Two new genera of isostictid damselflies from New Britain, Bougainville, and the Solomon Islands (Odonata: Zygoptera)

8 Pages·1993·2.8 MB·English

by  T W Donnelly

THOMASW. DONNELLY
Binghamton, N. Y., U. S.A.
TWO NEW GENERA OF ISOSTICTID DAMSELFLIES
FROM NEW BRITAIN, BOUGAINVILLE, AND THE
SOLOMON ISLANDS (ODONATA: ZYGOPTERA)
Donnelly, T. W., 1993. Two new genera of isostictid damselflies from New Britain,
Bougainville,andtheSolomonIslands(Odonata: Zygoptera).-TijdschriftvoorEntomologie
136: 125-132, figs. 1-23,tab. 1. [isSN0040-7496]. Published 10December 1993.
Titanosticta and Cnemisticta are new genera of the Isostictidae described from the eastern
Papuan - Melanesian region. Newspecies Titanostictamacrogaster(New Britain), Cnemisticta
angustilobata(NewBritain), and C. latilobata(Bougainville, Gizo, Malaita, andGuadalcanal)
are also described. The two genera bear no particularly close relationship with any ofthe
Papuan {Selysioneura, Tanymecostictd), NewCaledonia {Isostictd), orAustralian (sevengenera)
taxa.
Dr.ThomasW. Donnelly,2091 PartridgeLane, BinghamtonNY 13903USA.
Keywords.-Odonata,NewGuinea,SolomonIslands,newgenera,newspecies.
The damselfly family Isostictidae is reported from Orientalprotoneuridshaveaveryshortanalvein;this
the Austrahan subcontinent, the Papuan region (ex- vein is always totally lacking in isostictids. Another
tendingwestwardto Tanimbarand Halmahera), and characterofmostgeneraofthe isostictids isapromi-
the island ofNew Caledonia, where the type genus nently and elaborately developed hind lobe of the
occurs. In Australia, Watson et al. (1991) recognize prothorax; SelysioneuraandonespeciesofCnemisticta
seven genera. Tanymecosticta is widespread on New areconspicuousexceptions.
Guinea, has a single species in New Britain and an- Fraser (1955) discussed this group (which he con-
otheronWoodlarkontheeast,andoccursonMisool sidered a subfamily ofthe Protoneuridae) and sug-
andTanimbaronthewest. Selysioneuraiswidespread gested a relationship with the platycnemidids. In
on New Guinea, and occurs on Misool, Halmahera, common with the Protoneuridae, but conspicuously
and Morotai on the west, and Woodlark, different from the Plarycnemididae, the Isostictidae
D'Entrecasteaux, and the Louisiade Archipelago on have short legs with short leg spines. However
the east. I herein describe two new Papuan genera: Cnemistictahasabroaderwingwhichisabruptlynar-
Titanosticta and Cnemisticta, which occur in New rowed distal to the pterostigma and a relatively long
Britain and the Solomon Islands. The new genera CuP, both of which are reminiscent of the
overlap only slightly in range with either ofthe two Platycnemididae. The larvae ofthe Platycnemididae
Papuangenera: thus, theyfill ageographicgap in the havehighlyvariablecaudal lamellaeanddo notseem
rangeofthefamily. toformasinglecoherentgroup.
The Isostictidae had long been considered a sub- In the absence oflarval forms formostgenera it is
family of the Protoneuridae, but has recently been not profitable at this time to suggest relationships
separatedintoaseparatefamily,largelyonthebasisof within the family. The two new genera do not seem
larval characters (Lieftinck 1975). Adults resemble to have an especially close affmity with any other
the protoneurids, and differ from most otherwise Papuan or Australian genus. Cnemisticta is notably
similarOrientalCoenagrionoid familiesbytheirnar- distinctwithin thefamilybecauseofitsbroaderwing
row wings, with the anal portion highly reduced. with abruptterminal narrowing, andlongCuP.
They differ from the Protoneuridae by their absence
ofbright colours (protoneurid adults are almost in- Abbreviationsforcollectionsinwhichtypemateri-
variablymarkedwithbrightcolours, especiallyin the al is located: UZMC - Universitetets Zoologiske
males), their generallylonger CuP, and larvae (as far Museum, Copenhagen; RMNH - Rijksmuseum van
as known) with saccoid, rather than flat, caudal la- Natuurlijke Historic, Leiden; TD - Collection ofT.
mellae with subapical constriction. Some genera of Donnelly, Binghamton.
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TijdschriftvoorEntomologie,volumei36,1993
Figs. 1-2. Venation of hind
wings. — 1, Cnemisticta an-
gustilohata, gen. n., sp 2,
Titanosticta macrogaster, gen
n.,sp.n.
TITANOSTICTA
Titanostictagen. n. V.Jindrich(td).
(figs. 2, 3-7) Additional material.-An additional 9 in the Donnelly
collection,withthesamedataasMetelenRiverparatype, is
This is the largest damselfly in the family tnhoettdeersmiignnaaltesdegamepnatrastoyfpethbeecaabudsoemeitnl.acks both aheadand
Isostictidae and one ofthe longest Zygoptera in the
Oriental region. ItisdistinguishedbytheshortCuP,
which is two cells long (rarely one). Also, Ac is just Maleholotype.-Thisisanobscurelymarkedspe-
proximal toAxl in the fore wing, and slightlydistal cies varying from pale gray brown to dark, shining
in the hind wing; the arculus is distal to the Ax2 of brown.
bothwings;IR2arisesatthe7-8thPxoftheforewing Head:Labiumpalewithroundedtriangularcentral
and at 6 or 7th (rarely 5th) in the hindwing; R4+5 excavationabout2/5 thelengthofthesegment. Face
arises distal to the subnodus. The pterostigma is mainly pale; labrum shining black with thin apical
rhombic and longer than broad. The wing is nar- yellow rim and pale central, basal spot; postclypeus
rowedgraduallydistaltothepterostigma. Theinferi- pale with prominent black anterior and lateral mar-
or appendage ofthe sole species is much larger than gins; frons pale with small black spots anterior and
the superior. In common with other genera of the posterior to antennae and irregular black central
family, the legs are short with short spines, and the stripe enclosing front of lateral ocelli and median
bodycoloursaredull. ocellus; pedicel about 1.5 times the length of the
Typespecies: T. macrogasters^. n.;theonlyknown scape, both pale.
localityisNewBritain. Prothorax: Pale,smallpairedcentralblackspotson
Etymology: 'Titan', from mythology, signifying hind lobe and very small black marks on remainder
very large size, and '-sticta', the predominant suffix pronotum; hind lobe sharply recumbent, broadlyT-
forgenerainthisfamily. shaped,withabasalconstriction.
Pterothorax: Mesostigmal laminae small, slightly
Inadditionto itsverylargesize, Titanostictaisdis- taperedapically,withroundedtips;pterothoraxgray-
tinguishedfrom all otherisostictidgenerabythefol- ishgreen; mesepisternumwithstripeondorsalcarina
lowingcombinationofcharacters: inferiorappendage occupying 1/6ofsclerite;verythindarklineonante-
much larger than the superior; CuP two cells long, humeral suture; 2nd lateral suture with small dark
veinR4+5arisingdistaltosubnodus,verysmalltarsal spotoncaudalsixth.
claws,andAcclosetoAxl intheforewingandslight- Legs: Yellow with contrasting dark spines: 4 on
lydistal toAxl inthehindwing. outerrowofhindfemur, 5 on hindtibia.
Wings: Venation described in generic diagnosis;
venation brown, rhombic, paleredbrown.
Titanostictamacrogasters^.n. Abdomen: Pale, darker at tip; 1 and 2 greenish
(figs. 2, 3-7) gray;3to8yellow,darkeningapically;9and 10shin-
Typematerial.-Holorype 6: PapuaNewGuinea. New ing dark brown. Superior appendage dark, shorter
Britain.Yalom, 1000m,20May 1962. NoonaDanExped. than 10,constrictedapicallytoterminateinrounded,
M(eUZtMeCl)e.n ARlilvoetr,ype20?:mi.PapS.uEa. NoefwRuGaunignoe,a.JuNlyew19B7r0i,taiVn.. cylindricaltip,withlow,roundedbasal-ventralprom-
Jindrich (rmnh). Pararypes: 2 6 same localityas holotype, inence. Inferiorappendage 1.5 timeslengthofsuper-
19-20May1970(RMNH,TD); 1S PapuaNewGuinea.New ior, forcipate, laterally flattened, expanded abruptly
Britain. Metelen River, 20 mi. S.E. ofRuango,July, 1970, in caudal half, excavate on dorsal-apical corner to
126
Donnelly: Isostictiddamseiflies
Table 1. CharactersofgeneraofIsostictidae.-Explanation:CuP: Numberofcellslength; bothwingsconsidered. Inferior
appendage: ofmale, whether largeorsmaller than superiorappendage. Hind lobeofprothorax, male: whetherprominent
(flared,withhorns,orwithotherprocesses)orlow.AcorAxl:whichcrossveinisinmoredistalpositioninhindwing.Tarsal
claws:sizecomparedwithothercoenagrionoids. R4+5:originofveinwith respecttonodus.
Genus Range lengthofCuP, male hindlobe tarsal R4+5 hw:AcorAxl
cells inferior prothorax claws tonodus distal
appendages male
Isosticta NewCaledonia 1 -6
Selysioneura
TijdschriftvoorEntomologie,volumei36,1993
Figs. 3-7. Titanostictamacrogaster,gen. n.,sp. n.—3,malehindlobeofprothorax,dorsalview.4,femalehindlobeofpro-
thorax,dorsalview.5,maleabdominalappendages,dorsal-lateral-apicalview.6,maleabdominalappendages,lateralview.
7,penis,ventralandlateralview.
mensional ratio among New World Pseudostigmat- pendageofthemaleismuchlargerthanthesuperior.
idae,whichhaveextremelylongabdomensandwhich Thetwospecies rangefromNewBritaintoBougain-
fly much less vigorously than other Zygoptera. The ville, Gizo, Malaita, andGuadalcanal.
violation ofa constant ratio in the few specimens of Type species. - C. angustilobatasp. n., from New
Titanosticta raises the question as to whether the Britain.
flight of this genus (which has not been recorded) Etymology.-'Cnem-'fromtheslightresemblance
mightresembletheweakflightofthepseudostigmat- tosomeplatycnemidids.
ids.
This genus is distinguished from all other isostic-
tidsbyitsmuchlongerCuPandabruptnarrowingof
Cnemistictagen. n. the wing beyond the pterostigma. The two species
(figs. 3, 8-23) varyfromeachotherintheextentofdevelopmentof
Thisgenuscontainstwospeciesoflargeisostictids. thehindlobeoftheprothorax.Thespecies C. latilob-
It is immediately recognized by the length ofCuP, atahasaveryprominenthindlobe, similarto thatof
which in the type species C. angustilobata is 8 to 10 T. macrogaster, and to most ofthe other members of
cells long in the fore wing) and 8 (rarely 7) to 10 the family. The species C angustilobatahas a highly
(rarely 11) in the hind wing. IR2 arises at the 7-8th reduced hind lobe, in common with the mostwide-
Px in the fore wing (rarely 9th) and 5 to 6th in the spreadPapuan isostictid, Selysioneura.
hind wing. In C. latilobata IR2 arises at the 5-6th
(rarely 7th) Px in the fore wing and 4-5th Px in the
7h-i9ndiwnitnhge;hCiunPdiwsi8n-g1.0IcnellbsoltohngspiencitehsevfeoirnewAicngaraisneds (Cfnigesm.is1t,i8c-t1a5)angustilobatasp. n.
justdistal to theAxl oftheforewingand Xo thedis- Typematerial.-Holotype â: PapuaNewGuinea.New
tance between the 1st andAx2 in thehindwing; the Britain:Yalom, 1000m, 18May 1962,NoonaDanExped.
aprrcouxliumsalistdoisttahletsoutbhneodAuxs2iinnbbootthhwwiinnggss.;TRh4e+5ptaerriosse-s Me(xUacZyeMpCt1)9.c6olA2ll.l(ou1tZ8yM-pC1e)9.$MP:aarsyaatm1yep9e6ds2a:t3(acrîamsn1hh)9ol;ostPayamppeeu,daaetxNaceeapwsthGocuolliolnt.eya1p.9e
tigmaisrhombicandaswideaslong.Thetarsalclaws New Britain. Metelen River, 20 mi. S.E. ofRuango, July
are ofnormal length and the inferior abdominal ap- 1970, V. Jindrich (td); 1 6 Papua New Guinea. New
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Donnelly: Isostictiddamselflies
Britain: Gazelle Pen., upper Warango, 250-600 m, 28-30 to male but slightly larger, low triangular, with a
NoAvdd1i9t6i2o,naJ.lSemdaltaercieakl.(RM-NH4).additional 6 collected by stepped appearance. Colour of thorax: mesepister-
Sedlacek (rmnh) along with last named pararype are not numwith palestripeaboveantehumeral suture%the
designated as paratypes because they lack the terminal seg- widthandin thecephalic%ofthesclerite; mesepime-
mentsoftheabdomen. ron with short central elongate dark mark;
Metepisternum with small caudal dark mark.
Description Abdomen: Dorsum of8 to 10 pale; ovipositor dark,
Male holotype. This is adark, obscurelymarked extendingdistinctlybeyond 10 (cerei).
damselfly.
Head: labium palewith roundedexcavation in ap- Dimensions. - Holotype male: abdomen 44 mm,
ical M; frons rounded; face and top ofhead black; la- hind wing 29 mm. Allotype female: abdomen 45.5
brum black with pale, obscurely defined central mm. The dimensional range ofthe pararype series is
stripe; genae pale, anteclypeusobscurelypale; pedicel as follows: 5 paratype males have theabdomens43.5
slightly longer than scape, both dark; rear of head to 47.5 mm; 8 males have the hind wing 26 to 29
pale. mm. A paratype female has the abdomen 45.5 mm
Prothorax: Palelaterally, mottled darkon dorsum, andthehindwing32.
with large tringular paired dark spots on median
lobes; apodyne extended posteriorly as commissure Variation within paratype series. - The Gazelle
nearly to hindlobe; hind lobe small and low, round- PeninsulaandMetelen Rivermalesarepalerthanthe
edtriangularwithcentral partslightlythickened. Yalomseries; thedarkcolourofthesideofthethorax
Pterothorax: Mesostigmal laminae simple, parallel ranges to ashort central dark mark on mesepimeron
sided, rounded, slightly elevated lateral tip; mesepi- andmetepisternumalmosttotallypale.
sternumblack, mesepimerondarkwithpaleonmesal
% (adjacent to antehumeral suture) and cephalic X; Etymology. -The name refers to the vary narrow
mesinfraepisternum pale on outside, central half hindlobeoftheprothorax.
dark; thedarkcolourofthemesepisternumessential-
ly extensive to metepisternum with only thin pale
Cnemistictalatilobatasp. n.
lines on the two lateral sutures; metepisternum pale
with black spot on caudal %; metepipimeron and (figs. 16-23)
metastermumpale. Typematerial.-Holotype S: SolomonIslands.Malaita
Legs: Pale with thin dark dorsal lines on femora; I.,Kware'aRiverandtributaries,8kmEofDala, 100m, 19
smpuirneasnbdrohwinn,dntiobtiac.ontrastingwithlegs, 5onhindfe- IF1se3lb-a1nd41s.9F8eG7ub,ad1Ta9.l8c7aD,noanTln.eIl.D,loyHnonne(ilralmrynah,)(;RRMoNvAHle)l.oCtry-epeekPara9tarRySepseoeslr:ovomIiordn,
Wings:Venationasforgenus;IR2arisingat7(fore same data as holotype (td). Id, Papua New Guinea,
wing) and 5 (hind wing); CuP 9 cells long in fore BougainvilleI.,SouthNasiooi,AgricultureFieldStation, 19
wingandhindwing; pterostigmarounded, rhombic, May 1975,HowardR.Wimmer(RMNH).
asscuAlrobenldgyomadsaerwnki:doeP,nalpdea,olredsaruremkddoiosfnh3dbotrorosw7nu,.mwiotfh1apaincadl2X, doibs-- bNlauecsAkwhsddGaitureteirianmoeinianan.allvaBmloasluteeegygra,miiean7lnv,.ti8sl—lMeoa1fIây.,abBS19doo7okl5mou,emBnoHo)n.ngIW(,srilm5amnnJdmhsu)e.n,reGi11(z9âso5p6eIP,.c,aiJp.lmuoeLawn.
tinctlydarkeron 3 to 6; 7 uniform; 8 with obscurely Gressitt(rmnh) (highlyreneraispecimen).
darkdorsal markin caudal K; 10with obscurepaired
dark spots on caudal %. Superior appendage shorter Description
than 10, blunt, rounded, slightly expanded and Holotypemale. -Apale, obscurelymottled, dam-
branched in dorsal view, with mesal branch very selfly.
short; withventrallydirectedspine. Inferiorappend- Head: Labium white, with a quadrate apical exca-
age more than twice as longthan superior, forcipate, vation 'A ofits length; frons rounded; face black, la-
laterally flattened, with caudal half expanded into brumwith thin yellowapical rim; genae brownwith
prominent rounded keel on dorsal and apical por- yellowmesalmargin;palepedicelslightlylongerthan
tions. Peniswith terminalsegmentY-shaped. darkscape; topofheadblackborderedat rearbyyel-
low; obscure palespotslateral tolateral ocelli; rearof
Allotypefemale.-Similartomale. Facepale; post- headyellow.
clypeus pale with dark lateral margins; top ofhead Prothorax: pale, fore lobe with dark rim; medial
pale, about half dark, with an irregular dark mark lobes low, apodyne continued into a commissure
centeredontheocelli,smalldarkspotsanteriortoan- nearlytohindlobe; hindlobelarge,T-shaped,sharp-
tennae, and short transverse dark stripes posterior to ly recumbent, basally constricted, and sharply notch
lateral ocelli. Thorax: Hind lobeofprothoraxsimilar incenterofhindrim.
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TijdschriftvoorEntomologie,volume i36.1993
Figs.8-15. Cnemistictaangustilohata,gen.n.,sp.n.-8,malehindlobeofprothorax,dorsalview.9,malehindlobeofpro-
thoraxandmesostigmallamina,dorsal-lateralview. 10,femalehindlobeofprothorax,dorsalview. 11, femalehindlobeof
prothorax and mesostigmal lamina, dorsal- lateral view. 12, maleabdominal appendages, dorsal - lateral- apicalview. 13,
maleabdominalappendages,lateralview. 14,ovipositor. 15,penis,ventralandlateralviews.
Pterothorax: Mesostigmal laminae parallel sided, cally in dorsal view, with rounded, upturned apices.
flat, with rounded tips; colour ofpterothorax pale; Inferior apendage 3 times as long as superior, forci-
mesepisternum with dark stripe on dorsal carina oc- pate, with blunt, laterallyflattened, rounded tip and
cupying X ofsclerite; antehumeral suture with thin dorsal keel on expanded apical half, and with low,
blackline; 2nd lateral suturewith tinyblackspot on rounded, conical, dorsally directed spine in basal X.
caudal %. Legs: Yellow, with 4 contrasting black PeniswithterminalsegmentY-shaped.
spines (outer row) on hind femur, 5 on hind tibia.
Wings: Venation as in generic diagnosis; IR2 arising Allotype female. — Similar to male. Head: Face
at6(forewing) and 5 (hindwing);CiP8 (forewing), pale, paireddarkspotsanteriortolateralocelli. Small
9 (hindwing) cellslong. roundedpaleprotuberanceson rearofhead. Thorax:
Abdomen: Palelaterallyanddarkerdorsally; 3 and Hind lobeofprothoraxprominent, triangular, divid-
4 dominantly pale dorsally, slightly darker in basal ed into three nearlyequallywide lobes bydeepsulci;
halfand on apical X; 5 obscure, darkeron apical %\ 6 thecentral lobeemarginate, and thetwo lateral lobes
slightly pale in basal X; 7-10 dark, with limited pale lowandtaperinglaterallytopoints.Colourofthorax:
on sides, 8 and 9 with pale longitudinal dorsal lines Mesepisternum pale, thin black line adjacent to pale
on basal X, tapering caudally. Superior appendage dorsal carina; thin blacklinealongcaudal halfofan-
brown, shorter than 10, rounded and expanded api- tehumeralsuture; mesepimeronwith an obscurecen-
130
Donnelly: Isostictiddamselflies
Figs. 16-23. Cnemistictalatilohatagen. n.,sp. n.- 16,malehindlobeofprothorax,dorsalview. 17,malehindlobeofpro-
thoraxand mesostigmallamina, dorsal-lateralview. 18, femalehindlobeofprothorax, dorsalview. 19, femalehindlobeof
prothoraxandmesostigmallamina,dorsal-lateralview. 20,maleabdominalappendages,dorsal-lateral-apicalview.21,male
abdominalappendages,lateralview.22,ovipositor.23,penis,ventralandlateralviews.
trai darkmarkdeflectedlaterallyin cephalic portion. and apparently more Y-shaped than the allotype.
Abdomen: 9 and 10with prominentpalebasal-later- However the apparent difference in shape could be
alspots;ovipositorpale, extendstoendof10 (cerei). duetotwistingupon drying.
Dimensions. - Holotype male: abdomen 39 mm, Etymology.-Thenamereferstothewideanddec-
hind wing 26 mm. Allotype female: abdomen 35.5 orativehindlobeoftheprothorax.
mm, hindwing26.5 mm. Thedimensional range of
theparatypeseriesisasfollows: 2pararypemaleshave Remarks. - The two species ofCnemistictaresem-
abdomens 37 and 38.5 mm; 3 paratype males have ble each other in their peculiarly wide and apically
the hind wing 24 to 26 mm. The 2nd female speci- abruptlynarrowedwings,thelongCuP,andthemale
men isveryrenerai; thehindwingis27 mm. abdominal appendages. The species angustilobata is
slightlylargerthan latilobata. Thespeciesdiffermost
Variation within paratypeseries. -The male from prominentlyinthehindlobeoftheprothorax,which
Bougainvillehasthepalecolourofthetopofthehead isprominentlydevelopedin latilobataandreducedin
moreextensivethantheholotype,extendinganterior- angustilobata.Thespecies latilobataispale,butwitha
ly nearly to the antennal bases. Averyrenerai female darkerabdomen,andangustilobataisdark,butwitha
specimen has the hind lobe ofthe prothorax longer paler abdomen. The allotype female oflatilobatahas
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TijdschriftvoorEntomologie,volume i36,1993
aroundedprominenceontherearofthehead; thisis grateful to Dr. Watson for the loan ofspecimens of
lacking in angustilobata. The female ofangustilobata fourAustraliangenerawhichenabledmetocomplete
hasamuchlongerovipositorthan latilobata. Theve- thetableofgenericcharacters.
nation ofthetwospecies (above) differsmorethan is
appropriate for the slight dimensional differences References
betweenthetwospecies.
Fraser, F. C, 1955. A new isostictine dragonfly from
AustraliawithsomeremarksonthesubfamilyIsostictinae
Acknowledgements nov. (Odon.,Protoneuridae).—Entomologist'sMonthly
Magazine91:227-230.
IamindebtedtotheRMNH, Leiden,fortheloanof Lieftinck, M.A., 1975. Thedragonflies (Odonata) ofNew
specimens which M. A. Lieftinck had been studying Caledonia and the Loyalty Islands. Part 1. Imagines. —
atthetime ofhisdeath. I amfurtherverygrateful to Cahiers O. R. S. T. O. M., série Hydrobiologie 9(3):
VladimirJindrich, at that timeagraduatestudent in 127-166.
ourdepartment,forspecimensoftwoofthenewspe- Watson,J.A.L,G.Theischinger,andH.M.Abbey, 1991.
cCioesmmcoelnletcstedfdruorminDgrsa.geJoalongivcaalntrTiopltoaNndewAnBrtihtaoinny. TMehleboAuursntera,li2a7n8pd.ragonflies. - CSIRO, Canberra and
Watson on a draft ofthe manuscript have been very Received: 14April 1993
helpfulandaregratefullyacknowledged; Iamfurther Accepted: 14June 1993
132