Thanks to Scott Hartley who provided this update - Forest tent caterpillars have been reported in
high numbers across the province of Saskatchewan, primarily in urban areas, parks and
shelterbelts. Trees are the main host to this insect. Although there have been reports
of the caterpillars in alfalfa and canola, feeding damage will not be
significant.
Bacillus thuringiensis
var. kurstaki (Btk) is the recommended control product as it is specific to
moth and butterfly larvae (caterpillars). It is not considered dangerous to
pollinators due to the ingestion mode of action and as they are in a different
insect order the kurstaki strain of Bt is not toxic to the bees that may be
foraging in flowering trees. Although other chemical insecticides are
registered, they tend to affect a broad spectrum of insects including foraging
pollinators.