Overview

Overview

Lake Huron Locust (Trimerotropis huroniana) A State Endangered Species, the Lake Huron Locust is silvery gray to pale brown, yellow ochre or brick red with mottling, males more heavily than females. The long forewings usually have faint cross-bands; the hind wings are pale yellow with a smoky band. Males measure 19-21mm and females 26-28mm. Inhabits exposed, high quality open dunes as well as upper beach areas with very sparse grasses, forbs, and beach shrubs on the northern shores of the Great Lakes.

State status

Status and Natural Heritage Inventory documented occurrences in Wisconsin

The table below provides information about the protected status - both state and federal - and the rank (S and G Ranks) for Lake Huron Locust (Trimerotropis huroniana). See the Working List Key for more information about abbreviations. Counties shaded blue have documented occurrences for this species in the Wisconsin Natural Heritage Inventory database. The map is provided as a general reference of where occurrences of this species meet NHI data standards and is not meant as a comprehensive map of all observations.

Note: Species recently added to the NHI Working List may temporarily have blank occurrence maps.

Species guidance

Note: a species guidance document is not available at this time. Information below was compiled from publication PUB-ER-085-99 (now out-of-print).

Identification: This species may be confused with the related grasshopper Trimerotropis maritima (the seaside grasshopper). T. huroniana is silvery gray to pale brown, yellow ochre or brick red with mottling, males more heavily than females. The long forewings usually have faint cross-bands; the hind wings are pale yellow with a smoky band. The low pronotum is cut twice across the middle, the pronotal length behind the furrows nearly twice that anterior to the furrows. Males measure 19-21mm and females 26-28mm. The inner face of the hind femur is solid black on the proximal half in contrast to that of the cogeneric, T. maritima, with a narrow black band. Both species have a black band near the tip of the inner femur. The hind tibia is dull yellow.

Habitat: Inhabits exposed, high quality open dunes as well as upper beach areas with very sparse grasses, forbs, and beach shrubs on the northern shores of the Great Lakes. T. maritima is found farther south along the Great Lakes shorelines. Individuals, particularly males, may be found on sunny days in the least vegetated "blowout" areas of the dunes. The less mottled females have been observed more than the males on the sand/gravel beach just above the high water mark.

State Distribution: Recorded only from Door County in Wisconsin.

Phenology: The species is univoltine and overwinters as an egg in the sandy soil. Adults may be found from mid July until frost. The species is ground-dwelling and has not been observed climbing on vegetation. In stormy weather they will be found in the denser grass cover at the crest of the dunes. The flight sound is a peculiar crepitation interrupted about three times per second so that it seems to be composed of separate notes. The species is very alert but does not fly far when disturbed in contrast to T. maritima. In courtship, males stridulate in a series of trills when approaching females.

Management Guidelines: The Lake Huron locust has narrow habitat preferences and is threatened shoreline recreational development along the Great Lakes. Dune habitat conservation with minimized human use will benefit this species. Where disturbance jeopardizes the quality of the open dune habitat or at sites where vegetation becomes abundant, populations are lost and the species is replaced by more cosmopolitan grasshoppers. At sites where the habitat is narrow, high water years may lead to local extirpations.

Other resources

Links to additional Lake Huron Locust information

• Michigan Natural Features Inventory [PDF exit DNR]

Other links related to grasshoppers and allies

• NatureServe Explorer
• Guide to the Grasshoppers of Wisconsin
• The Field Museum [exit DNR]
• Michigan State University Extension [exit DNR]

Photos/Video

Photos

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