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Polyneoptera I. Lectures 4. Some major characteristics of Hexapoda : Maxillary plate present 3 body parts (head, thorax, abdomen) 3 thoracic segments each bearing a pair of legs Legs composed of 6 segments 11 maximum abdominal segments Trachea
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Polyneoptera I Lectures 4
Some major characteristics of Hexapoda: • Maxillary plate present • 3 body parts (head, thorax, abdomen) • 3 thoracic segments each bearing a pair of legs • Legs composed of 6 segments • 11 maximum abdominal segments • Trachea • Some major characteristics of Insecta: • External mouthparts • Malpighian tubules • Annulated antennae • 2 pretarsal claws articulated with tarsus • Johnston’s organ • Ovipositor • Posterior tentorial arms fused
Neoptera • “new wing”: wings capable of being folded back against their abdomen at rest, with wing articulations that derives from separate movable sclerites in the wing base.
Polyneoptera • Group that includes 10 orders of insects (Plecoptera, Mantodea, Blattodea, Grylloblattodea, Mantophasmatodea, Orthoptera, Phasmatodea, Embioptera, Dermaptera, and Zoraptera) • Monophyly uncertain, but likely • Diverse morphology, biology, and ecology
Major characteristics • Fore and hind wings nearly equal in size • At rest, wings partly wrap abdomen and extend beyond abdominal apex • Abdomen soft with filamentous cerci • Immature aquatic • Abdominal gills
Interesting biology • Sexual attraction via acoustic signals • Males drum by tapping the tip of the abdomen on the substrate • Females respond and answer with a drumming http://www.ias.unt.edu/~StoneflyHome/Home/
Interesting biology • Surface skimming: a nonflying form of aerodynamic locomotion to move across water surfaces • Body weight supported by water • Effective aerodynamic locomotion with small wings and weak flight muscles
Phylogeny of Plecoptera based on morphology (Zwick 2000) • 16 families, ~2000 species • Two suborder: Antarctoperlaria (southern) and Arctoperlaria (northern)
Common stoneflies of Florida • Perlidae • Perlodidae
Major characteristics • Common name: earwig • Elongate and flattened • Prognathous • Antennae short to moderate • Fore wings modified to leathery tegmina • Hind wings semi-circular • Cerci modified as forceps • Mostly omnivorous
Interesting biology • Small to large
Interesting biology • Ectoparasites • Suborder Hemimerina are ectoparasites of rats • Suborder Arixenina are ectoparasites of bats • Both viviparous Arixeniina Hemimerina
Interesting biology • Maternal care • Egg care • Nymphal care • Defense • Providing food
Diversity • ~2000 species • Family-level classification unstable • Three extent suborders (Forficulina, Arixeniina and Hemimerina), but monophyly questionable Jarvis et al. 2005 (Systematic Entomology)
Common earwigs of Florida • Forficulidae • European earwig • Brownish black • 15-20 mm in length • Occasional damage to crops
Common earwigs of Florida • Anisolabididae (used to be Carcinophoridae) • Seaside earwig • blackish brown • 20-25 mm in length
Common earwigs of Florida • Labiidae • 4-7 mm in length • Covered with golden hair
Major characteristics • Common name: webspinners • Elongate, cylindrical • Prognathous • Wingless in all females • Basal fore tarsus swollen with silk gland • Cerci two-segmented
Interesting biology • Silk production • All stages of development of both sexes • Basal tarsomere greatly swollen with numerous silk glands • http://youtu.be/k4ytfhnuuOo
Diversity • 9 families, ~400 species • Monophyly of several families not supported • Over emphasis on male genitalia might be the problem Szumik et al. 2008 (Cladistics)
Molecular data suggest some families to be paraphyletic Miller et al. 2012 (Syst. Ent.)
Common webspinners of Florida • Teratembiidae
Major characteristics • Small, termite-like • Gregarious lifestyle, with individuals living in colonies up to about 120 individuals • Polymorphism in populations; with blind, apterous individuals dominating during colony life, but populations produce eyed alates (individuals with wings) for dispersal and founding new colonies
Diversity • One family, Zorotyidae, ~30 species • Least known pterygote order • Phylogenetic placement uncertain Yoshizawa and Johnson (2005), MPE
Major characteristics • Common name: rock crawlers, icebugs • Found only at high elevations in the mountains of China, Siberia, Japan, and western United States and Canada • Wingless • Prognathous • Stout coxa adapted for running
Diversity • One family, Grylloblattidae • ~20 described species, probably more to be described
Major characteristics • Common name: heelwalkers • Newest order of insect discovered • Smallest order with 8 described species • Hypognathous • Long antennae • Wingless • Fore and mid legs raptorial • Endemic to South Africa