We think this is one of the more incredible insects you can find in Montana — shoutout to Hartley and Una for discovering it on the back of their mother’s shirt and for their spot-on description: “Kind of like a wasp, but it has weird legs!” At just about an inch long, the wasp mantidfly is a bizarre looking animal. They look like if you combined the front end of a praying mantis with the back end of a wasp. Like mantids, mantidfly adults are impressive predators, using their spiny front legs to capture small insect prey. If you don’t think the adults are amazing enough, after hatching from its egg a mantidfly larva needs to find and burrow into a spider’s egg sac for its food source. Since an egg sac is not always around when you need one, the larva will first find a spider and hitch a ride. If it is a female spider the larva rides along until the spider lays an egg sac and then jumps ship. If it is a male spider, the larva waits until the spider mates and then transitions to the female. Amazing! And, to be clear, this critter is not a mantis, fly, or wasp. It’s a relative of lacewings, in the order Neuroptera (family Mantispidae).
Photo by Hartley Kuhlman on 8/26/20 on Mount Sentinel near Missoula, MT