bluuebunny/crossref_metadata_2025_split huggingface dataset:
Une phéromone d'agrégation chez Forficula auricularia
Authors: Sauphanor B. 
Published: April 2011

RésuméUn comportement d'agrégation est fréquemment observé chez les larves et les adultes de Forficula auricularia L. L'hypothèse d'un controle phéromonal de ce comportement est confirmée expérimentalement par un test biologique qui, en condition de choix, met en évidence le regroupement des forficules dans des abris déjà visités par d'autres individus de l'espèce, préférentiellement aux abris témoins. Une interattractivité existe entre tous les stades de développement et la phéromone intervientgalement pendant la phase de soins maternels: les traces de larves du premier stade encore confinées dans le terrier maternel, ainsi que de femelles en période de soins, provoquent l'agrégation de larves âgées. La comparaison de l'attractivité de différents extraits par l'hexane (traces, fractions de corps, feces) indique la localisation de la sécrétion phéromonale au niveau des pattes, et désigne les glandes tibiales comme organes sécréteurs.SummaryAn aggregation pheromone in the European earwig, Forficula auriculariaAdults and nymphs of Forficula auricularia often present an aggregation behaviour. The hypothesis of a pheromonal control of this behaviour was demonstrated with a biological test, in which the earwigs aggregated in shelters already visited by insects of the same species. An interattractivity was observed between all developmental instars, and the pheromone also controls the parental behaviour: trails of first instar nymphs, still confined in maternal cell, or of females in nesting period, are also attractive for old nymphs. The anatomical source of the pheromone was determined with differential extracts in hexane: trails on filter papers, faeces, parts of the body. The secretions are localized in the legs, and originate from the tibial system already described in two species of Dermaptera.
Genetic structure of leaf‐beetles populations: microgeographic and sexual differentiation in Oreina cacaliae and O. speciosissima
Authors: Rowell‐Rahier M. 
Published: April 2011

AbstractWe used F‐statistics to quantify the population structure of two sympatric species of leaf beetles, Oreina cacaliae and O. speciosissima (Chrysomelinae, Coleoptera), which share the same microhabitat since they feed on the same herbaceous host plants. We measured genetic differentiation at six allozyme loci 1) among populations separated by relatively small distances (40 to 250 kilometers), 2) within each population, and 3) between sexes within populations. For both species, the populations studied are not panmictic. For each population, heterozygosities are relatively high, but the observed heterozygosities are generally lower than the expected values. Overall, within‐population differentiation is high and similar for both species (Fis = 0.326 for O. cacaliae and 0.332 for O. speciosissima). Additionally, populations of both species are highly differentiated (Fst = 0.234 versus 0.051 for O. speciosissima). For O. cacaliae, Fis and Fst are greater among females than among males, while for O. speciosissima, Fst is sustantially greater among the males while Fis is slightly greater among males. Differences in gene frequency among the sexes were statistically tested using a modified Fst with sex as the defining category, and the sexes differed significantly with the exception of one population in O. cacaliae. Possible explanations for this difference are discussed.
Size specific demography of three species of Anastrepha fruit flies
Authors: Liedo P. , Carey J. R. , Celedonio H. , Guillen J. 
Published: April 2011

AbstractIndividuals of three Anastrepha species: A. obliqua, A. ludens, and A. serpentina (Diptera: Tephritidae), were sorted according to pupal weight in cohorts of large and small flies. Demographic parameters and reproductive patterns and heterogeneity were determined for each cohort. Large flies of the three species presented greater expectation of life and gross fecundity rates.A. ludens was the species with the longest life span (expectation of life of large adults was 110 days) and the greatest gross fecundity rates (1597 eggs/female for the large flies). While, A. obliqua had the shortest mean age of reproduction (33 days), and the greatest daily egg production (14 eggs/female/day). Net fecundity was similar in these two. A. serpentina had lower fecundity rates.Reproductive information for each size and each species include: age‐by‐parity relations, fraction of sexually mature life in which females lay eggs, and frequency distribution of individual egg production. Results demonstrate that even under constant laboratory conditions and using standard artificial hosts, there is a great deal of life history variation among these Anastrepha species and among other tephritid fruit flies.
Photoperiodic responses during larval development and diapause of two geographic ecotypes of the rice stem maggot, Chlorops oryzae
Authors: Takeda M. , Nagata T. 
Published: April 2011

AbstractChlorops oryzae is bivoltine in northern Japan but trivoltine in the southern part of the country. In the bivoltine strain, both the egg and larval stages were found to be sensitive to photoperiod. When the egg stage was exposed to a long‐day photoperiod (16L:8D), larval development showed a short‐day type response, and mature third‐instar larvae entered a summer diapause under a long‐day photoperiod (15L:9D). When eggs experienced short days, the first‐instar larvae entered a winter diapause under short‐day conditions, and the critical photoperiod in the larval stage ranged from about 14L:10D to about 12L:12D as the photoperiod experienced by the eggs increased from 12L:12D to 14L:10D. However, the development of the larvae after overwintering was not influenced by the photoperiod. In the trivoltine strain, larval development was retarded under a 14L:10D photoperiod but not under either shorter or longer photoperiods, when larvae had spent the egg stage under a 16L:8D photoperiod. The critical photoperiod of the larval stage for the induction of a winter diapause in the first instar was about 12L:12D, though it varied to some extent with the photoperiod during the egg stage. Thus, Chlorops oryzae was able to adapt itself to the local climatic conditions by the development of variable and complicated photoperiodic responses.
Orientation of males of sorghum midge, Contarinia sorghicola to sex pheromones from virgin females in the field
Authors: Sharma H. C. , Vidyasagar P. 
Published: April 2011

AbstractThe orientation of males of the sorghum midge, Contarinia sorghicola Coq. (Diptera: Cecidomyiidae) towards virgin female baited sticky traps was studied in the field. Male response increased linearly with an increase in the number of virgin females in the sticky traps. Five females per vial were optimum for monitoring midge populations in the field. Numbers of males trapped were significantly greater in traps placed at 0.5 and 1.5 m above ground level compared with those placed at 2.5 m. Peak trap catches occurred at 0900 h. The number of males trapped decreased significantly after 1400 h; male catches continued till sunset. Trap catches followed the same pattern as the number of ovipositing females on sorghum panicles at the half‐anthesis stage. Midge activity decreased with an increase in temperature and a decrease in relative humidity. Peak midge density was observed during the second fortnight of October in the rainy season and during February‐March in the post‐rainy season. Sex pheromones can be used to monitor midge population dynamics for integrated pest management and to screen for host plant resistance to this insect.
Intraspecific variation of Drosophila buzzatii larval breeding success on Opuntia: A yeast‐plant‐insect relationship
Authors: Moreteau B. , Carton Y. , Pignal M. C. , David J. R. 
Published: April 2011

AbstractThe cactophilic species, Drosophila buzzatii, normally breeds in decaying pockets of Opuntia cladodes, in which there is a complex interaction with the microbial flora, especially yeast species. Isofemale lines were used to estimate genetic variation among larvae reared on their natural feeding substrate. Four naturally occurring cactophilic yeast species isolated from the same Tunisian oasis as the Drosophila population were used. Two fitness components were studied for each line, viability and developmental time. Genetic variations among D. buzzatii lines were observed for both traits. A significant yeast species × isofemale line interaction for viability was also evidenced, suggesting the occurrence of specialized genotypes for the utilization of breeding substrates. This genetic heterogeneity in the natural population may favor a better adaptation to the patchily distribution of yeasts.
Geographical variation in pheromone response of the European corn borer, Ostrinia nubilalis, in North Carolina
Authors: Sorenson C. E. , Kennedy G. G. , van Duyn W. , Bradley J. R. , Walgenbach J. F. 
Published: April 2011

AbstractThe response of male European corn borer, Ostrinia nubilalis (Hübner) to synthetic pheromone lures containing various isomeric blends of the sex pheromone 11‐tetradecenyl acetate was measured in 13 counties in North Carolina. The blends consisted of either 3% Z (‘E strain’), 97% Z (‘Z strain’), or 35% Z (‘hybrid’) 11‐tetradecenyl acetate. Response to E strain lures predominated in those counties located in the Coastal Plain (east) of the state, while response to the Z strain pheromone was dominant in the west. A zone of overlap of these broad strain distributions appears to occur in the eastern Piedmont. Within this zone there was substantial response to both E and Z blends. The proportion of these responses changed considerably between generations within years as well as between years. Significantly higher capture rates in hybrid baited traps in parts of the overlap zone may be indicative of increased rates of hybridization between the E and Z strains.
Relation entre aphides et fourmis dans la production et la récolte du miellat sur oranger
Authors: Dartigues D. 
Published: April 2011

AbstractLa fréquence des gouttelettes de miellat excrétées par Toxoptera aurantii (Boyer de F.) augmente en la présence de Tapinoma simrothi Krausse., mais le phénomène est seulement important quand les aphides sont familiarisés avec la visite des fourmis. En présence d'ouvrières pourvoyeuses âgées, le nombre de gouttelettes de miellat excrétées par une colonie d'aphides est multiplié par 4, 9. Les meilleures performances sont obtenues avec les larves, qui défèquent plus vite que les adultes. Les jeunes ouvrières âgées de moins de deux semaines et isolées juste avant la naissance, sont capables d'augmenter la production de gouttelettes, et ceci sans apprentissage. Mais l'effet est plutôt faible. Dans tous les cas, le nombre de sollicitations pour la nourriture est plus élevé que le nombre des gouttelettes excrétées. Habituellement, les fourmis collectent le miellat directement sur les aphides. Néanmoins, le miellat restant sur les feuilles peut ětre ramassé, mais cette récolte n'est pas très importante.
Modification de la fertilité du carpocapse Cydia pomonella à la suite du contact des adultes avec un régulateur ou un inhibiteur de croissance d'insectes
Authors: Charmillot P.‐J. , Pasquier D. 
Published: April 2011

RésuméDes papillons de carpocapse Cydia pomonella L., mâles et femelles séparés, sont soumis au contact des résidus secs du CGA 184′699, un inhibiteur de croissance d'insectes (ICI) et du fenoxycarb, un régulateur de croissance d'insectes (RCI). Ils sont ensuite regroupés dans des boîtes non traitées pour l'accouplement et la ponte. La fécondité du carpocapse n'est pratiquement pas affectée par ce conditionnement mais sa fertilité diminue avec l'augmentation de la concentration des produits et avec la durée d'exposition. Avec le CGA 184′699, l'efficacité ovicide induite atteint environ 50% suite à un contact de trois jours avec les résidus d'un traitement à 100 mg/l, alors qu'avec le fenoxycarb elle s'élève à 87% dans les mêmes conditions. Avec le CGA 184′699, seul le contact des femelles avec les résidus provoque cette réduction de fertilité, alors que le fenoxycarb agit sur les deux sexes.
Spring dispersal of Sitona lineatus: the use of aggregation pheromone traps for monitoring
Authors: Nielsen B.S. , Jensen T.S. 
Published: April 2011

AbstractThe spring dispersal of Sitona lineatus L. (Coleoptera; Curculionidae) was investigated on a Danish farm. S. lineatus dispersed by flight in the early spring on sunny, calm days with temperatures above ca. 15 °C.Two thirds of the population of S. lineatus dispersed from perennial leguminous crops (clover and lucerne) in the first period of flight activity. The next dispersal did not occur until one month later despite several intermediate flight activity periods. The first period of dispersal occurred before the germination of the spring sown summer host crop, Vicia faba L. The field bean crop was infested in three later invasions during a period of more than three weeks.The aggregation pheromone, 4‐methyl‐3,5‐heptanedione, had a significant effect on captures of both males and females in cone traps placed on the ground. There was no effect of the pheromone on captures in yellow sticky traps placed 1.5 m above ground. The pheromone effect is discussed in relation to behavioural observations.Both types of traps may be used in a survey system for monitoring spring dispersal of S. lineatus and optimal timing of insecticide spraying. However, the pheromone cone traps were highly specific whereas all kinds of flying insects were caught in the yellow sticky traps, thus making the latter traps less suitable for monitoring.
An improved leaf‐disk antifeedant bioassay and its application for the screening of Hokkaido plants
Authors: Escoubas P. , Lajide L. , Mitzutani J. 
Published: April 2011

AbstractIn the course of our search for new insect antifeedant substances from plants, we have devised an improved antifeedant leaf‐disk bioassay. Our system allows an accurate measurement of consumed disk surfaces, using a video camera interfaced with a computer. The scanned image of the leaf disks is stored, and the eaten areas are measured with the help of a video‐image analysis software. This new method allows for precise quantification of insect antifeedant activity tested on leaf material.This method was applied to the screening of Hokkaido plants for antifeedant activity. Out of 206 samples, seven demonstrated significant activity against larvae of the tobacco cutworm, Spodoptera litura.
Interactions between a specialist herbivore, Crocidosema plebejana, and its host plants Malva parviflora and cotton, Gossypium hirsutum: Larval performance
Authors: Hamilton J. G. , Zalucki M. P. 
Published: April 2011

AbstractPrevious studies have shown populations of tipworm, Crocidosema plebejana Zeller (Lepidoptera: Tortricidae), on Malva parviflora L. persist throughout the development of the plant while those on cotton are greatly reduced after plant flowering. We investigated larval performance of tipworm on plants of both species at various stages of development. Tipworm reared on M. parviflora developed faster, survived better and tended to be heavier than those reared on cotton. On M. parviflora all parts of the plant were eaten while on cotton large squares, flowers and small to medium bolls were never eaten. Cotton quality for tipworm development decreased markedly at flowering and remained low thereafter, as shown by low survival of neonate larvae and extended development time of late instar larvae. The poor performance of tipworm on flowering cotton is strongly correlated with major changes in plant chemistry at that stage of plant development.
Patterns of change in secondary and tertiary sex ratios of the Terebrantian thrips, Frankliniella occidentalis
Authors: Terry L. I. , Kelly C. K. 
Published: April 2011

AbstractAdult sex ratios (tertiary sex ratios) of the haplo‐diploid Terebrantian thrips species, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) were examined from several native and introduced hosts in an apple (Malus spp.) ecosystem. The ratios were variable and most were female‐biased, ranging from 0 to 61% males. Populations in apple bud clusters during early bloom were female‐biased (0–10% males). At later bloom states, populations were less female‐biased in open blossom clusters (up to 33% males) compared with those in either unopened buds or older petalless blossoms (<11% males). Changes in tertiary sex ratio in all hosts were associated with changes in resource quality, suggesting a possible effect of host quality on sex allocation. In contrast, larval (secondary) sex ratios within apples were slightly male‐biased (57%) with little change across apple bud reproductive stages or over time, indicating little to no differential sex allocation. Sex ratios of populations in flight were less female‐biased than those found on plants in 62 of 65 comparisons, which suggests that males are more likely to be in flight relative to females. The evidence supports that differential dispersal and distribution of sexes toward various host qualities together with a shorter longevity of adult males determines the pattern of adult sex ratios rather than any significant differential sex allocation.
Effects of host instar and size on parasitization efficiency and life history parameters of Opius dissitus
Authors: Petitt F.L. , Wietlisbach D.O. 
Published: April 2011

AbstractThe braconid parasitoid Opius dissitus Muesebeck (Hymenoptera, Braconidae) produced 1.7 to 3 times more offspring when provided second and third instar leafminers (Liriomyza sativae Blanchard) as compared to first instars. Females arising from parasitization of different instars did not differ significantly in numbers of chorionated eggs in their ovaries at adult eclosion. Development time was prolonged by about two days when parasitoid oviposition occurred in first, as compared to third instar hosts. Parasitoid length was positively correlated with host weight (r2 = 0.75). Because only 7% of variation in host weight could be explained by host density, parasitoid length varied considerably among hosts reared at the same density. Longevity and lifetime fecundity of parasitoids were inversely related to the weight of their hosts.
A comparison of food‐related behaviour between geographic populations of the Colorado potato beetle (Coleoptera, Chrysomelidae), on six solanaceous plant species
Authors: Szentesi A. , Jermy T. 
Published: April 2011

AbstractSome components of the food‐related behaviour (biting, feeding, walking on the plant or walking elsewhere, and resting) of two North American and three European Colorado potato beetle (CPB) populations, on six solanaceous plant species were monitored with the help of a microcomputer‐based program, testing the hypothesis whether populations showed differences at the behavioural level to alternative host plants (S. melongena, S. dulcamara, and Lycopersicon esculentum), as well as to non‐host plants occasionally encountered (S. luteum, S. nigrum). The few significant differences found were among populations of the same continent in 1) the number of activities monitored, 2) the duration of feeding periods, 3) the number of bites taken to the onset of feeding, 4) the ‘amount of behavioural plasticity’, and 5) the ‘behavioural diversity’. On the basis of two‐way ANOVA analyses, no plant‐by‐population interactions were detected indicating that the CPB populations studied did not have specific relationships with any of the plant species tested. The lack of substantial differences in food‐related behaviour was unexpected since considerable isolation in space and time exists between the populations occurring on the two continents.
A relationship between dry matter and damage by larvae of the turnip root fly Delia floralis in cultivars of the swedish turnip Brassica napus
Authors: Shaw M. W. , Allan R. M. , Hunter E. A. , Munro I. K. 
Published: April 2011

AbstractA series of trials from 1981–85 investigating the amount of damage caused by larvae of the turnip root fly Delia floralis (Fallen) to cultivars of Swedish turnip Brassica Napus (L.) of varying percentages of dry matter indicated that those of high dry matter were damaged less than low dry matter cultivars. Pupal numbers of turnip root fly gave good correlations with damage but there was no relationship between damage and cabbage root fly pupae.
Protein toxicity to aphids: an in vitro test on Acyrthosiphon pisum
Authors: Rahbé Y. , Febvay G. 
Published: April 2011

AbstractRecent progress in plant transformation for insect resistance has increased the interest in the potential toxicity of proteins towards insect pests. While studies have been targeted to a large array of insect species, phloem‐feeding Homoptera have not been investigated yet. The paper describes a routine test for screening toxicity and growth inhibition of purified proteins in artificial diets on Acyrthosiphon pisum (Harris). Twenty‐five commercially available proteins of different classes were tested and compared to some non‐protein chemicals (an insecticide, an antibiotic …). A. pisum proved to be very sensitive to all proteases tested and to some venoms with general cytolytic properties. A plant lectin, concanavalin A, displayed significant toxicity and growth inhibition, while various proteins such as a soybean proteinase inhibitor, a chitinase, and bovine serum albumin showed measurable impairments of growth only at higher dose (≥250 μg.ml−1). Some proteins were without short‐term effect on A. pisum physiology. The influence of these results on aphid‐plant interactions are discussed.RésuméToxicités des protéines pour les pucerons: un test in vitro sur Acyrthosiphon pisumL'effet de protéines alimentaires sur les insectes phloémophages, dont les pucerons, n'a jamais été étudié. Nous proposons ici un test biologique standardisé sur milieu artificiel permettant d'analyser les effets de différentes classes de protéines sur la physiologie d'A. pisum. La validité de ce test est éprouvée (protocole, reproductibilité) et les différentes données récoltées (mortalité et inhibition de croissance) permettent de définir des paramètres toxicologiques tels que concentration létale 50 ou concentration inhibitrice 50. Cette caractérisation toxicologique a été réalisée sur 25 protéines appartenant à des classes différentes, ainsi que plusieurs substances non protéiques utilisées comme témoin de toxicité (insecticide, antibiotique, inhibiteur de synthèse protéique et glucoside phénolique). Les regroupements de protéines par proximités de profils toxicologiques ont été corrélés aux activités biochimiques des différentes protéines. Les implications de ces résultats sur les interactions plante‐puceron sont discutées, ainsi que le potentiel d'une stratégie de création de variétés transgéniques résistantes aux pucerons.
Soybean leaf responses to threecornered alfalfa hopper petiole girdling
Authors: Spurgeon D. W. , Mueller A. J. 
Published: April 2011

AbstractSpecific leaf weight, percent moisture, and free sugar, starch, and amino nitrogen content of soybean (Glycine max (L.) Merrill) leaves were measured at 1, 3, 7, and 10 day(s) after petiole girdling by threecornered alfalfa hopper, Spissistilus festinus (Say) (Homoptera: Membracidae) nymphs. Leaf starch was increased at 1, 3, and 7 day(s) after girdling and largely accounted for corresponding increases in specific leaf weight and decreases in percent moisture, free sugars, and amino nitrogen. Specific leaf weight was increased at 10 days after girdling despite no increase in starch. Amino nitrogen content was decreased 10 days after girdling. When leaf dry weights were corrected for starch, free sugar content was not affected by girdling, and amino nitrogen content was reduced only at 3 and 10 days. The amino nitrogen: free sugar ratio was reduced only at 10 days after girdling. Changes in leaf starch indicated a rapid but reversible effect of girdling on leaf carbohydrate metabolism.