A new species of Heterospilus (Hymenoptera : Braconidae) associated with the deathwatch beetle, Hemicoelus gibbicollis (LeConte) (Coleoptera : Anobhdae)

摘要

Heterospilus luridostigmus Marsh, a new braconid wasp species, is described. This wasp was found in abundance emerging from pieces of Douglas-fir, Pseudotsuga menziesii (Mirbel) Franco, from an outdoor wooden deck in Daly City, California, that was infested with the deathwatch beetle, Hemicoelus gibbicollis (LeConte). Adult Heterospilus luridostigmus began emerging in May 1999 followed by emergence of Hemicoelus gibbicollis about 4 weeks later. Both species continued to emerge throughout the summer of 1999 and were the only species found in the boxes. During the summer of 2000, rearing boxes containing infested wood from the original source and from several homes in Alameda County, California yielded both Heterospilus luridostigmus and Hemicoelus gibbicollis as well as Odontocolon polymorphum Cushman (Hymenoptera: Ichneumonidae). Although we found no direct evidence of parasitism of Hemicoelus gibbicollis, wasps in the genera Heterospilus and Odontocolon are known to parasitize anobiids, and Heterospilus flavicollis (Ashmead) is a parasitoid of an eastern deathwatch beetle species, Hemicoelus carinatus (Say). This suggests that Heterospilus luridostigmus is a parasitoid of Hemicoelus gibbicollis. The synchrony of emergence of these two species during both years also is indicative of a host/parasitoid relationship between the two species. The discovery of a new insect species in a heavily populated urban environment is noteworthy and serves as a vivid reminder of the untold number of insect species that have yet to be discovered.