A hybridized Foundation population of the entomopathogenic nematode Steinernema feltiae was bidirectionally selected for enhanced and diminished host-finding ability. While there was no response to selection for diminished host-finding, 13 rounds of selection for enhancement produced a 20- to 27-fold increase. Moreover, the proportion of infectives initiating positive chemotaxis was increased from less than one-third to more than 80%. Nematodes failing to migrate out of the inoculation zone declined from 33 to 8% after 6 rounds of selection. Relaxation of selection pressure produced a gradual decrease in host-finding. This regression, coupled with the high realized heritability for enhanced host-finding (0.64), suggests that wild-type populations take a passive approach to host-finding. Because for inundative biological control it is desirable that infective stages quickly initiate host-seeking movements, improved host-finding may result in improved field efficacy.
All Science Journal Classification (ASJC) codes
- Ecology, Evolution, Behavior and Systematics
- Neoaplectana carpocapsae
- Steinernema feltiae
- entomopathogenic nematode
- genetic improvement
- nematode behavior