Olesicampe monticola (Hedwig) (Hymenoptera: Ichneumonidae) redescribed together with notes on its biology as a parasite of Cephalcia lariciphila (Wachtl) (Hymenoptera: Pamphiliidae)

Abstract

The sawfly Cephalcia lariciphila (Wachtl) is a pest of larch (Larix spp.) that has recently become widespread in Britain. Before taking measures to control the sawfly the status of parasites in the infestations was investigated. The only insect parasite species found was the ichneumonid Olesicampe monticola (Hedwig), which is new to Britain. As this insect is taxonomically so poorly known it is redescribed from specimens collected in South Wales. The preliminary biological observations show O. monticola to be welladapted to its host and that it can significantly reduce an infestation.

The classification, evolution and biology of the Costa Rican species of Cryptophion (Hymenoptera: Ichneumonidae)

“…A number of groups have radiated to exploit the larvae of other holometabolous insects occurring in similar situations. For example, species of the genus Olesicampe develop in the larvae of tenthredinoid symphytans (Pschorn-Walcher & Zinnert, 1971;Billany et al, 1985) and species of Lemophagus attack chrysomelids (Carlson, 1979). Oviposition is into the larva of the host (Fisher, 1959;Frilli, 1965).…”

Management of Pest Threats

“…Barbosa and Schaefer (1997) assessed this hypothesis in an analysis of invasions by four species of lymantriid moth in North America and concluded that there was little evidence to support the view that impacts were greater in the absence of the full spectrum of natural enemies. Populations were subsequently regulated to very low densities by an accidentally intro-duced parasitoid Olesicampe monticola (Hymenoptera: Ichneumonidae) (Billany & Brown 1980;Billany et al 1985), thereby restoring a specific host-parasitoid relationship that is a normal factor in the natural range of the sawfly in Europe. Extensive tree damage was observed in both situations and, in both cases, a baculovirus (nucleopolyhedrovirus) was introduced, either deliberately (Canada: Bird & Elgee 1957), or by natural appearance and spread (Wales: Entwistle et al 1983).…”