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Phylum Arthropoda Class Insecta Order Odonata Dragonflies and Damselflies. Odonate Characteristics. ‘Odonto’ refers to strong teeth on mandibles of adults Aquatic larva -> terrestrial (aerial) adult Highly predaceous larva or adult
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Phylum ArthropodaClass InsectaOrder OdonataDragonflies and Damselflies
Odonate Characteristics • ‘Odonto’ refers to strong teeth on mandibles of adults • Aquatic larva -> terrestrial (aerial) adult • Highly predaceous larva or adult • Usually considered beneficial for the large number of flying insects the adults eat • ~11 families and 407 species in NA • Hemimetabolous: egg -> nymph (naiad) -> adult • Some species are migratory • Adults often mate guard by flying in tandem after copulating • “Devil’s Darning Needle”; mosquito hawk
Natural History • Habitat-almost all in lentic waters • Feeding-zooplankton->larger invertebrates->larger items, even fish • Life history: • Most have one generation/yr • Some require 2 years; a few require 3-6 yrs (in cold climes) • Most oviposit in water; a few in plants above water line with a sword-like structure • Hatch in several weeks; species of vernal pools may enter diapause for 11 months • Larval stage averages 10 months (range-6 weeks to 6 years) • Molt 11-12 times (range 10-15)
More Natural History • Stop feeding several days prior to emergence • Climb out of water • Emergence takes 1-3 hrs; a very vulnerable stage; many emerge at night • Adults live 1 month (range: 2weeks-2 months) • Excellent vision; can rotate head almost 360 • Catch food on the wing in leg basket • Males territorial; may lek
SubordersAnisoptera and ZygopteraDragonflies Damselflies
Larvae • Labial mask for catching prey • Rectal gills • Stout body • Labial mask for catching prey • Three leaf-like gills at rear of abdomen • Body long and slender
Dragonfly LarvaeFamily Differences Aeshnidae Gomphidae Cordulugasteridae
Emergence: a dangerous time Teneral Stage