First detection of the woolly alder sawfly, Eriocampa ovata (Hymenoptera: Tenthredinidae), in Manitoba, Canada, on novel host Alnus hirsuta ‘Harbin’ (Betulaceae)

Abstract

Abstract Eriocampa ovata (Linnaeus) (Hymenoptera: Tenthredinidae), commonly known as woolly alder sawfly, is an introduced species to North America. Its larvae have six or more prolegs, a brown spot on the head’s vertex, and are woolly in appearance due to a wax secretion from epidermal glands. The author was contacted about six recently planted alder trees in Winnipeg and Victoria Beach, Manitoba, Canada. The trees were determined to be Alnus hirsuta ‘Harbin’ (Betulaceae) (Prairie HorizonTM Manchurian alder), a tree species that has recently gained popularity in Manitoban urban forestry. The defoliation was determined to be caused by larvae of E. ovata. This is the first published record of E. ovata in Manitoba and the first published record of E. ovata on A. hirsuta. This detection should inform pest inventories for E. ovata in Manitoba and provide the basis for a critical examination of biosecurity measures for A. hirsuta.