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Hübner
Kinds of Hübner Selected AbstractsImpact of avian and arthropod predation on lepidopteran caterpillar densities and plant productivity in an ephemeral agroecosystemECOLOGICAL ENTOMOLOGY, Issue 5 2003Cerruti R. R. Hooks Abstract., 1.,Most studies evaluating the combined impact of spiders and other predators on herbivore densities in agroecosystems have focused primarily on their trophic connections with invertebrate predators (e.g. carabids, chrysopids); however linkages among spiders and vertebrate predators may also help structure the population dynamics of insect herbivores. A field experiment was conducted to examine the impact of avian and spider predation on lepidopteran caterpillar densities and plant productivity within a Brassica agroecosystem. 2.,Arthropod abundance, leaf-chewing damage, and final plant productivity associated with broccoli, Brassica oleracea L. (var. italica), were recorded for four treatments: (1) bird present but spiders removed; (2) both birds and spiders present; (3) birds excluded, spiders present; and (4) birds and spiders both excluded. 3.,Densities of Artogeia rapae L. (Lepidoptera: Pieridae) and Trichoplusia ni Hübner (Lepidoptera: Noctuidae) large caterpillars and post feeding stages were reduced significantly by bird predation. The abundance of large caterpillars was also reduced on spider-inhabited plants during early plant growth; however the assemblage of birds and spiders did not suppress caterpillar densities more significantly than either predator alone. 4.,Plants protected by birds, spiders, and birds plus spiders sustained less folivory attributable to leaf chewing caterpillars than check plants. Plant productivity was also greater for predator-protected plants than check plants. 5.,Although spiders and parasitoids were responsible for some of the mortality inflicted upon lepidopteran caterpillars, it was concluded that in this study system, birds are the most important natural enemies of folivores. [source] Effects of elevated CO2 associated with maize on multiple generations of the cotton bollworm, Helicoverpa armigeraENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2010Jin Yin Abstract Under elevated environmental carbon dioxide (CO2), leaf chewers tend to compensate for decreased leaf nutritional quality with increased consumption; mortality and development times also increase and cause a reduction in the fitness of leaf chewers. However, the effect of elevated CO2 on multiple successive generations of these and other insects is not well understood. Furthermore, information about the direct effects of increased environmental CO2 on developmental time and consumption of herbivores is lacking. In this paper, we tested the hypothesis that cascade effects of elevated CO2 through plants, rather than the direct effects of elevated CO2, are the main factors decreasing the fitness of cotton bollworm, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae). We used two series of experiments to quantify the growth, development, and consumption of H. armigera fed on an artificial diet or C4 plants (maize) grown under two CO2 levels (ambient vs. double ambient). In the first series of experiments, elevated CO2 had no effect on the population abundance or individual consumption for three successive generations of cotton bollworms fed on an artificial diet. In the second series of experiments, elevated CO2 reduced population abundance of cotton bollworm larvae for two successive generations when they were fed maize milky grains. The specific effects were longer larval duration, lower fecundity, and decreased rm of cotton bollworms. Furthermore, elevated CO2 increased individual consumption when cotton bollworm was fed maize milky grains for two successive generations and decreased the population's total consumption in the first generation but increased it in the second generation. The results from this study indicate that: (1) The effects of elevated CO2 on three successive generations of cotton bollworm fed on artificial diet were weak, or even non-existent, and (2) elevated CO2 increased the consumption when cotton bollworm were fed maize. Our study also suggests that the damage inflicted by cotton bollworm on maize (a C4 plant) will be seriously affected by the increases in atmospheric CO2, which is unlike our previous results for spring wheat (a C3 plant). [source] Interspecific competition between the ichneumonid Campoletis chlorideae and the braconid Microplitis mediator in their host Helicoverpa armigeraENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2008Shen-Peng Tian Abstract We investigated interspecific competition between Campoletis chlorideae Uchida (Hymenoptera: Ichneumonidae) and Microplitis mediator (Haliday) (Hymenoptera: Braconidae) in their host, the cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) under laboratory conditions. Cotton bollworm larvae were allowed to be parasitized by both wasp species simultaneously or sequentially at different time intervals. When host larvae were parasitized simultaneously by both parasitoids, the majority of the cocoons produced were of M. mediator. When host larvae were parasitized initially by M. mediator followed by C. chlorideae at 12 or 24 h, parasitoids emerging from the multiparasitized hosts were mainly M. mediator. In contrast, when host larvae were parasitized initially by C. chlorideae, followed by M. mediator 12 or 24 h later, parasitoids emerging from the multiparasitized hosts were mainly C. chlorideae. Dissections of host larvae at various time intervals after parasitization by the two parasitoids showed that first instars of M. mediator could physically attack the larvae of C. chlorideae, but not the eggs of C. chlorideae. When a host was parasitized by both wasp species sequentially, more host larvae died and the number of wasp offspring was significantly reduced compared to a host parasitized by only one wasp. Conversely, in simultaneous multiparasitism, the host mortality and wasp offspring production were not significantly different from those parasitized by single wasp species. [source] Trapping noctuid moths with synthetic floral volatile luresENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 3 2002Robert L. Meagher Jr. Abstract Male and female noctuid moths were collected from plastic bucket traps that were baited with different synthetic floral chemicals and placed in peanut fields. Traps baited with phenylacetaldehyde, benzyl acetate, and a blend of phenylacetaldehyde, benzyl acetate, and benzaldehyde collected more soybean looper moths, Pseudoplusia includens (Walker), than benzaldehyde-baited or unbaited traps. Females comprised over 67% of the moths captured and most were mated. At peak capture, over 90 male and female moths per night were collected. In another experiment, phenylacetaldehyde delivered in plastic stoppers attracted more P. includens moths than traps baited using other substrates, but this chemical delivered in wax attracted more velvetbean caterpillar moths (Anticarsia gemmatalis Hübner). Other noctuid male and female moths collected included Agrotis subterranea (F.), Argyrogramma verruca (F.), Helicoverpa zea (Boddie), and several Spodoptera species. Aculeate Hymenoptera were collected in large numbers, especially in traps baited with phenylacetaldehyde delivered from stoppers. [source] Ancestral feeding and survival of offspring in European corn borerENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2002D.A. Andow Abstract Experiments were conducted to evaluate the influence of ancestral adult feeding by European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), on larval survival in the field and neonate movement behavior in laboratory. Larval survival was higher when either the grandparental or parental generation had fed, but the feeding sites of the surviving larvae were not affected by ancestral feeding condition. This is the first evidence that grandparental feeding could influence larval survival in the field. Larval movement was observed in the laboratory. Silking speed of neonates was faster when either grandparents or parents had fed, while walking speed was faster only when parents had fed. No broad-sense genetic correlation was found between silking speed and walking speed. Broad-sense heritability among feeding histories were not significant for silking speed, but was significantly greater than zero for walking speed when grandparents fed and parents did not. These intergenerational effects could induce complex population dynamics in this species. [source] Taxonomy of the Cidariini (Lepidoptera, Geometridae) in Korea (II)ENTOMOLOGICAL RESEARCH, Issue 1 2004Sei-Woong CHOI ABSTRACT Eight genera and 16 species of the Korean Cidariini, a tribe of Larentiinae (Lepidoptera, Geometridae), were revised: Dysstroma Hübner, Paradysstroma Choi, Callabraxas Butler, Thera Stephens, Heterothera Inoue, Pennithera Viidalepp, Polythrena Guenée and Xenortholitha Inoue. Pennithera comis (Butler) was newly added to the Korean fauna. Diagnostic and phylogenetic characters supporting the monophyly of the genera and a key to the genera were provided. For the species, diagnoses with figures of male and female genitalia and distributional data with maps in Korea, and taxonomic remarks were provided. [source] Taxonomy of the Cidariini (Lepidoptera, Geometridae) in Korea (I)ENTOMOLOGICAL RESEARCH, Issue 4 2002Sei-Woong CHOI ABSTRACT Among forty species of the Korean Cidariini, a tribe of Larentiinae (Lepidoptera, Geometridae), nineteen species of ten genera are revised: Ecliptopera Warren, Lampropteryx Stephens, Eustroma Hübner, Eveeliptopera Inoue, Lobogonodes Bastelberger, Hysterura Warren, Sibatania Inoue, Eulithis Hiibner, Gandaritis Moore, and Electrophaes Prout. The diagnostic characters and monophyly of each genus are provided. Figures of adults including male and female genitalia, and distribution maps in Korea are also provided. [source] piggyBac- like elements in cotton bollworm, Helicoverpa armigera (Hübner)INSECT MOLECULAR BIOLOGY, Issue 1 2008Z. C. Sun Abstract Two piggyBac -like elements (PLEs) were identified in the cotton bollworm, Helicoverpa armigera, and were designated as HaPLE1 and HaPLE2. HaPLE1 is flanked by 16 bp inverted terminal repeats (ITRs) and the duplicated TTAA tetranucleotide, and contains an open reading frame (ORF) of 1794 bp with the presumed DDD domain, indicating that this element may be an active autonomously mobile element. HaPLE2 was found with the same ITRs, but lacks the majority of an ORF-encoding transposase. Thus, this element was thought to be a non-autonomous element. Transposable element displays and distribution of the two PLEs in individuals from three different H. armigera populations suggest that transmobilization of HaPLE2 by the transposase of HaPLE1 may be likely, and mobilization of HaPLE1 might occur not only within the same individual, but also among different individuals. In addition, horizontal transfer was probably involved in the evolution of PLEs between H. armigera and Trichoplusia ni. [source] Efficacy of an esfenvalerate plus methoprene aerosol for the control of eggs and fifth instars of Plodia interpunctella (Lepidoptera: Pyralidae)INSECT SCIENCE, Issue 1 2010Emily A. Jenson Abstract, Aerosol insecticides may provide an alternative to fumigants for control of the Indianmeal moth, Plodia interpunctella (Hübner), the Indianmeal moth, a major insect pest of stored processed food. In this study, eggs and larvae (5th instars) of P. interpunctella were exposed to aerosol applications of the pyrethroid esfenvalerate and insect growth regulator methoprene, alone and in combination, in open and obstructed positions inside small sheds. When larvae were exposed to methoprene alone, adult emergence from those exposed larvae was 7.1%± 1.5%. In contrast, adult emergence was 92.5%± 3.5% when larvae were exposed to esfenvalerate alone. When eggs were exposed to methoprene, adult emergence of those exposed eggs was approximately 75%; however, when eggs were exposed to esfenvalerate, adult emergence was approximately 35%. In the combination treatment of methoprene plus esfenvalerate at their respective label rates, adult emergence following larval exposure was 0.91%± 0.61% compared to 16.3%± 9.6% when eggs were exposed. Based on our results, methoprene alone is highly effective in reducing adult emergence after larval exposure. However, it is not as effective on eggs as esfenvalerate. A combination treatment of esfenvalerate plus methoprene could be used to control eggs and the wandering-phase larval stages of P. interpunctella. An economic risk analysis also supports a strategy of combining methoprene and esfenvalerate. [source] Effects of neem-based insecticides on beet armyworm (Lepidoptera: Noctuidae)INSECT SCIENCE, Issue 1 2005SHOIL M. GREENBERG Abstract Three commercial neem [Azadirachta indica A. Juss (Meliaceae)]-based insecticides, Agroneem, Ecozin, and Neemix, and a non-commercial neem leaf powder, were evaluated for oviposition deterrence, antifeedant effect on larvae, and toxicity to eggs and larvae of the beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), on cotton leaves in the laboratory. Oviposition deterrence in no-choice, and two- and fivechoice assays, was observed for the neem-based insecticide treatments when compared with a non-treated control. Neem-based insecticides also deterred feeding by beet armyworm larvae. Direct contact with neem-based insecticides decreased the survival of beet armyworm eggs. Survival of beet armyworm larvae fed for 7 days on leaves treated with neembased insecticides was reduced to 27, 33, 60, and 61% for neem leaf powder, Ecozin, Agroneem, and Neemix, respectively. Possibilities for adoption of neem-based insecticides in commercial cotton for beet armyworm control are discussed. [source] The persistence in hedge fund performance: extended analysisINTERNATIONAL JOURNAL OF FINANCE & ECONOMICS, Issue 3 2009Daniel P. J. Capocci Abstract This study analyses and decomposes hedge fund returns to detect a systematic hedge fund selection criterion that enables investors to consistently and significantly outperform classical equities and bond indices over a full market cycle and over bullish and bearish market periods. The methodology used is adapted from Capocci and Hübner. The measures used include the returns, the volatility, the Sharpe score, the alpha, the beta, the skewness and the kurtosis. Measures incorporating the volatility display very strong ability to assist investors in creating alpha and consistently and significantly outperform classical indices. A sub-period analysis is performed to check the robustness of the results. Copyright © 2008 John Wiley & Sons, Ltd. [source] Response of multiple generations of beet armyworm, Spodoptera exigua (Hübner), feeding on transgenic Bt cottonJOURNAL OF APPLIED ENTOMOLOGY, Issue 2 2009G. Wu Abstract Development, reproduction and food utilization of three successive generations of beet armyworm, Spodoptera exigua (Hübner), fed on transgenic and non-transgenic Bt cotton were examined. Significantly longer larval life-span and lower pupal weight were observed in three successive generations of S. exigua fed on transgenic Bt cotton compared with non-transgenic Bt cotton. Significantly higher survival rate and adult fecundity of S. exigua were found in three successive generations of S. exigua fed on transgenic Bt cotton compared with non-transgenic Bt cotton. The survival rate and adult fecundity of S. exigua were occurred significant increase in the third generation compared with the first generation after feeding on transgenic Bt cotton. Significantly lower consumption, frass and relative growth rate (RGR) were observed in three successive generations of S. exigua fed on transgenic Bt cotton compared with non-transgenic Bt cotton. Cotton variety significantly affected all indices of larval consumption and utilization in three successive generations of S. exigua, except for efficiency of conversion of ingested food. However, beet armyworm generation only significantly affected RGR of S. exigua. The results of this study indicated food quality on the diet-utilization efficiency of S. exigua was different along with beet armyworm generation. Measuring multigenerational development and food utilization of S. exigua at individual and population level in response to Bacillus thuringiensis (Bt) can provide a more meaningful evaluation of long-term population dynamics than experiments on a single generation. It is imperative to develop an appropriate multigenerational pest management tactic to monitor the field population dynamics of non-target pests (e.g., beet armyworm) in agricultural Bt cotton ecosystem. [source] Altered mating behaviour in a Cry1Ac-resistant strain of Helicoverpa armigera (Lepidoptera: Noctuidae)JOURNAL OF APPLIED ENTOMOLOGY, Issue 5 2008X. C. Zhao Abstract Randomness of mating between susceptible and resistant individuals is a major factor that closely relates to the refuge strategy of resistance management for Helicoverpa armigera (Hübner) to Bacillus thuringiensis cotton. The mating behaviour of Cry1Ac-susceptible and Cry1Ac-resistant strains of H. armigera was compared to investigate the randomness of their mating. The percentage of mating was lower for Cry1Ac-resistant H. armigera compared with that of the susceptible strain under both no-choice and multiple-choice conditions. The low percentage of mating in the resistant strain indicates a reduced incidence of successful mating. The percentage of spermatophore-containing mated female H. armigera in the crossing of susceptible females × resistant males was significantly lower than in the crossing of resistant females × susceptible males, but the observed mating frequencies of these two types of cross were similar to each other. This indicates that resistant males reduce the incidence of mating paternity more than they do their mating frequency. The percentages of heterogametic matings (susceptible females × resistant males, resistant females × susceptible males) in the multiple-choice experiment were lower than those of homogametic matings (susceptible × susceptible, resistant × resistant) on peak mating nights. However, the difference between heterogametic and homogametic mating was not significant, indicating that there was a random mating between susceptible and resistant strains. The results presented here do not reflect reality in mating associated with Cry1Ac resistance but can provide insight into variable expression. [source] Effects of Bt-toxin Cry1Ac on Propylaea japonica Thunberg (Col., Coccinellidae) by feeding on Bt-treated Bt-resistant Helicoverpa armigera (Hübner) (Lep., Noctuidae) larvaeJOURNAL OF APPLIED ENTOMOLOGY, Issue 4 2006S.-Y. Zhang Abstract:,Propylaea japonica is an important predatory insect of common cotton pests. To assess the ecological effects of transgenic Bt cotton, expressing Cry1Ac toxin, on this predator, we examined the life history parameters of P. japonica for two generations by feeding them with Bt-resistant Helicoverpa armigera. After ingesting Bt-treated Bt-resistant H. armigera larvae in the third and fourth instar, the body mass and body length of adult P. japonica decreased, a combined effect of poor prey quality and Cry1Ac Bt-toxin may account for these effects. However, larval survivorship and development in these two instars, pupal mortality, fecundity and adult longevity of P. japonica were not affected in both the generations. These results suggest that ingesting Bt-toxin Cry1Ac-treated pests in advanced larval stage might have no significant effect on the fitness of predator P. japonica. [source] Response of multiple generations of cotton bollworm Helicoverpa armigera Hübner, feeding on spring wheat, to elevated CO2JOURNAL OF APPLIED ENTOMOLOGY, Issue 1 2006G. Wu Abstract:, The growth, development and consumption of three successive generations of cotton bollworm, Helicoverpa armigera (Hübner), reared on milky grains of spring wheat grown under elevated CO2 (double-ambient vs. ambient) in open-top chambers (OTCs) were examined. Decreases in protein, total amino acid, water and nitrogen content, and increases in total non-structure carbohydrates (TNCs) and ratio of TNC : nitrogen were found in wheat milky grains grown under elevated CO2 conditions. Changes in quality of wheat grains affected the growth, development and food utilization of H. armigera. Significantly longer larval lifespan for the third generation and lower pupal weight for all generations were observed in cotton bollworm fed on milky grains of spring wheat grown under elevated CO2 conditions. Bollworm fecundity was significantly decreased for the second and third generations under elevated CO2 levels. The consumption, frass per larva and relative consumption rate significantly increased in elevated CO2 compared with ambient CO2 conditions. However, the potential population consumption was significant reduced by elevated CO2 in the second and third generations. The results of this study indicate that elevated CO2 levels adversely affect grain quality, resulting in consistently increased consumption per larva for a longer period to produce less fecund bollworm through generations, suggesting that net damage of cotton bollworm on wheat will be less under elevated atmospheric CO2 levels because increased consumption is offset by slower development and reduced fecundity. [source] Foraging behaviour of Helicoverpa armigera first instar larvae on crop plants of different developmental stagesJOURNAL OF APPLIED ENTOMOLOGY, Issue 5 2005M.-L. Johnson Abstract:, Understanding how insect pests forage on their food plants can help optimize management strategies. Helicoverpa armigera (Hübner) (Lep., Noctuidae) is a major polyphagous pest of agricultural crops worldwide. The immature stages feed and forage on crops at all stages of plant development, damaging fruiting and non-fruiting structures, yet very little is known about the influence of host type or stage on the location and behaviour of larvae. Through semi-continuous observation, we evaluated the foraging (movement and feeding) behaviours of H. armigera first instar larvae as well as the proportion of time spent at key locations on mungbean [Vigna radiata (L.) Wilczek] and pigeon pea [Cajanus cajan (L.) Millspaugh] of differing developmental stages: seedling- and mature (flowering/pod fill)-stage plants. Both host type and age affected the behaviour of larvae. Larvae spent more time in the upper parts of mature plants than on seedlings and tended to stay at the top of mature plants if they moved there. This difference was greater in pigeon pea than in mungbean. The proportion of time allocated to feeding on different parts of a plant differed with host and age. More feeding occurred in the top of mature pigeon pea plants but did not differ between mature and seedling mungbean plants. The duration of key behaviours did not differ between plant ages in either crop type and was similar between hosts although resting bouts were substantially longer on mungbeans. Thus a polyphagous species such as H. armigera does not forage in equivalent ways on different hosts in the first instar stage. [source] Pattern of cross-resistance in pyrethroid-selected populations of Helicoverpa armigera Hübner (Lep., Noctuidae) from IndiaJOURNAL OF APPLIED ENTOMOLOGY, Issue 9-10 2004T. Ramasubramanian Abstract:, In Helicoverpa armigera, withdrawal of selection pressure resulted in a two- to fourfold increase in susceptibility to synthetic pyrethroids and continuous selection enhanced the resistance level by four- to fivefold to the respective pyrethroids at the end of the 14th generation. Populations selected for resistance to one pyrethroid showed positive cross-resistance to all other pyrethroids, but no cross-resistance to endosulfan and thiodicarb. There was a significant increase in mixed-function oxidase activity with advancing generation suggesting its possible role in the positive cross-resistance among the pyrethroids. The induction of carboxyl esterases in pyrethroid-selected populations may have resulted in the activation of indoxacarb, thereby accounting for the observed negative cross-resistance. [source] Bioefficacy and mode of action of rocaglamide from Aglaia elaeagnoidea (syn. A. roxburghiana) against gram pod borer, Helicoverpa armigera (Hübner)JOURNAL OF APPLIED ENTOMOLOGY, Issue 3 2004O. Koul Abstract:, Rocaglamide, a highly substituted benzofuran, was isolated and identified as the main biologically active component in Aglaia elaeagnoidea (syn. A. roxburghiana) for gram pod borer Helicoverpa armigera (Hübner). Addition of rocaglamide to an artificial diet retarded the growth of neonate larvae in a dose-dependent manner with EC50 values of 0.76 p.p.m. These values compared favourably with azadirachtin (EC50 = 0.23 p.p.m.). However, azadirachtin was apparently more potent than rocaglamide in inducing growth inhibition via oral administration to these first stadium larvae. The candidate compound was found to have LD50 and LD95 values of 0.40 and 1.02 ,g per larva, respectively, in topical application against third instar larvae 96 h post-treatment. However, these values for azadirachtin were 8.16 and 25.8 ,g per larva for the same period. This shows that azadirachtin was less effective against third instar H. armigera larvae in inducing acute toxicity via topical treatment in comparison with rocaglamide. However, severe morphological larval deformities were observed in such azadirachtin-treated larvae during the process of ecdysis. The cytotoxic nature of rocaglamide was established by evaluating dietary utilization and the results did not implicate any antifeedant effect but the toxicity-mediated effect due to reduced efficiency of conversion of ingested food. It was obvious that feeding deterrence is not the primary mode of action but a centrally mediated effect, which could be due to the induced cytotoxicity at non-specific cellular levels. [source] The influence of greenhouse chrysanthemum on the interaction between the beet armyworm, Spodoptera exigua, and the baculovirus SeMNPV: parameter quantification for a process-based simulation modelJOURNAL OF APPLIED ENTOMOLOGY, Issue 9-10 2001F. J. J. A. Bianchi During the building of a process-based simulation model for the epidemiology of the multicapsid nucleopolyhedrovirus of S. exigua (SeMNPV) in populations of Spodoptera exigua (Hübner) in greenhouse chrysanthemum, it was found that the effect of host plants had been under-rated. ,Missing links' included (i) the ,natural' background mortality of larvae of S. exigua in practical cropping conditions; (ii) the developmental rate of larvae of S. exigua on plant substrate in a glasshouse as compared to artificial medium in the laboratory; (iii) the validity of the results of dose-mortality and time-mortality bioassays conducted on artificial medium as compared to natural plant substrate; (iv) the distribution of inoculum released from deceased caterpillars over chrysanthemum leaves; and (v) the leaf visit rate of healthy caterpillars (as it affects horizontal transmission). Experiments were carried out to quantify these processes. Developmental rates of S. exigua larvae on greenhouse chrysanthemum were 36% lower than on an artificial diet. The fraction survival during the first, second, third and fourth instar S. exigua larvae in greenhouse chrysanthemum was 0.60, 0.80, 0.88 and 0.95, respectively. Forty percent of the first instar larvae reached the fifth larval stage. Second instar S. exigua larvae reared on chrysanthemum were significantly more susceptible to SeMNPV than larvae reared on an artificial diet. The food source had no effect on the time to kill S. exigua larvae. Cadavers of second, third and fourth instar S. exigua larvae contaminated on average 1.4, 2.5 and 3.3 chrysanthemum leaves. Second to fourth instar S. exigua larvae visited 2,3 leaves per day and spent 15,55% of the time on the underside of leaves. The above information is of critical importance for a trustworthy simulation of the epidemiology of SeMNPV in chrysanthemum. [source] Laboratory and field studies on the integrated pest management of Helicoverpa armigera (Hübner) in cotton, based on pheromone trap catch threshold levelJOURNAL OF APPLIED ENTOMOLOGY, Issue 5-6 2000G. V. P. Reddy Results revealed that egg parasitism in the laboratory by Trichogramma chilonis was 75.6%. Among the insecticides tested against T. chilonis and the predator Chrysoperla carnea, nimbecidine (neem product) and dipel resulted in zero mortality, with only a low level of mortality by dimethoate, cypermethrin, fenvalerate, alphamethrin and monocrotophos. Combinations of nimbecidine 2% + NPV at 250 larval equivalents (LE)/ha and dipel 8 l + NPV @250 LE/ha were the most effective treatments against H. armigera. The integrated pest management components (T. chilonis, C. carnea, NPV, nimbecidine, dipel and synthetic chemicals) were imposed at different intervals on the basis of pheromone trap threshold level (7 moths/trap per night) on a consolidated block of 40 ha cotton (MCU-1) fields at two locations, Shankarabanda and Korlagundi. The results demonstrated a significant superiority of the IPM strategy in terms of both cost versus benefit and environmental safety over that used in the farmer's fields where only conventional control methods were followed. [source] Calling behaviour of adult female Helicoverpa armigera (Hübner) (Lep., Noctuidae) of overwintering generation and effects of matingJOURNAL OF APPLIED ENTOMOLOGY, Issue 2 2000M. L. Hou The calling behaviour of overwintering generation females of Helicoverpa armigera and the effects of mating were studied in the laboratory at 24 ± 1°C and under reversed light-dark cycle (16 h light : 8 h dark). Age had a significant influence on calling patterns. Based on calling age, mean number of calling bouts and total calling length of virgin females increased significantly, and mean onset time of calling advanced significantly from calling day 1 to subsequent calling days. Females of the overwintering generation exhibited more short bouts in calling, and some females that initiated calling on a previous day did not call on subsequent days. Mating had no effect on the overall patterns, but did affect calling behaviour. Mated females did not resume calling after mating during the same scotophase and, on the day following mating, mated females called less frequently and for a shorter duration, but thereafter increased to the same level of virgin females of the same calling age. Furthermore, as the moth aged, the percentage of mated females calling was lower than that of virgin females. [source] Field performance and seasonal changes in the efficacy against Helicoverpa armigera (Hübner) of transgenic cotton expressing the insecticidal protein vip3AAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 2 2007Danny J. Llewellyn Abstract 1,Three years of field experiments in Eastern Australia were carried out on transgenic cotton (Gossypium hirsutum L.) event Cot102 expressing the insecticidal protein gene vip3A from Bacillus thuringiensis to evaluate performance against Helicoverpa armigera Hübner. Efficacy, defined as the capacity of plant tissues to induce larval mortality, was determined with a well-validated leaf bioassay fortnightly through the growth cycle of the cotton in each season. 2,Cot102 plants proved highly efficacious against H. armigera, particularly early in the season, although their efficacy declined as the season progressed, in a manner similar to, but not as dramatic as, that observed with commercial Cry1Ac expressing cotton (Bollgard or Ingard cotton). 3,Field surveys indicated that very few larvae survived beyond first instar on intact growing plants. 4,In one season efficacy declined for a period of approximately 20 days after a cool wet period, suggesting that this may have had a detrimental effect on the expression or efficacy of the gene, but this will need to be verified in further replicated trials. 5,Quantitative enzyme-linked immunosorbent assays indicated that there was no dramatic reduction in production of the vip3A protein during growth and maturation of the crop, suggesting that other host plant factors were affecting the efficacy of the insecticidal protein in the insect gut. 6,These data indicate that Cot102 cotton would provide a useful alternative to Bollgard cotton but, given the similar lytic mode of action of vip3A proteins in the insect midgut, there may be similar inherent vulnerabilities to resistance evolution for these proteins if used alone. Pyramiding of the vip3A trait with a second insecticidal gene would appear to be a high priority for achieving sustainable deployment against H. armigera or similar susceptible species. [source] Morphological and molecular examination of relationships and epitype establishment of Phacus pleuronectes, Phacus orbicularis, and Phacus hamelii,JOURNAL OF PHYCOLOGY, Issue 5 2007Sylwia Kosmala Verification of morphological diagnostic features and the establishment of three epitypes for three species of Phacus Dujardin,Phacus pleuronectes (O. F. Müll.) Dujardin, Phacus orbicularis Hübner, and Phacus hamelii Allorge et Lefčvre,was performed based on literature studies and analysis of morphological (cell shape, cell size, and periplast ornamentation) as well as molecular (18S rDNA) characters. Periplast ornamentation was recognized as a main diagnostic character, distinguishing P. orbicularis from P. pleuronectes and P. hamelii. Phacus orbicularis has struts running perpendicular to the longitudinal axis of the strips, while P. pleuronectes and P. hamelii do not. On the SSU rDNA tree, obtained by the Bayesian method, P. orbicularis, P. pleuronectes, and P. hamelii belong to three distinct clades. Some of the phylogenetic relationships are not resolved, but there are at least three Phacus species (P. hamatus, P. platyaulax, P. longicauda; for taxonomic authors, see Introduction) that are more closely related to P. orbicularis than is P. pleuronectes. Phacus hamelii is more closely related to P. ranula and the assemblage of several species of Phacus, which have small cells, than to P. orbicularis or P. pleuronectes. [source] A review of the genus Monopis Hübner from China (Lepidoptera, Tineidae, Tineinae)MITTEILUNGEN AUS DEM MUSEUM FUER NATURKUNDE IN BERLIN-DEUTSCHE ENTOMOLOGISCHE ZEITSCHRIFT, Issue 2 2006Yunli Xiao Abstract Fifteen species of the genus Monopis Hübner are treated from China, including four new species (M. similartasyras sp. n., M. semorbiculata sp. n., M. trunciformis sp. n. and M. guangxiensis sp. n.) and five newly recorded species for China (M. laevigella (Denis & Schiffermüller), M. zagulajevi Gaedike, M. spilotella (Tengström), M. imella (Hübner) and M. pallidella Zagulajev). The female of M. trapezoides Petersen & Gaedike is reported for the first time. Photographs of the adults, wing venation and genital structures of the new species are provided. Key to all the known Chinese species is given. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Characterization of polymorphic microsatellite markers in the Indian meal moth, Plodia interpunctella (Hübner)MOLECULAR ECOLOGY RESOURCES, Issue 2 2005TONY GRACE Abstract The Indian meal moth, Plodia interpunctella (Hübner), is a serious and widespread pest of stored food commodities worldwide. Studies on the population genetics and breeding structure of P. interpunctella are lacking. Understanding the breeding structure of this pest has implications for its management. Fifteen microsatellite loci were isolated, cloned and characterized using an enrichment method. Forty individuals from six subpopulations were tested for polymorphism. Nine loci were found to be polymorphic. The number of alleles varied from three to six per locus. [source] Evaluation of the toxicity of 17 essential oils against Choristoneura rosaceana (Lepidoptera: Tortricidae) and Trichoplusia ni (Lepidoptera: Noctuidae),PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 10 2010Cristina M Machial Abstract BACKGROUND: The obliquebanded leafroller, Choristoneura rosaceana Harris, and the cabbage looper, Trichoplusia ni Hübner, are serious fruit and vegetable pests requiring multiple insecticide applications per year. To reduce non-target exposure to hazardous insecticides and to curb resistance development, alternative controls are required. Accordingly, a selection of 17 essential oils was screened against both lepidopteran pests, and the influence of azinphos-methyl resistance on essential oil toxicity to C. rosaceana was studied. RESULTS: Of the 17 essential oils screened, patchouli oil (Pogostemon cablin Benth.) and thyme oil (Thymus vulgaris L.) were selected for further testing against C. rosaceana, whereas patchouli oil, garlic oil (Allium sativum L.) and lemongrass oil (Cymopogon nardus L.) were selected for further testing against T. ni. LC50 and LD50 values confirmed that patchouli oil was the most toxic to C. rosaceana larvae, with LC50 = 2.8 µL mL,1 and LD50 = 8.0 µg insect,1. Garlic oil was the most toxic oil to T. ni larvae with LC50 = 3.3 µL mL,1 and LD50 = 22.7 µg insect,1, followed by patchouli oil and lemongrass oil. Azinphos-methyl-resistant leafrollers were 1.5-fold more tolerant to patchouli oil and 2.0-fold more tolerant to thyme oil. CONCLUSIONS: Based on these results, patchouli oil and other essential oils have sufficient efficacy to be considered as components of an essential oil-based insecticide that targets these lepidopteran pests. Copyright © 2010 Crown in the right of Canada. Published by John Wiley & Sons, Ltd [source] Baseline sensitivity of lepidopteran corn pests in India to Cry1Ab insecticidal protein of Bacillus thuringiensisPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 8 2010Sushil K Jalali Abstract BACKGROUND: Genetically engineered corn (Bt corn) expressing Bacillus thuringiensis Berliner insecticidal protein Cry1Ab is a biotechnological option being considered for management of lepidopteran corn pests in India. As a resistance management practice it was essential to determine the sensitivity of multiple populations of the stalk borer Chilo partellus (Swinhoe), pink borer Sesamia inferens (Walker) and the cob borer Helicoverpa armigera (Hübner) to Cry1Ab protein through bioassays. The insect populations were collected during growing seasons of Rabi 2005 (October 2005 to February 2006) and Kharif 2006 (May to September 2006). RESULTS: Multiple populations of the three lepidopteran corn pests were found to be susceptible to Cry1Ab. Median lethal concentrations (LC50) ranged between 0.008 and 0.068 µg Cry1Ab mL,1 diet for 18 populations of C. partellus (across two seasons), between 0.12 and 1.99 µg mL,1 for seven populations of H. armigera and between 0.46 and 0.56 µg mL,1 for two populations of S. inferens. CONCLUSION: Dose,response concentrations for lethality and growth inhibition have been determined to mark baseline sensitivity of multiple populations of key lepidopteran corn pests in India to Cry1Ab protein. These benchmark values will be referenced while monitoring resistance to Cry1Ab should Bt corn hybrids expressing Cry1Ab be approved for commercial cultivation in India. Copyright © 2010 Society of Chemical Industry [source] Multiple P450 genes overexpressed in deltamethrin-resistant strains of Helicoverpa armigeraPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 8 2010Alexandra Brun-Barale Abstract BACKGROUND: Resistance to the pyrethroid insecticide deltamethrin has been a growing problem in the management of Helicoverpa armigera (Hübner) pest populations in West Africa. Detoxification by P450 enzymes appears to be a major mechanism of resistance, but the genes responsible for resistance are unknown. RESULTS: First, it was shown that deltamethrin resistance in strains from Burkina Faso (Kaya) and from Spain (Seville) were suppressible by piperonyl butoxide and by trichlorophenyl propynyl ether, thus indicating a major role of P450 enzyme(s) in resistance. The larval expression of 21 CYP genes encoding P450 enzymes from six CYP families were then compared by quantitative RT-PCR. Five genes, CYP4L5, CYP4L11, CYP6AE11, CYP332A1 and CYP9A14, were significantly overexpressed in the Kaya and Seville strains when compared with Heliar, a susceptible strain. Significant overexpression of multiple CYP genes (CYP4M6, CYP4M7, CYP6AE11, CYP9A12, CYP332A1 and CYP337B1) was also found in six field strains with different levels of resistance from Benin, Burkina Faso and Mali. CONCLUSION: Although functional or genetic evidence for the role of these P450s in resistance remains to be formally established, results suggest that multiple P450 enzymes contribute to deltamethrin resistance. This study is a first step towards the development of molecular tools for the detection of P450-based resistance in H. armigera. Copyright © 2010 Society of Chemical Industry [source] Gamma radiation sensitivity of the eggs, larvae and pupae of Indian meal moth Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae)PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 5 2008Abdurrahman Ayvaz Abstract BACKGROUND: This study focused on determining the minimal effective gamma radiation dose that prevents commodity damage caused by the Indian meal moth Plodia interpunctella (Hübner). The study was also designed to assess the effect of releasing either partially sterilized males alone or both partially sterilized males and females on the reproductive potential of P. interpunctella populations. RESULTS: The dose of radiation required to prevent larval emergence from irradiated eggs was 350 Gy, and the same dose was also required to prevent adult emergence from mature larvae. A dose of 300 Gy was not able to prevent adult emergence from irradiated pupae. The dose at which 100% sterility was achieved in treated females mated to treated males was 300 Gy for the parental generation of irradiated pupae. Fertility of the parental males from irradiated pupae was 48.17% at 300 Gy in treated males crossed with untreated females, but male progeny of irradiated male parents had a residual fertility of 11.06% at the same dose. CONCLUSION: F1 males from irradiated pupae were more sterile than parental males. To prevent larval emergence from irradiated eggs, a dose of 350 Gy is required. The same dose is required to prevent the larvae from reaching the adult stage. Copyright © 2008 Society of Chemical Industry [source] Efficacy of various pyrethroid structures against a highly metabolically resistant isogenic strain of Helicoverpa armigera (Lepidoptera: Noctuidae) from ChinaPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 10 2007Jianguo Tan Abstract BACKGROUND: Resistance to pyrethroids and other types of insecticides in Helicoverpa armigera (Hübner) has been documented in many countries. The isolation of specific resistance mechanisms in isogenic strains is an optimal approach to investigate cross-resistance pattern, and to validate resistance breaking pyrethroids. In this study an isogenic metabolic resistance CMR strain was successfully isolated from a field pyrethroid-resistant population of H. armigera. With this strain, cross-resistance among 19 pyrethroid insecticides with varying chemical structures was analysed. RESULTS: Resistance to pyrethroids in the CMR strain was likely to be due to enhanced oxidative metabolism. The most significant cross-resistance in the CMR strain was between pyrethroids such as fenvalerate, tau-fluvalinate and flumethrin characterised by having both phenoxybenzyl and aromatic acid moieties. Substitution of the phenoxybenzyl group with a polyfluorobenzyl group, as in tefluthrin, benfluthrin and transfluthrin, overcame most of this resistance. CONCLUSION: The findings in this study support the assertion that it is possible to find pyrethroids that are active against resistant populations. Such pyrethroids could be considered as possible partners or resistance breaking pyrethroids in a pyrethroid resistance management programme for H. armigera in China and in other Asian countries where the oxidative metabolism resistance is a dominant mechanism. Copyright © 2007 Society of Chemical Industry [source] | ||||||||||||||||