Aleochara bilineata and Aleochara bipustulata are staphylinid beetles that are attracted to pitfall traps baited with dimethyl disulphide (DMDS), but the role of DMDS in their biology has not been elucidated. In still air, first instar larvae of both Aleochara species exhibited area-restricted movement when they came near to DMDS. DMDS increased the frequency of parasitism of D. radicum puparia, the preferred host, but the frequency of attacks on unpreferred piophilid puparia was not affected by DMDS. In still air, adult A. bilineata and A. bipustulata distribution was not consistently influenced by DMDS. In a Y-tube olfactometer, newly-emerged females of both species avoided DMDS-laden air; after 10 days mated females chose air with DMDS. Newly emerged males also avoided DMDS, but after 10 days mated males neither avoided nor selected DMDS-laden air: the shift in response was associated with mating status rather than age.

Aleochara bilineata and Aleochara bipustulata are staphylinid beetles that are attracted to pitfall traps baited with dimethyl disulphide (DMDS), but the role of DMDS in their biology has not been elucidated. In still air, first instar larvae of both Aleochara species exhibited area-restricted movement when they came near to DMDS. DMDS increased the frequency of parasitism of D. radicum puparia, the preferred host, but the frequency of attacks on unpreferred piophilid puparia was not affected by DMDS. In still air, adult A. bilineata and A. bipustulata distribution was not consistently influenced by DMDS. In a Y-tube olfactometer, newly-emerged females of both species avoided DMDS-laden air; after 10 days mated females chose air with DMDS. Newly emerged males also avoided DMDS, but after 10 days mated males neither avoided nor selected DMDS-laden air: the shift in response was associated with mating status rather than age.

Thesis (Ph. D.)--Ohio State University, 1976. / Includes vita. Includes bibliographical references (leaves 178-186). Available online via OhioLINK's ETD Center.

No description available.

Thesis (M.Sc.), Memorial University of Newfoundland, 2000. / Restricted until June 2001. Bibliography: leaves 82-87.

In Quebec 11 840 kg of insecticides are used against the cabbage maggot, Delia radicum L. (Diptera: Anthomyiidae) each year. It is possible to decrease this quantity of insecticide by using natural enemies such as fungi, nematodes, predators and parasitoids. Aleochara bilineata Gyllenhal (Coleoptera: Staphylinidae) is a natural enemy of the cabbage maggot. Adults of this species are predators of eggs and larvae of cabbage maggot and the first instar larvae are ectoparasitoids of cabbage maggot pupae. A. bilineata oviposits its eggs in the soil, near plants infested with cabbage maggots. / Differences in size have been noted in the eggs of A. bilineata . In insects several factors can affect egg size. Certain females can oviposit small trophic eggs which serve as food for emerging larvae or egg size can be affected by factors such as size and age of female, as well as, food and host quality. These factors have been studied in A. bilineata in order to determine the conditions that favor the production of small eggs. (Abstract shortened by UMI.)

No description available.

No description available.

Intercropping systems offer potential benefits relative to monocultures of increased crop yields and improved pest control through physical, chemical, or behavioural interference and the enhancement of natural enemy populations, prompting increased predation and parasitism. Intercrops of canola (Brassica napus L.) and wheat (Triticum aestivum L.) in various proportions were investigated at three sites in Alberta, Canada, in 2005 and 2006, to determine effects on 1) agronomic parameters, including crop grain and biomass yields, crop quality (canola oil and canola and wheat protein), lodging, soil microbial communities, and wheat leaf diseases; 2) pest insects, including flea beetle (Phyllotreta spp.) (Coleoptera: Chrysomelidae) damage to seedling canola and root maggot (Delia spp.) (Diptera: Anthomyiidae) adult collection numbers, egg populations, and canola taproot damage; and 3) beneficial insects, including ground beetles (Coleoptera: Carabidae) and the predator-parasitoid Aleochara bilineata Gyllenhal (Coleoptera: Staphylinidae). Crop yields were similar in intercrops and monocultures, and benefits of intercropping were observed in enhanced crop quality characteristics in some site-years. Neither soil microorganisms nor wheat leaf diseases generally responded to intercropping regimes. Intercropping did not reduce flea beetle damage to canola seedlings. Flea beetle damage was greatest at the first true-leaf stage of canola development. Although a thiamethoxam seed treatment reduced flea beetle herbivory, untreated plots generally did not sustain greater than 20% damage, suggesting that seed treatments were usually unnecessary. Adult Delia did not respond to intercropping canola with wheat, but egg populations were lower in intercrops on a land area basis. Canola taproot damage was as much as 13% reduced in intercrops compared to monocultures. Carabid beetles appeared to respond to qualities of the intercrops and monocultures, such as ground cover, rather than to the level of vegetational diversity itself, but carabid diversity was enhanced in diverse intercrops compared to canola monocultures in one site-year. Aleochara bilineata adult populations and parasitism rates were favoured in canola monocultures, but a temporal shift in A. bilineata adult collection numbers suggests reduced preference for canola monocultures in early summer. Benefits of canola-wheat intercrops identified in this study do not appear sufficient to recommend these cropping systems for widespread adoption in western Canada. / Plant Science

Lorsque deux espèces exploitent la même niche écologique, elles entrent en compétition pour l'accès aux ressources. Or, un accès limité aux ressources réduit la fitness des individus. La compétition interspécifique va donc agir comme une pression de sélection qui peut mener à des modifications physiologiques ou comportementales pour partager les ressources, car si elles ne sont pas partagées la compétition entraînera le déplacement ou la disparition d'une des deux espèces. Aleochara bilineata et A. bipustulata sont deux coléoptères staphylins parasitoïdes qui s'attaquent à la mouche du chou Delia radicum. Elles ont des paramètres biologiques différents, notamment au niveau des traits d'histoire de vie (qui semblent avantager A. bipustulata) et du spectre d'hôtes (plus généraliste chez A. bipustulata). Ces deux espèces partagent cependant la même stratégie d'exploitation des hôtes et présentent l'originalité que la femelle pond ses œufs à proximité des hôtes et non à l'intérieur, ce qui les distingue des hyménoptères parasitoïdes qui font l'objet de nombreuses études. La larve Aleochara de premier stade est donc mobile et doit trouver et sélectionner elle même un hôte pour s'y développer. Il y a ainsi des possibilités d'adaptations comportementales à la compétition à la fois pour les adultes et les larves de premier stade. Dans ce projet de thèse, nous avons donc choisi d'explorer la niche écologique de ces deux espèces de façon originale en étudiant les modifications comportementales induites par la présence de compétiteurs à la fois chez les femelles adultes et les larves de premier stade. Nous avons également identifié les communautés bactériennes associées aux deux espèces en compétition mais aussi à leur hôte D. radicum et à un autre compétiteur parasitoïde, l'hyménoptère Trybliographa rapae, dans le but d'étudier ultérieurement les impacts des différents partenaires bactériens sur la niche écologique des deux espèces de coléoptères en compétition. Nos résultats montrent que les femelles de l'espèce spécialiste A. bilineata adaptent leurs comportements aux compétiteurs qu'elles rencontrent et sélectionnent les sites de ponte présentant les meilleures chances de succès parasitaire pour leurs larves. Par ailleurs, les larves de premier stade de l'espèce spécialiste dominent largement la compétition larvaire lorsqu'elles sont en compétition avec les larves de l'espèce généraliste. Enfin, les communautés bactériennes des deux espèces de coléoptères sont plus proches entre elles qu'avec les autres membres du réseau trophique étudiés mais comportent des différences à explorer. Ces résultats sont discutés dans le cadre de l'adaptation des choix comportementaux des individus d'une espèce spécialiste à la présence de compétiteurs généralistes et de la coexistence de ces deux espèces dans le milieu naturel. / When two species live in the same ecological niche, they compete for resources. Since a limited access to resources reduces fitness, interspecific competition represents a selection pressure that can lead to physiological or behavioral changes to share resources, because not sharing them will cause the displacement or disappearance of the weaker competitor. Aleochara bilineata and Aleochara bipustulata are two coleopteran parasitoids and attack the same host, the cabbage root fly Delia radicum. These two species have different biological parameters, particularly in their life history traits (which seem to favor A. bipustulata) and host spectrum (A. bipustulata is more generalist). These two species share the same strategy to exploit their host (idiobiont ectoparasitoid). Unlike parasitoid wasps (the object of most studies on parasitoids) coleopteran parasitoid females do not lay their eggs directly inside the host but in locations likely to harbour hosts. Aleochara first instars are mobile and need to find and select a host where they will develop. There is thus the possibility of behavioral adaptations to competition for both for adults and first instars. In this project, we have chosen to explore the ecological niche of these two species in an original way by studying behavioral changes induced by the presence of competitors both in adult females and first instars. We also studied bacterial communities associated to the two competing species but also those of their host D. radicum and of another competitor, the parasitoid wasp Trybliographa rapae, in order to later study the impacts of different bacterial partners in the ecological niche of the two beetle species in competition. Our results show that females of the specialist A. bilineata adapt their behavior to the competitors they face and select oviposition sites with the best probability of parasitism success. Moreover, first instars of A. bilineata dominate the larval competition when competing with larvae of the generalist A. bipustulata. Finally, bacterial communities of the two rove beetles are closer to each other than other members of the food web studied and their differences should be investigated. These results are discussed in the context of behavioral adaptation of specialists to the presence of generalist competitors and the coexistence of these two species in the field.