While out on a bug walk with the Montana Natural History Center’s Master Naturalist students this weekend, we were blown away by the number of mantises we found. What was once a semi-rare sighting seemed unusually abundant, and we weren’t even looking that hard!

Most people are shocked to find that we have mantids at all, and even more shocked to find that non-native mantids are routinely introduced into our local ecosystem (more on that later). The species we found that afternoon were all non-native European mantises, but native mantids, while somewhat rare, inhabit the arid regions of central and eastern Montana.

A non-native European mantis male, spotted at Fort Missoula

First, a primer on mantid language. You might be wondering, is it mantid, or mantis? The answer: both. Kind of. Mantis usually refers to praying mantises in the genus Mantis, including the common European mantis, Mantis religiosa, a non-native species. Mantid is more of a catch-all term, referring to all insects within the family Mantidae. That said, in casual conversation, I will use the terms interchangeably, as most people do.

Montana is host to at least two species of native mantid; Litaneutria minor and Litaneutria skinneri, both species of ground mantid. There’s little information on the latter (and only one sighting in Montana in the last 5-or-so years according to the Montana Field Guide), but, being in the same genus, both mantids share very similiar characteristics.

USA: Nebraska, Sioux Co., 3 mi N, 8.5 mi NW Harrison, Wilson Ranch. Shortgrass prairie.
Ted C. MacNae 2010

Ground mantids are characterized by – you guessed it – living out their lives on the ground. Whereas most mantid species prefer to hang out in shrubs and trees, waiting to ambush their prey as it flies by, ground mantids will actively hunt and chase their prey on the ground.

In the photo above, you’ll notice the highly reduced wings in this adult male L. minor; as an agile ground hunter, wings are unnecessary, and ground mantids lost them over time.

A gravid female Litaneutria minor

In addition to losing their wings, Litaneutria spp. have lost another mantis specialty: the ability to hear. Or at least, hear well. Flying mantids have evolved a highly specialized “ear” in order to detect the ultrasonic frequencies emitted by hunting bats. Once detected, the mantis will perform a series of aerial maneuvers to avoid being bat breakfast. But if flying predators are not your concern, why keep the specialized strategies that help you avoid them? Such is the case with Litaneutria.

Ground mantids prefer living in drier, arid conditions; they can be found in sagebrush steppe and grasslands of central and eastern Montana. Which brings me back to the mantids that have been spotted here, in Missoula.

A European mantis female

Mantis sightings aren’t necessarily common in Missoula, but certainly not unheard of. On Sunday afternoon, during an unusually sunny break in the weather, we spotted 4 adult European mantises, 3 of which were gravid females.⠀

European mantis oothecae can be purchased at any garden supply, and their non-native status is often overlooked in favor of their unmatched ability to prey on common garden pests. Yet as they grow, they start taking down larger prey items, including important native pollinators. ⠀

4 mantis sightings in a single afternoon (without even trying to find them) is exciting, but as we continue to experience mild winters, there’s a chance this introduced species is successfully reproducing in the wild without the help of local gardeners. The evidence for this is anecdotal at best, but it’s hard not to listen to that little twinge of concern in the back of my brain.