Psyche: A Journal of Entomology
A number of predatory animals use deception, including odors, signals, and bait-like body appendages or objects to lure prey (Alcock, 1984). Several spider species are known to emit chemical odors that mimic the sex attractants of certain noctuid or saturniid moths as a means of luring males to be captured (Tietjen and Rovner, 1982). Here we provide evidence that the social spider species, Mallos gregalis, uses a scented "bait" to attract prey. Our results indicate that this odor is produced by yeasts growing on the carcasses of previously fed-upon flies which these spiders incorporated into their webs.
Tietjen, William James; Ayyagari, L. Rao; and Uetz, George W., "Symbiosis Between Social Spiders and Yeast: The Role in Prey Attraction" (1987). Faculty Scholarship. 255.