bluuebunny/crossref_metadata_2025_split huggingface dataset:
Egg allocation of the autoparasitoid Encarsia tricolor at different relative densities of the primary host (Trialeurodes vaporariorum) and two secondary hosts (Encarsia formosa and E. tricolor)
Authors: Avilla J. , Anadón J. , Sarasúa M. J. , Albajes R. 
Published: April 2011

AbstractParasitism, offspring sex ratio and superparasitism of the facultative autoparasitoid Encarsia tricolor Foërster (Hymenoptera: Aphelinidae) when given access to arenae with different proportions of the primary host (Trialeurodes vaporariorum (Westwood)) and two species of secondary hosts (E. tricolor and Encarsia formosa Gahan) were studied.Parasitism and offspring sex ratio were not affected by female age in the range 3–10 days old. When the secondary hosts were young E. tricolor pupae, eggs were mostly laid on primary hosts, so the offspring sex ratio was more female‐biased than expected, and secondary hosts were not superparasitized at all. When the secondary hosts were fully grown E. formosa larvae, superparasitism was small and offspring sex ratio was more male‐biased than expected.E. tricolor females were able to discriminate between hosts previously parasitized by themselves and non‐parasitized hosts.
Host finding in the pine weevil Hylobius abietis: effects of conifer volatiles and added limonene
Authors: Nordlander G. 
Published: April 2011

AbstractThe attraction of Hylobius abietis (L.) (Coleoptera: Curculionidae) to α‐pinene was recently shown to be inhibited by limonene. This study shows that added limonene also affects the response of H. abietis to odours from natural host material. The experiments included both pieces of Scots pine suspended in pitfall traps and planted pine seedlings that had either been manually wounded or left intact. By adding a limonene dispenser, the catch of pine weevils in pine‐baited traps was reduced by about 80–90% in spring and autumn and by about 40–50% in summer. Limonene substantially reduced the rate at which manually wounded seedlings were attacked by weevils in spring and autumn. For intact seedlings, a limonene‐induced reduction in attack rate was found only in autumn. In the absence of limonene, a small wound made on the stem of a seedling increased its probability of being attacked by about fivefold. This figure was estimated by comparing data from all experimental periods with a model assuming a constant ratio of attack rates for the two kinds of seedlings.
Effects of temperature on acaricidal and insecticidal activities of the benzoylureas flucycloxuron and diflubenzuron
Authors: Grosscurt A. C. , Wixley R. A. J. 
Published: April 2011

AbstractEffects of temperature on the activity of flucycloxuron on larval stages of Panonychus ulmi (Koch), based on LC50 values, were highly significant (P < 0.001) with temperature coefficients of −1.7 in both the ranges of 15° to 25 °C and 20° to 30 °C. The slopes of probit regression lines at 15° and 20 °C were significantly steeper than those at 25° and 30 °C. As a consequence the temperature coefficients based on LC90 values were −4.4 and −2.2, for the 2 temperature ranges. The ovicidal activity of flucycloxuron on P. ulmi was low and was only statistically detectable at 20 °C (LC90 of 84 mg a.i./l). In studies with larvae of Aedes aegypti (Linnaeus), Leptinotarsa decemlineata (Say), Plutella xylostella (Linnaeus), Spodoptera exigua (Hübner) and Spodoptera littoralis (Boisduval) probit regression lines were parallel over temperature. The activity of flucycloxuron on these five insect species was not affected by temperature. Based on LC50 values, diflubenzuron showed positive temperature coefficients on P. xylostella of +2.1 at 15° to 25 °C and +2.5 at 20° to 30 °C. For S. littoralis the temperature coefficient was positive (+2.4) at 15° to 25 °C but negative (−1.9) at the 20° to 30 °C range. Temperature coefficients of diflubenzuron were neutral for A. aegypti, L. decemlineata and S. exigua. In the design and analysis of these studies special allowance was made for date effects and variation in natural mortality over temperature.
Effect of larval age and dosage of nuclear polyhedrosis virus on the susceptibility of diamondback moth, Plutella xylostella
Authors: Padmavathamma K. , Veeresh G. K. 
Published: April 2011

AbstractA laboratory experiment was conducted to study the efficacy of nuclear polyhedrosis virus (NPV) with nine concentrations against all stadia of Plutella xylostella (L). The susceptibility of the larvae was correlated negatively with the period of development of the larvae and positively with the virus concentrations. The highest mortality of 84% was recorded in first stadium larvae compared to lowest mortality of 38% in fourth stadium larvae. The LC50 was 5.5 × 101 and 4.0 × 104 polyhedral inclusion bodies (PIB)/ml for first and fourth stadium larvae, respectively.
The effect of groundcover and herbicide treatment on twospotted spider mite density and dispersal in southern Oregon pear orchards
Authors: Flexner J. L. , Westigard P. H. , Gonzalves P. , Hilton R. 
Published: April 2011

AbstractA total of 49 groundcover plant species representing 47 genera in 22 families were identified from a survey of 5 pear orchards. Density of twospotted spider mite (Tetranychus urticae Koch) inhabiting these plants was estimated visually several times during the field season. Plants were ranked in 1 of 3 categories depending on mite densities found on these plants during the summer. T. urticae was found to be highly abundant (category 3) on 26 species, at lower densities on 10 species (category 2), and was rarely or never found on the remaining 12 species (category 1). Dispersal of mites from groundcover plants into trees was found to be highly variable within and between orchards. Within orchard dispersal appeared to be related to the distribution and abundance of category 3 host plants in the orchard. Variability between orchards may also be affected by groundcover management techniques and levels of acaricide resistance in T. urticae. The use of herbicides to control groundcover plants significantly increased the dispersal of T. urticae into the orchard trees.
Effect of physiological state and fungal inoculation on chemically modulated host‐plant finding by Carpophilus hemipterus and Carpophilus lugubris
Authors: Blackmer J. L. , Phelan P. L. 
Published: April 2011

AbstractHost orientation by Carpophilus hemipterus L. and Carpophilus lugubris Murray (Coleoptera: Nitidulidae) was investigated in a horizontal wind tunnel to ascertain if these species differ in their response to aseptic and fungal‐inoculated hosts, and also to determine how age, nutritional status, diel period, and locomotory opportunity affect these behavioral responses. Both species responded to food odors beginning on Day 3 of adult life by walking upwind to the source; flight activity and flights to the odor source began for C. hemipterus on Day 4, but C. lugubris continued to walk to the source and rarely flew regardless of age. Both species displayed maximum response to food odors from 6 to 9 days after emergence and showed bimodality in host orientation during the photophase. C. hemipterus maintained with artificial diet took flight as frequently as when maintained with water only, as long as they were deprived of diet for 36 h before the test; however, after takeoff, beetles maintained with diet were less likely to fly to food odor in comparison to beetles maintained with water. C. lugubris maintained with diet until 36 h before the test displayed a reduction in walks upwind to sources of food odor compared to beetles maintained with water. Three hours of unrestricted locomotion under a high‐pressure sodium lamp did not enhance upwind orientation to host odors by C. hemipterus maintained with diet or water, or by C. lugubris maintained with water; however, such preexposure to a sodium lamp resulted in reduced takeoffs in C. hemipterus maintained with artificial diet. Both species were attracted to all fruit and vegetable substrates offered; however, aseptic substrates were less attractive than were substrates inoculated with Saccharomyces cerevisiae Hansen or Candida krusei (Castellani) Berkhout for C. lugubris. Despite the broad host range exhibited by these two nitidulid species, each responded to chemical cues from long‐range (2.5 m), a trait once assigned to specialists.
Fecundity and egg fertility in the adult Colorado beetle (Leptinotarsa decemlineata) surviving larval infection by the fungus Beauveria bassiana
Authors: Fargues J. , Delmas J.‐C. , Augé J. , Lebrun R. A. 
Published: April 2011

AbstractSecondary effects of the entomopathogenic hyphomycete Beauveria bassiana (Bals.) Vuill. were investigated on adults of Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae) treated as newly moulted 4th‐instar larvae. Fecundity and egg hatching were monitored in surviving females mated with surviving males. When reared at 22 °C, adult survivors showed a lessening of their reproductive potential during their whole life. According to the fungal inoculum dosage, the reductions of the total number of eggs laid per female and the mean number of eggs per egg mass ranged from 20% to 56% and from 18% to 46%, respectively. In contrast, at 25 °C, the fecundity of survivors was not affected by the fungal infection. This variability of the secondary effects of B. bassiana according to temperature conditions might be related to the lower infection level of treated larvae at 25 °C. Moreover, at both temperatures, eggs laid by females surviving fungal infection as larvae were as fertile as eggs laid by control insects. It is concluded that secondary effects of B. bassiana on the fecundity of the Colorado Potato Beetle are temperature‐dependent and that they could become negligible at high temperatures under field conditions.RésuméFécondité et fertilité du dorvphore (Leptinotarsa decemlineata) contaminé par l'hyphomycète Beauveria bassiana au 4ème stade larvaireLes effets secondaires de l'hyphomycète entomopathogène, Beauveria bassiana (Bals.) Vuill. sur la fécondité et la fertilité des insectes survivant à l'infection fongique ont été étudiés chez les adultes du doryphore Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae) issus de larves contaminées en début de 4ème stade. Les insectes maintenus à 22 °C ont présenté une réduction de leur potentiel reproductif. Ainsi, suivant la dose d'inoculum fongique, le nombre total d'oeufs pondus par femelle et le nombre moyen d'oeufs par ooplaque ont baissé de 20% à 56% et de 18% à 46%, respectivement. En revanche, à 25 °C la fécondité des adultes survivants n'a pas été affectée par la maladie. Cette variabilité en fonction des conditions thermiques peut être liée à la diminution de l'effet‐dose du champignon sur les larves à 25 °C par rapport à 22 °C. Par ailleurs, quelles que soient les conditions thermiques (22 °C ou 25 °C) on ne constate aucun changement significatif de la fertilité des oeufs pondus par les femelles survivantes. Les auteurs concluent que les effets secondaires de B. bassiana sur la fécondité du doryphore dépendent des conditions thermiques et qu'ils pourraient devenir n6gligeables à des températures é1evées en plein champ.
Effects of potassium levels over the range occurring in host plants on the growth of an insect herbivore (Manduca sexto)
Authors: Wulfson L. S. , Stamp N. E. 
Published: April 2011

AbstractThird instar tobacco hornworms (Manduca sexta L.: Sphingidae) on low dietary potassium had a lower relative growth rate than individuals on diets with potassium concentrations reflecting those in host‐plants, due to decreased consumption rate, lower efficiencies of conversion of ingested and digested food (ECI and ECD), and a prolonged growth/feeding phase. Furthermore, these larvae, when placed on a diet with a moderate potassium concentration through the fourth stadium, ended up being smaller due to lower ECI and less biomass gained, and had a prolonged growth phase, which suggest an irreversible cost of the previous low potassium diet. Third instar hornworms on high potassium diets had lower ECI and ECD, and they had a prolonged growth phase. These individuals, when placed on a moderate potassium diet in the fourth stadium, gained less biomass, than those previously offered hostplant‐like‐potassium diets. Body potassium concentrations (% dw) at the end of the third stadium were similar among treatment groups. With increasing potassium concentrations in the diet, utilization efficiencies of potassium decreased and potassium concentrations in the frass increased. Correspondingly, water content (% fw) of the newly‐molted fourth instar larvae declined with increasing potassium, indicating a passive loss of water during potassium excretion. Low and high dietary potassium reduced survivorship of third instar larvae; fourth instar caterpillars previously fed the low potassium diet also had poor survivorship. We conclude that, within the normal range of potassium concentrations in the hostplants, caterpillar performance is largely unaffected by potassium concentration, but that potassium‐poor and potassium‐rich diets, such as those hornworms may sometimes experience, can reduce growth and survivorship.
Effects of protease inhibitors and dietary protein level on the black field cricket Teleogryllus commodus
Authors: Burgess E. P. J. , Stevens P. S. , Keen G. K. , Laing W. A. , Christeller J. T. 
Published: April 2011

AbstractGrowth and survival responses were determined for black field crickets Teleogryllus commodus (Walker) (Orthoptera: Gryllidae) on artificial diets containing a range of levels of dietary protein, and protease inhibitors (PI's) at 0.33% (weight volume, w:v). The effect on cricket gut enzyme activities of adding PI's to a high protein diet was measured. All PI's which had in vitro binding activity against either trypsin or elastase (the two major cricket gut endopeptidases) reduced growth, but those which bound to both enzymes had the greatest effect. None of the PI's acted as a source of nutritional protein. Cricket growth rate increased with the addition of casein up to 3% w:v, but not with a similar addition of wheatgerm. The impact of PI's on growth was greatest on a 1.5% casein diet. On a high protein (3% casein) diet, the gut activity of trypsin was increased by potato proteinase inhibitors 1 and 2 while the activity of elastase and leucine amino peptidase were increased by soybean trypsin inhibitor and potato proteinase inhibitor 2. Increasing dietary casein up to 3.3% improved cricket survival. The potential of PI's as plant resistance factors against crickets was confirmed.
Exploitation of food resources by the cockroach Blattella germanica in an urban habitat
Authors: Rivault C. , Cloarec A. 
Published: April 2011

AbstractThe exploitation of food resources by the German cockroach, Blattella germanica (L.) (Dictyoptera: Blattellidae) was investigated experimentally in relation to distance from shelters and depletion of neighbouring food patches. In addition, the dynamics of exploitation of a patch were analysed. Observations were made after dark in a public swimming baths building and each one lasted 3 h. Food patches were placed in rows, at different distances from the shelters. The number of cockroaches in food dishes, in a 20 cm diameter circle round each food dish and in a 60 cm diameter circle round this first circle were recorded.Food items nearest the shelters were exploited first. Exploitation of row 2 and of row 3 food items started later, after row 1 food patches had been depleted. Under these conditions, the moment a food patch was exploited was related to its distance from shelter. Exploitation of food patches occurred in a step‐by‐step manner, one patch attracting animals when a nearby patch had been depleted, and not following a model of ideal free distribution.Although our experimental food patches were exploited in relation to their distance from shelter, we were able to demonstrate that distance did not influence the dynamics of exploitation of a food item. The mean number of cockroaches on a food patch, whatever its spatial position, increased regularly, reached a maximum at t = −10 min, and then decreased rapidly after all the food had been completely consumed, at t = 0 min. The mean number of animals in the 20 cm diameter circle round a food source peaked at t = 0 min, then decreased rapidly. This area appeared to be a transit area. The mean number of animals in a 60 cm diameter circle round the food source peaked later, and then decreased slowly. Animals remained in this area longer than in the area closer to the food dish, but their presence there was concomitant with the depletion of the food box.
Monitoring populations of the almond seed wasp, Eurytoma amygdali, with sex pheromone traps and other means, and optimal timing of chemical control
Authors: Katsoyannos B. I. , Kouloussis N. A. , Bassiliou A. 
Published: April 2011

AbstractDuring the four years 1986–1989 we monitored an adult male population of the almond seed wasp, Eurytoma amygdali Enderlein, in the region of Thessaloniki, using sex pheromone traps, each containing 25 living virgin females. The emergence of adults from infested almonds of the previous year was also monitored in cages in the field, as well as the progress of fruit infestation and egg hatching in the almonds of the Retsou variety. Finally, two chemical control experiments were done against the newly hatched larvae to determine the optimal time for chemical control.During the 4‐year study the start of adult captures occurred between April 13 and April 24, and the maximum between April 17 and May 11. In most cases, adult emergence from infested almonds in field cages began with a delay of 2 to 14 days in relation to the start of trap captures, and was affected by factors such as the date of cage installation. In all years most eggs hatched within 12–18 days of oviposition.A treatment with phosphamidon at a concentration of 0.06%, applied to tree branches of the Retsou variety with a hand‐sprayer on May 23, 1987, when 54.1% of the eggs had hatched, was very effective (final infestation in July was 4.7% as compared to 89.1% of the untreated control). Three treatments with phosphamidon 0.06%, applied each on different tree branches, on May 14, 20, and 25, 1988, when the percentage of egg hatching was 7.8%, 65.3%, and 93.5%, respectively, were all very effective (final infestation in July was 1.6%, 3,6%, and 4.2% respectively, as compared to 93,6% of the untreated control). However, the presence of mines in the perisperm and outer endosperm, caused by the feeding larvae before they were killed, was more conspicuous in the almonds treated when the percentage of egg hatching was high.Our data suggest that the almond seed wasp can be effectively controlled with a single treatment of a systemic insecticide against the newly hatched larvae, preferably applied when the percentage of egg hatching is low to medium (between 10%, and 50%). In the area of Thessaloniki, during 1986–89, 10% and 50% of egg hatching occurred about 21 and 27 days respectively after the beginning of male adult captures in pheromone traps.
Spider orb web as bioassay for pesticide side effects
Authors: Samu F. , Vollrath F. 
Published: April 2011

AbstractPesticides may affect the predatory and reproductive behaviour of beneficial arthropods short of having direct effects on their survival. We present a bioassay designed to test (ultimately in the field) such hidden effects of agrochemicals in their application concentrations. As a paradigm we chose the web‐building behaviour of the cross spider Araneus diadematus Clerck (Araneidea, Argiopidae) and we selected four commonly used pesticides: Oleo Rustica 11E (mild insecticide), Fastac (pyrethroid insecticide), Bayfidan and Sportak (fungicides). Neither fungicides nor the mild insecticide seem to affect web‐building behaviour significantly, whereas the pyrethroid insecticide suppressed web‐building frequency and severely affected web size and building accuracy.
Diapause induction in the codling moth, Cydia pomonella: effect of prediapause temperatures
Authors: Steinberg S. , Podoler H. , Applebaum S. W. 
Published: April 2011

AbstractThe effect of four prediapause temperatures (18, 22, 26 and 30 °C) on the photoperiodic response of the codling moth, Cydia pomonella (L.), was studied under controlled conditions. The highest rates of diapause were recorded, for all day‐lengths, at temperatures of 22 and 26 °C while relatively lower rates of diapause were elicited at 18 and 30 °C. The same trend was demonstrated by projecting the values of the critical photoperiod which induces 50% diapause (= CPhP50) over the prediapause temperature. The change in diapause incidence as a function of photoperiod, at all prediapause temperatures, exhibited a response characteristic of long‐day insects, i.e. high rates of diapause at short days (12–13.5 h) and a decrease in diapause incidence at long days (14–15 h). The results for temperatures 22, 26 and 30 °C support the view that lower prediapause temperatures enhance diapause induction, at a given photoperiod, while higher temperatures tend to avert or diminish the process. On the other hand, the low rates of diapause obtained at 18 °C contradict this view. Nevertheless, high correlation was found between the laboratory evidence and field data, indicating the adaptability of the Israeli codling moth to subtropical climate.
Can polyphagous predators control the bird cherry‐oat aphid (Rhopalosiphum padi) in spring cereals?: A simulation study
Authors: Ekbom B. S. , Wiktelius S. , Chiverton P. A. 
Published: April 2011

AbstractPredation by two carabid species, Bembidion lampros (Herbst.) and Pterostichus cupreus L., on the cereal aphid, Rhopalsiphum padi L., was described using a discrete event simulation model. The results were incorporated into an aphid population growth model. The aphid model was run using actual temperatures, R. padi emigration rates, field densities and distributions from three years with distinctly different aphid population levels. Predation was incorporated at different time periods. Predation during the arrival of emigrants and establishment of aphid populations had approximately the same effect as predation over the entire aphid period, whereas predation during the 20 days prior to peak had very little effect on resulting peak populations. We conclude that a) yearly levels of R. padi infestation are mainly determined by the volume and intensity of emigrants; b) peak levels are sensitive to changes in predator density; and c) in some cases an outbreak of R. padi may be prevented by the action of spring active polyphagous predators alone.