bluuebunny/crossref_metadata_2025_split huggingface dataset:
Feeding behavior and growth of Heliothis virescens larvae on diets containing Bacillus thuringiensis formulations or endotoxins
Authors: Gould F. , Anderson A. , Landis D. , Van Mellaert H. 
Published: April 2011

AbstractBacillus thuringiensis (Bt), spore/crystal mixtures, and purified Bt endotoxins were tested for effects on Heliothis virescens (F.) growth and behavior by use of diet‐incorporation bioassays. Larvae were exposed to three basic diet treatments: 1) feeding arenas containing only normal artificial diet, 2) feeding areas containing only a diet of B. thuringiensis formulation or endotoxin, and 3) feeding arenas where larvae could choose between normal diet and diet containing a Bt formulation or endotoxin. Young larvae avoided Bt formulations and Bt‐endotoxin‐containing diets. Even concentrations of formulations and Bt‐endotoxins that did not cause mortality or severely inhibit growth of young larvae caused avoidance. Fourth and fifth instar larvae avoided formulations and endotoxin‐containing diets when the concentrations used inhibited growth. Purified endotoxins produced by transformed E. coli cells caused avoidance similar to the spore/crystal mixture in Dipel®.RésuméComportement alimentaire et croissance de chenilles d' Heliothis virescens sur des régimes contenant différentes doses de Bacillus thuringiensis ou des endotoxinesLes effets, sur la croissance et le comportement d'Heliothis virescens F., d'endotoxines et de melanges de spores et de critaux de B. thuringiensis (Bt) ont été examinés par incorporation dans l'aliment. Les chenilles ont subi 3 types de traitements:

arènes alimentaires contenant exclusivement l'aliment artificiel;
arènes alimentaires avec uniquement un aliment contenant le mélange de Bt ou ses endotoxines;
arènes alimentaires dans lesquelles les chenilles pouvaient choisir entre un aliment normal et un aliment contenant un mélange de Bt ou des endotoxines.

Les jeunes chenilles ont évité l'aliment contenant un mélange de Bt ou des endotoxines. Même les concentrations des mélanges ou d'endotoxines qui ne sont pas mortelles ou n'inhibent pas sérieusement la croissance étaient répulsives pour les jeunes chenilles. Les chenilles de 4e et 5e stades évitaient les aliments contenant des mélanges ou des endotoxines dont les concentrations inhibent la croissance. Des endotoxines pures produites par des Escherichia coli modifies provoquent la même répulsion que le mélange spores/cristaux dans du Dipel.
Relationship of Heliothis zea predators, parasitoids and entomopathogens to canopy development in soybean as affected by Heterodera glycines and weeds
Authors: Alston D.G. , Bradley J.R. , Schmitt D.P. , Coble H.D. 
Published: April 2011

AbstractThe influence of canopy development in soybean on the survival of corn earworm, Heliothis zea (Boddie) (Lepidoptera: Noctuidae), egg and larval stages and population dynamics of arthropod fauna were evaluated in field trials during 1986–88 in eastern North Carolina. Soybean canopy size decreased as soybean cyst nematode, Heterodera glycines Ichinohe (Nematoda: Heteroderidae), initial population densities increased. Plant species composition of the soybean canopy was affected by weed population densities. Mortality of H. zea larvae due to parasitism and infection with entomopathogens was greater in closed canopy and (or) weedy soybeans than in very open and (or) weed free soybeans. Predation and parasitism of corn earworm eggs were similar across nematode and weed density treatments. Natural enemy populations increased to highest levels during July in closed canopy and (or) weedy soybeans, coinciding with availability of largest prey population reservoirs. A delay in colonization of very open and (or) weed free soybeans by beneficial arthropods until mid to late August allowed greater H. zea larval survival than in closed canopy and (or) weedy soybeans. Arthropod species richness was generally greatest in closed canopy and (or) weedy soybeans during mid to late July, with differences becoming nonsignificant in August and early September. Mean and maximum ambient temperatures were higher and relative humidities lower in open canopy than in closed canopy plots. These conditions were less favorable for development of pathogens and natural enemies.
Effects of dietary sucrose concentration on aphid honeydew carbohydrate levels and rates of excretion
Authors: Mittler T. E. , Meikle T. 
Published: April 2011

AbstractHoneydew droplets freshly excreted by two aphid species, Myzus persicae (Sulz.) and Acyrthosiphon pisum (Harr.), feeding on nutritionally adequate, artificial diets containing 10–40% w/v sucrose, were collected in oil. The volume, frequency of excretion, and carbohydrate content of the droplets were determined by measuring the diameter of the droplets in the oil, by recording the number of droplets excreted per aphid per hour, and by using a quantitative colorimetric method for estimating carbohydrates. Rates for the intake or excretion of fluid, the intake and absorption of sucrose, and the excretion of carbohydrate were consequently calculated for the two species on each dietary sucrose concentration. The percentage of dietary sucrose absorbed by the aphids ranged from 36% on diet with 40% sucrose to 97% on diet with 10% sucrose. Such honeydew/diet relationships may allow one to use honeydew carbohydrate concentrations to estimate the sucrose concentrations of the phloem sap ingested by aphids feeding on host plants.RésuméLa teneur en glucides du miellat et le taux d'excrétions chez des aphides nourris sur différentes concentrations de saccharoseDes gouttelettes de miellat fraîchement excrétées par deux espèces de pucerons, Myzus persicae (Sulz.) et Acyrthosiphon pisum (Harr.), pucerons nourris sur des régimes nutritifs synthétiques contenant 10–40% de saccharose, ont été récupérées dans de l'huile. Le volume des gouttelettes a été déterminé en mesurant leur diamètre individuel dans l'huile, la fréquence d'excrétion établie par le nombre de gouttelettes excrétées par puceron par heure, et la teneur en glucides par une méthode d'analyse colorimétrique quantitative. Les taux d'ingestion et d'excrétion de liquide, d'ingestion et d'absorption de saccharose ainsi que les taux d'excrétion de glucides ont été par la suite calculés pour les deux espèces d'aphides nourris sur les différentes concentrations de saccharose. Le pourcentage de saccharose alimentaire absorbé par les aphides a été de 36% sur le régime contenant 40% de ce glucide, mais s'est élevé à 97% sur le régime ne contenant que 10% de saccharose. D'après ces relations miellat/régime nutritif, et en connaissant la teneur du miellat en glucides, on peut faire une approximation de la concentration du saccharose dans la sève élaborée du phloème ingérée par les aphides.
Discharge by aphids of soluble secretions into dietary sources
Authors: Miles P. W. , Harrewijn P. 
Published: April 2011

AbstractSubstances secreted by aphids into diets through a rubber‐wax membrane can be detected by their absorption of low wavelength ultraviolet light. Their detection can be simplified by presenting water as diet. Of the substances secreted into water by non‐crowded aphids within 24 h, ca 35–55% of the absorbance at 200 nm can be accounted for by reactions with protein reagents and/or electrophoresis. Macrosiphum euphorbiae secreted over 30 ng of salivary protein in bovine serum albumin equivalents per mg fresh body weight. SDS‐PAGE revealed that the proteins initially secreted had subunits mostly of > 100,000 Daltons. When dead or dying aphids were present on the membrane, however, e.g. due to crowding or prolonged confinement in the feeding chamber, additional subunits of < 30,000 Daltons also appeared in the water. When feeding continued for more than 24 h, proteins separable by electrophoresis began to disappear, possibly as a result of leakage of lyzing enzymes into the water from aphids that had died with their mouth parts still inserted through the membrane.The initial secretions possessed oxidase activity. Invertase was not detected but the secretion caused non‐enzymatic reduction of a copper reagent used for detection of reducing sugars. Marked contrasts were noted between the electrophoretic protein patterns of the saliva of different species of aphids. The saliva of Macrosiphum euphorbiae and Myzus persicae contained over twice as much catechol oxidase activity per unit of salivary protein as that of Nasonovia ribisnigri and Aphis fabae.The significance of these findings in relation to use of artificial diets for colony maintenance and feeding experiments and for studies of aphid‐plant interactions is discussed.
Resistance in tomato to the greenhouse whitefly: analysis of population dynamics
Authors: Romanow Louise R. , de Ponti Orlando M. B. , Mollema Chris 
Published: April 2011

AbstractLife history parameters including longevity, developmental time, and reproduction were determined for whiteflies, Trialeurodes vaporariorum (Westwood), kept in clip‐on cages on susceptible parent, Lycopersicon esculentum, resistant parent, L. hirsutum glabratum, and intermediate breeding lines of tomato. Using the Lewontin triangular reproductive function, the intrinsic rate of increase (rm) was calculated for each genotype. This is an elegant tool for detecting resistance, as it incorporates all salient factors of life history. Comparing rm to the other parameters measured, selection criteria were chosen. Developmental time is not a suitable selection criterion as it varies very little even between the most susceptible and the most resistant genotypes. Additionally, developmental time of T. vaporariorum offspring was found to be highly significantly correlated to parental age on all tomato genotypes except L. hirsutum glabratum. Total reproduction, truncated population counts, and longevity appear good criteria for selection. This test, focusing on antibiotic factors, shows large differences between the resistant and susceptible parent genotypes, but much smaller differences between the breeding lines and the susceptible parent. Earlier screenings relying on a variety of tests appear to have maintained antixenotic rather than antibiotic properties in the breeding lines.
Dietary mixing in grasshoppers: switching induced by nutritional imbalances in foods
Authors: Bernays E. A. , Bright K. L. 
Published: April 2011

AbstractDietary mixing by nymphs of Schistocerca americana was studied in the laboratory using artificial diet cakes. Individuals were given either two different inadequate but complementary diet cakes or two adequate and identical ones. When unique flavors (coumarin or NHT) were added to the diet cakes, insects given the inadequate diet treatment switched between cakes more than insects exposed to the adequate diets. This was not the case when no identifying flavors were added.
Genetic control of pest Lepidoptera: construction of a balanced lethal strain in Ephestia kuehniella
Authors: Marec F. 
Published: April 2011

AbstractA genetic method for the suppression of Lepidopteran pests has been investigated in the Mediterranean flour moth, Ephestia kuehniella Zeller. The method is based on the release of males trans‐heterozygous for two sex‐linked recessive lethal mutations (SLRLMs). In this paper, characteristics of 16 new SLRLMs are presented. The construction of a balanced lethal strain, BL‐2, which was the last step to develop the method, is reported. Males of the strain are balanced for two non‐allelic SLRLMs, sl‐2 and sl‐15. Females carry either sl‐2 or sl‐15 in their Z chromosome and the T(W;Z)2 translocation on their W chromosome. The translocation includes wild‐type alleles of both lethal loci so that the females are viable. Matings between males of the BL‐2 strain and normal females of the wild‐type strain gave 99.74% male progeny. Exceptional females were due to recombination between the sl‐2 and sl‐15 loci. Thus, males of the BL‐2 strain have a potential to suppress wild populations of the pest. Another envisaged use of this method is for an effective sexing technique.
Attractants for the gravid Queensland fruit fly Dacus tryoni
Authors: Eisemann C. H. , Rice M. J. 
Published: April 2011

AbstractThe vapours of certain pure chemicals, typical of ripe fruits, elicited characteristic components of ovipositional behaviour from gravid Dacus tryoni (Froggat) in an olfactometer: the flies walked and flew upwind to the source of the vapour and then probed with their ovipositors. A range of alcohols, acids, ketones and esters having 2–6 carbon atoms were effective (1 and 10% of iso‐butyric acid, n‐butyric acid, methyl butyrate, ethyl butyrate, 2‐butanone, ethyl lactate and ethyl acetate; and 10% concentrations of ethanol and 2‐propanone). The most effective were 4–6 carbon acids, esters and ketones. Behavioural threshold for n‐butyric acid vapour at 26 °C was obtained from a 5 × 10−3% dilution in paraffin oil; maximum fly response occurred at about 200 times this concentration. Low concentrations of the 15‐carbon sesquiterpene, α‐farnesene, were also very effective, despite its lower volatility. These results suggest that at least three different types of olfactory sensory neurones are involved in the identification of fruit attractants by gravid D. tryoni.
Flight initiation in the egg parasitoid Trichogramma minutum: Effects of ambient temperature, mates, food, and host eggs
Authors: Forsse E. , Smith S. M. , Bourchier R. S. 
Published: April 2011

AbstractEmergence, preening, and flight initiation were studied in laboratory‐reared Trichogramma minutum Riley (Hymenoptera: Trichogrammatidae). Male parasitoids emerged first and flew before females. When both sexes were present in flight cylinders, female parasitoids flew before males. Flight propensity in males was negatively related to the number of emerging females, while flight propensity in females was independent of the number of males present. Ambient temperature significantly affected the propensity and timing of flight; between 70–80% of the parasitoids flew at 25 and 30 °C while less than 4%, mostly males, flew at 20 °C. No flights were observed at 15 °C. The presence of fresh host eggs caused a reduction in the proportion of female parasitoids that flew and a delay in the time to flight for the females that did fly. The presence of food increased the flight propensity of female parasitoids, but did not affect the timing of flight. The relationship between flight behaviour and the ‘efficiency’ of mass‐reared Trichogramma is discussed in terms of its importance for inundative release programmes.
In vitro rearing of Eucelatoria bryani: improvements and evaluation of factors affecting efficiency
Authors: Bratti A. , Nettles W. C. 
Published: April 2011

AbstractIn vitro rearing of Eucelatoria bryani Sabrosky (Diptera: Tachinidae) was made more efficient and economical. Absorbent cotton, used as a support to replace more expensive agar in an artificial medium, produced yields of adults equal to those reared on the agar‐based medium. The weights of pupae from the cotton‐supported medium were about 16% lighter than were the weights of pupae from the agar‐based medium. Evaluation of diet volumes (100, 200 and 250 μl) for individually reared flies revealed that highest adult yields (46.3%) were obtained when 200 μl per maggot of agar‐based diet were used in each well of microtiter plates; this is equivalent to 2,315 adults per liter of diet. The tachinids were small and the sizes were equal to those obtained when 10–15 maggots parasitize a single host. Costs could not be reduced by deleting free amino acids from the medium fed to older maggots because free amino acids are essential dietary ingredients for third instars of E. bryani.
Influence of some plant phenolics on the activity of δ‐endotoxin of Bacillus thuringiensis var. galleriae on Heliothis armigera
Authors: Sivamani E. , Rajendran N. , Senrayan R. , Ananthakrishnan T. N. , Jayaraman Kunthala 
Published: April 2011

AbstractBioassays with Bacillus thuringiensis var. galleriae Berliner δ‐endotoxin and plant phenolics on Heliothis armigera Hübner enhanced the activity of B.t. var. galleriae endotoxin. The presence of plant phenolics with B.t. var. galleriae endotoxin not only reduced feeding potential and weight gain by the larvae, but also enhanced the LC50 value of the toxin. Our study demonstrates the effect of phytochemicals from resistant crop plants on the biocidal activity of B. thuringiensis strains in laboratory conditions.
Field studies on colour preferences of Ctenarytaina thysanura in Tasmanian boronia farms
Authors: Mensah R. K. , Madden J. L. 
Published: April 2011

AbstractField tests on attraction of Ctenarytaina thysanura (Hemiptera: Psyllidae) adults to different coloured 30 × 30 cm sticky traps revealed a preference for yellow. Among the enamel colours tested, more psyllids were captured on yellow traps followed by green, then blue and least on red, cyan and magenta. Dilution of yellow enamel with 50% white (1Y:1W) and 75% white (1Y:3W) to produce yellow‐white hues resulted in a significant decrease in psyllid capture indicating that the psyllids response to yellow was one of positive attraction and could suggest true colour discrimination. Reflectance spectra of painted surfaces of the enamel colours and also yellow to white hues indicated that psyllid capture rates were directly related to the proportion of light reflected in the 500–560 nm region. The biological basis of the observed C. thysanura response may be that yellow is the most intensely reflective colour in the general part of the spectrum for leaves which reflect most light in the 500–600 nm (peak 550 nm) range.
The effects of a multispecies sequential diet on the growth and survival of a tropical polyphagous caterpillar
Authors: Pescador A. R. 
Published: April 2011

AbstractHylesia lineata Druce (Lepidoptera: Saturniidae) caterpillars are highly polyphagous at the individual level. I examined the effects of a multispecies sequential diet on the performance of the larvae. The experiment included three natural hosts respectively – Casearia corymbosa HBK, Thouinia paucidentata Radlk., and Erythroxylum havanense Jacq – used by ovipositing females in proportion as expected by their abundance; C. corymbosa and E. havanense representing the most and least abundant hosts respectively. All possible two‐host and single‐host diets were tested. Larval survival to the pupal stage (as protected by a field cage) did not differ among all diets. Also, for females, regardless of the identity of the initial host, the final weight and the developmental time depended entirely on the nature of the final host. Male performance, in contrast, only differed in terms of developmental time but again the initial host did not affect the final result. It was concluded that a host switch early in the development of the caterpillars does not affect further growth on the other host plants. Caterpillars that finished their development on E. havanense reached small sizes but females devoted a larger proportion of their resources to egg biomass; as a result female fertility was similar among females regardless of their feeding history. I concluded that the caterpillar's abilities and the female compensatory flexibility may oppose selection for a strong preference hierarchy in the female ovipositing behavior.
Sweetpotato whitefly resistance to insecticides in Hawaii: intra‐island variation is related to insecticide use
Authors: Omer A. D. , Johnson M. W. , Tabashnik B. E. , Costa H. S. , Ullman D. E. 
Published: April 2011

AbstractSusceptibility to acephate, methomyl, and permethrin was determined with laboratory bioassays of field‐collected adults from 15 populations of the B biotype of sweetpotato whitefly, Bemisia tabaci (Gennadius) (Homoptera:Aleyrodidae), from Hawaii. Comparisons at the LC50 showed up to 24‐fold resistance to acephate, 18‐fold resistance to methomyl, and 4‐fold resistance to permethrin. Analysis of variance showed significant intra‐island variation in susceptibility to each insecticide, but no significant variation among islands. Insecticide use varied from 4 to 103 insecticide sprays per site per season. Acephate and methomyl were used more often than permethrin. The frequency of application and LC50 for each insecticide were positively correlated across sites. These results suggest that local variation in insecticide use was a primary cause of variation in susceptibility. If local insecticide use is a key determinant of resistance, as our results suggest, growers can retard resistance development locally by reducing their own insecticide use.
Suitability of greenbugs, cotton aphids, and Heliothis virescens eggs for development and reproduction of Orius insidiosus
Authors: Bush L. , Kring T. J. , Ruberson J. R. 
Published: April 2011

AbstractDevelopment, fecundity, and longevity of the predator, Orius insidiosus (Say) (Heteroptera: Anthocoridae), when reared on greenbug [Schizaphis graminum (Rondani)], cotton aphid (Aphis gossypii Glover), or eggs of tobacco budworm [Heliothis virescens (F.)] with green beans or water were examined. Developmental time was shortest when predators were reared on H. virescens eggs and beans and longest when reared on cotton aphids and water. Predators were most fecund when fed H. virescens eggs. The inclusion of beans in the nymphal diet further enhanced fecundity when fed eggs. Longevity of both females and males was significantly shorter when reared on aphids than on eggs. Beans in the nymphal diet enhanced longevity of female predators only in combination with budworm eggs. Female O. insidiosus were largest when reared on H. virescens eggs. Addition of green beans in aphid treatments resulted in increased size of O. insidiosus when compared to aphids and free water.
Reproductive diapause and quiescence in a tropical rice bug, Leptocorisa oratorius
Authors: Ito Kiyomitsu , Nik Mohd. Noor N.S. 
Published: April 2011

AbstractExperiments were carried out to analyze the effects of food supply and photoperiod on the induction of dormancy in Leptocorisa oratorius Fabricius (Heteroptera: Alydidae) adults in Alor Setar (latitude 6.1° N), West Malaysia. When the adults were deprived of food, they ceased oviposition, became tolerant to starvation, and their oxygen consumption rate decreased, but they did not accumulate lipid. Their oxygen consumption rate again increased when they were allowed to resume feeding. Therefore, food limitation induced quiescence in the adult. On the other hand, diapause was induced by short daylength (critical photoperiod was 12L:12D), leading to immature ovaries, hypertrophied fat bodies, lipid accumulation and low oxygen consumption rate even when food was available. However, in the study area most of the bugs probably did not enter diapause at any time of the year, because the shortest outdoor daylength including civil twilight was longer than the critical daylength for diapause induction.