Susceptibility of the lesser peachtree borer (Lepidoptera : Sesiidae) to entomopathogenic nematodes under laboratory conditions

• Author(s): Cottrell, T.; Shapiro-Ilan, D.;
• Abstract: The lesser peach tree borer, Synanthedon pictipes (Grote and Robinson), is an important pest of Prunus spp. We determined the susceptibility of S. pictipes to six entomopathogenic nematode species: Heterorhabditis bacteriophora Poinar, H. indica Poinar, Karunakar and David, H. inarelatus Liu and Berry, Steinernema carpocapsae (Weiser), S. feltiae (Filipjev), and S. riobrave Cabanillas, Poinar and Raulston. Nematode virulence in S. pictipes was compared with virulence in two known susceptible hosts, Galleria mellonella L. and Tenebrio molitor L. In S. pictipes, the steinernematids were more virulent than the heterorhabditids, the virulence of S. carpocapsae was greater than S. riobrave, with S. feltiae being intermediate between the two, and no differences in virulence were detected among the heterorhabditids. Each nematode exhibited similar or greater virulence to S. pictipes than to T molitor, and the steinernematids virulence to S. pictipes was greater or similar to H. bacteriophora or H. marelatus virulence in G. mellonella. A quadratic dose-response relationship was detected between S. carpocapsae and S. pictipes, and an LC50 was estimated to be 7.99. Comparisons of steinernematid reproductive potential per host, or per milligram host, generally indicated the highest production in G. mellonella; production in S. pictipes was similar or greater than in T. molitor. In S. pictipes, no differences in reproduction were detected among nematode species. Based on our findings and other studies on related insect species, we conclude that the prospects for controlling S. pictipes with entomopathogenic nematodes are promising (particularly with S. carpocapsae and S.feltiae), and field testing is warranted.
• Publication Date: Apr 2006
• Journal: Environmental Entomology