Sympetrum chaconi spec. nov. from Auyan-Tepui, Venezuela, with notes on a Pantepuyan form of Tramea binotata (Rambur) (Anisoptera: Libellulidae)

8 Pages·1994·1.5 MB·English

by  De Marmels, J

Odonatologica23(4):405-412 December 1, 1994
Sympetrumchaconi spec. nov. from Auyan-Tepui,
Venezuela, with notes on a Pantepuyan formof
Tramea binotata (Rambur)
(Anisoptera: Libellulidae)
J.De Marmels
Institute deZoologiaAgrícola.Facultad deAgronomía,
Universidad Central deVenezuela, Apartado4579, Maracay 2101-A,Venezuela
Received July25, 1994 /AcceptedAugust 15, 1994
S. chaconisp.n. is describedand illustrated onthebasisofI S and I $ (holotype
6:Venezuela, Bolivar,Auyan-Tepui, 1730m. 1/7-II-1994;depositedatMIZA,Mara-
cay). The new sp. resembles S. roraimae De Marmels, 1988, but differs from it in
shapeofsuperiorcaudal appendagesand vulvar lamina. — A Pantepuyanform of
Tramea binotata (Ramb., 1842)with exceptionallylargehindwingbasal spotis also
broughtonrecord.The known Venezuelan distribution ofboth spp. ismapped.
INTRODUCTION
Thetable-top andothermountainsscatteredthrough southeasternandsouthern
Venezuelaand the adjoining regions ofBrazil and the Guyanas are known as
the ’’Guayana-Highlands”, or ’’Pantepui” (MAYR & PHELPS, 1967). Nu-
merousexpeditions havebeencarriedoutin thepast tenyears inordertoexplore
biodiversity ofsomeoftheseisolatedridges. Notsurprisingly, manynewodonate
species were discovered, severalofwhichhave already beennamed(DEMAR-
MELS, 1988, 1989, 1992a, 1992b).An additional new Sympetrum Newman,
1832,thesecondmemberofthis genus fromPantepui, is describedinthepresent
paper.
An interesting colour form of Tramea binotata (Rambur, 1842) has been
collectedso faronthreedistanttepuis. Albeitdifferencesin structuralcharacters
havenot been detected, it seems probable thatthis morph is a true Pantepuyan
subspecies ofthenominateform,whichis widespreadacross thetropical lowland
up to middleheights in the Andes.
Allspecimensreferred toin thetext, includingtypes,are depositedatthe "Museo delInstitute
406 J. DeMarmels
deZoologiaAgricola"(MIZA).Facultad deAgronomia,Universidad Central deVenezuela, Maracay.
SYMPETRUMCHACONI SPEC. NOV.
Figures 1-8;Map 1
Material. — Holotype 3, allotype 9; VENEZUELA: Bolivar. AuySn-Tepui, 05°53’N,
62°29’W, 1730m, 1/7-11-1994. Expedition"FundacionTerramar”,Caracas (A.Chacdn&J.Clavijo)
leg.Both specimens depositedatMIZA.
Etymology. - The newspecies is named afterMr. Anibal Chac6n, my invaluable companion
on many collectingtrips,andtechnical assistant atthe Section ofEntomologyofthe MIZA.He is
the collectorofthis andmany other fine Venezuelandragonflies.
MALE(holotype). — Colourpatternofliving, mature male(from colourtrans-
parencies): labiumcreamy;compound eyes brownabove,pale olivaceousbelow;
face andfrons on top,pale olivaceous; a black basal line in frontof vertex,this
line not descending laterally along eye suture; labrum yellowish. — Mesepister-
numpale olivaceouswithbroadbrownblackbandalong humeralsuture. Mesepi-
meron and metepimeron brown black in ventral halfalong sutures; eachwith a
pale band, which is narrow and whiteat its ventralend, becoming broader, less
sharply definedandbluishtowardsantealarridges.Notal scleritespale olivaceous,
but axillar plates bright red. Legs pale ferruginous, tipoftibiaeandtarsi black.
Wings hyaline, venationbrownbasally, black distally;pterostigmapaleredbrown.
Smallbrown black basal mark in forewing (FW) restricted to extreme base of
subcostal space; costal and medianspaces amberto halfway between base and
firstantenodalcross-vein(Ax). Basal spotinhindwing (HW)brownblack,almost
reaching to secondAx incostalandsubcostal spaces; medianand cubitalspaces
predominantly amberwith dark colourrestricted to extreme base. — Abdomen
chiefly chestnut dorsally, each tergite darkening distally; segment 2 yellowish-
-olivaceous; segments8 and9brownblack alongmediancarina. Ventral portion
oftergites 3-9 opaque yellow with broad black distalend. Caudal appendages
pale brown.
Structural features. — Vertex with two very low tubercleson top.
— Prothoracichindlobe narrowedatbaseandslightly bilobed,free marginbeset
with long hairs. FW with 10(9.5) Axand9postnodal cross-veins (Px); HW with
6Ax and 9 Px; triangle in FW crossed, in HW free; subtriangle of FW three-
-celled; Rspl enclosing onerow of7(8) cells inFW, 8 in HW, 2-3 cross-veins
distallyofpterostigma incostal space.Anal loop with anextra cellatanal angle
oftriangle, and one at heel.A duplicated cell (left HW) and an extra cell (right
HW) also betweenAspl and proximal vein of anal loop at level ofheel; loop
enclosing 23(20) cells. Three rows of cells between anal loop and hindborder
ofwing atlevelofarculus. — Abdominalsegment4withawell-definedaccessory
transverse keel. Secondary genitalia as illustrated (Figs 4-7). Superior caudal
appendages straight indorsalview, littleconverging towardstip; tips themselves
Sympelrumchaconi sp.n. 407
Figs 1-10. (Figs 1-7): Sympetrum chaconi sp.n., male (holotype); (1) caudal appendages,dorsal
view; - (2) same, left lateral view; - (3)left superiorappendage,ventral view; - (4)secondary
genitalia,rightlateral view; — (5)right hamule, ventralview; - (6) penis, ventral view; — (7)
same,rightlateral view. — (Fig. 8):S.chaconi sp.n.,female (allotype):vulvar lamina,ventralview.
— (Figs9-10):S. roraimae De Marmels: (9)left superiorcaudal appendage,ventral viewofamale
fromMtRoraima (I5-I-I99I,A.Chaconleg.); - (10)right hamule,ventralview ofamale paratype
from MtKukenam.
408 J.Do Marmels
parallel; in lateral view al-
most straight; in ventral
view the ventral row of
11-12 denticles strongly
curvedoutwards initspro-
ximalthird and occupying
the distal two fifths ofthe
distancebetween baseand
inferiorangle (last tooth)of
appendage. Inferiorappen-
dage withtwo distaldorsal
hooks (Figs 1-3).
Measurements (inmm).
— Totallength(including caudal
appendages) 37.5; — abdomen
(incl.app.)23.0; - superiorcau-
dalappendages 1.9; — hindwing
27.0.
female (allotype). -
Colour pattern similar to
male,butmorecontrasting.
Tergites 3-9 pale brown
dorsally in middle, with a
black lateralbandfollowed
by a yellow markatlateral
carina;dorsomediancarina
black. Wings hyaline with
basalspotsas inmale; axil-
lary plates pale brown,not
red. Vulvar laminashaped
Maps 1-2. Venezuela: (1) distribution ofthe two Pantepuyan
as inFigure 8. species ofSympetrum Newman: S. chaconi, Auydn-Tepui
Measurements (inmm). (typelocality); - S.roraimae. MtRoraimaandMtKukenam.
- Total length36.5; — abdomen —(2)distribution ofTrameabinotata (Rambur): Pantepuyan
23.8; - hindwing28.0. form; typicalform.
larva. — Unknown.
remarks. — The new species is a closely related vicariant ofSympetrum
roraimae De Marmels, 1988. The male ofthe latter has longer outer hamular
branch(Fig. 10)andstrongly convergentanddowncurvedsuperior caudalappen-
dages, with a longer and less sinuous ventral row of denticles (Fig. 9). The
femalesof the two species differmainly in shape ofthe vulvar lamina. — S.
chaconiwastakenoveraswampystrip withgrassyvegetationandslowlyrunning
and stagnantwater,betweena smallriverandaforest. Erythrodiplax transversa
Horror, 1957 was very common atthis spot. The latter was not foundon either
Mt. Roraimaor Mt. Kukenam, in therange ofS. roraimae.
Sympelrumchacnni sp.n. 409
TRAMEA BINOTATA (RAMBUR, 1842)
Figures 11-16,Map2
T. binotatais widespread in South Americaandoccurs inmost parts ofVene-
zuela, including theAndesandthe region Southofthe Orinoco (Map 2). Speci-
mens seem to vary littlein general colourationand size ofthe hindwing basal
spot. On the top of some mountains ofPantepui, however, populations exist,
which have this basal spot considerably enlarged, especially so in the females
(Figs 14-16).
Material ofthe "typical” form examined (17 <J, 5 2). - BOLIVIA: Buena Vista, 1 3,
Steinbach leg. (nofurther data). — BRAZIL: State ofRoraima,Rio Murupii,I 5, 21-11-1964,J.
Racenis leg. — VENEZUELA: State ofAragua,ElLim6n,430m. 2 3, 11-XI-1981;— Cataurito,
900 m, 1 3, I0-XI-198I (ex larva),all J.DeMarmels leg.; — State ofBolivar,Canaima,450 m,
1 2, 20-11-1958; — Guasipati, 1 3, 4-VIII-1960, both J.Racenis leg. ; — Rio Chiguao, 1 2,
7/13-IV-1983; roadSantaElenadeUairen-Icabaru, ElPildn,Peraitepui,1000m,23,20/31-1-1985,
all J.DeMarmelsleg.; - PasoCaruachi, 105m, 13, 14-V-1989,M.L.Gadouleg,; —ElBochinche,
200 m, 1 <J, I5/30-V-1994,P.Bleuzen leg.; — State ofGuarico,Calabozo, LagunadeLos Patos,
105 m, 1 3.27-X-1982,J.Limongi& J.De Marmels leg.; - Espino,2 3, 29/30-X1I-1953; 1 2,
27-XII-1954; 1 3,4-1-1955,allJ.Racenis leg.; 1 3. 18-IV-1954,Klisansleg.; - StateofMCrida,
road to Jaji,Las Cruces, Hacienda Las Mesas, 1650m, 1 3, 15-11-1983, J. DeMarmels leg.; —
State ofMonagas,Tonoro, 1 3, 13-VII-1964,J.Racenis leg.; — La Toscana, 127 m, 1 2, 14-X-
-1965, F. Fernandez Y.& C.J.Rosales leg.; — State ofZulia,Kunana, 1100 m, 1 3,26-X1I-1950,
F. Femdndez Y.leg.
Additional Venezuelan records ofthe ’’typical form”(includedin Map 2). —
State ofAmazonas: San Carlos de Rio Negro. State ofAragua: Camatagua,State ofBolivar: La
Escalera (roadkm 88-SantaElenade Uaircn),Jabillal(Caura),Los Pijiguaos,Puerto Ordaz. State
ofFalcon:Yaracal, StateofMCrida: PuenteChama. State ofTdchira: San AntoniodeCaparo.
Material ofthe "Pantepuyanform” examined(18 3,42). — StateofAmazonas:
Huachamakari,1700 m, 2<J, 3/5-II-1992,A.Chacon &J.Clavijoleg.; — State ofBolivar: Auydn-
-Tepui,Guayaraca, 1020m, 3 6,2 2, 16/26-IV-1956, J.Racenis leg.;Auyan-Tepui, 1600m, 3 3,
III-1973,Laime leg.; 1800 m, 1 3, 4/10-11-1988,A.Chac6nleg.; 1700 m,8i,22, 1/19-11-1994,
A.Chacon,J.Clavijo&J.L.Garcialeg.; - Waikinima, 1000m, 1 3,6/13-II-1990,J.DeMarmels
leg.
In all ofthe 17 malesof ’’typical” T. binotataexamined, the hindwing basal
spot does not, or only very slightly, surpass CuP (= cubito-analcrossing, see
RIEK & KUKALOVA-PECK, 1984)distally, from where it runs backwards in
aratherstraight line. Thesamecan be saidofthefive females studied,ofwhich
only onehas the basalspot somewhattransgressing CuPdistally.Inall specimens
the basal spot runs straight backwards to anal angle. 13 of the 17 males have
only one cross-vein (cx) betweenthetwo sectors ofarculus abovetriangle; three
specimens have two cx inone wing, onein theother, and onemale has two cx
in both wings. This figure is, however, variableforthe females.
Ofthe 18 Pantepuyan malesonly onehasthebasal spot ending atCuP. In the
remaining specimens this spot transgresses CuP distally fora variable distance.
410 J.De Marmcls
Figs 11-16. Tramea binotata Ramb.,wings: (Figs 11-13):IypicaI form: (II)righthindwingof
malefromAragua (El Union, 430 m); — (12) sameofmale from Merida (road toJaji, Hacienda
Las Mesas, 1650 m); — (13)left hindwing(transposed) offemale from Guarico (Espino, 100m).
— (Figs 14-16): Pantepuyan form: (14) right hindwingofmale from Bolivar (Guayaraca,
Auyan-Tepui. 1020 m); — (15)same ofmale fromAuyan-Tepui, 1800 m; — (16)sameoffemale
from Auyan-Tepui, 1730 m.
Sympeirumchaconi sp.n. 411
From its distalextreme the basal spot runs towards proximal (anal) margin of
wing diagonally, zigzagging, or in an irregular curve. Eight males have two cx
betweenthe two sectors ofarculus above triangle in both hindwings, two have
only one cx in each wing,and eight have two cx in one wing, one in the other.
In thefourPantepuyan femalesthebasal spot is so greatly enlarged as to render
any confusionwith ’’typical” femalesimpossible. The presenceofeitherone or
two cx betweenthe sectors ofarculus above triangle is variable.
REMARKS. — Structural differences, either in caudal appendages, secondary
genitalia or vulvar lamina,between typical andPantepuyan specimens, havenot
been found. Therefore, size ofthe basal spot in hindwing is the only character
which separatesthe two forms. In a few Pantepuyan males even this basal spot
is not excessively enlarged. Inone malefromAuyan-Tepui itstops atCuP,albeit
running from here towards proximal (anal) margin of wing in a strong curve.
Occasional vagrants fromthe surrounding lowland might cause geneflow, chal-
lenging genetic stability of the Pantepuyan populations. This hypothesis gets
some supportfromthecaptureon Auyan-Tepui ofapparentmigratory specimens
oftrue lowland dragonflies, such as Gynacantha nervosa Rambur, 1842 (1500
m, 3 <S, 3 9, X-1990,and 1740m, 1 d, 11-1994).Autochthonous populations
ofthis aeshnid are highly unlikely to occur on any ofthe differentterraces of
the plateau. Therefore, Pantepuyan T. binotataprobably represents a true relic
subspecies which occupies theplateau ofseveral, now isolatedtepuis. That two
Tepuyan subspecies might live in (geographically) closecontact is demonstrated
by a bird, viz. Zonotrichia capensis (Muller) (Aves: Emberizidae), which is
known to occur as one subspecies on the slopes and a differentone on top of
Mt Roraima(MAYR & PHELPS, 1967).
ACKNOWLEDGEMENTS
1amthankfultoProfessorFRANCISCOCERDAfortakingthe wingphotographs.To MrMARCO
GAIANI and toProfessorJOHN LATTKEIam indepbtedforrevisingthe manuscript.
REFERENCES
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