Control of grass grub (Costelytra zealandica (White)) by heavy rolling

Abstract

The use of an experimental roller on pasture produced up to 61% control of grass grubs, 44% higher pasture production in spring, and minor but beneficial changes in pasture composition. These results were similar to those caused by diazinon insecticide. However, only the combined effects of insecticide plus rolling persisted to give a lower density of grubs in the year after treatment. Although rolling induced mortality in grubs from the soil surface to below 5 cm, there was negligible mortality in earthworms.

Keywords:

• rolling pasture
• cultural control
• Coleoptera
• Scarabaeidae
• Costelytra zealandica
• earthworms
• pasture pests