FIELD AND LABORATORY EVALUATION OF A SEX-PHEROMONE TRAP FOR THE AUTODISSEMINATION OF THE FUNGAL ENTOMOPATHOGEN ZOOPHTHOVA RADICANS (ENTOMOPHTHORALES) BY THE DIAMOND-BACK MOTH, PLUTELLA-XYLOSTELLA (LEPIDOPTERA,YPONOMEUTIDAE)

The effectiveness of a sex pheromone trap designed specifically to del iver conidia (infective fungal propagules) of the entomopathogenic fun gus Zoophthora radicans Brefeld (Zygomycetes: Entomophthorales) to mal e Plutella xylostella (Linnaeus) was investigated. In field experiment s in the Cameron Highlands of Malaysia, synthetic pheromone lures attr acted adult males P. xylostella at all times of the day whereas lures of virgin female moths attracted males only between the hours of dusk and dawn, when females are known to produce their pheromone. Adult mal e moths attracted to traps baited with synthetic pheromone spent a geo metric mean time of 88 seconds within the inoculation chamber, a time compatible with the period adults must spend within a shower of Z. rad icans conidia produced by uniform mycelial mats in order to become inf ected. The field longevity of male and female P. xylostella adults was found to be similar, with individuals living for a mean time of 4.9 d ays. This was sufficient time for male moths to respond to the pheromo ne, enter the trap, become infected with Z. radicans and succumb to th at infection in the field (3-3.5 days) thereby releasing infective con idia into the cabbage crop.