Aspects of the biology and control of Thaumastocoris peregrinus

Over the past eight years a heteropteran, Thaumastocoris peregrinus, has had a devastating impact on many Eucalyptus species in the Sydney metropolitan area. The symptom of infestation is now so widespread it has a common name “winter bronzing”. Although the host range of this bug is increasing, two eucalypt species, Eucalyptus scoparia and E. nicholii, have been severely infested. These trees are very common as street and garden trees and contribute much to Sydney’s urban forest. Infested trees initially display a reddening of the leaves and, as the infestation progresses, the entire canopy turns reddish yellow. These leaves are then dropped. Trees can die but usually are removed at this point. Within the Sydney basin councils have been removing infested trees in great numbers. T. peregrinus infests eucalypts growing in regional centres over much of New South Wales and, more recently, has become an significant pest of Eucalyptus growing in South Africa and South America infesting and threatening millions of hectares of plantation.

Given the magnitude of the bug’s impact and its expanding host range a study of the insect was conducted. Here we report our findings.