This empty pupa belongs to a species of sphinx moth (family Sphingidae), the fast, powerful fliers that are often seen hovering at flowers to sip nectar. But a moth did not emerge, an ichneumon wasp did! Ichneumon wasps in the subfamily Ichneumoninae are internal parasites of caterpillars but emerge as adult wasps from the pupa of the host. Mothers seek their hosts on foliage or among leaf litter …and when one is found they oviposit an egg inside, providing a ready meal for their young. Females do have venom glands and some can sting weakly, but they pose little threat to us. We believe the one pictured is a male. Females typically have broad pale bands on dark antennae, while in males the bands are subdued or even absent.
Photos by Sandy Olson Arnold on 7/12/20 in Missoula, MT.