Seasonal occurrence and spatial distribution of resinosis, a symptom of Sirex noctilio (Hymenoptera: Siricidae) injury, on boles of Pinus sylvestris (Pinaceae)

Abstract

AbstractAn established population of the exotic woodwasp Sirex noctilio Fabricius (Hymenoptera: Siricidae) was first detected in North America in 2004. In order to develop survey guidelines for the detection of this major pest of Pinus Linnaeus species in the Southern Hemisphere, we examined 231 Pinus sylvestris biweekly to establish the timing and spatial distribution of resinosis symptoms of attack, and the timing of subsequent tree mortality. Fresh resin appeared between mid-July and late August, and on 70% of infested trees was observed on the mid bole. The occurrence of tree death varied between sites, from 2 weeks after the first detection of resinosis in one site to several months in seven other sites. Findings from our study provide key information to improve detection of S. noctilio and predict its impact on forest stands in its new range in northeastern North America.