MAYFLIES

Mayflies (many species)

Order: Ephemeroptera (Mayflies)

Size: 1⁄8–1" (without tail filaments)

Habitat: Freshwater streams, ponds, shallow lakes, and nearby habitats

Range: Throughout North America

The mayflies comprise a very large group of small, soft-bodied, delicate insects that are active not only in May, but throughout the summer as well. Adults have two pairs (seldom one pair) of thin, triangular wings, with the hindwing substantially smaller than the forewing, and both held closed high over the back when at rest. The abdomen is long and thin, and ends in two or three tail filaments that are up to two times as long as the body. They are generally plainly colored shades of yellow and brown with clear wings (darker in subadults). The nymphs are entirely aquatic, living under submerged rocks and logs for up to four years, molting into terrestrial forms that molt one more time to the mature adults. Adults do not feed and typically live for only one day or less. They are an important food source for many freshwater fish; indeed, many artificial flies used by anglers are made to look like mayflies. The Golden Mayfly adult is illustrated.