bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sources of variability in copula duration of Mediterranean Fruit Flies
Authors: Field Scott A. , Taylor Phillip W. , Yuval Boaz 
Published: October 2003

AbstractPrevious studies have reported considerable variation in copula duration in the Mediterranean Fruit Fly (medfly), Ceratitis capitata Weidemann (Diptera: Tephritidae). Presently, however, this variation is largely unexplained. In this study we measure copula duration in two medfly strains used in applied research in Israel and examine how much of the variation in copula duration is due to the strain, age, the time of day the mating begins and the relative size of the mating pair. We found the following: flies of a strain reared in the laboratory since 1976 (Vienna) copulated for longer than flies of a strain collected in 1969 and periodically refreshed with wild males (Sade); older flies copulated for longer than young flies; and pairs in which males were smaller than females copulated for longer than pairs in which males were larger or the sexes were more evenly size‐matched. The time of day the mating commenced (morning vs afternoon) had no effect. We discuss potential mechanisms underlying these variations in medfly copula duration.
The effect of aphid prey quality on searching behaviour of Adalia bipunctata and its susceptibility to insecticides
Authors: Kalushkov P. 
Published: October 2003

AbstractAfter consumption of one individual of a suitable prey, such as Phorodon humuli (Schrank) (Aphididae), Adalia bipunctata L. (Coleoptera, Coccinellidae) adults changed from extensive to intensive searching behaviour. However, after the consumption of one individual of three other aphid species: Aphis fabae Scop., Aphis craccivora Koch or Aphis spiraephaga Müller, which are unsuitable prey, this coccinellid remained immobile for 12–76 min and did not switch to intensive search after moving off. Adult A. bipunctata fed an unsuitable prey, A. fabae, for 2 weeks were 2–4 times more susceptible to pyrethroid insecticides (permethrin, deltamethrin, fenpropathrin, esfenvalerate, alfa‐cypermethrin and bioresmethrin) and insect growth regulators (diflubenzuron, triflumuron, fenoxycarb, flufenoxuron, teflubenzuron) than those fed a suitable prey, P. humuli.The searching behaviour of coccinellids could thus be another criterion for determining the suitability of aphids as prey. The fact that the nutritional quality of aphids can affect the susceptibility of predatory coccinellids to insecticides should be borne in mind in integrated pest management programs.
Influence of species of host plants on the predation of thrips by Neoseiulus cucumeris, Iphiseius degenerans and Orius laevigatus
Authors: Brown A.S. Scott , Simmonds M.S.J. , Blaney W.M. 
Published: October 2003

AbstractA leaf‐disc bioassay was used to compare the predation levels of two species of predatory mites (Neoseiulus cucumeris (Oudemans) and Iphiseius degenerans (Berlese)) and a predatory bug (Orius laevigatus (Fieber)), on the thrips Frankliniella occidentalis (Pergande) and Heliothrips haemorrhoidalis (Bouché), feeding on a range of susceptible plant species from twelve plant families. The predatory bug, O. laevigatus, reduced the number of thrips to a greater extent than the predatory mites and all three predators showed greater levels of predation on F. occidentalis than on H. haemorrhoidalis. The level of predation caused by each predator varied among the species of plants; the variation was greater on the plant hosts of H. haemorrhoidalis than of F. occidentalis.
Colour and odour responses of flying western flower thrips: wind tunnel and greenhouse experiments
Authors: Teulon David A.J. , Hollister Benedict , Butler Ruth C. , Cameron E. Alan 
Published: October 2003

AbstractThe behavioural responses of flying western flower thrips (Frankliniella occidentalis Pergande) (Thysanoptera: Thripidae) to the colour yellow and the odour anisaldehyde were examined. In a wind tunnel, upwind flight by female thrips was common in an airflow of 0.11 m s−1 but was impeded at 0.22 m s−1. In the absence of anisaldehyde, flying female thrips exhibited an oriented response towards a yellow cue in the wind tunnel at a wind speed of 0.11 m s−1. The main response of females to anisaldehyde in the wind tunnel was flight inhibition. There was no evidence of an odour‐induced visual response, an odour‐induced anemotactic response or chemotaxis by female thrips to anisaldehyde in wind tunnel bioassays, but chemokinesis was implicated. With a matrix of yellow or black water traps with and without anisaldehyde in a greenhouse sweet pepper crop, yellow traps with anisaldehyde caught more thrips adults than yellow traps without anisaldehyde, black traps with anisaldehyde and black traps without anisaldehyde (1.3, 28 and 721 times for males respectively and 2.4, 9 and 117 times for females, respectively). Differences between respective traps were statistically significant in almost all cases. Trapping experiments using a centre‐baited trap design to reduce the interaction of anisaldehyde between baited and unbaited traps were undertaken in tomato and sweet pepper greenhouse crops. When the spatial distribution of the thrips adult population within the greenhouse was taken into account, yellow water traps with anisaldehyde caught between 11 and 15 times more female and 3 and 20 times more male F. occidentalis adults than yellow traps without anisaldehyde.
Changes in amino acids in Cucumis melo in relation to life‐history traits and flight propensity of Bemisia tabaci
Authors: Blackmer J.L. , Byrne D.N. 
Published: October 2003

AbstractPhloem amino acids in Cucumis melo L. were measured to determine whether changes in nitrogen availability might affect life‐history traits and flight activity of Bemisia tabaci Gennadius (Homoptera: Aleyrodidae). During plant development, nineteen of the twenty common amino acids, plus hydroxyproline, citrulline, ornithine and γ‐aminobutyric acid (GABA) were identified. For most essential amino acids, there were two peaks observed: an initial large peak associated with young plants, and a later small peak associated with senescing plants. For histidine, ornithine and citrulline, medium to large peaks in relative abundance were observed in mature plants. Arginine peaked during the first few weeks of development and was no longer detectable after wk 7. Serine and glutamine/glutamic acid were the only amino acids that peaked during plant senescence. Factor analysis was used to create a reduced number of orthogonal factors, which corresponded well with the trends that were observed for the various groups of amino acids. No single or combination of factors explained a significant amount of the variability in oviposition. For both males and females, factor 1 (predominantly essential amino acids) was the single most important predictor of adult weight. As the relative concentrations of essential amino acids decreased, whitefly weights decreased. Factors 1 and 3 (predominantly histidine and ornithine) were the most important predictors of developmental time. As these amino acids decreased in relative concentration, developmental time increased. Percent emergence was positively associated with factor 1 and negatively associated with factor 6 (predominantly aspartic acid). The distributions of flight duration for whiteflies emerging from young, mature and senescing melon plants were compared and they were always skewed towards short flights; however, the frequency of long‐duration flights increased when melon plants began to senesce. Whiteflies from all plant‐age categories were capable of flying for more than 2 h with fully developed eggs, but the presence of more than four mature eggs was associated with flights of reduced duration.
What is the basis of pederin polymorphism in Paederus riparius rove beetles? The endosymbiotic hypothesis
Authors: Kellner Rupert L.L. 
Published: October 2003

Abstract Paederus riparius (Coleoptera:Staphylinidae) females are polymorphic with regard to their ability to synthesize the hemolymph toxin pederin, a character confined to that sex: (+)‐females endow their eggs with pederin whereas (−)‐females lay eggs devoid of the substance. When reared without access to conspecifics, (+)‐females can only be obtained from (+)‐mothers. Ingestion of (+)‐eggs during larval development, however, enables the offspring of (−)‐females to also become (+)‐females. This is only the case if untreated (+)‐eggs are eaten, while sterilized (+)‐eggs do not alter larval fate as (−)‐females. The character can thus be transferred to unrelated specimens. These experiments suggest that microorganisms might be involved in the biosynthesis of this unusual compound. Pederin appears to be the first defensive substance in insects traceable to endosymbionts.
The epizootiology of a Metarhizium infection in mini‐nests of the leaf‐cutting ant Atta sexdens rubropilosa
Authors: Jaccoud D.B. , Hughes W.O.H. , Jackson C.W. 
Published: October 2003

AbstractThere is growing interest in the use of entomopathogenic organisms to control leaf‐cutting ants (Hymenoptera: Formicidae: Attini). However, the way leaf‐cutting ants react as a colony to biohazards is poorly understood. We investigated the effects of Metarhizium anisopliae (Metschnikoff) (Deuteromycotina: Hyphomycetes) applied to the foraging arenas of mini‐nests (queenless sub‐colonies) of the leaf‐cutting ant Atta sexdens rubropilosa (Forel). Dry spores were applied either alone or mixed with citrus powder, at 0.5 g or 0.05 g per mini‐nest. The spores were removed four days after application, and all dead ants removed every three days. Ant numbers near the Metarhizium increased as the ants attempted to clean up the biohazard. The ants attempted to place the spores in piles, which they then covered over with other material. They were able to deal with the low doses in this way, but the high doses overwhelmed them. All treated mini‐nests suffered increased ant mortality during the first ten days after application. This mortality was particularly high in the media worker caste which had played the major role in attempting to clean up the spores. Foraging activity decreased, as did the health of the fungus gardens. The mini‐nests exposed to the low dose of spores mixed with citrus powder then recovered fully. The health of the other treated mini‐nests declined gradually until around 26 days after application, when they began deteriorating sharply. However, the decline of these mini‐nests after day 26 was not due directly to the pathogenic action of the Metarhizium, nor to the initial ant mortality it had caused. The results suggest that the social stress caused by even such a short‐lived Metarhizium epizootic was sufficient to cause the decline and ultimate death of the mini‐nests. This has important implications for the control of leaf‐cutting ants. It also demonstrates how important the social homeostasis of the colony is to leaf‐cutting ants.
Moisture is required for the termination of egg diapause in the chrysomelid beetle, Homichloda barkeri
Authors: Nahrung H.F. , Merritt D.J. 
Published: October 2003

AbstractFour factors (moisture, light regime, temperature, food type) were examined for their effects on the embryonic diapause of Homichloda (Weiseana) barkeri (Jacoby) (Coleoptera: Chrysomelidae), a biocontrol agent for prickly acacia, Acacia nilotica (L.) Willdenew ex Delile (Mimosaceae). Moisture is critical for termination of diapause. A single wetting of eggs resulted in a low hatch rate while a sequence of wetting events followed by periods of dryness produced a high hatch rate. A relatively constant proportion of embryos within each batch initiated development at each wetting event, with hatching complete after the eighth wetting event in these trials. An extended interval between wetting events, tested at up to 23 days, did not result in a decreased overall hatch rate. A threshold time of exposure to moisture of between 3 to 6 h is required before development proceeds. The response of eggs to the moisture regime is seen as a strategy for taking advantage of available food after rainfall by terminating diapause, rather than merely a quiescent response to the absence of moisture. Temperature affected development time and the proportion of eggs that developed. Experimental manipulations of photoperiod and host‐plant availability showed no effect on embryonic development.
Role of host fruit color in the behavior of the walnut fly Rhagoletis juglandis
Authors: Henneman M. Lawrence , Papaj Daniel R. 
Published: October 2003

AbstractObservations and sticky‐trap tests were used to assess the effect of fruit color on the behavior of adult male and female Rhagoletis juglandis Cresson (Diptera: Tephritidae), a tephritid that infests husks of Arizona walnut in southeastern Arizona. In the first experiment, during which flies were observed foraging among walnut models suspended from small walnut trees, models were painted green to appear ripe and uninfested or yellow with brown patches to appear ripe and infested. Flies used for this first experiment were also of two types: prior to observations, one group of flies had access to real walnuts for 1.5 days (prior experience) while the other group of flies was held without real walnut fruits (no prior experience). Regardless of prior experience with real walnut fruits, female flies landed on green models more than yellow/brown models. Experienced males also were more likely to land on green models than on yellow/brown models. More interactions also occurred on green models, because there were more landings.In the field behavioral assay, flies from a natural population given a choice of green, yellow, and yellow/brown models landed most often on green models, and all interactions and oviposition attempts occurred on green models. Flies also distinguished models by color in field sticky trap assays.These results suggest that female response to ripeness cues is innate, while males develop a preference for green based on their encounter rate with females.
The role of Pimpla hypochondriaca venom in the suppression of pupal Noctuid host immunity
Authors: Marris Gay C. , Bell Howard A. , Naylor Janet M. , Edwards John P. 
Published: October 2003

AbstractWhen pupae of the Tomato moth (Lacanobia oleracea L.) (Lepidoptera: Noctuidae) are injected with venom from the endoparasitoid wasp Pimpla hypochondriaca Retzius (Hymenoptera: Ichneumonidae), they show an increased susceptibility to the fungal entomopathogen Metarhizium anisopliae Sorokin (Fungi Imperfecti: Deuteromycotina). This observation, coupled with the fact that wasp eggs are comparatively unlikely to be encapsulated when implanted into envenomated pupae, suggests that venom of P. hypochondriaca suppresses the cellular immune defense mechanisms of L. oleracea. Injection of host pupae with the venom of P. hypochondriaca has a rapid, adverse effect on the normal respiration pattern of L. oleracea. It is possible that severe disruption to host‐metabolism may contribute to a general failure in the hosts' normal immune response repertoire.
Attraction of a generalist predator towards herbivore‐infested plants
Authors: Venzon Madelaine , Janssen Arne , Sabelis Maurice W. 
Published: October 2003

AbstractThe occurrence and strength of interactions among natural enemies and herbivores depend on their foraging decisions, and several of these decisions are based on odours. To investigate interactions among arthropods in a greenhouse cropping system, we studied the behavioural response of the predatory bug Orius laevigatus (Fieber) (Hemiptera: Anthocoridae) towards cucumber plants infested either with thrips (Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae)) or with spider mites (Tetranychus urticae Koch (Acari: Tetranychidae)). In greenhouse release‐recapture experiments, the predatory bug showed a significant preference for both thrips‐infested plants and spider mite‐infested plants over clean plants. Predatory bugs preferred plants infested with spider mites to plants with thrips. Experience with spider mites on cucumber leaves prior to their release in the greenhouse had no effect on the preference of the predatory bugs. However, this experience did increase the percentage of predators recaptured. Y‐tube olfactometer experiments showed that O. laevigatus was more attracted to odours from plants infested with spider mites than to odours from clean plants. Thus, O. laevigatus is able to perceive odours and may use them to find plants with prey in more natural conditions. The consequences of the searching behaviour for pest control are discussed.
Sublethal effects of insecticides on the intrinsic rate of increase of cotton aphid
Authors: Kerns D.L. , Stewart S.D. 
Published: October 2003

AbstractInsecticides are often implicated in causing outbreaks of the cotton aphid, Aphis gossypii (Glover) (Homoptera: Aphididae), through stimulation of reproduction. In this study we report the sublethal effects of dosages of bifenthrin, acephate, carbofuran or pyriproxifen on cotton aphid reproduction. We could not detect any increase or decrease in the intrinsic rate of increase of cotton aphids exposed to bifenthrin, acephate or carbofuran. However, we did detect some increases in the net reproductive rate of aphids treated with bifenthrin justifying further investigation of the effect on reproduction by this insecticide. Trends based on simple linear regression models suggest that sublethal dosages of bifenthrin or carbofuran have a negative impact on aphid population growth as dosages increase. These data suggest that stimulation of reproduction by these insecticides probably does not play a major role in cotton aphid outbreaks or resurgence. Pyriproxyfen is a juvenoid currently used for control of whiteflies in cotton. It demonstrated significant activity towards cotton aphid reared on treated cotton in our bioassays. Pyriproxyfen caused sterility in most aphids exposed to dosages exceeding 1 ppm, and reduced aphid longevity by approximately 50%. However, it did not appear to greatly influence the reproductive potential or longevity of reproductively mature aphids. A field study indicates that pyriproxyfen affects cotton aphid population structure and may have potential in managing cotton aphid outbreaks. Modifying aphid population structure and growth through the use of juvenoids such as pyriproxifen may prove to be an effective proactive approach to pest control without adversely impacting beneficial organisms or causing pest resurgence.
Learning used as a strategy for host stage location in an endophytic host‐parasitoid system
Authors: Dutton A. , Mattiacci L. , Dorn S. 
Published: October 2003

AbstractThe relationship between host stage selection and foraging behaviour of Pholetesor bicolor Nees (Hymenoptera: Braconidae), a larval parasitoid of Phyllonorycter spp. (Lepidoptera: Gracillariidae), was investigated under laboratory conditions. The endophytic host develops through two larval stages with different feeding habits, accordingly named sap‐ and tissue‐feeders. The parasitoid was able to find and parasitise both larval stages, even though it is most successful in parasitising the sap‐feeder stage. The influence of experience in the parasitoid's searching behaviour was observed in a choice bioassay. Searching activity increased when either contact experience with the sap‐ or the tissue‐feeder host was given. Furthermore, the ability of the parasitoid to locate a sap‐ or a tissue‐feeder infested plant was influenced by the type of experience given prior to the bioassay. Naive females were less active, and were observed with equal frequency on sap‐feeder, tissue‐feeder and non‐infested plants. In contrast, females that were given previous contact experience with sap‐feeders (i.e., the host stage which provided the most successful parasitism) were observed foraging more often on plants infested by the sap‐feeders, than on those infested by tissue‐feeders or on non‐infested plants. Experience with a tissue‐feeder host had no detectable effect on host stage location and only enhanced P. bicolor's foraging activity. The advantages of learning in this tritrophic system are discussed.
Sexual maturity and intraspecific mating success of two sibling species of the Bactrocera dorsalis complex
Authors: Wee Suk‐Ling , Tan Keng‐Hong 
Published: October 2003

Abstract Bactrocera carambolae Drew & Hancock and B. papayae Drew & Hancock (Diptera: Tephritidae), two closely related sibling species in the B. dorsalis (Hendel) complex were shown to have different rates of sexual maturity. The response of B. carambolae males to methyl eugenol was observed to begin 10 days after emergence and increased with age. The attractancy peaked at 28 days after emergence and above. The males were also found to require a higher dosage of methyl eugenol (1 mg) for optimal response. These results are in contrast with those of B. papayae reported previously. The response to methyl eugenol was also observed to correspond with the age when first mating was performed.After eclosion, both sexes of B. carambolae mated approximately 2 weeks later and showed significantly lower matings/individual when compared with B. papayae in a 60‐day observation period. Both sexes of B. papayae and males of B. carambolae were able to remate on the next day. However, B. carambolae females required a minimum refractory period of 8 days in order to be sexually receptive again.During the 60‐day period, the mating propensity in B. papayae (100% success) was higher than B. carambolae (71–87% success) (P < 0.05). This observation was substantiated by a higher intraspecific mating success of B. papayae as compared to B. carambolae in a field cage (P < 0.001).
Egg production in response to combined alternative foods by the predator Coccinella transversalis
Authors: Evans Edward W. 
Published: October 2003

AbstractInsect predators may commit to reproduction to varying degrees depending on the nature of the prey they consume. I compared egg production by females of the aphidophagous ladybird beetle Coccinella transversalis (F.) (Coccinellidae) maintained on differing diets. As expected, females laid most eggs on a diet of aphids (pea aphids, Acyrthosiphon pisum[Harris]). Upon being switched from a diet of aphids, females laid no eggs after the first 3 days when maintained on a water solution of sucrose, and laid almost no eggs when maintained on a diet of second‐instar larvae of the moth Helicoverpa armigera (Hübner). However, females laid eggs in small numbers (on average, 2.7 eggs per day) when provided both sucrose and Helicoverpa larvae. Females laid similar numbers of eggs when aphid honeydew was substituted for sucrose in combination with Helicoverpa larvae; in both cases, egg production was only 10–15% of that on a diet of aphids. The production of small numbers of eggs from consumption of non‐aphid foods may enhance the ability of aphidophagous ladybirds to optimize their timing of reproduction at short‐lived colonies of their preferred aphid prey.
The lethal effects of gamma irradiation on larvae of the Huhu beetle, Prionoplus reticularis: a potential quarantine treatment for New Zealand export pine trees
Authors: Lester Philip J. , Rogers David J. , Petry Robert J. , Connolly Patrick G. , Roberts Peter B. 
Published: October 2003

AbstractGamma irradiation was investigated as a possible method for disinfestation of huhu beetle larvae, Prionoplus reticularis White, in Pinus radiata D. Don. Larvae of four representative size classes were irradiated at six doses, and the lethal dose (LD99) calculated from mortality data 3 days and 10 days post treatment. All larval size classes showed a similar sensitivity to gamma irradiation and required 3677 Gray (Gy) and 2476 Gy for a LD99 3 and 10 days post‐treatment, respectively. The penetration of gamma irradiation into pine wood was found to be lowest in freshly cut logs, and decreased linearly at a rate of 0.698 Gy mm−1 of wood. The penetration was greatest in wood that had been stored for 2 years, and decreased 0.512 Gy mm−1 of wood. These results are likely to be correlated with wood moisture content. Gamma irradiation appears to be a potential alternative method to fumigation for quarantine treatment of P. reticularis.