bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of larval density on development and induction of reproductive diapause in Bruchidius atrolineatus
Authors: Desroches P. , Huignard J. 
Published: April 2011

AbstractIn Bruchidius atrolineatus (Pic), an increase in larval density inside the seed led to a reduction in the survival rate during post‐embryonic development, with only a limited decrease in the weight of adults. A high larval density increased the proportion of adults in reproductive diapause under certain thermoperiodic conditions. Under other conditions that already promote the emergence of a high proportion of diapausing beetles, an increase in larval density had no effect on diapause.There was no correlation between the larval developmental time and the weights of adults in a strain with a very low incidence of diapause. However, such a correlation was observed when both sexually‐active and diapausing beetles emerged. This correlation was explained by the longer developmental times and lower weights of diapausing beetles.RésuméInfluence de la densité larvaire sur le développement et l'induction de la diapause reproductrice chez Bruchidius atrolineatus Pic(Coléoptère, Bruchidae)Chez Bruchidius atrolineatus, l'accroissement de la densité larvaire à l'intérieur de la graine entraîne une augmentation de la mortalité alors que la réduction de poids des individus à l'émergence est relativement limitée. L'accroissement de la densité larvaire provoque une augmentation du taux d'adultes en diapause reproductrice, dans certaines conditions thermopériodiques. Dans d'autres conditions, permettant l'émergence d'un fort taux d'adultes diapausants, l'effet de la densité larvaire est nul. Lorsque l'on analyse l'effet de la densité chez les individus d'une souche ne présentant pas de phénomène de diapause, il n'y a pas de corrélation entre la durée de développement et le poids des adultes. Par contre, lorsqu'il y a émergence d'adultes sexuellement actifs et diapausants, il existe une corrélation entre la durée de développement et le poids des adultes émergeants. Cette corrélation est due au fait que les adultes diapausants, qui présentent les durées de développement les plus longues, sont ceux qui ont les poids les plus faibles.
Deterrence of oviposition in Dacus oleae by copper hydroxide
Authors: Prophetou‐Athanasiadou D. A. , Tzanakakis M. E. , & D. Myroyannis , Sakas G. 
Published: April 2011

AbstractGreen olives of three varieties were sprayed in the laboratory with 1% copper hydroxide plus 0.1% Agral‐90 in tap water. A few hours and 1 and 2 days later, the treated olives were offered for oviposition to 15–20‐day‐old females of Dacus oleae (Gmelin) (Diptera: Tephritidae), in two‐choice and no‐choice tests lasting 3 h. In all cases, copper hydroxide had a strong oviposition‐deterring effect, while Agral‐90 alone was ineffective.
Induction of sexual forms in the rose aphid Macrosiphum rosae
Authors: Wöhrmann K. , Hales D. F. , Tomiuk J. , Schmiedt E. M. , Rettenmeier G. 
Published: April 2011

AbstractThe rose aphid, Macrosiphum rosae (L.), was tested for its ability to produce sexual forms on rose leaves, after induction by environmental conditions in the field and in the laboratory. Clones were collected in Tübingen, Federal Republic of Germany, and in south‐eastern New South Wales, Australia. The German clones all produced sexual forms, while the response of the Australian clones was weak. There appeared to be a bias in the sex ratio towards females: This is discussed in developmental terms. The environmental and genetic factors influencing the response are considered.
Role of bilateral chemosensory input in food discrimination by Manduca sexta larvae
Authors: de Boer G. 
Published: April 2011

AbstractThe function of bilateral chemosensory input in food discrimination was examined using larvae of the tobacco hornworm, Manduca sexta (Johan.) (Lepidoptera: Sphingidae), in 2‐choice preference tests. Larvae having three different complements of chemosensory organs remaining after microsurgery were tested: unoperated, unilaterally‐ablated, and bilaterally‐ablated. Discrimination between Solanum pseudocapsicum (L.) and Pelargonium hortorum (Bailey) was reduced after unilateral removal of chemosensory organs. A similar effect was found in tests offering larvae a choice between one plant species or an ethanolic extract of S. pseudocapsicum and wetted filter paper, indicating an impaired food detection. These results demonstrate that both sets of chemosensory organs are required for normal feeding decisions about these plants.Six additional plant species were each tested against wetted filter paper. The function of bilateral chemosensory input in food discrimination varies with the plant species tested. Bilateral chemosensory input is required for discrimination of Vigna sinensis (Savi) and Raphanus sativus (L.), but not for that of Lycopersicon esculentum (Mill.), Datura innoxia (L.), Brassica napus (L.), and Canna generalis (Bailey). Discrimination of V. sinensis, S. pseudocapsicum, and P. hortorum by unoperated larvae is twice as strong as that by unilaterally‐ablated larvae, suggesting algebraic addition of unilateral sensory inputs. For R. sativus unilateral input does not mediate discrimination, but bilateral input does, indicating sensory processing which may be more than additive. These results show that information mediated by bilateral chemosensory organs of M. sexta is not redundant in mediating feeding decisions, but provide the necessary sensory input for normal discrimination. This suggests that, for some plant species, feeding decisions are based on both qualitative and quantitative aspects of chemosensory input.No difference in preferences between left‐sided and right‐sided operated larvae were observed which suggests functional duplication of each set of unilateral chemosensory organs. Possible neural mechanisms underlying feeding decisions mediated by bilateral versus unilateral chemosensory inputs are discussed.
Behavioral and physiological responses of susceptible and resistant diamondback moth larvae to Bacillus thuringiensis
Authors: Schwartz J. M. , Tabashnik B. E. , Johnson M. W. 
Published: April 2011

AbstractTo determine whether field‐selected resistance of diamondback moth (Plutella xylostella L.) (Lepidoptera: Plutellidae) to Bacillus thuringiensis is based on behavioral or physiological adaptation, we measured mortality, consumption, and movement of larvae from a susceptible and a resistant colony when placed on untreated and B. thuringiensis treated cabbage. Colonies did not differ in mortality, consumption, or movement on untreated cabbage. However, for a given amount of consumption of treated cabbage, resistant larvae had lower mortality than susceptible larvae, demonstrating that resistance had a physiological basis. The movement patterns could not account for the differences between colonies in survival. Resistant larvae did not avoid B. thuringiensis more than did susceptible larvae. Thus, we found no evidence for behavioral resistance.
Flight behaviour of the cabbage seedpod weevil
Authors: Kjær‐Pedersen C. 
Published: April 2011

AbstractThe influence of host odour, windspeed, position of the sun, and temperature on flight behaviour of the cabbage seedpod weevil (Ceutorhynchus assimilis Paykull) were studied. This weevil showed a positive anemotaxis (upwind flight) inside the odour plume of a host crop (Brassica napus L.). Outside the odour plume the weevil showed a pronounced phototaxis at windspeeds below 1.5 m/s. At higher windspeeds, the seedpod weevils flew downwind. The cabbage seedpod weevil flies most readily at low windspeeds (less than 0.5 m/s) and at temperatures above 22 °C.
Beyond origami: using behavioural observations as a strategy to improve trap design
Authors: Phillips A. D. G. , Wyatt T. D. 
Published: April 2011

AbstractIn contrast to ad hoc methods of developing traps for pest monitoring systems, a systematic approach using direct observation of animals allowed a greater understanding of the reasons why trap catch was significantly different in traps of basically similar design. The information gained using this approach could then be used to guide the further development of the trap. The same feature on two related designs of cockroach trap was varied: the slope of the ramp leading into the trap was either 60°, 30°, or 0°. The 30° ramp version of both traps caught significantly more Blattella germanica (L.) (Dictyoptera: Blattellidae). The 60° and 0° ramp versions both caught equal, lower, numbers but observation showed that these net catches were achieved by quite different means; few insects entered over the 60° ramps but none escaped, whereas all entered over the 0° ramps but half escaped. Similar approaches could be applied to other insect‐trap systems.
Variability in the efficacy of delayed inducible resistance in mountain birch
Authors: Ruohomäki K. , Hanhimäki S. , Haukioja E. , Iso‐Iivari L. , Neuvonen S. , Niemelä P. , Suomela J. 
Published: April 2011

AbstractThis paper summarizes the results from experiments during 12 years on effects of delayed inducible resistance of mountain birches (Betula pubescens Ehrh. ssp. tortuosa (Ledeb.) Nyman) on performance of a geometrid, Epirrita autumnata (Bkh.). Manual defoliation usually reduced significantly pupal mass of E. autumnata the next summer. The years interacted significantly with the defoliation treatment indicating variation among years in the responses of trees or larvae, or that the methodological differences between different experiments may have affected the results. Potential methodological sources for the annual variability were discussed and found unlikely. In addition, the efficacy of defoliation treatment in reducing the pupal mass was greatest when foliage quality in control trees was best, suggesting a contribution of biological causes to the annual variability.
Self‐selection and utilization efficiency of Heliothis zea larvae feeding on seeds and the walls of snap bean pods
Authors: Naeem M. , Waldbauer G. P. , Friedman S. 
Published: April 2011

AbstractFirst instar Heliothis zea larvae tended to feed on the leaves of snap beans, but later instars preferred to burrow in the pods. Fifth instars offered only leaves grew poorly because they ate them in small quantities, presumably because of deterrency. The utilization efficiency and growth of fifth instars fed pulp was slightly but significantly inferior to that of seed‐fed larvae but was greatly superior to that of leaf‐fed larvae. Since the dry matter content of pulp is less than one‐third that of seeds, larvae allowed to eat only pulp had abnormally large fresh weight intakes and devoted about three times as much time to feeding as did seed‐fed larvae. Larvae offered a mix of seeds and pulp ate both and had a total fresh weight food intake somewhat greater than that of seed‐fed larvae but much less than that of pulp‐fed larvae. Eating both seeds and pulp offers no obvious nutritional advantage but presumably offers a significant ecological advantage. It is argued that the number of foraging trips a larva must make to discover pods is minimized by feeding on a mix, thus reducing exposure to mortality factors such as predation.
Electroantennogram responses to plant volatiles in two species of Pieris butterflies
Authors: van Loon J. J. A. , Frentz W. H. , van Eeuwijk F. A. 
Published: April 2011

AbstractElectroantennogram (EAG) responses were recorded from females of two related butterfly species, Pieris brassicae L. and P. rapae L. (Lepidoptera: Pieridae) to 23 volatiles of plant origin, 19 of which have been reported to occur in the headspace of their preferred host plants, Brassica and Sinapis species (Cruciferae), In both species, selective responses were observed and the most effective compounds were the 6‐carbon fatty acid derivatives trans‐hex‐2‐enal, hexan‐1‐ol and hexanal, which are common green leaf volatiles. Of the 6 isoprenoids tested, myrcene and geraniol were most effective. Of the 4 crucifer‐specific compounds tested, phenylacetonitrile was a distinctly stronger stimulant than the three isothiocyanates in both species. The rank order of mean stimulating effectiveness of all compounds tested was strongly correlated between the two species. Statistical analysis of dose‐response relationships for 6 compounds revealed significant differences between compounds. The rank order of effectiveness changed with dose. Exclusive exposure to Sinapis arvensis during larval life and young adulthood resulted in quantitative changes in EAG responses to several compounds in both species, although the overall rank order of effectiveness was strongly correlated between the groups reared on the two host plants.
Effects of dietary nicotine and partial starvation of tobacco hornworm, Manduca sexta, on the survival and development of the parasitoid Cotesia congregata
Authors: Bentz J.‐A. , Barbosa P. 
Published: April 2011

AbstractA factorial experiment tested the effects of dietary nicotine and of partial starvation of fifth instar tobacco hornworm, Manduca sexta (L.) (Lepidoptera: Sphingidae), on the survival and development of the parasitoid Cotesia congregata (Say) (Hymenoptera: Braconidae) in the laboratory. More parasitoids failed to emerge from partially starved hosts when reared on 0.1% nicotine diet, than from partially starved hosts fed control diet. Parasitoids reared from hornworms starved by 75% on nicotine diet had the longest development. The number of wasps was reduced when reared from hosts that were fed less than 50% of their daily consumption on nicotine diet. Pupal mortality was increased by dietary nicotine.Nicotine, within the host tissues, may be directly toxic to the parasitoids before their emergence from hornworms. Our data suggest that nicotine may act by mediating the availability of nutrients or reduce assimilation of nutrients by developing parasitoids.
Oriented flight responses of female Mediterranean fruit flies to calling males, odor of calling males, and a synthetic pheromone blend
Authors: Landolt P. J. , Heath R. R. , Chambers D. L. 
Published: April 2011

AbstractMale Mediterranean fruit flies, Ceratitis capitata (Wiedemann), produce volatile chemicals thought to be attractive sex pheromones. We demonstrated for the first time that male odor elicits upwind flight and zigzagging upwind flight patterns in mature unmated females. Such flight patterns indicate the mechanisms involved in female location of the pheromone source and arrival at that source. Similar female oriented upwind flight responses occurred with a three component blend comprised of ethyl‐(E)‐octenoate, geranyl acetate, and E,E‐alpha farnesene. These findings clarify the role of male sex pheromone in mate‐location strategies in this species and provide new bioassay criteria for evaluating attraction responses to male pheromone and synthetic blends.
Effects of protein type and concentration on development and reproduction of the German cockroach, Blattella germanica
Authors: Cooper R. A. , Schal C. 
Published: April 2011

AbstractNymphal development and adult female reproduction were examined in the German cockroach, Blattella germanica, using a defined artificial diet in which the type of protein was varied. Milk proteins, including casein, supported development poorly compared to meat and plant proteins. Soybean protein supported development better than all other highly purified proteins including vitamin‐free casein which is commonly used in artificial diets. Last instar females fed the soybean‐based diet eclosed earlier at higher eclosion weights, developed their oocytes at a faster rate and experienced higher fecundity than females fed a vitamin‐free casein‐based diet. Last instar females exhibited different dose‐response patterns on diets containing soybean isolate or vitamin‐free casein. However, at all concentrations soybean protein was superior to casein in supporting development. The results of a food utilization study during the last instar revealed that consumption rates varied between females fed the soybean and casein based diets. However, approximate digestibility, efficiency of conversion of digested food and the efficiency of conversion of ingested food did not vary significantly between the two dietary treatments. Differential development of females fed the two diets was attributed to differences in stage‐specific consumption rates and the poorer quality of casein as a source of protein for development in this species.
Mode of inheritance of azinphosmethyl resistance in a laboratory‐selected strain of Trioxys pallidus
Authors: Brown E. J. , Cave F. E. , Hoy M. A. 
Published: April 2011

AbstractHomogeneity in azinphosmethyl resistance was assessed in males of a laboratory‐selected (Select‐17) and susceptible (Yolo) colony of Trioxys pallidus Haliday (Hymenoptera: Aphidiidae) using a time response assay. No evidence of heterogeneity within the two colonies was found. Reciprocal crosses between the Yolo and the Select‐19 (the Select‐17 colony following two additional selections) colonies resulted in F1 females that exhibited a semidominant response to azinphosmethyl with a dominance value (D) of 0.32, as well as no evidence of maternal effects or sex linkage. Responses of F2 progeny to azinphosmethyl suggest that more than one gene may be involved because no inflection was observed in the time response lines of F2 males. Additional research is required to fully elucidate the mode of inheritance.
Irrigation effects on European corn borer ‐ maize water relations
Authors: Ellsworth P. C. , Bradley J. R. , Kennedy G. G. , Patterson R. P. , Stinner R. E. 
Published: April 2011

AbstractThis study examined the impact of irrigation water on certain aspects of an insect‐plant relationship in the field including the assessment of plant‐mediated water effects on an herbivore's development, survival, and behavior, and plant damage parameters and host tissue water status. Maize (Zea mays L.) plants were arranged in a randomized complete block design in the field over two years in North Carolina (NC). Four blocks were subjected to three different irrigation treatments initiated ca. one week before anthesis: optimal, intermediate, deficit water supply. Each plant was infested with one (1986) or two (1987) black head stage, E‐race European corn borer [Ostrinia nubilalis (Hübn.)] (ECB) egg masses at tasselling. ECB development, tunnelling site, and survival as well as plant tissue water status (tissue % water contents [θ] & leaf water potentials [Ψ]) were recorded through July. The irrigation effect on ECB parameters was slight and variable. Internal stalk temperatures of optimal plants were consistently cooler than their deficit counterparts (1 day‐degree/day). With degree‐days included as an explanatory variable in the analyses, there were no significant irrigation effects on the ECB parameters, except for total proportion of ECB's bored into maize plant parts. More ECB's bored into drier plants than in optimal plants; however, this trend was not significant in 1987.Plant water indices showed that though responded to irrigation, there were only minor changes in tissue θ, particularly in view of the larger diurnal tissue changes observed and the relatively high, sustained stalk θ levels seen over all treatments. Examination of ECB pupal θ confirmed that dietary water changes were minor or non‐limiting to the insects' developmental physiology, because pupal θ was not sensitive to the irrigation treatments.Though water supply changes have drastic developmental and agronomic consequences for the maize plant, little or no changes were seen in the ECB feeding environment. Furthermore, a plant damage model was developed whereby the total % of ECB's tunnelled into maize was related to the mean larval age. The implications of this model on the understanding of ECB tunnelling behavior, damage potential, and pest management is noted.
Observers' bias in the assessment of pest and disease symptoms in leek
Authors: Theunissen J. , Legutowska H. 
Published: April 2011

AbstractIn the vegetable crop leek, Allium porrum L., the performance of observers was compared to the ‘real situation’ of pest and disease infestation. In two experiments the infestation of plants in a number of rows was meticulously investigated thus reflecting the ‘real situation’ as contrasted with the results of one or more observers. Included were the symptoms of leek moth (Acrolepiopsis assectella Zeller) feeding, both fresh and old, of onion thrips (Thrips tabaci Lindeman) feeding and of infestation with rust (Puccinia allii Rud.). The method of scouting was similar to growers' practice in commercial leek growing. The results show that even trained scouts vary considerably in accuracy when assessing infestation in rows at the same field. A group of observers show individual patterns of estimation, a wide variation in ability to make a correct assessment and a strong density dependency of deviations of the ‘real situation’ with the perceived density of the symptoms in the crop.
Diet‐switching by gypsy moth: effects of diet nitrogen history vs. switching on growth, consumption, and food utilization
Authors: Stockhoff B. A. 
Published: April 2011

AbstractGypsy moth (Lymantria dispar (L.) (Lepidoptera: Lymantriidae)) larvae were reared from hatch on 1.25% N or 3.5% N artificial diet (previous diet) and switched reciprocally to the other diet (current diet) after molting into the second, third, fourth, or fifth instar. The nitrogen concentration of food consumed during previous instars had a strong residual effect on the growth rate in subsequent instars when a diet switch was made during instars two through four, but did not affect growth rate of fifth‐instar larvae despite effects on food consumption and utilization. In early instars, larvae reared on 1.25% N artificial diet and then switched to 3.75% N diet had lower mass‐adjusted growth rates than larvae continuously reared on 3.75% N diet. Conversely, larvae reared on 3.75% N diet and switched to 1.25% N had higher mass‐adjusted growth rates than larvae reared continuously on 1.25% N diet. Relative to larvae previously reared on 1.25% N diet, fifth‐instar male larvae previously reared on 3.75% N diet had slightly lower consumption rates, higher net growth efficiency (ECD), and higher gross growth efficiency (ECI). Larvae previously reared on 3.75% N diet tended to have lower food assimilation efficiency (AD) and lower nitrogen assimilation efficiency (AD(N)). Although both previous and current diet nitrogen concentration strongly affected larval growth and food utilization, the interaction term between these was not significant for any response variables except ECD and ECI. Because the interaction term reflects the effect of switching per se, the results indicate that there was a metabolic cost associated with switching, but no inherent net cost or benefit of diet‐switching to growth.
Relationship between deterrence and toxicity of plant secondary compounds for the alfalfa weevil Hypera brunneipennis
Authors: Bernays E. A. , Cornelius M. 
Published: April 2011

AbstractA variety of plant secondary compounds, several of which are quite widespread in nature were tested for their deterrence to the specialist coleopteran Hypera brunneipennis (Boheman) in short‐term behavioral assays. The compounds were nicotine, quinine, sparteine, hordenine, linamarin, amygdalin, sinigrin, morin, juglone, chlorogenic acid, digitonin, mimosine, diosgenin, rutin and ursolic acid. Nine of these were then tested for their post‐ingestional effects over one to two weeks of adult life, using fecundity as a measure of the effects. In only one case was there any indication of a detrimental effect or any trend suggesting one. The evolutionary implications of these findings are discussed.