Efficacy of Imidacloprid in the Control of Thaumastocoris peregrinus on Eucalyptus scoparia in Sydney, Australia

Abstract

Thaumastocoris peregrinus, an Australian native, is a new and serious pest of urban eucalypts planted in Sydney and commercial centers of Australia. In recent years, it has spread to and attained pest status in South African Eucalyptus plantations and, more recently, has been discovered in Argentina and Uruguay. Mature Eucalyptus scoparia street trees, growing in a southern Sydney suburb, were microinjected with imidacloprid at three concentrations and monitored for three years. The abundance of T. peregrinus on treated eucalypts declined significantly compared to untreated trees over this time. Further, at the lowest concentration of chemical this insect was effectively controlled for two years. Imidacloprid (SilvaShield®; Bayer Environmental Science) has been registered in Australia for the control of T. peregrinus.