bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interactions of Russian wheat aphid, a hymenopterous parasitoid and resistant and susceptible slender wheatgrasses
Authors: Reed D. K. , Kindler S. D. , Springer T. L. 
Published: April 2011

AbstractInteractions among three trophic levels of resistant and susceptible slenderwheat grasses, Elymus trachycaulum (Link) Goule ex Shinners ex. H.F. Lewis, Russian wheat aphid, Diuraphis noxia (Mordvilko), and a hymenopterous parasitoid were studied in the laboratory and greenhouse. These relationships were compared with a commercial susceptible wheat Triticum aestivum L. variety. Aphids reared on the resistant entries showed significantly lower weights and numbers. Significant reduction of parasitoid mummy weight and adult size was positively correlated with the effects on the aphids. Resistant entries also induced a longer prereproductive period for both the aphids and parasitoids. Numbers of aphids and aphid damage were significantly modified by the addition of parasitoids. Parasitism was higher on plants that did not have leaf rolling. These findings may indicate that antibiosis resistance studied here is not the most desirable because it decreases natural enemy vitality.
Larval dispersal from potential hosts within a population of a generalist herbivore, Choristoneura rosaceana
Authors: Carrière Y. 
Published: April 2011

AbstractThe dispersal behavior of Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae) first in star larvae was studied in the laboratory. The objectives were to investigate the proximal factors influencing larval dispersal and to establish whether a correspondence exists between larval host acceptance and performance. A dispersal bioassay was validated by demonstrating the presence of a positive correlation between larval host acceptance in the laboratory and in the field. Larval age and family origin, as well as host species attributes were shown to influence larval dispersal rates. Seasonal changes in host plants slightly changed the rank order of larval host acceptance. Leaf texture and the availability of refuges on host plants seemed to be important factors influencing the rate of larval dispersal. Plant odor appeared to be used by the larvae to locate leaves. Nitrogen content of plant species corresponded to larval dispersal rates, but the cause of this association is unclear. Larval dispersal did not match host suitabilities as measured by larval performance. The relationship between host preference and suitability in the obliquebanded leafroller is discussed in an ecological and evolutionary perspective.
Electroantennogram responses of the Mediterranean fruit fly, Ceratitis capitata, to the volatile constituents of nectarines
Authors: Light D. M. , Jang E. B. , Flath R. A. 
Published: April 2011

AbstractElectroantennograms (EAGs) were recorded from laboratory‐reared, male and female Ceratitis capitata (medfly) in response to individual volatiles identified from ripe nectarines. Uniformity in EAG response between the sexes was observed for most test compounds. Only 10 volatiles, of the 44 nectarine volatiles tested, elicited significantly different EAG responses between the sexes. No correlation was observed between the magnitude of antennal responsiveness and the concentration of a particular volatile in the headspace odor of ripe nectarines. The most abundant (‘major’) nectarine volatiles were among the least EAG stimulatory compounds tested. And certain ‘minor’ and ‘trace’ volatiles were the most potent compounds in eliciting EAGs. Moreover, the magnitude of antennal response to a nectarine volatile was related to the functional‐group, chain‐length, and unsaturation of the compound. The degree of potency of the compounds was as follows: six‐carbon unsaturated aldehydes and alcohols > methyl and ethyl hexanoates and octanoates ≥ hexenyl acetates and monoterpenes > shorter chain‐length acetates and alcohols > lactones. Unsaturated aldehydes, alcohols, and acetates generally elicited larger EAGs than their saturated analogs, with the (E)‐2‐isomers being the most potent isomeric configurations. In addition, medfly antennae exhibited ‘long recovery’ periods (i.e., > 10 sec.) for the EAG tracings to return to baseline potential after stimulations with certain classes of compounds, e.g., C6 to C8 acid esters, monoterpenes, and hexen‐1‐ols. The potential adaptiveness to medflies for selective sensitivity to these volatiles is discussed.
Some effects of rearing the yellow dung fly Scatophaga stercoraria in cattle dung containing ivermectin
Authors: Strong L. , James S. 
Published: April 2011

AbstractIvermectin was added to cattle dung in controlled concentrations like those found in the pats of injected cattle, and the medium was used to rear larvae of the dung fly Scatophaga stercoraria. Ivermectin at 0.036 ppm (wt/wet weight) debilitates 50% of the larvae within 48 h. At 0.015 ppm, 50% of the larvae are unable to pupariate, while at 0.001 ppm, 50% of the larvae fail to reach the adult stage. Adults produced from larvae reared in pats containing 0.0005 ppm ivermectin show high levels of fluctuating asymmetry in wing characteristics as well as deformities in the wing veins themselves. The data are discussed in relation to the effects of excreted ivermectin on pastureland biology.
Optimization of bioassay conditions for the olive bark beetle Phloeotribus scarabaeoides
Authors: Peña A. , Kelly D. R. , Szauman‐Szumski C. , Campos M. 
Published: April 2011

AbstractBioassay conditions with a glass olfactometer for the olive bark beetle, Phloeotribus scarabaeoides Bern. (Coleoptera: Scolytidae), have been investigated. The best temperatures and light intensities were between 17 and 28 °C and 1000 and 1500 lux, respectively. The best response was obtained with newly emerged individuals from reproduction galleries with no feeding period.
Relationship between males caught with low pheromone doses and larval infestation of Argyrotaenia pulchellana
Authors: Faccioli G. , Antropoli A. , Pasqualini E. 
Published: April 2011

AbstractSex pheromone traps for Argyrotaenia pulchellana Haw. (Lep. Tortricidae) were loaded with two low pheromone doses (0.1 and 0.01 mg) and tested in apple and pear orchards of northern Italy's Emilia‐Romagna Region to estimate the relationship between male catches and subsequent larval infestation. While the lower dose captured fewer males, it registered an enhanced correlation to larval populations and a decrease in the number of episodes of high catches associated with no infestation. In all likelihood, the pheromone traps baited at the lower dose have a smaller active space and captured only males within the orchard. Lures with 0.01 mg of pheromone can be replaced every 6 weeks, just as the 1 mg lures now in widespread use in Italy. A threshold of 65 adults captured from the beginning of flight is proposed for the Emilia‐Romagna IPM project.
Observations on egg‐laying behaviour of the banana weevil, Cosmopolites sordidus (Germar)
Authors: Koppenhöfer A. M. 
Published: April 2011

AbstractBanana weevil females laid on an average 2.7 eggs/week in rhizome material and 0.7 eggs/week in pseudostem material in the laboratory. At extremely high weevil population densities the egg‐laying activity declined. Under controlled field conditions 0.7 eggs/week were laid in banana suckers and 1.3 eggs/week in stumps of harvested suckers. 25% of the weevil stages found in suckers in the field were eggs of which 78% were laid in the rhizome and 22% in the pseudostem base. The majority of eggs was deposited in the crown area of the rhizome followed by the remaining surface area of the rhizome, the walls of abandoned larval tunnels in rhizome and pseudostem and the leaf sheaths. 58% of the eggs found were considered accessible to egg predators.
Synthetic molecules designed as potential inhibitors in ecdysone biosynthesis
Authors: Roussel Jean‐Pierre 
Published: April 2011

AbstractFor fundamental studies as well as applied research, we have set up a programme for the synthesis of irreversible and selective inhibitors of ecdysone biosynthesis. Suicide substrate type inhibitors have been synthesized in order to react in the last steps of ecdysone biosynthesis on C‐22 and C‐25 hydroxylases which are cytochrome P‐450‐dependent monooxygenases. The most active inhibitors are formed of a steroid nucleus on which a short side chain, with an acetylenic or an allenic function closely linked to an hydroxyl group, has been grafted. The exact form of the steroid nucleus (as in cholesterol, 7‐dehydrocholesterol, 3‐dehydrocholesterol or a molecule with a saturated B cycle) did not appear essential for the activity of the chemicals. These molecules injected in vivo in larvae of Locusta migratoria induced some morphological modifications of the adults and a very slight delay in metamorphosis.RésuméDans le but d'inhiber la biosynthèse de l'ecdysone au cours du développement chez l'Insecte, plus de 50 molécules ont été synthétisées selon la conception des substrats‐suicides. Deux enzymes des dernières étapes de la biosynthèse de l'ecdysone, parfaitement connues, les C‐22 et C‐25 hydroxylases, qui sont des monooxygénases à cytochrome P‐450, ont été choisies pour cibles.A partir d'une molécule de base présentant à la fois un bon pouvoir inhibiteur et des caractéristiques d'activité de type substrat‐suicide, c'est‐à‐dire irréversibilité de l'action, spécificité de l'inhibition et sélectivité sur l'enzyme visé, de nombreuses modifications ont été introduites. Elles ont concernés notamment la longueur de la chaîne latérale, la nature et la position du groupement inhibiteur, la position du ou des groupements hydroxyles et la nature du noyau stéroïde.Des divers résultats obtenus, il est possible de conclure que les meilleurs inhibiteurs, qui diminuent significativement la production d'ecdysone des glandes prothoraciques incubées in vitro, sont composés d'une chaîne latérale courte à groupement inhibiteur alcyne ou allénique dans le voisinage d'un groupement hydroxyle et d'un noyau stéroïde qui peut‐être, indifféremment, de type cholestérol, 7‐déshydrocholestérol, 3‐déshydrocholestérol ou porter un cycle B saturé. On peut noter que les noyaux qui se rapprochent le plus de celui des ecdystéroïdes diminuent ou empêchent l'activité.Malheureusement, jusqu' à présent, ces molécules injectées in vivo chez des larves de Locusta migratoria n'ont qu'une action réduite: elles ne produisent, dans les meilleurs cas, que de rares retards de métamorphose et quelques modifications morphologiques chez les adultes.
Diploid males in the bumble bee Bombus terrestris
Authors: Duchateau M. J. , Hoshiba H. , Velthuis H. H. W. 
Published: April 2011

AbstractThe frequency of colonies that produce diploid males after brother‐sister (50%) and nephew‐niece (37.5%) matings proves that in B. terrestris the sex is determined by a single multi‐allelic sex locus. The diploid males which develop normally into adults make up 50% of the diploid brood. In the laboratory the growth rate of colonies with diploid males is influenced only slightly. Of 41 colony founding queens caught out of a natural population, all produced a colony without any diploid males. Therefore, the number of sex alleles in this population is estimated to be at least 24. This means that in commercial rearing systems for bumble bees, involving several generations, the occurrence of diploid males can largely be prevented by a good scheme for crossings.
Biological activity of maize leaf extracts against the African armyworm, Spodoptera exempta
Authors: Okello‐Ekochu E. J. , Wilkins R. M. 
Published: April 2011

AbstractMaize (Zea mays L.) leaf tissue of cv Bastille and cv Michoacan 12 was extracted with n‐hexane. The extracts were bioassayed against 5th instar African armyworm, Spodoptera exempta (Walker)(Lepidoptera: Noctuidae), by feeding the larvae on agar based media or sucrose impregnated glass fibre discs. The hexane extract of the ‘resistant’ cv Bastille exhibited feeding deterrency and toxicity which were not shown by the ‘susceptible’ cv Michoacan 12. The hexane extract of cv Bastille was adsorbed onto silica gel, the solution filtered off and the adsorbed component taken up into ethyl acetate. Bioassay of these fractions indicated that the toxic and deterrent action was retained in the ethyl acetate fraction. Preparative thin layer chromatography of the ethyl acetate fraction isolated two biologically active constituents. These were both growth inhibitors and lethal by ingestion to the 5th instar African armyworm. Implications for resistance in maize varieties to insect pests are discussed.
Role of photoperiod and temperature in the induction of overwintering pupal diapause in the spotted tentiform leafminer, Phyllonorycter blancardella
Authors: Trimble R. M. 
Published: April 2011

AbstractThe role of photoperiod and temperature in the induction of overwintering diapause in Phyllonorycter blancardella (F.) (Lepidoptera: Gracillariidae) was examined in the laboratory and field using leafminers from commercial apple orchards in Ontario, Canada. P. blancardella exhibited a long‐day response to photoperiod: long daylengths resulted in uninterrupted development whereas short daylengths induced diapause. The estimated critical photoperiod for diapause induction was L14.25:D9.75. The larvae of leafminers destined to enter diapause took ca. 3x longer to complete development than the larvae of non‐diapausing leafminers. The development prolonging effect of photoperiod decreased with decreasing daylength. Temperature modified the diapause inducing effect of photoperiod. At L14.25:D9.75, diapause incidence was similar at 15 and 20 °C but was lower at 25 °C. Photoperiod also altered the normal relationship between development rate and temperature. At L14.25:D9.75, the duration of larval development of diapausing leafminers was similar at 15, 20 and 25 °C. Temperature alone is unlikely to have a role in the induction of diapause because leafminers exposed to natural late summer and fall temperature regimes and L16:D8 did not enter diapause.
Aphid activities during sieve element punctures
Authors: Prado Ernesto , Tjallingii W. Freddy 
Published: April 2011

AbstractAphid salivation in sieve elements and phloem sap ingestion were linked to waveforms in the Electrical Penetration Graph (EPG). Non‐viruliferous Rhopalosiphum padi (L.) (Hemiptera, Aphididae) on barley yellow dwarf virus (BYDV) infected wheat could acquire the virus, which was used as an indication for phloem sap ingestion, whereas virus inoculation by viruliferous aphids on healthy plants was associated with salivation in sieve elements or other phloem cells. Probing was monitored and the waveforms recorded were related to ELISA results of test plants. The EPG patterns A, B, and C are indicative of the stylet pathway phase, whereas patterns E1 and E2 reflect the phloem (sieve element) phase with an unknown activity (E1) or with ingestion and concurrent salivation (E2). Aphids showing pathway and E1 rarely acquired virus, suggesting that little or no phloem sap ingestion can occur during these patterns, whereas those showing additionally pattern E2 did so substantially, indicating phloem sap ingestion. The main pattern related to virus inoculation was E1, although some aphids were able to inoculate plants during pathway. Pattern El clearly reflects the most important salivation into sieve elements. Pattern E2 had no clear contribution to virus inoculation, supporting the present hypothesis that during this pattern the saliva is mixed with the phloem sap in the single canal at the stylet tips and ingested immediately, without reaching the plant tissue. Sustained sap ingestion did not affect virus inoculation. So, BYDV inoculation mainly occurs during the first period of a sieve element puncture which is always formed by E1. Implications on persistent virus transmission are discussed.
Influence of pre‐emergence experience on response to host and host plant odours in the larval parasitoid Eupelmus vuilleti
Authors: Cortesero A. M. , Monge J. P. 
Published: April 2011

AbstractThe response to different host and plant species odours was investigated in Eupelmus vuilleti (Crw). This hymenopteran is a solitary ectoparasitoid of several species of bruchids developing inside Leguminosae seeds. The locomotor behaviour of females reared on Bruchidius atrolineatus (Pic) larvae developing in Vigna unguiculata (Walp) seeds was analysed using a tubular olfactometer. Females showed a specific sensitivity to the semiochemicals emanating from the host and the seed species on which they had developed. Odours from V. unguiculata seeds were attractive to the parasitoid and stimulated their locomotor activity. Odours from Vigna radiata (Wil) seeds had no effect on the locomotor behaviour. Odours from B. atrolineatus larvae were attractive to the females whereas odours from Callosobruchus maculatus (Fab), another bruchid species, had no effect. By isolating the females from the seed and the host at different developmental stages, we found that the specific sensitivity observed resulted from an early adult learning. This learning which occurs before the emergence from the seed while the imago is in the larval chamber of its host is dependent on contact with the seed and the host larval remains.
Genetic variability in the reactive distance in Trichogramma brassicae after automatic tracking of the walking path
Authors: Bruins E. B. A. W. , Wajnberg E. , Pak G. A. 
Published: April 2011

AbstractEfficiency of hymenopterous parasitoids to control pests in a biological control release program probably increases with increasing searching ability of the females, which, in return, likely depends on the distance from which females perceive their hosts (i.e., reactive distance). In this study, we first analyse this hypothesis with the help of a stochastic model simulating the walking path of isolated Trichogramma females during their searching behaviour. Then, this reactive distance is estimated using automatic recording and analysis of the walking path of female wasps. Finally, the genetic variability for this trait is analysed in a Trichogramma brassicae Bezdenko (Hym.; Trichogrammatidae) population. Three types of hosts were used: Eggs of Ephestia kuehniella Zeller (Lep.; Pyralidae), eggs of Mamestra brassicae L. (Lep.; Noctuidae) and 0.45 mm glass beads. M. brassicae eggs are perceived from 4.01 ± 0.15 mm, which is a significantly longer perceptive distance than for E. kuehniella eggs (3.69 ± 0.10 mm) and glass beads (3.67 ± 0.10 mm). Moreover, whatever the host tested, a significant genetic variation is observed in this trait in the population studied.The ecological and evolutionary implications and the agronomical importance of these results are discussed.
Seasonal acquisition of mineral nutrients by a chalcid gall on lowbush blueberry
Authors: Bagatto Giuseppe , Shorthouse Joseph D. 
Published: April 2011

AbstractSeasonal accumulation of various mineral nutrients by galls of the chalcid Hemadas nubilipennis on lowbush blueberry were examined in various phases of gall development. Levels of copper, nickel, iron, and zinc were higher in tissues of galls in initiation phase compared to tips of ungalled shoots and in general were higher than galls in growth and maturation phases. Levels of manganese and magnesium in gall tissues decrease throughout the season compared to ungalled shoots. Levels of calcium are less in gall tissues in initiation phase compared to ungalled shoots, and elevated in maturation phase. Patterns of mineral concentration within galls at various phases of development are related to known physiological roles of minerals in plant nutrition; however, we conclude that patterns are variable and their significance in gall physiology requires further study.
Resource utilization and sex allocation in response to host size in two ectoparasitoid wasps on subcortical beetles
Authors: Urano T. , Hijii N. 
Published: April 2011

AbstractPatterns of host resource utilization and sex ratio manipulation in relation to host size were investigated for two solitary ectoparasitoid wasps, Atanycolus initiator and Spathius brevicaudis (Hymenoptera Braconidae). Both species parasitize subcortical beetles on the trunks of Japanese pine trees. A. initiator is on average 8 times larger in body weight and has an ovipositor that is 3.7 times longer than that of S. brevicaudis. In both parasitoids, the size of emerging wasps was positively correlated with host size, but the host/wasp size regressions were linear for all three major host species in A. initiator, whereas in S. brevicaudis the regression was logarithmic for a relatively large host species. The sex ratios (proportion of males) of both parasitoids emerging from different host species decreased with increasing host size, but the overall sex ratio on each host species was male‐biased in A. initiator, while female‐biased in S. brevicaudis. How the proportion of host consumed changed in response to host size, differed between the two parasitoids for the same host species. In the field survey, the size and sex ratio of the emerging two parasitoids from a dead tree were closely related to host size. However, the spatial distribution of the two parasitoids depended on the bark thickness of the trunk. The data suggest that differences in the relative evaluation of host size and in ovipositor length may enable the coexistence of the two parasitoid wasps.
Life‐history parameters of western flower thrips on susceptible and resistant cucumber genotypes
Authors: Soria Carmen , Mollema Chris 
Published: April 2011

AbstractThe life‐history parameters reproduction rate, developmental time and age specific survival of the western flower thrips, Frankliniella occidentalis (Pergande) [Thysanoptera:Thripidae], were determined on susceptible and resistant cucumber (Cucumis sativus L.) genotypes. Both newly emerged and F. occidentalis females of mixed ages showed a substantial reduction (36 to 50%) of the reproduction rate on all resistant genotypes, in particular after the second day. On the resistant genotypes 9127 and 9140, F. occidentalis had a prolonged developmental period. This was primarily due to a prolongation of the second larval stage. On all resistant genotypes, F. occidentalis suffered from high (82 to 97%) preadult mortality, predominantly at the second larval stage. It is concluded that the resistant genotypes do not cause an immediate intoxication of adult nor preadult thrips stages.
Phenolic glucosides as feeding cues for willow‐feeding leaf beetles
Authors: Kolehmainen J. , Julkunen‐Tiitto R. , Roininen H. , Tahvanainen J. 
Published: April 2011

AbstractThe effects of individual phenolic glucosides and total glucoside fractions on the feeding behaviour of three willow‐feeding leaf beetles (Coleoptera: Chrysomelidae) were tested in the laboratory. Feeding preferences of the tested leaf beetles were strongly influenced by certain phenolic glucosides which are typical secondary compounds of willows (Salicaceae: Salix).Two of the tested leaf beetles, Galerucella lineola and Lochmaea capreae showed rather similar responses to glucoside treatments. Both of them were strongly stimulated by total glucoside fractions from Salix triandra and by its major glucoside salidroside. The third species, Phatora vitellinae, was attracted most by the fractions from S. myrsinifolia and S. pentandra, and by two related salicylate glucosides, tremulacin and salicortin. Food selection pattern of the tested beetles in the laboratory concords fairly well with their distributions in the field and with the occurrence of phenolic glucosides in their host willows. Phenolic glucoside extracts stimulated more feeding than individual pure glucosides. This indicates that different compounds have synergistic effects in the feeding behaviour of leaf beetles. Our results clearly show that willow leaf beetles select their food based on phenolic glucosides of their host plants.