bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hormonal control of egg maturation in the corn earworm, Heliothis zea
Authors: Satyanarayana K. , Yu J. H. , Bhaskaran G. , Dahm K. H. , Meola R. 
Published: April 2011

AbstractAt eclosion, the ovaries of female Corn earworm Heliothis zea do not contain mature eggs. Virgin‐unfed females produced approximately 400 mature eggs in 8 days; mating or feeding doubled this number, and mating plus feeding more than tripled it. Females allatectomized or decapitated at day 0 matured few eggs. Egg production was restored by implantation of active corpora allata (CA) or by treatment with the juvenile hormone (JH) analogue methoprene at day 0. 20‐Hydroxyecdysone, on the other hand, had no effect. Females in which the CA had been denervated or in which the median neurosecretory cells of the brain had been ablated at day 0 produced fewer eggs than sham‐operated animals. These results indicate that egg maturation is controlled by JH and that continuous input from the brain is required for sustained CA activity for maintaining a high rates of egg maturation.The rate of JH biosynthesis by CA in vitro was determined with a radiochemical assay. The major hormones produced were JH‐II and JH‐III with small quantities of JH‐I. The rates of JH synthesis were similar in all experimental groups which may indicate that the in vitro rate of JH synthesis does not reflect the actual state of CA activity in the female.
Decision to superparasitize based on larval survival: competition between aphid parasitoids Aphidius ervi and Aphidius smithi
Authors: McBrien H. , Mackauer M. 
Published: April 2011

AbstractOviposition by a parasitoid wasp in an already parasitized host (= superparasitism) may result in larval competition and the loss of offspring. Consequently, in solitary species, the decision to superparasitize should be based on the probability of offspring survival. Females of Aphidius ervi Haliday and A. smithi Sharma & Subba Rao (Hymenoptera: Aphidiidae), two parasitoids of the pea aphid, discriminated between conspecific‐ and heterospecific‐parasitized hosts. Both species showed partial preference for aphids previously attacked by A. smithi, a result predicted from the fact that A. ervi is superior to A. smithi in larval competition under most conditions. Females of A. smithi selectively attacked conspecific‐parasitized pea aphids when given a choice between these and self‐parasitized hosts. Results indicated that females of both species responded to an external pheromone‐like marker to discriminate between self‐, conspecific‐ and heterospecific‐parasitized aphids. In addition, A. smithi may use internal cues to recognize, and avoid oviposition in, aphids previously parasitized by A. ervi.RésuméLa décision de superparasiter basée sur la survie larvaire: compétition entre les parasites du puceron du pois Aphidius ervi et Aphidius smithiL'oviposition par une guêpe parasite dans un hôte qui a déjà été parasité (= superparasitisme) pourrait conduire à une compétition entre larves et à une perte de progéniture. Par conséquent, dans les espèces solitaires, la décision de superparasiter devrait être basée sur la probabilité de survie de la progéniture. Les femelles de Aphidius ervi Haliday et de A. smithi Sharma & Subba Rao (Hymenoptera: Aphidiidae), deux parasites du puceron du pois, ont discriminé entre les hôtes parasités par des individus de la même espèce et ceux parasités par des individus d'une espèece différente. Les deux espèces de parasite ont montré une préférence partielle pour les pucerons préalablement parasités par A. smithi, résultat qui était prévisible du fait que, dans la majorité des cas, A. ervi est supérieur à A. smithi dans la compétition entre larves. Les femelles de A. smithi ont sélectivement attaqué les pucerons parasités par un individu de la même espèce lorsqu'il leur était donné de choisir parmi ceux‐ci et ceux parasités par les même individu. Les résultats indiquaient que les femelles des deux espèces répondaient à une sorte de phéromone externe pour distinguer les pucerons parasités par le même individu de ceux parasités par un individu de la même espèce et ceux parasités d'une autre espèce. En plus, A. smithi pourrait utiliser des signaux internes pour reconnaître et éviter l'oviposition dans les pucerons préalablement parasités par A. ervi.
Influence of protein hydrolysate baits on oviposition in the apple maggot, Rhagoletis pomonella
Authors: Mohammad A. B. , AliNiazee M. T. 
Published: April 2011

AbstractOvipositional responses of apple maggot (AM), Rhagoletis pomonella (Walsh), females were studied in the laboratory on apples (var: Golden Delicious) treated with different rates of four protein hydrolysate baits in choice and no‐choice tests. Protein hydrolysate baits at rates of 0.5 and 1% had no significant effect, but oviposition was greatly reduced at higher rates of 5 and 10%. Apple maggot females exposed to apples treated with protein hydrolysate baits at a rate of 10% made 41–71% fewer punctures and laid 41–73% fewer eggs than in untreated control. No oviposition activity was shown on apples treated with 25 and 100% Nulure®. In no‐choice tests the AM females laid 75–96% fewer eggs in apples treated with 10 and 25% Nulure compared to controls and no oviposition occurred in apples treated with 100%, Nulure. Apple maggot females arrived in similar numbers on apples treated with 10% Nulure and untreated apples, but only 5% of those arriving on Nulure‐treated apples showed ovipositor boring with no egg deposition while 60% of females arriving on untreated apples showed ovipositor boring activity and laid an average of 2.5 eggs per apple. In another experiment, individual AM females displayed similar behavioral responses to 10% Nulure‐treated apples; none of the 56 females tested on treated apples displayed ovipositor boring activity, but 59% of the females (N = 56) tested on untreated apples displayed ovipositor boring within 5 min of their arrival. Ninetyeight percent of AM females stayed and fed on fruit surfaces for 5 min on Nulure‐treated apples without ovipositor boring compared to only 2% on untreated apples. Of the females that arrived on untreated apples, 39% flew away within 5 min without ovipositor boring compared to only 2% of those that arrived on Nulure‐treated apples. Results of these two behavioral experiments suggest that upon arrival on a protein bait‐treated apple, an apparent change of behavior occurs in AM females and instead of attempting to oviposit, they attempt to feed on fruit surfaces resulting in reduced oviposition activity. These results indicate that the feeding and oviposition‐related activities of AM females are probably mutually exclusive and that the feeding behavior preempts oviposition activities on host fruits treated with higher rates of protein hydrolysate baits.
Prey selection by in vitro‐ and field‐reared Geocoris punctipes
Authors: Hagler J. R. , Cohen A. C. 
Published: April 2011

AbstractThe patterns of prey selection of Geocoris punctipes (Say) (Hemiptera: Lygaeidae), reared continously on artificial diet for six years, were almost identical with patterns shown by their field‐derived counterparts.In paired choice experiments both the in vitro‐reared and the wild G. punctipes showed a significant preference for Lygus hesperus over Aphis nerii, Heliothis zea, H. virescens, and Spodoptera exigua. There were no significant differences in choices made by the in vitro‐reared and the wild G. punctipes. These similar feeding patterns suggest that in vitro rearing, even over extended periods, does not cause degradation in the prey selection characteristics of G. punctipes.
Sex pheromone components of female Cornutiplusia circumflexa
Authors: Mazor M. , Harel M. , Levsky S. , Dunkelblum E. 
Published: April 2011

AbstractCapillary gas chromatography indicated the presence of (Z)‐7‐dodecenyl alcohol and (Z)‐7‐dodecenyl acetate in the abdominal tip extracts of female Cornutiplusia circumflexa (L.) (Lepidoptera: Noctuidae: Plusiinae) moths. Gas chromatography combined with mass spectrometry and dimethyl disulfide derivatization confirmed the structure of these two principal pheromone components. In a flight‐tunnel bioassay, a 5:1 blend of alcohol and acetate elicited the complete courtship sequence by males. The response was comparable to that evoked by a live virgin female, but males spent significantly longer time at calling females than at the synthetic source. The 5:1 blend was also attractive to male C. circumflexa in the field, as indicated by catches in traps baited with this mixture. (Z)‐7‐dodecenyl alcohol alone was slightly attractive whereas (Z)‐7‐dodecenyl acetate alone was completely inactive. C. circumflexa is the first reported Plusiinae species which utilizes (Z)‐7‐dodecenyl alcohol as the major pheromone component.
Binomial sequential sampling of adult Saccharicoccus sacchari on sugarcane
Authors: Allsopp P. G. 
Published: April 2011

AbstractThe between‐stalk dispersion characteristics of adults of the pink sugarcane mealybug Saccharicoccus sacchari (Cockerell) were determined in southern Queensland. Iwao's patchiness regression was inappropriate to describe the relationship between mean and variance. Taylor's power law indicated that adults were aggregated, especially at the beginning and end of the ratoon growth period. Binomial data were modelled by the Nachman model; the model of Grout and two models of Wilson & Room were inappropriate to describe the relationship between proportion of stalks infested and mean numbers of adults per stalk. Relationships to determine sample sizes for fixed levels of precision and binomial fixed‐precision‐level stop lines are developed for different sampling times using Taylor's power law and Nachman's equation.
Nocturnal behaviour of female Mythimna convecta
Authors: . Del Socorro A. P. , Gregg P. C. 
Published: April 2011

AbstractNocturnal behaviour of Mythimna convecta (Walker) (Lepidoptera: Noctuidae) virgin females was studied in the laboratory under 20 °C and 16:8 LD conditions. The periodicity of activity, feeding, calling, pre‐oviposition extrusion and oviposition varied with female age and hour of the scotophase. Females called for the first time between the 2nd and 11th scotophases with the peak in the 4th scotophase. Maximum calling occurred on the 7th hour of the scotophase. Young moths called more frequently with shorter bouts while old moths called less often but with longer bouts. In the presence of older females, moths spent significantly more time in pre‐oviposition extrusion and resting and less in activity and feeding than they did when only females of the same age or younger were present. There were no significant differences for calling suggesting that pheromones of older calling females did not affect calling of younger females.
Effects on German cockroach nymphs of contact exposure to IGRs, singly and in combination
Authors: Ross M. H. , Cochran D. G. 
Published: April 2011

AbstractLate instar German cockroach male and female nymphs were exposed continuously for two weeks to surfaces treated with fenoxycarb, diflubenzuron, and pyriproxyfen, singly and in combination. Concentrations were determined that eliminated or nearly eliminated reproduction in matings with untreated mates, either through mortality, effects on reproduction, or a combination of mortality and ‘sterility’ (no hatch). The major effect of fenoxycarb, pyriproxyfen, and pyriproxyfen plus fenoxycarb was on reproduction. The major effect of diflubenzuron was mortality. No hatch occurred in matings of females that were exposed to low concentrations of pyriproxyfen and fenoxycarb (2 ng/cm2 and 6 ng/cm2, respectively); sterility was incomplete when females were exposed to 600 ng/cm2 of diflubenzuron. Mortality and sterility acted together to eliminate productive matings (matings that produced nymphs) when relatively high concentrations of diflubenzuron were combined with one or both of the other insect growth regulators (IGRs). In the triple combination, very small amounts of fenoxycarb and pyriproxyfen (total 1.1 ng/cm2) combined with 200 ng/cm2 of diflubenzuron eliminated productive matings of treated females, but similar results with treated males were found only at higher concentrations of each IGR.
Oviposition behavior of Edovum puttleri, reared on two hosts, Leptinotarsa decemlineata and L. texana
Authors: Corrigan J. E. , Lashomb J. H. , May M. L. , Schal C. 
Published: April 2011

AbstractFemale Edovum puttleri Grissell [Hymenoptera: Eulophidae], reared from eggs of Leptinotarsa decemlineata (Say) or Leptinotarsa texana Schaeffer [Coleoptera: Chrysomelidae], were videotaped as they attacked egg masses of L. decemlineata containing 20 host eggs. We identified 15 components of ovipositional behavior. Parasitoids reared on L. texana attacked and oviposited in significantly more host eggs than did females reared on L. decemlineata. Ethometric analyses of behavioral transitions and a clustering analysis of 34 behavioral parameters showed that females reared on L. texana attacked the host egg mass in a different manner than those reared from L. decemlineata. It was concluded that differences were associated with the host species upon which they were reared. Contrary to previous reports, mortality of unparasitized hosts was caused by an ovipositor probe of short duration, which was not related to host‐feeding.
Oviposition by the African migratory locust,Locusta migratoria migratorioides, in a crop environment in South Africa
Authors: Price R. E. 
Published: April 2011

AbstractOviposition by the African migratory locust,Locusta migratoria migratorioides(Orthoptera: Acrididae), was studied in maize and wheat crops on the Orange Free State Highveld. Maize was shown to be the most important oviposition habitat with peak laying taking place in autumn and early winter when highest pod densities were recorded. Laying was mainly concentrated along the middle of the crop interrows in maize and within clearings in the wheat crop. Despite the uniform layout of these crops, the distribution of egg pods was found to be aggregated. Non‐reproductive behaviour, such as locust aggregation, basking and feeding, as well as environmental factors appeared to influence the distribution of egg pods in these crops. Secondary selection for optimum soil moisture and compaction on the laying site enhanced the aggregation of pods.
The influence of nutritional and genetic factors on larval performance of the cinnabar moth, Tyria jacobaeae
Authors: Soldaat L. L. , Vrieling K. 
Published: April 2011

AbstractIn a laboratory experiment using full‐sibs, 60% of the variation in pupal weight of the monophage Tyria jacobaeae L. (Lepidoptera, Arctiidae) could be explained by variation in the nitrogen concentration of the food plant, Senecio jacobaea L. and only 4% by variation in sugar concentration. Larval weight and growth rates of young and old larvae were also positively correlated with nitrogen and sugar concentration. Developmental time was negatively correlated with nitrogen concentration. In a second experiment full‐sib families differed significantly in larval weight at day 7, mortality, growth rate and developmental time. Pupal weight did not differ significantly among families, but was positively correlated with nitrogen concentration of Senecio. Larval performance was not significantly influenced by concentrations of sugars or alkaloids. We conclude that larval performance of Tyria during most of the larval period is mainly determined by genetic factors, but pupal weights are primarily determined by nitrogen concentration of the food plant.
Discrimination of sunflower volatiles by the red sunflower seed weevil
Authors: Roseland C. R. , Bates M. B. , Carlson R. B. , Oseto C. Y. 
Published: April 2011

AbstractFive principle monoterpenoid and other constituent volatile chemicals of sunflower heads were combined to resemble two lines of sunflower (Helianthus annuus L.): one U.S.D.A. standard line and one French line which was ‘poorly visited by insects’ (Etievant et al., 1984). Field trials of attraction to red sunflower seed weevils (Smicronyx fulvus Le Conte, Coleoptera: Curculionidae) showed that one was clearly preferred over the other. The more attractive mixture contained α‐pinene, β‐pinene, limonene, camphene and bornyl acetate in a ratio resembling that of Flath et al. (1985) rather than that described by Etievant et al. (1984). One or two volatiles were deleted from the optimal blend but only mixtures of five volatiles showed the highest attraction. Substitution of sabinene, another volatile prominent in sunflower, for one of the five in the optimal blend also decreased attraction of seed weevils. When the monoterpenoid components and ‘green leaf volatiles’ in the traps resembled the ratios of most of the prominent volatiles of sunflower, attraction was significantly greater than controls.
Survival and behavior of Plutella xylostella larvae on cabbages with leaf waxes altered by treatment with S‐ethyl dipropylthiocarbamate
Authors: Eigenbrode S. D. , Shelton A. M. 
Published: April 2011

AbstractCabbages (Brassica oleracea L.) treated with S‐ethyl dipropylthiocarbamate (EPTC) herbicide had reduced amounts of leaf surface waxes (40.6% of controls) and reduced densities of leaf surface wax crystallites (20.8% of controls). Leaf waxes of EPTC‐treated plants chemically and morphologically resembled leaf waxes of genetically glossy cabbages resistant to the diamondback moth Plutella xylostella (L.) (Lepidoptera: Plutellidae). Survival of larvae was significantly reduced on EPTC‐treated cabbage plants in three out of four experiments (62.0–15.3% of survival on controls). P. xylostella neonates also moved more rapidly on EPTC‐treated plants than on untreated controls (1.84 ± 0.16 cm/min on controls vs. 3.94 ± 0.24 cm/min on treated plants; P = 0.0001). These results support the hypotheses that reduction in leaf waxes is the basis of resistance to P. xylostella in genetically glossy plants and that reduced acceptance by larvae is associated with this resistance. Modification of leaf surface waxes with EPTC or similar compounds may have potential as an economic control for P. xylostella in Brassica crops.
Time‐related rejection of parasitised hosts in the aphid parasitoid, Aphidius ervi
Authors: Micha S. G. , Wellings P. W. , Morton R. 
Published: April 2011

AbstractTime‐related changes in the patterns of host discrimination may have a complex form depending on whether or not hosts are marked following first parasitisation, the persistence of chemicals in these marks, and changes in the host as a result of being parasitised. Here we present an experimental design capable of detecting temporal patterns in host discrimination of solitary parasitoids. This method is tested against experimental data from Aphidius ervi attacking the aphid, Acyrthosiphon kondoi. The results demonstrate that there are statistically significant changes in the patterns of egg distribution in aphid hosts held for intervals between 1 and 48 h between parasitisation. These changes appear to be attributable to increasing oviposition restraint by the superparasitising female as the time interval between attacks is increased. The form of this relationship is not significantly different to a sigmoid function and the rate of change of restraint was greatest between 6–8 h after the first oviposition.
In vitro bioassay for the effect of Ajuga reptans phytoecdysteroids on Trialeurodes vaporariorum larval development
Authors: Melé E. , Messeguer J. , Gabarra R. , Tomás J. , Coll J. , Camps F. 
Published: April 2011

AbstractA rapid and reliable in vitro bioassay method to test the effects of synthetic and natural compounds on the development of greenhouse whitefly Trialeurodes vaporariorum Westwood (Homoptera Aleyrodidae) is described.Leaf fragments of Nicotiana glauca Graham infested with eggs of whitefly were cultured under aseptic conditions on half‐strength Murashige‐Skoog medium. The development of the insect in vitro and in vivo were comparable except for a higher mortality rate in the first larval instar.Ecdysteroids from Ajuga reptans L. were applied to leaf fragments by immersion in aqueous solution of the compounds or by addition to the culture medium. A high mortality rate of first larval instars was detected with 29‐norsengosterone and ajugalactone treatments. This effect was specially pronounced when the products were incorporated in the medium. A significant increase in mortality was also recorded in the pupal state with a 20‐hydroxyecdysone treatment. This effect was never observed before, because all whitefly larvae on A. reptans leaves die in the first larval instar.
Metabolism and elimination of ingested allelochemicals in a holometabolous and a hemimetabolous insect
Authors: Smirle M. J. , Isman M. B. 
Published: April 2011

AbstractExperiments were conducted to test the hypothesis that hemimetabolous insects such as Orthoptera utilize physical barriers in the gut to provide protection from ingested toxins, whereas holometabolous Lepidoptera metabolize such toxins more efficiently. Migratory grasshoppers, Melanoplus sanguinipes Fab. (Acrididae), eliminated the thiophene α‐terthienyl in their feces more quickly and metabolized it to a lesser degree than did variegated cutworms, Peridroma saucia Hübner (Noctuidae). Xanthotoxin, a phototoxic linear furanocoumarin, and digitoxin, a cardiac glycoside, underwent similar metabolic modification in both species. Rates of fecal elimination of xanthotoxin were similar, whereas digitoxin was voided more rapidly by P. saucia. Overall, our results fail to provide convincing evidence in support of the test hypothesis because the two species investigated do not differ markedly in the manner in which they metabolize and eliminate the allelochemicals utilized in these studies.
The protective role of dietary unsaturated fatty acids against 2‐undecanone‐induced pupal mortality and deformity in Helicoverpa zea
Authors: Farrar R. R. , Kennedy G. G. , Roe R. M. 
Published: April 2011

AbstractAs previously reported, the addition of 2‐undecanone to the diet of Helicoverpa (Heliothis) zea (Boddie) causes pupal mortality and deformity. These toxic effects are antagonised by the addition of the unsaturated fatty acid linolenic acid to diet, with pupal deformity eliminated and mortality reduced by as much as one‐half. Similar results were obtained with two other unsaturated fatty acids, linoleic and oleic acids, but not with saturated stearic acid. These unsaturated fatty acids also increased pupal weight and developmental time. However, measurement of food consumption indicated that the effect of unsaturated fatty acids on pupal mortality is not an artifact of dilution of the fatty acid dietary dosage by an increased body size or of evaporation of 2‐undecanone during prolonged larval development.
Interactions among three trophic levels: the influence of host plant on performance of Pieris brassicae and its parasitoid, Cotesia glomerata
Authors: Karowe D. N. , Schoonhoven L. M. 
Published: April 2011

AbstractThe relative suitability of four host plants was determined both for unparasitized Pieris brassicae L. caterpillars and for Cotesia glomerata (L.) developing in P. brassicae. For unparasitized P. brassicae, growth rate and pupal weight were highest on Brussels sprouts and Swedish turnip, intermediate on rape, and lowest on nasturtium. In contrast, C. glomerata larval developmental rate and adult longevity were greatest for wasps from P. brassicae reared on nasturtium.On all four plants, the host‐parasitoid complex attained a lower final weight than unparasitized P. brassicae, and it is argued that this difference is due primarily to reduced consumption by parasitized P. brassicae. Among parasitized caterpillars, however, complex weight was positively correlated with clutch size, suggesting that C. glomerata larvae are able to partially counteract the effect of parasitization per se on host consumption.The host plants of P. brassicae appear to face an evolutionary dilemma: in order to increase the total mass of parasitoids produced, they must suffer greater loss of foliage. This trade‐off, if common in nature, may represent a formidable constraint on coevolution between host plants and parasitoids.