The sesquiterpene (E)-β-farnesene (EBF) is the alarm pheromone for many species of aphids [1]. When released from aphids attacked by parasitoids or predators, it alerts nearby conspecifics to escape by walking away and dropping off the host plant [2, 3]. The reception of alarm pheromone in aphids is accomplished through a highly sensitive chemosensory system. Although olfaction-related gene fam...

Discussions of intraguild predation (IGP) have assumed that the nutritional quality of intraguild (IG) prey is similar to that of any other prey available to the IG predator. It has been suggested therefore that generalist predators do not distinguish between healthy and parasitized aphids and thus function as facultative predators of parasitoids. More recent studies have shown that predators m...

A model was developed to estimate the effect of predation by Episyrphus balteatus larvae on aphid populations in fields of winter wheat. Feeding rate of syrphid larvae was estimated from experiments in field cages using a Holling type-III function. During larval development, syrphids consumed a maximum of 396 aphids, which is only half the potential feeding rate reported from laboratory experim...

The pea aphid Acyrthosiphon pisum Harris has been shown to produce an increasing proportion of winged morphs among its offspring when exposed to natural enemies, in particular hoverfly larvae, lacewing larvae, adult and larval ladybirds and aphidiid parasitoids. While these results suggest that wing induction in the presence of predators and parasitoids is a general response of the pea aphid, t...

Explaining the coexistence of closely related species sharing a single resource has been a long-standing challenge in ecology. Here we report on studies comparing the aphids Aphis nerii and A. asclepiadis that feed sympatrically on the milkweed Asclepias syriaca in northeastern North America. We sought to identify tradeoffs among species’ attributes that might promote coexistence, but in most i...