EFFICACY OF ENTOMOPATHOGENIC NEMATODE (STEINERNEMA KARII ) IN CONTROL OF TERMITES (COPTOTERMES FORMOSANUS)

Abstract

Entomopathogenic Nematodes (EPNs) are soil parasites that infect different types of arthropods e.g. larva of butterflies, moth, beetles and grasshopper thus affecting them in various ways. This is through reducing their fertility or causing sterility, delaying development and shortening longevity of the arthropods. Termites also sometimes suffer chance infections from the Steinernematids that become naturally dispersed in ordinary soil. Often, this result in the death of the affected termite but the impact on the termite colony itself is generally minor and of limited duration. The main aim of this study was to determine the susceptibility of termites to EPNs (Steinernema karii) in a laboratory set up as a candidate for bio-control. The method used involved trapping the termites in petri dishes and infecting them with EPNs. Termites were also exposed to EPNs in a simulated natural habitat and the efficacy determined. It was found that infection in petri dish resulted in as high as 100% mortality especially in worker termites. There was little impact of EPNs on termites in the soil although workers showed higher mortality than soldier termites. At P=0.05, significant mortality difference was noted between EPNs-infected termites and control group in petri dish bioassays. Moreover, there was significance difference between soldiers and workers in terms of mortality rate. Infection in simulated natural habitat yielded less significant results compared to control group. It was concluded that S. karii has the potential to control termites, but methods have to be devised to allow maximum exposure of termites to the EPNs in their natural habitat.