Dispersal of Heterorhabditis baujardi LPP7 (Nematoda : Rhabditida) applied to the soil as infected host cadavers

In orchards, in cases where the insect pests are concentrated under the canopy, entomopathogenic nematodes can be applied as infected host cadavers. This study evaluated the distribution of Heterorhabditis baujardi Phan, Subbotin, Nguyen Moens strain LPP7 applied as one or 15 host cadavers per plot in a guava orchard. The plots were located between guava trees, with the host cadavers being placed in the centre. Soil samples were taken at 1, 3, 5, 8 and 10 weeks after cadaver application. On each date, the plots were sampled at 30, 60, 90 and 120cm from the cadaver application point and at three different depths (0-10, 10-20 and 20-30cm). The highest average number of recovered infective juveniles was found at 90cm from the cadaver application point, and at 10cm depth and on the fifth week after application. There was no significant effect on the number of recovered infective juvenile nematodes, when they were applied as one or 15 cadavers, although the most uniform dispersal was found when 15 host cadavers were applied. We discuss the significance of these results.