Quality assessment of commercially produced entomopathogenic nematodes

The quality of the most widely commercialized entomopathogenic nematodes, S teinernema carpocapsae (Weiser) and Heterorhabditis bacteriophora Poinar, w as assessed from 30 shipments from six United States suppliers mailed to th ree locations. These suppliers comprise a cottage industry aimed in large p art at a mail-order market. Most companies were accessible and reliably shi pped pure populations of the correct species on time, in sturdy containers, and often with superb accompanying instructions. Nematodes were received i n satisfactory condition with acceptable levels of viability. Consistency, however; was a problem, with each supplier having one or more weak spots to bolster. Most shipments did not contain the expected nematode quantity, an d one shipment had no nematodes. Pathogenicity of several products against Galleria mellonella (L.) larvae was not equivalent to our controls. H. bact eriophora was not always available when ordered. A few products contained m ixed populations of both nematode species. Application rate recommendations provided by some suppliers appeared unsound. We conclude that (1) the ento mopathogenic nematode cottage industry lacks rigorous quality control, (2) self-regulation is problematic without feedback on quality, and (3) consume rs are rarely able to provide this feedback. Improved reliability by the ne matode industry will most likely be achieved via industry-generated agreeme nt on standards for quality. (C) 2000 Academic Press.