Following closely on the heels of the European Praying Mantis, this beetle is our second highest reported insect as of late. Like the mantis, it is also an introduced species. It was introduced on purpose to help combat another exotic — spotted knapweed (primarily). Females lay their eggs on the top of the knapweed’s root crown. Once they hatch, the larvae burrow into the plant’s root, destroying the vascular root tissue and preventing the plant from transporting water and nutrients. Death of the plant can occur within two years. Research at Montana State University has shown up to a 99% reduction in knapweed density as result of knapweed root weevil introduction. Go weevils!
Size: 20 mm long
Photo by: Carolyn Taber on 8/21/21 in Missoula, MT