Patterns of insect herbivory on four Australian understory plant species

Abstract

AbstractAustralia harbours a very diverse phytophagous insect fauna, but little is known about the patterns of insect herbivory in dominant forest systems, especially in dry sclerophyll forests. Here, we assess variation in leaf herbivory in four species of narrow‐ranged sclerophyllous shrubs across their geographical distribution. We assessed leaf herbivory as the percentage of missing leaf area, and estimated the proportion of damage types, such as chewing, sucking and mining. We found that the levels of leaf herbivory and the proportions of damage types were consistent among plant species but showed considerable variability within single plant species among sites and individual plants. This variability is most likely due to the patchy distribution of herbivorous insects in space and time. Leaf damage was dominated by chewing, but mining and sucking occurred on all plant four species. Sap sucking, although much less conspicuous, was found to be a major damage type, demonstrating that neglect of sap sucking damage in leaf herbivory assessments could lead to a considerable underestimation of the total herbivore damage inflicted on host plants.