Monday, December 10, 2007 - 5:11 PM

Bee nest parasites (Meloe franciscanus) use sexual deception to obtain transport to host bee (Habropoda pallida) nest

Leslie Saul-Gershenz, lsaul@meer.net1, Jocelyn G. Millar, millar@ucr.edu2, and J. Steven McElfresh, steve.mcelfresh@ucr.edu2. (1) Center for Ecosystem Survival, Conservation Research, 699 Mississippi St, Suite 106, San Francisco, CA, (2) University of California - Riverside, Department of Entomology, 3401 Watkins Drive, Riverside, CA

Cooperative behaviors are common among social insects such as bees, wasps, ants, and termites, but they have not been reported from insect species that use aggressive mimicry to manipulate and exploit prey or hosts. Here we show that larval aggregations of the blister beetle Meloe franciscanus, which parasitize nests of the solitary bee Habropoda pallida, cooperate to exploit the sexual communication system of their hosts by producing a chemical cue that mimics the sex pheromone of the female bee. Male bees are lured to larval aggregations, and upon contact (pseudocopulation) the beetle larvae attach to the male bees. The larvae transfer to female bees during mating and subsequently are transported to the nests of their hosts. To mimic the chemical and visual signals of female bees effectively, the parasite larvae must cooperate, emphasizing the adaptive value of cooperation between larvae. The aggressive chemical mimicry by the beetle larvae and their subsequent transport to their hostsí nests by the hosts themselves provide an efficient solution to the problem of locating a critical but scarce resource in a harsh environment.

keywords: aggressive chemical mimicry, cooperative behavior, Habropoda pallida, Meloe franciscanus, phoresy, Mojave Desert

Species 1: Coleoptera Meloidae Meloe franciscanus (blister beetle)
Species 2: Hymenoptera Apidae Habropoda pallida (digger bee)