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BugGuide Gathering
Smoky Mountains
University of Tennessee Biological Field Station
August 8-10, 2008
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Photos from the last gathering (Minnesota 2007)

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Class Insecta - Insects

Classification
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Class Insecta (Insects)
Other Common Names
Bugs
Explanation of Names
From Latin insectum (plural insecta) for "cut into, cut up". This refers to the way the joints between body segments are marked by an indentation as if carved by a chisel. The word probably arose as a literal translation of Greek entomos (εντομος), which has the same meaning.
Numbers
29 orders (mantids and cockroaches in separate orders here)
949 families
Over 1 million species

U.S. & Canada: (2)
28 orders
612 recorded families
12,428 recorded genera
86,346 recorded species
Nearctica lists 34 orders.
Life Cycle
Hemimetabolus insects (e.g., dragonflies, mayflies, true bugs, grasshoppers) undergo gradual, or incomplete, metamorphosis. Immature stages (usually called nymphs) go through a series of molts, gradually assuming an adult form. Since the wings develop on the outside of the body, these groups are called exopterygotes. Some orders have immature stages that are aquatic. These possess specialized structures for aquatic life, such as gills, and are called naiads, or larvae.
Remarks
Pterygota--winged insects--was formerly considered a subclass of Insecta--see the linked glossary entry for more information.

Note on taxonomic sequence of insects
The sequence of orders of winged insects used in BugGuide follows, mostly, that used in Arnett, American Insects (2). There has been some disagreement about the sequence of orders in Insecta presented here. It has been the consensus both in the 2006 discussion and the 2007 discussion NOT to use an alphabetical sequence for the orders, because this places related groups far apart. Please discuss before making changes. As an organizational aid, see the alphabetical list below.

Alphabetic list of Pterygota orders
Anoplura - Sucking Lice
Coleoptera - Beetles
Dermaptera - Earwigs
Dictyoptera - Mantids and Cockroaches
Diptera - Flies
Embiidina - Webspinners
Ephemeroptera - Mayflies
Hymenoptera - Ants, Bees, Wasps and Sawflies
Hemiptera - True Bugs, Cicadas, Hoppers, Aphids and Allies
Isoptera - Termites
Lepidoptera - Butterflies and Moths
Mallophaga - Chewing Lice
Mecoptera - Scorpionflies, Hangingflies and Allies
Neuroptera - Antlions, Lacewings and Allies
Odonata - Dragonflies and Damselflies
Orthoptera - Grasshoppers, Crickets, Katydids
Phasmatodea - Walkingsticks
Plecoptera - Stoneflies
Psocoptera - Barklice and Booklice
Siphonaptera - Fleas
Strepsiptera - Twisted-winged Insects
Thysanoptera - Thrips
Trichoptera - Caddisflies
Zoraptera - Zorapterans
Print References
Arnett, American Insects, p. xvii--sequence of insect orders (2)
Bland and Jacques, p. 64 (3)
Borror and White, page 56 (4)
Castner, Photographic Atlas of Entomology (5)
Internet References
North Carolina State University: General Entomology--excellent site with systematics, descriptions, images.
Insect Morphology - a primer for beginners, University of Sydney
Australian National Museum: What is an Insect?
Tree of Life--Insecta, Pterygota
Insects of Cedar Creek--Taxonomic Survey--shows Arnett's sequence of orders
Wikipedia--Insect, Pterygota
Works Cited
1.Animal: The Definitive Visual Guide to the World's Wildlife
By Don E. Wilson, David Burnie
2.American Insects: A Handbook of the Insects of America North of Mexico
By Ross H. Arnett
3.How to Know the Insects
By Roger G. Bland, H.E. Jaques
4.A Field Guide to Insects
By Richard E. White, Donald J. Borror, Roger Tory Peterson
5.Photographic Atlas of Entomology and Guide To Insect Identification
By James L. Castner