Di. Shapiro et I. Glazer, COMPARISON OF ENTOMOPATHOGENIC NEMATODE DISPERSAL FROM INFECTED HOSTSVERSUS AQUEOUS SUSPENSION, Environmental entomology, 25(6), 1996, pp. 1455-1461
Dispersal of the entomopathogenic nematodes Heterorhabdidtis bacteriop
hora Poinar (HP88 strain) and Steinernema carpocapsae (Weiser) (All st
rain) was measured when nematodes were applied to sand either in Galle
ria mellonella (L.) cadavers or in aqueous suspension. Dispersal abili
ty was estimated as the percentage of nematodes that migrated through
sand or from sand onto an agar surface. Results of overnight assays in
dicated that the dispersal ability of both species was significantly g
reater when nematodes were applied in cadavers relative to when they w
ere applied in aqueous suspension. Assays that measured migration onto
an agar surface after 1 h also indicated. enhanced. dispersal of S. c
arpocapsae when exiting cadavers, but results from H. bacteriophora on
ly weakly supported the trend. The relatively greater movement of nema
todes exiting infected hosts was not the result of differences in nema
tode age or persistence in sand. Tile enhanced dispersal may have been
caused by physiological or behavioral differences between nematodes e
xiting hosts and those kept in aqueous suspension. Because of the disp
ersal advantage. application of entomopathogenic nematodes in infected
hosts may increase their efficacy in biological control. This study d
emonstrated a need to further investigate behavior of entomopathogenic
nematodes when they exit a host under natural conditions.