Effects of grass grub (Costelytra zealandica white) larvae on pasture plants

Abstract

Monocultures of perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.), and a 1:1 mixture of these two species, established in tins with and without 44 grass grubs (Costelytra zealandica White) .per 30 cm² were measured for 62 days.

In monocultures shoot and root weights of white clover were most depressed by grass grubs, and in the mixtures of ryegrass and white clover shoot weights of both species were similarly depressed by grass grubs. Survival of grass grubs tended to be lower beneath the plant mixture.