Aquatic Insects of Michigan

by Ethan Bright, Museum of Zoology Insect Division and School of Natural Resources and Environment
University of Michigan

Dixidae (Miniscus Midges) of Michigan - Identification

Adults
(adapted from Peters 1981)

1a	a. First flagellomere of antenna cylindrical, rarely slightly fusiform	Dixella Dyar & Shannon
	b. Katepisternal setae lacking
	c. Sclerotized inflections of female bursa, if present, consisting of a pair of solid cones or spinose area
	d. Male gonocoxite with apical lobe elongate, at least half as long as gonostylus, variously formed, rarely triangular
1b	a. First flagellomere of antenna cylindrical only slightly fusiform	Dixa Meigen
	b. Katepisternal setae frequently present
	c. Sclerotized inflections of female bursa, if present, consisting of groups of spines with bases contiguous but not originating from a single sclerotized unite
	d. Male gonocoxite with apical lobe < 0.5 x as long as gonostylus
	also: Gonostylus tapering in dorsal aspect, pointed or rounded apically; female with sclerotized inflections of bursa, if present, consisting of 1-3 groups of setae

Mature Larvae
(adapted from Courtney and Merritt 2008)

1a	a. Ab2-7 each with a dorsal corona	Dixa Meigen
1b	a. Abdominal segments each without such a dorsal corona	Dixella Dyar & Shannon

References

Courtney GW, Merritt RW. 2008. Chapter 22. Aquatic Diptera. Part One. Larvae of aquatic Diptera, pp. 687-722 in Merritt RW, Cummins KW, Berg MB, eds. An Introduction to the Aquatic Insects of North America. 4th Ed., Kendall/Hunt Publishing Co., Dubuque, Iowa, USA.
Peters TM. 1981. Dixidae, pp. 329-333 in McAlpine JF, Peterson BV, Shewell GE, Teskey, HJ, Vockeroth JR, Wood DM, coordinators. Manual of Nearctic Diptera. Volume 1. Curran, C. H. Book Monograph, Research Branch, Agriculture Canada.