Other Common Names
Burrowing Mayfly, Giant Mayfly, Golden Mayfly
Explanation of Names
Author of genus is Walsh, 1863. Genus name is apparently from hexa- Greek, six, plus genia, Greek, generation. This seems to mean "six generations", but the context is not obvious.
Numbers
Five North American species
(1)Identification
Very large mayflies with small hindwings. Usually pale golden yellow at least when freshly emerged, i.e., subimago. Several species dark with bold striped pattern as mature imagos. Wings not uniformly dark, as are some other genera of this family. Pale brown band across abdomen. Antennae, legs, and tails yellow. (Photographs show either pale golden mayflies--probably subimagos, or very dark individuals, full imagos?) H. limbata is very large (18-30 mm), widespread in east. H. bilineata is smaller, 14-18 mm, and is common in southeast.
Naiads have three anal filaments.
Range
Most species in eastern North America, at least one in west.
Life Cycle
Eggs are dropped onto water surface, sink to bottom. Larvae (naiads) burrow in muddy bottoms of streams, lakes at up to 20 meters (60 feet) in depth. They usually spend one year in this stage, perhaps two in northern areas. Adults emerge in evening, disperse widely, coming to lights--often far from bodies of water.
Remarks
This genus is pretty famous among trout fisherman, and is the model of many trout flies (lures).
See Also
Ephemera, another widespread genus in the same family
Print References
Arnett, pp. 116-117, describes H. limbata, H. bilineata.
(1)
Swan and Papp, p. 167, fi. 177A--adult H. limbata
(2)
Salsbury, p. 43--photo adult H. limbata
(4)
Milne, p. 361, fig. 392--photo of adult
Arnett and Jacques, #5--photo of adult H. bilineata
(5)Internet References
Mayflies of the United States--links to (incomplete)range maps
Mayflies of North and South Carolina--reports H. atrocaudata, bilineata, limbata, rigida from those states.
Contributed by
Cotinis on 24 March, 2005 - 4:42am
Last updated 24 March, 2005 - 10:28am
