Control of porina caterpillar (Wiseana spp.) in pasture by the fungus Metarhizium anisopliae

Abstract

Chipped wheat bait inoculated with Metarhizium anisopliae (Met.) Sor. was used to control porina caterpillar in pastures at 2 sites in North Island hill country. Caterpillars became infected after feeding on bait laid on the ground when they emerged from their subterranean burrows at night to forage. Porina populations were monitored by counting live larvae and dead, fungus-infected larvae in soil samples. Many larvae were killed by fungus in trials using 9.7-38.5 kg/ha bait (at 38.5 kg/ha 90% of larvae died from fungus infection). Greatest larval mortality was recorded when soil temperatures were high. Optimum temperature for growth of M. anisopliae was 17-20°C, and, in the laboratory, infected larvae died most rapidly at 19-25°C. M. anisopliae inoculated wheat baits show promise for controlling porina and other insects which will also accept these baits.

Keywords:

• Metarhizium anisopliae
• fungi
• Wiseana spp.
• Hepialidae
• porina
• biological control
• pasture pests
• bait pest control