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Genus Sialis - Alderflies

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Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Megaloptera (Alderflies, Dobsonflies, and Fishflies)
Family Sialidae (Alderflies)
Genus Sialis (Alderflies)
Explanation of Names
Sialis Latreille 1802
From Greek sialis (σιαλις) 'a type of bird'(1)
the most speciose megalopteran genus, with 23 spp. in our area and ~60 total(2)(3)
8-18 mm to wingtips(2)(4)(5)(3)
Black or dark brown insects that hold their heavily-veined wings folded roof-like over their backs. Lack ocelli. Antennae roughly half the body length. Fourth tarsal segment widened, has two lobes. Wing venation:

Identification of species requires microscopic examination of male genitalia.
keys to larvae (9 spp.) & adults (11 spp.)(6)
holarctic (widespread) and parts of the Neotropics; in our area, S. infumata, S. americana, and S. mohri are widespread; S. infumata represents a species complex(3)
Adult typically found on vegetation near larval habitat (streams, ponds)
Larvae prefer soft substrates (mud, silt, detritus) with plant debris accumulations. Many species are associated with specific waterbody types, e.g., S. joppa is found primarily in small streams, S. itasca is associated with lakes, other spp. (such as S. americana, S. vagans) are known from both lakes and streams.(5)
Typically May-Jun in most places, Apr-Jul in NC, Apr-May in KS, as early as Mar in TX(7)
Larvae prey on aquatic invertebrates (chironomids, tubificid worms, ostracods)(2)(5); adults eat little, if at all
Life Cycle
Larvae pupate above water level. Mating at night. Eggs laid near water. Pupae overwinter.
See Also
Plecoptera (Stoneflies; superficially similar, but unrelated)
Works Cited
1.Dictionary of Word Roots and Combining Forms
Donald J. Borror. 1960. Mayfield Publishing Company.
2.Aquatic Insects of North America
R. W. Merritt, K. W. Cummins, M.B. Berg. 2008. Kendall/Hunt.
3.A guide to the Megaloptera and aquatic Neuroptera of Florida
Rasmussen A.K., Pescador M.L. 2002. Florida Dept of Environmental Protection, Div. Water Resource Management. Tallahassee. iii+45 pp.
4.American Insects: A Handbook of the Insects of America North of Mexico
Ross H. Arnett. 2000. CRC Press.
5.A Guide To The Megaloptera And Aquatic Neuroptera Of Florida
6.Bright E. (2002-2011) Aquatic Insects of Michigan
7.Insects of the Texas Lost Pines (W.L. Moody, Jr., Natural History Series, No. 33)
Stephen W. Taber, Scott B. Fleenor. 2003. M University Press.