Chemical Detection of Natural Enemies by Arthropods: An Ecological Perspective

Abstract

Food webs are overlaid with infochemical webs that mediate direct and indirect interactions. The infochemicals may result in shifts in trait values, which affect the strength of species interactions. As a consequence, population dynamics and evolutionary changes can be affected. Chemical information can mediate the interactions between animals and their resources, competitors and enemies. Of all chemical information gathered by animals, cues about predation risk are of special significance because predation risk usually has important and immediate consequences on fitness. In this paper we selectively review the role of chemical information in enemy avoidance by arthropods. Arthropods not only constitute important components of food webs, being the largest group in numbers and species diversity; they also make excellent models for ecological studies. We discuss the evidence, the key mechanisms, and the trade-offs involved in chemical detection of enemies by potential arthropod prey. Further, we address the variation in prey responses and the evidence for learning in avoiding enemies by arthropods. Finally, we identify and prioritize major questions to be tackled by future studies.

“Sleeping with the enemy”—predator-induced diapause in a mite

“…Predator-associated volatile cues can stem directly from the predators, but they can also be produced by prey in reaction to the predator, for instance when prey is alarmed, injured or dead (Dicke and Grostal 2001). For spider mites, in particular, there is evidence that they respond to odours from injured conspecifics (Janssen et al 1997;Oku et al 2003), but to date, the relevant chemicals have not been identified.…”

Variability in Sensory Ecology: Expanding the Bridge Between Physiology and Evolutionary Biology

“…The influence of the sensory drive hypothesis on animal sensory performance is likely to be important outside the context of mate choice, especially in regard to such activities as the detection of predators or the procurement of food, but this line of research has barely been explored (but see Dicke and Grostal 2001 for the chemical detection of natural enemies by arthropods; Neuweiler 1989 for the role of hearing in bat foraging ecology; Dominy et al 2001 andRegan et al 2001 for the perception of visible light by primates to assess the edibility of food items). Dangles et al (2005) quantified the natural phenotypic variation in structure and performance of the air-flow sensing cercal system in five cricket populations from diverse habitats and predator communities.…”

Field Evidence of an Airborne Enemy-Avoidance Kairomone in Wolf Spiders

“…Semiochemicals among insects have been studied extensively, but comparable studies among spiders have received less attention (Francke and Schulz, 1999;Dicke and Grostal, 2001;Schulz, 2004). Of the studies documenting behavioral responses to chemical cues among spiders, the vast majority (reviewed in Schulz, 2004) have examined pheromones rather than kairomones or other types of semiochemicals.…”