NRE 516 - Aquatic Entomology

Notes on taxonomy / Recent synonymies / Notes on sexual dimorphism and other features / List of taxa presented / Table of habitat preferences / Michigan Emergence Sequence / References and Additional Taxonomic Works

Lab Notes for the Ephemeroptera - "Mayflies"

Readings in required texts:

Edmunds and Waltz 1996, pp. 126-130 in Merritt and Cummins (larvae and adults - genera)
Hilsenhoff 1995, pp. 4--6 (larvae)

Notes on Taxonomy

We follow McCafferty's (1991a) higher-level taxonomy in terms of sub-ordinal classification, which is now regularly updated on the Mayfly Central internet site. (See that site for a complete classification for all North American genera). The list below includes those genera found (or may be found) in Michigan. 

Notes on taxonomy / Recent synonymies / Notes on sexual dimorphism and other features / List of taxa presented / Table of habitat preferences / Michigan Emergence Sequence / References and Additional Taxonomic Works

Some recent synonymies for taxa found in Michigan (current = old)

Tricorythodes (Leptohyphidae) = Tricorythodes (Tricorythidae)
Litobrancha = Hexagenia
(Ephemerella + Drunella + Serratella + Eurylophella + Timpanoga + Attenella) = Ephemerella (sensu lat.)
Isonychia (Isonychiidae ) = Isonychia (Oligoneuriidae) = Isonychia (Siphlonuridae)
Ametropodidae + Metretopodidae = Ametropodidae (prt.)
(Stenonema + Stenacron) = Stenonema
Anepeorus = Spinadis
Nixe = Heptagenia (part)
Leucrocuta = Heptagenia (part)
Anthopotamus = Potamanthus
Acentrella = Pseudocloeon
Centroptilum = Cloeon (part)
Procloeon = Cloeon, Centroptilum (parts)
Acerpenna = Baetis (part)
Diphetor = Baetis (part)
Pseudocloeon = Labiobaetis, Baetis (part)
Plauditus = Baetis (part)

Notes on taxonomy / Recent synonymies / Notes on sexual dimorphism and other features / List of taxa presented / Table of habitat preferences / Michigan Emergence Sequence / References and Additional Taxonomic Works

Notes on Sexual dimorphism and other features of adult mayflies

In most Ephemeroptera, the eyes of the male are large and in proximity on the vertex, while those of the female are small and separate. In many species of Caenidae and Leptohyphidae, however, the eyes of both sexes are small. In males of Baetidae and some Leptophlebiidae, the upper facets of the eyes are raised on a stalk (= turbinate or semiturbinate).

Generally, the legs of Th1 are much longer than legs of Th2-3 in males, while in females, legs of Th1-3 are subequal. In Polymitarcyidae, however, the legs on Th2-3 in males and Th1-3 in females are vestigial. All legs of both sexes are vestigial in North American Behningiidae (genus Dolania).

In the families Leptohyphidae, Caenidae, Baetidae and in some Neotropical Leptophlebiidae, the HW (on Th3) are greatly reduced or completely absent. In some Baetidae, the HW are small and without a costal projection in males, and minute in females. In other baetids, HW are absent in both sexes. In at least a few populations, males have HW but females do not.
The abdomen externally consists of Ab1-10T and Ab1-10S. The posterior portion of Ab7S of males is called the subgenital plate and is variable in form. Paired appendages called the forceps (=claspers) arise from the posterior margin of the subgenital plate (fig. 11.96, p. 144 in Edmunds and Waltz (1996)). In some genera, the forceps are 1-segmented (e.g., Caenis, Tortopus). More generally, the forceps consist of 2, 3, or 4 segments. Dorsal to the subgenital plate are paired penes, which often are fused mesally. In most taxa, the penes are sclerotized, but in the Baetidae they are membranous and extrudable. The genitalia of male mayflies can be seen through the pellicle of the subimago and the mature nymph, although the structures are less developed than in the imago. The posterior portion of Ab9S of females is termed the subanal plate. The posterior margin of the subanal plate, although generally rounded and w/o prominent processes, is variable in form and can have taxonomic value. In a few genera, the female has a rudimentary ovipositor. Unassociated adult females can not in some cases (e.g., some Ephemerellidae and Leptohyphidae) be easily or reliably determined to genus.

Classification of wing venation will differ between authors. Early Ephemeropterists (e.g., Needham, Traver and Hsu 1935, Burks 1953) followed the Comstock classification of venation, and considered R4+5 to be a branch of R5. Later workers (Edmunds, Jensen and Berner 1976) used the system of Tillyard, which interpreted this vein as a branch of M. Thus, R4+5 of Comstock = MA of Tillyard (R4 = MA1 and R5 =MA2). Page 143 in Edmunds and Waltz (1996) gives Tillyard's (1932) system applied to Ephemeroptera. In the Tillyard system, MA (MA1 and MA2) is convex and MP (MP1 and MP2) is concave. The branched vein MA(+) is the most obvious landmark for identifying venation of the mayfly FW.

Venation is reduced in the HW and often is difficult to interpret. Reduction in the number of wing veins and wing size (especially HW) is frequently associated with reduction in body size, and apparently has evolved independently in several lineages (e.g., Caenidae, Baetidae, Leptohyphidae) (Edmunds 1972).

In North America, Heptageniidae and Baetidae A. have 2 caudal filaments, while Leptophlebiidae and Ephemerellidae A. have 3 caudal filaments. When the median terminal filament is vestigial, it often is represented by a tapered rudiment of 1 or few segments. When fully-developed caudal filaments have been broken, the basal remnants are of normal diameter.
Subimagines have dull, translucent wings, dull body surfaces, and setae on the wing margins. Imagines of some smaller species, however, retain setae on the wing margins. The caudal filaments are usually covered w/fine setae in subimagines and are glabrous in imagines. Caudal filaments generally are much longer in the imago than in the subimago. In some genera, the molt to the imago can be incomplete, with the wings retaining the subimaginal pellicle, and the caudal filaments may not be shed. In a few taxa, there is no imaginal stage in the females.

Notes on taxonomy / Recent synonymies / Notes on sexual dimorphism and other features / List of taxa presented / Table of habitat preferences / Michigan Emergence Sequence / References and Additional Taxonomic Works

List of Ephemeroptera Taxa Presented

You must be able to identify in a lab exam the following taxa, larvae to genus, adults to family, either by sight or using a taxonomic resource. Taxa denoted in blue are to be identified by sight, those in black are taxa to be identified using any resource you wish within a set period of time (e.g., 1 minute). (Taxa that are blank will not be presented during an exam).

Notes on taxonomy / Recent synonymies / Notes on sexual dimorphism and other features / List of taxa presented / Table of habitat preferences / Michigan Emergence Sequence / References and Additional Taxonomic Works

Table of Habitat Preferences

Notes on taxonomy / Recent synonymies / Notes on sexual dimorphism and other features / List of taxa presented / Table of habitat preferences / Michigan Emergence Sequence / References and Additional Taxonomic Works

Table of Emergence Sequence for Ephemeroptera

Mayflies found in a single gravel riffle in the Pere Marquette River with dates of emergence. (Data from
Leonard and Leonard 1962, p. 8; names have been taxonomically updated).
___________________________________________________________________________________
Taxa                                             April        May        June         July           Aug         Sept        
___________________________________________________________________________________
Baetis tricaudatus                             xxxxxx
Ephemerella subvaria                                    xxx
Paraleptophlebia praepedita                                xxxxx
Ephemerella invaria                                              xxxxxxx
Baetis cinctutus                                                        xxxxxxxxxxxxxxxxxxxxx
Leptophlebia cupida                                                   xxx
Siphlonurus quebecensis                                          xxxxxxx
Pseudocloeon punctiventris                                           xxxxxxxxxxxxxxxxxx
Epeorus vitreus                                                            xxxxxxxxxx
Stenonema vicarium                                                          xxxxxx
Ephemerella rotunda                                                             xxx
Paraleptophlebia mollis                                                           xxxxxxxxxxx
Baetisca laurentia                                                                    x
Ephemerella dorothea                                                              xx
Siphlonurus rapidus                                                                  x
Ephemerella needhami                                                                xxxxxx
Procloeon album                                                                            xxx
Drunella lata                                                                           xxxxxxxxxx
Stenonema modestum                                                                 xxxxxxxxxxxx
Siphlonurus alternatus                                                                     xxxxxxx
Drunella walkeri                                                                         xxxxxxx
Hexagenia limbata                                                                          xxxxxxxx
Leucrocuta hebe                                                                             xxxxxxxxxxxxxxxxxxx
Rhithrogena impersonata                                                                     x 
Timpanoga simplex                                                                              xxxxx      xx
Brachycercus lacustris                                                                          xxxxx
Serratella deficiens                                                                              xxxxx
Tricorythodes stygiatus                                                                               xxxxxxxxxxxxx
Isonychia bicolor                                                                                               xxxxxxxxx
___________________________________________________________________________________

Notes on taxonomy / Recent synonymies / Notes on sexual dimorphism and other features / List of taxa presented / Table of habitat preferences / Michigan Emergence Sequence / References and Additional Taxonomic Works

References and Recent Additional Taxonomic Works

Allen, R.K. 1980. Geographic distribution and reclassification of the subfamily Ephemerellidae (Ephemeroptera:Ephemerellidae). pp.71-79 in J. F. Flannagan & K. E. Marshall (eds.) Advances in Ephemeroptera biology. Plenum, N.Y. 552 pp.
Bae, Y. J., and W. P. McCafferty. 1991. Phylogenetic systematics of the Potamanthidae (Ephemeroptera). Transactions of the American Entomological Society 117:1-143.
Berner, L. 1950. The mayflies of Florida. University of Florida Studies Biological Science Service A 4:1-267.
_____________. 1975. The mayfly family Leptophlebiidae in the southeastern United States. Florida Entomologist 58:137-156.
Berner, L., and M. L. Pescador. 1980. The mayfly family Baetiscidae (Ephemeroptera). part I., pp. 511-524. In J. F. Flannagan and K. E. Marshall (eds.). Advances in Ephemeroptera biology. Plenum, New York. 552 pp.
Berner, L., and M. L. Pescador. 1988. The mayflies of Florida (rev. ed.). University Presses of Florida, Gainesville. 415 pp.
Burian, S. K., M. A Novak, R. W. Bode, and L. Abele. 1997. New record of Brachycercus maculates Berner (Ephemeroptera: Caenidae) from New York and a key to larvae of Northeastern species. The Great Lakes Entomologist 30(3):85-88.
Burks, D. D. 1953. The Mayflies of Illinois. Bulletin of the Illinois Natural History Survey 26:1-216. There is also a 1975 reprint with a 1974 new preface from G. F. Edmunds, Jr.
Edmunds, G. F. Jr., 1972. Biogeography and evolution of the Ephemeroptera. Annual Review of Entomology 17:21-43.
Edmunds, G. F, and R. D. Waltz. 1996. Ephemeroptera, pp. 126-163. In An introduction to the aquatic insects of North America, 3rd Edition. R. W. Merritt and K. W. Cummins (eds.). Kendell/Hunt Publishers, Dubuque, Iowa. 862 pp.
Edmunds, G. F, and W. P. McCafferty. 1996. New field observations on burrowing in Ephemeroptera from around the world. Entomological News 107:68-76.
Edmunds, G. F. Jr., S. L. Jensen and L. Berner, 1976. The mayflies of North and Central America. University of Minnesota Press, Minneapolis, 330 pp.
Flowers, R. W., and W. L. Hilsenhoff. 1975. Heptageniidae (Ephemeroptera) of Wisconsin. The Great Lakes Entomologist 8:201-218.
Funk, D. H., and B. W. Sweeney. 1994. The larvae of Eastern North American Eyrylophella Tiensuu (Ephemeroptera: Ephemerellidae). Transactions of the American Entomological Society 120(3):209-286.
Hilsenhoff, W. L. 1995. Aquatic insects of Wisconsin, 3rd Ed. Natural History Museums Council, University of Wisconsin-Madison. Madison, Wisconsin. 79 pp.
Koss, R. W. 1968. Morphology and taxonomic use of Ephemeropteran eggs. Annals of the Entomological Society of America 61:696-721.
Leonard, J. W. & F. A. Leonard. 1962. The mayflies of Michigan trout streams. Cranbrook Institute of Science Bulletin No. 43.
Lugo-Ortiz, C. R., and W. P. McCafferty. 1998. A new North American genus of Baetidae (Ephemeroptera) and key to Baetis complex genera. Entomological News 109(5):345-353.
_____________.1999. Definition and reorganization of the genus Pseudocloeon (Ephemeroptera: Baetidae) with new species descriptions and combinations. Transactions of the American Entomological Society 125(1-2)1-37.
_____________.1999. Global biodiversity of the mayfly family Baetidae (Ephemeroptera): a generic perspective. Trends in Entomology 2:45-54.
McCafferty, W. P. 1991a. Toward a phylogenetic classification of the Ephemeroptera (Insecta): A commentary on systematics. Annals of the Entomological Society of America 84:343-360.
_____________. 1991b. Comparison of Old and New World Acanthametropus (Ephemeroptera: Acanthametropodidae) and other psammophilous mayflies. Entomological News 102:205-214.
_____________. 1992. New larval descriptions and comparisons of North American Choroterpes (Ephemeroptera: Leptophlebiidae). The Great Lakes Entomologist 25:71-78.
_____________. 1994. Distributional and classificatory supplement to the burrowing mayflies (Ephemeroptera: Ephemeroidea) of the United States. Entomological News 105:1-13.
_____________. 1996. The Ephemeroptera species of North America and index to their complete nomenclature. Transactions of the American Entomological Society 122(1):1-54.
_____________. 1998. Ephemeroptera and the great America interchange. Journal of the North American Benthological Society 17(1):1-20.
McCafferty, W. P. & G. F. Edmunds Jr. 1979. The higher classification of the Ephemeroptera and its evolutionary basis. Annals of the Entomological Society of America 72:5-12.
McCafferty, W. P. and A. V. Provonsha. 1985. Systematics of Anepeorus (Ephemeroptera: Heptageniidae). The Great Lakes Entomologist 18:1-6.
McCafferty, W. P., and Y. J. Bae. 1990. Anthopotamus, a new genus for North American species previously known as Potamanthus  (Ephemeroptera: Potamanthidae). Entomological News 101:200-202.
McCafferty, W. P., and R. D. Waltz. 1990. Revisionary synopsis of the Baetidae (Ephemeroptera) of North and Middle America. Transactions of the American Entomological Society 116:769-799, Philadelphia.
McCafferty W. P., Y. P. Bae. 1992. Taxonomic status of historically confused species of Potamanthidae and Heptageniidae (Ephemeroptera). Proceedings of the Entomological Society of Washington 94:169-171.
McCafferty, W. P. and T. H. Klubertanz. 1994. Camelobaetidius (Ephemeroptera: Baetidae) in Indiana and Iowa: new species and range extension. Proceedings of the Entomological Society of Washington 96: 37-43.
McCafferty, W. P., and Wang T-Q. 1994. Phylogenetics and the classification of the Timpanoga complex (Ephemeroptera: Ephemerellidae). Journal of the North American Benthological Society 13:569-579.
_____________. 2000. Phylogenetic systematics of the major lineages of pannote mayflies (Ephemeroptera: Pannota). Transacations of the American Entomological Society 126(1):9-101.
McCafferty, W. P. and R. D. Waltz. 1995. Labiobaetis (Ephemeroptera: Baetidae): new status, new North American species, and related new genus. Entomological News 106: 19-28.
Muller-Liebenau, I. 1973. Morphological characters used in revising the European species of Baetis Leach, pp. 182-198. In W. L. Peters and J. G. Peters (eds.). Proceedings of the first international congress on Ephemeroptera. E. J. Brill, London.
Needham, J. G., J. P. Traver and Y. C. Hsu. 1935. The biology of mayflies with a systematic account of North American species. Comstock, Ithaca.
Randolph, R. P., and W. P. McCafferty. 1998. Diversity and distribution of the mayflies (Ephemeroptera) of Illinois, Indiana, Kentucky, Michigan, Ohio, and Wisconsin. Bulletin of the Ohio Biological Survey, New Series 13(1).
Tomka, I., and A. Zurwerra. 1985. Key to the genera of the Heptageniidae (Ephemeroptera) of the Holarctic, Oriental and Ethiopian Region. Entomogische Berichte Luzern 14:113-126.
Waltz, R. D., W. P. McCafferty, and J. H. Kennedy. 1989. Barbaetis, a new genus of eastern Nearctic mayflies (Ephemeroptera: Baetidae). Great Lakes Entomologist 18:161-165.
Zloty, J. 1996. A revision of the Nearctic Ameletus mayflies based on adult male, with descriptions of seven new species (Ephemeroptera: Ameletidae). Canadian Entomologist 128: 293-346.

Page created: January 19, 2001
Last page edit: January 24, 2005 (EB)