Protection Strategy against Spruce Budworm

David A Maclean

doi:10.3390/f10121137

Abstract

Spruce budworm is one of the most significant forest insects worldwide, in terms of outbreak extent, severity, and economic impacts. As a defoliator, spruce budworm larvae are susceptible to insecticide protection, and improvements in efficacy and reductions in non-target environmental effects have made such protection attractive. In this Special Issue, 12 papers describe the advances in spruce budworm protection, most notably an ‘early intervention strategy’ approach that after six years of trials in New Brunswick, Canada, shows considerable success to date in reducing budworm outbreak occurrence and severity.

Highlights

Spruce budworm (Choristoneura fumiferana (Clem.)) outbreaks are a dominant natural disturbance in forests of Canada and northeastern USA
Repeated annual defoliation typically lasts about 10 years during outbreaks, resulting in growth reductions up to 90% [3], mortality averaging 85% in mature balsam fir stands [4], and changes in regeneration and succession [5,6]
The total potential wood supply loss from a future spruce budworm outbreak in Atlantic Canada projected over 30 years is estimated at 96 million m3, which would generate approximately 66 Mt CO2 emissions [26]

Summary

Introduction

Spruce budworm (Choristoneura fumiferana (Clem.)) outbreaks are a dominant natural disturbance in forests of Canada and northeastern USA. The province of Nova Scotia, Canada decided not to protect forests with insecticide treatments during the severe 1970s–1980s spruce budworm outbreak, and suffered an average of 87% mortality in mature balsam fir stands [16]. The total potential wood supply loss from a future spruce budworm outbreak in Atlantic Canada projected over 30 years is estimated at 96 million m3 , which would generate approximately 66 Mt CO2 emissions [26]. Over the last five years, a $30 million research project has tested another possible management tactic, termed an early intervention strategy, aimed at area-wide management of spruce budworm populations [28] This includes intensive monitoring to detect ‘hotspots’ of rising budworm populations before defoliation occurs, targeted insecticide treatment to prevent spread, and detailed research into effects on target and non-target insects [28,29]

Description of Papers in This Special Issue

Findings

Conclusions