Lake Huron Locust (Trimerotropis huroniana)

Lake Huron Locust by David Cuthrell, MNFIIf you've walked along the beaches of the Great Lakes in the eastern Upper Peninsula or northern Lower Peninsula, you may have shared the beach with one of Michigan's rarest insects, the state-threatened Lake Huron locust (Trimerotropis huroniana). This member of the short-horned grasshopper family (Acrididae) inhabits coastal dune areas in northern Michigan, northeastern Wisconsin, and the central Lake Huron shoreline of Ontario.

The Lake Huron locust is a small insect, ranging from 1 to 1.6 inches (24-40 mm) in size. The body is usually silver to ash gray with darker brown and white markings. Males can easily be distinguished from females by their noisier flight and smaller body size.

The preferred habitat of the Lake Huron locust is sparsely vegetated, high quality coastal sand dunes. In these areas, it can occur in high numbers and is usually the dominant grasshopper species. Their numbers quickly decline where the open dunes progress inland into heavily vegetated, wooded, or disturbed areas. This species is ground dwelling, meaning it almost never climbs onto foliage or other supports.

Lake Huron locusts are herbivorous, feeding primarily by clipping off vegetation near the base of dune grasses and forbs. Species common in locust habitat include dune grass (Calamovilfa longifolia), beach grass (Ammophila breviligulata), and wild wormwood (Artemisia campestris). Nymphs (young locusts) may also supplement their diet by scavenging dead insects.

Reproduction occurs in mid-summer. Males attempt to gain the attention of females by crepitating (the cracking noise caused by the flashing and snapping of their wings) in a courtship flight. Once mating occurs, females lay their eggs in the soft beach sands where they remain over winter. Nymphs will emerge in late spring and mature by mid-July to begin the cycle anew.

Lake Huron Locust Range in MichiganExtensive development of the Great Lakes shoreline has degraded or destroyed much of the Lake Huron locust's former habitat. Management practices that keep natural dune processes in place are critical to the long-term survival of this species. You can do your part by: 1) Learning how to identify the Lake Huron locust and its habitat; 2) Keeping disturbance to a minimum; and 3) purchasing a critical habitat license plate. Revenues from license plate sales go directly towards the management of Michigan's nongame, threatened, and endangered fish and wildlife.

The next time you watch the sunrise or sunset on the Great Lakes, keep an eye on the beach too - you might just catch a glimpse of one of Michigan's most unique insects!.