bluuebunny/crossref_metadata_2025_split huggingface dataset:
Response of the braconid parasitoid Cotesia (=Apanteles) glomerata to volatile infochemicals: effects of bioassay set‐up, parasitoid age and experience and barometric flux
Authors: Steinberg S. , Dicke M. , Vet L. E. M. , Wanningen R. 
Published: April 2011

AbstractUpon initiating a research project on the role of volatile infochemicals in the tritrophic system Cotesia (= Apanteles) glomerata (L.) ‐ Pieris brassicae (L.) ‐ cabbage, a bioassay was developed to investigate the response of C. glomerata. The bioassay should be effective in terms of high responsiveness and minimum variability and constructed through a comparative approach. Twenty seven treatments, organized in a factorial randomized block design, compared the effect of three bioassay set‐ups (glasshouse flight chamber, wind‐tunnel and Y‐tube olfactometer), three parasitoid age groups (1–2, 4–5 and 8–9 days old females), three pre‐treatment experiences (naive, damage experienced and oviposition experienced wasps) and the day‐to‐day effect on response of C. glomerata to clean cabbage (CC) and plant‐host complex (PHC) in a dual choice test.The best results with regard to the strength and consistency of response to the PHC were obtained in the glasshouse flight‐chamber by 4–5 days old female wasps with either damage or oviposition experience (94 and 90%, respectively). It is therefore recommended as a suitable bioassay for studying the role of volatile infochemicals in host‐habitat location by C. glomerata.A day‐to‐day variation in response was found in the glasshouse and wind‐tunnel. It was correlated with the direction of change in barometric pressure within the time period of the experiment, showing that steadily increasing atmospheric pressure yields a significantly higher response than steadily decreasing or fluctuating barometric flux. To control for the day effect it is suggested to conduct further experiments in a block design, having day as a block. Several aspects of the infochemical ecology of C. glomerata are discussed.
Laboratory evaluation of parasitic hymenoptera used in attempts to biologically control aphid pests of crops in Australia
Authors: Hughes R. D. , Woolcock L. T. , Hughes M. A. 
Published: April 2011

AbstractAs an integral part of a programme to attempt the biological control of several crop‐infesting aphid pests in Australia by the introduction of specific hymenopterous parasites, a laboratory technique to try to predict their likely effectiveness in the field, was developed with the aim of improving selection of natural enemies in future. It was based on demonstrating whether the parasites attack a greater proportion of their hosts with increased host density, i.e. whether they show a Type 3 functional response (Holling, 1959). To overcome the problem of super‐parasitisation at low densities when a parasite is confined with aphids on one plant (van Lenteren & Bakker, 1976) we used several plants in a large cage, all with the same density of host aphids. A parasite released into such a cage searches for and attacks the aphids on one plant, then leaves it to repeat the process on a second plant, and so on. After a standard exposure time the parasitisation rate is estimated separately for the aphids on each plant and the average performance of the parasite calculated. Using this technique for seven parasites introduced into Australia for biological control of crop aphids, only one, Aphidius salicis Halliday, attacking carrot aphid showed a Type 3 response.
Flight responses in a wind tunnel of the parasitoid Microplitis croceipes to three spring and three summer host plants of Heliothis spp
Authors: Kaas J. P. , Elzen G. W. , Ramaswamy S. B. 
Published: April 2011

AbstractFlight responses of the parasitoid, Microplitis croceipes (Cresson) (Hymenoptera: Braconidae) to two phenological stages of spring host plants (crimson clover, Trifolium incarnatum L., hairy vetch, Vicia villosa Corbiere, and cutleaf geranium, Geranium dissectum L.) and summer host plants (cotton, Gossypium hirsutum L., sorghum, Sorghum bicolor L., and soybean Glycine max (L.) Merr.) of Heliothis virescens (F.), were measured in a dual choice situation in a wind tunnel. Preflowering clover was more attractive than preflowering geranium, followed by preflowering vetch. Clover was preferred over geranium in flowering stages as well. No within species differences were detected for the two phenological stages. Preflowering and flowering cotton and soybean were preferred over preflowering and flowering sorghum. The findings could be important in pre‐determining release sites for M. croceipes in the field.
Pitfall trap catches of and aphid predation byPterostichus melanariusandPterostichus madidusin insecticide treated and untreated potatoes
Authors: Dixon P. L. , McKinlay R. G. 
Published: April 2011

AbstractAphids were countedin situand carabid beetle populations assessed by pitfall trapping between 1983–1985 in potato fields in Scotland treated with demeton‐S‐methyl (DSM) or untreated.Macrosiphum euphorbiae(Thomas) (Homoptera: Aphididae) was the most abundant aphid. Nineteen species of carabid beetles were trapped but the fauna was dominated byPterostichus melanarius(Ill.) andPterostichus madidus(Fabr.) (Coleoptera: Carabidae). Pitfall trap catches of these carabids were variable but generally lower in sprayed than unsprayed plots for a few days after DSM application and higher a week or two later. Of 1800P. melanariusand 910P. madidusdissected, 14.4 per cent and 30.5 per cent respectively, contained aphid remains. The proportion that had eaten aphids often was higher in sprayed than unsprayed plots immediately after treatment. In additional experiments, aphids treated with DSM fell from plants; four to five per cent of the theoretically applied dose of DSM reached the ground in a closed‐canopy potato crop; and no mortality occurred whenPterostichusspp. were exposed to DSM in a field bioassay. It is proposed that observed patterns in trap catch ofPterostichusspp. around times of pesticide application may be due in part to aphids falling to the ground after treatment. Beetles that eat these fallen aphids may be less hungry, less active and less likely to be trapped. Later increases in catches may be attributed to hungry, more active beetles, a consequence of prey removal by the insecticide. Although this hypothesis requires further research, it is clear that the effects of insecticide treatment on carabid populations cannot be measured by pitfall trapping alone.
Resistance to Spodoptera exigua in Apium prostratum
Authors: Diawara M. M. , Trumble J. T. , Quiros C. F. , Millar J. G. 
Published: April 2011

AbstractTwo Apium accessions were compared with the commercial cultivar ‘Tall Utah’ 52–70R (A. graveolens [L.]) for resistance to Spodoptera exigua (Hübner)(Lepidoptera: Noctuidae). Oviposition rate was not significantly different between the three genotypes. In all accessions, eggs were usually placed on the upper half of the plants. Implications of this oviposition pattern on S. exigua management in celery are discussed. The wild species A. prostratum ssp prostratum var filiform (A230) showed a significantly higher resistance to S. exigua than 52–70R. The levels of carcinogenic and mutagenic linear furanocoumarins in the commercial cultivar 52–70R (1.41 μg/g in the petioles; 5.85 μg/g in the leaves) and in the plant accession A. nodiflorum (5.40 μg/g in the petioles; 2.99 μg/g in the leaves) were far below the concentration reported to produce acute contact dermatitis (18.0 μg/g). The levels of furanocoumarins in A. prostratum petioles (186.14 μg/g) and leaves (326.45 μg/g) were 10 and 18 times higher, respectively, than the concentration known to cause contact dermatitis. However, resistance in A. prostratum was primarily due to non‐preference and the linear furanocoumarins did not induce non‐preference. Therefore, the resistance shown by this plant accession does not appear to be furanocoumarin‐based and may be suitable for transfer to commercial celery for use in S. exigua management.
Interactive effects of temperature and concentration of the flavonol rutin on growth, molt and food utilization of Manduca sexta caterpillars
Authors: Stamp N. E. , Horwath K. L. 
Published: April 2011

AbstractA factorial experiment tested the effects of varying concentrations of the flavonol rutin and daytime temperatures of 20 and 30 °C on growth, molting and food utilization efficiencies of third instar tobacco hornworms (Manduca sexta (L.)). Cool temperature prolonged both the growth (= feeding) and non‐feeding periods and consequently the relative consumption rates (RCR) and relative growth rates (RGR). Temperature had no impact on the amount of food consumed and the utilization indices of efficiency of conversion of ingested food and efficiency of conversion of digested food to larval biomass. But rutin was more concentrated in the frass of the larvae at the warm temperature. With increasing levels of rutin in the diet, the efficiency of conversion of ingested food tended to decline. Rutin reduced RCR and RGR. At the cool temperature, rutin increased the time spent in the first portion of the non‐feeding period disproportionately. Analysis of growth rate intervals within the growth period indicated that at the cool temperature rutin had no discernible impact over the first half of the growth period, during which developmental competence to molt is likely achieved. Overall, these results indicate an overlap in the growth and molting phases and suggest that rutin interferes with physiological processes at the time of molt initiation, with these effects magnified at a cool temperature.
Behavioral responses of Ceratitis capitata flies to bait spray droplets and natural food
Authors: Prokopy R. J. , Papaj D. R. , Hendrichs J. , Wong T. T. Y. 
Published: April 2011

AbstractIn studies carried out on field‐caged non‐fruiting host trees, we examined effects of environmental and adult physiological and experiential state factors on responses of released Mediterranean fruit flies, Ceratitis capitata (Wiedemann), to droplets of proteinaceous bait (PIB‐7) with or without 20% insecticide (malathion). We confirmed that fresh PIB‐7 is both attractive and phagostimulatory to proteindeprived medflies and found that presence of 20% malathion ultra low volume concentrate (ULVC) in PIB‐7 droplets does not significantly repel medflies from approaching droplets but does significantly deter feeding on them. A single relatively fresh deposit of bird feces, an important source of protein for medflies in natural environments, attracted several times more laboratory‐cultured and wild medflies than 20 droplets of 80% PIB‐7/20% malathion ULVC (about the average number of droplets per m2of plant canopy in aerial bait spray programs). Attraction to protein was significantly greater among wild medflies deprived of protein continuously from eclosion than among wild medflies that had recent (within 3 days) or continuous access to protein. Attraction to protein increased significantly with increasing age (2, 7 and 12 days) of protein‐deprived wild medflies. But we found no significant positive impact of recent brief experience of wild medflies with protein on degree of subsequent attraction to protein. In final experiments that mimicked the size, density and distribution of bait spray droplets on tree foliage typical for an aerial medfly control program, very few (4%) or no released protein‐deprived wild medflies found a bait droplet within the 15 min test period even though most found a single deposit of bird feces. We conclude that the effectiveness of aerial bait sprays against medflies might be enhanced substantially (and the proportion of infested area treated with bait spray reduced considerably) by (1) including synthetic equivalents of attractive components of bird feces in the spray mixture, and (2) adjusting spatial and temporal patterns of bait spray applications according to estimates of the composition and abundance of natural medfly food and the age structure of medfly adult populations in infested regions.
The development of an improved model trap for monitoring Ephestia cautella
Authors: Quartey G. K. , Coaker T. H. 
Published: April 2011

AbstractDelta, Covered funnel and Uni‐traps containing pheromone used for monitoring male Ephestia cautella (Walker) (Lepidoptera: Phycitidae) moths were compared in a wind tunnel in moving and still air. The shape and design of the traps and the form of pheromone plume emitted from them determined the moth's latency time, numbers orientating, alighting on the traps and captured. To improve trap design, the visual responses of the moths to rectangles of different colours and sizes and to brown and white stripes, showed that more moths were attracted to darker coloured 6 × 50 cm vertical rectangles on a white background and to 7.5 mm brown and white stripes. A cylindrical trap containing pheromone incorporating these features captured 90% and 80% of the moths released in the wind tunnel in moving and still air respectively, compared with 70% and 35% for the best commercial traps.
Development of Aphelinus mali an endoparasitoid of woolly apple aphid, Eriosoma lanigerum at different temperatures
Authors: Asante S. K. , Danthanarayana W. 
Published: April 2011

AbstractDevelopmental times for both sexes of Aphelinus mali (Haldeman) (Hymenoptera: Aphelinidae) an endoparasitoid of woolly apple aphid, Eriosoma lanigerum (Hausmann) (Hemiptera: Pemphigidae) were studied at 13, 15, 18, 20, 25 and 30 °C and compared with those of E. lanigerum. Mean developmental times ranged from 11.7–53.3 days for males, 11.8–55.4 days for females and 11.8–54.4 days for both sexes combined and were significantly inversely related to temperature. A good linear model fit (r2 > 0.99) between developmental rate and temperature in the range 13–30 °C was observed. Results indicate significant differences between developmental times of males and females at 13, 18, 20, and 25 °C but no differences at 15 and 30 °C. The notional developmental threshold was 8.3 °C for both males and females. Compared with its host, A. mali has a higher lower developmental threshold. An average of 252.8, 256.7 and 254.8 degree‐days (DD) above the lower threshold were required by A. mali to complete development from time of oviposition to adult emergence for males, females and both sexes combined, respectively. Field experimentation also indicated that the developmental time of A. mali lags significantly behind that of its aphid host throughout the year. These findings are discussed in relation to its status as a biological control agent for E. lanigerum.
Occurrence of hop aphid phagostimulants in the honeydew of aphids
Authors: Dorschner K. W. , Kenny S. T. 
Published: April 2011

AbstractSeveral aphid honeydews were incorporated into sucrose solutions and presented to hop aphids, Phorodon humuli (Schrank), as artificial diets in free‐choice bioassays. Small additions of honeydew collected from two species of aphid feeding on hop, Humulus lupulus L., arrested the searching behavior of the hop aphid and appeared to stimulate prolonged periods of ingestion. This effect was more dependent on the host plant honeydew source than the species of aphid that produced the honeydew. Aphid honeydews collected from plants other than hop (non‐hosts to P. humuli) contained hop aphid phagostimulants that were less effective. Our results indicate that analysis of aphid honeydew could help describe chemical cues involved in the recognition of appropriate host plants by aphid species.
Caterpillars' compensatory feeding response to diluted nutrients leads to toxic allelochemical dose
Authors: Slansky F. , Wheeler G. S. 
Published: April 2011

AbstractMany herbivores increase their consumption rate as dietary nutrient concentration declines. This compensatory response can mitigate the fitness‐lowering impact of reduced food quality, but little is known about its costs. In this study we tested the hypothesis that one cost to a faster consumption rate can be the ingestion of a toxic dose of an allelochemical occurring in the food. We fed velvetbean caterpillars a diet with progressively diluted nutrient levels but containing the same concentration (% fresh mass, fm) of caffeine, a methylxanthine alkaloid. Larvae compensated for the reduced nutrient level, with those fed the most diluted diet increasing their biomass‐relative consumption rate (fm) 2.6‐fold over larvae fed the undiluted diet. Consequently, their rate of caffeine ingestion increased to a pharmacologically effective dose, interfering with food utilization, slowing growth, reducing subsequent feeding and lowering survival. These results suggest that greater allelochemical ingestion can be one cost of an increased consumption rate, although additional studies with other allelochemicals and species are necessary to more broadly evaluate whether insects can adaptively balance their intake of nutrients and allelochemicals through adjustments in consumption rate. In addition, these results highlight the importance of measuring consumption rates of allelochemicals and other ingested biocides, not just their dietary concentration, when assessing efficacy against herbivores.
Evolution of insect‐plant relationships ‐ a devil's advocate approach*
Authors: Jermy T. 
Published: April 2011

AbstractMost hypotheses concerning the evolution of insect‐plant relationships are based on the assumptions that, (1) phytophagous insects reduce plant fitness, and that (2) insect‐plant relationships are the result of unconstrained selection. It can be shown, however, that there is little evidence to support these assumptions. As an alternative, it is proposed that the evolution of insect‐plant relationships results primarily from autonomous evolutionary events; namely from heritable functional changes within the insects' nervous system that determine plant recognition and ultimately host plant specificity. These changes cannot be evoked by selective ecological agents. They originate from intrinsic changes (mutations sensu lato) within the insect genome. Ecological factors play a secondary role: by either supporting or preventing the establishment of the new genotype with the novel food preference.
Three inhibitor types from wheat endosperm are differentially active against α‐amylases of Lepidoptera pests
Authors: Gutierrez C. , Garcia‐Casado G. , Sänchez‐Monge R. , Gomez L. , Castañera P. , Salcedo G. 
Published: April 2011

AbstractCrude α‐amylase preparations from seven Lepidoptera pests were susceptible to inhibition by salt‐soluble proteins of bread wheat (Triticum aestivum L.) endosperm. Protein fractions that corresponded to tetrameric, dimeric, and monomeric wheat α‐amylase inhibitors, were decreasingly effective against the insect α‐amylase activity. To further confirm these results, purified inhibitors were tested against an α‐amylase preparation from Ephestia kuehniella (Zeller). This preparation showed decreased activity when increasing amounts of an heterotetrameric inhibitor (reconstituted from its isolated subunits WTAI‐CM2, ‐CM3 and ‐CM16) were assayed. Activity was only partially inhibited by homodimeric (WDAI‐1, synonym 0.53; WDAI‐2, synonym 0.19) and monomeric (WMAI‐1, synonym 0.28) inhibitors.
Improved two‐component blend of the synthetic female sex pheromone of Cryptophlebia leucotreta, and identification of an attractant for C. peltastica
Authors: Newton P. J. , Thomas C. D. , Mastro V. C. , Schwalbe C. P. 
Published: April 2011

AbstractA series of field evaluations using the Pherocon‐1C trap examined various doses and blends of the following synthetic pheromone compounds: (E)‐7‐dodecenyl acetate (E7–12:Ac), (E)‐8‐dodecenyl acetate (E8‐12:Ac), (Z)‐8‐dodecenyl acetate (Z8‐12:Ac), decyl acetate (10:Ac), dodecyl acetate (12:Ac), tetradecyl acetate (14:Ac), hexadecyl acetate (16:Ac), and octadecyl acetate (18:Ac). It was concluded that E7–12:Ac is not a true sex pheromone in Cryptophlebia leucotreta (Meyrick) because it only led to significant male catches at doses greater than 1 mg per lure and did not perform as well as mixtures of E8–12:Ac and Z8–12:Ac. The latter mixtures led to significantly higher catches of C. leucotreta when the ratio of E8–12:Ac to Z8–12:Ac was 9:1 rather than 1:1 as in commercial lures. Increases in dosages of this blend from 1 mg to 50 mg per lure did not lead to increases in male moth catches. An additional 10% 12:Ac had no consistent significant effect on numbers of captured males. 10:Ac, 12:Ac, 14:Ac, 16:Ac, and 18:Ac, individually or in various combinations with 9:1 E8–12:Ac and Z8‐12:Ac corresponding to their average proportions in female pheromone glands, did not lead to significant increases in C. leucotreta catches. Blends of E8–12:Ac and Z8–12:Ac at 1 mg per lure also resulted in catches of males of the litchi moth, Cryptophlebia peltastica (Meyrick), when containing 70% or more Z8–12:Ac. Maximum catches of C. peltastica occurred in traps baited with 100% Z8–12:Ac.
Flight periodicity of Prostephanus truncatus and longevity of attraction to synthetic pheromone
Authors: Tigar B. J. , Key G. E. , Flores‐S M. E. , Vazquez‐A M. 
Published: April 2011

AbstractDouble‐sided sticky traps were baited with polythene vials containing synthetic components of the aggregation pheromone of Prostephanus truncatus (Horn) and used to investigate the effect of time of day on capture of this insect. P. truncatus exhibited a bimodal pattern of flight activity with a major peak between 18.00 and 21.00 h, and a smaller peak between 07.00 and 09.00 h. The effective life of the pheromone bait was also investigated over 33 days. The highest numbers of P. truncatus were caught during the first 8 days and the majority of the beetles were caught within 14 days. Catches then showed a steady decline. Captures of the predatory histerid Teretriosoma nigrescens Lewis, were much lower than those of P. truncatus and showed fluctuations which did not appear related to numbers of its prey. Environmental factors such as rainfall, temperature, wind and trap positioning appeared to influence results, especially when considered over a short time scale.
Genetic control of geographic variation for cannibalism in the southwestern corn borer, Diatraea grandiosella
Authors: Tarpley M.D. , Breden F. , Chippendale G. M. 
Published: April 2011

AbstractThe southwestern corn borer, Diatraea grandiosella Dyar, is a subtropical insect whose range has expanded northward within this century. Geographic variation exists between populations at the extremes of the range for a suite of morphological and behavioral characters, including cannibalism. Laboratory colonies established from a Missouri population (37°N lat.) with a high cannibalism rate and a Mexican population (19°N lat.) with a low cannibalism rate were used to examine the genetic basis of cannibalism by means of a controlled breeding design. When larvae were held in pairs on artificial diet in 30 ml plastic cups at 30 °C 16L:8D, the highest incidence of cannibalism in both Missouri and Mexican populations was found in larvae 15 to 18 days‐of‐age (5th and 6th instars). Under these conditions, cannibalism was expressed in 33 % of the pairs formed from Missouri larvae and 11 % of the pairs formed from Mexican larvae. First and second generation crosses between Missouri and Mexican populations showed an intermediate level of cannibalism, whereas backcrosses to the parental generations showed a regression to the parental phenotypes. These results indicate that cannibalism is under additive genetic control. Larvae from the Missouri parental population were more likely to consume their victim (i.e., cannibalize) once intraspecific killing had occurred than were larvae from the Mexican parental population or from any of the crosses, and female larvae were cannibals more often than were males. Under the conditions employed, no advantage was detected for cannibalism over instraspecific killing for larval weight gain or growth rate.