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Sample records for bollworm

  1. 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)

  2. 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.

  3. 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)

  4. 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...

  5. Sustained susceptibility of pink bollworm to Bt cotton in the United States.

    Science.gov (United States)

    Tabashnik, Bruce E; Morin, Shai; Unnithan, Gopalan C; Yelich, Alex J; Ellers-Kirk, Christa; Harpold, Virginia S; Sisterson, Mark S; Ellsworth, Peter C; Dennehy, Timothy J; Antilla, Larry; Liesner, Leighton; Whitlow, Mike; Staten, Robert T; Fabrick, Jeffrey A; Li, Xianchun; Carrière, Yves

    2012-01-01

    Evolution of resistance by pests can reduce the benefits of transgenic crops that produce toxins from Bacillus thuringiensis (Bt) for insect control. One of the world's most important cotton pests, pink bollworm (Pectinophora gossypiella), has been targeted for control by transgenic cotton producing Bt toxin Cry1Ac in several countries for more than a decade. In China, the frequency of resistance to Cry1Ac has increased, but control failures have not been reported. In western India, pink bollworm resistance to Cry1Ac has caused widespread control failures of Bt cotton. By contrast, in the state of Arizona in the southwestern United States, monitoring data from bioassays and DNA screening demonstrate sustained susceptibility to Cry1Ac for 16 y. From 1996-2005, the main factors that delayed resistance in Arizona appear to be abundant refuges of non-Bt cotton, recessive inheritance of resistance, fitness costs associated with resistance and incomplete resistance. From 2006-2011, refuge abundance was greatly reduced in Arizona, while mass releases of sterile pink bollworm moths were made to delay resistance as part of a multi-tactic eradication program. Sustained susceptibility of pink bollworm to Bt cotton in Arizona has provided a cornerstone for the pink bollworm eradication program and for integrated pest management in cotton. Reduced insecticide use against pink bollworm and other cotton pests has yielded economic benefits for growers, as well as broad environmental and health benefits. We encourage increased efforts to combine Bt crops with other tactics in integrated pest management programs.

  6. 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

  7. Pink bollworm moth (Lepidoptera: Gelechiidae) catches in the Imperial Valley, California from 1989 to 2003

    Institute of Scientific and Technical Information of China (English)

    CHANG-CHI CHU; ERIC T.NATWICK; RAUL LE(O)N L(O)PEZ; JOLENE R.DESSERT; THOMAS J.HENNEBERRY

    2006-01-01

    We examined the patterns of male pink bollworm (PBW),Pectinophora gossypiella (Saunders),moth catches in gossyplure-baited traps over a 15-year period from 1989 to 2003 in the Imperial Valley,California,USA. Monitoring was conducted during periods when different pink bollworm areawide control strategies were being used. Numbers of male pink bollworm moths caught in gossyplure-baited traps progressively decreased each year from 1990 to 1994 during short-season cotton production. High numbers of male moths caught in traps from 1995 to 1997 may have been related to moth migrations from the large cotton acreages grown in the Mexicali Valley bordering the Imperial Valley. Transgenic Bollgard(R) (Bt) cotton was planted in 3% of the cotton area in 1996 and thereafter in 80%-94% of the cotton area from 1997 to 2003. Pink bollworm moth trap catches were significantly lower from 1998 to 2003 than catches in 1995 to 1997,except for 1999. The trapping results suggested that Bt cotton had significant input on reduction of pink bollworm populations,confirming results of other investigators and providing additional documentation on the benefits of the Bt cotton culture.

  8. Carbon dioxide receptor genes in cotton bollworm Helicoverpa armigera

    Science.gov (United States)

    Xu, Wei; Anderson, Alisha

    2015-04-01

    Carbon dioxide (CO2) is important in insect ecology, eliciting a range of behaviours across different species. Interestingly, the numbers of CO2 gustatory receptors (GRs) vary among insect species. In the model organism Drosophila melanogaster, two GRs (DmelGR21a and DmelGR63a) have been shown to detect CO2. In the butterfly, moth, beetle and mosquito species studied so far, three CO2 GR genes have been identified, while in tsetse flies, four CO2 GR genes have been identified. In other species including honeybees, pea aphids, ants, locusts and wasps, no CO2 GR genes have been identified from the genome. These genomic differences may suggest different mechanisms for CO2 detection exist in different insects but, with the exception of Drosophila and mosquitoes, limited attention has been paid to the CO2 GRs in insects. Here, we cloned three putative CO2 GR genes from the cotton bollworm Helicoverpa armigera and performed phylogenetic and expression analysis. All three H. armigera CO2 GRs (HarmGR1, HarmGR2 and HarmGR3) are specifically expressed in labial palps, the CO2-sensing tissue of this moth. HarmGR3 is significantly activated by NaHCO3 when expressed in insect Sf9 cells but HarmGR1 and HarmGR2 are not. This is the first report characterizing the function of lepidopteran CO2 receptors, which contributes to our general understanding of the molecular mechanisms of insect CO2 gustatory receptors.

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. Effects of Resistance to Bt Cotton on Diapause in the Pink Bollworm, Pectinophora gossypiella

    Science.gov (United States)

    Carrière, Yves; Ellers-Kirk, Christa; Biggs, Robert W.; Sims, Maria A.; Dennehy, Timothy J.; Tabashnik, Bruce E.

    2007-01-01

    Fitness costs associated with resistance to Bacillus thuringiensis (Bt) crops are expected to delay the evolution of resistance. In a previous study where pink bollworm, Pectinophora gossypiella (Lepidoptera: Gelechiidae), larvae overwintered in outdoor insectaries, individuals from Bt-resistant strains had lower survival than individuals from Bt-susceptible strains or F1 progeny from crosses between resistant and susceptible adults. To investigate the physiological basis of such recessive cost, diapause duration was experimentally manipulated in the laboratory. Compared to a Bt-susceptible strain and F1 progeny, we hypothesized that Bt-resistant strains could exhibit a lower propensity or intensity of diapause, faster weight loss during overwintering, lower initial weight of diapausing larvae, and reduced longevity of moths emerging from diapause. Results were as expected for initial weight of diapausing larvae and longevity of overwintered male moths or female moths remaining in diapause for a short period. However, a higher diapause induction and intensity and slower weight loss occurred in F1 progeny and Bt-resistant strains than in a Bt-susceptible strain. Moreover, F1 progeny had greater overwintering survival than the Bt-resistant and Bt-susceptible strains, and F1 female moths had the greatest longevity after sustaining long diapausing periods. All of these unexpected results may be explained by pleiotropic effects of resistance to Bt cotton that increased the strength of diapause in the F1 progeny and Bt-resistant strains. Incomplete resistance was reflected in disadvantages suffered by Bt-resistant individuals feeding on a Bt diet instead of a non-Bt diet, including lower diapause propensity, lower diapause intensity and reduced longevity of overwintered male moths. While this study suggests that the evolution of resistance to Bt cotton and feeding on a Bt diet in Bt-resistant individuals have pervasive effects on several traits associated with diapause

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. Acute, sublethal, and combination effects of azadirachtin and Bacillus thuringiensis on the cotton bollworm, Helicoverpa armigera.

    Science.gov (United States)

    Abedi, Zahra; Saber, Moosa; Vojoudi, Samad; Mahdavi, Vahid; Parsaeyan, Ehsan

    2014-01-01

    The cotton bollworm, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) is a polyphagous and cosmopolitan insect pest that causes damage to various plants. In this study, the lethal and sublethal effects of azadirachtin and Bacillus thuringiensis Berliner sub sp . kurstaki (Bacillales: Bacillaceae) were evaluated on third instar H. armigera under laboratory conditions. The LC50 values of azadirachtin and Bt were 12.95 and 96.8 µg a.i./mL, respectively. A total mortality of 56.7% was caused on third instar larvae when LC20 values of the insecticides were applied in combination with each other. The LT50 values of azadirachtin and Bt were 4.8 and 3.6 days, respectively. The results of the sublethal study showed that the application of LC30 value of azadirachtin and Bt reduced the larval and pupal weight and increased larval and pupal duration of H. armigera. The longevity and fecundity of female adults were affected significantly by the insecticides. Female fecundity was reduced by the treatments, respectively. The lowest adult emergence ratio and pupation ratio were observed in the azadirachtin treatment. The results indicated that both insecticides have high potential for controlling of the pest. PMID:25373177

  20. Three cadherin alleles associated with resistance to Bacillus thuringiensis in pink bollworm

    Science.gov (United States)

    Morin, Shai; Biggs, Robert W.; Sisterson, Mark S.; Shriver, Laura; Ellers-Kirk, Christa; Higginson, Dawn; Holley, Daniel; Gahan, Linda J.; Heckel, David G.; Carrière, Yves; Dennehy, Timothy J.; Brown, Judith K.; Tabashnik, Bruce E.

    2003-01-01

    Evolution of resistance by pests is the main threat to long-term insect control by transgenic crops that produce Bacillus thuringiensis (Bt) toxins. Because inheritance of resistance to the Bt toxins in transgenic crops is typically recessive, DNA-based screening for resistance alleles in heterozygotes is potentially much more efficient than detection of resistant homozygotes with bioassays. Such screening, however, requires knowledge of the resistance alleles in field populations of pests that are associated with survival on Bt crops. Here we report that field populations of pink bollworm (Pectinophora gossypiella), a major cotton pest, harbored three mutant alleles of a cadherin-encoding gene linked with resistance to Bt toxin Cry1Ac and survival on transgenic Bt cotton. Each of the three resistance alleles has a deletion expected to eliminate at least eight amino acids upstream of the putative toxin-binding region of the cadherin protein. Larvae with two resistance alleles in any combination were resistant, whereas those with one or none were susceptible to Cry1Ac. Together with previous evidence, the results reported here identify the cadherin gene as a leading target for DNA-based screening of resistance to Bt crops in lepidopteran pests. PMID:12695565

  1. [Evaluation of reference genes for quantitative real-time PCR normalization in cotton bollworm, Helicoverna armigera].

    Science.gov (United States)

    Chandra, G Sharath; Asokan, R; Manamohan, M; Kumar, N K K; Sita, T

    2014-01-01

    Reverse-transcription quantitative real-time PCR (RT-qPCR), a sensitive technique is being extensively employed in quantification of gene expression. However this requires normalization with suitable reference gene (RG) which is crucial in minimizing inter sample variations. Information regarding suitable RG is scarce in general and more so in insects, including the cotton bollworm, Helicoverpa armigera, an economically important pest. In management of this pest RNA interference (RNAi), is perceived as a potential tool, which is achieved by double-stranded RNA (dsRNA) delivery. These studies demand accurate quantification of gene silencing. In this study we assessed the suitability of five RGs viz. β-actin (ACTB), 18S rRNA (18S), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), β-tubulin (TUB) and elongation fator-1-alfa (EF1-α) for gene expression studies in dsRNA treatment and across different developmental stages of H. armigera and ranked using geNorm, NormFinder and BestKeeper software programs. Data analysis revealed that best ranked RGs were varied in dsRNA treatment and in developmental stages. Under dsRNA treatment, 18S and GAPDH were more stable whereas, TUB and GAPDH were more stable across developmental stages. We also demonstrate that inappropriate selection of RG led to erroneous estimation of the target gene, chymotrypsin, expression. These results facilitate accurate quantification of gene expression in H. armigera.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. Spatial and Temporal Distributions of the Fourth Generation Cotton Bollworm Eggs on Summer Corn Seeded at Different Times in North China

    Institute of Scientific and Technical Information of China (English)

    WANG Zhen-ying; HE Kang-lai; WEN Li-ping; ZHANG Guang-yi; ZHENG Li

    2002-01-01

    The spatial and temporal distributions of the cotton bollworm (Helicoverpa armigera Hübner) eggs on summer corn seeded at early-, middle- and late-times were studied in 1998 - 1999 in Hengshui, Hebei Province in North China. There were several egg peaks during the period from the middle to late August, which were coincided with the pollen-shedding or blister stage of summer corn depending on the change of bollworm occurrence. The eggs were mainly deposited on silks of ears, and leaves and sheaths above the ears.The number of eggs laid on middle- and late-seeded summer corn were higher than that on the early-planted one, resulting in more heavy damage the on late-seeded corn.

  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. Transgenic ice nucleation-active Enterobacter cloacae reduces cold hardiness of corn borer and cotton bollworm larvae.

    Science.gov (United States)

    Tang, Chaorong; Sun, Fuzai; Zhang, Xinjian; Zhao, Tingchang; Qi, Jiyan

    2004-12-27

    The ice nucleation (IN) gene iceA of Erwinia ananas 110 was integrated into the chromosomes of two Enterobacter cloacae strains (Enc1.2022 and Enc1.181). These two newly derived transgenic strains, designated Enc2022-I and Enc181-I, respectively, possessed ice nucleation activity at -2.5 degrees C, significantly higher than their parent strains (active at approx -10 degrees C or lower). After ingesting these transgenic bacteria, the mean supercooling points (SCPs) of corn borer and cotton bollworm larvae were -3 to -4 degrees C, significantly higher than those of untreated controls. The SCPs remained significantly elevated over the 9-day period after ingestion, which matched well with the efficient gut colonization of the bacteria during this period. All treated larvae froze and eventually died after exposure for 6 h to a temperature of -7 degrees C, and more than 95% died after 12 h at -5 degrees C. In contrast, few or none of the untreated control larvae froze and died under the same conditions. Furthermore, the growth ability of these transgenic ice nucleation-active (INA) En. cloacae strains on corn leaves was reduced, compared to that of wild-type epiphytic E. ananas, as revealed by pot tests conducted in both greenhouse and outdoor conditions. The stable colonization in insect guts and their lower affinity to plants would make these transgenic INA bacteria useful as a novel tool for biological control of insect pests in agricultural fields. PMID:16329857

  14. 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

  15. 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)

  16. Transgenic tobacco plants expressing synthetic Cry1Ac and Cry1le genes are more toxic to cotton bollworm than those containing one gene

    Institute of Scientific and Technical Information of China (English)

    LIAN Yun; JIA ZhiWei; HE KangLai; LIU YunJun; SONG FuPing; WANG BaoMin; WANG GuoYing

    2008-01-01

    Transgenic tobacco plants carrying Cry1Ac, Crylle or both genes were obtained. In the leaves of transgenic plants carrying both genes, the contents of CrylAc and Cry1le proteins were 0.173% and 0.131% of the total proteins, respectively, Cry1Ac protein content was 0.182 % and Cry1le protein con-tent was 0.124% of the total proteins in the leaves of transgenic plants containing only one Bt gone. Fresh leaves of transgenic tobacco and wild-type plants were used for the insect bioassay against wild-type and Cry1Ac-resistant cotton bollworm (Helicoverpa armigera). The bioassay results showed that transgenic plants carrying both genes were significantly more toxic to wild-type and Cry1Ac-resistant cotton bollworm than those carrying Cry1Ac or Cry1le alone. This study indicates that the higher toxicity of transgenic tobacco plants carrying both genes is caused by the cooperative function of both Bt proteins, thus providing a potential way to delay the development of insect resis-tance to transgenic crops.

  17. 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)

  18. Application and Research of Data Mining Technology on the Cotton Bollworm Disease Prediction%数据挖掘技术在棉铃虫害预测中的应用研究

    Institute of Scientific and Technical Information of China (English)

    武金萍; 王红霞

    2009-01-01

    采用SQL Server 2005 的Business Intelligence Development Studio工具,应用关联规则的Apriori挖掘算法,对山西省棉铃虫害指标进行了挖掘分析,建成了山西省棉铃虫害指标预测系统.在实际的应用中,利用最高气温、最低气温、日平均气温、空气湿度和降水量5个指标最近15 d的平均值,即可预测当前棉铃虫的发生程度.%This paper analyzes cotton bollworm disease index, and establishes cotton bollworm disease index predic-tion system in Shanxi province by adopting Business Intelligence Development Studio tools (SQL Server 2005) and the Apriori mining algorithm of association rules. In practical applications, using the average of maximum tempera-ture, minimum temperature, Daily average temperature, air humidity and precipitation in 15 days, to predict the current degree of cotton bollworm disease.

  19. 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

  20. 早熟素对棉铃虫滞育的终止作用%TERMINATION OF PUPAL DIAPAUSE IN THE BOLLWORM HELICOVERPA ARMIGERA BY PRECOCENE Ⅱ

    Institute of Scientific and Technical Information of China (English)

    王方海; 龚和

    2001-01-01

    用外源激素和某些化合物处理棉铃虫的滞育蛹,结果发现早熟素与蜕皮素-样可终止棉铃虫蛹的滞育,使其进入到发育阶段.而保幼激素类似物ZR-515,环腺氨酸(cAMP)和色氨类化合物(5-HT)则完全不具有终止棉铃虫滞育的作用.结合早熟素还可终止蚜虫寄生蜂Aphidius matricariae Haliday和Praon volucre Haliday的预蛹滞育的报道,建议早熟素应具有终止多种类昆虫滞育的功能.%Precocene Ⅱ terminated pupal diapause in the bollworm Helicoverpa armigera as 20-hydroxyecdysterone did, whereas juvenile hormone analog ZR-515, cyclic adenosine monophosphate (cAMP), and 5-hydroxytryptamine (5-HT) did not. The results indicate that precocene Ⅱ affects diapausing pupae in the similar way as what was found in the prepupae of the aphid parasitoids, Aphidius matricariae Haliday and Praon volucre Haliday (Hymenoptera: Aphidiidae). It is suggested that precocene Ⅱ may affect different kinds of termination of diapause in insects.

  1. Effect of Artemisia annua L. essential oil on toxicity, enzyme activities, and energy reserves of cotton bollworm Helicoverpa armigera (Hübner (Lepidoptera: Noctuidae

    Directory of Open Access Journals (Sweden)

    Mojarab-Mahboubkar Malahat

    2015-12-01

    Full Text Available The essential oil of Artemisia annua L., a weed collected from northern Iran, was studied for its toxicity and physiological aspects on 4th instar larva of the cotton bollworm Helicoverpa armigera Hübner in controlled conditions (26±1°C, 65±10% RH and 16 L : : 8 D h. The artificial diet was used as a medium for investigating the toxicity and the effect of LC10, LC30, LC50, and LC90 on the feeding efficiency of 4th instar larva. The essential oil in doses of LC10, LC30, LC50, and LC90 were estimated to be 2.01%, 3.86%, 6.07%, and 18.34%, respectively. The activity of α-amylase, protease, lipase, general esterases, and glutathione S-transferase and protein, triglyceride, glucose for treated larva were measured. The results showed that all of these parameters were decreased compared with the control. Hence, A. annua essential oil is suggested as a botanical for controlling this important pest of field crops.

  2. 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

  3. 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

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 甲氨蝶呤和紫杉醇对棉铃虫繁育能力的影响%Effects of Methotrexate and Paclitaxel on the Ability of Breeding of Cotton Bollworm, Helicoverpa armigera (Hübner)

    Institute of Scientific and Technical Information of China (English)

    马天文; 王俊刚; 何泽敏; 江海澜; 邓小霞; 彭俊

    2012-01-01

    [目的]研究药剂对棉铃虫繁育能力的影响,为安全有效的控制棉铃虫危害奠定理论基础.[方法]采用饲喂法处理棉铃虫成虫,对其产卵量、卵孵化率、实验前后成虫体重差、成虫寿命进行测定.[结果]甲氨蝶呤抑制棉铃虫产卵量效果优于紫杉醇,0.02%甲氨蝶呤处理的棉铃虫单雌产卵量(104粒)最低,比对照降低了72.48%;紫杉醇抑制卵孵化效果好于甲氨蝶呤,0.5%紫杉醇处理的卵孵化率为11.43%,平均校正不育卵率(89.19%)达到最高.甲氨蝶呤处理对雌虫的寿命比对照缩短l~2d.紫杉醇对棉铃虫雄虫有增重作用,而甲氨蝶呤对棉铃虫雌虫有减重作用.[结论]甲氨蝶呤和紫杉醇对棉铃虫繁育能力均有弱化作用,0.02%甲氨蝶呤弱化棉铃虫单雌产卵量效果最好,0.5%紫杉醇抑制卵孵化效果最佳.%[Objective] The purpose of this study was to investigate the effects of agenda on the ability of breeding of cotton bollworm, Helicoverpa armigera (Hübner) in order to lay foundation of controlling the harm of cotton bollworm safely and effectively. [ Method ] Feeding treatment with Methotrexate and Paclitaxel was used to determine the number of eggs laid by per female moth, hatching rate, body weight and lifetime of the adult. [ Result ] The inhibition effect of Methotrexate for laying eggs of cotton bollworm was better than Paclitaxel indoor environment. The number (104 head) of eggs laid by per female moth was the lowest after the treatment using 0.02% Methotrexate, 72.48% reduced than CK, while the inhibition effect of Paclitaxel for hatching rate of eggs was better than Methotrexate. The rate of hatching rate of eggs was 11.43% treated by using 0.5% Paclitaxel,and the revised sterility eggs rates(89. 19%) was the highest. Lifetime of adult moth was reduced by 1 to 2 days in female moths with Methotrexate treatment. Paclitaxel had the function of increasing weight of the male, but Methotrexate

  9. 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

  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. 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

  12. 新疆一枝蒿与黄花蒿粗提物抗棉铃虫与棉蚜的特性研究%The Study on Resistance of Artemisia rupestris and Artemisia annua to Cotton Bollworm ( Helicoverpa armigera ) and Cotton Aphid ( Aphis gossypii )

    Institute of Scientific and Technical Information of China (English)

    何海; 黄丽; 张学涛; 张雷; 李芬; 刘小宁

    2011-01-01

    [ Objective] This research can be a foundation for the development of new pollution - free botanical insecticides. [Method] Two types of coarse solutions from Artemisia rupestris and Artemisia annua were extracted with 97% ethanol, and toxicities of the two extracts to cotton bollworm and cotton aphid were determined, and expellent effect of Artemisia rupestris to laying eggs of cotton bollworms in both the laboratory and the field were also studied. [Result] The results showed: (1) The LC50 of extracts from Artemisia rupestris and Artemisia annua to cotton bollworm are 0 .956 and 2.047 4 g/1OOmL; (2) The LC50 of extracts from Artemisia rupestris and Artemisia annua to cotton aphid are 0.956 and 2.047 4 g/1OOmL; (3) The repellency of extracts of Artemisia rupestris on laying eggs of cotton bollworm in the laboratory and in the field are 28.39% and 80. 68% . [Conclusion] The findings demonstrate that the extracting coarse solutions from Artemisia rupestris are better than that from Artemisia annua as to the killing effect on cotton bollworm and cotton aphid, and it had an expellent effect on laying eggs of cotton bollworms in both the laboratory and the field .%[目的]为利用新疆一枝蒿研制新型无公害植物杀虫药剂奠定基础.[方法]采用97%乙醇对新疆一枝蒿(Artemisia rupestris)和黄花蒿(Artemisia annua)进行了总提,将所得粗提物对棉花重要害虫-棉铃虫(Helicoverpa armigera)与棉蚜(Aphis gossypii)进行了生物活性测定,同时还使用新疆一枝蒿粗提物对棉铃虫开展了室内、室外的驱避实验.[结果](1)新疆一枝蒿与黄花蒿粗提物对棉铃虫半致死浓度LC50分别为3.515 7与4.781 1 mL/100g;(2)新疆一枝蒿与黄花蒿粗提物对棉蚜半致死浓度LC50分别为0.956与2.047 4g/100mL;(3)新疆一枝蒿粗提物对棉铃虫室内室外趋避率分别为28.39%与80.68%.[结论]新疆一枝蒿粗提物对棉铃虫与棉蚜的毒杀作用较好并高于黄花蒿粗提物,且新

  13. 棉铃虫齿唇姬蜂的生物学特性%BIONOMIC OF CAMPOLETIS CHLORIDEAE (HYM: ICHNEUMONIDAE)AS A PARASITOID OF THE COTTON BOLLWORM HELICOVERPA ARMIGERA ( LEP: NOCTUIDAE)

    Institute of Scientific and Technical Information of China (English)

    游兰韶; 雷润华; 蒋杰贤; 柏连阳; 肖治术

    2002-01-01

    研究了湖南长沙地区棉铃虫齿唇姬蜂的生物学特性及田间消长规律.棉铃虫齿唇姬蜂在湖南长沙地区年发生约10代,以7个世代发生在棉田.田间出现3个寄生高峰,分别在5月上旬-6月下旬、8月中旬-9月上甸及9月中旬-10月中旬,寄生率平均在25,l-63,1%.从卵发育到成虫的平均历期变化范围为32.C下13天至11.6.C下75.5天.棉铃虫齿唇姬蜂能寄主棉铃虫、斜纹夜蛾和甜菜夜蛾,但偏爱寄主棉铃虫.该蜂能寄生棉铃虫l-3龄幼虫,很少寄生4-6龄幼虫,喜寄生2-3龄幼虫,每雌可寄生斜纹夜蛾2龄幼虫5-23头.本文建立了发育速率及成蜂寿命与温度关系的回归模型,探讨了越冬问题.比较了长江流域和黄河流域棉铃虫齿唇姬蜂生物学特性的差异.%The bionomics of Campoletis chlorideae and the regularity of its seasonal fluctuations were studied inChangsha district, Hunan province. Field investigation indicated that there were ten generations of C. chlorideae ayear, of which seven occurred in cotton fields. Three peaks of cotton bollworm parasitization by C. chlorideae were ob-served, early May to late June, mid August to early September, mid September to mid October respectively. One peakoccurred in tomato and tobacco fields, the other two in cotton fields. The parasitization rate ranged from 25.1% -63.1%. The total development time from egg to adult ranged from 13.0 days at 32.C to 75.5 days at 11.6.C. Eachwasp could parasitize the 5 - 23 second instar larvae of tobacco caterpillar. C. chlorideae could parasitize the cottonbollworm, beet armyworm and tobacco caterpillar, but preferred the cotton bollworm larvae. C. chlorideae could para-sitized 1st - 3rd instar larvae of the tobacco caterpillar, but seldom parasitzed 4th - 6th instar larvae. Moreover, C.chlorideae preferred second instar larvae. Theoretical models for developmental speed, adult longevity and the influenceof temperature were proposed. The overwintering of

  14. 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).

  15. 基于均匀设计与支持向量回归的棉铃虫幼虫全纯人工饲料配方优化%Optimization of chemically defined diet for larvae of the cotton bollworm (Helicoverpa armigera)based on uniform design and support vector regression

    Institute of Scientific and Technical Information of China (English)

    周世豪; 李俊; 姚润贤; 张星; 袁哲明

    2012-01-01

    昆虫全纯人工饲料配方是精细研究昆虫营养生理的前提.本研究以棉铃虫Helicoverpa armigera幼虫为供试对象,以本研究室前期发展的多因素多水平配方优化实验设计与分析方法UD-SVR为指导,以略加修改的苹浅褐卷蛾Epiphyas postvittana幼虫全纯人工饲料为初始配方,先优化20种天然氨基酸,再优化蔗糖等其他8种非氨基酸营养组分,经4轮97个处理组合,获得一个棉铃虫幼虫全纯人工饲料满意配方,平均蛹重、化蛹率分别由初始配方的0.160 g和10.4%高效增至满意配方的0.255 g和97.9%.该全纯人工饲料满意配方的获得,不但再次证实了 UD-SVR方法的有效性,同时为进一步深入研究棉铃虫营养需求与营养代谢奠定了基础.%In order to get a satisfying formula of the chemically artificial diet for larvae of the cotton bollworm, Helicoverpa armigera, we used UD-SVR, an experimental design and analysis method reported by our preliminary studies, for formula optimization. Based on the benchmark diet of a chemically artificial diet for the larvae of the light brown apple moth, Epiphyas postvittana, the contents of 20 natural amino acids were optimized first, and the contents of 8 non-amino acid nutrients including sucrose were optimized then. After 4 rounds of optimization with total 97 schemes, an optimal formula of the chemically artificial diet for the cotton bollworm larvae was obtained. When the H. Armigera larvae fed on this diet, their mean pupal weight and the pupation rate were 0. 255 g and 97. 9% , respectively; when the larvae fed on the benchmark diet, however, the above two indices were only 0. 160 g and 10. 4% ,respectively. The results reconfirmed the effectiveness of UD-SVR in the complex prescription optimization. More importantly, the optimized chemically artificial diet for the cotton bollworm provides the basis for further research on the requirement and metabolism of nutrition compounds in the moth.

  16. Glyphosate tolerance and effects of cotton bollworms on transgenic herbicide and insect resistant cotton%转基因抗虫抗除草剂棉花对棉铃虫抗性及对草甘膦耐受性研究

    Institute of Scientific and Technical Information of China (English)

    牛建群; 朱家林; 张青文; 刘小侠

    2012-01-01

    The tolerance of genetically modified cotton to glyphosate herbicides and its resistance to the cotton bollworm was investigated. The cotton had good tolerance to glyphusates. Growth was normal after spraying with glyphosate during the "four leaf" stage but spraying during the budding period may reduce the flowering and boll formation. This cotton variety and a control (a transgenic insect - resistant cotton) displayed good resistance to the cotton bollworm. The top leaves of the seeding stage were the most resistant but resistance declined to 49. 2% and 46. 6% with the growth of the cotton. During the boll opening stage resistance improved to 57.0% and 53.1% respectively.%本论文研究了抗虫又抗除草剂棉花对草甘膦的耐受程度,比较了这一双抗性状的棉花与单抗虫棉的抗虫效果.结果表明,抗虫又抗除草剂棉花对草甘膦有较好的耐受性,四叶期喷施草甘膦后抗虫抗除草剂棉花可以安全生长,蕾期喷施草甘膦对棉花的开花率和结铃率有影响.抗虫又抗除草剂棉花和单抗虫棉对棉铃虫Helicoverpa armigera(Hübner)均具有较好的防治效果,苗期棉花叶片对棉铃虫防治效果最好,后期防治效果下降到49.2%和46.6%,吐絮期防治效果又上升到57.0%和53.1%.

  17. 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。

  18. 新疆南部棉区转Bt基因棉花对棉铃虫抗性的季节性变化规律%The seasonal dynamics of resistance of transgenic Bt cotton to cotton bollworm in cotton planting region of southern Xinjiang

    Institute of Scientific and Technical Information of China (English)

    丁瑞丰; 李号宾; 刘建; 徐遥; 张永军; 阿克旦·吾外士

    2012-01-01

    The levels of Bt toxic protein in six kinds of transgenic Bt cottons in different periods were detected using ELISA and the levels of the resistance of those cottons against cotton bollworm larvae of local four generations were tested using laboratory bioassay. The levels of Bt toxic protein in tender leaves of transgenic Bt cotton decreased gradually with the cotton growing up. The level of Bt toxic protein was highest in cotyledon period, reaching 1 210.03 - 1 733.15 ng/g. Compared with the cotyledon period, the reduced ranges of the Bt toxic protein in tender leaves of three-leaf period, seven-leaf period, squaring period, flowering and little boll period, boll opening period were 2.5% -96.0%. The resistance of those cottons to 4th generation larvae was lower, and only up to 19.0% -41.3%. The corrected mortali- ty of the 4th generation larvae were merely only 12.0% - 36.2% , lower resistance were indicated.%采用ELISA检测和室内生物测定方法,测定6个转Bt基因棉花品种(系)不同生育期叶片中的Bt毒蛋白含量及其对各世代棉铃虫的抗性水平。转Bt基因棉花叶片中的Bt毒蛋白含量总体上随着棉花生育期的推进而逐渐下降,6个品种(系)叶片的Bt毒蛋白含量子叶期最高,达1210.03~1733.15ng/g,与子叶期相比,三叶期、七叶期、盛蕾期、花铃期、吐絮期Bt毒蛋白含量减少幅度为2.5%~96.0%。6个品种(系)对第4代棉铃虫幼虫抗虫性较低,毒杀效果仅为19.0%~41.3%。幼虫的校正死亡率逐代下降,各棉花品种对第4代幼虫的校正死亡率仅为12.0%~36.2%。

  19. 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

  20. Demographics and genetic variability of the new world bollworm (Helicoverpa zea) and the old world bollworm (Helicoverpa armigera) in Brazil.

    Science.gov (United States)

    Leite, Natália A; Alves-Pereira, Alessandro; Corrêa, Alberto S; Zucchi, Maria I; Omoto, Celso

    2014-01-01

    Helicoverpa armigera is one of the primary agricultural pests in the Old World, whereas H. zea is predominant in the New World. However, H. armigera was first documented in Brazil in 2013. Therefore, the geographical distribution, range of hosts, invasion source, and dispersal routes for H. armigera are poorly understood or unknown in Brazil. In this study, we used a phylogeographic analysis of natural H. armigera and H. zea populations to (1) assess the occurrence of both species on different hosts; (2) infer the demographic parameters and genetic structure; (3) determine the potential invasion and dispersal routes for H. armigera within the Brazilian territory; and (4) infer the geographical origin of H. armigera. We analyzed partial sequence data from the cytochrome c oxidase subunit I (COI) gene. We determined that H. armigera individuals were most prevalent on dicotyledonous hosts and that H. zea were most prevalent on maize crops, based on the samples collected between May 2012 and April 2013. The populations of both species showed signs of demographic expansion, and no genetic structure. The high genetic diversity and wide distribution of H. armigera in mid-2012 are consistent with an invasion period prior to the first reports of this species in the literature and/or multiple invasion events within the Brazilian territory. It was not possible to infer the invasion and dispersal routes of H. armigera with this dataset. However, joint analyses using sequences from the Old World indicated the presence of Chinese, Indian, and European lineages within the Brazilian populations of H. armigera. These results suggest that sustainable management plans for the control of H. armigera will be challenging considering the high genetic diversity, polyphagous feeding habits, and great potential mobility of this pest on numerous hosts, which favor the adaptation of this insect to diverse environments and control strategies.

  1. Demographics and genetic variability of the new world bollworm (Helicoverpa zea and the old world bollworm (Helicoverpa armigera in Brazil.

    Directory of Open Access Journals (Sweden)

    Natália A Leite

    Full Text Available Helicoverpa armigera is one of the primary agricultural pests in the Old World, whereas H. zea is predominant in the New World. However, H. armigera was first documented in Brazil in 2013. Therefore, the geographical distribution, range of hosts, invasion source, and dispersal routes for H. armigera are poorly understood or unknown in Brazil. In this study, we used a phylogeographic analysis of natural H. armigera and H. zea populations to (1 assess the occurrence of both species on different hosts; (2 infer the demographic parameters and genetic structure; (3 determine the potential invasion and dispersal routes for H. armigera within the Brazilian territory; and (4 infer the geographical origin of H. armigera. We analyzed partial sequence data from the cytochrome c oxidase subunit I (COI gene. We determined that H. armigera individuals were most prevalent on dicotyledonous hosts and that H. zea were most prevalent on maize crops, based on the samples collected between May 2012 and April 2013. The populations of both species showed signs of demographic expansion, and no genetic structure. The high genetic diversity and wide distribution of H. armigera in mid-2012 are consistent with an invasion period prior to the first reports of this species in the literature and/or multiple invasion events within the Brazilian territory. It was not possible to infer the invasion and dispersal routes of H. armigera with this dataset. However, joint analyses using sequences from the Old World indicated the presence of Chinese, Indian, and European lineages within the Brazilian populations of H. armigera. These results suggest that sustainable management plans for the control of H. armigera will be challenging considering the high genetic diversity, polyphagous feeding habits, and great potential mobility of this pest on numerous hosts, which favor the adaptation of this insect to diverse environments and control strategies.

  2. Resurgence of the cotton bollworm Helicoverpa armigera in northern Greece associated with insecticide resistance.

    Science.gov (United States)

    Mironidis, George K; Kapantaidaki, Despina; Bentila, Maria; Morou, Evangelia; Savopoulou-Soultani, M; Vontas, John

    2013-08-01

    Helicoverpa armigera has been controlled effectively with chemical insecticides in the major cotton crop production areas of northern Greece for many years. However, a resurgence of the pest was observed in 2010, which significantly affected crop production. During a 4-year survey (2007-2010), we examined the insecticide resistance status of H. armigera populations from two major and representative cotton production areas in northern Greece against seven insecticides (chlorpyrifos, diazinon, methomyl, alpha-cypermethrin, cypermethrin, gamma-cyhalothrin and endosulfan). Full dose-response bioassays on third instar larvae were performed by topical application. Lethal doses at 50% were estimated by probit analysis and resistance factors (RF) were calculated, compared to a susceptible laboratory reference strain. Resistance levels were relatively moderate until 2009, with resistance ratios below 10-fold for organophosphates and carbamates and up to 16-fold for the pyrethroid alpha-cypermethrin. However, resistance rose to 46- and 81-fold for chlorpyrifos and alpha-cypermethrin, respectively in 2010, when the resurgence of the pest was observed. None of the known pyrethroid resistance mutations were found in the pyrethroid-resistant insects. The possible association between resistance and H. armigera resurgence in Greece is discussed.

  3. 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.

  4. 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.

  5. 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

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

    Directory of Open Access Journals (Sweden)

    Jizhen Wei

    Full Text Available 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.

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

    Science.gov (United States)

    Wei, Jizhen; 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. 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

  9. Functional specificity of sex pheromone receptors in the cotton bollworm Helicoverpa armigera.

    Directory of Open Access Journals (Sweden)

    Yang Liu

    Full Text Available Male moths can accurately perceive the sex pheromone emitted from conspecific females by their highly accurate and specific olfactory sensory system. Pheromone receptors are of special importance in moth pheromone reception because of their central role in chemosensory signal transduction processes that occur in olfactory receptor neurons in the male antennae. There are a number of pheromone receptor genes have been cloned, however, only a few have been functionally characterized. Here we cloned six full-length pheromone receptor genes from Helicoverpa armigera male antennae. Real-time PCR showing all genes exhibited male-biased expression in adult antennae. Functional analyses of the six pheromone receptor genes were then conducted in the heterologous expression system of Xenopus oocytes. HarmOR13 was found to be a specific receptor for the major sex pheromone component Z11-16:Ald. HarmOR6 was equally tuned to both of Z9-16: Ald and Z9-14: Ald. HarmOR16 was sensitively tuned to Z11-16: OH. HarmOR11, HarmOR14 and HarmOR15 failed to respond to the tested candidate pheromone compounds. Our experiments elucidated the functions of some pheromone receptor genes of H. armigera. These advances may provide remarkable evidence for intraspecific mating choice and speciation extension in moths at molecular level.

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

    Science.gov (United States)

    Zhao, Zhuoya; Li, Yunhe; Xiao, Yutao; Ali, Abid; Dhiloo, Khalid Hussain; Chen, Wenbo; Wu, Kongming

    2016-01-01

    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.

  11. 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. T mean in October had the greatest influence on the pre-wintering density of pupae (PDP). Increasing soil temperatures in October, November, and autumn increased PDP. A higher PDP increased overwintering survival and advanced FD and prolonged DFEPE. The overwintering boundary air temperatures of H. armigera should be expanded due to higher soil temperature and snow covering. Thus, climate warming helped to enhance the survival of overwintering pupae.

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

    Science.gov (United States)

    Von Kanel, M B; Gore, J; Catchot, A; Cook, D; Musser, F; Caprio, M

    2016-04-01

    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.

  13. Isolation and Characterization of Gut Bacterial Proteases Involved in Inducing Pathogenicity of Bacillus thuringiensis Toxin in Cotton Bollworm, Helicoverpa armigera

    Science.gov (United States)

    Regode, Visweshwar; Kuruba, Sreeramulu; Mohammad, Akbar S.; Sharma, Hari C.

    2016-01-01

    Bacillus thuringiensis toxin proteins are deployed in transgenic plants for pest management. The present studies were aimed at characterization of gut bacterial proteases involved in activation of inactive Cry1Ac protoxin (pro-Cry1Ac) to active toxin in Helicoverpa armigera. Bacterial strains were isolated from H. armigera midgut and screened for their proteolytic activation toward pro-Cry1Ac. Among 12 gut bacterial isolates seven isolates showed proteolytic activity, and proteases from three isolates (IVS1, IVS2, and IVS3) were found to be involved in the proteolytic conversion of pro-Cry1Ac into active toxin. The proteases from IVS1, IVS2, and IVS3 isolates were purified to 11.90-, 15.50-, and 17.20-fold, respectively. The optimum pH and temperature for gut bacterial protease activity was 8.0 and 40°C. Maximum inhibition of total proteolytic activity was exerted by phenylmethane sulfonyl fluoride followed by EDTA. Fluorescence zymography revealed that proteases from IVS1, IVS2, and IVS3 were chymotrypsin-like and showing protease band at ~15, 65, and 15 kDa, respectively. Active Cry1Ac formed from processing pro-Cry1Ac by gut bacterial proteases exhibited toxicity toward H. armigera. The gut bacterial isolates IVS1, IVS2, and IVS3 showed homology with B. thuringiensis (CP003763.1), Vibrio fischeri (CP000020.2), and Escherichia coli (CP011342.1), respectively. Proteases produced by midgut bacteria are involved in proteolytic processing of B. thuringiensis protoxin and play a major role in inducing pathogenicity of B. thuringiensis toxins in H. armigera. PMID:27766093

  14. 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...

  15. 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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    Zhao, Zhuoya; Li, Yunhe; Xiao, Yutao; Ali, Abid; Dhiloo, Khalid Hussain; Chen, Wenbo; Wu, Kongming

    2016-01-01

    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. PMID:27399776

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

    Science.gov (United States)

    Zhao, Zhuoya; Li, Yunhe; Xiao, Yutao; Ali, Abid; Dhiloo, Khalid Hussain; Chen, Wenbo; Wu, Kongming

    2016-01-01

    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. PMID:27399776

  19. 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)

  20. 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

  1. 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.

  2. 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.

  3. 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

  4. 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...

  5. SEQUENCE OF THE 18S RIBOSOMAL RNA GENE OF COTTON BOLLWORM (HELICOVERPA ARMIGERA) AND MOLECULAR SYSTEMATICS ANALYSIS%棉铃虫18S核糖体RNA基因的序列分析及其分子系统学

    Institute of Scientific and Technical Information of China (English)

    王瑛; 陈晓峰; 刘伟; 周红章; 赵珩

    1999-01-01

    克隆并分析了鳞翅目棉铃虫Helicoverpa armigera (Hbner)18S核糖体RNA基因(18S rDNA)的全序列,将该序列与鞘翅目、膜翅目、同翅目、双翅目、捻翅目和弹尾目各一种昆虫的同源保守区进行了比较.序列分析结果显示:鳞翅目和双翅目昆虫在18S rDNA结构上彼此较为相似,捻翅目昆虫的18S rDNA分子结构表现出与其它目昆虫有较大的差异,但相对与弹尾目昆虫的18S rDNA较为接近.该结果支持了有关捻翅目属于一个独立的目级分类阶元的论点.

  6. 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.

  7. The transmission of sperm in the female reproduction tract of cotton bollworm,Helicoverpa armigera%棉铃虫精子在雌蛾生殖道内的转移动态

    Institute of Scientific and Technical Information of China (English)

    刘绪生; 李国清; 陈长琨

    2001-01-01

    The transmission and distribution of sperm in the reproduction tract of mated female Helicoverpa armigera,were studied with Feulgen smear and microscope count methods.The results were summarized as follows:(1)Both eupyrene and apyrene sperms started their transmission from the spermatophore to spermatheca at 1.5 h after copulation,and finished this process in half hour.Thereafter,the number of sperms in spermatheca decreased gradually;(2)After transferred to spermatheca,the sperms stored in the utriculus in the form of sperm mass.No sperm was found in lagena;(3)Transportation of sperm to the spermatheca was achieved by means of rhythmic muscular contraction of the female reproduction tract.The active apyrene sperm was also believed to assist in the transmission of the eupyrene sperm.%通过显微镜观察、孚尔根涂片法和显微镜计数法研究了棉铃虫精子在雌蛾生殖道内的转移、分布及转移的动力。结果表明:(1)交配结束后1.5 h,雌蛾精包内的真核精子和无核精子开始向受精囊转移,2 h时近2/3的精子已转入受精囊,其后受精囊内精子的数量逐渐下降;(2)精子转移至受精囊后只分布于主囊,成团聚集,副囊中没有精子;(3)雌虫生殖道肌肉的节律性收缩推动精子转移,同时无核精子的运动也有助于真核精子的移动。

  8. 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....

  9. 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.

  10. 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

  11. 不同光源和暗适应时间对棉铃虫蛾趋光行为的影响%Effects of different light source and dark-adapted time on phototactic behavior of cotton bollworms (Helicoverpa armigera )

    Institute of Scientific and Technical Information of China (English)

    靖湘峰; 罗峰; 朱芬; 黄求应; 雷朝亮

    2005-01-01

    In this paper, the phototactic behaviors of different emergence period Helicoverpa armigera were studied in a phototactic box. The results showed that under the five test wavelength lights, different emergence period female and male moths had no significant difference in their phototactic behaviors. The phototactic rate differed significantly when the dark-adapted time was between 15 and 30 min, but had no significant difference among 30, 45 and 60 min. No significant difference was also found in phototactic rate between dark-adapted time 0 and 15 min under test wavelength lights except green one (500~565 nm).

  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 301.52-7 - Attachment and disposition of certificates or permits.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Attachment and disposition of certificates or permits... Bollworm Quarantine and Regulations § 301.52-7 Attachment and disposition of certificates or permits. (a... document, the attachment of the certificate or permit to each container of the articles is not required....

  14. 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

  15. 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

  16. 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, ...

  17. Modelling biological control with wild-type and genetically modified baculoviruses in the Helicoverpa armigera-cotton system

    NARCIS (Netherlands)

    Sun, X.; Werf, van der W.; Bianchi, F.J.J.A.; Hu, Z.; Vlak, J.M.

    2006-01-01

    A comprehensive model was developed to simulate virus epizootics in a stage structured insect population and analyse scenarios for the biological control of cotton bollworm (CBW), Helicoverpa armigera, in cotton, using wild-type or genetically modified baculoviruses. In simulations on dosage and tim

  18. Genomics and genetic engineering of Helicoverpa armigera nucleopolyhedroviruses

    NARCIS (Netherlands)

    Chen, X.

    2001-01-01

    The single nucleocapsid nucleopolyhedrovirus (SNPV) of the bollworm Helicoverpa armigera has been extensively used to control this insect around the world, especially in China. However, in order to compete with chemical insecticides - mainly for speed of action -novel approaches are sought to improv

  19. 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.

  20. Control of moth pests by mating disruption: Successes and constraints

    NARCIS (Netherlands)

    Cardé, R.T.; Minks, A.K.

    1995-01-01

    Male moths generally find their mates by following the females' pheromone plume to its source. A formulated copy of this message is used to regulate mating of many important pests, including pink bollworm Pectinophora gossypiella, oriental fruit moth Grapholita molesta and tomato pinworm Keiferia ly

  1. 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.

  2. 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)

  3. The Recent Advances in Plant Protection Researches of China

    Institute of Scientific and Technical Information of China (English)

    GuoYuyuan; LiangGemei

    2005-01-01

    There are eight examples briefly given in this paper, namely, (1) Polymyxa graminis and the cereal viruses it transmits; (2) the geographical types and facultative migration of cotton bollworm as well as the safety of Bt transgenic cotton; (3) development of crop near-isogenic lines with resistance to diseases; (4) molecular-biological researches induced resistance of rice by infection of blast fungus;(5) to use cytological and molecular-biological techniques for breeding wheat varieties resistant to barley yellow dwarf virus; (6) mass rearing and field releasing of Microplitis mediator for cotton bollworm control; (7) identification and recombination of insecticidal crystal genes of Bacillus thuringiensis; and (8) interplanting of diverse resistance rice varieties for sustainable control of blast disease; which reflect the general situation of recent advances in plant protection researches of China.

  4. 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)

  5. A Toxin-Binding Alkaline Phosphatase Fragment Synergizes Bt Toxin Cry1Ac against Susceptible and Resistant Helicoverpa armigera

    OpenAIRE

    Wenbo Chen; Chenxi Liu; Yutao Xiao; Dandan Zhang; Yongdong Zhang; Xianchun Li; Bruce E Tabashnik; Kongming Wu

    2015-01-01

    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 p...

  6. 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...

  7. 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

  8. 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.

  9. Yeast one-hybrid screening the potential regulator of CYP6B6 overexpression of Helicoverpa armigera under 2-tridecanone stress.

    Science.gov (United States)

    Zhao, J; Liu, X N; Li, F; Zhuang, S Z; Huang, L N; Ma, J; Gao, X W

    2016-04-01

    In insect, the cytochrome P450 plays a pivotal role in detoxification to toxic allelochemicals. Helicoverpa armigera can tolerate and survive in 2-tridecanone treatment owing to the CYP6B6 responsive expression, which is controlled by some regulatory DNA sequences and transcription regulators. Therefore, the 2-tridecanone responsive region and transcription regulators of the CYP6B6 are responsible for detoxification of cotton bollworm. In this study, we used yeast one-hybrid to screen two potential transcription regulators of the CYP6B6 from H. armigera that respond to the plant secondary toxicant 2-tridecanone, which were named Prey1 and Prey2, respectively. According to the NCBI database blast, Prey1 is the homology with FK506 binding protein (FKBP) of Manduca sexta and Bombyx mori that belongs to the FKBP-C superfamily, while Prey2 may be a homology of an unknown protein of Papilio or the fcaL24 protein homology of B. mori. The electrophoretic mobility shift assays revealed that the FKBP of prokaryotic expression could specifically bind to the active region of the CYP6B6 promoter. After the 6th instar larvae of H. armigera reared on 2-tridecanone artificial diet, we found there were similar patterns of CYP6B6 and FKBP expression of the cotton bollworm treated with 10 mg g-1 2-tridecanone for 48 h, which correlation coefficient was the highest (0.923). Thus, the FKBP is identified as a strong candidate for regulation of the CYP6B6 expression, when the cotton bollworm is treated with 2-tridecanone. This may lead us to a better understanding of transcriptional mechanism of CYP6B6 and provide very useful information for the pest control. PMID:26696496

  10. 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.

  11. 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...

  12. 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)

  13. 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...

  14. Insecticidal activity of residual Bt protein at the second trophic level

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Measurements were taken of Bt protein expressed in the leaves of transgenic cotton (Gossypium hirsutum) transformed with a synthesized Bt (Bacillus thuringiensis) cry1A gene and its persistent level in larval bodies and faeces of a non-targeted insect pest, beet armyworm (Spodoptera exigua). We performed enzyme linked immunosorbent assays (ELISA) and bioassays using neonate larvae of cotton bollworm (Helicoverpa armigera) to detect the insecticidal activity of residual Bt protein at the second trophic level. The results showed that Bt protein content in functional leaves was different at various developmental stages and was different among plants at the same stage. Even though Bt protein concentration in the larval bodies and faeces decreased 97.5%-99% compared to that found in cotton leaves subsequently fed to beet armyworm larvae, it still had a lethal effect on neonate cotton bollworm larvae. Therefore, Bt protein present at the second trophic level had insecticidal activity. This result is important in understanding and predicting the effect of transgenic plants on nontarget organisms.

  15. 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

  16. 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

  17. 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

  18. 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

  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. Mitochondrial DNA COI characterization of Helicoverpa armigera (Lepidoptera: Noctuidae) from Paraguay and Uruguay.

    Science.gov (United States)

    Arnemann, J A; James, W J; Walsh, T K; Guedes, J V C; Smagghe, G; Castiglioni, E; Tay, W T

    2016-04-07

    Since its detection in Brazil in 2013, the Old World cotton bollworm Helicoverpa armigera has been reported in Argentina, Paraguay, and Bolivia. Here we present evidence extending the South American range of H. armigera to Uruguay, using polymerase chain reaction and sequencing of the partial mitochondrial DNA (mtDNA) cytochrome oxidase I region. Molecular characterization of this gene region from individuals from Paraguay also supports previous morphological identification of H. armigera in Paraguay. Shared mtDNA haplotypes in H. armigera from Brazil, Uruguay, and Paraguay were identified. Additional surveying of populations in this region will be imperative to better monitor and understand factors that are underpinning its presence and successful adaptation in these South American regions. We discuss our findings with respect to the development of resistance pest management strategies of this invasive insect pest in a predominantly monoculture soybean crop landscape in the Southern Cone region.

  1. Determination of lethal concentration (LC50 for different insecticides against third instar larvae of Helicoverpa armigera (Hubner (LEPIDOPTERA:NOCTUIDAE

    Directory of Open Access Journals (Sweden)

    M. Hamed

    2006-03-01

    Full Text Available The efficacy of LorsbanTM, Alpha-cypermethrinTM and KarateTM was assessed by larval dip bioassay against third instar larvae of American bollworm, Helicoverpa armigera (Hub. collected from a cotton field at Faisalabad and reared in the laboratory until F1 generation. Third instar larvae were used to assess the toxicity of insecticides after 48 hrs of insecticide treatments. Results showed that toxicity of Karate was above all with LC50 of 71.31ppm followed by Alpha-cypermethrin with LC50 287.87 and Lorsban 464.85, respectively. These results showed the increased resistance of H. armigera against Lorsban in F1 generation under laboratory conditions.

  2. 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.

  3. 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.

  4. 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.

  5. Chinese Scientists Elucidated the Influence Mechanisms of Bt Cotton Plantation on Populations of Target and Non-target Insects in Multiple Crops%中国科学家阐明转基因Bt棉种植对靶标与非靶标昆虫种群的影响机制

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ 2010年5月14日,国际著名杂志报道了中国农业科学院植物保护研究所吴孔明研究团队的研究论文"Mirid Bug Outbreaks in Multiple Crops Correlated with Wide-Scale Adoption of Bt Cotton China"(Bt棉花种植对盲蝽蟓种群区域性灾变影响机制)(Lu et al.,2010),这是继2008年9月19日该团队在Science杂志发表的研究论文(Suppression of Cotton Bollworm in Multiple Crops in China in Areas with Bt Toxin-Containing Cot-ton)以后的又一个重大研究成果(Wu et al.,2008).

  6. 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。

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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

  16. 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)

  17. 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

  18. The Research of Bt and OC Gene Cotransformation in Tobacco Chloroplast

    Institute of Scientific and Technical Information of China (English)

    SU Ning; YANG Bo; MENG Kun; LI Yi-nü; SUN Meng; SUN Bing-yao; SHEN Gui-fang

    2002-01-01

    The Bt Cry IA (C) chloroplast expression cassette and OC chloroplast expression cassette were constructed. The Bt expression cassette contained the 3.5 kb wild type Bt Cry IA (C) gene under the control of the strong light-induced psbA promoter and terminator from rice (Oryza sativa. L) chloroplast, the gene:trnH-psbA-trnk from tobacco (Nicotiana tabacum. L) as the homologous fragment. The OC chloroplast expression cassette contained the OC gene under the control of 16S promoter and terminator from tobacco, the tobacco gene: psbA-ORF512 as homologous fragment. The two cassettes both had the aadA gene expression cassette as the selectable marker. Leaves of tobacco were cotransformed with the particle bombardment method. After selection by spectinomycin, the transformants were obtained. The integration of Bt and OC gene were confirmed by Southern-blotting analysis, and Western-blotting analysis. Proteinase inhibitor assays showed that the Bt and OC gene had expressed. Bioassays showed that the transgenic tobacco had a significant resistance to the larvae of cotton bollworm ( helicoverpa zea ).

  19. Functional validation of cadherin as a receptor of Bt toxin Cry1Ac in Helicoverpa armigera utilizing the CRISPR/Cas9 system.

    Science.gov (United States)

    Wang, Jing; Zhang, Haonan; Wang, Huidong; Zhao, Shan; Zuo, Yayun; Yang, Yihua; Wu, Yidong

    2016-09-01

    Cadherins have been identified as receptors of Bacillus thuringiensis (Bt) Cry1A toxins in several lepidopteran insects including the cotton bollworm, Helicoverpa armigera. Disruption of the cadherin gene HaCad has been genetically linked to resistance to Bt toxin Cry1Ac in H. armigera. By using the CRISPR/Cas9 genome editing system (Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated protein 9), HaCad from the Cry1Ac-susceptible SCD strain of H. armigera was successfully knocked out. A single positive CRISPR event with a frame shift deletion of 4 nucleotides was identified and made homozygous to create a knockout line named SCD-Cad. Western blotting confirmed that HaCad was no longer expressed in the SCD-Cad line while an intact HaCad of 210 kDa was present in the parental SCD strain. Insecticide bioassays were used to show that SCD-Cad exhibited 549-fold resistance to Cry1Ac compared with SCD, but no significant change in susceptibility to Cry2Ab. Our results not only provide strong reverse genetics evidence for HaCad as a functional receptor of Cry1Ac, but also demonstrate that the CRISPR/Cas9 technique can act as a powerful and efficient genome editing tool to study gene function in a global agricultural pest, H. armigera.

  20. 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

  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. Large-scale test of the natural refuge strategy for delaying insect resistance to transgenic Bt crops.

    Science.gov (United States)

    Jin, Lin; Zhang, Haonan; Lu, Yanhui; Yang, Yihua; Wu, Kongming; Tabashnik, Bruce E; Wu, Yidong

    2015-02-01

    The 'natural refuge strategy" for delaying insect resistance to transgenic cotton that produces insecticidal proteins from Bacillus thuringiensis (Bt) relies on refuges of host plants other than cotton that do not make Bt toxins. We tested this widely adopted strategy by comparing predictions from modeling with data from a four-year field study of cotton bollworm (Helicoverpa armigera) resistance to transgenic cotton producing Bt toxin Cry1Ac in six provinces of northern China. Bioassay data revealed that the percentage of resistant insects increased from 0.93% in 2010 to 5.5% in 2013. Modeling predicted that the percentage of resistant insects would exceed 98% in 2013 without natural refuges, but would increase to only 1.1% if natural refuges were as effective as non-Bt cotton refuges. Therefore, the results imply that natural refuges delayed resistance, but were not as effective as an equivalent area of non-Bt cotton refuges. The percentage of resistant insects with nonrecessive inheritance of resistance increased from 37% in 2010 to 84% in 2013. Switching to Bt cotton producing two or more toxins and integrating other control tactics could slow further increases in resistance.

  3. Impacts of transgenic poplar-cotton agro-ecosystems upon target pests and non-target insects under field conditions.

    Science.gov (United States)

    Zhang, D J; Liu, J X; Lu, Z Y; Li, C L; Comada, E; Yang, M S

    2015-07-27

    Poplar-cotton agro-ecosystems are the main agricultural planting modes of cotton fields in China. With increasing acres devoted to transgenic insect-resistant poplar and transgenic insect-resistant cotton, studies examining the effects of transgenic plants on target and non-target insects become increasingly important. We systematically surveyed populations of both target pests and non-target insects for 4 different combinations of poplar-cotton eco-systems over 3 years. Transgenic Bt cotton strongly resisted the target insects Fall webworm moth [Hyphantria cunea (Drury)], Sylepta derogata Fabrieius, and American bollworm (Heliothis armigera), but no clear impact on non-target insect cotton aphids (Aphis gossypii). Importantly, intercrops containing transgenic Pb29 poplar significantly increased the inhibitory effects of Bt cotton on Fall webworm moth in ecosystem IV. Highly resistant Pb29 poplar reduced populations of the target pests Grnsonoma minutara Hubner and non-target insect poplar leaf aphid (Chaitophorus po-pulialbae), while Fall webworm moth populations were unaffected. We determined the effects of Bt toxin from transgenic poplar and cotton on target and non-target pests in different ecosystems of cotton-poplar intercrops and identified the synergistic effects of such combinations toward both target and non-target insects.

  4. 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.

  5. 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.

  6. 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.

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

    Science.gov (United States)

    Chen, Wenbo; Liu, Chenxi; Xiao, Yutao; Zhang, Dandan; Zhang, Yongdong; Li, Xianchun; Tabashnik, Bruce E; Wu, Kongming

    2015-01-01

    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. PMID:25885820

  8. 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.

  9. 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.

  10. 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.

  11. Effects of transgenic Cry1A+CpTI cotton and Cry1Ac toxin on the parasitoid, Campoketis chlorideae (Hymenoptera:Ichneumonidae)

    Institute of Scientific and Technical Information of China (English)

    XIAO-XIALIU; CHANG-GUISUN; QING-WENZHANG

    2005-01-01

    The effect oftransgenic double genes, Cry1A + CpTlcotton and Cry1Ac toxin on the parasitoid, Carnpoketis chlorideae Uchida of cotton bollworm, Helicoverpa armigera (Hübner), was investigated in the laboratory. Helicoverpa armigera larvae when in the first,second and third instar could not survive if fed on transgenic cotton leaves. Consequently,C. chlorideae larvae could not complete their development if parasitizing on such hosts.After H. armigera larvae were reared on transgenic or traditional cotton leaves for 12-48 hours, they were parasitized by C. chlorideae females. Parasitized larvae continued to feed on transgenic or traditional cotton for 12-48 h. The present results showed that the body weight of larvae of the parasitoids were significantly reduced when parasitized hosts fed on transgenic cotton leaves compared to those fed on traditional cotton. Duration of egg and larvae stage were significantly prolonged, pupal and adult weight of C. chloridae was decreased when the host larvae fed on transgenic cotton leaves longer than 48 h. The development duration of C. chlorideae pupae on the hosts fed on transgenic cotton leaves in each treatment was not significantly different from those of controls. The longevity of parasitoid females and males fed with a solution containing Cry1Ac toxin was not significantly different with that of the control.

  12. 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

  13. 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)

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

    Institute of Scientific and Technical Information of China (English)

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

    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 armigera Hilbner. The first and second instar larvae of C. carnea exhibited typeⅡ functional responses against both prey stages. However, the third instar larvae of C. carnea showed a typeⅡ functional response to the first instar larvae of H. armigera, but a typeⅢ functional response to the eggs. For the first instar larvae of C. carnea, the attack rate on H. armigera eggs was significantly higher than that on the larvae, whereas the attack rate of the second instar C. carnea on H. armigera larvae was significantly higher than that on the eggs. For the third instar larvae of C. carnea, the attack rate on the larvae was 1.015± 0.278/h, and the attack coefficient on the eggs was 0.036± 0.005. The handling times of the third instar larvae on larvae and eggs were 0.087± 0.009 and 0.071± 0.001 h, respectively. The highest predation rate was found for the third instar larvae of C. carnea on H. armigera eggs. Results of this study revealed that the larvae of C. carnea, especially the third instar, had a good predation potential in controlling H. armigera eggs and larvae. However, for a comprehensive estimation of the bio-control abilities of C. carnea toward//, armigera, further field-based studies are needed.

  16. 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

  17. 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.

  18. 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

  19. 天山北坡棉铃虫遗传多样性的RAPD分析%Random Amplified Polymorphic DNA Analysis of the Genetic Diversity of Helicoverpa armigera (Hübner) on the Northern Slope of Tianshan Mountains

    Institute of Scientific and Technical Information of China (English)

    邓菲菲; 王登元; 于江南

    2012-01-01

    [ Objective ] This paper aimed to analyze the genetic diversity of Helicoverpa armigera (Hubner) that came from Urumqi and Fukang on the level of DNA molecule. [Method] 11 RAPD primers were used for analyzing genetic diversity of 5 species of cotton bollworm. [Result]H. armigera had the highest levels of genetic diversity that lived on the 222th farming regiment; H. armigera had high levels of genetic diversity that fed on UYM. The lowest genetic diversity were described in H. armigera fed on CJNG. [ Conclusion ] Relatively high levels of migration and small genetic distance were characterized between H. armigera of corn, piemarker and cotton; compared with that from Fukang, high levels of migration were characterized between H. armigera from Changji and Urumqi.%[目的]对采自乌鲁木齐、三坪农场和阜康222团的棉铃虫从分子水平上进行遗传多样性分析.[方法]利用RAPD( Random Amplified Polymorphic DNA)技术.[结果]筛选出11条引物,并利用这些引物对棉铃虫的5个种群进行遗传分化的研究.222团番茄种群棉铃虫遗传多样性水平最高,乌鲁木齐玉米种群其次,昌吉南瓜种群最低.[结论]玉米、苘麻和棉花三种不同寄主间,棉铃虫基因交流更频繁;同阜康相比,昌吉和乌鲁木齐两个地理位置的棉铃虫更易进行基因交流.

  20. 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

  1. 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.

  2. 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.

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

    Science.gov (United States)

    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

  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. Influence of Crop Management and Environmental Factors on Wolf Spider Assemblages (Araneae: Lycosidae) in an Australian Cotton Cropping System.

    Science.gov (United States)

    Rendon, Dalila; Whitehouse, Mary E A; Hulugalle, Nilantha R; Taylor, Phillip W

    2015-02-01

    Wolf spiders (Lycosidae) are the most abundant ground-hunting spiders in the Australian cotton (Gossypium hirsutum L.) agroecosystems. These spiders have potential in controlling pest bollworms, Helicoverpa spp. (Lepidoptera: Noctuidae) in minimum-tilled fields. A study was carried out during a wet growing season (2011-2012) in Narrabri, New South Wales, Australia, to determine how different crop rotations and tillage affect wolf spider assemblages in cotton fields. Spider abundance and species richness did not differ significantly between simple plots (no winter crop) and complex plots (cotton-wheat Triticum aestivum L.-vetch Vicia benghalensis L. rotation). However, the wolf spider biodiversity, as expressed by the Shannon-Weaver and Simpson's indices, was significantly higher in complex plots. Higher biodiversity reflected a more even distribution of the most dominant species (Venatrix konei Berland, Hogna crispipes Koch, and Tasmanicosa leuckartii Thorell) and the presence of more rare species in complex plots. T. leuckartii was more abundant in complex plots and appears to be sensitive to farming disturbances, whereas V. konei and H. crispipes were similarly abundant in the two plot types, suggesting higher resilience or recolonizing abilities. The demographic structure of these three species varied through the season, but not between plot types. Environmental variables had a significant effect on spider assemblage, but effects of environment and plot treatment were overshadowed by the seasonal progression of cotton stages. Maintaining a high density and even distribution of wolf spiders that prey on Helicoverpa spp. should be considered as a conservation biological control element when implementing agronomic and pest management strategies.

  6. 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.

  7. Impact of FFS on farmer's adoption of IPM options for tomato: A case study from the Gezira State, Sudan

    Directory of Open Access Journals (Sweden)

    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.

  8. 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

  9. 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

  10. 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

  11. Study on Competitive Advantage of Glyphosate-resistant Cotton Hybrid F1%抗草甘膦棉花杂交种F1代竞争优势研究

    Institute of Scientific and Technical Information of China (English)

    刘亚平; 田绍仁; 杨兆光; 肖远龙; 涂祈钧

    2011-01-01

    [目的]筛选具有高产、优质、抗草甘膦,综合性状优良的棉花杂交种.[方法]以抗草甘膦棉花品种(系)作父本/母本,与常规优良品种(系)组配14个杂交组合,分析测定各杂交组合在产量、产量构成因子、抗虫和抗草甘膦方面的竞争优势表现.[结果]14个杂交组合生育期较对照赣棉杂1号提前,高抗草甘膦,其中组合① 、⑤ 、⑨ 、⑩ 、[11] 抗棉铃虫;组合②、⑤、⑥、⑩产量构成因子协调,籽、皮棉产量高于对照赣棉杂1号;组合① 、②、③ 、⑤ 、[14] 棉纤维品质较好.[结论]综合抗性、结铃进度、农艺性状、产量和纤维品质等性状,最终筛选出②、⑤、⑥ 、⑩ 等4个高产、优质、抗草甘膦、综合性状优良的杂交组合.%[ Objective ] The hybrid glyphosate-resistant cotton varieties with high yield, fine quality and good comprehensive properties were selected. [ Method] Glyphosate-resistant cotton was hybridized with conventional fine varieties to make 14 hybrid combinations whose yield,yield component factors, pest resistance and glyphosate resistance were analyzed and determined. [ Result ] The growth periods of these 14 hybrid combinations were all earlier than Ganmianza 1 ( CK2 ). They also showed high resistance to glyphosate, of which combinations number with ①、⑤、⑨、⑩ had resistance to cotton bollworm; combinations number with ②、⑤、⑥、⑩ had coordinated yield factors and higher seed plus lint yield than Ganzamian 1 (CK); combinations number with ①、② 、③、⑤、[14] had better lint quality. [ Conclusion] Based on characteristics of comprehensive resistance, bolling process, agronomic traits, yield and fiber quality, combinations numbered with ②、⑤、⑥、⑩ which had high yield, fine quality, glyphosate resistance and good comprehensive properties were selected.

  12. 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

  13. 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

  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. The Cloning and Sequence Analysis of Heat Shock Protein 70 Gene From Antheraea pernyi%柞蚕热休克蛋白70基因的克隆和序列分析

    Institute of Scientific and Technical Information of China (English)

    孙茜; 刘朝良; 朱保健; 刘秋宁

    2011-01-01

    HSP70 protein is stimulated by heat and other factors which induced the protein and it is a member of heat shock protein family, also the most important one.Using RT-PCR, we cloned Tussah (Antheraea pernyi) heat shock protein 70 gene (HSP70) of the ORF sequence.Bioinformatic analysis showed that the sequence encodes 650 amino acids with structural features of HSP70 conservative, and Cecropia moth (Antheraea yamamai), silkworm (Bombyx mor ), cabbage armyworm ( Mamestra brassica), cotton bollworm ( Heliothis viriplaca), beet armyworm ( Spodoptera exigua), tobacco armyworm (Manduca sexta ), Hymenoptera, parasitic wasps (Cotesia rubecula ) homology were 95.7 %, 78.5 %, 76.1%, 77.3 %, 76.6 %, 74.7 %, 65.9 %.According to their structure, we constructed a phylogenetic tree, and further established the kinship between them.%HSPTO蛋白是受热等因素刺激后而诱导产生的蛋白质,是热休克蛋白家族中最重要的一员.采用RTPCR方法克隆了柞蚕(Antherosa pernyi)热休克蛋白70基因(HSP70)的ORF序列(GenBank登录号:GU945199),该片段的序列长度为1905 bp.生物信息学分析表明,该序列共编码634个氨基酸,预测蛋白的等电点和分子量大小分别为5.62 kD和69.5 kD.具有HSPTO的保守性结构特征,与天蚕(Antheraea yamamai)、家蚕(Bombyx mor)、甘蓝夜蛾(Mamestra brassicae)、棉铃虫(Heliothis viriplaca)、甜菜夜蛾(Spodoptera exigua)、烟草夜蛾(Mandusa sextal)、膜翅目寄生蜂(Cotesia rubecula)的同源性分别为95.7%、78.5%、76.1%、77.3%、76.6%、74.7%、65.9%.根据它们的一级结构构建了系统进化树,进一步确立了它们之间的亲缘关系.

  16. 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

  17. 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

  18. Insect Resistance to Bacillus thuringiensis Toxin Cry2Ab Is Conferred by Mutations in an ABC Transporter Subfamily A Protein.

    Directory of Open Access Journals (Sweden)

    Wee Tek Tay

    2015-11-01

    Full Text Available The use of conventional chemical insecticides and bacterial toxins to control lepidopteran pests of global agriculture has imposed significant selection pressure leading to the rapid evolution of insecticide resistance. Transgenic crops (e.g., cotton expressing the Bt Cry toxins are now used world wide to control these pests, including the highly polyphagous and invasive cotton bollworm Helicoverpa armigera. Since 2004, the Cry2Ab toxin has become widely used for controlling H. armigera, often used in combination with Cry1Ac to delay resistance evolution. Isolation of H. armigera and H. punctigera individuals heterozygous for Cry2Ab resistance in 2002 and 2004, respectively, allowed aspects of Cry2Ab resistance (level, fitness costs, genetic dominance, complementation tests to be characterised in both species. However, the gene identity and genetic changes conferring this resistance were unknown, as was the detailed Cry2Ab mode of action. No cross-resistance to Cry1Ac was observed in mutant lines. Biphasic linkage analysis of a Cry2Ab-resistant H. armigera family followed by exon-primed intron-crossing (EPIC marker mapping and candidate gene sequencing identified three independent resistance-associated INDEL mutations in an ATP-Binding Cassette (ABC transporter gene we named HaABCA2. A deletion mutation was also identified in the H. punctigera homolog from the resistant line. All mutations truncate the ABCA2 protein. Isolation of further Cry2Ab resistance alleles in the same gene from field H. armigera populations indicates unequal resistance allele frequencies and the potential for Bt resistance evolution. Identification of the gene involved in resistance as an ABC transporter of the A subfamily adds to the body of evidence on the crucial role this gene family plays in the mode of action of the Bt Cry toxins. The structural differences between the ABCA2, and that of the C subfamily required for Cry1Ac toxicity, indicate differences in the

  19. Insect Resistance to Bacillus thuringiensis Toxin Cry2Ab Is Conferred by Mutations in an ABC Transporter Subfamily A Protein.

    Science.gov (United States)

    Tay, Wee Tek; Mahon, Rod J; Heckel, David G; Walsh, Thomas K; Downes, Sharon; James, William J; Lee, Sui-Fai; Reineke, Annette; Williams, Adam K; Gordon, Karl H J

    2015-11-01

    The use of conventional chemical insecticides and bacterial toxins to control lepidopteran pests of global agriculture has imposed significant selection pressure leading to the rapid evolution of insecticide resistance. Transgenic crops (e.g., cotton) expressing the Bt Cry toxins are now used world wide to control these pests, including the highly polyphagous and invasive cotton bollworm Helicoverpa armigera. Since 2004, the Cry2Ab toxin has become widely used for controlling H. armigera, often used in combination with Cry1Ac to delay resistance evolution. Isolation of H. armigera and H. punctigera individuals heterozygous for Cry2Ab resistance in 2002 and 2004, respectively, allowed aspects of Cry2Ab resistance (level, fitness costs, genetic dominance, complementation tests) to be characterised in both species. However, the gene identity and genetic changes conferring this resistance were unknown, as was the detailed Cry2Ab mode of action. No cross-resistance to Cry1Ac was observed in mutant lines. Biphasic linkage analysis of a Cry2Ab-resistant H. armigera family followed by exon-primed intron-crossing (EPIC) marker mapping and candidate gene sequencing identified three independent resistance-associated INDEL mutations in an ATP-Binding Cassette (ABC) transporter gene we named HaABCA2. A deletion mutation was also identified in the H. punctigera homolog from the resistant line. All mutations truncate the ABCA2 protein. Isolation of further Cry2Ab resistance alleles in the same gene from field H. armigera populations indicates unequal resistance allele frequencies and the potential for Bt resistance evolution. Identification of the gene involved in resistance as an ABC transporter of the A subfamily adds to the body of evidence on the crucial role this gene family plays in the mode of action of the Bt Cry toxins. The structural differences between the ABCA2, and that of the C subfamily required for Cry1Ac toxicity, indicate differences in the detailed mode

  20. 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

  1. 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

  2. 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

  3. 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'

  4. 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

  5. 转基因杨棉复合系统对节肢动物群落结构的影响%Effects of Transgenic Poplar-Cotton Compound Ecosystem on the Structure of Arthropod Community

    Institute of Scientific and Technical Information of China (English)

    陈辉惶; 温俊宝; 朱银飞; 李洪清

    2012-01-01

    The present research were designed to reveal arthropod community of 4 different poplar-cottons compound ecosystem:Bt poplar+Bt cotton patterns,Bt poplar+non Bt cotton patterns,non Bt poplar + Bt cotton patterns and non Bt patterns+non Bt cotton patterns,and to analyze the influence of Bt poplar cotton compound ecosystem on the community structure by using community ecological principals and method. The results indicated that the transgenic Bt poplar and transgenic Bt cotton agro-forestry ecosystem had dramatic effect on the community structure of arthropod by comparison with other 3 compound e-cosystems had significant impact on controlling the numbers and species of target insects and helped to control occurence of target insects,but to cause the increase of the numbers and species of other nontarget insects. Meanwhiles the Bt polar-Bt cotton compound system can increase the numbers and species of non-target inscets,and become a dominance population with natural pests. From the view of bollworm-resist-ant,it is worth spreading the agro-forestry arrangement patterns, because the average ratio between good and harm of Bt transgenic cotton of Bt transgenic cotton was 0. 5622. While,analyzing the diversity index, richness index , evenness index of Bt polar - Bt cotton ecosystem community structure , which revealed that the stability of community was decreasing,its dominant populations became singleness,maybe disturb the eco-nutrition recycle. Accordingly, in order to keep the stability of the compound ecosystem, the transgenic agroforestrial ecosystem,the strategy of ecological management should be introduced.%通过对转基因杨+转基因棉、转基因杨+非转基因棉、非转基因杨+转基因棉、非转基因杨+非转基因棉4种杨棉复合系统节肢动物群落进行调查,运用群落生态学原理和方法分析了转基因杨棉复合系统对节肢动物群落结构的影响.研究表明,与其他3种复合系统相比,转基因杨棉复合系

  6. 高产稳产多抗棉花新品种周棉6号的选育与应用%Breeding and Application of High and Stable Yield, Multi-resistant Cotton Cultivar Zhoumian No. 6

    Institute of Scientific and Technical Information of China (English)

    贾朝阳; 马威; 张海之; 刘德征; 张景峰; 雷亚柯; 魏秀丽

    2011-01-01

    Zhoumian No. 6 is a new upland cotton cultivar. Its female parent is from the F1 of Si 331×Zhou R- 3,and male parent is from the F3 of Lu 742 × 9708. After continuous selection in the segregating generation', we grained Zhoumian No. 6. It was released by Henan Crop Variety Approval Committee in 2009. The average lent yield and that before frost were 1 517.3 kg/ha and 1430.3kg/ha and the average yield increase rate were 10.3% and 9.0% in Henan province regional trials during 2006 and 2007 respectively. The range of average increasing reached very significant level. In 2006 to 2007, the fiber quality was integrative with on upper half mean length 29.4 mm,uniformity 85.5% ,strength 27.9 cN/tex,and Micronaire value 4.9. Zoumian No. 6 was high resistant to Fusariurn wilt, and was tolerant to Vertillium wilt, and also high resistance to bollworm. The cultivar integrated the characteristics of high-yield, stable-yield, high quality and multi-resistance. The popularization and application will have a tremendous prospect. We also provided the brief cultivated techniques of the new cultivar here.%周棉6号是周口市农业科学院以(泗331×周R-3)F代材料为母本,以(鲁742×9708)F代选系材料为父本,进行复合杂交,并对复合杂交分离群体进行多年连续选育而成的棉花新品种.2009年通过河南省农作物品种审定委员会审定.该品种在2006、2007年河南省棉花区域试验中,皮棉、霜前皮棉平均产量分别为1517.3 kg/hm和1430.3 kg/hm,与对照鲁棉21相比,平均增产率分别为10.3%和9.0%,均达极显著水平.周棉6号2a平均纤维品质:上半部平均纤维长度29.4 mm,整齐度85.5%,比强度27.9 cN/tex,马克隆值4.9.高抗枯萎病,耐黄萎痛,抗棉铃虫.周棉6号集高产、稳产、优质、多抗于一体,具有较好的推广应用前景.

  7. 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

  8. 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

  9. 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

  10. 农作物主要病虫害对甘肃气候暖干化的响应及应对技术的研究进展%The Response of Plant Diseases and Pests to Climatic Warmer-drying and Its Adaptive Technique in the Northwest China

    Institute of Scientific and Technical Information of China (English)

    邓振镛; 张强; 王润元; 赵鸿; 徐金芳; 刘明春; 赵红岩; 姚玉璧

    2012-01-01

    By analyzing meteorological elements of 80 meteorological stations in Gansu province from 1961 to 2010,we concluded that the warmer and drying in the northwest region was the basic features of modern climate changing.The results showed that the annual average temperature raised 0.29 ℃ per decade and temperature increased 1.4 ℃ during nearly half a century.The warmer years were in the period of from 1997 to 2008 within 48 years.Annual precipitation had been declining since 1961,and the turning point was in 1986,the average annual precipitation reduced by 20 to 40 mm during 1987 to 2008 than that in 1961 to 1986.We analyzed the relationship between the development of wheat stripe rust,potato epidemic,aphid,cotton bollworm and red mite and meteorological factors.We explored the impact of climate warm-drying on the safety of HIV strains overwinter and oversummer,breed generations,disease time,harmful region,area and degree.The five main harmful characteristics had been exposed.First,the kinds of pests increased and harmful range amplified.Second,the boundary line of overwinter moved northward and harmful degree increased.Third,the period of pest growth extended,the breed generations increased and pest population growth accelerated.Fourth,the viral disease increased and pandemic occurred easily.Last,the ecology system of host,parasite and natural enemy population changed and the pest produced rapidly.We also provided four countermeasures to adapt to climate warmer-drying.We should firstly build the assessment and early warning system for crop pest monitoring and first-rate service.Next,the new control model of plant diseases and pests should be set up to adapt to climate change.Then,we should adjust the plant structure by weather forecast and different climate model year.Lastly,we should make fining crop pests comprehensive and agricultural natural resources division and confirm the region of high plant disease risk and the spot of key prevention and control

  11. 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

  12. 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

  13. 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