bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetics of the ability of Phyllotreta nemorum larvae to survive in an atypical host plant, Barbarea vulgaris ssp. arcuata
Authors: Nielsen Jens Kvist 
Published: October 2003

AbstractA polymorphism in host plant exploitation has been discovered in the flea beetle, Phyllotreta nemorum L. (Coleoptera: Chrysomelidae: Alticinae) where one resistant population is able to use Barbarea vulgaris R.Br. ssp. arcuata (Opiz.) Simkovics (Brassicaceae) as a host plant while a susceptible population is not. Crosses (F1, F2, and backcrosses) between the two flea beetle populations were made, and survival of the progeny on B. v. ssp. arcuata was measured. The ability of P. nemorum larvae to survive in this plant species depended on the presence of major, dominant genes (R‐genes). The two most abundant R‐genes in the resistant flea beetle population were X‐ and Y‐linked, respectively. The use of B. v. ssp. arcuata as a natural host plant by the resistant population of P. nemorum seems to be an extension of the host plant range of the species. The role of sex‐linked genes in the evolution of host range is discussed.
The effects of thermal acclimation on immature mortality in the Queensland fruit fly Bactrocera tryoni and the light brown apple moth Epiphyas postvittana at a lethal temperature
Authors: Beckett S. J. , Evans D. E. 
Published: October 2003

AbstractMortality data for non‐acclimated and acclimated 3rd instar larvae and mid‐term eggs of Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) were obtained after immersing in hot water at 46 °C. Acclimation consisted of holding the larvae and eggs at 35 °C for 20 and 11 h respectively just prior to heat‐treatment. The median lethal time (LT50) for acclimated larvae was found to be 6.9 min compared to 2.5 min for non‐acclimated larvae. LT99.999 for acclimated larvae was 20.9 min compared to 8.7 min for non‐acclimated larvae. LT50 for acclimated eggs was 5.0 min compared to 2.4 min for non‐acclimated eggs. LT99.999 for acclimated eggs was 26.0 min compared to 6.6 min for non‐acclimated eggs. For 3rd instar larvae, most acclimation effect on mortality had occurred by 8 h. A notable residual response was present 20 h after acclimation had occurred, reducing mortality at 46 °C for 4.5 min by roughly 25%. Mortality data at 46 °C were also obtained for non‐acclimated and acclimated late instar larvae of Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae). With this species, LT50 for acclimated larvae was 2.5 min compared to 1.1 min for non‐acclimated larvae. LT99.999 for acclimated larvae was 9.5 min compared to 4.6 min for non‐acclimated larvae.
Mexican diabroticite beetles: I. Laboratory test on host breadth of Acalymma and Diabrotica spp.
Authors: Eben Astrid , Barbercheck Mary E. , Martín Aluja S. 
Published: October 2003

AbstractChoice tests were conducted to determine relative degree of specialization of feeding behavior of 11 Mexican diabroticite species in the genera Acalymma and Diabrotica (Chrysomelidae: Luperini). Adult beetles were offered a choice between cotyledons of a non‐bitter (not containing cucurbitacin) cucurbit (C. pepo L. var. Crookneck), corn (Zea mays L.), and beans (Phaseolus vulgaris L.). In a second assay a bitter (containing cucurbitacin) cucurbit (C. pepo L. var. Ambassador) was added to the array of plants offered. Neonates of two species of Acalymma and one species of Diabrotica were offered a choice between roots of a non‐bitter and a bitter cucurbit, and between a bitter cucurbit and corn.Adult insects showed distinct preferences in the first assay. All Acalymma spp. tested accepted only the non‐bitter cucurbit as host, whereas Diabrotica spp. preferred either the cucurbit or the noncucurbit hosts. When the bitter cucurbit was offered together with the other three hosts, all species changed their host choice and significantly preferred the bitter cucurbit. Neonates of all three species tested significantly preferred the bitter cucurbit roots over the non‐bitter roots, and the corn roots over the bitter cucurbit.The observation that all Mexican diabroticite species tested left suitable hosts when bitter cucurbits were offered in a choice situation supported the hypothesis that the association between diabroticites and Cucurbitaceae is mediated by plant chemical compounds. For both, the Acalymma spp., which were found to be cucurbit specialists, as well as for the polyphagous Diabrotica spp., cucurbitacin B acted as a strong feeding arrestant which implies that the chemical mediation of this interaction might be an evolutionary conservative trait within the tribe.
Increased parasitization of California red scale in the field after exposing its parasitoid, Aphytis melinus, to a synthetic kairomone
Authors: Hare J. Daniel , Morgan David J.W. , Nguyun Tuyun 
Published: October 2003

AbstractThe introduced parasitoid, Aphytis melinus DeBach (Hymenoptera: Aphelinidae), utilizes a kairomone, O‐caffeoyltyrosine, to recognize California red scale, Aonidiella aurantii (Maskell) (Homoptera: Diaspididae). Wasps used in augmentative release programs for California red scale on California citrus are reared on oleander scale, Aspidiotus nerii Bouché (Homoptera: Diaspididae), themselves reared on squash. Previous laboratory studies demonstrated that wasps reared on oleander scale but exposed to O‐caffeoyltyrosine before bioassay more readily accepted California red scale covers for probing than wasps reared similarly but not exposed to O‐caffeoyltyrosine. The goal of this study was to determine if wasps reared on oleander scale but exposed to O‐caffeoyltyrosine actually parasitized a greater number of field‐reared California red scale than unconditioned wasps. In order to distinguish between progeny of conditioned and unconditioned wasps in the field, we utilized two A. melinus strains that carried different electrophoretically distinguishable alleles. In half of the releases, Strain ‘A’ was conditioned to O‐caffeoyltyrosine and Strain ‘B’ served as the control, while this pattern of conditioning was reversed for the remaining releases. Although there were differences in the rates of population growth of the two strains, whichever strain was the conditioned strain left a greater than expected number of progeny compared to the control strain in all comparisons. Exposure of A. melinus reared in commercial insectaries to O‐caffeoyltyrosine prior to release may be a means to improve the effectiveness of such wasps in augmentative release programs to control California red scale.
Quiescence in the Colorado potato beetle, Leptinotarsa decemlineata
Authors: Acheampong S. , Mitchell B.K. 
Published: October 2003

AbstractQuiescence (death feigning) was induced in the Colorado potato beetle, Leptinotarsa decemlineata by mechanical disturbance of live and artificial plants on which beetles were walking, feeding or grooming. The response consisted of a sudden cessation of activity lasting 12 to 500 s. Recovery from this immobile state was usually preceded by either antennal or leg movement. The time taken for beetles to come out of the immobile state (i.e. recovery time) was not dependent on age or sex of beetles or on stimulus duration, but was dependent on degree of displacement and on satiation level. Repeated stimulations led to longer recovery times and to a smaller proportion of responding beetles. Stimulation within the immobile state also prolonged recovery time. The most effective frequency of mechanical disturbance for startling beetles was 30 Hz. This response is presumed to be part of the extensive defense repertoire of this beetle, but we have so far been unable to discover a natural enemy that will elicit it.
Potential impact of Coleomegilla maculata predation on adaptation of Leptinotarsa decemlineata to Bt‐transgenic potatoes
Authors: Arpaia Salvatore , Gould Fred , Kennedy George 
Published: October 2003

AbstractThe relationship between Leptinotarsa decemlineata Say egg density and Coleomegilla maculata DeGeer predatory behavior was investigated at different spatial scales (plant‐to‐plant and plot‐to‐plot). Both adult C. maculata location and daily egg consumption rates were monitored over time in greenhouse and field tests. Despite aggregation in areas of highest prey density by C. maculata, egg consumption was inversely related to egg mass density at the smallest and the largest spatial scales tested. The experimental data on predation rates in high and low density field treatments were included in a mathematical model to simulate impact of natural enemies on the rate of L. decemlineata adaptation to Bt‐toxin‐expressing transgenic potato plants when Bt‐expressing plants are mixed at the plot‐to‐plot level with normal potato plants. Results showed that C. maculata predatory behavior could decrease the rate at which L. decemlineata adapted to Bt‐toxins if plot‐to‐plot mixed‐plantings were used.
Spectral efficiency of the glasshouse whitefly Trialeurodes vaporariorum and Encarsia formosa its hymenopteran parasitoid
Authors: Mellor H. E. , Bellingham J. , Anderson M. 
Published: October 2003

AbstractUsing the electroretinogram (ERG) technique the spectral efficiency of the compound eye of the glasshouse whitefly Trialeurodes vaporariorum (Westwood) (Homoptera: Aleyrodidae) and its main parasitoid Encarsia formosa (Gahan) (Hymenoptera: Aphelinidae) was measured at selected wavelengths between 340 nm and 670 nm. The form of the ERG for both T. vaporariorum and E. formosa was found to be monophasic in nature. For both male and female T. vaporariorum and female E. formosa a primary peak of efficiency occurred in the blue‐green‐yellow region, peak 520 nm and a secondary peak in the ultraviolet (UV) region. The compound eye of female E. formosa gave a significantly greater response in the UV region than either the dorsal or ventral regions of the compound eye of T. vaporariorum relative to the responses in the blue‐green‐yellow region. T. vaporariorum has divided compound eyes with distinct dorsal and ventral regions. In this study it was found that the percentage response in the UV, of the dorsal region of the eye, is significantly greater than that of the ventral region of the eye relative to the percentage response in the blue‐green‐yellow region and there is a significant shift in the blue‐green yellow peak towards the right of the spectrum.
Effects of diet and mating status upon corpus allatum activity, oocyte growth, and salivary gland size in the ring‐legged earwig
Authors: Rankin Susan M. , Dossat Heather B. , Garcia Kathryn M. 
Published: October 2003

AbstractThe effect of diet on mating behavior and the subsequent effects of diet and mating status on the biosynthesis of juvenile hormone III, basal follicle length, salivary gland size and total body weight were assessed in the ring‐legged earwig, Euborellia annulipes (Lucas) (Family Carcinophoridae; subfamily Carcinophorinae) during the first 15 days of adult life (the first gonadotrophic cycle of those fed presumably near‐optimal diets of catfood) and again on day 25 (late vitellogenesis of the second gonadotrophic cycle of those fed catfood). Diets of catfood, honey, fructose and total starvation, respectively, imposed on 0‐day adult females did not affect sexual receptivity, mating success or duration of mating as assessed on day 7. With the addition of a group of virgin, catfood fed females, we noted that only those females maintained on catfood oviposited within 25 days; enforced virginity virtually abolished oviposition. Total food deprivation of females as well as diets of honey or fructose abolished the cycles in total body weight, basal follicle length, salivary gland size and juvenile hormone production. Thus, starvation decreased the reproductive success of these insects, and carbohydrates only (fructose) or in combination with trace amounts of nutrients and protein (honey) were not sufficient to promote reproduction and associated cycles in this insect. Furthermore, virgins failed to undergo the decreases in salivary gland size that were characteristic of mated females. Among mated, catfood‐fed females, the second cycle in juvenile hormone production appeared to be smaller than the first.
Infestation of maize by Prostephanus truncatus initiated by male‐produced pheromone
Authors: Scholz D. , Borgemeister C. , Meikle W.G. , Markham R.H. , Poehling H.‐M. 
Published: October 2003

AbstractDelta traps baited with maize cobs, which were infested each with one male Prostephanus truncatus (Horn) (Col.: Bostrichidae), were distributed in southern Benin and collected after one, two, three and four weeks. The numbers of P. truncatus caught during the different trapping periods were not significantly different. Sixty‐four percent of the trapped P. truncatus were females. Females attracted during the one‐week trapping period produced a mean of 6.9 progeny during the seven days. The sex ratio of the progeny was 1:1. Trap catches with the infested cobs were on average 13 times lower than catches with 2 mg of the artificial pheromone. Estimation of P. truncatus densities in a maize store at the beginning of the storage period (based on laboratory data) revealed that small initial numbers of P. truncatus, possibly attracted by a single male, sufficed to initiate high infestation rates later in the storage season.
Variation in performance of western flower thrips populations on susceptible and partially resistant cucumber
Authors: Jan de Kogel Willem , van der Hoek Marieke , Mollema Chris 
Published: October 2003

AbstractBiotypic variation is of major concern in breeding for host plant resistance to insects. The existence or development of aggressive biotypes can lead to a rapid break‐down of host plant resistance. Therefore the study of biotypic variation should be included in breeding programs for resistance to insects. In the present study we measured the reproduction of randomly collected females of ten different populations of the insect herbivore Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) on one susceptible and two resistant cucumber (Cucumis sativus L.) accessions. Significant differences between thrips populations were observed on all three cucumber accessions. None of the populations had a significantly higher reproduction than the Dutch reference population NL1. For three populations, the Dutch population NL1, a population from New Zealand (NZ), and an Italian population (IT), partial life history parameters, such as reproduction rate, developmental time and survival were determined and the relative rate of increase rr was calculated. On all three cucumber accessions the rr‐value of population NZ was lower than of populations NL1 and IT. It is concluded that there is biotypic variation in F. occidentalis with regard to performance on cucumber plants with different levels of resistance. Reproduction is a good criterion for differentiating biotypes of F. occidentalis on cucumber.
Discrimination of oilseed rape volatiles by the honeybee: combined chemical and biological approaches
Authors: Pham‐Delègue M. H. , Blight M. M. , Kerguelen V. , Le Métayer M. , Marion‐Poll F. , Sandoz J. C. , Wadhams L. J. 
Published: October 2003

AbstractHoneybees (Apis mellifera L.) were individually subjected to a classical conditioning procedure in order to obtain an olfactory conditioned proboscis extension response. To relate the behavioural response directly to antennal detection abilities, a technique was developped for coupling proboscis extension responses and electroantennogram recordings, with the stimulation being provided by the effluent of a gas chromatograph (GC). Bees were conditioned with a six‐component mixture being part of oilseed rape (Brassica napus L.) floral volatiles, and tested with the individual components separated by GC. Responses of the conditioned bees were compared to those of unconditioned bees. No behavioural response was obtained in the control group, neither to the individual components nor to the mixture. Conditioning induced behavioural responses for three components, and an increase of electroantennogram responses for all components. A second experiment was conducted with an air entrainment extract of oilseed rape flower volatiles. Behavioural responses of conditioned and unconditioned bees were recorded. Responses obtained from conditioned bees tested with the air entrainment extract showed six groups of behaviourally active GC peaks. Unconditioned bees showed the same pattern of responses but at a lower level. The coupled technique described here appears to be a reliable tool for locating active components in a synthetic as well as in a natural mixture of floral volatiles. The effects of conditioning on odour discrimination and on its sensory correlates are discussed.
Effect of entomopoxvirus infection of Pseudaletia separata larvae on the oviposition behavior of Cotesia kariyai
Authors: Kyei‐Poku George K. , Kunimi Yasuhisa 
Published: October 2003

AbstractParasitoid behavior and oviposition were monitored to investigate the ability of Cotesia kariyai (Watanabe) (Hymenoptera: Braconidae) to distinguish between entomopoxvirus‐infected and noninfected larvae of Pseudaletia separata Walker (Lepidoptera: Noctuidae). Comparison of individual means revealed that searching time was not significantly different between treatments. Ovipositional time, however, differed significantly after day 8 post virus inoculation. The parasitoid adopted ovipositional posture on infected and noninfected host irrespective of the stage of infection and did not distinguish infected from noninfected larvae up to 4 days post infection. Mean number of larvae stung by the parasitoid was not influenced by the length of time interval between exposure to the virus. However, duration of ovipositor insertion was influenced by the time interval between exposure to the virus and subsequent exposure to parasitoid females. Female parasitoids did not completely reject infected larvae as unsuitable for egg deposition. However, 5 days after virus inoculation they rejected significantly more infected than noninfected larvae. Furthermore, significantly more eggs were laid in noninfected than infected larvae from day 5 following virus administration. These observations suggest that probing by Cotesia kariyai may provide information concerning host suitability.
Foliar form, colour and surface characteristics influence oviposition behaviour of the carrot fly
Authors: Degen Thomas , Städler Erich 
Published: October 2003

AbstractVarious leaf models made of paper were presented to carrot flies, Psila rosae (F.) (Diptera: Psilidae) in choice assays to investigate the effect of non‐chemical plant traits on oviposition behaviour. The surrogate leaves differed in colour, shape, surface coating, size and stem length. In the presence of host‐plant extracts, physical factors strongly influenced oviposition. Green, yellow and orange three‐dimensional models similar in shape to host‐plant leaves (pinnately or ternately compound or dissected) and with a thin cover of paraffin wax were most acceptable to the females. Egg‐laying was not affected by leaf size, but was negatively correlated with stem length. The results obtained by testing models with simple leaf silhouettes were confirmed in an experiment using more lifelike imitations of real host and non‐host leaves. The findings are discussed by an extensive review of similar studies in three other phytophagous fly species (cabbage root fly, onion fly, Hessian fly).
Influence of temperature on bionomics of cotton aphid, Aphis gossypii, on cotton
Authors: Xia J.Y. , van, der Werf W. , Rabbinge R. 
Published: October 2003

AbstractLife table parameters of Aphis gossypii Glover (Homoptera: Aphididae) on Gossypium hirsutum L. were determined at six temperatures (10, 15, 20, 25, 30, and 35 ± 0.5 °C) in the laboratory. Relationships of life table parameters with temperature were described with mathematical equations. Development was fastest at 30 °C, with a pre‐larviposition period of 4.6 d. Survival to adult was greatest at 25 °C (81%). Fecundity was highest at 25 °C, with a total fecundity of 28.3 nymphs per female and a mean reproductive rate of 3.1 nymphs per female per day. Threshold temperatures for development in the first through fourth instar and the adult were 8.2, 8.0, 7.2, 6.2 and 7.9 °C, respectively. The durations of these stages, expressed as temperature sums above these thresholds, were 24.2, 23.7, 23.0, 25.5 and 168.8 degree‐days (D°), respectively. A. gossypii achieved its maximum net reproductive number (24.4 nymphs per female) and greatest intrinsic rate of increase (0.386 d−1) at 25 °C. The high relative rate of population increase at 25 °C results in a daily population increase of 47% and a doubling time of only 1.8 d, illustrating the tremendous growth capacity of A. gossypii populations under favourable conditions. Compared to literature sources, our source of A. gossypii, fed on cotton, showed a comparatively great heat tolerance.
The scaling of body size and mass in a host‐parasitoid association: influence of host species and stage
Authors: Nicol C.M.Y. , Mackauer M. 
Published: October 2003

AbstractWe describe the allometry of body mass and body size as measured by hind‐tibia length in males of Monoctonus paulensis (Ashmead) (Hymenoptera: Braconidae, Aphidiinae), a solitary parasitoid of aphids. To assess the influence of host quality on allometric relationships, we reared parasitoids on second and fourth nymphal instars of four different aphid species, Acyrthosiphon pisum (Harris), Macrosiphum creelii Davis, Myzus persicae (Sulzer) and Sitobion avenae (F.), under controlled conditions in the laboratory. Dry mass was positively correlated with hind‐tibia length, and could be predicted from it, in unparasitized aphids, in aphid mummies containing parasitoid pupae, and in the parasitoid. The reduced‐major‐axis scaling exponents for the regression of dry mass on hind‐tibia length were species‐specific in aphids, reflecting differences in volume and shape between species. In mummified aphids, the stage at death influenced the size/mass relationship. In males of M. paulensis, the allometric exponent varied between parasitoids developing in different kinds of host. Individuals developing in pea aphid were absolutely larger in dry mass as well as proportionately larger relative to their hind‐tibia length. We discuss the allometry of body size and body mass in relation to parasitoid fitness.
Evaluation of felt traps to estimate egg numbers of cabbage root fly, Delia radicum, and turnip root fly, Delia floralis in commercial crops
Authors: Bligaard J. , Meadow R. , Nielsen O. , Percy‐Smith A. 
Published: October 2003

AbstractThe use of felt traps to estimate oviposition by the cabbage root fly, Delia radicum (L.), and turnip root fly, Delia floralis (Fall.), was compared with soil sampling at seven localities between 1992 and 1994 in Denmark and Norway. In all, 281 comparisons were made, based on 6800 samples. In 4.6% of these comparisons no eggs were found by either method. In 16% of the comparisons, 2.0±0.41 (±S.E.) eggs were found per soil sample and no eggs were found in felt traps, whereas in 0.7% of the comparisons 0.10±0.03 eggs were found per felt trap and no eggs in soil samples. When eggs were found using both methods, the ratio between soil sampling and felt traps varied from 13.1±3.2 when the egg laying rate was very low to 1.8±0.2 at high egg laying rates. Regression analysis showed significant correlation between felt trap catches and soil sampling (P<0.001), whereas locality did not influence felt trap efficiency (P=0.096). The influence of the physical conditions of felt traps, i.e., whether they were clean and dry, were analysed in a single year. Tentative action thresholds for control measures against cabbage root flies and turnip root flies were developed for cauliflower, Brassica oleracea, convar. botrytis (L.) Alef., var. botrytis, based on data from the literature and the present results.