whiteip12
ip12 时间:2021-01-24 阅读:()
15Volume62February2003TheBeginner'sGuidetoCaddis(OrderTrichoptera)byIanWallaceKeeperofInvertebrateZoology,NationalMuseumsandGalleriesonMerseyside,WilliamBrownStreet,Liverpool,L38EN.
IllustratedbyPhilWilkins(7607)PeregrineProductions,TheSummerhouse,OrfordRoad,Tunstall,SuffolkIP122JA.
AdultRhyacophilaseptentrionisAgapetusfuscipeslarvaincaseCaddislarvae,livinginacasetheyhavemade,aresomeofthemostfamiliarfreshwaterinsects.
TheyarethoughttoderivetheirnamefromElizabethanstreethawkerscalledcaddicemenwhosoldbraidandhadsamplesstitchedtotheircoats.
Whilethecommonnameforthegroupisderivedfromthelarva,thescientificnamefortheorder,Trichoptera,alludestothehairycoveringoftheadult'swings.
AfewspeciesrelyonthehairstoformthewingpatterninthesamewaythattherelatedLepidopterarelyonscales.
However,inthemajorityofcaddisthebrownorgreypatternofthewingsisinthemembraneandcannotberemovedbyrubbing,unliketheLepidoptera.
Thereare198BritishandIrishspeciesin18families.
EncounteringadultcaddisAsexpectedforaninsectwithanaquaticlarvalstage,youwillencounterthelargestnumberandvarietyofcaddisnearwater.
Manyspeciesflyintheearlynightandpassthedayrestingonbank-sidevegetationfromwheretheycanbedislodgedontoabeatingtray.
Howeveryouwillfindthat,byenergeticleaping,theywillsoonescapefromthetray,eveniftheydonotflyoff.
Beatingintoasweepingnetismoresuccessful.
Manydoformday-flyingswarmsoverthewaterandthemostfamiliararethelong-hornedcaddisofthefamilyLeptoceridae,whose16BulletinoftheAmateurEntomologists'Societyantennaefarexceedthebodylength.
Theyformzig-zaggingswarmsclosetothewatersurfaceafewfeetfromtheshore.
Theymaylookeasytocatchbuthavepositionedthemselvesacertaindistancefromthebank.
Asyoucarefullywadeouttowardsthemyoubecomethebankandtheyobliginglymoveawayfromyou.
Speed,luckandwetnetsandclothesaretheorderoftheday!
AdultMystacideslongicornisTriaenodesbicolorcaseandlarvaLeptoceruscineiformislarvaandcase.
Adultsalsocometolighttrap,evenatadistancefromwater.
Particularlycommonintrapsawayfromwaterarethecaddisthatbreedinsitesthatdryupoversummer,whichseasonispassedasanadult.
Theselong-livedinsectsdiapauseinvariousplacesofwhichbunchesofgreenashkeysareespeciallyfavoured–afactdrawntomyattentionbyDrJimO'ConnoroftheNationalMuseumofIreland,Dublin.
Adultcaddisareimitatedbyfly-fishermenandseveralhavebeengivenangler'snames.
IdentifyingadultcaddisAdultcaddiscanbepinned,orpreservedinisopropylalcohol,availablefromchemists.
However,theiridentificationistroublesome.
Despitehavingpatternedwings,onlyaboutathirdofspeciescanbeidentifiedusingwingpatternsANDtherearecurrentlynobooksshowingthepatternsanyway.
Examinationofthegenitaliaisnecessarytogettospecieslevelinmostcases,andtheonlyin-printguidecostsabout150.
Enlistingtheassistanceofanexpertistheonlypracticalsolutionformostbeginners.
EncounteringthelarvalcaddisAnywaterbody(exceptthosethataredryformorethansixmonthsayear,oraremoderatelypolluted,orworse)islikelytohavecaddislarvae.
Caddislarvaefallintotwocategories.
However,likethesplitbetweenmicro-andmacro-moths,itisnotentirelybasedontheirtaxonomy.
Thegroupsarethe"cased"caddis,whichmakeatransportablecase,andtheso-called"case-less"caddis.
Thelattertermisveryconfusingasmostliveinafixedshelter,withonlyfourBritishspeciesinonegenusbeingtrulyfree-living.
Caddislarvaeshouldbepreservedinalcoholsuchasisopropylalcohol.
MethylatedorSurgicalSpiritarepossiblebutnotidealastheygocloudyondilutionandhaveotherchemicalsthatcouldaffectthecolourpatterning.
IdentifyingthecaddislarvaWhereastherearenoeasycharacterstoidentifygroupsofcaddisadults,severalgroupsofcaddislarvaeareeasytorecognise.
However,eventhenidentificationtothespeciesrequiresamicroscopeandidentificationkeys,butfortunately,thelatterarecomparativelyinexpensive.
The"caseless"larvaeRhyacophilalarvaeareunmistakable.
Thesefree-livingpredatorsofrunningwaterhavegreenbodies,yellowandblackheadsandbunchesofreddishgillsalongthesidesofthebody.
Therearefourspecies.
17Volume62February200318BulletinoftheAmateurEntomologists'SocietyThreefamiliesliveinsheltersbasedaroundnets.
Hydropsychids,withtheirstrongthoracicplatesandbunchesofwhiteventralgills,createarathercoarsemeshedsievetocatchpiecesofplantorverysmallanimalsfloatinginthecurrentofstreamsandrivers.
Thereareninespecies.
Philopotamidshavewhitebodiesandorangeheadsandliveinasocklikenetinfastflowingwater.
Themeshisveryfineandcatchessinglecelledplants.
Therearefivespecies.
ThelastgroupofnetmakersarethePolycentropodidswholiveinbothstillandslowlyflowingwater.
Thenetsof12ofthe13speciesaretangletraps,andactlikeunderwaterspider'swebstoensnareotheranimals;theenigmaticEcnomustenellus,ouronlyrepresentativeofthefamilyEcnomidaealsofeedsthisway.
TheexceptioninPolycentropodidaeisNeureclipsisbimaculata,whosefrenchhornshapednetsactassievesforfloatingmaterial.
ThesecanbeconspicuousRhyacophiladorsalislarvaHydropsydesp.
larvaandnetWormalldiasp.
larvaandnetHolocentropuspicicornislarvaandnetNeureclipsisbimaculatanetThefinalgroupofsheltermakingcaddis,thePsychomyiids,areverysmallandgrazealgaefromthesurfaceofrocksinstillandflowingwater.
Theycreateatubetocovertheiractivitiesandthisendsup19Volume62February2003meanderingoverthesurface.
Tenspeciesliveinthiswayandafurthertwo,inthegenusLype,buildtheirtubesonsubmergedrottingwood,onwhichtheyfeed.
Lypesp.
larvaandtunnelThe"cased"larvaeThemajorityofcaddishavelarvaethatbuildtransportablecases,andwithexperience,manycanbeidentifiedtospecieslevel.
However,forthebeginner,adepressinglylargenumberarenotparticularlycharacteristichavingcasesthatcouldbebestdescribedasbeingmadeofsandgrains,orhaphazardlyconnectedplantmaterial,oramixtureofsandgrainsandincorporatedplantfragments,dependingonwhatisavailable.
Forthatreasonitisnotpossibletoprovidefeaturestoenableidentificationofmostcasedcaddislarvae.
However,afewareverydistinctive.
Themicro-caddisofthefamilyHydroptilidaehavecasesonlyafewmillimetreslongbutmostofthegeneramakedistinctivecasesandallarelaterallyflattened.
Mostspeciescannotbeidentifiedbeyondgenuslevel.
SelectionofHydroptilidaecasesLtoR:Hydrophilasp.
,Ithytrichiasp.
,Oxyethirasp.
,Tricholeicohitonfagesii20BulletinoftheAmateurEntomologists'SocietyAnotherverydistinctivegroup,andverycommononrocksinrunningwater,andoccasionallakeshores,arethesixspeciesofGlossosomatidae.
Theymaketheirroundedhumpedcasesofcoarsesandgrains.
Iftheventralsideisexamineditwillbeseenthatthetwocaseopeningsareidenticali.
e.
thereisnofrontandback,andthelarvausesbothalternatelyasfront.
ForsomeunknownreasononlytwospeciesarefoundinsouthernBritain.
Theygrazealgaeandfinesettledorganicmatterfromthesurfaceofrocks.
Severalothercaddismakehumpedcasesi.
e.
iflookedatfromtheside,thetopedgeoverhangsthebottomedge,evenafternormalcasecurvatureistakenintoaccount.
HumpedcasesofcoarsesandgrainsinsmallspringstreamsaremadebyApataniamuliebrisaspecieswithoutmales.
Thefemaleslayfertileeggswithoutneedofmating.
SimilaronesonstonylakeshoresareofApataniawallengreniwhichdoeshavethenormalarrangementofmaleandfemale.
CaseslikethisfromariverwillprobablybeCeracleaannulicornisor,ifsmoothduetobeingmadeofsmallsandgrains–Ceracleadissimilis.
Beingdislodgedthenwashedaway,isalwaysaproblemforcaddis.
ThisistackledbythethreespeciesofGoeridaewhichincorporatelargeballastgrainsintothesidesoftheircases.
BaresandybottomsmayappeartobeanexposedpositionforacaddislarvabutMolannahascaseextensionsthatcompletelyobscuretheheadfromabove.
ApataniamuliebriscaseAgapitusfuscipeslarvaincaseGoerasp.
caseMolannaaugustatalarvaandcasefrombelowandcrosssection21Volume62February2003TriaenodesbicolorcaseandlarvaInrivers,adistinctivesquaresectioncasewillbeofLepidostomahirtum.
IfitisfixedfirmlytoapieceofvegetationwiththelarvasittingwithoutstretchedlegstocatchpassingparticlesthenitwillbefromonePhrygaenasp.
caseSamplingaweedypondorlakeanytimefromautumntolatespringwillcollectchunkycasesthathavethepiecesofcutplantmaterialattachedtransversely,ratherthanlengthways.
AgroupoffiveLimnephilusspeciesmakethis"log-cabin"typeofcaseandoneofthem,L.
stigma,whichusesgrassblades,producesoneofthebulkiestofallcaddiscasesintheformofashaggybarrelshapeditem.
Someofthefinestcraft-skilledcaddislarvaeusecarefullycutpiecesofplantmaterialtomaketheircases.
Joiningpiecesinaspiralfashionispopular.
Ifthecaseislargeandthelarvahasapropensitytoleaveit,theinvestigatorwillhavefoundoneofthefivespeciesofthefamilyPhryganeidae.
IfthecaseissmallandslenderandthelarvawithinrowsitselfandthecasethroughthewaterbyvigorousbeatingofthefringedbacklegsthenthelarvawillbeTriaenodesbicoloriffromstillwater,orthegenusYlodesiffromrunningorbrackishwater.
Limnephilisstigmacaseoftheangler'sgreatearlyspringfliestheGrannomBrachycentrussubnubilus.
OlderGrannomlarvaehavecasesthatareroundedinsection.
Lepidostomaalsoconstructsacasewiththeposteriorendofsandgainsandcircularincross-section,andthatisalsothesituationforCrunoeciairroratathatinhabitstinytrickles.
LepidostomahirtumlarvaandcaseCrunoeciairroratalarvaandcaseBrachycentrussubnubilisyoungcaseAcaddiscaseismadeofatubeofsilkenthreadstowhichotheritemsareattached,andsomecaddisdispensewiththeexternalmaterial.
Leptocerustineiformismakesaslendercaseandrowsthroughthewaterofpondsandlakesusingitsfringedlegs.
AgroupofthreespeciesinthegenusCeracleathathavecasesmadeonlyofsilkfeedonfreshwaterspongeandoftenattachdisguisingpiecesofspongetotheircases.
Somecaddischangetoasilkcaselateringrowth.
ArelativeofLeptocerustineiformisstartswithsandgrainsthenabruptlychangestoonlysilk,andtheGrannomstartswithplantpiecesandendswithmainlyacaseofsilk.
Ceracleaalbimaculacase,withspongeattachedBrachycentrussubnubilisoldercaseandlarva22BulletinoftheAmateurEntomologists'SocietyAlthoughcasesmadeofatubeofsandgrainstowhichlongsticksareattachedaremadebyseveralspecies,twodeservesinglingout.
Bothhaveblackmarkedyellowheads.
IfthecaseissmallandthehindlegsofthelarvaareconsiderablylongerthantheotherlegsitwillbeofthegenusMystacides.
IfthehindandmiddlelegsareofasimilarlengthandtheheadisparticularlyblotchyitwillbeAnabolianervosa.
Itissaidthatthesticksassistthelarvatoholdstationagainststrongcurrentbutitwillprobablyalsomakeitharderforafishtoapproachcloseenoughtohooverupthelarva.
Mystocidesunigralarva,caseandfaceAnabolianervosalarvalcaseandfaceItisunfortunatethatBritain'scommonestlargecaddisLimnephiluslunatusdoesnothaveadistinctivecase,orheadpattern.
However,acaddisfromflowingwater,inastraightcaseofplantmaterialwithorwithoutsandgrainsatthefrontendandwithabandedhead,islikelytobeLimnephiluslunatus.
Limnephiluslunatuslarva,caseandface23Volume62February2003EncounteringcaddispupaeWhenfullgrown,allfree-livingandshelterdwellingcaddismakeacaseofstonesorplantdebris,attachedtoastoneorlargeplant,inwhichtopupate;casedcaddislarvaealsoattachtheircasesandthensealupbothends,apartfromsmallgrillestoallowpassageofoxygenatingwater.
Toemerge,theadult,stillinitspupalskin,cutsoutofthecaseorshelterusingspecialmandibles.
Itthenrapidlyswimstothesurfaceofthewaterorthebank,usingfringedlegs.
Itisassistedinreachingthesurfacebyabubbleofgassecretedbetweentheadultandtheskin.
Thishowevermakesthemappearasasilverybubblethatisveryconspicuoustofish.
Largenumbersofcaddisarepredatedatthistime.
Manyspeciesemergeatnightwhenthefishcannotseethem–butwaitingDaubenton'sbatscandetectthesejuicymouthfuls.
Asuccessfulindividualsplitsthepupalskin,theadultrapidlyemergesexpandingitswingsinafewsecondsasitwrigglesoutoftheskin,thenfliestoanearbybushtodryitswingsforafewminutes.
Thepupalshuckfloatsaway,anemptyhusk.
RearingcaddisItmaybedifficulttoidentifycaddisbuttheycanbeinterestingtokeep.
Donottrytorearanyofthefree-livingorsheltermakersunlessyouhavetheabilitytocreateastronguni-directionalcurrent.
Casedcaddiscanbekeptwithvaryingdegreesofsuccess.
Agoodgrouptostartwitharethosethatliveinponds,suchasthe"log-cabin"limnephilids.
Theywillusuallyeatdeadleavesoftreeslikesycamore–butdonotoverfeed,andalittleaerationmightbehelpful.
AnotherintriguingcaddistorearisGlyphotaeliuspellucidus.
Lookoutforjellyeggsonleavesoftreesthatoverhangpondsandditchesorinplaceswherepondsandditcheswillbewhenthewaterlevelrises.
OnlyoneotherBritishcaddislayslikethis–thelargeandsuperbNemotauliuspunctatolineatusofPupaofGoerasp.
Glyphotaeliuspelluciduslarvaandcase24BulletinoftheAmateurEntomologists'SocietyHighlandblanketbogs.
Keeptheeggmassmoistbutnotwetuntiltinydarklarvaecanbeseenmovingwithinthejelly.
Submergingitwillletthemescape.
Theyfeedondeadtreeleavesanditisusefultohavebothsycamore(forfood)andoak(forcasemaking);thecaseisaflataffair.
Collectleavesfromthepondratherthanfromthegroundastheywillhavebothlosttherathertoxictanninsanddevelopedthemicro-fungiandbacteriawhicharewhatthelarvaearereallyafterasfoodwhentheyeatleaves.
Thoughitiseasytorearmanycasedcaddislarvae,itissurprisinglydifficulttogetsuccessfulemergenceofanadultfromthepupalskin.
Itisbesttoplacethesealedupcasesintoashallowandnotverticaledgedbowlfilledwithwater,butalsolinedwithnettingupwhichthecaddispupacanclimb.
Eventhen,manyrefusetoemergeandbecomeeventuallywater-loggedanddieseveraldayslater.
Incidentally,Britain'sonlyterrestrialcaddis,EnoicylapusillaoftheWyreForestwoodlands,isalsodifficulttoreartotheadult,usuallydyingduringpupation.
EnorcylapusillalarvaandcaseAssistancewithidentificationDuetotheabsenceofcheapbooks,Iampreparedtoidentifyvoucherexamplesofcaddisadultsbutnotbulksamplesandonlyifaskedinadvanceofsendingmaterialplease.
Ineedtoscheduleworkcarefully!
Iamalsoabletoconfirmtheidentityofcaddislarvae.
AgainIwouldwanttodovoucherspecimensonly.
Iwouldpreferablywantthecollectortohavetriedtousetheavailablekeysfirst.
Afteralittlefamiliaritymanycaddisadultsandlarvaecanbeidentifiedinthefield.
Myaimistoincreasethepoolofpeopleinterestedin,andrecordingcaddis,ratherthanjustaddtothesumtotalofrecords,valuablethoughthatis.
CaddisRecordingSchemeThereisanationalcaddisdistributionrecordingschemeoperatedundertheauspicesoftheBiologicalRecordsCentre,CEHMonksWood,25Volume62February2003AbbotsRipton,Huntingdon,CambridgeshirePE282LS.
Detailsofhowtocontributerecords,theaimsoftheschemeandsomeofitscurrentprojects,canbeobtainedfromtheBiologicalRecordsCentre,orfromitsweb-siteorfrommepersonally.
FurtherreadingHickin,N.
E.
(1967)CaddisLarvaepublishedbyHutchinson,London(agoodintroductiontocaddislarvae,withsomelovelyillustrationsbutout-ofdateforidentificationoflarvae;thekeytopupaehoweverremainsserviceable)Macan,T.
T.
(1973)AkeytotheadultsoftheBritishTrichopteraScientificPublicationsoftheFreshwaterBiologicalAssociation,Number43.
(longout-of-print,andwithafewerrors,butworthobtainingifyoucan.
AlistofproblemsthatmightbeencounteredwhenusingMacanisavailablefromIanWallaceatLiverpoolMuseum)Malicky,H.
(1983)AtlasoftheEuropeanTrichopteraJunk,TheHague.
(veryexpensive,andasitcoversalltheEuropeanspeciesitisnotabookforthebeginner)Edington,J.
M.
&Hildrew,A.
G.
(1995)ArevisedkeytotheCaselessCaddisLarvaeoftheBritishIslesScientificPublicationoftheFreshwaterBiologicalAssociation,Number53(thedefinitivekeytoidentifycaselesscaddislarvae)Wallace,I.
D.
,Wallace,B.
&Philipson,G.
N.
(2003)ArevisedkeytotheCasedCaddisLarvaeoftheBritishIslesScientificPublicationoftheFreshwaterBiologicalAssociation,inpress.
(thedefinitivekeytoidentifycasedcaddislarvae)Wallace,I.
D.
(1991)AreviewoftheTrichopteraofGreatBritainResearchandsurveyinnatureconservationNo.
32,publishedbytheNatureConservancyCouncil,NorthminsterHouse,Peterborough,UK(adistributionsummaryforeveryBritishspecies;afewareoutofdatebutanupdateisavailablefromIanWallaceatLiverpoolMuseum.
)26BulletinoftheAmateurEntomologists'SocietyVisittheAESWebsitetoday!
AESmemberscanalsojointheAESForumathttp://groups.
yahoo.
com/group/aes/http://www.
amentsoc.
org
IllustratedbyPhilWilkins(7607)PeregrineProductions,TheSummerhouse,OrfordRoad,Tunstall,SuffolkIP122JA.
AdultRhyacophilaseptentrionisAgapetusfuscipeslarvaincaseCaddislarvae,livinginacasetheyhavemade,aresomeofthemostfamiliarfreshwaterinsects.
TheyarethoughttoderivetheirnamefromElizabethanstreethawkerscalledcaddicemenwhosoldbraidandhadsamplesstitchedtotheircoats.
Whilethecommonnameforthegroupisderivedfromthelarva,thescientificnamefortheorder,Trichoptera,alludestothehairycoveringoftheadult'swings.
AfewspeciesrelyonthehairstoformthewingpatterninthesamewaythattherelatedLepidopterarelyonscales.
However,inthemajorityofcaddisthebrownorgreypatternofthewingsisinthemembraneandcannotberemovedbyrubbing,unliketheLepidoptera.
Thereare198BritishandIrishspeciesin18families.
EncounteringadultcaddisAsexpectedforaninsectwithanaquaticlarvalstage,youwillencounterthelargestnumberandvarietyofcaddisnearwater.
Manyspeciesflyintheearlynightandpassthedayrestingonbank-sidevegetationfromwheretheycanbedislodgedontoabeatingtray.
Howeveryouwillfindthat,byenergeticleaping,theywillsoonescapefromthetray,eveniftheydonotflyoff.
Beatingintoasweepingnetismoresuccessful.
Manydoformday-flyingswarmsoverthewaterandthemostfamiliararethelong-hornedcaddisofthefamilyLeptoceridae,whose16BulletinoftheAmateurEntomologists'Societyantennaefarexceedthebodylength.
Theyformzig-zaggingswarmsclosetothewatersurfaceafewfeetfromtheshore.
Theymaylookeasytocatchbuthavepositionedthemselvesacertaindistancefromthebank.
Asyoucarefullywadeouttowardsthemyoubecomethebankandtheyobliginglymoveawayfromyou.
Speed,luckandwetnetsandclothesaretheorderoftheday!
AdultMystacideslongicornisTriaenodesbicolorcaseandlarvaLeptoceruscineiformislarvaandcase.
Adultsalsocometolighttrap,evenatadistancefromwater.
Particularlycommonintrapsawayfromwaterarethecaddisthatbreedinsitesthatdryupoversummer,whichseasonispassedasanadult.
Theselong-livedinsectsdiapauseinvariousplacesofwhichbunchesofgreenashkeysareespeciallyfavoured–afactdrawntomyattentionbyDrJimO'ConnoroftheNationalMuseumofIreland,Dublin.
Adultcaddisareimitatedbyfly-fishermenandseveralhavebeengivenangler'snames.
IdentifyingadultcaddisAdultcaddiscanbepinned,orpreservedinisopropylalcohol,availablefromchemists.
However,theiridentificationistroublesome.
Despitehavingpatternedwings,onlyaboutathirdofspeciescanbeidentifiedusingwingpatternsANDtherearecurrentlynobooksshowingthepatternsanyway.
Examinationofthegenitaliaisnecessarytogettospecieslevelinmostcases,andtheonlyin-printguidecostsabout150.
Enlistingtheassistanceofanexpertistheonlypracticalsolutionformostbeginners.
EncounteringthelarvalcaddisAnywaterbody(exceptthosethataredryformorethansixmonthsayear,oraremoderatelypolluted,orworse)islikelytohavecaddislarvae.
Caddislarvaefallintotwocategories.
However,likethesplitbetweenmicro-andmacro-moths,itisnotentirelybasedontheirtaxonomy.
Thegroupsarethe"cased"caddis,whichmakeatransportablecase,andtheso-called"case-less"caddis.
Thelattertermisveryconfusingasmostliveinafixedshelter,withonlyfourBritishspeciesinonegenusbeingtrulyfree-living.
Caddislarvaeshouldbepreservedinalcoholsuchasisopropylalcohol.
MethylatedorSurgicalSpiritarepossiblebutnotidealastheygocloudyondilutionandhaveotherchemicalsthatcouldaffectthecolourpatterning.
IdentifyingthecaddislarvaWhereastherearenoeasycharacterstoidentifygroupsofcaddisadults,severalgroupsofcaddislarvaeareeasytorecognise.
However,eventhenidentificationtothespeciesrequiresamicroscopeandidentificationkeys,butfortunately,thelatterarecomparativelyinexpensive.
The"caseless"larvaeRhyacophilalarvaeareunmistakable.
Thesefree-livingpredatorsofrunningwaterhavegreenbodies,yellowandblackheadsandbunchesofreddishgillsalongthesidesofthebody.
Therearefourspecies.
17Volume62February200318BulletinoftheAmateurEntomologists'SocietyThreefamiliesliveinsheltersbasedaroundnets.
Hydropsychids,withtheirstrongthoracicplatesandbunchesofwhiteventralgills,createarathercoarsemeshedsievetocatchpiecesofplantorverysmallanimalsfloatinginthecurrentofstreamsandrivers.
Thereareninespecies.
Philopotamidshavewhitebodiesandorangeheadsandliveinasocklikenetinfastflowingwater.
Themeshisveryfineandcatchessinglecelledplants.
Therearefivespecies.
ThelastgroupofnetmakersarethePolycentropodidswholiveinbothstillandslowlyflowingwater.
Thenetsof12ofthe13speciesaretangletraps,andactlikeunderwaterspider'swebstoensnareotheranimals;theenigmaticEcnomustenellus,ouronlyrepresentativeofthefamilyEcnomidaealsofeedsthisway.
TheexceptioninPolycentropodidaeisNeureclipsisbimaculata,whosefrenchhornshapednetsactassievesforfloatingmaterial.
ThesecanbeconspicuousRhyacophiladorsalislarvaHydropsydesp.
larvaandnetWormalldiasp.
larvaandnetHolocentropuspicicornislarvaandnetNeureclipsisbimaculatanetThefinalgroupofsheltermakingcaddis,thePsychomyiids,areverysmallandgrazealgaefromthesurfaceofrocksinstillandflowingwater.
Theycreateatubetocovertheiractivitiesandthisendsup19Volume62February2003meanderingoverthesurface.
Tenspeciesliveinthiswayandafurthertwo,inthegenusLype,buildtheirtubesonsubmergedrottingwood,onwhichtheyfeed.
Lypesp.
larvaandtunnelThe"cased"larvaeThemajorityofcaddishavelarvaethatbuildtransportablecases,andwithexperience,manycanbeidentifiedtospecieslevel.
However,forthebeginner,adepressinglylargenumberarenotparticularlycharacteristichavingcasesthatcouldbebestdescribedasbeingmadeofsandgrains,orhaphazardlyconnectedplantmaterial,oramixtureofsandgrainsandincorporatedplantfragments,dependingonwhatisavailable.
Forthatreasonitisnotpossibletoprovidefeaturestoenableidentificationofmostcasedcaddislarvae.
However,afewareverydistinctive.
Themicro-caddisofthefamilyHydroptilidaehavecasesonlyafewmillimetreslongbutmostofthegeneramakedistinctivecasesandallarelaterallyflattened.
Mostspeciescannotbeidentifiedbeyondgenuslevel.
SelectionofHydroptilidaecasesLtoR:Hydrophilasp.
,Ithytrichiasp.
,Oxyethirasp.
,Tricholeicohitonfagesii20BulletinoftheAmateurEntomologists'SocietyAnotherverydistinctivegroup,andverycommononrocksinrunningwater,andoccasionallakeshores,arethesixspeciesofGlossosomatidae.
Theymaketheirroundedhumpedcasesofcoarsesandgrains.
Iftheventralsideisexamineditwillbeseenthatthetwocaseopeningsareidenticali.
e.
thereisnofrontandback,andthelarvausesbothalternatelyasfront.
ForsomeunknownreasononlytwospeciesarefoundinsouthernBritain.
Theygrazealgaeandfinesettledorganicmatterfromthesurfaceofrocks.
Severalothercaddismakehumpedcasesi.
e.
iflookedatfromtheside,thetopedgeoverhangsthebottomedge,evenafternormalcasecurvatureistakenintoaccount.
HumpedcasesofcoarsesandgrainsinsmallspringstreamsaremadebyApataniamuliebrisaspecieswithoutmales.
Thefemaleslayfertileeggswithoutneedofmating.
SimilaronesonstonylakeshoresareofApataniawallengreniwhichdoeshavethenormalarrangementofmaleandfemale.
CaseslikethisfromariverwillprobablybeCeracleaannulicornisor,ifsmoothduetobeingmadeofsmallsandgrains–Ceracleadissimilis.
Beingdislodgedthenwashedaway,isalwaysaproblemforcaddis.
ThisistackledbythethreespeciesofGoeridaewhichincorporatelargeballastgrainsintothesidesoftheircases.
BaresandybottomsmayappeartobeanexposedpositionforacaddislarvabutMolannahascaseextensionsthatcompletelyobscuretheheadfromabove.
ApataniamuliebriscaseAgapitusfuscipeslarvaincaseGoerasp.
caseMolannaaugustatalarvaandcasefrombelowandcrosssection21Volume62February2003TriaenodesbicolorcaseandlarvaInrivers,adistinctivesquaresectioncasewillbeofLepidostomahirtum.
IfitisfixedfirmlytoapieceofvegetationwiththelarvasittingwithoutstretchedlegstocatchpassingparticlesthenitwillbefromonePhrygaenasp.
caseSamplingaweedypondorlakeanytimefromautumntolatespringwillcollectchunkycasesthathavethepiecesofcutplantmaterialattachedtransversely,ratherthanlengthways.
AgroupoffiveLimnephilusspeciesmakethis"log-cabin"typeofcaseandoneofthem,L.
stigma,whichusesgrassblades,producesoneofthebulkiestofallcaddiscasesintheformofashaggybarrelshapeditem.
Someofthefinestcraft-skilledcaddislarvaeusecarefullycutpiecesofplantmaterialtomaketheircases.
Joiningpiecesinaspiralfashionispopular.
Ifthecaseislargeandthelarvahasapropensitytoleaveit,theinvestigatorwillhavefoundoneofthefivespeciesofthefamilyPhryganeidae.
IfthecaseissmallandslenderandthelarvawithinrowsitselfandthecasethroughthewaterbyvigorousbeatingofthefringedbacklegsthenthelarvawillbeTriaenodesbicoloriffromstillwater,orthegenusYlodesiffromrunningorbrackishwater.
Limnephilisstigmacaseoftheangler'sgreatearlyspringfliestheGrannomBrachycentrussubnubilus.
OlderGrannomlarvaehavecasesthatareroundedinsection.
Lepidostomaalsoconstructsacasewiththeposteriorendofsandgainsandcircularincross-section,andthatisalsothesituationforCrunoeciairroratathatinhabitstinytrickles.
LepidostomahirtumlarvaandcaseCrunoeciairroratalarvaandcaseBrachycentrussubnubilisyoungcaseAcaddiscaseismadeofatubeofsilkenthreadstowhichotheritemsareattached,andsomecaddisdispensewiththeexternalmaterial.
Leptocerustineiformismakesaslendercaseandrowsthroughthewaterofpondsandlakesusingitsfringedlegs.
AgroupofthreespeciesinthegenusCeracleathathavecasesmadeonlyofsilkfeedonfreshwaterspongeandoftenattachdisguisingpiecesofspongetotheircases.
Somecaddischangetoasilkcaselateringrowth.
ArelativeofLeptocerustineiformisstartswithsandgrainsthenabruptlychangestoonlysilk,andtheGrannomstartswithplantpiecesandendswithmainlyacaseofsilk.
Ceracleaalbimaculacase,withspongeattachedBrachycentrussubnubilisoldercaseandlarva22BulletinoftheAmateurEntomologists'SocietyAlthoughcasesmadeofatubeofsandgrainstowhichlongsticksareattachedaremadebyseveralspecies,twodeservesinglingout.
Bothhaveblackmarkedyellowheads.
IfthecaseissmallandthehindlegsofthelarvaareconsiderablylongerthantheotherlegsitwillbeofthegenusMystacides.
IfthehindandmiddlelegsareofasimilarlengthandtheheadisparticularlyblotchyitwillbeAnabolianervosa.
Itissaidthatthesticksassistthelarvatoholdstationagainststrongcurrentbutitwillprobablyalsomakeitharderforafishtoapproachcloseenoughtohooverupthelarva.
Mystocidesunigralarva,caseandfaceAnabolianervosalarvalcaseandfaceItisunfortunatethatBritain'scommonestlargecaddisLimnephiluslunatusdoesnothaveadistinctivecase,orheadpattern.
However,acaddisfromflowingwater,inastraightcaseofplantmaterialwithorwithoutsandgrainsatthefrontendandwithabandedhead,islikelytobeLimnephiluslunatus.
Limnephiluslunatuslarva,caseandface23Volume62February2003EncounteringcaddispupaeWhenfullgrown,allfree-livingandshelterdwellingcaddismakeacaseofstonesorplantdebris,attachedtoastoneorlargeplant,inwhichtopupate;casedcaddislarvaealsoattachtheircasesandthensealupbothends,apartfromsmallgrillestoallowpassageofoxygenatingwater.
Toemerge,theadult,stillinitspupalskin,cutsoutofthecaseorshelterusingspecialmandibles.
Itthenrapidlyswimstothesurfaceofthewaterorthebank,usingfringedlegs.
Itisassistedinreachingthesurfacebyabubbleofgassecretedbetweentheadultandtheskin.
Thishowevermakesthemappearasasilverybubblethatisveryconspicuoustofish.
Largenumbersofcaddisarepredatedatthistime.
Manyspeciesemergeatnightwhenthefishcannotseethem–butwaitingDaubenton'sbatscandetectthesejuicymouthfuls.
Asuccessfulindividualsplitsthepupalskin,theadultrapidlyemergesexpandingitswingsinafewsecondsasitwrigglesoutoftheskin,thenfliestoanearbybushtodryitswingsforafewminutes.
Thepupalshuckfloatsaway,anemptyhusk.
RearingcaddisItmaybedifficulttoidentifycaddisbuttheycanbeinterestingtokeep.
Donottrytorearanyofthefree-livingorsheltermakersunlessyouhavetheabilitytocreateastronguni-directionalcurrent.
Casedcaddiscanbekeptwithvaryingdegreesofsuccess.
Agoodgrouptostartwitharethosethatliveinponds,suchasthe"log-cabin"limnephilids.
Theywillusuallyeatdeadleavesoftreeslikesycamore–butdonotoverfeed,andalittleaerationmightbehelpful.
AnotherintriguingcaddistorearisGlyphotaeliuspellucidus.
Lookoutforjellyeggsonleavesoftreesthatoverhangpondsandditchesorinplaceswherepondsandditcheswillbewhenthewaterlevelrises.
OnlyoneotherBritishcaddislayslikethis–thelargeandsuperbNemotauliuspunctatolineatusofPupaofGoerasp.
Glyphotaeliuspelluciduslarvaandcase24BulletinoftheAmateurEntomologists'SocietyHighlandblanketbogs.
Keeptheeggmassmoistbutnotwetuntiltinydarklarvaecanbeseenmovingwithinthejelly.
Submergingitwillletthemescape.
Theyfeedondeadtreeleavesanditisusefultohavebothsycamore(forfood)andoak(forcasemaking);thecaseisaflataffair.
Collectleavesfromthepondratherthanfromthegroundastheywillhavebothlosttherathertoxictanninsanddevelopedthemicro-fungiandbacteriawhicharewhatthelarvaearereallyafterasfoodwhentheyeatleaves.
Thoughitiseasytorearmanycasedcaddislarvae,itissurprisinglydifficulttogetsuccessfulemergenceofanadultfromthepupalskin.
Itisbesttoplacethesealedupcasesintoashallowandnotverticaledgedbowlfilledwithwater,butalsolinedwithnettingupwhichthecaddispupacanclimb.
Eventhen,manyrefusetoemergeandbecomeeventuallywater-loggedanddieseveraldayslater.
Incidentally,Britain'sonlyterrestrialcaddis,EnoicylapusillaoftheWyreForestwoodlands,isalsodifficulttoreartotheadult,usuallydyingduringpupation.
EnorcylapusillalarvaandcaseAssistancewithidentificationDuetotheabsenceofcheapbooks,Iampreparedtoidentifyvoucherexamplesofcaddisadultsbutnotbulksamplesandonlyifaskedinadvanceofsendingmaterialplease.
Ineedtoscheduleworkcarefully!
Iamalsoabletoconfirmtheidentityofcaddislarvae.
AgainIwouldwanttodovoucherspecimensonly.
Iwouldpreferablywantthecollectortohavetriedtousetheavailablekeysfirst.
Afteralittlefamiliaritymanycaddisadultsandlarvaecanbeidentifiedinthefield.
Myaimistoincreasethepoolofpeopleinterestedin,andrecordingcaddis,ratherthanjustaddtothesumtotalofrecords,valuablethoughthatis.
CaddisRecordingSchemeThereisanationalcaddisdistributionrecordingschemeoperatedundertheauspicesoftheBiologicalRecordsCentre,CEHMonksWood,25Volume62February2003AbbotsRipton,Huntingdon,CambridgeshirePE282LS.
Detailsofhowtocontributerecords,theaimsoftheschemeandsomeofitscurrentprojects,canbeobtainedfromtheBiologicalRecordsCentre,orfromitsweb-siteorfrommepersonally.
FurtherreadingHickin,N.
E.
(1967)CaddisLarvaepublishedbyHutchinson,London(agoodintroductiontocaddislarvae,withsomelovelyillustrationsbutout-ofdateforidentificationoflarvae;thekeytopupaehoweverremainsserviceable)Macan,T.
T.
(1973)AkeytotheadultsoftheBritishTrichopteraScientificPublicationsoftheFreshwaterBiologicalAssociation,Number43.
(longout-of-print,andwithafewerrors,butworthobtainingifyoucan.
AlistofproblemsthatmightbeencounteredwhenusingMacanisavailablefromIanWallaceatLiverpoolMuseum)Malicky,H.
(1983)AtlasoftheEuropeanTrichopteraJunk,TheHague.
(veryexpensive,andasitcoversalltheEuropeanspeciesitisnotabookforthebeginner)Edington,J.
M.
&Hildrew,A.
G.
(1995)ArevisedkeytotheCaselessCaddisLarvaeoftheBritishIslesScientificPublicationoftheFreshwaterBiologicalAssociation,Number53(thedefinitivekeytoidentifycaselesscaddislarvae)Wallace,I.
D.
,Wallace,B.
&Philipson,G.
N.
(2003)ArevisedkeytotheCasedCaddisLarvaeoftheBritishIslesScientificPublicationoftheFreshwaterBiologicalAssociation,inpress.
(thedefinitivekeytoidentifycasedcaddislarvae)Wallace,I.
D.
(1991)AreviewoftheTrichopteraofGreatBritainResearchandsurveyinnatureconservationNo.
32,publishedbytheNatureConservancyCouncil,NorthminsterHouse,Peterborough,UK(adistributionsummaryforeveryBritishspecies;afewareoutofdatebutanupdateisavailablefromIanWallaceatLiverpoolMuseum.
)26BulletinoftheAmateurEntomologists'SocietyVisittheAESWebsitetoday!
AESmemberscanalsojointheAESForumathttp://groups.
yahoo.
com/group/aes/http://www.
amentsoc.
org
virmach：AMD平台小鸡，赌一把，单车变摩托？$7.2/年-512M内存/1核/10gSSD/1T流量，多机房可选
virmach送来了夏季促销，价格低到爆炸，而且在低价的基础上还搞首年8折，也就是说VPS低至7.2美元/年。不过，这里有一点要说明：你所购买的当前的VPS将会在09/30/2021 ~ 04/30/2022进行服务器转移，而且IP还会改变，当前的Intel平台会换成AMD平台，机房也会变动（目前来看以后会从colocrossing切换到INAP和Psychz），采取的是就近原则，原来的水牛城可能...
宝塔面板批量设置站点404页面
今天遇到一个网友，他在一个服务器中搭建有十几个网站，但是他之前都是采集站点数据很大，但是现在他删除数据之后希望设置可能有索引的文章给予404跳转页面。虽然他程序有默认的404页面，但是达不到他引流的目的，他希望设置统一的404页面。实际上设置还是很简单的，我们找到他是Nginx还是Apache，直接在引擎配置文件中设置即可。这里有看到他采用的是宝塔面板，直接在他的Nginx中设置。这里我们找到当前...
TMThosting夏季促销：VPS月付7折,年付65折,独立服务器95折,西雅图机房
TMThosting发布了一个2021 Summer Sale活动，针对西雅图VPS主机提供月付7折优惠码，年付65折优惠码，独立服务器提供95折优惠码，本轮促销活动到7月25日。这是一家成立于2018年的国外主机商，主要提供VPS和独立服务器租用业务，数据中心包括美国西雅图和达拉斯，其中VPS基于KVM架构，都有提供免费的DDoS保护，支持选择Windows或者Linux操作系统。Budget ...
ip12为你推荐
-
鬼武者3内存修改器鬼武者3修改器怎么使用月付百万的女人们男人们谈谈，和多大年龄的女人做爱最舒服腾讯空间首页怎么才能让自己ＱＱ空间被腾讯推荐在ＱＱ空间首页里面？集成显卡和独立显卡哪个好集成显卡和独立显卡是什么区别呢哪个好？录音软件哪个好什么录音软件最好用电陶炉和电磁炉哪个好电磁炉跟电陶炉哪个好股票软件哪个好股票软件哪个好，手机股票软件哪个好用oppo和vivo哪个好vivo和oppo建议买哪个云盘哪个好哪个网盘好用 而且下载速度快 还免费云盘哪个好网盘哪个好用？