animals that can estimate their desirable habitat quality are better able to accordingly adapt their life behaviors. the life cycles of parasitoids are so closely adapted as to match their hosts life behavior. among the various host-parasitoid interactions, a peculiarity is the seasonal synchrony between host and parasitoid activity. the foraging and oviposition behaviors of lysiphlebus fabarum...

the black bean aphid, aphis fabae scopoli, is a major pest of broad bean, vicia faba l. and sugar beet, beta vulgaris l., the most abundant parasitoid of a. fabae in agroecosystems is lysiphlebus fabarum (marshall), a multivoltine species with mainly thelytokous reproduction in central europe. since l. fabarum females mimic ants to obtain honeydew directly from aphids it was reasoned that a fem...

In Iran, Lysiphlebus fabarum (Marshall) (Hymenoptera: Braconidae: Aphidiinae) is a uniparental parasitoid of the black bean aphid, Aphis fabae Scopoli (Hemiptera: Aphididae), that possesses various highly evolved adaptations for foraging within ant-tended aphid colonies. Direct observations and video recordings were used to analyze the behavior of individual females foraging for A. fabae on bea...

The Asian parasitoid, Binodoxys communis (Gahan) (Hymenoptera: Braconidae), is a candidate for release against the exotic soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), in North America. In this study, we examined preferences by B. communis for the different developmental stages of A. glycines and investigated consequences of these preferences for parasitoid fitness. We also de...

Although kin selection is central to the modern study of social evolution, recent studies of social species have revealed that no simple relationship exists between levels of kinship and sociality. The soldier-producing aphids are unique among highly social animals because, barring movement by aphids between colonies, they occur in clonal groups of genetically identical individuals. Potentially...

Facultative endosymbionts can induce benefits and costs to their aphid hosts. In the pea aphid, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae), infection with ?-proteobacterium Hamiltonella defensa Moran et al. confer resistance against parasitoids, but may also reduce frequency of aggressive escape behaviours exhibited in response predators. potato aphids, Macrosiphum euphorbiae (Thomas) ...

Many insects are associated with heritable symbionts that mediate ecological interactions, including host protection against natural enemies. The cowpea aphid, Aphis craccivora, is a polyphagous pest that harbors Hamiltonella defensa, which defends against parasitic wasps. Despite this protective benefit, this symbiont occurs only at intermediate frequencies in field populations. To identify fa...

The benefits of mutualistic interactions are often highly context dependent. We studied the interaction between the milkweed aphid Aphis asclepiadis and a tending ant, Formica podzolica. Although this interaction is generally considered beneficial, variation in plant genotype may alter it from mutualistic to antagonistic. Here we link the shift in strength and relative benefit of the ant-aphid ...