INFLUENCE OF CORYMBIA HYBRIDISATION ON CROWN DAMAGE BY THREE ARTHROPOD HERBIVORES

Abstract

Nahrung HF, Waugh R, Hayes RA & Lee DJ. 2011. Influence of Corymbia hybridisation on crown damage
by three arthropod herbivores. Three common pests (eucalypt tortoise beetle Paropsis atomaria, leaf blister
sawfly Phylacteophaga froggatti and eriophyid mites) of commercial spotted gum plantations were assessed for
their crown damage levels on parent and hybrid Corymbia taxa (Corymbia torelliana, C. citriodora subsp. variegata
and their hybrid) at three common-garden field sites. Damage levels differed significantly between sites for all
three herbivore species, and between taxa for eriophyid mites and P. atomaria. However, herbivore response to
hybridisation only differed for P. atomaria between sites, even where damage levels did not. Hybrids exhibited
three common patterns of susceptibility relative to parent taxa, being most commonly intermediate to their
parents for crown damage (additive resistance pattern), or no difference between parents and hybrids, or
with one incidence of dominance for susceptibility.