资源描述：
《农大昆虫学ppt课件昆虫分类（三）》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。
1、蜻蜓目ODONATACommonNames:dragonflies,damselflies蜻蜓、豆娘Distribution:CosmopolitanDescriptionOdonataisaveryancientorderofinsectswithfossilsdatingfromtheUpperCarboniferous.Somespeciesfromthistimeperiodhad70cmwingspans.Damselfliesanddragonfliesareverysimilarinappearancebutdifferasfollows:at
2、rest,thewingsofdragonfliesarespreadoutperpendiculartothebody(resemblingaircraftwings),damselfliesbringtheirwingstogetherlooselyoverthebackoftheabdomen;dragonfliestendtobemorestronglybuiltinsects,damselfliestendtoberatherdelicatelybuilt;dragonflynymphsareheavilybuiltmud-dwellers,whi
3、ledamselflynymphsfrequenttangledvegetationatthesidesofthestreamorpondandhavetwoflattenedabdominalappendageswhichareabsentindragonflynymphs.Alladultshaveshortantennaecomposedofstraightsegments(filiform)andprominentcompoundeyes;simpleeyes(ocelli)areusuallypresent.Themandiblesarewelld
4、evelopedandalladultspeciesarepredatoryonotheraerialinsects.Thetwopairsofwingsarelarge,membranousandequalinsizewithprominentvenation.NaiadThereisnometamorphiccycleofegg,larva,pupaandadult.Insteadthejuvenileemergesfromtheeggasawinglessformoftheadult(nymph)(hemimetamorphsis).However,t
5、heoverallbodyshapemaybemuchshorterandrobust.Afeatureofdragonflynymphsistheextendablelowerlip(labium)ormaskwhichisequippedwithpincers.Thelabiumisthrustforwardveryrapidlytosecureprey.Astheydevelop,dragonflynymphsbecomecapableofsecuringquitelargepreyincludingtadpolesandsmallfish.Durin
6、gdevelopmentthroughanumberofmoults,wingsbegintoappear,butthesearenon-functional.Atmaturity,thenymphsmovetothesurfaceandemergeontoreedsorsimilarsurfaces.Theadultemergesbybreakingthroughthenymph’sfinalexoskeleton.Theadultlegsareusedtocaptureaerialinsectsbyforminga"basket"inwhichthepr
7、eyisfirstsecuredthentransferredtotheinsect’smouth.FoodWhenintheaquaticphase,anysuitablysizedanimaliscapturedforfood.Thismayincludeinsects,tadpoles,fish,wrigglers,etc.Oncetheadultformisreached,mostfoodiscapturedinflightandconsistsofotherwingedinsects,particularlythoseassociatedwithp
8、ondsorstreams.ImportanceDr
