bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanisms of resistance in sorghum to head bug, Calocoris angustatus
Authors: Sharma H.C. , Lopez V.F. 
Published: April 2011

AbstractCultivar preference/nonpreference for feeding is one of the components of resistance to the sorghum head bug, Calocoris angustatus Lethiery (Hemiptera: Miridae). IS 2761, IS 9692, IS 17610, IS 17618 and IS 17645 were not preferred by the adults of C. angustatus under multi‐ or two‐choice conditions. However, cultivar preference was not evident under no‐choice tests or headcage conditions.Reduced oviposition is an important component of resistance to head bugs in IS 17645, IS 17610 and IS 17618. Post‐embryonic development was extended by 1–2 days when nymphs were fed on these genotypes. Fifth instar nymphs and adults had lower weights when reared on IS 17610 and IS 9692. Nymphal survival was relatively lower on IS 9692, IS 17610 and IS 17645.Fourth instar nymphs were relatively less efficient in food utilization when fed on grain of IS 2761 and IS 6984 as compared with the susceptible cultivars CSH 5 and Swarna. Stage of grain development influenced the indices of consumption and utilization of food by head bugs. Consumption index (CI) and growth rate was lower on 20‐day‐old grain of IS 2761 as compared with 12‐day‐old grain.RésuméDéterminisme de la résistance du sorgho à Calocoris angustatusLes mécanismes de la résistance du sorgho à la punaise C. angustatus ont été examinés au champ et au laboratoire.Les préférences des adultes ont été examinées avec choix multiples au champ et au laboratoire sur les 5 cultivars relativement moins sensibles (IS 2761, IS 9692, IS 17610, IS 17618, IS 17645) comparés aux hybrides commerciaux très sensibles (CSH 1, CSH 5, CSH 9). Les différences ont été confirmées avec des choix binaires au laboratoire. L'absence de préférence pour un cultivar est une des composantes de la résistance du sorgho à la punaise. Mais l'absence de préférence n'est cependant pas prouvée en cage au champ au par des expériences en olfactomètre sans choix au laboratoire.La ponte a été étudié sur 8 ‘génotypes’; pendant la saison des pluies de 1983 et sur 6 génotypes pendant la saison des pluies et après celle‐ci en 1983–84. Les résultats montrent que la réduction de la ponte est une composante importante de la résistance sur IS 17645, IS 17610 et IS 17618.Pour définir le niveau d'antibiose, l'étude du cycle a été menée au laboratoire sur 5 cultivars relativement peu sensibles (IS 2761, IS 9692, IS 17610, IS 176618, IS 17645) et 3 sensibles (CSH 1, CSH 5, CSH 9). Le développement post‐embryonnaire est prolongé d'un jour au deux quand les larves sont élevées sur grains laiteux de IS 17610 ou IS 17645. Les larves de 5e stade et les adultes ont des poids plus faibles sur IS 17610 et IS 9692.Les indices de consommation et d'utilisation des aliments ont été calculés pour IS 2761, IS 6984, CSH 5 et Swarna; l'utilisation de grains de IS 2761 et IS 69884, comparée aux grains des cultivars CSH 5 et Swarna, est relativement moins efficace. C1 et GR sont plus faibles sur grains d'IS 2761 de 20 jours que de 12 jours.
Influence of olfactory stimulants on resistance/susceptibility of pearl millet, Pennisetum americanum to the rice weevil, Sitophilus oryzae
Authors: Seifelnasr Y. E. 
Published: April 2011

AbstractThe orientation responses of the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae) as influenced by the olfactory stimulants emanating from either resistant or susceptible pearl millet, Pennisetum americanum, kernels were studied using a Y‐tube olfactometer. The rice weevils were more attracted towards odours from millet grains than to blank controls and to susceptible entries more than to resistant entries, in general. However, there were exceptions. Odours from some resistant entries caused statistically the same, or even more positive orientations than those from some susceptible entries, and this suggests that the relative resistance of an entry and its olfactory attractiveness may not be strongly related, or that the resistance to infestation might be influenced by factors other than attractiveness. The partial damage of the millet kernel pericarp by abrasion slightly increased the orientational response of the weevils to odours from some susceptible and some resistant entries alike.
Influence of trap surface on the numbers of insects caught in water traps in brassica crops
Authors: Finch S. 
Published: April 2011

AbstractThe contribution of the various surfaces of a water trap to the trap's overall effectiveness was studied in brassica crops by painting black different parts of fluorescent‐yellow water‐traps. Three pest species, Delia radicum (L.), D. platura (Meig.), and Meligethes aeneus (Fab.)/Meligethes viridescens (Fab.), together with blowflies and syrphids, were caught in large numbers. Each insect responded differently to the yellow/black traps. The numbers of insect caught indicated that the area of trap involved in capturing D. radicum was effectively twice the surface area of the water. Yellow traps for monitoring D. radicum populations could be made more selective by painting the inner wall black, as such traps caught similar numbers of D. radicum to all‐yellow traps but 50% fewer D. platura, Meligethes sp. and blowflies, and 95% fewer syrphids.
Influence of phenolglucosides and trichome density on the distribution of insects herbivores on willows
Authors: Soetens Ph. , Rowell‐Rahier M. , Pasteels J. M. 
Published: April 2011

AbstractThe effects of both trichome density and phenolglucoside content of leaves of 76 willow hybrids (Salix alba × fragilis) were measured to estimate their influence on the distribution of Phratora vitellinae (L.), Plagiodera versicolora Baly (Coleoptera: Chrysomelidae) and Pontania proxima (Lepeletier 1823) (Hymenoptera: Tenthredinidae) in a nursery at Gramont, Belgium.The willows showed differences in their phenolglucoside content and pilosity of leaves and are classified on these basis into four groups by a clustering method. Correlations and multiple regressions showed that these chemical and physical characteristics are good predictors of the abundance of insects. First, the abundance of larvae of Ph. vitellinae, adults of Pl. versicolora and galls of P. proxima is correlated positively with a high phenolglucoside content and a low pilosity of the leaves. Secondly, the distribution of adults of Ph. vitellinae and of larvae of Pl. versicolora is influenced by neither the chemical nor the physical leaves characteristics studied.
Identifying bird cherry‐oat aphid Rhopalosiphum padi emigrants, alate exules and gynoparae: application of multivariate methods to morphometric and anatomical features
Authors: Simon J. C. , Dedryver C. A. , Pierre J. S. 
Published: April 2011

AbstractMultivariate analysis methods were used to distinguish between the three female alate morphs of Rhopalosiphum padi (L.) (emigrants, alate exules and gynoparae). Fourteen morphometric descriptors and seven anatomical parameters indicative of their potential fecundity were considered. Three populations or clones from distinct areas were also taken into account.The three alate morphs were separated with between 93% and 100% success. Some simplified criteria allowing distinction are described, and as an example one of them was applied to R. padi alatae caught in three suction traps.The reliability of the samples analysed is discussed. Practical use of identification techniques described may have implications for forecasting (e.g. Barley Yellow Dwarf Virus Disease), and for improving knowledge of aphid population biology.RésuméRecherche de critères morphométriques et anatomiques de différenciation des trois formes femelles ailées (émigrants, exules ailés et gynopares) du puceron des céréales Rhopalosiphum padiDes techniques d'analyse multivariée ont été appliquées sur des données morphométriques et anatomiques obtenues pour les trois formes femelles ailées (émigrants, exules ailés et gynopares) de Rhopalosiphum padi (L.) dans le but de les différencier.Pour cela des paramètres de la fécondité potentielle (nombre d'ovarioles, nombre d'embryons) et des variables morphologiques (mensurations, nombre de rhinaries) ont été évalués pour chacun des morphes sur des individus de trois populations ou clones d'origines géographiques distinctes (Angleterre, Normandie, Bretagne).Les analyses factorielles discriminantes réalisées sur ces données nous ont permis de séparer avec un taux de succès compris entre 93% et 100% les individus selon leur morphe. A partir de celles‐ci nous avons pu proposer des critères susceptibles de différencier ces trois formes ailées. Le rapport ARS/TARS2 (longueur de l'article apical du rostre/longueur du deuxième segment du tarse postérieur) semble très bien discriminer les émigrants des exules ailés et a été appliqué sur des ailés de R. padi capturés par deux pièges à succion français et un suisse. La séparation des gynopares des exules ailés est par contre moins simple.La représentativité de l'échantillon analysé a été discutée. Les possibilités d'application des méthodes d'identification des morphes de R. padi sur les ailés capturés aux pièges à succion ont été envisagées dans le cadre de la prévision des risques d'infection des céréales par le virus de la Jaunisse Nanisante de l'Orge (BYDV) et de l'amélioration des connaissances en Biologie des Populations aphidiennes.
Maintenance and termination of reproductive dormancy in an Australian stink bug, Biprorulus bibax
Authors: James D. G. 
Published: April 2011

AbstractReproductive dormancy in female Biprorulus bibax Breddin sampled during March‐October in Southern New South Wales was terminated by exposure to 25 °C under long (15h) and short (10h) photoperiods. 27% of individuals collected during March‐May failed to oviposit under short days. Pre‐oviposition period under short photoperiod was greatest during March‐June (22.4–61.7 d) and shortest during July‐October (4.2–14.4 d). Under long photoperiod it was greatest in April and May (20.1–22.3 d) and shortest during June‐October (4.9–16.6 d). Longevity ranged from 39.8–89.0 d, with longest lived females being collected in June and held under short days. Fecundity ranged from 51.6–164.4 and was greatest in individuals collected in June‐July and held under short days. In females held under long days fecundity was greatest in March and lowest in May. These data indicate that female B. bibax pass the winter in a photoperiodic ally maintained reproductive diapause.
Mechanism of whorl feeding resistance to fall armyworm among converted sorghum accessions
Authors: Diawara M. M. , Wiseman B. R. , Isenhour D. J. 
Published: April 2011

AbstractField studies were conducted in 1989 to evaluate selected converted sorghum (Sorghum bicolor [L.] Moench) accessions for resistance to whorl‐stage feeding by larvae of the fall armyworm (Spodoptera frugiperda J. E. Smith) and to determine the mechanism of resistance. The sorghum was infested in the whorl 26 days after planting (DAP) in experiment 1 and 33 DAP in experiment 2. In experiment 1, the plant accessions ‘IS7273C,’ ‘IS7444C,’ ‘IS12573C,’ ‘IS12678C,’ and ‘IS12679C’ were more resistant (rating < 3) to damage by S. frugiperda larvae than the resistant check CIMMYT (CM) 1821 (rating 6.2) at 14 days after infestation (DAI). These genotypes were also more resistant (ratings ≤ 4 at 7 DAI and < 3 at 14 DAI) than the resistant check CM1821 (ratings 5.6 at 7 DAI and 8 at 14 DAI) in experiment 2. The number of larvae that established/plant on IS7273C, IS7444C, IS12573C, or IS12679C was significantly less compared with establishment on the resistant check CM1821 at 14 DAI in experiment 1 and at 7 and 14 DAI in experiment 2. Resistance in IS7273C, IS7444C, IS12573C, and IS12679C was mainly due to their rapid rate of growth which induced a quick change in the plant morphology from the whorl‐ to the panicle‐stage and did not permit a sustained colonization of larvae. This new type of resistance could be referred to as ‘morphological non‐preference’ as apposed to chemical non‐preference where non‐preference is due to plant chemical factors. These genotypes had a significantly shorter cycle than the other sorghum genotypes. Host evasion, a type of pseudoresistance, was the basis for resistance in ‘IS7794C’ and ‘IS7947C’. Tolerance was the major mechanism of resistance in the resistant check CM 1821.
Toxicity of mycotoxins of Fusarium sambucinum for feeding in Galleria mellonella
Authors: Mulè G. , D'Ambrosio A. , Logrieco A. , Bottalico A. 
Published: April 2011

AbstractFusarium sambucinum Fuckel showed antifeedant activity towards larvae of Galleria mellonella L. when incorporated into insect diet. The activity appeared mostly due to the concentration of trichothecenes present in the fungal extracts. Diacetoxyscirpenol and neosolaniol showed similar levels of activity and were significant potent antifeedants against larvae at 50 and 100 ppm. On the contrary, enniatin B showed no activity up to 100 ppm.
Aestivo‐hibernal reproductive diapause in Drosophila moriwakii: flight as a controlling factor
Authors: Ichijô N. , Beppu K. , Kimura M. T. 
Published: April 2011

AbstractDrosophila moriwakii Okada & Kurokawa (Diptera; Drosophilidae) generally has only one generation per year and enters aestivo‐hibernal reproductive diapause in Sapporo, northern Japan, but a small fraction of the population produced a second generation in summer at a place where breeding resources were abundant. In this species, diapause seems to be controlled by flight activity. When flies were cultured in cages in which they were able to fly freely, they entered diapause irrespective of photoperiod, but they did not do so at long daylengths when cultured in small vials in which they were prevented from flying. Furthermore, flies with wings removed did not enter diapause at long daylengths even if they were cultured in the cages.
Acidic precipitation increases egg survival in Neodiprion sertifer
Authors: Heliövaara K. , Väisänen R. , Varama M. 
Published: April 2011

AbstractThe effects of simulated acidic precipitation on the egg viability of the European pine sawfly, Neodiprion sertifer Geoffrey (Hymenoptera: Diprionidae) were studied by spraying egg clusters with a mixture of sulphuric and nitric acid (1:1, pH 2, 3, 4, 5, 6, distilled water, natural precipitation) for a month in April‐May. Egg viability analyses showed that the proportion of hatched first instar larvae increased with increasing acidity. The better survival of sawfly eggs in pine needles in more acidic conditions may be partly due to changes in needle physiology affecting egg mortality. However, when the eggs were reared without needles in Petri‐dishes, the proportion of successfully hatched larvae likewise increased with increasing acidity indicating direct acid‐induced changes in the eggs themselves. Acidic precipitation as a stress factor of the host plant apparently changes population dynamics of pine sawflies and may be an important factor in triggering outbreaks.
Factors affecting Ctenarytaina thysanura oviposition on Boronia megastigma terminal shoots
Authors: Mensah R. K. , Madden J. L. 
Published: April 2011

AbstractField observations and experiments showed that the attractiveness or Boronia megastigma terminal shoots for Ctenarytaina thysanura (Hemiptera: Psyllidae) oviposition was effected by the quality and quantity of terminal shoots, relative hardness of the terminal shoot combined with a closed or open architecture of the shoot, nitrogenous fertilizer applications and intraspecific competition between psyllids. Heavy feeding either by nymphal or adult psyllids greatly reduces the attractiveness of terminal shoots for oviposition. This deterrence was associated with the production of honeydew resulting in the development of sooty moulds. When all nymphs had developed to adults, a further 21 days was required for the shoots to be restored to their original condition and suitability for oviposition.
Screenhouse trials on the potential of Nosema marucae for the control of Chilo partellus
Authors: Odindo M. O. 
Published: April 2011

AbstractTests were carried out in a screenhouse to determine the potential of a microsporidian pathogen, Nosema marucae (Microspora: Nosematidae), for the control of the spotted stalk borer, Chilo partellus (Lepidoptera: Pyralidae), on sorghum. Foliar application of an aqueous suspension of N. marucae spores on egg batches pasted on the sorghum plants reduced leaf‐damage in plants in the protected plots, and increased the proportion of plants with fully‐ and partially formed heads compared to unsprayed plots. Further, there was less tunnelling and fewer larvae in the sprayed plots. The pathogen also reduced pest infestation and damage to plants when the plots were infested with newly emerged larvae instead of eggs. N. marucae has a potential to control C. partellus.
Labelling the blueberry leaftier, Croesia curvalana with foliar sprays of rubidium chloride
Authors: Polavarapu S. , Lonergan G. C. , Seabrook W. D. 
Published: April 2011

AbstractThe feasibility of labelling blueberry leaftier by rearing the larvae on blueberry plants treated with foliar sprays of rubidium chloride (RbCl) at concentrations of 1000, 5000, 10000 and 20000 ppm were assessed. RbCl sprays above 5000 ppm significantly reduced survivorship to adult stage. The adult longevity, fecundity and mating were not affected when the larvae were reared on foliage treated with 5000 ppm RbCl solution. Reciprocal matings of 5000 ppm treated moths with untreated moths revealed transfer of label above the 0.1 μg Rb/insect threshold level from treated males to untreated females (in 8 out of 13 pairs) and vice versa (in 1 out of 9 pairs). Considerable loss of Rb (56–64%) occurred from the leaves over a 15 day period. All of the moths and pupae collected from the RbCl treated plots in 1989 and 1990 respectively, had a Rb content higher than the threshold level. In a preliminary dispersal study, marked male and female moths were found in sweepnet samples collected 20 and 60 m from the centre of the treated field. Labelled male moths were also captured in pheromone traps arranged in a circle, 40 m from the treated plot.
Chemical ‘generalists' and behavioral ‘specialists‘: a comparison of host finding by Stelidota geminata and Stelidota octomaculata
Authors: Blackmer J. L. , Phelan P. Larry 
Published: April 2011

AbstractHost orientation by two nitidulid beetles was compared: Stelidota geminata (Say), which is very broad in its' host range, and Stelidota octomaculata (Say), a species whose feeding is restricted primarily to acorns. In a no‐choice assay, both species responded to all food substrates offered and neither showed a significant preference among substrates (except banana versus wood fungi for S. octomaculata), or between aseptic and inoculated treatments; however, S. geminata readily displayed both phototactic flights and host‐orienting flights, whereas S. octomaculata never exhibited phototactic flight and never responded to food odors by flying to the source. Furthermore, when upwind‐walking response was compared, S. octomaculata walked to the source at a rate of 0.16 ± 0.01 cm/s, which was significantly lower than that of S. geminata, with a rate of 0.54 ± 0.02 cm/s. Turning frequency on the way to the source also differed between the two species, whereas distance traveled, number of pauses, and duration of pauses did not differ significantly. We submit that both species represent ‘olfactory generalists’, and that the restricted host range of S. octomaculata compared to S. geminata is not mediated by differences in long‐range response to host odors, but rather is due to differences in other behaviors such as a reduced rate of locomotion, post‐landing behavior, and possibly ecological factors.
The influence of aphids and honeydew on the leaving rate of searching aphid parasitoids from wheat plants
Authors: Budenberg W. J. , Powell W. , Clark S. J. 
Published: April 2011

AbstractDispersal cages were used to investigate the effects of aphids and treatment with artificial honeydew on the leaving rate of searching females of the parasitoid Aphidius rhopalosiphi from groups of wheat plants. Parasitoids which flew away from groups of plants placed in the centre of a cage were trapped on the sides and roof of the cage and thus were prevented from returning to the plants. The positions of trapped parasitoids suggested their direction of flight when dispersing from the plants. Parasitoids increased their residence times on groups of plants in the presence of aphids and of artificial honeydew, but the rate of parasitism of the host Sitobion avenae was not raised by the presence of artificial honeydew under the experimental conditions used. The direction of flight taken by the majority of parasitoids suggested that they were leaving the plants in order to locate further plants nearby to continue searching rather than to terminate searching and disperse away from the area. The need to consider plant patch size in studies of parasitoid searching behaviour is stressed.
Identification of compounds from the eggs of Ostrinia nubilalis and Mamestra brassicae having kairomone activity on Trichogramma brassicae
Authors: Renou M. , Nagnan P. , Berthier A. , Durier C. 
Published: April 2011

AbstractIn the presence of an extract of Ostrinia nubilalis or Mamestra brassicae eggs, female Trichogramma brassicae exhibited increased rates of upwind locomotion in the tubes of a linear olfactometer. GC and GC‐MS analyses of O. nubilalis and M. brassicae egg extracts revealed the presence of fatty acids, their ethyl esters, and various hydrocarbons. Exposing the wasps to a mixture of the five main saturated hydrocarbons (heneicosane, tricosane, pentacosane, heptacosane and nonacosane) increased the upwind progression in the olfactometer. Single hydrocarbons elicited reduced or no activity. Ethyl palmitate and palmitic acid were also effective in increasing upwind locomotion. Z11‐14: Ac, the main component of the female sex pheromone of O. nubilalis was inactive, regardless of its concentration. It is concluded that various compounds present on the surface of the O. nubilalis egg masses may play a role in the orientation of T. brassicae to its host.RésuméEn présence d'un extrait superficiel d'oeufs d'Ostrinia nubilalis, ou de Mamestra brassicae, les femelles du parasitoïde Trichogramma brassicae présentent une tendance accrue à la remontée du tube dans un olfactomètre linéaire. L'analyse des extraits d'oeufs par chromatographie en phase gazeuse couplée à la spectrométrie de masse révèle la présence d'acides gras, de leurs esters éthyliques, et de divers hydrocarbures. Un mélange des principaux hydrocarbures saturés (hénéicosane, tricosane, pentacosane, heptacosane et nonacosane) déclenche également une remontée plus rapide et plus importante du tube. Chacun de ces hydrocarbures pris isolément présente une activité nulle ou réduite. D'autres constituants des extraits, l'acide palmitique et son ester éthylique, présentent également une certaine activité. En revanche, le Z11‐14: Ac, constituant majoritaire de la phéromone sexuelle d'O. nubilalis, est inactif, quelle que soit la dose utilisée. En conclusion, divers constituants présents à la surface des oeufs de la pyrale du maïs modifient le comportement locomoteur de femelles de T. maïdis et pourraient done jouer un rôle dans l'orientation de ce parasitoïde vers son hôte.