Summary: S H O R T C O M M U N I C A T I O N
Consequences of thrips-infested plants for attraction
of conspeci®cs and parasitoids
A N U R A G A . A G R A W A L and R A M A N A G . C O L F E R Department of Entomology,
Center for Population Biology, University of California, Davis, U.S.A.
Key words. Competition, Frankliniella occidentalis, Gossypium hirsutum, induced
resistance, omnivory, plant defence, plant±insect interactions, plant volatiles,
Tetranychus urticae, tri-trophic interactions.
Tri-trophic interactions among plants, herbivores, and natural
enemies of herbivores are important in determining the
abundance and distribution of organisms in natural and
managed ecosystems. Understanding of the complexity of
these interactions has grown tremendously since Price et al.
(1980) wrote a seminal review of the topic. In particular, the
role that the plant±herbivore interaction plays in affecting the
third trophic level is of growing interest (Takabayashi &
Dicke, 1996; Agrawal & Rutter, 1998; Thaler, 1999). Plants
infested with herbivores release cues that can provide
information to herbivores, predators, and parasitoids in the