Ponderous Borer vs Burrowing Mayfly

Side-by-side species comparison

Attribute Ponderous Borer Burrowing Mayfly
Scientific Name Trichocnemis spiculatus Hexagenia limbata
Order Coleoptera Ephemeroptera
Family Cerambycidae Ephemeridae
Size 40-60 mm 18-32 mm body
Habitat Ponds & Lakes Ponds & Lakes
Diet Wood Feeders Omnivores
Regions Western United States, British Columbia North America
Conservation Least Concern Least Concern

Ponderous Borer

One of the largest cerambycids in North America, this prionine breeds in the roots and lower trunks of dead ponderosa pines. Adults are dark brown with a somewhat rough body surface. They are nocturnal and attracted to lights.

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Did You Know?

Larval development can take up to six years in dry dead wood, one of the longest development times for any beetle.

Burrowing Mayfly

Creates massive synchronized emergences so dense they appear on weather radar. Billions emerge simultaneously from lake bottoms where nymphs burrowed for up to two years.

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Did You Know?

Mayfly emergences along the Mississippi River are so massive they show up on Doppler weather radar — billions of insects rising simultaneously look like approaching thunderstorms.