Virulence of the plant-associated endophytic fungus Lecanicillium muscarium to diamondback moth larvae

Abstract

Plutella xylostella (diamondback moth) is a prominent pest of brassicas which is now resistant to most insecticides. Despite years of research, the range of available products used in biological control of diamondback moth is still somewhat limited. We isolated putative endophytic fungi from New Zealand cabbage plants to search for unique biological control agents of diamondback moth larvae. The larvae were fed leaf discs from commercially grown cabbage covered in spores from endophytic fungal isolates to test the insecticidal properties of these fungi. Twenty of the 52 fungal isolates tested failed to kill any diamondback moth larvae. However, three isolates of Lecanicillium muscarium induced mortality greater than 80%. While these isolates have potential for use in biological control applications, further research into propagation, formulation, and method, rate and timing of application is needed.