting mold contamination during production (not eating on the work site, efficient ventilation systems); (2) to desiccate the products before sending them; and (3) to closely control the levels of dampness during storage and transport.

  7. Reduction of aflatoxins by Rhizopus oryzae and Trichoderma reesei.

    Science.gov (United States)

    Hackbart, H C S; Machado, A R; Christ-Ribeiro, A; Prietto, L; Badiale-Furlong, E

    2014-08-01

    This study evaluated the ability of the microorganisms Rhizopus oryzae (CCT7560) and Trichoderma reesei (QM9414), producers of generally recognized as safe (GRAS) enzymes, to reduce the level of aflatoxins B1, B2, G1, G2, and M1. The variables considered to the screening were the initial number of spores in the inoculum and the culture time. The culture was conducted in contaminated 4 % potato dextrose agar (PDA) medium, and the residual mycotoxins were determined every 24 h by HPLC-FL. The fungus R. oryzae has reduced aflatoxins B1, B2, and G1 in the 96 h and aflatoxins M1 and G2 in the range of 120 h of culture by approximately 100 %. The fungus T. reesei has reduced aflatoxins B1, B2, and M1 in the 96 h and aflatoxin G1 in the range of 120 h of culture by approximately 100 %. The highest reduction occurred in the middle of R. oryzae culture.

  8. Alternative respiration and fumaric acid production of Rhizopus oryzae.

    Science.gov (United States)

    Gu, Shuai; Xu, Qing; Huang, He; Li, Shuang

    2014-06-01

    Under the conditions of fumaric acid fermentation, Rhizopus oryzae ME-F14 possessed at least two respiratory systems. The respiration of mycelia was partially inhibited by the cytochrome respiration inhibitor antimycin A or the alternative respiration inhibitor salicylhydroxamic acid and was completely inhibited in the presence of both antimycin A and salicylhydroxamic acid. During fumaric acid fermentation process, the activity of alternative respiration had a great correlation with fumaric acid productivity; both of them reached peak at the same time. The alternative oxidase gene, which encoded the mitochondrial alternative oxidase responsible for alternative respiration in R. oryzae ME-F14, was cloned and characterized in Escherichia coli. The activity of alternative respiration, the alternative oxidase gene transcription level, as well as the fumaric acid titer were measured under different carbon sources and different carbon-nitrogen ratios. The activity of alternative respiration was found to be comparable to the transcription level of the alternative oxidase gene and the fumaric acid titer. These results indicated that the activity of the alternative oxidase was regulated at the transcription stage under the conditions tested for R. oryzae ME-F14.

  9. Iron starvation induces apoptosis in Rhizopus oryzae in vitro.

    Science.gov (United States)

    Shirazi, Fazal; Kontoyiannis, Dimitrios P; Ibrahim, Ashraf S

    2015-01-01

    Mortality associated with mucormycosis remains high despite current antifungals. Iron-starvation strategies have been shown to have promising activity against Mucorales. We hypothesized that iron starvation enhances apoptosis in Rhizopus oryzae. Apoptosis was characterized in R. oryzae transformed with RNAi plasmid targeting FTR1 expression (iron permease mutant) or empty plasmid grown in iron rich (0.125% FeCl3) and iron depleted media (YNB+1mM ferrozine and 1 mM ascorbic acid). Increased apoptosis was observed with dihydrorhodamine-123 and rhodamine-123 staining in the iron starved mutant FTR1 when compared to empty plasmid, followed by increased extracellular ATP levels. In addition, DNA fragmentation and metacaspase activity were prominent in FTR1. In contrast, Rhizopus strains grown in iron-rich medium displayed minimal apoptosis. Our results demonstrate a metacaspase dependent apoptotic process in iron deprived condition and further support the role of iron starvation strategies as an adjunct treatment for mucormycosis, a mechanism by which iron starvation affects R. oryzae.

  10. Data on the abundance of the banana weevil Cosmopolites sordidus and of the earwig Euborellia caraibea in bare soil and cover crop plots

    Directory of Open Access Journals (Sweden)

    Dominique Carval

    2016-06-01

    Full Text Available The data presented in this article are related to the research article entitled “Cover cropping reduces the abundance of the banana weevil Cosmopolites sordidus but does not reduce its damage to the banana plants” (Carval et al., in press [1]. This article describes how the abundance of the banana weevil, Cosmopolites sordidus, and the abundance of the earwig Euborellia caraibea were affected by the addition of a cover crop. The field data set is made publicly available to enable critical or extended analyzes.

  11. A mutation in the aroE gene affects pigment production, virulence, and chemotaxis in Xanthomonas oryzae pv. oryzae.

    Science.gov (United States)

    Kim, Hong-Il; Noh, Tae-Hwan; Lee, Chang-Soo; Park, Young-Jin

    2015-01-01

    Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial blight (BB) in rice. To study its function, a random insertion mutation library of Xoo was constructed using the Tn5 transposon. A mutant strain with decreased virulence against the susceptible rice cultivar IR24 was isolated from the library (aroE mutant), which also had extremely low pigment production. Thermal asymmetric interlaced-polymerase chain reaction (TAIL-PCR) and sequence analysis of the mutant revealed that the transposon was inserted into the aroE gene (encoding shikimate dehydrogenase). To investigate gene expression changes in the pigment- and virulence-deficient mutant, DNA microarray analysis was performed, which showed downregulation of 20 genes involved in the chemotaxis of Xoo. Our findings reveal that mutation of the aroE gene affects virulence and pigment production, as well as expression of genes involved in Xoo chemotaxis.

  12. Impact of Engineered Nanoparticles on Virulence of Xanthomonas oryzae pv oryzae and on Rice Sensitivity at its Infection

    Directory of Open Access Journals (Sweden)

    Giuliano Degrassi

    2014-12-01

    Full Text Available The present work of nanocotoxicity wants to propose a new plant model starting from the rice plant. The model takes into consideration the impact of engineered nanoparticles (Ag, Co, Ni, CeO2, Fe3O4, TiO2 on rice plants that were weakened by infections of Xanthomonas oryzae pv oryzae bacteria. The results indicate that some NPs increase the rice sensitivity to the pathogen while others decrease the virulence of the pathogen towards rice. No-enrichment in component metal concentration is detected in above organs of rice, with exception of Ni-NPs treatment. An imbalance of major elements in infected rice crops treated with NPs was investigated.

  13. Production of bacterial blight resistant lines from somatic hybridization between Oryza sativa L.and Oryza meyeriana L.

    Institute of Scientific and Technical Information of China (English)

    严成其; 钱凯先; 薛刚平; 吴忠长; 陈跃磊; 颜秋生; 张雪琴; 吴平

    2004-01-01

    Novel bacterial blight (BB) resistance gene(s) for rice was (were) introduced into a cultivated japonica rice variety Oryza sativa (cv. 8411), via somatic hybridization using the wild rice Oryza meyeriana as the donor of the resistance gene(s). Twenty-nine progenies of somatically hybridized plants were obtained. Seven somatically hybridized plants and their parents were used for AFLP (amplified fragment length polymorphism) analysis using 8 primer pairs. Results confirmed that these plants were somatic hybrids containing the characteristic bands of both parents. The morphology of the regenerated rice showed characters of both O. sativa and O. meyeriana. Two somatic hybrids showed highest BB resistance and the other 8 plants showed moderate resistance. The new germplasms with highest resistance have been used in the rice bfeeding program for the improvement of bacterial blight resistance.

  14. Production of bacterial blight resistant lines from somatic hybridization between Oryza sativa L. and Oryza meyeriana L.

    Institute of Scientific and Technical Information of China (English)

    严成其; 钱凯先; 薛刚平; 吴忠长; 陈跃磊; 颜秋生; 张雪琴; 吴平

    2004-01-01

    Novel bacterial blight (BB) resistance gene(s) for rice was (were) introduced into a cultivated japonica rice variety Oryza sativa (cv. 8411), via somatic hybridization using the wild rice Oryza meyeriana as the donor of the resistance gene(s). Twenty-nine progenies of somatically hybridized plants were obtained. Seven somatically hybridized plants and their parents were used for AFLP (amplified fragment length polymorphism) analysis using 8 primer pairs. Results confirmed that these plants were somatic hybrids containing the characteristic bands of both parents. The morphology of the regenerated rice showed characters of both O.sativa and O.meyeriana. Two somatic hybrids showed highest BB resistance and the other 8 plants showed moderate resistance. The new germplasms with highest resistance have been used in the rice breeding program for the improvement of bacterial blight resistance.

  15. Development and Identification of Introgression Lines from Cross of Oryza sativa and Oryza minuta

    Institute of Scientific and Technical Information of China (English)

    GUO Si-bin; WEI Yu; LI Xiao-qiong; LIU Kai-qiang; HUANG Feng-kuan; CHEN Cai-hong; GAO Guo-qing

    2013-01-01

    Introgression line population is effectively used in mapping quantitative trait loci (QTLs),identifying favorable genes,discovering hidden genetic variation,evaluating the action or interaction of QTLs in multiple conditions and providing the favorable experimental materials for plant breeding and genetic research.In this study,an advanced backcross and consecutive selfing strategy was used to develop introgression lines (ILs),which derived from an accession of Oryza minuta (accession No.101133) with BBCC genome,as the donor,and an elite indica cultivar IR24 (O.sativa),as the recipient.Introgression segments from O.minuta were screened using 164 polymorphic simple sequence repeat (SSR) markers in the genome of each IL.Introgressed segments carried by 131 ILs covered the whole O.sativa genome.The average number of homozygous O.minuta segments per introgression line was about 9.99.The average length of introgressed segments was approximate 14.78 cM,and about 79.64%of these segments had sizes less than 20 cM.In the genome of each introgression line,the O.minuta chromosomal segments harbored chromosomal fragments of O.sativa ranging from 1.15% to 27.6%,with an overall average of 8.57%.At each locus,the ratio of substitution of O.minuta alleles had a range of 1.5%-25.2%,with an average of 8.3% Based on the evaluation of the phenotype of these ILs,a wide range of alterations in morphological and yield-related traits were found.After inoculation,ILs 41,11 and 7 showed high resistance to bacterial blight,brown planthopper and whitebacked planthopper,respectively.These O.minuta-O.sativa ILs will serve as genetic materials for identifying and using favorable genes from O.minuta.

  16. Growth Performance of the Red-Stripe Weevil Rhynchophorus schach Oliv. (Insecta: Coleoptera: Curculionidae on Meridic Diets

    Directory of Open Access Journals (Sweden)

    Choon-Fah J. Bong

    2008-01-01

    Full Text Available Biology and growth performance of Red Stripe Weevil, Rhynchophorus schach Oliv. were studied using meridic diets. The diets consisted of sugarcane (Saccharum officinarum L. bagasse, copra (Cocos nucifera L. cake and sago (Metroxylon sagus Rottb. flour as main ingredients. Larvae or locally known as sagoworm, in copra cake diet exhibited the fastest growth with maximum weight gain of 1609 mg in week 5, while those of sugarcane bagasse diet had slowest growth with peak weight gain of 1024 mg in week 9. Sago flour diet gave the longest larval period at 96.3 days with the highest final larval weight of 8132.1 mg. The R. schach larvae had 8 instars. Head capsule width within each instar was constant irrespective of diets given. Instar period was dependent on diets given and varied from 6.3-12 days. Pupal duration ranged from 38.5-41 days. Adult emergence was 90%. Sago flour diet had the heaviest pupae and adults. Male weevils emerged earlier than the females, but females lived 10-13 days longer. Fecundity was low at 67 eggs per female but the hatchability was 92%. Life cycle for the insect ranged from 130.2-138.8 days, with a lifespan of 178.2-183.8 days. Larvae raised on sago flour diet had the highest fat content at 57.8% but with the lowest fiber at 4.7%. Larvae were generally rich in Mg, Ca, Zn and Fe, but low in Cu. This study showed that sago flour constituted the most suitable diet. The results also suggested that growth and development of the weevil could be further improved by incorporating copra cake and sugarcane bagasse into the sago flour diet. Larvae could be readily mass produced as a source of nutritious food, besides its potential use as a laboratory test organism.

  17. ECOLOGICAL-FAUNISTIC AND ZOOGEOGRAPHICAL CHARACTERISTIC OF BEETLE-WEEVILS OF ISLAND CHECHEN OF THE CASPIAN SEA

    Directory of Open Access Journals (Sweden)

    Y. G. Arsanov

    2014-01-01

    Full Text Available Aim. Ecological-faunistic investigations of island Chechen are great interest for understanding the law of formation of island biotas and reconstruction of zoogeological history of the Caspian Sea. Faunistic investigations of islands and coastal areas , habitats and others chorologic aspects illuminate the ways of their probable settlement,explains the paradoxes of propagation of some species. Study of relationships with host plants appear the crucial stage of ecological-faunistic investigathions of the weevils.Location. Materials of the work were expeditionary duties of the authors, as well as staff and the students of ecologo-geografical faculty of Dagistan State University and the Institute for Applied Ecology ( Makhachkala from 2009 to 2013 year for the island Chechen.Methods. Charges were made with the help of light traps, soil traps, including trap, enhanced light source .Geografpical coordinates of all locations were recorded using GPS- navigator: T1 - 43°57’58” N 47°38’35” E; T2 - 43°58’17” N 47°42’55”; T3 - 43°59’08” N 47°44’39” E; T4 - 43°57’27” N 47°45’05” E; T5 - 43°58’11” N47°38’46” E.Results. As a result of studies were set the species composition of the faun of the beetle-weevils of the island Chechen, the analyses of the distribution of species by locality; mounted forage plants of the beetles and quantitative distribution of the beetls for families forage plants; conduct the zoogeographical analysis of studied fauna.Main conclusions. The studies on the island of Chechen were collected 187 specimens belonging to 16 species and 14 geniuse; the most common type was Coniatus splendidulus. The food base of the weevil beetles in the island of Chechen are 10 plant families,thelargest number of species focused on Chenopodiаceae, then followed Polygonaceae, Poaceae, Fabaceae. Analysis of fauna habitats of the beetle- weevils of the island Chechen allowed to allocate 7

  18. Insecticidal activity of alpha-cypermethrin against small banded pine weevil Pissodes castaneus (Coleoptera: Curculionidae in forest plantations and thickets

    Directory of Open Access Journals (Sweden)

    Prokocka Aleksandra

    2016-09-01

    Full Text Available Scots pine (Pinus sylvestris plantations and thickets damaged by biotic and abiotic factors are particularly attractive to small-banded pine weevil Pissodes castaneus, whose larvae excavate feeding tunnels in the stems of young trees, causing their death. There are no chemical methods that can be applied to protect forest plantations and thickets against this pest. Therefore, the studies were undertaken aimed at the assessment of the efficacy of alpha-cypermethrin used to reduce the numbers of this pest within restock areas. The scope of work included laboratory and field estimation of insecticidal activity of alpha-cypermethrin.

  19. Identification of secreted proteins of Aspergillus oryzae associated with growth on solid cereal substrates

    NARCIS (Netherlands)

    Biesebeke, R. te; Boussier, A.; Biezen, N. van; Hondel, C.A.M.J.J. van den; Punt, P.J.

    2006-01-01

    Filamentous growth of Aspergillus oryzae on solid cereal substrates involves secretion of substrate converting enzymes and a solid substrate specific polarised hyphal growth phenotype. To identify proteins produced under these specific conditions, the extracts of A. oryzae grown on wheat-based media

  20. Identification of secreted proteins of Aspergillus oryzae associated with growth on solid cereal substrates

    NARCIS (Netherlands)

    Biesebeke, R. te; Boussier, A.; Biezen, N. van; Hondel, C.A.M.J.J. van den; Punt, P.J.

    2006-01-01

    Filamentous growth of Aspergillus oryzae on solid cereal substrates involves secretion of substrate converting enzymes and a solid substrate specific polarised hyphal growth phenotype. To identify proteins produced under these specific conditions, the extracts of A. oryzae grown on wheat-based media

  1. Identification, Biochemical Characterization, and Evolution of the Rhizopus oryzae 99-880 Polygalacturonase Gene Family

    Science.gov (United States)

    A search of the recently sequenced Rhizopus oryzae strain 99-880 genome database uncovered 18 putative polygalacturonase genes with 2 genes being identical and only 1 with similarity to a previously reported R. oryzae polygalacturonase gene. The 17 different genes share 50% to greater than 90% iden...

  2. High Affinity Iron Permease is Required for Virulence of Rhizopus oryzae

    Science.gov (United States)

    Rhizopus oryzae is the most common cause of mucormycosis. Clinical and animal model data clearly demonstrate that the presence of elevated available serum iron predisposes the host to develop mucormycosis. The high affinity iron permease gene (rFTR1) is required for R. oryzae iron transport in iro...

  3. First Report of Rhizopus oryzae as a Postharvest Pathogen of Apple in Korea

    OpenAIRE

    Kwon, Jin-Hyeuk; Kim, Jinwoo; Kim, Won-Il

    2011-01-01

    Soft rot in apple caused by Rhizopus oryzae was found for the first time in Korea. A detailed description of the specimen is given along with its internal transcribed spacer rDNA sequence. The fungus was identified as Rhizopus oryzae based on the mycological characteristics, molecular data, and pathogenicity testing.

  4. Susceptibility of different developmental stages of large pine weevil Hylobius abietis (Coleoptera: Curculionidae) to entomopathogenic fungi and effect of fungal infection to adult weevils by formulation and application methods.

    Science.gov (United States)

    Ansari, Minshad A; Butt, Tariq M

    2012-09-15

    The large pine weevil, Hylobius abietis, is a major pest in European conifer forests causing millions of Euros of damage annually. Larvae develop in the stumps of recently felled trees; the emerging adults feed on the bark of seedlings and may kill them. This study investigated the susceptibility of different developmental stages of H. abietis to commercial and commercially viable isolates of entomopathogenic fungi, Metarhizium and Beauveria. All the developmental stages of H. abietis can be killed by Metarhizium robertsii, Metarhizium brunneum, and Beauveria bassiana. The most virulent isolate of M. robertsii ARSEF4556 caused 100% mortality of pupae, larvae and adults on day 4, 6 and 12, respectively. This strain was further tested against adult weevils in different concentrations (10(5)-10(8) conidia cm(-2) or ml(-1)) using two types of fungal formulation: 'dry' conidia and 'wet' conidia (suspended in 0.03% aq. Tween 80) applied on different substrates (tissue paper, peat and Sitka spruce seedlings). 'Dry' conidia were more effective than 'wet' conidia on tissue paper and on spruce or 'dry' conidia premixed in peat. The LC(50) value for 'dry' conidia of isolate ARSEF4556 was three folds lower than 'wet' conidia on tissue paper. This study showed that 'dry' conidia are more effective than 'wet' conidia, causing 100% adult mortality within 12 days. Possible strategies for fungal applications are discussed in light of the high susceptibility of larvae and pupae to fungal pathogen.

  5. In vitro antibacterial activity of sphaeropsidins and chemical derivatives toward Xanthomonas oryzae pv. oryzae, the causal agent of rice bacterial blight.

    Science.gov (United States)

    Evidente, Antonio; Venturi, Vittorio; Masi, Marco; Degrassi, Giuliano; Cimmino, Alessio; Maddau, Lucia; Andolfi, Anna

    2011-12-27

    Sphaeropsidin A, the main phytotoxin produced by Diplodia cupressi, as well as the two natural analogues sphaeropsidins B and C and 14 derivatives obtained by chemical modifications were assayed for antibacterial activity against Xanthomonas oryzae pv. oryzae, Pseudomonas fuscovaginae, and Burkholderia glumae, the causal agents of severe bacterial rice diseases. The results showed a strong and specific activity of sphaeropsidin A against X. oryzae pv. oryzae, while no activity was observed against the other two pathogens. The results of structure-activity relationship studies showed that structural features important to impart this antibacterial activity are the presence of the C-7 carbonyl group and the hemiketalic lactone functionality. The C-13 vinyl group, the double bond of ring C, and/or the tertiary C-9 hydroxy group, as well as the pimarane arrangement of the tricylic carbon skeleton, were also important for the antibacterial activity. These findings may be useful in designing novel compounds for practical applications in agriculture.

  6. Suppression of Rice Blast by Preinoculation with Avirulent Pyricularia oryzae and the Nonrice Pathogen Bipolaris sorokiniana.

    Science.gov (United States)

    Manandhar, H K; Lyngs Jørgensen, H J; Mathur, S B; Smedegaard-Petersen, V

    1998-07-01

    ABSTRACT Avirulent isolates of Pyricularia oryzae and isolates of Bipolaris sorokiniana, a nonrice pathogen, were used to suppress rice blast caused by P. oryzae. In greenhouse experiments, both fungi substantially reduced leaf blast when applied 24 h or more before the pathogen. B. sorokiniana, but not avirulent isolates of P. oryzae, systemically reduced disease in leaf 5 when applied to whole plants at the four-leaf stage. In field experiments, both fungi were able to reduce neck blast significantly. No increase in grain yield was obtained by using avirulent isolates of P. oryzae, whereas five sprays with B. sorokiniana from seedling to heading stages increased the grain yield in two of three experiments conducted at two locations in Nepal. The significant increase in yield was observed under high inoculum pressure of P. oryzae. Induced resistance is suggested to be involved in the suppression of disease.

  7. Transgenic cotton expressing Cry10Aa toxin confers high resistance to the cotton boll weevil.

    Science.gov (United States)

    Ribeiro, Thuanne Pires; Arraes, Fabricio Barbosa Monteiro; Lourenço-Tessutti, Isabela Tristan; Silva, Marilia Santos; Lisei-de-Sá, Maria Eugênia; Lucena, Wagner Alexandre; Macedo, Leonardo Lima Pepino; Lima, Janaina Nascimento; Santos Amorim, Regina Maria; Artico, Sinara; Alves-Ferreira, Márcio; Mattar Silva, Maria Cristina; Grossi-de-Sa, Maria Fatima

    2017-01-12

    Genetically modified (GM) cotton plants that effectively control cotton boll weevil (CBW), which is the most destructive cotton insect pest in South America, are reported here for the first time. This work presents the successful development of a new GM cotton with high resistance to CBW conferred by Cry10Aa toxin, a protein encoded by entomopathogenic Bacillus thuringiensis (Bt) gene. The plant transformation vector harbouring cry10Aa gene driven by the cotton ubiquitination-related promoter uceA1.7 was introduced into a Brazilian cotton cultivar by biolistic transformation. Quantitative PCR (qPCR) assays revealed high transcription levels of cry10Aa in both T0 GM cotton leaf and flower bud tissues. Southern blot and qPCR-based 2(-ΔΔCt) analyses revealed that T0 GM plants had either one or two transgene copies. Quantitative and qualitative analyses of Cry10Aa protein expression showed variable protein expression levels in both flower buds and leaves tissues of T0 GM cotton plants, ranging from approximately 3.0 to 14.0 μg g(-1) fresh tissue. CBW susceptibility bioassays, performed by feeding adults and larvae with T0 GM cotton leaves and flower buds, respectively, demonstrated a significant entomotoxic effect and a high level of CBW mortality (up to 100%). Molecular analysis revealed that transgene stability and entomotoxic effect to CBW were maintained in T1 generation as the Cry10Aa toxin expression levels remained high in both tissues, ranging from 4.05 to 19.57 μg g(-1) fresh tissue, and the CBW mortality rate remained around 100%. In conclusion, these Cry10Aa GM cotton plants represent a great advance in the control of the devastating CBW insect pest and can substantially impact cotton agribusiness.

  8. Evaluation of toxicity of biorational insecticides against larvae of the alfalfa weevil

    Directory of Open Access Journals (Sweden)

    Gadi V.P. Reddy

    2016-01-01

    Full Text Available The alfalfa weevil, Hypera postica (Coleoptera: Curculionidae, is a major pest of alfalfa Medicago sativa L. (Fabaceae. While H. postica usually causes the most damage before the first cutting, in summer of 2015 damaging levels of the pest persisted in Montana well after the first harvest of alfalfa. Although conventional insecticides can control H. postica, these chemicals have adverse effects on non-target organisms including pollinators and natural enemy insects. In this context, use of biorational insecticides would be the best alternative options, as they are known to pose less risk to non-target organisms. We therefore examined the six commercially available biorational insecticides against H. postica under laboratory condition: Mycotrol® ESO (Beauveria bassiana GHA, Aza-Direct® (Azadirachtin, Met52® EC (Metarhizium brunneum F52, Xpectro OD® (B. bassiana GHA + pyrethrins, Xpulse OD® (B. bassiana GHA + Azadirachtin and Entrust WP® (spinosad 80%. Concentrations of 0.1, 0.5, 1.0, and 2.0 times the lowest labelled rates were tested for all products. However, in the case of Entrust WP, additional concentrations of 0.001 and 0.01 times the lowest label rate were also assessed. Mortality rates were determined at 1–9 days post treatment. Based on lethal concentrations and relative potencies, this study clearly showed that Entrust was the most effective, causing 100% mortality within 3 days after treatment among all the tested materials. With regard to other biorational, Xpectro was the second most effective insecticide followed by Xpulse, Aza-Direct, Met52, and Mycotrol. Our results strongly suggested that these biorational insecticides could potentially be applied for H. postica control.

  9. Transcriptome analysis in cotton boll weevil (Anthonomus grandis) and RNA interference in insect pests.

    Science.gov (United States)

    Firmino, Alexandre Augusto Pereira; Fonseca, Fernando Campos de Assis; de Macedo, Leonardo Lima Pepino; Coelho, Roberta Ramos; Antonino de Souza, José Dijair; Togawa, Roberto Coiti; Silva-Junior, Orzenil Bonfim; Pappas-Jr, Georgios Joannis; da Silva, Maria Cristina Mattar; Engler, Gilbert; Grossi-de-Sa, Maria Fatima

    2013-01-01

    Cotton plants are subjected to the attack of several insect pests. In Brazil, the cotton boll weevil, Anthonomus grandis, is the most important cotton pest. The use of insecticidal proteins and gene silencing by interference RNA (RNAi) as techniques for insect control are promising strategies, which has been applied in the last few years. For this insect, there are not much available molecular information on databases. Using 454-pyrosequencing methodology, the transcriptome of all developmental stages of the insect pest, A. grandis, was analyzed. The A. grandis transcriptome analysis resulted in more than 500.000 reads and a data set of high quality 20,841 contigs. After sequence assembly and annotation, around 10,600 contigs had at least one BLAST hit against NCBI non-redundant protein database and 65.7% was similar to Tribolium castaneum sequences. A comparison of A. grandis, Drosophila melanogaster and Bombyx mori protein families' data showed higher similarity to dipteran than to lepidopteran sequences. Several contigs of genes encoding proteins involved in RNAi mechanism were found. PAZ Domains sequences extracted from the transcriptome showed high similarity and conservation for the most important functional and structural motifs when compared to PAZ Domains from 5 species. Two SID-like contigs were phylogenetically analyzed and grouped with T. castaneum SID-like proteins. No RdRP gene was found. A contig matching chitin synthase 1 was mined from the transcriptome. dsRNA microinjection of a chitin synthase gene to A. grandis female adults resulted in normal oviposition of unviable eggs and malformed alive larvae that were unable to develop in artificial diet. This is the first study that characterizes the transcriptome of the coleopteran, A. grandis. A new and representative transcriptome database for this insect pest is now available. All data support the state of the art of RNAi mechanism in insects.

  10. Transcriptome analysis in cotton boll weevil (Anthonomus grandis and RNA interference in insect pests.

    Directory of Open Access Journals (Sweden)

    Alexandre Augusto Pereira Firmino

    Full Text Available Cotton plants are subjected to the attack of several insect pests. In Brazil, the cotton boll weevil, Anthonomus grandis, is the most important cotton pest. The use of insecticidal proteins and gene silencing by interference RNA (RNAi as techniques for insect control are promising strategies, which has been applied in the last few years. For this insect, there are not much available molecular information on databases. Using 454-pyrosequencing methodology, the transcriptome of all developmental stages of the insect pest, A. grandis, was analyzed. The A. grandis transcriptome analysis resulted in more than 500.000 reads and a data set of high quality 20,841 contigs. After sequence assembly and annotation, around 10,600 contigs had at least one BLAST hit against NCBI non-redundant protein database and 65.7% was similar to Tribolium castaneum sequences. A comparison of A. grandis, Drosophila melanogaster and Bombyx mori protein families' data showed higher similarity to dipteran than to lepidopteran sequences. Several contigs of genes encoding proteins involved in RNAi mechanism were found. PAZ Domains sequences extracted from the transcriptome showed high similarity and conservation for the most important functional and structural motifs when compared to PAZ Domains from 5 species. Two SID-like contigs were phylogenetically analyzed and grouped with T. castaneum SID-like proteins. No RdRP gene was found. A contig matching chitin synthase 1 was mined from the transcriptome. dsRNA microinjection of a chitin synthase gene to A. grandis female adults resulted in normal oviposition of unviable eggs and malformed alive larvae that were unable to develop in artificial diet. This is the first study that characterizes the transcriptome of the coleopteran, A. grandis. A new and representative transcriptome database for this insect pest is now available. All data support the state of the art of RNAi mechanism in insects.

  11. Evaluation and modeling of synergy to pheromone and plant kairomone in American palm weevil

    Directory of Open Access Journals (Sweden)

    Rochat Didier

    2011-04-01

    Full Text Available Abstract Background Many behavioral responses to odors are synergistic, particularly in insects. In beetles, synergy often involves a pheromone and a plant odor, and pest management relies on them for the use of combined lures. To investigate olfactory synergy mechanisms, we need to distinguish synergistic effects from additive ones, when all components of the mixture are active. Results As versatile tools and procedures were not available, we developed a bioassay, and a mathematical model to evaluate synergy between aggregation pheromone (P and host plant odors (kairomone: K in the American palm weevil, a pest insect showing enhanced responses to P+K mixtures. Responses to synthetic P and natural K were obtained using a 4-arm olfactometer coupled to a controlled volatile delivery system. We showed that: (1 Response thresholds were ca. 10 and 100 pg/s respectively for P and K. (2 Both stimuli induced similar maximum response. (3 Increasing the dose decreased the response for P to the point of repellence and maintained a maximum response for K. (4 P and K were synergistic over a 100-fold range of doses with experimental responses to P+K mixtures greater than the ones predicted assuming additive effects. Responses close to maximum were associated with the mixture amounts below the response threshold for both P and K. Conclusion These results confirm the role of olfactory synergy in optimizing active host-plant localization by phytophagous insects. Our evaluation procedure can be generalized to test synergistic or inhibitory integrated responses of various odor mixtures for various insects.

  12. The ColRS system of Xanthomonas oryzae pv. oryzae is required for virulence and growth in iron-limiting conditions.

    Science.gov (United States)

    Subramoni, Sujatha; Pandey, Alok; Vishnu Priya, M R; Patel, Hitendra Kumar; Sonti, Ramesh V

    2012-09-01

    Xanthomonas oryzae pv. oryzae, the causal agent of bacterial blight of rice, produces siderophores only under iron-limiting conditions. We screened 15 400 mTn5-induced mutants of X. oryzae pv. oryzae and isolated 27 mutants that produced siderophores even under iron-replete conditions. We found that the mTn5 insertions in 25 of these mutants were in or close to six genes. Mutants with insertions in five of these genes [colS, XOO1806 (a conserved hypothetical protein), acnB, prpR and prpB] exhibited a deficiency for growth on iron-limiting medium and a decrease in virulence. Insertions in a sixth gene, XOO0007 (a conserved hypothetical protein), were found to affect the ability to grow on iron-limiting medium, but did not affect the virulence. Targeted gene disruptants for colR (encoding the predicted cognate regulatory protein for ColS) also exhibited a deficiency for growth on iron-limiting medium and a decrease in virulence. colR and colS mutants were defective in the elicitation of hypersensitive response symptoms on the nonhost tomato. In addition, colR and colS mutants induced a rice basal defence response, suggesting that they are compromised in the suppression of host innate immunity. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis demonstrated that a functional ColRS system is required for the optimal expression of several genes encoding components of the type 3 secretion system (T3SS) of X. oryzae pv. oryzae. Our results demonstrate the role of several novel genes, including colR/colS, in the promotion of growth on iron-limiting medium and the virulence of X. oryzae pv. oryzae.

  13. Diversity of the Ty-1 copia retrotransposon Tos17 in rice (Oryza sativa L.) and the AA genome of the Oryza genus

    OpenAIRE

    Petit, J.; Bourgeois, E; Stenger, W.; Bes, M.; Droc, G.; Meynard, D.; Courtois, B.; Ghesquière, Alain; Sabot, François; Panaud, O.; Guiderdoni, E.

    2009-01-01

    Retrotransposons are mobile genetic elements, ubiquitous in Eukaryotic genomes, which have proven to be major genetic tools in determining phylogeny and structuring genetic diversity, notably in plants. We investigate here the diversity of the Ty1-copia retrotransposon Tos17 in the cultivated rice of Asian origin (Oryza sativa L.) and related AA genome species of the Oryza genus, to contribute understanding of the complex evolutionary history in this group of species through that of the eleme...

  14. Phylogeography and the geographic cline in the armament of a seed-predatory weevil: effects of historical events vs. natural selection from the host plant.

    Science.gov (United States)

    Toju, Hirokazu; Sota, Teiji

    2006-11-01

    Japanese camellia (Camellia japonica) and its seed predator, the camellia weevil (Curculio camelliae), provide a notable example of a geographic mosaic of coevolution. In the species interaction, the offensive trait of the weevil (rostrum length) and the defensive trait of the plant (pericarp thickness) are involved in a geographically-structured arms race, and these traits and selective pressures acting on the plant defence vary greatly across a geographical landscape. To further explore the geographical structure of this interspecific interaction, we tested whether the geographical variation in the weevil rostrum over an 800-km range along latitude is attributed to local natural selection or constrained by historical (phylogeographical) events of local populations. Phylogeographical analyses of the mitochondrial DNA sequences of the camellia weevil revealed that this species has experienced differentiation into two regions, with a population bottleneck and subsequent range and/or population expansion within each region. Although these phylogeographical factors have affected the variation in rostrum length, analyses of competing factors for the geographical variation revealed that this pattern is primarily determined by the defensive trait of the host plant rather than by the effects of historical events of populations and a climatic factor (annual mean temperature). Thus, our study suggests the overwhelming strength of coevolutionary selection against the effect of historical events, which may have limited local adaptation.

  15. Integrated biological control of water hyacinths, Eichhornia crassipes by a novel combination of grass carp, Ctenopharyngodon idella (Valenciennes, 1844), and the weevil, Neochetina spp.

    Institute of Scientific and Technical Information of China (English)

    GOPALAKRISHNAN Ayyaru; RAJKUMAR Mayalagu; SUN Jun; PARIDA Ajay; VENMATHI MARAN Balu Alagar

    2011-01-01

    The efficacy of grass carp Ctenopharyngodon idella (Cyprinidae) and weevils Neochetina spp. (Curculionidae) to control the aquatic weed, water hyacinth, is investigated in a square net cage (happas) setting at a farm in Cuddalore District, South India. This novel combination of insects and fish is found to be superior to individual treatments for controlling the weed growth within 110 d. The biomass of the weed, number of plants, percentage of flowered plants and chlorophyll contents were studied. The weed biomass is reduced from 5 kg (dayto 0.33 kg (day 110) when exposed to grass carp and weevils. The number of plants is reduced to 0.75 in grass carp and weevil exposed happas, while it is 741.5 in the control. The mean number of leaves per plant is also reduced. In addition, the chlorophyll a and b are significantly reduced in happas exposed to the combination of fish and insects when compared to the other treatments. Based on the results of this study, we consider the combined use of grass carp and weevils to be more efficient and sustainable for managing water hyacinths than the use of these organisms individually.

  16. The weevil genus Achia champion (Coleoptera: Curculionidae): new species associate with urvillea (Sapindaceae) and New Serjania Host Plant records for A. ancile Burke and A. affinis Hustache

    Science.gov (United States)

    Three new species of the weevil genus Achia Champion are described: A. urvilleae Clark and Burke from the state of Santa Catarina, Brazil and Misiones Province, Argentina; A. uniformis Clark and Burke from Bolivia; and A. boliviana Clark and Burke from Bolivia and Salta and Santiago del Estero prov...

  17. Recent developments in the use of acoustic sensors and signal processing tools to target early infestations of red palm weevil (Coleopter: Curculionidae) in agricultural environments

    Science.gov (United States)

    Much of the damage caused by red palm weevil larvae to date palms, ornamental palms, and palm offshoots could be mitigated by early detection and treatment of infestations. Acoustic technology has potential to enable early detection, but the short, high-frequency sound impulses produced by red palm ...

  18. Recent developments in the use of acoustic sensors and signal processing tools to target early infestations of Red Palm Weevil in agricultural environments

    Science.gov (United States)

    Much of the damage caused by red palm weevil larvae to date palms, ornamental palms, and palm offshoots could be mitigated by early detection and treatment of infestations. Acoustic technology has potential to enable early detection, but the short, high-frequency sound impulses produced by red palm ...

  19. Estimating of larval stadia of West Indian sweetpotato weevil Euscepes postfasciatus (Fairmaire) developed in the artificial larval diet by measuring larval head widths.

    OpenAIRE

    下地, 幸夫; Shimoji, Yukio; 琉球産経株式会社

    2003-01-01

    The survey conducted by measuring larval head widths of West Indian sweetpotato weevil Euscepes postfasciatus developed in the artificial larval diet revealed that there were five larval stadia in the developmental period. The result of this experiment can be used to estimate the larval stadia approximately in the artificial larval diet.

  20. Identification of genome regions controlling cotyledon, pod wall/seed coat and pod wall resistance to pea weevil through QTL mapping.

    Science.gov (United States)

    Aryamanesh, N; Zeng, Y; Byrne, O; Hardie, D C; Al-Subhi, A M; Khan, T; Siddique, K H M; Yan, G

    2013-11-15

    Pea weevil, Bruchus pisorum, is one of the limiting factors for field pea (Pisum sativum) cultivation in the world with pesticide application the only available method for its control. Resistance to pea weevil has been found in an accession of Pisum fulvum but transfer of this resistance to cultivated pea (P. sativum) is limited due to a lack of easy-to-use techniques for screening interspecific breeding populations. To address this problem, an interspecific population was created from a cross between cultivated field pea and P. fulvum (resistance source). Quantitative trait locus (QTL) mapping was performed to discover the regions associated with resistance to cotyledon, pod wall/seed coat and pod wall resistance. Three major QTLs, located on linkage groups LG2, LG4 and LG5 were found for cotyledon resistance explaining approximately 80 % of the phenotypic variation. Two major QTLs were found for pod wall/seed coat resistance on LG2 and LG5 explaining approximately 70 % of the phenotypic variation. Co-linearity of QTLs for cotyledon and pod wall/seed coat resistance suggested that the mechanism of resistance for these two traits might act through the same pathways. Only one QTL was found for pod wall resistance on LG7 explaining approximately 9 % of the phenotypic variation. This is the first report on the development of QTL markers to probe Pisum germplasm for pea weevil resistance genes. These flanking markers will be useful in accelerating the process of screening when breeding for pea weevil resistance.

  1. Pre-release evaluation of Neochetina weevils potential for the management of Eichhornia crassipes [Mart.] Solm. In the Rift valley of Ethiopia

    NARCIS (Netherlands)

    Gebregiorgis, F.Y.; Struik, P.C.; Lantinga, E.A.; Taye, T.

    2016-01-01

    The present study aimed at evaluating the host-specificity, potential efficacy and optimum densities of the two weevils (Neochetina bruchi and N. eichhorniae) as water hyacinth control agents in the Rift Valley of Ethiopia. Density-plant damage relationship was monitored for two years (2012 to 2014)

  2. Adaptability of two weevils (Neochetina bruchi and Neochetina eichhorniae) with potential to control water hyacinth in the Rift Valley of Ethiopia

    NARCIS (Netherlands)

    Firehun, Y.; Struik, P.C.; Lantinga, E.A.; Taye, T.

    2015-01-01

    Neochetina weevils have potential as biocontrol agents for water hyacinth, an aquatic weed which seriously affects irrigation water supply in sugarcane, vegetables and other horticultural crop production in the Rift Valley of Ethiopia. A study was conducted on (i) the adaptability and duration of de

  3. 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...

  4. Trapping sweetpotato weevil, Cylas formicarius elegantulus (Coleoptera: Brentidae), with high doses of sex pheromone: Catch enhancement and weathering rate in Hawaii

    Science.gov (United States)

    Sweetpotato, Ipomoea batatas (L.) Lamarck, one of the top ten staple crops produced worldwide, has increased in production in Hawaii in recent years. The sweetpotato weevil, Cylas formicarius elegantulus (Summers)(Coleoptera: Brentidae), is a major economic and quarantine pest of sweetpotato in Hawa...

  5. Dielectric properties of cowpea weevil, black eyed peas and mung beans with respect to the development of radio frequency heat treatments

    Science.gov (United States)

    In developing radio frequency (RF) and microwave (MW) disinfestation treatments for chickpeas and lentils, large amounts of product infested with cowpea weevil must be treated to validate treatment efficacy. To accomplish this, black-eyed peas and mung beans are being considered for use as surrogate...

  6. New records of Paracrias Ashmead (Hymenoptera, Eulophidae as parasitoids on weevil larvae (Coleoptera, Curculionidae in Brazil, with the description of a new species

    Directory of Open Access Journals (Sweden)

    Luciano Palmieri

    2013-09-01

    Full Text Available Paracrias strii Schauff, 1985 and P. ceratophaga Palmieri & Hansson sp. nov. are first record in Brazil and both are associated with Ceratopus Schoenherr larvae (Coleoptera, Curculionidae reared from syconia of two species of fig-trees. Both Paracrias species are diagnosed and illustrated. Males of P. ceratophaga sp. nov. are described. The association of Paracrias with weevil larvae is briefly discussed.

  7. First field collection of the Rough Sweetpotato Weevil, Blosyrus asellus(Olivier)(Coleoptera: Curculionidae) on Hawaii Island, with notes on detection methods

    Science.gov (United States)

    Rough sweetpotato weevil, Blosyrus asellus(Olivier)(Coleoptera: Curculionidae), was first detected in the state of Hawaii at a commercial Okinawan sweetpotato farm in Waipio, Oahu, on 14 November 2008. Reported here is, the first detection of this pest in sweetpotato fields on the island of Hawaii (...

  8. The RpfB-Dependent Quorum Sensing Signal Turnover System Is Required for Adaptation and Virulence in Rice Bacterial Blight Pathogen Xanthomonas oryzae pv. oryzae.

    Science.gov (United States)

    Wang, Xing-Yu; Zhou, Lian; Yang, Jun; Ji, Guang-Hai; He, Ya-Wen

    2016-03-01

    Xanthomonas oryzae pv. oryzae, the bacterial blight pathogen of rice, produces diffusible signal factor (DSF) family quorum sensing signals to regulate virulence. The biosynthesis and perception of DSF family signals require components of the rpf (regulation of pathogenicity factors) cluster. In this study, we report that RpfB plays an essential role in DSF family signal turnover in X. oryzae pv. oryzae PXO99A. The production of DSF family signals was boosted by deletion of the rpfB gene and was abolished by its overexpression. The RpfC/RpfG-mediated DSF signaling system negatively regulates rpfB expression via the global transcription regulator Clp, whose activity is reversible in the presence of cyclic diguanylate monophosphate. These findings indicate that the DSF family signal turnover system in PXO99A is generally consistent with that in Xanthomonas campestris pv. campestris. Moreover, this study has revealed several specific roles of RpfB in PXO99A. First, the rpfB deletion mutant produced high levels of DSF family signals but reduced extracellular polysaccharide production, extracellular amylase activity, and attenuated pathogenicity. Second, the rpfB/rpfC double-deletion mutant was partially deficient in xanthomonadin production. Taken together, the RpfB-dependent DSF family signal turnover system is a conserved and naturally presenting signal turnover system in Xanthomonas spp., which plays unique roles in X. oryzae pv. oryzae adaptation and pathogenesis.

  9. Morphology of salivary gland and distribution of dopamine and serotonin on red palm weevil (RPW), Rhynchophorus ferrugineus (Coleoptera: Curculionidae)

    Science.gov (United States)

    Hidayah, A. S. Nurul; Wahida, O. Nurul; Shafinaz, M. N. Norefrina; Idris, A. G.

    2013-11-01

    The Red Palm Weevil (RPW), Rhynchophorus ferrugineus (Olivier, 1790) is insect pest to plants of the family Palmaceae. No study has been reported on the digestive mechanism of Red Palm Weevil (RPW). Salivary glands are responsible in the feeding regulation of insect while serotonin and dopamine play a significant role in the regulation of this gland. It is great to see the morphology of the salivary gland and how dopamine and serotonin possibly play their role in this gland. Two variation of RPW, striped and spotted RPW were chosen. The morphology of the gland of both RPW variants examined by using light microscopy was found to be a tubular type. Immunohistochemical analysis conducted showed that serotonin and dopamine in both variations did not innervate the glands suggesting they are not act as neurotransmitter. However, it can be detected on few areas within the glands. This suggests that serotonin and dopamine may act as a hormone because there is no evidence on the nerve fibers. The role of these biogenic amines in the salivary gland of RPW needs further investigation. Hopefully the data would help in understanding the mechanism of salivary glands control by biogenic amines in RPW specifically and insects with sucking mouthpart generally.

  10. Abundance and Frequency of the Asiatic Oak Weevil (Coleoptera: Curculionidae) and Defoliation on American, Chinese, and Hybrid Chestnut (Castanea)

    Science.gov (United States)

    Case, Ashley E.; Mayfield, Albert E.; Clark, Stacy L.; Schlarbaum, Scott E.; Reynolds, Barbara C.

    2016-01-01

    The Asiatic oak weevil, Cyrtepistomus castaneus Roelofs (Coleoptera: Curculionidae), is a nonnative defoliator of trees in the Fagaceae family in the United States but has not been studied on Castanea species in the southern Appalachian Mountains. Planted trees of Castanea dentata (Marsh.) Borkh. (Fagales: Fagaceae), Castanea mollissima Blume (Fagales: Fagaceae), and four hybrid breeding generations were evaluated in 2012 for insect defoliation and C. castaneus abundance and frequency. Defoliation was visually assessed throughout the growing season at two sites in the southern Appalachian Mountains (western North Carolina and eastern Tennessee). C. castaneus abundance and frequency were monitored on trees using beat sheets and emergence was recorded from ground traps. Asiatic oak weevils were more abundant and more frequently collected on American chestnut (Ca. dentata) and its most closely related BC3F3 hybrid generation than on the Asian species Ca. mollissima. In most months, C. castaneus colonization of hybrid generations was not significantly different than colonization of parental species. Frequency data for C. castaneus suggested that adults were distributed relatively evenly throughout the study sites rather than in dense clusters. Emergence of C. castaneus was significantly higher under a canopy dominated by Quercus species than under non-Quercus species or open sky. C. castaneus emergence began in May and peaked in late June and early July. These results may be useful for resource managers trying to restore blight-resistant chestnut to the Southern Appalachians while minimizing herbivory by insect pests. PMID:27001964

  11. Host plant phenology affects performance of an invasive weevil, Phyllobius oblongus (Coleoptera: Curculionidae), in a northern hardwood forest.

    Science.gov (United States)

    Coyle, David R; Jordan, Michelle S; Raffa, Kenneth F

    2010-10-01

    We investigated how host plant phenology and plant species affected longevity, reproduction, and feeding behavior of an invasive weevil. Phyllobius oblongus L. (Coleoptera: Curculionidae) is common in northern hardwood forests of the Great Lakes Region. Adults emerge in spring, feed on foliage of woody understory plants, and oviposit in the soil. Preliminary data indicate that adults often feed on sugar maple, Acer saccharum Marshall, foliage early in the season, then feed on other species such as raspberry, Rubus spp. Whether this behavior reflects temporal changes in the quality of A. saccharum tissue or merely subsequent availability of later-season plants is unknown. We tested adult P. oblongus in laboratory assays using young (newly flushed) sugar maple foliage, old (2-3 wk postflush) sugar maple foliage, and raspberry foliage. Raspberry has indeterminate growth, thus always has young foliage available for herbivores. Survival, oviposition, and leaf consumption were recorded. In performance assays under no-choice conditions, mated pairs were provided one type of host foliage for the duration of their lives. In behavioral choice tests, all three host plants were provided simultaneously and leaf area consumption was compared. Adults survived longer on and consumed greater amounts of young maple and raspberry foliage than old maple foliage. P. oblongus preferred young maple foliage to old maple foliage early in the season, however, later in the growing season weevils showed less pronounced feeding preferences. These results suggest how leaf phenology, plant species composition, and feeding plasticity in host utilization may interact to affect P. oblongus population dynamics.

  12. Pepper Weevil (Coleoptera: Curculionidae) Preferences for Specific Pepper Cultivars, Plant Parts, Fruit Colors, Fruit Sizes, and Timing.

    Science.gov (United States)

    Seal, Dakshina R; Martin, Cliff G

    2016-03-04

    Peppers (Capsicum spp.) are an important crop in the USA, with about 32,000 ha cultivated in 2007, which resulted in $588 million in farm revenue. The pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae), is the most troublesome insect pest of peppers in the southern United States. It is therefore urgent to find different vulnerabilities of pepper cultivars, fruit and plants parts, fruit colors and sizes, and timing to infestation by A. eugenii. Also relevant is testing whether fruit length and infestation state affect fruit numbers, weights, and proportions of fruit that are infested. Counts of A. eugenii adults and marks from oviposition and feeding suggested that C. chinense Jacquin "Habanero" was least susceptible, and C. annuum L. cultivars "SY" and "SR" were most susceptible. Comparison of plant parts and fruit sizes revealed that A. eugenii preferred the peduncle, calyx, and top of pepper fruits over the middle, bottom, leaves, or remainder of flowers. Anthonomus eugenii does not discriminate between green or yellow fruit color nor vary diurnally in numbers. Based on adult counts, medium to extra-large fruits (≥1.5 cm long) attracted more weevils than small fruits (eugenii by reduced susceptibility or by synchronous fruit drop of infested fruits. Our results are potentially helpful in developing scouting programs including paying particular attention to the preferred locations of adults and their sites of feeding and oviposition on the fruit. The results also suggested the potential value of spraying when the fruits are still immature to prevent and control infestation.

  13. Assessing the virulence of ophiostomatoid fungi associated with the pine-infesting weevils to scots pine Pinus sylvestris L. seedlings

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    Robert Jankowiak

    2013-07-01

    Full Text Available The pine-infesting weevils are known to be effective vectors of ophiostomatoid fungi. To understand more about fungal virulence of these fungi, inoculation studies were conducted on Scots pine (Pinus sylvestris L.. Two-year-old seedlings were wound-inoculated with one of eleven ophiostomatoid fungi associated with pine-infesting weevils. After 11 weeks, a darkened lesion, extending from the point of inoculation, was observed in all species, except for Ophiostoma cf. abietinum Marm. & Butin, Ophiostoma quercus (Georgev. Nannf., and Sporothrix inflata de Hoog. Seedling mortality was observed in seedlings inoculated with Leptographium truncatum (M.J. Wingf. & Marasas M.J. Wingf., Leptographium lundbergii Lagerb. & Melin, Leptographium procerum (W.B. Kendr. M.J. Wingf., Grosmannia radiaticola (J.J. Kim, Seifert & G.H. Kim Zipfel, Z.W. de Beer & M.J. Wingf., Ophiostoma floccosum Math.-Käärik, Ophiostoma minus (Hedgc. Syd. & P. Syd., and Ophiostoma piliferum (Fr. Syd. & P. Syd. Ophiostoma minus and L. truncatum caused the largest lesions and sapwood blue-stain in Scots pine. Grosmannia radiaticola, Ophiostoma piceae (Münch Syd. & P. Syd., O. floccosum, O. piliferum, L. lundbergii,and L. procerum produced significantly smaller lesions and sapwood blue-stain than O. minus and L. truncatum, while O. cf. abietinum, O. quercus and S. inflata did not cause any lesions.

  14. Larval competition in weevils Revena rubiginosa (Coleoptera: Curculionidae) preying on seeds of the palm Syagrus romanzoffiana (Arecaceae)

    Science.gov (United States)

    Alves-Costa, Cecília P.; Knogge, Christoph

    2005-06-01

    Inter- and intraspecific local resource competition may lead to the selection of specific adaptive individual characteristics to overcome interference competition. A highly selective scenario is predictable for interference competition among seed preying weevil larvae that live in and feed upon a single host seed. This scenario is found in Syagrus romanzoffiana palm seeds which are predated by Revena rubiginosa (Curculionidae) larvae. Although multiple infestation of one seed by weevil larvae can occur, invariably only one individual survives and develops in each host seed. A strong competition between the first instar larvae in a restricted window of host fruit development stages leads to physical interactions of conspecifics by ovicide or direct fighting using falcate mandibles. The occurrence of this type of mandible is synchronized with fruit development and restricted to instars with probable competition, as infestation occurs only while the endocarp is soft. Only after lignification of the endocarp the larva changes into the next instar. Mandibles of subsequent instars differ markedly from those of the first instar. The new mandibles can scrape the solid endosperm but are unable to perforate and kill conspecifics. These findings give strong evidence for the selective pressure of intraspecific competition, where special behaviour, mandible morphology and synchronization of its changes with the seed development contribute to individual benefit that involves the killing of conspecifics, since one host seed can only maintain a single larva throughout its complete development.

  15. Assessment of Insecticidal Efficacy of Diatomaceous Earth and Powders of Common Lavender and Field Horsetail against Bean Weevil Adults.

    Science.gov (United States)

    Bohinc, T; Vayias, B; Bartol, T; Trdan, S

    2013-12-01

    In the search for an effective and sustainable control method against the bean weevil Acanthoscelides obtectus (Say), an important insect pest affecting stored common beans and other legumes, three different powders were tested against adult been weevils under laboratory conditions. The three powders were diatomaceous earth (DE) (commercial product SilicoSec®), common lavender (Lavandula angustifolia) powder and field horsetail (Equisetum arvense) powder. The substances were tested at five temperatures (15, 20, 25, 30, and 35°C), two relative humidity levels (RH) (55 and 75%), and four concentrations (100, 300, 500, and 900 ppm). The mortality of adults was measured after the 1st, 2nd, 4th, and 7th days of exposure. The efficacy of the powders increased with the temperature, whereas in general, RH did not have a significant effect on the adults' survival. According to common practice of storing common beans, we recommend the use of DE against the pest in question, as this inert powder showed the highest efficacy at lower temperatures and concentrations. Concerning the wider use of common lavender and field horsetail powders, we suggest studying their combined use with other environmentally friendly methods with the aim of achieving the highest synergistic effect possible.

  16. 香蕉根颈象甲研究进展%Advance in Banana Weevil, Cosmopolites sordidus(Germar)

    Institute of Scientific and Technical Information of China (English)

    邱海燕; 刘奎; 谢艺贤; 张欣

    2011-01-01

    香蕉根颈象甲是危害香蕉的重要害虫,在部分地区的留芽蕉园内发生较为严重.本文对国内外香蕉根颈象甲的生物学特性、香蕉根颈象甲的农业防治、化学防治、信息化合物防治及生物防治方面的研究进行了综述,并对其前景进行讨论,旨在为国内开展香蕉根颈象甲的研究和在生产中的防治提供参考.%The banana weevil, Cosmopolites sordidus (Germar), is regarded as an important insect pest of banana and plantain, and in some ratoon crops it's damage is more serious. The research achievements about biological characteristics, integrated management which included cultural control, chemical control, infochemicals control and biological control of Cosmopolites sordidus (Germar)were summarized, and the future research work was also discussed. The aim was to offer reference for the national research and the integrated management about the banana weevil.

  17. Ripening for improving the quality of inoculated cheese Rhizopus oryzae

    Directory of Open Access Journals (Sweden)

    ARTINI PANGASTUTI

    2010-01-01

    Full Text Available Estikomah SA, Sutarno, Pangastuti A 2010. Ripening for improving the quality of inoculated cheese Rhizopus oryzae. Nusantara Bioscience 2: 1-6. Cheese is dairy product resulted from fermented milk in which the fermentation process can be done by lactic acid bacteria or fungus. Rhizopus oryzae is able to produce lactic acid, protease and lipase. The ripening process changes the taste and texture. The purpose of this study is ripening to improve the quality of inoculated cheese R. oryzae. In this research the ripening was conducted the concentration variation of temperature (5oC, 10oC, 15oC, and time (7 days, 14 days. The procedure of research consisted of two steps, namely un-ripened cheese preparation followed by ripening cheese preparation. Cheese produced in this study analyzed the value of pH, fat content, protein content, amino acid levels and identification of microbe with ANOVA then followed by DMRT at 5% level of significance. Data results were analyzed with the like’s nonparametric statistical test, followed by Fridman Wilcoxon Signed Rank Test (WSRT at 5% level significance. The results showed that the preferred ripened cheese panelist was at a temperature of 15oC for 14 days. Ripening conditions affect pH, fat content, protein content and do not affect the levels of amino acids that formed ripened cheese. The best quality ripened cheese i.e. at a temperature of 15°C for 14 days, had a pH value of 4.40, the highest protein content of 9.78%, and fat content of 35.02%. The results of identified microbe in un-ripened cheese and ripened cheese include Enterococcus hirae (Enterococcus faecalis, Bacillus subtilis, and Aspergillus sp.

  18. Pemeraman untuk meningkatkan kualitas keju yang diinnokulasi Rhizopus oryzae

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    SOLIKAH ANA ESTIKOMAH

    2010-11-01

    Full Text Available Estikomah SA, Sutarno, Pangastuti A. 2010. Pemeraman untuk meningkatkaan kualitas keju yang diinokulasi Rhizopus oryzae. Bioteknologi 7: 55-62. Keju merupakan makanan hasil fermentasi dari susu yang proses fermentasinya dilakukan oleh bakteri asam laktat maupun jamur. Rhizopus oryzae diketahui mampu menghasilkan asam laktat, protease, dan lipase. Perubahan cita rasa dan tekstur keju terjadi selama pemeraman keju. Tujuan penelitian ini adalah untuk meningkatkan kualitas keju yang diinokulasi R. oryzae melalui pemeraman. Pemeraman dilakukan dengan variasi waktu (7, 14 hari dan suhu (5ºC, 10ºC, 15ºC. Penelitian ini terdiri dua tahap, yaitu pembuataan keju mentah diikuti pemeraman keju mentah tersebut. Keju penelitian dianalisis nilai pH, kadar lemak, kadar protein, kadar asam amino dan diidentifikasi mikrobanya. Data hasil penellitian dianalisis dengan uji siidik ragam (ANAVA, kemudian dilanjutkan dengan uji berjarak ganda Duncan (DMRT pada taraf signifikansi 5%. Data hasil tingkat kesukaan dianalisis dengan statistik nonparametrik uji Fridman yang dilanjutkaan dengan Wilcoxon Signed Rank Test (WSRT pada taraf sigifikansi 5%. Hasil penelitian menunjukkan bahwa keju peram yang disukai panelis adalah keju peram pada suhu 15ºC selama 14 hari. Kondisi pemeraman berpengaruh terhadap nilai pH, kadar lemak,, kadar proteinn dan tidak berpengaruh pada kadar asam amino. Kualitas keju peram terbaik terdapat pada kondisi suhu 15°C selama 14 hari, memiliki nilai pH 4,40, kadar protein tertinggi yaitu sebesar 99,78%, dan kadar lemak sebesar 35,02%. Hasil identifikasi mikroba pada keju mentah dan keju peram meliputi Enterococcus hirae (Enterococcus faecalis, Bacillus subtilis, dan Aspergillus sp.

  19. Subcutaneous mucormycosis caused by Rhizopus oryzae: probable nosocomial acquired infection

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    Flávio de Queiroz Telles Filho

    1985-08-01

    Full Text Available The Authors present a case of subcutaneous mucormycosis occurring in a patient with clinical and biochemical evidence of diabetic ketoacidosis. The clinical, mycological and histopathological features are described, emphasizing the relevance of a rapid diagnosis in order to stablish early treatment. The clinical forms of mucormycosis and the main associated conditions are briefly reviewed as well as the most probable conditions which may lead to the enhanced susceptibility to infection in the diabetic patient in ketoacidosis. The recovery of Rhizopus oryzae from the air of the room of the patient suggests a nosocomial infection acquired through contamination of venous puncture site by air borne spores.

  20. Evidence for biotrophic lifestyle and biocontrol potential of dark septate endophyte Harpophora oryzae to rice blast disease.

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    Zhen-Zhu Su

    Full Text Available The mutualism pattern of the dark septate endophyte (DSE Harpophora oryzae in rice roots and its biocontrol potential in rice blast disease caused by Magnaporthe oryzae were investigated. Fluorescent protein-expressing H. oryzae was used to monitor the colonization pattern. Hyphae invaded from the epidermis to the inner cortex, but not into the root stele. Fungal colonization increased with root tissue maturation, showing no colonization in the meristematic zone, slight colonization in the elongation zone, and heavy colonization in the differentiation zone. H. oryzae adopted a biotrophic lifestyle in roots accompanied by programmed cell death. Real-time PCR facilitated the accurate quantification of fungal growth and the respective plant response. The biocontrol potential of H. oryzae was visualized by inoculation with eGFP-tagged M. oryzae in rice. H. oryzae protected rice from M. oryzae root invasion by the accumulation of H2O2 and elevated antioxidative capacity. H. oryzae also induced systemic resistance against rice blast. This systemic resistance was mediated by the OsWRKY45-dependent salicylic acid (SA signaling pathway, as indicated by the strongly upregulated expression of OsWRKY45. The colonization pattern of H. oryzae was consistent with the typical characteristics of DSEs. H. oryzae enhanced local resistance by reactive oxygen species (ROS and high antioxidative level and induced OsWRKY45-dependent SA-mediated systemic resistance against rice blast.

  1. Evidence for biotrophic lifestyle and biocontrol potential of dark septate endophyte Harpophora oryzae to rice blast disease.

    Science.gov (United States)

    Su, Zhen-Zhu; Mao, Li-Juan; Li, Na; Feng, Xiao-Xiao; Yuan, Zhi-Lin; Wang, Li-Wei; Lin, Fu-Cheng; Zhang, Chu-Long

    2013-01-01

    The mutualism pattern of the dark septate endophyte (DSE) Harpophora oryzae in rice roots and its biocontrol potential in rice blast disease caused by Magnaporthe oryzae were investigated. Fluorescent protein-expressing H. oryzae was used to monitor the colonization pattern. Hyphae invaded from the epidermis to the inner cortex, but not into the root stele. Fungal colonization increased with root tissue maturation, showing no colonization in the meristematic zone, slight colonization in the elongation zone, and heavy colonization in the differentiation zone. H. oryzae adopted a biotrophic lifestyle in roots accompanied by programmed cell death. Real-time PCR facilitated the accurate quantification of fungal growth and the respective plant response. The biocontrol potential of H. oryzae was visualized by inoculation with eGFP-tagged M. oryzae in rice. H. oryzae protected rice from M. oryzae root invasion by the accumulation of H2O2 and elevated antioxidative capacity. H. oryzae also induced systemic resistance against rice blast. This systemic resistance was mediated by the OsWRKY45-dependent salicylic acid (SA) signaling pathway, as indicated by the strongly upregulated expression of OsWRKY45. The colonization pattern of H. oryzae was consistent with the typical characteristics of DSEs. H. oryzae enhanced local resistance by reactive oxygen species (ROS) and high antioxidative level and induced OsWRKY45-dependent SA-mediated systemic resistance against rice blast.

  2. Sunflower stem weevil and its larval parasitoids in native sunflowers: is parasitoid abundance and diversity greater in the U.S. Southwest?

    Science.gov (United States)

    Ode, Paul J; Charlet, Laurence D; Seiler, Gerald J

    2011-02-01

    Classical biological control programs often target a pest's region of origin as a likely source for new biological control agents. Here, we use this approach to search for biological control agents of the sunflower stem weevil (Cylindrocopturus adspersus LeConte), an economically important pest of commercial sunflower. We conducted surveys of weevil natural enemy diversity and abundance across a transect running from the northern Great Plains to the southwestern U.S. (the presumed area of endemism of annual sunflower species in the genus Helianthus). Accordingly, natural enemy diversity and abundance were expected to be greater in the southwestern U.S. C. adspersus and their larval parasitoids were collected from stems of four native sunflower species (Helianthus annuus, H. nuttallii, H. pauciflorus, and H. petiolaris) from 147 sites across eight states. Native H. annuus constituted the majority of the sunflower populations. Mean weevil densities were significantly higher in sunflower stalks that were larger in diameter. Mean weevil densities within sites did not differ across the range of longitudes and latitudes sampled. After accounting for the effects of stalk diameter and location, weevil densities did not differ among the four sunflower species nor did they differ as a function of elevation. C. adspersus in H. annuus and H. petiolaris were attacked by seven species of parasitoids. No parasitoids were found attacking C. adspersus in H. nuttallii or H. pauciflorus stalks. C. adspersus were twice as likely to be attacked by a parasitoid when feeding on H. petiolaris than H. annuus. Furthermore, the likelihood that C. adspersus would be parasitized decreased with increasing elevation and increasing stem diameters. All parasitoid species have been previously reported attacking C. adspersus larvae in cultivated sunflower. Species richness was less diverse in these collections than from previous studies of cultivated sunflower. Our findings suggest that the species

  3. Toxicidade por fumigação, contato e ingestão de óleos essenciais para Sitophilus zeamais Motschulsky, 1885 (Coleoptera: Curculionidae Toxicity by fumigation, contact and ingestion of essential oils in Sitophilus zeamais Motschulsky, 1885 (Coleoptera: Curculionidae

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    Rodrigo Leandro Braga de Castro Coitinho

    2011-02-01

    Full Text Available A espécie Sitophilus zeamais é uma das principais pragas do milho armazenado no Brasil. O controle é feito, comumente, utilizando-se medidas de higienização e limpeza, bem como inseticidas sintéticos fumigantes e protetores. A busca por produtos menos tóxicos, biodegradáveis e seguros do ponto de vista ecológico, é muito bem aceita pela sociedade. Assim, os objetivos do presente trabalho foram testar a toxicidade de contato e ingestão e fumigante de óleos essenciais e do composto orgânico natural eugenol para adultos de S. zeamais. Os valores de CL50 dos óleos essenciais provenientes de folhas de Piper hispidinervum, Eugenia uniflora, Cinnamomum zeylanicum, P. marginatum, Schinus terebinthifolius, Melaleuca leucadendron, dos frutos verdes de S terebinthifolius e do composto eugenol, nos testes de contato e ingestão, foram estimados em 1,0; 11,6; 14,2; 21,1; 57,7; 75,8; 98,8 e 14,8 µL/40 g de milho, respectivamente. As razões de toxicidade (RT variaram entre 1,3 e 98,8. Na fumigação em adultos, as concentrações letais dos óleos variaram de 0,53 a 94,7 µL/L de ar, obedecendo à seguinte ordem decrescente de toxicidade: P. hispidinervum > P. aduncum > S. terebinthifolius > frutos verdes de S. terebinthifolius > P. marginatum > eugenol e as RT variaram entre 2,0 a 178,7.The Sitophilus zeamais species is a major pest of stored maize in Brazil. The control is made, usually, using measures of hygiene and cleanliness, synthetic insecticides and fumigant protectors. The search for less toxic products, biodegradable and safe from an ecological point of view is very well accepted by society. the objective of this study was to test the toxicity by contact and ingestion and fumigant of essential oils and eugenol natural organic compound for adults of S. zeamais. The values of LC50 in oil from leaves of Piper hispidinervum, Eugenia uniflora, Cinnamomum zeylanicum, P. marginatum, Schinus terebinthifolius, Melaleuca leucadendron, green

  4. 鹿蹄草对两种储粮害虫成虫的毒力测定%TOXICITY TEST OF PYROLA DECORATA EXTRACT AGAINST RHIZOPERTHA DOMINICA AND SITOPHILUS ZEAMAIS

    Institute of Scientific and Technical Information of China (English)

    巩蔼

    2004-01-01

    用鹿蹄草(Pyrola decorata)的萃取物对玉米象(Sitophilus zeamais)和谷蠹(Rhizopertha dominica)进行了毒力测定.测定结果为:玉米象y=1.9799x+2.9761,谷蠹y=1.7407x+2.8173,加入增效醚后,玉米象y=1.8603x+3.6897,谷蠹y=1.5779x+2.8751.实验结果表明鹿蹄草对以上两种害虫均有毒力,加入增效醚,对玉米象的毒力有所增加,但对谷蠹无显著变化.

  5. Cladal relatedness among Aspergillus oryzae isolates and Aspergillus flavus S and L morphotype isolates.

    Science.gov (United States)

    Chang, Perng-Kuang; Ehrlich, Kenneth C; Hua, Sui-Sheng T

    2006-04-25

    Aspergillus flavus is the main etiological agent for aflatoxin contamination of crops. Its close relative, A. oryzae, does not produce aflatoxins and has been widely used to produce fermented foods. We compared the phylogeny of A. oryzae isolates and L- and S-type sclerotial isolates of A. flavus using single nucleotide polymorphisms in the omtA gene in the aflatoxin biosynthesis gene cluster and deletions in and distal to the norB-cypA intergenic region as phylogenetic signals. Aflatoxin-producing ability and sclerotial size also were weighted in the analysis. Like A. flavus, the A. oryzae isolates form a polyphyletic assemblage. A. oryzae isolates in one clade strikingly resemble an A. flavus subgroup of atoxigenic L-type isolates. All toxigenic S-type isolates closely resemble another subgroup of atoxigenic L-type isolates. Because atoxigenic S-type isolates are extremely rare, we hypothesize that loss of aflatoxin production in S-type isolates may occur concomitantly with a change to L-type sclerotia. All toxigenic L-type isolates, unlike A. oryzae, have a 1.0 kb deletion in the norB-cypA region. Although A. oryzae isolates, like S-type, have a 1.5 kb deletion in the norB-cypA region, none were cladally related to S-type A. flavus isolates. Our results show that A. flavus populations are genetically diverse. A. oryzae isolates may descend from certain atoxigenic L-type A. flavus isolates.

  6. WRKY transcription factor genes in wild rice Oryza nivara.

    Science.gov (United States)

    Xu, Hengjian; Watanabe, Kenneth A; Zhang, Liyuan; Shen, Qingxi J

    2016-08-01

    The WRKY transcription factor family is one of the largest gene families involved in plant development and stress response. Although many WRKY genes have been studied in cultivated rice (Oryza sativa), the WRKY genes in the wild rice species Oryza nivara, the direct progenitor of O. sativa, have not been studied. O. nivara shows abundant genetic diversity and elite drought and disease resistance features. Herein, a total of 97 O. nivara WRKY (OnWRKY) genes were identified. RNA-sequencing demonstrates that OnWRKY genes were generally expressed at higher levels in the roots of 30-day-old plants. Bioinformatic analyses suggest that most of OnWRKY genes could be induced by salicylic acid, abscisic acid, and drought. Abundant potential MAPK phosphorylation sites in OnWRKYs suggest that activities of most OnWRKYs can be regulated by phosphorylation. Phylogenetic analyses of OnWRKYs support a novel hypothesis that ancient group IIc OnWRKYs were the original ancestors of only some group IIc and group III WRKYs. The analyses also offer strong support that group IIc OnWRKYs containing the HVE sequence in their zinc finger motifs were derived from group Ia WRKYs. This study provides a solid foundation for the study of the evolution and functions of WRKY genes in O. nivara.

  7. Produksi Gula Reduksi oleh Rhizopus oryzae dari Substrat Bekatul

    Directory of Open Access Journals (Sweden)

    ARTINI PANGASTUTI

    2005-05-01

    Full Text Available Rice bran was produced from rice-hulling process. Rice bran was contain high starch, therefore it was used to saccharification process. The aim of this research was to study the optimum concentration of rice bran to produce reducing sugar on saccharification process by Rhizopus oryzae. The 100 mL-rice bran medium (5, 10, 15, 20, 25, and 30% were sterilized at 1210C, for 15 minutes and inoculated with R. oryzae (± 2x106 cfu and incubated for3 days. The concentration of reducing sugar, starch, pH value, and biomass were analyzed everyday. Concentration of starch was decreasing during saccharification process. However, the concentration of reducing sugar was maximum at first day saccharification. The optimum concentration of rice bran for saccharification process was showed by maximum production of reducing sugar (15,347 mg/mL; it was in 20% concentration of medium. The pH value was decreasing during saccharification process, and the biomass was reversed.

  8. Construction of Oryza Sativa genome contigs by fingerprint strategy

    Institute of Scientific and Technical Information of China (English)

    TAOQUAZHOU; GUOFANHONG; 等

    1995-01-01

    We described the construction of BAC contigs of the genome of a indica variety of Oryza sativa.Guang Lu Ai 4. An entire representative(Sixfold coverage of rice chromosomes)and genetically stable BAC library of rice genome constructed in this lab has been systematically analysed by restriction enzyme fragmentation and polyacrylamide gel electrophoresis.And all the images thus obtained were subject to image-processing,which consisted of preliminary location of bands,cooperative tracking of lanes by correlation of adjacent bads.a precise densitometric pass,alignment at the marker bands with the standard,optional interactive editing,and normalization of the accepted bands.The contigs were generated based on the Computer Software specially designed for genome mapping.The number of contigs with 600 kb in length on average was 464.of contigs with 1000kb in length on average was 107; of contigs with 1500 kb in length on average was Construction of Oryza Sativa genome contigs.23.Therefor,all the contigs we have obtained ampunted up to 420 megabases in length.Considering the size of rice genome(430 megabased),the contigs generated in this lab have covered nearly 98% of the rice genome.We are now in the process of mapping the contigs to chromosomes.

  9. Toward understanding of rice innate immunity against Magnaporthe oryzae.

    Science.gov (United States)

    Azizi, P; Rafii, M Y; Abdullah, S N A; Nejat, N; Maziah, M; Hanafi, M M; Latif, M A; Sahebi, M

    2016-01-01

    The blast fungus, Magnaporthe oryzae, causes serious disease on a wide variety of grasses including rice, wheat and barley. The recognition of pathogens is an amazing ability of plants including strategies for displacing virulence effectors through the adaption of both conserved and variable pathogen elicitors. The pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and effector-triggered immunity (ETI) were reported as two main innate immune responses in plants, where PTI gives basal resistance and ETI confers durable resistance. The PTI consists of extracellular surface receptors that are able to recognize PAMPs. PAMPs detect microbial features such as fungal chitin that complete a vital function during the organism's life. In contrast, ETI is mediated by intracellular receptor molecules containing nucleotide-binding (NB) and leucine rich repeat (LRR) domains that specifically recognize effector proteins produced by the pathogen. To enhance crop resistance, understanding the host resistance mechanisms against pathogen infection strategies and having a deeper knowledge of innate immunity system are essential. This review summarizes the recent advances on the molecular mechanism of innate immunity systems of rice against M. oryzae. The discussion will be centered on the latest success reported in plant-pathogen interactions and integrated defense responses in rice.

  10. Safety evaluation of a lipase expressed in Aspergillus oryzae.

    Science.gov (United States)

    Greenough, R J; Perry, C J; Stavnsbjerg, M

    1996-02-01

    A programme of studies was conducted to establish the safety of a lipase artificially expressed in Aspergillus oryzae to be used in the detergent industry and as a processing aid in the baking industry. Laboratory animal studies were used to assess general and inhalation toxicity, skin sensitization, and skin and eye irritation. Its potential to cause mutagenicity and chromosomal aberrations was assessed in microbial and tissue culture in vitro studies. The pathogenicity of A. oryzae, the organism used to produce the lipase, was also assessed in laboratory animals. Basic ecotoxicity in a variety of test species was studied. General and inhalation toxicity was low. There was evidence of mild skin irritation. There was no evidence of eye irritation, skin sensitization, mutagenic potential, chromosomal aberrations, exotoxicity or notable pathogenicity. Comparison of these results with human exposure levels and previously published data indicates that the lipase appears safe for consumers in the given applications, requires no special occupational health precautions in manufacture and is of low environmental impact. Furthermore, the organism used in production of the lipase hs no notable pathogenicity.

  11. Enhanced acid tolerance of Rhizopus oryzae during fumaric acid production.

    Science.gov (United States)

    Liu, Ying; Lv, Chunwei; Xu, Qing; Li, Shuang; Huang, He; Ouyang, Pingkai

    2015-02-01

    Ensuring a suitable pH in the culture broth is a major problem in microorganism-assisted industrial fermentation of organic acids. To address this issue, we investigated the physiological changes in Rhizopus oryzae at different extracellular pH levels and attempted to solve the issue of cell shortage under low pH conditions. We compared various parameters, such as membrane fatty acids' composition, intracellular pH, and adenosine triphosphate (ATP) concentration. It was found that the shortage of intracellular ATP might be the main reason for the low rate of fumaric acid production by R. oryzae under low pH conditions. When 1 g/l citrate was added to the culture medium at pH 3.0, the intracellular ATP concentration increased from 0.4 to 0.7 µmol/mg, and the fumaric acid titer was enhanced by 63% compared with the control (pH 3.0 without citrate addition). The final fumaric acid concentration at pH 3.0 reached 21.9 g/l after 96 h of fermentation. This strategy is simple and feasible for industrial fumaric acid production under low pH conditions.

  12. Support Vector Machine Based Red Palm Weevil (Rynchophorus Ferrugineous, Olivier Recognition System

    Directory of Open Access Journals (Sweden)

    Ghulam M. Hassan

    2012-01-01

    Full Text Available Problem statement: Red palm weevil (Rynchophorus Ferrugineous, Oliveir is an insect which threatens the existence of palm trees. The proposed research is to develop a RPW identification system using Support Vector Machine method. The problem is to extract image features from an image and using SVM to find out the existence of RPW in an image. Approach: Images are snapped and image processing techniques of Regional Properties and Zernike Moments are used to extract different features of an image. The obtained features are fed into the SVM based system individually as well as in combination. The database used to train and test the system includes 326 RPW and 93 other insect images. The input data from database is selected randomly and fed into the system in three steps i.e., 25, 50 and 75% while remaining database is used for testing purpose. In SVM, polynomial kernel function and Radial Basis Function are used for training. Each experiment is repeated 10 times and the average results are used for analysis. Results: The optimal results are obtained by using Radial Basis Function in SVM at lower values of sigma σ while Polynomial kernel function is not successful in returning adequate results. Further detailed analysis of results for σ value of 10 and 15 revealed that proposed system works well with large training data and with inputs obtained by Regional Properties. The optimal value of σ for proposed system is found to be 10 when training data ratio is 50%. The training time for proposed system depends on size of database and is found to be 0.025 sec per image while time consumed by proposed system for identification of RPW in an image is found to be 15 milli sec. The proposed systems success in identification of RPW and other insect is found to be 97 and 93% respectively. Conclusion: It is concluded that SVM based system using Radial Basis Function having σ value of 10 is optimal in identifying RPW from an image. The optimal input

  13. Cell wall degrading enzyme induced rice innate immune responses are suppressed by the type 3 secretion system effectors XopN, XopQ, XopX and XopZ of Xanthomonas oryzae pv. oryzae.

    Science.gov (United States)

    Sinha, Dipanwita; Gupta, Mahesh Kumar; Patel, Hitendra Kumar; Ranjan, Ashish; Sonti, Ramesh V

    2013-01-01

    Innate immune responses are induced in plants and animals through perception of Damage Associated Molecular Patterns. These immune responses are suppressed by pathogens during infection. A number of studies have focussed on identifying functions of plant pathogenic bacteria that are involved in suppression of Pathogen Associated Molecular Pattern induced immune responses. In comparison, there is very little information on functions used by plant pathogens to suppress Damage Associated Molecular Pattern induced immune responses. Xanthomonasoryzae pv. oryzae, a gram negative bacterial pathogen of rice, secretes hydrolytic enzymes such as LipA (Lipase/Esterase) that damage rice cell walls and induce innate immune responses. Here, we show that Agrobacterium mediated transient transfer of the gene for XopN, a X. oryzae pv. oryzae type 3 secretion (T3S) system effector, results in suppression of rice innate immune responses induced by LipA. A xopN (-) mutant of X. oryzae pv. oryzae retains the ability to suppress these innate immune responses indicating the presence of other functionally redundant proteins. In transient transfer assays, we have assessed the ability of 15 other X. oryzae pv. oryzae T3S secreted effectors to suppress rice innate immune responses. Amongst these proteins, XopQ, XopX and XopZ are suppressors of LipA induced innate immune responses. A mutation in any one of the xopN, xopQ, xopX or xopZ genes causes partial virulence deficiency while a xopN (-) xopX (-) double mutant exhibits a greater virulence deficiency. A xopN (-) xopQ (-) xopX (-) xopZ (-) quadruple mutant of X. oryzae pv. oryzae induces callose deposition, an innate immune response, similar to a X. oryzae pv. oryzae T3S(-) mutant in rice leaves. Overall, these results indicate that multiple T3S secreted proteins of X. oryzae pv. oryzae can suppress cell wall damage induced rice innate immune responses.

  14. Crystal structures of d-alanine-d-alanine ligase from Xanthomonas oryzae pv. oryzae alone and in complex with nucleotides.

    Science.gov (United States)

    Doan, Thanh Thi Ngoc; Kim, Jin-Kwang; Ngo, Ho-Phuong-Thuy; Tran, Huyen-Thi; Cha, Sun-Shin; Min Chung, Kyung; Huynh, Kim-Hung; Ahn, Yeh-Jin; Kang, Lin-Woo

    2014-03-01

    D-Alanine-D-alanine ligase (DDL) catalyzes the biosynthesis of d-alanyl-d-alanine, an essential bacterial peptidoglycan precursor, and is an important drug target for the development of antibacterials. We determined four different crystal structures of DDL from Xanthomonas oryzae pv. oryzae (Xoo) causing Bacteria Blight (BB), which include apo, ADP-bound, ATP-bound, and AMPPNP-bound structures at the resolution between 2.3 and 2.0 Å. Similarly with other DDLs, the active site of XoDDL is formed by three loops from three domains at the center of enzyme. Compared with d-alanyl-d-alanine and ATP-bound TtDDL structure, the γ-phosphate of ATP in XoDDL structure was shifted outside toward solution. We swapped the ω-loop (loop3) of XoDDL with those of Escherichia coli and Helicobacter pylori DDLs, and measured the enzymatic kinetics of wild-type XoDDL and two mutant XoDDLs with the swapped ω-loops. Results showed that the direct interactions between ω-loop and other two loops are essential for the active ATP conformation for D-ala-phosphate formation.

  15. Molecular and pathogenic characterization of new Xanthomonas oryzae pv. oryzae strains from the coastline region of Fangchenggang city in China.

    Science.gov (United States)

    Yang, Shu-Qing; Liu, Shu-Yan; Zhao, Shuai; Yu, Yan-Hua; Li, Rong-Bai; Duan, Cheng-Jie; Tang, Ji-Liang; Feng, Jia-Xun

    2013-04-01

    Virulence assays and DNA polymorphism analyses were used to characterize 33 Xanthomonas oryzae pv. oryzae (Xoo) strains collected from the coastline region of Fangchenggang city in China. Two new pathogenic races (FXP1 and FXP2), were determined by leaf-clipping inoculation of 12 near-isogenic International Rice-Bacterial Blight (IRBB) rice lines, each containing a single resistance gene. Race FXP1 consisted of twenty-eight strains that were incompatible on IRBB5 and IRBB7, while race FXP2 included five strains that were incompatible on IRBB5 and IRBB7 and moderately virulent on IRBB8 containing the xa8 gene. Restriction fragment length polymorphism (RFLP) analysis revealed that each probe of avrXa10 and IS1112 resolved two haplotypes. In a dendrogram generated from the combined RFLP data, the 33 Xoo strains were resolved into two clusters. There was a weak correlation (r = 0.53) between race and haplotype. All of the rice cultivars planted in the coastline region of Fangchenggang city were susceptible to the representative Xoo strains tested above. However, we found that four rice cultivars used as breeding materials in the laboratory could fully resist infection by the Xoo strains, suggesting that the isolated Xoo strains could be used to detect resistant rice cultivars suitable for planting in the local rice field.

  16. Electrophysiological and behavioral activity of (E)-2-hexenal in the granary weevil and its application in food packaging.

    Science.gov (United States)

    Germinara, G S; Conte, A; De Cristofaro, A; Lecce, L; Di Palma, A; Rotundo, G; Del Nobile, M A

    2012-02-01

    The purpose of this work was to develop a biodegradable carrier material to control insect pests in cereal products. To this aim, (E)-2-hexenal was used, being a natural compound with antimicrobial activity that is also commonly adopted as a flavoring agent. Three coating layers of polycaprolactone (PCL) were spread onto the internal side of a paperboard carton, the first being the active coating containing (E)-2-hexenal. The antennal sensitivity of Sitophilus granarius to a broad range of doses of (E)-2-hexenal was first demonstrated. Next, the ability of different concentrations of this compound to disrupt the orientation of adult S. granarius beetles to odors of intact wheat kernels was established in a two-choice pitfall bioassay. In addition, invasion tests were carried out over an 8-week period to highlight the effects of the biobased repellent packaging and their potential persistence. The results demonstrated that during the entire monitoring period, the percentage of S. granarius adults found in cartons coated with (E)-2-hexenal-loaded multilayer PCL was about 10 % of the total number of insects used in the bioassay, very low compared with the respective control samples, thus assessing both the effectiveness and persistence of the repellent system developed. Although the infestation level of treated packages was reduced relative to the infestation levels in the controls, any infestation of food packages is unacceptable to consumers, so further tests are required to determine whether infestation can be completely prevented using (E)-2-hexenal.

  17. Kinetic studies of acid inactivation of alpha-amylase from Aspergillus oryzae

    DEFF Research Database (Denmark)

    Carlsen, Morten; Nielsen, Jens Bredal; Villadsen, John

    1996-01-01

    The stability of alpha-amylase from Aspergillus oryzae has been studied at different pH. The enzyme is extremely stable at neutral pH (pH 5-8), whereas outside this pH-range a substantial loss of activity is observed. The acid-inactivation of alpha-amylase from A. oryzae was monitored on-line by ......The stability of alpha-amylase from Aspergillus oryzae has been studied at different pH. The enzyme is extremely stable at neutral pH (pH 5-8), whereas outside this pH-range a substantial loss of activity is observed. The acid-inactivation of alpha-amylase from A. oryzae was monitored on...

  18. Genetic variation in a population of Bipolaris oryzae based on RAPD ...

    African Journals Online (AJOL)

    ONOS

    2010-09-06

    Sep 6, 2010 ... Isolates of Bipolaris oryzae were analysed by RAPD techniques to determine the ... samples for DNA extraction were grown on potato-dextrose broth ... Then for determining DNA quantity as empirical, the genomic DNA.

  19. Improved annotation through genome-scale metabolic modeling of Aspergillus oryzae

    DEFF Research Database (Denmark)

    Vongsangnak, Wanwipa; Olsen, Peter; Hansen, Kim;

    2008-01-01

    to a genome scale metabolic model of A. oryzae. Results: Our assembled EST sequences we identified 1,046 newly predicted genes in the A. oryzae genome. Furthermore, it was possible to assign putative protein functions to 398 of the newly predicted genes. Noteworthy, our annotation strategy resulted......Background: Since ancient times the filamentous fungus Aspergillus oryzae has been used in the fermentation industry for the production of fermented sauces and the production of industrial enzymes. Recently, the genome sequence of A. oryzae with 12,074 annotated genes was released but the number...... of hypothetical proteins accounted for more than 50% of the annotated genes. Considering the industrial importance of this fungus, it is therefore valuable to improve the annotation and further integrate genomic information with biochemical and physiological information available for this microorganism and other...

  20. Spinosad Induces Antioxidative Response and Ultrastructure Changes in Males of Red Palm Weevil Rhynchophorus ferrugineus (Coleoptera: Dryophthoridae)

    Science.gov (United States)

    Abdelsalam, Salaheldin A.; Alzahrani, Abdullah M.; Elmenshawy, Omar M.; Abdel-Moneim, Ashraf M.

    2016-01-01

    The red palm weevil, Rhynchophorus ferrugineus, is of great concern worldwide, especially in the Middle East, where dates are a strategic crop. Despite their ecological hazard, insecticides remain the most effective means of control. A bioinsecticide of bacterial origin, spinosad is effective against several pests, and its efficacy against male R. ferrugineus was assessed in the present study. The antioxidative responses of key enzymes including catalase (CAT), superoxide dismutase (SOD), and glutathione-S-transferase (GST) to spinosad were investigated in the midgut and testes, and the effects of this insecticide on the cell ultrastructure of the midgut, Malpighian tubules, and testes were also determined. The lethal concentration 50 of spinosad was measured at 58.8 ppm, and the insecticide inhibited the activities of CAT, SOD, and GST in the midgut. However, no significant changes in the activities of these enzymes were observed in the testes. Spinosad treatment resulted in concentration-dependent changes in the cellular organelles of the midgut, Malpighian tubules, and testes of R. ferrugineus, and some of these effects were similar to those exerted by other xenobiotics. However, specific changes were observed as a result of spinosad treatment, including an increase in the number and size of concretions in Malpighian tubule cells and the occasional absence of the central pair of microtubules in the axonemes of sperm tails. This study introduces spinosad for potential use as an insecticide within an integrated control program against male red palm weevils. Additionally, the study provides biochemical and ultrastructural evidence for use in the development of bioindicators.

  1. Pepper Weevil (Coleoptera: Curculionidae Preferences for Specific Pepper Cultivars, Plant Parts, Fruit Colors, Fruit Sizes, and Timing

    Directory of Open Access Journals (Sweden)

    Dakshina R. Seal

    2016-03-01

    Full Text Available Peppers (Capsicum spp. are an important crop in the USA, with about 32,000 ha cultivated in 2007, which resulted in $588 million in farm revenue. The pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae, is the most troublesome insect pest of peppers in the southern United States. It is therefore urgent to find different vulnerabilities of pepper cultivars, fruit and plants parts, fruit colors and sizes, and timing to infestation by A. eugenii. Also relevant is testing whether fruit length and infestation state affect fruit numbers, weights, and proportions of fruit that are infested. Counts of A. eugenii adults and marks from oviposition and feeding suggested that C. chinense Jacquin “Habanero” was least susceptible, and C. annuum L. cultivars “SY” and “SR” were most susceptible. Comparison of plant parts and fruit sizes revealed that A. eugenii preferred the peduncle, calyx, and top of pepper fruits over the middle, bottom, leaves, or remainder of flowers. Anthonomus eugenii does not discriminate between green or yellow fruit color nor vary diurnally in numbers. Based on adult counts, medium to extra-large fruits (≥1.5 cm long attracted more weevils than small fruits (<1.5 cm. However based on proportions of fruit numbers or fruit weights that were infested, there were no differences between large and small fruits. Choice of pepper cultivar can thus be an important part of an IPM cultural control program designed to combat A. eugenii by reduced susceptibility or by synchronous fruit drop of infested fruits. Our results are potentially helpful in developing scouting programs including paying particular attention to the preferred locations of adults and their sites of feeding and oviposition on the fruit. The results also suggested the potential value of spraying when the fruits are still immature to prevent and control infestation.

  2. Effects of entomopathogenic fungus species, and impact of fertilizers, on biological control of pecan weevil (Coleoptera: Curculionidae).

    Science.gov (United States)

    Shapiro-Ilan, David I; Gardner, Wayne A; Wells, Lenny; Cottrell, Ted E; Behle, Robert W; Wood, Bruce W

    2013-04-01

    The pecan weevil, Curculio caryae (Horn), is a key pest of pecan, Carya illinoinensis (Wangenh.) K. Koch. Prior research indicated the potential for use of Hypocreales fungi to suppress C. caryae. We compared the efficacy of two fungal spp., Beauveria bassiana (GHA strain) and Metarhizium brunneum (F52), in their ability to cause C. caryae mortality. The fungus, B. bassiana, was applied to trunks of pecan trees (a method previously shown to be effective in C. caryae suppression) and efficacy was compared with M. brunneum applied to the ground or to the trunk with or without SoyScreen Oil as an ultraviolet protecting agent. Results indicated B. bassiana to be superior to M. brunneum regardless of application method; consequently, the potential for applying B. bassiana to control C. caryae was explored further. Specifically, the impact of different fertilizer regimes (as used by pecan growers) on the persistence of B. bassiana (GHA) in soil was determined. B. bassiana was applied to soil in a pecan orchard after one of several fertilizer treatments--i.e., ammonium nitrate, crimson clover, poultry litter, clover plus poultry litter, and a no-fertilizer control. B. bassiana persistence up to 49 d in 2009 and 2010 was assessed by plating soil onto selective media and determining the number of colony forming units, and by baiting soil with a susceptible host, Galleria mellonella (L.). Fertilizer treatments did not impact B. bassiana persistence. We conclude that standard fertilizers for nitrogen management, when applied according to recommended practices, are unlikely to negatively impact survival of B. bassiana in pecan orchards when the fungus is applied for C. caryae suppression during weevil emergence. Additional research on interactions between entomopathogenic fungi and fertilizer amendments (or other tree nutrition or soil management practices) is merited.

  3. Biological Control Against the Cowpea Weevil (Callosobruchus Chinensis L., Coleoptera: Bruchidae Using Essential Oils of Some Medicinal Plants

    Directory of Open Access Journals (Sweden)

    Fatiha Righi Assia

    2014-07-01

    Full Text Available Chickpea (Cicer arietinum L. is a valuable foodstuff but unfortunately this legume is prone to insect attacks from the chick pea weevil (Callosobruchus chinensis L.. This serious pest damages the chickpea and causes decreases in the yield and in the nutritional quality. Biological control is being used to deal with this problem. We tried different doses of the essential oils of three new medicinal plants, namely Salvia verbenaca L., Scilla maritima L., and Artemisia herba-alba Asso to limit the damage of the chick pea weevil pest, and to protect consumer’s health. To determine the effect and efficiency of the oil, the tests were conducted using the different biological parameters of fertility, longevity, and fecundity, under controlled temperature and relative humidity (28°C and 75%. The effectiveness of organic oils was demonstrated. We tested these oils on the germination of seeds. The obtained results showed that the tested plant oils have a real organic insecticide effect. The essential oil of Artemisia proved most effective as a biocide; achieving a mortality rate of 100%. A significant reduction in longevity was observed under the effect of 30 μl of S. maritima (1.3 days and S. verbenaca (2.8, 4.6 days, respectively, for males and females compared to 8 and 15 days for the control. For fecundity, an inhibition of oviposition was obtained using 30 μl of Salvia and Scilla essential oils. The test on the seed germination using different essential oils, showed no damage to the germinating seeds. The germination rate was 99%. These findings suggest that the tested plants can be used as a bioinsecticide for control of the C. chinensis pest of stored products.

  4. Spinosad Induces Antioxidative Response and Ultrastructure Changes in Males of Red Palm Weevil Rhynchophorus ferrugineus (Coleoptera: Dryophthoridae).

    Science.gov (United States)

    Abdelsalam, Salaheldin A; Alzahrani, Abdullah M; Elmenshawy, Omar M; Abdel-Moneim, Ashraf M

    2016-01-01

    The red palm weevil, Rhynchophorus ferrugineus, is of great concern worldwide, especially in the Middle East, where dates are a strategic crop. Despite their ecological hazard, insecticides remain the most effective means of control. A bioinsecticide of bacterial origin, spinosad is effective against several pests, and its efficacy against male R. ferrugineus was assessed in the present study. The antioxidative responses of key enzymes including catalase (CAT), superoxide dismutase (SOD), and glutathione-S-transferase (GST) to spinosad were investigated in the midgut and testes, and the effects of this insecticide on the cell ultrastructure of the midgut, Malpighian tubules, and testes were also determined. The lethal concentration 50 of spinosad was measured at 58.8 ppm, and the insecticide inhibited the activities of CAT, SOD, and GST in the midgut. However, no significant changes in the activities of these enzymes were observed in the testes. Spinosad treatment resulted in concentration-dependent changes in the cellular organelles of the midgut, Malpighian tubules, and testes of R. ferrugineus, and some of these effects were similar to those exerted by other xenobiotics. However, specific changes were observed as a result of spinosad treatment, including an increase in the number and size of concretions in Malpighian tubule cells and the occasional absence of the central pair of microtubules in the axonemes of sperm tails. This study introduces spinosad for potential use as an insecticide within an integrated control program against male red palm weevils. Additionally, the study provides biochemical and ultrastructural evidence for use in the development of bioindicators. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America.

  5. The chemical heritage of Aspergillus flavus in A. oryzae RIB 40

    DEFF Research Database (Denmark)

    Rank, Christian; Klejnstrup, Marie Louise; Petersen, Lene Maj

    Aspergillus oryzae is a very important species in biotechnology and has been used for centuries in traditional Asian fermentation. The RIB40 strain is particularly interesting as it was one of the first genome sequenced Aspergilli together with A. flavus, a prominent food and feed contaminant...... with indications to specific genetic changes. Several new metabolites and changes in biosynthetic routes have been found in A. oryzae, indicating subtle changes in the genomic heritage from A. flavus....

  6. High-level expression and characterization of a chimeric lipase from Rhizopus oryzae for biodiesel production

    OpenAIRE

    Yu, Xiao-Wei; Sha, Chong; Guo, Yong-Liang; Xiao, Rong; Xu, Yan

    2013-01-01

    Background Production of biodiesel from non-edible oils is receiving increasing attention. Tung oil, called “China wood oil” is one kind of promising non-edible biodiesel oil in China. To our knowledge, tung oil has not been used to produce biodiesel by enzymatic method. The enzymatic production of biodiesel has been investigated extensively by using Rhizopus oryzae lipase as catalyst. However, the high cost of R. oryzae lipase remains a barrier for its industrial applications. Through differ...

  7. Transcriptome Analysis of Salt Stress Responsiveness in the Seedlings of Dongxiang Wild Rice (Oryza rufipogon Griff.)

    OpenAIRE

    Yi Zhou; Ping Yang; Fenglei Cui; Fantao Zhang; Xiangdong Luo; Jiankun Xie

    2016-01-01

    Dongxiang wild rice (Oryza rufipogon Griff.) is the progenitor of cultivated rice (Oryza sativa L.), and is well known for its superior level of tolerance against cold, drought and diseases. To date, however, little is known about the salt-tolerant character of Dongxiang wild rice. To elucidate the molecular genetic mechanisms of salt-stress tolerance in Dongxiang wild rice, the Illumina HiSeq 2000 platform was used to analyze the transcriptome profiles of the leaves and roots at the seedling...

  8. A successful treatment of rhinocerebral mucormycosis due to Rhizopus oryzae

    Directory of Open Access Journals (Sweden)

    Rasoul Mohammadi

    2014-01-01

    Full Text Available Mucormycosis is an invasive fungal infection caused by filamentous fungi of the Mucoraceae family. The genera most commonly responsible are Mucor or Rhizopus. The disease occurs mostly in association with diabetic ketoacidosis. Mucormycosis has an extremely high death rate even when aggressive surgery is done. Death rates range from 25-85% depending on the body area involved. A case of rhinocerebral mucormycosis in a 65-year-old diabetic male patient typically presenting as headache, especially in parietal and frontal lobes, with nose and left eye discharge. After clinical and laboratory examination, mucormycosis was diagnosed, and Rhizopus oryzae was isolated. Systemic therapy with amphotericin B administered intravenously then replaced by posaconazole by a combination of aggressive surgery. The patient was treated and followed up for one year. We emphasize the importance of early detection and aggressive treatment in the management of this fatal disease.

  9. The whole chloroplast genome of wild rice (Oryza australiensis).

    Science.gov (United States)

    Wu, Zhiqiang; Ge, Song

    2016-01-01

    The whole chloroplast genome of wild rice (Oryza australiensis) is characterized in this study. The genome size is 135,224  bp, exhibiting a typical circular structure including a pair of 25,776  bp inverted repeats (IRa,b) separated by a large single-copy region (LSC) of 82,212  bp and a small single-copy region (SSC) of 12,470  bp. The overall GC content of the genome is 38.95%. 110 unique genes were annotated, including 76 protein-coding genes, 4 ribosomal RNA genes, and 30t RNA genes. Among these, 18 are duplicated in the inverted repeat regions, 13 genes contain one intron, and 2 genes (rps12 and ycf3) have two introns.

  10. Oxygen dynamics in submerged rice (Oryza sativa L.)

    DEFF Research Database (Denmark)

    Colmer, Timothy D.; Pedersen, Ole

    2008-01-01

    Complete submergence of plants prevents direct O2 and CO2 exchange with air. Underwater photosynthesis can result in marked diurnal changes in O2 supply to submerged plants. Dynamics in pO2 had not been measured directly for submerged rice (Oryza sativa), but in an earlier study, radial O2 loss...... from roots showed an initial peak following shoot illumination.  O2 dynamics in shoots and roots of submerged rice were monitored during light and dark periods, using O2 microelectrodes. Tissue sugar concentrations were also measured.  On illumination of shoots of submerged rice, pO2 increased rapidly...... of magnitude higher than in darkness, enhancing also pO2 in roots.The initial peak in pO2 following illumination of submerged rice was likely to result from high initial rates of net photosynthesis, fuelled by CO2 accumulated during the dark period. Nevertheless, since sugars decline with time in submerged...

  11. Monoolein production by triglycerides hydrolysis using immobilized Rhizopus oryzae lipase.

    Science.gov (United States)

    Ghattas, Nesrine; Abidi, Ferid; Galai, Said; Marzouki, M Nejib; Salah, Abderraouf Ben

    2014-07-01

    Lipase extracted from Rhizopus oryzae was immobilized in alginate gel beads. The effects of the immobilization conditions, such as, alginate concentration, CaCl2 concentration and amount of initial enzyme on retained activity (specific activity ratio of entrapped active lipase to free lipase) were investigated. The optimal conditions for lipase entrapment were determined: 2% (w/v) alginate concentration, 100mM CaCl2 and enzyme ratio of 2000IU/mL.In such conditions, immobilized lipase by inclusion in alginate showed a highest stability and activity, on olive oil hydrolysis reaction where it could be reused for 10 cycles. After 15min of hydrolysis reaction, the mass composition of monoolein, diolein and triolein were about 78%, 10% and 12%. Hydrolysis' products purification by column chromatography lead to a successful separation of reaction compounds and provide a pure fraction of monoolein which is considered as the widest used emulsifier in food and pharmaceutical industries.

  12. Interaction of malathion, an organophosphorus pesticide with Rhizopus oryzae biomass

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Subhankar; Das, Sujoy K.; Chakravarty, Rajdeep; Chakrabarti, Adrita [Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India); Ghosh, Subrata [West Bengal Pollution Control Board, Paribesh Bhawan, Kakinara, 24 Parganas (N), PIN - 743126 (India); Guha, Arun K., E-mail: bcakg@mahendra.iacs.res.in [Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India)

    2010-02-15

    Adsorption of malathion on Rhizopus oryzae biomass (ROB) with special reference to binding mechanism has been described. ROB has been found to adsorb {approx}85% of malathion from its aqueous solution as against 47-68% by other fungal biomasses. Hydrogen ion concentration does not influence the adsorption of malathion by ROB which follows Langmuir-Freundlich dual equilibrium isotherm model (r{sup 2} = 0.998). Both physical and chemical interactions are responsible for binding of malathion on ROB. Scanning electron micrographs and EDXA spectra exhibit adsorption of the pesticide on cell surface of ROB. Studies with cell surface polysaccharides show that chitosan through its amine groups contributes largely in the adsorption of malathion. Extraction of lipids from ROB decreases its adsorption capacity to the extent of 36.37-94.02%, depending on the polarity of the solvent.

  13. EFICIÊNCIA DE FUNGICIDAS NO CONTROLE DE MANCHA PARDA (Bipolaris oryzae EM ARROZ (Oryza sativa EFFICIENCY OF FUNGICIDES IN THE CONTROL OF RICE (Oryza sativa BROWN SPOT (Bipolaris oryzae

    Directory of Open Access Journals (Sweden)

    Eric Guicherit

    2007-09-01

    Full Text Available

    Em situações nas quais a brusone tem pouca importância na sanidade da lavoura de arroz, o controle da mancha parda (Bipolaris Oryzõe pode mostrar-se altamente eficiente com pulverizações de fungicidas no campo. Assim, realizou-se um experimento em Indiara (GO com o objetivo de comparar a eficácia de diferentes produtos fungicidas no controle da mancha parda em condições pouco favoráveis à brusone. Foram comparados difenoconazole, propiconazole e tryfloxystrobin em diferentes combinações e dosagens, e os resultados mostraram que, em situações nas quais a brusone tem pouca importância na sanidade da lavoura do arroz, o controle da mancha parda pode mostrar-se altamente eficiente com pulverizações de fungicidas no campo.

    PALAVRAS-CHAVE: Helminthosporium oryzae; controle químico; patógeno; doença.

    In situations where the blight (Pyricularia grisea is not limiting the rice crop, the brown spot (Bipolaris oryzae control can be extremely efficient with field sprayings. This experiment was conduced in Indiara (GO aiming to compare the efficiency of different fungicides in one or two dosages in the control of brown spot under low blight conditions. All treatments showed efficiency in the control of brown spot, with no signifficant difference among them.

    KEY-WORDS: Chemical control; pathogens; disease.

  14. CHROMIUM BIOREMOVAL FROM TANNERY INDUSTRIES EFFLUENT BY ASPERGILLUS ORYZAE

    Directory of Open Access Journals (Sweden)

    M. Nouri Sepehr, S. Nasseri, M. Mazaheri Assadi and K. Yaghmaian

    2005-10-01

    Full Text Available Recently laboratory studies had recognized the capability of alge, fungi, and bacteria in the removal of heavy metals from industrial effluent. In this research, growth of Aspergillus oryzae in the tanning house effluent, and its capability in chromium bioremoval were assessed. Aspergillus oryzae can grow in different concentration of Cr+, 120-1080 mg/l. Maximum biomass growth and chromium removal rate at pH, 3.3, Cr+3 concentration equal to 240 mg/l and inoculum size equal to 0.12% (dry weight were 0.25% (dry weight and 94.2%, respectively. Effects of various factors such as pH, temperature, shaking velocity and nutrients were also investigated. At optimum conditions (ie: pH=5; temperature=30ºC, shaking velocity = 150 rpm, and nitrogen source of dihydrogen ammonium phosphate concentration=0.3%, biomass growth and chromium removal rate were found as 0.45% of dry weight and 99.8%, respectively. Effect of detention time showed that after 30h, biomass growth and chromium removal rate were 0.28% and 97.6%, respectively. Statistical studies on factors such as pH, temperature, shaking velocity, type and concentration of nutrients on the “biomass growth” and “residual chromium”, showed that all of the factors had significant effects ( α = 0.05, P < 0.001 . Therefore A.niger capable grow in the tannery industries effluent with 240 mg/l chromium and 97.6% chromium removal rate .

  15. Production of flavor compounds from olive mill waste by Rhizopus oryzae and Candida tropicalis.

    Science.gov (United States)

    Guneser, Onur; Demirkol, Asli; Yuceer, Yonca Karagul; Togay, Sine Ozmen; Hosoglu, Muge Isleten; Elibol, Murat

    The purpose of this study was to investigate the production of flavor compounds from olive mill waste by microbial fermentation of Rhizopus oryzae and Candida tropicalis. Olive mill waste fermentations were performed in shake and bioreactor cultures. Production of flavor compounds from olive mill waste was followed by Gas Chromatography-Mass spectrometry, Gas chromatography- olfactometry and Spectrum Sensory Analysis(®). As a result, 1.73-log and 3.23-log cfu/mL increases were observed in the microbial populations of R. oryzae and C. tropicalis during shake cultures, respectively. C. tropicalis can produce a higher concentration of d-limonene from olive mill waste than R. oryzae in shake cultures. The concentration of d-limonene was determined as 185.56 and 249.54μg/kg in the fermented olive mill waste by R. oryzae and C. tropicalis in shake cultures respectively. In contrast, R. oryzae can produce a higher concentration of d-limonene (87.73μg/kg) d-limonene than C. tropicalis (11.95μg/kg) in bioreactor cultures. Based on sensory analysis, unripe olive, wet towel, sweet aromatic, fermented aromas were determined at high intensity in olive mill waste fermented with R. oryzae meanwhile olive mill waste fermented with C. tropicalis had only a high intensity of unripe olive and oily aroma. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  16. Linoleic and linolenic acids analysis of soybean tofu with Rhizopus oryzae and Rhizopus oligosporus as coagulant

    Directory of Open Access Journals (Sweden)

    SUPYANI

    2009-07-01

    Full Text Available Sudaryatiningsih C, Supyani. 2009. Linoleic and linolenic acids analysis of soybean tofu with Rhizopus oryzae and Rhizopus oligosporus as coagulant. Nusantara Bioscience 1: 110-116. The aims of this research are to know the potency of Rhizopus oligosporus and Rhizopus oryzae as a coagulant in tofu processing for increasing the amount of linoleic and linolenic acids, and to know the time that needed by R. oligosporus and R. oryzae for increasing the amount of linoleic and linolenic acids. It uses PDA for inoculating fungi, and it is done at Sub-Lab Chemistry, Central Laboratory for Mathematics and Natural Sciences, Sebelas Maret University, Surakarta. The tofu making was done in “Dele Emas” Tofu Factory, Surakarta. Analysis of linoleic and linolenic acids were done by Gas Chromatography, in LPPT-UGM Yogyakarta. The conclusion of this research are R. oligosporus dan R. oryzae having a potency as a coagulant in tofu processing for increasing the amount of linoleic and linolenic acids. R. oryzae needs 18 hours to coagulate the tofu, and R. oligosporus needs 12 hours for the same process. The highest amount of linoleic and linolenic acids were obtained by R. oryzae at 6 hours of fermentation (0.26% and 0.14%, and 24 hours of fermentation by R. oligosporus (0.06% and 0.04%.

  17. Random Mutagenesis of the Aspergillus oryzae Genome Results in Fungal Antibacterial Activity

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    Cory A. Leonard

    2013-01-01

    Full Text Available Multidrug-resistant bacteria cause severe infections in hospitals and communities. Development of new drugs to combat resistant microorganisms is needed. Natural products of microbial origin are the source of most currently available antibiotics. We hypothesized that random mutagenesis of Aspergillus oryzae would result in secretion of antibacterial compounds. To address this hypothesis, we developed a screen to identify individual A. oryzae mutants that inhibit the growth of Methicillin-resistant Staphylococcus aureus (MRSA in vitro. To randomly generate A. oryzae mutant strains, spores were treated with ethyl methanesulfonate (EMS. Over 3000 EMS-treated A. oryzae cultures were tested in the screen, and one isolate, CAL220, exhibited altered morphology and antibacterial activity. Culture supernatant from this isolate showed antibacterial activity against Methicillin-sensitive Staphylococcus aureus, MRSA, and Pseudomonas aeruginosa, but not Klebsiella pneumonia or Proteus vulgaris. The results of this study support our hypothesis and suggest that the screen used is sufficient and appropriate to detect secreted antibacterial fungal compounds resulting from mutagenesis of A. oryzae. Because the genome of A. oryzae has been sequenced and systems are available for genetic transformation of this organism, targeted as well as random mutations may be introduced to facilitate the discovery of novel antibacterial compounds using this system.

  18. SSR Analysis on Diversity of AA Genome Oryza Species in the Southeast and South Asia

    Institute of Scientific and Technical Information of China (English)

    LU Jian-zhen; ZHANG Xiao-li; WANG Hai-gang; YUAN Xiao-ping; XU Qun; WANG Yi-ping; YU Han-yong; TANG Sheng-xiang; WEI Xing-hua

    2008-01-01

    To investigate genetic diversities among the AA genome Oryza species in the Southeast and South'Asia, a total of 428 accessions of the AA genome Oryza species were genotyped using 36 simple sequence repeats (SSR) markers distributed throughout the rice genome. All of the 36 SSR markers generated polymorphic bands, revealing 100% polymorphism. The number of alleles per locus ranged from 3 to 17 with the mean of 8.6. The Nei's genetic diversity index (He) ranged from 0.337 at RM455 to 0.865 at RM 169 with an average value of 0.650. The genetic diversity of the AA genome Oryza species in the Southeast Asia was obviously higher than that in the South Asia. Among the detected Oryza species in the South and Southeast Asia, O. rufipogon showed the highest genetic diversity. Meanwhile, a higher genetic differentiation (Fst) was found among the detected Oryza species in the Southeast Asia than in the South Asia. The Fst value between O. nivara and O. sativa was the highest. The results from the number of specific alleles, specific loci, and allele frequency confirmed the greater genetic variation among the detected species. In addition, the specific allele in RM161 displayed higher frequency (0.193), suggesting its important function in identifying Oryza species of AA genome.

  19. SSR Analysis on Diversity of AA Genome Oryza Species in the Southeast and South Asia

    Directory of Open Access Journals (Sweden)

    Jian-zhen LU

    2008-12-01

    Full Text Available To investigate genetic diversities among the AA genome Oryza species in the Southeast and South Asia, a total of 428 accessions of the AA genome Oryza species were genotyped using 36 simple sequence repeats (SSR markers distributed throughout the rice genome. All of the 36 SSR markers generated polymorphic bands, revealing 100% polymorphism. The number of alleles per locus ranged from 3 to 17 with the mean of 8.6. The Nei's genetic diversity index (He ranged from 0.337 at RM455 to 0.865 at RM169 with an average value of 0.650. The genetic diversity of the AA genome Oryza species in the Southeast Asia was obviously higher than that in the South Asia. Among the detected Oryza species in the South and Southeast Asia, O. rufipogon showed the highest genetic diversity. Meanwhile, a higher genetic differentiation (Fst was found among the detected Oryza species in the Southeast Asia than in the South Asia. The Fst value between O. nivara and O. sativa was the highest. The results from the number of specific alleles, specific loci, and allele frequency confirmed the greater genetic variation among the detected species. In addition, the specific allele in RM161 displayed higher frequency (0.193, suggesting its important function in identifying Oryza species of AA genome.

  20. Genomics of Aspergillus oryzae: learning from the history of Koji mold and exploration of its future.

    Science.gov (United States)

    Machida, Masayuki; Yamada, Osamu; Gomi, Katsuya

    2008-08-01

    At a time when the notion of microorganisms did not exist, our ancestors empirically established methods for the production of various fermentation foods: miso (bean curd seasoning) and shoyu (soy sauce), both of which have been widely used and are essential for Japanese cooking, and sake, a magical alcoholic drink consumed at a variety of ritual occasions, are typical examples. A filamentous fungus, Aspergillus oryzae, is the key organism in the production of all these traditional foods, and its solid-state cultivation (SSC) has been confirmed to be the secret for the high productivity of secretory hydrolases vital for the fermentation process. Indeed, our genome comparison and transcriptome analysis uncovered mechanisms for effective degradation of raw materials in SSC: the extracellular hydrolase genes that have been found only in the A. oryzae genome but not in A. fumigatus are highly induced during SSC but not in liquid cultivation. Also, the temperature reduction process empirically adopted in the traditional soy-sauce fermentation processes has been found to be important to keep strong expression of the A. oryzae-specific extracellular hydrolases. One of the prominent potentials of A. oryzae is that it has been successfully applied to effective degradation of biodegradable plastic. Both cutinase, responsible for the degradation of plastic, and hydrophobin, which recruits cutinase on the hydrophobic surface to enhance degradation, have been discovered in A. oryzae. Genomic analysis in concert with traditional knowledge and technology will continue to be powerful tools in the future exploration of A. oryzae.

  1. The Xanthomonas oryzae pv. oryzae PilZ Domain Proteins Function Differentially in Cyclic di-GMP Binding and Regulation of Virulence and Motility.

    Science.gov (United States)

    Yang, Fenghuan; Tian, Fang; Chen, Huamin; Hutchins, William; Yang, Ching-Hong; He, Chenyang

    2015-07-01

    The PilZ domain proteins have been demonstrated to be one of the major types of receptors mediating cyclic di-GMP (c-di-GMP) signaling pathways in several pathogenic bacteria. However, little is known about the function of PilZ domain proteins in c-di-GMP regulation of virulence in the bacterial blight pathogen of rice Xanthomonas oryzae pv. oryzae. Here, the roles of PilZ domain proteins PXO_00049 and PXO_02374 in c-di-GMP binding, regulation of virulence and motility, and subcellular localization were characterized in comparison with PXO_02715, identified previously as an interactor with the c-di-GMP receptor Filp to regulate virulence. The c-di-GMP binding motifs in the PilZ domains were conserved in PXO_00049 and PXO_02374 but were less well conserved in PXO_02715. PXO_00049 and PXO_02374 but not PXO_02715 proteins bound to c-di-GMP with high affinity in vitro, and the R(141) and R(10) residues in the PilZ domains of PXO_00049 and PXO_02374, respectively, were crucial for c-di-GMP binding. Gene deletion of PXO_00049 and PXO_02374 resulted in significant increases in virulence and hrp gene transcription, indicating their negative regulation of virulence via type III secretion system expression. All mutants showed significant changes in sliding motility but not exopolysaccharide production and biofilm formation. In trans expression of the full-length open reading frame (ORF) of each gene in the relevant mutants led to restoration of the phenotype to wild-type levels. Moreover, PXO_00049 and PXO_02374 displayed mainly multisite subcellular localizations, whereas PXO_02715 showed nonpolar distributions in the X. oryzae pv. oryzae cells. Therefore, this study demonstrated the different functions of the PilZ domain proteins in mediation of c-di-GMP regulation of virulence and motility in X. oryzae pv. oryzae.

  2. Ketoglutarate transport protein KgtP is secreted through the type III secretion system and contributes to virulence in Xanthomonas oryzae pv. oryzae.

    Science.gov (United States)

    Guo, Wei; Cai, Lu-Lu; Zou, Hua-Song; Ma, Wen-Xiu; Liu, Xi-Ling; Zou, Li-Fang; Li, Yu-Rong; Chen, Xiao-Bin; Chen, Gong-You

    2012-08-01

    The phytopathogenic prokaryote Xanthomonas oryzae pv. oryzae is the causal agent of bacterial leaf blight (BB) of rice and utilizes a type III secretion system (T3SS) to deliver T3SS effectors into rice cells. In this report, we show that the ketoglutarate transport protein (KgtP) is secreted in an HpaB-independent manner through the T3SS of X. oryzae pv. oryzae PXO99(A) and localizes to the host cell membrane for α-ketoglutaric acid export. kgtP contained an imperfect PIP box (plant-inducible promoter) in the promoter region and was positively regulated by HrpX and HrpG. A kgtP deletion mutant was impaired in bacterial virulence and growth in planta; furthermore, the mutant showed reduced growth in minimal media containing α-ketoglutaric acid or sodium succinate as the sole carbon source. The reduced virulence and the deficiency in α-ketoglutaric acid utilization by the kgtP mutant were restored to wild-type levels by the presence of kgtP in trans. The expression of OsIDH, which is responsible for the synthesis of α-ketoglutaric acid in rice, was enhanced when KgtP was present in the pathogen. To our knowledge, this is the first report demonstrating that KgtP, which is regulated by HrpG and HrpX and secreted by the T3SS in Xanthomonas oryzae pv. oryzae, transports α-ketoglutaric acid when the pathogen infects rice.

  3. Biological Characteristics and Control Measures of Hazelnut weevil%榛实象甲的生物学特性及防治对策

    Institute of Scientific and Technical Information of China (English)

    李华; 钟思兰; 刘剑锋

    2016-01-01

    The harm, morphological characteristics, and life history of Hazelnut weevil were introduced firstly, and then some measures to pre-vent and control H.weevil by chemical agents, artificially killing, forest management, and biological control were proposed.%分析了榛实象甲给我国榛子产业造成的危害,介绍了棒实象甲的形态特征和生活史,并有针对性地提出了化学药剂防治、人工捕杀、营林措施、生物防治等榛实象甲综合防治措施。

  4. Notes on chromosome numbers and C-banding patterns in karyotypes of some weevils from central Europe (Coleoptera, Curculionoidea: Apionidae, Nanophyidae, Curculionidae).

    Science.gov (United States)

    Lachowska, Dorota; Holecová, Milada; Rozek, Maria

    2004-01-01

    Chromosome numbers and C-banding patterns of sixteen weevil species are presented. The obtained results confirm the existence of two groups of species with either a small or large amount of heterochromatin in the karyotype. The first group comprises twelve species (Apionidae: Oxystoma cerdo, Eutrichapion melancholicum, Ceratapion penetrans, Ceratapion austriacum, Squamapion flavimanum, Rhopalapion longirostre; Nanophyidae: Nanophyes marmoratus; Curculionidae: Centricnemus (=Peritelus) leucogrammus, Sitona humeralis, Sitona lineatus, Sitona macularis, Sitona suturalis). In weevils with a small amount of heterochromatin, tiny grains on the nucleus during interphase are visible, afterwards appearing as dark dots during mitotic and meiotic prophase. The second group comprises four species from the curculionid subfamily Cryptorhynchinae (Acalles camelus, Acalles commutatus, Acalles echinatus, Ruteria hypocrita) which possess much larger heteropycnotic chromosome parts visible during all nuclear divisions. The species examined have pericentromeric C-bands on autosomes and on the X chromosome.

  5. Systematics of the weevil genus Mecinus Germar, 1821 (Coleoptera: Curculionidae). I. Taxonomic treatment of the species.

    Science.gov (United States)

    Caldara, Roberto; Fogato, Valter

    2013-01-01

    Palaearctic species of the weevil genus Mecinus Germar, 1821 are revised. A total of 47 species are recognized, one of which, M. baridioides sp. n. is new to science. Mecinus dorsalis var. tavaresi Hoffmann, 1958 (stat. rev.) is considered as a distinct species, whereas M. alboscutellatus var. atratulus (Solari, 1933) is maintained as a subspecies of M. alboscutellatus (Hustache, 1913). The following new synonymies are proposed: Mecinus barbarus Gyllenhal, 1838 (= M. longiusculus var. subcylindricus Pic, 1896 syn. n.); M. caucasicus (Reitter, 1907) (= Gymnetron caucasicum var. rubricum Reitter, 1907 syn. n.); M. comosus Boheman, 1845 (= M. setosus Kiesenwetter, 1864 syn. n.; = M. hesteticus Vitale, 1906 syn. n.; = M. pici Reitter, 1907 syn. n.; = M. pici var. theresae Reitter, 1907 syn. n.); M. elongatus (H. Brisout de Barneville, 1862) (= G. pyrenaeum H. Brisout de Barneville, 1862 syn. n.); M. haemorrhoidalis (H. Brisout de Barneville, 1862) (= M. fairmairei Tournier, 1873 syn. n.; = G. variabile var. brevipenne Desbrochers des Loges, 1893 syn. n.; = G. variabile var. curtulum Reitter, 1907 syn. n.); M. humeralis Tournier, 1873 (= M. tournieri Fairmaire, 1876 syn. n.; = M. lineicollis Reitter, 1907 syn. n.); M. paratychioides (Hoffmann, 1965) (= G. longirostre Pic, 1921 syn. n.); M. longulus (Desbrochers des Loges, 1893) (= G. nigronotatum Pic, 1906 syn. n.; = G. nigronotatum var. vaulogeri Pic, 1930 syn. n.); M. pipistrellus (Marseul, 1871) (= G. concavirostre Stöcklein, 1950 syn. n.); M. plantaginis (Eppelsheim, 1875) (= G. zherichini Korotyaev, 1994 syn. n.); M. pyraster (Herbst, 1795) (= M. schneideri Kirsch, 1870 syn. n.; = M. hariolus Reitter, 1907 syn. n.; = M. pici var. favarcqui Pic, 1915 syn. n.); M. sanctus (Desbrochers des Loges, 1893) (= G. laterufum Pic, 1900 syn. n.); M. simus (Mulsant & Rey, 1859) (= G. mixtum Mulsant & Godart, 1873 syn. n.); M. tychioides (H. Brisout de Barneville, 1862) (= G. aestivum Hoffmann, 1956 syn. n.); M. vulpes (Lucas

  6. A revision of the New Zealand weevil genus Irenimus Pascoe, 1876 (Coleoptera: Curculionidae: Entiminae).

    Science.gov (United States)

    Brown, Samuel D J

    2017-05-08

    The taxonomy of the New Zealand weevil genus Irenimus Pascoe, 1876 is revised, resulting in a narrower concept of the genus than has been considered in recent decades. In total, the genus now contains only seven species. In addition to the type species, I. parilis Pascoe, 1876, the genus contains I. duplex (Broun, 1904) and five newly described species: I. aniptus new species (type locality, Oamaru, DN), I. crinitus new species (type locality, Hakataramea Valley, SC), I. minimus new species (type locality, Alexandra, CO), I. stichus new species (type locality, Tekapo, MK) and I. thoracicus new species (type locality, Oamaru, DN). The genus Chalepistes new genus is established to contain the majority of species previously described in the genus Catoptes Schönherr, 1842, but also including species described in Brachyolus White, 1846; Irenimus Pascoe, 1876; Inophloeus Pascoe, 1875; and Nicaeana Pascoe, 1877. A total of 27 valid described species are new combinations with Chalepistes: C. aequalis (Broun, 1895) (from Irenimus), C. albosparsus (Broun, 1917) (from Irenimus), C. apicalis (Broun, 1923) (from Catoptes), C. asperatus (Broun, 1914) (from Brachyolus), C. compressus (Broun, 1880) (from Irenimus), C. costifer (Broun, 1886) (from Inophloeus), C. curvus (Barratt & Kuschel, 1996) (from Irenimus), C. dehiscens (Broun, 1917) (from Catoptes), C. dugdalei (Barratt & Kuschel, 1996) (from Irenimus), C. egens (Broun, 1904) (from Irenimus), C. inaequalis (Sharp, 1886) (from Brachyolus), C. instabilis (Marshall, 1931) (from Catoptes), C. latipennis (Broun, 1893) (from Catoptes), C. limbatus (Broun, 1909) (from Catoptes), C. lobatus (Broun, 1921) (from Catoptes), C. patricki (Barratt & Kuschel, 1996) (from Irenimus), C. pensus (Broun, 1914) (from Inophloeus), C. placidus (Broun, 1914) (from Nicaeana), C. posticalis (Broun, 1893) (from Irenimus), C. rhesus (Pascoe, 1875) (from Inophloeus), C. rubidus (Broun, 1881) (from Inophloeus), C. similis (Barratt & Kuschel, 1996) (from

  7. Evidence for Biotrophic Lifestyle and Biocontrol Potential of Dark Septate Endophyte Harpophora oryzae to Rice Blast Disease

    OpenAIRE

    Zhen-Zhu Su; Li-Juan Mao; Na Li; Xiao-Xiao Feng; Zhi-Lin Yuan; Li-Wei Wang; Fu-Cheng Lin; Chu-Long Zhang

    2013-01-01

    The mutualism pattern of the dark septate endophyte (DSE) Harpophora oryzae in rice roots and its biocontrol potential in rice blast disease caused by Magnaporthe oryzae were investigated. Fluorescent protein-expressing H. oryzae was used to monitor the colonization pattern. Hyphae invaded from the epidermis to the inner cortex, but not into the root stele. Fungal colonization increased with root tissue maturation, showing no colonization in the meristematic zone, slight colonization in the e...

  8. Response of Pisum sativum (Fabales: Fabaceae) to Sitona lineatus (Coleoptera: Curculionidae) infestation: effect of adult weevil density on damage, larval population, and yield loss.

    Science.gov (United States)

    Vankosky, M A; Cárcamo, H A; Dosdall, L M

    2011-10-01

    Sitona lineatus L. (Coleoptera: Curculionidae) is an invasive pest in North America and its geographical range is currently expanding across the Canadian prairies. Adults and larvae of S. lineatus feed upon the foliage and root nodules, respectively, of field pea, Pisum sativum L. (Fabales: Fabaceae), and may contribute to economic losses when population densities are high. Integrated pest management (IPM) programs that incorporate economic thresholds should be used to manage S. lineatus populations in a sustainable manner. The impact of nitrogen fertilizer on field pea yield and the relationships between adult weevil density and above- and below-ground damage and yield were investigated in southern Alberta, Canada using exclusion cages on field pea plots. In each cage, 32 field pea plants were exposed to weevil densities ranging from zero to one adult weevil per plant. Nitrogen-fertilized plants yielded 16% more than unfertilized plants. Nitrogen-fertilized plants had fewer root nodules than unfertilized plants, but fertilizer had no effect on foliar feeding by S. lineatus. Adult density affected foliar feeding damage, with increases in above-ground damage associated with increases in S. lineatus density. Adult density did not affect root nodule damage, larval density, foliar biomass or seed weight. Overall, these results indicate that terminal leaf damage may be used to estimate adult weevil density but cannot be used to predict larval density or yield loss. Further research is required to better understand the impact of larval damage on yield and determine if economic thresholds can be developed using data from large-scale production systems.

  9. Susceptibility of Anthonomus grandis (cotton boll weevil) and Spodoptera frugiperda (fall armyworm) to a cry1ia-type toxin from a Brazilian Bacillus thuringiensis strain.

    Science.gov (United States)

    Grossi-de-Sa, Maria Fatima; Quezado de Magalhaes, Mariana; Silva, Marilia Santos; Silva, Shirley Margareth Buffon; Dias, Simoni Campos; Nakasu, Erich Yukio Tempel; Brunetta, Patricia Sanglard Felipe; Oliveira, Gustavo Ramos; Neto, Osmundo Brilhante de Oliveira; Sampaio de Oliveira, Raquel; Soares, Luis Henrique Barros; Ayub, Marco Antonio Zachia; Siqueira, Herbert Alvaro Abreu; Figueira, Edson L Z

    2007-09-30

    Different isolates of the soil bacterium Bacillus thuringiensis produce multiple crystal (Cry) proteins toxic to a variety of insects, nematodes and protozoans. These insecticidal Cry toxins are known to be active against specific insect orders, being harmless to mammals, birds, amphibians, and reptiles. Due to these characteristics, genes encoding several Cry toxins have been engineered in order to be expressed by a variety of crop plants to control insectpests. The cotton boll weevil, Anthonomus grandis, and the fall armyworm, Spodoptera frugiperda, are the major economically devastating pests of cotton crop in Brazil, causing severe losses, mainly due to their endophytic habit, which results in damages to the cotton boll and floral bud structures. A cry1Ia-type gene, designated cry1Ia12, was isolated and cloned from the Bt S811 strain. Nucleotide sequencing of the cry1Ia12 gene revealed an open reading frame of 2160 bp, encoding a protein of 719 amino acid residues in length, with a predicted molecular mass of 81 kDa. The amino acid sequence of Cry1Ia12 is 99% identical to the known Cry1Ia proteins and differs from them only in one or two amino acid residues positioned along the three domains involved in the insecticidal activity of the toxin. The recombinant Cry1Ia12 protein, corresponding to the cry1Ia12 gene expressed in Escherichia coli cells, showed moderate toxicity towards first instar larvae of both cotton boll weevil and fall armyworm. The highest concentration of the recombinant Cry1Ia12 tested to achieve the maximum toxicities against cotton boll weevil larvae and fall armyworm larvae were 230 microg/mL and 5 microg/mL, respectively. The herein demonstrated insecticidal activity of the recombinant Cry1Ia12 toxin against cotton boll weevil and fall armyworm larvae opens promising perspectives for the genetic engineering of cotton crop resistant to both these devastating pests in Brazil.

  10. A Novel Manganese Efflux System, YebN, Is Required for Virulence by Xanthomonas oryzae pv. oryzae

    Science.gov (United States)

    Li, Chunxia; Tao, Jun; Mao, Daqing; He, Chaozu

    2011-01-01

    Manganese ions (Mn2+) play a crucial role in virulence and protection against oxidative stress in bacterial pathogens. Such pathogens appear to have evolved complex mechanisms for regulating Mn2+ uptake and efflux. Despite numerous studies on Mn2+ uptake, however, only one efflux system has been identified to date. Here, we report on a novel Mn2+ export system, YebN, in Xanthomonas oryzae pv. oryzae (Xoo), the causative agent of bacterial leaf blight. Compared with wild-type PXO99, the yebN mutant was highly sensitive to Mn2+ and accumulated high concentrations of intracellular manganese. In addition, we found that expression of yebN was positively regulated by Mn2+ and the Mn2+-dependent transcription regulator, MntR. Interestingly, the yebN mutant was more tolerant to methyl viologen and H2O2 in low Mn2+ medium than PXO99, but more sensitive in high Mn2+ medium, implying that YebN plays an important role in Mn2+ homoeostasis and detoxification of reactive oxygen species (ROS). Notably, deletion of yebN rendered Xoo sensitive to hypo-osmotic shock, suggesting that YebN may protect against such stress. That mutation of yebN substantially reduced the Xoo growth rate and lesion formation in rice implies that YebN could be involved in Xoo fitness in host. Although YebN has two DUF204 domains, it lacks homology to any known metal transporter. Hence, this is the first report of a novel metal export system that plays essential roles in hypo-osmotic and oxidative stress, and virulence. Our results lay the foundations for elucidating the complex and fascinating relationship between metal homeostasis and host-pathogen interactions. PMID:21789199

  11. Identification of an avirulence gene,avrxa5,from the rice pathogen Xanthomonas oryzae pv.oryzae

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Xanthomonas oryzae pv.oryzae,the causal agent of bacterial blight in rice,interacts with rice plants in a gene-for-gene manner.The specificity of the interaction is dictated by avirulence(avr) genes in the pathogen and resistance(R) genes in the host.To date,no avr genes that correspond to recessive R genes have been isolated.We isolated an avrBs3/pthA family gene,avrxa5,from our previously isolated clone p58,which was originally from strain JXOIII.The avrxa5 gene converted the PXO99A strain from compatible to incompatible in rice cultivars containing the recessive xa5 gene,but not in those containing the dominant Xa5 gene.Sequencing indicated that avrxa5,which is highly similar to members of the avrBs3/pthA family,encodes a protein of 1238 amino acid residues with a conserved carboxy-terminal region containing three nuclear localization signals and a transcription activation domain.It has 19.5 34-amino-acid direct repeats,but the 13th amino acid is missing in the fifth and ninth repetitive units.Domain swapping of the repetitive regions between avrxa5 and avrXa7 changed the avirulence specificity of the genes in xa5 and Xa7 rice lines,respectively.This indicates that avrxa5 is distinct from previously characterized avrBs3/pthA members.The specificity of avrxa5 toward recessive xa5 in rice could help us better understand the molecular mechanisms of plant-pathogen specific interactions.

  12. A novel manganese efflux system, YebN, is required for virulence by Xanthomonas oryzae pv. oryzae.

    Science.gov (United States)

    Li, Chunxia; Tao, Jun; Mao, Daqing; He, Chaozu

    2011-01-01

    Manganese ions (Mn(2+)) play a crucial role in virulence and protection against oxidative stress in bacterial pathogens. Such pathogens appear to have evolved complex mechanisms for regulating Mn(2+) uptake and efflux. Despite numerous studies on Mn(2+) uptake, however, only one efflux system has been identified to date. Here, we report on a novel Mn(2+) export system, YebN, in Xanthomonas oryzae pv. oryzae (Xoo), the causative agent of bacterial leaf blight. Compared with wild-type PXO99, the yebN mutant was highly sensitive to Mn(2+) and accumulated high concentrations of intracellular manganese. In addition, we found that expression of yebN was positively regulated by Mn(2+) and the Mn(2+)-dependent transcription regulator, MntR. Interestingly, the yebN mutant was more tolerant to methyl viologen and H(2)O(2) in low Mn(2+) medium than PXO99, but more sensitive in high Mn(2+) medium, implying that YebN plays an important role in Mn(2+) homoeostasis and detoxification of reactive oxygen species (ROS). Notably, deletion of yebN rendered Xoo sensitive to hypo-osmotic shock, suggesting that YebN may protect against such stress. That mutation of yebN substantially reduced the Xoo growth rate and lesion formation in rice implies that YebN could be involved in Xoo fitness in host. Although YebN has two DUF204 domains, it lacks homology to any known metal transporter. Hence, this is the first report of a novel metal export system that plays essential roles in hypo-osmotic and oxidative stress, and virulence. Our results lay the foundations for elucidating the complex and fascinating relationship between metal homeostasis and host-pathogen interactions.

  13. Mapping of quantitative trait loci for fiber and lignin contents from an interspecific cross Oryza sativa×Oryza rufipogon

    Institute of Scientific and Technical Information of China (English)

    Jian-kun XIE; Xiang-li KONG; Jie CHEN; Biao-lin HU; Piao WEN; Jie-yun ZHUANG; Jin-song BAO

    2011-01-01

    Rice straw is always regarded as a by-product of rice production,but it could be a significant energy source for ruminant animals.Knowledge of the genetic variation and genetic architecture of cell wall traits will facilitate rice breeders by improving relevant traits through selective breeding and genetic engineering.The common wild rice,Oryza rufipogon Griff.,which is considered to be the progenitor of Oryza sativa,has been widely utilized for the identification of genes of agronomic importance for rice genetic improvement.In the present study,the mapping of quantitative trait loci (QTLs) for acid detergent fiber (ADF),neutral detergent fiber (NDF),acid detergent lignin (ADL),and ADL/NDF ratio was carried out in two environments using a backcrossed inbred line (BIL) population derived from a cross between the recurrent parent Xieqingzao B (XB) and an accession of Dongxiang wild rice (DWR).The results indicated that all four traits tested were continuously distributed among the BILs,but many BILs showed transgressive segregation.A total of 16 QTLs were identified for the four traits,but no QTLs were in common in two environments,suggesting that environment has dramatic effects on fiber and lignin syntheses.Compared to the QTL positions for grain yield-related traits,there were no unfavorable correlations between grain yield components and cell wall traits in this population.The QTLs identified in this study are useful for the development of dual-purpose rice varieties that are high in grain yield and are also high in straw quality.

  14. Five types of olfactory receptor neurons in the strawberry blossom weevil Anthonomus rubi: selective responses to inducible host-plant volatiles.

    Science.gov (United States)

    Bichão, Helena; Borg-Karlson, Anna-Karin; Araújo, Jorge; Mustaparta, Hanna

    2005-02-01

    Plants release hundreds of volatiles that are important in the interaction with herbivorous animals, but which odorants are detected by which species? In this study, single receptor neurons on the antenna of the oligophagous strawberry blossom weevil Anthonomus rubi were screened for sensitivity to naturally produced plant compounds by the use of gas chromatography linked to electrophysiological recordings from single cells. The narrow tuning of the neurons was demonstrated by responses solely to a few structurally related sesquiterpenes, aromatics or monoterpene hydrocarbons out of hundreds of plant constituents tested. We present five olfactory receptor neuron types, identified according to one primary odorant i.e. the compound to which the neurons are most sensitive. These odorants, (-)-germacrene D, (-)-beta-caryophyllene, methyl salicylate, E-beta-ocimene and (3E)-4,8-dimethyl-1,3,7-nonatriene, present in the intact strawberry plant, are induced in higher amounts by weevil feeding. This suggests that these compounds can provide information about the presence of conspecifics. We used protocols especially designed to allow comparison with previously investigated species. Striking similarities, but also differences, are demonstrated between receptor neuron specificity in the strawberry weevil and moths.

  15. Selection of Beauveria bassiana sensu lato and Metarhizium anisopliae sensu lato isolates as microbial control agents against the boll weevil (Anthonomus grandis) in Argentina.

    Science.gov (United States)

    Nussenbaum, A L; Lecuona, R E

    2012-05-01

    The boll weevil (Anthonomus grandis) is the main pest of cotton in the Americas. The aim of this work was to evaluate isolates of the entomopathogenic fungi Beauveria bassiana sensu lato and Metarhizium anisopliae sensu lato virulent against A. grandis. Screening was performed to evaluate the pathogenicity of 28 isolates of M. anisopliae s.l. and 66 isolates of B. bassiana s.l. against boll weevil adults. To select the isolates, LC(50) values of the most virulent isolates were calculated, and compatibility between the fungi and insecticides was studied. In addition, the effects of these isolates on the feeding behavior of the adults were evaluated. Isolates Ma 50 and Ma 20 were the most virulent against A. grandis and their LC(50) values were 1.13×10(7) and 1.20×10(7) conidia/ml, respectively. In addition, these isolates were compatible with pyrethroid insecticides, but none with endosulfan. On the other hand, infected females reduced the damage caused by feeding on the cotton squares and their weight gain. This shows that entomopathogenic fungi cause mortality in the insects, but also these fungi could influence the feeding behavior of the females. In summary, these results indicate the possibility of the use of M. anisopliae s.l. as a microbiological control agent against boll weevils. Also, this species could be included in an Integrated Pest Management program.

  16. Silencing the Olfactory Co-Receptor RferOrco Reduces the Response to Pheromones in the Red Palm Weevil, Rhynchophorus ferrugineus.

    Science.gov (United States)

    Soffan, Alan; Antony, Binu; Abdelazim, Mahmoud; Shukla, Paraj; Witjaksono, Witjaksono; Aldosari, Saleh A; Aldawood, Abdulrahman S

    2016-01-01

    The red palm weevil (RPW, Rhynchophorus ferrugineus), one of the most widespread of all invasive insect pest species, is a major cause of severe damage to economically important palm trees. RPW exhibits behaviors very similar to those of its sympatric species, the Asian palm weevil (R. vulneratus), which is restricted geographically to the southern part of Southeast Asia. Although efficient and sustainable control of these pests remains challenging, olfactory-system disruption has been proposed as a promising approach for controlling palm weevils. Here, we report the cloning and sequencing of an olfactory co-receptor (Orco) from R. ferrugineus (RferOrco) and R. vulneratus (RvulOrco) and examine the effects of RferOrco silencing (RNAi) on odorant detection. RferOrco and RvulOrco encoding 482 amino acids showing 99.58% identity. The injection of double-stranded RNA (dsRNA) from RferOrco into R. ferrugineus pupae significantly reduced RferOrco gene expression and led to the failure of odor-stimulus detection, as confirmed through olfactometer and electroantennography (EAG) assays. These results suggest that olfactory-system disruption leading to reduced pheromone detection holds great potential for RPW pest-control strategies.

  17. Infectivity of Steinernema carpocapsae and S. feltiae to Larvae and Adults of the Hazelnut Weevil, Curculio nucum: Differential Virulence and Entry Routes.

    Science.gov (United States)

    Batalla-Carrera, Laia; Morton, Ana; Shapiro-Ilan, David; Strand, Michael R; García-Del-Pino, Fernando

    2014-09-01

    We investigated the existing susceptibility differences of the hazelnut weevil, Curculio nucum L. (Coleoptera:, Curculionidae) to entomopathogenic nematodes by assessing the main route of entry of the nematodes, Steinernema carpocapsae strain B14 and S. feltiae strain D114, into larvae and adult insects, as well as host immune response. Our results suggested that S. carpocapsae B14 and S. feltiae D114 primarily entered adult insects and larvae through the anus. Larvae were more susceptible to S. feltiae D114 than S. carpocapsae B14 and adults were highly susceptible to S. carpocapsae B14 but displayed low susceptibility to S. feltiae D114. Penetration rate correlated with nematode virulence. We observed little evidence that hazelnut weevils mounted any cellular immune response toward S. carpocapsae B14 or S. feltiae D114. We conclude the differential susceptibility of hazelnut weevil larvae and adults to S. carpocapsae B14 and S. feltiae D114 primarily reflected differences in the ability of these two nematodes to penetrate the host.

  18. Silencing the Olfactory Co-Receptor RferOrco Reduces the Response to Pheromones in the Red Palm Weevil, Rhynchophorus ferrugineus

    Science.gov (United States)

    Soffan, Alan; Abdelazim, Mahmoud; Shukla, Paraj; Witjaksono, Witjaksono; Aldosari, Saleh A.; Aldawood, Abdulrahman S.

    2016-01-01

    The red palm weevil (RPW, Rhynchophorus ferrugineus), one of the most widespread of all invasive insect pest species, is a major cause of severe damage to economically important palm trees. RPW exhibits behaviors very similar to those of its sympatric species, the Asian palm weevil (R. vulneratus), which is restricted geographically to the southern part of Southeast Asia. Although efficient and sustainable control of these pests remains challenging, olfactory-system disruption has been proposed as a promising approach for controlling palm weevils. Here, we report the cloning and sequencing of an olfactory co-receptor (Orco) from R. ferrugineus (RferOrco) and R. vulneratus (RvulOrco) and examine the effects of RferOrco silencing (RNAi) on odorant detection. RferOrco and RvulOrco encoding 482 amino acids showing 99.58% identity. The injection of double-stranded RNA (dsRNA) from RferOrco into R. ferrugineus pupae significantly reduced RferOrco gene expression and led to the failure of odor-stimulus detection, as confirmed through olfactometer and electroantennography (EAG) assays. These results suggest that olfactory-system disruption leading to reduced pheromone detection holds great potential for RPW pest-control strategies. PMID:27606688

  19. The complete mitochondrial genomes of two weevils, Eucryptorrhynchus chinensis and E. brandti: conserved genome arrangement in Curculionidae and deficiency of tRNA-Ile gene

    Directory of Open Access Journals (Sweden)

    Liu Zhen-Kai

    2016-01-01

    Full Text Available The weevils Eucryptorrhynchus chinensis and Eucryptorrhynchus brandti (Coleoptera: Curculionidae, are two of the most important pests of the tree-of-heaven, Ailanthus altissima, which is found throughout China. In this study, the complete mitogenomes of the two weevils have been sequenced using Illumina HiSeqTM 2000. The mitogenomes of E. chinensis and E. brandti are 15,628bp and 15,597bp long with A+T contents of 77.7% and 76.6%, respectively. Both species have typical circular mitochondrial genomes that encode 36 genes. Except the deficiency of tRNA-Ile, the gene composition and order of E. chinensis and E. brandti are identical to the inferred ancestral gene arrangement of insects. In both mitochondrial genomes, the start codons for COI and ND1 are AAT and TTG, respectively. A5bp motif (TACTA is detected in intergenic region between the tRNA-Ser (UCN and ND1 genes. The ATP8/ATP6 and ND4L/ND4 gene pairs appear to overlap four or seven nucleotides (ATAA/ATGATAA in different reading frames. The complete sequences of AT-rich region have two regions including tandem repeats. The study identifies useful genetic markers for studying the population genetics, molecular identification and phylogeographics of Eucryptorrhynchus weevils. The features of the mitochondrial genomes are expected to be valuable in

  20. Naturally occurring entomopathogenic fungi infecting stored grain insect species in Punjab, Pakistan.

    Science.gov (United States)

    Wakil, Waqas; Usman Ghazanfar, Muhammad; Yasin, Muhammad

    2014-01-01

    The occurrence of entomopathogenic fungi isolated from stored grain insect pests sampled from various geographical regions of Punjab, Pakistan, was investigated. In total, 25,720 insects from six different species were evaluated, and 195 isolates from 24 different fungal species were recovered. These included the Ascomycetes Beauveria bassiana sensu lato (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae), Metarhizium anisopliae sensu lato (Metschnikoff) Sorokin (Hypocreales: Clavicipitaceae), Purpureocillium lilacinum (Thorn) Samson (Hypocreales: Ophiocordycipitaceae), and Lecanicillium attenuatum (Zare and W. Gams) (Hypocreales: Clavicipitaceae). The cadavers of red flour beetle Tribolium castaneum (Herbst.) (Coleoptera: Tenebrionidae) were significantly infected with the fungi followed by rice weevil Sitophilus oryzae (L.) (Coleoptera: Curculionidae), lesser grain borer Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae), rusty grain beetle Cryptolestes ferrugineus (Stephens) (Coleoptera: Cucujidae), and cowpea weevil Callosobruchus maculatus (F.) (Coleoptera: Bruchidae); however, the least were recovered from khapra beetle Trogoderma granarium (Everts) (Coleoptera: Dermestidae). The geographical attributes (altitude, longitude, and latitude) greatly influenced the occurrence of entomopathogenic fungi with highest number of isolates found from >400 (m) altitude, 33°-34' N latitude, and 73°-74' E longitude. The findings of the current surveys clearly indicated that the entomopathogenic fungi are widely distributed in the insect cadavers, which may later be used in successful Integrated Pest Management programs.