Hyperparasitism: Multitrophic ecology and behavior

Hyperparasitoids are secondary insect parasitoids that develop at the expen se of a primary parasitoid, thereby representing a highly evolved fourth tr ophic level. This review evaluates multitrophic relationships and hyperpara sitoid ecology. First, hyperparasitoid communities of various taxa of phyto phagous and predacious insects are described. Second, specific patterns of hyperparasitoid community organization and hyperparasitoid ecology are desc ribed in detail, using the aphid-parasitoid-hyperparasitoid food web as a m odel system. Aphid hyperparasitoid communities consist of ecto- and endohyp erparasitoids, with ectohyperparasitoids being less host specific than endo hyperparasitoids. Lifetime fecundity and intrinsic rate of increase of hype rparasitoids are generally lower than those of their primary hosts. Aphid e ctohyperparasitoids search randomly for hosts and do not use specific cues, whereas endohyperparasitoids gain information that originates from host pl ants or hosts for long-range search. Interactions with adult primary parasi toids do not influence hyperparasitoid searches, but aphid-attending ants t ypically prevent successful hyperparasitoid foraging. Impact of hyperparasi tism on biological control is reviewed.