The communication in social hymenoptera involves the use of antennae as sensory appendages to perceive various signals among which the pheromones have an extremely important role. However, the fact that antennae are not exclusively receivers of signals, but also producers and emitters of chemicals, discloses intriguing new hypothesis about the ways members of the colony can send and receive a message. This situation applies to all three major taxonomic groups of social Hymenopterans, i.e. ants, wasps and bees. Here we present some new data on some Vespoidea and Apoidea.
The number of the glanded antennomeres varies between 11 (A3-A13 in Polistes gallicus and Vespa crabro), 10 (A3-A12 in Bombus pascuorum) and 1 to 5 (A5-A9 in Apis mellifera). The external features of the release sites can be conspicuous, such as tyloids in V. crabro or slightly raised areas in B. pascuorum, or incospicuous as in A. mellifera. Cuticular pores of glands type 3 are visible with SEM, while those of type 1 can only be seen with TEM. In case of the former gland type, a paste-like secretion is often present externally. Both types of glands can be associated with the same release site, e.g. V. crabro, P. gallicus and B. pascuorum, or only gland type 1 can be present, as in A. mellifera. A unique feature, observed in V. crabro is a well developed cuticular apodeme corresponding to the release site.
Observations on mating behaviour and morphology carried out on some parasitoids (Terebrantia) and on a solitary bee (Aculeata) have shown that the secretion, either volatile or acting on contact, induces sex recognition in the female. In light of this, although behavioural observations are still lacking or unclear, we hypothesize also for social hymenopterans the existence of a courtship pheromone.
Species 1: Hymenoptera Apidae Apis mellifera (honey bee)
Species 2: Hymenoptera Apidae Bombus pascuorum (bumbl ebee)
Species 3: Hymenoptera Vespidae Vespa crabro (European hornet)
Keywords: sex pheromone, mating behavior
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA