Biological performance of the white pine weevil in different host species and in two ecological regions of southern Quebec

The performance of the white pine weevil (Pissodes strobi Peck) was studied on five different host species: Norway spruce (Picea abies (L.) Karst.), w hite spruce (Picea glauca (Moench) Voss), red spruce (Picea rubens Sarg.), jack pine (Pinus banksiana Lamb.), and eastern white pine (Pinus strobus L. ). Attacked terminal leaders were collected prior to adult emergence, withi n two different ecological regions of Quebec, the Outaouais and Appalaches regions. According to their natural range, jack pine was studied only in th e Outaouais region and red spruce only in the Appalaches one. Weevil perfor mance did not differ between regions but differed among host species. The n umber of eggs laid per leader was greatest on jack pine, white pine, and No rway spruce (279, 219, and 218 eggs per leader, respectively). Adults emerg ing from white pine were the heaviest (0.0104 g). The number of adults per leader was greater on Norway spruce and white pine (34 and 23 adults, respe ctively), and survival tended to be greater on Norway spruce and white spru ce leaders (18 and 15%, respectively). Norway spruce had the longest leader s, and jack pine had the thickest ones. Leader dimensions were correlated w ith all variables of weevil performance, except insect survival, but these characteristics explain only a small part of the variation in weevil perfor mance. Norway spruce and white pine can be considered favourable hosts for rapid population buildup according to the high number of emerging adults pe r attacked leader.