bluuebunny/crossref_metadata_2025_split huggingface dataset:
Behaviour of male oriental fruit moth, Grapholita molesta, in overlapping sex pheromone plumes in a wind tunnel
Authors: Valeur P. G. , Löfstedt C. 
Published: March 2011

AbstractThe behaviour of Grapholita molesta (Busck) (Lepidoptera: Tortricidae) males was studied in overlapping sex pheromone plumes in a wind tunnel. The ultimate aim of the study was to assess the effect of different treatments on male behaviour and consider the observed changes within the context of the suggested mechanisms underlying mating disruption. Two baits were placed either in series or parallel using both synthetic pheromone blends and female extracts. One bait, the reference containing (Z)‐8‐dodecenyl acetate/(E)‐8‐dodecenyl acetate/(Z)‐8‐dodecenol in a ratio of 100/6/10 was kept constant at a dose of 100 μg of the main component, giving a composition and a release rate close to that of a female. The dose of the other bait varied between 0.1 and 100 times the concentration of the reference and was a mixture of one, two or three pheromone components. Males clearly discriminated between different blends and doses in the overlapping plumes, for regardless if the lures were presented in series or in parallel they followed the complete plume. Complete suppression of the response to the reference was only achieved with 300 μg of the optimal three‐component blend on the other lure. When tested singly, a bait consisting of Z8–12:OAc/E8–12:OAc/Z8–12:O Hin a 100/0.2/0.4 ratio, attracted a high proportion of the males when placed 75 cm upwind of the male release site, but no males from 150 cm. Our data suggest that complete pheromone blends should be more effective than any incomplete blends in mating disruption formulations for G. molesta.
La prise d'informations visuelles chez la coccinelle Harmonia axyridis
Authors: Lambin M. , Ferran A. , Maugan K. 
Published: March 2011

RésuméLes capacités visuelles de la coccinelle H. axyridis, espèce utilisée en lutte biologique, ont été étudiées l'aide de formes géométriques différentes et de leurres qui miment un puceron. Les larves et les adultes de cette coccinelle semblent présenter une vision à ‘distance’ (perception de formes géométriques) et une vision de ‘proximité’ (perception de leurres comparables à des proies). Cette vision qui est plus développée chez les adultes, permet à cette coccinelle de changer l'orientation de ses déplacements soit pour entrer en contact avec ces cibles artificielles soit pour passer à proximité. Toutefois, ces performances ont été mises en évidence dans des conditions particulières, les cibles et les leurres présentant un fort contraste par rapport à l'environnement.SummaryPerception of visual information in the ladybird Harmonia axyridis PallasThe sensorial relationships of predators to plant and prey are seldom taken into account in biological control programmes. However, methods of conditioning, attracting and/or settling predator populations may result from a knowledge of their visual and/or olfactive sensorial capacities. The study of the visual capacities of Harmonia axyridis Pallas (Col., Coccinellidae), a species used in France for aphid control, was undertaken to this aim with artificial targets and dummies. Larvae and adults of this coccinellid seemed to present ‘a long distance’ vision (perception of geometric shapes) and ‘a short distance’ vision (perception of aphid‐like dummies). This vision, which is more accurate in adults, allows this coccinellid to change the orientation of its movement in order either to contact the targets (or the dummies), or to walk close to them. Under field conditions, these visual capacities may participate in the localisation of tall objects such as plants. After plant exploration, which is controlled by internal factors (tropism) and external ones either physical (leaf vein and edge) or chemical (plant secretion due to aphid infestation, olfactive trails, honeydew or pheromones), visual capacities may also participate in prey perception.
Competition between Gyranusoidea tebygi and Anagyrus mangicola, parasitoids of the mango mealybug, Rastrococcus invadens: interspecific host discrimination and larval competition
Authors: Bokonon‐Ganta A. H. , VAN Alphen J. J. M. , Neuenschwander P. 
Published: March 2011

AbstractThe competition between Gyranusoidea tebygi Noyes and Anagyrus mangicola Noyes (both Hymenoptera: Encyrtidae), exotic parasitoids of the mango mealybug, Rastrococcus invadens Williams (Homoptera: Pseudococcidae) was studied in the laboratory. No significant differences were found in the way each parasitoid species examined, attacked, stung, and oviposited into hosts, unparasitized, or previously parasitized by the other species. This suggests that neither species discriminates against each other. The total number of parasitoids of either species emerging did not significantly differ between competition experiments. When A. mangicola was the first parasitoid to attack a host, it had no significant advantage over G. tebygi. However, when A. mangicola followed G. tebygi by either 4 or 24 h, it clearly won. Overall A. mangicola won the competition in 70.9% of all cases. The level of the competition, either at the egg or larval stage, and factors responsible for the elimination of older larvae by younger ones could not be assessed in these experiments. The coexistence of the two parasitoids as complementary for the biological control of the mango mealybug is discussed.
The effect of egg load on superparasitism by the snowberry fly
Authors: VAN Randen E. J. , Roitberg B. D. 
Published: March 2011

AbstractIn studies conducted with fruits of the host plant, Symphoricarpus albus (L.), we examine the influence of egg load on the oviposition behaviour of Rhagoletis zephyria Snow (Diptera: Tephritidae). By altering the availability of exogenous protein, three classes of females with progressively increasing egg loads were produced, while keeping confounding factors such as age, experience, and mating status constant. Flies from all three classes were randomly presented with either a pheromone marked fruit, or with an unmarked fruit. Results indicate that increased egg load led to a greater propensity to accept, or superparasitize, the pheromone marked fruit. Upon dissection it was revealed that females which superparasitized had a mean egg load of 19.5 eggs (n = 22), while females which rejected marked fruit had a mean egg load of 13.5 eggs (n = 26). These results are consistent with the theory of adaptive superparasitism.
Bi‐ and trivoltine complex life cycles in a Kanto (Japan) population of a wild bruchid Kytorhinus sharpianus
Authors: Ishihara Michihiro , Shimada Masakazu 
Published: March 2011

AbstractThe partial trivoltinism and overwintering of Kytorhinus sharpianus Bridwell (Coleoptera: Bruchidae) was studied in the Kanto district, Japan. The later in the summer eggs were laid by the first‐generation adults, the higher was the incidence of larval diapause in the second generation. The incidence of diapause also fluctuated between years, influencing the abundance of third‐generation larvae. A relatively large proportion of third‐generation larvae did not attain the diapause stage by the beginning of winter. The diapause development of larvae in diapause was completed by mid‐January. Immature larvae of the third generation also overwintered and emerged as adults in the spring.
Effects of GNA and other mannose binding lectins on development and fecundity of the peach‐potato aphid Myzus persicae
Authors: Sauvion Nicolas , Rahbé Yvan , Peumans Willy J. , VAN Damme Els J. M. , Gatehouse John A. , Gatehouse Angharad M. R. 
Published: March 2011

AbstractThree mannose‐binding lectins were assayed in artificial diets for their toxic and growth‐inhibitory effects on nymphal development of the peach‐potato aphid Myzus persicae. The snowdrop (Galanthus nivalis) lectin GNA was the most toxic, with an induced nymphal mortality of 42% at 1500 μg ml−1 (30 μM) and an IC50 (50% growth inhibition) of 630 μg ml−1 (13 μM). The daffodil (Narcissus pseudonarcissus) lectin NPA and a garlic (Allium sativum) lectin ASA induced no significant mortality in the range 10–1500 μg ml−1, but did result in growth inhibition of 59% (NPA) and 26% (ASA) at 1500 μg ml−1 (40 μM for NPA, 63 μM for ASA). All three lectins were responsible for a slight but significant growth stimulation when ingested at 10 μg ml−1, reaching + 26%, + 18% and + 11% over the control values for the garlic lectin, the daffodil lectin and the snowdrop lectin, respectively. GNA, as well as the glucose/mannose binding lectin Concanavalin A, were also provided at sublethal doses throughout the life cycle of the aphids, and effects on adult performance were monitored. Adult survival was not significantly altered, but both lectins adversely affected total fecundity and the dynamics of reproduction, resulting in significant reduction in calculated rm's (population intrinsic rate of natural increase) on lectin‐containing diets. These effects are discussed in relation to the use of transgenic plants expressing these toxic lectins for potential control of aphid populations.
Transgenic potato plants with enhanced resistance to the peach‐potato aphid Myzus persicae
Authors: Gatehouse Angharad M. R. , Down Rachel E. , Powell Kevin S. , Sauvion Nicolas , Rahbé Yvan , Newell Christine A. , Merryweather Andrew , Hamilton William D. O. , Gatehouse John A. 
Published: March 2011

AbstractPotato plants (Solanum tuberosum) cv. Desireé were transformed with the genes encoding the proteins bean chitinase (BCH), snowdrop lectin (GNA) and wheat α‐amylase inhibitor (WAI) under the control of the constitutive CaMV 35S promoter. Transgenic plants with detectable levels of foreign RNA were then selected for further characterisation with respect to protein expression levels by immunodot blot analysis using polyclonal antibodies raised against the respective protein. With the exception of WAI, plants expressing high levels of RNA, expressed correspondingly high levels of the foreign protein (1.5–2.0% of the total soluble protein). Although high levels of WAI mRNA were detected in some of the transformants, the protein could not be detected. On the bases of expression levels, two lines, designated PWG6#85 (transformed with the double construct WAI/GNA) and PBG6#47 (transformed with the double construct BCH/GNA), were selected for testing in aphid trials for enhanced levels of resistance.Both transgenic lines had a marked and significant effect on fecundity. The number of nymphs produced per female per day peaked at 4.1 and 4.2 for lines PBG6#47 and PWG6#85 respectively, compared to a value of 5.4 on control plants. Total nymphal production was also significantly lower on either of the transgenic lines compared to control plants (P<0.001) with the differences between the lines being only just significant (P=0.058). On line PBG6#47 there was a delay in nymphal production of 1.6 days, representing a delay of 1 5%, and on line PWG6#85 this was 3.2 days, representing a delay of ca. 30%. The intrinsic rates of increase (rm) were also significantly lower on both of the transgenic lines in comparison to that on control plants (P<0.001), however the differences between the lines were not significant. The potential of using such genes as part of an over all strategy for the control of aphid populations is discussed.
Feeding behaviour, sensory physiology and nutrient feedback: a unifying model
Authors: Simpson S. J. , Raubenheimer D. 
Published: March 2011

AbstractThe design features of gustatory systems are considered in relation to the need for insect herbivores (or indeed any animal) to regulate their nutrient intake. The gustatory system (defined to include both peripheral and central components) should ideally be designed to reflect: (a) the average nutritional requirements of the insect during its various developmental stages; (b) the ‘predictably unpredictable’ variation in nutrient supply‐demand which occurs about that average; and (c) the distribution and composition of foods available in the environment. A mathematical model is presented which makes detailed predictions regarding behavioural and electrophysiological responses to foods or simple solutions varying in nutrient content.
Pattern and process in the evolution of insect‐plant associations:Yponomeutaas an example
Authors: Menken Steph B. J. 
Published: March 2011

AbstractPhylogenetic studies are increasing our understanding of the evolution of associations between phytophagous insects and their host plants. Sequential evolution, i.e. the shift of insect herbivores onto pre‐existing plant species, appears to be much more common than coevolution, where reciprocal selection between interacting insects and plants is thought to induce chemical diversification and resistance in plants and food specialization in insects.Extreme host specificity is common in phytophagous insects and future studies are likely to reveal even more specialization. Hypotheses that assume that food specialists have selective advantages over generalists do not seem to provide a general explanation for the ubiquity of specialist insect herbivores. Specialists are probably committed to remain so, because they have little evolutionary opportunity to reverse the process due to genetically determined constraints on the evolution of their physiology or nervous system. The same constraints might result in phylogenetic conservatism, i.e. the frequent association of related insect herbivores with related plants. Current phylogenetic evidence, however, indicates that there is no intrinsic direction to the evolution of specialization.Historical aspects of insect‐host plant associations will be illustrated with the small ermine moth genusYponomeuta.Small ermine moths show an ancestral host association with the family Celastraceae. The genus seems to be committed to specialization per se rather than to a particular group of plants. Whatever host shift they have made in their evolutionary past (onto Rosaceae, Crassulaceae, and Salicaceae), they remain monophagous. The oligophagousY padellusis the only exception. This species might comprise a mosaic of genetically divergent host‐associated populations.
Reproductive biology of viviparous and oviparous species of the leaf beetle genusOreina
Authors: Dobler S. , Rowell‐Rahier M. 
Published: March 2011

AbstractIn five species of the genusOreinaChevrolat (Coleoptera, Chrysomelidae) we compared the size of offspring, the fecundity of the females, the timing of offspring production and female investment over the season. Two of the species,O. elongataandO. luctuosa, laid eggs, whileO. cacaliae, O. gloriosaandO. variabilisgave birth to larvae. Offspring size corrected for female size was similar in the two oviparous species and in the viviparousO. cacaliae.In the two other viviparous species the larvae were two to three times bigger in relation to the female. The greater size of the offspring was not traded off for lower fecundity in these latter two species, yet the production of bigger larvae was associated with a longer laying period and thereby a spreading of reproductive investment over the season. The prediction of life history theory that higher investment in individual offspring should be traded off for lower fecundity could not be confirmed. The investigation of egg and larval development showed that in one of the oviparous species,O. luctuosa, the length of the egg stage was more variable. This corroborates the view that in this species the eggs can be retained for varying times before being laid. Greater size at birth does not necessarily lead to shortened developmental times: the larval periods ofO. cacaliae, O. elongata, O. gloriosaandO. variabiliswere all comparable although the larvae of the first two species were relatively smaller when laid; only the small larvae ofO. luctuosaneeded significantly longer for their development. For all growth parameters examined the differences between species were larger than the differences between populations. A comparison of larval growth of the oligophagous speciesO. cacaliaeon three plant genera showed that larval growth rate is influenced by the food plant. However, the plant on which the larvae grew worst is apparently not chosen for oviposition in the field. A comparison with a phylogeny of the species based on allozymes suggests that species with similar reproductive parameters are closely related, yet that viviparity evolved independently inO. cacaliaeon one hand andO. variabilisandO. gloriosaon the other.
Influence of environmental conditions and parasitoid quality on field performance of Trichogramma minutum
Authors: Bourchier R. S. , Smith S. M. 
Published: March 2011

AbstractThe effects of weather conditions and two parasitoid quality attributes, realized fecundity and host acceptance, were assessed on the field efficacy of mass‐released Trichogramma minutum. Temperature was the most important single variable, explaining up to 75% of the variation in field parasitism. There were significant positive relationships between both the sum of the maximum temperatures and the number of degree‐hours above a 15 °C threshold, accumulated in the three days following the release, and parasitism in the field. There was a significant negative relationship between the mean relative humidity and the odds of parasitism in the field. Quality parameters based on parasitoid biology were not effective for predicting field efficacy if poor weather conditions persisted after a release. If weather conditions were ‘good’ (i.e. accumulated maximum temperatures above 62 °C, in the 3 days following the release), then parameters such as release rate and fecundity in the lab were useful predictors of field performance. There was no relationship between host acceptance measured in the lab and field parasitism. Given the importance of field temperatures for field performance, selection for cold tolerance of T. minutum would be desirable.
Non‐reciprocal cross‐incompatibility in Trichogramma deion
Authors: Stouthamer Richard , Luck Robert F. , Pinto John D. , Platner Gary R. , Stephens Beth 
Published: March 2011

AbstractIn non‐reciprocal cross‐incompatibility (NRCI), the crossing of a female of a strain A with a male of a strain B results in hybrid offspring, whereas the reciprocal cross produces few or no hybrids. Only females are of hybrid origin in Hymenoptera because they arise from fertilized eggs; males arise from unfertilized (haploid) eggs. Crosses between many strains of Trichogramma deion showed some degree of NRCI. Crosses between a T. deion culture collected in Seven Pines, California (SVP) with one from Marysville, California (MRY) showed an extreme form of NRCI in which practically no female offspring was produced when MRY females were crossed with SVP males. The reciprocal cross produced a close to normal proportion of female and male offspring. Detailed studied of this cross indicated that 1) the female offspring produced in the compatible interstrain cross were not the result of parthenogenesis but were true hybrids, 2) the incompatible interstrain cross did not produce female offspring because fertilized eggs died during development, 3) the death of these eggs could not be prevented by either antibiotic or temperature treatment, 4) cytoplasmically inherited factors causing NRCI could be discounted because backcrossed females with the genome of MRY and the cytoplasm of SVP, exhibit the NRCI relationship characteristic of their genome. Therefore the NRCI between these strains appears to be caused by a modification coded for by the nuclear genes of MRY that results in incompatibility when SVP sperm fertilizes MRY eggs. In addition the level of incompatibility in crosses between the SVP females and MRY males is temperature sensitive, the higher the rearing temperature the lower the level of compatibility.
Citrus limonoid effects on Colorado potato beetle larval survival and development
Authors: Murray Kathleen D. , Groden Eleanor , Drummond Francis A. , Alford A. Randall , Storch Richard H. , Bentley Michael D. 
Published: March 2011

AbstractThe effects of citrus limonoids, applied topically to potato (Solanum tuberosum L. var. ‘Katahdin’) foliage, on Colorado potato beetle (Leptinotarsa decemlineata (Say) (Chrysomelidae) larval development, growth, and survival were quantified in laboratory assays and a small‐plot field test. In laboratory assays, survival, development rate, and body weight decreased with increasing limonoid concentration, however these measures of larval response did not significantly differ among varying periods of limonoid exposure (three, six, or nine days). Significant limonoid application concentration and frequency effects on survival, development rate, and defoliation were observed in the field test. These results indicate the potential utility of lethal and non‐lethal effects of citrus limonoids for management of the Colorado potato beetle.
Biological activities of extracts from traditionally used Nigerian plants against the European corn borer, Ostrinia nubilalis
Authors: Ewete F. K. , Arnason J. T. , Larson J. , Philogène B. J. R. 
Published: March 2011

AbstractPreliminary investigations with ethanolic (EtOH) extracts from five Nigerian plants show that extracts of Piper guineense Schum and Thonn (Piperaceae), Cedrela odorata L. (Meliaceae), Dennettia tripetala G. Baker (Annonaceae) and Aframomum melegueta (Rosch) K. Schum (Zingiberaceae) in artificial diets significantly reduced larval growth of European corn borer (ECB), Ostrinia nubilalis Hubner, at a concentration of 1000 ppm (0.1%). An extract of Xylopia aethiopica (Dunal) A. Rich (Annonaceae) was ineffective. When the extracts were subsequently incorporated into artificial diets at 300 ppm and offered to neaonates, larval mortality increased in the order A. melegueta (13%), D. tripetala (13%), P. guineense (27%), and C. odorata (48%). Larval and adult emergence periods increased with increasing concentration of P. guineense, C. odorata and D. tripetala indicating a toxic response. Nutritional indices for habituated third instar larvae with the two most promising plant extracts, P. guineense and C. odorata, showed that the efficiencies of conversion of digested food (ECD) was significantly reduced at 300 ppm suggesting a postdigestive toxicity of the extracts. P. guineense and C. odorata extracts show the best potential for development as botanical insecticides.
Approximate digestibility of fibre for a graminivorous caterpillar
Authors: Hochuli Dieter F. , Roberts Fiona M. 
Published: March 2011

AbstractFinal instarPersectania ewingii(Westwood) (Lepidoptera: Noctuidae) were fed seedlingTriticum aestivumL. for 2 days to determine the approximate digestibility of the cell wall and cell content fractions. Cell wall content was estimated using a micro‐analytical neutral detergent fibre technique. Approximate digestibilities of neutral detergent fibre, neutral detergent solubles and dry matter were calculated for individuals and pooled samples.P. ewingiilarvae digested a small but significant proportion of the fibre ingested (13–21%), higher than that previously reported for herbivorous insects. The micro‐analytical and previously used macro‐analytical techniques produced similar estimates of digestibility although both techniques have inherent shortcomings, the latter requiring the pooling of samplex and the former limiting the number of replicates during chemical analysis. Differences in the amount of larval frass collected during the feeding trial (corrected for consumption) explained much of the variation in digestibility values, while there were no effects of larval mass, overall consumption and total frass produced on digestibility estimates. These results confirm that plant cell contents are the major source of nutrients to larval Lepidoptera although there is some chemical disruption of the plant cell wall.