Coenonympha oedippus is a rare and seriously threatened butterfl y species all across most of Europe, and is listed in the Annexes II and IV of the EU Habitats Directive. In Italy this species is restricted to the Padano-Venetian plains, which represent the southernmost part of its European range. 14 of the 108 Italian populations are known to have become extinct. All Italian populations of C. oedippus are closed populations, almost invariably located at reciprocal distances incompatible with adults inter-exchange, as well as with the creation of a meta-population structure. At least in some cases, however, the population density is still high and some populations are very large (Balletto et al. 2005). We studied a C. oedippus population in 2 adjoining areas within the «Baraggia » Regional Oriented Reserve, in Piedmont. The fi rst study area is represented by a regularly mown Molinia coerulea grassland. The second area has a mixed Calluna vulgaris and M. coerulea cover. We investigated the adults’ population dynamics by mark-release-recapture methods and obtained information on their spatial behaviour by noting the position of every captured and recaptured individual. We also studied females’ oviposition behaviour. In the 2 years of our study, adults emerged in mid June and fl ew until the fi rst decade of July. The overall estimated population size was of 1404 adults in 2005, and of 2141 adults in 2006. The operational sex ratio was 1.88:1 (♂♂/♀♀). Females generally laid their eggs on Molinia coerulea, or otherwise on Calluna vulgaris. The larvae consumed on the fi rst plant only. We discuss possible conservation strategies and try to elucidate reasons underlying the still relatively good conservation status of Italian populations
Ecology of Coenonympha oedippus (FABRICIUS, 1787)(Lepidoptera: Nymphalidae) in Italy
BONELLI, Simona;CANTERINO, SARA;BALLETTO, Emilio
2010-01-01
Abstract
Coenonympha oedippus is a rare and seriously threatened butterfl y species all across most of Europe, and is listed in the Annexes II and IV of the EU Habitats Directive. In Italy this species is restricted to the Padano-Venetian plains, which represent the southernmost part of its European range. 14 of the 108 Italian populations are known to have become extinct. All Italian populations of C. oedippus are closed populations, almost invariably located at reciprocal distances incompatible with adults inter-exchange, as well as with the creation of a meta-population structure. At least in some cases, however, the population density is still high and some populations are very large (Balletto et al. 2005). We studied a C. oedippus population in 2 adjoining areas within the «Baraggia » Regional Oriented Reserve, in Piedmont. The fi rst study area is represented by a regularly mown Molinia coerulea grassland. The second area has a mixed Calluna vulgaris and M. coerulea cover. We investigated the adults’ population dynamics by mark-release-recapture methods and obtained information on their spatial behaviour by noting the position of every captured and recaptured individual. We also studied females’ oviposition behaviour. In the 2 years of our study, adults emerged in mid June and fl ew until the fi rst decade of July. The overall estimated population size was of 1404 adults in 2005, and of 2141 adults in 2006. The operational sex ratio was 1.88:1 (♂♂/♀♀). Females generally laid their eggs on Molinia coerulea, or otherwise on Calluna vulgaris. The larvae consumed on the fi rst plant only. We discuss possible conservation strategies and try to elucidate reasons underlying the still relatively good conservation status of Italian populations
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
