Aquatic Insects of Michigan

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

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Megaloptera of Michigan


Chauliodes rasticornis courtesy of Linda Benoche, Ann Arbor, Michigan. Adult was found clinging to the side of the USGS Great Lakes Science Center building in the afternoon.

This small holometabolous order has just two families, Corydalidae (Dobsonflies, Fishflies) and Sialidae (Alderflies), both of which occur in Michigan. There are normally 10-11 larval instars, and life cycles of most species are 1-3 years, with emergence in late spring or early summer. Larvae of all species are carnivorous; little is known about the feeding habits of our short-lived adults.

The larvae of Corydalyidae are known as hellgrammites. Eggs are laid terrestrially, proximate to water, and hatch rapidly 3-5 days after laying, with first instar larvae dropping into the water. Larvae are predacious, feeding principally on mayflies, dragon- and damselflies, caddisflies and dipterans. After growth of 2-5 years, larvae leave the water for a distance of 20-35 cm (but can be considerably farther) to a log or moist terrestrial environment to construct a pupal chamber. Adults are short-lived, generally poor fliers, emerge at night and fly into trees to locate each other and mate. Adults are photophilous, and are often collected in light traps and ordinary street or house lights. Males have large mandibles, obstensively for courtship purposes.

Alderfly larvae generally inhabit depositional silt in lentic and lotic environments. Life history is very similar to Corydalidae: females oviposit eggs terrestrially, often in large numbers on vegetation proximate to water. Eggs hatch rapidly 3-5 days after laying, with the first instar larvae dropping into the water. Larvae are predacious, feeding principally on small mayflies and midges. Larvae are both lentic and lotic, usually burrowing into depositional areas of silt. Common in littoral zones of some lakes, but also can be found further out from shore.There are 10 larval instars requiring 1-2 years to reach the terminal larval instar. Pupation is terrestrial, and adults do not feed. Adults are short-lived and are generally poor fliers. Adults are not photophilous; larvae and adults lack ocelli. One must either collect them on the wing or among nearby vegetation. Sialid larvae are distinct from corydalids in that the last abdominal segment does not have anal claws, but rather has a long, slender median terminal filament.

Genera are denoted in green; species denoted in bold blue have been recorded in Michigan; species denoted in black bold are likely to occur in Michigan based on their known distribution with nearby state/provincial localities from which certified records have been published. You can use the Find function in your web browser to locate families, genera, and species. Synonomous species (indented) are listed below the current valid species (denoted in bold) with its taxonomic status indicated.

    CORYDALIDAE Leach, 1815 (Dobsonflies and Fishflies)

    Five species in four genera are recorded from Michigan, with one additional species possibly to be encountered in the state based on existing regional distributional records. Neohermes concolor is known in Michigan only from several blacklight-collected specimens from the extreme southwestern Lower Peninsula. Michigan specimens of Nigronia fasciatus in the UMMZ-Insect Division were determined by the author to be misidentified N. serricornis. However, based on this species known distribution, it may occur in the southern part of the Lower Peninsula.

      Corydalus Latreille, 1802 (Subfamily Corydalinae)
        Corydalus cornutus (Linneaus, 1758) Hemerobius (orig.)
          (syn.) Raphidia cornuta Linnaeus, 1767
          (syn.) Corydulus cognatus Hagen, 1861
          (syn.) Corydulus luteus Hagen, 1861
          (syn.) Corydalus crassicornis McLachlan, 1867
          (syn.) Corydalus inamabilis McLachlan, 1867
          (syn.) Corydalus texana Banks, 1903
          (syn.) Corydalus texanus Banks, 1903

      Chauliodes Latreille 1796 (Subfamily Chauliodinae)
        Chauliodes pectinicornis (Linneaus, 1763) Hemerobius (orig.) - Davis 1903: 461-462; Hazard 1960: 9-12, 47; Tarter et al. 1977: 72
          (comb.) Semblis pectinicornis Fabricius, 1781
          (syn.) Hemerobius virginiensis Drury, 1773
          (syn.) Chauliodes virginiensis; Westwood, 1839
        Chauliodes rastricornis Rambur, 1842 - Hazard 1960: 12-14, 49; Tarter et al. 1977: 73
          (syn.) Hermes indecisus Walker, 1853
          ( Chauliodes pectinicornis; Moody, 1877:97

      Neohermes Banks, 1908 (Subfamily Chauliodinae)
        Neohermes concolor (Davis, 1903) Chauliodes (orig.) - Berrien Co., 1965, 1966 - Cook Collection, MSU, East Lansing, Michigan

      Nigronia Banks, 1908 (Subfamily Chauliodinae)
        Nigronia fasciata (Walker, 1853) Chauliodes (orig.) - IN, OH, south (Hazard 1960: 19-21, 51)
          (syn.) Chauliodes lunatus Hagen, 1863
        Nigronia serricornis (Say, 1824) Chloroperia (orig.) - Hazard 1960: 21-25, 53
          (syn.) Nevromus maculatus Rambur, 1842
        Photo: Sialis lutaria, photo by Mick Talbot (January 2012)

    SIALIDAE Leach, 1815 (Alderflies)

      Sialis Latreille, 1802
        Sialis aequalis Banks, 1920 - Ross 1937; Canterbury 1978: 87; Whiting 1991: 51
        Sialis americana (Rambur, 1842) Semblis (orig.)
          (syn.) Sialis ferrugineus Walker, 1853
          (syn.) Protosialis americana Van der Wheele, 1909
        Sialis driesbachi Flint, 1964 - Flint 1964: 10
        Sialis hasta Ross, 1937 - Ross 1937: 74; Canterbury 1978: 27-29, 89
        Sialis infumata Newman, 1838 - Ross 1937: 73; Canterbury 1978: 34-36, 89
        Sialis itasca Ross, 1937 - Ross 1937: 72; Canterbury 1978: 87
        Sialis joppa Ross, 1937 - Ross 1937; Canterbury 1978: 43-46, 89; Tarter et al. 1978: 232
        Sialis mohri Ross, 1937 - Ross 1937: 74; Canterbury 1978: 43-46, 87
        Sialis vagans Ross, 1937 - Ross 1937: 77; Canterbury 1978: 39-41
        Sialis velata Ross, 1937 - Ross 1937: 71; Canterbury 1978: 46-47, 87


    Canterbury LE. 1978. Studies of the genus Sialis (Sialidae: Megaloptera) in Eastern North American. Ph.D dissertation, University of Louisville, Louisville, Kentucky. x + 92 pp.
    Davis KC. 1903. Part 7. Sialididae of North and South America, pp. 442-486 in Aquatic insects in New York State. New York State Museum Bulletin 68: 442-487.
    Hazard EI. 1960. A revision of the genera Chauliodes and Nigronia (Megaloptera: Corydalidae). M.S. thesis, The Ohio State University, Columbus, Ohio, USA. iii + 53 pp.
    Ross, HH. 1937. Studies of Nearctic aquatic insects. I. Nearctic alder flies of the genus Sialis (Megaloptera, Sialidae). Bulletin of the Illinois [State] Natural History Survey 21:57-78 [Errata: printed on a free slip of paper inserted in the work].
    Penny ND, Adams PA, Stange LA. 1997. Species catalog of the Neuroptera, Megaloptera, and Raphidioptera of America North of Mexico. Proceedings of the California Academy of Sciences 50(3): 39-114.
    Tarter DC, Waktins WD, Little ML, Ashley DL. 1977. Seasonal emergence patterns of fishflies east of the Rocky Mountains (Megaloptera: Corydalidae). Entomological News 88(3-4): 69-76.
    Tarter DC, Watkins WD, Ashley DL, Goodwin JT. 1978. New state records and seasonal emergence patterns of alderflies east of the Rocky Mountains (Megaloptera: Sialidae). Entomological News 89(9-10): 231-234.
Page edits:
    December 19, 2012
    • Added citations from Tarter et al. (1977, 1978) and Penny et al. (1997).
    • Added Chauliodes lunatus as synonym of Nigronia fasciata, per Penny et al. 1997

    November 07, 2012
    • Beginning to keep track of changes to the web site pages
    • Removed individual pages for families into one long list, families accessed from left menu via anchor redirects within page.

Page created: November 01, 2002; Last updated: July 18, 2016 (EB)