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Sample records for bollworm helicoverpa armigera

  1. Field dispersal ability of irradiated cotton bollworm Helicoverpa armigera (Hubner)

    International Nuclear Information System (INIS)

    The field dispersal ability of cotton bollworm, Helicoverpa armigera (Hubner) irradiated with 300 Gy of γ-rays was studied. The results showed that about 97% of cotton bollworm was dispersed in 720 m. The 615 m was the farthest of average dispersal distance. The dispersal density of cotton bollworm was correlated with the reciprocal of dispersal distance, as the model: N = -0.83 + 1647.34/x. the dispersal of cotton bollworm had taxis to the green and fresh host

  2. A eukaryotic initiation factor 5C is upregulated during metamorphosis in the cotton bollworm, Helicoverpa armigera

    Directory of Open Access Journals (Sweden)

    Zhao Xiao-Fan

    2009-03-01

    Full Text Available Abstract Background The orthologs of eukaryotic initiation factor 5C (eIF5C are essential to the initiation of protein translation, and their regulation during development is not well known. Results A cDNA encoding a polypeptide of 419 amino acids containing an N-terminal leucine zipper motif and a C-terminal eIF5C domain was cloned from metamorphic larvae of Helicoverpa armigera. It was subsequently named Ha-eIF5C. Quantitative real-time PCR (QRT-PCR revealed a high expression of the mRNA of Ha-eIF5C in the head-thorax, integument, midgut, and fat body during metamorphosis. Immunohistochemistry suggested that Ha-eIF5C was distributed into both the cytoplasm and the nucleus in the midgut, fat body and integument. Ha-eIF5C expression was upregulated by 20-hydroxyecdysone (20E. Furthermore, the transcription of Ha-eIF5C was down regulated after silencing of ecdysteroid receptor (EcR or Ultraspiracle protein (USP by RNAi. Conclusion These results suggested that during metamorphosis of the cotton bollworm, Ha-eIF5C was upregulated by 20E through the EcR and USP transcription factors.

  3. Functional Characteristics of a Novel Chemosensory Protein in the Cotton Bollworm Helicoverpa armigera (Hübner)

    Institute of Scientific and Technical Information of China (English)

    ZHANG Tian-tao; WANG Wei-xuan; ZHANG Zi-ding; ZHANG Yong-jun; GUO Yu-yuan

    2013-01-01

    A chemosensory protein named HarmCSP5 in cotton bollworm Helicoverpa armigera (Hübner) was obtained from antennal cDNA libraries and expressed in Escherichia coli. The real time quantitative PCR (RT-qPCR) results indicated that HarmCSP5 gene was mainly expressed in male and female antennae but also expressed in female legs and wings. Competitive binding assays were performed to test the binding affinity of recombinant HarmCSP5 to 60 odor molecules including some cotton volatiles. The resules showed that HarmCSP5 showed strong binding abilities to 4-ehtylbenzaldehyde and 3,4-dimethlbenz aldehyde, whereas methyl phenylacetate, 2-decanone, 1-pentanol, carvenol, isoborneol, nerolidol, 2-nonanone and ethyl heptanoate have relatively weak binding affinity. Moreover, the predicted 3D model of HarmCSP5 consists of sixα-helices located among residues 33-38 (α1), 40-48 (α2), 62-72 (α3), 80-96 (α4), 98-108 (α5), and 116-119 (α6), two pairs of disulfide bridges Cys49-Cys55, Cys75-Cys78. The two amino acid residues, Ile94 and Trp101, may play crucial roles in HarmCSP5 binding with ligands and need further study for confirmation.

  4. Radiation Induced F-1 Sterility For The Control Of Cotton Bollworm , Helicoverpa armigera (Huebner) In Pilot Test

    International Nuclear Information System (INIS)

    Pilot trials of radiation induced F-1 sterility for the control of cotton bollworm Helicoverpa armigera (Hubner) were studied for 3 cotton crop seasons in 3 locations at Amphor Takfa, Nakornsawan province in 2002, 2003 and 2004. Irradiated male pupae at a sub sterilizing dose of 150 Gy were released : approximately 11,170 42,900 and 36,400 pupae from July to December of 2002, 2003 and 2004, respectively. The insecticide plots were maintained as a comparison to determine the efficiency of this method. Checking of larvae on cotton plants by the systematic random sampling method and the cotton yield were used to evaluate the impact of the pupal release. It was found that the releasing plots and the insecticide plots gave similar results in terms of the number of larvae and the cotton yield. Therefore, the F-1 sterility method was a possible method for the control of cotton bollworm

  5. Effects of dietary quercetin on performance and cytochrome P450 expression of the cotton bollworm, Helicoverpa armigera.

    Science.gov (United States)

    Liu, D; Yuan, Y; Li, M; Qiu, X

    2015-12-01

    Quercetin is ubiquitous in terrestrial plants. The cotton bollworm Helicoverpa armigera as a highly polyphagous insect has caused severe crop losses. Until now, interactions between this pest and quercetin are poorly understood at the biochemical and molecular levels. In this study, we investigated the in vivo effects of quercetin on performance of cotton bollworm and on cytochrome P450 (P450) expression. Deleterious effects of quercetin on the performance of the cotton bollworm, including growth, survival, pupation and adult emergence were observed after oral administration of 3 and 10 mg g(-1) quercetin to larvae since the third instar, whereas no significant toxic effect was found at 0.1 mg g(-1) quercetin treatment. Piperonyl butoxide treatment enhanced the toxicity of quercetin. In vitro metabolism studies showed that quercetin was rapidly transformed by gut enzymes of fifth instar larvae of the cotton bollworm. qRT-PCR results revealed that the effect of quercetin on P450 expression was tissue- and dose-specific. Quercetin regulated P450 expression in a mild manner, and it could serve as P450 inducer (CYP337B1, CYP6B6) or repressor (CYP337B1, CYP6B7, CYP6B27, CYP9A14, CYP6AE11, and CYP4M7). These findings are important for advancing our understanding of the biochemical and molecular response of insects to plant toxins and have implications for a smart pest control. PMID:26440448

  6. Commercial production of transgenic Bt insect-resistant cotton varieties and the resistance management for bollworm (Helicoverpa armigera Hubner)

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    There are currently three kinds of transgenic Bt insect-resistant cotton germplasm lines, Shanxi 94-24, Zhongxin 94 and R19, in China. They showed high resistance to the neonate larvae of bollworm (Helicoverpa armigera). Transgenic Bt insect-resistant cotton varieties or hybrids have been bred using the three kinds of germplasm lines as parents. Our researches reveal that there exist different expressions in resistant level at different developmental stages in the three categories of germplasm lines. When neonate larvae are fed with leaves of cotton plant at the seeding stage with less than 10 leaves on the main stem, the mortality of the neonate larvae is 100%, but the resistance level will decline at later season. When Bt gene has been transferred to the cotton genome, it can be steadily transferred to the progeny, the level of resistance to bollworm keeps fundamentally uniform. Such insects as tobacco budworm (Heliothis virencens) in laboratory directive selection are very apt to produce resistance to the Bt insecticidal crystal protein. From the present crop system of cotton region in the Yangtze and Yellow River Valleys, and the expression characteristic of transgenic Bt resistant cotton, we suggest that the resistance to toxin protein in bollworm is not apt to be produced if the transgenic Bt insect-resistant cotton varieties are released and grown in the regions except in the Xinjiang cotton region. The managing strategies to delay or retard the resistance are discussed.

  7. DNA synthesis in the imaginal wing discs of the American bollworm Helicoverpa armigera (Hübner)

    Indian Academy of Sciences (India)

    A Josephrajkumar; B Subrahmanyam

    2002-03-01

    The effect of two insect growth regulators of plant origin viz. plumbagin and azadirachtin and the ecdysteroids 20-hydroxyecdysone, makisterone A and a phytoecdysteroid on DNA synthesis in imaginal wing discs of day 4 final instar Helicoverpa armigera larvae was studied. DNA synthesis increased with increase in time of incubation up to 8 h and decreased later without the addition of moulting hormone. Addition of 20-hydroxyecdysone supported long term acquisition of competence for DNA synthesis in the wing discs. Both DNA synthesis and protein content were drastically reduced in plumbagin and azadirachtin-treated insects. Under in vitro conditions, plumbagin had a more pronounced inhibitory effect than azadirachtin. All the ecdysteroids tested, viz. makisterone A, 20-hydroxyecdysone and the ecdysteroidal fraction from the silver fern Cheilanthes farinosa enhanced DNA synthesis.

  8. Efifciency of Different Methods for dsRNA Delivery in Cotton Bollworm (Helicoverpa armigera)

    Institute of Scientific and Technical Information of China (English)

    YANG Jing; HAN Zhao-jun

    2014-01-01

    RNAi trigged by dsRNA not only facilitates the development of molecular biology, but also initiates a new way for pest control by silence of fatal genes. However, one of the key limitations in pest control is lack of the convenient and efifcient method for dsRNA delivery. In this study, different dsRNA delivery methods at their own optimum conditions were evaluated comparatively for their efifciency with Helicoverpa armigera as test animal. It was found that the popular one-time injection of larvae with dsRNA could reduce the pupation rate by 43.0%and enhance larva mortality by 11.7%. One-time ingestion of dsRNA did not result in any signiifcant effect on phenotype. Continuous ingestion of in vitro synthesized dsRNA by refreshing the bait diet every day caused 40.4% decrease in successful pupation and 10.0% increase in larval mortality, which was similar as one-time injection. The most efifcient method was found to be the continuous ingestion of the bacteria containing dsRNA expressed, which reduced the rate of pupation by 68.7%and enhanced the larval mortality by 34.1%. Further analysis found that dsRNA was degraded faster in midgut juice than in hemolymph. However, the cell of bacteria could protect dsRNA and delay the degradation in the midgut juice of H. armigera. These results throw light on the application of dsRNA in pest management with proper ways.

  9. Response of successive three generations of cotton bollworm, Helicoverpa armigera (Hübner), fed on cotton bolls, under elevated CO2

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The growth, development and consumption of successive three generations of cotton bollworm, Helicoverpa armigera (Hübner), fed on cotton bolls grown under elevated CO2 (double-ambient vs. ambient) in open-top chambers were examined. Significant decreases in protein, total amino acid, water and nitrogen content and increases in free fatty acid were observed in cotton bolls. Changes in quality of cotton bolls affected the growth, development and food utilization of H. armigera. Significantly longer larval development duration in three successive generations and lower pupal weight of the second and third generations were observed in cotton bollworm fed on cotton bolls grown under elevated CO2. Significantly lower fecundity was also found in successive three generations of H. armigera fed on cotton bolls grown under elevated CO2. The consumption per larva occurred significant increase in successive three generations and frass per larva were also significantly increased during the second and third generations under elevated CO2. Significantly lower relative growth rate, efficiency of conversion of ingested food and significant higher relative consumption rate in successive three generations were observed in cotton bollworm fed on cotton bolls grown under elevated CO2. Significantly lower potential female fecundity, larval numbers and population consumption were found in the second and third generations of cotton bollworm fed on cotton bolls grown under elevated CO2. The integrative effect of higher larval mortality rate and lower adult fecundity resulted in significant decreases in potential population consumption in the latter two generations. The results show that elevated CO2 adversely affects cotton bolls quality, which indicates the potential population dynamics and potential population consumption of cotton bollworm will alleviate the harm to the plants in the future rising CO2 atmosphere.

  10. The olfactory basis for attraction of the Bollworm helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) to host-plant flowers

    OpenAIRE

    Bruce, Toby Johann

    2000-01-01

    The objective of this work was to investigate whether or not olfactory clues play a role in host plant location by the polyphagous moth, Helicoverpa armigera. Volatiles collected from flowers of African marigold, Tagetes erecta, and sweet pea, Lathyrus odouratus, were found to elicit electroantennographic (EAG) responses from the antennae of female H. armigera. Compounds active in GC-EAG analyses of T. erecta floral headspace samples, identified by GC-MS and comparison of retention times on p...

  11. Molecular Characterization and Function Analysis of the Vitellogenin Receptor from the Cotton Bollworm, Helicoverpa armigera (Hübner) (Lepidoptera, Noctuidae)

    Science.gov (United States)

    Xiao, Haijun; Xie, Bingtang; Smagghe, Guy; Guo, Yuyuan; Liang, Gemei

    2016-01-01

    Developing oocytes accumulate plentiful yolk protein during oogenesis through receptor-mediated endocytosis. The vitellogenin receptor (VgR), belonging to the low-density lipoprotein receptor (LDLR) family, regulates the absorption of yolk protein. In this work, the full-length vitellogenin receptor (HaVgR) in the cotton bollworm Helicoverpa armigera was identified, encoding a 1817 residue protein. Sequence alignment revealed that the sequence of HaVgR contained all of the conservative structural motifs of LDLR family members, and phylogenetic analysis indicated that HaVgR had a high identity among Lepidoptera and was distinct from that of other insects. Consistent with other insects, HaVgR was specifically expressed in ovarian tissue. The developmental expression pattern showed that HaVgR was first transcribed in the newly metamorphosed female adults, reached a peak in 2-day-old adults and then declined. Western blot analysis also revealed an ovarian-specific and developing expression pattern, which was consistent with the HaVgR mRNA transcription. Moreover, RNAi-mediated HaVgR knockdown strongly reduced the VgR expression in both the mRNA and protein levels, which inhibited the yolk protein deposition in the ovaries, led to the dramatic accumulation of vitellogenin and the up-regulation of HaVg expression in hemolymph, and eventually resulted in a declined fecundity. Together, all of these findings demonstrate that HaVgR is a specific receptor in uptake and transportation of yolk protein for the maturation of oocytes and that it plays a critical role in female reproduction. PMID:27192057

  12. The seesaw effect of winter temperature change on the recruitment of cotton bollworms Helicoverpa armigera through mismatched phenology.

    Science.gov (United States)

    Reddy, Gadi V P; Shi, Peijian; Hui, Cang; Cheng, Xiaofei; Ouyang, Fang; Ge, Feng

    2015-12-01

    Knowing how climate change affects the population dynamics of insect pests is critical for the future of integrated pest management. Rising winter temperatures from global warming can drive increases in outbreaks of some agricultural pests. In contrast, here we propose an alternative hypothesis that both extremely cold and warm winters can mismatch the timing between the eclosion of overwintering pests and the flowering of key host plants. As host plants normally need higher effective cumulative temperatures for flowering than insects need for eclosion, changes in flowering time will be less dramatic than changes in eclosion time, leading to a mismatch of phenology on either side of the optimal winter temperature. We term this the "seesaw effect." Using a long-term dataset of the Old World cotton bollworm Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) in northern China, we tested this seesaw hypothesis by running a generalized additive model for the effects of the third generation moth in the preceding year, the winter air temperature, the number of winter days below a critical temperature and cumulative precipitation during winter on the demography of the overwintering moth. Results confirmed the existence of the seesaw effect of winter temperature change on overwintering populations. Pest management should therefore consider the indirect effect of changing crop phenology (whether due to greenhouse cultivation or to climate change) on pest outbreaks. As arthropods from mid- and high latitudes are actually living in a cooler thermal environment than their physiological optimum in contrast to species from lower latitudes, the effects of rising winter temperatures on the population dynamics of arthropods in the different latitudinal zones should be considered separately. The seesaw effect makes it more difficult to predict the average long-term population dynamics of insect pests at high latitudes due to the potential sharp changes in annual growth rates

  13. Cotton bollworm, Helicoverpa armigera (Lepidoptera: Noctuidae): Large scale rearing and the effect of gamma radiation on selected life history parameters of this pest in China

    International Nuclear Information System (INIS)

    Effective large scale rearing of the cotton bollworm, Helicoverpa armigera (Huebner), has been developed in China. A 'celled unit' system was developed to replace the traditional test tube for cotton bollworm laboratory rearing. Larvae are reared at 26.5 deg. C, ∼ 70% RH, and a long day photoperiod of 14L:10D. Pupae are harvested at about day 20. Percent adult emergence is between 89-93%, and adult females lay an average of 768 eggs. Under this rearing system one generation is completed in 40-42 days and percent pupation is about 66-71%. Mature Helicoverpa armigera female and male pupae were treated with different doses of gamma radiation and out-crossed with untreated mates. Mating ability of both sexes was not affected by radiation. Treated females were highly sterile and laid significantly fewer eggs than untreated controls. Females treated with 300 Gy were completely sterile, while females treated with 250 Gy and 200 Gy still had minimal residual fertility. (author)

  14. Identification and characterization of hydrolytic enzymes from the midgut of the cotton bollworm, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae)

    OpenAIRE

    Özgür, Ebru; Yücel, Meral; Öktem, Hüseyin Avni

    2009-01-01

    Midgut hydrolytic enzymes of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) were identified and partially characterized. Km, Vmax, optimum pH, and specific activity were determined for proteolytic enzymes and a-amylases. All hydrolytic enzyme activity had an optimum pH value in the alkaline pH range. We observed major serine protease activity, together with minor cysteine-like activity, the former being significantly inhibited by soybean trypsin inhibitor (SBTI) and aprotinin. Moreover,...

  15. Laboratory testing and molecular analysis of the resistance of wild and cultivated soybeans to cotton bollworm, Helicoverpa armigera(Hübner)

    Institute of Scientific and Technical Information of China (English)

    Xiaoyi; Wang; Haifeng; Chen; Aihua; Sha; Rong; Zhou; Zhihui; Shang; Xiaojuan; Zhang; Chanjuan; Zhang; Limiao; Chen; Qingnan; Hao; Zhonglu; Yang; Dezhen; Qiu; Shuilian; Chen; Xinan; Zhou

    2015-01-01

    Identifying a superior soybean variety with high defoliator resistance is important to avoid yield loss. Cotton bollworm(Helicoverpa armigera Hübner) is one of the major defoliators of soybean(Glycine max [L.] Merr.) worldwide. In this study, we evaluated the effect of H. armigera larvae on ED059, a wild soybean(Glycine soja Sieb. et Zucc.), and three cultivated soybean varieties: Tianlong 2, PI 535807, and PI 533604, in choice and no-choice assays. The percentage of ED059 leaflets consumed by H. armigera was lower than that of the three cultivated soybeans. Larvae that fed on ED059 exhibited low weight gain and high mortality rate.Waldbauer nutritional indices suggested that ED059 reduced the growth, consumption, and frass production of H. armigera larvae. Larvae that fed on ED059 showed lower efficiency of conversion of ingested and of digested food than those that fed on Tianlong 2 and PI 533604.However, they showed statistically similar consumption index and approximate digestibility compared with those fed on the three cultivated soybeans. Quantitative real-time PCR analysis revealed that 24 h after insect attack, ED059 had higher transcript levels of Kunitz trypsin inhibitor 3, Cysteine proteinase inhibitor 2, and Nerolidol synthase 1 but a lower transcript level of Pathogenesis-related protein 1 than Tianlong 2. The gene expression results were consistent with the presence of higher levels of jasmonic acid(JA) and transcript levels of the JA biosynthesis enzyme allene oxide cyclase 3 in ED059 than in Tianlong 2. Our findings indicate that ED059 is a superior soybean line with strong insect resistance that may be mediated via the JA pathway.

  16. Laboratory testing and molecular analysis of the resistance of wild and cultivated soybeans to cotton bollworm, Helicoverpa armigera (Hübner

    Directory of Open Access Journals (Sweden)

    Xiaoyi Wang

    2015-02-01

    Full Text Available Identifying a superior soybean variety with high defoliator resistance is important to avoid yield loss. Cotton bollworm (Helicoverpa armigera Hübner is one of the major defoliators of soybean (Glycine max [L.] Merr. worldwide. In this study, we evaluated the effect of H. armigera larvae on ED059, a wild soybean (Glycine soja Sieb. et Zucc., and three cultivated soybean varieties: Tianlong 2, PI 535807, and PI 533604, in choice and no-choice assays. The percentage of ED059 leaflets consumed by H. armigera was lower than that of the three cultivated soybeans. Larvae that fed on ED059 exhibited low weight gain and high mortality rate. Waldbauer nutritional indices suggested that ED059 reduced the growth, consumption, and frass production of H. armigera larvae. Larvae that fed on ED059 showed lower efficiency of conversion of ingested and of digested food than those that fed on Tianlong 2 and PI 533604. However, they showed statistically similar consumption index and approximate digestibility compared with those fed on the three cultivated soybeans. Quantitative real-time PCR analysis revealed that 24 h after insect attack, ED059 had higher transcript levels of Kunitz trypsin inhibitor 3, Cysteine proteinase inhibitor 2, and Nerolidol synthase 1 but a lower transcript level of Pathogenesis-related protein 1 than Tianlong 2. The gene expression results were consistent with the presence of higher levels of jasmonic acid (JA and transcript levels of the JA biosynthesis enzyme allene oxide cyclase 3 in ED059 than in Tianlong 2. Our findings indicate that ED059 is a superior soybean line with strong insect resistance that may be mediated via the JA pathway.

  17. Effects of climate change on overwintering pupae of the cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)

    Science.gov (United States)

    Huang, Jian; Li, Jing

    2015-07-01

    Climate change significantly affects insects' behaviors. Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is one of the most serious insect pests in the world. Much is known about the survival of the overwintering population and spring emergence of H. armigera. However, little is known about the effects of climate change on overwintering and spring emergence of H. armigera. This study investigated the effects of changes of air and soil temperatures and precipitation on overwintering pupae of H. armigera by analyzing historical data from Magaiti County in northwest China using statistical methods. The results showed that during the period of 1989-2006, the climate warming advanced the first-appearance date of overwintering pupae eclosion (FD) and end date of overwintering pupae eclosion (ED) by 1.276 and 0.193 days per year, respectively; the duration between the FD and ED (DFEPE) was prolonged by 1.09 days per year, which resulted in more eclosion of overwintering pupae. For a 1 °C increase in the maximum air temperature ( T max) in winter, the FD became earlier by 3.234 days. Precipitation in winter delayed the FD and ED and produced little relative influence on DFEPE. A 1-mm increase of precipitation in winter delayed the FD and ED by 0.850 and 0.494 days, respectively. Mean air temperature ( T mean) in March, with a 41.3 % relative influence, precipitation in winter, with a 49.0 % relative influence, and T mean in March, with a 37.5 % relative influence, were the major affecting factors on FD, ED, and DFEPE, respectively. T max in February with a 53.0 % relative influence was the major affecting factor on the mortality of overwintering pupae (MOP). Increased soil temperatures in October and November and autumn and air temperatures in winter could decrease the MOP, though the relative influences were lower than T max in February. Increased precipitation in winter increased the MOP, but the relative influence was only 4.2 % because of little precipitation

  18. Distribution and Metabolism of Bt-Cry1Ac Toxin in Tissues and Organs of the Cotton Bollworm, Helicoverpa armigera

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    Zhuoya Zhao

    2016-07-01

    Full Text Available Crystal (Cry proteins derived from Bacillus thuringiensis (Bt have been widely used in transgenic crops due to their toxicity against insect pests. However, the distribution and metabolism of these toxins in insect tissues and organs have remained obscure because the target insects do not ingest much toxin. In this study, several Cry1Ac-resistant strains of Helicoverpa armigera, fed artificial diets containing high doses of Cry1Ac toxin, were used to investigate the distribution and metabolism of Cry1Ac in their bodies. Cry1Ac was only detected in larvae, not in pupae or adults. Also, Cry1Ac passed through the midgut into other tissues, such as the hemolymph and fat body, but did not reach the larval integument. Metabolic tests revealed that Cry1Ac degraded most rapidly in the fat body, followed by the hemolymph, peritrophic membrane and its contents. The toxin was metabolized slowly in the midgut, but was degraded in all locations within 48 h. These findings will improve understanding of the functional mechanism of Bt toxins in target insects and the biotransfer and the bioaccumulation of Bt toxins in arthropod food webs in the Bt crop ecosystem.

  19. Identification of gene expression changes associated with the initiation of diapause in the brain of the cotton bollworm, Helicoverpa armigera

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    Xu Wei-Hua

    2011-05-01

    Full Text Available Abstract Background Diapause, a state of arrested development accompanied by a marked decrease of metabolic rate, helps insects to overcome unfavorable seasons. Helicoverpa armigera (Har undergoes pupal diapause, but the molecular mechanism of diapause initiation is unclear. Using suppression subtractive hybridization (SSH, we investigated differentially expressed genes in diapause- and nondiapause-destined pupal brains at diapause initiation. Results We constructed two SSH libraries (forward, F and reverse, R to isolate genes that are up-regulated or down-regulated at diapause initiation. We obtained 194 unique sequences in the F library and 115 unique sequences in the R library. Further, genes expression at the mRNA and protein level in diapause- and nondiapause-destined pupal brains were confirmed by RT-PCR, Northern blot or Western blot analysis. Finally, we classified the genes and predicted their possible roles at diapause initiation. Conclusion Differentially expressed genes at pupal diapause initiation are possibly involved in the regulation of metabolism, energy, stress resistance, signaling pathways, cell cycle, transcription and translation.

  20. Biological activities of Solanum pseudocapsicum (Solanaceae) against cotton bollworm, Helicoverpa armigera Hübner and armyworm, Spodoptera litura Fabricius (Lepidotera:Noctuidae)

    Institute of Scientific and Technical Information of China (English)

    Alagarmalai Jeyasankar; Selvaraj Premalatha; Kuppusamy Elumalai

    2012-01-01

    Objective:To evaluate the antifeedant, insecticidal and growth inhibition activities of Solanum pseudocapsicum (S. pseudocapsicum) seed extracts against Spodoptera litura (S. litura) and Helicoverpa armigera (H. armigera). Methods:Hexane, diethyl ether, dichloromethane and ethyl acetate seed extracts were prepared and tested for antifeedant, insecticidal and growth inhibitory activities against fourth instar larvae of S. litura and H. armigera. Results:Ethyl acetate extract showed promising antifeedant and insecticidal activities against S. litura and H. armigera. Percentage of deformed larvae, pupae and adults were maximum in treatment of ethyl acetate extract. Percentage of successful adult emergence was deteriorated by seeds on extract treated larvae. Conclusions: Ethyl acetate extracts of S. pseudocapsicum, showed higher efficiency of antifeedant, insecticidal and growth inhibition activities. Hence, it can be used to controll agricultural insect pests, S. litura and H. armigera.

  1. Insecticidal and antifeedant activities of clerodane diterpenoids isolated from the Indian bhant tree, Clerodendron infortunatum, against the cotton bollworm, Helicoverpa armigera.

    Science.gov (United States)

    Abbaszadeh, Gholamreza; Srivastava, Chitra; Walia, Suresh

    2014-01-01

    The Indian bhant tree, Clerodendron infortunatum L. (Lamialus: Lamiaceae), is a well-known medicinal plant, but little information about its bioefficacy against agricultural pests exists. This scarcity was addressed in the present study, in which dried leaves of C. infortunatum were subjected to extraction with hexane and methanol and then partitioned using different solvents of varying polarity. In a preliminary bioassay, the antifeedant effects of the crude extracts and fractions were tested on a highly polyphagous pest, the cotton bollworm, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae), using the no-choice test method with cabbage leaf discs. The methanol fraction resulted in maximum antifeedant activity. This fraction was further subjected to crystallization and column chromatography in order to isolate the compounds responsible for the activity. Three pure compounds were isolated and identified as clerodin (CL), 15-methoxy-14, 15-dihydroclerodin (MD), and 15-hydroxy-14, 15-dihyroclerodin (HD). The antifeedant activity of these compounds was studied using a choice as well as a no-choice test method with 24 and 48 hr observation periods. Insecticidal activity was measured using the topical application method at 0.5, 1, 1.5, 2, 2.5, and 3% concentrations, and data were recorded 24, 48, and 72 hr after treatment. In the no-choice test conditions, compounds CL and MD showed significantly higher antifeedant activity compared to the key ingredient in many commercial pesticides, azadirachtin, at its highest concentration. Compound HD also showed very good antifeedant activity, which did not differ significantly from that of azadirachtin. In the choice test conditions, all three compounds and azadirachtin showed 100% antifeedant activity at the highest concentration. Antifeedant Index (AI50) values of CL, MD, and HD were 6, 6, and 8 ppm in choice tests, and increased to 8, 9, and 11 ppm in the no-choice tests, respectively. Insecticidal activity of the isolated

  2. A simple and reliable method for discriminating between Helicoverpa armigera and Helicoverpa assulta (Lepidoptera: Noctuidae)

    Institute of Scientific and Technical Information of China (English)

    Jia Chen; Yu-Chun Wu; Xin Chen; Ya-Jie Ji; De-Xinh Zhang

    2011-01-01

    The cotton bollworm Helicoverpa armigera and the oriental tobacco budworm H.assulta are sibling species,both being important agricultural pests.Morphologically,the two insects are almost indistinguishable at the egg,larval and pupal stages.One of the big challenges in the study of these insects,in particular in integrated pest management,is a timely and dependable identification of these insects at their early stages of development.Here,we report a H.armigera-specific nuclear DNA marker,and demonstrate that it can be employed to reliably discriminate between H.armigera and H.assulta by simple polymerase chain reaction amplification experiment.

  3. Pertussis toxin modulation of sodium channels in the central neurons of cyhalothrin-resistant and cyhalothrin-susceptible cotton bollworm, Helicoverpa armigera

    Institute of Scientific and Technical Information of China (English)

    QIANG ZHAO; DE-LING KONG; BING-JUN HE; YAN-QIANG LIU; XIAN-LIN FAN; AN-XI LIU

    2007-01-01

    Pertussis toxin (PTX) inhibits the activation of the α-subunit of the inhibitory heterotrimeric G-proteins (Gαi/o) and modulates voltage-gated sodium channels, which may be one of the primary targets of pyrethroids. To investigate the potential mechanisms of agricultural pests resistance to pyrethroid insecticides, we examined the modulations by PTX on sodium channels in the central neurons of the 3rd-4th instar larvae of cyhalothrin-resistant (Cy-R) and cyhalothrin-susceptible (Cy-S) Helicoverpa armigera by the whole-cell patch-clamp technique.The isolated neurons were cultured for 12-16 h in an improved L15 insect culture medium with or without PTX (400 ng/mL). The results showed that both the Cy-R and Cy-S sodium channels exhibited fast kinetics and tetrodotoxin (TTX) sensitivity. The Cy-R sodium channels exhibited not only altered gating properties, including a 8.88-mV right shift in voltage-dependent activation (V0.5act) and a 6.54-mV right shift in voltage-dependent inactivation (V0.5inact), but also a reduced peak in sodium channel density (Idensity) (55.2% of that in Cy-S neurons). Cy-R sodium channels also showed low excitability, as evidenced by right shift of activation potential (Vacti) by 5-10 mV and peak potential (Vpeak) by 20 mV. PTX exerted significant effects on Cy-S sodium channels,reducing sodium channel density by 70.04%, right shifting V0.5act by 14.41 mV and V0.5inact by 9.38 mV. It did not cause any significant changes of the parameters mentioned above in the Cy-R sodium channels. The activation time (Tpeak) from latency to peak at peak voltage and the fast inactivation time constant (τinact) in both Cy-S and Cy-R neurons were not affected. The results suggest that cotton bollworm resistant to pyrethroid insecticides involves not only mutations and allosteric alterations of voltage-gated sodium channels, but also might implicate perturbation of PTX-sensitive Gαi/o-coupled signaling transduction pathways.

  4. Comparative study on the responses of maxillary sensilla styloconica of cotton bollworm Helicoverpa armigera and Oriental tobacco budworm H. assulta larvae to phytochemicals

    Institute of Scientific and Technical Information of China (English)

    汤德良; 王琛柱; 罗林儿; 钦俊德

    2000-01-01

    Using the electro-physiological technique, the sensory mechanisms of maxillary sensilla styloconica to stimulants and deterrents were explored on two closely related species, the generalist Helicoverpa armigera and the specialist H. assulta. The results showed that: (i) in both species, cells sensitive to sucrose and azadirachtin were mainly in the lateral sensillum styloconicum, and those to inositol were in the medial sensillum styloconicum; (ii) sensitivity of medial sensillum styloconicum in H. assulta to inositol was higher than that in H. armigera; (iii) among 6 tested deterrents, only azadirachtin evoked high impulse discharge from the lateral sensillum styloconicum in both insects; (iv) the deterrents could disturb stimulants evoking impulse discharge from maxillary sensilla styloconica of both species in different degrees: To sucrose evoking impulses on lateral sensillum styloconicum, for H. armigera capsaicin had a strong inhibition and gossypol had a weak inhibition, while for H. assulta tann

  5. A Brave New World for an Old World Pest: Helicoverpa armigera (Lepidoptera: Noctuidae) in Brazil

    OpenAIRE

    Tay, Wee Tek; MIGUEL F SORIA; Walsh, Thomas; Thomazoni, Danielle; Silvie, Pierre; Behere, Gajanan T.; Anderson, Craig; Downes, Sharon

    2013-01-01

    The highly polyphagous Old World cotton bollworm Helicoverpa armigera is a quarantine agricultural pest for the American continents. Historically H. armigera is thought to have colonised the American continents around 1.5 to 2 million years ago, leading to the current H. zea populations on the American continents. The relatively recent species divergence history is evident in mating compatibility between H. zea and H. armigera under laboratory conditions. Despite periodic interceptions of H. ...

  6. Comparative study on the responses of maxillary sensilla styloconica of cotton bollworm Helicoverpa armigera and Oriental tobacco budworm H. assulta larvae to phytochemicals

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Using the electro-physiological technique, the sensory mechanisms of maxillary sensilla styloconica to stimulants and deterrents were explored on two closely related species, the generalist Helicoverpa armigera and the specialist H. assulta. The results showed that: (i) in both species, cells sensitive to sucrose and azadirachtin were mainly in the lateral sensillum styloconicum, and those to inositol were in the medial sensillum styloconicum; (ii) sensitivity of medial sensillum styloconicum in H. assulta to inositol was higher than that in H. armigera; (iii) among 6 tested deterrents, only azadirachtin evoked high impulse discharge from the lateral sensillum styloconicum in both insects; (iv) the deterrents could disturb stimulants evoking impulse discharge from maxillary sensilla styloconica of both species in different degrees: To sucrose evoking impulses on lateral sensillum styloconicum, for H. armigera capsaicin had a strong inhibition and gossypol had a weak inhibition, while for H. assulta tannic acid, gossypol, and tomatine all had strong inhibition except nicotine and capsaicin; to inositol evoking impulses on medial sensilum styloconicum, for H. armigera inhibition of tomatine was strong but that of gossypol was weak; and for H. assulta inhibition of gossypol was strong but that of nicotine was weak.

  7. Effects of soil temperature and snow cover on the mortality of overwintering pupae of the cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae).

    Science.gov (United States)

    Huang, Jian

    2016-07-01

    Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is one of the most damaging insect pests in the world. However, little is known about the effects of snow cover and soil temperature on the overwintering pupae of H. armigera. A field experiment was conducted from November 2, 2012 to April 24, 2013 at the agrometeorological experimental station in Wulanwusu, China. Overwintering pupae were embedded into the soil at depths of 5, 10, and 15 cm in the following four treatments: without snow cover, snow cover, and increased temperatures from 600 and 1200 W infrared lights. The results showed that snow cover and rising temperatures could all markedly increase soil temperatures, which was helpful in improving the survival of the overwintering pupae of H. armigera. The mortality of overwintering pupae (MOP) at a depth of 15 cm was the highest, and the MOP at a depth of 5 cm followed. The lower accumulated temperature (≤0 °C) (AT ≤ °C) led to the higher MOP, and the lower diurnal soil temperature range (DSTR) likely led to the lower MOP. After snowmelt, the MOPs at the depths of 5 and 10 cm increased as the soil temperature increased, especially in April. The AT of the soil (≤0 °C) was the factor with the strongest effect on MOP. The soil moisture content was not a major factor affecting the MOP in this semiarid region because precipitation was 45 mm over the entire experimental period. With climate warming, the MOP will likely decrease, and the overwintering boundary air temperatures of H. armigera should be expanded due to higher soil temperatures and increased snow cover. PMID:26514355

  8. Natural control of Helicoverpa armigera in smallholder crops in East Africa.

    NARCIS (Netherlands)

    Berg, van de H.

    1993-01-01

    The African bollworm, Helicoverpa (=Heliothis) armigera , is one of the worst agricultural pests in Africa, attacking a variety of food and cash crops. For development of sustainable pest management, it is essential to study the ecology and natural mortality factors of the pest, and recently, the ne

  9. Potential of sorghum and physic nut (Jatropha curcas for management of plant bugs (Hemiptera: Miridae and cotton bollworm (Helicoverpa armigera on cotton in an assisted trap-cropping strategy

    Directory of Open Access Journals (Sweden)

    JM Vassal

    2009-12-01

    Full Text Available The cotton bollworm (CBW Helicoverpa armigera andto a lesser extent plant bugs (PB (Hemiptera: Miridaeare important pests of cotton in Africa. For sustainabilityreasons, it is necessary to reduce use of chemical controlmeasures for these pests. A promising alternative tochemical control of both CBW and PB is trap cropping,assisted with botanical pesticides sprays, if needed. Wereport studies conducted from 1995–98 on sorghumattractiveness to PB and CBW, on the potential of physicnut (Jatropha curcas extracts [particularly the phorbolester (PE fraction of the oil] for sorghum protection fromPB damage, and on the insecticidal activity of Jatrophaextracts on CBW. At the ICRISAT research station(Samanko, Mali, infestation by the five main species ofPB (accounting for 96% of total was much higher onsorghum than on cotton. In the Kolokani region, CBWinfestation was negligible on the Guinea loose-panicledsorghum cultivar Bibalawili, while it was significant onboth compact-panicled PB susceptible ICSH 89002 andPB resistant Malisor 84-7. At Samanko, Jatropha oilapplication on sorghum panicles showed some effect onPB when damage level was high, better than Jatrophaand neem aqueous extracts. However, it did not competewith pyrethroid protection level. PE contact toxicity onCBW larvae was too low to determine a LC 50. Aningestion insecticidal activity of PE was found on alltested larval instars. Contact toxicity LC 50 of PE on eggswas 1.66 g ml-1. Development of larvae and reproductiveability of adults derived from new-laid eggs treated with solutions of 0.35 g ml-1 PE and above were considerablyaffected. Prospects for using sorghum and Jatrophaextracts for cotton protection against insect pests in anassisted trap-cropping strategy are discussed.

  10. The cotton bolloworms Helicoverpa armigera (Huebner) control by gamma irradiation

    International Nuclear Information System (INIS)

    The cotton bollworms, Helicoverpa armigera (Huebner) were reared on an artificial medium consisting of mungbeans, brewer's yeast, vitamins, water, preservatives and antibiotic (Tetracycline hydrochloride) at 26 +- 1 deg C, 70-75% R.H., and 8-hr light duration. The development of this species were not significantly different (p = 0.05) in percent egg hatch, pupal recovery, adult eclosion, and pupal weight in each of 4 successive generations. Effects of gamma irradiation, obtained from Cesium-137 source, on eggs, larvae, pupae and adults of the cotton bollworm were also studied. All sterilizing doses, for various stages of the cotton bollworm, did not reduce the longevity both sexes of the insect. However, sterilized males emerged from eggs, larvae, pupae appeared to mate less frequently than normal males did. In contrast, males sterilized as adults mated as frequently as normal males. The sperms of sterilized males emerged from various stages were probably less motile and possibly less numerous than sperms from normal males. The results of this experiment can be concluded that, it is more effective to control this insect by sterilization in both pupal and adult stages with 150 and 200 gray respectively

  11. Effects of gamma irradiation on the sperm transmission and oviposition response in Helicoverpa armigera (L. Noctuidae)

    International Nuclear Information System (INIS)

    The transmission of sperm by unirradiated and irradiated cotton bollworm, Helicoverpa armigera, was studied by live dissection of the female immediately after the initiation of mating. In cotton bollworm the sperm transfer was a rather complex process. In fact, the unirradiated male failed to transfer sperm in about 19% of their matings. After being irradiated with 250 Gy and 400 Gy, the aberrations of sperm transmission were about 21% and 50% respectively. The failure of spermatophore 'cap' location was an important reason of sperm transmission aberrations. When female mated to high-dose-irradiated males, its oviposition response appeared abnormal

  12. Digital gene expression analysis of Helicoverpa armigera in the early stage of infection with Helicoverpa armigera nucleopolyhedrovirus.

    Science.gov (United States)

    Li, Zhen; Lu, Zhenqiang; Wang, Xiu; Zhang, Songdou; Zhang, Qingwen; Liu, Xiaoxia

    2015-11-01

    Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus (HearNPV) is an obligatory and lethal parasite of the cotton bollworm and has been extensively used in China for the control of this notorious pest. Digital gene expression (DGE) analysis was adopted for an overall comparison of transcriptome profiling between HearNPV-infected and control healthy Helicoverpa armigera larvae during an early stage post-inoculation. A total of 908 differentially expressed genes (DEGs) were identified, of which 136 were up-regulated and 597 were down-regulated. GO category and KEGG pathway analysis demonstrated that the identified DEGs involved in ribosome biogenesis, aminoacyl-tRNA biosynthesis, protein processing in endoplasmic reticulum, biosynthesis of valine, leucine, isoleucine and the spliceosome were significantly down-regulated, whereas genes involved in pancreatic secretion, protein digestion and absorption and salivary secretion showed obviously up-regulated transcription. The DEGs were verified by quantitative real-time PCR, and genes that participated in defensive response, nutritional digestion and developmental regulation exhibited specific expression patterns in a continuous time-course assessment. These results provide basic data for future research on the molecular mechanism of HearNPV infection and the interactions between lepidopteran hosts and their specific NPV parasites. PMID:26296928

  13. Tissue-specific expression of glutathione S-transferases induced by 2-tridecanone or quercetin in cotton bollworms, Helicoverpa armigera (Hübner)

    Institute of Scientific and Technical Information of China (English)

    TANG Fang; LIANG Pei; GAO Xiwu

    2005-01-01

    The tissue-specific expression of glutathione S-transferases (GSTs) in the cotton bollworm and the expression level induced by 2-tridecanone and quercetin were examined using the methods of biochemistry and the quantitative PCR. The relative expression level of GST mRNA was unanimous with the GSTs activity conjugaging with 1-chloro-2, 4-dimitro-benzene (CDNB) in fat bodies,midguts, heads and integuments of cotton bollworms. The GSTs activity in fat bodies was the highest, then midguts, heads and integuments in turn, which was in consistent with the relative expression level of GST mRNA. The specific activity of GSTs and the relative expression level of GST mRNA could be significantly induced by 2-tridecanone and quercetin, and after the induction the order of the GSTs activity and the relative expression level of GST mRNA in the above four tissues in cotton bollworms was not different from the control.The induction of GSTs by 2-tridecanone was stronger than by quercetin in all four tissues, which was in accordance with the relative expression level of GST mRNA. It suggested that the increase of GSTs activity induced by plant allelochemicals was associated with the elevated expression of GST mRNA in cotton bollworms.

  14. Immune responses of Helicoverpa armigera to different kinds of pathogens

    Directory of Open Access Journals (Sweden)

    Zhao Xiao-Fan

    2010-03-01

    Full Text Available Abstract Background Insects react against pathogens through innate immunity. The cotton bollworm Helicoverpa armigera (H. armigera is an important defoliator and an extremely destructive pest insect of many crops. The elucidation of the mechanism of the immune response of H. armigera to various pathogens can provide a theoretical basis for new approaches to biologically control this pest. Results Four kinds of pathogens Bacillus thuringiensis, Klebsiella pneumoniae, Candida albicans, and Autographa californica multiple nucleocapsid nucleopolyhedrovirus harbored green fluorescence protein and polyhedron (AcMNPV-GFP were used to challenge the insect. The cellular and humoral immune responses to the pathogens were analyzed in the challenged H. armigera. The results show that in the five kinds of haemocytes, only granulocytes phagocytized the Gram-negative and Gram-positive bacteria and fungi. All haemocytes can be infected by AcMNPV. Fourteen immune-related genes including pattern recognition receptors (PRRs such as peptidoglycan recognition proteins (HaPGRP and HaPGRP C and Gram-Negative Bacteria-Binding Protein (HaGNBP, and antimicrobial peptides (AMPs such as cecropin-1, 2 and 3 (HaCec-1, 2 and 3, lysozyme (HaLys, attacin (HaAtt, gallerimycin-like (HaGall, gloverin-like (HaGlo, moricin-like (HaMor, cobatoxin-like (HaCob, galiomicin-like (HaGali, and immune inducible protein (HaIip appeared in different expression profiles to different pathogen infections. The transcripts of 13 immune related genes (except HaPGRPC are obviously up-regulated by Gram-positive bacteria. HaCec-1 and 3, HaMor, HaAtt, HaLys, HaIip, HaPGRP and HaGNBP are greatly up-regulated after fungal infection. HaGNBP, HaCec-2, HaGall, HaGlo, HaMor, HaCob, HaGali obviously increased in Gram-negative bacterial infection. Only five genes, HaGNBP, HaCec-1, HaGali, HaGlo, and HaLys, are weakly up-regulated after viral infection. The AMP transcripts had higher expression levels than the

  15. Cry1Fa对Cry1Ac抗性棉铃虫的毒力评价%Evaluation of the toxicity of Cry1Fa to the Cry1Ac-resistant cotton bollworm,Helicoverpa armigera(Lepidoptera:Noctuidae)

    Institute of Scientific and Technical Information of China (English)

    魏纪珍; 郭予元; 高希武; 张涛; 梁革梅

    2012-01-01

    为了防治多种鳞翅日害虫,表达Cry1 Fa的转基因玉米和棉花已在美国商业化种植.明确棉铃虫Helicoverpa armigera对Cry1Fa与Cry1 Ac的交互抗性及这两种杀虫蛋白之间的协同作用,可以为表达Cry1 Fa+Cry1 Ac的转双价抗虫棉花的合理应用提供依据.本实验测定了Cry1 Fa对棉铃虫敏感品系(96S)及用Cry1Ac筛选的抗性品系(BtR,抗性倍数2194.15倍)的毒力,发现Cry1 Fa对敏感棉铃虫的毒力远低于Cry1 Ac,LC50值是Cry1 Ac的504.80倍;而且抗性品系BtR对Cry1Fa存在19.98倍的交互抗性.Cry1 Fa与Cry1 Ac混用可以提高Cry1 Fa毒杀敏感棉铃虫的效果,尤其是Cry1 Fa浓度较低时,加入Cry1Ac,可以显著增加Cry1 Fa的毒力;但只有加入较高浓度的Cry1 Fa时才能增加Cry1 Ac的毒力.由于BtR品系已经对Cry1 Ac产生抗性,Cry1Ac对抗性棉铃虫的毒力明最降低;在较高浓度的Cry1Ac中加入Cry1 Fa可以显著增加棉铃虫的死亡率(P=0.0015,F=6.88,df=6),但最高死亡率仅为58.33%.D-饱和最优试验的结果证实,Cry1 Ac对于敏感棉铃虫的死亡率的影响达到显著水平(t1=13.76>t0.os),Cry1Ac 与 Cry1Fa的交互作用对毒力的影响也达到显著水平(t22=2.42>t0.05;t11=6.95>t0.05;t12=3.43>t0.05).Cry1Ac和Cry1Fa对抗性棉铃虫死亡率的影响都达到显著水平(t1=3.03>t0.05;t2=2.59>t0.05),但Cry1 Ac是决定抗、感棉铃虫死亡率的关键因素;Cry1Ac与Cry1 Fa最佳浓度配比范围都是1.41~2.10 μg/cm2;在抗性品系中,Cry1 Ac和Cry1 Fa的交互作用不显著.所以,尽管Cry1F+Cry1A作物扩大了杀虫谱,但棉铃虫对这两种蛋白存在交互抗性,而且这两种蛋白混用对治理抗Cry1 Ac棉铃虫的效果不理想,因此不建议在中国种植表达Cry1F+Cry1A的棉花.%Cry 1 Fa-expressing corn and cotton have been commercially planted in U. S in order to effectively control several Lepidoptera pests. Making clear the cross-resistance of cotton bollworms (Helicoverpa armigera

  16. Elevated CO2 Reduces the Resistance and Tolerance of Tomato Plants to Helicoverpa armigera by Suppressing the JA Signaling Pathway

    OpenAIRE

    Guo, Huijuan; Sun, Yucheng; Ren, Qin; Zhu-Salzman, Keyan; Kang, Le; Wang, Chenzhu; Li, Chuanyou; Ge, Feng

    2012-01-01

    Both resistance and tolerance, which are two strategies that plants use to limit biotic stress, are affected by the abiotic environment including atmospheric CO2 levels. We tested the hypothesis that elevated CO2 would reduce resistance (i.e., the ability to prevent damage) but enhance tolerance (i.e., the ability to regrow and compensate for damage after the damage has occurred) of tomato plants to the cotton bollworm, Helicoverpa armigera. The results showed that elevated CO2 reduced resist...

  17. A brave new world for an old world pest: Helicoverpa armigera (Lepidoptera: Noctuidae in Brazil.

    Directory of Open Access Journals (Sweden)

    Wee Tek Tay

    Full Text Available The highly polyphagous Old World cotton bollworm Helicoverpa armigera is a quarantine agricultural pest for the American continents. Historically H. armigera is thought to have colonised the American continents around 1.5 to 2 million years ago, leading to the current H. zea populations on the American continents. The relatively recent species divergence history is evident in mating compatibility between H. zea and H. armigera under laboratory conditions. Despite periodic interceptions of H. armigera into North America, this pest species is not believed to have successfully established significant populations on either continent. In this study, we provide molecular evidence via mitochondrial DNA (mtDNA cytochrome oxidase I (COI and cytochrome b (Cyt b partial gene sequences for the successful recent incursion of H. armigera into the New World, with individuals being detected at two sites (Primavera do Leste, Pedra Preta within the State of Mato Grosso in Brazil. The mtDNA COI and Cyt b haplotypes detected in the Brazilian H. armigera individuals are common throughout the Old World, thus precluding identification of the founder populations. Combining the two partial mtDNA gene sequences showed that at least two matrilines are present in Brazil, while the inclusion of three nuclear DNA Exon-Primed Intron-Crossing (EPIC markers identified a further two possible matrilines in our samples. The economic, biosecurity, resistance management, ecological and evolutionary implications of this incursion are discussed in relation to the current agricultural practices in the Americas.

  18. A brave new world for an old world pest: Helicoverpa armigera (Lepidoptera: Noctuidae) in Brazil.

    Science.gov (United States)

    Tay, Wee Tek; Soria, Miguel F; Walsh, Thomas; Thomazoni, Danielle; Silvie, Pierre; Behere, Gajanan T; Anderson, Craig; Downes, Sharon

    2013-01-01

    The highly polyphagous Old World cotton bollworm Helicoverpa armigera is a quarantine agricultural pest for the American continents. Historically H. armigera is thought to have colonised the American continents around 1.5 to 2 million years ago, leading to the current H. zea populations on the American continents. The relatively recent species divergence history is evident in mating compatibility between H. zea and H. armigera under laboratory conditions. Despite periodic interceptions of H. armigera into North America, this pest species is not believed to have successfully established significant populations on either continent. In this study, we provide molecular evidence via mitochondrial DNA (mtDNA) cytochrome oxidase I (COI) and cytochrome b (Cyt b) partial gene sequences for the successful recent incursion of H. armigera into the New World, with individuals being detected at two sites (Primavera do Leste, Pedra Preta) within the State of Mato Grosso in Brazil. The mtDNA COI and Cyt b haplotypes detected in the Brazilian H. armigera individuals are common throughout the Old World, thus precluding identification of the founder populations. Combining the two partial mtDNA gene sequences showed that at least two matrilines are present in Brazil, while the inclusion of three nuclear DNA Exon-Primed Intron-Crossing (EPIC) markers identified a further two possible matrilines in our samples. The economic, biosecurity, resistance management, ecological and evolutionary implications of this incursion are discussed in relation to the current agricultural practices in the Americas. PMID:24260345

  19. Effect of 60Co-γ irradiation on mating ability of males of Helicoverpa armigera

    International Nuclear Information System (INIS)

    The effects of γ-rays irradiation on the mating ability and flight capability of male cotton bollworm Helicoverpa armigera were studied in laboratory and field cages. The results showed that when the irradiation dose increased from 0Gy to 400Gy, the flight capability decreased: flight distance decreased from 69.65km to 38.30km; average flight distance decreased from 44.19km to 13.55km. The longevity of the irradiated males was significantly shorter than that of the wilds but there was no significant difference according to different doses. Egg hatchability was affected significantly by irradiation but there was no significant difference in eggs laid per female, fecundation eggs as increasing treated doses. When the ratio of sterilized males (treated dose 200 Gy) to fertile males was as 5:1 in field cages, the F1 hatchability was significantly decreased and the purpose of controlling cotton bollworm population could be effectively achieved. (authors)

  20. Genetic variation and virulence of nucleopolyhedroviruses isolated worldwide from the heliothine pests Helicoverpa armigera, Helicoverpa zea, and Heliothis virescens

    Science.gov (United States)

    A PCR-based method was used to classify 90 samples of nucleopolyhedrovirus (NPV; Baculoviridae: Alphabaculovirus) obtained worldwide from larvae of Heliothis virescens, Helicoverpa zea, and Helicoverpa armigera. Partial nucleotide sequencing and phylogenetic analysis of three highly conserved genes...

  1. Inheritance of electrophysiological responses to leaf saps of host- and nonhost plants in two helicoverpa species and their hybrids

    NARCIS (Netherlands)

    Tang, Q.B.; Huang, L.Q.; Wang, C.Z.; Tang, Q.B.T.; Zhan, H.; Loon, van J.J.A.

    2014-01-01

    The polyphagous cotton bollworm Helicoverpa armigera (Hubner) and the oligophagous oriental tobacco budworm Helicoverpa assulta (Guenee) (Lepidoptera: Noctuidae) display contrasting heritable feeding preferences for cotton and pepper leaves. In this study, electrophysiological response patterns to c

  2. Insecticidal activity of venomous saliva from Rhynocoris fuscipes (Reduviidae against Spodoptera litura and Helicoverpa armigera by microinjection and oral administration

    Directory of Open Access Journals (Sweden)

    K Sahayaraj

    2011-01-01

    Full Text Available Rhynocoris fuscipes is a potential predator of many economically important pests in India. In the present study, its venomous saliva (VS was collected by milking and diluted with HPLC grade water to different concentrations (200, 400, 600, 800 and 1000 ppm. Microinjection of Rhynocoris fuscipes VS was more toxic than its oral administration in Helicoverpa armigera (cotton bollworm and Spodoptera litura (tobacco cutworm. Thus, R. fuscipes VS was found to be toxic to third instar S. litura and H. armigera with respective LD50s of 846.35 and 861.60 ppm/larva at 96 hours after microinjection. The current results showed that VS of Rhynocoris fuscipes caused mortality of H. armigera and S. litura. Active peptides from VS may be isolated, identified and assessed for their impact in order to ascertain how they alter the physiology of these pests, information that could be applicable in pest management programs.

  3. Hybridization between Helicoverpa armigera and Helicoverpa assulta (Lepidoptera: Noctuidae): development and morphological characterization of F1 hybrids

    NARCIS (Netherlands)

    Zhao, X.C.; Dong, J.F.; Tang, Q.B.; Yan, Q.B.; Celbic, I.; Loon, van J.J.A.; Wang, C.Z.

    2005-01-01

    Reciprocal hybridizations between Helicoverpa armigera (Hubner) and Helicoverpa assulta (Guenee) were studied. The cross between females of H. armigera and males of H. assulta yielded only fertile males and sterile individuals lacking an aedeagus, valva or ostium bursae. A total of 492 larvae of the

  4. Management of Helicoverpa armigera: A Review and Prospectus for Pakistan

    Directory of Open Access Journals (Sweden)

    Shahid Karim

    2000-01-01

    Full Text Available Helicoverpa armigera is a key pest of agriculture and horticulture in Pakistan. Costs of management and damage are gigantic in a wide range of food and fiber crops. It has been recorded on more than 100 cultivated and wild host plants. Key factors contributing to the pest status of H. armigera are its polyphagy, mobility, diapause and high fecundity. Control of H. armigera heavily depends on the use of chemical pesticides. However, resistance to all commercially available insecticides has been detected in H. armigera. The increasing emergence of resistance problems means there is an urgent need for the development of management strategies, which are less dependent on chemical insecticides and/or less conducive to the development of resistance to the control measures, used.

  5. Investigation on mating habit and sexual competition ability of Helicoverpa armigera sterilized by irradiation

    International Nuclear Information System (INIS)

    Mating habit and sexual competition ability of Helicoverpa armigera irradiated with 300 Gy of γ-rays were observed. The results showed that when reared in laboratory, most adults mated at 4-7 o'clock, a small proportion of adults mated at 2-3 o'clock or at 8-9 o'clock in the morning, meanwhile wild population mated two and a half hours earlier than laboratory populations did. No difference in mating habit and sexual competition ability was found between the irradiation-sterilized and normal adults except that the effective mating rate of the former was 61.6%, one third less than that of the latter ones. Most irradiation-sterilized adults mated one time in their whole lives, only a few could mate 2-3 times and even 5 times, indicating that the multi-mating characteristic of Helicoverpa armigera was not changed by irradiation. It can be concluded that irradiated sterile insect technique is feasible for integrated controlling the cotton bollworm

  6. 新疆北部棉铃虫寄主来源与转基因棉区庇护所评估%Analysis of Larval host types of Cotton Bollworm (Helicoverpa armigera) Populations for Evaluation of Bt Refuges in Northern Xinjiang

    Institute of Scientific and Technical Information of China (English)

    李娜; 张娟; 刘永健; 张豹; 熊建喜; 王佩玲; 吕昭智

    2015-01-01

    Transgenic cotton, expressing an insecticidal toxin from Bacillus thuringiensis (Bt cotton), has been widely cultivated for a long period in some areas of China. Therefore, there is the potential for the cotton bollworm, Helicoverpa armigera, to develop resistance to Bt cotton toxins. The United States Environmental Protection Agency ( US EPA) is rethinking the requirement for some regions to delay developing natural refuge crops where Bt cotton growth has been highly successful. The policy of establishing refuges was intended to delay pest population development of Bt-toxin resistance. Bt cotton is widely grown in Xinjiang Province, which is the largest cotton-producing area in China, but no studies have been conducted on potential refuges in this region of China. In recent years, stable carbon isotope techniques (δ13 C) have been In this study, intelligent forecast light traps were established to collect adult cotton bollworms from May to September 2013, from the 147th and 121st regiments of the Shihezi reclamation area located in northern Xinjiang. The captured moths were placed into bottles and preserved in 95% alcohol until analysis. At each of the sites, 50 males and 30 females moths were selected on the day of capture, their wings combined into two bulked samples respectively to analyze their host type ( C3 or C4 ) using δ13 C analysis. At the same time, 30 female′s wings and corresponding spermatophore were separated to one single sample to analyze the mating type and percentage of mating frequency between C3 and C4 host. A total of 23 bulked samples from the 147th regiment and 25 bulked samples from the 121st regiment were tested. The proportions of C3 and C4 hosts were calculated according to a standard curve constructed in 2012. Approximately 50% of cotton bollworms were derived from C4 hosts, and approximately 50% from C3 hosts in late May and from early August to September. From June to July, 100% of cotton bollworms were derived from C4 hosts. To

  7. Relative Fitness of Helicoverpa armigera (Lepidoptera: Noctuidae) on Seven Host Plants: A Perspective for IPM in Brazil.

    Science.gov (United States)

    Reigada, C; Guimarães, K F; Parra, J R P

    2016-01-01

    The cotton bollworm Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is a widespread pest of many cultivated and wild plants in Europe, Africa, Asia, and Australia. In 2013, this species was reported in Brazil, attacking various host crops in the midwestern and northeastern regions of the country and is now found countrywide. Aiming to understand the effects of different host plants on the life cycle of H. armigera, we selected seven species of host plants that mature in different seasons and are commonly grown in these regions: cotton (Gossypium hirsutum, "FM993"), corn (Zea mays, "2B587"), soybean (Glycine max, "99R01"), rattlepods (Crotalaria spectabilis), millet (Pennisetum glaucum, "ADR300"), sorghum (Sorghum bicolor, "AGROMEN70G35"), and cowpea (Vigna unguiculata, "SEMPRE VERDE"). The development time of immatures, body weight, survivorship, and fecundity of H. armigera were evaluated on each host plant under laboratory conditions. The bollworms did not survive on corn, millet, or sorghum and showed very low survival rates on rattlepods. Survival rates were highest on soybean, followed by cotton and cowpea. The values for relative fitness found on soybean, cotton, cowpea, and rattlepods were 1, 0.5, 0.43, and 0.03, respectively. Survivorship, faster development time, and fecundity on soybean, cotton, and cowpea were positively correlated. Larger pupae and greater fecundity were found on soybean and cotton. The results indicated that soybean, cotton, and cowpea are the most suitable plants to support the reproduction of H. armigera in the field. PMID:26798139

  8. Host plant induced variation in gut bacteria of Helicoverpa armigera.

    Science.gov (United States)

    Priya, Natarajan Gayatri; Ojha, Abhishek; Kajla, Mayur K; Raj, Anand; Rajagopal, Raman

    2012-01-01

    Helicoverpa are important polyphagous agricultural insect pests and they have a worldwide distribution. In this study, we report the bacterial community structure in the midgut of fifth instar larvae of Helicoverpa armigera, a species prevalent in the India, China, South Asia, South East Asia, Southern & Eastern Africa and Australia. Using culturable techniques, we isolated and identified members of Bacillus firmus, Bacillus niabense, Paenibacillus jamilae, Cellulomonas variformis, Acinetobacter schindleri, Micrococcus yunnanesis, Enterobacter sp., and Enterococcus cassiliflavus in insect samples collected from host plants grown in different parts of India. Besides these the presence of Sphingomonas, Ralstonia, Delftia, Paracoccus and Bacteriodetes was determined by culture independent molecular analysis. We found that Enterobacter and Enterococcus were universally present in all our Helicoverpa samples collected from different crops and in different parts of India. The bacterial diversity varied greatly among insects that were from different host plants than those from the same host plant of different locations. This result suggested that the type of host plant greatly influences the midgut bacterial diversity of H. armigera, more than the location of the host plant. On further analyzing the leaf from which the larva was collected, it was found that the H. armigera midgut bacterial community was similar to that of the leaf phyllosphere. This finding indicates that the bacterial flora of the larval midgut is influenced by the leaf surface bacterial community of the crop on which it feeds. Additionally, we found that laboratory made media or the artificial diet is a poor bacterial source for these insects compared to a natural diet of crop plant. PMID:22292034

  9. Incidence of Winter and Summer Diapause in Helicoverpa armigera (Hübner (Lepidoptera: Noctuidae in Andhra Pradesh, India

    Directory of Open Access Journals (Sweden)

    Deepak R. Jadhav

    2013-05-01

    Full Text Available The incidence of winter and summer diapause was studied by large-scale field samplings of larvae and pupae of the cotton bollworm, Helicoverpa armigera (Hüb conducted over a period of 13-years during winter and summer seasons in Andhra Pradesh, India. Induction of winter diapause was associated with cooler prevailing temperatures and shorter day lengths of 32°C during March-April resulting in greater adult emergence with the onset of the monsoon season during mid-June to early July. In summer, few alternate hosts are available for larvae to sustain by allowing local populations colonizing newly germinated host crops with the onset of the rainy season. In addition, the incidence of winter and summer diapause was higher in male pupae than females in the ratio of 4:1 and 3:1 (♂:♀, respectively. Diapause populations of H. armigera were most common in the cyclonic weather prevailed for several weeks during 1977-78 (15.11% and 1995-96 (17.64%. Under these conditions, an average of <4% and <6% of pupae entered winter and summer diapause, respectively and was associated with severe outbreaks of H. armigera in subsequent seasons. Higher populations of H. armigera on pigeonpea and chickpea entered winter diapause on pigeonpea and chickpea and summer diapause on irrigated maize, pigeonpea, chickpea and a common weed host, Datura metel.

  10. Complete Genome Sequences of Seven Helicoverpa armigera SNPV-AC53-Derived Strains

    Science.gov (United States)

    2016-01-01

    Wild-type baculovirus isolates typically consist of multiple strains. We report the full genome sequences of seven alphabaculovirus strains derived by passage through tissue culture from Helicoverpa armigera SNPV-AC53 (KJ909666). PMID:27151787

  11. Parasitism of Helicoverpa armigera pupae (Lepidoptera: Noctuidae) by Tetrastichus howardi and Trichospilus diatraeae (Hymenoptera: Eulophidae)

    OpenAIRE

    Harley Nonato de Oliveira; Juliana Simonato; Daniele Fabiana Glaeser; Fabrício Fagundes Pereira

    2016-01-01

    Helicoverpa armigera is a pest that was recently detected in Brazil, which causes significant losses in various crops in different regions of the country. Biological control has been reported to offer a promising alternative in the management of this pest. Thus, this study evaluated the ability of the parasitoids Tetrastichus howardi and Trichospilus diatraeae to parasitize pupae of H. armigera in the laboratory. H. armigera pupae were individually exposed to 15 female Trichospilus diatraeae ...

  12. Influence of CO2 and Temperature on Metabolism and Development of Helicoverpa armigera (Noctuidae: Lepidoptera).

    Science.gov (United States)

    Akbar, S Md; Pavani, T; Nagaraja, T; Sharma, H C

    2016-02-01

    Climate change will have a major bearing on survival and development of insects as a result of increase in CO2 and temperature. Therefore, we studied the direct effects of CO2 and temperature on larval development and metabolism in cotton bollworm, Helicoverpa armigera (Hübner). The larvae were reared under a range of CO2 (350, 550, and 750 ppm) and temperature (15, 25, 35, and 45°C) regimes on artificial diet. Elevated CO2 negatively affected the larval survival, larval weight, larval period, pupation, and adult emergence, but showed a positive effect on pupal weight, pupal period, and fecundity. Increase in temperature exhibited a negative effect on larval survival, larval period, pupal weights, and pupal period, but a positive effect on larval growth. Pupation and adult emergence were optimum at 25°C. Elevated CO2 and temperature increased food consumption and metabolism of larvae by enhancing the activity of midgut proteases, carbohydrases (amylase and cellulase), and mitochondrial enzymes and therefore may cause more damage to crop production. Elevated CO2 and global warming will affect insect growth and development, which will change the interactions between the insect pests and their crop hosts. Therefore, there is need to gain an understanding of these interactions to develop strategies for mitigating the effects of climate change. PMID:26363173

  13. Mitigation of Insecticide Resistance in Helicoverpa armigera (Hubner) (Lepidoptera:Noctuidae) by Conjunctive Use of Trap Crops, Neem and Trichogramma chilonis Ishii in Cotton

    OpenAIRE

    A. Regupathy; P. Duraimurugan

    2005-01-01

    Trichogramma chilonis Ishii was evaluated against cotton bollworm, Helicoverpa armigera (Hubner) under field conditions. Neem seed kernel extract (NSKE) was applied on cotton crop leaving trap crops (okra and pigeonpea) commencing from 46 DAS at weekly interval to increase the pushing of H. armigera away from cotton. Application of NSKE on cotton improved the oviposition preference ratio from 1:1.35 and 1:1.40 to 1:3.02 and 1:2.43 on cotton:okra and cotton:pigeonpea, respectively. Egg parasit...

  14. Elevated CO2 reduces the resistance and tolerance of tomato plants to Helicoverpa armigera by suppressing the JA signaling pathway.

    Directory of Open Access Journals (Sweden)

    Huijuan Guo

    Full Text Available Both resistance and tolerance, which are two strategies that plants use to limit biotic stress, are affected by the abiotic environment including atmospheric CO(2 levels. We tested the hypothesis that elevated CO(2 would reduce resistance (i.e., the ability to prevent damage but enhance tolerance (i.e., the ability to regrow and compensate for damage after the damage has occurred of tomato plants to the cotton bollworm, Helicoverpa armigera. The results showed that elevated CO(2 reduced resistance by decreasing the jasmonic acid (JA level and activities of lipoxygenase, proteinase inhibitors, and polyphenol oxidase in wild-type (WT plants infested with H. armigera. Consequently, the activities of total protease, trypsin-like enzymes, and weak and active alkaline trypsin-like enzymes increased in the midgut of H. armigera when fed on WT plants grown under elevated CO(2. Unexpectedly, the tolerance of the WT to H. armigera (in terms of photosynthetic rate, activity of sucrose phosphate synthases, flower number, and plant biomass and height was also reduced by elevated CO(2. Under ambient CO(2, the expression of resistance and tolerance to H. armigera was much greater in wild type than in spr2 (a JA-deficient genotype plants, but elevated CO(2 reduced these differences of the resistance and tolerance between WT and spr2 plants. The results suggest that the JA signaling pathway contributes to both plant resistance and tolerance to herbivorous insects and that by suppressing the JA signaling pathway, elevated CO(2 will simultaneously reduce the resistance and tolerance of tomato plants.

  15. Hybridization between Helicoverpa armigera and Helicoverpa assulta (Lepidoptera: Noctuidae): development and morphological characterization of F1 hybrids

    Czech Academy of Sciences Publication Activity Database

    Zhao, X. C.; Dong, J. F.; Tang, Q. B.; Yan, Y. H.; Gelbič, Ivan; Van Loon, J. J. A.; Wang, C. Z.

    2005-01-01

    Roč. 95, č. 5 (2005), s. 409-416. ISSN 0007-4853 Grant ostatní: Chinese Academy of Sciences(CN) KSCX2-SW-105; Major State Basic Research Project of China(CN) 2000016208; National Natural Science Foundation of China(CN) 30330100 Institutional research plan: CEZ:AV0Z50070508 Keywords : Helicoverpa armigera * Helicoverpa assulta * Noctuidae Subject RIV: ED - Physiology Impact factor: 1.333, year: 2005

  16. A toxin-binding alkaline phosphatase fragment synergizes Bt toxin Cry1Ac against susceptible and resistant Helicoverpa armigera.

    Directory of Open Access Journals (Sweden)

    Wenbo Chen

    Full Text Available Evolution of resistance by insects threatens the continued success of pest control using insecticidal crystal (Cry proteins from the bacterium Bacillus thuringiensis (Bt in sprays and transgenic plants. In this study, laboratory selection with Cry1Ac yielded five strains of cotton bollworm, Helicoverpa armigera, with resistance ratios at the median lethal concentration (LC50 of activated Cry1Ac ranging from 22 to 1700. Reduced activity and reduced transcription of an alkaline phosphatase protein that binds Cry1Ac was associated with resistance to Cry1Ac in the four most resistant strains. A Cry1Ac-binding fragment of alkaline phosphatase from H. armigera (HaALP1f was not toxic by itself, but it increased mortality caused by Cry1Ac in a susceptible strain and in all five resistant strains. Although synergism of Bt toxins against susceptible insects by toxin-binding fragments of cadherin and aminopeptidase N has been reported previously, the results here provide the first evidence of synergism of a Bt toxin by a toxin-binding fragment of alkaline phosphatase. The results here also provide the first evidence of synergism of a Bt toxin by any toxin-binding peptide against resistant insects.

  17. Host selection of Helicoverpa armigera and H.assulta and its inheritance

    Institute of Scientific and Technical Information of China (English)

    WANG Chenzhu; DONG Junfeng; TANG Deliang; ZHANG Jihong; LI Wei; QIN Junde

    2004-01-01

    The difference in host selection between the polyphagous Helicoverpa armigera (Hübner) and the oligophagous H. assulta Quenée was examined, with cotton (Gossypium hirsutum), tomato (Lycopersicon esculentum) (hosts of H. armigera), tobacco (Nicotiana tobaccum) (host of both H. armigera and H. assulta), and bush redpepper (Capsicum frutescens) (host of H. assulta) as testing plants. A multiple-choice test was used with caged plant cuttings for adult oviposition and with leaf discs for larval feeding. A no-choice test was run for evaluating larval growth rate. The results indicated that the relationship between larval performance and adult preference of H. assulta was more conspicuous than that of H. armigera. Reciprocal hybridization between H. armigera and H. assulta followed by backcrossing of the hybrids (F1) with H. armigera was also carried out for genetic study on host selection of these two insect species. A two-choice test with cotton and bush redpepper leaf discs showed that H. armigera larvae preferred to feed on cotton, and H. assulta larvae to bush redpepper; feeding preferences of the two F1 lines were intermediate between those of their parents, but close to that of their female parent; preference indexes of backcross lines also showed that both maternal factor and chromosomal inheritance were involved in feeding selection of two Helicoverpa species.

  18. Bioactivity of non-edible oil seed extracts and purified extracts against Helicoverpa armigera (Hubner).

    Science.gov (United States)

    Pawar, Pushpa; Joseph, Mary; Tungikar, Vijay; Joshi, Swati

    2004-01-01

    Extracts and purified extracts of seeds of two plant species, Madhuca latifolia and Calophyllum inophyllum when evaluated against the 2nd instar larvae of Helicoverpa armigera reared on synthetic diet, exhibited high larval mortality, prolongation of developmental period, morphological deformities and highly significant reduction in adult emergence. The reduction in larval weights in the treatments was also highly significant. PMID:15274488

  19. Rapid identification of Helicoverpa armigera and Helicoverpa zea (Lepidoptera: Noctuidae) using ribosomal RNA internal transcribed spacer 1.

    Science.gov (United States)

    Perera, Omaththage P; Allen, Kerry C; Jain, Devendra; Purcell, Matthew; Little, Nathan S; Luttrell, Randall G

    2015-01-01

    Rapid identification of invasive species is crucial for deploying management strategies to prevent establishment. Recent Helicoverpa armigera (Hübner) invasions and subsequent establishment in South America has increased the risk of this species invading North America. Morphological similarities make differentiation of H. armigera from the native Helicoverpa zea (Boddie) difficult. Characteristics of adult male genitalia and nucleotide sequence differences in mitochondrial DNA are two of the currently available methods to differentiate these two species. However, current methods are likely too slow to be employed as rapid detection methods. In this study, conserved differences in the internal transcribed spacer 1 (ITS1) of the ribosomal RNA genes were used to develop species-specific oligonucleotide primers that amplified ITS1 fragments of 147 and 334 bp from H. armigera and H. zea, respectively. An amplicon (83 bp) from a conserved region of 18S ribosomal RNA subunit served as a positive control. Melting temperature differences in ITS1 amplicons yielded species-specific dissociation curves that could be used in high resolution melt analysis to differentiate the two Helicoverpa species. In addition, a rapid and inexpensive procedure for obtaining amplifiable genomic DNA from a small amount of tissue was identified. Under optimal conditions, the process was able to detect DNA from one H. armigera leg in a pool of 25 legs. The high resolution melt analysis combined with rapid DNA extraction could be used as an inexpensive method to genetically differentiate large numbers of H. armigera and H. zea using readily available reagents. PMID:26516166

  20. A Multiplex Real-Time PCR Assay to Diagnose and Separate Helicoverpa armigera and H. zea (Lepidoptera: Noctuidae in the New World.

    Directory of Open Access Journals (Sweden)

    Todd M Gilligan

    Full Text Available The Old World bollworm, Helicoverpa armigera (Hübner, and the corn earworm, H. zea (Boddie, are two of the most important agricultural pests in the world. Diagnosing these two species is difficult-adults can only be separated with a complex dissection, and larvae cannot be identified to species using morphology, necessitating the use of geographic origin for identification in most instances. With the discovery of H. armigera in the New World, identification of immature Helicoverpa based on origin is no longer possible because H. zea also occurs in all of the geographic regions where H. armigera has been discovered. DNA barcoding and restriction fragment length polymorphism (RFLP analyses have been reported in publications to distinguish these species, but these methods both require post-PCR processing (i.e., DNA sequencing or restriction digestion to complete. We report the first real-time PCR assay to distinguish these pests based on two hydrolysis probes that bind to a segment of the internal transcribed spacer region 2 (ITS2 amplified using a single primer pair. One probe targets H. armigera, the second probe targets H. zea, and a third probe that targets a conserved segment of 18S rDNA is used as a control of DNA quality. The assay can be completed in 50 minutes when using isolated DNA and is successfully tested on larvae intercepted at ports of entry and adults captured during domestic surveys. We demonstrate that the assay can be run in triplex with no negative effects on sensitivity, can be run using alternative real-time PCR reagents and instruments, and does not cross react with other New World Heliothinae.

  1. Reduction of Bacillus thuringiensis Cry1Ac Toxicity Against Helicoverpa armigera by a Soluble Toxin-Binding Cadherin Fragment

    Science.gov (United States)

    A cadherin-like protein has been identified as a putative receptor for Bacillus thuringiensis (Bt) Cry1Ac toxin in Helicoverpa armigera and plays a key role in Bt insecticidal action. In this study, we produced a fragment from this H. armigera Cry1Ac toxin-binding cadherin that included the predict...

  2. Relationships of Helicoverpa armigera, Ostrinia nubilalis and Fusarium verticillioides on MON 810 Maize

    OpenAIRE

    Béla Darvas; Hajnalka Bánáti; Eszter Takács; Éva Lauber; Árpád Szécsi; András Székács

    2011-01-01

    MON 810 maize was developed against Ostrinia nubilalis and is suggested to indirectly decrease Fusarium spp. infestation in maize ears. To evaluate this effect, co-occurrence of insect and fungal pests on MON 810 maize was studied. During 2009, exceptionally high maize ear infestation occurred in Julianna-major (Hungary). From investigation of some thousands of maize ears, the majority of the larval damage originated from Helicoverpa armigera larvae, while O. nubilalis larvae contributed sign...

  3. Trichogramma chilotraeae PARASITOID TELUR Helicoverpa armigera (Hubner PADA POPULASI INANG RENDAH

    Directory of Open Access Journals (Sweden)

    - Sujak

    2011-03-01

    Full Text Available Helicoverpa armigera Hubner is an insect pest of corn and cotton crops. Eggs are laid by  H. armigera imago on corn silk and cotton crops often have high mortality, mainly caused by egg parasitoid. H. armigera egg on various agroecosystem reported can  be parasited by at least 12 species of  Trichogrammatidae. The purpose of this study was to determine the diversity of  Trichogrammatidae family as  parasitoid eggs of  H. armigera on  low population. H. armigera egg sample taken from Asembagus, Lamongan and Blora at 1 m2 field  both monoculture and intercropping. Observation of parasitoids and predators  done at the Laboratory of Biological Control Balittas Malang. Parasitoid that appears preserved in the Hoyer medium for identification purposes. low population of  H. armigera Egg in Asembagus is  4 eggs/m2 in both monoculture maize and intercropping with 86-100 days after transplanting (DAT cotton and  4.5 egg/m2 on cotton monoculture and intercropping with 75  DAT soybean, while 2 eggs/m2 in the Lamongan and Blora corn agroecosystem. The dominant egg parasitoid in Asembagus is T. chilotraea, as well as in Lamongan and Blora.

  4. Parasitism of Helicoverpa armigera pupae (Lepidoptera: Noctuidae by Tetrastichus howardi and Trichospilus diatraeae (Hymenoptera: Eulophidae

    Directory of Open Access Journals (Sweden)

    Harley Nonato de Oliveira

    2016-02-01

    Full Text Available Helicoverpa armigera is a pest that was recently detected in Brazil, which causes significant losses in various crops in different regions of the country. Biological control has been reported to offer a promising alternative in the management of this pest. Thus, this study evaluated the ability of the parasitoids Tetrastichus howardi and Trichospilus diatraeae to parasitize pupae of H. armigera in the laboratory. H. armigera pupae were individually exposed to 15 female Trichospilus diatraeae or 15 female Tetrastichus howardi for 24 h. The pupae remained under observation until the emergence of parasitoids. Parasitism by both parasitoids was observed in 100% of the pupae. Further, 100% of Tetrastichus howardi and 90% of Trichospilus diatraeae emerged. The life cycle of Tetrastichus howardi parasitizing pupae of H. armigera was 15 ± 0.0 days, while that of Trichospilus diatraeae was 15.90 ± 0.10 days. The numbers of offspring from Tetrastichus howardi and Trichospilus diatraeae were 669.3 ± 33.47 and 816.11 ± 89.22 per pupae, with a sex ratio of 0.91 ± 0.01 and 0.94 ± 0.01, respectively. Tetrastichus howardi and Trichospilus diatraeae were shown to successfully parasitize H. armigera pupae in laboratory conditions, suggesting that this host could be used for rearing both parasitoids. However, further detailed studies of the host-parasitoid relationship are needed to assess the feasibility of including these parasitoids in integrated management programs of H. armigera.

  5. The effects of radiation on the biology and reproduction of Helicoverpa armigera (Lepidoptera: Noctuidae)

    International Nuclear Information System (INIS)

    The effect of irradiating male Helicoverpa armigera with a substerilizing dose (100 Gy) of gamma radiation on the growth, development and reproduction of subsequent generations was studied in the laboratory. This dose of gamma radiation had no significant detrimental effects on larval and pupal weights or on the duration of the pupal period in the F1 progeny. However, it lengthened the duration of the larval period by two days. In the F2 generation, the progeny of the Tf1FxTf1M cross had significantly lighter pupae. The effects of this substerilizing dose of radiation and of the resulting inherited sterility on the reproduction of Helicoverpa armigera were similar to those described for other species of Lepidoptera. No detrimental effects on P1 and F1 female fecundity were recorded. Crosses involving Tf1 females laid only about one half the number of eggs laid by the controls, however the range in the number of eggs laid by these females fell within the normal range for Helicoverpa armigera. Fertility of crosses involving P1 males was greatly affected; fertility in these females was only 61% of that exhibited by the controls. This deleterious effect was inherited in the F1 and F2 generations and was maximally expressed when F1 progeny of the NFxTM cross were inbred. Egg hatch was almost completely inhibited in sibling crosses while outcrosses of the F1 progeny showed a 64-70% reduction in egg hatch when compared to controls. (author)

  6. Data of in vitro synthesized dsRNAs on growth and development of Helicoverpa armigera.

    Science.gov (United States)

    Chikate, Yojana R; Dawkar, Vishal V; Barbole, Ranjit S; Tilak, Priyadarshini V; Gupta, Vidya S; Giri, Ashok P

    2016-06-01

    The data presented in this article is related to the research article "RNAi of selected candidate genes interrupts growth and development of Helicoverpa armigera" (Chikate et al., 2016) [1]. RNA interference (RNAi) is emerging as a potent insect pest control strategy over current methods and their resistance by pest. In this study we tested 15 different in vitro synthesized dsRNAs for gene silencing in Helicoverpa armigera. These dsRNAs were specific against H. armigera enzymes/proteins such as proteases like trypsins (HaTry2, 3, 4 and 6), chymotrypsin (HaChy4) and cysteine proteases such as cathepsin (HaCATHL); glutathione S-transferases (HaGST1a, 6 and 8); esterases (HaAce4, HaJHE); catalase (HaCAT); super-oxide-dismutase (HaCu/ZnSOD); fatty acid binding protein (HaFabp) and chitin deacetylase (HaCda5b). These dsRNAs were fed to second instar larvae at an optimized dose (60 µg/day) for 3 days separately. Effects of dsRNA feeding were observed in terms of larval mass gain, percentage mortality and phenotypic abnormalities in later developmental stages of H. armigera. These findings might provide potential new candidates for designing sequence-specific dsRNA as pesticide in crop protection. PMID:27222861

  7. X-ray radiation and development inhibition of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae)

    International Nuclear Information System (INIS)

    Effect of X-ray radiation on the development inhibition was evaluated for all stages of the life cycle of Helicoverpa armigera to determine a radiation dose for potential quarantine treatment against the insect. ED99 values for inhibition of hatching, pupation, and adult emergence from irradiated eggs were 413, 210, and 154 Gy, respectively. ED99 values for inhibition of pupation and adult emergence from irradiated larvae were 221 and 167 Gy, respectively. Pupa was the most tolerant to X-ray radiation. ED99 value for inhibition of adult emergence from irradiated pupae was as high as 2310 Gy, whereas that for inhibition of F1 egg hatching was only 66 Gy. ED99 value for inhibition of hatching of F1 eggs which were laid by irradiated adults was estimated to 194 Gy. X-ray irradiation against H. armigera is recommended as an alternative method to methyl bromide fumigation for phytosanitary treatments during quarantine. X-ray radiation dose of 200 Gy is proposed as a potential quarantine treatment dose for H. armigera eggs and larvae. - Highlights: • X-ray irradiation induced abnormal development of Helicoverpa armigera. • ED99 value for inhibition of pupation and adult emergence of irradiated egg was estimated at 210 and 154 Gy, respectively. • ED99 value for inhibition of pupation and adult emergence of irradiated larva was estimated at 221 and 167 Gy, respectively

  8. Expression of Aminopeptidase N1(APN1),the Main Receptor Protein for Bacillus thuringiensis Cry1A Toxin from Helicoverpa armigera Larval Midgut in Trichoplusia ni cells

    Institute of Scientific and Technical Information of China (English)

    CHANG Hong-lei; LIANG Ge-mei; WANG Gui-rong; YU Hong-kun; GUO Yu-yuan; WU Kong-ming

    2008-01-01

    The aim of this article is to successfully express the Bt(Bacillus thuringiensis)toxin receptor protein located on the internal membrane of larval midgut of cotton bollworm(Helicoverpa armigera Hiibner)within eukaryotic expression system,which is one of the key links for clarifying the relationship between receptor and Bt resistance.The fragments of aminopeptidase N1(APN1)gene without signal peptide in the susceptible and the resistant H. armigera were cloned separately using PCR method,and were separately cloned into pUC 19 vector.After sequencing the gene,the fragments encoding for APN1 without signal peptide were cloned into the Bac-to-Bac baculovirus expression system with transfer vector pFastBacHTB under the polyhedron gene promoter.The recombinant transposing plasmid pFastBacHTB/APN1 was screened and then transformed into Escherichia coli DH10Bac.It was cultured in LB medium,which contained Te, Kan,Ge,X-gal,and IPTG.The resulting recombinant bacmid was transfected into cells of the insect Trichoplusia ni and recombinant baculoviruse was obtained.The lysate of cells infected with recombinant baculoviruse was analyzed by SDS-PAGE and blot analysis.The results showed that the recombinant baculoviruse was fully capable of expressing APN1.The APN1 gene successfully expressed in T. ni cell established the base for continuing the research on its function and relationship of resistance with Bt.

  9. Significance of Penicillium ochrochloron chitinase as a biocontrol agent against pest Helicoverpa armigera.

    Science.gov (United States)

    Patil, Nilambari S; Jadhav, Jyoti P

    2015-06-01

    Penicillium ochrochloron chitinase purified by DEAE-cellulose ion exchange chromatography was evaluated for its antifeedant and growth inhibitory activities against Helicoverpa armigera at different concentrations of 2000, 1000, 500, 250 and 100 U mL(-1). It reduced the successful pupation and increased larval and pupal mortality, adult emergence in a dosage-dependent manner when applied topically. The highest mortalities were recorded for groups treated with 2000 U mL(-1) chitinase activity. The studies showed P.ochrochloron chitinase can affect the growth of H.armigera larvae. Since this insect pest species has developed resistance and resurgence to chemical insecticides, only alternate is the usage of enzyme-based pesticide formulations as an environmentally friendly pest management tool. PMID:25723715

  10. Differential Induction of Flavonoids in Groundnut in Response to Helicoverpa armigera and Aphis craccivora Infestation

    Science.gov (United States)

    War, Abdul Rashid; Sharma, Suraj Prasad; Sharma, Hari Chand

    2016-01-01

    Flavonoids are important plant secondary metabolites, which protect plants from various stresses, including herbivory. Plants differentially respond to insects with different modes of action. High performance liquid chromatography (HPLC) fingerprinting of phenols of groundnut (Arachis hypogaea) plants with differential levels of resistance was carried out in response to Helicoverpa armigera (chewing insect) and Aphis craccivora (sucking pest) infestation. The genotypes used were ICGV 86699, ICGV 86031, ICG 2271 (NCAc 343), ICG 1697 (NCAc 17090), and JL 24. Most of the identified compounds were present in H. armigera- and A. craccivora-infested plants of ICGV 86699. Syringic acid was observed in all the genotypes across the treatments, except in the uninfested control plants of ICG 2271 and aphid-infested plants of ICG 1697. Caffeic acid and umbelliferone were observed only in the H. armigera-infested plants of ICGV 86699. Similarly, dihydroxybenzoic acid and vanillic acid were observed in H. armigera- and aphid-infested plants of ICG 2271 and JL 24, respectively. The peak areas were transformed into the amounts of compounds by using internal standard peak areas and were expressed in nanograms. Quantities of the identified compounds varied across genotypes and treatments. The common compounds observed were chlorogenic, syringic, quercetin, and ferulic acids. These results suggest that depending on the mode of feeding, flavonoids are induced differentially in groundnut plants. PMID:27398031

  11. Assimilatory potential of Helicoverpa armigera reared on host (Chickpea) and nonhost (Cassia tora) diets.

    Science.gov (United States)

    Dawkar, Vishal V; Chikate, Yojana R; Gupta, Vidya S; Slade, Susan E; Giri, Ashok P

    2011-11-01

    Adaptation to plant allelochemicals is a crucial aspect of herbivore chemical ecology. To understand an insect ecology, we studied an effect of nonhost Cassia tora seed-based diet (Ct) on growth, development, and molecular responses in Helicoverpa armigera. We employed a comparative approach to investigate the proteomic differences in gut, hemolymph, and frass of H. armigera reared on a normal (chickpea seed-based, Cp) and Ct diet. In this study, a total of 46 proteins were identified by nano-LC-MS(E). Among them, 17 proteins were up-regulated and 29 proteins were down-regulated when larvae were exposed to the Ct diet. Database searches combined with GO analysis revealed that gut proteases engrossed in digestion, proteins crucial for immunity, adaptive responses to stress, and detoxification were down-regulated in the Ct fed larvae. Proteins identified in H. armigera hemolymph were found to be involved in defense mechanisms. Moreover, proteins found in frass of the Ct fed larvae were observed to participate in energy metabolism. Biochemical and quantitative real-time PCR analysis of selected candidate proteins showed differential gene expression patterns and corroborated with the proteomic data. Our results suggest that the Ct diet could alter expression of proteins related to digestion, absorption of nutrients, adaptation, defense mechanisms, and energy metabolism in H. armigera. PMID:21936543

  12. Toxicity of Bacillus thuringiensis Cry proteins to Helicoverpa armigera (Lepidoptera: Noctuidae) in South Africa.

    Science.gov (United States)

    Li, Hua; Bouwer, Gustav

    2012-01-01

    The susceptibility of one of the most important pests in southern Africa, Helicoverpa armigera (Lepidoptera: Noctuidae), to Bacillus thuringiensis Cry proteins was evaluated by bioassay. Cry proteins were produced in Escherichia coli BL21 cells that were transformed with plasmids containing one of six cry genes. The toxicity of each Cry protein to H. armigera larvae was determined by the diet contamination method for second instar larvae and the droplet feeding method for neonate larvae. For each of the proteins, dose-mortality and dose-growth inhibition responses were analyzed and the median lethal dose (LD(50)) and median inhibitory dose (ID(50)) determined. Second instar larvae were consistently less susceptible to the evaluated Cry proteins than neonate larvae. The relative toxicity of Cry proteins ranked differently between neonate larvae and second instar larvae. On the basis of the LD(50) and ID(50) values, Cry1Ab, Cry1Ac, and Cry2Aa were the most toxic of the evaluated proteins to H. armigera larvae. The study provides an initial benchmark of the toxicity of individual Cry proteins to H. armigera in South Africa. PMID:22019386

  13. Bioactivity of Pseudocalymma alliaceum (Lam.) Sandwith (Bignoniaceae) against Spodoptera litura Fabricius and Helicoverpa armigera Hübner (Lepidotera:Noctuidae)

    Institute of Scientific and Technical Information of China (English)

    Alagarmalai Jeyasankar; Tamilarasu Chinnamani

    2014-01-01

    Objective: To evaluate the antifeedant, larvicidal and insect growth inhibitory activities of crude extracts of Pseudocalymma alliaceum tested against fourth instar larvae of Spodoptera litura (S. litura) and Helicoverpa armigera (H. armigera). Methods: Hexane, chloroform and ethyl acetate extracts were prepared and tested for antifeedant, insecticidal and growth inhibitory activities against fourth instar larvae of S. litura and H. armigera.Results:Ethyl acetate extract showed promising antifeedant, insecticidal activity against S. litura and H. armigera. Maximum percentage of deformed larvae, pupae and adults were found on treatment with ethyl acetate extract. Percentage of successful adult emergence was deteriorated by extract treated larvae. Ethyl acetate extracts of Pseudocalymma alliaceum, showed higher percentage of antifeedant, insecticidal and growth inhibition activities.Conclusions:This is the first report on S. litura and H. armigera. Further, the active compounds isolated from the ethyl acetate extracts will be useful for controlling economically important insect pests.

  14. Testes and chromosomes in interspecific hybrids between Helicoverpa armigera (Hübner) and Helicoverpa assulta (Guenée)

    Institute of Scientific and Technical Information of China (English)

    TANG Qingbo; YAN Yunhua; ZHAO Xincheng; WANG Chenzhu

    2005-01-01

    The interspecific hybridization between Helicoverpa armigera females and Helicoverpa assulta males yielded F1 hybrids (RS), fertile males and sterile individuals with abnormal genitals. The reverse hybridization between H. assulta females and H. armigera males yielded F1 hybrids (SR)――fertile males and fertile females. The morphology of testes and the karyotype of chromosomes of larvae in the hybrids were investigated. Among the 2d old fifth-instar SR larvae, individuals without testes were fertile females and those with testes were fertile males. The length and breadth of testes between SR and parental species were not significantly different (p>0.05). Among the 2d old fifth-instar RS larvae, the testes were observed in all the individuals, but it could be classified into two types. The length and the breadth of testes in Type 1 larvae were not significantly different from those of their parental species (p>0.05), while those in Type 2 were significantly less than those of their parental species (p<0.01). Mitotic metaphase I of brain cells showed the diploid chromosomes number of both reciprocal hybrids was 2n=62, as many as their parents. The haploid number of 31 was confirmed by counts from spermatocytes at meiotic metaphase from SR male larvae and Type 1 larvae of RS. Meiosis was not observed in spermatocytes of Type 2 larvae of RS. Considering the characteristics of adult hybrids of RS, it was concluded that Type 1 individuals in RS were fertile and those of Type 2 were sterile. The sterility of Type 2 individuals in RS is attributed to the abnormity in development of testes and the failing meiosis of spermatocytes. As a result, the normal spermatozoon could not been produced.

  15. Experience-based behavioral and chemosensory changes in the generalist insect herbivore Helicoverpa armigera exposed to two deterrent plant chemicals

    NARCIS (Netherlands)

    Zhou, D.; Loon, van J.J.A.; Wang, C.Z.

    2010-01-01

    Behavioral and electrophysiological responses of larvae of the polyphagous moth species Helicoverpa armigera to two plant-derived allelochemicals were studied, both in larvae that had been reared on a diet devoid of these compounds and in larvae previously exposed to these compounds. In dual-choice

  16. Behaviour of wild-type and genetically modified baculoviruses in the Helicoverpa armigera - cotton system: a simulation approach

    NARCIS (Netherlands)

    Sun, X.

    2005-01-01

    Keywords:   Helicoverpa armigera , baculovirus, genetic modification, cotton,transmissionGenome sequence of Acinetobacter sp. strain HA, isolated from the gut of the polyphagous insect pest Helicoverpa armigera.

    Science.gov (United States)

    Malhotra, Jaya; Dua, Ankita; Saxena, Anjali; Sangwan, Naseer; Mukherjee, Udita; Pandey, Neeti; Rajagopal, Raman; Khurana, Paramjit; Khurana, Jitendra P; Lal, Rup

    2012-09-01

    In this study, Acinetobacter sp. strain HA was isolated from the midgut of a fifth-instar larva of Helicoverpa armigera. Here, we report the draft genome sequence (3,125,085 bp) of this strain that consists of 102 contigs, 2,911 predicted coding sequences, and a G+C content of 41%. PMID:22933775

  17. The potential distribution of invading Helicoverpa armigera in North America: is it just a matter of time?

    Directory of Open Access Journals (Sweden)

    Darren J Kriticos

    Full Text Available Helicoverpa armigera has recently invaded South and Central America, and appears to be spreading rapidly. We update a previously developed potential distribution model to highlight the global invasion threat, with emphasis on the risks to the United States. The continued range expansion of H. armigera in Central America is likely to change the invasion threat it poses to North America qualitatively, making natural dispersal from either the Caribbean islands or Mexico feasible. To characterise the threat posed by H. armigera, we collated the value of the major host crops in the United States growing within its modelled potential range, including that area where it could expand its range during favourable seasons. We found that the annual value of crops that would be exposed to H. armigera totalled approximately US$78 billion p.a., with US$843 million p.a. worth growing in climates that are optimal for the pest. Elsewhere, H. armigera has developed broad-spectrum pesticide resistance; meaning that if it invades the United States, protecting these crops from significant production impacts could be challenging. It may be cost-effective to undertake pre-emptive biosecurity activities such as slowing the spread of H. armigera throughout the Americas, improving the system for detecting H. armigera, and methods for rapid identification, especially distinguishing between H. armigera, H. zea and potential H. armigera x H. zea hybrids. Developing biological control programs, especially using inundative techniques with entomopathogens and parasitoids could slow the spread of H. armigera, and reduce selective pressure for pesticide resistance. The rapid spread of H. armigera through South America into Central America suggests that its spread into North America is a matter of time. The likely natural dispersal routes preclude aggressive incursion responses, emphasizing the value of preparatory communication with agricultural producers in areas suitable for

  18. Relationships of Helicoverpa armigera, Ostrinia nubilalis and Fusarium verticillioides on MON 810 Maize

    Directory of Open Access Journals (Sweden)

    Béla Darvas

    2011-01-01

    Full Text Available MON 810 maize was developed against Ostrinia nubilalis and is suggested to indirectly decrease Fusarium spp. infestation in maize ears. To evaluate this effect, co-occurrence of insect and fungal pests on MON 810 maize was studied. During 2009, exceptionally high maize ear infestation occurred in Julianna-major (Hungary. From investigation of some thousands of maize ears, the majority of the larval damage originated from Helicoverpa armigera larvae, while O. nubilalis larvae contributed significant damage only at a single plot. Fusarium verticillioides infection appeared only in a small portion (~20–30% of the insect damaged cobs. H. armigera and O. nubilalis larvae feeding on F. verticillioides mycelia can distribute its conidia with their fecal pellets. MON 810 maize showed 100% efficacy against O. nubilalis in the stem, but lower efficacy against O. nubilalis and H. armigera in maize ears. The ~Cry1Ab toxin content of maize silk, the entry site of H. armigera, was lower than that in the leaves/stem/husk leaves of MON 810. Fusarium-infected MON 810 cobs are rarely found and only after larval damage by O. nubilalis. H. armigera larvae could not tolerate well F. verticillioides infected food and attempted to move out from the infected cobs. For further feeding they re-entered the maize ears through the 8–12 husk leaves, but in the case of the MON 810 variety, they usually could not reach the kernels. Apical damage on cobs resulted in only a minor (about one-tenth of the cob decrease in yield.

  19. Characterization of a new Helicoverpa armigera nucleopolyhedrovirus variant causing epizootic on a previously unreported host, Helicoverpa gelotopoeon (Lepidoptera: Noctuidae).

    Science.gov (United States)

    Ferrelli, M L; Taibo, C; Fichetti, P; Sciocco-Cap, A; Arneodo, J D

    2016-07-01

    This paper reports the first biological and molecular characterization of a nucleopolyhedrovirus isolated from the soybean and cotton pest Helicoverpa gelotopoeon. Studies were performed following a virus outbreak in a rearing facility and in wild H. gelotopoeon populations in Córdoba, Argentina. Host identity was corroborated by partial sequencing of the COI gene. Scanning electron microscope observations of purified OBs revealed their polyhedral morphology and an average diameter of 0.89±0.14μm. Ultrathin sections of infected larvae examined by transmission electron microscopy showed the intranuclear occurrence of polyhedra and virus particles in fat body cells. Nucleocapsids were singly enveloped. Phylogenetic analysis of lef-8, lef-9, polh, orf5/5b and hr3-orf62 viral sequences identified this new NPV isolate (hereafter HegeSNPV) as a variant of Helicoverpa armigera nucleopolyhedrovirus (HearNPV). Furthermore, HegeSNPV was closely related to the so-called "HzSNPV Group" within HearNPV, although having particular characteristics. PMID:26296927

  1. Bioefficacy of Caesalpinia bonducella extracts against tobacco cutworm, Helicoverpa armigera (Hub. (Lepidoptera: Noctuidae

    Directory of Open Access Journals (Sweden)

    Backiyaraj Muthusamy

    2015-05-01

    Full Text Available Objective: To evaluate the antifeedant, oviposition deterrent, ovicidal and larvicidal activities of benzene, dichloromethane, diethylether, ethyl acetate and methanol extracts of Indian medicinal plant, Caesalpinia bonducella (C. bonducella at different concentrations against Lepidopteran agricultural field pest Helicoverpa armigera (Lepidoptera: Noctuidae. Methods: Antifeedant activities of the selected plant extract were studied using leaf disc nochoice method and oviposition deterrent, ovicidal and larvicidal activities were also assessed by adapting the standard protocols. Results: The antifeedant activity of C. bonducella showed significant antifeedant activity in methanol extract. Oviposition deterrency is higher in methanol extract than the other solvent extracts. Similarly, maximum egg mortality was observed in methanol leaf extract of C. bonducella Lethal concentration, LC50 value of benzene, diethylether, dichloromethane, ethyl acetate and methanol extract of C. bonducella were 470.02, 469.00, 465.47, 460.52 and 443.87 mg/L respectively. The Chi-square values are significant at P< 0.05 level. Among five solvent extracts, the methanol extract was responsible for strong lethal activity observed against selected pest species. Conclusions: Results of this study show that the selected Indian medicinal plant C. bonducella could be a potent source of natural antifeedant, oviposition deterrent, ovicidal and larvicidal agent against the field pest Helicoverpa armigera.

  2. Effect of electron beam irradiation on developmental stages of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae)

    International Nuclear Information System (INIS)

    Helicoverpa armigera Hübner (Lepidoptera: Noctuidae), is an economically important and polyphagous pest, which harms various kinds of food crops and important agricultural plants, such as cotton and paprika. Effects of electron beam irradiation at six dose levels between 50 and 350 Gy on the egg (24–48 h old), the larval (4–5th instar), and the pupal (7-d old for female, 5-d old for male) development, and on the adult (1-d old) reproduction were tested to identify a potential quarantine treatment dose. Increased doses of irradiation on eggs decreased egg hatchability, pupation and adult emergence and increased larval period. ED99 values for inhibition of hatching, pupation and emergence were 460.6, 236.9 and 197.8 Gy, respectively. When larvae were irradiated with more than 280 Gy, no larvae could develop into pupae. ED99 values for inhibition of pupation and adult emergence were 265.6 and 189.6 Gy, respectively. Even though the irradiation on pupa did not completely inhibit adult emergence, most of the pupae emerged to deformed adults. When adults were irradiated, fecundity was not affected. However, F1 egg hatching was completely inhibited at the dose of 350 Gy. ED99 value for inhibition of adult emergence was estimated at 366.5 Gy. Our results suggest that electron beam irradiation could be recommendable as an alternative to MB and as a phytosanitary treatment for quarantine. A treatment dose of less than or equal to 220 Gy is suggested as a potential quarantine treatment to H. armigera egg for prevention of pupation and to larva for prevention of adult emerge. - Highlights: • Electron beam irradiation induced abnormal development of Helicoverpa armigera. • ED99 value for inhibition of adult emergence was estimated at 197.8 Gy for egg. • ED99 value for inhibition of adult emergence was estimated at 189.6 Gy for larva

  3. Bacterial Expression and Kinetic Analysis of Carboxylesterase 001D from Helicoverpa armigera

    Directory of Open Access Journals (Sweden)

    Yongqiang Li

    2016-04-01

    Full Text Available Carboxylesterasesare an important class of detoxification enzymes involved in insecticide resistance in insects. A subgroup of Helicoverpa armigera esterases, known as Clade 001, was implicated in organophosphate and pyrethroid insecticide resistance due to their overabundance in resistant strains. In this work, a novel carboxylesterasegene 001D of H. armigera from China was cloned, which has an open reading frame of 1665 nucleotides encoding 554 amino acid residues. We used a series of fusion proteins to successfully express carboxylesterase 001D in Escherichia coli. Three different fusion proteins were generated and tested. The enzyme kinetic assay towards 1-naphthyl acetate showed all three purified fusion proteins are active with a Kcat between 0.35 and 2.29 s−1, and a Km between 7.61 and 19.72 μM. The HPLC assay showed all three purified fusion proteins had low but measurable hydrolase activity towards β-cypermethrin and fenvalerate insecticides (specific activities ranging from 0.13 to 0.67 μM·min−1·(μM−1·protein. The enzyme was stable up to 40 °C and at pH 6.0–11.0. The results imply that carboxylesterase 001D is involved in detoxification, and this moderate insecticide hydrolysis may suggest that overexpression of the gene to enhance insecticide sequestration is necessary to allow carboxylesterases to confer resistance to these insecticides in H. armigera.

  4. Momordica charantia trypsin inhibitor Ⅱ inhibits growth and development of Helicoverpa armigera

    Institute of Scientific and Technical Information of China (English)

    Manasi Alok Telang; Prashant Pyati; Mohini Sainani; Vidya Shrikant Gupta; Ashok Prabhakar Giri

    2009-01-01

    Bitter gourd (Momordica charantia L.) seeds contain several squash-type serine proteinase inhibitors (PIs),which inhibit the digestive proteinases of the polyphagous insect pest Helicoverpa armigera.In the present work isolation of a DNA sequence encoding the mature peptide of a trypsin inhibitor McTI-Ⅱ,its cloning and expression as a recombinant protein using Pichia pastoris have been reported.Recombinant McTI-Ⅱinhibited bovine trypsin at 1:1 molar ratio,as expected,but did not inhibit chymotrypsin or elastase.McTI-Ⅱalso strongly inhibited trypsin-like proteinases (81% inhibition) as well as the total proteolytic activity of digestive proteinases (70% inhibition) from the midgut of H.armigera larvae.The insect larvae fed with McTI-Ⅱ-incorporated artificial diet suffered over 70% reduction in the average larval weight after 12 days of feeding.Moreover,ingestion of McTI-Ⅱresulted in 23% mortality in the larval population.The strong antimetabolic activity of McTI-Ⅱtoward H.armigera indicates its probable use in developing insect tolerance in susceptible plants.

  5. Insecticidal potential of defense metabolites from Ocimum kilimandscharicum against Helicoverpa armigera.

    Science.gov (United States)

    Singh, Priyanka; Jayaramaiah, Ramesha H; Sarate, Priya; Thulasiram, Hirekodathakallu V; Kulkarni, Mahesh J; Giri, Ashok P

    2014-01-01

    Genus Ocimum contains a reservoir of diverse secondary metabolites, which are known for their defense and medicinal value. However, the defense-related metabolites from this genus have not been studied in depth. To gain deeper insight into inducible defense metabolites, we examined the overall biochemical and metabolic changes in Ocimum kilimandscharicum that occurred in response to the feeding of Helicoverpa armigera larvae. Metabolic analysis revealed that the primary and secondary metabolism of local and systemic tissues in O. kilimandscharicum was severely affected following larval infestation. Moreover, levels of specific secondary metabolites like camphor, limonene and β-caryophyllene (known to be involved in defense) significantly increased in leaves upon insect attack. Choice assays conducted by exposing H. armigera larvae on O. kilimandscharicum and tomato leaves, demonstrated that O. kilimandscharicum significantly deters larval feeding. Further, when larvae were fed on O. kilimandscharicum leaves, average body weight decreased and mortality of the larvae increased. Larvae fed on artificial diet supplemented with O. kilimandscharicum leaf extract, camphor, limonene and β-caryophyllene showed growth retardation, increased mortality rates and pupal deformities. Digestive enzymes of H. armigera - namely, amylase, protease and lipase- showed variable patterns after feeding on O. kilimandscharicum, which implies striving of the larvae to attain required nutrition for growth, development and metamorphosis. Evidently, selected metabolites from O. kilimandscharicum possess significant insecticidal activity. PMID:25098951

  6. Bacterial Expression and Kinetic Analysis of Carboxylesterase 001D from Helicoverpa armigera.

    Science.gov (United States)

    Li, Yongqiang; Liu, Jianwei; Lu, Mei; Ma, Zhiqing; Cai, Chongling; Wang, Yonghong; Zhang, Xing

    2016-01-01

    Carboxylesterasesare an important class of detoxification enzymes involved in insecticide resistance in insects. A subgroup of Helicoverpa armigera esterases, known as Clade 001, was implicated in organophosphate and pyrethroid insecticide resistance due to their overabundance in resistant strains. In this work, a novel carboxylesterasegene 001D of H. armigera from China was cloned, which has an open reading frame of 1665 nucleotides encoding 554 amino acid residues. We used a series of fusion proteins to successfully express carboxylesterase 001D in Escherichia coli. Three different fusion proteins were generated and tested. The enzyme kinetic assay towards 1-naphthyl acetate showed all three purified fusion proteins are active with a Kcat between 0.35 and 2.29 s(-1), and a Km between 7.61 and 19.72 μM. The HPLC assay showed all three purified fusion proteins had low but measurable hydrolase activity towards β-cypermethrin and fenvalerate insecticides (specific activities ranging from 0.13 to 0.67 μM·min(-1)·(μM(-1)·protein)). The enzyme was stable up to 40 °C and at pH 6.0-11.0. The results imply that carboxylesterase 001D is involved in detoxification, and this moderate insecticide hydrolysis may suggest that overexpression of the gene to enhance insecticide sequestration is necessary to allow carboxylesterases to confer resistance to these insecticides in H. armigera. PMID:27049381

  7. BIONOMICS AND EVALUATION OF DIFFERENT BIO PERTICIDES AGAINST HELICOVERPA ARMIGERA (HUBNER HARDWICH INFESTING GROUNDNUT

    Directory of Open Access Journals (Sweden)

    H. A. GADHIYA

    2014-03-01

    Full Text Available Studies on bionomics of Helicoverpa armigera (Hubner Hardwick on groundnut under laboratory conditions revealed that freshly laid eggs were nearly hemispherical round shaped with flattened base, giving a shining yellowish white at first and changing to dark brown prior to hatching. The incubation period of egg was 2 to 4 days. There were five larval instars length of completely developed larva was 26 to 30 mm and larval period was 3 to 7 days. The pre-pupal period was 1 to 4 days. The pupal period was different for both male and female, it was 15 to 18 and 14 to 20 days, respectively. The sex of adult moths were differentiated in the pupal stage by examining the location of genital slit in relation to anal slit. The total life span for male and female was 49.40 ± 5.21 and 52.40 ± 7.03 days, respectively. The fecundity was 255.88 ± 43.21 eggs per female. The sex ratio (male : female was 1 : 1.12 and 1 : 1.13 under laboratory and field condition, respectively. Out of the nine bio pesticides evaluated against H. armigera infesting groundnut, HaNPV (450 LE/ha was noticed most effective against H. armigera and also registered highest yield among all treatments.

  8. Life table and consumption capacity of corn earworm, Helicoverpa armigera, fed asparagus, Asparagus officinalis.

    Science.gov (United States)

    Jha, Ratna Kumar; Tuan, Shu-Jen; Chi, Hsin; Tang, Li-Cheng

    2014-01-01

    The life table and consumption rate of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) reared on asparagus, Asparagus officinalis L. (Asparagales: Asparagaceae) were studied under laboratory conditions to assess their interaction. Development, survival, fecundity, and consumption data were analyzed by the age-stage, twosex life table. This study indicated that asparagus is a natural host of H. armigera. However, the poor nutritional content in asparagus foliage and the poor fitness of H. armigera that fed on asparagus indicated that asparagus is a suboptimal host in comparison to hybrid sweet corn. The uncertainty associated with life table parameters was estimated by using jackknife and bootstrap techniques, and the results were compared for statistical inference. The intrinsic rate of increase (r), finite rate of increase (λ), net reproductive rate (R0), and mean generation time (T) were estimated by the jackknife technique to be 0.0780 day(-1), 1.0811 day(-1), 67.4 offspring, and 54.8 days, respectively, while those estimated by the bootstrap technique were 0.0752 day(-1), 1.0781 day(-1), 68.0 offspring, and 55.3 days, respectively. The net consumption rate of H. armigera, as estimated by the jackknife and bootstrap technique, was 1183.02 and 1132.9 mg per individual, respectively. The frequency distribution of sample means obtained by the jackknife technique failed the normality test, while the bootstrap results fit the normal distribution well. By contrast, the relationship between the mean fecundity and the net reproductive rate, as estimated by the bootstrap technique, was slightly inconsistent with the relationship found by mathematical proof. The application of the jackknife and bootstrap techniques in estimating population parameters requires further examination. PMID:25373181

  9. Evaluation of advanced chickpea genotypes for resistance to pod borer, helicoverpa armigera (hubner) (lepidoptera: noctuidae)

    International Nuclear Information System (INIS)

    Field studies were conducted to evaluate the comparative varietal resistance in thirteen advanced desi chickpea genotypes against chickpea pod borer (CPB), Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) during 2007-2008. Weekly observations showed that mean larval population of CPB in different genotypes ranged from 0.33 to 4.33 per meter row from first week of March to third week of April, where the pod damage varied from 7.4 to 14.2%. The results manifest that among the tested genotypes, B 8/02, showed the maximum resistant to CPB along with B 8/03, CH 4/02 and CH 9/02 with highest resistant to CPB, less larval population per plant, minimum pod damage and highest grain yield with increase of 256.8 to 285.7% with respect to check. Therefore, conclude that these genotypes can be used in crossing/evolving new elite chickpea varieties. (author)

  10. 玉米田四代棉铃虫老熟幼虫空间分布型应用%Spatial Distribution Pattern Application of Fourth-Generation Mature Larvae of Cotton Bollworm (Helicoverpa armigera Hübner) in Maize Field

    Institute of Scientific and Technical Information of China (English)

    李贺年; 齐巧丽; 李德新; 姚克荣

    2011-01-01

    [ Objective ] The paper was to study the spatial distribution pattern of fourth-generation mature larvae of cotton bollworm in maize field. [ Method] The plots with different occurrence densities of fourth-generation cotton bollworm were investigated during August to September in 2009. Six groups of sampling data were obtained, and seven indicators were used to determined its spatial distribution pattern. including aggregation index method, lwao method and Taylor method, etc. [ Result] Aggregation index test showed that in all plots, Moore I < 0,Lloyod m*/m < 1, Kuno Ca <0, diffusion coefficient C < 1, diffusion index Iδ < 1, negative binomial distribution K <0, indicating that mature larvae of cotton bollworm showed uniform distribution in summer maize. Iwao regression equation of fourth-generation mature larvae of cotton bollworm in summer maize was m * =0. 090 6 +0. 766 9m, r =0.986 3, indicating that the basic components of cotton bollworm distribution was single individual, and mature larvae of cotton bollworm in summer maize showed uniform distribution. The optimal sampling number of fourth-generation mature larvae of cotton bollwonn in maize under different population densities could be calculated using formula N1 =( 1. 090 6/m - 0. 233 1 )/D2. [ Conclusion ] The result provided basis for accurate evaluation of population quantities and variation law of cotton bollworm, as well as prediction and control of the pest.%[目的]研究玉米田四代棉铃虫老熟幼虫空间分布型.[方法]于2009年8~9月,对第4代棉铃虫不同发生密度地块进行调查,取得了6组样本资料,应用聚集度指标法、Iwao法和Taylor法等7种指标分析,对其空间分布型进行检验.[结果]聚集度指标的检验结果表明:所有样地Moore I<0,Lloyod m*/m<1,Kuno Ca<0,扩散系数C<1,扩散型指数 Iδ<1,负二项分布,K<0,表明棉铃虫老熟幼虫在夏玉米上均呈均匀分布.棉铃虫第4代老熟幼虫在夏

  11. Identification and characterization of the Sudanese Bacillus thuringiensis and related bacterial strains for their efficacy against Helicoverpa armigera and Tribolium castaneum.

    Science.gov (United States)

    Gorashi, N E; Tripathi, M; Kalia, V; Gujar, G T

    2014-06-01

    Forty-four isolates of Bacillus thuringiensis like bacteria from various sources in different locations from Sudan were tested for their insecticidal activity. The toxicity of these isolates ranged from 6.6 to 70% to the neonates of cotton bollworm, Helicoverpa armigera at 10 ppm concentration. The most effective ones are Kb-29, St-6 and Wh-1 comparable with HD-1. Toxicity of isolates to larvae of the red flour beetle, Tribolium castaneum ranged from 20 to 100%. Isolates St-2 and St-23 gave 100% larval mortality within 15 days of exposure and were at par with Ab-8, Ab-12, Kb-26, Kb-30, Om-4, Po-2, Po-5, Po-7, Sa-8 and Wh-5 and were also comparable with E. coli clone expressing Cry3 toxin. The most effective five isolates viz., Kb-29, St-2, St-6, St-23 and Wh-1 belonged to B. thuringiensis. The St-6 isolate, which also showed high toxicity to T. castaneum larvae, had cry1 genes along with coleopteran active cry28 genes, but not cry3 genes. Of the 25 isolates characterized with 16s DNA sequencing, seven belonged to Paenibacillus spp., one Lysinibacillus sphaericus, one Bacillus pumilus, four Bacillus spp., and rest 12 belonged to B. thuringiensis. Biochemical characterization in each species showed variation. The present study shows potential of some isolates like Kb-29, St-2, St-6, St-23 and Wh-1 as promising bioinsecticides. PMID:24956895

  12. Identification, isolation and characterization of the antifeedant constituent of Clausena anisata against Helicoverpa armigera (Lepidoptera: Noctuidae)

    Institute of Scientific and Technical Information of China (English)

    Olufemi O.R.Pitan; O.O.Ayelaagbe; Hong-Lei Wang; Chen-Zhu Wang

    2009-01-01

    Hexane, petroleum ether, chloroform, ethyl acetate, methanol and water extracts of Clausena anisata [(Willd.) Hook F. Ex Benth] leaves and roots were evaluated against Helicoverpa armigera (Hubner) for antifeedant activities. Antifeedant activity was confirmed, and was found to be higher in root extracts than those of the leaf. Chloroform and petroleum ether extracts of the root showed strongest antifeedant activities (DC50S [concentration (C) causing 50% deterrence compared with the control] 0.014% and 0.016% respectively), and root extracts were fractionated using silica gel column chromatography. One fraction of the chloroform and one of the petroleum ether root extracts was active; and on the basis of mass spectroscopy and 1H and 13C nuclear magnetic resonance spectral data, the active compounds in the two fractious were confirmed to be identical, and identified as osthol [2H-I-Benzopyran-2-one, 7-methoxy-8-(3-methyl-2-butenyl)]. The highest concentratiun of osthol was found in the chloroform root extract. Antifeedant activities of the root extracts, as measured by DC50 values, were highly correlated with their osthol contents. Approximately 99% of the variation in bioactivity of the root extracts could be accounted for by variation in osthol content; osthol therefore, appeared to be an antifeedant component of C. Anisata to H. Armigera. This may provide a new approach to managing this pest.

  13. Influences of insecticides on toxicity and cuticular penetration of abamectin in Helicoverpa armigera

    Institute of Scientific and Technical Information of China (English)

    QIANGWANG; JIA-ANCHENG; ZHONG-MINLIU; SHENG-GANWU; XUE-PINGZHAO; CHANG-XINGWU

    2005-01-01

    Synergistic actions for mixtures of abamectin with other insecticides in some insect pests were evaluated, and the possible synergistic mechanism was studied by the comparison in toxicity and cuticular penetration of abamectin between with and without other insecticides or synergists in Helicoverpa armigera larvae. The results of bioassay showed that horticultural mineral oil (HMO), hexaflumuron, chlorpyrifos, and some other insecticides were synergistic to abamectin with 152.0-420.0 of co-toxicity coefficient(CTC) in some agricultural insect pests. In topical application tests, HMO or piperonyl butoxide (PBO) increased the toxicity of abamectin in larvae of H. armigera, but the mortality was not affected by s,s,s-tributylphorotrithioate (DEF) and triphenylphosphate (TPP). The synergistic action of HMO was obviously higher than PBO, and when treated simultaneously with abamectin, HMO gave a more significant synergism than if treated 2 hours ahead. The highest synergistic effect (SE) was found in the mixture of ‘abamectin+HMO (1:206)'. The mortality did not increase or the toxicity drop, when a synergist or HMO was added into the mixture of ‘abamectin+HMO' or ‘abamectin+synergist', respectively. Results from the isotope tracing experiments showed that HMO significantly enhanced the penetration of 3H-abamectin through the cuticle of H.armigera larvae, which resulted in the synergism of the mixture. The cuticular penetration of 3H-abamectin was not accumulatively affected by chlorpyrifos, nor by hexaflumuron,though there was an inhibition within 30 seconds or 1 hour after treated by these two chemicals respectively. Results suggested that the synergism of abamectin mixed with hexaflumuron or chlorpyrifos might be related to inhibition of metabolic enzymes or target sites in the larvae.

  14. Functional validation of the carbon dioxide receptor in labial palps of Helicoverpa armigera moths.

    Science.gov (United States)

    Ning, Chao; Yang, Ke; Xu, Meng; Huang, Ling-Qiao; Wang, Chen-Zhu

    2016-06-01

    Adult moths possess an organ in their labial palps, the labial-palp pit organ, which is specialized for sensing carbon dioxide (CO2). They use CO2 as a cue to detect healthy plants and find food or lay eggs on them. The molecular bases of the CO2 receptor in Drosophila melanogaster and Aedes aegypti have been reported, but the molecular mechanisms of the CO2 receptor in Lepidoptera remains elusive. In this study, we first re-examined three putative Helicoverpa armigera CO2 gustatory receptor genes (HarmGr1, HarmGr2, and HarmGr3), and then analyzed expression patterns of them. RT-PCR results verified they were predominantly expressed in the labial palps of H. armigera. Thus, we used in situ hybridization to localize the expression of three genes in the labial palps. We found that all three genes were co-expressed in the same cells of the labial palps. Next, we employed the Xenopus laevis oocyte expression system and the two-electrode voltage-clamp recording to study the function of the three genes. Results showed that only oocytes co-expressing HarmGr1 and HarmGr3 or co-expressing HarmGr1, HarmGr2 and HarmGr3 gave robust responses to NaHCO3. Finally, we confirmed that the sensory cells in labial palps of both females and males show dose dependent responses to CO2 stimuli by using single sensillum recording. Our work uncovers that HarmGr1 and HarmGr3 are indispensable and sufficient for CO2 sensing in labial palps of H. armigera. PMID:27060445

  15. In vivo and in vitro effect of Acacia nilotica seed proteinase inhibitors on Helicoverpa armigera (Hübner) larvae

    Indian Academy of Sciences (India)

    S Ramesh Babu; B Subrahmanyam; Srinivasan; I M Santha

    2012-06-01

    Acacia nilotica proteinase inhibitor (AnPI) was isolated by ammonium sulphate precipitation followed by chromatography on DEAE-Sephadex A-25 and resulted in a purification of 10.68-fold with a 19.5% yield. Electrophoretic analysis of purified AnPI protein resolved into a single band with molecular weight of approximately 18.6+1.00 kDa. AnPI had high stability at different pH values (2.0 to 10.0) except at pH 5.0 and are thermolabile beyond 80°C for 10 min. AnPI exhibited effective against total proteolytic activity and trypsin-like activity, but did not show any inhibitory effect on chymotrypsin activity of midgut of Helicoverpa armigera. The inhibition kinetics studies against H. armigera gut trypsin are of non-competitive type. AnPI had low affinity for H. armigera gut trypsin when compared to SBTI. The partially purified and purified PI proteins-incorporated test diets showed significant reduction in mean larval and pupal weight of H. armigera. The results provide important clues in designing strategies by using the proteinase inhibitors (PIs) from the A. nilotica that can be expressed in genetically engineered plants to confer resistance to H. armigera.

  16. Effect of electron beam irradiation on developmental stages of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae)

    Science.gov (United States)

    Kim, Junheon; Chung, Soon-Oh; Jang, Sin Ae; Jang, Miyeon; Park, Chung Gyoo

    2015-07-01

    Helicoverpa armigera Hübner (Lepidoptera: Noctuidae), is an economically important and polyphagous pest, which harms various kinds of food crops and important agricultural plants, such as cotton and paprika. Effects of electron beam irradiation at six dose levels between 50 and 350 Gy on the egg (24-48 h old), the larval (4-5th instar), and the pupal (7-d old for female, 5-d old for male) development, and on the adult (1-d old) reproduction were tested to identify a potential quarantine treatment dose. Increased doses of irradiation on eggs decreased egg hatchability, pupation and adult emergence and increased larval period. ED99 values for inhibition of hatching, pupation and emergence were 460.6, 236.9 and 197.8 Gy, respectively. When larvae were irradiated with more than 280 Gy, no larvae could develop into pupae. ED99 values for inhibition of pupation and adult emergence were 265.6 and 189.6 Gy, respectively. Even though the irradiation on pupa did not completely inhibit adult emergence, most of the pupae emerged to deformed adults. When adults were irradiated, fecundity was not affected. However, F1 egg hatching was completely inhibited at the dose of 350 Gy. ED99 value for inhibition of adult emergence was estimated at 366.5 Gy. Our results suggest that electron beam irradiation could be recommendable as an alternative to MB and as a phytosanitary treatment for quarantine. A treatment dose of less than or equal to 220 Gy is suggested as a potential quarantine treatment to H. armigera egg for prevention of pupation and to larva for prevention of adult emerge.

  17. Cantharidin Impedes Activity of Glutathione S-Transferase in the Midgut of Helicoverpa armigera Hübner.

    Science.gov (United States)

    Khan, Rashid Ahmed; Liu, Ji Yuan; Rashid, Maryam; Wang, Dun; Zhang, Ya Lin

    2013-01-01

    Previous investigations have implicated glutathione S-transferases (GSTs) as one of the major reasons for insecticide resistance. Therefore, effectiveness of new candidate compounds depends on their ability to inhibit GSTs to prevent metabolic detoxification by insects. Cantharidin, a terpenoid compound of insect origin, has been developed as a bio-pesticide in China, and proves highly toxic to a wide range of insects, especially lepidopteran. In the present study, we test cantharidin as a model compound for its toxicity, effects on the mRNA transcription of a model Helicoverpa armigera glutathione S-transferase gene (HaGST) and also for its putative inhibitory effect on the catalytic activity of GSTs, both in vivo and in vitro in Helicoverpa armigera, employing molecular and biochemical methods. Bioassay results showed that cantharidin was highly toxic to H. armigera. Real-time qPCR showed down-regulation of the HaGST at the mRNA transcript ranging from 2.5 to 12.5 folds while biochemical assays showed in vivo inhibition of GSTs in midgut and in vitro inhibition of rHaGST. Binding of cantharidin to HaGST was rationalized by homology and molecular docking simulations using a model GST (1PN9) as a template structure. Molecular docking simulations also confirmed accurate docking of the cantharidin molecule to the active site of HaGST impeding its catalytic activity. PMID:23528854

  18. Cantharidin Impedes Activity of Glutathione S-Transferase in the Midgut of Helicoverpa armigera Hübner

    Directory of Open Access Journals (Sweden)

    Ya Lin Zhang

    2013-03-01

    Full Text Available Previous investigations have implicated glutathione S-transferases (GSTs as one of the major reasons for insecticide resistance. Therefore, effectiveness of new candidate compounds depends on their ability to inhibit GSTs to prevent metabolic detoxification by insects. Cantharidin, a terpenoid compound of insect origin, has been developed as a bio-pesticide in China, and proves highly toxic to a wide range of insects, especially lepidopteran. In the present study, we test cantharidin as a model compound for its toxicity, effects on the mRNA transcription of a model Helicoverpa armigera glutathione S-transferase gene (HaGST and also for its putative inhibitory effect on the catalytic activity of GSTs, both in vivo and in vitro in Helicoverpa armigera, employing molecular and biochemical methods. Bioassay results showed that cantharidin was highly toxic to H. armigera. Real-time qPCR showed down-regulation of the HaGST at the mRNA transcript ranging from 2.5 to 12.5 folds while biochemical assays showed in vivo inhibition of GSTs in midgut and in vitro inhibition of rHaGST. Binding of cantharidin to HaGST was rationalized by homology and molecular docking simulations using a model GST (1PN9 as a template structure. Molecular docking simulations also confirmed accurate docking of the cantharidin molecule to the active site of HaGST impeding its catalytic activity.

  19. Push-pull Strategy with Trap Crops, Neem and Nuclear Polyhedrosis Virus for Insecticide Resistance Management in Helicoverpa armigera (Hubner) in Cotton

    OpenAIRE

    P. Duraimurugan; A. Regupathy

    2005-01-01

    Insecticide resistance in Helicoverpa armigera (Hubner) is a major threat to cotton production in India. The virus infection was found to increase the susceptibility of H. armigera to the insecticides. But, use of Nuclear Polyhedrosis Virus (NPV) on a larger scale and on cotton due to leaf alkalinity poses certain practical problems. Hence, studies were carried out to assess the effects of push-pull strategy with trap crops, neem and NPV in cotton for the management of insecticide resistant H...

  20. Bacillus subtillis RTSBA6 6.00, a new strain isolated from gut of Helicoverpa armigera (Lepidoptera: Noctuidae) produces chymotrypsin-like proteases

    OpenAIRE

    Shinde, Ashok A.; Shaikh, Faiyaz K.; Padul, Manohar V.; Kachole, Manvendra S.

    2012-01-01

    Exploring bacterial communities with proteolytic activity from the gut of the Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) insect pests was the purpose of this study. As initial efforts to achieve this goal here we report the isolation of new Bacillus subtillis RTSBA6 6.00 strain from the gut of H. armigera and demonstrated as proteases producer. Zymographic analysis revealed 12 proteolytic bands with apparent molecular weights ranging from 20 to 185 kDa. Although some activity was ...

  1. Effects of ultraviolet light irradiation on several isozymes in Helicoverpa armigera adults

    International Nuclear Information System (INIS)

    The effects of ultraviolet (UV)light stress on esterase, peroxidases (POX ), and catalase (CAT) isozymes in Helicoverpa armigera (Hiiber) adults were studied by isozyme eleetrophoresis. When exposed to UV light irradiation, zymogram of esterase isozyme changed mainly in number and activity of isozyme. After 30 min and 60 min exposure, the intensity of isozyme bands E4, E9 and El0 were enhanced, E2 and E8 were weakened. The bands E1, E5, E7 and Ell disappeared after UV light irradiation, while E3 and E6 newly emerged. At the longest exposure time (90 min), the intensity of isozyme bands E4 and E9 was enhanced, while the intensity of E2 and E8 was weakened. The bands E1, E5 and E7 disappeared after UV light irradiation, whereas E3 and E6 newly emerged. The intensity of POX band P5 was enhanced in adults following the exposure to UV light for 30, 60, 90 minutes. The intensity of CAT band C1 was enhanced in adults following the exposure to UV light for 30, 60, 90 minutes, but that of band C2 was weakened after 30 min and 90 min exposure in comparison with the control

  2. BIO-EFFICACY OF INSECTICIDES AGAINST FRUIT BORER (HELICOVERPA ARMIGERA IN TOMATO (LYCOPERSICON ESCULENTUM

    Directory of Open Access Journals (Sweden)

    Ravi Kumar Katroju,

    2014-02-01

    Full Text Available Field experiment carried out during kharif, 2012 at Student’s Farm, College of Agriculture, Rajendranagar, Hyderabad to evaluate the efficacy of insecticides viz., emamectin benzoate 5 SG @11 g a.i. ha-1, emamectin benzoate 5 SG @ 22 g a.i. ha-1, profenophos 50 EC @ 500 g a.i. ha-1, profenophos 50 EC @1000 g a.i. ha-1, spinosad 45 SC @ 100 g a.i. ha-1, bifenthrin 10 EC @ 100 g a.i. ha-1 and Bacillus thuringiensis @ 25 g a.i. ha-1against tomato fruit borer (Helicoverpa armigera. Among all the insecticides, profenophos (1000 g a.i. ha-1 was found to be the most effective one with a maximum reduction in fruit borer population (65.20%, minimum per cent of fruit damage (28.80% and maximum yield (26.43 kg/20 m2 followed by bifenthrin @ 100 g a.i.ha-1 with reduced larval population of 64.51% and damaged fruits 32.60%.

  3. Functional response of Chrysoperla carnea (Neuroptera: Chrysopidae) to Helicoverpa armigera (Lepidoptera: Noctuidae): effect of prey and predator stages

    DEFF Research Database (Denmark)

    Hassanpour, Mehdi; Mohaghegh, Jafar; Iranipour, Shahzad; Nouri-Ganbalani, Gadir; Enkegaard, Annie

    2011-01-01

    Understanding predator–prey interactions has a pivotal role in biological control programs. This study evaluated the functional response of three larval instars of the green lacewing, Chrysoperla carnea (Stephens), preying upon eggs and first instar larvae of the cotton bollworm, Helicoverpa...

  4. Diapause in Two Tachinid (Diptera: Tachinidae Parasitoids of Helicoverpa armigera (Hübner (Lepidoptera: Noctuidae in Southern India

    Directory of Open Access Journals (Sweden)

    Deepak R. Jadhav

    2013-11-01

    Full Text Available Two larval-pupal tachinid parasitoids; Goniophthalmus halli (Mesnil and Senometopia(Eucarcelia illota (Curran were recorded from the pupae of Helicoverpa armigera (Hubner on pigeonpea crop in Andhra Pradesh, India, between 1974 and 1996. Both the parasitoids enter in diapause following the signals received from their host and maintain close proximity in their development in nondiapausing and diapausing H. armigera populations. It is suggested that parasitoid diapause is induced by the physiological changes in late larval or pupal stage of the host and was observed in seasons when host diapause occurred and followed synchrony in terms of emergence for both the host and parasitoids. This is the first report of diapause in tachinid parasitoids from the southern region of Indian sub-continent.

  5. Adaptation of Habrobracon hebetor (Hymenoptera: Braconidae) to Rearing on Ephestia kuehniella (Lepidoptera: Pyralidae) and Helicoverpa armigera (Lepidoptera: Noctuidae)

    Science.gov (United States)

    Naseri, Bahram; Mohammadzadeh-Bidarani, Mozhgan

    2016-01-01

    Food characteristics strongly regulate digestive enzymatic activity of insects through direct influences on their midgut mechanisms. Insect performance is better on diets that contain nutrients in proportions that fit its digestive enzymes. Little is known about the influences of rearing history on parasitism success of Habrobracon hebetor Say. This research focused on the effect of nutrient regulation on survival, development, and parasitism of H. hebetor. Life history and digestive enzyme activity of fourth-stage larvae of H. hebetor were studied when reared on Ephestia kuehniella Zeller. This parasitoid was then introduced to Helicoverpa armigera (Hübner), and above-mentioned parameters were also studied in the first and fourth generations after transfer. In term of parasitism success, H. hebetor preferred E. kuehniella over He. armigera. When the first and fourth generations of He. armigera-reared H. hebetor were compared, the rearing history affected the life history and enzymatic activity of the parasitoid. A better performance of H. hebetor was achieved after it was reared on He. armigera for the four generations. Because, digestive α-amylase and general protease of the parasitoid were matched with the new host, it used reserve energy for a better performance. Thus, a better performance of H. hebetor could be obtained when the parasitoid was reared on its original host for at least four generations. PMID:26839317

  6. Mutation of an aminopeptidase N gene is associated with Helicoverpa armigera resistance to Bacillus thuringiensis Cry1Ac toxin.

    Science.gov (United States)

    Zhang, Shaoping; Cheng, Hongmei; Gao, Yulin; Wang, Guirong; Liang, Gemei; Wu, Kongming

    2009-07-01

    A Cry1Ac-resistant strain (Bt-R) of Helicoverpa armigera, with 2971-fold resistance, was derived by selection with Cry1Ac toxin for 75 generations. We used cDNA-amplified fragment length polymorphism analysis to identify those genes differentially expressed in the Cry1Ac-resistant and -susceptible strains, which revealed 212 differentially expressed transcripts among 2000 screened cDNAs. Among these transcript-derived fragments (TDFs), 37 showed some homology to known sequences, including Aminopeptidase N (APN), which is expressed in the midgut epithelium and has been implicated as a Cry1A subfamily receptor in several moths, including H. armigera. We confirmed the TDF by RT-PCR and identified a deletion mutation of apn1 in the Bt-R strain. We expressed the TDF in bacteria. The partial HaAPN1-96S wild-type protein, bound to Cry1Ac on ligand blots, whereas HaAPN1-BtR did not. This suggested that HaAPN1 is a receptor for Bt Cry1Ac and that its deletion mutation is associated with Cry1Ac resistance in H. armigera. The absence of one binding site is responsible for its resistance to Cry1Ac. We developed an allele-specific PCR to monitor whether the apn1 gene in an H. armigera field population produced a similar mutation. No deleted mutants were found in 2250 individuals collected from the field in 2006-2007. PMID:19376227

  7. Adaptation of Habrobracon hebetor (Hymenoptera: Braconidae) to Rearing on Ephestia kuehniella (Lepidoptera: Pyralidae) and Helicoverpa armigera (Lepidoptera: Noctuidae).

    Science.gov (United States)

    Borzoui, Ehsan; Naseri, Bahram; Mohammadzadeh-Bidarani, Mozhgan

    2016-01-01

    Food characteristics strongly regulate digestive enzymatic activity of insects through direct influences on their midgut mechanisms. Insect performance is better on diets that contain nutrients in proportions that fit its digestive enzymes. Little is known about the influences of rearing history on parasitism success of Habrobracon hebetor Say. This research focused on the effect of nutrient regulation on survival, development, and parasitism of H. hebetor. Life history and digestive enzyme activity of fourth-stage larvae of H. hebetor were studied when reared on Ephestia kuehniella Zeller. This parasitoid was then introduced to Helicoverpa armigera (Hübner), and above-mentioned parameters were also studied in the first and fourth generations after transfer. In term of parasitism success, H. hebetor preferred E. kuehniella over He. armigera. When the first and fourth generations of He. armigera-reared H. hebetor were compared, the rearing history affected the life history and enzymatic activity of the parasitoid. A better performance of H. hebetor was achieved after it was reared on He. armigera for the four generations. Because, digestive α-amylase and general protease of the parasitoid were matched with the new host, it used reserve energy for a better performance. Thus, a better performance of H. hebetor could be obtained when the parasitoid was reared on its original host for at least four generations. PMID:26839317

  8. The expression of proteins involved in digestion and detoxification are regulated in Helicoverpa armigera to cope up with chlorpyrifos insecticide.

    Science.gov (United States)

    Dawkar, Vishal V; Chikate, Yojana R; More, Tushar H; Gupta, Vidya S; Giri, Ashok P

    2016-02-01

    Helicoverpa armigera is a key pest in many vital crops, which is mainly controlled by chemical strategies. To manage this pest is becoming challenging due to its ability and evolution of resistance against insecticides. Further, its subsequent spread on nonhost plant is remarkable in recent times. Hence, decoding resistance mechanism against phytochemicals and synthetic insecticides is a major challenge. The present work describes that the digestion, defense and immunity related enzymes are associated with chlorpyrifos resistance in H. armigera. Proteomic analysis of H. armigera gut tissue upon feeding on chlorpyrifos containing diet (CH) and artificial diet (AD) using nano-liquid chromatography-mass spectrometry identified upregulated 23-proteins in CH fed larvae. Database searches combined with gene ontology analysis revealed that the identified gut proteins engrossed in digestion, proteins crucial for immunity, adaptive responses to stress, and detoxification. Biochemical and quantitative real-time polymerase chain reaction analysis of candidate proteins indicated that insects were struggling to get nutrients and energy in presence of CH, while at the same time endeavoring to metabolize chlorpyrifos. Moreover, we proposed a potential processing pathway of chlorpyrifos in H. armigera gut by examining the metabolites using gas chromatography-mass spectrometry. H. armigera exhibit a range of intriguing behavioral, morphological adaptations and resistance to insecticides by regulating expression of proteins involved in digestion and detoxification mechanisms to cope up with chlorpyrifos. In these contexts, as gut is a rich repository of biological information; profound analysis of gut tissues can give clues of detoxification and resistance mechanism in insects. PMID:25284010

  9. Assessment of beneficial role of an insectivorous bird, jungle babbler (Turdoides striatus) predation, on Helicoverpa armigera infesting pigeon pea (Cajanus cajan) crop Evaluación del rol benéfico de Turdoides striatus como predator de Helicoverpa armigera en el cultivo de guandul (Cajanus cajan)

    OpenAIRE

    Bhavna Bharucha; G. S. Padate

    2010-01-01

    Jungle babbler (Turdoides striatus), a widely spread sub-tropical insectivorous passerine is considered beneficial to agro-ecosystem, as they devour voraciously on insect matter especially Helicoverpa armigera, the gram pod borer, a notorious pest infesting and causing heavy loses to crops like pigeon pea (Cajanus cajan) which is a vital crop of semi-arid tropical and subtropical farming system, providing high quality vegetable protein. Helicoverpa is known to feed on flowers, pods, and seeds...

  10. Weakening density dependence from climate change and agricultural intensification triggers pest outbreaks: a 37-year observation of cotton bollworms

    OpenAIRE

    Ouyang, Fang; Hui, Cang; Ge, Saiying; Men, Xin-Yuan; Zhao, Zi-Hua; Shi, Pei-Jian; Zhang, Yong-Sheng; Li, Bai-Lian

    2014-01-01

    Understanding drivers of population fluctuation, especially for agricultural pests, is central to the provision of agro-ecosystem services. Here, we examine the role of endogenous density dependence and exogenous factors of climate and human activity in regulating the 37-year population dynamics of an important agricultural insect pest, the cotton bollworm (Helicoverpa armigera), in North China from 1975 to 2011. Quantitative time-series analysis provided strong evidence explaining long-term ...

  11. Gene cloning and expression of cadherin in midgut of Helicoverpa armigera and its Cry1A binding region

    Institute of Scientific and Technical Information of China (English)

    WANG Guirong; WU Kongming; LIANG Gemei; GUO Yuyuan

    2005-01-01

    Cadherins belong to one of the families of animal glycoproteins responsible for calcium-dependent cell-cell adhesion. Recent literatures showed that the cadherin-like in midgut of several insects served as the receptor of Bt toxin Cry1A and the variation of cadherin-like is related to insect's resistance to Cry1A. The full-length cDNA encoding cadherin-like of Helicoverpa armigera is cloned by degenerate PCR and RACE techniques and the gene was designated as BtR-harm, which is 5581 bp in full-length, encoding 1730 amino acid residues (BtR-harm was deposited in GenBank and the accession number is AF519180). Its predicted molecular weight and isoelectric point were 195.39 kDa and 4.23, respectively. The inferred amino acid sequence includes a signal sequence, 11 cadherin repeats, a membrane-proximal region, a transmembrane region and a cytoplasmic region. Sequence analysis indicated that the deduced protein sequence was most similar to the cadherin-like from Heliothis virescens with 84.2% identity and highly similar to three other lepidopteran cadherin from Bombyx mori, Manduca sexta and Pectinophora gossypiella, with the sequence identities of 60.3.6%, 57.5% and 51.0%, respectively. The cDNA encoding cadherin gene was expressed successfully in E. coli and the recombinant proteins can bind with Cry1Ac. Truncation analysis and binding experiment of BtR-harm revealed that the Cry1A binding region was a contiguous 244-amino acid sequence, which located between amino acid 1217 and 1461. Semi-quantitative RT-PCR analysis showed that BtR-harm was highly expressed in midgut of H. armigera, very low expressed in foregut and hindgut and was not expressed in other tissues. After H. armigera producing resistance to Cry1Ac, the expression quantity of BtR-harm significantly decreased in midgut of H. armigera. It is the first confirmation that BtR-harm can function as receptor of Cry1Ac in H. armigera and the binding region was located on a contiguous 244 amino acid sequence

  12. Gene cloning and expression of cadherin in midgut of Helicoverpa armigera and its Cry1A binding region.

    Science.gov (United States)

    Wang, Guirong; Wu, Kongming; Liang, Gemei; Guo, Yuyuan

    2005-08-01

    Cadherins belong to one of the families of animal glycoproteins responsible for calcium-dependent cell-cell adhesion. Recent literatures showed that the cadherin-like in midgut of several insects served as the receptor of Bt toxin Cry1A and the variation of cadherin-like is related to insect's resistance to Cry1A. The full-length cDNA encoding cadherin-like of Helicoverpa armigera is cloned by degenerate PCR and RACE techniques and the gene was designated as BtR-harm, which is 5581 bp in full-length, encoding 1730 amino acid residues (BtR-harm was deposited in GenBank and the accession number is AF519180). Its predicted molecular weight and isoelectric point were 195.39 kDa and 4.23, respectively. The inferred amino acid sequence includes a signal sequence, 11 cadherin repeats, a membrane-proximal region, a transmembrane region and a cytoplasmic region. Sequence analysis indicated that the deduced protein sequence was most similar to the cadherin-like from Heliothis virescens with 84.2% identity and highly similar to three other lepidopteran cadherin from Bombyx mori, Manduca sexta and Pectinophora gossypiella, with the sequence identities of 60.3.6%, 57.5% and 51.0%, respectively. The cDNA encoding cadherin gene was expressed successfully in E. coli and the recombinant proteins can bind with Cry1Ac. Truncation analysis and binding experiment of BtR-harm revealed that the Cry1A binding region was a contiguous 244-amino acid sequence, which located between amino acid 1217 and 1461. Semi-quantitative RT-PCR analysis showed that BtR-harm was highly expressed in midgut of H. armigera, very low expressed in foregut and hindgut and was not expressed in other tissues. After H. armigera producing resistance to Cry1Ac, the expression quantity of BtR-harm significantly decreased in midgut of H. armigera. It is the first confirmation that BtR-harm can function as receptor of Cry1Ac in H. armigera and the binding region was located on a contiguous 244 amino acid sequence

  13. Species From the Heliothinae Complex (Lepidoptera: Noctuidae) in Tucumán, Argentina, an Update of Geographical Distribution of Helicoverpa armigera

    Science.gov (United States)

    Murúa, M. Gabriela; Cazado, Lucas E.; Casmuz, Augusto; Herrero, M. Inés; Villagrán, M. Elvira; Vera, Alejandro; Sosa-Gómez, Daniel R.; Gastaminza, Gerardo

    2016-01-01

    The Heliothinae complex in Argentina encompasses Helicoverpa gelotopoeon (Dyar), Helicoverpa zea (Boddie), Helicoverpa armigera (Hübner), and Chloridea virescens (Fabricius). In Tucumán, the native species H. gelotopoeon is one of the most voracious soybean pests and also affects cotton and chickpea, even more in soybean-chickpea succession cropping systems. Differentiation of the Heliothinae complex in the egg, larva, and pupa stages is difficult. Therefore, the observation of the adult wing pattern design and male genitalia is useful to differentiate species. The objective of this study was to identify the species of the Heliothinae complex, determine population fluctuations of the Heliothinae complex in soybean and chickpea crops using male moths collected in pheromone traps in Tucuman province, and update the geographical distribution of H. armigera in Argentina. The species found were H. gelotopoeon, H. armigera, H. zea, and C. virescens. Regardless of province, county, crop, and year, the predominant species was H. gelotopoeon. Considering the population dynamics of H. gelotopoeon and H. armigera in chickpea and soybean crops, H. gelotopoeon was the most abundant species in both crops, in all years sampled, and the differences registered were significant. On the other hand, according to the Sistema Nacional Argentino de Vigilancia y Monitoreo de Plagas (SINAVIMO) database and our collections, H. armigera was recorded in eight provinces and 20 counties of Argentina, and its larvae were found on soybean, chickpea, sunflower crops and spiny plumeless thistle (Carduus acanthoides). This is the first report of H. armigera in sunflower and spiny plumeless thistle in Argentina. PMID:27324588

  14. Species From the Heliothinae Complex (Lepidoptera: Noctuidae) in Tucumán, Argentina, an Update of Geographical Distribution of Helicoverpa armigera.

    Science.gov (United States)

    Murúa, M Gabriela; Cazado, Lucas E; Casmuz, Augusto; Herrero, M Inés; Villagrán, M Elvira; Vera, Alejandro; Sosa-Gómez, Daniel R; Gastaminza, Gerardo

    2016-01-01

    The Heliothinae complex in Argentina encompasses Helicoverpa gelotopoeon (Dyar), Helicoverpa zea (Boddie), Helicoverpa armigera (Hübner), and Chloridea virescens (Fabricius). In Tucumán, the native species H. gelotopoeon is one of the most voracious soybean pests and also affects cotton and chickpea, even more in soybean-chickpea succession cropping systems. Differentiation of the Heliothinae complex in the egg, larva, and pupa stages is difficult. Therefore, the observation of the adult wing pattern design and male genitalia is useful to differentiate species. The objective of this study was to identify the species of the Heliothinae complex, determine population fluctuations of the Heliothinae complex in soybean and chickpea crops using male moths collected in pheromone traps in Tucuman province, and update the geographical distribution of H. armigera in Argentina. The species found were H. gelotopoeon, H. armigera, H. zea, and C. virescens. Regardless of province, county, crop, and year, the predominant species was H. gelotopoeon Considering the population dynamics of H. gelotopoeon and H. armigera in chickpea and soybean crops, H. gelotopoeon was the most abundant species in both crops, in all years sampled, and the differences registered were significant. On the other hand, according to the Sistema Nacional Argentino de Vigilancia y Monitoreo de Plagas (SINAVIMO) database and our collections, H. armigera was recorded in eight provinces and 20 counties of Argentina, and its larvae were found on soybean, chickpea, sunflower crops and spiny plumeless thistle (Carduus acanthoides). This is the first report of H. armigera in sunflower and spiny plumeless thistle in Argentina. PMID:27324588

  15. Selección de un aislado del nucleopoliedrovirus de Helicoverpa armigera (HearNPV) para su uso como base de un bioinsecticida

    OpenAIRE

    Dimcheva Ivanova, Iskra

    2014-01-01

    Helicoverpa armigera (Lepidoptera; Noctuidae), conocida como el taladro del tomate, es una especie polífaga y de amplia distribución, responsable de grandes pérdidas económicas en más de 60 cultivos a lo largo de las regiones tropicales y subtropicales del mundo. Estas plagas se controlan mayoritariamente con plaguicidas químicos, aunque existe un gran interés por desarrollar otros agentes de control biológico. Entre estos, se encuentra el nucleopoliedrovirus de Helicoverpa arm...

  16. Electrophysiological and behavioral responses of female Helicoverpa armigera to compounds identified in flowers of African marigold, Tagetes erecta.

    Science.gov (United States)

    Bruce, T J; Cork, A

    2001-06-01

    Seven electrophysiologically active compounds were detected in air-entrained headspace samples of live flowers of Tagetes erecta analyzed by gas chromatography (GC) linked to a female Helicoverpa armigera electroantennograph (EAG) using polar and nonpolar capillary columns. These compounds were subsequently identified using GC linked to mass spectrometry as benzaldehyde, (S)-(-)-limonene, (R,S)-(+/-)-linalool, (E)-myroxide, (Z)-beta-ocimene, phenylacetaldehyde, and (R)-(-)-piperitone. Electrophysiological activity was confirmed by EAG with a 1-microg dose of each compound on filter paper eliciting EAG responses that were significantly greater than the solvent control response from female moths. Wind-tunnel bioassays with T. erecta headspace samples, equivalent to 0.4 flower/hr emission from a live flower, elicited a significant increase in the number of upwind approaches from female H. armigera relative to a solvent control. Similarly, a seven-component synthetic blend of EAG-active compounds identified from T. erecta presented in the same ratio (1.0:1.6:0.7:1.4:0.4:5.0:2.7, respectively) and concentration (7.2 microg) as found in the natural sample elicited a significant increase in the number of upwind approaches relative to a solvent control during a 12-min bioassay that was equivalent to that elicited by the natural T. erecta floral volatiles. PMID:11504018

  17. Know your ABCs: Characterization and gene expression dynamics of ABC transporters in the polyphagous herbivore Helicoverpa armigera.

    Science.gov (United States)

    Bretschneider, Anne; Heckel, David G; Vogel, Heiko

    2016-05-01

    Polyphagous insect herbivores are adapted to many different secondary metabolites of their host plants. However, little is known about the role of ATP-binding cassette (ABC) transporters, a multigene family involved in detoxification processes. To study the larval response of the generalist Helicoverpa armigera (Lepidoptera) and the putative role of ABC transporters, we performed developmental assays on artificial diet supplemented with secondary metabolites from host plants (atropine-scopolamine, nicotine and tomatine) and non-host plants (taxol) in combination with a replicated RNAseq experiment. A maximum likelihood phylogeny identified the subfamily affiliations of the ABC transporter sequences. Larval performance was equal on the atropine-scopolamine diet and the tomatine diet. For the latter we could identify a treatment-specific upregulation of five ABC transporters in the gut. No significant developmental difference was detected between larvae fed on nicotine or taxol. This was also mirrored in the upregulation of five ABC transporters when fed on either of the two diets. The highest number of differentially expressed genes was recorded in the gut samples in response to feeding on secondary metabolites. Our results are consistent with the expectation of a general detoxification response in a polyphagous herbivore. This is the first study to characterize the multigene family of ABC transporters and identify gene expression changes across different developmental stages and tissues, as well as the impact of secondary metabolites in the agricultural pest H. armigera. PMID:26951878

  18. Assessment of beneficial role of an insectivorous bird, jungle babbler (Turdoides striatus) predation, on Helicoverpa armigera infesting pigeon pea (Cajanus cajan) crop

    OpenAIRE

    Bhavna Bharucha; G. S. Padate

    2010-01-01

    Jungle babbler (Turdoides striatus), a widely spread sub-tropical insectivorous passerine is considered beneficial to agro-ecosystem, as they devour voraciously on insect matter especially Helicoverpa armigera, the gram pod borer, a notorious pest infesting and causing heavy loses to crops like pigeon pea (Cajanus cajan) which is a vital crop of semi-arid tropical and subtropical farming system, providing high quality vegetable pr...

  19. Response dynamics of three defense related enzymes in cotton leaves to the interactive stress of Helicoverpa armigera (Hübner) herbivory and omethoate application

    Institute of Scientific and Technical Information of China (English)

    SHA Pin-jie; FAN Yin-jun; WANG Zhi-chao; SHI Xue-yan

    2015-01-01

    In order to explore the response dynamics of the activities of defense related enzymes in cotton leaves towards the inter-active stress of Helicoverpa armigera herbivory and omethoate application, the activities of phenylalanine ammonia-lyase (PAL), lipoxygenase (LOX), and polyphenol oxidase (PPO) were examined from 6 to 126 h after cotton leaves were treated 12 h of H. armigera herbivory, and then sprayed with 800 mg L–1 omethoate. The results showed that the changes in the activities of PAL, LOX and PPO that occured under the interactive stress of H. armigera herbivory and omethoate application relfected the interactive effects of the two stresses on cotton defense. The similarity between the response dynamics of PAL, LOX, and PPO activities in cotton leaves under the interactive stress and that under H. armigera herbivory treatment alone showed that the induction of H. armigera herbivory on the activities of PAL, LOX and PPO in cotton leaves played a leading role in the interactive effects, and the effect of omethoate application played only a minor role. A joint factor analysis was performed according to a method which has been used to analyze the joint toxicity of pesticides;this analysis sought to clarify if there was a synergistic, antagonistic, or additive effect on PAL, LOX, and PPO activity in cotton leaves resulting from the interactive H. armigera herbivory and omethoate treatment. In the interactive effect on the response of PAL activity in cotton leaves, antagonistic effects of the omethoate application towards H. armigera herbivory were observed at 6 and 12 h. Synergistic effects were then observed at 18 and 30 h. Antagonistic effects were observed from 54 to 78 h and syn-ergistic effects were ifnal y observed at 126 h. The correlation between H. armigera herbivory and omethoate application in the interactive effect on cotton defense responses of LOX activity also lfuctuated from synergism to antagonism during the time course. In the interactive

  20. Stimulo-deterrent Diversionary Strategy with Conjunctive Use of Trap Crops, Neem and Bacillus thuringiensis Berliner for the Management of Insecticide Resistant Helicoverpa armigera (Hubner in Cotton

    Directory of Open Access Journals (Sweden)

    P. Duraimurugan

    2005-01-01

    Full Text Available Studies were carried out to assess the effects of stimulo-deterrent diversionary strategy with trap crops, neem and Bacillus thuringiensis Berliner in cotton for the management of insecticide resistant Helicoverpa armigera (Hubner at Agricultural Research Station, Vaigaidam and Agricultural Research Station, Bhavanisagar, Tamil Nadu Agricultural University, Tamil Nadu during 2003-2004. Field experiments were conducted on cotton (MCU7 with trap crops (okra and pigeonpea and neem was used to diversify the pests to trap crops where by the control of these pest was assessed with the application of Bt (Delfin�. The preference of H. armigera was towards okra and pigeonpea as a trap crop compared to cotton. Application of NSKE on cotton diversified the H. armigera towards untreated okra and pigeonpea. Stimulo-deterrent diversionary strategy with conjunctive use of trap crops (okra and pigeonpea, restricted application of NSKE on cotton leaving trap crops and restricted application of Bt on trap crops was highly effective in reducing the incidence of H. armigera and damage to fruiting bodies, boll, locule and inter locule basis over cotton sole crop (untreated check. The percent recovery of Bt infected larvae varied from 43.3-48.8, 40.0-48.3 and 32.7-38.6% on okra, pigeonpea and cotton, respectively. The synthetic pyrethroids resistance in field survived H. armigera at the end of the season was reduced from 88.0-92.7 to 81.1-89.7%.

  1. Histopathological Effects of the Protein Toxin from Xenorhabdus nematophila on the Midgut of Helicoverpa armigera

    Institute of Scientific and Technical Information of China (English)

    NANGONG Zi-yan; WANG Qin-ying; SONG Ping; YANG Jun; MAO Wen-jie

    2006-01-01

    Xenorhabdus nematophila HB310, which is highly virulent for many insects, is symbiotic with Steinernema carpocapsae HB310. Toxin Ⅱ was obtained using methods such as salting out and native-PAGE from the cells of X. Nematophila HB310. The histopathology of toxin Ⅱ on H. Armigera larvae was studied by dissecting an olefin slice of the midgut. The symptoms showed that the histopathology of the H. Armigera midgut was similar to that of other novel midgut-active toxins such as the δ-endotoxins from Bacillus thuringiensis, as well as Tca from Photorhabdus luminescens W14. The midgut tissues of H. Armigera fourth-instar larvae began to transform after the oral intake of the toxin Ⅱ over 6 h. First, the anterior region of the peritrophic membrane (PM) began to degrade followed by the elongation of the columnar cells.The epithelium decomposed gradually, and the midgut tissues were either loose or disordered. The PM disappeared after 12 h but reappeared after 72 h following transient or sublethal exposure to the toxin Ⅱ. Toxin Ⅱ also directly destroyed in vitro PMs of H. Armigera.

  2. Push-pull Strategy with Trap Crops, Neem and Nuclear Polyhedrosis Virus for Insecticide Resistance Management in Helicoverpa armigera (Hubner in Cotton

    Directory of Open Access Journals (Sweden)

    P. Duraimurugan

    2005-01-01

    Full Text Available Insecticide resistance in Helicoverpa armigera (Hubner is a major threat to cotton production in India. The virus infection was found to increase the susceptibility of H. armigera to the insecticides. But, use of Nuclear Polyhedrosis Virus (NPV on a larger scale and on cotton due to leaf alkalinity poses certain practical problems. Hence, studies were carried out to assess the effects of push-pull strategy with trap crops, neem and NPV in cotton for the management of insecticide resistant H. armigera. Field experiments were conducted on cotton (MCU5 with trap crops (okra and pigeonpea and neem was used to diversify the pests to trap crops whereby the control of these pests was assessed with the application of NPV. The preference of H. armigera was towards okra and pigeonpea as a trap crop compared to cotton. Application of NSKE on cotton diversified the H. armigera towards untreated okra and pigeonpea. Push-pull strategy with the conjunctive use of trap crops, restricted application of NSKE on cotton leaving trap crops and restricted application of NPV on trap crops was highly effective in reducing the incidence of H. armigera and damage to fruiting bodies, boll, locule and inter locule basis over cotton sole crop (untreated check. The percent recovery of NPV infected larvae varied from 37.5-47.5, 32.8-39.2 and 14.2-20.2% on okra, pigeon pea and cotton respectively. The synthetic pyrethroids resistance in field survived H. armigera at the end of the season was reduced from 87.5-93.1% to 76.4-84.3%.

  3. Isotopes and trace elements as natal origin markers of Helicoverpa armigera--an experimental model for biosecurity pests.

    Directory of Open Access Journals (Sweden)

    Peter W Holder

    Full Text Available Protecting a nation's primary production sector and natural estate is heavily dependent on the ability to determine the risk presented by incursions of exotic insect species. Identifying the geographic origin of such biosecurity breaches can be crucial in determining this risk and directing the appropriate operational responses and eradication campaigns, as well as ascertaining incursion pathways. Reading natural abundance biogeochemical markers using mass spectrometry is a powerful tool for tracing ecological pathways as well as provenance determination of commercial products and items of forensic interest. However, application of these methods to trace insects has been underutilised to date and our understanding in this field is still in a phase of basic development. In addition, biogeochemical markers have never been considered in the atypical situation of a biosecurity incursion, where sample sizes are often small, and of unknown geographic origin and plant host. These constraints effectively confound the interpretation of the one or two isotope geo-location markers systems that are currently used, which are therefore unlikely to achieve the level of provenance resolution required in biosecurity interceptions. Here, a novel approach is taken to evaluate the potential for provenance resolution of insect samples through multiple biogeochemical markers. The international pest, Helicoverpa armigera, has been used as a model species to assess the validity of using naturally occurring δ2H, 87Sr/86Sr, 207Pb/206Pb and 208Pb/206Pb isotope ratios and trace element concentration signatures from single moth specimens for regional assignment to natal origin. None of the biogeochemical markers selected were individually able to separate moths from the different experimental regions (150-3000 km apart. Conversely, using multivariate analysis, the region of origin was correctly identified for approximately 75% of individual H. armigera samples. The

  4. Next-generation sequencing-based transcriptome analysis of Helicoverpa armigera Larvae immune-primed with Photorhabdus luminescens TT01.

    Directory of Open Access Journals (Sweden)

    Zengyang Zhao

    Full Text Available Although invertebrates are incapable of adaptive immunity, immunal reactions which are functionally similar to the adaptive immunity of vertebrates have been described in many studies of invertebrates including insects. The phenomenon was termed immune priming. In order to understand the molecular mechanism of immune priming, we employed Illumina/Solexa platform to investigate the transcriptional changes of the hemocytes and fat body of Helicoverpa armigera larvae immune-primed with the pathogenic bacteria Photorhabdus luminescens TT01. A total of 43.6 and 65.1 million clean reads with 4.4 and 6.5 gigabase sequence data were obtained from the TT01 (the immune-primed and PBS (non-primed cDNA libraries and assembled into 35,707 all-unigenes (non-redundant transcripts, which has a length varied from 201 to 16,947 bp and a N50 length of 1,997 bp. For 35,707 all-unigenes, 20,438 were functionally annotated and 2,494 were differentially expressed after immune priming. The differentially expressed genes (DEGs are mainly related to immunity, detoxification, development and metabolism of the host insect. Analysis on the annotated immune related DEGs supported a hypothesis that we proposed previously: the immune priming phenomenon observed in H. armigera larvae was achieved by regulation of key innate immune elements. The transcriptome profiling data sets (especially the sequences of 1,022 unannotated DEGs and the clues (such as those on immune-related signal and regulatory pathways obtained from this study will facilitate immune-related novel gene discovery and provide valuable information for further exploring the molecular mechanism of immune priming of invertebrates. All these will increase our understanding of invertebrate immunity which may provide new approaches to control insect pests or prevent epidemic of infectious diseases in economic invertebrates in the future.

  5. Identification of mariner-like elements belonging to the cecropia subfamily in two closely related Helicoverpa species

    Institute of Scientific and Technical Information of China (English)

    Jianjun Wang; Thomas A. Miller; Yoonseong Park

    2011-01-01

    Mariner transposons are widespread in eukaryote genomes and have been used as transposon vectors in insect transgenesis.We examined two closely related Helicoverpa species,the cotton bollworm Helicoverpa armigera and corn earworm Helicoverpa zea,for the presence of mariner-like elements (MLEs).Multiple copies of two distinct MLEs,Hamarl and Hamar2,were isolated in H.armigera,and a MLE showing a high degree of conservation to Hamarl was detected in H.zea and was named Hzmarl.These MLEs belong to the cecropia subfamily,containing indels in the transposase coding region.Sequence analysis indicated the earlier invasion of Hamarl and relatively recent activity of Hamar2.

  6. EAG and behavioral responses of Helicoverpa armigera males to volatiles from poplar leaves and their combinations with sex pheromone

    Institute of Scientific and Technical Information of China (English)

    邓建宇; 黄永平; 魏洪义; 杜家纬

    2004-01-01

    Electroantennogram (EAG) evaluation of selected compounds from wilted leaves ofblack poplar,Populus nigra,showed that phenyl acetaldehyde, methyl salicylate, (E)-2-hexenal elicited strong responses from male antennae of Helicoverpa armigera. When mixed with sex pheromone (Ph), some volatiles, e.g. phenyl acetaldehyde, benzyl alcohol,phenylethanol, methylsalicylate, linalool, benzaldehyde, (Z)-3-hexenol, (Z)-3-hexenylacetate, (Z)-6-nonenol, cineole, (E)-2-hexenal, and geraniol elicited stronger responses from male antennae than Ph alone. Wind tunnel bioassay demonstrated that various volatiles could either enhance or inhibit the effect of synthetic sex pheromone. (E)-2-hexenal, (Z)-3-hexenol and linalool in combination with Ph could not induce any male to land on source at all, whereas phenyl acetaldehyde, benzaldehyde, (Z)-6-nonenol and salicylaldehyde combined with Ph enhanced male response rates by 58.63%,50.33%, 51.85% and 127.78%, respectively, compared to Ph alone. These results suggested that some volatiles should modify sex pheromone caused behavior and that some of them could possibly be used as a tool for disrupting mating or for enhancing the effect of synthetic sex pheromone in the field.

  7. Genetic differentiation of Helicoverpa armigera (Hübner) and H.Assulta (Guenée) (Lepidoptera: Noctuidae) based on AFLP markers

    Institute of Scientific and Technical Information of China (English)

    QING-LEI MING; CHEN-ZHU WANG

    2006-01-01

    Here we use amplified fragment length polymorphism (AFLP) to assess genetic differentiation of Helicoverpa armigera and H. assulta. The results indicated that both species-specific fingerprints and cluster analysis showed the ability of AFLP technique to discriminate the two sibling species; among a total 1963 AFLP markers amplified from nine primer combinations: 777 (39.6%) were H. armigera-specific,602 (30.7%) were H. assultaspecific,and 584 (29.7%) were common bands. The mean number of H. armigera-specific bands was significantly more than that of H. assulta-specific bands for nine primer combinations (P<0.05); the intraspecific distance of H. armigera and H. assulta was 0.123 0 and 0.110 7 respectively,and the interspecific distance was 0.178 3. In addition,the percentage of polymorphic loci and estimated average heterozygosity were used to estimate genetic diversity of the two species. This study therefore demonstrates that AFLP analysis is a sensitive and reliable technique to study genetic differentiation and genetic relationships between species and provides sufficient molecular markers for future linkage map construction,location and eventual cloning of genes involved in traits differentiation.

  8. Negative Effects of a Nonhost Proteinase Inhibitor of ~19.8 kDa from Madhuca indica Seeds on Developmental Physiology of Helicoverpa armigera (Hübner)

    OpenAIRE

    Farrukh Jamal; Dushyant Singh; Pandey, Prabhash K.

    2014-01-01

    An affinity purified trypsin inhibitor from the seed flour extracts of Madhuca indica (MiTI) on denaturing polyacrylamide gel electrophoresis showed that MiTI consisted of a single polypeptide chain with molecular mass of ~19.8 kDa. MiTI inhibited the total proteolytic and trypsin-like activities of the midgut proteinases of Helicoverpa armigera larvae by 87.51% and 76.12%, respectively, at concentration of 5 µg/mL with an IC50 of 1.75 µg/mL against trypsin like midgut proteinases. The enzyme...

  9. Mrpho-physical Factors Affecting Consumption and Coefficient of Utilization of Helicoverpa armigera (Hubner

    Directory of Open Access Journals (Sweden)

    Muhammad Ashfaq

    2003-01-01

    Full Text Available The selected plants in order of preference on the basis of consumption were Sorghum > Maize > Bermuda grass > Tomato > Cotton (NIAB-98 > Alfalfa > Rice >Castor oil > Okra > Cattail > Cotton (CIM-446 > Horse purslane > Rape seed > Winter cherry> Calotrope. The order of the preference on the basis of Coefficient of Utilization (CU was Sorghum > Bermuda grass > Maize > Cotton (NIAB-98 > Tomato > Winter cherry > Castor oil > Alfalfa > Okra > Rice > Cotton (CIM-446 > Horse purslane > Calotrope > Rape seed > Cattail. None of the plants was found completely resistant to H. armigera. The correlation between food consumption and CU was significantly positive. Moisture content showed positive while thickness of leaf lamina played negative role both for consumption and CU. Moisture percentage alone contributed 50.8% and 40.5% role towards resistance in term of consumption and CU, respectively. The cumulative effect of all the morpho-physical plant factors was 80.1% for consumption and 57.8% for CU.

  10. Feeding behaviour of helicoverpa armigera HBN (LEP. noctuidae) on tomatoes in greenhouse

    International Nuclear Information System (INIS)

    The feeding behaviour of larvae of Helicoverpa arminegera was studied on tomato plants grown in a greenhouse using 32P-labelled caterpillars. When first larvae emerged from eggs deposited onto usual egg-laying sites, they fed on leaves, occasionally onto Inflorescence, and some burrowed into fruit when they reached the third instars. During the fourth and fifth instar, they fed alternately on leaves and fruit, and occasionally on stems. Toward the end of their development, the caterpillars went through a searching phase to look for a shelter for metamorphosis. This typical sequence could be altered and become more complex in relation with the emerging site of the caterpillars. Green fruits of tomato are usually damaged by larvae of at least 7-8 day old which made several entry holes. These entries were not usually followed by feeding, but they nevertheless damaged an average of 2 ± 0.75 fruits. (author). 13 refs., 4 figs

  11. PROTECTION OF SWEET CORN FROM OSTRINIA NUBILALIS HBN. AND HELICOVERPA ARMIGERA HBN.

    Science.gov (United States)

    Vuković, S; Indić, D; Grahovac, M; Franeta, F

    2015-01-01

    O. nubilalis and H. armigera regularly occur and cause significant damages in corn crops in Serbia, particularly under global warming conditions. Several measures are applied against these pests (crop rotation, tolerant and resistant hybrids, monitoring, forecast, chemical measures). Larvae damage stem, panicle and ear, which favour development of saprophytes and secondary infections by mycotoxin producing, pathogenic fungi. The aim of the paper was to test the efficacy of the insecticides azadirachtin and indoxacarb in sweet corn protection against the mentioned pests. The trials were conducted in 2014 at two localities (Becej B. and PoIjanice P.) on sweet corn, hybrid Enterprise according to standard OEPP methods (PP1/13; 1/152; 1/135). Products on the basis of azadirachtin (10 g a.i./I of product) at a rate of 0.4 and 0.5% and indoxacarb (150 g a.i./I of product) at a rate of 0.25 I/ha, were applied. Treatments were conducted on the 5th of August with tractor sprayers (high clearance). The plot size was 5000 m². Three assessments were made. The first one prior to treatment, on 25 randomly selected plants per replicate, and the number of O. nubilalis and H. armigera egg masses and larvae on silk was registered. In the second assessment (18th of August), on 20 randomly selected plants per replicate, the number of damaged plants and the number of vital larvae was registered. In the third assessment, immediately before harvest (28th of August, i.e. 12th of September) on 20 randomly selected plants per replicate, the number of plants broken below ear (fallen on the ground), damaged ears and vital larvae, was determined. Results are presented as means, efficacy (E%) according to Abbott and significance of differences by LSD test (5%). At B locality egg masses of O. nubilalis were registered on ear silk on 13-19% of plants and larvae on 3-7%, and larvae of H. armigera on 2-4%. At P locality egg masses of O. nubilalis were present on 34-40.8% of plants. After 13 days

  12. Toxicity and binding analyses of Bacillus thuringiensis toxin Vip3A in Cry1Ac-resistant and-susceptible strains of Helicoverpa armigera (Hübner)

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qian; CHEN Li-zhen; LU Qiong; ZHANG Yan; LIANG Ge-mei

    2015-01-01

    The Bacil us thuringiensis vegetative insecticidal protein, Vip3A, represents a new family of Bt toxin and is currently ap-plied to commercial transgenic cotton. To determine whether the Cry1Ac-resistant Helicoverpa armigera is cross-resistant to Vip3Aa protein, insecticidal activities, proteolytic activations and binding properties of Vip3Aa toxin were investigated using Cry1Ac-susceptible (96S) and Cry1Ac-resistant H. armigera strain (Cry1Ac-R). The toxicity of Vip3Aa in Cry1Ac-R slightly reduced compared with 96S, the resistance ratio was only 1.7-fold. The digestion rate of ful-length Vip3Aa by gut juice extracts from 96S was little faster than that from Cry1Ac-R. Surface plasmon resonance (SPR) showed there was no signiifcant difference between the binding afifnity of Vip3Aa and BBMVs between 96S and Cry1Ac-R strains, and there was no signiifcant competitive binding between Vip3Aa and Cry1Ac in susceptible or resistant strains. So there had little cross-resistance between Vip3Aa and Cry1Ac,Vip3A+Cry proteins maybe the suitable pyramid strategy to control H. armigera in China in the future.

  13. A bifunctional α-amylase/trypsin inhibitor from pigeonpea seeds: Purification, biochemical characterization and its bio-efficacy against Helicoverpa armigera.

    Science.gov (United States)

    Gadge, Prafull P; Wagh, Sandip K; Shaikh, Faiyaz K; Tak, Rajesh D; Padul, Manohar V; Kachole, Manvendra S

    2015-11-01

    This paper evaluates α-amylase inhibitor (α-AI) mediated defense of pigeonpea against Helicoverpa armigera. A bifunctional α-amylase/trypsin inhibitor was purified from the seeds of pigeonpea by native liquid phase isoelectric focusing (N-LP-IEF), affinity chromatography and preparative electrophoresis. Its in-vivo and in-vitro interaction with midgut amylases of H. armigera was studied along with growth inhibitory activity. One and two dimensional (2D) zymographic analyses revealed that the purified inhibitor is dimeric glycoprotein (60.2kDa and 56kDa) exist in a multi-isomeric form with five pI variants (pI 5.5 to 6.3). It was found to be heat labile with complete inactivation up to 80°C and stable over a wide range of pH (4-11). The slow binding and competitive type of α-amylase inhibition was observed with 0.08μM of dissociation constant (Ki) for the enzyme-inhibitor complex (EI). The internal protein sequence of two subunits obtained by mass spectrometry matched with cereal-type α-AI, a conserved domain from AAI_LTSS superfamily and sialyltransferase-like protein respectively. In-vivo studies indicated up-regulation of total midgut α-amylase activity with negative effect on growth rate of H. armigera suggesting its suitability for pest control. PMID:26615146

  14. Different pairs of male and female of Campoletis chlorideae (Hymenoptera: Ichneumonidae) parasitised the chick pea pod borer, Helicoverpa armigera (Lepidoptera: Noctuidae), in Myanmar

    International Nuclear Information System (INIS)

    In Myanmar, chickpea is of great importance not only for the export but also for local consumption. In 1999-2000, the total area of chickpea was 323,000 acres, with an annual production of 83,000 tons of which 352 metric tons were exported. Campoletis chlorideae Uchida (Hymenoptera: Ichneumonidae) is a solitary larval parasitoid that parasitises the larvae of Helicoverpa armigera Huebner (Lepidoptera: Noctuidae) in Myanmar. H. armigera is the major insect pest causing damage to the chickpea crop and significantly reducing yields. The attack of pods seeds varies from 3 to 50%. Conservation of the parasitoid C. chlorideae is important to minimise damage by H. armigera during the reproductive stage of chickpea. Laboratory (potted plants) and field experiments were conducted at the Biological Control Laboratory, Paleik, Singaing Township during the 2002-2003 winter season. Results - Laboratory experiments: The number of C. chlorideae (2 pairs, 3 pairs, 4 pairs and 5 pairs / 30 larvae of H. armigera of 1st stage, 2nd stage, and 3rd stage) significantly and differently affected the survival of different stages of H. armigera larvae (p=0.0001 each R2 = 0.963, C. V 10.98) Replication effects of the experiment were not significant (p=0.1718). Different pairs of C. chlorideae significantly affected the mean survival of larvae H. armigera when the results of four different pairs of parasitoid C. chlorideae were compared (Tukey's studentized range test). The largest difference between the means was observed between 5 pairs and 2 pairs of parasitoids released and the smallest was between 4 and 3 pairs of parasitoids. The results from Tukey's studentised range test showed that 2 pairs of parasitoid C. chlorideae significantly affected the 30 larvae of H. armigera. Different pairs of the parasitoid C. chlorideae also significantly affected the mean parasitism when the results of three different stages of larvae of H. armigera were compared (Tukey's studentised test was used). The

  15. Characterization and functional analysis ofβ-1,3-galactosyltransferase involved in Cry1Ac resistance from Helicoverpa armigera (Hübner)

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li-li; LIANG Ge-mei; GAO Xi-wu; CAO Guang-chun; GUO Yu-yuan

    2015-01-01

    Carbohydrate chains are the principal antigens by which Bacil us thuringiensis (Bt) identify receptor proteins. The interaction between the antigen and Bt causes a pore in the membrane of midgut epithelial cel s of insects. Receptor proteins, such as aminopeptidase N and alkaline phosphatase, are glycoproteins. Cadherin is another cel surface receptor protein which has potential glycosylation sites. Glycosyltransferase is very important for the synthesis and modiifcation of receptor proteins. It can indirectly inlfuence the function of Bt. The 1 950 bp ful-length cDNA encodingβ-1,3-galactosyltransferase was cloned from the the midgut of Helicoverpa armigera by degenerative PCR combined with RACE techniques (GAL-Harm, GenBank accession no.:GQ904195.1) with two potential N-glycosylation sites (157NNTI160 and 272NKTL275). Protein sequence alignments revealed that H. armigeraβ-1,3-galactosyltransferase shared high identity withβ-1,3-galactosyltransferase in other insect species. The expression level of theβ-1,3-galactosyltransferase gene in Cry1Ac-resistant H. armigera larvae was 9.2-fold higher than that in susceptible strain. The function ofβ-1,3-galactosyltransferase was investigated using RNAi technique. The result showed Cry1Ac enhanced the toxicity against the siRNA-treated larvae compared with non-siRNA-treated ones, which indicatedβ-1,3-galactosyltransferase played an important role for the insecticidal toxicity of Cry1Ac in H. armigera.

  16. Reduced plant nutrition under elevated CO2 depresses the immunocompetence of cotton bollworm against its endoparasite

    Science.gov (United States)

    Yin, Jin; Sun, Yucheng; Ge, Feng

    2014-04-01

    Estimating the immunocompetence of herbivore insects under elevated CO2 is an important step in understanding the effects of elevated CO2 on crop-herbivore-natural enemy interactions. Current study determined the effect of elevated CO2 on the immune response of Helicoverpa armigera against its parasitoid Microplitis mediator. H. armigera were reared in growth chambers with ambient or elevated CO2, and fed wheat grown in the concentration of CO2 corresponding to their treatment levels. Our results showed that elevated CO2 decreases the nutritional quality of wheat, and reduces the total hemocyte counts and impairs the capacity of hemocyte spreading of hemolymph of cotton bollworm larvae, fed wheat grown in the elevated CO2, against its parasitoid; however, this effect was insufficient to change the development and parasitism traits of M. mediator. Our results suggested that lower plant nutritional quality under elevated CO2 could decrease the immune response of herbivorous insects against their parasitoid natural enemies.

  17. Negative effects of a nonhost proteinase inhibitor of ~19.8 kDa from Madhuca indica seeds on developmental physiology of Helicoverpa armigera (Hübner).

    Science.gov (United States)

    Jamal, Farrukh; Singh, Dushyant; Pandey, Prabhash K

    2014-01-01

    An affinity purified trypsin inhibitor from the seed flour extracts of Madhuca indica (MiTI) on denaturing polyacrylamide gel electrophoresis showed that MiTI consisted of a single polypeptide chain with molecular mass of ~19.8 kDa. MiTI inhibited the total proteolytic and trypsin-like activities of the midgut proteinases of Helicoverpa armigera larvae by 87.51% and 76.12%, respectively, at concentration of 5 µg/mL with an IC50 of 1.75 µg/mL against trypsin like midgut proteinases. The enzyme kinetic studies demonstrated that MiTI is a competitive inhibitor with a K i value of 4.1 × 10(-10) M for Helicoverpa trypsin like midgut proteinases. In vivo experiments with different concentrations of MiTI in artificial diet (0.5, 1.0, and 1.5% w/w) showed an effective downfall in the larval body weight and an increase in larval mortality. The concentration of MiTI in the artificial diet to cause 50% mortality (LD50) of larvae was 1.5% w/w and that to cause reduction in mass of larvae by 50% (ED50) was 1.0% w/w. Nutritional indices observations suggest the toxic and adverse effects of MiTI on the growth and development of H. armigera larvae. The results suggest a strong bioinsecticidal potential of affinity purified MiTI which can be exploited in insect pest management of crop plants. PMID:25298962

  18. Negative Effects of a Nonhost Proteinase Inhibitor of ~19.8 kDa from Madhuca indica Seeds on Developmental Physiology of Helicoverpa armigera (Hübner

    Directory of Open Access Journals (Sweden)

    Farrukh Jamal

    2014-01-01

    Full Text Available An affinity purified trypsin inhibitor from the seed flour extracts of Madhuca indica (MiTI on denaturing polyacrylamide gel electrophoresis showed that MiTI consisted of a single polypeptide chain with molecular mass of ~19.8 kDa. MiTI inhibited the total proteolytic and trypsin-like activities of the midgut proteinases of Helicoverpa armigera larvae by 87.51% and 76.12%, respectively, at concentration of 5 µg/mL with an IC50 of 1.75 µg/mL against trypsin like midgut proteinases. The enzyme kinetic studies demonstrated that MiTI is a competitive inhibitor with a Ki value of 4.1×10−10 M for Helicoverpa trypsin like midgut proteinases. In vivo experiments with different concentrations of MiTI in artificial diet (0.5, 1.0, and 1.5% w/w showed an effective downfall in the larval body weight and an increase in larval mortality. The concentration of MiTI in the artificial diet to cause 50% mortality (LD50 of larvae was 1.5% w/w and that to cause reduction in mass of larvae by 50% (ED50 was 1.0% w/w. Nutritional indices observations suggest the toxic and adverse effects of MiTI on the growth and development of H. armigera larvae. The results suggest a strong bioinsecticidal potential of affinity purified MiTI which can be exploited in insect pest management of crop plants.

  19. New insight to structure-function relationship of GalNAc mediated primary interaction between insecticidal Cry1Ac toxin and HaALP receptor of Helicoverpa armigera.

    Directory of Open Access Journals (Sweden)

    Anindita Sengupta

    Full Text Available Over the last few decades Cry1Ac toxin has been widely used in controlling the insect attack due to its high specificity towards target insects. The pore-forming toxin undergoes a complex mechanism in the insect midgut involving sequential interaction with specific glycosylated receptors in which terminal GalNAc molecule plays a vital role. Recent studies on Cry toxins interactions with specific receptors revealed the importance of several amino acid residues in domain III of Cry1Ac, namely Q509, N510, R511, Y513 and W545, serve as potential binding sites that surround the putative GalNAc binding pocket and mediate the toxin-receptor interaction. In the present study, alanine substitution mutations were generated in the Cry1Ac domain III region and functional significance of those key residues was monitored by insect bioassay on Helicoverpa armigera larvae. In addition, ligand blot analysis and SPR binding assay was performed to monitor the binding characteristics of Cry1Ac wild type and mutant toxins towards HaALP receptor isolated from Helicoverpa armigera. Mutagenesis data revealed that, alanine substitutions in R511, Y513 and W545 substantially impacted the relative affinity towards HaALP receptor and toxicity toward target insect. Furthermore, in silico study of GalNAc-mediated interaction also confirmed the important roles of these residues. This structural analysis will provide a detail insight for evaluating and engineering new generation Cry toxins to address the problem of change in insect behavioral patterns.

  20. Radiation Induced Sterility On Control Bollworm Helicoverpa armigera Hubner (Lepidoptera: Noctuide) And Inherited Sterility In The F 1 Generation

    International Nuclear Information System (INIS)

    The objectives of this experiments were to obtain the optimum dose of irradiation that caused high sterility level that descended to the next generation ( FI ) and determined the value of mating competitiveness. Nine days old of male pupae were irradiated by gamma rays at doses of 0, 50, 60, 70, 80 , 90, 100, 110, and 120 Gy respectively. The emergence of male moths after irradiation mated with untreated females in two kinds of mating pair combination, first 5 ? IR ( irradiated ) x 5 ? UT ( untreated ), second 15? IR X 5? UT x 5? UT. The irradiated male moths emerging from the first offspring ( F I ) was also mated with the untreated females as the same kind of mating pair combination as the parent. The parameters observed were the number of egg production, egg hatched and the value of mating competitiveness. The experimental design was completed randomized design, a factorial experiment. the first factor was irradiation doses and the second factor was mating pair combination. The data obtained was statistically analyzed using Duncan's Multiple Range test. The result showed a very significant effect of irradiation dosage treatment to the number of eggs whether in parent as well as in F I generation moths. However there was no significant different the effect a vector of mating pair combination to the egg production. The lowest average number of eggs produced by couple 1? IR x I? irradiated by 120 Gy were 201.71 eggs while the untreated couple were 612.31 eggs. The result also indicated that the doses of irradiation did not affect significant different in the percentage of egg hatchet in the parent as well as in the FI moths. The lowest percentage of egg hatched was 0.00 % (or 100 % sterility) produced by 110 and 120 Gy treatment from pair moths of I ? IR x I ? UT. But this was not significant deferent to tile dose of 100 Gy caused 4.27 % egg hatched. The mating competitiveness value due to the treatment of 100 Gy were 0,56 and 0,40 respectively in the parent male and in the FI male moths

  1. Effects of different brush border membrane vesicle isolation protocols on proteomic analysis of Cry1 Ac binding proteins from the midgut of Helicoverpa armigera

    Institute of Scientific and Technical Information of China (English)

    Li-Zhen Chen; Ge-Mei Liang; Brian G.Rector; Jie Zhang; Kong-Ming Wu; Yu-Yuan Guo

    2008-01-01

    Brush border membrane vesicles(BBMV)isolated from insect midguts have been widely used to study CrylA binding proteins.Sample preparation is important in two-dimensional electrophoresis(2-DE),so to determine a suitable BBMV preparation method in Helicoverpa armigera for 2-DE,we compared three published BBMV preparation methods mostly used in sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE).All mctllods yielded similar types and numbers of binding proteins,but in different quantifies.The Abdul.Rauf and Ellar protocol was the best of the three,but had limitations.Sufficient protein qu antity iS important for research involving limited numbers of insects,such as studies of insect resistance to Bacillus thuringiensis in the field.Consequently,we integrated the three BBMV isolation methods into a single protocol that yielded high quantities of BBMV proteins from H.armigera larval midguts.which proved suitable for 2-DE analysis.

  2. Purification of Aminopeptidase N Protein and Differences in cDNAs Encoding APN1 Between Susceptible and Resistant Helicoverpa armigera Strains to Bacillus thuringiensis Toxins

    Institute of Scientific and Technical Information of China (English)

    LIANG Ge-mei; WANG Gui-rong; XU Guang; WU Kong-ming; GUO Yu-yuan

    2004-01-01

    The brush border membrane vesicles (BBMVs) in midgut of Helicoverpa armigera were successfully separated, and most of the Aminopeptidase N (APN) activities in BBMV were preserved. The 3-[(3-chlor-amidopropyl) dimethylammonio]-l-propane-sulphonate (CHAPS)can enhance the dissolution of BBMV, and phosphatidylinositol-specific phosopholipase C (PI-PLC) can cleave the APN from midgut membrane. The APN was primarily purified using a Mono-Q column. The results of immunoblotting showed that the 120 and 170 kDa proteins in the BBMV could bind CrylAc, and 120kDa APN was a glycosylphosphalidylinositol(GPI)anchored protein. Two Bt-resistant strains (Bt-P, Bt-M) were obtained after being selected for more than five years in laboratory using Bt insecticides and Bt transgenic cotton incorporated into diet separately. The resistance of Bt-P and Bt-M were 1 083.3and 48.7 times that of susceptible strain. The genes encoding APN1 in midgut of susceptible and resistant H.armigera were cloned by PCR and RACE techniques. The inferred amino acid sequences of APN1 possessed the common character of APN family in insects. In comparison with APN1 in susceptible strain, three nucleotide mutations were observed in the APN1 of Bt-M strain and resulted in two amino acid replace in the putative protein sequences, and eight nucleotide mutations were observed in Bt-P strain and resulted in five amino acid replace.

  3. Effects of UV-A exposures on longevity and reproduction in Helicoverpa armigera, and on the development of its F1 generation

    Institute of Scientific and Technical Information of China (English)

    Chang-Yu Zhang; Jian-Yu Meng; Xiao-Ping Wang; Fen Zhu; Chao-Liang Lei

    2011-01-01

    Helicoverpa armigera adults display a conspicuous positive phototacdc behavior to light stimuli,and are especially sensitive to ultraviolet (UV) light.The effects of UV-A (longwave) exposures on adult longevity and reproduction in H.armigera were investigated,as well as the development of the F1 generation.Paired adults were exposed to UV-A for various time periods (0,1,5 and 9 h/day),until the end of adult life.The results showed that adult longevity decreased with increasing exposure time for both sexes,and a significant decrease was observed after exposure for 5 and 9 h/day.Fecundity increased when adults were exposed for 1 and 5 h/day,and a significant difference was observed in the 5 h/day group.Oviposition rates of females in all treatments were significantly higher than in the control.Exposure to UV-A for longer periods (5 and 9 h/day) caused a decline in cumulative survival of F1 immature stages,but no significant differences were found in egg hatch,pupation and eclosion.The developmental periods of F1 larvae were significantly prolonged after exposure to UV-A for 5 and 9 h/day.UV-A radiation had no significant effects on F1 pupal period.

  4. Transgenic plants over-expressing insect-specific microRNA acquire insecticidal activity against Helicoverpa armigera: an alternative to Bt-toxin technology.

    Science.gov (United States)

    Agrawal, Aditi; Rajamani, Vijayalakshmi; Reddy, Vanga Siva; Mukherjee, Sunil Kumar; Bhatnagar, Raj K

    2015-10-01

    The success of Bt transgenics in controlling predation of crops has been tempered by sporadic emergence of resistance in targeted insect larvae. Such emerging threats have prompted the search for novel insecticidal molecules that are specific and could be expressed through plants. We have resorted to small RNA-based technology for an investigative search and focused our attention to an insect-specific miRNA that interferes with the insect molting process resulting in the death of the larvae. In this study, we report the designing of a vector that produces artificial microRNA (amiR), namely amiR-24, which targets the chitinase gene of Helicoverpa armigera. This vector was used as transgene in tobacco. Northern blot and real-time analysis revealed the high level expression of amiR-24 in transgenic tobacco plants. Larvae feeding on the transgenic plants ceased to molt further and eventually died. Our results demonstrate that transgenic tobacco plants can express amiR-24 insectice specific to H. armigera. PMID:25947089

  5. Toxicidade e capacidade de ligação de proteínas Cry1 a receptores intestinais de Helicoverpa armigera (Lepidoptera: Noctuidae

    Directory of Open Access Journals (Sweden)

    Isis Sebastião

    2015-11-01

    Full Text Available Resumo: O objetivo deste trabalho foi avaliar a toxicidade e a capacidade de ligação das proteínas Cry1Aa, Cry1Ab, Cry1Ac e Cry1Ca, de Bacillus thuringiensis, a receptores intestinais de Helicoverpa armigera. Realizou-se análise de ligação das proteínas ativadas às vesículas de membrana da microvilosidade apical (VMMA do intestino médio deH. armigera, além de ensaios de competição heteróloga para avaliar sua capacidade de ligação. Cry1Ac destacou-se como a proteína mais tóxica, seguida por Cry1Ab e Cry1Aa. A proteína Cry1Ca não foi tóxica às lagartas e, portanto, não foi possível determinar os seus parâmetros de toxicidade CL50 e CL90. As proteínas Cry1Aa, Cry1Ab e Cry1Ac são capazes de se ligar a um mesmo receptor nas membranas intestinais, o que aumenta o risco do desenvolvimento de resistência cruzada. Portanto, a utilização conjunta dessas proteínas deve ser evitada.

  6. The impact of ingested potato type II inhibitors on the production of the major serine proteases in the gut of Helicoverpa armigera.

    Science.gov (United States)

    Stevens, J A; Dunse, K M; Guarino, R F; Barbeta, B L; Evans, S C; West, J A; Anderson, M A

    2013-02-01

    The flowers of the ornamental tobacco produce high levels of a series of 6 kDa serine protease inhibitors (NaPIs) that are effective inhibitors of trypsins and chymotrypsins from lepidopteran species. These inhibitors have a negative impact on the growth and development of lepidopteran larvae and have a potential role in plant protection. Here we investigate the effect of NaPIs on the activity and levels of serine proteases in the gut of Helicoverpa armigera larvae and explore the adaptive mechanisms larvae employ to overcome the negative effects of NaPIs in the diet. Polyclonal antibodies were raised against a Helicoverpa punctigera trypsin that is a target for NaPIs and two H. punctigera chymotrypsins; one that is resistant and one that is susceptible to inhibition by NaPIs. The antibodies were used to optimize procedures for extraction of proteases for immunoblot analysis and to assess the effect of NaPIs on the relative levels of the proteases in the gut and frass. We discovered that consumption of NaPIs did not lead to over-production of trypsins or chymotrypsins but did result in excessive loss of proteases to the frass. PMID:23247047

  7. Assessment of beneficial role of an insectivorous bird, jungle babbler (Turdoides striatus predation, on Helicoverpa armigera infesting pigeon pea (Cajanus cajan crop

    Directory of Open Access Journals (Sweden)

    Bhavna Bharucha

    2010-04-01

    Full Text Available Jungle babbler (Turdoides striatus, a widely spread sub-tropical insectivorous passerine is considered beneficial to agro-ecosystem, as they devour voraciously on insect matter especially Helicoverpa armigera, the gram pod borer, a notorious pest infesting and causing heavy loses to crops like pigeon pea (Cajanus cajan which is a vital crop of semi-arid tropical and subtropical farming system, providing high quality vegetable protein. Helicoverpa is known to feed on flowers, pods, and seeds and is the most important biotic constraint affecting pigeon pea yields. Jungle babblers have a peculiar foraging style which helps expose the Helicoverpa larvae as well as pupae through various phenological stages of pigeon pea. For comparative assessment of their beneficial role and as a possible bio control agent, in Baroda city (State of Gaujarat, India, was studied, two crops of pigeon pea (insecticide treated and untreated (control were selected. In both treated and control crops, the number of jungle babblers were maximum in pigeon pea fields during october and november in both small pod stage and large pod stage which had heavy infestation of Helicoverpa. Least number of birds was seen during the flowering stage in September. Later in treatment crop three applications of Dunnate and Monocrotophos insecticide spray was done after which the pest population decreased which is reflected in number of birds in the field, while the bird number in control crops grew since insecticide spray was not done and number of larvae increased with the stage of the crop. Along with the main crop pigeon pea, comparative study was also done to see the food preference by these birds in crops like sorghum, maize, cow pea and ploughed and unploughed fields. Maximum number of birds was seen in unploughed field and least in sorghum suggesting that Helicoverpa is preferred food over sorghum grains thus pigeon pea and sorghum can be used as mixed crops to protect the crop from

  8. Assessment of beneficial role of an insectivorous bird, jungle babbler (Turdoides striatus predation, on Helicoverpa armigera infesting pigeon pea (Cajanus cajan crop

    Directory of Open Access Journals (Sweden)

    Bharucha Bhavna

    2010-06-01

    Full Text Available Jungle babbler (Turdoides striatus, a widely spread sub-tropical insectivorous passerine is considered beneficial to agro-ecosystem, as they devour voraciously on insect matter especially Helicoverpa armigera, the gram pod borer, a notorious pest infesting and causing heavy loses to crops like pigeon pea (Cajanus cajan which is a vital crop of semi-arid tropical and subtropical farming system, providing high quality vegetable protein. Helicoverpa is known to feed on flowers, pods, and seeds and is the most important biotic constraint affecting pigeon pea yields. Jungle babblers have a peculiar foraging style which helps expose the Helicoverpa larvae as well as pupae through various phenological stages of pigeon pea. For comparative assessment of their beneficial role and as a possible bio control agent, in Baroda city (State of Gaujarat, India, was studied, two crops of pigeon pea (insecticide treated and untreated (control were selected. In both treated and control crops, the number of jungle babblers were maximum in pigeon pea fields during october and november in both small pod stage and large pod stage which had heavy infestation of Helicoverpa. Least number of birds was seen during the flowering stage in September. Later in treatment crop three applications of Dunnate and Monocrotophos insecticide spray was done after which the pest population decreased which is reflected in number of birds in the field, while the bird number in control crops grew since insecticide spray was not done and number of larvae increased with the stage of the crop. Along with the main crop pigeon pea, comparative study was also done to see the food preference by these birds in crops like sorghum, maize, cow pea and ploughed and unploughed fields. Maximum number of birds was seen in unploughed field and least in sorghum suggesting that Helicoverpa is preferred food over sorghum grains thus pigeon pea

  9. Insecticidal Efficacy of Azadirachta indica, Nucleopolyhedrovirus and Chlorantraniliprole Singly or Combined against Field Populations fo Helicoverpa armigera Hübner (Lepidoptera: Noctuidae Eficacia Insecticida de Azadirachta indica, Nucleopolihedrovirus y Clorantraniliprol solo y sus Aplicaciones Integradas contra Poblaciones de Campo de Helicoverpa armigera Hübner (Lepidoptera: Noctuidae

    Directory of Open Access Journals (Sweden)

    Waqas Wakil

    2012-03-01

    Full Text Available The development of resistance in cosmopolitan insect Helicoverpa armigera Hubner (Lepidoptera: Noctuidae forced the researchers for alternative control measures. In the present study, insecticidal efficacy of formulations of Azadirachta indica, a Nucleopolyhedrovirus (NPV, and new anthranilic diamide insecticide (chlorantraniliprole formulations was determined against 2nd, through 5th larval instars of H. armigera collected from diverse geographical locations in the Punjab province, Pakistan. Azadirachta indica was applied at 5 μL L-1; NPV at 2.1 x 10(5 polyhedral occlusion bodies (POB mL4 and chlorantraniliprole at 0.01 μL L-1, either alone or in combinations with each other. The bioassays were conducted at 27 ± 1 °C and 65 ± 5% relative humidity. The mortality varied greatly among treatments, larval instars, and locations. The combinations of NPV with A. indica and chlorantraniliprole caused higher mortality, pupation and produced an additive effect compared to their application singly in all the tested populations. The population from Rawalpindi was always susceptible while the Gujranwala was the resistant. The results herein suggest that the effectiveness of NPV and A. indica can be improved by the presence of chlorantraniliprole against the larvae of H. armigera.Se determinó la eficacia insecticida de formulaciones de Azadirachta indica, Nucleopolihedrovirus (VPN y el nuevo insecticida diamida antranílico (clorantraniliprol en contra de segundo, tercero, cuarto y quinto estadios larvales de Helicoverpa armigera Hubner (Lepidoptera: Noctuidae recogidos de diversas ubicaciones geográficas de la provincia de Punjab, Pakistán. Azadirachta indica se aplicó en dosis de 5 μL L-1; VPN en dosis 2.1 x 10(5 POB mL-1 y clorantraniliprol fue 0,01 μL L-1 ya sea solos o en combinaciones. Los bioensayos se realizaron a 27 ± 1 °C y 65 ± 5% de humedad relativa. La mortalidad fue notablemente variada entre los tratamientos, estadios larvales y

  10. [The effects of transgenic Cry1Ac+Cry2Ab cotton on cotton bollworm control and functional response of predators on whitefly].

    Science.gov (United States)

    Junyu, Luo; Shuai, Zhang; Limin, L V; Chunyi, Wang; Xiangzhen, Zhu; Jinjie, Cuil

    2015-06-01

    In this study, we detected and clarified the roles of transgenic Cry1Ac+Cry2Ab cotton "639020" in controlling cotton bollworm (Helicoverpa armigera) during critical periods of bud stage (second generation of bollworm), flowering stage (third generation of bollworm) and bolling stage (fourth generation of bollworm) as well as the influences of 639020 cotton on functional response of the main predators (Chrysopa sinica larvae, Propylaea japonica, Orius and Erigonidium graminicola ) on whitefly using transgenic Cry1Ac cotton "CCRI41" and conventional cotton "CCRI49" as the control. Our results showed that the 639020 cotton well controlled the second and third generation of bollworm, and the level of insect resistance increased by 52.85% and 16.22% separately compared with that of CCRI41, with a significant effect on the second generation of bollworm. Moreover, the number of bollworm eggs in 639020 cotton field was lower than that in CCRI41 and CCRI49 cotton fields (except the second generation of bollworm) during the cotton bud, flowering and bolling stages. Although the number of bollworm larvae in 639020 cotton field was significantly lower than that in CCRI49 field, and both under the controlling index, it has no significant difference compared with that in CCRI41 cotton field. There were also no obvious changes in predator functions of Chrysopa sinica, Propylaea japonica, Orius and Erigonidium graminicola on bemisia tabaci between 639020, CCRI41 and CCRI49 cotton filed. This study evaluated the safety of new transgenic cotton on environment, anti-insect activity of exogenous gene and the safety of production and application prospect. PMID:26351054

  11. The Binding Characterization of Cry Insecticidal Proteins to the Brush Border Membrane Vesicles of Helicoverpa armigera, Spodoptera exigua, Spodoptera litura and Agrotis ipsilon

    Institute of Scientific and Technical Information of China (English)

    LU Qiong; CAO Guang-chun; ZHANG Li-li; LIANG Ge-mei; GAO Xi-wu; ZHANG Yong-jun; GUO Yu-yuan

    2013-01-01

    Cry toxins produced by Bacillus thuringiensis (Bt) are effective biological insecticides against certain insect species. However, there are potential risks of the evolved resistance of insects to Cry toxin owing to decreased binding of toxins to target sites in the brush border membranes of the larva midgut. The Cry toxins with different binding sites in the larval midgut have been considered to be a good combination to deploy in delaying resistance evolution. Bioassay results demonstrated that the toxicity of different Cry toxins ranked differently for each species. The toxicity ranking was Cry1Ac>Cry1Ab>Cry2Ab for Helicoverpa armigera, Cry1B>Cry1C>Cry2Ab for Spodoptera exigua, and Cry2Ab>Cry1B>Cry1C for S. litura. Only Cry2Ab was toxic to Agrotis ipsilon. Binding experiments were performed with 125I-Cry1Ab, 125I-Cry1Ac, 125I-Cry1B, 125I-Cry1C, 125I-Cry2Ab and the brush border membranes vesicles (BBMV) from H. armigera, S. exigua, S. litura and A. ipsilon. The binding of Cry1Ab and Cry1Ac was shown to be saturable by incubating with increasing concentrations of H. armigera BBMV (Kd=(45.00±2.01) nmol L-1 and (12.80±0.18) nmol L-1, respectively;Bmax=(54.95±1.79) ng and (55.44±0.91) ng, separately). The binding of Cry1B was shown to be saturable by incubating with increasing concentrations of S. exigua BBMV (Kd=(23.26±1.66) nmol L-1;Bmax=(65.37±1.87) ng). The binding of 125I-Cry toxins was shown to be non-saturable by incubating with increasing concentrations of S. litura and A. ipsilon BBMV. In contrast, Cry1B and Cry1C showed some combination with the BBMV of S. litura, and a certain amount of Cry2Ab could bind to the BBMV of A. ipsilon. These observations suggest that a future strategy could be devised for the focused combination of specific cry genes in transgenic crops to control target pests, widen the spectrum of insecticide effectiveness and postpone insect resistance evolution.

  12. Assessment of beneficial role of an insectivorous bird, jungle babbler (Turdoides striatus predation, on Helicoverpa armigera infesting pigeon pea (Cajanus cajan crop Evaluación del rol benéfico de Turdoides striatus como predator de Helicoverpa armigera en el cultivo de guandul (Cajanus cajan

    Directory of Open Access Journals (Sweden)

    Bhavna Bharucha

    2010-04-01

    Full Text Available Jungle babbler (Turdoides striatus, a widely spread sub-tropical insectivorous passerine is considered beneficial to agro-ecosystem, as they devour voraciously on insect matter especially Helicoverpa armigera, the gram pod borer, a notorious pest infesting and causing heavy loses to crops like pigeon pea (Cajanus cajan which is a vital crop of semi-arid tropical and subtropical farming system, providing high quality vegetable protein. Helicoverpa is known to feed on flowers, pods, and seeds and is the most important biotic constraint affecting pigeon pea yields. Jungle babblers have a peculiar foraging style which helps expose the Helicoverpa larvae as well as pupae through various phenological stages of pigeon pea. For comparative assessment of their beneficial role and as a possible bio control agent, in Baroda city (State of Gaujarat, India, was studied, two crops of pigeon pea (insecticide treated and untreated (control were selected. In both treated and control crops, the number of jungle babblers were maximum in pigeon pea fields during october and november in both small pod stage and large pod stage which had heavy infestation of Helicoverpa. Least number of birds was seen during the flowering stage in September. Later in treatment crop three applications of Dunnate and Monocrotophos insecticide spray was done after which the pest population decreased which is reflected in number of birds in the field, while the bird number in control crops grew since insecticide spray was not done and number of larvae increased with the stage of the crop. Along with the main crop pigeon pea, comparative study was also done to see the food preference by these birds in crops like sorghum, maize, cow pea and ploughed and unploughed fields. Maximum number of birds was seen in unploughed field and least in sorghum suggesting that Helicoverpa is preferred food over sorghum grains thus pigeon pea and sorghum can be used as mixed crops to protect the crop from

  13. Influence of Dual-Bt Protein Corn on Bollworm, Helicoverpa zea (Boddie), Survivorship on Bollgard II Cotton

    Science.gov (United States)

    Gore, J.; Catchot, A.; Cook, D.; Musser, F.; Caprio, M.

    2016-01-01

    Similar Cry proteins are expressed in both Bt corn, Zea mays L., and cotton, Gossypium hirsutum (L.), commercial production systems. At least one generation of corn earworm, Helicoverpa zea (Boddie), completes development on field corn in the Mid-South before dispersing across the landscape into other crop hosts like cotton. A concern is that Bt corn hybrids may result in selection for H. zea populations with a higher probability of causing damage to Bt cotton. The objective of this study was to determine the susceptibility of H. zea offspring from moths that developed on non-Bt and VT Triple Pro (VT3 PRO) field corn to lyophilized Bollgard II cotton tissue expressing Cry1Ac and Cry2Ab. Offspring of individuals reared on VT3 PRO expressing Cry1A.105 and Cry2Ab had a significantly higher LC50 two out of the three years this study was conducted. Excess larvae were placed on artificial diet and allowed to pupate to determine if there were any inheritable fitness costs associated with parental development on VT3 PRO corn. Offspring resulting from males collected from VT3 PRO had significantly lower pupal weight and longer pupal duration compared with offspring of individuals collected from non-Bt corn. However, offspring from females collected from VT3 PRO were not different from non-Bt offspring. Paternal influence on offspring in insects is not commonly observed, but illustrates the side effects of development on a transgenic plant expressing less than a high dose, 25 times the concentration needed to kill susceptible larvae. PMID:26809264

  14. Réponse des stades larvaires de Helicoverpa armigera (Hübner (Lepidoptera : Noctuidae à l'application de champignons entomopathogènes Metarhizium anisopliae et Beauveria bassiana

    Directory of Open Access Journals (Sweden)

    Tamò, M.

    2012-01-01

    Full Text Available Response of the nymphs of Helicoverpa armigera (Hübner (Lepidoptera: Noctuidae to entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana. Two experiments on dose/mortality response between the instars of Helicoverpa armigera and two strains of entomopathogenic fungi, Metarhizium anisopliae (Met 31 and Beauveria bassiana (Bb 11 were carried out in laboratory conditions. In the first experiment, M. anisopliae Met 31 was tested on the third instar of H. armigera, while in the second experiment, both Met 31 and Bb 11 were tested on the fourth instar. In all the experiments, the following different doses of conidia per insect were used: 104, 105, 106, 107. The following parameters were measured: mortality and sporulation rates, the number of pupae formed and the number of adults that emerged. Abbott's formula was used to correct the treatment mortality rates. LD50 was determined using Cox-regression. For the third instar in experiment one, no significant difference was observed between high doses (106 and 107 conidia per insect. For instar L4, only the dose of 107 conidia per insect showed high mortality rates (74%. For the strain Bb 11, in spite of the variation observed between the mortality rates induced by high doses (106 and 107 conidia per insect, no significant difference was recorded at the 5% level. No mycosis was observed from cadavers resulting from lower doses when tested on L4. The control recorded the highest numbers of pupae and adults. These two parameters were related to the level of dosage: the higher the dose, the lower the numbers of pupae and adults that emerged. For all the strains of fungi used, whatever the larval stage of H. armigera, the dose/mortality response was significant.

  15. Regional management strategy of cotton bollworm in China

    International Nuclear Information System (INIS)

    Cotton bollworm Helicoverpa armigera, is one of the most important insect pests in cotton, corn and vegetable production of China. Its regional population dynamics and management strategy derived from Bt-transgenic cotton were investigated in recent years. The researches indicated that the populations of H. armigera in the whole country can be divided into four regional groups, namely, the tropical, subtropical, temperate and Xinjiang geotypes. Their adaptive zones are respectively in southern China, middle and lower Changjiang River Region, including Sichun Province, Hunan Province, Hubei Province and Zhejiang Province etc., Yellow River Region, including Henan Province, Hebei Province, and Shandong Province etc., and the Xinjiang Uygur Autonomous Region and Gansu Province. Based on the analysis of H. armigera population dynamics and climate environment, it is suggested that the Beijing area is probably the northern boundary for the temperate zone geotype of the cotton bollworm. Damage to cotton by larvae of the temperate zone geotype can extend into areas of northeastern China such as Liaoning and Jilin provinces by long distance, facultative migration during the summer East Asia monsoon. Transgenic cotton that expresses a gene from the bacterium Bacillus thuringiensis (Bt) has been deployed for combating the pest since 1997. Its use expanded rapidly to 1.1 million ha in 2000 and 2.8 million ha in 2003, equivalent to 58% of the total cotton area of 4.8 million ha in 2003. The pest management tactics associated with Bt-cotton have resulted in a drastic reduction in insecticide use, which usually caused a significantly increase in populations of beneficial insects and thus contributed to improved natural control of some pests. The risk assessment shows that the natural refuges derived from the mixed planting system of cotton, corn, soybean and peanut on small-scale single-family holdings, play an important function in delaying the development of cotton bollworm

  16. Genome-wide transcriptomic and proteomic analyses of bollworm-infested developing cotton bolls revealed the genes and pathways involved in the insect pest defence mechanism.

    Science.gov (United States)

    Kumar, Saravanan; Kanakachari, Mogilicherla; Gurusamy, Dhandapani; Kumar, Krishan; Narayanasamy, Prabhakaran; Kethireddy Venkata, Padmalatha; Solanke, Amolkumar; Gamanagatti, Savita; Hiremath, Vamadevaiah; Katageri, Ishwarappa S; Leelavathi, Sadhu; Kumar, Polumetla Ananda; Reddy, Vanga Siva

    2016-06-01

    Cotton bollworm, Helicoverpa armigera, is a major insect pest that feeds on cotton bolls causing extensive damage leading to crop and productivity loss. In spite of such a major impact, cotton plant response to bollworm infection is yet to be witnessed. In this context, we have studied the genome-wide response of cotton bolls infested with bollworm using transcriptomic and proteomic approaches. Further, we have validated this data using semi-quantitative real-time PCR. Comparative analyses have revealed that 39% of the transcriptome and 35% of the proteome were differentially regulated during bollworm infestation. Around 36% of significantly regulated transcripts and 45% of differentially expressed proteins were found to be involved in signalling followed by redox regulation. Further analysis showed that defence-related stress hormones and their lipid precursors, transcription factors, signalling molecules, etc. were stimulated, whereas the growth-related counterparts were suppressed during bollworm infestation. Around 26% of the significantly up-regulated proteins were defence molecules, while >50% of the significantly down-regulated were related to photosynthesis and growth. Interestingly, the biosynthesis genes for synergistically regulated jasmonate, ethylene and suppressors of the antagonistic factor salicylate were found to be up-regulated, suggesting a choice among stress-responsive phytohormone regulation. Manual curation of the enzymes and TFs highlighted the components of retrograde signalling pathways. Our data suggest that a selective regulatory mechanism directs the reallocation of metabolic resources favouring defence over growth under bollworm infestation and these insights could be exploited to develop bollworm-resistant cotton varieties. PMID:26799171

  17. The movement and distribution of Helicoverpa armigera (Hübner) larvae on pea plants is affected by egg placement and flowering.

    Science.gov (United States)

    Perkins, L E; Cribb, B W; Hanan, J; Zalucki, M P

    2010-10-01

    The distribution and movement of 1st instar Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) larvae on whole garden pea (Pisum sativum L.) plants were determined in glasshouse trials. This economically-important herbivore attacks a wide variety of agricultural, horticultural and indigenous plants. To investigate the mechanisms underlying larval intra-plant movement, we used early-flowering and wild-type plant genotypes and placed eggs at different vertical heights within the plants, one egg per plant. Leaf water and nitrogen content and cuticle hardness were measured at the different plant heights. Of 92 individual larvae, 41% did not move from the node of eclosion, 49% moved upwards and 10% moved downwards with the distance moved being between zero and ten plant nodes. Larvae from eggs placed on the lower third of the plant left the natal leaf more often and moved further than larvae from eggs placed in the middle or upper thirds. The low nutritive value of leaves was the most likely explanation for more movement away from lower plant regions. Although larvae on flowering plants did not move further up or down than larvae on non-flowering plants, they more often departed the leaflet (within a leaf) where they eclosed. The final distribution of larvae was affected by plant genotype, with larvae on flowering plants found less often on leaflets and more often on stipules, tendrils and reproductive structures. Understanding intra-plant movement by herbivorous insects under natural conditions is important because such movement determines the value of economic loss to host crops. Knowing the behaviour underlying the spatial distribution of herbivores on plants will assist us to interpret field data and should lead to better informed pest management decisions. PMID:20504381

  18. High Susceptibility to Cry1Ac and Low Resistance Allele Frequency Reduce the Risk of Resistance of Helicoverpa armigers to Bt Soybean in Brazil.

    Science.gov (United States)

    Dourado, Patrick M; Bacalhau, Fabiana B; Amado, Douglas; Carvalho, Renato A; Martinelli, Samuel; Head, Graham P; Omoto, Celso

    2016-01-01

    The Old World bollworm, Helicoverpa armigera (Hübner), was recently introduced into Brazil, where it has caused extensive damage to cotton and soybean crops. MON 87701 × MON 89788 soybean, which expresses the Bt protein Cry1Ac, was recently deployed in Brazil, providing high levels of control against H. armigera. To assess the risk of resistance to the Cry1Ac protein expressed by MON 87701 × MON 89788 soybean in Brazil, we conducted studies to evaluate the baseline susceptibility of H. armigera to Cry1Ac, in planta efficacy including the assessment of the high-dose criterion, and the initial resistance allele frequency based on an F2 screen. The mean Cry1Ac lethal concentration (LC50) ranged from 0.11 to 1.82 μg·mL-1 of diet among all H. armigera field populations collected from crop seasons 2013/14 to 2014/15, which indicated about 16.5-fold variation. MON 87701 × MON 89788 soybean exhibited a high level of efficacy against H. armigera and most likely met the high dose criterion against this target species in leaf tissue dilution bioassays up to 50 times. A total of 212 F2 family lines of H. armigera were established from field collections sampled from seven locations across Brazil and were screened for the presence of MON 87701 × MON 89788 soybean resistance alleles. None of the 212 families survived on MON 87701 × MON 89788 soybean leaf tissue (estimated allele frequency = 0.0011). The responses of H. armigera to Cry1Ac protein, high susceptibility to MON 87701 × MON 89788 soybean, and low frequency of resistance alleles across the main soybean-producing regions support the assumptions of a high-dose/refuge strategy. However, maintenance of reasonable compliance with the refuge recommendation will be essential to delay the evolution of resistance in H. armigera to MON 87701 × MON 89788 soybean in Brazil. PMID:27532632

  19. Can other host species of cotton bollworm be non-Bt refuges to prolong the effectiveness of Bt-cotton?

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The potential ecological risks of Bacillus thurigiensis (Bt) insecticides and Bt-crops have caused increasing concern since their commercial release in the field,among which pests' resistance to Bt-crops is the major ecological risk. Refuge tactic, which can produce sensitive populations, has proved to be a key and sound resistance management strategy in USA and Australia; however, no tactics have been performed in China where Bt-cotton is mostly planted with other host crops of cotton bollworm.Genetic variation and gene flow among different host populations of the cotton bollworm Helicoverpa armigera were analyzed using PCR fingerprinting method. The results show that maize and castor-oil plant, as well as cotton can take effect as refuges to prevent resistance of cotton bollworm to Bt-cotton, while peanut and sesame are not as suitable for planting with Bt-cotton as refuges in the field as low gene flow was detected among populations on peanut, sesame and Bt cotton.

  20. Increased frequency of pink bollworm resistance to Bt toxin Cry1Ac in China.

    Directory of Open Access Journals (Sweden)

    Peng Wan

    Full Text Available Transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt kill some key insect pests, but evolution of resistance by pests can reduce their efficacy. The main approach for delaying pest adaptation to Bt crops uses non-Bt host plants as "refuges" to increase survival of susceptible pests. To delay evolution of pest resistance to transgenic cotton producing Bt toxin Cry1Ac, the United States and some other countries have required refuges of non-Bt cotton, while farmers in China have relied on "natural" refuges of non-Bt host plants other than cotton. The "natural" refuge strategy focuses on cotton bollworm (Helicoverpa armigera, the primary target of Bt cotton in China that attacks many crops, but it does not apply to another major pest, pink bollworm (Pectinophora gossypiella, which feeds almost entirely on cotton in China. Here we report data showing field-evolved resistance to Cry1Ac by pink bollworm in the Yangtze River Valley of China. Laboratory bioassay data from 51 field-derived strains show that the susceptibility to Cry1Ac was significantly lower during 2008 to 2010 than 2005 to 2007. The percentage of field populations yielding one or more survivors at a diagnostic concentration of Cry1Ac increased from 0% in 2005-2007 to 56% in 2008-2010. However, the median survival at the diagnostic concentration was only 1.6% from 2008 to 2010 and failure of Bt cotton to control pink bollworm has not been reported in China. The early detection of resistance reported here may promote proactive countermeasures, such as a switch to transgenic cotton producing toxins distinct from Cry1A toxins, increased planting of non-Bt cotton, and integration of other management tactics together with Bt cotton.

  1. Identificação morfológica e molecular de Helicoverpa armigera (Lepidoptera: Noctuidae e ampliação de seu registro de ocorrência no Brasil

    Directory of Open Access Journals (Sweden)

    Alexandre Specht

    2013-06-01

    Full Text Available O objetivo deste trabalho foi descrever métodos para a caracterização morfológica e molecular de Helicoverpa armigera e ampliar o registro de ocorrência da praga no Brasil. As mariposas foram obtidas de lagartas coletadas nas culturas de algodão, milho e soja, com uso de armadilhas luminosas. As coletas foram realizadas na Bahia, no Distrito Federal, no Mato Grosso e no Paraná. A identificação foi baseada na genitália masculina e nas análises das sequências dos genes mitocondriais do citocromo B e da região cox1-tRNALeu-cox2. A genitália masculina foi comparada com as descrições morfológicas na literatura, e as sequências de genes, com as depositadas no GenBank. Ambas as análises confirmaram a presença de H. armigera nos locais de coleta. Ampliou-se o registro de ocorrência da praga para a região Sul do país.

  2. Effects of nuclear polyhedrosis virus on cannibalism in Helicoverpa armigera%核型多角体病毒感染对棉铃虫幼虫同类相残行为的影响

    Institute of Scientific and Technical Information of China (English)

    李静雯; 褚艳娜; 王琼; 刘小侠; 张青文

    2012-01-01

    The effects of nuclear polyhedrosis virus infection on cannibalism in Helicoverpa armigera ( H(u)bner) was evaluated under laborratory conditions. The number of infected larvae preyed on by healthy larvae increased with the progress of the disease. There was no significant difference in the percentage of dead infected larvae, frozen infected larvae and frozen healthy larvae that were preyed on by healthy larvae. This suggests that infected larvae and dead infected larvae are more likely to be cannibalized simply because they become less vigorous and less capable of defending themselves than healthy larvae. There was no significant difference in the frequency of cannibalism of frozen infected larvae by healthy larvae and infected larvae. This suggests that the tendency towards cannibalism is not altered by infection. Cannibalism is potentially costly. The pupation and eclosion rate of healthy larvae that ate infected larvae was lower than that of those that had not cannibalized infected larvae.%在室内研究核型多角体病毒(HaSNPV)感染对棉铃虫Helicoverpa armigera(Hübner)幼虫同类相残行为的影响.结果显示:感病棉铃虫随感病程度的加重,越容易被健康棉铃虫残食,而自然死亡的感病棉铃虫、冻死的感病棉铃虫和冻死的健康棉铃虫三者被健康棉铃虫残食的百分率无显著差异.表明感病棉铃虫和病虫尸体更易于被健康棉铃虫残食,是由于棉铃虫体力减弱而失去反击能力,不是由于病毒本身的影响.以健康棉铃虫、感病棉铃虫为残食者,冻死的病虫为被残食者,相残率无显著差异,表明病毒并未改变棉铃虫残食同类的天性.残食病虫的健康棉铃虫的化蛹率和羽化率均低于正常的健康棉铃虫,残食者为相残行为付出了很高的代价.

  3. Characterization of the resistance to Vip3Aa in Helicoverpa armigera from Australia and the role of midgut processing and receptor binding

    OpenAIRE

    Maissa Chakroun; Núria Banyuls; Tom Walsh; Sharon Downes; Bill James; Juan Ferré

    2016-01-01

    Crops expressing genes from Bacillus thuringiensis (Bt crops) are among the most successful technologies developed for the control of pests but the evolution of resistance to them remains a challenge. Insect resistant cotton and maize expressing the Bt Vip3Aa protein were recently commercialized, though not yet in Australia. We found that, although relatively high, the frequency of alleles for resistance to Vip3Aa in field populations of H. armigera in Australia did not increase over the past...

  4. Characterization of the resistance to Vip3Aa in Helicoverpa armigera from Australia and the role of midgut processing and receptor binding.

    Science.gov (United States)

    Chakroun, Maissa; Banyuls, Núria; Walsh, Tom; Downes, Sharon; James, Bill; Ferré, Juan

    2016-01-01

    Crops expressing genes from Bacillus thuringiensis (Bt crops) are among the most successful technologies developed for the control of pests but the evolution of resistance to them remains a challenge. Insect resistant cotton and maize expressing the Bt Vip3Aa protein were recently commercialized, though not yet in Australia. We found that, although relatively high, the frequency of alleles for resistance to Vip3Aa in field populations of H. armigera in Australia did not increase over the past four seasons until 2014/15. Three new isofemale lines were determined to be allelic with previously isolated lines, suggesting that they belong to one common gene and this mechanism is relatively frequent. Vip3Aa-resistance does not confer cross-resistance to Cry1Ac or Cry2Ab. Vip3Aa was labeled with (125)I and used to show specific binding to H. armigera brush-border membrane vesicles (BBMV). Binding was of high affinity (Kd = 25 and 19 nM for susceptible and resistant insects, respectively) and the concentration of binding sites was high (Rt = 140 pmol/mg for both). Despite the narrow-spectrum resistance, binding of (125)I-labeled Vip3Aa to BBMV of resistant and susceptible insects was not significantly different. Proteolytic conversion of Vip3Aa protoxin into the activated toxin rendered the same products, though it was significantly slower in resistant insects. PMID:27095284

  5. Ha83, a Chitin Binding Domain Encoding Gene, Is Important to Helicoverpa armigera Nucleopolyhedrovirus Budded Virus Production and Occlusion Body Assembling.

    Science.gov (United States)

    Yu, Huan; Xu, Jian; Liu, Qiang; Liu, Tong-Xian; Wang, Dun

    2015-01-01

    Helicoerpa armigera nucleopolyhedrovirus (HearNPV) ha83 is a late expressed gene that encodes a chitin binding protein. Chitin domain truncation studies revealed that the cysteine at the 128 amino acid position probably played an important role in both chitin binding ability and protein transmission of Ha83. In order to study the function of ha83 in the HearNPV infection cycle, an ha83 knockout HearNPV (Ha83KO) was constructed via homologous recombination. Viral growth and viral DNA replication curves showed that fewer budded virions were produced in Ha83KO transfected cells, while viral DNA replication was increased. Electron microscopy revealed that fewer nucleocapsids were transmitted from virogenic stroma in the Ha83KO transfected cell nucleus, and the morphology of occlusion bodies was prominently larger and cube-shaped. Furthermore, DNA quantity in occlusion bodies of Ha83KO was significantly lower than the occlusion bodies of HaWT. The transcription analysis indicated that these changes may be due to the decreased expression level of viral structural associated genes, such as polyhedrin, p10, pif-2, or cg30 in Ha83KO infected cells. Above results demonstrated that the cysteine at the 128 amino acid position in Ha83 might be the key amino acid, and Ha83 plays an important role in BVs production and OBs assembling. PMID:26057202

  6. 棉铃虫幼虫中栓锥感器对肌醇和糖类的电生理反应%Responses of medial sensillum of Helicoverpa armigera (Hiibner) (Lepidoptera:Noctuidae) larvae to inositol and sugars

    Institute of Scientific and Technical Information of China (English)

    张雪凝; 汤清波; 蒋金炜; 马英; 胡锡敏; 闫凤鸣

    2011-01-01

    The gustatory electrophysiological responses of medial sensillum of the polyphagous caterpillar, Helicoverpa armigera, to 7 kinds of sugars, inositol and their mixtures were measured by top recording technology. The responding cells in medial sensillum corresponding different stimulus and the interactions of different compounds in mixtures during the process of electrophysiological responses were analyzed. The results showed that: (1) the electrophysiological responses of medial sensillum to D-inositol, D-fructose, xylose, D-arabinose, D-glucose, maltose, D-trehalose and L-rhamnose were obvious, but the responding patterns between sugars and innositol were different trom a concentration-dependent responses in inositol and non-concentration-dependent responseses in sugars; (2) the differences of responding patterns between the pure sugar compounds and the mixture of fructose, arabinose and trehalose were not significant, indicating the same cell responding the 3 kinds of sugars; (3) Responses of the mixtures of fructose and inositol indicated that inositol-sensitive cell responded to fructose. The firing rate of mixture of fructose and inositol were higher than that of the two pure compounds, suggesting the synergistic interaction of responses of the two stimulus. All the results suggested that the inisitol-sensitive cell in medial sensillum of the polyphagous species of H. armigera may be one of “broad-spectrum” taste cells.%利用电生理学技术,以多食性的棉铃虫为研究对象,测定幼虫下颚中栓锥感器对7种糖和肌醇及其混合物的味觉电生理反应,分析不同物质诱导中栓锥感器内对应的味觉感受细胞及不同物质之间诱导昆虫电生理反应的交互作用.结果表明:(1)棉铃虫幼虫下颚中栓锥感器对肌醇、果糖、木糖、阿拉伯糖,葡萄糖、麦芽糖、海藻糖和鼠李糖的单一物质都有明显的电生理反应,但是对肌醇和糖类的反应模式不同,肌醇诱导的反

  7. Effect of emamectin benzoate on mortality, proboscis extension, gustation and reproduction of the corn earworm, Helicoverpa zea

    Science.gov (United States)

    Newly emerged bollworm adults, Helicoverpa zea (Boddie) require carbohydrate source from plant exudates and nectars for reproduction. Adults actively seek such feeding sites upon eclosion in their natural habitat. We wanted to evaluate this nocturnal behavior of the bollworm for potential use as a p...

  8. Non-recessive Bt toxin resistance conferred by an intracellular cadherin mutation in field-selected populations of cotton bollworm.

    Directory of Open Access Journals (Sweden)

    Haonan Zhang

    Full Text Available Transgenic crops producing Bacillus thuringiensis (Bt toxins have been planted widely to control insect pests, yet evolution of resistance by the pests can reduce the benefits of this approach. Recessive mutations in the extracellular domain of toxin-binding cadherin proteins that confer resistance to Bt toxin Cry1Ac by disrupting toxin binding have been reported previously in three major lepidopteran pests, including the cotton bollworm, Helicoverpa armigera. Here we report a novel allele from cotton bollworm with a deletion in the intracellular domain of cadherin that is genetically linked with non-recessive resistance to Cry1Ac. We discovered this allele in each of three field-selected populations we screened from northern China where Bt cotton producing Cry1Ac has been grown intensively. We expressed four types of cadherin alleles in heterologous cell cultures: susceptible, resistant with the intracellular domain mutation, and two complementary chimeric alleles with and without the mutation. Cells transfected with each of the four cadherin alleles bound Cry1Ac and were killed by Cry1Ac. However, relative to cells transfected with either the susceptible allele or the chimeric allele lacking the intracellular domain mutation, cells transfected with the resistant allele or the chimeric allele containing the intracellular domain mutation were less susceptible to Cry1Ac. These results suggest that the intracellular domain of cadherin is involved in post-binding events that affect toxicity of Cry1Ac. This evidence is consistent with the vital role of the intracellular region of cadherin proposed by the cell signaling model of the mode of action of Bt toxins. Considered together with previously reported data, the results suggest that both pore formation and cell signaling pathways contribute to the efficacy of Bt toxins.

  9. Comparison of Numbers of Cotton Bollworm Moths Caught in Water Traps Baited with Pheromone vs Blacklight Traps%性信息素水盆诱捕器和黑光灯诱捕棉铃虫成虫数量的比较

    Institute of Scientific and Technical Information of China (English)

    盛承发; 宣维健; 苏建伟; 王红托; 王德忠

    2001-01-01

    A comparison of moth catches of the cotton bollworm,Helicoverpa armigera (Hübner),in water tray traps(20~30×7~10cm) baited with synthetic sex pheromone vs blacklight traps (20w) was made at 3 locations in Shandong and Anhui Provinces,China in 1993 and 1996.The results show that male catches per trap per night in water traps were 4.18 and 2.49 times as many as that in blacklight traps at location 1 and 2,respectively.Both the differences were statistically significant (P<0.05).However,at location 3 the mean catches in water traps were only 56% of that in blacklight traps but the difference was not significant (P<0.40).It is seemed that the catching efficiency of water traps decreased with season and might be lower than that of blacklight traps in August and September.Therefore it is generally suitable to use the pheromone traps for monitoring of the bollworm population dynamics,especially during the overwintered and 1st generations (commonly during late April to early July in most China′s cotton areas).

  10. Early warning of cotton bollworm resistance associated with intensive planting of Bt cotton in China.

    Directory of Open Access Journals (Sweden)

    Haonan Zhang

    Full Text Available Transgenic crops producing Bacillus thuringiensis (Bt toxins kill some key insect pests, but evolution of resistance by pests can reduce their efficacy. The predominant strategy for delaying pest resistance to Bt crops requires refuges of non-Bt host plants to promote survival of susceptible pests. To delay pest resistance to transgenic cotton producing Bt toxin Cry1Ac, farmers in the United States and Australia planted refuges of non-Bt cotton, while farmers in China have relied on "natural" refuges of non-Bt host plants other than cotton. Here we report data from a 2010 survey showing field-evolved resistance to Cry1Ac of the major target pest, cotton bollworm (Helicoverpa armigera, in northern China. Laboratory bioassay results show that susceptibility to Cry1Ac was significantly lower in 13 field populations from northern China, where Bt cotton has been planted intensively, than in two populations from sites in northwestern China where exposure to Bt cotton has been limited. Susceptibility to Bt toxin Cry2Ab did not differ between northern and northwestern China, demonstrating that resistance to Cry1Ac did not cause cross-resistance to Cry2Ab, and implying that resistance to Cry1Ac in northern China is a specific adaptation caused by exposure to this toxin in Bt cotton. Despite the resistance detected in laboratory bioassays, control failures of Bt cotton have not been reported in China. This early warning may spur proactive countermeasures, including a switch to transgenic cotton producing two or more toxins distinct from Cry1A toxins.

  11. The effects of Helicoverpa armigera herbivory on the activity of phenylanlanine ammonialyase, lipoxygenase and polyphenol oxidase in cotton seedling leaves%棉铃虫持续取食对棉花三种防御酶活性的作用

    Institute of Scientific and Technical Information of China (English)

    沙品洁; 亓永凤; 吕超; 李秀霞; 史雪岩; 高希武

    2012-01-01

    Defense-related enzymes of cotton are greatly influenced by various environmental stresses, including insect herbivory. The defense response to insect herbivory plays an important part in the ecological relationship between insects and plants. In order to explore the dynamic interaction between plant defense and Helicoverpa armigera herbivory, the effect of H. Armigera herbivory and the cessation of herbivory on the activity of three defense related enzymes in cotton seedlings was investigated. Changes in the activity of phenylanlanine ammonialyase (PAL), lipoxygenase (LOX) and polyphenol oxidase (PPO) in the leaves of cotton seedlings were measured after these had been fed on by H. Armigera for 2, 6,12, 18 and 24 hours. Changes in PAL, LOX, and PPO activity were measured after removing H. Armigera that had been feeding for 12 hours. The results indicate that the three enzymes responded differently to H. Armigera herbivory. After 2 h and 6 h, PAL activity had not changed significantly but this increased markedly after 12, 18 and 24 h. LOX activity increased significantly after 2, 6, 12, 18 and 24 h, and PPO activity increased after 6 and 24 h. After removing H. Armigera that had been feeding for 12, PAL activity increased until 36 h, whereas LOX activity increased until 24 hthen returned to normal. PPO activity increased only at 12 h and 24 h. There was a positive correlation between changes in PAL, LOX and PPO activity in cotton seeding leaves and the duration of feeding by H. Armigera. The activities of the three defense related enzymes also increased after removing H. Armigera. In contrast, mechanical injury of leaves did not induce change in the activity of the three defense related enzymes comparing to the untreated control. This suggests that the activities of the three defense related enzymes were influenced by insect herbivory, and that this may change the physiological and biochemical properties of cotton leaves.%昆虫取食作为一种关键的生物胁

  12. 棉铃虫中肠氨肽酶 APN4与 Cry1Ac、Cry2Aa 结合能力的比较%Comparison of the binding affinity of the APN4 receptor in Helicoverpa armigera (Hübner) to the Cry1Ac and Cry2Aa insecticidal proteins

    Institute of Scientific and Technical Information of China (English)

    袁向东; 葛朝虹; 肖玉涛; 梁革梅

    2015-01-01

    Objectives] Bt (Bacillus thuringiensis) insecticidal proteins have been widely adopted to control agricultural pests because of their high target specificity. The binding of a Bt insecticidal protein to its specific receptor in the insect midgut plays a key role in the insecticidal action process. Aminopeptidase N (APN) is one of the major Bt protein receptors. To better characterize the molecular mechanism underlying the insecticidal activity of different Bt insecitcidal proteins, and lay the foundation for Bt resistance management and novel Bt insecticidal protein development, we analyzed the binding affinity of aminopeptidase N4 (APN4) to the Cry1Ac and Cry2Aa insecitcidal proteins in Helicoverpa armigera. [Methods] The binding affinity of aminopeptidase N4 (APN4) was assessed using ligand blot analysis and an ELISA binding assay, respectively. [Results] The results show that recombinant APN4 could bind to both Cry1Ac and Cry2A; their respective dissociation constants were 46.7 nmol/L and 26.5 nmol/L. [Conclusion] The results suggest that there was no significant difference in the binding affinity of APN4 to Cry1Ac and Cry2Aa in H. armigera.%【目的】 Bt 杀虫蛋白(Bacillus thuringiensis)具有高度的靶标特异性,已经被广泛用于农业害虫防治。Bt 杀虫蛋白要发挥杀虫活性,必须首先与其受体蛋白结合,氨肽酶 N(Aminopeptidase N)是一类重要的 Bt 受体蛋白。因此,分析该受体与 Bt 杀虫蛋白的结合能力,可为进一步明确不同 Bt 的分子作用机制、Bt 的抗性治理以及新 Bt 的开发应用等提供借鉴。【方法】本文利用 Ligand blot 和 Elisa 方法比较了棉铃虫 Helicoverpa armigera 中肠 APN4(Aminopeptidase N4,APN4)与 Cry1Ac、Cry2Aa 的结合能力。【结果】原核表达的 APN4片段与活化的 Cry1Ac、Cry2Aa 都可以结合,解离常数(Kd)分别是48.59 nmol/L和21.73 nmol/L。【结论】 APN4片段与 Cry1Ac、Cry2Aa 的结合能力

  13. 低剂量60Co-γ辐射对棉铃虫蛾羽化、寿命、趋光行为和性信息素滴度的影响%Effects of low-dose 60Co-γ radiation on the emergence, longevity,phototactic behavior and sex pheromone titer in Helicoverpa armigera (Lepidoptera: Noctuidae) adults

    Institute of Scientific and Technical Information of China (English)

    闫硕; 朱家林; 张璟; 朱威龙; 张青文; 刘小侠

    2012-01-01

    To illustrate the effects of low-dose 60Co-γ radiation on the development, phototactic behavior and sex pheromone titer in Helicoverpa armigera ( Hübner) , we examined the emergence rate, the deformity rate and longevity of H. armigera adults under five doses of radiation, and determined the rate of phototaxis and sex pheromone titer of H. armigera by phototactic behavior trial and pheromone extraction method. The results indicated that ( 1) there were no effects of 60Co-ü radiation on adult emergence, deformity and longevity of the moth except for the irradiation of 20 Gy, under which the emergence rate was remarkably decreased by 16. 67% ( female) and 20. 00% ( male) , and the deformity rate was increased by 10.00% (both female and male). (2) Both in photophase and scotophase, the rate of phototaxis and sex pheromone titer were increased. The biggest jump of the rate of phototaxis occurred in 3-day-old females in photophase (28. 33%±3. 33% -91. 67% ±4.41% ) , while that of sex pheromone titer occurred in 5-day-old females in scotophase (36. 27 ±4. 26 ng -59. 13 ±4. 63 ng) , indicating that this dose irradiation (50 Gy) probably promoted the occurrence of phototactic behavior and the production of sex pheromone, while the radiation at five doses had no significant effects on phototaxis. (3) There was a declining trend following an increasing trend of the rate of phototaxis and sex pheromone titer as age increased. The biggest jump of the rate of phototaxis occurred in females in photophase and males in scotophase both after radiation (91.67%±4.41% -3.33%±1.67%), while that of sex pheromone titer occurred in females in scotophase after radiation (71. 00 ± 5. 22 ng - 3. 63 ± 1.47 ng). (4) There were no obvious differences in the emergence rate, the deformity rate, longevity and the rate of phototaxis between females and males in most treatments. This research may provide some theoretical basis for exploring the changes in phototaxis and physiological and

  14. Response of last instar Helicoverpa armigera larvae to Bt toxin ingestion: changes in the development and in the CYP6AE14, CYP6B2 and CYP9A12 gene expression.

    Directory of Open Access Journals (Sweden)

    Pilar Muñoz

    Full Text Available Bt crops are able to produce Cry proteins, which were originally present in Bacillus thuringiensis bacteria. Although Bt maize is very efficient against corn borers, Spanish crops are also attacked by the earworm H. armigera, which is less susceptible to Bt maize. Many mechanisms could be involved in this low susceptibility to the toxin, including the insect's metabolic resistance to toxins due to cytochrome P450 monooxygenases. This paper examines the response of last instar H. armigera larvae to feeding on a diet with Bt and non-Bt maize leaves in larval development and in the gene expression of three P450 cytochromes: CYP6AE14, CYP6B2 and CYP9A12. Larvae fed on sublethal amounts of the Bt toxin showed reduced food ingestion and reduced growth and weight, preventing most of them from achieving the critical weight and pupating; additionally, after feeding for one day on the Bt diet the larvae showed a slight increase in juvenile hormone II in the hemolymp. Larvae fed on the non-Bt diet showed the highest CYP6AE14, CYP6B2 and CYP9A12 expression one day after feeding on the non-Bt diet, and just two days later the expression decreased abruptly, a finding probably related to the developmental programme of the last instar. Moreover, although the response of P450 genes to plant allelochemicals and xenobiotics has been related in general to overexpression in the resistant insect, or induction of the genes when feeding takes place, the expression of the three genes studied was suppressed in the larvae feeding on the Bt toxin. The unexpected inhibitory effect of the Cry1Ab toxin in the P450 genes of H. armigera larvae should be thoroughly studied to determine whether this response is somehow related to the low susceptibility of the species to the Bt toxin.

  15. Genetic Variation for Resistance to Bacillus thuringiensis Toxins in Helicoverpa zea (Lepidoptera: Noctuidae) in Eastern North Carolina

    Science.gov (United States)

    In order to evaluate resistance to Bacillus thuringiensis Berliner toxins, female bollworm moths, Helicoverpa zea (Boddie), were collected from four light trap locations in two eastern North Carolina counties from August-October during 2001 and 2002. Moths were allowed to oviposit, and upon hatch, ...

  16. Fight plant pests using RNA interference

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ CAS plant physiologists have recently invented a plant-mediated RNA interference (RNAi) technique to effectively and specifically control the gene expression of the cotton bollworm (Helicoverpa armigera) and stunt its growth.

  17. Interpretation of the biological species concept from interspecific hybridization of two Helicoverpa species

    Institute of Scientific and Technical Information of China (English)

    WANG ChenZhu

    2007-01-01

    The biological species concept defines species in terms of interbreeding. Interbreeding between species is prevented by reproductive isolation mechanisms. Based on our results of interspecific hybridization between Helicoverpa armigera and Helicoverpa assulta, reproductive isolation mechanisms of the two species are analyzed. A combination of prezygotic factors (absent sex attraction and physical incompatibility of the genitalia) and postzygotic factors (female absence and partial sterility in F1 hybrids) causes reproductive isolation of the two species. In addition, the role of interspecific hybridization in speciation is discussed.

  18. Development of a novel-type transgenic cotton plant for control of cotton bollworm.

    Science.gov (United States)

    Yue, Zhen; Liu, Xiaoguang; Zhou, Zijing; Hou, Guangming; Hua, Jinping; Zhao, Zhangwu

    2016-08-01

    The transgenic Bt cotton plant has been widely planted throughout the world for the control of cotton budworm Helicoverpa armigera (Hubner). However, a shift towards insect tolerance of Bt cotton is now apparent. In this study, the gene encoding neuropeptide F (NPF) was cloned from cotton budworm H. armigera, an important agricultural pest. The npf gene produces two splicing mRNA variants-npf1 and npf2 (with a 120-bp segment inserted into the npf1 sequence). These are predicted to form the mature NPF1 and NPF2 peptides, and they were found to regulate feeding behaviour. Knock down of larval npf with dsNPF in vitro resulted in decreases of food consumption and body weight, and dsNPF also caused a decrease of glycogen and an increase of trehalose. Moreover, we produced transgenic tobacco plants transiently expressing dsNPF and transgenic cotton plants with stably expressed dsNPF. Results showed that H. armigera larvae fed on these transgenic plants or leaves had lower food consumption, body size and body weight compared to controls. These results indicate that NPF is important in the control of feeding of H. armigera and valuable for production of potential transgenic cotton. PMID:26841044

  19. Pink bollworm: Trials and tribulations

    International Nuclear Information System (INIS)

    Preparations for a limited field test/release of a genetically modified strain of Pink Bollworm are described. The insects to be released in a field cage have been transgenically marked with a piggyBac transposable element coding the fluorescent protein EGFP. Certain biological characteristics of the transformed strain are detailed. The release experiment is described, as are events associated with obtaining a permit for release of this genetically modified insect. Descriptions and responses to the comments and criticisms received during the public commentary and the comment period are detailed and analyzed. Certain of the critiques are summarized, as are the responses to those critiques. (author)

  20. Screening and Identification of Differentially Expressed Genes Induced by Cotton Bollworm Infestation from Cotton Plants with cDNA Microarray Method%基因芯片技术鉴定棉铃虫胁迫后棉花差异表达基因

    Institute of Scientific and Technical Information of China (English)

    武娟; 齐放军; 田文华; 韩榕; 张永军; 郭予元

    2011-01-01

    In general, gene expression changes when cotton is infested by phytophagous insects. Screening and identification of these regulatory genes induced by cotton bollworm (Helicoverpa armigera Hiibner) infestation will help us understand the molecular mechanism of the host plants resistance to insect pests. In this paper, cotton {Gossypium spp.cv. Zhongl2) was as test material. The cotton plants were divided into control groups and pest stress treatment groups (including 6, 12, 24 and 48 h, pest stress treatments, respectively). The total RNA were extracted from control groups and different pest stress treatments, and the Affymetrix cotton gene chip analysis were applied to explore gene expression profiles. It was found that a total of 4 109 genes (28%) in leaves weredifferentially expressed after induced 6 h, 1 917 of them was up-regulated and 2 192 of them was down-regulated, respectively. After 12 h, a total of 2 605 genes(l 8%) were differentially expressed, 1 326 of them was up-regulated and 1 279 of them was down-regulated, separately. After 24 h, a total of 3 213 genes (22%) were differentially expressed, 1 424 of them is up-regulated and 1 789 of them was down-regulated, respectively. After 48 h, a total of 2 763 genes (19%) were differentially expressed, 1 450 of them was up-regulated and 1 313 of them is down-regulated, separately. Bioinformatics analysis revealed that function of some differentially expressed genes involved roxidative stress response, defense response, signal transduction, transcriptional regulation, flavone and flavonol biosynthesis, terpenoids synthesis and metabolism, biosynthesis of alkaloids derived from many kinds of amino acids, etc. Furthermore, some potential genes which regulate specific volatiles emission in cotton were also identified. It was found that the gene expression of farnesyl pyrophosphate synthase was regulated by circadian rhythm. Meanwhile, (+)-delta-cadinenesynthase gene expression level increased when cotton plants

  1. Resistance Evaluation of Btcry1Ah-transgenic Maize to Asian Corn Borer,Cotton Bollworm and Oriental Armyworm%转Bt cry1Ah基因抗虫玉米对亚洲玉米螟、棉铃虫和黏虫的抗性评价

    Institute of Scientific and Technical Information of China (English)

    宋苗; 汪海; 张杰; 何康来; 梁革梅; 朱莉; 黄大昉; 郎志宏

    2016-01-01

    Bt cry1Ah gene was transferred into inbred line maize Zong31 via Agrobacterium-mediated method,and transgenic maize HGK60 with significant resistance to corn borer was acquired. In order to investigate its insecticidal activity to Lepidoptera pests,we evaluated the insecticidal effects of HGK60 to Asian corn boner(Ostrinia furnacalis),cotton bollworm(Mythimna separate(Walker))and oriental armyworm(Helicoverpa armigeraHubne)through laboratory and field bioassay. The results of laboratory bioassay indicated that no Asian corn boner feeding on HGK60 leaves survived. HGK60 presented the toxic effect on neonate of cotton bollworm,and different tissues of it had different insecticidal effects. Compared to the non-transgenic maize,the body-weight of armyworm neonate was significantly inhibited after a week of feeding HGK 60 leaves. The results of field bioassay showed that HGK60 had solid insecticidal effects to O. furnacalis and H. armigera in high resistance level,while the efficacy to M. separate was in resistance level.%利用农杆菌介导法将Btcry1Ah基因转入玉米自交系综31,获得对玉米螟有显著抗性的转基因玉米HGK60,为了研究其对鳞翅目害虫的杀虫活性,在室内和田间分别用亚洲玉米螟、棉铃虫和黏虫幼虫对HGK60玉米的杀虫效果进行检测。室内生物活性检测结果表明,取食HGK60玉米心叶的亚洲玉米螟幼虫在3d后死亡率达100%;HGK60玉米对棉铃虫幼虫有毒杀作用,玉米不同部位对棉铃虫幼虫的杀虫效果存在差异;与非转基因玉米对照相比,取食HGK60玉米叶片一周后的黏虫幼虫体重增长明显受到抑制。田间生物活性检测结果表明,HGK60玉米对于亚洲玉米螟和棉铃虫有很强的杀虫活性,达到高抗级别,对于黏虫有一定的杀虫活性,为抗性级别。

  2. 棉铃虫中肠cDNA文库的构建及EST分析%cDNA library construction and EST analysis of the larval midgut of Helicoverpa armnigera ( Lepidoptera: Noctuidae)

    Institute of Scientific and Technical Information of China (English)

    邹朗云; 曹广春; 张谦; 张彦; 梁革梅; 吴孔明; 郭予元

    2011-01-01

    Midgut is the main target for Bacillus thuringiensis (Bt) action, and a number of insect midgut proteins have been proposed as putative Bt toxin receptors. In order to study the resistance mechanism of the cotton bollworm, Helicoverpa armigera to Bt, we constructed a larval midgut cDNA library of the cotton bollworm using the Switching Mechanism at 5' end of the RNA Transcript (SMART)technique.The total RNA of 5th instar larval midgut was extracted and the double-stranded cDNA synthesized. After the normalization treatment, cDNAs were digested and ligated into vector, and then the recombinants were transformed into competent cells. The titer was tested and the cDNA library was amplified and sequenced. The quality evaluation showed that the library had a complexity of 2 × 106 pfu/mL, and the recombination rate was 100%. The average length of inserted cDNA fragments was over 1 000 bp, and 50% fragments were in the full-length form. A total of 1 098 expressed sequence tags (ESTs) were generated successfully after editing and trimming the vector and ambiguous sequences, and 789 unigene sequences were identified, including 132 contigs and 657 singlets. The assembled 789 ESTs were analyzed with Blast in NT, NR and SWISSPORT database of NCBI. The Blast analysis showed that 218 ESTs (27.62%) had no comparable sequences in databases, 119 ESTs (15.08%) had no definite annotations, and the rest 452 ESTs (57.29%) had high homologies with the available sequences, which had definite annotation with over 300 protein products. Through this study, a high-quality cDNA library of the larval midgut of H. armigera has been constructed, which will be a useful tool for studing gene functions in H. armigera midgut.%中肠是苏云金芽孢杆菌Bacillus thuringiensis(Bt)发挥作用的主要部位,中肠上很多蛋白被认为是Bt毒素的结合蛋白.为了探索棉铃虫Helicoverpa armigera对Bt的抗性机制,我们运用RNA转录过程中的5'

  3. C3和C4植物寄主对华北地区棉铃虫越冬代和第一代的影响%Contribution of C3 and C4 host plants for the overwintering and 1st generation of Helicoverpa armigera(Hübner)in Northern China

    Institute of Scientific and Technical Information of China (English)

    叶乐夫; 付雪; 戈峰

    2011-01-01

    It is a key step for cotton bollworm (CBW) management to determine the ratio of moths of cotton bollworm originating from C3 and C4 host plants for the overwintering generation and their contribution to the next spring first generation in North China. In this study, the development times of larva from the female moths captured in wheat field in 2007 were observed systematically. Moreover, δ13C values in the wings of each female moth were tested with GC-MS apparatus to determine larval host plant type. Results showed that 53.1% of moths trapped during spring emergence (the overwintering generation CBW) came from larva grown in late autumn C3 host plants (cotton), 46.9% came from larva grown in late autumn C4 host plants (corn). 57.9% of eggs laid by the overwintering generation moths were determined as progeny of C3 phenotype via stable isotope examination on the wings of moth, individually. Significantly higher hatching rate were observed in the eggs laid by the moths from larva grown in C3 host plants than C4 host plants. Furthermore, about 63.7% first instar larva on spring wheat was determined as progeny of C3 phenotype moths. Moreover, about 47.9% larva at the third instar, 45.5% fourth instar larva, 46.9% fifth instar larva, 55.1% last instar larva of 1st generation of CBW originated from C3 host plants. The larva from first instar to third instar of moths from C3 phenotype develop quicker compared with from C4 phenotype. However, larva from fourth instar to sixth instar from C3 phenotype developed slowly than C4 phenotype. The larva originated from C3 phenotype displayed lower survival rate at lower instar larva and higher survival rate at higher instar larva while compared to the C4 phenotype progeny. In the whole, quicker development for lower instar larva with lower survival rate, and slower development for large larva with higher survival rate occurred during their larval developmental process, However, total developmental duration and

  4. Biology, Ecology, and Evolving Management of Helicoverpa zea (Lepidoptera: Noctuidae) in Sweet Corn in the United States.

    Science.gov (United States)

    Olmstead, Daniel L; Nault, Brian A; Shelton, Anthony M

    2016-08-01

    The corn earworm, Helicoverpa zea (Boddie), is a polyphagous pest found throughout the United States, where it attacks many field and vegetable crops. Although H. zea has long been a traditional pest of sweet corn, its importance to this crop has increased dramatically over the past two decades. In this review, we summarize information critical for current and future management of H. zea in sweet corn production in the United States. First, we discuss the pest status of H. zea and its life history, including migration, infestation and larval development, diapause, overwintering, and abiotic factors that affect its biology. Next we describe monitoring methods, crop protection decision-making processes, chemical control options, and the use of genetic technologies for control of H. zea Alternative H. zea management options including biological control, cultural controls, host plant resistance, and pheromone disruption are also reviewed. The role of climate change and its effects on H. zea and its ecology are discussed, as well as the recent invasion of its relative, Helicoverpa armigera (Hübner), which is a major pest of corn in other parts of the world. To conclude, we suggest future research opportunities for H. zea and H. armigera management in sweet corn. PMID:27329622

  5. A New Strategy of Insect Pest Control:Down-regulating Cotton Boliworm Gene Expression by Engineering Plant Double Stranded RNA

    Institute of Scientific and Technical Information of China (English)

    MAO Ying-bo; XUE Xue-yi; WANG Ling-jiang; CHEN Xiao-ya

    2008-01-01

    @@ Cotton bollworm (Helicoverpa armigera ) is an important agricultural pest that causes severeyield loss to crops,particularly to cotton.Transgenic Bt crops have been successful in protectingplants,however,Bt proteins are toxic to all lepidopteran insects but have little effects to sucking pests,such as aphids.Furthermore,the continuous use of Bt crops increases insect resistance.

  6. Molecular research and genetic engineering of resistance to Verticillium wilt in cotton: A review

    Science.gov (United States)

    Verticillium dahliae, a soil-borne pathogen, causes Verticillium wilt, one of the most serious diseases in cotton, deleteriously influencing the crop’s production and quality. Verticillium wilt has become a major obstacle in cotton production since Helicoverpa armigera, the cotton bollworm, became e...

  7. Activation of Bt Protoxin Cry1Ac in Resistant and Susceptible Cotton Bollworm

    Science.gov (United States)

    Liang, Gemei; Wang, Bingjie; Zhong, Feng; Chen, Lin; Khaing, Myint Myint; Zhang, Jie; Guo, Yuyuan; Wu, Kongming; Tabashnik, Bruce E.

    2016-01-01

    Crystalline (Cry) proteins from Bacillus thuringiensis (Bt) are used extensively for insect control in sprays and transgenic plants, but their efficacy is reduced by evolution of resistance in pests. Here we evaluated reduced activation of Cry1Ac protoxin as a potential mechanism of resistance in the invasive pest Helicoverpa armigera. Based on the concentration killing 50% of larvae (LC50) for a laboratory-selected resistant strain (LF120) divided by the LC50 for its susceptible parent strain (LF), the resistance ratio was 1600 for Cry1Ac protoxin and 1200 for trypsin-activated Cry1Ac toxin. The high level of resistance to activated toxin as well as to protoxin indicates reduced activation of protoxin is not a major mechanism of resistance to Cry1Ac in LF120. For both insect strains, treatment with either the trypsin inhibitor N-a-tosyl-L-lysine chloromethyl ketone (TLCK) or the chymotrypsin inhibitor N-a-tosyl-L-phenylalanine chloromethyl ketone (TPCK) did not significantly affect the LC50 of Cry1Ac protoxin. Enzyme activity was higher for LF than LF120 for trypsin-like proteases, but did not differ between strains for chymotrypsin-like proteases. The results here are consistent with previous reports indicating that reduced activation of protoxin is generally not a major mechanism of resistance to Bt proteins. PMID:27257885

  8. Function, oligomerization and N-linked glycosylation of the Helicoverpa armigera single nucleopolyhedrovirus envelope fusion protein

    NARCIS (Netherlands)

    Long, G.; Westenberg, M.; Wang, H.; Vlak, J.M.; Hu, Z.

    2006-01-01

    In the family Baculoviridae, two distinct envelope fusion proteins are identified in budded virions (BVs). GP64 is the major envelope fusion protein of group I nucleopolyhedrovirus (NPV) BVs. An unrelated type of envelope fusion protein, named F, is encoded by group II NPVs. The genome of Helicoverp

  9. Impacts on transfer of the sperm of helicoverpa Armigera by irradiation (L. noctuidae)

    International Nuclear Information System (INIS)

    Gamma irradiation did not influence the quantity of the eupyrene sperm bundles in duplex and that of the eupyrene sperm in spermatophore, but affected the maturing of eupyrene sperm bundles. When males were given sterilizing dose of 400 Gy, the quantity and the activity of the eupyrene sperm in the spermatheca were reduced significantly (P < 0.05)

  10. The influence of a 21 kDa Kunitz-type trypsin inhibitor from nonhost madras thorn, Pithecellobium dulce, seeds on H. armigera (Hübner) (Lepidoptera: Noctuidae).

    Science.gov (United States)

    Pandey, Prabhash K; Singh, Dushyant; Jamal, Farrukh

    2015-05-01

    A trypsin inhibitor purified from the seeds of the Manila tamarind, Pithecellobium dulce (PDTI), was studied for its effects on growth parameters and developmental stages of Helicoverpa armigera. PDTI exhibited inhibitory activity against bovine trypsin (∼86%; ∼1.33 ug/ml IC50). The inhibitory activity of PDTI was unaltered over a wide range of temperature, pH, and in the presence of dithiothreitol. Larval midgut proteases were unable to digest PDTI for up to 12 h of incubation. Dixon and Lineweaver-Burk double reciprocal plots analysis revealed a competitive inhibition mechanism and a Ki of ∼3.9 × 10(-8) M. Lethal dose (0.50% w/w) and dosage for weight reduction by 50% (0.25% w/w) were determined. PDTI showed a dose-dependent effect on mean larval weight and a series of nutritional disturbances. In artificial diet at 0.25% w/w PDTI, the efficiency of conversion of ingested food, of digested food, relative growth rate, and growth index declined, whereas approximate digestibility, relative consumption rate, metabolic cost, consumption index, and total developmental period were increased in larvae. This is the first report of antifeedant and antimetabolic activities of PDTI on midgut proteases of H. armigera. PMID:25580830

  11. Development and evaluation of a conditionally lethal transgenic pink bollworm

    International Nuclear Information System (INIS)

    A new area-wide pest control strategy using the pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae), genetically transformed with a conditionally lethal gene, is under development. Conditional lethality of several transgenic pink bollworm strains was demonstrated in a series of laboratory rearing experiments. Pink bollworms were transformed with genetic constructs using the RIDL technology (Release of Insects with a Dominant Lethal gene) for development of an autocidal biological control system for possible supplement or replacement of radiation based sterile insect release. LA1124 is a lethal construct controlled by a tetracycline repressible transactivator protein (tTA), in which binding of tTA to its specific target sequence tetO drives production of more tTA. In the absence of tetracycline, this leads to lethality by high expression of tTA. When tetracycline is present, tTA does not bind tetO, and so the positive feedback cycle is not established and tTA remains at a low, non-lethal level for more detail on the tetO-tTA system). Tetracycline (in the form of chlortetracycline or CTC) is a normal part of the pink bollworm artificial diet, so such a strain of pink bollworm could readily be incorporated into the current mass-rearing system. Eight laboratory rearing experiments have been conducted with the LA1124 lines where pink bollworm heterozygous for the RIDL gene were crossed to wild type pink bollworm to produce an F1 generation with a 1:1 ratio of progeny of two genotypes: one that is heterozygous for the RIDL gene and one that is wild type. These were reared with and without CTC and mortality was scored at larval, pupal, and adult stages. This experiment was designed to simulate progeny mortality that would occur from the mating of a homozygous RIDL moth with a wild type pink bollworm after release of RIDL moths in a cotton field, while also including an internal wild type control (the wild type siblings of the heterozygous F1

  12. Characterization of mechanisms of resistance to common insecticides in noctuid pest species and resistance risk assessment for the new lepidopteran specific compound flubendiamide

    OpenAIRE

    Konanz, Stefanie

    2009-01-01

    Noctuid species, such as the beet armyworm Spodoptera exigua, the cotton bollworm Helicoverpa armigera and the tobacco budworm Heliothis virescens, are well-known pests in many agricultural cropping systems worldwide. The extensive and widespread use of insecticides against these species has led to the development of resistance against almost all commercially used compounds. The focus of this thesis was on the novel lepidopteran specific compound flubendiamde, to get a detailed overview about...

  13. Oviposition behaviour of Heliothis armigera Hubner

    International Nuclear Information System (INIS)

    Field experiments under screen cages on tomato plants of an undeterminate growth balkan cultivar led to the localization of oviposition sites of Heliothis armigera radiolabelled with sup 3 sup 2 P. Results show that females appear to have a significant preference (82 %) for oviposition on leaflets, in the upper half of the plant, and particularly on those near flowers or fruit clusters. The eggs, most of them isolated, are equally detected on the upper or lower side of leaves. Open flowers only bear 5% of the eggs whereas buds, stems and fruits are minor laying sites. A rapid egg sampling method was developed for use on integrated pest management program. (author). 19 refs., 4 tabs

  14. Expression in antennae and reproductive organs suggests a dual role of an odorant-binding protein in two sibling Helicoverpa species.

    Directory of Open Access Journals (Sweden)

    Ya-Lan Sun

    Full Text Available Odorant-binding proteins (OBPs mediate both perception and release of semiochemicals in insects. These proteins are the ideal targets for understanding the olfactory code of insects as well as for interfering with their communication system in order to control pest species. The two sibling Lepidopteran species Helicoverpa armigera and H. assulta are two major agricultural pests. As part of our aim to characterize the OBP repertoire of these two species, here we focus our attention on a member of this family, OBP10, particularly interesting for its expression pattern. The protein is specifically expressed in the antennae of both sexes, being absent from other sensory organs. However, it is highly abundant in seminal fluid, is transferred to females during mating and is eventually found on the surface of fertilised eggs. Among the several different volatile compounds present in reproductive organs, OBP10 binds 1-dodecene, a compound reported as an insect repellent. These results have been verified in both H. armigera and H. assulta with no apparent differences between the two species. The recombinant OBP10 binds, besides 1-dodecene, some linear alcohols and several aromatic compounds. The structural similarity of OBP10 with OBP1 of the mosquito Culex quinquefasciatus, a protein reported to bind an oviposition pheromone, and its affinity with 1-dodecene suggest that OBP10 could be a carrier for oviposition deterrents, favouring spreading of the eggs in these species where cannibalism is active among larvae.

  15. Efficacy of insecticides of different chemistries against Helicoverpa zea (Lepidoptera: Noctuidae) in transgenic Bacillus thuringiensis and conventional cotton.

    Science.gov (United States)

    Brickle, D S; Turnipseed, S G; Sullivan, M J

    2001-02-01

    Six insecticides of different chemistries were evaluated against the cotton bollworm, Helicoverpa zea (Boddie), in non-B.t. (Deltapine 'DP 5415', Deltapine 'DP 5415RR') and transgenic Bacillus thuringiensis (Berliner) (B.t.) (Deltapine 'NuCOTN 33B', Deltapine 'DP 458 B/RR') cotton. In 1998, treatments consisted of three rates each of a pyrethroid (lambda-cyhalothrin), spinosyn (spinosad), carbamate (thiodicarb), pyrrole (chlorfenapyr), oxadiazine (indoxacarb), and avermectin (emamectin benzoate) in a nonirrigated field. In 1999, treatments consisted of three rates each of lambda-cyhalothrin, spinosad, thiodicarb, and indoxacarb in an irrigated and a nonirrigated (dryland) field. The highest rate of each insecticide corresponded to normal grower-use rates. Spinosad and thiodicarb controlled H. zea in non-B.t. cotton, whereas other materials were less effective. Even though H. zea is becoming increasingly resistant to pyrethroid insecticides, lambda-cyhalothrin was highly effective in dryland B. thuringiensis cotton. Spinosad and thiodicarb were equally effective. Data indicated that reduced rates of lambda-cyhalothrin, spinosad, and thiodicarb could be used for control of H. zea in dryland B.t. cotton systems. However, reduced rates of these insecticides in a heavily irrigated B.t. cotton system did not provide adequate control. PMID:11233138

  16. Field performance of a genetically engineered strain of pink bollworm.

    Directory of Open Access Journals (Sweden)

    Gregory S Simmons

    Full Text Available Pest insects harm crops, livestock and human health, either directly or by acting as vectors of disease. The Sterile Insect Technique (SIT--mass-release of sterile insects to mate with, and thereby control, their wild counterparts--has been used successfully for decades to control several pest species, including pink bollworm, a lepidopteran pest of cotton. Although it has been suggested that genetic engineering of pest insects provides potential improvements, there is uncertainty regarding its impact on their field performance. Discrimination between released and wild moths caught in monitoring traps is essential for estimating wild population levels. To address concerns about the reliability of current marking methods, we developed a genetically engineered strain of pink bollworm with a heritable fluorescent marker, to improve discrimination of sterile from wild moths. Here, we report the results of field trials showing that this engineered strain performed well under field conditions. Our data show that attributes critical to SIT in the field--ability to find a mate and to initiate copulation, as well as dispersal and persistence in the release area--were comparable between the genetically engineered strain and a standard strain. To our knowledge, these represent the first open-field experiments with a genetically engineered insect. The results described here provide encouragement for the genetic control of insect pests.

  17. Integration of pheromones and biological control for the management of cotton bollworms in Pakistan

    International Nuclear Information System (INIS)

    The management of cotton bollworms in a semi-isolated area through the use of inundative releases of the egg parasitoid Trichogramma chilonis (Hymenoptera: Trichogrammatidae) in conjunction with pheromones suppressed populations of the pink and spotted bollworms to sub-economic levels. The parasitoid was more effective against pink bollworm than spotted bollworm. Applications of either pheromones or parasitoids by themselves were less effective when compared to the combined treatment. The level of parasitism in the cotton field was comparatively low in June and July but gradually increased during August and September. Maximum parasitism was recorded in November. Studies indicated that temperature affected the establishment of the parasitoid, and populations increased significantly when favourable conditions prevailed in the cotton field. (author)

  18. 烟夜蛾血淋巴凝集素活性的研究%Hemagglutination activity of lectins in the hemolymph of Helicoverpa assulta

    Institute of Scientific and Technical Information of China (English)

    张利芬; 白素芬; 李欣

    2013-01-01

    利用血凝法检测烟夜蛾Helicoverpa assulta血淋巴对红细胞的凝集活性和不同发育期凝集素水平,同时选取13种糖进行凝集素糖抑制反应,以明确该凝集素与烟夜蛾发育的关系和糖结合特性.研究结果表明,在烟夜蛾的不同发育期均检测有凝集素,但各龄幼虫及不同日龄蛹的凝集活性存在明显差异,雌蛹凝集素水平高于同日龄的雄蛹,表明凝集素与发育期、虫龄及蜕皮过程有关,且与性别相关.烟夜蛾蛹血淋巴凝集素活性与近缘种棉铃虫H.armigera的相类似,均被D-半乳糖、L-鼠李糖、麦芽糖、乳糖明显抑制;D-葡萄糖、D-果糖、L-岩藻糖和蔗糖等也有抑制作用,但抑制程度不同;L-阿拉伯糖与棉铃虫凝集素的专一性结合更强;N-乙酰葡萄糖胺和L-山梨糖只对棉铃虫凝集素有抑制作用,而对烟夜蛾凝集素无抑制作用,说明这2个近缘种的凝集素不完全相同.%To understand the relationship between lectins and development in H.assulta,and the sugar-binding specificity of H.assulta lectin,Hemagglutination assays were used to determine the hemagglutinating activity (HA) of haemolymph extracted from Helicoverpa assulta to the erythrocytes,and the changes of HA titer during different developmental stages of H.assulta.Meanuhile,thirteen sugars were tested to determine their inhibitory effect on H.assulta lectin.The results showed that lectins were detected during all developmental stages of H.assulta.Hemagglutination activity (HA) titer fluctuated between and within the various developmental stages,particularly in different larval instars and pupal ages,female pupal H.assulta had higher HA titer than their male cohorts.These results indicated that HA of lectins may be related to developmental stage,larval instar and molting process,and was dependent on sex.The carbohydrate binding specificity of the lectins in pupal hemolymph from H.assulta and H.armigera was determined by

  19. Field Longevity of a Fluorescent Protein Marker in an Engineered Strain of the Pink Bollworm, Pectinophora gossypiella (Saunders)

    OpenAIRE

    Michelle Walters; Morrison, Neil I.; John Claus; Guolei Tang; Caroline E Phillips; Robin Young; Zink, Richard T.; Luke Alphey

    2012-01-01

    The cotton pest, pink bollworm (Pectinophora gossypiella (Saunders)), is a significant pest in most cotton-growing areas around the world. In southwestern USA and northern Mexico, pink bollworm is the target of the sterile insect technique (SIT), which relies on the mass-release of sterile pink bollworm adults to over-flood the wild population and thereby reduce it over time. Sterile moths reared for release are currently marked with a dye provided in their larval diet. There are concerns, ho...

  20. Cloning and Sequencing of a Gene Encoding Aminopeptidase N in the Midgut of Helicoverpa armigera (Hübner)

    Institute of Scientific and Technical Information of China (English)

    WANG Gui-rong; LIANG Ge-mei; WU Kong-ming; GUO Yu-yuan

    2003-01-01

    A cDNA encoding aminopeptidase N was cloned by degenerated PCR combined with RACEtechnique in this paper. The full-length of APN-Harm is 3 043 bp. Open reading frame is 2 856 bp inlength, encoding 951 amino acid residues. Its predicted molecular weight and isoelectric point are 108.3kDa and 5.29, respectively. This deduced amino acid sequence shares some common structural features withaminopeptidase N from several moth species, including the consensus zinc-binding motif HEXXHX18 E and the GAMEN motif common to gluzincin aminopeptidases. The first 20 amino acid residues at N-termini ishydrophobic transmembrane helix. The sequence of APN-Harm was deposited in GenBank and the accessionnumber is AY181026.

  1. Proteomic identification of differentially expressed and phosphorylated proteins in epidermis involved in larval-pupal metamorphosis of Helicoverpa armigera

    Directory of Open Access Journals (Sweden)

    Song Qi-Sheng

    2009-12-01

    Full Text Available Abstract Background Metamorphosis is an important process in the life cycle of holometabolous insects and is regulated by insect hormones. During metamorphosis, the epidermis goes through a significant transformation at the biochemical and molecular levels. Results To identify proteins and phosphoproteins involved in this process, we separated and compared epidermal protein profiles between feeding larvae and metamorphically committed larvae using two-dimensional gel electrophoresis and Pro-Q Diamond Phosphoprotein Staining. Sixty-one spots showing differential expression and/or phosphorylation were analyzed by mass spectrometry and eighteen proteins were proved related to larval-pupal transformation. Eight of them were further examined at the mRNA level by Reverse Transcription Polymerase Chain Reaction (RT-PCR and two of them were examined at the protein level by Western blot. Calponin was highly expressed in the metamorphic epidermis and phosphorylated by protein kinase C. Conclusion Our results suggest that the expression and phosphorylation of these proteins may play important roles in coordinating the biochemical processes involved in larval-pupal metamorphosis.

  2. Identification and expression profile of a putative basement membrane protein gene in the midgut of Helicoverpa armigera

    Directory of Open Access Journals (Sweden)

    Xu Da-Wei

    2007-06-01

    Full Text Available Abstract Background The midgut undergoes histolysis and remodeling during the larval to adult transition in holometabolous insects, but the molecular mechanisms underlying this process are not well understood. Results Using Suppression Subtractive Hybridization (SSH, we identified a 531 bp cDNA predicted to encode a 176 amino acid protein, which we call hmg176. Northern and western blot analysis suggested that high levels of hmg176 are expressed in the midgut during molting, but not during metamorphosis. HMG176 protein was detected by immunofluorescence within the membrane of fat bodies and the basement membrane of the midgut of both molting and feeding larvae, but not in metamorphically committed larvae. In situ hybridization revealed that hmg176 transcripts mainly localized to the columnar cells of the midgut. Interestingly, a non-steroidal ecdysone agonist, RH-2485, significantly upregulated expression of hmg176. Conclusion These observations suggest that hmg176 encodes a larval-specific protein that may participate in sustaining larval midgut during larval development, possibly in response to ecdysteroid in vivo. This study will enlighten our understanding of the molecular mechanisms of tissue histolysis during metamorphosis.

  3. Forecasting Helicoverpa populations in Australia: A comparison of regression based models and a bioclimatic based modelling approach

    Institute of Scientific and Technical Information of China (English)

    MYRONP.ZALUCKI; MICHAELJ.FURLONG

    2005-01-01

    Long-term forecasts of pest pressure are central to the effective management of many agricultural insect pests. In the eastern cropping regions of Australia, serious infestations of Helicoverpa punctigera (Wallenglen) and H. armigera (Hübner)(Lepidoptera:Noctuidae) are experienced annually. Regression analyses of a long series of light-trap catches of adult moths were used to describe the seasonal dynamics of both species. The size of the spring generation in eastern cropping zones could be related to rainfall in putative source areas in inland Australia. Subsequent generations could be related to the abundance of various crops in agricultural areas, rainfall and the magnitude of the spring population peak. As rainfall figured prominently as a predictor variable, and can itself be predicted using the Southern Oscillation Index (SOI), trap catches were also related to this variable. The geographic distribution of each species was modelled in relation to climate and CLIMEX was used to predict temporal variation in abundance at given putative source sites in inland Australia using historical meteorological data. These predictions were then correlated with subsequent pest abundance data in a major cropping region. The regression-based and bioclimatic-based approaches to predicting pest abundance are compared and their utility in predicting and interpreting pest dynamics are discussed.

  4. Effect of weather factors on the incidence and development of pink bollworm on flowers of advance cotton genotypes

    International Nuclear Information System (INIS)

    Ten advance genotypes of cotton Viz. BH-121, NIAB KRISHMA, DNH-137, VH-142, VH-142 BH-125, MNH-635, SLH-267, FNH-245, CRIS-467 and CRIS-82 were used to determine the effect of different weather factors on the incidence and development of pink bollworm (Pectinophora gossyiella) infestation at Nuclear institute for Agriculture and Biology (NIAB) Faisalabad. Trials were laid out using Randomized Complete Block Design (RCBD) with four replications. Finally data were subjected to statistical analysis and for correlation studies between weather factors and pink bollworm. Temperature and relative humidity and rainfall affected negatively for the infestation of pink bollworm on flowers in advance genotypes of cotton. (author)

  5. Engineered repressible lethality for controlling the pink bollworm, a lepidopteran pest of cotton.

    Directory of Open Access Journals (Sweden)

    Neil I Morrison

    Full Text Available The sterile insect technique (SIT is an environmentally friendly method of pest control in which insects are mass-produced, irradiated and released to mate with wild counterparts. SIT has been used to control major pest insects including the pink bollworm (Pectinophora gossypiella Saunders, a global pest of cotton. Transgenic technology has the potential to overcome disadvantages associated with the SIT, such as the damaging effects of radiation on released insects. A method called RIDL (Release of Insects carrying a Dominant Lethal is designed to circumvent the need to irradiate insects before release. Premature death of insects' progeny can be engineered to provide an equivalent to sterilisation. Moreover, this trait can be suppressed by the provision of a dietary antidote. In the pink bollworm, we generated transformed strains using different DNA constructs, which showed moderate-to-100% engineered mortality. In permissive conditions, this effect was largely suppressed. Survival data on cotton in field cages indicated that field conditions increase the lethal effect. One strain, called OX3402C, showed highly penetrant and highly repressible lethality, and was tested on host plants where its larvae caused minimal damage before death. These results highlight a potentially valuable insecticide-free tool against pink bollworm, and indicate its potential for development in other lepidopteran pests.

  6. An experiment on the reuse of artificial medium for rearing Pink Bollworm, Pectinophora gossypiella (Saunders)

    International Nuclear Information System (INIS)

    The development of pink bollworm, Pectinophora gossypiella (Saunders) was compared on rearing on used-diet or the medium remaining after larval use, with no supplements added versus used-diet with 100 percent supplement of vitamins, choline chloride and the heat sensitive antimicrobial agents (Fumidil B, Aureomycin and formaldehyde). In another evaluation of used diet it was mixed at 0, 25, 50, and 75 percent with the new diet and compared to 100 percent new diet. Used diet with no supplement and used diet with 100 percent supplement of vitamins and heat sensitive antimicrobial agents had no significant effect on the development of the pink bollworm except in adult emergence. Some pupae which developed from unsupplemented used-diet died before moth emergence. Used diet mixed with 75 percent new ingredients was the best rate for reclamation of the used diet and produced the same results in pupal production rate pupal weight, adult emergence, adult longevity and egg production of female pink bollworm when compared to those from diet prepared with 100 percent new ingredients. The other rates supplemented with 0,25 and 50 percent new ingredients were significantly poorer by most criteria

  7. Integrated systems for control of pink bollworm in cotton

    International Nuclear Information System (INIS)

    Full text: Pink bollworm (PBW), Pectinophora gossypiella (Saunders), an introduced pest from Mexico, first occurred in United States cotton production in Texas in 1917. Unacceptable economic losses have occurred. The development of PBW sterile moth release technology, gossyplure sex pheromone behavioral control, cotton plant cultural control to reduce overwintered PBW populations, and the transfer of the insect toxin protein gene into cotton from Bacillus thuringiensis kurstaki (Berliner) have provided an effective integrated pest management (IPM) system with PBW eradication potential. Sterile insect release was considered a potential option for PBW population suppression in the early 1960s. Research on the isolated island of St. Croix, (US Virgin Islands) demonstrated its validity. Reductions of larval infestations in bolls following sterile moth releases began when ratios of released PBW sterile male to native male moths averaged 70:1 in gossyplurebaited traps. Numbers of larvae per boll decreased from 1.2 to 0.3. Infestations increased and ranged from 1 to 2.9 larvae per boll for seven months when ratios of released sterile male to native male moths averaged 20:1. When releases of sterile moths were terminated, PBW larvae per boll increased from 1 to 3.7 per boll over a 58-day period following the last release. Sex pheromone behavioral control for PBW was demonstrated to be a viable IPM component during the early to mid-1990s. Single applications of pheromone rope or multiple applications of NoMate Attract N' Kill formulations were applied when cotton was at the six leaf growth stage. Percentages of bolls infested with PBW larvae decreased from a pre-programme high of 23.35 to 0.38 during the fifth year of the programme. Conventional insecticide use decreased from 6.2 applications in 1990 to 0.3 applications in 1995. Overall control costs were reduced from a historical average of USD 172 per ha to USD 69 per ha. PBW overwinter in diapause in the last larval

  8. Preliminary studies on differential defense responses induced during plant communication

    Institute of Scientific and Technical Information of China (English)

    Jin Ying PENG; Zhong Hai LI; Hui XIANG; Jian Hua HUANG; Shi Hai JIA; Xue Xia MIAO; Yong Ping HUANG

    2005-01-01

    We compared the expression patterns of three representative genes in undamaged tomato and tobacco plants in response to exposure to either tomato or tobacco fed on by Helicoverpa armigera (cotton bollworm). When tomato and tobacco, two species of one family, were incubated in the chambers with the tomato plants damaged by the cotton bollworm, the expression of the PR1, BGL2, and PAL genes was up-regulated in leaves of both plants. However, the levels of gene expression were significantly higher in the tomato than that in the tobacco. In addition, the activities of enzymes, peroxidase, polyphenol oxidase, and lipoxygenase were found to be higher in the tomato than those in the tobacco. Similar results were obtained when the damaged plants were replaced by the tobacco.

  9. Effect of pyramiding Bt and CpTI genes on resistance of cotton to Helicoverpa armigera (Lepidoptera: Noctuidae) under laboratory and field conditions

    NARCIS (Netherlands)

    Cui, J.J.; Luo, J.Y.; Werf, van der W.; Ma, Y.; Xia, J.Y.

    2011-01-01

    Transgenic cotton (Gossypium hirsutum L.) varieties, adapted to China, have been bred that express two genes for resistance to insects. the Cry1Ac gene from Bacillus thuringiensis (Berliner) (Bt), and a trypsin inhibitor gene from cowpea (CpTI). Effectiveness of the double gene modification in confe

  10. Improvement of pest resistance in transgenic tobacco plants expressing dsRNA of an insect-associated gene EcR.

    Science.gov (United States)

    Zhu, Jin-Qi; Liu, Shumin; Ma, Yao; Zhang, Jia-Qi; Qi, Hai-Sheng; Wei, Zhao-Jun; Yao, Qiong; Zhang, Wen-Qing; Li, Sheng

    2012-01-01

    The adoption of pest-resistant transgenic plants to reduce yield loss and pesticide utilization has been successful in the past three decades. Recently, transgenic plant expressing double-stranded RNA (dsRNA) targeting pest genes emerges as a promising strategy for improving pest resistance in crops. The steroid hormone, 20-hydroxyecdysone (20E), predominately controls insect molting via its nuclear receptor complex, EcR-USP. Here we report that pest resistance is improved in transgenic tobacco plants expressing dsRNA of EcR from the cotton bollworm, Helicoverpa armigera, a serious lepidopteran pest for a variety of crops. When H. armigera larvae were fed with the whole transgenic tobacco plants expressing EcR dsRNA, resistance to H. armigera was significantly improved in transgenic plants. Meanwhile, when H. armigera larvae were fed with leaves of transgenic tobacco plants expressing EcR dsRNA, its EcR mRNA level was dramatically decreased causing molting defects and larval lethality. In addition, the transgenic tobacco plants expressing H. armigera EcR dsRNA were also resistant to another lepidopteran pest, the beet armyworm, Spodoptera exigua, due to the high similarity in the nucleotide sequences of their EcR genes. This study provides additional evidence that transgenic plant expressing dsRNA targeting insect-associated genes is able to improve pest resistance. PMID:22685585

  11. Improvement of pest resistance in transgenic tobacco plants expressing dsRNA of an insect-associated gene EcR.

    Directory of Open Access Journals (Sweden)

    Jin-Qi Zhu

    Full Text Available The adoption of pest-resistant transgenic plants to reduce yield loss and pesticide utilization has been successful in the past three decades. Recently, transgenic plant expressing double-stranded RNA (dsRNA targeting pest genes emerges as a promising strategy for improving pest resistance in crops. The steroid hormone, 20-hydroxyecdysone (20E, predominately controls insect molting via its nuclear receptor complex, EcR-USP. Here we report that pest resistance is improved in transgenic tobacco plants expressing dsRNA of EcR from the cotton bollworm, Helicoverpa armigera, a serious lepidopteran pest for a variety of crops. When H. armigera larvae were fed with the whole transgenic tobacco plants expressing EcR dsRNA, resistance to H. armigera was significantly improved in transgenic plants. Meanwhile, when H. armigera larvae were fed with leaves of transgenic tobacco plants expressing EcR dsRNA, its EcR mRNA level was dramatically decreased causing molting defects and larval lethality. In addition, the transgenic tobacco plants expressing H. armigera EcR dsRNA were also resistant to another lepidopteran pest, the beet armyworm, Spodoptera exigua, due to the high similarity in the nucleotide sequences of their EcR genes. This study provides additional evidence that transgenic plant expressing dsRNA targeting insect-associated genes is able to improve pest resistance.

  12. Use of radiation induction to improve new cotton lines resistant to Heliothis armigera

    International Nuclear Information System (INIS)

    Ratchada 1 (R1) seeds irradiated with 300 gray of gamma rays in order to obtain new cotton lines resistant to the American bollworm with high yield and good quality were compared with Srisamrong 2 (SR1) and Ratchada 1 (R1), the present recommended varieties to the farmers. The experiments were conducted under both laboratory and field conditions for 3 consecutive years and 2 new lines, A P1 and A P2 in M5 with the required attribute, were finally selected. In the lab, after feeding 2 nd instar bollworm larvae with young leaves of tested lines and the controls the increased weight, larval length, pupal weight of new lines were found to be better than those of SR2 and R1 including % gossypol and flavonoids, the substances being expected to give antibiotic effect to the insects. Physical aberration was also noticed in A P1. As of the field condition, with the similar amount of bollworm numbers, the 10 fresh boll weight, lint weight, seed weight, % lint, micronaire fibre strength, and fibre length were found to be higher and better than those of both controls as well. However, further tests in large scale of farmers' field a period of time will have to be undertaken to ascertain the result

  13. Field longevity of a fluorescent protein marker in an engineered strain of the pink bollworm, Pectinophora gossypiella (Saunders.

    Directory of Open Access Journals (Sweden)

    Michelle Walters

    Full Text Available The cotton pest, pink bollworm (Pectinophora gossypiella (Saunders, is a significant pest in most cotton-growing areas around the world. In southwestern USA and northern Mexico, pink bollworm is the target of the sterile insect technique (SIT, which relies on the mass-release of sterile pink bollworm adults to over-flood the wild population and thereby reduce it over time. Sterile moths reared for release are currently marked with a dye provided in their larval diet. There are concerns, however, that this marker fails from time to time, leading to sterile moths being misidentified in monitoring traps as wild moths. This can lead to expensive reactionary releases of sterile moths. We have developed a genetically marked strain that is engineered to express a fluorescent protein, DsRed2, which is easily screened under a specialised microscope. In order to test this marker under field conditions, we placed wild-type and genetically marked moths on traps and placed them in field cages. The moths were then screened, in a double-blind fashion, for DsRed2 fluorescence at regular intervals to determine marker reliability over time. The marker was shown to be robust in very high temperatures and generally proved reliable for a week or longer. More importantly, genotyping of moths on traps by PCR screening of the moths was 100% correct. Our findings indicate that this strain--and fluorescent protein markers in general--could make a valuable contribution to SIT.

  14. Long distance migration in Helicoverpa zea: What we know and need to know

    Science.gov (United States)

    This paper identifies knowledge and knowledge gaps in the areas of biology and ecology, and migratory flight of corn earworm, Helicoverpa zea (Boddie). The paper focuses on results from studies of H. zea population dynamics and migration in Texas during a period of substantial irrigated corn produc...

  15. Molecular cloning and functional characterization of the diapause hormone receptor in the corn earworm Helicoverpa zea

    Science.gov (United States)

    The diapause hormone (DH) in the heliothine moth has shown its activity in termination of pupal diapause, while the orthology in the silkworm is known to induce embryonic diapause. In the current study, we cloned the diapause hormone receptor from the corn earworm Helicoverpa zea (HzDHr) and tested ...

  16. Pink bollworm integrated management using sterile insects under field trial conditions, Imperial Valley, California

    International Nuclear Information System (INIS)

    The pink bollworm moth (Pectinophora gossypiella Saunders) feeds almost exclusively on cotton (Gossypium spp.) and causes economic loss (Pfadt 1978). The pink bollworm (PBW) is often the key pest of cotton in Arizona, southern California, and northwestern Mexico. The larvae (immature stages) bore into the developing cotton fruit, where they feed on the cotton lint and seeds, causing significant damage and dramatically reducing the yield of cotton lint (Pfadt 1978). The PBW is difficult to control with conventional means (insecticides) because it spends the destructive larval phase inside the cotton boll where it is well protected from control measures. Cultural controls, such as a short growing season, have successfully decreased the population in the Imperial Valley (Chu et al. 1992) to the point where eradication may be possible using sterile insects and genetically engineered cotton. Because the PBW is an introduced insect, with few plant hosts other than cultivated cotton, its eradication from continental USA is a desirable and economically attractive alternative to the continued use of pesticides and/or further loss to the pest. Mass releases of sterile insects began in earnest in 1970 in the San Joaquin Valley, California, in order to inhibit normal reproduction and to eradicate the pest in an environmentally responsible manner. Sterile release involves mass production and sexual sterilisation using irradiation (20 krad for PBW adults). This was accomplished by building a rearing facility in Phoenix, AZ. The facility has 6,410 square metres of permanent laboratories, rearing and irradiation chambers and insect packing rooms. The facility operates the year round but with a variable production rate, that is, maximal during the cotton growing season (May through September). Sterile insect technology is based on the monitoring of the native and sterile populations in the field and the subsequent release of appropriate numbers of sterile insects in order to

  17. Genetic control of cotton insects: The pink bollworm as a working programme

    International Nuclear Information System (INIS)

    Establishment of a continuous population has been prevented over a 24 year period in the San Joaquin Valley, USA, through continuous, daily in-season release of sterile pink bollworms based on an extensive trap monitoring programme. A post-harvest crop destruction ordinance and occasional use of pheromones as disruptants were the only other factors used by programme management, except in 1990. In 1990, the programme used a conventional insecticide on 280 acres (113 ha) out of 1.18 million acres (477,546 ha) of cotton. During the four year period 1986-1989, a management system was explored using a high rate pheromone disruption system and sterile insects. Major reductions in conventional insecticide usage, while maintaining extremely low populations, were evident in this semi-isolated valley of southern California. It is hoped that this will provide a model for a future large scale test on up to 20,000 acres (8100 ha) of cotton. (author). 11 refs, 1 fig., 7 tabs

  18. Complete mitochondrial genome of the pink bollworm Pectinophora gossypiella (Lepidoptera: Gelechiidae).

    Science.gov (United States)

    Zhao, Jing; Sun, Yang; Xiao, Liubin; Tan, Yongan; Dai, Hanyang; Bai, Lixin

    2016-05-01

    Pectinophora gossypiella (Lepidoptera: Gelechiidae) is a key pest in many cotton-growing countries of the world. In this study, the complete mitochondrial (mt) genome of the pink bollworm P. gossypiella was determined, which is 15,202 bp in length (GenBank accession number: KM225795) containing 37 typical animal mitochondrial gene and an A + T-rich region. The gene order of P. gossypiella mtDNA was different from the insect ancestral gene order in the translocation of trnM, as shared by previously sequenced lepidopteran mtDNAs. The protein-coding genes (PCGs) have typical mitochondrial start codons ATN, with the exception of COI, Nad5, which uses the start codons CGA, GTT. Eight PCGs stop with complete termination codons (TAA), whereas five PCGs use incomplete stop codon T. All of the tRNA genes had typical cloverleaf secondary structures except for trnS1(AGN), in which the dihydrouridine (DHU) arm did not form a stable stem-loop structure. Like other insects, the control region is located between rrnS and trnM with a length of 309 bp and an A + T content of 94.8%, which is the most AT-rich region and comparatively simple, with little evidence of long tandem repeats, but harbors a conserved structure combining the motif ATAGA and a 18-bp poly-T stretch. PMID:25231711

  19. Effect of host change on demographic fitness of the parasitoid, Trichogramma brassicae.

    Science.gov (United States)

    Iranipour, Shahzad; Vaez, Nahid; Ghanbalani, Ghadir Nouri; Zakaria, Rasoul Asghari; Mashhadi Jafarloo, Mohammad

    2010-01-01

    Trichogramma brassicae (Bezdenko) is the most important species of Trichogramma parasitoids in Iran. The cotton bollworm, Helicoverpa armigera (Hubner) is a polyphagous insect pest that attacks many crops including cotton, maize, soybean, tomato, etc. The bollworm egg is a suitable target for many Trichogramma species. Factitious hosts such as eggs of the flour moth, Anagasta kuehniella (Zeller) and cereal moth, Sitotroga cerealella (Hubner) are used for mass rearing purposes. But a problem that arises sometimes in laboratory cultures is the development of a tendency toward laboratory hosts following a few generations rearing with them. This may tend to a low efficiency on target pest in field conditions. In this study the possibility of declining efficiency of the parasitoid on target pest by developing such a preference to alternative hosts in previous generations were investigated when the flour moth or cereal moth uses as laboratory host. Two generations of T. brassicae were reared on each of the mentioned hosts and then transferred to H. armigera eggs for two further generations. The intrinsic rate of natural increase as well as other life table parameters were used for monitoring fitness of the parasitoid at successive generations. Even generations were included to determine if previously rearing host affected parasitoid performance. Results revealed that host shift from cereal moth to bollworm caused a sudden fall in population growth parameters (both intrinsic rate of natural increase and net replacement rate). Further rearing on bollworm eggs led to a relapse in both parameters. No similar effect was observed in cultures initiated with the flour moth. As a whole, cereal moth was a more suitable host than flour moth. PMID:20673197

  20. In vivo and in vitro metabolism of sitosterol in Heliothis armigera (Huebner) and Locusta migratoria L

    International Nuclear Information System (INIS)

    Since sitosterol is the major plant sterol which fulfills all sterol requirements of H. armigera and L. migratoria, metabolism of dietary 14C sitosterol has been studied in the above insects both, in vivo and in the alimentary canal and fat body in vitro. Radioactivity is detected in cholesterol, isofucosterol and an unidentified sterol in addition to sitosterol indicating that sitosterol is metabolized to cholesterol with isofucosterol being a probable intermediate. Midgut and fat body are the sites of sitosterol dealkylation. The possibility of fucosterol being an intermediate in this dealkylation cannot be ruled out. (author). 25 refs., 3 tabs

  1. Effects of four nematode species on fitness costs of pink bollworm resistance to Bacillus thuringiensis toxin Cry1Ac.

    Science.gov (United States)

    Hannon, Eugene R; Sisterson, Mark S; Stock, S Patricia; Carrière, Yves; Tabashnik, Bruce E; Gassmann, Aaron J

    2010-10-01

    Evolution of resistance by pests can reduce the efficacy oftransgenic crops that produce insecticidal toxins from the bacterium Bacillus thuringiensis Berliner (Bt). In conjunction with refuges of non-Bt host plants, fitness costs can delay the evolution of resistance. Furthermore, fitness costs often vary with ecological conditions, suggesting that agricultural landscapes can be manipulated to magnify fitness costs and thereby prolong the efficacy of Bt crops. In the current study, we tested the effects of four species of entomopathogenic nematodes (Steinernematidae and Heterorhabditidae) on the magnitude and dominance of fitness costs of resistance to Bt toxin CrylAc in pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae). For more than a decade, field populations of pink bollworm in the United States have remained susceptible to Bt cotton Gossypium hirsutum L. producing CrylAc; however, we used laboratory strains that had a mixture of susceptible and resistant individuals. In laboratory experiments, dominant fitness costs were imposed by the nematode Steinernema riobrave Cabanillas, Poinar, and Raulston but no fitness costs were imposed by Steinernema carpocapsae Weiser, Steinernema sp. (ML18 strain), or Heterorhabditis sonorensis Stock, Rivera-Orduño, and Flores-Lara. In computer simulations, evolution of resistance to Cry1Ac by pink bollworm was substantially delayed by treating some non-Bt cotton refuge fields with nematodes that imposed a dominant fitness cost, similar to the cost observed in laboratory experiments with S. riobrave. Based on the results here and in related studies, we conclude that entomopathogenic nematodes could bolster insect resistance management, but the success of this approach will depend on selecting the appropriate species of nematode and environment, as fitness costs were magnified by only two of five species evaluated and also depended on environmental factors. PMID:21061986

  2. Asymmetrical cross-resistance between Bacillus thuringiensis toxins Cry1Ac and Cry2Ab in pink bollworm.

    Science.gov (United States)

    Tabashnik, Bruce E; Unnithan, Gopalan C; Masson, Luke; Crowder, David W; Li, Xianchun; Carrière, Yves

    2009-07-21

    Transgenic crops producing Bacillus thuringiensis (Bt) toxins kill some key insect pests and can reduce reliance on insecticide sprays. Sustainable use of such crops requires methods for delaying evolution of resistance by pests. To thwart pest resistance, some transgenic crops produce 2 different Bt toxins targeting the same pest. This "pyramid" strategy is expected to work best when selection for resistance to 1 toxin does not cause cross-resistance to the other toxin. The most widely used pyramid is transgenic cotton producing Bt toxins Cry1Ac and Cry2Ab. Cross-resistance between these toxins was presumed unlikely because they bind to different larval midgut target sites. Previous results showed that laboratory selection with Cry1Ac caused little or no cross-resistance to Cry2A toxins in pink bollworm (Pectinophora gossypiella), a major cotton pest. We show here, however, that laboratory selection of pink bollworm with Cry2Ab caused up to 420-fold cross-resistance to Cry1Ac as well as 240-fold resistance to Cry2Ab. Inheritance of resistance to high concentrations of Cry2Ab was recessive. Larvae from a laboratory strain resistant to Cry1Ac and Cry2Ab in diet bioassays survived on cotton bolls producing only Cry1Ac, but not on cotton bolls producing both toxins. Thus, the asymmetrical cross-resistance seen here does not threaten the efficacy of pyramided Bt cotton against pink bollworm. Nonetheless, the results here and previous evidence indicate that cross-resistance occurs between Cry1Ac and Cry2Ab in some key cotton pests. Incorporating the potential effects of such cross-resistance in resistance management plans may help to sustain the efficacy of pyramided Bt crops. PMID:19581574

  3. Rearing and gamma radiation effects on mature pupae of pink bollworm and their F1 progeny

    International Nuclear Information System (INIS)

    Pink bollworm larvae were successfully reared in captivity on a casein wheat germ diet. The substitution of casein with soyflour, corn-cob grit and wheat germ, and casein for peanut flour, resulted in delayed development, reduced pupal recovery and fecundity of the adult moths. This reduction was more drastic in corn-cob grit and peanut flour diets. The irradiation of mature pupae at 50-200 Gy resulted in decreased adult emergence with increased gamma radiation doses, and more deformed moths were recorded at a dose of 200 Gy. Adults following irradiation of mature pupae when crossed with untreated males or females or treated individuals crossed to treated exhibited reduced fecundity and fertility with the increasing doses. This reduction was more pronounced when treated males were crossed with treated females. Females were relatively more sensitive to gamma radiation, as a reduced number of eggs was obtained when treated females were crossed with untreated males. At 200 Gy, no F1 progeny were obtained from any cross involving treated parents. The fecundity and fertility were reduced significantly when F1 males or F1 females from male parents irradiated as mature pupae were mated with untreated insects at both 100 and 150 Gy. However, inherited sterility was more pronounced when F1 males were crossed with untreated females than when F1 females were crossed with untreated males. Similarly reduced fecundity and fertility in F1 progeny from female parents irradiated as mature pupae, both at 100 and 150 Gy, were also recorded in crosses as described for male F1 progeny. The fecundity and fertility were the lowest in F1 progeny of both male and female parents irradiated as mature pupae when compared with the F1 progeny of male or female irradiated parents separately. (author). 28 refs, 7 tabs

  4. Inherited Sterility in Progeny of Gamma-Irradiated Spiny Bollworm, Earias Insulana Boisd

    International Nuclear Information System (INIS)

    The inherited sterility of the spiny bollworm Earias Insulana Boisd. Irradiated as parental male adults, with sub sterilizing doses of 100-200 Gy has been studied throughout three successive generations. In general, the female fecundity decreased at the three doses of irradiations (100, 150 and 200 Gy) throughout P1. F1, F2 and F3 generations as compared to control. The reduction was insignificant in all treatments with some exceptions at 200 Gy, in the parental generation and 150 and 200 Gy bin F2 generation. Egg hatch of the parental generation was obviously reduced at 100, 150 and 200 Gy treatments as compared to the control. The progeny of F1 males were evidently more sterile than their irradiated male parents. The effect continued in the F2, population, however F3 males almost regained their fertility. Irradiation of P1 males did not greatly affect mating ability among P1, F1, F2 and F3 generations. The reduction in mating ability was significant only at 200 Gy for P1 males and at 150 and 200 Gy for F1 males as compared to control. Larvae reaching the adult stage decreased in number as the irradiation dose was increased. The effect was obvious at F1 generation. In general, larval and pupal durations were not significantly affected among F1, F2 or F3 generation, except at 100 Gy in the F3 generation. The sex ratio was slightly altered in favour of males at F1 and F2 at the dose level of 200 Gy. The longevity of irradiated male moths (P1) increased significantly at 200 Gy only, while F1 males lived shorter periods than the untreated ones. Adult longevity for males and females throughout F2 and F3 generations did not show any significant differences as compared to untreated adults

  5. Binding and Oligomerization of Modified and Native Bt Toxins in Resistant and Susceptible Pink Bollworm.

    Directory of Open Access Journals (Sweden)

    Josue Ocelotl

    Full Text Available Insecticidal proteins from Bacillus thuringiensis (Bt are used extensively in sprays and transgenic crops for pest control, but their efficacy is reduced when pests evolve resistance. Better understanding of the mode of action of Bt toxins and the mechanisms of insect resistance is needed to enhance the durability of these important alternatives to conventional insecticides. Mode of action models agree that binding of Bt toxins to midgut proteins such as cadherin is essential for toxicity, but some details remain unresolved, such as the role of toxin oligomers. In this study, we evaluated how Bt toxin Cry1Ac and its genetically engineered counterpart Cry1AcMod interact with brush border membrane vesicles (BBMV from resistant and susceptible larvae of Pectinophora gossypiella (pink bollworm, a global pest of cotton. Compared with Cry1Ac, Cry1AcMod lacks 56 amino acids at the amino-terminus including helix α-1; previous work showed that Cry1AcMod formed oligomers in vitro without cadherin and killed P. gossypiella larvae harboring cadherin mutations linked with >1000-fold resistance to Cry1Ac. Here we found that resistance to Cry1Ac was associated with reduced oligomer formation and insertion. In contrast, Cry1AcMod formed oligomers in BBMV from resistant larvae. These results confirm the role of cadherin in oligomerization of Cry1Ac in susceptible larvae and imply that forming oligomers without cadherin promotes toxicity of Cry1AcMod against resistant P. gossypiella larvae that have cadherin mutations.

  6. Characterization of insecticidal peptides from venom Australian funnel-web spiders

    Directory of Open Access Journals (Sweden)

    E. J. Vonorax

    2006-04-01

    Full Text Available Australian funnel-web spiders are relatively large primitive hunting spiders. Male Atrax robustus spiders have been responsible for a number of human deaths. Venom was collected from the species Hadronyche infensa (Hickman [female], H. formidabilis [male and female], H. versuta [female], and A. robustus (Cambridge [male] and was fractionated by high performance liquid chromatography. This resulted in the isolation and purification of a homologous series of 7 insecticidal peptides of relatively low molecular mass (approximately 4kDa. The amino acid sequences of these toxins consisted of 36 or 37 amino acids and were named atracotoxins. For the major bioassay of these toxins, we used the cotton bollworm, Helicoverpa armigera (Hubner, due to the great damage it causes to crops worldwide. These toxins, when injected subcutaneously into fifth or sixth instar larvae of Helicoverpa armigera,were lethal or caused an apparently irreversible writhing. The toxin from H. versuta venom showed no significant toxicity when subcutaneously injected into newborn mice. One of the toxins was found to have a free acid carboxyl terminus. These toxins have great potential as lead compounds for insecticide design or for incorporation in recombinant baculovirus insecticides.

  7. Cotton fertilization using PGPR Bacillus amyloliquefaciens FZB42 and compost: Impact on insect density and cotton yield in North Benin, West Africa

    Directory of Open Access Journals (Sweden)

    Thiery B. Charles Alavo

    2015-12-01

    Full Text Available This work has compared the effects of the biofertilizer Bacillus amyloliquefaciens FZB42 with that of compost for cotton production. The population dynamics of pests and predators have been studied in order to check whether the use of both fertilization materials can contribute to pest management in cotton. Three treatments were considered: (i dressing of seeds in rhizobacteria suspension, (ii introduction of rhizobacterial suspension directly in the pocket, same time with the seeds, and (iii fertilization with compost. The study was carried out in northwest Benin (West Africa. Results showed that cotton aphids, Aphis gossypii, pink bollworm, Pectinophora gossypiella, leaf roller, Sylepta derogata, and cotton bugs, Dysdercus sp. are the major insect pests encountered in the experimental plots. Cotton bollworm, Helicoverpa armigera, was present but under the economic threshold. The coccinellid predators, Cheilomenes spp., occurred in the experimental plots and almost suppressed aphid proliferation. Other natural enemies such as chrysopids and ant species also occurred and probably contributed to maintain the cotton bollworm under the economic threshold. The treatment with seeds dressed with the rhizobacteria suspension yielded 39% more cotton compared to the compost fertilization. The use of both fertilization materials without application of chemicals can contribute to pest management in cotton.

  8. 棉铃虫发生程度与降雨量关系的研究%Studies on the Relationship between Occurrence Degree of Cotton Boll-worm and Rainfall

    Institute of Scientific and Technical Information of China (English)

    刘学义; 王洪涛; 高伟力; 范小九; 李淑英; 卫金燕; 崔素华; 王华; 申予鲁

    2008-01-01

    [Objective] The aim of the study is to investigate the factors causing the outbreak of cotton boUworm and to provide effective measures for con-trolling cotton bollworm. [Method] Based on the analysis of the data about insect and weather situation in Luyi County in 32 years, the meteorological pre-diction model was established for monitoring the quarterly or monthly, occurrence trend of cotton bollworm. [Result] The cotton bnflworm oceurred slightly in the years with rainfalls of 3 months over 500 nm and severely in the years with rainfalls of 3 months less than 400 nm. The results of correlation analysis show that annual occurrence degrees of cotton bollworm and occurrence degrees of 4th generation of cotton bollworm are extremely negatively correlated with rainfall during June - August ; the occurrence degrees of 3rd and 4th generations of cotton bollworra are also extremely negatively correlated with rainfall in July. [Condusion] The occurrence of cotton bollworm in field is heavily influenced by rainfall in at its occurrence stage, moreover, the rainfall during June - August is the decisive factors influencing the occurrence of cotton bollworm.

  9. The recent disciplinal progresses of agricultural entomology in China

    Institute of Scientific and Technical Information of China (English)

    Guo Yuyuan; Liang Gemei

    2009-01-01

    In this paper, four recent advances and achievements of China in agricultural insect research, namely, on the genome of silkworm (Bombyx mori Linnaeus), on the geographical differentiation and regional migration of cotton boll-worm (Helicoverpa armigera (Htthner)) , on the standardized monitoring techniques for safety of honey bee (Apis mel-lifera Linnaeus) products, and on the virus transmission property of small brown planthopper (Laodelphax striatellus (Fallén)) as well as the interactions between vector and rice stripe virus (RSV), were reported. All of these resear-ches are very important for controlling agricultural insect pests and the diseases they transmit, accelerating the molecular biological research of silkworm, and promoting the international trade of honey bee products. Most of these achievements mentioned above have got the national, provincial, ministerial or municipal awards on science and technology.

  10. Effects of entomopathogenic nematodes on evolution of pink bollworm resistance to Bacillus thuringiensis toxin Cry1Ac.

    Science.gov (United States)

    Gassmann, Aaron J; Hannon, Eugene R; Sisterson, Mark S; Stock, S Patricia; Carrière, Yves; Tabashnik, Bruce E

    2012-06-01

    The evolution of resistance by pests can reduce the efficacy of transgenic crops that produce insecticidal toxins from Bacillus thuringiensis (Bt). However, fitness costs may act to delay pest resistance to Bt toxins. Meta-analysis of results from four previous studies revealed that the entomopathogenic nematode Steinernema riobrave (Rhabditida: Steinernematidae) imposed a 20% fitness cost for larvae of pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae), that were homozygous for resistance to Bt toxin Cry1Ac, but no significant fitness cost was detected for heterozygotes. We conducted greenhouse and laboratory selection experiments to determine whether S. riobrave would delay the evolution of pink bollworm resistance to Cry1Ac. We mimicked the high dose/refuge scenario in the greenhouse with Bt cotton (Gossypium hirsutum L.) plants and refuges of non-Bt cotton plants, and in the laboratory with diet containing Cry1Ac and refuges of untreated diet. In both experiments, half of the replicates were exposed to S. riobrave and half were not. In the greenhouse, S. riobrave did not delay resistance. In the laboratory, S. riobrave delayed resistance after two generations but not after four generations. Simulation modeling showed that an initial resistance allele frequency > 0.015 and population bottlenecks can diminish or eliminate the resistance-delaying effects of fitness costs. We hypothesize that these factors may have reduced the resistance-delaying effects of S. riobrave in the selection experiments. The experimental and modeling results suggest that entomopathogenic nematodes could slow the evolution of pest resistance to Bt crops, but only under some conditions. PMID:22812141

  11. Toxicidade de óleo de mamona a Helicoverpa zea e a Trichogramma pretiosum

    OpenAIRE

    Luziani Rezende Bestete; Dirceu Pratissoli; Vagner Tebaldi de Queiroz; Flávio Neves Celestino; Lorena Contarini Machado

    2011-01-01

    O objetivo deste trabalho foi avaliar os efeitos do óleo de mamona sobre a broca-grande do tomateiro, Helicoverpa zea, e sobre o parasitoide de ovos Trichogramma pretiosum. Foi determinada a mortalidade larval da broca, que foi submetida ao óleo de mamona por ingestão e contato às concentrações 0,5, 1,0, 1,5, 2,0, 2,5 e 3,0% (v v-1). A ação do óleo de mamona sobre T. pretiosum foi determinada mediante testes de seletividade e suscetibilidade. As maiores mortalidades de larvas foram observadas...

  12. Similar genetic basis of resistance to Bt toxin Cry1Ac in Boll-selected and diet-selected strains of pink bollworm.

    Directory of Open Access Journals (Sweden)

    Jeffrey A Fabrick

    Full Text Available Genetically engineered cotton and corn plants producing insecticidal Bacillus thuringiensis (Bt toxins kill some key insect pests. Yet, evolution of resistance by pests threatens long-term insect control by these transgenic Bt crops. We compared the genetic basis of resistance to Bt toxin Cry1Ac in two independently derived, laboratory-selected strains of a major cotton pest, the pink bollworm (Pectinophora gossypiella [Saunders]. The Arizona pooled resistant strain (AZP-R was started with pink bollworm from 10 field populations and selected with Cry1Ac in diet. The Bt4R resistant strain was started with a long-term susceptible laboratory strain and selected first with Bt cotton bolls and later with Cry1Ac in diet. Previous work showed that AZP-R had three recessive mutations (r1, r2, and r3 in the pink bollworm cadherin gene (PgCad1 linked with resistance to Cry1Ac and Bt cotton producing Cry1Ac. Here we report that inheritance of resistance to a diagnostic concentration of Cry1Ac was recessive in Bt4R. In interstrain complementation tests for allelism, F(1 progeny from crosses between AZP-R and Bt4R were resistant to Cry1Ac, indicating a shared resistance locus in the two strains. Molecular analysis of the Bt4R cadherin gene identified a novel 15-bp deletion (r4 predicted to cause the loss of five amino acids upstream of the Cry1Ac-binding region of the cadherin protein. Four recessive mutations in PgCad1 are now implicated in resistance in five different strains, showing that mutations in cadherin are the primary mechanism of resistance to Cry1Ac in laboratory-selected strains of pink bollworm from Arizona.

  13. Risk assessment for Helicoverpa zea (Lepidoptera: Noctuidae) resistance on dual-gene versus single-gene corn

    Science.gov (United States)

    Recent changes in EPA regulations have prompted concern in some experts that transgenic corn expressing two lepidopteran-active genes from the soil bacterium Bacillus thuringiensis (Bt) (dual-gene) may result in more rapid selection for resistance in Helicoverpa zea (Boddie) than corn expressing a s...

  14. Engineering a Recombinant Baculovirus with a Peptide Hormone Gene and its Effect on the Corn Earworm, Helicoverpa zea

    Science.gov (United States)

    The helicokinins are peptides identified from Helicoverpa zea that when injected into the larvae were found to cause excessive diuresis and loss of feeding activity. Of the three peptides, helicokinin II (HezK-II) was found to be most potent. A synthetic gene encoding HezK-II was constructed based o...

  15. Characterization of the Helicoverpa assulta nucleopolyhedrovirus genome and sequence analysis of the polyhedrin gene region

    Indian Academy of Sciences (India)

    Soo-Dong Woo; Jae Young Choi; Yeon Ho Je; Byung Rae Jin

    2006-09-01

    A local strain of Helicoverpa assulta nucleopolyhedrovirus (HasNPV) was isolated from infected H. assulta larvae in Korea. Restriction endonuclease fragment analysis, using 4 restriction enzymes, estimated that the total genome size of HasNPV is about 138 kb. A degenerate polymerase chain reaction (PCR) primer set for the polyhedrin gene successfully amplified the partial polyhedrin gene of HasNPV. The sequencing results showed that the about 430 bp PCR product was a fragment of the corresponding polyhedrin gene. Using HasNPV partial predicted polyhedrin to probe the Southern blots, we identified the location of the polyhedrin gene within the 6 kb EcoRI, 15 kb NcoI, 20 kb XhoI, 17 kb BglII and 3 kb ClaI fragments, respectively. The 3 kb ClaI fragment was cloned and the nucleotide sequences of the polyhedrin coding region and its flaking regions were determined. Nucleotide sequence analysis indicated the presence of an open reading frame of 735 nucleotides which could encode 245 amino acids with a predicted molecular mass of 29 kDa. The nucleotide sequences within the coding region of HasNPV polyhedrin shared 73.7% identity with the polyhedrin gene from Autographa californica NPV but were most closely related to Helicoverpa and Heliothis species NPVs with over 99% sequence identity.

  16. Analysis of the Genome of the Sexually Transmitted Insect Virus Helicoverpa zea Nudivirus 2

    Directory of Open Access Journals (Sweden)

    Zhiqiang Lu

    2012-01-01

    Full Text Available The sexually transmitted insect virus Helicoverpa zea nudivirus 2 (HzNV-2 was determined to have a circular double-stranded DNA genome of 231,621 bp coding for an estimated 113 open reading frames (ORFs. HzNV-2 is most closely related to the nudiviruses, a sister group of the insect baculoviruses. Several putative ORFs that share homology with the baculovirus core genes were identified in the viral genome. However, HzNV-2 lacks several key genetic features of baculoviruses including the late transcriptional regulation factor, LEF-1 and the palindromic hrs, which serve as origins of replication. The HzNV-2 genome was found to code for three ORFs that had significant sequence homology to cellular genes which are not generally found in viral genomes. These included a presumed juvenile hormone esterase gene, a gene coding for a putative zinc-dependent matrix metalloprotease, and a major facilitator superfamily protein gene; all of which are believed to play a role in the cellular proliferation and the tissue hypertrophy observed in the malformation of reproductive organs observed in HzNV-2 infected corn earworm moths, Helicoverpa zea.

  17. 影响微孢子虫对棉铃虫幼虫致病力的因子%Factors Affecting Pathogenicity of Microsporidian to Larvae of Helicoverpa armigera

    Institute of Scientific and Technical Information of China (English)

    冉红凡; 潘文亮; 冯书亮; 范秀华; 王容燕

    2003-01-01

    1997年田间调查时,发现一种寄生于棉铃虫的微孢子虫,对棉铃虫具有很强的致病力.为明确环境因子对该微孢子虫及其致病力的影响,测定了温度与紫外线对该微孢子虫及其杀虫效果的影响.结果表明,该微孢子虫孢子耐受温度范围较宽,最高温度上限为55℃.温度对其致病力有显著影响,在一定温度范围内,随着生境温度的升高,微孢子虫对棉铃虫幼虫致病力增强.该微孢子虫对紫外线较敏感,在紫外线照射下易失活而丧失致病力.

  18. Preliminary Study on Insecticidal Activity of Transgenic Corn Expressing Bt Insecticidal Protein Gene to Helicoverpa armigera Hübner%转Bt基因抗虫玉米对棉铃虫杀虫活性的初步评价

    Institute of Scientific and Technical Information of China (English)

    芮昌辉; 范贤林; 孟香清; 董丰收

    2000-01-01

    @@ 国内外在转Bt基因抗虫作物的研究和应用上已取得重大进展,其中Bt抗虫棉已在美国、澳大利亚、中国等进入商品化应用阶段,近年来种植面积增长很快,并取得了显著的经济、生态 和社会效益.

  19. Assessment of Lupin Induced Mutants for Quality Traits and Susceptibility to Callosbruchus chinensis and Heliothis armigera insects

    International Nuclear Information System (INIS)

    This study was conducted to assess 23 induced mutants and two parental varieties Giza1 and Giza2 in the three generations (M3, M4, and M5) for seed quality traits, and susceptibility to two insects i.e C. chinnensis and H.armigera. The obtained results exhibited highly significant decrease for alkaloid content of mutants 20 and 23 as compared with the two local varieties. Most of mutants and Giza 2 showed marked increase for protein content as compared with Giza1, however, the increase did not reach the level of significance for the most mutants as compared with Giza2 in the three generations. Except of M4 generation. marked resistance for infestations with C.chinensis and H.armigera was obtained for mutants 1, 5 and 11 in the three generations. However, for total infestation with the two insects, resistance was obtained in mutants 4 and 10. Except of mutant lines 1, 5 and 11, all mutants showed higher loss percentage than that of the local varieties

  20. Feasibility of integrating radiation-induced F1 sterility and biological control for population suppression of the pink bollworm, Pectinophora gossypiella, in Pakistan

    International Nuclear Information System (INIS)

    Substitution of casein and wheat germ with locally available ingredients (chickpea flour, soybean flour, wheat husk and sawdust) in the specified casein-wheat germ diet affected various biological parameters of pink bollworm (PBW), Pectinophora gossypiella. The diet containing chickpea flour performed significantly better and is more economical than the other diets tested. The highest PBW field populations were recorded in the month of October when large numbers of fruiting bodies were present in the cotton. Field behavioural observations revealed that mating and other sexual activities of treated and native moths varied significantly with time of night and peak activity was during 03:00-04:00 hours. Male moths treated with 100 Gy as mature pupae responded well to gossyplure baited traps. The attraction of male moths to irradiated virgin females decreased significantly with increasing doses of radiation. Male moths responded more readily to virgin untreated females than to irradiated females. Field-cage studies demonstrated that irradiated moths (100 Gy) released at a 50:1 treated to normal ratio at three week intervals reduced larval infestations inside the cages to subeconomic level. Studies suggested that there is a great potential for integrating the egg parasitoid, Trichogramma chilonis, with the sterile insect technique to control cotton bollworms. (author)

  1. Evolution of Resistance by Helicoverpa zea (Lepidoptera: Noctuidae) Infesting Insecticidal Crops in the Southern United States.

    Science.gov (United States)

    Pan, Zaiqi; Onstad, David; Crain, Philip; Crespo, Andre; Hutchison, William; Buntin, David; Porter, Pat; Catchot, Angus; Cook, Don; Pilcher, Clint; Flexner, Lindsey; Higgins, Laura

    2016-04-01

    We created a deterministic, frequency-based model of the evolution of resistance by corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), to insecticidal traits expressed in crops planted in the heterogeneous landscapes of the southern United States. The model accounts for four generations of selection by insecticidal traits each year. We used the model results to investigate the influence of three factors on insect resistance management (IRM): 1) how does adding a third insecticidal trait to both corn and cotton affect durability of the products, 2) how does unstructured corn refuge influence IRM, and 3) how do block refuges (50% compliance) and blended refuges compare with regard to IRM? When Bt cotton expresses the same number of insecticidal traits, Bt corn with three insecticidal traits provides longer durability than Bt corn with two pyramided traits. Blended refuge provides similar durability for corn products compared with the same level of required block refuge when the rate of refuge compliance by farmers is 50%. Results for Mississippi and Texas are similar, but durabilities for corn traits are surprisingly lower in Georgia, where unstructured corn refuge is the highest of the three states, but refuge for Bt cotton is the lowest of the three states. Thus, unstructured corn refuge can be valuable for IRM but its influence is determined by selection for resistance by Bt cotton. PMID:26637533

  2. Incipient resistance of Helicoverpa punctigera to the Cry2Ab Bt toxin in Bollgard II cotton.

    Directory of Open Access Journals (Sweden)

    Sharon Downes

    Full Text Available Combinations of dissimilar insecticidal proteins ("pyramids" within transgenic plants are predicted to delay the evolution of pest resistance for significantly longer than crops expressing a single transgene. Field-evolved resistance to Bacillus thuringiensis (Bt transgenic crops has been reported for first generation, single-toxin varieties and the Cry1 class of proteins. Our five year data set shows a significant exponential increase in the frequency of alleles conferring Cry2Ab resistance in Australian field populations of Helicoverpa punctigera since the adoption of a second generation, two-toxin Bt cotton expressing this insecticidal protein. Furthermore, the frequency of cry2Ab resistance alleles in populations from cropping areas is 8-fold higher than that found for populations from non-cropping regions. This report of field evolved resistance to a protein in a dual-toxin Bt-crop has precisely fulfilled the intended function of monitoring for resistance; namely, to provide an early warning of increases in frequencies that may lead to potential failures of the transgenic technology. Furthermore, it demonstrates that pyramids are not 'bullet proof' and that rapid evolution to Bt toxins in the Cry2 class is possible.

  3. Unique synteny and alternate splicing of the chitin synthases in closely related heliothine moths.

    Science.gov (United States)

    Shirk, Paul D; Perera, Omaththage P; Shelby, Kent S; Furlong, Richard B; LoVullo, Eric D; Popham, Holly J R

    2015-12-10

    Chitin is an extracellular biopolymer that contributes to the cuticular structural matrix in arthropods. As a consequence of its rigid structure, the chitinous cuticle must be shed and replaced to accommodate growth. Two chitin synthase genes that encode for chitin synthase A (ChSA), which produces cuticular exoskeleton, and chitin synthase B (ChSB), which produces peritrophic membrane, were characterized in the genomes of two heliothine moths: the corn earworm/cotton bollworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) and the cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae). In both moths, the two genes were arranged in tandem with the same orientation on the same strand with ChSB located 5' of ChSA. Sequence comparisons showed that the coding sequences were highly conserved with homologues from other species but that the tandem juxtaposed genomic arrangement of the two genes was unique in these insects. The mechanism that has led to this arrangement is unclear but is most likely a recent recombinational event. Transcript mapping of HzChSB and HzChSA in H. zea demonstrated that both transcripts were differentially spliced in various tissues and larval stages. The identification of the HzChSB-E12b alternate spliced transcript is the first report of alternate splicing for the ChSB group. The importance of this splice form is not clear because the protein produced would lack any enzymatic activity but retain the membrane insertion motifs. As for other insects, these genes provide an important target for potential control through RNAi but also provide a subject for broad scale genomic recombinational events. PMID:26253161

  4. Structural organization of the Helicoverpa zea gene encoding the precursor protein for pheromone biosynthesis-activating neuropeptide and other neuropeptides.

    OpenAIRE

    Ma, P W; Knipple, D C; Roelofs, W.L.

    1994-01-01

    Sex pheromone biosynthesis in a number of moth species is induced by a conserved 33-amino acid amidated neuropeptide PBAN (pheromone biosynthesis-activating neuropeptide). We have isolated and characterized the Helicoverpa zea PBAN cDNA corresponding to a 766-nucleotide mRNA that is expressed in the subesophageal ganglion of adult moths. This mRNA is encoded on a transcription unit comprising 6 exons. The longest open reading frame of the cDNA encodes a 194-amino acid precursor protein that c...

  5. Diapause hormone in the corn earworm, Helicoverpa zea: Optimum temperature for activity, structure–activity relationships, and efficacy in accelerating flesh fly pupariation

    Czech Academy of Sciences Publication Activity Database

    Zhang, Q.; Žďárek, Jan; Nachman, R. J.; Denlinger, D. L.

    2008-01-01

    Roč. 29, č. 2 (2008), s. 196-205. ISSN 0196-9781 Institutional research plan: CEZ:AV0Z40550506 Keywords : diapause hormone * neuropeptide analogs * diapause termination * pupariation * Helicoverpa zea Subject RIV: CC - Organic Chemistry Impact factor: 2.565, year: 2008

  6. Diapause hormone in the corn earworm, Helicoverpa zea: Optimum temperature for activity, structure-activity relationships, and efficacy in accelerating flesh fly pupariation

    Science.gov (United States)

    Diapause hormone (DH) effectively terminated pupal diapause in Helicoverpa zea. This effect was temperature-dependent, with an optimum of 21 degrees C. The dose-response curve indicated an ED50 of DH for diapause termination of approximately 100 pmol. The core sequence and essential amino acids w...

  7. Toxicidade de óleo de mamona a Helicoverpa zea e a Trichogramma pretiosum

    Directory of Open Access Journals (Sweden)

    Luziani Rezende Bestete

    2011-08-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos do óleo de mamona sobre a broca-grande do tomateiro, Helicoverpa zea, e sobre o parasitoide de ovos Trichogramma pretiosum. Foi determinada a mortalidade larval da broca, que foi submetida ao óleo de mamona por ingestão e contato às concentrações 0,5, 1,0, 1,5, 2,0, 2,5 e 3,0% (v v-1. A ação do óleo de mamona sobre T. pretiosum foi determinada mediante testes de seletividade e suscetibilidade. As maiores mortalidades de larvas foram observadas no tratamento por contato com as menores concentrações (0,5 e 1,0%, enquanto com as concentrações intermediárias (1,5; 2,0 e 2,5%, não houve diferença entre as vias de aplicação. À maior concentração testada (3,0%, o tratamento por ingestão proporcionou mortalidade superior àquela obtida por contato. O número de ovos parasitados por T. pretiosum, no teste de seletividade, foi afetado negativamente pelo óleo de mamona, contudo, os demais parâmetros avaliados quanto à seletividade e à suscetibilidade não foram afetados. O óleo de mamona reduz a sobrevivência de larvas de H. zea tanto por ingestão quanto por contato. Além disso, não prejudica o desenvolvimento de T. pretiosum, desde que as pulverizações sejam realizadas após as liberações do parasitoide.

  8. Integration of inherited sterility and other pest management strategies for Helicoverpa zea: Status and potential

    International Nuclear Information System (INIS)

    The corn earworm, Helicoverpa zea (Boddie), is one of the most destructive pests of field crops in the United States of America. Currently, control of H. zea is achieved almost entirely through the use of synthetic insecticides. However, successful application of the inherited sterility principle to a wild population of H. zea during a pilot test has encouraged further development of this pest control strategy. Data from recent studies and population models suggest that the full potential of inherited sterility as an area wide control strategy for H. zea and other lepidopteran pests may be realized only when inherited sterility is integrated with other suppression methods. Applications of singular, non-insecticidal methods for area wide suppression of H. zea have had limited success and have been vulnerable to temporary programme failures (e.g. inclement weather, reduced insect rearing output, etc.). An integrated approach would be horizontally diversified through the use of several strategies which use different modes of action and, therefore, would be less vulnerable to temporary programme failures than would a single strategy. Combining two or more control strategies with additive effects may increase programme efficiency. However, the greatest benefit in combining inherited sterility with other control strategies is the dynamic synergistic effects. The demonstrated potential of inherited sterility to reduce the reproductive ability of H. zea and the demonstrated capacity of inherited sterility to perform compatibly and synergistically with other control strategies suggest that inherited sterility should be major component of future integrated approaches to managing H. zea. (author). 13 refs, 2 figs

  9. Rice8987 g_array: cDNA information: 6783 [

    Lifescience Database Archive (English)

    Full Text Available g_6783 SA0966 >HVSCOAT_1(L37299|pid:g609504) Helicoverpa armigera Stunt Virus RNA2 coat protein ... tics, makes tube-like structures when expressed in bacteria , unstable when expressed in baculovirus, start cod ...

  10. Suppression of feral Helicoverpa zea (Lepidoptera: Noctuidae) populations following the infusion of inherited sterility from released substerile males

    International Nuclear Information System (INIS)

    A pilot test was conducted in small mountain valleys from 1986 through 1990 in western North Carolina to assess the influence of released, substerilized males on wild populations of Helicoverpa zea (Boddie), and to measure the level of inherited sterility in wild populations. The number of wild males captured per ha was positively correlated with the distance from the release site of irradiated males. Analyses of seasonal population curves of wild H. zea males calculated from mark-recapture data suggest that seasonal increases of wild H. zea males were significantly delayed or reduced (or both) in mountain valleys where irradiated males were released. The incidence of larvae with chromosomal aberrations (progeny of irradiated, released males) collected from the test sites during the growing seasons indicated that irradiated males were competitive with wild males in mating with wild females, and were successful in producing F1 progeny which further reduced the wild population

  11. Identification of a G protein-coupled receptor for pheromone biosynthesis activating neuropeptide from pheromone glands of the moth Helicoverpa zea

    OpenAIRE

    Choi, Man-Yeon; Fuerst, Emily-Jean; Rafaeli, Ada; Jurenka, Russell

    2003-01-01

    Pheromone biosynthesis-activating neuropeptide (PBAN), a peptide produced by the subesophageal ganglion, is used by a variety of moths to regulate pheromone production. PBAN acts directly on pheromone gland cells by using calcium and cAMP as second messengers. We have identified a gene encoding a G protein-coupled receptor (GPCR) from pheromone glands of the female moth Helicoverpa zea. The gene was identified based on sequence identity to a group of GPCRs from Drosoph...

  12. Inherited Sterility Induced in Progeny of Gamma Irradiated Males Spiny Bollworm, Earias insulana Boisd. II. Effect on Larval and Pupal Mortality, Development and Sex Ratio

    International Nuclear Information System (INIS)

    Spiny bollworm, Earias insulana Boisd. adult males were irradiated with sub sterilizing doses of 50,80,100 and 150 Gray (Gy) of gamma radiation. The number of surviving larvae was dose dependant and larval/pupal mortality increased as the dose applied to P1 males was increased. The larval mortality among F3 was reduced compared with that of the F1 and F2. The average developmental time from egg hatch to adult emergence at the four tested doses was slightly affected among the progeny descendant of irradiated P1 males through the three successive generations. The percentage of adult emergence was evidently reduced among F1 and F2 progeny resulting from parental males exposed to the three higher irradiation doses (80,100 and 150 Gy).The sex ratio was slightly altered in favor of males among the majority of all treatments. Raman studies of irradiated and unirradiated stones at different temperatures and irradiation times showed a relation between the bands of scattered peaks corresponding to (OH) stretching modes of vibration with the color changes

  13. Inherited sterility induced in progeny of gamma irradiated males and females spiny bollworm, Earias Insulana boisd ,effect on fecundity, fertility and mating

    International Nuclear Information System (INIS)

    adult males and females, less than 24 hours old, of the spiny bollworm, Earias Insulana boisd. were irradiated with sub sterilizing doses of 50,80,100 and 150 gray (Gy). treated moths were out crossed with normal adults and observed for their ability to reproduce. inherited deleterious effects resulting from irradiation of p1 moths were recorded for several generations. the reduction in both fecundity and egg viability increased by increasing the dose applied to p1 adult moths .at all tested doses, the females were more radiosensitive than males, as for reduction in fecundity and egg viability. the progeny from irradiated parental females are not as sterile as the progeny from irradiated parental males. the reduction of egg hatching continued in the progeny of irradiated males through F1 and to lesser extent through F2 .on the other hand , irradiation of P1 females reduced the rate of egg hatching among parental generation and to lesser extent among the first filial generation . in general, gamma irradiation did not significantly affect the mating ability or mating frequency among P1 nd their F1 and F2 generations

  14. Capturing the interaction types of two Bt toxins Cry1Ac and Cry2Ab on suppressing the cotton bollworm by using multi-exponential equations.

    Science.gov (United States)

    Shi, Pei-Jian; Wei, Ji-Zhen; Sandhu, Hardev S; Liang, Ge-Mei

    2016-08-01

    Transgenic crops are increasingly promoted for their practical effects on suppressing certain insect pests, but all transgenic crops are not equally successful. The insect pests can easily develop resistance against single Bacillus thuringiensis (Bt) toxin transgenic crops. Therefore, transgenic crops including two or more mixed Bt-toxins can solve this problem by delaying the resistance development and killing the majority of targeted pests before the evolution of resistance. It is important to test the controlling effects of transgenic crops including multiple mixed toxins on a particular insect pest. Previous research has checked the cross-resistance and interactions between Bt toxins Cry1Ac and Cry2Ab against one susceptible and four resistant strains of cotton bollworm. The results showed that independence was the main interaction type between two toxins for the susceptible strain, whereas synergism was the main interaction type for any one resistant strain. However, the optimal combinations of two toxins were not obtained. In the present study, we developed two multi-exponential equations (namely bi- and tri-exponential equations) to describe the combination effects of two Bt toxins. Importantly, the equations can provide predictions of combination effects of different continuous concentrations of two toxins. We compared these two multi-exponential equations with the generalized linear model (GLM) in describing the combination effects, and found that the bi- and tri-exponential equations are better than GLM. Moreover, the bi-exponential equation can also provide the optimal dose combinations for two toxins. PMID:26314801

  15. Spotted bollworm : effects of substerilizing doses of gamma radiation to the male parent on development and level of sterility in F1 progeny

    International Nuclear Information System (INIS)

    Males of spotted bollworm of cotton, Earias vittella F. were irradiated with substerilizing doses of 75,100 and 125 Gy and were crossed with untreated females. Level of sterility induced among males was found to increase with increasing dose when evaluated on the basis of egg hatch. Survival and development of F1 larva showed dose dependent response. F1 male progeny from 75 Gy irradiated males were found to be more sterile than F1 female progeny when outcrossed to normal partners. In the case of 100 Gy treatment to male parent, F1 males were completely sterile and F1 females were partially sterile. Intercross between F1 males and females at all doses tested also resulted in no progeny production. However, both sexes of F1 progeny from male parent exposed to 125 Gy were completely sterile too. There was a marginal shift in favour of males in the lowest dose treatment given to the p1 male. (author). 3 tabs., 23 refs

  16. Evaluación de Diferentes Especies de Trichogramma spp. para el Control de Helicoverpa zea (Boddie (Lepidoptera: Noctuidae Evaluation of Different Species of Trichogramma spp. to the Control of Helicoverpa zea (Boddie (Lepidoptera: Noctuidae

    Directory of Open Access Journals (Sweden)

    Claudia Velásquez F

    2006-12-01

    Full Text Available El cultivo del maíz (Zea mays L. es dañado anualmente por larvas del gusano del choclo, Helicoverpa zea (Boddie (Lepidoptera: Noctuidae. Se realizaron dos estudios con el objeto de definir la especie de Trichogramma más adecuada para el control del gusano del choclo. En laboratorio se comparó el parasitismo de T. nerudai, T. maidis, T. evanescens, T. cacoeciae, T. pretiosum (raza 1 y T. pretiosum (raza 2, sobre huevos de H. zea, Sitotroga cerealella y Anagasta kuehniella, evaluando el porcentaje de parasitismo a los siete días de exposición. La especie nativa T. nerudai resultó con igual o superior eficiencia de parasitación que las especies introducidas, por lo cual se seleccionó para el ensayo de campo. En el campo se evaluó el efecto de cuatro densidades de liberación 200.000; 400.000; 800.000 y 1.600.000 huevos parasitados ha-1 de la especie nativa T. nerudai sobre H. zea en el cultivo del maíz. Con la mayor densidad de liberación, el daño se redujo en valores cercanos al 20%, comparada con el testigo que tuvo un 90,5% de daño El uso de Trichogramma se presenta como una alternativa efectiva en el control de esta plagaCorn (Zea mays L. crops are damaged every year by corn earworm Helicoverpa zea (Boddie larvae (Lepidoptera: Noctuidae. Two studies were carried out with the objective of defining the most adequate Trichogramma species to control the corn earworm. In the laboratory Trichogramma nerudai, T. maidis, T. evanescens, T. cacoeciae, T. pretiosum (strain 1 and T. pretiosum (strain 2 parasitism rates were compared on H. zea, Sitotroga cerealellaand Anagasta kuehniella eggs evaluating the percentage of parasitism at seven days after exposition. Native T. nerudai was effective or superior to the imported species, and it was, therefore, selected for field trials. The remaining tested Trichogramma species were less effective. In the field experiments the effect of four densities (200 000, 400 000, 800 000 and 1 600 000

  17. Biological and Histological Studies on The Effect of Gamma Irradiation on Sex Pheromone Gland of Female Spiny Bollworm Earias Insulana Boisd

    International Nuclear Information System (INIS)

    The present study was carried out to investigate the effect of sex pheromone extraction and bioassay production male attractiveness to alive females on male response and the histological structure of pheromone glands in normal and irradiated females of the spiny bollworm, Earias insulana Boisd. with 100 and 150 Gy. Reproduction of adults irradiated as moths less than 24 hours old or three days was also investigated. Sex pheromone extracts from 1 day old females were less active than those from 3 day old females. The percentage of male moths response to alive female moths at 1 day old was lower than at 3 days old. The sex pheromone production by females was increased as the females became older (from 3 days old to up). The gland of normal female moths is found between 8th and 9th abdominal segments travelling deep inside the body cavity and has large, darkly stained and well defined epithelial cells. The scent gland is of the well developed, tubular and closed ring shaped type. In parental females less than 24 hours old irradiated with 100 Gy, the glandular epithelial cells became loose, rupture, disappeared, shrink, irregular, abnormal or broken and were separated from each other and their nuclei were not clear. The scales were abnormal or loose and there are many vacuoles. The histological effects following gamma irradiation were also noticed in case of parental moths irradiated with 150 Gy. The glandular epithelial cells lost their peculiar shape with the appearance of some vacuoles between them, broken and disappeared in another place and also many secretory cells disappeared and the glands showed increasing. The effects of radiation were continued among females of F1 , generation moths less than 24 hours old descendant of irradiated parental male with 100 and 150 Gy and decreased the fecundity and egg hatch ability significantly. The effect was dose dependent

  18. How does atmospheric elevated CO2 affect crop pests and their natural enemies? Case histories from China

    Institute of Scientific and Technical Information of China (English)

    Yu-Cheng Sun; Jin Yin; Fa-Jun Chen; Gang Wu; Feng Ge

    2011-01-01

    Global atmospheric CO2 concentrations have risen rapidly since the Industrial Revolution and are considered as a primary factor in climate change.The effects of elevated CO2 on herbivore insects were found to be primarily through the CO2-induced changes occurring in their host plants,which then possibly affect the intensity and frequency of pest outbreaks on crops.This paper reviews several ongoing research models using primary pests of crops (cotton bollworm,whitefly,aphids) and their natural enemies (ladybeetles,parasitoids) in China to examine insect responses to elevated CO2.It is generally indicated that elevated CO2 prolonged the development of cotton bollworm,Helicoverpa armigera,a chewing insect,by decreasing the foliar nitrogen of host plants.In contrast,the phloemsucking aphid and whitefly insects had species-specific responses to elevated CO2 because of complex interactions that occur in the phloem sieve elements of plants.Some aphid species,such as cotton aphid,Aphis gossypii and wheat aphid,Sitobion avenae,were considered to represent the only feeding guild to respond positively to elevated CO2 conditions.Although whitefly,Bemisia tabaci,a major vector of Tomato yellow leaf curl virus,had neutral response to elevated CO2,the plants became less vulnerable to the virus infection under elevated CO2.The predator and parasitoid response to elevated CO2 were frequently idiosyncratic.These documents from Chinese scientists suggested that elevated CO2 initially affects the crop plant and then cascades to a higher trophic level through the food chain to encompass herbivores (pests),their natural enemies,pathogens and underground nematodes,which disrupt the natural balance observed previously in agricultural ecosystems.

  19. 我国棉铃虫研究核心期刊载文计量分析%Quantitative Analysis on Cotton Bollworm Literatures Published in Core Journals in China

    Institute of Scientific and Technical Information of China (English)

    苑士涛

    2012-01-01

    [ Objective ] The study aimed to provide the literature data for further research on the prevention and control of the occurrence of the cotton bollworm. [ Method ] Based on the documentmetrology analysis method, with Chinese Journal Full-text Database published by China Academic Journal Electronic Magazine Office as the data sources, the statistical analysis were conduct on the year number, research field, core journals, the main publishing unit for the research literature in the-relevant core journals about cotton bollworm in China in 2001 -2010. [Result] It was concluded that the effective literature about the cotton bollworm was 519 articles; the paper number relevant with the cotton bollworm published in Chinese core periodicals in 2001 -2010 showed the decreasing trend; on the study of cotton bollworm, the Chinese agricultural workers paid the more attention to the occurrence and control in the field and had some research on the ecological, physiological and behavior, etc. At same time; the Acta Entomologica Sinica was the core journals that published the largest literature number, followed by the Chinese Cotton and the Insects Knowledge; the main output units in the literature was 5 institutes such as Plant Protection Institute of Jiangsu A-cademy of Agricultural Sciences, Animal Institute of Chinese Academy of Sciences. [Conclusion] The research provided the valuable literature data for the study on the occurrence and damage of cotton bollwonn in China.%[目的]为进一步研究棉铃虫的发生与防治提供文献数据.[方法]基于文献计量学分析方法,以中国学术期刊电子杂志社的《中国期刊全文数据库》为数据来源,对2001 ~ 2010年我国有关棉铃虫核心期刊研究文献的年份数量、研究领域、核心期刊、文献主要产出单位情况进行统计分析.[结果]得出棉铃虫研究文献有效篇目519篇;2001 ~ 2010年我国核心期刊发表的棉铃虫相关论文数量呈逐年递减的趋

  20. Transgenic plants expressing the AaIT/GNA fusion protein show increased resistance and toxicity to both chewing and sucking pests.

    Science.gov (United States)

    Liu, Shu-Min; Li, Jie; Zhu, Jin-Qi; Wang, Xiao-Wei; Wang, Cheng-Shu; Liu, Shu-Sheng; Chen, Xue-Xin; Li, Sheng

    2016-04-01

    The adoption of pest-resistant transgenic plants to reduce yield losses and decrease pesticide use has been successful. To achieve the goal of controlling both chewing and sucking pests in a given transgenic plant, we generated transgenic tobacco, Arabidopsis, and rice plants expressing the fusion protein, AaIT/GNA, in which an insecticidal scorpion venom neurotoxin (Androctonus australis toxin, AaIT) is fused to snowdrop lectin (Galanthus nivalis agglutinin, GNA). Compared with transgenic tobacco and Arabidopsis plants expressing AaIT or GNA, transgenic plants expressing AaIT/GNA exhibited increased resistance and toxicity to one chewing pest, the cotton bollworm, Helicoverpa armigera. Transgenic tobacco and rice plants expressing AaIT/GNA showed increased resistance and toxicity to two sucking pests, the whitefly, Bemisia tabaci, and the rice brown planthopper, Nilaparvata lugens, respectively. Moreover, in the field, transgenic rice plants expressing AaIT/GNA exhibited a significant improvement in grain yield when infested with N. lugens. This study shows that expressing the AaIT/GNA fusion protein in transgenic plants can be a useful approach for controlling pests, particularly sucking pests which are not susceptible to the toxin in Bt crops. PMID:25641865

  1. Genomewide transcriptional signatures of migratory flight activity in a globally invasive insect pest.

    Science.gov (United States)

    Jones, Christopher M; Papanicolaou, Alexie; Mironidis, George K; Vontas, John; Yang, Yihua; Lim, Ka S; Oakeshott, John G; Bass, Chris; Chapman, Jason W

    2015-10-01

    Migration is a key life history strategy for many animals and requires a suite of behavioural, morphological and physiological adaptations which together form the 'migratory syndrome'. Genetic variation has been demonstrated for many traits that make up this syndrome, but the underlying genes involved remain elusive. Recent studies investigating migration-associated genes have focussed on sampling migratory and nonmigratory populations from different geographic locations but have seldom explored phenotypic variation in a migratory trait. Here, we use a novel combination of tethered flight and next-generation sequencing to determine transcriptomic differences associated with flight activity in a globally invasive moth pest, the cotton bollworm Helicoverpa armigera. By developing a state-of-the-art phenotyping platform, we show that field-collected H. armigera display continuous variation in flight performance with individuals capable of flying up to 40 km during a single night. Comparative transcriptomics of flight phenotypes drove a gene expression analysis to reveal a suite of expressed candidate genes which are clearly related to physiological adaptations required for long-distance flight. These include genes important to the mobilization of lipids as flight fuel, the development of flight muscle structure and the regulation of hormones that influence migratory physiology. We conclude that the ability to express this complex set of pathways underlines the remarkable flexibility of facultative insect migrants to respond to deteriorating conditions in the form of migratory flight and, more broadly, the results provide novel insights into the fundamental transcriptional changes required for migration in insects and other taxa. PMID:26331997

  2. Insect eggs can enhance wound response in plants: a study system of tomato Solanum lycopersicum L. and Helicoverpa zea Boddie.

    Science.gov (United States)

    Kim, Jinwon; Tooker, John F; Luthe, Dawn S; De Moraes, Consuelo M; Felton, Gary W

    2012-01-01

    Insect oviposition on plants frequently precedes herbivory. Accumulating evidence indicates that plants recognize insect oviposition and elicit direct or indirect defenses to reduce the pressure of future herbivory. Most of the oviposition-triggered plant defenses described thus far remove eggs or keep them away from the host plant or their desirable feeding sites. Here, we report induction of antiherbivore defense by insect oviposition which targets newly hatched larvae, not the eggs, in the system of tomato Solanum lycopersicum L., and tomato fruitworm moth Helicoverpa zea Boddie. When tomato plants were oviposited by H. zea moths, pin2, a highly inducible gene encoding protease inhibitor2, which is a representative defense protein against herbivorous arthropods, was expressed at significantly higher level at the oviposition site than surrounding tissues, and expression decreased with distance away from the site of oviposition. Moreover, more eggs resulted in higher pin2 expression in leaves, and both fertilized and unfertilized eggs induced pin2 expression. Notably, when quantified daily following deposition of eggs, pin2 expression at the oviposition site was highest just before the emergence of larvae. Furthermore, H. zea oviposition primed the wound-induced increase of pin2 transcription and a burst of jasmonic acid (JA); tomato plants previously exposed to H. zea oviposition showed significantly stronger induction of pin2 and higher production of JA upon subsequent simulated herbivory than without oviposition. Our results suggest that tomato plants recognize H. zea oviposition as a signal of impending future herbivory and induce defenses to prepare for this herbivory by newly hatched neonate larvae. PMID:22616005

  3. Bt Maize Seed Mixtures for Helicoverpa zea (Lepidoptera: Noctuidae): Larval Movement, Development, and Survival on Non-transgenic Maize.

    Science.gov (United States)

    Burkness, Eric C; Cira, T M; Moser, S E; Hutchison, W D

    2015-12-01

    In 2012 and 2013, field trials were conducted near Rosemount, MN, to assess the movement and development of Helicoverpa zea (Boddie) larvae on non-Bt refuge corn plants within a seed mixture of non-Bt and Bt corn. The Bt corn hybrid expressed three Bt toxins-Cry1Ab, Cry1F, and Vip3A. As the use of seed mixtures for insect resistance management (IRM) continues to be implemented, it is necessary to further characterize how this IRM approach impacts resistance development in ear-feeding Lepidopteran pests. The potential for Bt pollen movement and cross pollination of the non-Bt ears in a seed mixture may lead to Bt toxin exposure to larvae developing on those refuge ears. Larval movement and development by H. zea, feeding on non-Bt refuge plants adjacent to either transgenic Bt or non-Bt plants, were measured to investigate the potential for unintended Bt exposure. Non-Bt plants were infested with H. zea eggs and subplots were destructively sampled twice per week within each treatment to assess larval development, location, and kernel injury. Results indicate that H. zea larval movement between plants is relatively low, ranging from 2-16% of larvae, and occurs mainly after reaching the second instar. Refuge plants in seed mixtures did not produce equivalent numbers of H. zea larvae, kernel injury, and larval development differed as compared with a pure stand of non-Bt plants. This suggests that there may be costs to larvae developing on refuge plants within seed mixtures and additional studies are warranted to define potential impacts. PMID:26318006

  4. Helicoverpa zea (Lepidoptera: Noctuidae) and Spodoptera frugiperda (Lepidoptera: Noctuidae) Responses to Sorghum bicolor (Poales: Poaceae) Tissues From Lowered Lignin Lines.

    Science.gov (United States)

    Dowd, Patrick F; Sattler, Scott E

    2015-01-01

    The presence of lignin within biomass impedes the production of liquid fuels. Plants with altered lignin content and composition are more amenable to lignocellulosic conversion to ethanol and other biofuels but may be more susceptible to insect damage where lignin is an important resistance factor. However, reduced lignin lines of switchgrasses still retained insect resistance in prior studies. Therefore, we hypothesized that sorghum lines with lowered lignin content will also retain insect resistance. Sorghum excised leaves and stalk pith Sorghum bicolor (L.) Moench (Poales: Poaceae) from near isogenic brown midrib (bmr) 6 and 12 mutants lines, which have lowered lignin content and increased lignocellulosic ethanol conversion efficiency, were examined for insect resistance relative to wild-type (normal BTx623). Greenhouse and growth chamber grown plant tissues were fed to first-instar larvae of corn earworms, Helicoverpa zea (Boddie) and fall armyworms Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), two sorghum major pests. Younger bmr leaves had significantly greater feeding damage in some assays than wild-type leaves, but older bmr6 leaves generally had significantly less damage than wild-type leaves. Caterpillars feeding on the bmr6 leaves often weighed significantly less than those feeding on wild-type leaves, especially in the S. frugiperda assays. Larvae fed the pith from bmr stalks had significantly higher mortality compared with those larvae fed on wild-type pith, which suggested that bmr pith was more toxic. Thus, reducing lignin content or changing subunit composition of bioenergy grasses does not necessarily increase their susceptibility to insects and may result in increased resistance, which would contribute to sustainable production. PMID:25601946

  5. 棉铃虫核型多角体病毒感染对宿主昆虫GST活性及其表达水平的影响%Effect of Helicoverpa armigera nucleopolyhedrovirus infection on GST activity and GST expression on host insect

    Institute of Scientific and Technical Information of China (English)

    黄诗迪; 黄彩萍; 于欢; 王敦

    2015-01-01

    [目的]研究棉铃虫核型多角体病毒(HearNPV)感染宿主昆虫后对宿主谷胱甘肽S转移酶(GST)活性与基因表达水平的影响,明确病毒在侵染宿主过程中对宿主昆虫GST的调控作用.[方法]采用50和100 PIB/只2种剂量的HearNPV病毒感染3龄棉铃虫,测定感染后不同时间试虫中肠GST活性与其编码基因的表达水平,对比分析病毒感染与未感染健康试虫的GST活性及其编码基因表达水平的差异.[结果]棉铃虫在HearNPV感染初期,GST活性显著提高,同时GST表达水平显著上调;随着感染时间的推移,GST活性与其编码基因的表达水平均显著下降,表明病毒感染后对宿主昆虫GST活性的影响与其对GST表达水平的调控相关.[结论]HearNPV感染棉铃虫过程中,病毒入侵能够激活宿主GST基因的表达,但病毒的持续感染最终会抑制GST编码基因的表达水平.

  6. Actividad de polvo, extractos y aceite esencial de Peumus boldus Molina solos y en mezcla con Bacillus thuringiensis Berliner contra Spodoptera frugiperda (J.E. Smith) y Helicoverpa zea (Boddie).

    OpenAIRE

    Silva Aguayo, Gonzalo Iván

    2010-01-01

    Se evaluaron en condiciones de laboratorio e invernadero las propiedades insecticidas del polvo, aceite esencial y extracto en cloruro de metileno de Boldo (Peumus boldus Molina), además del alcaloide boldina y el terpeno 1-8-cineol (eucaliptol), solos y en combinación con Bacillus thuringiensis Berliner contra larvas de Spodoptera frugiperda (J.E. Smith) y Helicoverpa zea Boddie. Se realizaron bioensayos para evaluar mortalidad, efecto en el ciclo de vida y las preferencias alimenticias de l...

  7. Agricultural production - Phase 2. Indonesia. Insect ecology studies and insect pest control

    International Nuclear Information System (INIS)

    This document reviews the activities of the Pest Control Research Group in Indonesia. Pests under study are the diamondback moth (Plutella xylostella), the rice stem borer (Chilo suppressalis), the sugar cane borer (Chilo auricilius), bean flies (Agromyza spp.), tobacco insects (Heliothis armigera and Spodoptera litura) and cotton insects, especially the pink bollworm

  8. Bioactivity of a water extract of boldus (Peumus boldus Molina against Spodoptera frugiperda (J.E. Smith and Helicoverpa zea Boddie (Lepidoptera: Noctuidae

    Directory of Open Access Journals (Sweden)

    Gonzalo Silva

    2013-06-01

    Full Text Available The insecticidal properties of water-extract of Peumus boldus Molina and its effect on the development cycle and feeding habits of Spodoptera frugiperda J.E. Smith and Helicoverpa zea Boddie were evaluated under laboratory conditions in concentrations of 0.25, 0.5, 1.0, 2.0, 4.0, and 8.0% (w/w. Spodoptera frugiperda was the most susceptible with 75% mortality at 7 d at 8% P. boldus concentration, while H. zea had only 30% mortality. LC50 was 2.31 mL kg-1 for S. frugiperda and 16.05 mL kg¹ for H. zea. When the extract concentration increased in the diet, larval size and weight, percentage of pupation and number of adults decreased, and the time required to reach those states was greater. Neonate larvae fed primarily on the diet with the lower extract concentration and the control was preferred by more than 50% of larvae. Inhibition of feeding, growth, weight gain of 3rd instar larvae as well as new biomass production decreased with concentration of the extract.

  9. QUANTIFICAÇÃO DA PROTEÍNA CRY1AB EM FOLHAS, CAULES E GRÃOS DE DOIS HÍBRIDOS DE MILHO BT E CONTROLE DAS PRAGAS Spodoptera frugiperda E Helicoverpa zea

    OpenAIRE

    Balieiro Neto, Geraldo; Cividanes, Terezinha; Branco, Roberto; Félix, M. Rosário; Rei, Fernando; Nogueira, José

    2013-01-01

    RESUMO: Procedeu-se à avaliação do nível de infestação e respectivos danos associados à presençadas lagartas Spodoptera frugiperda e Helicoverpa zea, em dois milhos híbridos geneticamentemodificados (OGM), Dekalb DKB390 e Agroceres AG8088, que expressam a proteína Cry1Ab. Foi estabelecido em blocos casualizados, com dois fatores (hibrido e gene cry1Ab), sendo utilizadascomo controles os mesmos híbridos sem a proteína Cry1Ab (NOGM). A concentração da proteína Cry1Ab foi determinada pela ...

  10. Isolation of an orally active insecticidal toxin from the venom of an Australian tarantula.

    Directory of Open Access Journals (Sweden)

    Margaret C Hardy

    Full Text Available Many insect pests have developed resistance to existing chemical insecticides and consequently there is much interest in the development of new insecticidal compounds with novel modes of action. Although spiders have deployed insecticidal toxins in their venoms for over 250 million years, there is no evolutionary selection pressure on these toxins to possess oral activity since they are injected into prey and predators via a hypodermic needle-like fang. Thus, it has been assumed that spider-venom peptides are not orally active and are therefore unlikely to be useful insecticides. Contrary to this dogma, we show that it is possible to isolate spider-venom peptides with high levels of oral insecticidal activity by directly screening for per os toxicity. Using this approach, we isolated a 34-residue orally active insecticidal peptide (OAIP-1 from venom of the Australian tarantula Selenotypus plumipes. The oral LD50 for OAIP-1 in the agronomically important cotton bollworm Helicoverpa armigera was 104.2±0.6 pmol/g, which is the highest per os activity reported to date for an insecticidal venom peptide. OAIP-1 is equipotent with synthetic pyrethroids and it acts synergistically with neonicotinoid insecticides. The three-dimensional structure of OAIP-1 determined using NMR spectroscopy revealed that the three disulfide bonds form an inhibitor cystine knot motif; this structural motif provides the peptide with a high level of biological stability that probably contributes to its oral activity. OAIP-1 is likely to be synergized by the gut-lytic activity of the Bacillus thuringiensis Cry toxin (Bt expressed in insect-resistant transgenic crops, and consequently it might be a good candidate for trait stacking with Bt.

  11. Isolation of an orally active insecticidal toxin from the venom of an Australian tarantula.

    Science.gov (United States)

    Hardy, Margaret C; Daly, Norelle L; Mobli, Mehdi; Morales, Rodrigo A V; King, Glenn F

    2013-01-01

    Many insect pests have developed resistance to existing chemical insecticides and consequently there is much interest in the development of new insecticidal compounds with novel modes of action. Although spiders have deployed insecticidal toxins in their venoms for over 250 million years, there is no evolutionary selection pressure on these toxins to possess oral activity since they are injected into prey and predators via a hypodermic needle-like fang. Thus, it has been assumed that spider-venom peptides are not orally active and are therefore unlikely to be useful insecticides. Contrary to this dogma, we show that it is possible to isolate spider-venom peptides with high levels of oral insecticidal activity by directly screening for per os toxicity. Using this approach, we isolated a 34-residue orally active insecticidal peptide (OAIP-1) from venom of the Australian tarantula Selenotypus plumipes. The oral LD50 for OAIP-1 in the agronomically important cotton bollworm Helicoverpa armigera was 104.2±0.6 pmol/g, which is the highest per os activity reported to date for an insecticidal venom peptide. OAIP-1 is equipotent with synthetic pyrethroids and it acts synergistically with neonicotinoid insecticides. The three-dimensional structure of OAIP-1 determined using NMR spectroscopy revealed that the three disulfide bonds form an inhibitor cystine knot motif; this structural motif provides the peptide with a high level of biological stability that probably contributes to its oral activity. OAIP-1 is likely to be synergized by the gut-lytic activity of the Bacillus thuringiensis Cry toxin (Bt) expressed in insect-resistant transgenic crops, and consequently it might be a good candidate for trait stacking with Bt. PMID:24039872

  12. Inhibition of Helicoverpa zea (Lepidoptera: Noctuidae) Growth by Transgenic Corn Expressing Bt Toxins and Development of Resistance to Cry1Ab.

    Science.gov (United States)

    Reisig, Dominic D; Reay-Jones, Francis P F

    2015-08-01

    Transgenic corn, Zea mays L., that expresses the Bacillus thuringiensis (Bt) toxin Cry1Ab is only moderately toxic to Helicoverpa zea (Boddie) and has been planted commercially since 1996. Growth and development of H. zea was monitored to determine potential changes in susceptibility to this toxin over time. Small plots of corn hybrids expressing Cry1F, Cry1F × Cry1Ab, Cry1Ab × Cry3Bb1, Cry1A.105 × Cry2Ab2 × Cry3Bb1, Cry1A.105 × Cry2Ab2, and Vip3Aa20 × Cry1Ab × mCry3A were planted in both 2012 and 2013 inNorth and South Carolina with paired non-Bt hybrids from the same genetic background. H. zea larvae were sampled on three time periods from ears and the following factors were measured: kernel area injured (cm(2)) by H. zea larvae, larval number per ear, larval weight, larval length, and larval head width. Pupae were sampled on a single time period and the following factors recorded: number per ear, weight, time to eclosion, and the number that eclosed. There was no reduction in larval weight, number of insect entering the pupal stadium, pupal weight, time to eclosion, and number of pupae able to successfully eclose to adulthood in the hybrid expressing Cry1Ab compared with a non-Bt paired hybrid. As Cry1Ab affected these in 1996, H. zea may be developing resistance to Cry1Ab in corn, although these results are not comprehensive, given the limited sampling period, size, and geography. We also found that the negative impacts on larval growth and development were greater in corn hybrids with pyramided traits compared with single traits. PMID:26314074

  13. The Impact of Inter-Kernel Movement in the Evolution of Resistance to Dual-Toxin Bt-Corn Varieties in Helicoverpa zea (Lepidoptera: Noctuidae).

    Science.gov (United States)

    Caprio, Michael A; Martinez, Jeannette C; Porter, Patrick A; Bynum, Ed

    2016-02-01

    Seeds or kernels on hybrid plants are primarily F(2) tissue and will segregate for heterozygous alleles present in the parental F(1) hybrids. In the case of plants expressing Bt-toxins, the F(2) tissue in the kernels will express toxins as they would segregate in any F(2) tissue. In the case of plants expressing two unlinked toxins, the kernels on a Bt plant fertilized by another Bt plant would express anywhere from 0 to 2 toxins. Larvae of corn earworm [Helicoverpa zea (Boddie)] feed on a number of kernels during development and would therefore be exposed to local habitats (kernels) that varied in their toxin expression. Three models were developed for plants expressing two Bt-toxins, one where the traits are unlinked, a second where the traits were linked and a third model assuming that maternal traits were expressed in all kernels as well as paternally inherited traits. Results suggest that increasing larval movement rates off of expressing kernels tended to increase durability while increasing movement rates off of nonexpressing kernels always decreased durability. An ideal block refuge (no pollen flow between blocks and refuges) was more durable than a seed blend because the refuge expressed no toxins, while pollen contamination from plants expressing toxins in a seed blend reduced durability. A linked-trait model in an ideal refuge model predicted the longest durability. The results suggest that using a seed-blend strategy for a kernel feeding insect on a hybrid crop could dramatically reduce durability through the loss of refuge due to extensive cross-pollination. PMID:26527792

  14. Biocontrol potential of Steinernema thermophilum and its symbiont Xenorhabdus indica against lepidopteran pests: virulence to egg and larval stages

    Science.gov (United States)

    Under laboratory conditions, the biocontrol potential of Steinernema thermophilum was tested against eggs and larval stages of two important lepidopteran insect pests, Helicoverpa armigera and Spodoptera litura (polyphagous pests), as well as Galleria mellonella (used as a model host) . In terms of ...

  15. Development of Transgenics in Chickpea.

    Science.gov (United States)

    Chickpea (Cicer arietinum L.) is an important food crop in much of the developing world and ranks third in production among food legumes. Chickpea production is limited worldwide by drought, insect damage from Helicoverpa armigera, Callosobruchus maculatus and C. chinensis and disease pressure from ...

  16. 烟青虫幼虫味觉可塑性行为研究%Study on Taste Plasticity in Helicoverpa assulta Larva

    Institute of Scientific and Technical Information of China (English)

    周东升; 龙九妹

    2012-01-01

    [Objective] The aim was to provide a reference for pest control by studying the taste plasticity in Helicoverpa assulta, [Method] The two choices assays and taste seosilla ablation were used to investigate the taste plasticity on the deterrents in 5th instar larvae of & assula which were reared on different artificial diets. [Result] The larvae reared on normal artificial diets were sensitive to the deterrents, the caterpillars with ablation of the lateral sensillum styloconica reacted to the deterrents as normal larvae. Meantime, the caterpillars with ablation of the medial sensillum styloconica were insensitive to the deterrents.However, the caterpillars reared on the artificial diets containing low deterrents showed insensitivity to the deterrents. [Conclusion] The medial sensillum styloconica contains the taste neurons which is sensitive to deterrents and there is a taste plasticity in different food experienced caterpillars of H. assulta..c%[目的]研究烟青虫幼虫的可塑性行为,为害虫防治提供参考.[方法]采用行为试验双选法和切除味觉感受器研究了不同取食经历烟青虫5龄幼虫对取食抑制素的味觉可塑性行为.[结果]正常人工饲料饲养幼虫对取食抑制素十分敏感,切除了侧栓锥感受器的幼虫对取食抑制素的反应与正常幼虫相似,切除了中栓锥感受器的幼虫对取食抑制素不敏感.而用含有低浓度取食抑制素的人工饲料饲养的幼虫对取食抑制素不敏感.[结论]中栓锥感受器中含有对取食抑制素敏感的味觉神经元,不同取食经历的烟青虫幼虫对取食抑制素具有行为可塑性.

  17. Influence of life history differences of two tachinid parasitoids ofHelicoverpa zea (Boddie) (Lepidoptera: Noctuidae) on their interactions with glandular trichome/methyl ketone-based insect resistance in tomato.

    Science.gov (United States)

    Farrar, R R; Kennedy, G G; Kashyap, R K

    1992-03-01

    The effects of glandular trichome/methyl ketone (2-tridecanone and 2-undecanone) -based insect resistance in the wild tomato,Lycopersicon hirsutum f.glabratum C.H. Mull, accession PI 134417, onArchytas marmoratus (Townsend) andEucelatoria bryani (Sabrosky) (Diptera: Tachinidae), both parasitoids ofHelicoverpa (=Heliothis)zea (Boddie) (Lepidoptera: Noctuidae), were investigated in the laboratory.A. marmoratus deposits larvae (planidia) on the foliage of its host's food plant; planidia attach to passing hosts, penetrate the cuticle, and develop in the host pupae.E. bryani larviposits directly into its host; its larvae develop in the host larva.A. marmoratus planidia are killed by glandular trichomes of PI 134417 and also by trichomes of hybrid lines with no methyl ketones. The methyl ketones are toxic to planidia, but at least part of the effect is due to other factors, possibly physical entanglement. Both species can be affected indirectly by methyl ketones in the diet of the host. 2-Undecanone reduces the percentage ofA. marmoratus larvae that reach pupation. This effect is evidently due to premature death and desiccation of the host pupa caused by 2-undecanone. 2-Tridecanone in host diets had no effect onA. marmoratus. InE. bryani, 2-tridecanone in the diet of the host reduced the number of parasitoids yielded by each parasitized host, although not the overall percentage of hosts parasitized. 2-Undecanone in the diet of the host had no effect onE. bryani. PMID:24254953

  18. Electrophysiological and behavioral responses of Microplitis mediator (Hymenoptera: Braconidae) to caterpillar-induced volatiles from cotton.

    Science.gov (United States)

    Yu, Huilin; Zhang, Yongjun; Wyckhuys, Kris A G; Wu, Kongming; Gao, Xiwu; Guo, Yuyuan

    2010-04-01

    Microplitis mediator Haliday (Hymenoptera: Braconidae) is an important larval endoparasitoid of various lepidopteran pests, including Helicoverpa armigera (Hübner). In China, H. armigera is a key pest of cotton and is currently the focus of several biological control efforts that use M. mediator as principal natural enemy of this pest. To improve the success of biological control efforts, behavioral studies are needed that shed light on the interaction between M. mediator and H. armigera. In this study, we determined M. mediator response to volatile compounds from undamaged, mechanically injured, or H. armigera--damaged plants and identified attractive volatiles. In Y-tube olfactometer assays, we found that mechanically damaged plants and/or plants treated with H. armigera oral secretions did not attract wasps. However, volatiles from H. armigera-damaged plants elicited a strong attraction of both M. mediator sexes. Headspace extracts from H. armigera-damaged cotton were analyzed by coupled gas chromatography-electroantennographic detection (GC-EAD), and a total of seven different compounds were found to elicit electroantennogram (EAG) responses, including an unknown compound. Six different EAD-active volatiles were identified from caterpillar-damaged cotton plants, of which 3, 7-dimethyl-1, 3, 6-octatriene and (Z)-3-hexenyl acetate were the principal compounds. Olfactometer assays indicated that individual synthetic compounds of 3, 7-dimethyl-1, 3, 6-octatriene, (Z)-3-hexenyl acetate, and nonanal were attractive to M. mediator. Field cage studies showed that parasitism of H. armigera larvae by M. mediator was higher on cotton plants to which 3,7-dimethyl-1,3, 6-octatriene was applied. Our results show that the combination of terpenoids and green leaf volatiles may not only facilitate host, mate, or food location but may also increase H. armigera parasitism by M. mediator. PMID:20388293

  19. History and Current Status of Development and Use of Viral Insecticides in China

    Directory of Open Access Journals (Sweden)

    Xiulian Sun

    2015-01-01

    Full Text Available The use of insect viruses as biological control agents started in the early 1960s in China. To date, more than 32 viruses have been used to control insect pests in agriculture, forestry, pastures, and domestic gardens in China. In 2014, 57 products from 11 viruses were authorized as commercial viral insecticides by the Ministry of Agriculture of China. Approximately 1600 tons of viral insecticidal formulations have been produced annually in recent years, accounting for about 0.2% of the total insecticide output of China. The development and use of Helicoverpa armigera nucleopolyhedrovirus, Mamestra brassicae nucleopolyhedrovirus, Spodoptera litura nucleopolyhedrovirus, and Periplaneta fuliginosa densovirus are discussed as case studies. Additionally, some baculoviruses have been genetically modified to improve their killing rate, infectivity, and ultraviolet resistance. In this context, the biosafety assessment of a genetically modified Helicoverpa armigera nucleopolyhedrovirus is discussed.

  20. Dicty_cDB: Contig-U12971-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available :none) Salinispora arenicola CNS-205, ... 46 5e-04 AE014299_1044( AE014299 |pid:none) Shewanella oneide...:none) Streptococcus mutans UA159, com... 50 2e-05 AP006841_673( AP006841 |pid:none) Bacteroides fragi...nsis MR-1, com... 46 5e-04 CP000447_3218( CP000447 |pid:none) Shewanella frigidimarina NCIMB ... 45 6e...:none) Helicoverpa armigera midgut aminop... 67 3e-10 AF020389_1( AF020389 |pid:none) Plutella xylostella...e-10 EU568874_1( EU568874 |pid:none) Helicoverpa armigera note Bt-Cry1A... 66 4e-10 AF109692_1( AF109692 |pid:none) Plutella

  1. Dicty_cDB: Contig-U16413-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 44 2 ( FJ770081 ) Homo sapiens chromosome 7 PCR sequence PCR_NA1895... 36 0.45 5 ( FG600160 ) PF_T3_09R_E06_25JUL2003_040 Opium pop...|pid:none) Mouse DNA sequence from clone RP23... 61 3e-07 (Q6PAJ1) RecName: Full=Breakpo... DNA sequence from clone ... 57 4e-06 TVHUA2( A26664 )bcr (breakpoint cluster region) protein, splice fo... ...7 4 ( U67259 ) Helicoverpa armigera nucleopolyhedrovirus RING-fing... 34 0.37 4 ( AF090533 ) Dictyostelium d...iscoideum unconventional myosin he... 40 0.37 5 ( U67262 ) Helicoverpa armigera nucleopolyhedrovirus RING-fi

  2. Functional Analysis of Polyphenol Oxidases by Antisense/Sense Technology

    Directory of Open Access Journals (Sweden)

    Jutharat Attajarusit

    2007-07-01

    Full Text Available Polyphenol oxidases (PPOs catalyze the oxidation of phenolics to quinones, the secondary reactions of which lead to oxidative browning and postharvest losses of many fruits and vegetables. PPOs are ubiquitous in angiosperms, are inducible by both biotic and abiotic stresses, and have been implicated in several physiological processes including plant defense against pathogens and insects, the Mehler reaction, photoreduction of molecular oxygen by PSI, regulation of plastidic oxygen levels, aurone biosynthesis and the phenylpropanoid pathway. Here we review experiments in which the roles of PPO in disease and insect resistance as well as in the Mehler reaction were investigated using transgenic tomato (Lycopersicon esculentum plants with modified PPO expression levels (suppressed PPO and overexpressing PPO. These transgenic plants showed normal growth, development and reproduction under laboratory, growth chamber and greenhouse conditions. Antisense PPO expression dramatically increased susceptibility while PPO overexpression increased resistance of tomato plants to Pseudomonas syringae. Similarly, PPO-overexpressing transgenic plants showed an increase in resistance to various insects, including common cutworm (Spodoptera litura (F., cotton bollworm (Helicoverpa armigera (Hübner and beet army worm (Spodoptera exigua (Hübner, whereas larvae feeding on plants with suppressed PPO activity had higher larval growth rates and consumed more foliage. Similar increases in weight gain, foliage consumption, and survival were also observed with Colorado potato beetles (Leptinotarsa decemlineata (Say feeding on antisense PPO transgenic tomatoes. The putative defensive mechanisms conferred by PPO and its interaction with other defense proteins are discussed. In addition, transgenic plants with suppressed PPO exhibited more favorable water relations and decreased photoinhibition compared to nontransformed controls and transgenic plants

  3. Recent Advances in Biological Control of Pest Insects by Using Viruses in China

    Institute of Scientific and Technical Information of China (English)

    Xiu-lian SUN; Hui-yin PENG

    2007-01-01

    Insect viruses are attractive as biological control agents and could be a feasible alternative to chemical insecticides in the management of insect infestations. This review describes recent advances in the development of wild-type and genetically modified viruses as insecticides. A new strategy of application of insect viruses in China is reviewed. Also, the assessment of biosafety of genetically modified Helicoverpa armigera Nucleopolyhedovirus (HearNPV) is emphasized as a case-study.

  4. Plant phenolics are detoxified by prophenoloxidase in the insect gut

    OpenAIRE

    Kai Wu; Jie Zhang; Qiaoli Zhang; Shoulin Zhu; Qimiao Shao; Clark, Kevin D.; Yining Liu; Erjun Ling

    2015-01-01

    Plant phenolics are a group of important secondary metabolites that are toxic to many animals and insects if ingested at high concentrations. Because most insects consume plant phenolics daily, they have likely evolved the capacity to detoxify these compounds. Here, we used Drosophila melanogaster, Bombyx mori and Helicoverpa armigera as models to study the metabolism of plant phenolics by prophenoloxidases. We found that insect foreguts release prophenoloxidases into the lumen, and that the ...

  5. A Survey of the Insect Pests and Farmers' Practices in the Cropping of Tomato in Nigeria

    OpenAIRE

    Umeh, VC.; Kuku, FO.; Nwanguma, EI.; Adebayo, OS.; Manga, AA.

    2002-01-01

    A survey of some tomato producing areas of Nigeria indicated that the major insects attacking tomato included the fruit borer Helicoverpa armigera Hübner, the grasshopper Zonocerus variegatus L., the whitefly Bemisia tabacci Gennadius, and various species of aphids, mostly Aphis gossypii Glover. Interviews conducted to assess farmers' practices which contribute to insect damage showed that inappropriate application of insecticides and the use of wrong dosages may have contributed to insect co...

  6. Comparative Efficacy of Insecticides, Insect Growth Regulator and M.Y. Strategy Against Insect Pets of Okra (Abelmoschus esculentus

    Directory of Open Access Journals (Sweden)

    Muhammad Tariq

    2000-01-01

    Full Text Available The efficacy of Azodrin and Pirate (insecticides, Cascade (insect growth regulator and Pressurized water spray (M. Y. strategy was evaluated against insect pests of okra. Cascade was found to be the best efficient against Helicoverpa armigera and Earias spp. Pirate showed maximum efficacy against Amrasca biguttula biguttula, whereas, against Bemisia tabaci, the most effective treatment was Azodrin followed by M.Y. strategy.

  7. Streptomyces avermitilis from marine

    Institute of Scientific and Technical Information of China (English)

    XIONG Li-xia; LI Jian-zhong; WANG Hui-li

    2005-01-01

    The insecticidal strain 173 was isolated from marine source and its activity was explored by the bioassay of brine shrimp and Helicoverpa armigera. Based on morphological, physiological and molecular properties, the insecticidal strain 173 was identified as Streptonycetes avermitilis, which is the best insecticidal microorganism found in the terrestrial environment. The taxonomy of the strain173, insecticidal spectrum and properties of the corresponding insecticidal antibiotics are reported.

  8. Developing a neem-based pest management product: laboratory evaluations of neem extracts on insect pests resistance to synthetic pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, I.; Permana, A.D.; Rahadian, R.; Wibowo, S.A

    1998-12-16

    Laboratory studies has been conducted as a part of a project aimed at the development of a neem-based insecticide for pest management purposes. Permethrin, a pyrethroid insecticide, and neem (Azadirachta indica) products were tested against larvae of Diamondback Moth Plutella xylostella, and Helicoverpa armigera collected from several locations in West Java, Indonesia. The results of bioassay showed that the average LC{sub 50} values of permethrin for Plutella xylostella had been 60-100 fold higher as compared with the normal dosage recommended. Similarly, the LC{sub 50} values obtained for Helicoverpa armigera had been 46-73 fold as compared with the recommended dosage. These facts suggest that both insects have developed resistance to permethrin. The results of bioassay with neem-products tested against Plutella xylostella and Helicoverpa armigera larvae showed that statistically LC{sub 50} values of neem-products for each strain of either Plutella xylostella or Helicoverpa armigera were not significantly different one to another. We also found that neem-treated insects, even though they were not killed directly by the insecticide, were not able to molt to the next instar or pupae, so that very low percentage of adults emerged. The susceptibility of neem-products could not be easily determined by only measuring the LC{sub 50} values from the larval stage, but the disruption of the growth and development of the insect should be considered as well. Our findings suggest that neem-products could be used effectively to control insects which have developed resistance to conventional insecticide. (author)

  9. Processing of Pheromone Information in Related Species of Heliothine Moths

    Directory of Open Access Journals (Sweden)

    Bente G. Berg

    2014-10-01

    Full Text Available In heliothine moths, the male-specific olfactory system is activated by a few odor molecules, each of which is associated with an easily identifiable glomerulus in the primary olfactory center of the brain. This arrangement is linked to two well-defined behavioral responses, one ensuring attraction and mating behavior by carrying information about pheromones released by conspecific females and the other inhibition of attraction via signal information emitted from heterospecifics. The chance of comparing the characteristic properties of pheromone receptor proteins, male-specific sensory neurons and macroglomerular complex (MGC-units in closely-related species is especially intriguing. Here, we review studies on the male-specific olfactory system of heliothine moths with particular emphasis on five closely related species, i.e., Heliothis virescens, Heliothis subflexa, Helicoverpa zea, Helicoverpa assulta and Helicoverpa armigera.

  10. Scenario of Entomological Research in Legume Crops in Nepal

    Directory of Open Access Journals (Sweden)

    Bishnu Prasad Neupane

    2015-09-01

    Full Text Available This review paper highlights scenario of entomological research in grain legumes in Nepal into headings of the monitoring, survey and surveillance, insect pest management, existing problem and future strategies. A survey study on yield loss assessment of chickpea due to Helicoverpa pod borer under field condition has been recorded up to 75% in the year 1996-1998 at Banke and Bardiya district. While monitored Helicoverpa armigera through pheromone trap, during the 2nd week of March, peak catches of 91 male moths were recorded at Rampur, while it was the maximum (42 male moths during the 3rd week of March. Synthetic pyrethroids, deltamethrin, fenvalerate and cypermethrin used at 0.01% concentration (a.i., were effective in controlling the chickpea pod borer, Helicoverpa armigera Hubner. Genotypes NCH-18, NCH -31, NCH-138 and ICC 3075 WR were found resistant. Ripcord 10%@0.05% was found to be superior and effective chemical insecticides to control stem fly and soybean hairy caterpillar. The late sowing date December, 10 showed significantly higher percentage of chickpea pod borer damage with lower grain yield. Inter crops combinations of Chickpea +wheat (2:1 ratio was found effective against Helicoverpa armigera damage (1.2% followed by chickpea+barley (2.36% and Chickpea+linseed (2:1 ratio (3.7%. Bakaino (Melia azederach L. was identified as the best indigenous pesticides to check the normal growth of hairy caterpillar (Spilarctia casigneta kollar under laboratory condition. Metarhizium anisopliae was found effective for the management of Helicoverpa armigera that caused maximum mortality (94.67%, infection (45.33% within 7.49 days (LT50. Similarly, Beauveria bassiana caused maximum mortality (98.67%, infection (80.00% with the least LT50 value (5 days. Crop sprayed with HaNPV had the lowest pod damage (0.3% and the highest in Racer (2.2%. This review work provided a lot of information to conduct entomological research activity conducted in grain

  11. Induction of nicotine in tobacco by herbivory and its relation to glucose oxidase activity in the labial gland of three noctuid caterpillars

    Institute of Scientific and Technical Information of China (English)

    ZONG Na; WANG Chenzhu

    2004-01-01

    Tobacco Nicotiana tabacum L. Is a host plant of Helicoverpa armigera (Hüibner), Helicoverpa assulta Guenée and Spodoptera litura (Fabricius) (Lepidoptera, Noctuidae).The difference in leaf nicotine response to the feeding by these three larvae and the mechanical simulation of their feeding was examined by HPLC. Results indicated that nicotine induction was suppressed by H. Armigera and H. Assulta larvae feeding or by simulated damage treated with their labial glands extracts. The production of nicotine was also suppressed by the glucose oxidase from Aspergillus niger when it was treated on mechanically wounded leaf area. On the contrary, the nicotine production was stimulated by S.litura larva feeding or by simulated damage treated with its labial gland extract. Heat denature can not counteract the stimulation effect of the S. Litura labial gland extracts to tobacco nicotine production. The glucose oxidase activity was detected in labial gland extracts of both H. Arrnigera and H.assulta, but the activity in H. Armigera was significantly higher than that in H. Assulta. No glucose oxidase activity was detected in labial gland extracts of S. Litura. It is shown that the glucose oxidase activity in labial glands of caterpillars plays an important role in the nicotine response to herbivory. The glucose oxidase was mainly contained in the labial gland of H. Armigera larva, and had the highest activity at pH 7.0. D-Glucose was the optimal substrate of the glucose oxidase. Labial gland glucose oxidase activities varied daily during larval development with high activities found when larvae were actively feeding.

  12. Introgression of Bt Genes in Novel Germplasm and Contribution to Indian Cotton Economy

    Institute of Scientific and Technical Information of China (English)

    VIDYASAGAR Parchuri

    2008-01-01

    @@ Emergence of transgenic Bt-cotton technology has opened up a new chapter in Indian cotton production in 21st century.The crylAc gene of Monsanto derived from American Upland Coker-312 background was not directly suitable for varied cotton growing situations in India.Delivery of Bt-gene technology to Indian farming systems should be superimposed on hybrid technology,fiber quality,and superior agronomic adaptation.Protection offered by this alien Bt-gene against major serious pest Helicoverpa armigera,by preventing annual losses ranging from 15~35 percent,automaticaly contributed to higher yield.

  13. Arthropodes associés à la culture cotonnière au Tchad : ravageurs, prédateurs et parasites

    OpenAIRE

    Silvie, Pierre; Delvare, G.; Maldes, J.M.

    1989-01-01

    Les auteurs dressent la liste des arthropodes (acariens, diplopodes et insectes) préalablement signalés sur culture cotonnière au Tchad ou relevés par eux-mêmes au cours des années 1984 à 1987. Les études entreprises ont permis de recenser pour la première fois dans ce pays 51 espèces et 24 genres. Les principaux déprédateurs des organes fructifères sont les lépidoptères #Helicoverpa (=Heliothis) armigera, Diparopsis watersi, Earias biplaga$, alors que les chenilles de syllepte derogata const...

  14. La résistance des insectes aux insecticides : problématique et enjeux en Afrique centrale

    OpenAIRE

    Brévault, Thierry; Beyo, Jacques; Nibouche, Samuel; Vaissayre, Maurice

    2003-01-01

    Les observations indiquent que des cas de résistance aux insecticides sont apparus dans la zone des savanes d'Afrique centrale chez plusieurs espèces de ravageurs des cultures cotonnière et maraîchères. La résistance aux insecticides de la famille des pyréthrinoïdes mise en évidence chez la noctuelle, Helicoverpa armigera (Hübner), en Afrique de l'ouest semble désormais concerner l'Afrique centrale. Au Cameroun, les résultats obtenus au laboratoire confirment l'apparition d'une résistance aux...

  15. Dicty_cDB: Contig-U15420-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available nome... 40 3.9 2 ( AM432345 ) Vitis vinifera contig VV78X071289.3, whole genome... 40 4.5 2 ( AF303045 ) Helicoverpa armiger...a nuclear polyhedrosis virus, ... 38 4.8 2 ( AF271059 ) Heliocoverpa armiger...fyikyiyiy* shptrp*sefhksncfsf*chylyvfiflki*qnskk*efstlhnfvhsvgseffsfstl rndrvivpvrnfyfsfenflffecsrtf*kiilniwei...Slime mold (D.discoideum) DIRS-1 right inverted ter... 141 3e-96 4 ( K03072 ) Slime mold (D.discoideum) DIRS-1 right inverted ter...... 141 1e-88 3 ( K03068 ) Slime mold (D.discoideum) DIRS-1 right inverted ter

  16. Cloning and characterization of an insecticidal crystal protein gene from Bacillus thuringiensis subspecies kenyae

    Indian Academy of Sciences (India)

    Hari S. Misra; Nivedita P. Khairnar; Manjula Mathur; N. Vijayalakshmi; Remesh S. Hire; T. K. Dongre; S. K. Mahajan

    2002-04-01

    A sporulating culture of Bacillus thuringiensis subsp. kenyae strain HD549 is toxic to larvae of lepidopteran insect species such as Spodoptera litura, Helicoverpa armigera and Phthorimaea operculella, and a dipteran insect, Culex fatigans. A 1.9-kb DNA fragment, PCR-amplified from HD549 using cryII-gene-specific primers, was cloned and expressed in E. coli. The recombinant protein produced 92% mortality in first-instar larvae of Spodoptera litura and 86% inhibition of adult emergence in Phthorimaea operculella, but showed very low toxicity against Helicoverpa armigera, and lower mortality against third-instar larvae of dipteran insects Culex fatigans, Anopheles stephensi and Aedes aegypti. The sequence of the cloned crystal protein gene showed almost complete homology with a mosquitocidal toxin gene from Bacillus thuringiensis var. kurstaki, with only five mutations scattered in different regions. Amino acid alignment with different insecticidal crystal proteins using the MUTALIN program suggested presence of the conserved block 3 region in the sequence of this protein. A mutation in codon 409 of this gene that changes a highly conserved phenylalanine residue to serine lies in this block.

  17. Cloning and characterization of an insecticidal crystal protein gene from Bacillus thuringiensis subspecies kenyae.

    Science.gov (United States)

    Misra, Hari S; Khairnar, Nivedita P; Mathur, Manjula; Vijayalakshmi, N; Hire, Ramesh S; Dongre, T K; Mahajan, S K

    2002-04-01

    A sporulating culture of Bacillus thuringiensis subsp. kenyae strain HD549 is toxic to larvae of lepidopteran insect species such as Spodoptera litura, Helicoverpa armigera and Phthorimaea operculella, and a dipteran insect, Culex fatigans. A 1.9-kb DNA fragment, PCR-amplified from HD549 using cryII-gene-specific primers, was cloned and expressed in E. coli. The recombinant protein produced 92% mortality in first-instar larvae of Spodoptera litura and 86% inhibition of adult emergence in Phthorimaea operculella, but showed very low toxicity against Helicoverpa armigera, and lower mortality against third-instar larvae of dipteran insects Culex fatigans, Anopheles stephensi and Aedes aegypti. The sequence of the cloned crystal protein gene showed almost complete homology with a mosquitocidal toxin gene from Bacillus thuringiensis var. kurstaki, with only five mutations scattered in different regions. Amino acid alignment with different insecticidal crystal proteins using the MUTALIN program suggested presence of the conserved block 3 region in the sequence of this protein. A mutation in codon 409 of this gene that changes a highly conserved phenylalanine residue to serine lies in this block. PMID:12357073

  18. Cloning, characterization and expression of a novel haplotype cry2A-type gene from Bacillus thuringiensis strain SWK1, native to Himalayan valley Kashmir.

    Science.gov (United States)

    Reyaz, A L; Arulselvi, P Indra

    2016-05-01

    Bacillus thuringiensis (Bt) is a gram positive bacterium which is effectively being used in pest management strategies as an eco-friendly bioinsecticide. In the present study a new cry2A gene was cloned from a promising indigenous B. thuringiensis SWK1 strain previously characterized for its toxicity against Spodoptera litura and Helicoverpa armigera larvae. The nucleotide sequence of the cloned cry2A gene pointed out that the open reading frame has 1902 bases encoding a polypeptide of 634 amino acid residues with a probable molecular weight of 70kDa. Homology comparisons showed that the deduced amino acid sequence of Cry2A had a similarity of 94% compared to that of the known Cry2Aa protein in the NCBI database and this gene has been named as cry2Al1 by the B. thuringiensis δ-endotoxin Nomenclature Committee. cry2Al1 was ligated into pET 22b vector and expressed in Escherichia coli BL21 (DE3) pLysS under the control of T7 promoter induced by isopropyl-beta-d-thiogalactopyranoside (IPTG). SDS-PAGE analysis confirmed the expression of cry2Al1 as ∼65kDa protein. Insect pest bioassays with neonate larvae of S. litura and H. armigera showed that the purified Cry2Al1 are toxic to S. litura and H. armigera with LC50 2.448μg/ml and H. armigera with 3.374μg/ml respectively. PMID:26906447

  19. Understanding heliothine (Lepidoptera: Heliothinae) pests: what is a host plant?

    Science.gov (United States)

    Cunningham, John Paul; Zalucki, Myron P

    2014-06-01

    Heliothine moths (Lepidoptera: Heliothinae) include some of the world's most devastating pest species. Whereas the majority of nonpest heliothinae specialize on a single plant family, genus, or species, pest species are highly polyphagous, with populations often escalating in size as they move from one crop species to another. Here, we examine the current literature on heliothine host-selection behavior with the aim of providing a knowledge base for research scientists and pest managers. We review the host relations of pest heliothines, with a particular focus on Helicoverpa armigera (Hübner), the most economically damaging of all heliothine species. We then consider the important question of what constitutes a host plant in these moths, and some of the problems that arise when trying to determine host plant status from empirical studies on host use. The top six host plant families in the two main Australian pest species (H. armigera and Helicoverpa punctigera Wallengren) are the same and the top three (Asteraceae, Fabaceae, and Malvaceae) are ranked the same (in terms of the number of host species on which eggs or larvae have been identified), suggesting that these species may use similar cues to identify their hosts. In contrast, for the two key pest heliothines in the Americas, the Fabaceae contains approximately 1/3 of hosts for both. For Helicoverpa zea (Boddie), the remaining hosts are more evenly distributed, with Solanaceae next, followed by Poaceae, Asteraceae, Malvaceae, and Rosaceae. For Heliothis virescens (F.), the next highest five families are Malvaceae, Asteraceae, Solanaceae, Convolvulaceae, and Scrophulariaceae. Again there is considerable overlap in host use at generic and even species level. H. armigera is the most widely distributed and recorded from 68 plant families worldwide, but only 14 families are recorded as a containing a host in all geographic areas. A few crop hosts are used throughout the range as expected, but in some cases there

  20. Studies on the gamma irradiation effects on the spiny bollworm, Earias Insulana boisd

    International Nuclear Information System (INIS)

    Adult moths, less than 24 hours old, of the spiny bollrorm earias insulana boisd. were gamma irradiated with the doses of 100, 200, 300, 400, 500 and 600 Gy. The effects on repoduction were studied. The reduction in both fecundity and egg viability increased by ibcreasing the dose applied to adult males or females. Inregard to egg viability it was evident that both sexes have the same sensitivity and respondency to gamma radiation. In another trial, adult parental males irradiated with low doses of 100, 150 or 200 Gy were crossed with unirradiated females. The resulting F1 males were mated with normal females in order to obtain F2 generation of which only the males were pooled out to continue the male line for the third generation. The effects on reproduction, development, sex ratio and adult longevity were the biological aspects studied among P1, F1, F2 and F3 generations . Also, the effects of sub - and sterilizing doses on mating competitiveness of irradiated males were investigated. The fecundity of females was not significantly affected at the dose level 100, 150 and 200 Gy throughout the three auccessive generations. The egg hatch of parental generation was obviously reduced at 100, 150 and 200 Gy treatments as compared to the untreated (control). The F1 generation was evidently more sterile than irradiated parent. The successive lethals continued in the population through F2, however, F3 males regained almost their fertility. irradiation of P1 males did not greatly effect mating ability among P1, F1, F2 and F3 generations. The larvalpupal mortality of F1 was high and dose - dependent, however, thet among F2 was lower. Theaverage developmental time from egg hatch to adult emergence was not significantly affected among the progeny descendant of irradiated P1 males. The sex ratio among the progeny of irradiated males was slightly changed in favour of males throughout F1 and F2 at dose level of 200 Gy. The longevity of irradiated male moths (P1) was significantly increased at 200Gy. However, F1 males lived shorter periods than the untreated (control). Adult males irradiated with substerilizing doses of 100 or 300 Gy were more competitive than males irradiated with sterilizing dose of 600 Gy against males in mating with normal females. Increasing the ratio of irradiated males to normal nales from 1:1 to 5:1 decreased the rate of egg viability.7 tabs.,6 figs.,58 refs

  1. Binding of Bacillus thuringiensis toxin CrylAc to multiple sites of cadherin in pink bollworm

    Science.gov (United States)

    Toxins from Bacillus thuringiensis (Bt) are widely used for pest control. In particular, Bt toxin Cry lAc produced by transgenic cotton kills some key lepidopteran pests. We found that CrylAc binds to recombinant peptides corresponding to extracellular regions of a cadherin protein (BtR) in a major ...

  2. Caractérisation du savoir paysan sur les insectes nuisibles du pois d'Angole (Cajanus Cajan (L. Millsp. dans le Nord de l'Ouganda

    Directory of Open Access Journals (Sweden)

    Velay F.

    2001-01-01

    Full Text Available Characterization of indigenous traditional knowledge on insect pests of pigeonpea (Cajanus cajan (L. Millsp. in Northern Uganda. In order to assess the perception of the main insect pests of pigeonpea (Cajanus cajan (L. Millsp. by small farmers and to inventoriate methods traditionally used to control these insects, a survey was conducted in 41 households of Northern Uganda (Lira and Apac districts. Virtually all small farmers (95/ considered blister beetle (Mylabris sp., which is the most conspicious insect damaging pigeonpea at the flowering stage, as the main pest of the crop. This is conflicting with field observations made earlier in Northern Uganda which pointed out pod borers (Helicoverpa armigera Huebner and Maruca vitrata Geyer and pod sucking bugs (mainly Clavigralla sp. as the most damaging pests for pigeonpea production. A new pest of pigeonpea, Luprops baldius Mueller, was identified during this survey. Its adults and larvae are damaging to mature pods in case of late harvest.

  3. The natural refuge policy for Bt cotton (Gossypium L. in Pakistan – a situation analysis

    Directory of Open Access Journals (Sweden)

    Muhammad Sajjad Ali

    2013-07-01

    Full Text Available Bt cotton (event Cry1Ac was formally commercialized in Pakistan in 2010. However, there has been an increasing trend of planting unauthorized Bt cotton germplasm in farmers' fields since 2003 with a high rate of adoption in the core cotton areas especially in the province Punjab. The transgenic cotton technology has provided the growers with substantial economic benefits and has reduced their dependence on pesticides for pest control, especially against Helicoverpa armigera (Hubner. However, keeping in view the capacity of this insect to develop resistance against novel chemical formulations, it is easily speculated that Bt toxin, too, is no exception. Refuge crop policy for mono transgenic crop events has helped in delaying the rate of resistance evolution in the target pests. Thus, in Pakistan, where planting of structured refuge crops along Bt cotton fields is not mandatory, the effectiveness and durability of Bt cotton technology may decrease due to a number of factors which are discussed in this review.

  4. Dicty_cDB: Contig-U13331-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 5566_1( EU325566 |pid:none) Helicoverpa armigera clone CA707 p... 33 7.8 >CP000685_2124( CP000685 |pid:none) Flavobacteri... producing significant alignments: (bits) Value N ( C24642 ) Dictyostelium discoideum slug... cDNA, clone SL-X042. 486 0.0 3 ( C89630 ) Dictyostelium discoideum slug cDNA, clone SSA392. 456 0.0 3 ( AU038893 ) Dictyostelium dis...coideum slug cDNA, clone SSM110. 456 0.0 3 ( C93939 ) Dictyostelium disco...ideum slug cDNA, clone SSL885. 432 0.0 4 ( C89942 ) Dictyostelium discoideum slug cDNA, clo

  5. Dicty_cDB: Contig-U07450-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 7_1( BC152627 |pid:none) Danio rerio zgc:92237, mRNA (cDNA ... 91 1e-17 DQ223557_1( DQ223557 |pid:none) Ovis aries...90423_1( EU190423 |pid:none) Helicoverpa armigera RpS6 (RpS6) g... 34 1.4 (Q8TQL4) RecName: Full=30S ribosom...ments: (bits) Value N ( AU271571 ) Dictyostelium discoideum gamete cDNA clone:FC-... pa... 214 1e-51 1 >( AU271571 ) Dictyostelium discoideum gamete cDNA clone:FC-IC...0.318 0.134 0.401 Gapped Lambda K H 0.267 0.0410 0.140 Matrix: BLOSUM62 Gap Penalties: Existence: 11, Extension: 1 Number

  6. Enhancement of Bacillus thuringiensis insecticidal activity by combining Cry1Ac and bi-functional toxin HWTX-XI from spider.

    Science.gov (United States)

    Sun, Yunjun; Fu, Zujiao; He, Xiaohong; Yuan, Chunhua; Ding, Xuezhi; Xia, Liqiu

    2016-03-01

    In order to assess the potency of bi-functional HWTX-XI toxin from spider Ornithoctonus huwena in improving the insecticidal activity of Bacillus thuringiensis, a fusion gene of cry1Ac and hwtx-XI was constructed and expressed in an acrystalliferous B. thuringiensis strain Cry(-)B. Western blot analysis and microscopic observation revealed that the recombinant strain could express 140-kDa Cry1Ac-HWTX-XI fusion protein and produce parasporal inclusions during sporulation. Bioassay using the larvae of Helicoverpa armigera and Spodoptera exigua showed that the Cry1Ac-HWTX-XI fusion was more toxic than the control Cry1Ac protoxin, as revealed by 95% lethal concentration. Our study indicated that the HWTX-XI from spider might be a candidate for enhancing the toxicity of B. thuringiensis products. PMID:25721170

  7. A Survey of the Insect Pests and Farmers' Practices in the Cropping of Tomato in Nigeria

    Directory of Open Access Journals (Sweden)

    Umeh, VC.

    2002-01-01

    Full Text Available A survey of some tomato producing areas of Nigeria indicated that the major insects attacking tomato included the fruit borer Helicoverpa armigera Hübner, the grasshopper Zonocerus variegatus L., the whitefly Bemisia tabacci Gennadius, and various species of aphids, mostly Aphis gossypii Glover. Interviews conducted to assess farmers' practices which contribute to insect damage showed that inappropriate application of insecticides and the use of wrong dosages may have contributed to insect control failures. Intercropping tomato with crops such as cereals tubers and other vegetables reduced infestation in some areas. However, most farmers' practices did not affect insect pest abundance. Insect populations and percentages of infestation were, in most cases, found to be significantly higher in Oyo state (in the rain forest agro-ecological zone than in other surveyed states located in the savannah agro-ecological zones.

  8. Biological characteristics of Bacillus thuringiensis strain Btll and identification of its cry-type genes

    Institute of Scientific and Technical Information of China (English)

    Tinghui LIU; Wei GUO; Weiming SUN; Yongxiang SUN

    2009-01-01

    A novel strain of Bacillus thuringiensis Bt11, isolated from soil samples in China, was classified and characterized in terms of its crystal proteins, cry genes content. The Bt11 strain showed high toxicity against Spodoptera exigua and Helicoverpa armigera neonates. Btll strain shares morphological and biochemical characteristics with the previously described Bacillus thuringiensis subsp. kurstaki. SDS-polyacrylamide gel electrophoresis revealed that crystals were composed of several polypeptides ranging from 20 to 130 kDa, of which the 35, 80, and 130 kDa proteins were the major components. PCR-RFLP with total DNA from strain Btll and specific primers for cryl, cry2, cry3, cry4/10, cry7, cry8, cry9, and cryll genes revealed that crylAa, crylAb, crylla, and cry9Ea genes were present.

  9. Development of specific ITS markers for plant DNA identification within herbivorous insects.

    Science.gov (United States)

    Pumariño, L; Alomar, O; Agustí, N

    2011-06-01

    DNA-based techniques have proved to be very useful methods to study trophic relationships between pests and their natural enemies. However, most predators are best defined as omnivores, and the identification of plant-specific DNA should also allow the identification of the plant species the predators have been feeding on. In this study, a PCR approach based on the development of specific primers was developed as a self-marking technique to detect plant DNA within the gut of one heteropteran omnivorous predator (Macrolophus pygmaeus) and two lepidopteran pest species (Helicoverpa armigera and Tuta absoluta). Specific tomato primers were designed from the ITS 1-2 region, which allowed the amplification of a tomato DNA fragment of 332 bp within the three insect species tested in all cases (100% of detection at t=0) and did not detect DNA of other plants nor of the starved insects. Plant DNA half-lives at 25°C ranged from 5.8 h, to 27.7 h and 28.7 h within M. pygmaeus, H. armigera and T. absoluta, respectively. Tomato DNA detection within field-collected M. pygmaeus suggests dietary mixing in this omnivorous predator and showed a higher detection of tomato DNA in females and nymphs than males. This study provides a useful tool to detect and to identify plant food sources of arthropods and to evaluate crop colonization from surrounding vegetation in conservation biological control programs. PMID:21092379

  10. The Characterization of SaPIN2b, a Plant Trichome-Localized Proteinase Inhibitor from Solanum americanum

    Directory of Open Access Journals (Sweden)

    Zeng-Fu Xu

    2012-11-01

    Full Text Available Proteinase inhibitors play an important role in plant resistance of insects and pathogens. In this study, we characterized the serine proteinase inhibitor SaPIN2b, which is constitutively expressed in Solanum americanum trichomes and contains two conserved motifs of the proteinase inhibitor II (PIN2 family. The recombinant SaPIN2b (rSaPIN2b, which was expressed in Escherichia coli, was demonstrated to be a potent proteinase inhibitor against a panel of serine proteinases, including subtilisin A, chymotrypsin and trypsin. Moreover, rSaPIN2b also effectively inhibited the proteinase activities of midgut trypsin-like proteinases that were extracted from the devastating pest Helicoverpa armigera. Furthermore, the overexpression of SaPIN2b in transgenic tobacco plants resulted in enhanced resistance against H. armigera. Taken together, our results demonstrated that SaPIN2b is a potent serine proteinase inhibitor that may act as a protective protein in plant defense against insect attacks.

  11. Defensive Sesquiterpenoids from Leaves of Eupatorium adenophorum

    Institute of Scientific and Technical Information of China (English)

    石伟; 骆世洪; 黎胜红

    2012-01-01

    The invasive plant Eupatorium adenophorum Spreng has caused great economic loss in China, and is gravely threatening the native biodiversity and ecosystem. The plant has been phytochemically investigated for the defen- sive chemical substances in its leaves. Three active sesquiterpenoids were isolated and identified, which include a new sesquiterpenoid (1), and two known sesquiterpenoids (2, 3). Their structures were established by spectroscopic studies such as 1D- and 2D-NMR and MS analyses. Meanwhile, the antifeedant activities of these compounds against two generalist plant-feeding insects, Helicoverpa armigera and Spodoptera exigua, were carried out. Com- pound 1 showed significant antifeedant activity against S. exigua with ECs0 = 7.46 μg/cm^2, while compounds 2 and 3 were more active against H. armigera (EC50=2.57 and 3.04 μg/cm^2 respectively). These findings suggest a de- fensive role of sesquiterpenoids in E. adenophorum against herbivores.

  12. Pollen-mediated gene flow from transgenic cotton under greenhouse conditions is dependent on different pollinators.

    Science.gov (United States)

    Yan, Shuo; Zhu, Jialin; Zhu, Weilong; Li, Zhen; Shelton, Anthony M; Luo, Junyu; Cui, Jinjie; Zhang, Qingwen; Liu, Xiaoxia

    2015-01-01

    With the large-scale release of genetically modified (GM) crops, there are ecological concerns on transgene movement from GM crops to non-GM counterparts and wild relatives. In this research, we conducted greenhouse experiments to measure pollen-mediated gene flow (PGF) in the absence and presence of pollinators (Bombus ignitus, Apis mellifera and Pieris rapae) in one GM cotton (resistant to the insect Helicoverpa armigera and the herbicide glyphosate) and two non-GM lines (Shiyuan321 and Hai7124) during 2012 and 2013. Our results revealed that: (1) PGF varied depending on the pollinator species, and was highest with B. ignitus (10.83%) and lowest with P. rapae (2.71%); (2) PGF with B. ignitus depended on the distance between GM and non-GM cottons; (3) total PGF to Shiyuan321 (8.61%) was higher than to Hai7124 (4.10%). To confirm gene flow, we tested hybrids carrying transgenes for their resistance to glyphosate and H. armigera, and most hybrids showed strong resistance to the herbicide and insect. Our research confirmed that PGF depended on pollinator species, distance between plants and the receptor plant. PMID:26525573

  13. Bioefficacy and mode-of-action of some limonoids of salannin group from Azadirachta indica A. Juss and their role in a multicomponent system against lepidopteran larvae

    Indian Academy of Sciences (India)

    Opender Koul; Gurmeet Singh; Rajwinder Singh; Jasbir Singh; W M Daniewski; Stanislaw Berlozecki

    2004-12-01

    Biological activities of the salannin type of limonoids isolated from Azadirachta indica A. Juss were assessed using the gram pod borer Helicoverpa armigera (Hubner) and the tobacco armyworm Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae). Inhibition of larval growth was concomitant with reduced feeding by neonate and third instar larvae. All three compounds exhibited strong antifeedant activity in a choice leaf disc bioassay with 2.0, 2.3 and 2.8 g/cm2 of 3-O-acetyl salannol, salannol and salannin, respectively deterring feeding by 50% in S. litura larvae. In nutritional assays, all three compounds reduced growth and consumption when fed to larvae without any effect on efficiency of conversion of ingested food (ECI), suggesting antifeedant activity alone. No toxicity was observed nor was there any significant affect on nutritional indices following topical application, further suggesting specific action as feeding deterrents. When relative growth rates were plotted against relative consumption rates, growth efficiency of the H. armigera fed diet containing 3-O-acetyl salannol, salannol or salannin did not differ from that of starved control larvae (used as calibration curve), further confirming the specific antifeedant action of salannin type of limonoids. Where the three compounds were co-administered, no enhancement in activity was observed. Non-azadirachtin limonoids having structural similarities and explicitly similar modes of action, like feeding deterrence in the present case, have no potentiating effect in any combination.

  14. Expansion of a bitter taste receptor family in a polyphagous insect herbivore.

    Science.gov (United States)

    Xu, Wei; Papanicolaou, Alexie; Zhang, Hui-Jie; Anderson, Alisha

    2016-01-01

    The Insect taste system plays a central role in feeding behaviours and co-evolution of insect-host interactions. Gustatory receptors form the interface between the insect taste system and the environment. From genome and transcriptome sequencing we identified 197 novel gustatory receptor (GR) genes from the polyphagous pest Helicoverpa armigera. These GRs include a significantly expanded bitter receptor family (180 GRs) that could be further divided into three categories based on polypeptide lengths, gene structure and amino acid sequence. Type 1 includes 29 bitter Gr genes that possess introns. Type 2 includes 13 long intronless bitter Gr genes, while Type 3 comprises 131 short intronless bitter Gr genes. Calcium imaging analysis demonstrated that three Type 3 GRs (HarmGR35, HarmGR50 and HarmGR195) can be activated by a crude extract of cotton leaves. HarmGR195, a GR specifically and selectively expressed in adult tarsi, showed a specific response to proline, an amino acid widely present in plant tissues. We hypothesise that the expansion in the H. armigera GR family may be functionally tied to its polyphagous behavior. Understanding the molecular basis of polyphagy may provide opportunities for the development of new environmentally friendly pest control strategies. PMID:27032373

  15. Pheromone Lure and Trap Color Affects Bycatch in Agricultural Landscapes of Utah.

    Science.gov (United States)

    Spears, Lori R; Looney, Chris; Ikerd, Harold; Koch, Jonathan B; Griswold, Terry; Strange, James P; Ramirez, Ricardo A

    2016-08-01

    Aerial traps, using combinations of color and attractive lures, are a critical tool for detecting and managing insect pest populations. Yet, despite improvements in trap efficacy, collection of nontarget species ("bycatch") plagues many insect pest surveys. Bycatch can influence survey effectiveness by reducing the available space for target species and increasing trap screening time, especially in areas where thousands of insects are captured as bycatch in a given season. Additionally, bycatch may negatively impact local nontarget insect populations, including beneficial predators and pollinators. Here, we tested the effect of pheromone lures on bycatch rates of Coccinellidae (Coleoptera), Apoidea (Hymenoptera), and nontarget Lepidoptera. Multicolored (primarily yellow and white) bucket traps containing a pheromone lure for capturing one of three survey target species, Spodoptera litura (F.), S. littoralis (Boisduval), or Helicoverpa armigera (Hübner), were placed in alfalfa and corn fields, and compared to multicolored traps without a pheromone lure. All-green traps with and without H. armigera lures were employed in a parallel study investigating the effect of lure and trap color on bycatch. Over 2,600 Coccinellidae representing seven species, nearly 6,400 bees in 57 species, and >9,000 nontarget moths in 17 genera were captured across 180 traps and seven temporal sampling events. Significant effects of lure and color were observed for multiple taxa. In general, nontarget insects were attracted to the H. armigera lure and multicolored trap, but further studies of trap color and pheromone lure specificity are needed to better understand these interactions and to minimize nontarget captures. PMID:27412193

  16. Cell Culture for Production of Insecticidal Viruses.

    Science.gov (United States)

    Reid, Steven; Chan, Leslie C L; Matindoost, Leila; Pushparajan, Charlotte; Visnovsky, Gabriel

    2016-01-01

    While large-scale culture of insect cells will need to be conducted using bioreactors up to 10,000 l scale, many of the main challenges for cell culture-based production of insecticidal viruses can be studied using small-scale (20-500 ml) shaker/spinner flasks, either in free suspension or using microcarrier-based systems. These challenges still relate to the development of appropriate cell lines, stability of virus strains in culture, enhancing virus yields per cell, and the development of serum-free media and feeds for the desired production systems. Hence this chapter presents mainly the methods required to work with and analyze effectively insect cell systems using small-scale cultures. Outlined are procedures for quantifying cells and virus and for establishing frozen cells and virus stocks. The approach for maintaining cell cultures and the multiplicity of infection (MOI) and time of infection (TOI) parameters that should be considered for conducting infections are discussed.The methods described relate, in particular, to the suspension culture of Helicoverpa zea and Spodoptera frugiperda cell lines to produce the baculoviruses Helicoverpa armigera nucleopolyhedrovirus, HearNPV, and Anticarsia gemmatalis multicapsid nucleopolyhedrovirus, AgMNPV, respectively, and the production of the nonoccluded Oryctes nudivirus, OrNV, using an adherent coleopteran cell line. PMID:27565495

  17. Nucleopolyhedrovirus Introduction in Australia

    Institute of Scientific and Technical Information of China (English)

    Patrick Buerger; Caroline Hauxwell; David Murray

    2007-01-01

    Nucleopolyhedrovirus (NPV) has become an integral part of integrated pest management (IPM) in many Australian agricultural and horticultural crops. This is the culmination of years of work conducted by researchers at the Queensland Department of Primary Industries and Fisheries (QDPI&F) and Ag Biotech Australia Pty Ltd. In the early 1970's researchers at QDPI&F identified and isolated a virus in Helicoverpa armigera populations in the field. This NPV was extensively studied and shown to be highly specific to Helicoverpa and Heliothis species. Further work showed that when used appropriately the virus could be used effectively to manage these insects in crops such as sorghum, cotton, chickpea and sweet corn. A similar virus was first commercially produced in the USA in the 1970's. This product, Elcar(R), was introduced into Australia in the late 1970's by Shell Chemicals with limited success. A major factor contributing to the poor adoption of Elcar was the concurrent enormous success of the synthetic pyrethroids. The importance of integrated pest management was probably also not widely accepted at that time. Gradual development of insect resistance to synthetic pyrethroids and other synthetic insecticides in Australia and the increased awareness of the importance of IPM meant that researchers once again turned their attentions to environmentally friendly pest management tools such NPV and beneficial insects. In the 1990's a company called Rhone-Poulenc registered an NPV for use in Australian sorghum, chickpea and cotton. This product, Gemstar(R), was imported from the USA. In 2000 Ag Biotech Australia established an in-vivo production facility in Australia to produce commercial volumes of a product similar to the imported product. This product was branded, ViVUS(R), and was first registered and sold commercially in Australia in 2003. The initial production of ViVUS used a virus identical to the American product but replicating it in an Australian Helicoverpa

  18. 转基因作物对生物多样性的影响%Effect of transgenic crops on biodiversity

    Institute of Scientific and Technical Information of China (English)

    钱迎倩; 魏伟; 桑卫国; 马克平

    2001-01-01

    Effect of transgenic crops on biodiversity is one of important environmental issues. Concerned experimental reports have been published recently. It was reported by Xia Jingyuan et al. that transgenic Bt cotton in field trial harms seriously the parasitic rate, emergence rate and quality of cocoon of Campoletis chlorideae and Microplitis sp.,and the dominant parasitic natural enemies of the larvae of bollworm (Helicoverpa armigera). Results on convincible experiments were published by entomologists, especially Losey's et al. results that transgenic pollen harms monarch larvae in his laboratory assay, published on Nature (399: 214, 20 May, 1999), caused strong repercussions worldwide.The U.S. government hold uncompromising stand on the effect of GMOs on potential ecological risks and public health, started to become flexible. USDA Secretary announced a new biotechnology advisory committee that will bring advice from a wide range of biotech stakeholders. Two U.S. processing companies that represent nearly half of the U.S. corn-processing market, announced that they will no longer accept transgenic corn varieties that are not approved by the EU. EU announced on May 21, the next day after publishing of Losey′s paper, that it would freeze its approval pending further investigation. UK recently announced it would wait 3 years before approving crops with built-in Bt; Austria, Luxembourg and Norway have banned the corn in spite of EU approval; Greece voted against the EU approval. Scientific and technological circles and the public opinions vary. Related Ministries and Agencies in our country have to pay enough attention, especially to strengthen the studies on the effect of GMOs on the potential ecological risks and public health and the monitoring after release of GMOs in the commercialized scale.%转基因作物对生物多样性的影响是重要的环境问题之一,近年来,已有这类实验的报道。夏敬源等的研究说明大田种植转基因Bt抗虫

  19. Chloroplast-targeted expression of recombinant crystal-protein gene in cotton: an unconventional combat with resistant pests.

    Science.gov (United States)

    Kiani, Sarfraz; Mohamed, Bahaeldeen Babiker; Shehzad, Kamran; Jamal, Adil; Shahid, Muhammad Naveed; Shahid, Ahmad Ali; Husnain, Tayyab

    2013-07-10

    Plants transformed with single Bt gene are liable to develop insect resistance and this has already been reported in a number of studies carried out around the world where Bt cotton was cultivated on commercial scale. Later, it was envisaged to transform plants with more than one Bt genes in order to combat with resistant larvae. This approach seems valid as various Bt genes possess different binding domains which could delay the likely hazards of insect resistance against a particular Bt toxin. But it is difficult under field conditions to develop homozygous plants expressing all Bt genes equally after many generations without undergoing recombination effects. A number of researches claiming to transform plants from three to seven transgenes in a single plant were reported during the last decade but none has yet applied for patent of homozygous transgenic lines. A better strategy might be to use hybrid-Bt gene(s) modified for improved lectin-binding domains to boost Bt receptor sites in insect midgut. These recombinant-Bt gene(s) would express different lectin domains in a single polypeptide and it is relatively easy to develop homozygous transgenic lines under field conditions. Enhanced chloroplast-localized expression of hybrid-Bt gene would leave no room for insects to develop resistance. We devised and successfully applied this strategy in cotton (Gossypium hirsutum) and data up to T3 generation showed that our transgenic cotton plants were displaying enhanced chloroplast-targeted Cry1Ac-RB expression. Laboratory and field bioassays gave promising results against American bollworm (Heliothis armigera), pink bollworm (Pictinophora scutigera) and fall armyworm (Spodoptera frugiperda) that otherwise, were reported to have evolved resistance against Cry1Ac toxin. Elevated levels of hybrid-Bt toxin were confirmed by ELISA of chloroplast-enriched protein samples extracted from leaves of transgenic cotton lines. While, localization of recombinant Cry1Ac-RB protein in

  20. Effect of gamma radiation on reproduction and mating competitiveness in the spiny bollworm, Enrias Insulana, (BOISD). Vol. 4

    International Nuclear Information System (INIS)

    Adult moths less than 24 hours of the spiny bell worm, E. Insulana were exposed to 100, 200, 300, 400, 500, and 600 Gy of gamma radiation. The irradiated adults were paired with the untreated opposite sex. Fecundity of females decreased, almost proportionally with the increase in dose. The effect on fecundity was more pronounced in the case of irradiated females being paired with normal males than when normal were mated to irradiated males. Egg hatch was also dose dependent, as it decreased gradually with the increase in the radiation dose applied to adult males or females. however, both irradiated males and females have almost the same sensitivity and respondency to gamma radiation as reduction in hatch ability was concerned. Adult males irradiated with sub sterilizing doses of 100 or 300 Gy were more competitive than males irradiated with sterilizing dose of 600 Gy against untreated males in mating with normal females. Increasing the ratio of irradiated males to normal males from 1:1 to 5:1 decreased the rate of egg viability. 3 tabs

  1. Cis-mediated down-regulation of a trypsin gene associated with Bt resistance in cotton bollworm

    Science.gov (United States)

    Transgenic plants producing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) are useful for pest control, but their efficacy is reduced when pests evolve resistance. Previously identified mechanisms of resistance to Bt toxins include reduced binding of activated Bt toxins to m...

  2. Screening of tomato genotypes for resistance to tomato fruit borer (helicoverpa armiger hubner) in Pakistan

    International Nuclear Information System (INIS)

    Tomato genotypes viz., Roma Local, Rio Grande, Tanja, Chico III, Long Tipped, Red-Top, FS-8001, FS-8002, Tropic, Pakit, Peelo, NARC-1, Roma VFN, Pant Bahr, Ebein, Nova Mech, Rockingham, Nagina, Shalkot-96, Pomodoro, Manik, Gressilesse, Nadir, Early Mech, Tommy, Pusha Rubi, Tropic boy, Big Long, Sahil, Sun 6002, Money-Maker and Royesta were evaluated to screen out the suitable resistant/susceptible genotypes against the fruit borer in Pakistan. The results imparted that the percentage of fruit infestation and larval population per plant on tested genotypes of tomato varied significantly. Roma VF, NARC-1 and FS-8002 were categorized as susceptible genotypes with fruit infestation (37.69%, 37.08% and 36.41%, respectively) and larval population per plant (1.02%, 1.02% and 0.84 %, respectively). Whereas, the genotypes Sahil, Pakit and Nova Mecb had fruit infestation (12.30%, 13.14% and 13.96%, respectively) and larval population per plant (0.42%, 0.42% and 0.43%, respectively) and declared as resistant genotypes to tomato fruit borer. Lower values of host plant susceptibility indices (HPSI) were recorded on resistant genotypes. Sahil, Pakit and Nova Mecb could be used as a source of resistance for developing tomato genotypes resistant to tomato fruit borer. (author)

  3. Comparative Toxicity of Mycotoxins to Navel Orangeworm (Amyelois transitella) and Corn Earworm (Helicoverpa zea)

    Science.gov (United States)

    Mycotoxins, such as aflatoxins and ochratoxins, are widely distributed in nature and are frequently problematic crop contaminants that cause millions of dollars of annual losses in the United States. Insect infestations of crop plants significantly exacerbate mycotoxin contamination. Damage to a v...

  4. Evaluation of total phenolic compounds and insecticidal and antioxidant activities of tomato hairy root extract.

    Science.gov (United States)

    Singh, Harpal; Dixit, Sameer; Verma, Praveen Chandra; Singh, Pradhyumna Kumar

    2014-03-26

    Tomatoes are one of the most consumed crops in the whole world because of their versatile importance in dietary food as well as many industrial applications. They are also a rich source of secondary metabolites, such as phenolics and flavonoids. In the present study, we described a method to produce these compounds from hairy roots of tomato (THRs). Agrobacterium rhizogenes strain A4 was used to induce hairy roots in the tomato explants. The Ri T-DNA was confirmed by polymerase chain reaction amplification of the rolC gene. Biomass accumulation of hairy root lines was 1.7-3.7-fold higher compared to in vitro grown roots. Moreover, THRs efficiently produced several phenolic compounds, such as rutin, quercetin, kaempferol, gallic acid, protocatechuic acid, ferulic acid, colorogenic acid, and caffeic acid. Gallic acid [34.02 μg/g of dry weight (DW)] and rutin (20.26 μg/g of DW) were the major phenolic acid and flavonoid produced by THRs, respectively. The activities of reactive oxygen species enzymes (catalase, ascorbate peroxidase, and superoxide dismutase) were quantified. The activity of catalase in THRs was 0.97 ± 0.03 mM H2O2 min(-1) g(-1), which was 1.22-fold (0.79 ± 0.09 mM H2O2 min(-1) g(-1)) and 1.59-fold (0.61 ± 0.06 mM H2O2 min(-1) g(-1)) higher than field grown and in vitro grown roots, respectively. At 100 μL/g concentration, the phenolic compound extract caused 53.34 and 40.00% mortality against Helicoverpa armigera and Spodoptera litura, respectively, after 6 days. Surviving larvae of H. armigera and S. litura on the phenolic compound extract after 6 days showed 85.43 and 86.90% growth retardation, respectively. PMID:24635720

  5. The insect SNMP gene family.

    Science.gov (United States)

    Vogt, Richard G; Miller, Natalie E; Litvack, Rachel; Fandino, Richard A; Sparks, Jackson; Staples, Jon; Friedman, Robert; Dickens, Joseph C

    2009-07-01

    SNMPs are membrane proteins observed to associate with chemosensory neurons in insects; in Drosophila melanogaster, SNMP1 has been shown to be essential for the detection of the pheromone cis-vaccenyl acetate (CVA). SNMPs are one of three insect gene clades related to the human fatty acid transporter CD36. We previously characterized the CD36 gene family in 4 insect Orders that effectively cover the Holometabola, or some 80% of known insect species and the 300 million years of evolution since this lineage emerged: Lepidoptera (e.g. Bombyx mori, Antheraea polyphemus, Manduca sexta, Heliothis virescens, Helicoverpa assulta, Helicoverpa armigera, Mamestra brassicae); Diptera (D. melanogaster, Drosophila pseudoobscura, Aedes aegypti, Anopheles gambiae, Culex pipiens quinquefasciatus); Hymenoptera (Apis mellifera); and Coleoptera (Tribolium castaneum). This previous study suggested a complex topography within the SNMP clade including a strongly supported SNMP1 sub-clade plus additional SNMP genes. To further resolve the SNMP clade here, we used cDNA sequences of SNMP1 and SNMP2 from various Lepidoptera species, D. melanogaster and Ae. aegypti, as well as BAC derived genomic sequences from Ae. aegypti as models for proposing corrected sequences of orthologues in the D. pseudoobscura and An. gambiae genomes, and for identifying orthologues in the B. mori and C. pipiens q. genomes. We then used these sequences to analyze the SNMP clade of the insect CD36 gene family, supporting the existence of two well supported sub-clades, SNMP1 and SNMP2, throughout the dipteran and lepidopteran lineages, and plausibly throughout the Holometabola and across a broad evolutionary time scale. We present indirect evidence based on evolutionary selection (dN/dS) that the dipteran SNMPs are expressed as functional proteins. We observed expansions of the SNMP1 sub-clade in C. pipiens q. and T. castaneum suggesting that the SNMP1s may have an expanded functional role in these species. PMID

  6. Evaluation of pest vulnerability of 'Benning' soybean value added and insect resistant near isogenic lines.

    Science.gov (United States)

    Samuel-Foo, Michelle; All, John N; Boerma, H Roger

    2013-04-01

    Crop enhancement with value added traits may affect vulnerability to insects, and evaluating the susceptibility levels of the various value added traits in elite germplasm would aid in developing integrated pest management strategies. During 2007-2008, five 'Benning' soybean (Glycine max (L.) Merr) lines with different value added nutritional traits and four insect resistant quantitative trait loci (QTL) lines were evaluated in an effort to determine their pest vulnerability under artificial and natural insect pest populations. The lines showed variable susceptibility to lepidopterous insect pests classified as defoliators and stem feeders in replicated greenhouse and field tests. The study was carried out in Athens and Midville, GA. The green cloverworm (Hypena scabra (F.)) was the most common lepidopteran defoliator occurring in the fields. Other caterpillar pests found included the soybean looper (Pseudoplusia includens (Walker)), the bollworm (Helicoverpa zea (Boddie)), and the velvetbean caterpillar (Anticarsia gemmatalis (Hübner)). Data indicated that there was no significantly increased pest susceptibility among the value added cultivars with improved nutritional qualities, with the insect resistant quantitative trait loci lines Benning M and Benning MGH consistently being less susceptible to lepidopterous (Noctuidae) leaf injury. PMID:23786071

  7. Molecular characterization and developmental expression of the gene encoding the prothoracicotropic hormone in the beet armyworm,Spodoptera exigua

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Prothoracicotropic hormone (PTTH), a neuropeptide hormone stimulating the prothoracic glands to synthesize ecdysone, plays an important role in regulating postembryonic development in insects. The cDNA encoding PTTH was isolated and sequenced from the beet armyworm, Spodoptera exigua (Spe). The deduced a?mino acid sequence is composed of a signal peptide, a peptide (65 amino acids) of un-known function, and a mature PTTH molecule (111 amino acids). The Spe-PTTH shows similarities (45.5%―70.3%) to other known PTTHs reported in Lepidoptera species, but 7 cysteine r?esidues and the hydrophobic regions were conserved. Whole-mount immunocytochemistry by using an antiserum against recombinant Helicoverpa armigera PTTH showed that Spe-PTTH was synthesized in two pairs of neurosecretory cells in the S. exigua brain. Northern blot analysis demonstrates the presence of a 1.2-kb transcript in the brain. The Spe-PTTH mRNA is detectable at high levels at the wandering larval stage, early pupal stage, and pharate adult stage, suggesting that the Spe-PTTH gene might be corre-lated with molting, metamorphosis, and reproduction.

  8. The Steroid Hormone 20-Hydroxyecdysone Enhances Gene Transcription through the cAMP Response Element-binding Protein (CREB) Signaling Pathway.

    Science.gov (United States)

    Jing, Yu-Pu; Wang, Di; Han, Xiao-Lin; Dong, Du-Juan; Wang, Jin-Xing; Zhao, Xiao-Fan

    2016-06-10

    Animal steroid hormones regulate gene transcription through genomic pathways by binding to nuclear receptors. These steroid hormones also rapidly increase intracellular calcium and cyclic adenosine monophosphate (cAMP) levels and activate the protein kinase C (PKC) and protein kinase A (PKA) nongenomic pathways. However, the function and mechanism of the nongenomic pathways of the steroid hormones are unclear, and the relationship between the PKC and PKA pathways is also unclear. We propose that the steroid hormone 20-hydroxyecdysone (20E) activates the PKA pathway to enhance 20E-induced gene transcription in the lepidopteran insect Helicoverpa armigera The expression of the catalytic subunit 1 of PKA (PKAC1) increased during metamorphosis, and PKAC1 knockdown blocked pupation and repressed 20E-responsive gene expression. 20E regulated PKAC1 phosphorylation at threonine 200 and nuclear translocation through an ecdysone-responsive G-protein-coupled receptor 2. PKAC1 induced cAMP response element-binding protein (CREB) phosphorylation at serine 143, which bound to the cAMP response element on DNA to enhance 20E-responsive gene transcription. Through ecdysone-responsive G-protein-coupled receptor 2, 20E increased cAMP levels, which induced CREB PKA phosphorylation and 20E-responsive gene expression. This study demonstrates that the PKA/CREB pathway tightly and critically regulates 20E-induced gene transcription as well as its relationship with the 20E-induced PKC pathway. PMID:27129227

  9. Allelopathic effects of essential oil from Eucalyptus grandis × E.urophylla on pathogenic fungi and pest insects

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This study on the allelopathic effects and chemical components of the essential oil from Eucalyptus grandis × E.urophylla shows that the leaf oil emulsion of E.grandis × E.urophylla can inhibit the proliferation of pathogenic fungi Fusarium oxysporum,Pyriculerie grisea,Glorosprium musa rum and Phytophthora capsici.Pupation and feeding of the pest insects Spodopteralitura Fabricius and Helicoverpa armigera Hubner are shown to be affected with restraining effects which increase with the increasing levels of oil concentration.A GC/MS analysis of the leaf oil indicated that the main components,with a relative content of≥3%,were alloocimene (43.22%),α-pinene (13.63%),γ-terpinene (5.49%),(E)-3,7-dimethyl-2,6-octadien-1-ol (3.58%),β-fenchyl alcohol (4.58%),and 2-amino-3,5-dicyano-6-(4-methoxyphenoxy)-pyridine (3.67%).Terpenes played an important role in the inhibitory effects of E.grandis × E.urophylla essential oil on pathogenic fungi and pest insects.Poor biodiversity of eucalyptus plantations is a function of allelopathy.

  10. Herbivore defense responses and associated herbivore defense mechanism as revealed by comparing a resistant wild soybean with a susceptible cultivar

    Directory of Open Access Journals (Sweden)

    Xiaoyi Wang

    2015-12-01

    Full Text Available Plants have evolved sophisticated defense mechanisms against herbivores to help them adapt to the environment. Understanding the defense mechanisms in plants can help us control insects in a more effective manner. In this study, we found that compared with Tianlong 2 (a cultivated soybean with insect susceptibility, ED059 (a wild soybean line with insect resistance contains sharper pubescence tips, as well as lower transcript levels of wound-induced protein kinase (WIPK and salicylic acid-induced protein kinase (SIPK, which are important mitogen-activated protein kinases involved in early defense response to herbivores. The observed lower transcript levels of WIPK and SIPK induced higher levels of jasmonic acid (JA, JA biosynthesis enzymes (AOC3 and some secondary metabolites in ED059. Functional analysis of the KTI1 gene via Agrobacterium-mediated transformation in Arabidopsis thaliana indicated that it plays an important role in herbivore defense in ED059. We further investigated the molecular response of third-instar Helicoverpa armigera (Hübner larvae to Tianlong 2 and ED059. We found apoptotic cells only in the midguts of larvae that fed on ED059. Compared with larvae reared on the susceptible cultivar Tianlong 2, transcript levels of catalase (CAT and glutathione S-transferase (GST were up-regulated, whereas those of CAR, CHSB, and TRY were down-regulated in larvae that fed on the highly resistant variety ED059. We propose that these differences underlie the different herbivore defense responses of ED059 and Tianlong 2.

  11. Generalist insects behave in a jasmonate-dependent manner on their host plants, leaving induced areas quickly and staying longer on distant parts.

    Science.gov (United States)

    Perkins, Lynda E; Cribb, Bronwen W; Brewer, Philip B; Hanan, Jim; Grant, Murray; de Torres, Marta; Zalucki, Myron P

    2013-04-01

    Plants are sessile, so have evolved sensitive ways to detect attacking herbivores and sophisticated strategies to effectively defend themselves. Insect herbivory induces synthesis of the phytohormone jasmonic acid which activates downstream metabolic pathways for various chemical defences such as toxins and digestion inhibitors. Insects are also sophisticated animals, and many have coevolved physiological adaptations that negate this induced plant defence. Insect behaviour has rarely been studied in the context of induced plant defence, although behavioural adaptation to induced plant chemistry may allow insects to bypass the host's defence system. By visualizing jasmonate-responsive gene expression within whole plants, we uncovered spatial and temporal limits to the systemic spread of plant chemical defence following herbivory. By carefully tracking insect movement, we found induced changes in plant chemistry were detected by generalist Helicoverpa armigera insects which then modified their behaviour in response, moving away from induced parts and staying longer on uninduced parts of the same plant. This study reveals that there are plant-wide signals rapidly generated following herbivory that allow insects to detect the heterogeneity of plant chemical defences. Some insects use these signals to move around the plant, avoiding localized sites of induction and staying ahead of induced toxic metabolites. PMID:23390101

  12. Molecular basis of the remarkable species selectivity of an insecticidal sodium channel toxin from the African spider Augacephalus ezendami

    Science.gov (United States)

    Herzig, Volker; Ikonomopoulou, Maria; Smith, Jennifer J.; Dziemborowicz, Sławomir; Gilchrist, John; Kuhn-Nentwig, Lucia; Rezende, Fernanda Oliveira; Moreira, Luciano Andrade; Nicholson, Graham M.; Bosmans, Frank; King, Glenn F.

    2016-01-01

    The inexorable decline in the armament of registered chemical insecticides has stimulated research into environmentally-friendly alternatives. Insecticidal spider-venom peptides are promising candidates for bioinsecticide development but it is challenging to find peptides that are specific for targeted pests. In the present study, we isolated an insecticidal peptide (Ae1a) from venom of the African spider Augacephalus ezendami (family Theraphosidae). Injection of Ae1a into sheep blowflies (Lucilia cuprina) induced rapid but reversible paralysis. In striking contrast, Ae1a was lethal to closely related fruit flies (Drosophila melanogaster) but induced no adverse effects in the recalcitrant lepidopteran pest Helicoverpa armigera. Electrophysiological experiments revealed that Ae1a potently inhibits the voltage-gated sodium channel BgNaV1 from the German cockroach Blattella germanica by shifting the threshold for channel activation to more depolarized potentials. In contrast, Ae1a failed to significantly affect sodium currents in dorsal unpaired median neurons from the American cockroach Periplaneta americana. We show that Ae1a interacts with the domain II voltage sensor and that sensitivity to the toxin is conferred by natural sequence variations in the S1–S2 loop of domain II. The phyletic specificity of Ae1a provides crucial information for development of sodium channel insecticides that target key insect pests without harming beneficial species. PMID:27383378

  13. Assessment of pest and pesticide trends in vegetable crops in united arab emirates and sultanate of oman

    International Nuclear Information System (INIS)

    A preliminary survey on pesticide uses in 40 vegetable-growing farms representing different agricultural areas in Oman and the UAE, twenty farms from each country, revealed that all the vegetable farms used pesticides for crop protection. Among the major insect-pests, white flies (Bemisia tabaci), leafminers (Liriomyza trifolii), melon fruit flies (Bactrocera ciliatus), aphids (Aphis spp.) and tobacco leafworm (Spodoptera litteralis) were recorded in Omani farms. In the UAE, white flies, leafminers, cutworms (Agrotis ypsilan), tomato fruitworms (Helicoverpa armigera) and eggplant fruitworms (Leucinodes orbonalis) were the 5 top insect-pests. Among the plant diseases, powdery mildew (Erysiphe spp.), blight (Alternaria spp.), damping off (Pythium spp.), leafspot (Alternaria spp.) and mosaic (CMV) Were major cause of vegetable diseases in Omani farms; whereas, damping off (Pythium aphanidermatum), downy mildew (Pseudoperonspora cubensis), early blight (Alternaria solani), septoria leaf spot (Septoria lycopersici) and anthracnose rip rot (colletotrichum spp.) were the most predominant diseases encountered in most UAE farms. Among the most commonly used pesticides, 29 insecticides, 16 fungicides and 3 herbicides were used by the vegetable farmers. Around 55% of Omani farms used routine application of pesticides, irrespective of the pest presence. Whereas, in the UAE, most farmers started to spray pesticides at 6-20% pest (insect, disease and weeds) infection. Over 65 of the farms, in both the countries, received chemical pest management information from the sales representatives. (author)

  14. Chlorophyll degradation in the gut of generalist and specialist Lepidopteran caterpillars.

    Science.gov (United States)

    Badgaa, Amarsanaa; Jia, Aiqun; Ploss, Kerstin; Boland, Wilhelm

    2014-12-01

    Plant feeding herbivores excrete most of the ingested chlorophyll (Chl) as partly degraded derivatives lacking the phytol side chain and the central magnesium ion. An ecological role of digested and degraded Chls in the interactions between insects, their food plant and other insects has been described recently. To gain more information on common degradation patterns in plant-feeding insects, the orals secretions and frass of five Lepidopteran caterpillars covering generalists and specialists, namely Spodoptera littoralis, Spodoptera eridania, Heliothis virescens, Helicoverpa armigera, Manduca sexta, and, for comparison, of the leaf beetle larva Chrysomela lapponica were analyzed for chlorophyll catabolites. The major degradation products were determined as pheohorbide a/b and pyropheophorbide a/b by using LC-MS, LC-NMR, UV, and fluorescence spectrometry. The compounds were not present in fresh leaves of the food plants (Phaseolus lunatus, Nicotiana tabacum). The catabolite spectrum in generalists and specialists was qualitatively similar and could be attributed to the action of gut proteins and the strongly alkaline milieu in the digestive tract. Due to the anaerobic environment of the larval gut, the tetrapyrrole core of the Chl catabolites was not cleaved. Substantial amounts of Chl a/b metabolites were strongly complexed by a protein in the mid-gut. PMID:25416033

  15. Enhanced methanol production in plants provides broad spectrum insect resistance.

    Directory of Open Access Journals (Sweden)

    Sameer Dixit

    Full Text Available Plants naturally emit methanol as volatile organic compound. Methanol is toxic to insect pests; but the quantity produced by most of the plants is not enough to protect them against invading insect pests. In the present study, we demonstrated that the over-expression of pectin methylesterase, derived from Arabidopsis thaliana and Aspergillus niger, in transgenic tobacco plants enhances methanol production and resistance to polyphagous insect pests. Methanol content in the leaves of transgenic plants was measured using proton nuclear spectroscopy (1H NMR and spectra showed up to 16 fold higher methanol as compared to control wild type (WT plants. A maximum of 100 and 85% mortality in chewing insects Helicoverpa armigera and Spodoptera litura larvae was observed, respectively when fed on transgenic plants leaves. The surviving larvae showed less feeding, severe growth retardation and could not develop into pupae. In-planta bioassay on transgenic lines showed up to 99 and 75% reduction in the population multiplication of plant sap sucking pests Myzus persicae (aphid and Bemisia tabaci (whitefly, respectively. Most of the phenotypic characters of transgenic plants were similar to WT plants. Confocal microscopy showed no deformities in cellular integrity, structure and density of stomata and trichomes of transgenic plants compared to WT. Pollen germination and tube formation was also not affected in transgenic plants. Cell wall enzyme transcript levels were comparable with WT. This study demonstrated for the first time that methanol emission can be utilized for imparting broad range insect resistance in plants.

  16. Plant phenolics are detoxified by prophenoloxidase in the insect gut.

    Science.gov (United States)

    Wu, Kai; Zhang, Jie; Zhang, Qiaoli; Zhu, Shoulin; Shao, Qimiao; Clark, Kevin D; Liu, Yining; Ling, Erjun

    2015-01-01

    Plant phenolics are a group of important secondary metabolites that are toxic to many animals and insects if ingested at high concentrations. Because most insects consume plant phenolics daily, they have likely evolved the capacity to detoxify these compounds. Here, we used Drosophila melanogaster, Bombyx mori and Helicoverpa armigera as models to study the metabolism of plant phenolics by prophenoloxidases. We found that insect foreguts release prophenoloxidases into the lumen, and that the survival of prophenoloxidase-deletion mutants was impaired when fed several plant phenolics and tea extracts. Using l-DOPA as a model substrate, biochemical assays in large Lepidopteran insects demonstrated that low levels of l-DOPA are rapidly metabolized into intermediates by phenoloxidases. Feeding with excess l-DOPA showed that the metabolic intermediate 5,6-dihydroxyindole reached the hindgut either by passing directly through the midgut, or by transport through the hemolymph. In the hindgut, 5,6-dihydroxyindole was further oxidized by prophenoloxidases. Intermediates exerted no toxicity in the hemocoel or midgut. These results show that plant phenolics are not toxic to insects unless prophenoloxidase genes are lost or the levels of phenolics exceed the catalytic activity of the gut prophenoloxidases. PMID:26592948

  17. Leptin receptor overlapping transcript (LepROT) gene participates in insulin pathway through FoxO.

    Science.gov (United States)

    Wang, Chuan-Xu; Zhao, Ai-Hua

    2016-08-01

    Leptin receptor overlapping transcript (LepROT) is co-transcribed with the leptin receptor (LepR). However, the function and mechanism of LepROT in insulin pathway is unclear. In this study, we report the function of LepROT in maintaining consistent FoxO transcription. LepROT is constitutively expressed during larval development. 20-Hydroxyecdysone, methoprene, and insulin have no effect on the transcription of LepROT. However, the knockdown of LepROT by dsRNA injection in larvae causes delay of the development of Helicoverpa armigera. Knockdown of LepROT results in the upregulation of FoxO and downregulation of PI3K. The knockdown of LepROT also results in the subcellular translocation of FoxO from cytoplasm to nuclei. By contrast, overexpression of LepROT in the HaEpi cell line inhibits FoxO expression. Results suggest that LepROT participates in insulin signaling. PMID:27106118

  18. Cyclic di-GMP contributes to adaption and virulence of Bacillus thuringiensis through a riboswitch-regulated collagen adhesion protein.

    Science.gov (United States)

    Tang, Qing; Yin, Kang; Qian, Hongliang; Zhao, Youwen; Wang, Wen; Chou, Shan-Ho; Fu, Yang; He, Jin

    2016-01-01

    Cyclic di-GMP is a ubiquitous second messenger that regulates diverse cellular processes in bacteria by binding to various protein or riboswitch effectors. In Bacillus thuringiensis BMB171, a c-di-GMP riboswitch termed Bc2 RNA resides in the 5'-untranslated region (5'-UTR) of an mRNA that encodes a collagen adhesion protein (Cap). The expression of cap was strongly repressed in parent strain BMB171 because of the presence of Bc2 RNA but was significantly promoted in the Bc2 RNA markerless deletion mutant. Bc2 RNA acts as a genetic "on" switch, which forms an anti-terminator structure to promote cap read-through transcription upon c-di-GMP binding. As a result, cap transcription was de-repressed under high c-di-GMP levels. Therefore, Bc2 RNA regulates cap expression using a repression/de-repression model. Bc2 RNA-regulated Cap was also found to be tightly associated with motility, aggregation, exopolysaccharide secretion, biofilm formation, and virulence of B. thuringiensis BMB171 against its host insect Helicoverpa armigera. PMID:27381437

  19. Molecular characterization and developmental expression of the gene encoding the prothoracicotropic hormone in the beet armyworm, Spodoptera exigua

    Institute of Scientific and Technical Information of China (English)

    XU Jun; SU JianYa; SHEN JinLiang; XU WeiHua

    2007-01-01

    Prothoracicotropic hormone (PTTH), a neuropeptide hormone stimulating the prothoracic glands to synthesize ecdysone, plays an important role in regulating postembryonic development in insects. The cDNA encoding PTTH was isolated and sequenced from the beet armyworm, Spodoptera exigua (Spe).The deduced amino acid sequence is composed of a signal peptide, a peptide (65 amino acids) of unknown function, and a mature PTTH molecule (111 amino acids). The Spe-PTTH shows similarities(45.5%-70.3%) to other known PTTHs reported in Lepidoptera species, but 7 cysteine residues and the hydrophobic regions were conserved. Whole-mount immunocytochemistry by using an antiserum against recombinant Helicoverpa armigera PTTH showed that Spe-PTTH was synthesized in two pairs of neurosecretory cells in the S. exigua brain. Northern blot analysis demonstrates the presence of a 1.2-kb transcript in the brain. The Spe-PTTH mRNA is detectable at high levels at the wandering larval stage, early pupal stage, and pharate adult stage, suggesting that the Spe-PTTH gene might be correlated with molting, metamorphosis, and reproduction.

  20. Bt resistance in Australian insect pest species.

    Science.gov (United States)

    Downes, Sharon; Walsh, Tom; Tay, Wee Tek

    2016-06-01

    Bt cotton was initially deployed in Australia in the mid-1990s to control the polyphagous pest Helicoverpa armigera (Hübner) which was intractably resistant to synthetic chemistries. A conservative strategy was enforced and resistance to first generation single toxin technology was managed. A decade later, shortly after the release of dual toxin cotton, high baseline frequencies of alleles conferring resistance to one of its components prompted a reassessment of the thinking behind the potential risks to this technology. Several reviews detail the characteristics of this resistance and the nuances of deploying first and second generation Bt cotton in Australia. Here we explore recent advances and future possibilities to estimate Bt resistance in Australian pest species and define what we see as the critical data for enabling effective pre-emptive strategies. We also foreshadow the imminent deployment of three toxin (Cry1Ac, Cry2Ab, Vip3A) Bollgard 3 cotton, and examine aspects of resistance to its novel component, Vip3A, that we believe may impact on its stewardship. PMID:27436735

  1. Insect Pest Incidence on Cowpea in the Cameroonian Southwest Forest and Western Derived Savanna Zones, their Contribution to Yield Loss in Foumbot and their Control

    Directory of Open Access Journals (Sweden)

    Parh, LA.

    1999-01-01

    Full Text Available In 1986 and 1987, insect pests sampled on cowpea in the Cameroonian Southwest forest and Western derived savanna ecological 1 zones included Maruca vitrata, Leguminivora (Cydia ptychora, Helicoverpa (Heliothis armigera, Melanagromyza vignalis, Apion disjunctum, Aphis craccivora, heteropteran bugs and bruchids. Under eight different deltamethrin spray schedules evaluated for their control at Foumbot, western derived savanna ecozone, the yield loss they caused ranged from 123.60 kg/ha in plants sprayed twice at the reproductive stage to 362.51 kg/ha in unsprayed plants in 1988 ; 21.86 kg/ha in plants sprayed thrice at the reproductive stage to 90.73 kg/ha in unsprayed plants in 1989 and 91.72 kg/ha in plants sprayed 5 to 6 times at fortnightly intervals, to 184.08 kg/ha in unsprayed plants in 1990. The percentage loss due to Maruca vitrata, Melanagromyza vignalis and heteropteran bugs was high in sprayed and unsprayed plots. In 1989 and 1990, seedyields were significantly increased by spraying deltamethrin either forthnightly or once at 75-100 % flowerbuds and once at 75-100 % podding, or once at 75-100 % flowering and once at 75-100 % podding.

  2. Sterile insect technique (SIT) for control of spotted bollworm of cotton: field experiments confirm dose fractionation improves mating competitiveness of sterile males

    International Nuclear Information System (INIS)

    Earias vittella Fabricius causes serious economic damage to cotton and is being targeted for control by SIT. Experiments were conducted under simulated and actual field conditions with sterile males obtained using dose fractionation (75 x 4 Gy ). Under group mating conditions a 6 sterile : 1 normal male ratio resulted in an egg hatch of only 1.4 % compared to 93.5 % in control. Field studies using the same release ratio showed that sterile - males could search the females from a long distance and egg hatch remained only 2.1% for days. These studies confirmed the competitiveness of sterile males obtained using dose fractionation. (author)

  3. Effectiveness of synthetic pheromone traps for monitoring of important polyphagous field crop pests on large areas

    International Nuclear Information System (INIS)

    Full text: Gram pod borer (Helicoverpa armigera Hub.), diamond back moth (Plutella xylostella) and fruit fly (Bactrocera dorsalis) are the major pests of different field crops of commercial importance. These pests are difficult to manage using insecticides. It is, therefore, essential to monitor their population in field crops before undertaking any control measures. The pheromones of these pests were synthesized in the laboratory and the evaluation of the performance of different pheromone lures under field conditions was carried out in different crops viz., pigeon pea, chickpea, tomato, chilli, cabbage and guava orchards in the present study. Studies were conducted at the Research Farm of Mahatma Phule Krishi Vidyapeeth, Rahuri as well as at different locations on farmers' field during April 1997 to December 1998. The pheromones were synthesised by the National Chemical Laboratory, Pune for three different pests such as (Z)-11-Hexadecenal and (Z)-9-Hexadecenal (97:3) for H. armigera, (Z)-Hexadecenal, (Z)-11-Hexadecenyl acelate and (Z)-11-Hexadecenol for P. xylostella and 3,4-Dimethoxy propyl benzene for B. dorsalis. These pheromone lures were successfully loaded in the septa and evaluated in field crops in different concentrations to find out the effective dose. These septa were replaced in traps every four weeks. Trapped moths were removed daily, and data are compiled per meteorological week. In tomato, pheromone traps were installed at a distance of 50 m from each other and moth catches were monitored daily using (Z)-11-Hexadecenal and (Z)-9-Hexadecenal (97:3) pheromones in 1, 2 and 5 mg concentrations at two separate locations. It was observed that the pheromones at the concentration of 5 mg per trap were most effective in attracting H. armigera moths. Maximum moth activity (93 moths/trap) was observed in the 21st meteorological week and declined in subsequent weeks. In chilli crop, two pheromone traps were installed in a 0.4 ha area at MPKV Farm to monitor H

  4. Optimal Cotton Insecticide Application Termination Timing: A Meta-Analysis.

    Science.gov (United States)

    Griffin, T W; Zapata, S D

    2016-08-01

    The concept of insecticide termination timing is generally accepted among cotton (Gossypium hirsutum) researchers; however, exact timings are often disputed. Specifically, there is uncertainty regarding the last economic insecticide application to control fruit-feeding pests including tarnished plant bug (Lygus lineolaris (Palisot de Beauvois)), boll weevil (Anthonomus grandis), bollworm (Helicoverpa zea), tobacco budworm (Heliothis virescens), and cotton fleahopper (Pseudatomoscelis seriatus). A systematic review of prior studies was conducted within a meta-analytic framework. Nine publicly available articles were amalgamated to develop an optimal timing principle. These prior studies reported 53 independent multiple means comparison field experiments for a total of 247 trial observations. Stochastic plateau theory integrated with econometric meta-analysis methodology was applied to the meta-database to determine the shape of the functional form of both the agronomic optimal insecticide termination timing and corresponding yield potential. Results indicated that current university insecticide termination timing recommendations are later than overall estimated timing suggested. The estimated 159 heat units (HU) after the fifth position above white flower (NAWF5) was found to be statistically different than the 194 HU termination used as the status quo recommended termination timing. Insecticides applied after 159 HU may have been applied in excess, resulting in unnecessary economic and environmental costs. Empirical results also suggested that extending the insecticide termination time by one unit resulted in a cotton lint yield increase of 0.27 kilograms per hectare up to the timing where the plateau began. Based on economic analyses, profit-maximizing producers may cease application as soon as 124 HU after NAWF5. These results provided insights useful to improve production systems by applying inputs only when benefits were expected to be in excess of the

  5. Assessing the potential for interaction between the insecticidal activity of two genetically engineered cotton events combined by conventional breeding: An example with COT102 × MON 15985.

    Science.gov (United States)

    Levine, Steven L; Mueller, Geoffrey M; Uffman, Joshua P

    2016-08-01

    Bollgard(®) III was developed by combining cotton events COT102 and MON 15985 through conventional breeding to improve efficacy against lepidopteran feeding damage. COT102 produces the Vip3Aa19 protein and MON 15985 produces the Cry1Ac and Cry2Ab2 proteins. COT102 × MON 15985 has also been bred with Roundup Ready Flex(®) cotton (MON 88913) that confers glyphosate tolerance. This study evaluated the activity of COT102 and MON 15985 and the combined activity of COT102 and MON 15985 against the cotton bollworm (CBW, Helicoverpa zea). COT102, MON 15985, COT102 × MON 15985 and COT102 × MON 15985 × MON 88913 have comparable Vip3Aa19 and/or Cry1Ac, Cry2Ab2 protein expression levels as determined by enzyme-linked immunosorbent assay. CBW demonstrated concentration-dependent growth inhibition after 7-days of feeding on lyophilized leaf tissue derived from COT102, MON 15985, COT102 × MON 15985 and COT102 × MON 15985 × MON 88913 incorporated into an artificial diet. Observed EC50 values for COT102 × MON 15985 and COT102 × MON 15985 × MON 88913 were comparable (≤4% deviation) with the predicted EC50 value under the assumption of additivity using the combined activity of COT102 and MON 15985. No interaction in biological activity between COT102 and MON 15985 is consistent with results from competition and ligand blotting assays that demonstrated that Vip3Aa does not inhibit the binding of either Cry1Ac or Cry2Ab2 and vice versa. The results from this study demonstrate that the activity of COT102 × MON 15985 against CBW is consistent with predictions of additivity. PMID:27155596

  6. Comparative analysis of the UDP-glycosyltransferase multigene family in insects.

    Science.gov (United States)

    Ahn, Seung-Joon; Vogel, Heiko; Heckel, David G

    2012-02-01

    UDP-glycosyltransferases (UGT) catalyze the conjugation of a range of diverse small lipophilic compounds with sugars to produce glycosides, playing an important role in the detoxification of xenobiotics and in the regulation of endobiotics in insects. Recent progress in genome sequencing has enabled an assessment of the extent of the UGT multigene family in insects. Here we report over 310 putative UGT genes identified from genomic databases of eight different insect species together with a transcript database from the lepidopteran Helicoverpa armigera. Phylogenetic analysis of the insect UGTs showed Order-specific gene diversification and inter-species conservation of this multigene family. Only one family (UGT50) is found in all insect species surveyed (except the pea aphid) and may be homologous to mammalian UGT8. Three families (UGT31, UGT32, and UGT305) related to Lepidopteran UGTs are unique to baculoviruses. A lepidopteran sub-tree constructed with 40 H. armigera UGTs and 44 Bombyx mori UGTs revealed that lineage-specific expansions of some families in both species appear to be driven by diversification in the N-terminal substrate binding domain, increasing the range of compounds that could be detoxified or regulated by glycosylation. By comparison of the deduced protein sequences, several important domains were predicted, including the N-terminal signal peptide, UGT signature motif, and C-terminal transmembrane domain. Furthermore, several conserved residues putatively involved in sugar donor binding and catalytic mechanism were also identified by comparison with human UGTs. Many UGTs were expressed in fat body, midgut, and Malpighian tubules, consistent with functions in detoxification, and some were expressed in antennae, suggesting a role in pheromone deactivation. Transcript variants derived from alternative splicing, exon skipping, or intron retention produced additional UGT diversity. These findings from this comparative study of two lepidopteran UGTs

  7. Complexity and variability of gut commensal microbiota in polyphagous lepidopteran larvae.

    Directory of Open Access Journals (Sweden)

    Xiaoshu Tang

    Full Text Available BACKGROUND: The gut of most insects harbours nonpathogenic microorganisms. Recent work suggests that gut microbiota not only provide nutrients, but also involve in the development and maintenance of the host immune system. However, the complexity, dynamics and types of interactions between the insect hosts and their gut microbiota are far from being well understood. METHODS/PRINCIPAL FINDINGS: To determine the composition of the gut microbiota of two lepidopteran pests, Spodoptera littoralis and Helicoverpa armigera, we applied cultivation-independent techniques based on 16S rRNA gene sequencing and microarray. The two insect species were very similar regarding high abundant bacterial families. Different bacteria colonize different niches within the gut. A core community, consisting of Enterococci, Lactobacilli, Clostridia, etc. was revealed in the insect larvae. These bacteria are constantly present in the digestion tract at relatively high frequency despite that developmental stage and diet had a great impact on shaping the bacterial communities. Some low-abundant species might become dominant upon loading external disturbances; the core community, however, did not change significantly. Clearly the insect gut selects for particular bacterial phylotypes. CONCLUSIONS: Because of their importance as agricultural pests, phytophagous Lepidopterans are widely used as experimental models in ecological and physiological studies. Our results demonstrated that a core microbial community exists in the insect gut, which may contribute to the host physiology. Host physiology and food, nevertheless, significantly influence some fringe bacterial species in the gut. The gut microbiota might also serve as a reservoir of microorganisms for ever-changing environments. Understanding these interactions might pave the way for developing novel pest control strategies.

  8. High Expression of Cry1Ac Protein in Cotton (Gossypium hirsutum) by Combining Independent Transgenic Events that Target the Protein to Cytoplasm and Plastids

    Science.gov (United States)

    Singh, Amarjeet Kumar; Paritosh, Kumar; Kant, Uma; Burma, Pradeep Kumar; Pental, Deepak

    2016-01-01

    Transgenic cotton was developed using two constructs containing a truncated and codon-modified cry1Ac gene (1,848 bp), which was originally characterized from Bacillus thuringiensis subspecies kurstaki strain HD73 that encodes a toxin highly effective against many lepidopteran pests. In Construct I, the cry1Ac gene was cloned under FMVde, a strong constitutively expressing promoter, to express the encoded protein in the cytoplasm. In Construct II, the encoded protein was directed to the plastids using a transit peptide taken from the cotton rbcSIb gene. Genetic transformation experiments with Construct I resulted in a single copy insertion event in which the Cry1Ac protein expression level was 2–2.5 times greater than in the Bacillus thuringiensis cotton event Mon 531, which is currently used in varieties and hybrids grown extensively in India and elsewhere. Another high expression event was selected from transgenics developed with Construct II. The Cry protein expression resulting from this event was observed only in the green plant parts. No transgenic protein expression was observed in the non-green parts, including roots, seeds and non-green floral tissues. Thus, leucoplasts may lack the mechanism to allow entry of a protein tagged with the transit peptide from a protein that is only synthesized in tissues containing mature plastids. Combining the two events through sexual crossing led to near additive levels of the toxin at 4–5 times the level currently used in the field. The two high expression events and their combination will allow for effective resistance management against lepidopteran insect pests, particularly Helicoverpa armigera, using a high dosage strategy. PMID:27391960

  9. Manthar-03: a high-yielding cultivar of wheat released for general cultivation in Southern Punjab

    International Nuclear Information System (INIS)

    We report the release of a new wheat variety Manthar-03. 'Manthar-03' is a high yielding and rust resistant variety of bread wheat with erect growth habit. It was released in the year 2003 as a general purpose variety. Manthar-03 is a selection from CIMMYT material (Entry No. 42 of 29 International Bread Wheat Screening Nursery) made at Regional Agricultural Research Institute (RARI), Bahawalpur during 1996-97. This strain has the famous CIMMYT line 'Kauz' in its parentage (KAUZ//ALTAR 84/AOS). Its pedigree is CM11163-6M-20Y-10M- 0M-0B. It is a more adapted and a high yielder. Genetically, this strain differs from existing commercial cultivars of Punjab. Resistance against leaf rust (5MRMS to 10MR), RRI value of 6.7 and 7.6 for leaf rust and ACI values of 3.4 and 0.7 for leaf rust) and high yield potential (6300 kg ha-1 ) are the major attributes of Manthar-03 that make it a superior variety for its target regions. Manthar-03 is tolerant to wheat aphid and Helicoverpa armigera. The thousand seed weight of this variety is 40-44 g. Seed is amber in color and contains 12.97% protein, 8.2% dry gluten and 1.55% ash. It has good chapati making quality. Plant type of Manthar-03 is erect with plant height 94 cm and droopy flag leaves. It is lodging resistant. It completes heading in 98 days and matures in 142 days. Manthar-03 performs better when planted from 15, November to 1, December, keeping 125 kg ha/sup -1/ seed rate and 125-85-50 kg NPK ha/sup -1/ are applied. (author)

  10. Expression and purification of virus like particles (VLPs) of foot-and-mouth disease virus in Eri silkworm (Samia cynthia ricini) larvae.

    Science.gov (United States)

    Kumar, Manoj; Saravanan, P; Jalali, S K

    2016-03-01

    Foot-and-mouth disease (FMD) is a highly contagious viral disease, which causes severe economic loss to livestock. Virus like particles (VLPs) produced by recombinant DNA technology are gaining importance because of their immunogenic properties and safety in developing a new vaccine for FMD. In the present study, a practical and economically feasible approach of expression, purification and characterization of VLPs of FMDV in Eri silkworm (Samia cynthia ricini) larvae was described. Although three lepidopteran insect larvae (Helicoverpa armigera, Spodoptera litura and Samia cynthia ricini) were tested for production of VLPs, expression was obtained only in Eri silkworm larvae. High titred recombinant baculovirus encoding the polyprotein P1-2A-3C of FMDV was prepared in Sf9 cells. Injection of recombinant baculovirus into hemocoel of Eri silkworm larvae resulted in increasing levels of expression of VLPs in the hemolymph from 3 to 7 days post infection (dpi) compared to low level expression by oral feeding. The VLPs reacted in Sandwich ELISA with serum raised against whole virus particles of FMDV type O/IND/R2/75 and protein banding pattern of 26, 37 and 47 kDa in Western blotting demonstrated their antigenic resemblance to native virus. Sucrose density gradient purified VLPs were used for immunization of rabbits and guinea pigs for assessing immunogenicity. Further, the reactivity of serum samples of rabbits and guinea pigs in Indirect-ELISA with titres (1.30-2.81 Log10) indicated that the VLPs were antigenic and immunogenic in nature. We demonstrate that Eri silkworm larvae could be used for production of VLPs of FMDV type O/IND/R2/75 for the first time. This approach could be useful for large scale production of recombinant VLPs for vaccine or diagnostic use in FMD control programme. PMID:26925448

  11. High Expression of Cry1Ac Protein in Cotton (Gossypium hirsutum) by Combining Independent Transgenic Events that Target the Protein to Cytoplasm and Plastids.

    Science.gov (United States)

    Singh, Amarjeet Kumar; Paritosh, Kumar; Kant, Uma; Burma, Pradeep Kumar; Pental, Deepak

    2016-01-01

    Transgenic cotton was developed using two constructs containing a truncated and codon-modified cry1Ac gene (1,848 bp), which was originally characterized from Bacillus thuringiensis subspecies kurstaki strain HD73 that encodes a toxin highly effective against many lepidopteran pests. In Construct I, the cry1Ac gene was cloned under FMVde, a strong constitutively expressing promoter, to express the encoded protein in the cytoplasm. In Construct II, the encoded protein was directed to the plastids using a transit peptide taken from the cotton rbcSIb gene. Genetic transformation experiments with Construct I resulted in a single copy insertion event in which the Cry1Ac protein expression level was 2-2.5 times greater than in the Bacillus thuringiensis cotton event Mon 531, which is currently used in varieties and hybrids grown extensively in India and elsewhere. Another high expression event was selected from transgenics developed with Construct II. The Cry protein expression resulting from this event was observed only in the green plant parts. No transgenic protein expression was observed in the non-green parts, including roots, seeds and non-green floral tissues. Thus, leucoplasts may lack the mechanism to allow entry of a protein tagged with the transit peptide from a protein that is only synthesized in tissues containing mature plastids. Combining the two events through sexual crossing led to near additive levels of the toxin at 4-5 times the level currently used in the field. The two high expression events and their combination will allow for effective resistance management against lepidopteran insect pests, particularly Helicoverpa armigera, using a high dosage strategy. PMID:27391960

  12. 使用SSI模型描述昆虫温发育速率的SAS程序

    Institute of Scientific and Technical Information of China (English)

    时培建; 戈峰

    2014-01-01

    Sharpe-Schoolfield-Ikemoto(SSI)模型是用来描述温度对昆虫发育速率影响的一个重要数学方程,它既能够很好地拟合温发育速率的数据,又能提供若干个重要温参数,特别是内禀最适发育温度(TΦ)。此温度反映了昆虫生存的最佳温环境。然而,由于SSI模型的参数过多,结构显得较为复杂,给实际的数据拟合带来了困难。一个基于R平台的软件包已经被开发出来,专门用于执行SSI模型的参数拟合。但目前由于国内许多研究者青睐于使用SAS统计软件,所以本文提供了一个基于SAS统计软件的程序,用以快速拟合SSI模型的参数。通过拟合棉铃虫Helicoverpa armigera Hübner蛹期的温发育速率数据,发现此SAS程序具有很好的拟合效果,同时进一步证明了SSI模型对描述温度对昆虫发育速率影响的有效性。

  13. High Expression of Cry1Ac Protein in Cotton (Gossypium hirsutum by Combining Independent Transgenic Events that Target the Protein to Cytoplasm and Plastids.

    Directory of Open Access Journals (Sweden)

    Amarjeet Kumar Singh

    Full Text Available Transgenic cotton was developed using two constructs containing a truncated and codon-modified cry1Ac gene (1,848 bp, which was originally characterized from Bacillus thuringiensis subspecies kurstaki strain HD73 that encodes a toxin highly effective against many lepidopteran pests. In Construct I, the cry1Ac gene was cloned under FMVde, a strong constitutively expressing promoter, to express the encoded protein in the cytoplasm. In Construct II, the encoded protein was directed to the plastids using a transit peptide taken from the cotton rbcSIb gene. Genetic transformation experiments with Construct I resulted in a single copy insertion event in which the Cry1Ac protein expression level was 2-2.5 times greater than in the Bacillus thuringiensis cotton event Mon 531, which is currently used in varieties and hybrids grown extensively in India and elsewhere. Another high expression event was selected from transgenics developed with Construct II. The Cry protein expression resulting from this event was observed only in the green plant parts. No transgenic protein expression was observed in the non-green parts, including roots, seeds and non-green floral tissues. Thus, leucoplasts may lack the mechanism to allow entry of a protein tagged with the transit peptide from a protein that is only synthesized in tissues containing mature plastids. Combining the two events through sexual crossing led to near additive levels of the toxin at 4-5 times the level currently used in the field. The two high expression events and their combination will allow for effective resistance management against lepidopteran insect pests, particularly Helicoverpa armigera, using a high dosage strategy.

  14. Environmental Factors in the Growth of Jatropha at Potorono Village, Yogyakarta

    Directory of Open Access Journals (Sweden)

    Mohammad Nurcholis

    2015-01-01

    Full Text Available Jatropha curcas is a perennial crop that has been known by Indonesian people for more than seven decades as a plant that produces renewable biofuel. In the present decade, plants producing biofuel are expected to be developed to overcome the lowering nonrenewable fuel reserves. There is a myth that jatropha can grow well on marginal lands and draught condition, perform well on non-fertile soils, no need for agronomic management and is resistant to plant pests and diseases. This study was conducted to identify the environmental factors that influenced the growth of jatropha on the marginal land at Potorono village, Yogyakarta Province, Indonesia. Jatropha has been planted by local people at the village road sides and on the marginal land field at the local governmental land in this village. They grew jatropha on these areas with the purpose of preventing competition of area utilization with food crops. The results showed that the growth of jatropha was restricted by low content of organic matter, plant nutrition and poor soil drainage. Applications of manure and macro nutrients (N, P and K to this crop were able to increase crop performance. The number of shoots, flowers and fruit bunches increased by manure and nutrients treatments. Field observation showed that there were several plant pests, such as Aspidiotus sp., Paracoccus marginatus, Poliphagotarsonemus latus, Selenothrips rubrocinctus, Chrysochoris javanus, Valanga nigricornis, Chloracris prasina, and Helicoverpa armigera that attacked plant leaves and fruits. There were plant leaf necrotic symptoms that caused by plant pathogens were also observed. The diseases are bacterial leaf spot (Xanthomonas ricinicola, cercospora leaf spot (Cercospora ricinella and rust (Phakopsora jatrophicola. Thus, jatropha is like any other plants that need a good agro-ecological condition to grow well and produce high yield.

  15. Two Year Field Study to Evaluate the Efficacy of Mamestra brassicae Nucleopolyhedrovirus Combined with Proteins Derived from Xestia c-nigrum Granulovirus

    Directory of Open Access Journals (Sweden)

    Chie Goto

    2015-03-01

    Full Text Available Japan has only three registered baculovirus biopesticides despite its long history of studies on insect viruses. High production cost is one of the main hindrances for practical use of baculoviruses. Enhancement of insecticidal effect is one possible way to overcome this problem, so there have been many attempts to develop additives for baculoviruses. We found that alkaline soluble proteins of capsules (GVPs of Xestia c-nigrum granulovirus can increase infectivity of some viruses including Mamestra brassicae nucleopolyhedrovirus (MabrNPV, and previously reported that MabrNPV mixed with GVPs was highly infectious to three important noctuid pests of vegetables in the following order, Helicoverpa armigera, M. brassicae, and Autographa nigrisigna. In this study, small-plot experiments were performed to assess concentrations of MabrNPV and GVPs at three cabbage fields and a broccoli field for the control of M. brassicae. In the first experiment, addition of GVPs (10 µg/mL to MabrNPV at 106 OBs/mL resulted in a significant increase in NPV infection (from 53% to 66%. In the second experiment, the enhancing effect of GVP on NPV infection was confirmed at 10-times lower concentrations of MabrNPV. In the third and fourth experiments, a 50% reduction in GVPs (from 10 µg/mL to 5 µg/mL did not result in a lowering of infectivity of the formulations containing MabrNPV at 105 OBs/mL. These results indicate that GVPs are promising additives for virus insecticides.

  16. Maize silk antibiotic polyphenol compounds and molecular genetic improvement of resistance to corn earworm (Helicoverpa zea Boddie) in sh2 sweet corn

    OpenAIRE

    Baozhu Guo; Ana Butrón; Scully, Brian T.

    2010-01-01

    The flavor of sh2 super-sweet corn is preferred by consumers. Unfortunately, sh2 sweet corn has little genetic variation for insect resistance. In this paper we review the functions of two loci, p1 and a1. The P1 allele has a major role in sh2 sweet corn resistance to corn earworm, an allele that was lost in historical selection because of its pleiotropic effect on undesirable cob color and silk browning. The P1 allele has significant effects on biosyntheses of silk antibiotic compounds, mays...

  17. Maize silk antibiotic polyphenol compounds and molecular genetic improvement of resistance to corn earworm (Helicoverpa zea Boddie in sh2 sweet corn

    Directory of Open Access Journals (Sweden)

    Baozhu Guo

    2010-01-01

    Full Text Available The flavor of sh2 super-sweet corn is preferred by consumers. Unfortunately, sh2 sweet corn has little genetic variation for insect resistance. In this paper we review the functions of two loci, p1 and a1. The P1 allele has a major role in sh2 sweet corn resistance to corn earworm, an allele that was lost in historical selection because of its pleiotropic effect on undesirable cob color and silk browning. The P1 allele has significant effects on biosyntheses of silk antibiotic compounds, maysin, apimaysin, methoxymaysin, and chlorogenic acid. The effect of a1 shows gene action for lowered maysin and significant epistatic action with p1. The dominant functional allele A1 causes anthocyanin pigments in aleurone, plant, and pericarp tissues; the recessive a1 allele causes absence of pigment in these tissues. If silk browning and cob color are critical factors for maysin production but lack the customer’s preference, then separating red cob and browning silk, which are controlled by the P1 allele, may be difficult if not impossible. One high silk maysin sh2 sweet corn germ­plasm, shrunken Zapalote Chico, has been released. There is some field corn germplasm with p1-wwr alleles, but the amount of antibiotic flavones and their potential as a donor need further investigation.

  18. Expression of a maize Myb transcription factor driven by a putative silk-specific promoter significantly enhances resistance to Helicoverpa zea in transgenic maize

    Science.gov (United States)

    Hi II maize (Zea mays) plants were engineered to express maize p1 cDNA, a Myb transcription factor, controlled by a putative silk specific promoter, for secondary metabolite production and corn earworm resistance. Transgene expression did not enhance silk color, but about half of the transformed p...

  19. 病毒感染对棉铃虫C型凝集素的诱导表达研究%The Distribution of Cotton Bollworm Ha-lectin after HaNPV Infection

    Institute of Scientific and Technical Information of China (English)

    王楠; 柴连琴; 孟景会; 张海玲

    2014-01-01

    本文采用Northern blot和原位杂交方法检测了棉铃虫C型凝集素(Ha-lectin)的组织表达特异性,并利用显微镜观察棉铃虫核型多角体病毒(HaNPV)对血细胞的感染状况,结合Real-time cqPCR技术,检测HaNPV感染对Ha-lectin在不同组织表达变化的影响.结果显示,血细胞特异表达的Ha-lectin,随着HaNPV的感染,在血细胞、中肠及脂肪体中均被诱导上调表达,说明Ha-lectin可能在病毒感染过程中发挥重要功能.

  20. BEHAVIOR OF Pectinophora gossypiella (GELECHIIDAE (PINK BOLLWORM MALES MONITORED WITH PHEROMONE TRAP IN COTTON Comportamiento de Pectinophora gossypiella (Gelechiidae (oruga rosada machos capturados con trampas de feromona sintética en campos de algodón

    Directory of Open Access Journals (Sweden)

    ELMO PONTES DE MELO

    2012-12-01

    Full Text Available The objective of the present study was to evaluate the behavior of P. gossypiella males captured with pheromone-baited traps in cotton field. Three experiments were done during the 2001-02 and 2002-03 growing seasons using the Delta Opal cotton cultivar. The first experiment was related to the insect population captured during the crop cycle by of two commercially available Delta type traps, the second experiment was conducted to evaluate the efficiency of traps in capturing P. gossypiella males and, the third experiment assessed the nocturnal circadian rhythm. It was realized a descriptive analysis of the data collected to first and third experiment. Used in this second experiment consisted of comparing randomly selected groups, and the means were compared by t-test, the significance level was set at 5 %, and, the canonical correlation analysis was performed. The Delta pheromone trap was more efficient in capturing P. gossypiella than was the PET pheromone trap. Nocturnal activity peaks were found to be related with the time of year and it occurs between 11:00 p.m. and 2:00 a.m.El objetivo de este estudio fue evaluar el comportamiento de P. gossypiella machos capturados con trampas de feromona sintética en campos de algodón Delta Opal. Se realizaron tres experimentos durante las épocas de cultivo de los años 2001-2002 y 2002-2003. En el primer experimento se capturaron los insectos durante el ciclo de cultivo, utilizando dos trampas Delta. En el segundo experimento se evaluó la eficiencia de las trampas y en el tercer experimento se determinó el ritmo circadiano nocturno. Se realizó un análisis descriptivo de los datos recogidos en el primer y tercer experimento. En el análisis estadístico utilizado en el segundo experimento se compararon grupos pareados y las medias fueron verificadas por prueba de t; el nivel de significancia se fijó en 5 % y se realizó un análisis de correlación canónica. La trampa de feromonas Delta fue más eficiente en la captura de P. gossypiella que la trampa de feromona PET. Los picos de actividad nocturna están relacionados con la época del año y ocurrieron entre las 2 y 23 horas.

  1. LANDSCAPE CHANGES IN A LOWLAND IN BENIN: ECOLOGICAL IMPACT ON PESTS AND NATURAL ENEMIES.

    Science.gov (United States)

    Boucher, A; Silvie, P; Menozzi, P; Adda, C; Auzoux, S; Jean, J; Huat, J

    2015-01-01

    Habitat management involving conservative biological control could be a good crop pest management option in poor African countries. A survey was conducted from August 2013 to July 2014 in a rainfed lowland region near Pélébina, northern Benin, in order to characterize spatiotemporal landscape changes and investigate their influence on the main crop pests and their associated natural enemies. The area was mapped mainly regarding crop fields and fallows. Visual observations were recorded and a database was compiled. Major landscape composition changes were noted between rainy and dry seasons, which affected the presence of both pests and natural enemies. Cereals (rice, maize and sorghum) and cotton were grown in the humid season, and then okra (Abelmoschus esculentus) was the dominant vegetable crop in dry season. These modifications impacted fallow abundance throughout the lowland. Different cotton (e.g. Helicoverpa armigera, Dysdercus sp., Zonocerus variegatus) or rice (e.g. Diopsis longicornis, D. apicalis) pests were observed during dry season in okra crops. Dry season surveys of Poaceae in two types of fallows ('humid', 'dry') revealed the presence of very few stem borers: only 0.04% of stems sampled were infested by stem borers, with a mean of 1.13 larvae per stem. Known cereal stem borer species such as Busseola fusco, Coniesta ignefusalis, Sesamia calamistis were not clearly identified among these larvae because of their diapausing stage and white color. Unexpected pollinators (Hymenoptera Apidae, genus Braunsapis, Ceratina and Xylocopa) and predators (Crabronidae, genus Dasyproctus) were found in the stems. Sweep-net collection of insects in humid fallows allowed us to describe for the first time in Benin seven Diopsidae species (23% of adults bearing Laboulbeniomycetes ectoparasitic fungi). Some of these species were captured in rice fields during rainy season. Parasitoids (adult Chalcidoidae and Ichneumonoidae) were observed during both seasons but their

  2. Management of lepidopterans through irradiations

    International Nuclear Information System (INIS)

    suppression by irradiation include Spodoptera litura, S.exigua, S.frugiperda, Helicoverpa armigera, H.zea, Pectinophora gossypiella, Diatraea saccharalis, Cydia pomonella, C.molesta, Ectomyelois ceratoniae, Ephestia kuehniella, Crocidolomia binotalis, Chilo suppressalis, Ostrinia furnacalis, O.nubilalis, Plutella xylostella and Spilosoma obliqua. (author)

  3. 粘虫类钙粘蛋白基因的克隆、序列分析及时空表达%Cloning, sequence analysis and spatio-temporal expression of cadherin-like protein gene in the oriental armyworm, Mythimna separata (Lepidoptera:Noctuidae)

    Institute of Scientific and Technical Information of China (English)

    王玲; 江幸福; 罗礼智; 胡毅; 张蕾

    2011-01-01

    The cadherin-like proteins, located in the brush border membrane vesicles ( BBMV) of insect midgut, are major receptors of Bacillus thuringiensis insecticidal crystal protein. The complete cDNA sequence of cadherin-like protein gene was amplified from the oriental armyworm, Mythimna separata, using RT-PCR and RACE techniques. The full cDNA sequence (named as Msclp, GenBank accession no. JF951432) is 5 642 bp in length, encoding 1 757 amino acid residues, and the deduced amino acid sequence shows typical characteristics of the known insect cadherin proteins, including a signal peptide, a proprotein region, twelve cadherin repeats, a membrane-proximal region, a transmembrane region and a cytoplasmic region. The predicted molecular mass and isoelectric point are 196. 786 kD and 4. 5, respectively. The cadherin-like protein from M. Separata shows the close relationship to cadherin proteins from Helicoverpa assulta, Heliothis virescens, Helicoverpa armigera and Spodoptera exigua, with the amino acid identities of 61.77% , 61.66% , 61.26% and 58. 14% , respectively. The real-time RT-PCR results showed that relative expression levels of cadherin-like gene were significantly different in different instars of larvae (P < 0. 01) , which was the highest in the 4th instar larvae and the lowest in the newly-hatched larvae. The cadherin-like gene was majorly expressed in the midgut and very lowly expressed in other parts of the larval body. The results provide the basis for revealing the insecticidal mechanism of Bt to oriental armyworm, and the resistance mechanism of oriental armyworm to Bt.%昆虫中肠膜类钙粘蛋白( cadherin-like protein,CLP)是苏云金芽孢杆菌Bacillus thuringiensis (Bt)毒素的重要受体之一,与Bt毒素的杀虫作用机制以及昆虫对Bt毒素的抗性等密切相关.本研究应用RT-PCR和RACE技术,克隆了迁飞性重要害虫粘虫Mythimna separata类钙粘蛋白基因全长cDNA序列(命名为Msclp,GenBank登录号为JF951432),

  4. IMPACT OF A MORE INTENSIVE INSECT PEST INFESTATION LEVEL ON COTTON PRODUCTION: TEXAS HIGH PLAINS

    OpenAIRE

    Masud, Sharif M.; Ronald D. Lacewell; Stoll, John R.; Walker, J. Knox; Leser, James F.; Sellar, Christine

    1985-01-01

    This study evaluated implications of increased bollworm problems in a 20-county area of the Texas High Plains relative to cotton yields and economic impact. Results did not indicate a serious effect of bollworms upon lint yield when insecticides were used for control. However, estimated annual reduction in farmer profit due to the bollworm for 1979-81 was over $30 million. Yields were estimated to decline about 300,000 bales without insecticide use and about 30,000 bales with insecticide use....

  5. Duração do desenvolvimento de Mythimna unipuncta, Xestla c-nigrum, Agrotis ipsilon, Heliothis armigera, Peridroma saucia, Spodoptera littoralis (Lep.: Noctuidae) e Pieris brassicae azorensis (Lep.: Piralidae).

    OpenAIRE

    Melo, Rui; Oliveira, Luísa; Tavares, João

    1998-01-01

    III Simpósio Fauna e Flora das Ilhas Atlânticas / Symposium Fauna and Flora of the Atlantic Islands, Universidade dos Açores, Ponta Delgada (Açores), 21 - 25 September, 1998. A influência dos factores abióticos sobre o desenvolvimento de espécies de Lepidópteros, nomeadamente no estado larvar, foi e será objecto de numerosos estudos, contribuindo assim para o conhecimento dos seus limites teóricos, duração/velocidade de desenvolvimento e percentagem de mortalidade no estado larvar. A...

  6. 7 CFR 319.37-6 - Specific treatment and other requirements.

    Science.gov (United States)

    2010-01-01

    ... All Pectinophora gossypiella (Saunders) (pink bollworm). Allium sativum (garlic) bulbs Algeria... noxious weeds listed in 7 CFR 360.200. Hibiscus spp. (hibiscus, rose mallow) seeds All, with the...

  7. Efficacy of some natural hosts on the development of chrysoperla carnea (stephens) (neuroptera: chrysopidae) - a laboratory investigation

    International Nuclear Information System (INIS)

    Biology and feeding potential of the predator, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) were studied on different hosts with particular reference to cotton crop. Various hosts viz., aphids (nymphs/ adults) and the eggs of cotton bollworms were used for the rearing of C. carnea and compared with the factitious host, Angoumois grain moth (Sitotroga cerealella) eggs on which the culture of the predator is maintained for the last many generations at the laboratory. The studies indicated that larval and pupal durations of the predator were significantly affected by the change of the hosts and the total developmental period was significantly shorter when the predator was offered with aphids for feeding. The fecundity, fertility, pupation, hatch ability and longevity of the predator were also higher on aphids followed by pink bollworm, spotted bollworm, Angoumois grain moth and American bollworm eggs. However, the sex ratio was not affected due to change in the type of hosts. An identical trend in all the observed parameters was recorded in parental and first filial generations on all the tested hosts. Based on the studies, aphids appeared to be the most promising host for mass rearing of the predator. Further, successful predation on the cotton bollworm eggs manifested the potential of C. carnea for the management of cotton bollworms in the field. (author)

  8. RADIOIMMUNOASSAY ANALYSIS OF BACULOVIRUS GRANULINS AND POLYHEDRINS

    Science.gov (United States)

    Granulin and polyhedrin proteins were purified by preparative sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis from the baculoviruses Autographa californica, Rachiplusia ou, Heliothis zea, Heliothis armigera, Trichoplusia ni, and Spodotera frugiperda. Antisera were...

  9. Isotopes and trace elements as geo-location markers for biosecurity: determining the origin of exotic pests.

    Science.gov (United States)

    Holder, Peter W.; Armstrong, Karen; Clough, Tim; Frew, Russell; van Hale, Robert; Baker, Joel A.; Millet, Marc-Alban

    2010-05-01

    Background. The benefits of accurate point of origin discrimination in biosecurity include achieving appropriate operational responses in exotic pest eradication and post-border incursion campaigns, and identifying risk pathways. Reading natural abundance biogeochemical markers via mass spectrometry methods is a powerful tool for tracing ecological pathways and provenance determination of agricultural products and items of forensic interest. However, the application of these methods to trace insects - man's most damaging competitors - has been underutilised to date and our understanding in this field is still in a phase of basic development. Stable isotope ratio analyses using δ2H, δ13C have given spatial resolution in the monarch butterfly, single host system in eastern North America. Subsequently, the same method was employed in an attempt to determine the origin of important biosecurity pests in New Zealand. However, the results were contentious as the accuracy and limitations of the method in a biosecurity application were unknown. Further investigation has shown the value of existing invertebrate stable isotope geo-location methodology (i.e., using only two light elements) is tenuous in the biosecurity context, where the sample sizes are usually only one or two insects, and the specimens are generally polyphagous and accidentally introduced, and so from an unknown and unpredictable place, point in time and host: The spatial distribution of 2H in New Zealand may not be reliable over insect life-span time-scales; and fractional variables are un-quantified and potentially overwhelm any New Zealand signal. Further, the geo-location value of 13C is uncertain, especially for polyphagous insects. Research aims. The internationally distributed Helicoverpa armigera [Noctuidae] is being used to examine the processes fundamental to the location-to-plant-to-insect biogeochemical profile imprinting in phytophagous insects, including the turn over of elements in adult

  10. Thwarting one of cotton's nemeses

    International Nuclear Information System (INIS)

    There's not much good to be said for the pink bollworm, cotton's most destructive pest, except that it is being controlled to cut crop damage. Scientists have developed strategies, such as increasing native populations of predatory insects and pest-resistant cotton varieties. Thanks to research, growers today can also use cultural practices such as early plowdown of harvested cotton to break up stalks and bury overwintering pink bollworms. And they can disrupt normal mating by releasing sterile insects and using copies of natural compounds, called pheromones, that the pink bollworm uses to attract mates. Such strategies, together with judicious use of insecticides, put together in various combinations, form what is called an integrated pest management system

  11. Differential activity of multiple saponins against omnivorous insects with varying feeding preferences

    Science.gov (United States)

    A variety of saponin glycosides and aglycones from seven different plant families (Aquifoliaceae, Asparagaceae, Caryophyllaceae, Dioscoreaceae, Leguminosae, Rosaceae, Sapindaceae) were tested against the corn earworm, Helicoverpa zea, and the fall armyworm, Spodoptera frugiperda. The corn earworm fe...

  12. A decade of Bt cotton in Chinese fields: Assessing the direct effects and indirect externalities of Bt cotton adoption in China

    Institute of Scientific and Technical Information of China (English)

    Scott; ROZELLE; Carl; PRAY

    2010-01-01

    The objective of this study is to examine whether or not the gains from reduced spraying for bollworms are being sustained more than one decade after the initial adoption in 2007. Based on farm-level data collected by the authors in 1999–2007 in 16 villages from 4 provinces, this study shows that insecticides applied for controlling bollworms have declined. This analysis supports Chinese policy makers’ decision to not require refuges of non-Bt cotton fields. It also suggests that past studies may have underestimated the benefits from adopting Bt technology.

  13. 7 CFR 301.52-8 - Inspection and disposal of regulated articles and pests.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Inspection and disposal of regulated articles and pests. 301.52-8 Section 301.52-8 Agriculture Regulations of the Department of Agriculture (Continued... Bollworm Quarantine and Regulations § 301.52-8 Inspection and disposal of regulated articles and pests....

  14. IPM at the cross-roads with a realistic approach: A success story of IPM on rainfed cotton in tribal areas of Maharashtra, India on a whole village approach system

    International Nuclear Information System (INIS)

    Full text: Cotton is an important commercial crop in India and ranks third in the world in production, next to China and USA. The productivity of cotton is variable in the country being as low as 194 kg / lint ha in Maharashtra as compared to the national average of 294 kg lint / ha. Though the area under cotton crop in the country is only 5 % of the total cropped area, chemical pesticides, to the tune of 45 %, are being used for the control of pests on this crop. This excessive and indiscriminate use of chemicals on cotton has led to many problems. There are a number of reports on successful IPM programmes against different pests on major crops in different states of this country, but those are scattered demonstrations covering an acre of a crop in a village. The rapid spread of the IPM technology requires proper implementation in a whole village with coordination of farmers. In this context, IPM demonstration was undertaken on rainfed cotton as an ideal example for others so that IPM will get momentum in a real sense. During 2001-02 an IPM programme was organised on rainfed cotton at Budki, Tal. Shirpur, Dist. Dhule on 64.4 ha (161 acres) comprising of 61 farm families in a tribal area of Maharashtra. The IPM components were imidacloprid 70 ws 10 g/kg seed treatment, sowing within a week in a whole village, inter/mix crops viz., Setaria, maize and cowpea, pheromone traps, Trichogramma, Neem seed extract sprays, collection of larvae and HaNPV. The population of all sucking pests i.e. aphids, jassids and thrips was much less in IPM cotton fields as compared to non-IPM fields. So also, the population of Helicoverpa larvae was lower in IPM fields than non-IPM fields throughout the crop growth period. The percentage of bolls and loculi damage due to bollworms was considerably lower in IPM fields than non- IPM fields. The population of predators viz., lady bird beetles and Chrysopa and parasitoids was comparatively higher in IPM fields than non-IPM fields. The average

  15. Suppressing Resistance to Bt Cotton with Sterile Insect Releases

    International Nuclear Information System (INIS)

    Genetically engineered crops that produce insecticidal toxins from Bacillus thuringiensis (Bt) are grown widely for pest control. However, insect adaptation can reduce the toxins' efficacy. The predominant strategy for delaying pest resistance to Bt crops requires refuges of non-Bt host plants to provide susceptible insects to mate with resistant insects. Variable farmer compliance is one of the limitations of this approach. Here we report the benefits of an alternative strategy where sterile insects are released to mate with resistant insects and refuges are scarce or absent. Computer simulations show that this approach works in principle against pests with recessive or dominant inheritance of resistance. During a largescale, four-year field deployment of this strategy in Arizona, resistance of pink bollworm (Pectinophora gossypiella) to Bt cotton did not increase. A multitactic eradication program that included the release of sterile moths reduced pink bollworm abundance by >99%, while eliminating insecticide sprays against this key invasive pest. (author)

  16. Technological advances to enhance agricultural pest management.

    Science.gov (United States)

    Miller, Thomas A; Lauzon, Carol R; Lampe, David J

    2008-01-01

    Biotechnology offers new solutions to existing and future pest problems in agriculture including, for the first time, possible tools to use against insect transmitted pathogens causing plant diseases. Here, we describe the strategy first described as Autocidal Biological Control applied for the development of conditional lethal pink bollworm strains. When these strains are mass-reared, the lethal gene expression is suppressed by a tetracycline repressor element, which is activated by the presence of chlorotetracycline, a normal component of the mass-rearing diet. Once removed from the tetracycline diet, the lethal genes are passed on to offspring when ordinary lab-reared pink bollworms mate with special lethal strains. Lethality is dominant (one copy sufficient for lethality), expressed in the egg stage and affects all eggs (100% lethal expression). The initial investment by the California Cotton Pest Control Board is an outstanding example of research partnerships between agriculture industry, the USDA and land grant universities. PMID:18510021

  17. Noctuid migration in the nocturnal aeroecological boundary layer

    Science.gov (United States)

    Long-distance migration of adult corn earworm moths (Helicoverpa zea), and several other noctuid moth species, facilitates seasonal expansion of pest populations and consequent increased infestations of agricultural crops on a continental scale in North America. Long-term field studies of populatio...

  18. Impact of transgenic sweet corn silks to two noctuid pests

    Science.gov (United States)

    Eight Bacillus thuringiensis (Bt) transgenic sweet corn hybrids were evaluated (with two controls) for their efficacy against two ear-feeding insects; the corn earworm [Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae)], and the fall armyworm (Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuid...

  19. Structural basis of the resistance of an insect carboxypeptidase to plant protease inhibitors

    NARCIS (Netherlands)

    Bayés, A.; Comellas-Bigler, M.; Rodriquez de la Vega, M.; Maskos, K.; Bode, W.; Aviles, F.X.; Beekwilder, M.J.; Vendrell, J.

    2005-01-01

    Corn earworm (Helicoverpa zea), also called tomato fruitworm, is a common pest of many Solanaceous plants. This insect is known to adapt to the ingestion of plant serine protease inhibitors by using digestive proteases that are insensitive to inhibition. We have now identified a B-type carboxypeptid

  20. Competitive release and outbreaks of non-target pests associated with transgenic Bt cotton

    Science.gov (United States)

    This study tests a competitive release hypothesis that Helicoverpa zea larval herbivory will 1) deter oviposition and increase leaving rates of the stink bugs, Euchistus servus and Nezara viridula and that 2) that these effects will be stronger for E. servus than for N. viridula. By spatially separa...

  1. Changes in trace metals in hemolymph of baculovirus infected noctuid larvae

    Science.gov (United States)

    We studied how biologically relevant trace metals (i.e., micronutrients) in the plasma of larvae of Heliothis virescens and Helicoverpa zea (Lepidoptera: Noctuidae) changed in response to per os baculovirus infection, larval development, and injection of heat-killed bacteria. Concentrations of plas...

  2. Probe data: 1164 [RED

    Lifescience Database Archive (English)

    Full Text Available R06-003380-1AR RED AU078263 AU056903 S20966 SA0966 >HVSCOAT_1(L37299|pid:g609504) Helicoverpa ar ... tics, makes tube-like structures when expressed in bacteria , unstable when expressed in baculovirus, start cod ...

  3. Genetic mechanisms underlying apimaysin and maysin synthesis and corn earworm antibiosis in maize (Zea mays L.).

    OpenAIRE

    Lee, E A; Byrne, P.F.; McMullen, M D; Snook, M E; Wiseman, B. R.; Widstrom, N W; Coe, E. H.

    1998-01-01

    C-glycosyl flavones in maize silks confer resistance (i.e., antibiosis) to corn earworm (Helicoverpa zea [Boddie]) larvae and are distinguished by their B-ring substitutions, with maysin and apimaysin being the di- and monohydroxy B-ring forms, respectively. Herein, we examine the genetic mechanisms underlying the synthesis of maysin and apimaysin and the corresponding effects on corn earworm larval growth. Using an F2 population, we found a quantitative trait locus (QTL), rem1, which account...

  4. Structural basis of the resistance of an insect carboxypeptidase to plant protease inhibitors

    OpenAIRE

    Bayés, A.; Comellas-Bigler, M.; Rodriquez de la Vega, M.; Maskos, K.; Bode, W; Aviles, F. X.; Beekwilder, M.J.; Vendrell, J

    2005-01-01

    Corn earworm (Helicoverpa zea), also called tomato fruitworm, is a common pest of many Solanaceous plants. This insect is known to adapt to the ingestion of plant serine protease inhibitors by using digestive proteases that are insensitive to inhibition. We have now identified a B-type carboxypeptidase of H. zea (CPBHz) insensitive to potato carboxypeptidase inhibitor (PCI) in corn earworm. To elucidate the structural features leading to the adaptation of the insect enzyme, the crystal struct...

  5. Isolation of bacillus thuringiensis from different samples from Mansehra District

    International Nuclear Information System (INIS)

    The insecticidal activity of Bacillus thuringiensis has made it very interesting for the control of a variety of agricultural pests and human disease vectors. The present study is an attempt to explore the potential and diversity. of Bacillus thuringiensis. from the local environment for the control of cotton spotted bollworm (Earias sp.), a major pest of cotton. Two hundred and ninety eight samples of soil, grain dust, wild animal dung, birds dropping, decaying leaves and dead insects were collected from different ecological environments of Mansehra District yielding 438 Bacillus thuringiensis isolates that produce parasporal crystalline inclusions. In this study the soil samples were found to be the richest source for Bacillus thuringiensis. (author)

  6. Development and Adoption of Bt Cotton in India : Economic, Environmental and Health Issues

    OpenAIRE

    -, Dr S Saravanan; -, Dr V Mohanasundaram

    2016-01-01

    Bt Cotton, is genetically engineered with Bt (Bacillus thuringiensis), a bio-toxin which comes from soil bacterium. Bt which was isolated from soil in 1911, has been available to farmers as an organic pesticide since 1930..The engineered Bt gene produces a protein that cuts into the guts of specific insects, rendering the cotton resistant to these insects. Biotechnology for control of bollworms is made available in the seed itself. Farmers have to just sow the Bt cotton seeds as they do with...

  7. Control of insect pests using slow release pheromone containing devices

    International Nuclear Information System (INIS)

    A number of slow release devices are being or have been developed and commercialised for the detection of insect pests, in the form of monitoring lures, and for their control, by lure and kill or mating disruption techniques. The devices are based upon matrix-type polymer formulations with pheromone or attractant distributed therein. Release profiles of devices were determined by gas chromatographic analysis of pheromone residing in the devices, as a function of time; release rates were then derived, also as a function of time, and compared with bioefficacy results of field tests. The lower rate limit, consistent with mating disruption, can be determined, and will be appropriate to, and dependent upon the field test conditions eg temperature, wind conditions, point source density, insect pressure, the presence of beneficials, and the influence of other attractants such as plant volatiles. Such an approach has been taken in the development of products for Pectinophora gossypiella (Pink Bollworm), Chilo suppressalis (Rice Stem Borer) Lymantria dispar (Gypsy moth), Ceratitis capitata (Mediterranean Fruit Fly), Rhyacionia buoliana (European Pine Shoot Moth), and Keiferia lycopersicella (Tomato Pinworm). It is essential that the cost of pheromone be minimized in order to maximize the possibility of successful product development. To this end, the metathesis route has been found useful in some cases eg for Pink Bollworm pheromone (50/50) Z,E/Z,Z-7,11-hexadecadienyl acetate. 9 refs, 4 figs

  8. Pest Control Section Biochemical Group, Progress Report 1982-86

    International Nuclear Information System (INIS)

    Reserch efforts in the Pest Control Section, BARC, a continuator of insect sterilization and pest control section of the erstwhile Biology and Agriculture Division, were continued to develop integrated management practices for the control of important insect pests of agricultural and medical importance. Insect pests chosen are, ubiquitous potato tuberworm, a serious pest of potatoes, cotton bollworms with particular reference to spotted bollworms and a mosquito (Culex fatigans), a vector of filariasis. Keeping these insects as targets, research activities have been concentrated in the fields of biological control with parasities, pathogens and sterile insects, sex pheromones and insect plant interaction with a view to integrate pest management programme. Besides, the research activity also encompasses investigations of basic nature in the fields of insect sex pheromones, insect pathology and insect plant interaction. Studies on insect pheromones relate to the modifying influence of abiotic and biotic factors of the environment on pheromone production and perception and the possibility of insect developing resistance to pheromones. Studies in the field of insect plant interaction are directed towards identifying weak links in the insect plant relationship with a view to exploit them for developing control. Basic studies in the field of insect pathology relate to isolation and identification of entomopathogens, source of their pathogenecity, improvement in their virulence and formulation of cheaper and potent microbial insecticides. This report pertains to the period 1982-86. (Orig.). 11 tables, 5 figures

  9. Integration of behavioral and biological control for the management of cotton insect pests: Significance and cost benefits

    International Nuclear Information System (INIS)

    The pink, Pectinophora gossypiella; spotted, Earias vittella and spiny, E. insulana, bollworms are major pests of cotton in Pakistan. Development of insect resistance has compelled the farmers to apply more insecticides to achieve effective control. Application of insecticide in the cotton crop has been increased more than three-fold during the last decade. Augmentative releases of egg parasitoids, Trichogramma chilonis alone or in combination with pheromones to suppress the infestation of the cotton bollworms were evaluated at Habib Farm on 80 ha of cotton during the 2000 and 2001 seasons. The experimental field was divided in four different blocks (20 ha each) and each block was given a separate treatment. One block was treated with egg parasitoids, T. chilonis, reared on eggs of Angoumois grain moth in the laboratory maintained at 25 -± 2 deg. C and 60-70 % relative humidity. The parasitoids prior to adult emergence were released by attaching the cards on the lower side of the cotton leaves at fortnightly intervals at the rate of approximately 20,000 parasitoids per hectare. Two thousand parasitoids were released at ten uniformly distributed locations per hectare. The second block was treated with both pheromones and parasitoids. The pheromones were applied once in a season at the start of square formation stage of the crop at the rate of 1000 ropes per hectare. The third block was treated with pheromones only, obtained from the Shin-Etsu Chemical Company, Japan through the Karachi office of the Mitsubishi Corporation. It comprised the pink bollworm pheromone, gossyplure, a 1:1 mixture of Z, Z-and Z, E 7,11 hexadecadienyl acetate and a 10:1 mixture of the E, E-10, 12-hexadecadienal and Z-11 hexadecenal components for the two Earias spp. The formulation is named as PB/SB-ROPE. This 'twist-tie' PB/SB-ROPE, consisted of a wire-reinforced hollow polyethylene tube, 20 cm in length, sealed at both ends, containing normally, 38.5mg a.i. of gossyplure plus 40 mg of

  10. Alguns dados sobre a Fauna entomológica da ilha das Flores - Açores

    OpenAIRE

    Vieira, Virgílio; Tavares, João; Anunciada, Lorete; McNeil, Jeremy

    1990-01-01

    IV Expedição Científica do Departamento de Biologia - Flores 1989 Com este trabalho, realizado em Julho de 1989 nas Flores - a ilha mais ocidental do Arquipélago dos Açores -, acrescentaram-se onze espécies de Lepidópteros à lista referenciada para aquela ilha, pertencendo uma à família Lycaenidae (Lampides boeticus L.), oito a familia Noctuidae (Agrotis ipsilon HFN., Brotolomia meticulosa L., Chrysodeixis chalcites ESPER., Heliothis armigera HBN., Noctua atlantica WARREN, Noctua pronub...

  11. p13 from group II baculoviruses is a killing-associated gene

    Directory of Open Access Journals (Sweden)

    Yipeng Qi

    2012-12-01

    Full Text Available p13 gene was first described in Leucania separata multinuclearpolyhedrosis virus (Ls-p13 several years ago, but the functionof P13 protein has not been experimentally investigated todate. In this article, we indicated that the expression of p13from Heliothis armigera single nucleocapsid nucleopolyhedrovirus(Ha-p13 was regulated by both early and late promoter.Luciferase assay demonstrated that the activity of Ha-p13promoter with hr4 enhancer was more than 100 times inheterologous Sf9 cells than that in nature host Hz-AM1 cells.Both Ls-P13 and Ha-P13 are transmembrane proteins. Confocalmicroscopic analysis showed that both mainly located in thecytoplasm membrane at 48 h. Results of RNA interferenceindicated that Ha-p13 was a killing-associated gene for hostinsects H. armigera. The AcMNPV acquired the mentionedkilling activity and markedly accelerate the killing rate whenexpressing Ls-p13. In conclusion, p13 is a killing associatedgene in both homologous and heterologous nucleopolyhedrovirus.

  12. STUDY OF AIRBORNE INSECT ALLERGEN IN ASTHMATIC PATIENTS

    Institute of Scientific and Technical Information of China (English)

    孙秀珍; 刘云; 周玎

    2004-01-01

    Objective To study the variety of airborne allergenic insects and its sensibility in asthmatic patients. Methods 300 asthmatic patients and 100 normal controls underwent skin prick test (SPT) with 13 kinds of superior airborne insect vaccine, and sera sIgE of those whose SPT results were positive were tested by BSA-ELISA. Results The total positive rate of SPT with 13 kinds of insect vaccine in asthmatic patients was 58%, and it was significantly higher than that of normal control (P<0.01). The results of SPT with Stayridae, Heliothis armigera, Psilgramma menephorn and other 7 kinds of insects were more than 30% in asthmatic patients which meant these 10 kinds of insects were main allergenic insects to asthmatic patients. The positive rate of sIgE in asthmatic patients was more than 85%, while the normal control was only 6.0%. There was significant difference between two groups (P<0.01). Conclusion Stayridae, Heliothis armigera, Psilgramma menephorn and other 7 kinds of insects were main allergenic insects to asthmatic patients and perhaps they were the main allergens to the onset of asthma at the end summer or the early autumn.

  13. Dicty_cDB: Contig-U13978-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available .......................done Score E Sequences producing significant alignments: (bits) Value N ( L41839 ) Dictyostelium disco...ne:dds21p16, 5' ... 1092 0.0 2 ( AU261410 ) Dictyostelium discoideum vegetative cDNA clone:VS... 1088 0.0 1 ... AU270053 ) Dictyostelium discoideum vegetative cDNA clone:VS... 182 2e-41 1 ( BJ...386776 ) Dictyostelium discoideum cDNA clone:dds10k13, 5' ... 182 2e-41 1 ( AU270054 ) Dictyostelium discoideum vegetative...78_1( DQ196178 |pid:none) Triticum monococcum cultivar DV92 ... 113 2e-23 AF337638_1( AF337638 |pid:none) Helicoverpa armiger

  14. Development and Integration of Alternative Management Strategies Using Inherited Sterility and Natural Enemies to Control Lepidopteran Pests

    International Nuclear Information System (INIS)

    Lepidopteran pests such as corn earworm, Helicoverpa zea, fall armyworm, Spodoptera frugiperda, beet armyworm, Spodoptera exigua, and diamondback moth, Plutella xylostella, are often the most destructive pests of field crops in the United States. Insecticide resistance, increasing concern over pesticide pollution, and the desire to effectively manage lepidopteran pests on an area-wide basis have motivated scientists to identify and develop new pest management tactics that are compatible with current IPM practices. IPM-based systems, including genetic methods and biological control, offer the best long-term solutions to pesticide reduction and the management of destructive agricultural pests. F1 sterility has emerged as a promising control strategy for lepidopteran pests.

  15. Recurrent selection for corn earworm resistance in three corn synthetics.

    OpenAIRE

    Butrón Gómez, Ana María; Widstrom, N. W.; Snook, M E; Wiseman, B. R.

    2000-01-01

    Corn (Zea mays L.) grown in the Southeastern U. S. is often severely damaged by corn earworm (Helicoverpa zea Boddie), which feed on developing kernels on the ear. Natural resistance to this insect due to husk cover and chemicals in the silks has been identified. we studied the improvement in the resistance to ear injury by the corn earworm in the population 10LDDSR after 10 cycles of S1 recurrent selection and in the population cross DDSA x DDSB after seven cycles of reciprocal recurrent sel...

  16. Eficácia do indoxacarb para o controle de pragas em hortaliças

    OpenAIRE

    Martinelli Samuel; Montagna Marco Aurélio; Picinato Nilton César; Silva Fábio M.A.; Fernandes Odair Aparecido

    2003-01-01

    A eficiência do indoxacarb foi avaliada no controle dos lepidópteros-pragas em hortaliças: Plutella xylostella (Lepidoptera: Yponeumatidae), Trichoplusia ni (Lepidoptera: Noctuidae), Neoleucinodes elegantalis (Lepidoptera: Pyralidae) e Helicoverpa zea (Lepidoptera: Noctuidae). Os experimentos foram conduzidos em três locais diferentes nas culturas do repolho e tomate. Os inseticidas utilizados foram indoxacarb (no tomate de 2,4 a 6,0 g i.a./100 L e no repolho de 18 a 42 g i.a./ha), esfenvaler...

  17. Inseticidas para o controle da traça-do-tomateiro e broca-grande e seu impacto sobre Trichogramma pretiosum Insecticides for the control of the South American tomato pinworm and the corn earworm and impact of those products on Trichogramma pretiosum

    OpenAIRE

    Marina Castelo Branco; Ludimilla A. Pontes; Pablo S.T. Amaral; Manoel V. Mesquita Filho

    2003-01-01

    Experimentos de campo foram conduzidos entre maio e outubro de 2000 para determinar a eficiência de diversos inseticidas para o controle de Tuta absoluta e Helicoverpa zea e o impacto desses produtos sobre a emergência do parasitóide Trichogramma pretiosum. Os inseticidas testados, bem como as doses em g i.a./ha foram: metoxifenozide (120; 144), clorpirifós (540; 675), tiacloprid (72; 96) e triflumuron (144). O delineamento experimental foi de blocos ao acaso com oito tratamentos (inseticidas...

  18. Eficácia do indoxacarb para o controle de pragas em hortaliças Efficacy of indoxacarb in the control of vegetable pests

    OpenAIRE

    Samuel Martinelli; Marco Aurélio Montagna; Nilton César Picinato; Fábio M.A. Silva; Odair Aparecido Fernandes

    2003-01-01

    A eficiência do indoxacarb foi avaliada no controle dos lepidópteros-pragas em hortaliças: Plutella xylostella (Lepidoptera: Yponeumatidae), Trichoplusia ni (Lepidoptera: Noctuidae), Neoleucinodes elegantalis (Lepidoptera: Pyralidae) e Helicoverpa zea (Lepidoptera: Noctuidae). Os experimentos foram conduzidos em três locais diferentes nas culturas do repolho e tomate. Os inseticidas utilizados foram indoxacarb (no tomate de 2,4 a 6,0 g i.a./100 L e no repolho de 18 a 42 g i.a./ha), esfenvaler...

  19. Biodiversity of Indian Germplasm of Cotton and Its Use for Genetic Enhancement

    Institute of Scientific and Technical Information of China (English)

    MAYEE C D; KRANTHI K R

    2008-01-01

    @@ Cotton production in India was stagnant at 12.3 to 17.7 million bales over the decade 1992-2003.The introduction of new technologies during the early part of the decade,notably Bt-cotton technology,hybrids,and insecticides with novel modes of action resulted in doubling of production and productivity from 2001-2007.It is generally believed that amongst the new technologies,Bt-cotton has contributed the greatest in enhancing productivity levels in all the major cotton producing countries of the world.However,Bt-cotton incorporated CrylAc,which is the most toxic Bt-protein to bollworms,known to be the best amongst all known Bt-toxins characterized until date.

  20. Research Progress of Ap-plication of Insect Mi-crosporidia in Biological Control of Agricultural Pests%微孢子虫在害虫生物防治中的应用研究进展

    Institute of Scientific and Technical Information of China (English)

    王玉强

    2015-01-01

    The insect microsporidia may cause epizootics of insects, they are the potential microbial insecticides. The research progress of insect microsporidia controlling agricultural pests, such as grasshopper, red fire ant, cotton boll-worm, corn borer, Yunnan pine caterpil-lar were summarized, the current prob-lems and theirs application prospect were also described.%昆虫微孢子虫能引起昆虫的流行病,是一种很有应用潜力的微生物杀虫剂。综述昆虫微孢子虫在防治蝗虫、红火蚁、棉铃虫、玉米螟、云南松毛虫等农业害虫上的研究进展,并对目前存在的问题及其应用前景进行了展望。

  1. Agrobacterium-meditated Genetic Transformation of an Upland Cotton (Gossypium hirsutum cv Coker 310) Using a Novel Bt Gene Cry 2Ac

    Institute of Scientific and Technical Information of China (English)

    THIRUVENGADAM V; RASHMI J A; UDYASURIAN V; BALASUBRAMANIAN P; RAVEENDRAN T S

    2008-01-01

    @@ The development of transgenic cotton varieties resistant to bollworms has been a major success of applying plant genetic engineering technology to agriculture,evidenced by phenomenal increase in the cultivable area under (B.thuringiensis) Bt cotton in recent years worldwide.Of late,there are reports of insects developing resistance against the most commonly used Bt toxin CrylAc.Hence,there is an urgent need to broaden the source of resistance by employing new genes in order to reduce the chances of insects developing Bt resistance.Keeping this objective in view,cotton (Gossypium hirsuturn cv Coker 310) plants expressing a novel insecticidal crystal protein Cry2Ac were developed in the present study.

  2. Bt Cotton in China: Are Secondary Insect Infestations Offsetting the Benefits in Farmer Fields?

    Institute of Scientific and Technical Information of China (English)

    WANG Zi-jun; LIN Hai; HUANG Ji-kun; HU Rui-fa; Scott Rozelle; Carl Pray

    2009-01-01

    The area sown to Bt cotton has expanded rapidly in China since 1997. It has effectively controlled the bollworm. However, in recent years, concern has surfaced about the emergence of secondary insect pests, particular mirids, in Bt cotton fields. This study measures the patterns of insecticide use based on farm-level from 1999 to 2006, the analysis demonstrates a rise in insecticide use to control mirids between 2001 and 2004, secondary insect infestations is largely related to the rise of mirids, but this rising did not continue in more than half of sample villages studied in 2004-2006. Moreover, the increase in insecticide use for the control of secondary insects is far smaller than the reduction in total insecticide use due to Bt cotton adoption. Further econometric analyses show that rise and fall of mirids is largely related to local temperature and rainfall.

  3. Dispersal and parasitizing potential of trichogramma chilonis ishii in early and late sown cotton variety NIAB-Karishma

    International Nuclear Information System (INIS)

    Egg parasitoids, Trichogramma chilonis have enormous potential to control lepidopterous pests of many crops especially the bollworms of cotton. In the present studies dispersal ability of laboratory reared T. chilonis to varying distance ranging from one to five meters and its percent parasitization to its fictitious host (S. cerealella) eggs placed in early and late sown (fifteen days interval) cotton variety NIAB-Karishma was evaluated at the NIAB, field Faisalabad during 2000-2001 crop season. Results showed that percent parasitization to host eggs decreased with the increase in distance. More parasitization was recorded after 24 than that of 48 hrs at all distances from the site of parasitoid released. Efficiency of parasitoids in terms of percent parasitization increased during the months of July and September. (author)

  4. Natural refuge crops, buildup of resistance, and zero-refuge strategy for Bt cotton in China

    Institute of Scientific and Technical Information of China (English)

    ROZELLE; Scott; WILEN; James

    2010-01-01

    In the context of genetically modified crops expressing the Bacillus thuringiensis (Bt) toxin, a ‘refuge’ refers to a crop of the same or a related species that is planted nearby to enable growth and reproduction of the target pest without the selection pres- sure imposed by the Bt toxin. The goal of this study is to discuss the role of natural refuge crops in slowing down the buildup of resistance of cotton bollworm (CBW), and to evaluate China’s no-refuge policy for Bt cotton. We describe in detail the dif- ferent factors that China should consider in relation to the refuge policy. Drawing on a review of scientific data, economic analyses of other cases, and a simulation exercise using a bio-economic model, we show that in the case of Bt cotton in China, the no-refuge policy is defensible.

  5. Mediterranean fruit fly preventative release programme in southern California

    International Nuclear Information System (INIS)

    California employs several area-wide pest management programmes that use the release of sterile insects to protect its commercial and dooryard agriculture. The first was developed in response to the discovery of the Mexican fruit fly, Anastrepha ludens, in Tijuana, Mexico and adjacent areas in San Diego County, California. Initially pesticide sprays of malathion and bait were applied to host plants around each fly find site. Additionally, soil sprays of diazion (0.05 kg per 93 m2) were applied under every host plant around each fly find site. It soon became apparent that this approach was expensive and environmentally damaging. This led the interested parties, the California Department of Food and Agriculture (CDFA), the United States Department of Agriculture (USDA) and the government of Mexico to develop a programme that utilises the release of sterile Mexican fruit flies over the city of Tijuana in order to prevent the establishment of a breeding population of this fly in the city. The belief is that preventing the Mexican fruit fly from breeding in Tijuana will help protect both that city and California. To date, no Mexican fruit fly larvae have been found in Tijuana or the adjacent areas of California. The second programme was developed in response to the discovery of the pink bollworm, Pectinophora gossypiella, in cotton in the Imperial Valley area of southern California. As the pink bollworm spread throughout the cotton growing region of southern California, it became a significant pest that threatened the 405,000 hectares of cotton grown in the San Joaquin Valley to the north. To keep this pest out of the San Joaquin Valley, the CDFA/USDA and California cotton growers use the large-scale releases of sterile pink bollworms in areas in which wild pink bollworms are captured each year. Thus far, the pink bollworm has been prevented from establishing a permanent presence in the San Joaquin Valley and the cotton growers in southern California, Arizona and

  6. Effects of methoxyfenozide, indoxacarb, and other insecticides on the beneficial egg parasitoid Trichogramma nr. brassicae (Hymenoptera: Trichogrammatidae) under laboratory and field conditions.

    Science.gov (United States)

    Hewa-Kapuge, Swarna; McDougall, Sandra; Hoffmann, Ary A

    2003-08-01

    Trichogramma nr. brassicae is a common egg parasitoid of Helicoverpa species in Australian processing tomatoes, but its effectiveness can be severely curtailed by insecticide applications. To identify insecticides that are potentially compatible with this species, the effects of seven insecticides, including newly introduced compounds and a surfactant, were screened in laboratory and glasshouse assays for their toxicity to the wasps. Assays involved direct applications on adults, residual effects on adults, and applications on life stages still inside the host. Methoxyfenozide and indoxacarb were not toxic to Trichogramma in any assay when applied at field rates. Naled and chlorfenapyr caused 100% mortality when directly applied to adults, and 95% mortality when adults were exposed to residues of these chemicals within 24 h of application. The effects of naled residues were short lived (Naled and chlorfenapyr were also toxic when applied to Trichogramma developing inside host eggs, reducing emergence of adults by >25%. Imidacloprid, emamectin, and tau-fluvalinate were toxic in some experiments; they caused >97% mortality in adults 1 h after direct application and in residue assays they caused 23-64% mortality during the first 24 h. In field trials, methoxyfenozide had no harmful effects on emergence from sprayed parasitized eggs, whereas indoxacarb had a small impact (<8%) on emergence. Methoxyfenozide and indoxacarb are potentially suitable for inclusion in integrated pest management strategies for management of Helicoverpa because they do not influence adult survival or development of immature stages, whereas other chemicals need to be treated cautiously. PMID:14503578

  7. Transgenic tobacco plants harboring tomato proteinase inhibitor II gene and their insect resistance

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The plant expression vectors pBCT2 and pBT2 were constructed with the cDNA sequence (tin2) and genomic DNA sequence (tin2i) of tomato proteinase inhibitor II gene respectively. Then the two expression vectors were transferred into tobacco via the Agrobacterium tumefaciens strain LBA4404, and transgenic tobacco plants were generated. Molecular analysis and trypsin activity assay showed that both cDNA and genomic DNA were expressed properly in the transgenic plants. Insecticidal activities in these transgenic plants indicated that transgenic tobacco plants carrying tin2i sequence were more resistant to 2-instar larvae of Heliothis armigera Hubner than those carrying tin2 sequence. Therefore the intron of tin2i sequence might be a contributor to insecticidal activity of the transgenic tobacco.

  8. Application of radioisotopes in entomology

    International Nuclear Information System (INIS)

    Radioisotope techniques are effective in entomology and studies on insects physiology. The study presents the use of radioisotopes in pest control programs: Methods of insects irradiation and the concept of biological half-life of the radioisotopes in comparison with physical half-life are explained. Main radioisotopes used in entomology are:3H, 14Ca, 32P, 35S, 38Cl. Other radioisotopes contributing to studies on insects are: 198Au, 134Cs, 131I, 86Rb, 65Zn, 59Fe, 45Ca, 24Na, 22Na. Radiation doses specific to each radioisotopes are given in tables. As an example of the application of radioisotopes in pest control: the determination of insects population density by means of releasing irradiated male insects than chasing them; studying of reproduction activity of Agrotis ipsilon; studying of egg laying of Heliocoverpa armigera moth. 15 refs. 2 figs. 2 tabs

  9. Utilization of fodder yeast and agro-industrial by-products in production of spores and biologically - active endotoxins from Bacillus thuringiensis.

    Science.gov (United States)

    Salama, H S; Foda, M S; Selim, M H; El-Sharaby, A

    1983-01-01

    A number of newly-devised fermentation media were evaluated with respect to their ability to support sporulation and biosynthesis of endotoxins by strains of Bacillus thuringiensis that are biologically active against Spodoptera littoralis, Heliothis armigera, and Spodoptera exigua. Fodder yeast from dried cells of Saccharomyces cerevisiae could be used as a complete mono-component medium for production of highly active spore-delta-endotoxin complexes from B. thur., vars. entomocidus, kurstaki and galleriae. Highest sporulation titers were obtained at 2% fodder yeast concentration with endotoxin yields ranging between 7 to 9 grams per liter of medium. Ground horse beans and kidney bean seeds could also be used successfully as complete media for sporulation and endotoxin production. Extracts of potato tubers and sweet potato roots were efficient media for active endotoxin production from B. thur. var. kurstaki, although the obtained yields were much lower than those produced in fodder yeast media. The utilization of fish meal, cotton seed meal, and residues of chicken from the slaughter-house as media for the production of endotoxins active against Spodoptera littoralis, was not successful. On the other hand, minced citrus peels, ground seeds of dates, and wheat bran could be successfully used in combination with fodder yeast as media for production of endotoxins, active against Heliothis armigera and Spodoptera exigua. Re-utilization of culture supernatants in a second fermentation cycle after supplementation with some nutrients gave promising results with some of the strains tested. The data obtained are discussed in view of their feasibility of application. PMID:6666415

  10. Mass rearing of the oriental tobacco budworm for sterile insect technique programs

    International Nuclear Information System (INIS)

    The main purpose of the study is to find out a proper technique for mass rearing the oriental tobacco budworm, Helicoverpa assulta Guenee. The oriental tobacco budworms larvae were reared with different formulation diets and kept in traditional glass test tubes or in specially-designed cell-unit devices. When the diets including vitamin C and tomato source, and the ratio of corn and soybean powder was set as 1:2, the pupae weight, moth weight, pupation, emergence, fecundity and hatchability were increased significantly. When reared in cell-units, there is no significant difference in insect compared with those in glass test tubes, but the production efficiency was much higher and the cost was lower than the latter. The results of this study provide a key technical support for the application of sterile insect technique in control of oriental tobacco budworm. (authors)

  11. Dicty_cDB: Contig-U09476-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available AC146570 |pid:none) Medicago truncatula clone mth2-103... 53 2e-05 (Q0MW30) RecName: Full=E3 ubiquitin-protein...Name: Full=52 kDa Ro protein; AltName: Full=Sjoegren... 39 0.33 AF334030_64( AF334030 |pid:none) Helicoverpa zea sing...6963 |pid:none) Caligus rogercresseyi clone crog-e... 37 0.96 (Q9C019) RecName: Full=Tripartite motif-containing protein...abase: CSM 6905 sequences; 5,674,871 total letters Score E Sequences producing significa.....................................................done Score E Sequences producing significant alignmen

  12. Dicty_cDB: Contig-U11361-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 7383 ) RTDR1_12_H08.g1_A015 Loblolly pine roots recoveri... 56 0.007 1 ( DC441670 ) Gryllus bimaculatus mRNA...none) Drosophila melanogaster Adrift (ad... 40 0.32 AF334030_65( AF334030 |pid:none) Helicoverpa zea single ... producing significant alignments: (bits) Value N ( BJ335143 ) Dictyostelium discoideum cDNA clone:dda49h05..., 5' ... 1318 0.0 1 ( BJ420409 ) Dictyostelium discoideum cDNA clone:ddv39p01, 5'... ... 1306 0.0 1 ( BJ418328 ) Dictyostelium discoideum cDNA clone:ddv32k07, 5' ... 1279 0.0 1 ( BJ422268 ) Dictyostelium disco

  13. Recovery of infectious pariacoto virus from cDNA clones and identification of susceptible cell lines.

    Science.gov (United States)

    Johnson, K N; Ball, L A

    2001-12-01

    Pariacoto virus (PaV) is a nodavirus that was recently isolated in Peru from the Southern armyworm, Spodoptera eridania. Virus particles are non enveloped and about 30 nm in diameter and have T=3 icosahedral symmetry. The 3.0-A crystal structure shows that about 35% of the genomic RNA is icosahedrally ordered, with the RNA forming a dodecahedral cage of 25-nucleotide (nt) duplexes that underlie the inner surface of the capsid. The PaV genome comprises two single-stranded, positive-sense RNAs: RNA1 (3,011 nt), which encodes the 108-kDa catalytic subunit of the RNA-dependent RNA polymerase, and RNA2 (1,311 nt), which encodes the 43-kDa capsid protein precursor alpha. In order to apply molecular genetics to the structure and assembly of PaV, we identified susceptible cell lines and developed a reverse genetic system for this virus. Cell lines that were susceptible to infection by PaV included those from Spodoptera exigua, Helicoverpa zea and Aedes albopictus, whereas cells from Drosophila melanogaster and Spodoptera frugiperda were refractory to infection. To recover virus from molecular clones, full-length cDNAs of PaV RNAs 1 and 2 were cotranscribed by T7 RNA polymerase in baby hamster kidney cells that expressed T7 RNA polymerase. Lysates of these cells were infectious both for cultured cells from Helicoverpa zea (corn earworm) and for larvae of Galleria mellonella (greater wax moth). The combination of infectious cDNA clones, cell culture infectivity, and the ability to produce milligram amounts of virus allows the application of DNA-based genetic methods to the study of PaV structure and assembly. PMID:11711613

  14. Transgenic Bt cotton driven by the green tissue-specific promoter shows strong toxicity to lepidopteran pests and lower Bt toxin accumulation in seeds.

    Science.gov (United States)

    Wang, Qing; Zhu, Yi; Sun, Lin; Li, Lebin; Jin, Shuangxia; Zhang, Xianlong

    2016-02-01

    A promoter of the PNZIP (Pharbitis nil leucine zipper) gene (1.459 kb) was cloned from Pharbitis nil and fused to the GUS (β-glucuronidase) and Bacillus thuringiensis endotoxin (Cry9C) genes. Several transgenic PNZIP::GUS and PNZIP::Cry9C cotton lines were developed by Agrobacterium-mediated transformation. Strong GUS staining was detected in the green tissues of the transgenic PNZIP::GUS cotton plants. In contrast, GUS staining in the reproductive structures such as petals, anther, and immature seeds of PNZIP::GUS cotton was very faint. Two transgenic PNZIP::Cry9C lines and one transgenic cauliflower mosaic virus (CaMV) 35S::Cry9C line were selected for enzyme-linked immunosorbent assay (ELISA) and insect bioassays. Expression of the Cry9C protein in the 35S::Cry9C line maintained a high level in most tissues ranging from 24.6 to 45.5 μg g(-1) fresh weight. In green tissues such as the leaves, boll rinds, and bracts of the PNZIP::Cry9C line, the Cry9C protein accumulated up to 50.2, 39.7, and 48.3 μg g(-1) fresh weight respectively. In contrast, seeds of the PNZIP::Cry9C line (PZ1.3) accumulated only 0.26 μg g(-1) fresh weight of the Cry9C protein, which was 100 times lower than that recorded for the seeds of the CaMV 35S::Cry9C line. The insect bioassay showed that the transgenic PNZIP::Cry9C cotton plant exhibited strong resistance to both the cotton bollworm and the pink bollworm. The PNZIP promoter could effectively drive Bt toxin expression in green tissues of cotton and lower accumulated levels of the Bt protein in seeds. These features should allay public concerns about the safety of transgenic foods. We propose the future utility of PNZIP as an economical, environmentally friendly promoter in cotton biotechnology. PMID:26728504

  15. Safety and advantages of Bacillus thuringiensis-protected plants to control insect pests.

    Science.gov (United States)

    Betz, F S; Hammond, B G; Fuchs, R L

    2000-10-01

    Plants modified to express insecticidal proteins from Bacillus thuringiensis (referred to as Bt-protected plants) provide a safe and highly effective method of insect control. Bt-protected corn, cotton, and potato were introduced into the United States in 1995/1996 and grown on a total of approximately 10 million acres in 1997, 20 million acres in 1998, and 29 million acres globally in 1999. The extremely rapid adoption of these Bt-protected crops demonstrates the outstanding grower satisfaction of the performance and value of these products. These crops provide highly effective control of major insect pests such as the European corn borer, southwestern corn borer, tobacco budworm, cotton bollworm, pink bollworm, and Colorado potato beetle and reduce reliance on conventional chemical pesticides. They have provided notably higher yields in cotton and corn. The estimated total net savings to the grower using Bt-protected cotton in the United States was approximately $92 million in 1998. Other benefits of these crops include reduced levels of the fungal toxin fumonisin in corn and the opportunity for supplemental pest control by beneficial insects due to the reduced use of broad-spectrum insecticides. Insect resistance management plans are being implemented to ensure the prolonged effectiveness of these products. Extensive testing of Bt-protected crops has been conducted which establishes the safety of these products to humans, animals, and the environment. Acute, subchronic, and chronic toxicology studies conducted over the past 40 years establish the safety of the microbial Bt products, including their expressed insecticidal (Cry) proteins, which are fully approved for marketing. Mammalian toxicology and digestive fate studies, which have been conducted with the proteins produced in the currently approved Bt-protected plant products, have confirmed that these Cry proteins are nontoxic to humans and pose no significant concern for allergenicity. Food and feed derived

  16. Applying the sterile insect technique to the control of insect pests

    International Nuclear Information System (INIS)

    The sterile insect technique involves the mass-rearing of insects, which are sterilized by gamma rays from a 60Co source before being released in a controlled fashion into nature. Matings between the sterile insects released and native insects produce no progeny, and so if enough of these matings occur the pest population can be controlled or even eradicated. A modification of the technique, especially suitable for the suppression of the moths and butterflies, is called the F, or inherited sterility method. In this, lower radiation doses are used such that the released males are only partially sterile (30-60%) and the females are fully sterile. When released males mate with native females some progeny are produced, but they are completely sterile. Thus, full expression of the sterility is delayed by one generation. This article describes the use of the sterile insect technique in controlling the screwworm fly, the tsetse fly, the medfly, the pink bollworm and the melon fly, and of the F1 sterility method in the eradication of local gypsy moth infestations. 18 refs, 5 figs, 1 tab

  17. Impact of moth suppression/eradication programmes using the sterile insect technique or inherited sterility

    International Nuclear Information System (INIS)

    Numerous lepidopteran species have been investigated as candidates for control using the sterile insect technique (SIT) or inherited sterility (IS). However to date only two programmes are operational - the pink bollworm containment programme in the San Joaquin Valley, California, USA, and the codling moth suppression programme in British Columbia, Canada. Both of these programmes have been highly successful in controlling the pest populations, reducing insecticide use, and improving interactions between growers and the general public. However, other benefits, including the positive economic impacts of these programmes, have not been fully quantified. Methods to reduce the cost of lepidopteran programmes might include combining the SIT/IS with other pest control tactics such as mating disruption or the release of natural enemies, the development of genetic sexing strains, or the application of molecular technologies to develop genetic markers and genetic sterility. In future the greatest potential for impact of lepidopteran SIT/IS programmes may be in combating key invasive threats such as the eradication of an outbreak of the painted apple moth in New Zealand. (author)

  18. Performance of some transgenic cotton cultivars against insect pest complex, virus incidence and yield

    International Nuclear Information System (INIS)

    Five cultivars of cotton i.e., IR4-NIBGE, IR5-NIBGE Bt-121, Sitara-10M and Sitara-11M were screened for resistance against insect pest complex and Cotton Leaf Curl Virus (CLCuV) incidence in the research area of Cotton Research Station, Multan. The result depicted that the most resistant variety against jassids was IR4-NIBGE and Sitara-11M whereas IR4-NIBGE showed the maximum resistance against whitefly infestation. The least susceptible variety to the infestation of thrips was Sitara-10M. The most susceptible variety to the prevalence of Red Cotton Bug (RCB) was IR4-NIBGE. The genotype Bt-121 showed the attack of spotted bollworm. The high population of Dusky Cotton Bug (DCB) was observed on Bt-121 throughout the season. The incidence of virus percentage increased with the passage of time; however, the variety IR5-NIBGE exhibited maximum level of tolerance. Variety Bt-121 gave the maximum yield i.e., 1852 kg per acre followed by IR5-NIBGE, Sitara-11M, Sitara-10M 1584, 1503, 1466 kg per acre respectively. Our results suggest that IR4-NIBGE and Sitara -11M are comparatively tolerant to jassids and whitefly which are the yield losing pest. So IR4-NIBGE and Sitara -11M varieties can be included in IPM programme for the management of these voracious pests. (author)

  19. FIELD EFFICACY OF NEEM ( Azadirachta indica A. Juss BASED BIOPESTICIDES FOR THE MANAGEMENT OF INSECT - PESTS OF COTTON IN NORTHERN GHANA

    Directory of Open Access Journals (Sweden)

    Nboyine JA

    2013-09-01

    Full Text Available Cotton is an important fiber crop grown in northern Ghana. Its cultivation is beset with numerous insect pest problems. Current pest management practices in cotton fields are based on the use of chlorpyrifos and lamda cyhalothrin based synthetic insecticides which is unaffordable to most peasant cotton farmers. Hence, this study aimed at assessing the field efficacy of neem based biopesticides like neem seed kernel extract (NSK E and neem seed oil (NSO as an alternative for the management of insect pests of cotton in northern Ghana. The treatments were 2% NSO, 5% NSO, 5% NSKE, 10% NSKE, chlorpyrifos alternated with lamda cyhalothrin and untreated control. The results showed that 10% NSKE significantly ( P <0.05 reduced the abundance of bollworms, aphids and white flies to 0.75, 3.71 and 3.29 respectively while for the untreated control they were as high as 3.07, 14.14 and 6.75 respectively. The neem was non - toxic to the natural e nemies. Seed cotton yield were between 52.20% and 90.82% higher in the neem treated plots than the untreated control while yield loss was 64.79% lower on the 10% NSKE treated plots than the untreated control plots

  20. Breeding for insect resistance in cotton

    International Nuclear Information System (INIS)

    The importance of cultivated cottons as fibre and food crops was discussed. More pest control research has been conducted on cotton than in any other crop plant. The different control measures such as use of chemicals, agronomic and cultural operations and utilization of parasites and predators were discussed in details. For breeding resistant cultivars the cooperation of the breeder and the entomologist is essential for a successful breeding programme. Plant resistance should be looked upon as the degree of interaction between the insect and its host plant under certain physiological, genetical and environmental conditions affecting both the insect and its host plant. Therefore more studies on the insect - plant relationship are to be carried out by the breeders and the entomologists. Breeding for jassid and bollworm resistance in the Sudan was discussed in details. The characters frego-bract, glabrous plant body, nectariless flower and leaf together with high gossypol content may confer resistance to, many insects in cotton. The possibilities of utilizing induced mutations in insect and host plants were discussed. (author)

  1. Research Results

    Science.gov (United States)

    2012-01-01

    In situ Oxidation Study of Pt (110) and Its Interaction with CO Chinese Scientists Published a Paper on Prevention of Drug Craving and Relapse by Memory Retrieval-extinction Procedure in Science Series Papers Published in Energy Policy: Modeling Energy Use of China's Road Transport and Policy Evaluation Breakthrough in the Ambient Catalytic Destruction of Formaldehyde Novel Findings for High Altitude Adaptation from the Yak Genome Binary Colloidal Structures Assembled through Ising Interactions Reemergence of superconductivity at 48K in Compressed Iron Selenide Based Superconductors Nucleosomes Suppress Spontaneous Mutations Base-Specifically in Eukaryotes Single-Chain Fragmented Antibodies Guided SiRNA Delivery in Breast Cancer Does Yeast Suicide? China Scientists Developed Important Methodologies for Spatiotemporal Detecting and Manipulating of Cellular Activities Scorpions Inspire Chinese Scientists in Making Bionic Non-eroding Surfaces for Machinery Research on Phylogenetic Placement of Borthwickia and Description of a New Family of Angiosperms, Borthwickiaceae Plasmoid Ejection and Secondary Current Sheet Generation from Magnetic Reconnection in Laser-plasma Interaction Cotton Bollworm Adapts to Bt Cotton via Diverse Mutations A Histone Acetyltransferase Regulates Active DNA Demethylation in Arabidopsis

  2. Isolation of imidacloprid degrading bacteria from industrial sites

    International Nuclear Information System (INIS)

    Immidacloprid is a cyclodiene organochlorine used as an insecticide all over the world and possessing a serous environmental threat. It is mostly used for cotton insects (bollworm, aphid and white fly). For isolation of imidacloprid degrading bacteria, two soil samples were collected from industrial contaminated sites of Kala Shah Kahu district sheikupura, having ten year history of use. Soil samples were analyzed by measuring pH and electric conductivity. The isolation of imidacroprid degrading bacteria was performed by enrichment technique. Eight bacterial strains, S/sub 1-a/ S/2-2-b/ S/2-c/ S/2-d/ S/2-e/ S/sub 2-f/ and S/sub 2-g/ and S/sub e-a/ were isolated on the basis of their colony morphologies. The purified colonies were characterized morphologically, physiologically and biochemically. Gram staining was done and Gram negative strain were confirmed on MacConkey agar and Eosin Methylene Blue. Bacterial strains were also checked for different minimal media in which only carbon source was the imidcloprid. For this purpose. FTW, FTW without N/sub 2/ NSM, M/sub 9/ and MM/sub 2/ media were used and their optical densities were taken on spectrophotometer isolates were checked for resistance to antibiotics and heavy metals. On these characteristics, S/sub 2-d/ and S/sub c-a/ were assigned to Enterobacteriaceae, S/sub 2-b/ to Pseudomonad and rest of the bacterial isolates were affiliated to bacillaceae. (author)

  3. A case study for assessment of microbial community dynamics in genetically modified Bt cotton crop fields.

    Science.gov (United States)

    Kapur, Manisha; Bhatia, Ranjana; Pandey, Gunjan; Pandey, Janmejay; Paul, Debarati; Jain, Rakesh K

    2010-08-01

    Bt cotton was the first genetically modified crop approved for use in India. However, only a few studies have been conducted to assess the feasibility of its commercial application. Bt cotton is genetically modified to express a proteinaceous endotoxin (Cry) encoded by cry gene of Bacillus thuringiensis that has specific insecticidal activity against bollworms. Therefore, the amount of pesticides used for growing Bt cotton is postulated to be considerably low as compared to their non-Bt counterparts. Alternatively, it is also speculated that application of a genetically modified crop may alter the bio-geochemical balance of the agriculture field(s). Microbial community composition and dynamics is an important descriptor for assessment of such alterations. In the present study, we have assessed the culturable and non-culturable microbial diversities in Bt cotton and non-Bt cotton soils to determine the ecological consequences of application of Bt cotton. The analyses of microbial community structures indicated that cropping of Bt cotton did not adversely affect the diversity of the microbial communities. PMID:20098990

  4. Variation induced by DNA rearrangement in a transgenic Bt+CpTI cotton strain

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In the development of transgenic Bt + CpTI cotton cultivars, one male and female sterile mutant has been found in a homozygous T4 strain in our laboratory. The mutant plant, as well as its leaves, buds and flowers, is only 1/2-1/3 as large as that of the wild transgenic Bt + CpTI bivalant cotton plants. Cytological observation found that the chromosome number of the mutant is 2n = 52; however, there are 4 - 8 univalents observed in meiosis Ⅰ of pollen mother cells. Laboratory bioassay indicated that the mutant was highly resistant to bollworm as the wild plants. PCR amplification revealed that Bt and CpTI genes in the mutant were still intactly inserted. However, small deletion of flanked area had been observed in the mutant by Southern blotting analysis. So it is proposed that the mutant phenotype might result from either the DNA deletion or T-DNA trans-ferring in plant genome. No such report has been presented that the rearrangement of chromosome structure in a homo-zygous transgenic line occurred. Further analysis is ongoing.

  5. Biointensive Integrated Pest Management for Bt Cotton

    Directory of Open Access Journals (Sweden)

    N. Sathiah

    2006-01-01

    Full Text Available Biointensive Integrated Pest Management (BIPM modules were compared with the Farmers` Package of Practices (FPP for MECH 162 Bt and MECH 162 N Bt The incidence of leaf hopper, aphids, thrips and whiteflies in different modules was in the order of FPP-MECH 162 Bt > BIPM MECH 162 Bt > BIPM MECH 162 N Bt > FPP MECH 162 N Bt. Natural enemies population were more in BIPM modules than the FPP. Coccinellids such as Menochilus sexmaculatus, Coccinella transversalis and spiders Oxyopes spp., Argiope spp., Neoscona spp., Araenus spp. and Plexippus spp. were frequently observed in the field trials. Incidence of bollworm population was more in winter field trial than that in the summer field trials. Fruiting bodies damage, open boll, locule and inter locule damage in different modules was in the order of BIPM MECH 162 Bt > FPP MECH 162 Bt > BIPM MECH 162 N Bt > FPP MECH 162 N Bt. Seed cotton yield in BIPM MECH 162 Bt, BIPM MECH 162 N Bt, FPP MECH 162 Bt and FPP MECH 162 N Bt modules at Alandurai field trial were 1920, 1640, 1800 and 1440 kg ha-1. The results indicated the better performance of Bt cotton in both the modules. BIPM approach reduces the insecticide usage. The IPM approach is essential for gaining higher advantage from Bt cotton as it takes care of varying pest situation.

  6. Photoprotection of Bacillus thuringiensis kurstaki from ultraviolet irradiation

    International Nuclear Information System (INIS)

    Irradiation of Bacillus thuringiensis var. kurstaki HD1 at 300-350 nm for up to 12 hr using a photochemical reactor results in a rapid loss of its toxicity to larvae of Heliothis armigera. Photoprotection of the toxic component was obtained by adsorption of cationic chromophores such as acriflavin (AF), methyl green, and rhodamine B to B. thuringiensis. AF gave the best photoprotection and a level of 0.42 mmol/g dye absorbed per gram of B. thuringiensis was highly toxic even after 12 hr of ultraviolet (uv) irradiation as compared to the control (77.5 and 5% of insect mortality, respectively). Ultraviolet and Fourier-transform infrared spectroscopic studies indicate molecular interactions between B. thuringiensis and AF. The nature of these interactions and energy or charge transfer as possible mechanisms of photoprotection are discussed. It is speculated that tryptophan residues are essential for the toxic effect of B. thuringiensis. It is suggested that photoprotection is attained as energy is transferred from the excited tryptophan moieties to the chromophore molecules

  7. Adsorption and Insecticidal Activity of Toxin from Bacillus thuringiensis on Rectorite

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xue-Yong; HUANG Qiao-Yun; CAI Peng; YU Zi-Niu

    2007-01-01

    The adsorption and desorption of the toxin from Bacillus thuringiensis strain WG-001 on rectorite were studied at different toxin and/or rectorite concentrations, pH values and temperatures. The insecticidal activity of the adsorbed toxin was evaluated by determining the lethal concentration to kill 50% of the larvae of Heliothis armigera (Lcso). The adsorption of the toxin on rectorite in sodium carbonate buffer (pH 9) reached equilibrium within 0.5-1.0 h and the adsorption isotherm of the toxin followed the Langmuir equation (R2>0.99). In the pH range from 9 to 11 (carbonate buffer), the adsorbed toxin decreased with increasing pH. The adsorption amounts decreased with increasing rectoritettoxin ratio. The adsorption was not significantly affected by the temperature between 10 and 50 °C. The X-ray diffraction analysis indicated occurrence of the intercalation of the rectorite by the toxin. The infrared absorption spectrum showed that the binding of the toxin did not alter its structure. The Lcgo values of the adsorbed toxin were smaller than those of the free toxin. The rectorite protected the toxin from ultraviolet irradiation damage. The desorption of the adsorbed toxin in water ranged from 37.5% to 56.4% and from 27.4% to 41.8% in a carbonate buffer. The desorption percentage also decreased with increasing rectorite:toxin ratio.

  8. The future of IPM: whither or wither?

    International Nuclear Information System (INIS)

    The acronym IPM (integrated pest management) has been around for over 50 years and now not only supposedly guides research and extension in pest management but also markets pesticides, is claimed to be undertaken by many growers, and even resonates with public perceptions and politicians. Whether or not IPM programs are sustainable in the longer term under the conflicting stresses and strains of the modern agricultural environment is debatable. We analyse three case studies of IPM development in Australia: citrus IPM in central Queensland, Brassica IPM in southeast Queensland and Helicoverpa management in cotton in eastern Australia. Many management practices for these pests have changed over time. In the more stable citrus system classical biological control along with changed practices (reduced pesticide use) have effectively controlled imported scale insect pests. In Brassicas and cotton, IPM is predominantly of the sample and spray variety where, increasingly, less broad-spectrum insecticides are used and, in cotton, Helicoverpa management includes the deployment of transgenic plants. We question whether or not IPM principles are always consistent with market forces and whether or not the approach is universally applicable for all pest insects when implemented at the small (field or farm) scale. Farmers will adopt cost-effective approaches that minimise their financial risks. For Australia as a whole over the last 30 years insecticide input costs per hectare have increased faster than the price index, reflecting more costly insecticides, changes to the combinations of crops grown and an increase in the overall area of crops cultivated together with possible concomitant changes in pest abundance. Any pest crisis will ensure rapid changes in practice and adoption of technologies, in order to mitigate the short-term financial stresses caused. However, regression to former practices tends to follow (e.g. in Brassica crops). In most cases, we cannot objectively test

  9. Inseticidas para o controle da traça-do-tomateiro e broca-grande e seu impacto sobre Trichogramma pretiosum Insecticides for the control of the South American tomato pinworm and the corn earworm and impact of those products on Trichogramma pretiosum

    Directory of Open Access Journals (Sweden)

    Marina Castelo Branco

    2003-12-01

    Full Text Available Experimentos de campo foram conduzidos entre maio e outubro de 2000 para determinar a eficiência de diversos inseticidas para o controle de Tuta absoluta e Helicoverpa zea e o impacto desses produtos sobre a emergência do parasitóide Trichogramma pretiosum. Os inseticidas testados, bem como as doses em g i.a./ha foram: metoxifenozide (120; 144, clorpirifós (540; 675, tiacloprid (72; 96 e triflumuron (144. O delineamento experimental foi de blocos ao acaso com oito tratamentos (inseticidas e testemunha e cinco repetições, com 40 plantas/parcela. Frutos de tomate foram coletados aos 58, 80 e 87 dias após o transplante das mudas para a determinação da percentagem de frutos danificados pelos insetos. O impacto dos inseticidas sobre T. pretiosum foi avaliado mediante a coleta de 20 ovos de H. zea por parcela aos 61 dias após o transplante, onde foi realizada a avaliação da emergência do parasitóide. Todos os inseticidas reduziram significativamente os danos causados por H. zea. Contudo, nenhum deles foi eficiente para o controle de T. absoluta. Metoxifenozide e clorpirifós (540 não reduziram significativamente o número de ovos parasitados por T. pretiosum quando comparados à testemunha.Field studies were conducted from May to October 2000 to determine the effectiveness of several insecticides in controlling Tuta absoluta and Helicoverpa zea and their impact on emergence of the parasitoid Trichogramma pretiosum. The insecticides tested were: methoxyfenozide (120; 144, clorpirifós (540; 675, tiacloprid (72; 96 and triflumuron (144. Application rates of all insecticides are expressed as g a.i./ha. The experiment was designed as randomized complete block with eight treatments (insecticides and untreated plots with five replications. Tomato fruits were harvested 58; 80 and 87 days after transplanting and the percentage of damaged fruits by both pests determined. The impact of insecticides on T. pretiosum survival was determined

  10. Insect pests management of bt cotton through the manipulation of different eco-friendly techniques

    International Nuclear Information System (INIS)

    This study was designed to manage insect pests of Bt cotton through the manipulation of different eco-friendly techniques. A perusal of data, based on the overall performance of different treatments reflected that lowest population of jassids (0.29) was observed in bio-control treated Bt cotton followed by bio-control treated conventional cotton (0.41). Mean per leaf population of thrips was found lowest in insecticide treated Bt cotton (0.97) which was statically at par with bi-control treated conventional cotton (0.95), biocontrol treated Bt cotton (1.09) and colour traps treated Bt cotton (1.50). In case of white flies, bio-control treated Bt cotton and bio-control treated conventional cotton again proved effective in maintaining the population at lower levels per leaf (0.33 and 0.35 respectively). No bollworms infestation was recorded in transgenic cotton whereas higher attack of the same was observed in the untreated conventional cotton block. The best results were achieved with the application of bio-control agents in combination with Bt cotton resulting in least infestation by insect pests and maximum seed yield of 3657 kg/ha. The population of Chrysoperla carnea was significantly higher in Bt and conventional cotton treated with bio-control agents as compared to the other treatments. The parasitism percentage of Trichogramma chilonis was observed significantly higher in bio-control treated conventional cotton. The studies manifested that combination of bio-control technology with Bt cotton effectively preserves the local beneficial insect fauna indicating its potential to be used as integrated management system against different insect pests of cotton. (author)

  11. Biosafety management and commercial use of genetically modified crops in China.

    Science.gov (United States)

    Li, Yunhe; Peng, Yufa; Hallerman, Eric M; Wu, Kongming

    2014-04-01

    As a developing country with relatively limited arable land, China is making great efforts for development and use of genetically modified (GM) crops to boost agricultural productivity. Many GM crop varieties have been developed in China in recent years; in particular, China is playing a leading role in development of insect-resistant GM rice lines. To ensure the safe use of GM crops, biosafety risk assessments are required as an important part of the regulatory oversight of such products. With over 20 years of nationwide promotion of agricultural biotechnology, a relatively well-developed regulatory system for risk assessment and management of GM plants has been developed that establishes a firm basis for safe use of GM crops. So far, a total of seven GM crops involving ten events have been approved for commercial planting, and 5 GM crops with a total of 37 events have been approved for import as processing material in China. However, currently only insect-resistant Bt cotton and disease-resistant papaya have been commercially planted on a large scale. The planting of Bt cotton and disease-resistant papaya have provided efficient protection against cotton bollworms and Papaya ringspot virus (PRSV), respectively. As a consequence, chemical application to these crops has been significantly reduced, enhancing farm income while reducing human and non-target organism exposure to toxic chemicals. This article provides useful information for the colleagues, in particular for them whose mother tongue is not Chinese, to clearly understand the biosafety regulation and commercial use of genetically modified crops in China. PMID:24493253

  12. Insect Pest Control Newsletter, No. 81, July 2013

    International Nuclear Information System (INIS)

    In response to requests from our readers, this introduction is mainly dedicated to the ongoing efforts to develop alternatives for insect reproductive sterilization and blood sterilization for their use in insect pest control programmes with a sterile insect technique (SIT) component. Radioisotope irradiators that are loaded with either cobalt-60 or caesium-137 producing gamma rays have been routinely used for many decades and have proven to be extremely reliable and safe for these purposes in successful area-wide insect eradication or suppression programmes. These include industrial panoramic-type irradiators in larger programmes, all the way to smaller self-contained irradiators. Nevertheless, the transboundary shipment of self-contained gamma irradiators or radioactive material has become logistically more complex due to security issues. This situation was exacerbated when the production of the Gamma Cell 220 (GC220), the source most commonly used for irradiating insects for sterilization purposes, was discontinued. These events may have created the impression that the use of gamma radiation has become a less viable option, unattainable for insect pest control programmes that want to integrate the SIT. Nevertheless, some of the biggest SIT operational programmes have in recent years been equipped with new self-contained cobalt-60 sources, including the SIT programme against the pink bollworm in Phoenix, Arizona; El Pino Mediterranean fruit fly facility in Guatemala; and the screwworm programme in Panama. Thus these larger and more expensive irradiators, together with panoramic units (that are also costlier than self-contained gamma irradiators) have remained over the years a valid option, especially for larger operational programmes. In addition, the reloading of smaller units with new cobalt or the purchase of refurbished used self-contained irradiators remain viable alternatives

  13. Novel acetylcholinesterase target site for malaria mosquito control.

    Directory of Open Access Journals (Sweden)

    Yuan-Ping Pang

    Full Text Available Current anticholinesterase pesticides were developed during World War II and are toxic to mammals because they target a catalytic serine residue of acetylcholinesterases (AChEs in insects and in mammals. A sequence analysis of AChEs from 73 species and a three-dimensional model of a malaria-carrying mosquito (Anopheles gambiae AChE (AgAChE reported here show that C286 and R339 of AgAChE are conserved at the opening of the active site of AChEs in 17 invertebrate and four insect species, respectively. Both residues are absent in the active site of AChEs of human, monkey, dog, cat, cattle, rabbit, rat, and mouse. The 17 invertebrates include house mosquito, Japanese encephalitis mosquito, African malaria mosquito, German cockroach, Florida lancelet, rice leaf beetle, African bollworm, beet armyworm, codling moth, diamondback moth, domestic silkworm, honey bee, oat or wheat aphid, the greenbug, melon or cotton aphid, green peach aphid, and English grain aphid. The four insects are house mosquito, Japanese encephalitis mosquito, African malaria mosquito, and German cockroach. The discovery of the two invertebrate-specific residues enables the development of effective and safer pesticides that target the residues present only in mosquito AChEs rather than the ubiquitous serine residue, thus potentially offering an effective control of mosquito-borne malaria. Anti-AgAChE pesticides can be designed to interact with R339 and subsequently covalently bond to C286. Such pesticides would be toxic to mosquitoes but not to mammals.

  14. Isolation of imidacloprid degrading bacteria from cotton fields

    International Nuclear Information System (INIS)

    Imidacloprid is cyclodiene organochlorine, used as an insecticide all over the world an possess a serious environmental threat. It is mostly used for cotton insects (bollworm, aphid and white fly). For isolation of imidacloprid degrading bacteria three soil samples were collected from cotton fields of district Layyah having five years history of use. Soil samples were analyzed by measuring pH and electric conductivity. The isolation of imidacroprid degrading bacteria was performed by enrichment technique. Fourteen bacterial strains: S/sub i-a/, S/sub i-b/, S/sub i-c/, S/sub i-d/, S/sub i-e/, S/sub a-a/, S/a-b/, S/a-c/, S/a-d/, S/sub b-a/, S/sub b-b/, S/sub b-c/, S/sub b-d/ and S/b-e/ were isolated on the basis of their colony morphologies. The purified colonies were characterized morphologically physiologically and biochemically. Gram staining was done and Gram staining was done and Gram negative strains were confirmed on macConkey agar and Eosin methylene blue. Bacterial strains were also checked for different minimal media in which only carbon source was the imidacloprid. For this purpose FTW, FTW without N/sun 2/, NSM, M/sub 9/ and MM/sub 2/ media were used and their optical densities were taken on spectrophotometer, isolates were checked for resistance to antibiotics and heavy metals. On the basis of these characteristics. S/sub a-c/ and S/sub l-d/ were assigned to Enterobacteriaceae, S/sub a-b/ to Pseudomonadaceae and rest of the bacterial isolates were affiliated. (author)

  15. Impact of FFS on farmer's adoption of IPM options for tomato: A case study from the Gezira State, Sudan

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    Ahmed Mirghani Abdel Rahman

    2012-09-01

    Full Text Available In Sudan pests and diseases are the major problem of vegetables production. Tomato crop is considered as the most important vegetable crop in the country according to its economic and nutrition value. There are many pest and diseases retarding tomato production such as whitefly, American bollworm, TYLCV and powdery mildew. Therefore some IPM options for tomato and onion were validated in FFS in order to help farmers in controlling the most important pests and diseases. The main objective of this study was to determine the impact of FFS on farmer's adoption of IPM options for tomato in the Gezira State, Sudan. Field survey was used to collect data from three Farmer Field Schools in the Gezira State namely: Um Dagarsi, Hantoub and Faris in the 2009/2010 growing season. All FFS participants were used, i.e. 30 FFS- participants from each school. Equal number of non-FFS participants (90 was used for comparison, by using the simple random sampling technique. The collected data were statistically analyzed and interpreted using percentage, frequency distribution and chi-square test. The results showed that the FFS schools were positively affected farmer's adoption of IPM options for tomato. It can be concluded that the FFS approach is very efficient in the transfer of farm technology for vegetable farmers through their participation in various activities of FFS schools. Thus, FFS approach must become national policy, share authority of extension organizations in control and execution of FFS activities with farmer unions for more effective participations of clientele in all activities of the schools and More efforts should be exerted in distribution of all inputs to farmers with reasonable prices through various agricultural centres.

  16. Expression of an engineered synthetic cry2Aa (D42/K63F/K64P) gene of Bacillus thuringiensis in marker free transgenic tobacco facilitated full-protection from cotton leaf worm (S. littoralis) at very low concentration.

    Science.gov (United States)

    Gayen, Srimonta; Mandal, Chandi Charan; Samanta, Milan Kumar; Dey, Avishek; Sen, Soumitra Kumar

    2016-04-01

    Emergence of resistant insects limits the sustainability of Bacillus thuringiensis (Bt) transgenic crop plants for insect management. Beside this, the presence of unwanted marker gene(s) in the transgenic crops is also a major environmental and health concern. Thus, development of marker free transgenic crop plants expressing a new class of toxin having a different mortality mechanism is necessary for resistance management. In a previous study, we generated an engineered Cry2Aa (D42/K63F/K64P) toxin which has a different mortality mechanism as compared to first generation Bt toxin Cry1A, and this engineered toxin was found to enhance 4.1-6.6-fold toxicity against major lepidopteran insect pests of crop plants. In the present study, we have tested the potency of this engineered synthetic Cry2Aa (D42/K63F/K64P) toxin as a candidate in the development of insect resistant transgenic tobacco plants. Simultaneously, we have eliminated the selectable marker gene from the Cry2Aa (D42/K63F/K64P) expressing tobacco plants by exploiting the Cre/lox mediated recombination methodology, and successfully developed marker free T2 transgenic tobacco plants expressing the engineered Cry2Aa toxin. Realtime and western blot analysis demonstrated the expression of engineered toxin gene in transgenic plants. Insect feeding assays revealed that the marker free T2 progeny of transgenic plants expressing Cry2Aa (D42/K63F/K64P) toxin showed 82-92 and 52-61 % mortality to cotton leaf worm (CLW) and cotton bollworm (CBW) respectively. Thus, this engineered Cry2Aa toxin could be useful for the generation of insect resistant transgenic Bt lines which will protect the crop damages caused by different insect pests such as CLW and CBW. PMID:26925624

  17. Insecticidal plant cyclotides and related cystine knot toxins.

    Science.gov (United States)

    Gruber, Christian W; Cemazar, Masa; Anderson, Marilyn A; Craik, David J

    2007-03-15

    Cyclotides are small disulphide-rich peptides found in plants from the violet (Violaceae), coffee (Rubiaceae) and cucurbit (Cucurbitaceae) families. They have the distinguishing structural features of a macrocyclic peptide backbone and a cystine knot made up of six conserved cysteine residues, which makes cyclotides exceptionally stable. Individual plants express a suite of cyclotides in a wide range of tissue types, including leaves, flowers, stems and roots and it is thought that their natural function in plants is as defence agents. This proposal is supported by their high expression levels in plants and their toxic and growth retardant activity in feeding trials against Helicoverpa spp. insect pests. This review describes the structures and activities of cyclotides with specific reference to their insecticidal activity and compares them with structurally similar cystine knot proteins from peas (Pisum sativum) and an amaranthus crop plant (Amaranthus hypocondriancus). More broadly, cystine knot proteins are common in a wide range of organisms from fungi to mammals, and it appears that this interesting structural motif has evolved independently in different organisms as a stable protein framework that has a variety of biological functions. PMID:17224167

  18. Insect damages on structural, morphologic and composition of Bt maize hybrids to silage

    Directory of Open Access Journals (Sweden)

    Geraldo Balieiro Neto

    2013-03-01

    Full Text Available It was aimed to evaluate the effect of insect damage on the morphologic and structural characteristics and chemical composition from maize hybrids DKB 390 and AG 8088 with the Cry1Ab trait versus its nonbiotech counterpart. The GMO did not receive insecticide application and the conventional hybrids received one deltametrina (2.8% application at 42 days. The damages caused bySpodoptera frugiperda and Helicoverpa zea in hybrids with Cry1Ab were smaller than its nonbiotech counterpart. After harvest, 95 days after seedling plants were separated in stalks, ears, leafs, dead leafs and floral pennant. The experimental design was randomized block in factorial arrangement 2 x 2. The height of plant and height of ear, percentage and amount of dead leafs from hybrids with the Cry1Ab were higher than its nonbiotech counterpart. There was higher nutrients transfer from stalks to grain filling and smaller rate stalks:ear on transgenic plant. The quality of the transgenic plants can be better when harvest earlier, by increasing no fiber carbohydrates, but when harvest latter, by increasing stalk percentage and stalk lignin content.

  19. A challenge for the seed mixture refuge strategy in Bt maize: impact of cross-pollination on an ear-feeding pest, corn earworm.

    Directory of Open Access Journals (Sweden)

    Fei Yang

    Full Text Available To counter the threat of insect resistance, Bacillus thuringiensis (Bt maize growers in the U.S. are required to plant structured non-Bt maize refuges. Concerns with refuge compliance led to the introduction of seed mixtures, also called RIB (refuge-in-the-bag, as an alternative approach for implementing refuge for Bt maize products in the U.S. Maize Belt. A major concern in RIB is cross-pollination of maize hybrids that can cause Bt proteins to be present in refuge maize kernels and negatively affect refuge insects. Here we show that a mixed planting of 5% nonBt and 95% Bt maize containing the SmartStax traits expressing Cry1A.105, Cry2Ab2 and Cry1F did not provide an effective refuge for an important above-ground ear-feeding pest, the corn earworm, Helicoverpa zea (Boddie. Cross-pollination in RIB caused a majority (>90% of refuge kernels to express ≥ one Bt protein. The contamination of Bt proteins in the refuge ears reduced neonate-to-adult survivorship of H. zea to only 4.6%, a reduction of 88.1% relative to larvae feeding on ears of pure non-Bt maize plantings. In addition, the limited survivors on refuge ears had lower pupal mass and took longer to develop to adults.

  20. Heliothine caterpillars differ in abundance of a gut lumen aminoacylase (L-ACY-1)-Suggesting a relationship between host preference and fatty acid amino acid conjugate metabolism.

    Science.gov (United States)

    Kuhns, Emily H; Seidl-Adams, Irmgard; Tumlinson, James H

    2012-03-01

    Fatty acid amino acid conjugates (FACs) in the oral secretions of Lepidopteran larvae are responsible for eliciting plant defense responses. FACs are present despite fitness costs which suggests that they are important for larval survival. In previous work, an aminoacylase (L-ACY-1) was identified as the enzyme responsible for hydrolysis of FACs within the larvae gut. This gene is present in three related Heliothine species: Heliothis virescens, Helicoverpa zea, and Heliothis subflexa. Transcript levels in gut tissues are predictive of protein abundance and enzyme activity in the frass. H. zea has the least amount of L-ACY-1 present in gut tissue and frass, while H. virescens has intermediate protein levels and H. subflexa has the highest amount of L-ACY-1 in gut tissue as well as in frass samples. These species differ in their host range and protein intake targets, and recently, it has been shown that FACs, the substrates of L-ACY-1, are involved in nitrogen metabolism. The correlation between protein intake and degree of host range specialization suggests that this aminoacylase may allow specialized larvae to obtain nitrogen requirements despite limitations in diet heterogeneity. PMID:22266147

  1. Synthesis and Insecticidal Activity of Spinosyns with C9-O-Benzyl Bioisosteres in Place of the 2',3',4'-Tri-O-methyl Rhamnose.

    Science.gov (United States)

    Oliver, M Paige; Crouse, Gary D; Demeter, David A; Sparks, Thomas C

    2015-06-17

    The spinosyns are fermentation-derived natural products active against a wide range of insect pests. They are structurally complex, consisting of two sugars (forosamine and rhamnose) coupled to a macrocyclic tetracycle. Removal of the rhamnose sugar results in a >100-fold reduction in insecticidal activity. C9-O-benzyl analogues of spinosyn D were synthesized to determine if the 2',3',4'-tri-O-methyl rhamnose moiety could be replaced with a simpler, synthetic bioisostere. Insecticidal activity was evaluated against larvae of Spodoptera exigua (beet armyworm) and Helicoverpa zea (corn earworm). Whereas most analogues were far less active than spinosyn D, a few of the C9-O-benzyl analogues, such as 4-CN, 4-Cl, 2-isopropyl, and 3,5-diOMe, were within 3-15 times the activity of spinosyn D for larvae of S. exigua and H. zea. Thus, although not yet quite as effective, synthetic bioisosteres can substitute for the naturally occurring 2',3',4'-tri-O-methyl rhamnose moiety. PMID:25993441

  2. Bats track and exploit changes in insect pest populations.

    Directory of Open Access Journals (Sweden)

    Gary F McCracken

    Full Text Available The role of bats or any generalist predator in suppressing prey populations depends on the predator's ability to track and exploit available prey. Using a qPCR fecal DNA assay, we document significant association between numbers of Brazilian free-tailed bats (Tadarida brasiliensis consuming corn earworm (CEW moths (Helicoverpa zea and seasonal fluctuations in CEW populations. This result is consistent with earlier research linking the bats' diet to patterns of migration, abundance, and crop infestation by important insect pests. Here we confirm opportunistic feeding on one of the world's most destructive insects and support model estimates of the bats' ecosystem services. Regression analysis of CEW consumption versus the moth's abundance at four insect trapping sites further indicates that bats track local abundance of CEW within the regional landscape. Estimates of CEW gene copies in the feces of bats are not associated with seasonal or local patterns of CEW abundance, and results of captive feeding experiments indicate that our qPCR assay does not provide a direct measure of numbers or biomass of prey consumed. Our results support growing evidence for the role of generalist predators, and bats specifically, as agents for biological control and speak to the value of conserving indigenous generalist predators.

  3. Bats track and exploit changes in insect pest populations.

    Science.gov (United States)

    McCracken, Gary F; Westbrook, John K; Brown, Veronica A; Eldridge, Melanie; Federico, Paula; Kunz, Thomas H

    2012-01-01

    The role of bats or any generalist predator in suppressing prey populations depends on the predator's ability to track and exploit available prey. Using a qPCR fecal DNA assay, we document significant association between numbers of Brazilian free-tailed bats (Tadarida brasiliensis) consuming corn earworm (CEW) moths (Helicoverpa zea) and seasonal fluctuations in CEW populations. This result is consistent with earlier research linking the bats' diet to patterns of migration, abundance, and crop infestation by important insect pests. Here we confirm opportunistic feeding on one of the world's most destructive insects and support model estimates of the bats' ecosystem services. Regression analysis of CEW consumption versus the moth's abundance at four insect trapping sites further indicates that bats track local abundance of CEW within the regional landscape. Estimates of CEW gene copies in the feces of bats are not associated with seasonal or local patterns of CEW abundance, and results of captive feeding experiments indicate that our qPCR assay does not provide a direct measure of numbers or biomass of prey consumed. Our results support growing evidence for the role of generalist predators, and bats specifically, as agents for biological control and speak to the value of conserving indigenous generalist predators. PMID:22952782

  4. Insect Larvae: A New Platform to Produce Commercial Recombinant Proteins.

    Science.gov (United States)

    Targovnik, Alexandra M; Arregui, Mariana B; Bracco, Lautaro F; Urtasun, Nicolas; Baieli, Maria F; Segura, Maria M; Simonella, Maria A; Fogar, Mariela; Wolman, Federico J; Cascone, Osvaldo; Miranda, Maria V

    2016-01-01

    In Biotechnology, the expression of recombinant proteins is a constantly growing field and different hosts are used for this purpose. Some valuable proteins cannot be produced using traditional systems. Insects from the order Lepidoptera infected with recombinant baculovirus have appeared as a good choice to express high levels of proteins, especially those with post-translational modifications. Lepidopteran insects, which are extensively distributed in the world, can be used as small protein factories, the new biofactories. Species like Bombyx mori (silkworm) have been analyzed in Asian countries to produce a great number of recombinant proteins for use in basic and applied science and industry. Many proteins expressed in this larva have been commercialized. Several recombinant proteins produced in silkworms have already been commercialized. On the other hand, species like Spodoptera frugiperda, Heliothis virescens, Rachiplusia nu, Helicoverpa zea and Trichoplusia ni are widely distributed in both the occidental world and Europe. The expression of recombinant proteins in larvae has the advantage of its low cost in comparison with insect cell cultures. A wide variety of recombinant proteins, including enzymes, hormones and vaccines, have been efficiently expressed with intact biological activity. The expression of pharmaceutically proteins, using insect larvae or cocoons, has become very attractive. This review describes the use of insect larvae as an alternative to produce commercial recombinant proteins. PMID:26956108

  5. Ensacamento de frutos do tomateiro visando ao controle de pragas e à redução de defensivos Paper bags for pest control and pesticide use reduction on tomato fruits

    Directory of Open Access Journals (Sweden)

    Alexandre Luis Jordão

    2002-06-01

    Full Text Available O ensacamento de frutos durante o seu desenvolvimento na planta, além do objetivo de controlar pragas pode reduzir resíduos de defensivos e manejar aspectos qualitativos. Com o objetivo de controle das pragas Neoleucinodes elegantalis, Helicoverpa zea e Tuta absoluta e redução de resíduos de inseticidas, pencas de tomates, foram ensacadas com papel-manteiga. Além do efeito do ensacamento, foram testados dois repelentes de insetos. Foram realizados cinco tratamentos. A eficiência do ensacamento e dos repelentes foi verificada por meio do número médio de lagartas encontradas por tratamento. A quantidade de resíduo de metamidofós encontrada nos frutos ensacados e nos frutos expostos diretamente à pulverização foi comparada ao limite máximo permitido. Verificou-se, também, a qualidade dos frutos produzidos pelo método do ensacamento através de análises físico-químicas dos tomates. Os custos do método do ensacamento foram comparados aos do método químico. O ensacamento, associado ou não aos repelentes, reduz o ataque das lagartas N. elegantalis e H. zea aos frutos. Para o controle de T. absoluta é necessária a integração com controle químico nas épocas de maior infestação. Os frutos não ensacados possuíam quantidade de metamidofós seis vezes superiores ao máximo tolerado e os frutos ensacados quantidade três vezes inferiores a este limite. O ensacamento das pencas de tomates não modificou os parâmetros físico-químicos dos frutos produzidos. O método do ensacamento requer maior investimento econômico, porém esse investimento atinge um mercado diferencial, com preços mais elevados.The development of fruits in paper bags aims at the control of pests, reduction of pesticide residues and the management of qualitative aspects. This work evaluates the efficacy of paper bags in combination with deodorant tablets and garlic clove on the control of the pest agents Neoleucinodes elegantalis, Helicoverpa zea and Tuta

  6. Cloning and sequence analysis of the cadherin-like protein gene in beet armyworm, Spodoptera exigua%甜菜夜蛾类钙粘蛋白基因全长cDNA的克隆及序列分析

    Institute of Scientific and Technical Information of China (English)

    王玲; 江幸福; 罗礼智; 胡毅; 张蕾

    2012-01-01

    昆虫中肠膜上的类钙粘蛋白(cadherin-like protein)是Bt毒素的一类重要受体,它与Bt毒素对昆虫的杀虫作用机制以及昆虫对Bt毒素的抗性等密切相关.本研究根据已报道的其它昆虫的类钙粘蛋白基因的保守区设计简并引物,应用RT-PCR和RACE技术克隆了迁飞性重要害虫甜菜夜蛾Spodoptera exigua (Hübner)类钙粘蛋白基因全长cDNA序列(命名为SeGAD,GenBank登录号为HQ647122),全长5 582 bp,编码1 739个氨基酸,推导的氨基酸序列包括1个信号肽、1个前蛋白区、11个钙粘蛋白重复、1个近膜区、1个跨膜区和1个胞质区.预测的分子量和等电点分别为196.447 ku和4.47.该蛋白与同科的大螟Sesamia inferens、蛀茎夜蛾.S.nonagrioides、烟芽夜蛾Heliothis virescens、烟夜蛾Helicoverpa assulta亲缘关系更近,氨基酸序列一致性分别为61.28%、60.34%、60.14%、60.08%.这些结果对于揭示转Bt基因作物对非靶标、迁飞性甜菜夜蛾的杀虫作用机制以及评价其潜在的对Bt毒素抗性机制等奠定了基础.%The cadherin-like proteins, located in the brush border membrane vesicles (BBMV) of the insect midgut, are major receptors of Bacillus thuringiensis inseetieidal crystal protein. The complete cDNA sequence of the cadherin-like protein gene in the beet armyworm, Spodoptera exigua (Hiibner) was amplified using RT-PCR and RACE techniques. The full cDNA sequence (named as SeCAD, GenBank accession no. HQ647122) is 5 582 bp in length, encoding 1 739 amino acid residues. The deduced amino acid sequence shows typical characteristics of the known insect cadherin proteins, including a signal peptide, a proprotein region, eleven cadherin repeats, a membrane-proximal region, a transmembrane region and a cytoplasmic region. The predicted molecular weight and isoelectric point are 196. 447 ku and 4. 47, respectively. The cadherin-like protein from S. exigua shows a close relationship to cadherin proteins from

  7. Eficácia do indoxacarb para o controle de pragas em hortaliças Efficacy of indoxacarb in the control of vegetable pests

    Directory of Open Access Journals (Sweden)

    Samuel Martinelli

    2003-09-01

    Full Text Available A eficiência do indoxacarb foi avaliada no controle dos lepidópteros-pragas em hortaliças: Plutella xylostella (Lepidoptera: Yponeumatidae, Trichoplusia ni (Lepidoptera: Noctuidae, Neoleucinodes elegantalis (Lepidoptera: Pyralidae e Helicoverpa zea (Lepidoptera: Noctuidae. Os experimentos foram conduzidos em três locais diferentes nas culturas do repolho e tomate. Os inseticidas utilizados foram indoxacarb (no tomate de 2,4 a 6,0 g i.a./100 L e no repolho de 18 a 42 g i.a./ha, esfenvalerate (apenas no tomate de 1,75 g i.a./100 L, metomil (no tomate na dose de 21,5 g i.a./100 L e no repolho a 172 g i.a./ha, deltametrina (apenas no repolho na dose de 6 g i.a./ha e triflumuron (apenas no tomate na dose de 15 g i.a./100 L. Adotou-se o delineamento estatístico em blocos ao acaso com quatro repetições em todos os experimentos. Todas as doses avaliadas do produto indoxacarb apresentaram excelente desempenho no controle de P. xylostella e T. ni. Assim, a menor dose avaliada (18 g i.a./ha pode ser recomendada para o controle dessas pragas. Todos os produtos avaliados alcançaram níveis de eficiência maiores que 80% no controle de H. zea na cultura do tomate. Indoxacarb foi tão eficiente quanto o produto padrão adotado (triflumuron. N. elegantalis foi eficientemente controlada pelos inseticidas avaliados após nove aplicações, sendo que indoxacarb pode ser recomendado na menor dose utilizada (2,4 g i.a./100 L.The efficacy of indoxacarb was evaluated for controlling lepidopterous pests on vegetables: Plutella xylostella (Lepidoptera: Yponeumatidae, Trichoplusia ni (Lepidoptera: Noctuidae, Neoleucinodes elegantalis (Lepidoptera: Pyralidae, Helicoverpa zea (Lepidoptera: Noctuidae. The experiments were carried out at three different sites on cabbage and tomato crops. The utilized insecticides were indoxacarb (for tomato from 2.4 to 6.0 g a.i./100 L and for cabbage from 18 to 42 g i.a./ha, esfenvalerate (only for tomato at 1.75 g a.i./100 L

  8. Pragas e inimigos naturais na soja e no milho cultivados em sistemas diversificados Pests and their natural enemies on soybean and corn grown in diversified systems

    Directory of Open Access Journals (Sweden)

    Francisco Jorge Cividanes

    2002-12-01

    Full Text Available A consorciação de culturas e o plantio direto podem influenciar a dinâmica populacional de insetos, aumentando ou diminuindo a densidade populacional de pragas e de inimigos naturais. Deste modo, avaliaram-se os efeitos de sistemas de plantio direto e da consorciação soja [Glycine max (L. Merrill] e milho (Zea mays L. sobre as populações de insetos-pragas e inimigos naturais. Os tratamentos constituíram um fatorial 3x2 (monocultura de soja, monocultura de milho, consorciação soja-milho em plantio direto e plantio convencional. Os insetos foram amostrados pelo método do pano, rede entomológica e procura visual. No milho, a ocorrência de insetos-pragas da parte aérea e insetos predadores não foi influenciada pelo manejo do solo. Lagartas de Helicoverpa zea ocorreram em maior número (5,1 no milho em consorciação. Na soja, adultos de Anticarsia gemmatalis e do predador Cycloneda sanguinea foram mais abundantes em plantio direto, respectivamente, 0,4 e 2,4 insetos. Observou-se maior número do sirfídeo Toxomerus sp. em plantio convencional (1,3. Nas condições de consorciação, verificou-se baixo número de Diabrotica gracilenta (11,5 na soja, enquanto que Maecolaspis sp. (5,0 e Megascelis sp. (17,0 e os predadores C. sanguinea (2,3, Doru sp. (0,8, Geocoris sp. (1,5 e Toxomerus sp. (1,4 ocorreram em alta densidade.Intercropping and no-tillage systems can affect the population dynamics of insects, increasing or decreasing the population density of pests and natural enemies. The objective of this study was to evaluate the effects of no-tillage and strip intercropping of soybean [Glycine max (L. Merrill] and corn (Zea mays L. on the abundance of insect pests and their natural enemies. Plots were arranged in a randomized complete block design in a 3 x 2 factorial experiment (soybean monoculture, corn monoculture, strip intercropping of soybean-corn under no-tillage and conventional tillage. Insects were sampled using sweep net

  9. Multifaceted effects of host plants on entomopathogenic nematodes.

    Science.gov (United States)

    Hazir, Selcuk; Shapiro-Ilan, David I; Hazir, Canan; Leite, Luis G; Cakmak, Ibrahim; Olson, Dawn

    2016-03-01

    The success of parasites can be impacted by multi-trophic interactions. Tritrophic interactions have been observed in parasite-herbivore-host plant systems. Here we investigate aspects of multi-trophic interactions in a system involving an entomopathogenic nematode (EPN), its insect host, and host plant. Novel issues investigated include the impact of tritrophic interactions on nematode foraging behavior, the ability of EPNs to overcome negative tritrophic effects through genetic selection, and interactions with a fourth trophic level (nematode predators). We tested infectivity of the nematode, Steinernema riobrave, to corn earworm larvae (Helicoverpa zea) in three host plants, tobacco, eggplant and tomato. Tobacco reduced nematode virulence and reproduction relative to tomato and eggplant. However, successive selection (5 passages) overcame the deficiency; selected nematodes no longer exhibited reductions in phenotypic traits. Despite the loss in virulence and reproduction nematodes, first passage S. riobrave was more attracted to frass from insects fed tobacco than insects fed on other host plants. Therefore, we hypothesized the reduced virulence and reproduction in S. riobrave infecting tobacco fed insects would be based on a self-medicating tradeoff, such as deterring predation. We tested this hypothesis by assessing predatory success of the mite Sancassania polyphyllae and the springtail Sinella curviseta on nematodes reared on tobacco-fed larvae versus those fed on greater wax moth, Galleria mellonella, tomato fed larvae, or eggplant fed larvae. No advantage was observed in nematodes derived from tobacco fed larvae. In conclusion, our results indicated that insect-host plant diet has an important effect on nematode foraging, infectivity and reproduction. However, negative host plant effects, might be overcome through directed selection. We propose that host plant species should be considered when designing biocontrol programs using EPNs. PMID:26896698

  10. Re-evaluation of the PBAN receptor (PBANR molecule: characterization of PBANR variants expressed in the pheromone glands of moths

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    Jae Min Lee

    2012-01-01

    Full Text Available Sex pheromone production in most moths is initiated following pheromone biosynthesis activating neuropeptide receptor (PBANR activation. PBANR was initially cloned from pheromone glands (PGs of Helicoverpa zea and Bombyx mori. The B. mori PBANR is characterized by a relatively long C-terminus that is essential for ligand-induced internalization, whereas the H. zea PBANR has a shorter C-terminus that lacks features present in the B. mori PBANR critical for internalization. Multiple PBANRs have been reported to be concurrently expressed in the larval CNS of Heliothis virescens. In the current study, we sought to examine the prevalence of multiple PBANRs in the PGs of three moths and to ascertain their potential functional relevance. Multiple PBANR variants (As, A, B, and C were cloned from the PGs of all species examined with PBANR-C the most highly expressed. Alternative splicing of the C-terminal coding sequence of the PBAN gene gives rise to the variants, which are distinguishable only by the length and composition of their respective C-terminal tails. Transient expression of fluorescent PBANR chimeras in insect cells revealed that PBANR-B and PBANR-C localized exclusively to the cell surface while PBANR-As and PBANR-A exhibited varying degrees of cytosolic localization. Similarly, only the PBANR-B and PBANR-C variants underwent ligand-induced internalization. Taken together, our results suggest that PBANR-C is the principal receptor molecule involved in PBAN signaling regardless of moth species. The high GC content of the C-terminal coding sequence in the B and C variants, which makes amplification using conventional polymerases difficult, likely accounts for previous preferential amplification of PBANR-A like receptors from other species.

  11. Manejo de lepidópteros-praga na cultura do milho com o evento Bt piramidado Cry1A.105 e Cry2Ab2

    Directory of Open Access Journals (Sweden)

    José Magid Waquil

    2013-12-01

    Full Text Available O objetivo deste trabalho foi avaliar a eficácia do evento piramidado (MON 89034, que expressa as proteínas Cry1A.105 e Cry2Ab2, no controle dos principais lepidópteros-praga da cultura do milho no Brasil, Spodoptera frugiperda, Helicoverpa spp. e Diatraea saccharalis. Os ensaios foram conduzidos em quatro regiões do país, com o híbrido DKB 390, submetido a seis tratamentos: híbrido com o evento piramidado, híbrido com o evento que expressa apenas a proteína Cry1A(b (MON 810 e híbrido convencional (não Bt, todos com e sem manejo integrado de S. frugiperda. Para o evento piramidado, não foi necessário o controle químico em nenhum dos locais avaliados. Diferenças significativas foram observadas entre os tratamentos quanto aos danos e à presença de lagartas. Em geral, essas variáveis foram mais baixas no híbrido com o evento piramidado e mais altas no híbrido convencional, sem controle químico. Sob alta infestação, o controle químico reduziu os danos causados por S. frugiperda e D. saccharalis, tanto no evento que expressa apenas uma proteína, como no híbrido convencional. Com base nos danos causados pelos insetos, o evento piramidado Cry1A.105 e Cry2Ab2 é eficiente no controle dos principais lepidópteros-pragas do milho no Brasil.

  12. Characterization of a single-nucleocapsid nucleopolyhedrovirus of Thysanoplusia orichalcea L. (Lepidoptera: Noctuidae) from Indonesia.

    Science.gov (United States)

    Cheng, X W; Carner, G R

    2000-05-01

    A single-nucleocapsid nucleopolyhedrovirus (NPV) isolated from Thysanoplusia orichalcea L. (Lepidoptera:Noctuidae) (ThorNPV) in Indonesia has tetrahedral occlusion bodies (OBs) with a width of 1. 22 microm (range = 0.803-1.931 microm). The length of the virion with an envelope averaged 0.29 and 0.23 microm without an envelope. ThorNPV was propagated in Pseudoplusia includens (Walker) and its authenticity was confirmed by sequence analysis of the polyhedrin gene of the ThorNPV produced in T. orichalcea and P. includens. Polyhedrin amino acid sequence analysis revealed that ThorNPV belongs to Group II of baculoviruses and is closely related to Trichoplusia ni single nucleocapsid NPV, sharing 97.6% sequence identity. Infectivity of ThorNPV against third instar P. includens was low, with a LD(50) value of 65,636 OBs/larva. Electron microscopy of infected tissues showed many polyhedra without virions embedded, which might explain the low virulence against P. includens. Differences in virion occlusion rates between individual cells in the same tissue suggested that the inoculum consisted of at least two variants that differed in the gene(s) controlling virion occlusion. In a host range test using the LD(50) value to P. includens against Spodoptera exigua, S. frugiperda, S. eridania, Anticarsia gemmatalis, Helicoverpa zea, Trichoplusia ni, and P. includens, P. includens was the only species infected. The virus infected primarily the fat body, tracheal epithelium, and hypodermis. The genomic size of the ThorNPV is 135 kb. PMID:10843835

  13. Biological and molecular characterization of a multicapsid nucleopolyhedrovirus from Thysanoplusia orichalcea (L.) (Lepidoptera: Noctuidae).

    Science.gov (United States)

    Cheng, Xiao-Wen; Carner, Gerald R; Lange, Martin; Jehle, Johannes A; Arif, Basil M

    2005-02-01

    A multicapsid nucleopolyhedrovirus (ThorMNPV) that was co-isolated with a single nucleocapid ThorSNPV from mixed infected larvae of Thysanoplusia orichalcea L. (Lepidoptea: Noctuidae) is characterized. Scanning electron microscopy of ThorMNPV showed a dodecahedral-shaped occlusion body (OB). The occluded virions contained one to as many as eight nucleocapsids/virion. Virion band profiles in gradient centrifugation were consistent in at least 10 rounds of centrifugation from different virion sample preparations. The ThorMNPV had high virulence to third instar Trichoplusia ni and Pseudoplusia includens with LD50 values of 17 and 242OBs per larva, respectively. However, ThorMNPV did not cause mortality in Spodoptera exigua, Spodoptera frugiperda, Spodoptera eridania, Anticarsia gemmatalis, and Helicoverpa zea. ThorMNPV replicates in cells of various tissues such as the fat body and tracheal epithelium cells. T. ni High 5 cells were permissive to ThorMNPV in terms of infection and viral DNA transfection, but SF-21 was less permissive and the infection process was slower. Production of OBs by ThorMNPV in the nuclei of SF-21 was not well pronounced. The genome size of ThorMNPV was estimated to be 136 kb. The polyhedrin gene open reading frame (ORF) was cloned and completely sequenced. The promoter sequence is identical to that of Autographa californica MNPV. Phylogenetic analyses using partial sequences of the polh, lef-8, and lef-9 revealed that ThorMNPV is a member of the Group I NPVs and is related but distinct from the AcMNPV/Rachiplusia ou NPV/Bombyx mori NPV cluster. PMID:15766929

  14. Comparison of field-collected ascovirus isolates by DNA hybridization, host range, and histopathology.

    Science.gov (United States)

    Hamm, J J; Styer, E L; Federici, B A

    1998-09-01

    Six field-collected ascovirus isolates obtained from five noctuid species in the continental United States were compared with respect to the general relatedness of their DNA, host range, and histopathology. Two isolates were from Spodoptera frugiperda, and the other four were from Autographa precationis, Heliothis virescens, Helicoverpa zea, and Trichoplusia ni. DNA-DNA hybridization studies showed that the six isolates belonged to three distinct viral species, with the isolates from S. frugiperda composing one species, those from A. precationis and H. virescens a second species, and those from H. zea and T. ni a third species. The host range and histopathology of each isolate was studied in eight noctuid species, S. frugiperda, Spodoptera ornithogalli, Spodoptera exigua, Spodoptera eridania, H. virescens, H. zea, A. precationis, and Feltia subterranea. Though some variation existed between the different isolates of each viral species, distinct patterns were apparent for each. The viral species from S. frugiperda had a host range that was limited primarily to Spodoptera species and both isolates of this virus only replicated and caused significant pathology in the fat body, whereas the viral species from A. precationis and H. virescens had a much broader host range that included most of the species tested, but also had a tissue tropism primarily restricted to the fat body. The viral species from T. ni and H. zea readily infected all the hosts tested, where the principal site of replication and significant pathology was the epidermis. In many test hosts, however, this viral species also replicated and caused significant pathology in the tracheal epithelium and to a lesser extent in the fat body. Aside from contributing to knowledge of ascovirus biology, these studies indicate that DNA hybridization profiles combined with studies of host range and tissue tropism can be used as characters for defining ascovirus species. PMID:9709014

  15. Impact of recombinant baculovirus field applications on a nontarget heliothine parasitoid, Microplitis croceipes (Hymenoptera: Braconidae).

    Science.gov (United States)

    Smith, C R; Heinz, K M; Sansone, C G; Flexner, J L

    2000-08-01

    The kill times of two viruses infectious to the heliothine pest complex indigenous to Texas cotton have been significantly reduced by expressing a scorpion toxin gene. Autographa californica nucleopolyhedrovirus (NPV) and Helicoverpa zea NPV express the toxin only in permissive lepidopteran hosts. The toxin, however, could indirectly harm members of upper trophic levels that feed upon and parasitize infected larvae producing the toxin. In this study, the effects of recombinant and wild-type viruses on Microplitis croceipes (Cresson) were studied in cotton using Heliothis virescens (F.) (Lepidoptera: Noctuidae) as hosts. Two recombinant viruses, their two wild-type progenitor viruses, and untreated cotton served as the five treatments of study. Larvae were previously parasitized 2 and 4 d before being confined for 72 h to cotton terminals treated with field rates of virus or left untreated. The sexes of adult M. croceipes that emerged from the recovered H. virescens larvae were determined and their head capsule widths were measured. Polymerase chain reaction (PCR) searched their extracts for virus DNA. There were no differences in percentage emergence and sex ratios of parasitoids among recombinant, wild-type, and control treatments. Significantly more wasps emerged from the 4-d cohort, but these wasps were significantly smaller than wasps from the 2-d cohort regardless of treatment. Finally, PCR found only 15-25% of the recovered H. virescens larvae and none of the emergent M. croceipes had detectable levels of viral DNA. Recombinant and wild-type viruses had a similar, minimal impact on emergent wasps, and the probability of virus dispersal via parasitoids is low in the system tested. PMID:10985020

  16. Maize death acids, 9-lipoxygenase-derived cyclopente(a)nones, display activity as cytotoxic phytoalexins and transcriptional mediators.

    Science.gov (United States)

    Christensen, Shawn A; Huffaker, Alisa; Kaplan, Fatma; Sims, James; Ziemann, Sebastian; Doehlemann, Gunther; Ji, Lexiang; Schmitz, Robert J; Kolomiets, Michael V; Alborn, Hans T; Mori, Naoki; Jander, Georg; Ni, Xinzhi; Sartor, Ryan C; Byers, Sara; Abdo, Zaid; Schmelz, Eric A

    2015-09-01

    Plant damage promotes the interaction of lipoxygenases (LOXs) with fatty acids yielding 9-hydroperoxides, 13-hydroperoxides, and complex arrays of oxylipins. The action of 13-LOX on linolenic acid enables production of 12-oxo-phytodienoic acid (12-OPDA) and its downstream products, termed "jasmonates." As signals, jasmonates have related yet distinct roles in the regulation of plant resistance against insect and pathogen attack. A similar pathway involving 9-LOX activity on linolenic and linoleic acid leads to the 12-OPDA positional isomer, 10-oxo-11-phytodienoic acid (10-OPDA) and 10-oxo-11-phytoenoic acid (10-OPEA), respectively; however, physiological roles for 9-LOX cyclopentenones have remained unclear. In developing maize (Zea mays) leaves, southern leaf blight (Cochliobolus heterostrophus) infection results in dying necrotic tissue and the localized accumulation of 10-OPEA, 10-OPDA, and a series of related 14- and 12-carbon metabolites, collectively termed "death acids." 10-OPEA accumulation becomes wound inducible within fungal-infected tissues and at physiologically relevant concentrations acts as a phytoalexin by suppressing the growth of fungi and herbivores including Aspergillus flavus, Fusarium verticillioides, and Helicoverpa zea. Unlike previously established maize phytoalexins, 10-OPEA and 10-OPDA display significant phytotoxicity. Both 12-OPDA and 10-OPEA promote the transcription of defense genes encoding glutathione S transferases, cytochrome P450s, and pathogenesis-related proteins. In contrast, 10-OPEA only weakly promotes the accumulation of multiple protease inhibitor transcripts. Consistent with a role in dying tissue, 10-OPEA application promotes cysteine protease activation and cell death, which is inhibited by overexpression of the cysteine protease inhibitor maize cystatin-9. Unlike jasmonates, functions for 10-OPEA and associated death acids are consistent with specialized roles in local defense reactions. PMID:26305953

  17. Maize death acids, 9-lipoxygenase–derived cyclopente(a)nones, display activity as cytotoxic phytoalexins and transcriptional mediators

    Science.gov (United States)

    Christensen, Shawn A.; Huffaker, Alisa; Kaplan, Fatma; Sims, James; Ziemann, Sebastian; Doehlemann, Gunther; Ji, Lexiang; Schmitz, Robert J.; Kolomiets, Michael V.; Alborn, Hans T.; Mori, Naoki; Jander, Georg; Ni, Xinzhi; Sartor, Ryan C.; Byers, Sara; Abdo, Zaid; Schmelz, Eric A.

    2015-01-01

    Plant damage promotes the interaction of lipoxygenases (LOXs) with fatty acids yielding 9-hydroperoxides, 13-hydroperoxides, and complex arrays of oxylipins. The action of 13-LOX on linolenic acid enables production of 12-oxo-phytodienoic acid (12-OPDA) and its downstream products, termed “jasmonates.” As signals, jasmonates have related yet distinct roles in the regulation of plant resistance against insect and pathogen attack. A similar pathway involving 9-LOX activity on linolenic and linoleic acid leads to the 12-OPDA positional isomer, 10-oxo-11-phytodienoic acid (10-OPDA) and 10-oxo-11-phytoenoic acid (10-OPEA), respectively; however, physiological roles for 9-LOX cyclopentenones have remained unclear. In developing maize (Zea mays) leaves, southern leaf blight (Cochliobolus heterostrophus) infection results in dying necrotic tissue and the localized accumulation of 10-OPEA, 10-OPDA, and a series of related 14- and 12-carbon metabolites, collectively termed “death acids.” 10-OPEA accumulation becomes wound inducible within fungal-infected tissues and at physiologically relevant concentrations acts as a phytoalexin by suppressing the growth of fungi and herbivores including Aspergillus flavus, Fusarium verticillioides, and Helicoverpa zea. Unlike previously established maize phytoalexins, 10-OPEA and 10-OPDA display significant phytotoxicity. Both 12-OPDA and 10-OPEA promote the transcription of defense genes encoding glutathione S transferases, cytochrome P450s, and pathogenesis-related proteins. In contrast, 10-OPEA only weakly promotes the accumulation of multiple protease inhibitor transcripts. Consistent with a role in dying tissue, 10-OPEA application promotes cysteine protease activation and cell death, which is inhibited by overexpression of the cysteine protease inhibitor maize cystatin-9. Unlike jasmonates, functions for 10-OPEA and associated death acids are consistent with specialized roles in local defense reactions. PMID:26305953

  18. Efficacy of Silk Channel Injections with Insecticides for Management of Lepidoptera Pests of Sweet Corn.

    Science.gov (United States)

    Sparks, A N; Gadal, L; Ni, X

    2015-08-01

    The primary Lepidoptera pests of sweet corn (Zea mays L. convar. saccharata) in Georgia are the corn earworm, Helicoverpa zea (Boddie), and the fall armyworm, Spodoptera frugiperda (J. E. Smith). Management of these pests typically requires multiple insecticide applications from first silking until harvest, with commercial growers frequently spraying daily. This level of insecticide use presents problems for small growers, particularly for "pick-your-own" operations. Injection of oil into the corn ear silk channel 5-8 days after silking initiation has been used to suppress damage by these insects. Initial work with this technique in Georgia provided poor results. Subsequently, a series of experiments was conducted to evaluate the efficacy of silk channel injections as an application methodology for insecticides. A single application of synthetic insecticide, at greatly reduced per acre rates compared with common foliar applications, provided excellent control of Lepidoptera insects attacking the ear tip and suppressed damage by sap beetles (Nitidulidae). While this methodology is labor-intensive, it requires a single application of insecticide at reduced rates applied ∼2 wk prior to harvest, compared with potential daily applications at full rates up to the day of harvest with foliar insecticide applications. This methodology is not likely to eliminate the need for foliar applications because of other insect pests which do not enter through the silk channel or are not affected by the specific selective insecticide used in the silk channel injection, but would greatly reduce the number of applications required. This methodology may prove particularly useful for small acreage growers. PMID:26470329

  19. Intraguild Competition of Three Noctuid Maize Pests.

    Science.gov (United States)

    Bentivenha, J P F; Baldin, E L L; Hunt, T E; Paula-Moraes, S V; Blankenship, E E

    2016-08-01

    The western bean cutworm Striacosta albicosta (Smith), the fall armyworm Spodoptera frugiperda (J. E. Smith), and the corn earworm Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) are among the major lepidopteran pests of maize in the United States, belonging to the same guild and injuring the reproductive tissues of this crop. Here, intraguild competition of these lepidopterans on non-Bt maize was evaluated through survival analysis of each species under laboratory and field conditions. Competition scenarios were carried out in arenas containing maize silk or ear tissue, using larvae on different stadium of development. Fitness cost competition studies were conducted to examine the influence of intraguild competition and cannibalism and predation rates on larval development. The survival of S. albicosta competing with the other species was significantly lower than in intraspecific competition, even when the larvae were more developed than the competitor. For S. frugiperda, survival remained high in the different competition scenarios, except when competing in a smaller stadium with H. zea Larvae of H. zea had a high rate of cannibalism, higher survival when competing against S. albicosta than S. frugiperda, and reduced survival when the H. zea larvae were at the same development stadium or smaller than the competitors. Based on fitness cost results, the absence of a competitor for the feeding source may confer an advantage to the larval development of S. frugiperda and H. zea Our data suggest that S. frugiperda has a competitive advantage against the other species, while S. albicosta has the disadvantage in the intraguild competition on non-Bt maize. PMID:27330146

  20. Survival of Corn Earworm (Lepidoptera: Noctuidae) on Bt Maize and Cross-Pollinated Refuge Ears From Seed Blends.

    Science.gov (United States)

    Crespo, André Luiz Barreto; Alves, Analiza Piovesan; Wang, Yiwei; Hong, Bonnie; Flexner, John Lindsey; Catchot, Angus; Buntin, David; Cook, Donald

    2016-02-01

    Refuge is mandated in the United States where genetically modified maize (Zea mays L.) expressing insecticidal proteins derived from Bacillus thuringiensis Berliner (Bt) are cultivated. Currently, refuge is deployed in different ways including blocks, field strips, or seed blends containing Bt and non-Bt maize. Seed blends provide practical advantages for refuge implementation. However, concerns related to the movement of insect larvae, potential differential survival of heterozygous resistant larvae, reduction in insect production, and cross-pollination of ears resulting in sublethal selection, have delayed seed blend use for Lepidoptera in the southern United States, where maize plantings are used as refuge for Helicoverpa zea (Boddie). In this study, we evaluated the relative survival of H. zea in Bt events and in seed blends compared with pure stand refuge and the relative survival of H. zea on the individual components of the pyramid 1507xMON810xMIR162. The results showed variation on the production of H. zea in refuge plants from seed blends compared with pure stand refuge plants. The relative survival of H. zea on the events 1507, MON810, MIR162, and 1507xMON810xMIR162 ranked similarly across the three locations tested. These results can be used in computer simulation modeling efforts to evaluate the feasibility of seed blends as a refuge deployment strategy with the pyramid 1507xMON810xMIR162. Because the reduction on survival of H. zea due to blending was variable, a sensitivity analysis that includes all possible scenarios of reduction in survival should be considered. PMID:26357846

  1. Effects of Interplanting Flowering Plants on the Biological Control of Corn Earworm (Lepidoptera: Noctuidae) and Thrips (Thysanoptera: Thripidae) in Sweet Corn.

    Science.gov (United States)

    Manandhar, Roshan; Wright, Mark G

    2016-02-01

    Natural enemy exploitation of food resources and alternative hosts in noncrop vegetation has been shown to be an effective means of enhancing natural enemy populations in diversified agro-ecosystem. Field trials were conducted in Hawaii to examine effects of interplanting flowering plants on 1) parasitism of corn earworm, Helicoverpa zea (Boddie) eggs by Trichogramma spp., and 2) abundance of Orius spp. in relation to prey (H. zea eggs and thrips [primarily, Frankliniella occidentalis (Pergande) and Frankliniella williamsi Hood]). Sweet corn (maize), Zea mays L., was interplanted with three flowering plants, buckwheat, Fagopyrum esculentum Moench, cowpea, Vigna unguiculata (L.), and sunn hemp, Crotolaria juncea L., at 2:1 and 4:1 (corn: flowering plant) ratios in 2009 and 2010, respectively. In 2009, the abundance of Orius spp. was significantly greater in the buckwheat-interplanted treatment compared to the monocrop control at similar levels of prey availability, indicating buckwheat flowers might have provided both prey and nectar resources. In 2010, cowpea and sunn hemp flowering plants provided a source of an alternate host insect's eggs for Trichogramma spp. oviposition, resulting in significantly higher parasitism of H. zea eggs in the cowpea- and sunn hemp-interplanted treatments compared to the monocrop control. Despite of differences in pest and natural enemy interactions in two field trials, our findings suggested that provisioning of an alternate host insect's eggs through flowering plants is an effective means for enhancing Trichogramma spp. and provisioning of both nectar and prey resources through flowering plants is important for enhancing predation by Orius spp. PMID:26500338

  2. Competitive release and outbreaks of non-target pests associated with transgenic Bt cotton.

    Science.gov (United States)

    Zeilinger, Adam R; Olson, Dawn M; Andow, David A

    2016-06-01

    The adoption of transgenic Bt cotton has, in some cases, led to environmental and economic benefits through reduced insecticide use. However, the distribution of these benefits and associated risks among cotton growers and cotton-growing regions has been uneven due in part to outbreaks of non-target or secondary pests, thereby requiring the continued use of synthetic insecticides. In the southeastern USA, Bt cotton adoption has resulted in increased abundance of and damage from stink bug pests, Euschistus servus and Nezara viridula (Heteroptera: Pentatomidae). While the impact of increased stink bug abundance has been well-documented, the causes have remained unclear. We hypothesize that release from competition with Bt-susceptible target pests may drive stink bug outbreaks in Bt cotton. We first examined the evidence for competitive release of stink bugs through meta-analysis of previous studies. We then experimentally tested if herbivory by Bt-susceptible Helicoverpa zea increases stink bug leaving rates and deters oviposition on non-Bt cotton. Consistent with previous studies, we found differences in leaving rates only for E servus, but we found that both species strongly avoided ovipositing on H. zea-damaged plants. Considering all available evidence, competitive release of stink bug populations in Bt cotton likely contributes to outbreaks, though the relative importance of competitive release remains an open question. Ecological risk assessments of Bt crops and other transgenic insecticidal crops would benefit from greater understanding of the ecological mechanisms underlying non-target pest outbreaks and greater attention to indirect ecological effects more broadly. PMID:27509747

  3. A comparison of Bt transgene, hybrid background, water stress, and insect stress effects on corn leaf and ear injury and subsequent yield.

    Science.gov (United States)

    Brewer, Michael J; Odvody, Gary N; Anderson, Darwin J; Remmers, Jeffrey C

    2014-06-01

    Experimentally manipulated water and insect stresses were applied to field-grown corn with different Bacillus thuringiensis (Bt) transgenes and no Bt transgenes, and different nontransgenic hybrid backgrounds (2011 and 2012, Corpus Christi, TX). Differences in leaf injury, ear injury, and yield were detected among experimental factors and their interactions. Under high and low water stress, injury from noctuid larvae (Lepidoptera: Noctuidae) on leaves during vegetative growth (primarily from fall armyworm, Spodoptera frugiperda J.E. Smith) and on developing ears (primarily from corn earworm, Helicoverpa zea [Boddie]) was lowest on more recent releases of Bt hybrids (newer Bt hybrids) expressing Cry1A.105+Cry2Ab2 and Cry 3Bb1, compared with earlier Bt hybrids (older Bt hybrids) expressing Cry1Ab and Cry3Bb1 and non-Bt hybrids. High water stress led to increased leaf injury under substantial fall armyworm feeding pressure in 2011 (as high as 8.7 on a 1-9 scale of increasing injury). In contrast, ear injury by corn earworm (as high as 20 cm(2) of surface area of injury) was greater in low water stress conditions. Six hybrid backgrounds did not influence leaf injury, while ear injury differences across hybrid backgrounds were detected for non-Bt and older Bt hybrid versions. While newer Bt hybrids expressing Cry1A.105+Cry2Ab2 and Cry 3Bb1 had consistent low leaf injury and high yield and low but less consistent ear injury across six hybrid backgrounds, water stress was a key factor that influenced yield. Bt transgenes played a more variable and lesser role when interacting with water stress to affect yield. These results exemplify the interplay of water and insect stress with plant injury and yield, their interactions with Bt transgenes, and the importance of these interactions in considering strategies for Bt transgene use where water stress is common. PMID:24780114

  4. Pest-managing activities of plant extracts and anthraquinones from Cassia nigricans from Burkina Faso.

    Science.gov (United States)

    Georges, Kambou; Jayaprakasam, Bolleddula; Dalavoy, Sanjeev S; Nair, Muraleedharan G

    2008-04-01

    Insecticidal activity of eight plants collected from Burkina Faso was studied using mosquito (Ochlerotatus triseriatus), Helicoverpa zea and Heliothis virescens larvae and adult white fly (Bemisia tabaci). The n-hexane, ethyl acetate and methanol extracts of Pseudocedrela kotschyi, Strophantus hispidus, Securidaca longepedunculata, Sapium grahamii, Swartzia madagascariensis, Cassia nigricans, Jatropha curcas and Datura innoxia were used in this study. Extracts were tested at 250 microg/mL concentration. All three extracts of C. nigricans, J. curcas (skin and seeds) and D. innoxia exhibited 100% mortality on fourth instar mosquito (O. triseriatus) larvae. In addition, the n-hexane and ethyl acetate extracts of S. hispidus, S. longepedunculata, S. grahamii showed 100% mortality. The ethyl acetate extract of S. madagascariensis was the most active on adult white fly and exhibited 80% mortality. Extracts of all other plants exhibited 30-50% mortality on B. tabaci. In the antifeedant assays against H. zea and H. virescens, the MeOH extracts of C. nigricans, S. madagascarensis and S. hispidus were more effective against H. zea as indicated by 74% larval weight reduction as compared to the control. Since C. nigricans is commonly used in West Africa to protect grain storage from insects, we have characterized the insecticidal components present in its extract. Bioassay directed isolation of C. nigricans leaf extract yielded anthraquinones emodin, citreorosein, and emodic acid and a flavonoid, luteolin. Emodin, the most abundant and active anthraquinone in C. nigricans showed approximately 85% mortality on mosquito larvae Anopheles gambiaea and adult B. tabaci at 50 and 25 microg/mL, respectively, in 24 h. These results suggest that the extract of C. nigricans has the potential to be used as an organic approach to manage some of the agricultural pests. PMID:17478091

  5. Biotechnology for Sustainable Crop Production and Protection: Challenges and Opportunities

    Directory of Open Access Journals (Sweden)

    T. M. Manjunath

    2010-07-01

    Full Text Available In 2009, transgenic crops were grown on 134 million hectares in 25 countries, including India, in six continents by about 14million farmers, marking an 80-fold increase in the area since their first commercialization on 1.7 m ha in the USA and fiveother countries in 1996. The dominant transgenic traits were herbicide tolerance and insect resistance, deployed either alone orboth stacked in the same plant. A recent survey of the global impact of biotech crops estimated that in 2008 alone, the totalcrop production gain globally for the 4 principal biotech crops - maize, soybean, cotton and canola - was 29.6 million metrictons while the net economic benefit to the biotech farmers was US$ 9.2 billion. The cumulative benefits for the period 1996-2008 were yield gains of 167 million tons and economic returns of US$ 51.9 billion. In India, the area planted with Bt-cottonincreased significantly from year to year since its introduction in 2002 and reached 8.4 million hectares in 2009. The overallbenefits from Bt-cotton included an yield increase of up to 63% due to effective control of bollworms, pesticide reduction by50%, net profit to farmers up to Rs.10,000/hectare and turned India from an importer to a major exporter of cotton. Theseindicate that biotechnology has made significant contributions to higher productivity, lower costs of production and increasedeconomic benefits and that it has enormous potential for the future with new traits, events and crops. Over 60 countries,including India, are engaged in research on about 55 crop species to incorporate transgenes to bestow various traits such asresistance to pests, diseases or herbicides; tolerance to environmental stresses like drought, cold or salinity; enhanced cropyields, nutrition or shelf-life, etc. However, unreasonable opposition to biotechnology and undue delays in regulatoryapprovals are some of the major challenges that need to be addressed so as to make full use of this technology which

  6. Nutrigenomics in Arma chinensis: transcriptome analysis of Arma chinensis fed on artificial diet and Chinese oak silk moth Antheraea pernyi pupae.

    Directory of Open Access Journals (Sweden)

    Deyu Zou

    Full Text Available BACKGROUND: The insect predator, Arma chinensis, is capable of effectively controlling many pests, such as Colorado potato beetle, cotton bollworm, and mirid bugs. Our previous study demonstrated several life history parameters were diminished for A. chinensis reared on an artificial diet compared to a natural food source like the Chinese oak silk moth pupae. The molecular mechanisms underlying the nutritive impact of the artificial diet on A. chinensis health are unclear. So we utilized transcriptome information to better understand the impact of the artificial diet on A. chinensis at the molecular level. METHODOLOGY/PRINCIPAL FINDINGS: Illumina HiSeq2000 was used to sequence 4.79 and 4.70 Gb of the transcriptome from pupae-fed and artificial diet-fed A. chinensis libraries, respectively, and a de novo transcriptome assembly was performed (Trinity short read assembler. This resulted in 112,029 and 98,724 contigs, clustered into 54,083 and 54,169 unigenes for pupae-fed and diet-fed A. chinensis, respectively. Unigenes from each sample's assembly underwent sequence splicing and redundancy removal to acquire non-redundant unigenes. We obtained 55,189 unigenes of A. chinensis, including 12,046 distinct clusters and 43,143 distinct singletons. Unigene sequences were aligned by BLASTx to nr, Swiss-Prot, KEGG and COG (E-value <10(-5, and further aligned by BLASTn to nt (E-value <10(-5, retrieving proteins of highest sequence similarity with the given unigenes along with their protein functional annotations. Totally, 22,964, 7,898, 18,069, 15,416, 8,066 and 5,341 unigenes were annotated in nr, nt, Swiss-Prot, KEGG, COG and GO, respectively. We compared gene expression variations and found thousands of genes were differentially expressed between pupae-fed and diet-fed A. chinensis. CONCLUSIONS/SIGNIFICANCE: Our study provides abundant genomic data and offers comprehensive sequence information for studying A. chinensis. Additionally, the physiological

  7. History of the sterile insect technique

    International Nuclear Information System (INIS)

    During the 1930s and 1940s the idea of releasing insects of pest species to introduce sterility (sterile insect technique or SIT) into wild populations, and thus control them, was independently conceived in three extremely diverse intellectual environments. The key researchers were A. S. Serebrovskii at Moscow State University, F. L. Vanderplank at a tsetse field research station in rural Tanganyika (now Tanzania), and E. F. Knipling of the United States Department of Agriculture. Serebrovskii's work on chromosomal translocations for pest population suppression could not succeed in the catastrophic conditions in the USSR during World War II, after which he died. Vanderplank used hybrid sterility to suppress a tsetse population in a large field experiment, but lacked the resources to develop this method further. Knipling and his team exploited H. J. Muller's discovery that ionizing radiation can induce dominant lethal mutations, and after World War II this approach was applied on an area-wide basis to eradicate the New World screwworm Cochliomyia hominivorax (Coquerel) in the USA, Mexico, and Central America. Since then very effective programmes integrating the SIT have been mounted against tropical fruit flies, some species of tsetse flies Glossina spp., the pink bollworm Pectinophora gossypiella (Saunders), and the codling moth Cydia pomonella (L.). In non-isolated onion fields in the Netherlands, the onion maggot Delia antiqua (Meigen) has since 1981 been suppressed by the SIT. In the 1970s there was much research conducted on mosquito SIT, which then went into 'eclipse', but now appears to be reviving. Development of the SIT for use against the boll weevil Anthonomus grandis grandis Boheman and the gypsy moth Lymantria dispar (L.) has ended, but it is in progress for two sweetpotato weevil species, Cylas formicarius (F.) and Euscepes postfasciatus (Fairmaire), the false codling moth Cryptophlebia leucotreta (Meyrick), the carob moth Ectomyelois ceratoniae

  8. Insect and pest control newsletter. No. 59

    International Nuclear Information System (INIS)

    Analysis and implications of the meeting on 'Status and Risk Assessment of the Use of Transgenic Arthropods in Plant Protection' that took place at FAO headquarters in Rome in April 2002 are discussed in this issue. This very timely meeting was jointly organized by FAO/IAEA and the International Plant Protection Convention (IPPC) secretariat and chaired by Alan Robinson. Experts in both the technology of transformation as well as regulatory procedures and risk assessment participated. Transgenic technology is now almost routinely used in many insect species and currently arthropod transgenesis is mainly concerned with the stability and fitness of these strains. These topics will probably be the main issues to be addressed in a new Coordinated Research Project (CRP), is being proposed for initiation in 2003. From the regulatory point of view, risk assessment is mainly focused on horizontal transmission and the impact on biodiversity, and these concerns will need to be addressed when moving on a case-by-case basis, from the laboratory through field cages to open field release. Regulatory approval in the USA for the first field cage release of genetically transformed arthropod (pink bollworm) provided a timely background for the meeting. The proceedings of the meeting should provide the basis for the rational development of the use of transgenic arthropods. Following resolutions by IAEA and also FAO governing bodies in support of the PATTEC initiative, that was launched by African Heads of State (reported in previous issues), several press releases and media reports have been issued on this topic. Of particular importance is a press release issued jointly by FAO, IAEA, OAU and WHO (text given inside this newsletter) at the beginning of the World Food Summit - Five Years Later, recently held in Rome in June 2002. This joint press release acknowledges the magnitude of the tsetse problem in tsetse-infested areas of sub-Saharan Africa, where about 85 percent of the poor

  9. Soil microflora and enzyme activities in rhizosphere of Transgenic Bt cotton hybrid under different intercropping systems and plant protection schedules

    Science.gov (United States)

    Biradar, D. P.; Alagawadi, A. R.; Basavanneppa, M. A.; Udikeri, S. S.

    2012-04-01

    Field experiments were conducted over three rainy seasons of 2005-06 to 2007-08 on a Vertisol at Dharwad, Karnataka, India to study the effect of intercropping and plant protection schedules on productivity, soil microflora and enzyme activities in the rhizosphere of transgenic Bt cotton hybrid. The experiment consisted of four intercropping systems namely, Bt cotton + okra, Bt cotton + chilli, Bt cotton + onion + chilli and Bt cotton + redgram with four plant protection schedules (zero protection, protection for Bt cotton, protection for intercrop and protection for both crops). Observations on microbial populations and enzyme activities were recorded at 45, 90, 135 and 185 (at harvest) days after sowing (DAS). Averaged over years, Bt cotton + okra intercropping had significantly higher total productivity than Bt cotton + chilli and Bt cotton + redgram intercropping system and was similar to Bt cotton + chilli + onion intercropping system. With respect to plant protection schedules for bollworms, protection for both cotton and intercrops recorded significantly higher yield than the rest of the treatments. Population of total bacteria, fungi, actinomycetes, P-solubilizers, free-living N2 fixers as well as urease, phosphatase and dehydrogenase enzyme activities increased up to 135 days of crop growth followed by a decline. Among the intercropping systems, Bt cotton + chilli recorded significantly higher population of microorganisms and enzyme activities than other cropping systems. While Bt cotton with okra as intercrop recorded the least population of total bacteria and free-living N2 fixers as well as urease activity. Intercropping with redgram resulted in the least population of actinomycetes, fungi and P-solubilizers, whereas Bt cotton with chilli and onion recorded least activities of dehydrogenase and phosphatase. Among the plant protection schedules, zero protection recorded maximum population of microorganisms and enzyme activities. This was followed by the

  10. Preliminary Note on the Use of Radioisotopes to Study Some Cotton-Plant Pests in Africa

    International Nuclear Information System (INIS)

    The larva of Diparopsis watersi Roth is harmful to the cotton-plant, destroying the flower and the boll. This noctuid, which is practically monophagous, passes the quiescent season either in the ground in the chrysalid-at-diapause form (from 10 November onwards) or in continuing generation (polyvoltine) on plants left standing. Laboratory studies have served to elucidate the main mechanisms initiating and terminating diapause. In the field, the rapid multiplication of the pest during the crop period is due both to univoltine individuals hatching out towards April-May and to non-diapause generations. The respective roles played by these two different sources need to be determined fairly accurately in order to decide which methods of control are appropriate: uprooting of the cotton-plant, destruction of the pupae at diapause in the ground, bringing the crop forward, etc. Radioisotope labelling of larvae coming to maturity at critical periods should make it possible to tackle this problem at the practical level. Preliminary experiments for determining simple labelling techniques have been carried out at Tikem (Republic of Chad). In a first trial, P32 in atomized solution was applied direct to the foliage of young cottonplants. Despite the effects of rain, absorption by the plant reached about 10% in a few hours. Radioactivity is not retained by various phyllophagous larvae (Sylepta derogata, Prodenia litura), but those feeding on the fruit-bearing parts of the plant (Heliothis armigera, Earias insulana, Diparopsis watersi, etc.) are easily detectable three months after the application. In a second trial, P32 and S35 were applied to old cotton-plants immediately before the natural time for Diparopsis to enter diapause. The overall findings give hope of being able to distinguish without too much difficulty, among chrysalid populations taken from the ground, those which fed on the cotton-plant before labelling, and hence which underwent a diapause. A control experiment

  11. Use of natural enemies and biorational pest control of corne

    Directory of Open Access Journals (Sweden)

    Cipriano García Gutiérrez

    2012-09-01

    Full Text Available A general analysis of the potential use of natural enemies and biorational insecticides for control of main pests of corn in thestate of Sinaloa is presented. A discuss on their composition, dosage, toxicity and type of effect on beneficial organisms(natural enemies and pollinators is too included. The work revealed that is possible implement the use of these natural enemies and products for the control of neonate larvae of Spodoptera frugiperda fall armyworm (J. E Smith with Nomuraea rileyi (Farlow (Samson; against thrips Frankliniella occidentalis (Pergande using the nematodes Steinernema riobravis (Cabanillas and Poinar, S. feltiae (Filipjev and Heterorhabditis bacteriophora (Poinar at doses of 10,000 IJ (4x10 ~ IJ/m; against the corn silk fly Euxesta stigmatias (Loew encouraging the natural parasitism of Spalangia sp., while for the cutworm Agrotis ipsilon (Hufnagel can be with spinosad (soluble concentrate at doses of 0.123 kg a. i, and to the corn earwormHelicoverpa zea (Boddie using the analog of methoxyfenozide molting hormone (24% at 144 mg of a. i/L. The biorational control agents that not affect significantly to the natural enemies were the nucleopoliedrosis virus SfMNPV and SeMNPV; N. rileyi and Isaria fumosorosea (Wize; Bacillus thuringiensis (Berlinier; the azadirachtin (neem and parasitoids. In the case of products of chemical synthesis: Spinosad, oxymatrine and bifenthrin showed high rates of mortality in the control of corn pests, so these are considered as of high and moderate risk to Aphis mellifera (L. bees, the methoxyfenozide presented relatively low toxicity to natural enemies. In general, biorational products have repellent effect on larvae and adults of these insects, inhibit feeding and induce molting, also causing deformities and impede the development and growth, too interfere with sexual intercourse and copulate, reducing the oviposition, as well as cause sterility of adults, so these may also constitute a risk to

  12. Suitability of different lepidopteran host species for development of Bracon hebetor (Hymenoptera: Braconidae).

    Science.gov (United States)

    Ghimire, Mukti N; Phillips, Thomas W

    2010-04-01

    Bracon hebetor Say (Hymenoptera: Braconidae) is a gregarious larval ectoparasitoid of several species of Lepidoptera that are associated with stored products. The suitability of 12 potential lepidopteran host species representing four families was studied in this study for the development and reproduction of B. hebetor. The Lepidoptera species used were the Indianmeal moth, Plodia interpunctella (Hübner), Mediterranean flour moth, Ephestia kuehniella (Zeller), almond moth, E. cautella (Walker), rice moth, Corcyra cephalonica (Walker), navel orangeworm, Amyelois transitella (Stainton), greater wax moth (laboratory reared and commercial), Galleria mellonella (Linnaeus) (all Pyralidae); tobacco budworm, Heliothis virescens (Fabricus), corn earworm, Helicoverpa zea (Boddie), beet armyworm, Spodoptera exigua (Hübner) (all Noctuidae); webbing clothes moth, Tineola bisselliella (Hummel) (Tineidae); and Angoumois grain moth, Sitotroga cerealella (Olivier) (Gelichiidae). Experiments were conducted using petri dishes (100 by 15 mm) as experimental arenas at 29 +/- 1 degrees C, 65 +/- 5% RH, and a photoperiod of 14:10 (L: D) h. B. hebetor females were introduced singly into arenas and given a full-grown host larva every day for 5 consecutive d. Paralysis of the host larvae and oviposition by B. hebetor females were significantly affected by host species. The cumulative fecundity in the 5-d period was highest on A. transitella (106.42 +/- 5.19) and lowest on T. bisselliella (9.64 +/- 1.28). The egg-to-adult survivorship and progeny sex ratio were also significantly affected by the host species. The highest percentage of parasitoid survival to the adult stage was on A. transitella (84.07 +/- 2.26) and zero on T. bisselliella. Egg to adult development time was shortest on E. cautella (9.75 +/- 0.25 d) and longest on G. mellonella (12.63 +/- 0.28 d). Results from these studies suggest that B. hebetor females can use a wide range of lepidopteran hosts for paralysis and

  13. 昆虫性信息素在印度的研究及应用%INSECT SEX PHEROMONE RESEARCHES AND ITS AP PLICATION IN INDIA

    Institute of Scientific and Technical Information of China (English)

    C.P. Srivastava; S. Satpathy

    2001-01-01

    Sex pheromones of insect pests have several characteristics, which are highly desirable in insect pest management programmes. Being extremely potent, only small amounts of these material are required to incite species specific behavioural responses. In India, the first report about the existence of sex pheromone in an insect called almond moth, Cadra cautella (Walker) was made in the year 1967. The real research work and application of pheromones for different purposes picked up in late seventies. Since then sex pheromones of about twenty economically important insect pests of agricultural crops and of about ten stored grain pests have been identified, isolated and synthesized. The sex pheromones of these insect pests are mostly used for population monitoring, followed by mass trapping and mating disruption. Mating disruption have been successful in pink bollworm in cotton, yellow stem borer in rice,codling moth in apple, gypsy moth in apple and apricot and potato tuber moth in storage. The extensive research on sex pheromones of some insect pests of fruits and vegetables are very much required, particularly of those insect pests, which have developed resistance against most of the commonly available and safe insecticides. Strong collaborative research is needed among the institutes working in applied entomology, insect ecology, chemical ecology and chemical technology to address the different aspects of pheromone research and its application in IPM.%只需要少量的性信息素就能诱发昆虫产生极强的行为反应.这一特点展现了昆虫性信息素在害虫防治中的广阔前景.印度在1967年首次报道了杏仁蛾Cadra cautella(Walker)的性信息素.在70年代后期,性信息素的研究及应用得到了突飞猛进的发展.从那时起,分离和鉴定了二十种重要的作物害虫和十种仓储害虫的性信息素,并进行了合成.在用性信息素进行种群控制时,主要采用大量诱捕和交配干扰的办法.用交配

  14. 江西省烟田主要害虫及其天敌种群动态%Population Dynamics of the Main Pests and Natural Enemies in Tobacco Fields in Jiangxi Province

    Institute of Scientific and Technical Information of China (English)

    徐昭焕; 罗妹; 喻敏; 张超群; 王建国

    2013-01-01

    通过采用5点调查法,对江西省南昌市烟田主要害虫及其天敌种群数量进行调查并对其进行动态分析。结果显示:烟蚜在烟草整个生长期均有发生,其种群数量动态变化呈双峰曲线,第1个蚜量高峰期出现在6月初,第2个蚜量高峰期出现在6月末至7月初,且蚜量雨后显著降低,雨后高温则又明显增加。烟青虫和斑须蝽在5月初开始发生,其种群数量动态变化均呈单峰曲线。烟青虫虫量高峰期出现在5月末至6月初,斑须蝽虫量高峰期则在6月中旬。烟田内主要天敌有烟蚜茧蜂、蜘蛛类、瓢虫和草蛉。天敌与烟蚜、烟青虫具一定的虫量跟随关系,其中烟蚜茧蜂和草蛉分别在烟草生长前后期与烟蚜跟随关系明显,蜘蛛则在烟青虫发生后与其跟随关系较为明显。%Based on the survey method of five points, we investigated into the population of the pests and natural enemies in tobacco fields in Nanchang, Jiangxi Province, and analyzed their dynamic changes. The experimental results indicated that the population of Myzus persicae had two peaks within a year, the first in early June, and the second from the end of June to early July. Also the population of M. persicae decreased significantly after the rain, and then increased significantly after high temperature. The population of Helicoverpa assulta and Dolycoris baccarum, respectively, had one peak within a year. The peak of H. assulta population occurred from the end of May to early June, and the peak of D. baccarum population occurred in the middle of June. The main natural enemies of the pests in tobacco fields included Aphidius gifuensis, spiders, lacewings and lady beetles. These natural enemies showed synchronization with M. persicae and H. assulta. Of the natural enemies, A. gifuensis and lady beetles, respectively, showed obvious synchronization with M. persicae at the early or later period of the tobacco growth, and

  15. New systems for the large-scale production of male tsetse flies (Diptera: Glossinidae)

    International Nuclear Information System (INIS)

    into the production cages in the right sex and number. This eliminates the need for manual sex separation before mating and the same procedure can be used to produce only males for release. For the SIT aerial release in Zanzibar, sterile flies were placed in boxes and dropped from an aircraft along predetermined flight paths. Boxes are expensive and require much space within the aircraft. For fruit flies, pink bollworms and screw-worms, a chilled adult release system was developed and this will also be required for future tsetse SIT programmes. Limited experiments were carried out on the long-term effects of chilling on male tsetse flies

  16. Adoption of Bt Cotton: Threats and Challenges Adopción de Algodón Bt: Desafíos y Amenazas

    Directory of Open Access Journals (Sweden)

    Muhammad Faisal Bilal

    2012-09-01

    Full Text Available Adopting new technology always involves advantages and risks; Bt cotton (Gossypium hirsutum L. is a new technology well known in developed countries for its many advantages, such as reduced pesticide application, better insect pest control, and higher lint yield. However, its success in developing countries is still a question mark. Global adoption of Bt cotton has risen dramatically from 0.76 million ha when introduced in 1996 to 7.85 million ha in the 2005 cotton-growing season where 54% of the cotton crops in the USA, 76% in China, and 80% in Australia were grown with single or multiple Bt genes. Bollworms are serious cotton pests causing 30-40% yield reduction in Pakistan and 20-66% potential crop losses in India. The major advances shown in this review include: (1 Evolution of Bt cotton may prove to be a green revolution to enhance cotton yield; (2 adoption of Bt cotton by farmers is increasing due to its beneficial environmental effects by reducing pesticide application: however, a high seed price has compelled farmers to use illegal non-approved Bt causing huge damage to crops because of low tolerance to insect pests; and (3 some factors responsible for changes in the efficiency of the Bt gene and Bt cotton yield include internal phenology (genetics, atmospheric changes (CO2 concentration, nutrition, insect pests, boll distribution pattern, disease and nematodes, removal of fruiting branch and/or floral bud, introduction of Bt gene, and terpenoids and tannin production in the plant body.La adopción de nueva tecnología siempre involucra ventajas y riesgos; algodón Bt (Gossypium hirsutum L. es una nueva tecnología bien conocida en países desarrollados por muchas ventajas como reducida aplicación de pesticidas, mejor control de insectos plaga, y mayor producción de fibra, pero su éxito en países en desarrollo aún conlleva dudas. La adopción global de algodón Bt ha aumentado dramáticamente de 0,76 millones de hectáreas en su

  17. Economics of area-wide pest control

    International Nuclear Information System (INIS)

    Area-wide pest management is commonly practised throughout the world, probably much more so than is generally recognised (Lindquist 2000, Klassen 2000). Apart from highly publicised area-wide schemes such as the sterile insect technique (SIT) for fruit flies, pheromone disruption for cotton bollworms and classical biological control, there are many examples of actions such as concerted host plant eradication, enforced closed crop seasons, organised pesticide rotation for resistance management, coordination of resistant crop genotypes, etc., some going back several centuries, which should also be considered as area-wide practices. Each of these is faced with many of the economic issues generally associated with area-wide management which will be discussed below. In general, there are to be four major questions to answer in devising an area-wide pest management programme: 1) Should a particular pest be controlled locally or area-wide? 2) What is an appropriate area over which management should be attempted? 3) Within that area what form of control is most efficient? 4) What level of organisation should be used to get the job done? It should be noted that apart from clearly objective measures such as technical effectiveness (say, mortality) or cost efficiency (mortality per dollar), there are many subjective measures that come into the evaluation of area-wide control due to the element of risk (for example, in quarantine and eradication), the boundaries of externalities (for example, variable probabilities of pesticide drift under different conditions or target organism sensitivities) and time preferences for returns on capital investments (such as insect rearing facilities or research to develop pheromone technologies). As a result of these subjective components, it may sometimes be difficult to reach clearly agreed decisions based on objective economic analyses, even with a consensus on the data used. There are three general classes of economic problems in comparing

  18. 气候变暖对甘肃省武威市主要病虫害发生趋势的影响%Influences of Climate Warming on Main Diseases and Insect Pests' Occurrence Trend in Wuwei City, Gansu Province

    Institute of Scientific and Technical Information of China (English)

    刘明春; 蒋菊芳; 魏育国; 徐生海

    2009-01-01

    [Objective]The research aimed to study the influences of climate warming on main diseases and pests' occurrence trend in Wuwei City, Gansu Province.[Method] Taking the Liangzhou County for example, the record heat and water condition change were analyzed during the occurrence and disappear critical period(wintering period and development period) of the crop main diseases and insect pests such as wheat aphid,wheat stripe rust, corn bollworm, and the internal relations between weather elements and diseases and insect pests.[Result] The results showed that in the context of global warming, Liangzhou County warming rate quickened year by year and the linear tendency value of temperature was 0.535℃/10 a since the 1980s. The occurrence probability of abnormal warming year, warming year increased. The winter linear tendency value of temperature was 0.538℃/10 a, which higher than the other seasons. The heat conditions of diseases and insect pests occurrence period (March-September) improved, ≥5℃ accumulated temperature and ≥10℃ accumulated temperature increased significantly. The precipitation overall had the increased trend, and the rapidly increase season was in Spring and Summer, but the order of magnitude was smaller. The climate change indicated that warming winter could help pest and eggs safely pass winter, the base of passing winter increased, the occurrence period was earlier in the coming year, and the occurrence area increased. That the heat increased and the illumination was adequate during growth could help wheat aphid, corn red spider occurrence and development, extended the period of damage, increased the number of generations and the degree of damage. The increased precipitation was bad to the propagation of pests, but it was of help the spread and occurrence of wheat stripe rust and scabs.[Conclusion] The study had positive significance for effectively guiding the prevention of plant diseases and insect pests, alleviating agricultural pollution

  19. Heterosis and nutrition composition of dominant low gossypol hybrid cotton%显性低酚杂交棉的杂种优势及营养成分分析

    Institute of Scientific and Technical Information of China (English)

    田一秀; 马晓杰; 狄佳春; 陈旭升

    2012-01-01

    To study the yield heterosis and pest and disease resistance of the dominant low gossypol cotton Suza501 and Suza502, the gossypoi, protein, fat and free amino acid contents were determined. The results showed that two hybrids (Suza501 and Suza502) expressed obvious mid-parent heterosis. Suza 502 had positive competitive advantage, the yields of unginned and ginned cotton being 3.41% and 0. 11% higher than those of Suza 6, respectively. Suza 501 owned a certain negative competitive advantage, the yields of unginned and ginned cotton being 1. 02% and 4. 72% lower, respectively. Suza 501 and Suza 502 were resistant to Verticillium wilt, with their relative disease indexes of 25. 9 and 24. 7, respectively. They were both resistant to bollworm, with the average resistance values of 2. 50 and 3. 42, respectively. After deoil, the gossypol contents of Suza501 and Suza502 were 30.42 mg/kg and 39. 34 mg/kg, respectively, and their F2 generation were 373.22 mg/kg and 367. 92 mg/kg, respectively, which were all in safety range for animal feed. SSR fingerprints for two hybrid cotton Suza501 and Suza502 was constructed. Using the primer MH0454, the dominant low gossypol cotton from the parents was differentiated, and the hybrid dominant low gossypol cotton from conventional dominant low gossypol cotton was differentiated as well.%为了研究显性低酚杂交棉苏杂501(F1)、苏杂502(F1)的产量杂种优势、抗病虫特性,测定了其棉酚含量、蛋白质含量、氨基酸含量和脂肪含量,结果显示:2个显性低酚杂交棉均具有明显的中亲优势,其中苏杂502(F1)的籽、皮棉产量均具有正向竞争优势,分别比对照(苏杂6号)增产3.41%、0.11%;苏杂501(F1)的籽、皮棉产量表现一定的负向竞争优势,分别比对照减产1.02%、4.72%.苏杂501(F1)和苏杂502(F1)的黄萎病相对病指分别为25.9、24.7,均表现为耐病;对棉铃虫的平均抗性值分别为2.50、3.42,均达抗级水平.去油后苏杂501

  20. 高产 稳产 高效 广适快育66的选育%Breeding of High Yield, Stable Yield, Efficient and Wide Adaptability Cotton Variety Kuaiyu 66

    Institute of Scientific and Technical Information of China (English)

    徐显; 杨帆; 谷良志

    2012-01-01

    The new cotton variety Kuaiyu 66 was developed by crossing between Bt transgenic variety GK12 (female parent) which was bred using G. hirsutum, G. barbadense, G. thurberi, and wild Thurber's material, with resistance to bollworm, and high-yield potential, adaptable line 01-698 (male parent) selected from Jimian No. 8, Kuaiyu 66 was crossed, selected and increased generation in greenhouse, combining with field selection, 3 generations per year cotton breeding technique and excellent plant type selection method for breach. Through adding generations in greenhouse, selling homozygous and field identification and selection, the new transgenic variety concentrated the good traits of high and stable yield, high efficiency and wide suitable, the lint yield, prefrost lint yield of the variety were respectively 1 518 kg/hm2 and 1 405.5 kg/hm2, and the pre-frost lint increased up to an extremely significant level in transgenic conventional cotton variety regional trials of South-central of Hebei Province in 2007 - 2009; In transgenic conventional cotton variety production test of south-central of Hebei Province in 2010, yields of 8 time points were all increased, lint yield, pre-frost lint yield were 1 401 kg/hm2 and 1 314 kg/hm2, increased by 7.7% and 10. 5% respectively comparing to control Jimian 958, which were all the highest one among the tested lines. This breed was disease resistant ( high resistance to Fusarium wilt, resistance to Verticillium dahli strength was 28.3 ae ), fiber quality comprehensive ( body length was 29 mm, uniformity was 84.9%, specific cN/tex, micronaire value was 5.3), management cheaper, comprehensive performance prominent.%快育66是以含有海岛棉、陆地棉、野生瑟伯氏血缘以及转胁抗棉铃虫基因的高抗棉铃虫品种GK12为母本,以丰产潜力大、适应性强的冀棉8号01.698为父本,二者在温室内杂交,利用温室加代与大田选择相结合的1a3代棉花快速育种技术、以选

  1. IN VITRO CULTIVATION OF THE ENTOMOGENOUS NEMATODE OVOMERMIS SINENSIS%中华卵索线虫的体外培养

    Institute of Scientific and Technical Information of China (English)

    王国秀; 陈曲侯; 陈果

    2001-01-01

    在研究中华卵索线虫的体外培养方法的同时,对其在不同培养基中的生长发育情况进行了观察。结果表明:以培养基TC-199加20%热灭活胎牛血清的培养效果较为理想,大多数线虫可存活3个月,最大虫体长55.1 mm、宽204.13 μm,其发育程度大致与该种索线虫在宿主粘虫体内寄生8~9天的情况相近。培养期间观察到2次蜕皮:第一次蜕皮在卵内,第二次在培养6~8天之后。口针消失,虫体内滋养物体发育明显,尾部附器已经形成,没有观察到生殖原基的发育。%The insectparasitic nematode, Ovomermis sinensis Chenet al, 1991 has the potential for the biological control of a range of insect pests due to many insect sep ecies are susceptible to this nematode. For example Leucania separata, Helioth is armigera, Prodenia litura, Spodoptera exigua, Plutella xylostella, Pieris rapae, Agrotis ypsilon, Euxoa segetumetc. The insect host invariably dies when the juvenile nematode completes its parasitic development and exits from the host's hemocoel's hemocoel. There is an important significance for studying the mass cultivation of O. sinensis for field trials. This paper describes the techniques of in vitro cultivation of O. sinensis.   Gravid females of O. sinensis collected from sand were washed three times with an antibiotic solution of 200 U penicillin/ml and 200 μg/ml streptomycin/ml per ml solution. Surface washed gravid female were placed in 25 ml culture tubes containing 1~10 ml deionized water, 100 U penicillin/ml, and 100 μg streptomycin /ml for oviposition. Eggs were collected and their surface were sterilized by immersing them for 5~10 min in 0.13%~0.5% sodium hypochlorite solution and rinsing four times with sterile distilled water. Surface sterilized eggs were incubated at 26±1℃ in the culture media. The preparasites which emerged from those eggs were utilized for culture work. The four media were