G. it. Ent., 8 (46): 309-313
August 31, 1997
Biology of Xylocopa (Xylocopa) violacea (Linnaeus, 1758)
(Hymenoptera: Apidae)
Male sexual behaviours. I
by
SALVATORE VICIDOMINI
Abstract - The ethological patterns involved in male-male interactions, interspecific interactions and wrong attempts at mating in males of Xylocopa violacea are described. Male-male interactions are involved (except wrong attempts at mating) in sexual recognition. In wrong attempts at homosexual mating (14 cases; 6.7% of all catches performed by males) a patroller male catches a second male and the homosexual couple alights on a perch; the patrolling male attempts copulation rubbing his hind legs against the metasomal sides, and his fore tarsi against the head apex of the caught male, buzzing continuously; moreover, the catcher male tries to bring into contact the two metasomal apexes. Homosexual attempts at mating may be explained as follows: a) changed secretion in the male intercepted; b) gynandromorphic individuals; c) alteration in the development of the behaviour of the male intercepted; d) traumatic insemination of the male intercepted; e) alteration in the sensorial systems of the catcher male. The interference by a male in a couple flight (7.6% of all catches performed by males) is explained in function of the sperm competition within the female involved in a polygamous mating system.
