Potential of using entomopathogenic nematodes in the management of diamondback moth Plutella xylostella (L.) (Lepidoptera:Plutellidae) in Kenya

Abstract

Laboratory studies were conducted on diamondback moth (DBM) larvae, Plutella xylostella (Linnaeus) (Lepidoptera: Plutellidae) using five different entomopathogenic nematodes (EPNS) isolates obtaine d from National Agricultural Research Laboratories, Kenya. The DBM larvae were obtained from field collections at Kabete Campus Field Station . The exposure time fifty ( ET 50 ) of the entomopathogenic nematode isolates to DBM larvae was determined by leaf dis c bioassay method. All the entomopathogenic nematode isolates tested caused mortality to the DMB larvae . The ET 50 of Steinernema karii was significantly higher than that of Heterorhabditis indica and Steinernema waiseri ( 95% fiducial limits at 1% level ). Th e ET 50 of the entomopathogenic nematodes tested ranged from 20.27 to 38.12 hours . The effect of time on the percentage mortality was significant ( d . f = 2,214 ; F = < 0.001 ). Average penetration rate for Heterorhabditis sp. , Steinernema sp., Steinernema kari i, Heterorhabditis indica, and Steinernema waiseri was 19.17% 31.67% 27.17% 46.41% and 75% respectively This study revealed that entomopathogenic nematodes (EPNs) have a great potential that should be exploited in diamondback moth management