Territorial and reproductive behaviour in a sympatric species complex of the neotropical damselfly Cora Selys (Zygoptera: Polythoridae)

Sympatric populations of i C. semiopaca, C. notoxantha and C. obscura were studied along a forest creek at El Rodeo Biological Reserve in Costa Rica. Territorial and reproductive behaviour of these 3 spp. are described and compared with C. marina. the only other Cora sp. studied to date. Males defended territories centered around rotting wood in the creek bed, used by females for oviposition. Territories of C. semiopaca. C. notoxaniha and C. ohscura were interspersed along the creek and were occupied simultaneously during the day. Extensive spatial and temporal overlap of resource use by the 3 spp. allowed for considerable interspecific interaction at the study site. Aggressive behaviour of males was similar among the 3 spp., with the exception of an escalated ascending spiral contest, observed only between C. semiopaca males. Reproductive behaviour was not elaborate; males did not perform courtship or postcopulatory site displays to females. Males of all spp. were rarely observed transferring sperm to their accessory genitalia, either while in tandem or while perched alone. The authors were unable to distinguish between females of the 3 Cora spp. at the study site. From records of marked individuals it also appears that semiopaca, notoxantha and obscura males could not distinguish between females of the 3 spp. since a high percentage (32%) of multiple mating females copulated with males of more than one Cora spp. Interspecific mating involved full (unshortened) copulation, often followed by oviposition. Recent sympatry of these 3 spp. is the most plausible explanation for an apparent lack of a premating reproductive isolating mechanism in these species. However, the possibility that these putative species are morphological variants of the same species is suggested.