Abstract
Disturbance events reveals the diversity in the composition of invertebrate communities in forest landscapes. Attack by longhorned borers (Cerambycidae) of drought stressed trees, provides a substrate for further infestation by other invertebrates. A study was conducted to determine the interdependence of invertebrates associated with borers in native forests.
In jarrah forest of Southwestern Australia, following a severe drought event, stressed Eucalyptus jarrah and marri trees were infested by either longhorned borer Phoracantha semipunctata or Coptocercus rubripes. Emerging borers and other associated insects were captured by surrounding stressed tree trunks with aluminium mesh cages and sorted into taxonomic groups.
A range of insects were associated with borer infestations, with predatory beetles being the most abundant followed by parasitic wasps. The combined richness of predatory beetles and parasitic wasps was slightly higher in marri compared to jarrah, though was similar between trees infested by C. rubripes and P. semipunctata. The braconid wasps and predatory clerid beetles were associated with infestation by both C. rubripes and P. semipunctata borers, whereas ichneumonid wasps occurred where P. semipunctata was present while staphylinid predatory beetles occurred where C. rubripes was present.
There was a diversity of insects in different trophic levels associated with woodborer infestation in forests. Drought stressed forests are a crucial habitat for maintaining biodiversity values of borers, predatory beetles, and parasitic wasps. This study highlights the important contribution of these landscapes in maintaining insect diversity during climate change in Australia.