Entomology 3rd edition - C.Gillott - Chapter 6 pdf

6 P aleopter a 1 . Intr oduc t ion I n the infraclass Paleoptera are the orders Ephemeroptera (ma y flies) and Odonata (dra g- onflies and damselflies), the livin g species of which represent the few remains of tw o formerl y ver y extensive g roups. Althou g h both are placed in the Paleoptera, authorities di sagree on w h et h er t h etwoor d ers are monop h y l et i cor h ave separate or i g i ns (see C h ap - t er 2, Sect i on 3.2). Even if monop h y l et i c, t h eEp h emeroptera an d O d onata are two ver y diff erent g roups t h at must h ave di ver g e d ataver y ear ly sta g e i nt h eevo l ut i on o f w i n g e d insects. The y possess the followin g common features that unite them as Paleoptera: win gs t hat cannot be folded back a g ainst the bod y when not in use, retention of the anterio r me di an w i ng ve i n, net lik e arrangement o f w i ng ve i ns (many crossve i ns), aquat i c j uve- n il e stage, an d cons id era bl ec h ange f rom j uven il etoa d u l t f orm. In mem b ers o fb ot h or d ers, w i n gd eve l opment i s externa l ,t h ou gh t hi s f eature i s not, o f course, restr i cte d to Paleo p tera. 2 . Ephemeropter a S ynonyms: P lecto p tera, E p hemerida C ommon names : m a y flies, shadflies Adults small- to medium-sized elongate fragile insects; antennae short and setaceous, mouthpart s v est i g i a l , compoun d eyes l arge, t h ree oce lli present; genera ll ytwopa i rs o f mem b ranous w i ngs (t h ou gh hi n d pa i r g reat ly re d uce d ) h e ld vert i ca lly over b o dy w h en at rest, w i t h man y crossve i ns; abdomen terminated with two very long cerci and frequently a median caudal filament; with s u bi ma gi na l an di ma gi na l w i n g e d sta g es. L arvae aquat i c; b o d y campo d e if orm; antennae s h ort, compoun d eyes we ll - d eve l ope d , bi t i ng mout h parts; a bd omen usua lly w i t hl on g cerc i an d ame di an cau d a lfil ament, an df our to seven pairs of segmental tracheal gills. Approx i mate l y 2100 spec i es o f t hi sw id e l y di str ib ute d or d er h ave b een d escr ib e d , th oug h t hi s may represent on l ya b out one-t hi r d o f t h e extant spec i es. O f t h e d e - scribed species, about 67 5 occur in North America, 84 in Australia, and about 5 0in B ritain . 12 7 128 CHAPTER 6 Structur e A du lt . Th e h ea di str i angu l ar i ns h ape w h en v i ewe df rom a b ove. T h e compoun d eye s are l ar g e, espec i a lly i nma l es w h ere t h e y o f ten meet m idd orsa lly an d t y p i ca lly are di v id e d horizontall y into an upper re g ion with lar g e facets and a lower re g ion with smaller facet s ( Fi g ure 6.1). This arran g ement provides a male with both hi g h acuit y and g ood sensitivit y, a ll ow i ng hi mto d etect an d capture an i n di v id ua lf ema l e i n a swarm at l ow li g h t i ntens i ty. T h ree oce lli are present, t h etwo l atera l so f ten l arge. T h e antennae are sma ll ,mu l t i annu l ate, setaceous structures. T h e mout h parts are vest igi a l .T h et h orac i cre gi on i s d om i nate dby the lar g e mesothoracic se g ment. Pleural sulci are poorl y developed or absent even on th e pterothorax. Two pairs of fra g ile win g s are g enerall y present, thou g h the hind pair is alwa y s re d uce d or a b sent. T h ew i ng venat i on i spr i m i t i ve, t h eme di an ve i n b e i ng di v id e di nto anter i or an d poster i or b ranc h es. T h e l egs are somet i mes re d uce d , assoc i ate d w i t h t h e h a bi t of pass i ng t h e ent i re a d u l t lif eont h ew i ng. However, t h e f ore l egs o f ma l es are usua ll y e nlar g ed and used to g rip a female durin g matin g . Primitivel y there are five tarsal se g ments, but t he basal one or two se g ments ma y fuse with the tibia in hi g her families. The apex of th e abdomen has three, usually very long, multiannulate caudal filaments, consisting of the tw o l atera l cerc i an d ame di an fil ament (t hi s i s somet i mes re d uce d or a b sent). In f ema l es pa i re d gonopores open b e hi n d t h e sevent h a bd om i na l sternum. A typ i ca l ov i pos i tor i sa b sent. In m ales a pair of claspers occurs on the ninth sternum. Between these claspers lies a pair of penes. T he most noteworthy internal feature is the modification of the gut as an aerostati c o rgan to re d uce t h e spec ifi c grav i ty o f t h e i nsect. T h e esop h agus i s a narrow tu b e equ i ppe d wi t h musc l es t h at regu l ate t h e amount o f a i r i nt h e gut. Swa ll owe d a i r i s h e ld i nt h em id gut, w hich no lon g er has a di g estive function and is lined with pavement rather than columnar e pithelium. The hind g ut also has a valve to prevent loss of air. The reproductive or g ans ar e v er y primitive; accessor yg lands are absent, and the g onoducts are paired in both sexes . La r v a . M ay fl y l arvae ex hibi taw id e range o fb o d y f orm assoc i ate d w i t h t h e di vers e habitats in which the y are found. The bod y is of varied shape but is often flattened dorsoven - trall y . The antennae, compound e y es, and ocelli differ little from those of adults. Larvae possess well-developed bitin g mouthparts. The structure of the le g s varies accordin g to wh et h er a l arva i sasw i mm i ng, b urrow i ng, or c li ng i ng f orm. T h ea bd omen i s term i nate d wi t h apa i ro fl ong cerc i an d usua ll yame di an cau d a lfil ament. Between f our an d seven pa i rs of trac h ea l gill s occur on t h ea bd omen. In open-water f orms t h e gill s are usua lly l ame ll ate; i n burrowin g species the y tend to be plumose. In some species g ills ma y not be directl y im- portant in g aseous exchan g e. The y are capable of coordinated flappin g movements and ma y serve s i mp l y to create a current o f water fl ow i ng ove r t h e b o d y. In some spec i es accessory g ill - lik e resp i ratory structures d eve l op on t h et h orax an dh ea d . F IGURE 6.1. D orsa l v i ew o fh ea d o f ma le Ata l op hl e b ia ( Lep - t op hl e biid ae) s h ow i n gl ar g e compoun d e y e di v id e di nto upper part w ith large facets and lower part with small facets. [From W. L. Peters an d I. C. Camp b e ll , 1991, Ep h emeroptera, i n: Th e Insects of Aus - tra l ia , 2n d e d ., Vo l . I (CSIRO, e d .), Me lb ourne Un i vers i t y Press. B y permission of the Division of Entomology, CSIRO.] 129 PA LE O PTER A Life Histor y and Habits Adult ma y flies are commonl y found in the vicinit y of water, often in hu g e matin g swarms. T h ey are s h ort- li ve d creatures, ex i st i ng f or on l ya f ew h ours (most l y nocturna l spec i es) or a f ew d ays. A swarm cons i sts genera ll yon l yo f ma l es, o f ten i nt h et h ousan d s, flyi n gi n an up-an d - d own pattern over water or a spec ifi c mar k er suc h as a roc k , b us h ,o r shoreline. Swarmin g commonl y occurs at dusk in temperate species, li g ht intensit y an d t emperature bein g the ma j or determinants of when it occurs. Females enter a swarm, and mat i ng usua ll y occurs i mme di ate l yan dl asts f or l ess t h anam i nute. Part h enogenes i s h as b een reported for about 5 0 species, though it is rarely obligate. The egg-laying habits ar e quite varied, as is the number of eggs laid (generally from 5 00 to 3000). In some short-lived species e gg s are lai d en ma sse on the water surface. The clutch breaks up and the e gg s sink, becomin g scattered over the substrate. In species that survive for several da y s the eggs may be laid in small batches ; B aet is s pp . females descend below the water surface t o secure t h e eggs on t h esu b strate. Eggs o f ten h ave spec i a l structures t h at serve to anc h o r th em i n pos i t i on. T h ey usua ll y h atc h w i t hi n 10–20 d ays, b ut i na f ew spec i es t h eegg s enter a diapause to overcome low winter temperatures. Consequentl y , the y do not hatch u ntil the followin g sprin g . In some species that have a relativel y lon g adult life (up to 3 weeks) ovoviviparity occurs, females retaining fertilized eggs in the genital tract for severa ld ays pr i or to ov i pos i t i on. Em b ryos t h en h atc hf rom t h e eggs w i t hi na f ew m i nutes o f d epos i t i on . I n most ma y fl y species the larval life span is 2–4 months; however, some ma y fl y larvae a re lon g -lived, with a development time of at least a y ear and, in some instances, of 2 or 3 y ears. Durin g this period the y molt man y times (15–30 is most common, but as man y a s 5 0 have been recorded). Larvae occupy a wide range of habitats, though each one is charac- t er i st i c f or a part i cu l ar spec i es. T h ey may b urrow i nto t h esu b strate, hid e b eneat h stones an d l o g s, c l am b er a b out amon g water p l ants, or c li n g to t h e upper sur f ace o f roc k san d stones in f ast-flowing streams. With the exception of a few carnivorous forms, larvae feed on algae, f f or plant detritus, and thus pla y ake y role in ener gy flow and nutrient rec y clin g in freshwate r ecosystems. Popu l at i ons o fl arva l may fli es s h ow c h aracter i st i c movements at spec ifi ct i mes d ur i ng t h e i r lif e. T h ese may b e di urna l , seasona l ,an d /or di rect i ona l . For examp l e, spec i es i n runn i ng water may h ave d a il ym i grat i ons i nto an d out o f t h esu b strate, or t h ey may mov e into the substrate durin g periods of heav y water flow. T y picall y , in both still and movin g waters larvae move toward the shore durin g the later sta g es of their existence. And some species, especially of B aet is , h ave characteristic nocturnal rhythms of downstream drift. Fo r ot h er spec i es, d r if t i s i n fl uence db y b ot hl arva l c h aracters (e.g., age an d popu l at i on d ens i ty) an d env i ronmenta lf actors suc h as temperature, oxygen, current ve l oc i ty, se di ment, an d food. How species compensate for the potential decrease in population upstream is not well u nderstood, thou g h for some upstream movement of larvae has been demonstrated, while for others the ima g os undertake upstream fli g hts before oviposition. May fli es are un i que among li v i ng Pterygota i nt h at t h ey mo l t i nt h ea d u l t stage. A matur e l arva, on l eav i ng i ts aquat i cenv i ronment, mo l ts i ntoasu bi mago, a w i nge d a d u l t f orm ( b u t see C h apter 2, Sect i on 3.2), o f ten capa bl eo f fligh t.Asu bi ma g o can b e di st i n g u i s h e df rom t he ima g o into which it molts b y its duller coloration and b y the translucent win g s, which are often frin g ed with hairs. A subima g o exists usuall y for about 24 hours before moltin g t ot h e i mago. Un d er a d verse con di t i ons, h owever, a su bi mago may surv i ve f or many d ays. I na f ew except i ona l spec i es t h esu bi mago never mo l ts b ut i st h e repro d uct i ve stage. I t h as b een specu l ate d t h at t h ea d u l tmo l tma yb eapr i m i t i ve tra i t reta i ne db ecause o f a l ac k 130 CHAPTER 6 o f selection pressure on the short-lived sta g es to have a sin g le adult instar. An alternative su gg estion is that an adult molt became necessar y to complete elon g ation of the cauda l filaments and adult forele g s (Maiorana, 1979). In populations of subtropical and tropical m ay fli es emergence ten d s to occur over a cons id era bl e l engt h o f t i me, w h ereas i n spec i es f rom coo l er c li mates i t i so f ten hi g hl y sync h ron i ze d , l ea di ng to t h e pro d uct i on o f enormous swarms f or s h ort per i o d so f t h e y ear.Ona d a y -to- d a yb as i s, h owever, emer g ence ma y s h ow distinct rh y thmicit y or require environmental cues such as a minimum water temperatur e o r full moon for its initiation . P hylo g eny and C lass ifi cat i o n Although the basic groups within the Ephemeroptera have been recognized since the w ork of Eaton (1883–1888, cited in Edmunds, 1962), differences of opinion continue t o e x i st w i t h re g ar d to t h e taxonom i c ran k t h at s h ou ld b e ass ig ne d t h ese g roups, an d t he relationships amon g the g roups. The primar y obstacle to determinin g these relationships is the hi g hde g ree of parallel evolution that has occurred amon g members of different g roups. In many i nsect groups t hi s pro bl em can b e overcome usua ll y b y compar i ng a num b er o f diff erent c h aracters f rom a ll stages o f t h e lif e hi story (E d mun d s, 1972). Un f ortunate l y, man y m ay fli es are k nown on l y f rom t h e j uven il eort h ea d u l t f orm . T he scheme used here is based on McCaffert y (1991), Wan g and McCaffert y (1995), Bae and McCaffert y (1995), and McCaffert y (personal communication). It proposes tha t the order be arranged in 23 families shared among four suborders. A proposed phylogeny o f these groups is depicted in Figure6.2. According to McCafferty and Edmunds (1979), the an - c estor o f mo d ern may fli es may h ave resem bl e d mem b ers o f t h e extant f am il yS i p hl onur id ae FIGURE 6.2. Propose d p h y l ogenet i cre l at i ons hi ps w i t hi nt h eEp h emeroptera . 131 PA LE O PTER A t hat show a lar g e number of primitive features; that is, the y have evolved relativel y littl e compared to other ma y fl yg roups. From this siphlonuridlike ancestor, two ma j or line s ev o lved. One led to the suborder Carapacea, the other to the suborders Furcater g alia , Set i sura (w hi c h are s i ster groups) an d P i sc if orma. T h oug h re l at i ons hi ps o f t h e f am ili es i nt h e fi rst t h ree su b or d ers are reasona bl yc l ear, t h ose f or t h eP i sc if orma rema i nto be esta bli s h e d. S u b or d er Cara p ace a Mem b ers o f t h e Carapacea (an a ll us i on to t h e carapace lik een l argement o f t h e l arva l mesonotum) are i nc l u d e di nas i ng l e super f am il y Prosop i stomato id ea. Super f amily Prosopistomatoidea The two small families in this g roup, the BAETISCIDAE [12 North American species of Baet i sc a ( Fi g ure 6.3)] and PROSOPISTOMATIDAE (11 species of P rosop i stoma w ith aw id e di str ib ut i on i nc l u di ng A f r i ca, Austra li a, Europe, an d sout h ern As i a), s h ow cons id - era bl e para ll e l evo l ut i on i nt h e l arva l stage. In d ee d ,t h e i r l arvae are remar k a bl e i n h av i n g an enormous, poster i or ly pro j ect i n g mesonota l s hi e ld t h at protects t h e gill ssot h at t h e y su- perficiall y resemble notostracan crustacea, into which g roup Proso p istom a w as ori g inall y placed b y the French zoolo g ist Latreille in 1833 (Berner and Pescador, 1980). Larvae of most spec i es li ve i nmov i ng water, f rom streams to l arge r i vers, w h ere t h e b ottom h as san d, fi ne grave l ,orsma ll stones. A d u l t b aet i sc id s, w hi c h are me di um-s i ze di nsects, h aveanun- u sua lly l ar g e mesot h orax; t h ee y es o f ma l es are l ar g ean d a l most cont ig uous b ut not di v id e d h orizontall y . Prosopistomatid adults of both sexes have small, widel y separated e y es; males h ave relativel y short forele g s; the le g s of females are vesti g ial; and females do not have an a d u l tmo l t . S uborder Pisciforma McCa ff ert y (1991) i ntro d uce d t h esu b or d er P i sc if orma (t h e name re f ers to t h em i n - nowlike bod y and actions of the larvae) for a g roup of families whose relationships remai n u nclear. For this reason, no arran g ement into superfamilies is undertaken, thou g h in earlier F I GU RE 6.3 . Larva o f B aetisca b aj k ovi ( Baetiscidae ) . [From B. D. Burks, 19 5 3 , The mayflies, or Ephemeroptera, of Illinois, B ull. Ill. Nat. Hist. S ur v. 26 (1). B y p erm i ss i on o f t h eI lli no i s Natura l H i story Survey.] 132 CHAPTER 6 FI GU RE 6.4. L ar v aof B aet i sva g an s ( Baetidae ) . [From B. D. Burks, 1953, The mayflies, or Ephemeroptera, of Illinois , B ull. Ill. Nat. Hist. Surv . 2 6 (1) .By p erm i ss i on o f t h eI lli no i s Natura l H i stor y Surve y .] sc h emes t h e f am ili es were l umpe di nas i ng l e super f am il y Baeto id ea. On l yt h ema j or f am- i lies are outlined here . T he SIPHLONURIDAEis a fairl y lar g e, probabl y paraph y letic, famil y containin g abou t 1 60 described species with a worldwide distribution but especiall y diverse in the holarcti c reg i on. T h e stream li ne d , act i ve l arvae are f oun d on t h e b ottom o ff ast- fl ow i ng streams o r among vegetat i on i nst ill -water h a bi tats. Some are pre d aceous. A d u l ts are me di um- to l arge - s i ze d ma yfli es, an d t h e sexes are s i m il ar i nco l orat i on. In b ot h sexes t h e compoun d e y es are l ar g e and have a transverse band dividin g the upper and lower re g ions. In males the e y es are usuall y conti g uous . T he BAETIDAE (Figure 6.4) is easily the largest family of Ephemeroptera ( > 500 spec i es) an dh asawor ld w id e di str ib ut i on. T h e torpe d o-s h ape dl arvae are f oun di navar i et y of h a bi tats b ut common ly on t h e b ottom o ff ast- fl ow i n g streams w h ere t h e y ma yb ewe ll c amoufla g ed. Adults are g enerall y small and sexuall y dimorphic. The hind win g s are g reatl y reduced or absent. The compound e y es of males are lar g e and divided horizontall y int o di st i nct parts; i n f ema l es t h e eyes are sma ll an d s i mp l e . Suborder Setisura Included in this suborder are the families listed under the superfamil y Hepta g enioide a i n older classifications. The ma j or famil y is the HEPTAGENIIDAE (Fi g ure 6.5) which ranks next to the Baetidae in terms of number of described species (380). Heptageni- id s are an a l most ent i re l y h o l arct i can d or i enta l group an d are not represente di nt he A ustra l as i an reg i on. T h e genera ll y d ar kl yco l ore dl arvae are typ i ca ll y f oun d c li ng i ng to the underside (occasionall y the exposed face) of stones in fast-flowin g streams and o n wav e -washed shores of lar g e lakes. The y are remarkabl y well adapted for this life. Their body is extremely flattened dorsoventrally; the femora are broad and flat; the tarsal claw s h ave d ent i c l es on t h e l ower s id e; t h eg ill s are strengt h ene d on t h e i r anter i or marg i n; i n some spec i es t h e ent i re b o d yta k es on t h es h ape (an df unct i on) o f a suc ki ng di sc. Some l arvae have fore tarsi with numerous setae that filter al g ae, etc. from the water and g ive th e 133 PA LE O PTER A F I GU RE 6.5 . L arva o f H eptagenia fl avescen s (Hepta g en iid ae). [From B. D . B urks, 1953, The mayflies, or Ephemeroptera, of Illinois, B ull. Ill. N at. Hist. S urv. 2 6 ( 1). By perm i ss i on o f t h eI lli no i s Natura l H i story Survey. ] su b or d er i ts name. A d u l ts are o f var i e d s i ze an d co l or. T h e eyes o f ma l es are l arge b ut not cont ig uous. S uborder Furcatergali a The Furcater g alia is the lar g est ma y fl y suborder. It name derives from the forked natur e of the larval g ills. The g roup includes five superfamilies: Leptophlebioidea, Behnin g ioidea, E phemeroidea (burrowing mayflies), Ephemerelloidea, and Caenoidea. The last two super- f am ili es co ll ect i ve l y f orm t h e pannote may fli es, so-ca ll e db ecause o f t h e f use df ore w i ng pa d so f t h e l arvae . Superfamily Leptophlebioide a T h e LEPTOPHLEBIIDAE (a b out 380 d escr ib e d spec i es, represent i n g per h aps on ly about 10% of the total) is another lar g e and probabl y paraph y letic g roup of worldwid e d istribution but especiall y common in the Southern Hemisphere. A g ood deal of paralle l e v o lution of habits and morphologyappears to have taken placebetween the Leptophlebiida e i nt h e Austra l as i an reg i on an d t h e Baet id ae an d Heptagen iid ae i nt h e h o l arct i creg i on. T h us , many l eptop hl e biid spec i es are f oun d as l arvae i nst ill or s l ow-mov i ng water, an d , i n som e instances, the adults closel y resemble baetids. Larvae of other species are found clin g in g to rocks in fast-flowin g waters and resemble hepta g eniid larvae . Super f amily Behningioide a All members of this ver y small g roup (seven extant species) are included in the famil y B EHNINGIIDAE (tuskless burrowing mayflies). The family is holarctic, with representa - ti ves i n eastern Europe, S ib er i a, an d T h a il an d ,p l us one spec i es i nt h e eastern U.S.A. T h e l arvae are pre d aceous an db urrow i n san di nr i vers . 134 CHAPTER 6 S uper f ami l yEp h emeroi d ea M ost species in this lar g el y Northern Hemisphere g roup, the tusked ma y flies, belon g t o the EPHEMERIDAE (about 100 species) (Figure 6.6) or the POLYMITARCYIDAE (about 7 0 spec i es). Ep h emer id l arvae h ave t h et ibi ae o f t h e f ore l egs mo difi e df or b urrow i ng i nt h e m u d or san d o fl ar g e l a k es, r i vers, an d streams. T h e man dibl es (tus k s) are l on g an d use df o r l iftin g the roof of the burrow. Most of the bod y and the appenda g es are covered with fine hairs. These become coated with silt, and the insect is thereb y well camoufla g ed. Adults ar e genera ll ymo d erate l ys i ze d to l arge i nsects. T h e i rw i ngs are h ya li ne, t h oug h t h ey may be spotte di n some spec i es. In Po l ym i tarcy id ae t h em iddl e l egs an dhi n dl egs o f ma l es, an d a ll l e g so ff ema l es, are vest igi a l .L ik eep h emer id s, po ly m i tarc yid l arvae h ave diggi n gf ore l e g s and tusks and are burrowers, usuall y in mud or fine sand, thou g h some tunnel into cla y on the banks of lar g e rivers. S uper f ami l yEp h emere ll oi d e a With about 100 described s p ecies, the EPHEMERELLIDAE is wides p read in the hol - arct i creg i on, w i t h genera a l so i n Sout h Amer i ca, As i a, an d sout h ern A f r i ca. Austra li a, by c ontrast, h as b ut one spec i es. Ep h emere llid l arvae are f oun di naw id evar i ety o f st ill -an d m ovin g -water habitats, especiall y cold, fast-flowin g streams. Adults are small- to medium- sized ma y flies. Members of the related famil y TRICORYTHIDAE (about 120 species), a predominantly Asian, African, and North American group, are generally similar in thei r h a bi ts to e ph emere llid s. S uperfami l y Caenoi d e a T he CAENIDAE (Figure 6.7), with some 80 described species, is a widely distribute d f am il yo f genera ll y sma ll may fli es. T h e h a i ry l arvae spraw l on t h e sur f ace o ffi ne se di ments i n still or slow-movin g water. The second pair of g ills is enlar g ed and stren g thened, formin g a 135 PA LE O PTER A F I GU RE 6.7 . L ar v ao f C aenis simulans ( Caenidae ) . [From B. D. Burks, 19 5 3. Th e m ayflies, or Ephemeroptera, of Illinois, B ull. Ill. Nat. Hist. S ur v . 26 ( 1). By permission of th eI lli no i s Natura l H i stor y Surve y . ] plate that overlaps andprotects the remaining four pairs of gills. The plate is alternately raised an dl owere d to e ff ect water c i rcu l at i on. Ma l ean df ema l ea d u l ts appear a l most id ent i ca l . Th e compoun d eyes are not espec i a ll y l arge, b ut t h e l atera l oce lli are a b out h a lf t h es i ze o f t he compound e y es. The hind win g s are absent . Literatur e G enera l accounts o f t h e structure an dbi o l ogy o f may fli es are prov id e db y Nee dh am et al. ( 193 5) , Edmund s et al. ( 197 6) , Brittain ( 1982 ) , Edmunds ( 1984 ) , Harker ( 1989 ) , and Peters and Campbell (1991). More specialized treatments, especiall y of life histories, are given by Clifford (1982) and in the volumes edited by Flannagan and Marshall (1980) an d Camp b e ll (1990). For an apprec i at i on o f t h e cont i nu i ng controversy regar di ng t h ep h y l ogen y a n d c l ass ifi cat i on o f Ep h emeroptera, see McCa ff erty an d E d mun d s (1979), Lan d aan d Soldan (198 5 ), McCaffert y (1991), Bae and McCaffert y (199 5 ), and Klu g e (1998). Edmund s et al. (197 6 ) and Edmunds (1984) provide ke y s for the North American g enera, Maca n (1970), Kimmins (1972), and Harker (1989) for the British s p ecies, and Peters and Cam p bell (1991) f or t h e Austra li an f am ili es. B ae, Y. J., and McCaffert y , W. P., 199 5 , Ephemeroptera tusks and their evolution, in : C urrent Directions in researc h o nE p hemero p ter a ( L. D. Corkum and J. J. H. Ciborowski, eds.), Canadian Scholars’ Press, Toronto. B erner, L., an d Pesca d or, M. L., 1980, T h e may fl y f am il y Baet i sc id ae (Ep h emeroptera). Part I, i n : A d vances in Ep h emeroptera Bio l ogy (J. F. F l anna g an an d K. E. Mars h a ll ,e d s.), P l enum Press, New Yor k. B rittain, J. E., 1982, Biology of mayflies , A nnu. Re v . Entomol . 2 7:119–147. Camp b e ll , I. C., (e d .), 1990 , M ayflies an d Stoneflies: Life Histories an d Bio l ogy , K l uwer, Dor d rec h t . C liff or d , H. F., 1982, L if ec y c l es o f ma yfli es (Ep h emeroptera), w i t h spec i a l re f erence to vo l t i n i sm , Q uaest. Entomo l . 18 :15–90. E dmunds, G. F., Jr., 19 6 2, The principles applied in determining the hierarchic level of the higher categories o f Eph emero p tera , S yst. Zoo l . 11 :22– 3 1. E dmunds, G. F., Jr., 1972, Biogeography and evolution of Ephemeroptera, Annu. Re v . Entomol. 1 7 : 21–42 . Ed mun d s, G. F., Jr., 1984, Ep h emeroptera, i n: An Intro d uction to t h e Aquatic Insects of Nort h America,2n d e d. ( R. W. Merr i tt an d K. W., Cumm i ns, e d s.), Ken d a ll /Hunt, Du b u q ue, IA . E dmunds, G. F., Jr., Jensen, S. L., and Berner, L., 1976 , T he Mayflies o f North and Central America, University o f M i nnesota Press, M i nneapo li s. Fl anna g an, J. F., an d Mars h a ll , K. E., (e d s.), 1980 , Ad vances in Ep h emeroptera Bio l og y , P l enum Press , New Yor k. 136 CHAPTER 6 H arker , J. , 1989 , Ma y flies , Richmond Publishin g Co., Slou g h, U.K . Kimmins, D. E., 1972, A revised key to the adults of the British species of Ephemeroptera with notes on their e co l o gy (secon d rev i se d e di t i on) , S ci. Pu bl . F.W. Bio l . Assoc . 1 5 : 7 5pp . Klu g e, N. J., 1998, Ph y lo g en y and hi g her classification of Ephemeroptera , Zoos y stemat i c a 7 :2 55 –26 9 . Landa, V., and Soldan, T., 1985, Phylogeny and higher classification of the order Ephemeroptera: A discussio n f rom t h e com p arat i ve anatom i ca lp o i nt o f v i ew , Stu d ie Cs l . Aca d .Ve d. 4 : 1–121 . Macan, T. T., 1970, A ke y to the n y mphs of British species of Ephemeroptera (2nd revised ed.), S ci. Publ. F. W . B io l . Assoc. 2 0:63 pp . Ma i orana, V. C., 1979, W hy d oa d u l t i nsects not mou l t ? B io l . J . Linn. S oc. 11 :2 5 3–2 5 8. McCafferty, W. P., 1991, Toward a phylogenetic classification of the Ephemeroptera (Insecta): A commentary o n systemat i cs , A nn. Entomo l . Soc. Am. 84 :343–360 . McCa ff ert y ,W.P.,an d E d mun d s, G. F., Jr., 1979, T h e high er c l ass ifi cat i on o f t h eEp h emeroptera an di ts evo l ut i onar y b asis, Ann. Entomol. S oc. Am . 7 2: 5 –12 . Needham. J. G., Traver, J. R., and Hsu, Y C., 1935 , Th e Bio l ogy of Mayflies , Comstoc k ,NewYor k . P eters, W. L., an d Cam pb e ll , I. C., 1991, E ph emero p tera, i n: Th e Insects of Austra l i a ,2n d e d ., Vo l .I ( CSIRO, e d . ) , Melbourne University Press, Carlton, Victoria. Wang, T. W., and McCafferty, W. P., 1995, Relationships of the Arthropleidae, Heptageniidae, and Pseudironidae (Ep h emeroptera: Hepta g en i o id ea) , Entomo l Ne ws 106 :2 5 1–2 5 6. 3. O donat a S ynonym: P araneuropter a C ommon names: d ragonflies and damselflie s Ad u l ts me di um-s i ze d to l arge e l ongate i nsects, f requent l y str iki ng l y mar k e d ; h ea d w i t h antenna e s h ort an d setaceous, compoun d e y es prom i nent, bi t i n g mout h parts; t h orax w i t h two pa i rs o f m embranous wings of approximately equal size and with netlike venation, pterostigma usually p resent; a bd omen o f ma l ew i t h copu l ator y or g ans on secon d an d t hi r d sterna . Larvae aquat i c; b o d y campo d e if orm; h ea d equ i ppe d w i t h extens ibl e “mas k ” (mo difi e dl a bi um) for catchin g pre y , antennae small, compound e y es lar g e; abdomen terminated with three pro- c esses, either short and stocky or extended into large lamellate structures. Almost 5000 s p ecies of Odonata have been identified from different areas of the world. A bout 10% of these are from North America. Some 45 s p ecies are found in the Britis h f auna, an d 300 spec i es h ave b een d escr ib e df rom Austra li a. Structur e A du lt . Th e b o d yo f a d u l tO d onata i s remar k a bl e f or i ts co l ors, b ot h p i gmentary an d structura l ,t h at f requent ly f ormac h aracter i st i c pattern over t h e d orsa l re gi on (F ig ure 6 .12A). Most adults ran g e from 30 to 90 mm in len g th and are sturd y , activel y fl y in g insects. The head is freel y articulated with the thorax, and a lar g e part of its surface, especiall y in A n i soptera ( d ragon fli es), i s occup i e db yt h ewe ll - d eve l ope d compoun d eyes. T h ree oce lli f ormatr i ang l eont h e vertex. T h e antennae are s h ort, h a i r lik e structures t h at apparent l y carry f ew sense or g ans. T h e mout h parts are power f u l structures o f t h e bi t i n g an d c h ew i n g t y pe . The thorax is somewhat parallelo g ram-shaped, with the le g s placed anteroventrall y and the w in g s situated posterodorsall y . The prothorax is distinct but small, and in female Z yg opter a ( damselflies) is sculptured so as to articulate with the claspers of the male during mating. T h e mesot h orax an d metat h orax are l arge an df use d toget h er. T h ep l eura o f t h ese segment s are very l arge an d possess prom i nent su l c i .T h e l egs are wea k an d unsu i ta bl e f or wa lki ng. The y serve to g rasp the pre y and hold it to the mouth durin g feedin g .InZ yg optera the for e and hind win g s are almost identical; in Anisoptera the hind win g is somewhat broader nea r [...]... rectum is greatly folded and well supplied with tracheae, forming “rectal gills.” Water FIGURE 6. 8 Lateroventral view of head of dragonfly larva showing mask [After A D Imms, 1957, A General Textbook of Entomology, 9th ed (revised by O W Richards and R G Davies), Methuen and Co.] 137 PALEOPTERA 138 CHAPTER 6 is continually pumped in and out of the rectum Interestingly, the musculature used to ventilate... fast-flowing water The PROTONEURIDAE (220 species) are a widespread group, though absent from the palearctic region They are most common in shaded localities, including forests, and breed in slowly moving water Most of the 130 species of PLATYSTICTIDAE are oriental though some species occur in the New World tropics Typically, they are found in forests, breeding in fast-flowing streams 142 CHAPTER 6 FIGURE... cosmopolitan families, though the former is a paraphyletic group Corduliids ( 360 species) breed in a range of still- and moving-water habitats, including temporary pools and swamps, and the larvae of some species are able to withstand limited desiccation A few species have terrestrial larvae Libellulidae (900 species) principally breed in still-water habitats, though larvae of some species are stream dwellers... Oregon,’ July 28, 1915, by C H Kennedy: Figures 134, 1 46, and 147 Washington D.C., U.S Government Printing Office, 19 16. ] Literature The Odonata have been one of the most popular insect groups for study, and the literature on them is abundant General accounts of their biology are given by Tillyard (19l7), Walker (1953), Corbet et al (1 960 ), Corbet (1 962 , 1980, 1999), Miller (1987), Watson and O’Farrell... adult, though it differs in possession of the “mask,” the elongated labium (Figure 6. 8), used to capture prey At rest the mask (so-called because it often covers the other mouthparts) is folded at the junction of the postmentum and prementum and held between the bases of the legs It is extended extremely rapidly (in about 16 25 msec) by means of localized blood pressure changes, assisted by the release... in other Zygoptera Superfamily Calopterygoidea Members of the cosmopolitan family CALOPTERYGIDAE ( 160 species) are medium to large, broad-winged damselflies characterized by the brilliant metallic coloring of their bodies, and, in males, the wings also Larval Calopterygidae are found at the margins of fast-flowing water; they have relatively long and stout antennae, long spidery legs, and elongate caudal... wingspans of more than 16 cm Their larvae are semiaquatic burrowers, living in swamps or beside steams The AESHNIDAE form a large and cosmopolitan family of about 375 species of large, strongly flying insects characterized by their enormous eyes that meet broadly in the midline of the head Larvae are mostly stout, elongate insects found among vegetation in a variety of still- or moving-water habitats; a... superfamily contains only one small family CORDULEGASTRIDAE (60 species), with a palearctic and oriental distribution Its members carry a combination of aeshnoid and libelluloid characters Some species are open-country forms that breed in small ponds or streams; others are associated with mountain streams Superfamily Libelluloidea Both the CORDULIIDAE (Figure 6. 12) and the LIBELLULIDAE are large, cosmopolitan... (Zygoptera) A relatively few species have colonized temporary bodies of 140 CHAPTER 6 water through the use of such strategies as very rapid growth or burrowing into the substrate to avoid desiccation Very rarely species have semiaquatic larvae or larvae that live in moist litter in rain forests The majority of Odonata are warm-temperate or tropical species in which larval development is rapid so that... including some of the most strikingly marked Anisoptera with pale wings bearing spots or bands of pigment, commonly dark but sometimes bright shades of orange or reddish brown 143 PALEOPTERA 144 CHAPTER 6 FIGURE 6. 12 A dragonfly, Macromia magnifica (Corduliidae) (A) Adult male; (B) larva, dorsal view; and (C) larva, lateral view with labium extended [Reproduced by permission of the Smithsonian Institution . one-t hi r d o f t h e extant spec i es. O f t h e d e - scribed species, about 67 5 occur in North America, 84 in Australia, and about 5 0in B ritain . 12 7 128 CHAPTER 6 Structur e A du lt . Th e h ea di str i angu l ar i ns h ape. a ll ow i n g ot h er c onspeci c males to occup y the space. Should a receptive female conspeci c enter the territor y and be reco g nized b y the male (probabl y usin g visual cues), he will attempt. t h e j uven il eort h ea d u l t f orm . T he scheme used here is based on McCaffert y (1991), Wan g and McCaffert y (1995), Bae and McCaffert y (1995), and McCaffert y (personal communication). It proposes tha t the