FACTORS AFFECTING PROPAGATION OF HETERORHABDITTIS BACTERIOPHORA POINAR, AN ENTOMOPATHOGENIC NEMATODE IN PLUTELLA XYLOSTELLA (L.)

Abstract

Entotomopathogenic nematode, Heterorhabittis bacteriophora possess tremendous potential for biological control of Plutella xylostella (L.) commonly known as the diamond back moth (DBM), major pest of cabbage and cauliflower. Five parameters viz., incubation dose, host body weight, incubation temperature, host food plant and host feeding status were taken to determine their effect on the propagation of H. bacteriophora in final instar of P. xylostella. The number of infective juveniles (IJs) produced increased with the increase in the inoculation dose up to 15 (IJs) per larva. Further increase in dose adversely affected the nematode progeny production because of overcrowding. A positive correlation between host body weight and number of IJs/mg body weight was observed (r=0.8343). Optima temperature for H. bacteriophora was found to be 25oC and the range was 15oC to 35oC. There was no significant difference in nematode progeny production and host food plant viz., cabbage, cauliflower, knolknol and mustard. Similarly IJs production per mg body weight was not significantly different in starved and fed larvae (host feeding status).