A new species and a key to species of Polyrhachis Smith (Hymenoptera: Formicidae) from India.

2004·0.23 MB·English

by  Karmaly, K. A.

40
PerspectivesonBiosystematicsandBiodiversity
T.C.N. Com.Vol. March 2004 539 -551
:
A NEW SPECIES AND A KEY TO
SPECIES OF POLyZ?HACHK SMITH
(HYMENOPTERA: FORMICIDAE)
FROM INDIA
K.A. KARMALY
DepartmentofZoology
St.Xavier's CollegeforWomen,Aluva-683101, Kerala, India
ABSTRACT
Anew speciesofPolyrhachisSmith,VizP.narendranispnov
fromKeralaisdescribedandillustrated.Theaffinitiesofthisspecies
withitsclosestrelativesarediscussedandakeytoIndianspeciesis
alsoprovided.
Keywords: Formicidae,Polyrhachisnarendrani,newspecies,
India.
INTRODUCTION
ThegenusPolyrhachiscomesunderthesubfamilyFormicinae.
It is found to be the third largest group in the subfamily with 477
speciesallovertheworld. [BOLTON1995] .Sofar48speciesand13
sub species has been reported from India and 13 species and 10
subspecies from Kerala. This genus was erected by Smith (1857)
based on the type species Formica bihamata. Gerstaecker (1858)
erectedanothergenusHopolomyrmuswiththetypespeciesHopolo
schistancevs.Later Mayr ( 1863) synoymised this series with
Polyrhachis. Now thereare 14 subgenera in Polyrhachisincluding
the nominal genus. In this paper, A new species is described from
Kerala and a key to species isprovided. Thenew species isnamed
inhonourofProf.T.CNarendranforhissignificantcontributionto
thestudyofTaxonomyofOrientalInsects.Theholotypeisdeposited
in theDZCU forthetimebeing, buteventuallywillbe transferred
to theZSIC.
MATERIALS AND METHODS
Ants were mostly collected by hand picking with fine zero
pointbrushandwithhelpofaspirator.Theywerealsocollectedby
sweeping method.
Specimens were preserved in 70% alcohol in plastic vials.
Observations were made in field where ants were found making
nestsonthetwigs, soilsurfaceand foliages.
W
ABBREVIATIONS:F-Funicularsegments; -Worker;TL-Total
length-Toal lengthofspecimen fromapexofmandibleto apexof
gmaasntdeirbl;eHsL;-HHWea-dHelaedngwthid-thLe-nMgtahxiofmuhmeawdidptrhopoefrheeaxdcliundifunlgl
;faScIe-viSecwap;eCII-ndCeepxhiael.i(cSiLndxe1x0ie0.)(/HHWWx;1E0D0)-/EHyLe;SdLia-mSectaepre;lePnWgth-
Pronotalwidth-Maximumwidthofpronotumindorsalview;Fj-
Fo|fIZ-oFoulnoigcyul,aCrasleicgumtenUtnisv;eArsLit-yA;liZtSrIuCnk-lZeonogltohg;icDaZlCsUur-vDeeypoafrtInmdeinat,
Calicut.
RESULTS AND DISCUSSION
Polyrhachis (Myrma) narendrani sp. nov.
(Figs. 1-2)
Worker. TL = 6.2 mm; HL = 1.8 mm; HW = 1.4 mm;CI = 77
mm;SL= 1.6mm;SI= 114.28mm;ED=0.2mm;PW= 2.4mm;AL
=2.2mm.
Colour. Head,thorax,nodeofpedicel,gasterblack;legsmore
or less castaneous red; silkysilvery hairs; pubescencewhite; tibial
spinesreddishyellow;tarsal spurreddishbrown.
Sculpture and Hairpattern: Head, thorax and abdomen
shining; head and thorax minutely regulose; abdomen more
minutely regulose than head and thorax; pubescence adpressed,
sparse on body, dense on antennae and on thorax laterally; silky
silvery erect hairs scattered on head, thorax and gaster, more
abundantonapexofgasterunderneath.
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I
Head: Very convex in front and at the sides, tending to be
moreconvergentinfrontoftheeyes,roundedposteriorly;mandibles
sublinear,5-toothed;clypeuscarinate,tectiform,itsanteriormargin
arcuatewithashallowmedianlobe;frontallobessmall,subparallel;
frontalcarinaeprominent;parallel;antennalcarinaedistinct;scrobe
indistinct,torulusrounded,horizontal;antennalinsertionseparated
from posterior clypeal margin by a distinct gap, antennae short,
slender, 12jointed; antennal scape extending little beyond thetop
ofhead; all segments offuniculus longer thanbroad, 1st funicular
segment longer than remaining segments, last segment thickened
and club shaped. Relative measurements of length of antennal
segments: Scape = 1.6mm;F^ =0.9mm;F^=0.35mm;F^=0.2mm;
F^=0.2mm;F^=0.2mm;F^=0.2mm;F^=0.2mm;Fg=6.15mm;F,
=0.2mm;F,„=0.2mm;Club(F,,)=0.3mm; Eyesmoderatelylarge
placed, more towards the posteriorend, slightly above the lateral
sides.
TTicyax: More or less flat above; sides margined along their
wholelength;pronotumbroadposteriorly,narroweranteriorly,two
strong long erect spines on anterolateral angles of pronotum,
pointing forwards; pro-mesonotal suture very distinct; meso-
metanotal impressions present, but no distinct suture; metanotal
groove indistinct; metanotum unarmed; propodeum anteriorly
margined and anterior corners projecting upwards, thorax deeply
emarginateatpro-mesoand meso-metanotal stutures;propodeum
situated at a level below the pro-mesonotum, emarginate, the
dorsum very oblique and sloping into the vertical and weakly
concavedeclivity,ends witha carina; legs slender,elongate;tibiae
cylindricalwitha spinebeneath;tarsiwithtarsalspurs.
Abdomen: Infrontviewthesidesofpetioledivergefromthe
base, pass through the rounded angle and then converge dorsally
to the base of a pair of curved spines; petiolar node rhomboidal,
biconvex slightly arched at middle, bearing two long spines on
dorsolateraledgesguardedbytwosmallteethonsides;longspines
slightly curved backwards attheir tips. Caster globose, withfour
visible segments, first gastral segment larger, covering more than
half of its length, apex of last gastral segment with circular anal
orificeguardedbyguard hairs.
Holotype: Worker. INDIA: Kerala, Thiruvananthapuram -
Palode,Karmaly.K.A., lO.iii-2000. [DZCU].
nm-
Etymology. Named inhonourof Prof. T. C. Narendran.
Distribution INDIA [Kerala: Thiruvananthapuram].
: :
Bioogy Unknown.
Habitat. Disturbed withsmall plants and trees.
Discussion: Thisnewspecies resemblesPolyrhachisconvexa
Rogerinthe following features: 1. Antennae12jointed;2Clypeus
tectiform; 3. Thorax flat above, sides margined along their whole
length. HoweverthisnewspeciesdiffersfromPolyrhachisconvexa
Roger in having: 1. Pronotal spine long (in Polyrhachis convexa
pronotal spine short); 2. Legs with spines and erect hairs (in
Polyrhachis convexa legs devoid of spines and erect hairs); 3.
Petiolar node rhomboidal, biconvex with two long spines on
dorsolateral edges guarded by two small teeth on sides (in
Polyrhachisconvexapetiolarnodebroad,biconvexwithfourshort
subequal spines,equidistantfromeachother).
KEY TO INDIAN SPECIES OF POLYRHACHISF. SMITH
[Based on Workers]
1. Thoraxarmedwithspinesorteeth[Fig.3] 2
Thoraxunarmed[Fig.4] 60
2. Thoraxroundedabove,sidesnotmarginedalongtheirwhole
length 3
- Thorax flat above, sides margined along their whole length
37
3. Mesonotumarmedwithspines 4
Mesonotumunarmed 6
4. Petiole spines parallel, not divergent from base [Fig.5]
5
Petiolespinesnotparallel,butdivergentfrombase [Fig.6] ....
P.ypsilonEmery.
5. Pronotal spines pointing outwards and curved laterally
backwards,forminghooks [Fig.7] P.bihamata[Drury]
Pronotal spines pointing outwards and downwards, not
curved,notforminghooks [Fig.8] P. bell—icosaSmi^h
——- —
--H542I
^ '
6. Metanotumarmedwithspines[Fig.9] 7
Metanotumunarmed [Fig.lO] 33
7. Pubescencesofterectandabundant 8
- Pubescence silky, short and recumbent, or sparse and erect,
orentirelywanting 10
8. Spines on petiole forming hooks [Fig.11] [Kerala]
F./ureafaSmith
Spinesonpetiolenotforminghooks [Fig.l2] 9
9. Head smooth, shining, not punctured
P.gracilioriForel [= weiieriDonisthorpe]
Headnotsmooth, notshining,butcoarselypunctured
P.ru/ipesF.Smith[=p/iipsoniForel]
10. Spinesonmetanotumforminghooks[Fig.l3] 11
Spines on metanotum not forming hooks [Fig.14]
13
11. Abdomenclothedwithgoldenhairs P.rupicapraRoger
Abdomennotclothedwithhairs 12
12. Head and abdomen opaque; thorax finely punctured
P.hodgsoniFoiel
- Head and abdomen not opaque, shining; thorax coarsely
punctured P.arac/ineEmery
13. Basal portion of metanotum without margin laterally
14
Basal portion ofmetanotumwithmargin laterally 27
14. Pubescencesparseorentirelywanting 15
- Pubescencedense,silkyandrecumbent 23
15. Spines on petiole wide-spread encircling front of abdomen
16
- Spinesonpetiolenotwide-spread,andnotencirclingabdomen
18
16. Headwithatubercleoneithersidebehindtheeyes
— .P. tubericepsFoTel
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1 I ^ ^
—
- Headwithouta tubercle on eithersidebehind theeyes 17
17. Propodealspinesslightlycurved[Kerala]
P.lacteipennisSmith[inpart]
- Propodealspinesnotcurved P.f/iompson/Bingham
18. Head, thorax and abdomen shining; metallic blue or purple
P. venusForel
Head, thorax and abdomen not shining, black; abdomen
sometimesred 19
19. Head,thoraxand petiole node coarselypunctured 20
- Head,thoraxand petiolenodefinelypunctured 21
20. Abdomenblack;petiolenodecubical P.armataLeGuillou
- Abdomenferruginous;petiolenodearcuatewithacutespines
P.fortisEmery
21. Petiolar node with two median vertical short acute spines
between spines on upper lateral angles of node [Fig.15]
P.hauxwelUBingham
- Petiolarnodewithoutmedianspinesbetweenspinesonupper
lateralanglesofnode[Fig.16] 22
22. Metanotal spines erect, slightly bent outwards [Kerala]
P.lacteipennisF. Smith.[=simplexMayr]
Metanotal spines not erect, strongly curved inwards
m
P. ene7asForel
23. Abdomenred F.WcoiorSmith
- Abdomenblack 24
24. Pubescencegoldenorbronzyyellow 25
Pubescencesilvery[Kerala] P. tibialistibialisSmith
25. Two small teeth between spines on upper lateral angles of
petiolarnode 26
- Three small teeth between spines on upper lateral angles of
petiolarnode P. vicinaSmith
26. Headshortandbroad P. divesd/vesSmith
—— Headlongandbroad P. divesbelli—Forel
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1 I
.
27. Spinesonpronotum and metanotumsubequal 28
- Spinesonpronotum and metanotumnotsubequal 30
28. Petiolarnodelongerthanwide 29
Petiolarnodenotlongerthan wide,butcubical
P.ctialybeaSmith
29. Abdomenred;length7mm-9mm P.SectorSmith
[= abdominalisSmith
= mutatusSmith
=mufafaSmith, r. ajaxForel]
- Abdomenbronzegreen;length6mm-7mm
P.aedipusFoiel
30. Pronotalspinesshort,stoutandstraight[Kerala]
P.binghamiiVorel
- Pronotal spines long, acute, pointing divergent or straightly
pointingforwards 31
31 Basalportionofmetanotumposteriorlytransverselymargined
P.pubescensMayT
Basal portion of metanotum posteriorly bunded by a faint
transversecarina 32
32. Thoraxstronglyarched P. aculeataaculeataMayr
Thoraxmoregibbous P.aculeatagibbosaForel
33. Metanotumwithspines[Fig.9] 35
Metanotumwithoutspines[Fig.7] 34
34. Abdomen, legs reddish yellow; antennae and front of head
reddish P.laevissimadichroa¥oie\
- Abdomen,antennaeand frontofheadblack; legsblood red
P.laevissimalaevissima Smith
35. Abdomenveryconvexabove,notdepressed 36
- Abdomenslightlyconvexabove,stronglydepressed
P. wroughtoniForel
36. Abdomenred,smoothandshining P.laevigataSmith
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Abdomenblack,feeblyreticulate,punctateandslightlyshining
P.hippomanesceylonensisEmery
37. Pronotum, mesonotum and metanotum with spines
P.cracfcfociciBingham
- Pronotumwithspine, mesonotumand metanotum withor
withoutspines,teethortubercles 38
38. Pronotum always with a spine; mesonotum and metanotum
withtriangularlamina P.horriiEmery
- Pronotum with or without spines; mesonotum unarmed;
metanotum with teeth or lamina or spine or tubercle
39
39. Pronotumwithlongershortspine 40
- Pronotumwithoutspine 57
40. Pronotumwithlongspines [Fig.17] 41
- Pronotumwithshortspinesorteeth[Fig.9] 51
41. Petiole node with two long spines on upper angles, and two
shortlateralspinesorteeth 42
- Petiolenodewithfourshortsubequal spines 49
42. Lateral spinesorteethtruncate orbimucronateatapex.... 43
Lateralspinesorteethpointed,nottruncatenorbimucronate
atapex 44
43. Verydensepubescenceonbodyhidingthesculpture
P.proximaproximaRoger
- Verysparsepubescenceonbody nothiding thesculpure
P.illaudataintermediaForel.
44. Pubescenceonbodyverydense[Kerala]
P. illaudataillaudataWalker [=P.mayrimayriRoger]
- Pubescenceonbody verysparseorwanting 45
45. Basal portion of metanotum convex
F./le/niopfiCOidesMukerjee
- Basal portion of metanotum not convex, but transversely
submargined 46
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—
. T
46. Antennalcarinae long, divergentposteriorly 47
- Antennalcarinaeshort, notdivergentposteriorly 48
47. Abdomenfinelypuncturedandthepuncturesseemtoruninto
tninutelyfinestriae P.striatastriataMayr
Abdomen simply recticulate punctuate, without the trace of
striae P.striataassamensisForel
48. Meso-metanotal suture very distinct; legs densely covered
withlongerecthairs P. sumatrensishamulataEmery
- Meso-metanotalsuturenotverydistinct;legsnotcoveredwith
longerecthairs,smooth P.yerburyiVorel
mm
49. Pubescence, recumbent and yellowish, length 9 - 10
mm P.striatorugossaMay
mm
- Pumbemscence,recumbentandglisteninggreyish,length5 -
6 50
50. Pronotalspineshort P. convexaRoger
- Pronotal spinelong P. n^rendrgni sp. nov.
51 Petiolenodewithtwolongspinesonupperlateralanglesand
twoshortobtuseteethbetweenthem P.jerdoni¥oTel
- Petiolenodewiththreeor fourspinesorteeth 52
52. Petiolenodequadridentateorquadrispinous 53
Petiolenodetrispinous 55
53. Clypeuscarinate 54
- Clypeus not carinate [Kerala]
P.punctillatafergusoniFoiel
54. Clypeusmediallycarinate[Kerala]
P.punctillatapunctillataRoger
Clypeus posteriorly carinate
P.punctiliatasmythiesiVorel
55. Antennalcarinaedivergentposteriorly 56
— —
—
{547}- •—
^
- Antennalcarinaenotdivergentposteriorly
P.frauenfeldiMayr
56. Node of pedicel longer than wide [Kerala]
P. thrinaxthrinax^oger
- Node of pedicel as long as wide
P. thrimaxwar./ancear/usForel
57. Metanotal spines vertical, very small [Fig.20] [Kerala]
P.halidayiEmery
Metanotal spines broad, triangular, pointing backwards
[Fig.21] 58
58. Headandthoraxpunctured,notstriate 59
- Headandthoraxnotpunctured,butstriate[Kerala]
P.exercitarastrataEmery
59. Petiolar node quadrispinous, equidistantfromone another
[Fig.90] [Kerala] P. exeriita exercita[Walker]
[=P. clypeata clypeataMayr]
- Petiolarnodequadrispinous,notequidistantfromoneanother
P.exercitaobtusisquamaForel
60. Viewed from side thorax very convex, strongly arched and
gibbous anteriorly P. rastellata rastellata [Latreille]
Viewedfromside thoraxnearlyasconvex,roundedanteriorly
P.rastellatapagana Santschi
ACKNOWLEDGEMENTS
The author is grateful to Dr. T.C.Narendran, Professor,
Department of Zoology, University of Calicut for his benevolent
help. She thanks UGC for financial assistance. For facilities, she
thanks theauthoritiesofUniversityofCalicut.Withgreatpleasure
the help rendered by Dr. Rudolf J.Kohout, Queensland Museum,
Australia is acknowledged.
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