Induced defences in kawakawa (Macropiper excelsum): do caterpillars avoid previous leaf damage?

Abstract

This study examined whether two species of lepidopteran larvae (Cleora scriptaria and Epiphyas postvittana) were deterred from feeding on the leaves of kawakawa (Macropiper excelsum) after the leaves had been damaged in three different ways: by larval feeding, using a hole punch or a metal rasp. A hierarchy of choice experiments was performed in the laboratory, examining the feeding 'preference' of these insects between undamaged or previously damaged tissue within the same leaf, between different leaves and between different plants. On no occasion did larvae of either species show a significant preference for undamaged or damaged leaves. It is concluded that, on present evidence, kawakawa does not have a system of induced chemical defences which deters the feeding of these two insects.