A synopsis of the genus Philosina with descriptions of the larvae of P. alba and P. buchi (Odonata: Megapodagrionidae)

2011·0.78 MB·

by  Haomiao Zhang

InternationalJournalofOdonatology
Vol.14,No.1,March2011,55–68
A synopsis of the genus Philosina with descriptions of the larvae
of P. alba and P. buchi (Odonata: Megapodagrionidae)
HaomiaoZhanga*,VincentJ.KalkmanbandXiaoliTonga
aDepartmentofEntomology,CollegeofNaturalResourcesandEnvironment,SouthChinaAgricultural
University,Guangzhou510642,PRChina;bNationalMuseumofNaturalHistory,POBox9517,2300RA
Leiden,theNetherlands
(Received29May2010;finalversionreceived31November2010)
AsynopsisofthegenusPhilosinaisprovided.Larvaeofthetwoknownspecies,P.albaandP.buchiare
describedforthefirsttime.Thedistributionofbothspeciesisdiscussedandinformationonbehaviour
andhabitatissummarized.ThespecializedlarvaeofPhilosinashowastrongresemblancetothoseof
Rhinagrion, suggesting that they are sister genera. The unique characters of the larva, especially the
arrangementandstructureofthecaudallamellae,meanthatneithergenusfitsintoanyofthecurrently
recognizedfamiliesofZygoptera.Itisnotedthatthesegeneracouldbeplacedintheirownfamily.However,
cautionisexercisedpendingabetterunderstandingofthefamilyMegapodagrionidaebasedonDNAwork,
andtheyarethereforeretainedinMegapodagrionidae.
Keywords: Odonata;dragonfly;Zygoptera;Megapodagrionidae;Philosina;Rhinagrion;taxonomy;Asia
Introduction
The genus Philosina was established for Philosina buchi Ris, 1917, which was described in
thesamepaperfromFujian,China.PhilosinawasplacedinMegapodagrionidaebasedonwing
venation,butwasconsideredsufficientlydistinctfromothergenerainthisfamilytobeplacedinits
ownsubfamilyPhilosininaebyKennedy(1925)andlaterauthors(e.g.Davies&Tobin,1984).In
1999asecondspeciesofthegenus,P.albaWilson,1999,wasdescribedfromGuangdong.Onlya
handfulofrecordshavebeenpublishedforeitherspecies,informationontheirdistribution,habitat
and behaviour is scarce, and no larva has been described for the genus. Based on resemblance
oftheadultsandpreliminaryDNAresultsKalkman,Choong,OrrandSchütte(2010)suggested
thatPhilosinaandRhinagrionCalvert,1913mightbecloselyrelated.ThelarvaofRhinagrionis
structurallyuniqueamongtheZygopteraanditwassuggestedthatlarvalcharactersofPhilosina,
oncediscovered,wouldeitherconfirmorfalsifythehypothesisofacloserelationshipbetween
PhilosinaandRhinagrion.HZwasabletocollectlarvaeofbothPhilosinaalbaandP.buchiwhich
areheredescribedforthefirsttime.
*Correspondingauthor.Email:[email protected]
ISSN1388-7890print/ISSN2159-6719online
©2011WorldwideDragonflyAssociation
DOI:10.1080/13887890.2011.568189
http://www.informaworld.com
56 H.Zhangetal.
Materialandmethods
TerminologylargelyfollowsWatsonandO’Farrell(1991).
Acronymsforcollectionsareasfollows:
SCAU SouthChinaAgriculturalUniversity,Guangzhou,China
CUMZ CambridgeUniversityMuseumofZoology,Cambridge,UK
NMSF ForschungsinstitutundNaturmuseumSenckenberg,Frankfurta.M,Germany
RMNH NationaalNatuurhistorischMuseumNaturalis,Leiden,theNetherlands
RecognitionofPhilosina
Adults of Philosina can be distinguished from all zygopteran genera except Rhinagrion by the
combinationofthefollowingcharacters:(1)twoantenodalcrossveins;(2)Ptmorethantwiceas
longasbroad;(3)R4andIR3originatingwellbeyondmidpointbetweenthearculusandthelevel
ofthesubnodus;(4)mediancleftoflabiumdeep,abouthalfthelengthoftheprementumitself.
PhilosinaalbaWilson,1999;(Figures1–4,5a–d)
Specimensstudied
Adults:2(cid:2),China,HainanProvince,LishuiCounty,Mt.Diaoluoshan,900m,24April2009,leg:
HZ, SCAU. — 4 (cid:2), 1 (cid:3), China, Guangdong Province, Conghua City, Liuxihe National Forest
Park(23◦43(cid:3)51(cid:3)(cid:3)N,113◦48(cid:3)24(cid:3)(cid:3)E),15May2009,leg.HZ,SCAU.—1(cid:3),China,HainanProvince,
LishuiCounty,Mt.Diaoluoshan,23April2009,leg:HZ,RMNH.—1(cid:2),China,HainanProvince,
LishuiCounty,Mt.Diaoluoshan,15May2009,leg:HZ,RMNH.
Larvae(finalinstar):1(cid:2),1(cid:3),China,GuangdongProvince,ConghuaCity,LiuxiheNational
ForestPark(23◦43(cid:3)51(cid:3)(cid:3)N,113◦48(cid:3)24(cid:3)(cid:3)E),12March2009,leg.HZ,SCAU.—1(cid:2),samelocation,
25November2008,RMNH.
Differentialdiagnosisofadults
Malesareeasilyrecognisedinthefieldbytheirhabitofperchingwiththeirwingsheldflat,their
mediumsize(Hw28–31mm),moderatelyheavybuildandthewhitish-bluepruinositycovering
allsegmentsoftheabdomen(Figure5a–c).ThethoraxdoesnotbecomeaspruinoseasinP.buchi
Figure 1. DistributionofthespeciesofPhilosina.
SynopsisofPhilosina 57
Figure 2. HabitusoffinalstadiumlarvaofPhilosinaalba.
and the yellow antehumeral stripes are clearly visible even in fully mature males. Females are
lessstrikingthanmalesbutarestilleasytoidentifybytheirmediumsizeandblackabdomenwith
broadlateralyellowstripesandathinmedianstripeonS1-7(Figure5d).Theonlyspecieswith
a very similar pattern is P. buchi, but in this species the antehumeral stripe runs the full length
of the mesepimeron (only for four-fifths in P. alba), and there is an additional thin yellow line
belowthemesopleuralsuturewhichisabsentoronlypresentalongtheposteriorhalfofthesuture
inP.alba.
Descriptionofthelarva
A stout, brownish larva with depressed head and short abdomen (Figure 2), surface of body
coveredwithminutepyramidalnodules.
Head. Headflattenedabove,widestacrosstheeyes,rearofheadsquarebuthindcornerrounded
andbearingirregularstoutspines,hindmarginofocciputconcave.Rowofsixshortspinesalong
the eye-margin on the underside of the head. The labrum, clypeus and frons are entirely dark
brown; anterior margin of anteclypeus with a row of fine setae. Ocellar triangle pale brown,
ocelli large and distinct.Antenna with seven segments, long and filiform with fine setae, pale
brown (Figure 3d).Antennal segments 1, 2, 4 and 5 each with a black subapical ring. Length
of each antennal segment (mm): 0.40; 0.60; 0.68; 0.64; 0.40; 0.28; 0.20. Mandibles biramous,
incisoroftherightmandiblewithsixteeth,identicaltotheleftone,themolarsurfacewithone
tooth,lessdeveloped,hookshapedandnotbifidapically(Figure4a).Incisoroftheleftmandible
with six teeth, the molar surface with one large tooth, apically bifid (Figure 4b). Maxilla with
four long, stout dorsal hooks and three smaller ventral hooks, sharply pointed (Figures 4c, d).
Basallywithlongsetae.Maxillarypalpcurvedandtaperingtoabluntpoint,bearingdense,long
setae. Labium broad and flat (Figure 3a). Length to width ratio of prementum 1.25:1. Median
lobestronglydeveloped,anteriormarginstronglyconvexwithregularshort,crenulationsandan
58 H.Zhangetal.
Figure 3. LarvalstructureofPhilosinaalba:(a)labium,dorsalview;(b)ventralviewoffemaleabdomenshowing
gonapophyses;(c)rightlateralpalpoflabium,dorsalview;(d)antenna(setaenotshown);(e)patternonmedianlamella,
lateralview;(f)patternonlaterallamella,lateralview.
apicallyclosedmediancleft(Figure3c).Outermarginofprementumwithstrong,sharp,forward
pointingdenticles.Prementalsetaeabsent.Labialpalpnarrow,bearingthreeinner,subapicalsetae
andapicallywiththreestrongandsharplypointedhooks,themedianonelargest;movablehook
longandsharplypointed(Figure3c).
Thorax. Thoraxbrown,sidesofprothoraxwithtwoprominences,onebeneathpronotumwiththe
outermarginslightlyconcave,theloweronepyramid-shaped,approachingthefrontcoxa.Distal
SynopsisofPhilosina 59
Figure 4. LarvalstructureofPhilosinaalba:(a)rightmandible,ventralview;(b)leftmandible,ventralview;(c)right
maxilla,ventralview;(d)same,dorsalview.
marginsoftheseprominenceswithpyramidalspines.Pronotumwelldevelopedandshield-shaped;
brown with a pair of black spots near the hind margin.Anterior margin more or less straight,
anterior corner forming an angle of 135◦, posterior corner rounded. Synthorax dark brown and
robust, wing buds narrow, reaching the hind margin of abdominal S8. Legs with hind femora
reachingS9,coveredwithfinesetaeandwithrowsofshortspines.Allfemoraandtibiaebrown
withthreepalebands.Anteriormarginofeachfemurwitharowofshortpyramidalspines.Tarsi
withthreesegments,clawssimple.
Abdomen. Brownanddenselycoveredwithfinesetae.Cylindricalinshapeandslightlytapering
backwards,withapalemiddorsallineoneachsegment.Lateralspinesanddorsalhooksabsent.
Caudal lamellae arranged vertically, broad and oblong, largely black with marginal pale spots,
themarginbearingwithlong,finesetae.Themedianlamella(Figure3e)isshorterthanthelateral
ones(Figure3f)andhasonbothsidesaslightlyexpandedmidrib,whichisfreeofspines.The
laterallamellaehavebasallyanexpandedmidribontheexterior,bearingdense,shortspines.The
medianlamellaisthinnerthanthefleshy,undulatinglaterallamellae.Femalegonapophyseslong,
almosttwiceaslongasS9-10(Figure3b).
60 H.Zhangetal.
Figure 5. AdultsofPhilosinaspecies.P.alba:(a)malefromMt.Diaoluoshan;(b)pairinwheelfromDiaoluoshan;
(c)malefromLiuxiheForestPark;(d)femalefromLiuxiheForestPark.P.buchi:(e)malefromLongsheng;(f)female
fromLongsheng.PhotosbyHZ(a,b,c,d),andVJK(e,f).
Measurements(mm). Bodylength(includinglamellae):14.1;maximumwidthofhead:4.4hind
femur:5.0;hindwingbuds:4.8;medianlamella:3.8;laterallamellae:5.5.
Distribution,habitatandbehaviour
PhilosinaalbawasdescribedfromDinghushan,ZhaoqingCity,Guangdong,China(Wilson,1999;
Wilson&Xu,2007)andhassincebeenfoundintheChineseprovinceofHainan(Wilson&Reels,
2001)andintheLakSaoareainLaos(Karube,2002)(Figure1).
SynopsisofPhilosina 61
The habitats at Diaoluoshan and at Liuxihe National Forest Park are largely shaded, large,
rockybrooksinforest(Figure10).Thespecieshasbeenrecordedfrom350–500ma.s.l.(Liuxihe
NationalForestPark)andbetween850–1000ma.s.l.(Diaoluoshan).
The earliest seasonal record is that of an immature male on 25 March 2008 at Diaoluoshan
NationalNatureReserve,Hainan,observedbyHZandShanlianMo.InlateAprilofthatyearmore
than10maturemaleswereobservedinthreedays.AtLiuxiheNationalForestPark(Guangdong
Province)morethan50maleswereseenonasingledayinmidMay.Thespecieswasstillcommon
thereinJunebutbymidJulyonlytwooldmalescouldbefound.Basedontheserecordstheflight
periodextendsfromtheendofMarchwellintoJuly,withthehighestdensitiesfoundfromlate
ApriltoJune.
WilsonandReels(2001)statedthatmaleshold“territoryonhorizontalsurfacesoflogsandtree
roots,whichoverhangsmallfastrunninghillstreams”.AtDiaoluoshanandatLiuxiheNational
ForestParkmalesusuallyoccupiedterritoriesontheslowerflowingpartsofthestreamatplaces
borderedbydensevegetation.Theyperchedontreesorbranchesalongtheshadystreamsatabout
0.5–2mheightandestablishedterritoriesbutseldompatrolled.Maleswithaterritorywereseento
driveothermalesaway,duringwhichactivitytheywerehoveringfacetofacemidair.Following
a chase the male was seen to return to his territory.When disturbed, they quickly moved away
withasuddenandrapidflight.Nocourtshipwasobserved;asinglecopulationwasobservedin
theafternoon.
PhilosinabuchiRis,1917(Figures1,5e–f,6–9)
Specimensstudied
Adults:15(cid:2),1(cid:3)(syntypes),FujianProvince,1916,leg.P.A.Buch,NMSF(numberedas7192,
7193, 7194, 7200, 7205, 7210–7212, 7214–7217, 7219, 7220, 7222, 7223 (female)). — 17(cid:2),
FujianProvince,1917,leg.P.A.Buch,NMSF(numberedas7191,7195–7199,7201–7204,7206–
7209,7213,7218,7221).—2(cid:2),2(cid:3),China,GuangxiProvince,GuilinCity,Longsheng,11–15
July2005,leg.VJK,RMNH.—1(cid:2),4(cid:3),China,GuangxiProvince,betweenLongshengandhot
springs,13July2005,leg.VJK,RMNH.—2(cid:2),China,GuizhouProvince,LiboCounty,Maolan
Figure 6. HabitusoffinalinstarlarvaofPhilosinabuchi.
62 H.Zhangetal.
Figure 7. LarvalstructureofPhilosinabuchi:(a)labium,dorsalview;(b)ventralviewoffemaleabdomenshowing
gonapophyses;(c)rightlateralpalpusoflabium,dorsalview;(d)mediancleft,dorsalview;(e)antenna(setaenotshown);
(f)patternonmedianlamella,lateralview;(g)patternonlaterallamella,lateralview.
NatureReserve,ZhangjiangRiver,7May2007,leg.HZ,SCAU.—1(cid:2),China,samelocality,27
July2008,leg.HZ,SCAU.
Additional records: China, Guangxi Province, Guilin City, Longsheng, 11–15 July 2000,
M.Wasscher(pictureofmalepublishedonwww.asia-dragonfly).
Larva: 1 (cid:3), China, Guangdong Province,Yingde City, Qiaotou,Wengjiang River (24◦16(cid:3)36(cid:3)(cid:3)
N,113◦46(cid:3)38(cid:3)(cid:3)E),27February2009,leg.YufengWang,SCAU.
SynopsisofPhilosina 63
Figure 8. Larval structure of Philosina buchi: (a) right mandible, ventral view; (b) left mandible, ventral view;
(c)leftmaxilla,ventralview;(d)same,dorsalview.
Differentialdiagnosisofadults
Malesareverystrikingandareeasilyrecognizedbytheirlargesize(Hw39–41mm),bluepru-
inosityonhead,thorax,S1-6andS10andbrightredS7-9oftheabdomen(Figure5e).Withtheir
sizeandstrongflighttheycanbemistakenforAnisoptera,especiallyonthewing,butnoChinese
Anisoptera species has S7-9 red with the remainder of the abdomen blue.The genital ligula is
illustrated in Figure 9a, b. Females are less striking than males but are still easy to identify by
theirlargesizeandblackabdomenwithbroadlateralstripesandathinmedianstripefromS1-7.
DifferencesfromthefemaleofP.albaaregiveninthediagnosisofthatspecies.
Descriptionofthelarva
A stout, brownish larva with depressed head and short abdomen (Figure 6), surface of body
coveredwithminutepyramidalandroundednodules.
Head. Headflattenedabove,widestacrosstheeyes,rearofheadsquarebuthindcornerrounded,
withabroadblackstripeoneachside,andbearingstoutdenticles;hindmarginofocciputconcave.
Six spines are present along the eye-margin on the underside of the head. Labrum and clypeus
entirely dark brown. Frons largely brown with a pale central spot. Ocellar triangle pale brown;
ocelli large and distinct.Antenna with seven segments, long and filiform with fine setae; pale
64 H.Zhangetal.
Figure 9. SEMphotographsofthegenitalligulaof:(a)Philosinabuchi,China,Gaungxi,nearLongsheng,2005,ventral
view;(b)samelateralview.Photos:DirkGassmann.
brown, darkening toward the apex of each segment except the basal one (Figure 7e). Length
of each antennal segment (mm): 0.52; 0.88; 0.72; 0.44; 0.56; 0.56; 0.48. Mandibles biramous,
incisor of the right mandible with six teeth, similar to the left one, the molar surface with one,
less developed, tooth (Figure 8a). Incisor of the left mandible with six teeth, the molar surface
withonelargetooth,apicallybifidandpointed(Figure8b).Outermarginofeachmandiblewith
two rows of well developed large spines. The ventral row contains six sharply pointed dentate
spines.Maxillawithfourlong,stoutdorsalhooksandthreesmallerventralhooks,sharplypointed.
Basallywithlongsetae.Maxillarypalpcurvedandtaperedtoabluntpoint,bearingdense,long
setae.Labiumbroadandflat(Figure7a).Ratiooflengthtowidthofprementum1.3:1.Median
lobestronglydeveloped,anteriormarginstronglyprojectingwithregularshortcrenulationsandan
apicallyclosedmediancleft(Figure7d).Outermarginofprementumwithstrong,sharp,forward
pointingdenticles.Prementalsetaeabsent.Labialpalpusnarrow,withthreesubapicalsetaeand
threestrongandsharplypointedhooksapically,themedianonelargest;movablehooklongand
sharplypointed(Figure7c).
Thorax. Thoraxbrown,sidesofprothoraxwithtwoprominences,onebeneathpronotumbifid
apically;theloweronepyramidal,approachingthefrontcoxa.Distalmarginsoftheseprominences
withpyramidalspines.Pronotumshield-shaped,itsanteriormarginmoreorlessstraight,anterior
corner forming an angle of 135◦, posterior corner rounded. Synthorax dark brown and robust,
wingbudsnarrow,reachingthehindmarginofS7.Legswithhindfemorareachinghalfwayalong
S8, covered with fine setae and rows of short spines. All femora and tibiae brown with three