This work details theory in which selection favors generalists in a more variable environment. Specifically, in a two-host-one-parasitoid model, temporal variation in host abundances alters the optimal searching strategy and leads to the evolution of more generalist parasitoid strategies. Consistent with empirical observations, parasitoids learn host/plant odors, and use them as a cue to search...

The obliquebanded leafroller, Choristoneura rosaceana (Harris), is one of the major arthropod pests of apple in the United States. In 1999 and 2000, a survey of the obliquebanded leafroller parasitoid complex in commercially managed apple orchards in Michigan's two largest fruit production regions was conducted to determine the species present and their importance to obliquebanded leafroller po...

Flexibility in adult body size allows generalist parasitoids to use many host species at a cost of producing a range of adult sizes. Consequently, host selection behaviour must also maintain a level of flexibility as adult size is related to capture efficiency. In the present study, we investigated covariance of two plastic traits--size at pupation and host size selection behaviour-using Aphidi...

Biological control on crop infesting insects represent an useful method in modem agriculture. A search for parasitoids of the macadamia nutborer was carried out during a three year study, and their effect on the population fluctuation of the borer was determined. An egg parasitoid belonging to the family Trichogrammatidae and four larval parasitoids, Microgastrine I, Microgastrine II, Ascogaste...

Aspects of Biosteres arisanus (Sonan) (= Opius oophilus Fullaway) (Hymenoptera: Braconidae) development on the oriental fruit fly, Bactrocera (= Dacus) dorsalis (Hendel), were investigated to facilitate mass production in the insectary. Life table statistics were generated for cohorts of B. arisanus females. Overlap in the emergence of fruit flies and parasitoids necessitated a procedure for se...

Backround: Helicoverpa armigera is major maize pest, while Conopomorpha cramerella cocoa main insect pest. Their larvaes lie in corn cob and pulp which can be controlled using egg parasitoids. Methods: Exploring H. eggs on female flowers a plant along the 50 m line at 10 points with 4 distance to obtain C. cramrella. Egg parasitoids were obtained by taking from cacao pod, Corcyra cephalonica tr...

piezodorus guildinii (hemiptera: pentatomidae) is an important soybean pest, and one of its main natural enemies is telenomus podisi (hymenoptera: platygastridae). rearing of the parasitoid is constrained by the hosts' egg quality, which deteriorates after few generations in laboratory, therefore, cold-stored host eggs utilization could be a useful tool for augmentative biological control. thus...

The whiteflies Bemisia tabaci Gennadius and Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) are two of the main pests in tomato crops. Their biological control in Mediterranean IPM systems is based on the predators Macrolophus pygmaeus (Rambur) and Nesidiocoris tenuis Reuter (Hemiptera: Miridae), as well as on the parasitoids Eretmocerus mundus (Mercet) and Encarsia pergandiella H...

The introduction of an exotic species may alter food webs within the ecosystem and significantly affect the biodiversity of indigenous species at different trophic levels. It has been postulated that recent introduction of the brown marmorated stinkbug (Halyomorpha halys (Stål)) represents an evolutionary trap for native parasitoids, as they accept H. halys egg masses as a host but produce no v...

Theory predicts that intraguild consumers such as predators or parasitoids may displace more specialized heterospecific competitors and thereby actually increase the population densities of a shared host or prey. We tested this idea with a native primary parasitoid, Eretmocerus eremicus, and an exotic autoparasitoid Encarsia sophia, both attacking the sweetpotato whitefly Bemisia tabaci. Autopa...