bluuebunny/crossref_metadata_2025 huggingface dataset:
Foraging behavior of Campoletis sonorensis in response to Heliothis virescens and cotton plants
Authors: Baehrecke E. H. , Vinson S. B. , Williams H. J.
Published: April 2011

Wind tunnel flight behavior of inexperienced female Campoletis sonorensis (Cameron) (Hymenoptera; Ichneumonidae) in response to its larval host Heliothis virescens (F.) (Lepidoptera: Noctuidae) feeding on the host plant cotton (Gossypium hirsutum L.) is described. The flight behavioral sequence was determined by quantification of frequencies of observed behaviors and probabilities of first‐order behavioral transitions. Comparison of inexperienced C. sonorensis flights to undamaged and damaged cotton indicated that stimuli from undamaged plants alone are adequate to elicit the complete flight behavioral sequence observed in response to H. virescens feeding on cotton.

Parasitoid foraging behavior was also analyzed after landing on the stimulus. This behavior appeared to be random in its initial stages, but became sequential after location of evidence of a host. Analysis of foraging on undamaged and 3 treatments of damaged cotton resulted in the determination that parasitoids tend to remain on damaged plants longer than undamaged plants although no significant difference was detected. C. sonorensis spent a greater percentage of their time foraging on host damaged plants than on undamaged plants.

Influence de la présence d'Heliothis virescens et de pieds de colon sur le comportement de prospection de C. sonorensis

Les comportements d'évaluation de l'effectif d'hôtes potentiels et de la position des hôtes par C. sonorensis (Hyméno.: Ichneumonidae) ont été quantifiés pour déterminer les séquences significatives des événements comportementaux. La localisation de la colonie potentielle d'hôtes est apparue comme une séquence régulière des événements comportementaux. Une fois que le parasitoïde a localisé une colonie potentielle, on a constaté que la recherche au hasard des hôtes se poursuit jusqu'à ce qu'il ait la démonstration qu'il s'agit d'une plante attaquée. La localisation par le parasitoïde d'un hôte certain a constitué une autre séquence régulière des événements comportementaux terminant la localisation de l'hôte.

L'influence de pieds de colon intacts, de pieds abîmés mécaniquement et de pieds occupés par des chenilles du 3ème stade de l'hôte et de plantes dont les chenilles ont été retirées juste avant l'expérience a été déterminée en modifiant la composition du complexe hôte/plante. Des femelles naïves de C. sonorensis ont montré en présence de pieds de coton intacts apparemment toutes les séquences comportementales de vol impliquées dans la localisation d'une colonie potentielle d'hôtes. Une fois que le parasitoïde a atteint la colonie potentielle d'hôtes, la présence de dégâts de l'hôte n'a pas modifié le temps passé sur la plante, mais a modifié le temps consacré à la prospection.
Pteridine compounds in adults of the pink‐spotted bollworm, Pectinophora scutigera
Authors: Noble R. M. , Walker P. W.
Published: April 2011

The amounts of four pteridine compounds, xanthopterin, isoxanthopterin, 6‐biopterin and pterin and a further unidentified substance, termed ‘modified xanthopterin’, were determined in the heads of adult Pectinophora scutigera (Holdaway) (Lepidoptera: Gelechiidae), aged between 2 and 50 days and reared in the laboratory at 25 °C. The level of isoxanthopterin was also determined in the thoraces and abdomens of moths aged between 2 and 40 days. The levels of xanthopterin, and ‘modified xanthopterin’ decreased markedly in the heads of males and females with increasing moth age, while those of pterin decreased more slowly and 6‐biopterin remained largely unchanged. Isoxanthopterin decreased in male heads from 38.3 ng/head at 2 days to 22.7 ng/head at 50 days, but in females levels increased from 41.2 ng/head at 2 days to 150.4 ng/head at 50 days. Similar changes in the amounts of isoxanthopterin with increasing moth age were observed in male and female thoraces and abdomens. The results are discussed in relation to using pteridine compounds for estimating the physiological age of P. scutigera.

Composés ptéridiniques des Pectinophora scutigera adultes

En chromatographic liquide à haute performance (HPLC) à détection par fluorescence, 4 composés ptéridiniques: la xanthoptérine, l'isoxanthoptérine, la 6‐bioptérine et la ptérine ont été décelés dans les têtes de P. scutigera Holdaway (Lep. Gelechiidae) adultes. Un autre composé, dénommé ‘xanthoptérine modifiée’, a été décelé aussi dans les têtes de papillons; de même l'isoxanthoptérine a été décelée dans les thorax et abdomens.

Les concentrations de ces ptérines ont été dosées dans les têtes des papillons de 2 à 50 jours au laboratoire à 25 °C. Les concentrations d'isoxanthoptérine ont été dosées dans les thorax et les abdomens de 2 à 40 jours. La xanthoptérine de la ‘xanthoptérine modifiée’ diminuent nettement avec l'âge, tandis que la ptérine diminue plus lentement et que la 6‐bioptérine se maintient pratiquement sans changements. L'isoxanthoptérine diminue dans les têtes de mâles de 38,3 ng/tête à 2 j à 22,7 ng/tête à 50 j, mais chez les femelles les concentrations augmentent nettement de 41,2 ng/tête à 2 j à 150,4 ng/tête à 50 j. Des modifications de même type ont été observées dans les thorax et les abdomens des mâles et des femelles.

Les modifications de concentration de la ‘xanthoptérine modifiée’ des têtes de papillons peuvent être utilisées pour évaluer l'âge physiologique de mâles et des femelles de P. scutigera. La confiance dans ces estimations peut être améliorée en se référant aux concentrations d'isoxanthoptérine dans les thorax des mâles et au rapport isoxanthoptérine/'xanthoptérine modifiée' dans les têtes de femelles.
Studies on the horizontal migration of dipterous stem borers (Oscinella spp.) in direct drilled Italian ryegrass
Authors: Bentley B.R. , Clements R.O.
Published: April 2011

The distance stem boring dipterous larvae e.g. Oscinella frit L. migrate in direct drilled Italian ryegrass (Lolium multiflorum) was investigated. First, adjacent contrasting swards of Italian ryegrass or Cocksfoot (Dactylis glomerata) were grown which were, respectively, expected to be either infected with large populations of larvae or likely to be free of larvae. Sampling revealed that these expectations were realised. Swards were then desiccated by herbicide, and subsequently direct drilled with Italian ryegrass. Over 50% of the larvae in original, infested part of the sward migrated to infest tillers of the newly sown ares. The distance larvae migrated was gauged by assessing how far they were found from the perimeter of a previously uninfested area which had been reseeded. Most larvae migrated 20 cm or less, but a small proportion appeared to migrate several metres, apparently passing many suitable host tillers as they did so.

Etude de la migration horizontale de larves d'Oscinella spp. directement vers des sillons de ryegrass (Lolium multiflorum)

La distance parcourue par des larves d'O. frit directement vers des sillons de ryegrass italien (L. multiflorum) a été examinée. Dans un premier temps, de 2 pelouses adjacentes de ryegrass italien et de Dactylis glomerata ont été cultivées avec l'espoir que la première serait contaminée par des populations abondantes de larves et la seconde indemne. L'échantillonnage a montré que ces espoirs étaient justifiés. Les pelouses ont alors été brulées avec de l'herbicide et ensuite directement ensemencées avec du ryegrass en sillons. Plus de 50% des larves de la pelouse originellement contaminée ont migré pour infester les zones nouvellement semées. La distance de la migration a été évaluée d'après l'éloignement du périmètre de la zone primitivement non contaminée. La plupart des larves avaient parcouru au maximum 20 cm, mais quelques unes paraissaient avoir par couru plusieurs mètres, passant vraisemblablement devant des souches d'hôtes plus convenables.
Ovarian development rates in the Old World screw‐worm fly, Chrysomya bezziana
Authors: Spradbery J. P. , Vogt W. G. , Sands D. P. A. , Drewett N.
Published: April 2011

Rates of ovarian development in relation to temperature were determined for autogenous females of the screw‐worm fly, Chrysomya bezziana. Percentage durations of the different ovarian stages (scaled 2–10) were estimated on the basis of observed lengths of the developing oocytes. Mean durations (h) of each ovarian stage was determined at 20, 25, 28 and 35 °C. A model of ovarian development rate (%/d) in relation to temperature (T) is presented, the fitted curve being give by R(T) = EXP (–2.73 + 0.362T – 0.0055T2).
Aspects of life‐table studies and functional response of Lysiphlebia mirzai
Authors: Tripathi R. N. , Singh R.
Published: April 2011

The fecundity, reproductive rate, and survival of Lysiphlebia mirzai parasitising third instar nymphs of the cereal aphid Rhopalosiphum maidis were measured at six different host densities under constant laboratory conditions. The survival rate (lx) of the female parasitoids was unaffected by host density, with an average adult life‐span of 5–6 days at all densities. The age‐specific fecundity rate (mx) was host density‐dependent. The value of mx decreased rapidly from the first day of parasitisation. The number of hosts available determined the maximum possible number of mummies. At 200 hosts available per day, the average fecundity was 184.6 mummies/female; the maximum number of mummies yielded by any female was 200. The relationship between host density and the number of aphids parasitised per female was linear at ≤50 aphids/cage/day, but at higher host densities (≥100 aphids/cage/day) a significant curvilinear regression was observed. The intrinsic rate of natural increase (rm) increased with increasing host density. Maximum value of rm (0.262) was obtained at a host density of 200. The response of rm to changes in host density and parasitoid sex ratio is shown. A typical type II functional response was observed for L. mirzai. The curve was described by a logistic curve, Np = 200/[1 + exp(5.65 − 1.60 ln No)]. The search rate of the parasitoid was inverse host density‐dependent. No significant variation in the sex ratio of F1 offspring was observed at different initial host densities. Sex ratio values exceeded 0.5 at all host densities. The results evaluated the reproductive potential of L. mirzai as a promising biological control agent.
Detoxification spectrum of the cigarette beetle symbiont Symbiotaphrina kochii in culture
Authors: Shen S. K. , Dowd P. F.
Published: April 2011

The ability of cultures of the cigarette beetle symbiont, Symbiotaphrina kochii Jurzitza ex. W. Gams and v. Arx, to utilize toxins as carbon sources and produce detoxifying enzymes was tested. This yeast could apparently use many of the plant allelochemicals, meal toxins, mycotoxins, insecticides, and herbicides tested as carbon sources, suggesting the ability to detoxify these compounds. Detoxifying enzymes that were detected using representative substrates included aromatic ester hydrolase, glucosidase, phosphatase, and glutathione transferase. This yeast was also able to hydrolyze the organophosphorus insecticide parathion. Thus, this yeast appears to have broad‐spectrum detoxifying capabilities. Either this strain of yeast, improved strains, or other microorganisms to which genetic material from this yeast has been transferred may be of use in decontaminating materials containing multiple toxins.
Nutritional performance of first and penultimate‐final Instar bagworm larvae on two unrelated hosts as influenced by host of origin
Authors: Ward K. E. , Ramaswamy S. B. , Nebeker T. E.
Published: April 2011

Nutritional performance of early and late instar bagworm (Thyridopteryx ephemeraeformis Haworth) larvae was investigated as a function of host of origin and host type, using two taxonomically distant wild hosts, Salix nigra (Marshall) and Juniperus virginiana (L.). First instar growth and survival were higher on S. nigra; overall performance was similar on the two hosts in penultimate‐final instars. There was no evidence for host associated differentiation with respect to nutritional performance. There were, however, significant genotype & environment interactions for several characters studied, suggesting that the potential for host associated differentiation exists.
Selection for pesticide resistance in Aphytis
Authors: Havron A. , Rosen D. , Prag H. , Rössler Y.
Published: April 2011

Field‐collected populations of Aphytis holoxanthus DeBach (Hymenoptera: Aphelinidae), a parasite of Chrysomphalus aonidum (L.) (Homoptera: Diaspididae), were tested for malathion and for azinphosmethyl tolerance, and selected for increased resistance. Initial tolerance for malathion was not significantly different between populations, and could not be significantly increased by 30 selection cycles. Two field populations showed relatively high levels of azinphosmethyl tolerance, which were further increased by selection to 24–48 times that of a susceptible laboratory population.

The differences in response to the two organophosphorus insecticides are discussed in relation to differences in their modes of application, detoxification by insects and the genetic bottleneck experienced by an imported species.
Duration of diapause in the stem borers, Busseola fusca and Chilo partellus
Authors: Kfir Rami
Published: April 2011

The duration of diapause in the stem borers Busseola fusca (Fuller) and Chilo partellus (Swinhoe) was studied in South Africa by collecting diapausing larvae from the field throughout winter (April–August). B. fusca larvae emerged as moth around the middle of October regardless of the date of collection and the length of time they were kept in the laboratory under constant 21 °C. C. partellus larvae collected in April‐June emerged in November, those collected in July emerged in October, and those collected in August emerged in September. Regardless of the collection date C. partellus started to emerge from diapause earlier and moth emergence lasted up to twice as long as in B. fusca. Under laboratory conditions at 60% RH both borer larvae lost about 50% of their body mass during diapause. When provided with water B. fusca larvae lost about 30% of their body mass and adults emerged 20 days earlier than when kept dry. C. partellus, on the other hand, lost only 13% of their body weight and emerged 34 days earlier. The differences between the two species are discussed in light of different types of diapause; i.e., obligatory diapause in B. fusca and facultative diapause in C. partellus.
Potential of Margosan‐O, an azadirachtin‐containing formulation from neem seed extract, as a control agent for spruce budworm, Choristoneura fumiferana
Authors: Thomas A. W. , Strunz G. M. , Chan T. H. , Chiasson M.
Published: April 2011

The effects on spruce budworm larvae, Choristoneura fumiferana (Clem.), produced by ingestion of Margosan‐O, a commercially available neem seed extract formulation containing 0.3% azadirachtin, were investigated. Bioassays with the test material were conducted using various instars of spruce budworm larvae, with either artificial diet, cut branches of balsam fir, Abies balsamea (L.) Mill., or small growing balsam fir trees as substrates. The dose‐response data on feeding reduction, developmental retardation, and mortality (LC50, LC95, and LD50) suggest that Margosan‐O has promise as a control agent for spruce budworm in an integrated pest management program.
Consumption of sugars, hemicellulose, starch, pectin and cellulose by the grasshopper Aracris flavolineata
Authors: Ferreira C. , Marana S. R. , Terra W. R.
Published: April 2011

Adults (0.61 g, fresh‐weight) of Abracris flavolineata De Geer (Orthoptera: Acrididae) feeding on Brassica oleracea acephala leaves ingest 21 mg dry‐weight/day with an approximate digestibility of 42%. Chemical determinations performed on the leaves ingested and on the feces expelled led to the determination of the approximate digestibilities (%) of the major carbohydrates of leaves as follows: soluble carbohydrates, 91; pectin, 32.1; hemicellulose, 0; starch, 66; cellulose, 15. The results are not sufficient to disregard the possibility that digestible hemicellulose polymers contaminate the pectin and the cellulose fraction. Thus, it is possible that the digestibility of hemicellulose is different from zero, and that the digestibility of pectin and cellulose are somewhat lower than reported. The data are used to propose physiological roles of the enzyme activities previously found in the A. flavolineata midgut.
Azadirachtin inhibits secretion of trypsin in midgut of Manduca sexta caterpillars: reduced growth due to impaired protein digestion
Authors: Timmins W. A. , Reynolds S. E.
Published: April 2011

When given by injection to tobacco hornworm caterpillars, Manduca sexta, the allelochemical azadirachtin inhibits growth without reducing food intake. The growth reducing effect of azadirachtin is therefore in this case independent of the compound's well‐known antifeedant effect. The cause of this reduced rate of growth is an increase in the costs associated with growth. These increased costs are largely a consequence of a decrease in the efficiency of utilisation of dietary nitrogen. This is associated with a drastic reduction in the activity of midgut trypsin. Azadirachtin has no effect on the activity of trypsin in vitro. Thus azadirachtin directly or indirectly inhibits the production of trypsin by the enzyme‐secreting cells of the midgut wall; it is suggested that this is the cause of the increased costs and reduced rate of growth. The interesting parallel between this plant defence strategy and that of direct inhibition of herbivore proteinases by allelochemical proteinase inhibitors is discussed.
Dung burial activity and development of ivermectin exposed Diastellopalpus quinquedens in a field experiment
Authors: Sommer C. , Grønvold J. , Holter P. , Madsen M. , Nansen P.
Published: April 2011

The amount of cattle dung buried in the field by afrotropical dung beetles, mainly Diastellopalpus quinquedens Bates, was not affected by previous subcutaneous injection of the cattle with 0.2 mg kg − 1ivermectin. The numbers of D. quinquedens larvae developing in brood masses, however, were reduced; only 28% of the brood masses made of dung voided two days after treatment of the cattle contained live larvae. When the brood masses were made of dung excreted 8 and 16 days after treatment 90 and 94%, respectively, contained live larvae.
Induction of adult diapause and of low and high reproductive states in a parasitoid wasp, Ooencyrtus nezarae, by photoperiod and temperature
Authors: Numata H.
Published: April 2011

Ooencyrtus nezarae Ishii (Hymenoptera: Encyrtidae) was reared on eggs of Riptortus clavatus (Thunberg) (Heteroptera: Alydidae) at various temperatures under long‐day (L16:D8) or short‐day (L10:D14) conditions. There was no diapause during egg, larval or pupal stages under any set of conditions examined. However, at 15 °C under short‐day conditions, vitellogenesis was arrested in all adult females and they entered diapause. At 15 °C under long‐day conditions, or at 20 °C under short‐day conditions, some adult females entered diapause. Under the latter set of conditions, the adult females laid eggs but they laid fewer eggs than under long‐day conditions. Even at 25 °C, under short‐day conditions, adult females laid fewer eggs than under long‐day conditions, and this low rate of oviposition was attributed to the retarded development of ovaries. Diapause adults reared at 15 °C were more resistant to low temperature than nondiapause adults reared at 25 °C.
Interactions between a specialist herbivore, Crocidosema plebejana, and its host plants Malva parviflora and cotton, Gossypium hirsutum: Oviposition preference
Authors: Hamilton J.G. , Zalucki M.P.
Published: April 2011

Ovipositional responses of gravid female Crocidosema plebejana Zeller (Lepidoptera: Tortricidae) to all stages of development of its host plants Malva parviflora L. and cotton, Gossypium hirsutum L., were studied in no‐choice and choice experiments. In no‐choice experiments the site of oviposition and the number of eggs laid reflected the suitability of the host plant for larval survival and development. The same was true of choice experiments although conclusions drawn from these are more tentative due to high levels of heterogeneity. Results from a natural (unplanned) choice experiment in the field, suggested flowering cotton was rejected as a site for oviposition by gravid females. Results from this paper and a previous paper by the authors are combined to explain the failure of tipworm populations to persist on cotton crops after flowering.
Role of sex pheromone components in the orientation behaviour of Ephestia cautella
Authors: Quartey G. K. , Coaker T. H.
Published: April 2011

The orientation behaviour of male tropical warehouse moths, Ephestia cautella (Walker) (Lepidoptera: Phycitidae) was observed in a flight tunnel in response to synthetic pheromone components. A blend of 2:1 (Z, E)9, 12–14: Ac (ZETA) and (Z)9–14:Ac (ZTA) equivalent to that released by virgin female moths caused more moths to fly upwind, alight at the lure and display hairpencils than ZETA alone. No response was obtained from the minor component ZTA alone, but the addition of (Z, E)9, 12–14:OH (ZETOH) to a ZETA + ZTA blend inhibited upwind flight by male moths. Analysis of the flight tracks of male moths in ZETA + ZTA and ZETA plumes showed that the moths flew faster and straighter towards the ZETA + ZTA source by decreasing the track reversal distance and track angle. The numbers of moths caught on sticky traps with ZETA were increased by the addition of ZTA.
Sex pheromone components of Heliothis maritima: chemical identification, flight tunnel and field tests
Authors: Szõcs G. , Raina A. , Tóth M. , Leonhardt B. A.
Published: April 2011

Three sex pheromonal components, (Z)‐11‐hexadecenal (Z11–16: Ald), (Z)‐11‐hexadecenol (Z11–16:OH), and hexadecanal (16:Ald), in a ratio of 88.0:7.2:4.8, were identified from ovipositor extracts of the fulvous clover moth, Heliothis maritima Grasl. (Lepidoptera: Noctuidae) by gas chromatography‐mass spectrometry. In addition, trace amounts of (Z)‐9‐hexadecenal (Z9–16: Ald) were detected in the extracts by GC. A blend of Z11–16: Ald, Z11–16:OH and 16:Ald in a ratio of 100:6:3, as well as in combination with 0.1 or 1 part Z9–16: Ald was tested at 0.01, 0.1, 1.0 and 10.0 μg doses in a flight tunnel. In flight tunnel tests male behavioral responses elicited by 0.1 or 1.0 μg doses of the 100:6:3:1 blend were similar to those elicited by an ovipositor extract at 2 female equivalents. Deletion of Z9–16: Ald from the blend at 0.1 μg dose caused a decrease in the male response. In the field test, however, presence or absence of Z9–16: Ald did not significantly influence the number of males trapped in sticky traps with rubber septa containing 100 μg of the respective blends.
13C and 31P NMR spectroscopic studies on glucose metabolism in Tribolium confusum
Authors: Nishina M. , Matsushita K. , Hori E. , Takahashi M. , Kato K.
Published: April 2011

Nuclear magnetic resonance (NMR) technology was applied to study the glucose metabolism in Tribolium confusum (Coleoptera). 13C signals of D‐(1‐13C)glucose eaten by beetles were clearly detected in such metabolites of the glucose metabolism as glycogen, trehalose, triacylglycerol, alanine and proline by 13C‐NMR. After glucose feeding the 31P‐NMR spectra of T. confusum showed the signal intensity increases in arginine‐phosphate, sugar‐phosphate and uridine diphosphoglucose. The results demonstrated the potential of NMR analysis for the study of glucose metabolism in T. confusum.
Influence of larval food consumption on the fecundity of the lacewing Chrysoperla carnea
Authors: Zheng Y. , Daane K. M. , Hagen K. S. , Mittler T. E.
Published: April 2011

The effects of food consumption on larval growth and development and adult fecundity of the common green lacewing, Chrysoperla carnea (Stephens), were studied on two populations of larvae derived from either a laboratory colony or from field‐collected adults. The number of eggs of the Mediterranean flour moth, Anagasta kuehniella (Zeller), provided to individual lacewing larvae was varied to produce three food‐supply treatments: low, intermediate, and high. Food‐supply was found to influence larval growth and development and adult fecundity. Lacewing larvae provided with an overabundance of moth eggs developed faster than larvae provided with fewer moth eggs than they could have consumed. Adult females that developed from the high feeding treatment had a substantially shorter preoviposition period, a later decline in egg deposition, and a significantly higher fecundity than adults arising from the other feeding classes. Unrestricted feeding by adult lacewings on an artificial diet did not compensate for prior low feeding regimes. The overall performance of the lacewings derived from the laboratory colony was substantially poorer than that of the lacewings derived from field‐collected adults. This effect was accentuated when the larvae were given a low food‐supply. This overall decrease in vigor is attributed to inbreeding of the laboratory culture over a one year period. These finds are relevant to mass rearing programs for this biological control agent.
Biological factors affecting leafhopper transmission of purified maize chlorotic dwarf machlovirus
Authors: Creamer R. , Nault L. R. , Gingery R. E.
Published: April 2011

A helper component from maize chlorotic dwarf machlovirus (MCDV)‐infected plants was necessary for insect transmission of purified MCDV. Purified MCDV, WS strain, when acquired by membrane feeding, was transmitted by Graminella nigrifrons (Forbes) (Homoptera:Cicadellidae) which fed first on MCDV (M1 strain)‐infected maize. Conversely, feeding on MCDV‐WS‐infected maize allowed transmission of purified MCDV‐M1, indicating that the helper component was not strain specific. Viruliferous G. nigrifrons lost the ability to transmit MCDV‐M1 after feeding for 24 h on healthy maize, but retained the ability to acquire and transmit purified MCDV‐WS for up to 36 h. When G. nigrifrons fed initially on MCDV‐infected plants and then on a second strain of purified MCDV, the second strain of MCDV could be transmitted alone, suggesting that the helper component from MCDV‐infected plants was something other than the virion itself. Lengthening acquisition feeding of G. nigrifrons on MCDV‐M1‐infected maize or purified MCDV‐WS did not significantly change the transmission frequency of MCDV‐WS. Amblysellus grex (Oman), an experimental vector of MCDV, also transmitted purified MCDV‐WS after an initial acquisition feeding on MCDV‐M1‐infected maize. This suggests that the helper component is not vector species specific.
Production of Nosema marucae for biological control of cereal stem borers
Authors: Odindo M. O. , Amutalla P. A. , Opondo‐Mbai M. , Odero T. Anyango
Published: April 2011

In a study covering 3 years, experiments were carried out in order to determine the feasibility of producing a microsporidian pathogen Nosema marucae in the spotted stalkborer Chilo partellus. A maximum yield of 4.9 times 108 spores/larva (equivalent to 3.1 times 1010 spores/g fresh larval body weight) was obtained in 3rd instar larvae. It is considered that the production is inexpensive and can be readily adapted for small scale pathogen propagation systems in the tropics.
Age‐dependent physiological responses of last instar Helicoverpa zea larvae to oral and topical application of precocene II
Authors: Binder B. F. , Bowers W. S.
Published: April 2011

Newly‐ecdysed last instar larvae of H. zea grouped into 100‐, 200‐, 300‐, or 400‐mg categories were fed diet containing precocene II or given precocene II topically on the abdomen. The time for larvae to reach a maximal weight, time to pupation, growth rate, and the amount of precocene II excreted were calculated. Younger larvae of lower weights, which were fed or topically treated with precocene II required more time to reach their maximal weight, had a lower maximal weight, a lower growth rate, and required more time to pupate than control larvae. Older larvae represented by the largest weight category were less sensitive to precocene II, had a shorter delay in reaching maximal weight, and a shorter delay in the time to pupation than control larvae; larvae in the largest weight category that were fed precocene II also had smaller decreases in the growth rate. Growth rate declines for larvae given topical doses of precocene II, however, were largest for the oldest larvae. All larvae given a single topical dose excreted precocene II for several days and were most efficient at eliminating smaller doses; larger, older larvae excreted more precocene II than smaller, younger larvae. Age‐dependent responses to precocene II indicate that growth and metabolic processes, as well as xenobiotic metabolism, change in last instar larvae.
Overwintering survival and spring emergence in Meligethes aeneus: effects of body weight, crowding, and soil treatment with Beauveria bassiana
Authors: Hokkanen H. M. T.
Published: April 2011

High overwintering mortality was recorded for Meligethes aeneus in the field in Finland, ranging from 85 to 98% depending on the source of the overwintering population. The main factor explaining variation in survival was the body weight of the beetles in the autumn: only the heaviest beetles survived. Body weight, on the other hand, was influenced by treatment of the rape field soil with Beauveria bassiana, resulting in a 50% decrease in winter survival compared with the reference. The soil treatment did not appear to have direct mortality effects (pathogenesis) on the beetle neither in the summer nor in the winter, and there was no apparent effect on survival of crowding of the insects at the overwintering site. Density dependence in overwintering survival of M. aeneus may function through the availability of pollen food in the autumn, and intraspecific competition for it. Treatment of the rape field soil with B. bassiana may be a feasible way to increase the winter mortality and to lower the pollen beetle populations, but requires further research.
Oviposition behaviour of Drosophila subobscura and its parasitoid Asobara tabida in the laboratory
Authors: Prophetou‐Athanasiadou D. , Hodgson P. J. , Kouloussis N. , Jones T. H.
Published: April 2011

At 18 °C, adult Asobara tabida emerge 21 days after oviposition within the host; Drosophila subobscura emerges 18 days after oviposition. The relatively short pre‐oviposition period of adult A. tabida (4 days), compared to that of D. subobscura (4–8 days) results in the generation times of both host and parasitoid being approximately similar. A yeast source is necessary for D. subobscura females to mature their eggs; female flies will not oviposit on patches without a yeast source. While surface roughness is an important characteristic for maximum D. subobscura oviposition, A. tabida oviposition, and consequent levels of parasitism, is enhanced by coating patches with a skin of active yeast. When presented with a multi‐patch environment, experienced and inexperienced female wasps showed no significant difference in their level of attack.
Analyse comportementale des interactions entre la fourmi Tapinoma simrothi et le puceron Toxoptera aurantii
Authors: Dartigues D.
Published: April 2011

Cette note constitue une approche comportementale de la relation entre Tapinoma simrothi Krausse. et Toxoptera aurantii (Boyer de F.). Les fourmis sont plus attirées par les jeunes larves groupées et les aphides aptères. Ce phénomène est analogue quel que soit le degré de familiarisation des aphides aux fourmis ou l'âge des ouvrières. Les fourmis sollicitent plus longtemps les aphides non familiarisés (ceux qui déféquent le moins). Les jeunes ouvrières sont moins actives que les ouvrières pourvoyeuses âgées. Ces résultats sont associés dans notre discussion avec ceux préalablement obtenus, dans les mêmes conditions expérimentales, concernant l'excrétion des aphides. Même si la liaison dans le temps entre ces deux espèces paraît assez faible, la stratégie mise en oeuvre par les fourmis dans la récolte du miellat semble cohérente au regard de la biologie de ces insectes.

Behavioural analysis of the interactions between the ant Tapinoma simrothi and the aphid Toxoptera aurantii

This note constitutes a behavioural approach to the relationship between Tapinoma simrothi Krausse and Toxoptera aurantii (Boyer de F.). The ants are more attracted by groups of young larvae and apterous aphids. This phenomenon is analogous whatever the degree of familiarization of aphids with ants or the age of antworkers. The ants sollicit longer the unfamiliarized aphids (those which defecate least). Young antworkers are less effective than old foraging antworkers. These results are connected in our discussion with those obtained beforehand, under similar experimental conditions, concerning aphid excretion. Although the connection in time between these two species appears rather weak, the strategy brought into play by the ants in the gathering of honeydew seems coherent with the biology of these insects.
Effects of the cytolytic seed protein enterolobin on coleopteran and lepidopteran insect larvae
Authors: Sousa M. V. , Morhy L. , Richardson M. , Hilder V. A. , Gatehouse A. M. R.
Published: April 2011

Enterolobin, a novel 55 KDa cytolytic and inflammatory protein from Enterolobium contortisiliquum seeds, was tested for its toxic effects on larvae of the coleopteran Callosobruchus maculatus and the lepidopteran Spodoptera littoralis. Bioassays performed with enterolobin incorporated into artificial seeds showed that the phytocytolysin was toxic to larvae of C. maculatus, causing 70% mortality at a concentration of 0.01% (w/w) and 100% mortality at 0.025%. The protein proved to be innocuous to larvae of S. littoralis. In vitro proteolysis studies using larval gut enzymes, analysed on SDS‐PAGE, showed that only S. littoralis proteases could digest enterolobin, suggesting that the insect's digestive proteases were able to inactivate the cytolysin before it could exert any toxic effect; C. maculatus proteases, on the other hand, were unable to hydrolyse enterolobin. The mechanism of toxicity of enterolobin did not appear to involve any damage to the microvilli of the epithelial gut cells of C. maculatus as shown by electron microscopy. Some tentative hypotheses are considered in order to explain the toxic mechanism of action of enterolobin towards C. maculatus.
Evolution de la diapause du psylle du poirier Cacopsylla pyri dans les conditions naturelles
Authors: Lyoussoufi A. , Gadenne C. , Rieux R. , D'arcier F. Faivre
Published: April 2011

Dans la région d'Avignon, la forme hivernale de Cacopsylla pyri (L.) apparaît dans la nature au cours de la lère décade de septembre. Ses émergences se poursuivent jusqu'en janvier et même au‐delà. Le sex‐ratio de la population, d'abord élevé, reste voisin de 1 puis décroît à la mi‐janvier avec la mortalité plus précoce des mâles. Les femelles traversent une longue période d'immaturité au cours de laquelle leurs ovaires se développent lentement. La diapause ne semble pas rallonger préférentiellement un stade ovarien et son achèvement n'apparaît pas non plus s'effectuer à un stade plutôt qu'à un autre. L'accouplement n'est pas assujetti à l'achèvement de la diapause des femelles d'hiver. Ces dernières ne s'accouplent cependant pas avec les mâles d'été encore présents en automne.

Diapause development of the pear psylla, Caco‐psylla pyri (L.) under natural conditions

In the Avignon area, the winter‐form of the pear psylla, Cacopsylla pyri (L.), appears during the first 10 days of September. Adults continue to emerge throughout the winter until January and even later. The sex‐ratio is at first high, stabilizes at about 1 and then decreases in mid‐January with the precocious mortality of males. Throughout winter, immature ovaries of winter‐form females undergo a slow but constant development. Diapause does not prolong any particular ovarian stage and its completion seems to occur at any stage. The mating process is not strictly linked with the completion of diapause of winter‐form females. However, the latter do not mate with males of the summer‐form which are still present in autumn.
Age‐dependent foraging behaviour and host‐instar preference of the aphid parasitoid Lysiphlebus cardui
Authors: Weisser Wolfgang W.
Published: April 2011

Foraging behaviour and host‐instar preference of young and old females of the solitary aphid parasitoid, Lysiphlebus cardui Marshall (Hymenoptera: Aphidiidae), were studied in the laboratory. The analysis of interactions between parasitoids and different stages of Aphis fabae cirsiiacanthoidis Scop. (Homoptera: Aphididae) revealed that encounter rates between aphids and parasitoid females and defence reactions of the aphids influenced the degree to which a particular aphid age class is parasitized. Encounter rates between hosts and parasitoid females depended on the foraging pattern of the parasitoid, which varied with age. In mixed aphid colonies patch residence time increased with parasitoid age. Furthermore, younger parasitoids (≤ 1 day old) laid more eggs into second and third instars, while older parasitoids (≥ 4 days old) did not show distinct host instar preferences. It is suggested that the oviposition behaviour of L. cardui is influenced by the physiological state, i.e. the age of the wasp.
Larval secretions and food odors affect orientation in female Plodia interpunctella
Authors: Phillips Thomas W. , Strand Michael R.
Published: April 2011

Substrates contaminated by wandering fifth instar larvae of Plodia interpunctella (Hübner)(Lepidoptera: Pyralidae) elicit oviposition by conspecific female moths, and larval rearing diet enhances oviposition and also induces upwind flight. Two‐choice oviposition assays determined that four‐day‐old gravid female P. interpunctella preferred to lay eggs on dishes containing cornmeal‐based rearing diet compared to empty dishes. Pieces of cheesecloth contaminated by fifth instar larvae elicited more oviposition than untreated cheesecloth or dishes with food. The combination of larval contamination and food was preferred over food only or larval contamination only in both two‐ and four‐choice experiments. The factor(s) in larval contamination responsible for eliciting oviposition in female moths was extracted in hexane, confirming that organic semiochemicals are responsible for the effect. The oviposition‐eliciting activity of larval contamination was retained on cheesecloth for up to 30 days following treatment with larvae, suggesting the active component(s) is stable and of low relative volatility. In two‐choice windtunnel bioassays female moths initiated flight only when rearing food was present in one of the treatments, and they displayed the highest landing responses to a combination of larval contamination and food. Earlier work on P. interpunctella and related pyralid species found that larval contamination due to secretions from the mandibular glands acted as both a spacing pheromone for wandering larvae and as a kairomone for host‐seeking parasitoid wasps. The present study suggests that the same or a similar secretion acts as an oviposition‐eliciting pheromone for conspecific females.
High variation in host adaptation among clones of the pea aphid, Acyrthosiphon pisum on peas, Pisum sativum
Authors: Sandström Jonas
Published: April 2011

The performance of one clone of the pea aphid, Acyrthosiphon pisum (Harris), was assessed on 37 different cultivars and species of Pisum L. In addition, random samples of 36 pea aphid clones collected on alfalfa and clover were tested on a selection of five Pisum sativum L. cultivars. Aphid performance was evaluated in terms of the mean relative growth rate (MRGR) during the first five days of life or other life history variables. The MRGR of the first‐mentioned pea aphid clone differed little between cultivars. No significant differences in MRGR were found between wild and cultivated Pisum species or between modern and old P. sativum cultivars. There was considerable variation in host adaptation among the 36 pea aphid clones within each sampled field. The pea aphid clones showed no consistent pattern in performance on four of the five pea cultivars i.e. there was a significant pea aphid genotype — pea genotype interaction. On one of the cultivars all clones performed well. Pea aphid clones collected from red clover generally performed relatively poorly on pea cultivars, in contrast to the pea aphid clones collected on alfalfa. There was no difference in performance between the two pea aphid colour forms tested. Possible reasons for the high variation and the observed adaptation patterns are discussed. The fact that all clones were collected in two adjacent fields indicates that A. pisum shows high local intraspecific variability in terms of host adaptation.
Identification of volatile compounds from fungus‐infected date fruit that stimulate upwind flight in female Ectomyelois ceratoniae
Authors: Cossé Allard A. , Endris Julia J. , Millar Jocelyn G. , Baker Thomas C.
Published: April 2011

Four volatile compounds emitted from fungus‐infected date fruit, Phoenix dactylifera L., were identified using coupled gas chromatographic‐electroantennographic recordings, coupled gas chromatographic‐mass spectrometric analysis, electroantennographic assays of synthetic standards, and wind tunnel bioassays. These compounds were ethyl hexanoate, ethanol, acetaldehyde, and 2‐phenylethanol. Wind tunnel bioassays showed that ethyl hexanoate was capable of stimulating upwind flight and landing on the source by mated female carob moths, Ectomyelois ceratoniae (Zeller). Addition of both ethanol and acetaldehyde to ethyl hexanoate resulted in an increase in attraction to a level similar to that found for date fruits. No such effect was noted for additions of 2‐phenylethanol at the dosages tested. In this study, it appears that ethyl hexanoate is a dominant olfactory stimulant and attractant for mated female carob moths, and represents a novel compound with regard to previously identified lepidopteran host odor attractants.
Two tachinid species discriminate between parasitized and non‐parasitized hosts
Authors: López Rolando , Ferro D. N. , Van Driesche R. G.
Published: April 2011

The abilities of Myiopharus doryphorae (Riley) and M. aberrans (Townsend) (Diptera: Tachinidae) to discriminate between parasitized and non‐parasitized Colorado potato beetle (host) Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae) larvae, were investigated under laboratory and field conditions. Laboratory experiments showed that both Myiopharus species have a significantly greater frequency for larvipositing in non‐parasitized hosts over parasitized ones. Direct field observations of larvipositional behavior of both Myiopharus species over three growing seasons showed effective restraint from larviposition into parasitized hosts, while larviposition into non‐parasitized ones occurred readily. Avoidance of previously‐parasitized hosts occurred after the larvipositing flies briefly landed on host larvae without attempting to insert the larvipositor.

The low levels of superparasitism which occurred in the caged experiments and in the field appeared to be due to a breakdown of the larvipositing parasitoids' restraint when they met only parasitized hosts or when many parasitoids competed for reduced numbers of hosts late in the season.
In vitro rearing of Exorista larvarum on tissue culture‐based diets
Authors: Bratti Alessandro , Coulibaly Amadou Konotié
Published: April 2011

Exorista (= Tachina) larvarum (L.) (Diptera, Tachinidae), a polyphagous parasitoid that attacks Lymantria dispar L. and Hyphantria cunea (Drury), was reared in vitro from egg to adult on four tissue culture media‐based diets (TMM‐FH, SCHNEIDER'S, EX‐CELL 400, and SF‐900). The kind of tissue culture media in the diets did not influence the adult yield (34 to 55%) and puparium weight (26–27 mg). Adult yield and the puparium weight of E. larvarum developed on TNM‐FH and SCHNEIDER'S‐based diets containing different amounts of Galleria mellonella pupal extract (PE) (0, 1.25, 2.5 and 5%), were lower on diets without PE. In diets without PE development times from oviposition to adult emergence, were shorter on TNM‐FH (19 days) than on SCHNEIDER'S‐based diet (25–26 days). The adults that developed on artificial diets were able to parasitize the factitious host G. mellonella and produce viable progeny. The results demonstrate that E. larvarum is the most promising parasitoid ever studied for in vitro mass production.
Local dispersal of male Helicoverpa zea
Authors: Culin Joseph D.
Published: April 2011

Local dispersal of Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) males as they emerged following the F1 and F2 generations in dent corn was examined in a 4 km diam. area in South Carolina, USA. Males were marked at artificial nectar feeding stations using RbCl, and recovered in traps baited with a synthetic pheromone. Effects of nocturnal boundary layer winds, crop pattern at the pheromone traps, and crop pattern between the marking area and pheromone traps were examined. Local movement of captured male moths was predominantly downwind in both flights in both years of the study. Crop pattern at the traps had no effect on capture of marked moths. During some flights, flowering crops between the marking area and traps had a negative effect on the number of marked moths captured.
Comparison of biological and demographic parameters for Mononychellus progresivus and Oligonychus gossypii on cassava: influence of temperature
Authors: Bonato O. , Baumgärtner J. , Gutierrez J.
Published: April 2011

The effect of five constant temperatures (16, 22, 26, 31 and 36 °C) on biological (survival and duration of developmental stages, fecundity and longevity of females, sex‐ratio) and demographic parameters (Ro, G, rm and Δ) of the two main phytophagous mites that attack cassava in Africa, Mononychellus progresivus Doreste and Oligonychus gossypii (Zacher), was studied in the laboratory. Experiments were performed simultaneously on the two mite species reared on the same cassava variety (1M20) under controlled conditions: 70 ± 10% r.h. and 12L:12D. The lower thermal threshold was 13 °C for M. progresivus and 11 °C for O. gossypii. Both species developed in the range from 22 to 36 °C. The shortest development time was obtained at 31 °C for both species; it was 7.2 days for M. progresivus and 8.2 days for O. gossypii. Maximum fecundity of both species was recorded at 26 °C with 42.1 eggs for M. progresivus and 36.3 eggs for O. gossypii The highest intrinsic rate of increase (rm) was obtained at 31 °C for both species with 0.289 and 0.214 for M. progresivus and O. gossypii, respectively.
A sex pheromone component novel to the Geometridae identified from Epirrita autumnata
Authors: Zhu J. W. , Löfstedt C. , Philipp P. , Francke W. , Tammaru T. , Haukioja E.
Published: April 2011

(Z,Z,Z)‐1, 3, 6, 9‐Heneicosatetraene was identified as a sex pheromone component of Epirrita autumnata (Borkhausen), (Lepidoptera: Geometridae). Gas chromatography coupled with electroantennographic detection revealed one active peak‐from female pheromone gland extracts. The chemical identification of the compound was based on gas chromatography‐mass spectrometry, chemical micro‐reactions and unambiguous synthesis. In a field test, a rubber septum loaded with 3000 μg of this compound showed highest attraction of male E. autumnata moths compared to lower doses and the control. The attraction of males to a 300 μg bait was equivalent to that obtained using live virgin females.