If
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.
Extensive 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.
For more information on the Lake Huron locust and many other species in
Michigan, visit the MNFI species abstracts on the web. Simply visit
http://web4.msue.msu.edu/mnfi/pub/abstracts.cfm and click on the abstract you would like to
read.
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!.