Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Global incursion pathways of Thaumastocoris peregrinus, an invasive Australian pest of eucalypts.

Abstract

The bronze bug, Thaumastocoris peregrinus, is an endemic Australian eucalypt pest that has become a serious threat to the global forestry industry. Following a large outbreak within its native range in 2002, introduced populations of the bronze bug appeared in South Africa and Argentina. Since then, T. peregrinus has spread rapidly around the world, with the number of reported incursions increasing steadily. Despite the problems posed by the bronze bug, little is known about its global invasion pathways. In this study, we used multiple different population genetic methods to (1) gain new insight into aspects of bronze bug population history within Australia, and (2) characterise the spread of the bronze bug throughout South America, South Africa, New Zealand and the Mediterranean Basin. Taken together, the genetic data and the outbreak records suggest that, across the international regions surveyed, at least three separate introductions of T. peregrinus from Australia have occurred over the decade 2003 - 2012-one into South Africa, another into Argentina and a third into New Zealand-each of which is likely to have originated in Sydney. Populations in Europe and Israel appear to have become established from individuals introduced from South America, rather than from within the native Australian range, suggesting the existence of a bridgehead effect. These findings provide an important framework for understanding the global spread of invasive bronze bug populations. They may be used to inform management decisions and improve the effectiveness of control strategies.