bluuebunny/crossref_metadata_2025_split huggingface dataset:
Host discrimination and evidence for a host marking pheromone in the almond seed wasp, Eurytoma amygdali
Authors: Kouloussis N. A. , Katsoyannos B. I. 
Published: April 2011

AbstractLaboratory experiments and observations on the oviposition behaviour of the almond seed wasp Eurytoma amygdali Enderlein (Hymenoptera, Eurytomidae) revealed that the females of this species deposit a host‐marking pheromone, immediately after an oviposition, by dragging the tip of their abdomen on the fruit surface. This pheromone enables them to discriminate between the infested and uninfested fruit and to select for oviposition the latter. Its primary function is apparently the prevention of repeated ovipositions in already infested fruit, thus contributing to the optimal utilisation of the available resources for larval development. The responses of individual females to different treatments of almonds, in a series of two‐choice tests, revealed that the pheromone can be perceived by the females on direct contact and, when at high concentrations, also olfactorily from a short distance. The pheromone was present inside the abdomen and thorax of females but not of males, and, although water soluble, could not be entirely removed from heavily infested almonds when rinsed with water. Direct observations revealed that after an average of 3.7 successive visits to pheromone‐bearing almonds, females were induced to walk or, most often, fly away from the experimental set‐up. This suggests that the pheromone may also contribute to the dispersion of the wasps.RésuméDiscrimination entre des fruits infectés et non‐infectés et évidence d'une phéronome de marquage de l'hôte chez Eurytoma amygdaliDes expériences de laboratoire et des observations concernant le comportement de ponte de Eurytoma amygdali Enderlein (Hymenoptera, Eurytomidae) ont montré que, immédiatement après la ponte, les femelles déposent une phéromone de marquage de l'hôte en trainant le bout de leur abdomen sur la surface de l'amande. Cette phéromone les rends capable de distinguer les fruits infectés des non‐infectés et de sélectionner pour la ponte les derniers. Apparemment, la fonction principale de cette phéromone est la prévention de la répétition des ovipositions dans les fruits déjà infectés et la répartition uniforme des œufs dans les amandes, contribuant ainsi à la meilleure utilisation des ressources disponsibles pour le développement des larves. Des expériences de deux choix entre des fruits de différents traitements ont montré que la phéromone pouvait être perçue par les femelles par le direct contact et, quand elle était à hautes concentrations, par olfaction d'une courte distance. La phéromone était présente dans l'abdomen et dans le thorax des femelles, et bien qu'elle soit soluble à l'eau, elle ne pouvait pas s'éloigner entièrement par lavage des amandes sérieusement infectées à l'eau. Les observations ont démontré qu'après un numéro de 3.7 visites successives sur des amandes portant de la phéromone les femelles s'éloignaient du lieu de ponte en marchant ou, le plus souvant, en s'envolant, ce qui suggère que la phéromone contribue à la dispersion des femelles.
Foraging patterns of two aphid parasitoids, Lysiphlebus testaceipes and Aphidius colemani on banana
Authors: Stadler B. , Völki W. 
Published: April 2011

AbstractThe searching behaviour of two aphid parasitoids, Lysiphlebus testaceipes (Cresson) and Aphidius colemani Viereck (Hymenoptera, Aphidiidae), was analysed. Both species searched banana plants (Musa spec.) infested with the banana aphid Pemalonia nigronervosa Coq. in a different way. L. testaceipes restricted its search to open plant structures and avoided concealed areas. A. colemani partitioned its time spent on the plant between open and concealed areas. This general pattern was independent of aphid colony size and was also observed in the absence of aphids. As a consequence of these searching tactics, the borders of a host patch differed for both parasitoid species. For L. testaceipes, the patch consisted only of aphids feeding on open structures, while it comprised the whole aphid colony for A. colemani. The observed searching patterns resulted in a different exploitation of the aphid colonies.ZusammenfassungDas Wirtssuchverhalten zweier Blattlausparasitoide, Lysiphlebus testaceipes und Aphidius colemani, an BananenpflanzenEine Analyse des Suchverhaltens der beiden Blattlausparasitoide Lysiphlebus testaceipes (Cresson) and Aphidius colemani Viereck zeigte, daß beidc Arten Bananenpflanzen (Musa spec.), die von der Bananenblattlaus Pentalonia nigronervosa Coq. befallen waren, auf unterschiedliche Weise absuchten. L. testaceipes beschränkte seine Wirtssuche auf frei zugängliche Pflanzenteile und vermied ein Eindringen in geschützte Pflanzenstrukturen. Dagegen hielt sich A. colemani gleichermaßen häufig auf offenen und in geschützten Pflanzenteilen auf. Dieses generelle Suchmuster war unabängig von der Blattlauskoloniegröße und wurde auch beim Fehlen von Wirten beobachtet. Als Konsequenz aus diesem unterschiedlichen Suchverhalten ergaben sich verschiedene ‘Patchgrenzen’ für beide Parasitoide. Für L. testaceipes bestand der Patch nur aus Blattläusen, die an frei zugänglichen Pflanzenstrukturen saugten, während der Patch für A. colemani alle Blattläuse einschließlich der Tiere umfaßte, die sich in geschützten Pflanzenteilen aufhielten. Damit führte dieses unterschiedliche Suchverhalten beider Parasitoidenarten zu einer unterschiedlichen Ausnutzung der Blattlauskolonien.
Preference of white‐backed planthopper, Sogatella furcifera to different rice varieties
Authors: Mishra N. C. , Misra B. C. 
Published: April 2011

AbstractPreference studies of the white‐backed planthopper, Sogatella furcifera (Horvath) (Delphacidae: Homoptera) (WBPH) for different growth stages of rice, Oryza sativa L., indicated that WBPH selected its preferred variety for feeding by alighting on the plant and feeding briefly, ‘tasting’ the plant. Differential preference for shelter, food or oviposition by WBPH were observed for different rice varieties and for different stages of a variety. With the advancement of plant age, rice varieties became more unsuitable for feeding and a process progressing more rapidly in resistant varieties. Most of the resistant varieties viz. Pundia, Landi Sarakanti and Ptb‐33, unsuitable for shelter and feeding were usually not preferred for oviposition. However, the tolerant variety Mahia bankoi, though suitable for shelter and feeding was also not preferred for oviposition. Therefore, when screening varieties by only measuring feeding preference sources having tolerance mechanisms of resistance may be overlooked.
Factors affecting entomophilic activity ofNeoaplectana feltiaein mushroom compost
Authors: Tomalak M. , Lipa J. J. 
Published: April 2011

AbstractThe host‐searching ability ofNeoaplectana feltiaeFilipjev (=S. bibionisBovien) (Nematoda: Steinernematidae) in response to larvae of a mushroom fly,Lycoriella solaniWinn. was examined in a mushroom substrate. Individuals ofL. solaniwere less attractive for the parasite than larvae ofGalleria mellonellaL. The nematode juveniles penetrated a 22 cm layer of casing mixture within 2–4 days. In the casing alone nematode effectiveness was better than in mushroom compost or in compost and casing together. In the casing mixture parasite dosages of 20 and 100 juveniles per cm2led to 22% and 45% parasitization ofL. solanirespectively, while allG. mellonellalarvae were parasitized at both dosages. The prevalence of nematode infection depended on the content of water in the mushroom substrate. The highestN. feltiaeinfectivity was observed, when the ratio of the dry casing weight to the weight of water content was 1:2.5. The practical aspects of the observed phenomena, essential for the use ofN. feltiaein the protection of commercial mushroom cultivation are discussed.
The effect of colour of the substrate on the landing and oviposition behaviour of the cabbage root fly
Authors: Košťtál V. 
Published: April 2011

AbstractField and laboratory experiments were made in order to understand the relation between the spectral characteristic of a substrate and its attractiveness for Delia radicum (L.) (Diptera: Anthomyiidae) flies to land or oviposit. Landing females preferred substrates with high reflectance of green and particularly of yellow wavelengths, but substrates with a high proportion of the blue and green reflectance simultaneously (light blue and white) were also very attractive. Unattractive substrates had either low reflectance across the whole insect‐visible spectrum (dark blue) or increased reflectance only in orange or red region of the spectrum (red) or a large proportion of UV reflectance (aluminium). Landing males were most attracted to the substrates with the highest total reflection. Oviposition attractiveness of a substrate grew with an increase in the proportion of reflectance in the blue and a decrease in the green regions of the spectrum. In addition, the oviposition attractiveness increased with increasing total reflection and contrast with the background, and decreased with a high proportion of UV reflectance.
Genetic variation among apple and hawthorn host races of Rhagoletis pomonella across an ecological transition zone in the Mid‐Western United States
Authors: Feder J. L. , Bush G. L. 
Published: April 2011

AbstractIn previous studies, we have shown that apple and hawthorn populations of Rhagoletis pomonella (Diptera: Tephritidae) represent partially reproductively isolated and genetically differentiated host races; a result consistent with predictions of sympatric speciation models. The geographic pattern of allozyme variation for these flies is complex, however, as inter‐host differences are superimposed on latitudinal allele frequency clines within the races. In addition, pronounced allele frequency shifts exist among R. pomonella populations across three major ecological transition zones in the mid‐western United States. This suggests that selection related to environmental heterogeneity is responsible for the allele frequency shifts, but does not rule out secondary contact as an alternative possibility. Resolution of this issue is important, because if secondary contact is involved, then we would have to reassess the relationship host race formation has with speciation in the R. pomonella group.Here, we present results from a detailed genetic analysis of fly populations spanning the deciduous/prairie transition zone near the border between the states of Wisconsin and Illinois. Allele frequencies for hawthorn populations within the zone formed ‘spikes’, rather than the expected steps, and these frequency peaks correlated with variation in local ambient temperature conditions. Ambient temperature, and not secondary contact, therefore appears to be an important determinant of the shape of R. pomonella allele frequency clines. Allele frequency heterogeneity was also observed among apple populations, but was less pronounced compared to that for hawthorn flies. This suggests that ambient temperature differentially affects the host races, possibly through differences in the fruiting phenologies of apple and hawthorn trees. Several pairs of linked loci displayed concordant allele frequency changes and were in disequilibrium among both apple and hawthorn populations along the Wisconsin/Illinois transect. Although we do not know the reason for the observed pattern of disequilibrium, site to site variation in levels of inter‐host migration, coupled with selection, seem the most likely explanations. We conclude by discussing how host specific adaptations, such as those associated with ambient temperature, may interact with host recognition traits to drive the sympatric speciation process for R. pomonella group flies.
Evaluation of techniques for monitoring emergence of the banded fruit weevil, Phlyctinus callosus, in deciduous fruit orchards
Authors: Barnes B. N. 
Published: April 2011

AbstractFour methods of monitoring emergence of the banded fruit weevil, Phlyctinus callosus (Schoenherr) (Coleoptera: Curculionidae), in deciduous fruit orchards were evaluated to develop an accurate and practical system for use by growers. Box emergence traps placed in the drip area of the trees were the most accurate method of detecting the onset of adult emergence in spring. Limb‐jarring and trunk‐bands detected emergence 2 weeks after that by box traps. Cone emergence traps were less sensitive to the onset of emergence than box traps, but more practical, and are judged to be the best method of monitoring the spring emergence of P. callosus adults. The strategic placement of cone traps over weed hosts particularly favoured by P. callosus will increase the accuracy of these traps in detecting the onset of emergence.
Searching behavior and time budgets of the predator Podisus maculiventris
Authors: Wiedenmann R. N. , O'Neil R. J. 
Published: April 2011

AbstractSearching behavior of the predaceous insect Podisus maculiventris (Say) (Heteroptera: Pentatomidae) was investigated in the laboratory to verify assumptions made in a predator search model. Female predators were placed into an arena containing 30 lima bean plants (Phaseolus lunatus L.), each having five numbered leaflets. Prey were third‐instar larvae of Mexican bean beetle (Epilachna varivestis Mulsant) at two densities. Predators were observed for 4 h periods as they searched the plant canopy. Results showed that predators searched a greater area and for longer at low prey density than at high prey density. Predators apparently searched plants without using cues, did not search areas of the canopy repeatedly after attacks, and spent approximately 1 h handling prey. Predators spent more time resting than searching, and attack rates were negatively correlated with rest time, but were not correlated with search time. Long resting periods by predators may be a result of energy conservation. The implications for using predators such as P. maculiventris against pests in crops are (i) the predators' searching behavior limits the number of prey attacked, and (ii) the predator may be able to persist at low prey densities better than species with different searching behaviors.
Bean tumbling as a control measure for the common bean weevil, Acanthoscelides obtectus
Authors: Quentin M. E. , Spencer J. L. , Miller J. R. 
Published: April 2011

AbstractRecognizing that it takes Acanthoscelides obtectus (Say) (Coleoptera: Bruchidae) larvae over 24 h to bore into a dry red kidney bean {Phaseolus vulgaris L.) and that boring can occur only at particular sites where a bean abuts some other surface, we postulated that this pest might be controlled by periodic tumbling of beans so as to place initiated holes out of register with requisite touching surfaces. Larvae repeatedly forced to initiate holes might die of exhaustion, if not smashed by tumbling beans. Indeed, brief daily tumbling of beans held in half‐filled jars, buckets, and gunny sacks reduced A. obtectus populations by 97% relative to stationary controls. We recommend that small lots of beans can be protected indefinitely from the bean weevil when stored in <75% filled cylinders rolled ca 1 circumference every morning and evening. This control method should be immediately useful, particularly among subsistence families, since the only external input is knowledge. Also, this control principle might be broadly applicable to other bean and grain pests having strict spatial and temporal requirements for seed penetration.
Analysis of orientation behaviour of Tribolium castaneum and T. confusum to synthetic aggregation pheromone
Authors: Obeng‐Ofori D. 
Published: April 2011

AbstractAdult male T. castaneum (Herbst) and T. confusum (du Val) secretes an aggregation pheromone that is attractive to both sexes. Orientation behaviour of the two Tribolium species responding to different concentrations of synthetic aggregation pheromone in still and moving air was studied in an 2.5 m × 0.4 m olfactometer. Analysis of Tribolium tracks indicated that the aggregation pheromone stimulated the beetles to walk faster at higher concentrations to increase the frequency and magnitude of turning and to decrease track reversal distances and distances between turns. The mean walking speed of both species was lowest at the highest air speed. The behavioural responses of the beetles to the pheromone in still and moving air were similar, indicating chemotaxis as the major orientation mechanism used by both species to locate an odour source. The beetles showed greater orientation efficiency within a discrete pheromone plume than a diffuse plume.
Resistance to the cowpea weevil (Callosobruchus maculatus) larva in pods of cowpea (Vigna unguiculata)
Authors: Kitch L. W. , Shade R. E. , Murdock L. L. 
Published: April 2011

AbstractThirty cowpea, Vigna unguiculata (L.) Walpers, cultivars were evaluated as intact pods to determine if any possessed resistance to the cowpea weevil, Callosobruchus maculatus (Fabr.). Pod resistance was measured as pre‐establishment larval mortality (PreM); those larvae dying after egg hatch but before penetrating into the seeds, and as post‐establishment within‐seed mortality (PostM); those larvae dying after penetrating into the seeds. Among the 30 varieties examined, PreM ranged from 57.9% to 99.4% and PostM ranged from 6.7%, to 82.6%. Ten varieties exhibited total intact pod mortality (mortality from egg hatch to adult emergence from the seed) greater than 95%.Physical measurements were made of several pod and seed characteristics to ascertain whether the observed pod resistance was due to seed factors, pod‐wall factors, or to interactions between the pod and seeds. Although resistance to breakage (from handling plus pod dehiscence) is a necessary characteristic for overall pod protection against C. maculatus; other factors are also important. Among the other pod and seed characteristics measured to identify major resistance factors, seed coat thickness was the one most highly correlated with pod resistance. Our results suggest that interactions between pod‐wall and seed coat characteristics play a large role in pod resistance of cowpeas to C. maculatus.
Patterns of morphometric and allozyme variation in Aedes albopictus
Authors: Kambhampati S. , Rai K. S. 
Published: April 2011

AbstractA survey of microgeographic variation using morphometric and allozyme analyses was conducted on 19 US populations of Aedes albopictus (Skuse) (Diptera: Culicidae), a mosquito that was recently introduced into the US. There was considerable variation within and among populations both in morphometric traits and allele frequencies. A multivariate discriminant analysis enabled the separation of populations into distinct groups; separation among the populations in the morphometric analysis was incomplete with an average of 70% of the individuals being correctly classified. In the allozyme analysis, the discrimination was complete. The populations from Texas were placed close together in the morphometric analysis, whereas in the allozyme analysis a geographic clustering of populations could not be detected. A test of association between the distance matrices derived from the morphometric and allozyme analyses was statistically nonsignificant. The results are discussed in the context of the colonization of the US by A. albopictus. The possible factors underlying the differences in the patterns of variation derived from morphometric and allozyme analyses are also discussed.
Sulfhydryl‐reagent alteration of soybean resistance to the cabbage looper, Trichoplusia ni
Authors: Neupane F. P. , Norris D. M. 
Published: April 2011

AbstractThe hypothesis that the sulfhydryl reagent, N‐ethylmaleimide, would function as an elicitor of alterable resistance in soybean (Glycine max) plants to Trichoplusia ni herbivory was tested experimentally under greenhouse conditions. This elicitory chemical, which allows receptor thiols to add across its carbon‐carbon double bond, altered the resistance in one or more leaves of plants at one or more intervals after treatment; and thus yielded results supporting the hypothesis. Leaf dipping and soil application were both effective methods of treatment. Results support the interpretation that an elicitor may function in intact plants by altering the integrity of sulfhydryl groups in receptor macromolecules which are also involved in signaling a change in the plant's biosynthesis of characteristic defensive compounds such as phenyl‐propanoids including antifeedant and antibiotic flavonoids. Induced feeding non‐preference by T. ni was highly correlated positively with the amount of glyceollins in the leaf.
Bionomics and population growth statistics of apterous virginoparae of woolly apple aphid, Eriosoma lanigerum, at constant temperatures
Authors: Asante S. K. , Danthanarayana W. , Heatwole H. 
Published: April 2011

AbstractDevelopment, survival, reproduction and population growth statistics of apterous virginoparae of woolly apple aphid, Eriosoma lanigerum (Hausmann) (Hemiptera: Aphididae) at constant temperatures of 10, 13, 15, 20, 25, 30 and 32 °C are reported. The developmental times of all life stages were inversely related to temperature ranging from 10 to 30 °C. Span of total development (time from birth to adulthood) decreased from 57.8 days at 10 °C to 11.7 days at 30 °C and increased to 16.8 days at 32 °C. A good linear model fit (R2 > 0.96) between developmental rate and temperature in the range 10–25 °C was observed for all life stages. The lower developmental threshold was estimated at 5.8 °C for instar I, 4.8 °C for instar II, 4.9° for instar III and 4.4 °C for instar IV. The lower temperature threshold for total development was estimated at 5.2 °C. The upper developmental limit was found to be 32 °C. Mean degree‐day accumulations required for completion of instars I, II, III, IV and total development were: 125.6, 51.0, 47.7, 50.7 and 267.6, respectively. Fecundity, larviposition period and adult longevity were reduced with increasing temperature. Net reproductive rate was greatest at 15 °C whereas intrinsic rate of increase peaked at 25 °C. Optimal performance, as measured by fecundity, survival and intrinsic rate of increase, ocurred in the range 13–25 °C.
Variation in biological characteristics and esterase patterns among populations of Bemisia tabaci, and the association of one population with silverleaf symptom induction
Authors: Costa H. S. , Brown J. K. 
Published: April 2011

AbstractBiological characteristics (oviposition and survival rates) and esterase banding patterns in native PAGE were investigated to evaluate variation among three populations of Bemisia tabaci Gennadius (Homoptera: Aleyrodidae). Reproductive capabilities of whiteflies from cotton (Gossypium hirsutum L.) and pumpkin (Cucurbita maxima Duchesne) populations were similar on the three host plant species tested. These populations, which had the same wild‐type field origin, reproduced better on either cotton and pumpkin than on poinsettia (Euphorbia pulcherrima Willdenow). In contrast, poinsettia whiteflies exhibited relatively similar reproductive capabilities for the three host species tested. Pumpkin and cotton whiteflies had similar esterase banding patterns (‘A’ type), while poinsettia whiteflies yielded a different banding pattern (‘B’ type). In transmission studies, whiteflies from cotton or pumpkin sources did not induce silverleaf (SSL) or white stem (WS) symptoms in Cucurbita spp. tested. In contrast, poinsettia whiteflies were associated routinely with SSL and WS symptoms in Cucurbita spp. following colonization by whitefly adults. From these data, it was possible to correlate a specific esterase banding pattern (A or B) with reproductive capabilities and the ability to induce SSL and WS symptoms.