Heterorhabditis spp., Neoaplectana spp., and Steinernema kraussei: interspecific and intraspecific differences in infectivity for insects.

The effectiveness of various dosages of different species/strains of nematodes was compared for Galleria mellonella and various pest insects that live in or pupate in soil. Neoaplectana feltiae (= carpocapsae), the only nematode species tested by most other workers, was never the most infective for any of the insect species tested and was least infective for two. All species/strains of nematode were able to kill insects of each species. The degree of infectivity of each of the nematode species/strains for different hosts varied considerably, and no one species/strain of nematode was the most infective for all insect species. This indicates the importance of testing a number of nematode species against any particular insect before commencing field evaluations for biological control.