Still invasive after all these years: Keeping gypsy moth out of British Columbia

Abstract

The gypsy moth is an alien invasive insect in North America. In Canada, management objectives and approaches have often collided with public opposition and resulted in a shifting public policy. The history of this interaction between science and policy is best illustrated in British Columbia where gypsy moth remains unestablished after 30 years of repeated invasions and eradications. The case study provides unique lessons to improve science-public dialogue in achieving common socioeconomic objectives. It shows that despite the availability of sufficient scientific knowledge and technical capacity to reduce risk, the absence of effective risk communication can compromise the effectiveness of management action and increase the risk of invasion.

The influence of Canadian research on semiochemical-based management of forest insect pests in Canada

“…Delta traps baited with 500 µg of (+)-disparlure (Grant 1991) are deployed annually across Canada. In British Columbia, where the European gypsy moth has been repeatedly introduced but has not established, pheromone-baited traps are deployed in a grid pattern at a density of one trap per 2.6 km 2 (Nealis 2009) and play a key role in directing eradication efforts against this insect (Fig. 2).…”

A risk analysis framework for forest pest management

“…Gypsy moth management in BC has been evolving for more than 30 years since the original introduction and eradication programs in the late 1970s (Nealis 2009). What o 1 -THE FORESTRY CHRONICLE started as a poorly communicated, technically focussed program driven by legislation is now an effective and transparent pest management plan rigorous enough to address international phytosanitary requirements but flexible enough to satisfy domestic social concerns that plagued the program from the beginning.…”

“…Knowledge-based technologies such as climate suitability models were developed so that surveillance could be targeted and spray applications timed more precisely, improving efficacy while reducing environmental exposure (Nealis et al 2001). Public health studies on spray exposure were carried out and alternative response options including community-based egg-mass searches and mass trapping of adults evaluated (Nealis 2009). Accelerated development of a more publicly acceptable formulation of the bacterial insecticide Btk was requested by the public, promoted by government, and satisfied by industry.…”

“…When outbreaks are extensive or remote, only a small portion of the outbreak can be treated so action must be strategic in hope of net benefits in the face of overwhelming population pressure. On the other hand, most alien species first show up as discrete infestations in our most accessible and populated areas where the dominant issues are urgency, uncertainty, and communication (Nealis 2009). In all cases we are faced with the practical challenges of playing stewards to an enormous and diverse resource, which varies by location and in time, and we do this with significant limits on available knowledge, tools and budgets.…”

“…By the end of the 20 th century, gypsy moth had invaded and become established in most of its climatically suitable range in eastern Canada from the Great Lakes to the Atlantic coast (Régnière et al 2009). Recurrent introductions outside this regulated zone occurred west of the Great Lakes but the insect is not established there, in part as a result of repeated eradication programs (Nealis 2009). …”