Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), the spotted-wing drosophila, is an invasive pest of fruit crops, which appeared in eastern Canada in 2010. It represents a major threat to lowbush blueberry (Vaccinium angustifolium Aiton; Ericaceae) in the Saguenay-Lac-Saint-Jean region, Québec, Canada, at the northern limits of its distribution. The dynamics, overwintering capacity, population fluctuations, and damage to lowbush blueberry of D. suzukii are unknown in Saguenay-Lac-Saint-Jean. We aimed to 1) document D. suzukii abundance and phenology in lowbush blueberry in separate localities; 2) evaluate the potential of D. suzukii to overwinter and examine population dynamics over three seasons; and 3) study the spatial distribution of D. suzukii in lowbush blueberry fields with respect to forested borders. Drosophila suzukii is abundant in lowbush blueberry fields of Saguenay-Lac-Saint-Jean. In spring, D. suzukii were absent until late June, when few summer-morph females appeared. Drosophila suzukii densities started to increase regularly in August, with increasing male proportions, to culminate in fall at high levels with balanced sex ratios. Overwintering remains uncertain, D. suzukii being undetectable in spring despite intensive trapping. Appearance of diapausing winter morphs at high densities indicates that D. suzukii responds appropriately to local conditions preceding cold winter. Models of variation of D. suzukii densities and lowbush blueberry fruit infestation with distance from borders indicate that forest borders are favoured habitats over lowbush blueberry fields and the source of D. suzukii moving to some extent into lowbush blueberry fields.

斑蝶果蝇（Drosophila suzukii（Matsumura）（双翅目：Drosophilidae））是一种果蝇的入侵性害虫，于2010年在加拿大东部出现。它是对矮灌木蓝莓（Vaccinium angustifolium Aiton; Ericaceae）的主要威胁。加拿大魁北克省Saguenay-Lac-Saint-Jean地区，位于其分布的北部。动态，越冬能力，种群波动以及对低矮蓝莓D的损害。铃木在Saguenay-Lac-Saint-Jean中是未知的。我们的目标是1）在不同地区的矮灌木蓝莓中记录铃木D. suzukii的丰度和物候学；2）评估铃木D.的潜力越冬并检查三个季节的人口动态；3）研究矮灌木蓝莓田中铃木的相对于森林边界的空间分布。果蝇铃木在Saguenay-Lac-Saint-Jean的矮灌木蓝莓田中盛产。在春天，铃木D.一直缺席到六月下旬，当时很少有夏季变态的雌性出现。八月，果蝇的铃木密度开始有规律地增加，随着男性比例的增加，在秋季达到高水平，男女比例均衡。越冬仍然不确定，尽管有大量诱捕，但在春季仍无法发现铃木D .。在高密度下，滞育性冬季形态的出现表明D. suzukii对寒冷的冬季之前的当地条件做出了适当的反应。铃木D.密度和矮灌木蓝莓果实出没的距离随边界距离的变化模型表明，森林边界是矮灌木蓝莓田的首选生境，而铃木D.的来源在一定程度上转移到矮灌木蓝莓田。