Mayfly

Scientific Name: Ephemeroptera

Order & Family: Order: Ephemeroptera (Multiple families)

Size: Typically 1 cm to 3 cm in length, excluding long tail filaments.

Found near freshwater sources like rivers, lakes, and streams as larvae; adults are often found on vegetation or window screens near water.

Larvae (nymphs) eat algae and organic debris; adults have non-functional mouthparts and do not eat.

They exhibit a unique life cycle with a subimago stage; adults emerge in massive swarms, mate, and die within 24-48 hours.

Harmless to humans; they are vital bioindicators of water quality and serve as a critical food source for fish and birds.

Identified on: 5/22/2026