bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ambulatory dispersal and life history response to food deprivation in twospotted spider mites
Authors: Krainacker David A. , Carey James R. 
Published: April 2011

AbstractA major life history characteristic of the twospotted spider mite, Tetranychus urticae Koch, is the ability to disperse between different hosts. This may be done by aerial or ambulatory means. Although there have been a number of studies dealing with mite dispersal, most have been qualitative in nature and examine only the overall process. In this study we measure the ambulatory dispersal capabilities of twospotted spider mite adult females and males, as well as that of deutonymphs, protonymphs and larvae at distances up to 480 cm. Additionally, for adult females only vertical (upwards and downwards) distances of up to 240 cm were measured. We also measured the influence of food deprivation on spider mite longevity and fecundity by depriving mites of food for one, two or three days immediately after ecdysis at 24 or 30 °C, or food deprivation for one, two or three days (at 24 °C) after feeding as adults for five days. Dispersal efficiency, defined as the percentage of individuals successfully crossing the test distance, generally increased with time and decreased with distance. As expected, dispersal efficiency was shown to be related to stage, with adults the most efficient and larvae the least. Food deprivation studies revealed that at 24 °C mites were capable of withstanding two days without food before longevity and fecundity began to decrease.RésuméL'aptitude à la dispersion de Tetranychus urticaeTetranychus urticae Koch est caractérisé par son aptitude à la dispersion sur différents hôtes. Nous examinons 2 aspects de celle‐ci: 1) aptitude à la dispersion à faible distance en rampant; 2) effet de la perte de contact avec l'hôte (par suite de la dispersion) sur la survie et la fécondité. En ce qui concerne la dispersion à faible distance, la mesure a porté sur l'aptitude de chaque stade à parcourir différentes distances jusqu'à 480 cm. De plus, pour les femelles la mesure a concerné seulement la dispersion verticale jusqu'à 240 cm. L'efficacité de la dispersion était plus élevée sur les faibles distances; l'aptitude à la dispersion était liée au stade, les adultes étant meilleurs que les larves. Les effets de la privation de nourriture ont été en particulier:a) que les acariens sont capables de survivre 2 jours à 24 °C sans aliments avant que longévité et fécondité ne diminuent;b que des acariens privés d'aliments pendant 3 jours à 24 ou 30 °C ont présenté une mortalité très élevée. Aucun acarien ne survécut à 3 jours de jeûne à 30 °C;c) La température pendant le jeûne a déterminé le temps pendant lequel les acariens ont pu supporter le jeûne.
In vivo effect of mixtures of allelochemicals on the life cycle of the European corn borer, Ostrinia nubilalis
Authors: Bernard C.‐B. , Arnason J. T. , Philogène B. J. R. , Lam J. , Waddell T. 
Published: April 2011

AbstractThe phenylpropanoid, dillapiol, a compound capable of inhibiting the activity of cytochrome P‐450 epoxidase in microsomal preparations of midguts of the European corn borer (ECB), Ostrinia nubilalis Hubner (Lepidoptera), did not enhance the toxicity of two insecticidal allelochemicals from the Asteraceae: the sesquiterpene lactone, tenulin or the phenylacetylene, phenylheptatriyne, when ingested simultaneously. Dillapiol alone was toxic to ECB larvae, and inhibited their growth. Possible reasons for the lack of synergism or potentiation by dillapiol of the insecticidal activity of the other allelochemicals are considered.RésuméEffets in vitro des mixtures de substances allélochimiques sur le cycle biologique de la pyrale du maïs, Ostrinia nubilalisLe dillapiolc, un phénylpropanoide monomère d'un lignait et contenant un groupement méthylènedioxyhphényl (MDP), a la capacité d'inhiber in vitro les enzymes d'oxydations multiples à cytochrome P‐450 (PSMO) utilisées par la pyrale du maïs (ECB), Ostrinia nubilalis, pour dctoxifier les substances allélochimiques. Les composés contenant un groupe MDP comptent parmi les plus nombreux et puissants synergistes d'insecticides. Cependant, aucun synergisme n'est observé lorsque le dillapiole est ingéré par la pyrale en association avec l'une ou l'autre ou les deux substances secondaires insecticides des Astéraceae, la lactone sesquiterpène ténuline ou/et le polyacétylène phénylheptatriyne (PHT). Plutôt, le dillapiole est une toxine qui diminue la prise de poids des larves et retarde leur développement. Les effets toxiques sont plus importants avec le dillapiole seul que lorsque celui‐ci est associé à la ténuline ou/et au PHT. Les expications possibles de ces résultats sont discutées.
Pathogenic fungal dynamics in a fall population of the blackmargined aphid (Monellia caryella)
Authors: Ekbom Barbara Sohm , Pickering John 
Published: April 2011

AbstractA fall population of the blackmargined aphid, Monellia caryella (Fitch) (Homoptera; Aphididae), was monitored daily for mortality caused by fungi and parasitoids. Three species of Entomophthorales fungi were found. Fungal‐induced mortality was found to be correlated with minimum temperature. During the period when the minimum temperature was consistently above 8 °C, fungal‐induced mortality was positively correlated with the sum of hours of leaf‐wetness on days 5, 6, and 7 before sampling. Parasitoid wasps killed fewer hosts than fungi and were not affected by environmental factors.RésuméDynamique des champignons pathogènes d'une population automnale du puceron Monellia caryellaLa mortalité quotidienne provoquée par des parasitoïdes et des champignons sur une population automnale de M. caryella Fitch (Homopt. Aphididae) a été suivie à Byron (Géorgie, USA), avec enregistrement de la température, de la pluie et de l'humidité des feuilles. 3 espèces de champignons entomophthorales ont été trouvées: Neozygites sp., Entomophthora planchoniana et Erynia sp. 54% des pucerons morts étaient contaminés par Neozygites et 46% par E. planchoniana. Seuls 2 pucerons avaient été tués par Erynia sp. Les taux de mortalité quotidienne par champignons s'élevaient après les périodes pluvieuses et d'humidité des feuilles. La mortalité due au parasitisme était inférieure à la mortalité due aux champignons et ne semblait pas liée aux conditions écologiques. La discussion porte sur l'importance de la mortalité provoquée par les champignons sur la dynamique de la population de pucerons.
Evolutionary genetics of the aphid Cryptomyzus, with a preliminary analysis of the inheritance of host plant preference, reproductive performance and host‐alteration
Authors: Guldemond J. Adriaan 
Published: April 2011

AbstractThe aphid species Cryptomyzus galeopsidis (Kaltenbach) includes several distinct forms which have different host plant relationships and life cycles. Cross breeding was used to elucidate the taxonomic status of these forms and to investigate the inheritance of host preference, reproductive performance and host‐alternation. One of the forms appeared to be a distinct species because of the reduced fitness of the hybrids. Other host‐alternating and non host‐alternating forms are considered conspecific and represent two life cycle strategies. Reproductive performance is probably controlled polygenically, since hybrids show an intermediate performance. Host preference in hybrids showed some degree of dominance and seemed to be determined by only a few genes. Host‐alternation is presumed to be inherited monofactorially. The implications for speciation are discussed.RésuméEtude de l'hybridation chez les pucerons du genre Cryptomyzus, et observations sur la génétique du choix des hôtes, de leur alternance et des performances reproductivesC. galeopsidis Kaltenbach contient plusieurs formes qui ont différentes relations avec des plantes hôtes et des cycles distincts. Des croisements ont permis d'élucider la taxonomie de ces formes et d'étudier l'hérédité de préférences d'hôtes, des performances reproductives et de l'alternance d'hôtes. Une des formes apparaît comme une espèce distincte par suite de la valeur adaptative réduite des hybrides. Les autres formes avec alternance ou non des hôtes sont considérées comme conspécifiques et représentant deux stratégies vitales différentes. Les performances reproductives sont probablement polygéniques puisque les hybrides ont des performances intermédiaires. Les préférences d'hôtes des hybrides montrent certains degrés de dominance et semblent déterminées par quelques gènes seulement. L'alternance des hôtes est envisagée comme ayant une hérédité monofactorielle. Les conséquences sur la spéciation sont discutées.
Ascending flights for migration of the oriental armyworm, Pseudaletia separata
Authors: Hirai Kazuo 
Published: April 2011

AbstractFlight behavior of Pseudaletia (= Mythimna) separata Walker (Lepidoptera: Noctuidae) was observed around sunset in a grassland habitat at Morioka in northern Japan. Take‐off flights by both females and males commenced on the first day following emergence. The proportion of moths flying increased gradually with age from 62% on day 1 to 86% on day 5. Flight could be categorized as ‘ascending’ or ‘short range’, 2 to less than 10 m flights in the observation. The proportion of adults making ascending flights increased from 47% on day 1 to a maximum of 55% on day 2, and then gradually decreased to 29% on day 5. It is considered that the ascending flight is connected with long‐distance migration. Mated femáles with matured eggs did not make ascending flights, but mated males did. Adults embarked on those flights at temperatures of 7.5 °C or greater. On rainy days fewer adults flew upwards than on non‐rainy days. The related species, Leucania pallens, did not fly up, but flew at slow speed at low altitude.RésuméVols ascendants initiateurs de migrations de Pseudaletia separataLe comportement de vol de Pseudaletia (Mythimna) separata Walker (Lep., Noct.) a été observé vers le crépuscule au dessus de prairies à Morioka (Japon septentrional). Les envois des femelles et des mâles débutent le jour suivant l'émergence. La proportion de papillons en vol augmente progressivement, de 62% le premier jour, à 86% le 5e jour. Les vols peuvent être classés en ascendants (2 à 10 m) ou à courte distance (inférieurs à 2 m). La proportion d'adultes effectuant des vols ascendants augmente, de 47% le premier jour, à un maximum de 55% le 2e jour, pour diminuer progressivement jusqu'à 29% le 5e jour. On considère que les vols ascendants sont lié aux migrations à longue distance. Les femelles fécondées contenant des œufs mûrs ne font pas de vols ascendants, tandis que les mâles ayant eu une activité sexuelle le font. Les adultes effectuent de tels vols aux températures supérieures ou égales à 7.5 °C. Par temps pluveuxmoins d'adultes ont des vols ascendants que par temps sec. L'espèce voisine, Leucania pallens n'effectue pas de vols ascendants, mais vole à faible vitesse à basse altitude.
Realized heritability estimation for pesticide resistance traits
Authors: Rosenheim J.A. 
Published: April 2011

AbstractTanaka & Noppun (1989) have described a procedure for estimating realized heritabilities, h2, from artificial selection experiments for pesticide resistance. Here I describe three processes especially relevant to such selection experiments that may introduce important biases into resulting estimates of h2. First, imperfect bioassays, in which different individuals receive different doses, have diminished abilities to discriminate between individuals on the basis of their tolerances. This results in an overestimate of S, the selection differential, and a corresponding underestimate of h2. Second, sublethal effects of pesticide exposure may generate variation in reproductive output among survivors of a round of artificial selection, with more tolerant individuals frequently producing more progeny. This results in an underestimate of S and a corresponding overestimate of h2. Third, unequal selection applied to males and females, especially likely to occur when mass selection is applied to adults of both sexes after mating has occurred, may cause S to be overestimated and h2 to be underestimated. Biases introduced by these processes may in some cases be large, adding an unacceptable amount of uncertainty to h2 estimates. Only if these biases are avoided can heritability estimates be usefully incorporated into prospective models of resistance evolution.RésuméEstimation réaliste de l'héritabilité de la résistance aux pesticidesTanaka & Noppun (1989) ont décrit une procédure d'estimation réaliste de l'héritabilité, h2, lors d'expériences de sélection artificielle de résistance aux pesticides. Je décris ici 3 processus liés particulièrement à de telles expériences de sélection pouvant introduire des biais importants dans l'estimation de h2. Premièrement, des tests imparfaits, au cours desquels différents individus reçoivent différentes doses, ont réduit les possibilités de distinguer les individus en fonction de leur tolérance; ceci conduit à la surestimation de S, la sélection différentielle, et à une sous‐estimation parallèle de h2. Deuxièmement, les effets sublétaux de l'exposition aux pesticides peuvent provoquer une variation de l'impact reproducteur des survivants au cours de la sélection artificielle, les individus les plus tolérants produisant souvent plus de descendants; ceci entraine une sous‐estimation de S et une surestimation correspondante de h2. Troisièmement, une sélection inégale des mâles et des femelles, particulièrement quand une sélection de masse affecte les adultes des deux sexes après les accouplements, peut provoquer une surestimation de S et une sous‐estimation de h2. Les biais introduits par ces processus peuvent être dans certains cas importants, ajoutant une part inacceptable d'incertitude dans les estimations de h2. Ce n'est que si biais sont évités que l'estimation de l'héritabilité peut être incorporée utilement dans les modèles prospectifs de l'évolution de la résistance.
Stimuli influencing host microhabitat location in the parasitoid Campoletis sonorensis
Authors: McAuslane H.J. , Vinson S.B. , Williams H.J. 
Published: April 2011

AbstractThe host microhabitat location behavior of females of the generalist parasitoid Campoletis sonorensis (Cameron) (Hymenoptera: Ichneumonidae) was studied in a wind tunnel. Visual cues associated with the host plant cotton, Gossypium hirsutum L., were important and significantly more parasitoids completed flights to a damaged 4‐leaf cotton plant bearing a Heliothis virescens (F.) (Lepidoptera: Noctuidae) larva and frass than to a similarly damaged single leaf with frass and a larva. This difference in completed flights was not due to differences in amounts of volatiles released by the two stimuli, Both naive and experienced parasitoids responded differently to an undamaged cotton leaf, a mechanically damaged leaf, a naturally damaged leaf with the host removed and a naturally damaged leaf with a host larva. Parasitoids completed significantly fewer flights to the undamaged sources of volatiles than to damaged sources of volatiles. Experienced females responded strongly to all types of damage. The number of flights completed by naive females to the three types of damage differed but not significantly and was less than the number completed by experienced females. Components of the preflight experience were varied to determine which factors were responsible for the higher response of experienced females to the host/plant complex. Oviposition was the most important component of this experience. Contact with host frass or plant damage followed by oviposition did not increase the response over that exhibited by females allowed oviposition only. When frass or damaged plant material were contacted without subsequent oviposition, females completed fewer flights than naive females.
Food acceptance by a monophagous and an oligophagous insect in relation to seasonal changes in host plant suitability
Authors: Kooi R. E. , Van de Water T. P. M. , Herrebout W. M. 
Published: April 2011

AbstractFood acceptance by larvae of two lepidopteran species feeding on Rosaceae, viz. Yponomeuta evonymellus (monophagous) and Y. padellus (oligophagous), was compared. The influence of seasonal changes in plants as food for both insects was examined, in particular, the effects of nitrogen and sorbitol in leaves. In the laboratory, Y. evonymellus accepts Crataegus monogyna, a host plant of Y. padellus, and Y. padellus accepts Prunus padus, the host plant of Y. evonymellus. P. padus is the most suitable food plant for Y. evonymellus. No difference in food‐quality for Y. padellus was found between C. monogyna and P. padus. The performance of both species on P. padus is less influenced by seasonal changes than on Crataegus. The suitability of Crataegus decreases during the season. This is probably caused by the decrease of its nitrogen content, and not by the decrease of sorbitol in the plant. The monophagous, Y. evonymellus, is more sensitive to seasonal changes in its food when fed with a non host plant than the oligophagous Y. padellus. In oviposition experiments both species have a preference for their normal host‐plants.
Feeding site selection of first‐instar larvae of Cnaphalocrocis medinalis on susceptible and resistant rice plants
Authors: Ramachandran R. , Khan Z. R. 
Published: April 2011

AbstractMore first‐instar larvae of the rice leaffolder, Cnaphalocrocis medinalis (Guenée), were recovered from susceptible IR36 and Roxoro rice varieties than resistant TKM6 and Oryza perennis, 24 h after infestation. Within a rice plant, a higher proportion of larvae was recovered from young whorl leaf, followed by mature leaves and leafsheaths on all the four rice varieties tested. However, differences were observed between susceptible and resistant varieties in the distribution of larvae on these three plant parts. In laboratory choice tests, first‐instar larvae preferred to settle on the young leaves of IR36 and TKM6 when presented with their respective mature leaves. No such preference was observed in tests with Rexoro and O. perennis. Larval survival was similar on young and mature leaves of Rexoro. Young leaves of IR36 and TKM6 were more suitable for survival in comparison with their respective mature leaves while the reverse was true for O. perennis. Larval movement was slower on the mature leaves and larvae took longer to reach the whorl leaf of TKM6 than on IR36. The density of trichomes of the abaxial surface of TKM6 was higher than that of the other varieties tested. Adaptive significance of feeding in the leafwhorl to young larvae is discussed.
Glyphosate‐induced changes in the attack success and development of the mountain pine beetle and impact of its natural enemies
Authors: Bergvinson D. J. , Borden J. H. 
Published: April 2011

AbstractRoundup (active ingredient glyphosate) administered into the sapwood around the root collar of lodge‐pole pine trees, Pinus contorta var. latifolia Engelm., was investigated as a tool for creating trap trees for the mountain pine beetle (MPB), Dendroctonus ponderosae Hopk. MPB's attacked semiochemical‐baited, glyphosate‐treat trees before attacking baited control trees. Bark samples disclosed an increase in survival of MPB eggs and early instar larvae, enhanced larval development and increased attacks by insect parasites and predators in treated trees. The braconid wasp, Coeloides dendroctoni Cush., parasitized MPB larvae found at high densities in treated trees two months following attack. The dipteran predator, Medetera aldrichii Wh., was only found in treated trees. Increased competition by Ips pini (Say) had a negative impact on MPB survivorship. The enhanced impact of insectan agents apparently offset any glyphosate‐induced gains in MPB survival or development, but did not cause a significant reduction in MPB emergence.
Sex pheromones of Spilonota ocellana and Spilonota laricana
Authors: Witzgall P. , Bengtsson M. , Buser H.‐R. , Chambon P.‐J. , Priesner E. , Wildbolz T. , Arn H. 
Published: April 2011

AbstractThe sex pheromones of Spilonota ocellana D. & S. and Spilonota laricana Hein. (Lepidoptera:Tortricidae) were identified by chemical analysis and field trapping. Female moths of the two species produce (Z)‐8‐tetradecenyl acetate, (Z)‐8‐tetradecen‐1‐ol and dodecyl acetate in almost the same proportions (98:1:1 and 97:3:1). Males of both species were best attracted to a blend of 10:1 to 1:1 Z8‐14Ac:Z8‐14OH. This indicates that mating barriers other than sex pheromones exist between sympatric populations.
Factors restricting the feeding of the cabbage stem flea beetle (Psylliodes chrysocephala)
Authors: & E. Bartlet , Williams I. H. 
Published: April 2011

AbstractThe feeding acceptability of 40 different plants to Psylliodes chrysocephala L. (Coleoptera: Chrysomelidae) was determined using leaf disc consumption tests for the adult, and stem or petiole penetration tests for the larvae. Only plants that contained glucosinolates were accepted as food, but addition of the glucosinolate sinigrin to rejected food plants did not make them acceptable to adults. Of the 34 plants that contained glucosinolates, nine were either totally or mostly rejected. Solvent extracts of the rejected plants applied to oilseed rape inhibited feeding by adults. The feeding of P. chrysocephala within the group of plants tested is influenced by the presence or absence of glucosinolates, which may act as feeding stimulants, and other, unidentified chemicals which act as feeding inhibitors.
Interference competition in desert subterranean termites
Authors: Jones S. C. , Trosset M. W. 
Published: April 2011

AbstractWe examined interspecific aggression between two subterranean termite species, Heterotermes aureus (Snyder) (Rhinotermitidae) and Gnathamitermes perplexus (Banks) (Termitidae). In laboratory tests with worker termites, neither species was the inherently superior fighter, but rather the outcome of interspecific encounters depended on the number of conspecifics. We then investigated patterns of resource use by these species during a 13‐month period in the Sonoran Desert. Baits consisted of toilet‐paper rolls, which have been shown to be a mutually acceptable food source. Analyses of foraging activity demonstrated that the two species did not forage independently of each other. Not only were the two species negatively associated spatially, but extended periods of temporal segregation were observed. G. perplexus took significantly longer to return to sites that it had simultaneously occupied with H. aureus than to sites that G. perplexus had occupied alone. The pattern of co‐occurrence of these two species is consistent with the hypothesis that interspecific interference competition affects their spatial and temporal distribution.
Resistance and susceptibility of Boronia megastigma cultivars to infestations by the psyllid Ctenarytaina thysanura
Authors: Mensah R. K. , Madden J. L. 
Published: April 2011

AbstractStudies were conducted on 23 boronia cultivars to determine the mechanisms of resistance and susceptibility to the psyllid, Ctenarytaina thysanura Ferris and Klyver. No antibiosis effects were detected in any of the boronia cultivars investigated. No cultivar was tolerant to C. thysanura attack. However, in both free‐choice and no‐choice tests in the glasshouse, ovipositional antixenosis (non‐preference) was detected in cultivar HC27, whereas cultivars HC4 and HC142 were most preferred for oviposition. Measurement of terminal shoot hardness of cultivars revealed variations in relative hardness. Given a choice between boronia cultivars of the same size and colour but of differing hardness of the terminal shoots, C. thysanura laid more eggs on those cultivars with softer terminal shoots (HC4 and HC142) and laid fewest eggs on harder terminal shoots (HC27). This may explain differences in the psyllid population on different cultivars in the field. Fewer eggs were laid on terminal shoots exceeding a hardness rating of 80 g/mm terminal shoot thickness.