The detection of range shifts is an important part of tracking species’ responses to climate warming and anthropogenic disturbance. Here, arguments in support of such change-induced expansion of the thread-waisted wasps, Sphex pensylvanicus and Sphex ichneumoneus (Hymenoptera: Sphecidae), into Atlantic Canada are made on the basis of collections in southwestern New Brunswick. Despite their large size, bold colouration, and active presence on wildflowers in open areas, no previous records for either species exist from Atlantic Canada. Increases in mean annual temperature, as well as increases in the abundance, regional diversity, and uniformity in the ranges of katydids (Tettigoniidae), the preferred nest provision for both Sphex species, may be promoting northward colonization by Sphex wasps.
Sphex ichneumoneus and Sphex pensylvanicus (Hymenoptera: Sphecidae) in Atlantic Canada: evidence of recent range expansion into the region
