Caenidae

Adults (adapted from Edmunds and Waltz 1996)

1a	a. Prosternum half as long as broad, rectangular in shape	Brachycercus Curtis
	b. Forecoxae widely separated on venter
	also: Spines on Ab6 tergum slightly bent dorsally; pedicel at least 1.5-2.0x longer than scape; eggs oval, two to three times longer than broad
	note: Uncommon
1b	a. Prosternum 2-3x as long as broad, triangular in shape	Caenis Stephens
	b. Forecoxae close together on venter
	note: Widespread

Nymphs (adapted from Edmunds and Waltz 1996)

1a	a. Head with three prominent ocellar tubercles	Brachycercus Curtis
	b. Palps of maxilla and labia 2-segmented
	c. Fore legs distinctly shorter than middle and hind legs
	also: Anterior margin of mesosternum flat, without bristles; spines on Ab6 tergum not curved medially
	note: Uncommon
1b	a. Head without prominent ocellar tubercles	Caenis Stephens
	b. Palps of maxilla and labia 3-segmented
	c. Fore legs subequal in length to middle and hind legs
	also: Inner margin of fore tibiae and tarsi with a row of stout spines; segment 3 of labial palp subequal or shorter than segment 2, with few long setae and spines; outer margin of operculate gills fringed with long setae
	note: Widespread

References

Edmunds GF, Waltz RD. 1996. Ephemeroptera, pp. 126-163 in Merritt RW, Cummins KW (editors), An Introduction to the Aquatic Insects of North America, 3rd Edition. Kendall/Hunt Publishing Company: Dubuque, Iowa.

Page created: June 15, 2003 (EB)
Page last reviewed: August 7, 2003 (EB)