Systematic studies on Pseudomyrmex acacia-ants (Hymenoptera: Formicidae: Pseudomyrmecinae)

52 Pages·1993·21.8 MB·

by  P S Ward

J.HYM.RES.
2(1), 1993pp.117-168
Systematicstudieson Pseudomyrmexacacia-ants
(Hymenoptera:Formicidae:Pseudomyrmecinae)
PhilipS.Ward
DepartmentofEntomology.UniversityofCalifornia.Davis.CA95616
—
Aobfsstwroalclt.en-tThhoernoabclaicgaitaesaincatchiea-naonrttshe(rPnsNeeuotdroompyircsm.exAfetrarxuognionmeiucsrgervoiuspi)onaroefwtehlelsekannotswnleaasdsdetofetnhseirveecionghnaibtiitoanntosf
tenspecies:P.ferrugineus(F.Smith),P.flavicornis(F.Smith),P.janzeni,sp.nov.,P.mixtecus,sp.nov.,P.
nigrocinctus(Emery),P.particeps,sp.nov.,P.peperi(Forel),P.satanicus(Wheeler),P.spinicola(Emery),and
P.veneficus(Wheeler).Thefollowingnewsynonymyisproposed:P.nigrocinctus=P.alfari(Forel)=P.bicinctus
(Santschi)=P.peltatus(Menozzi);P.spinicola=P.atrox(Forel)=P.gaigei(Forel)=P.infernalis(Wheeler)=
P.scelerosus(Wheeler).Diagnosticdescriptionsandtaxonomiccommentsarealsoprovidedfortenotherunrelated
speciesofPseudomyrmexwhichhavebecomesecondarilyassociatedwithswollen-thornacaciaseitherasobligate
and,inatleastonecase,parasiticoccupants(P.nigropilosus(Emery),P.simulansKempfandP.subtilissimus
(Emery);P.reconditus,sp.nov.,mayalsobelonginthiscategory)orasfacultativeinhabitants(P.boopis(Roger),
P.gracilis(Fabricius),P.hesperius,sp.nov.,P.ita(Forel).stat.nov.,P.kuenckeli(Emery)andP.opaciceps,sp.
nov.). AcladisticanalysisoftheP.ferrugineusgroupyieldsthefollowingresultwhichappearstobefairlyrobust
insofarasthereiscongruenceamongthetreesderivedfromworker-,queen-,andmale-basedcharactersets:
{(nigrocinctus+particeps)+{peperi+({satanicus+spinicola)+ferrugineuscomplex))). The"ferrugineus
complex"comprisesfivespecieswhosephylogeneticrelationshipsarenotfullyclarified. Thecompositedataset
(47charactersfromallthreecastes)supportsthefollowingpartialresolution:{ferrugineus+janzeni+{flavicornis
+{mixtecus+veneficus))). ThecladogramoftheP.ferrugineusgroupindicatesthatspeciationinthegrouphas
occurredprimarily asaconsequenceofgeographical isolation,andthattheantsandtheirhostacaciashave
experienceddiffusecoevolutionratherthanstrictcospeciation.
INTRODUCTION meritshaveappearedintheecologicalliterature.In
this paperI present ataxonomic revisionofthe
Pseudomyrmexferrugineus(F.Smith)andre- obligate acacia-ants {Pseudomyrmexferrugineus
latedspeciesofantsformawell-defined mono- group) and an assessment oftheir phylogenetic
phyleticgroup,themembersofwhichnestexclu- relationships. Ialsoattempttoclarifytheidentities
sivelyinthehollow,swollenthornsofseveralNew ofother,unrelatedspeciesofPseudomyrmexwhich
WorldAcaciaspecies. Becauseoftheiraggressive havebecomesecondarilyassociatedwithswollen-
behaviorandpredictableoccurrenceontheacacias, thornacacias.
these ants have received considerable attention Theearliertaxonomicliteratureonacacia-ants
fromtropicalbiologists(Belt1874;Safford1922; isscatteredinmorethanadozenpaperscontaining
Skwarra1934a.1934b;Wheeler1942;Janzen1966, descriptions of various species, subspecies, and
1973). The landmark studies ofJanzen (1966, "varieties". Twoofthemorecomprehensivetreat-
1967b)providedstrongexperimentalevidenceof ments are those ofEmery (1890) and Wheeler
themutualisticnatureofthePseudomyrmex/Aca- (1942). Inpresentingtheresultsofhisecological
ciaassociation,andtherelationshipbetweenthe studiesJanzen(1966, 1967b, 1973) summarized
two organisms is often cited in discussions of hisunderstandingofacacia-anttaxonomy. Ward
coevolvedmutualisms(e.g.Gilbert 1983;Beattie (1989) provided a brief diagnosis of the P.
1985; Futuyma 1986). At the same time, the ferrugineus group, together with taxonomic and
systematicsoftheacacia-antshasbeenneglected, nomenclaturalnotesonthecommonerspecies,
withtheresultthatmisidentificationsandmisstate-
118 JournalofHymenopteraResearch
MATERIALSANDMETHODS
Paris,France
Collections MZSP Museo de Zoologia da Universidade de
SaoPaulo,Brazil
NHMB
Materialforthepresentstudywasexaminedin Naturhistorisches Museum, Basel, Swit-
AthMefNoHlloAwmienrgiccoalnleMcutisoensu:mofNaturalHistory,New NHMVNzaetrulrahnidstorischesMuseum,Vienna,Aus-
York,NY,USA tria
ANSP Academy ofNatural Sciences, Philadel- PSWC P.S.WardCollection,UniversityofCali-
BMNHTphhiea,NPaAt.urUalSAHistory Museum, London, SEMC SfonroniwaEanttDoamvoilso,giCcAa,lUMSusAeum,University
U.K. ofKansas,Lawrence,KS,USA
CASC CaliforniaAcademyofSciences,SanFran- UCDC BohartMuseumofEntomology,Univer-
cisco,CA,USA sityofCaliforniaatDavis,CA,USA
CHAH C.H.A. HespenheideCollection, Univer- UCRC UCR Entomological Collection, Univer-
CISC CsiatlyiofforCnailaifoIrnsneicatatSLuorsveAyn,gelUensi,veCrAsi,tUySoAf USNM NsiattyioofnaClaliMfuorsneiaumatRoifveNrasitduer,alCAH,isUtoSrAy,
CUIC CCaolrinfeolrlniaUnaitvBeerrskietlyey,InCsAe,ctUCSoAllection, WPMCWWa.sPh.inMgatconK,ayDCC,olUleScAtion, El Paso, TX,
Ithaca,NY,USA USA
EBCC Estacion de Biologfa Chamela, Jalisco, ZMHB Zoologisches Museum, Museum fur
Mexico Naturkunde der Humboldt-Universitat,
FFIC dFeerBnoagnodtoa,FeCronlaonmdbeizaCollection,SantaFe ZMUCZBeorollino.giGsekrmaMnuyseum, University of
GBFM Graham B. Fairchild Museo de Copenhagen,Denmark
ZMUH
Invertebrados, Universidad de Panama, Zoologisches Institut und Zoologisches
Panama MuseumderUniversitat Hamburg, Ger-
GCWCG.C. & J. Wheeler Collection, Silver many
Springs,FL,USA ZSMC Zoologische Staatssammlung, Munich,
INBC InstitutoNacionaldeBiodiversidad(col- Germany
lectionspreviouslyheldinMNCR:Museo
NacionaldeCostaRica),SanJose,Costa Special mention should be made ofthe very
Rica largeandimportantseriesofPseudomyrmexcol-
INHS IllinoisNaturalHistorySurveyInsectCol- lectedbyD.H.Janzenfrom1963to1974andnow
lection,Champaign,IL,USA housed in the Natural History Museum ofLos
JTLC J.T.LonginoCollection,EvergreenState Angeles County (LACM). The Janzen material
College,Olympia,WA,USA includesalargenumberofpinnedspecimens(usu-
KSUC KansasStateUniversityInsectCollection, allygluedtothesideofthepinratherthanpoint-
LACM NMaatnuhraatltaHni,stKoSr,yUMuSsAeumofLosAngeles omvoeurnltaepdpi)nagndwainthexttheenspiivnenaeldcosheorliceosllbeucttiionnc(lpuadritnlgy
County,LosAngeles,CA,USA additionalaccessions). Janzen'sfieldnotesper-
MCSN MuseoCivicodiStoriaNaturale,Genoa, tainingtothecollectionoftheseantshavealsobeen
Italy deposited in LACM. Obligate acacia-ants (P.
MCZC MuseumofComparativeZoology,Harvard ferrugineusgroup)constitutethebulkofthecol-
University,Cambridge,MA,USA lectedmaterial.Theyoccuraslongnestseriesfrom
MHNGMuseum d'Histoire Naturelle, Geneva, throughoutCentralAmerica,withveryusefulqueen-
Switzerland male-workerassociations,makingthismaterialof
MNHNMuseum National d'Histoire Naturelle, inestimablevaluetothecurrentrevision.
Volume2,Number1,1993 119
When the Janzen collection was received at The following measurements and indices are
LACM in 1984 most specim—ens had only code citedinthisstudy(thefirstsixmeasurementsare
numbersassociatedwiththem amongthepinned takenwiththeheadinafull-face,dorsalview):
specimensasingleindividualpernestseriestypi- HW Head width: maximum width ofhead, in-
csaplelcyicmoenntsabieniendgaucnoladbeenlluemdb—era,nwdiitnhstohmeereinmsatiannicnegs VW cVleurdtienxgwtihdethe:yewsi.dthoftheposteriorportion
difficultiesaroseinretrievingfulldataforcoded ofthehead(vertex),measuredalongaline
specimensfromJanzen'sfieldnotes.Inothercases drawnthroughthelateralocelli.
thefieldnotescontradictedtheapparentidentityor HL Headlength:midlinelengthofheadproper,
compositionofanestseries. Thislatterproblem fromtheanteriorclypealmargintothemid-
appliedmainly topinnedspecimens;thealcohol pointofalinedrawnacrossthe•'occipital"
materialappearedtobereliablylabelledorcoded, (i.e.posterior)margin.
i.e.thecontentsofthevialsagreedwiththefield EL Eyelength: lengthofcompoundeye; note
notes.ThankstotheeffortsofRoySnellingand thatthisis measured with thehead in full
JackLongino,whoincorporatedtheJanzencollec- face,dorsalview,unlikeEW(below).
tionintotheLACM,manyofthesediscrepanciesor OD Ocellardistance:distancefromthemiddleof
uncertainties were resolved, but there remains a themedianocellustothemidpointofaline
residueof"problemmaterial"forwhichcollection drawnbetweenthelateralocelli.
dataarelackingorambiguous. Amongthepinned OODOculo-ocellar distance: distance from the
specimens this comprises twelve drawers in the middleofthemedianocellustothemidpoint
LACMcollectionwhichhavebeenspecificallyset ofalinedrawnacrosstheposteriormargins
asidefromthemaincollection. Noneofthisprob- ofthecompoundeyes(thisdistanceisnega-
lematical material has been cited in the present tiveinvalueiftheposteriormarginofthe
study,butIhaveexamineditanddeterminedthat compoundeyeexceedsthemedianocellus).
noadditional speciesarerepresentedthere. Al- MFC Minimumfrontalcarinaldistance:minimum
thoughomissionofthismaterialmeansthepoten- distancebetweenthefrontalcarinae,poste-
tiallossofsomelocalitydata,Ihaveexaminedthe riortotheirfusionwith,orapproximationto,
entirealcoholcollectionandpoint-mountedrepre- theantennalsclerites.
sentativesamplessothatgeographiccoveragere- ASD Antennal sclerite distance: maximum dis-
mainsextensive.ThemainpinnedseriesofLACM tancebetweenthelateralmarginsoftheme-
acacia-ants,i.e.thatforwhichaccuratedatalabels dianlobesoftheantennalsclerites,measured
areavailable,comprises30drawersandapproxi- infull-face,dorsalviewofthehead.
mately 20,000 specimens, the great majority of ASO Antennal sclerite distance, outer margins:
whichwerecollectedbyJanzen. maximumdistancebetweentheouter,lateral
marginsoftheantennalsclerites.
MetricMeasurementsandIndices CLWWidth of median clypeal lobe, measured
between the anterolateral angles (in
All measurements were made under a Wild Pseudomyrmexsatanicus and P. spinicola
microscopeat50Xpower,usinganorthogonalpair only;seeFigs. 10, 11).
ofNikonmicrometerswiredtoadigitalreadout. MD4,MD5.MD8.MD9 Aseriesofmandibular
Measurementconventionsfollowthosedescribed measurements (see Ward 1989, figure 2).
in Ward (1985, 1989). Note that a full-face or MD4: distancealongthebasalmarginofthe
dorsal viewoftheheadinvolvespositioningthe mandiblefromthebasetothemesialbasal
posterior margin and the anterolateral margins tooth;MD5:lengthofthebasalmargin;MD8:
(abovethemandibularinsertions)sothattheyliein distancealongthemasticatorymarginfrom
thesameplaneofview. theapextothefourthtooth,countingfrom
theapex;MD9: lengthofthemasticatory
margin.
120 JournalofHymenopteraResearch
EW Eye width: maximum width ofcompound PL Petiole length: length ofthe petiole, mea-
eye, measured along its short axis in an suredinlateralviewfromthelateralflanges
obliquedorsolateralviewofthehead. oftheanteriorpeduncletotheposteriormar-
SL Scape length: length ofthe first antennal ginofthepetiole(seeWard1985,figure4).
segment,excludingtheradicle. PND Petiolar node distance: distance from the
LF1 Lengthoffirstfunicularsegment:maximum lateral flanges ofthe anterior petiolar pe-
measurablelengthofthefirstfunicularseg- duncletothemaximumheightofthenode,
ment(pedicel),includingitsbasalarticula- measured from the same view as PL and
tioninworkersandqueensbutexcludingthe along the same line ofmeasurement (see
basalarticulationinmales(whereitisusu- Ward1985,figure4).
allyhidden). PH Petioleheight:maximumheightofthepeti-
LF2 Lengthofsecondfunicularsegment:maxi- ole,measuredinlateralviewatrightangles
mum measurable length of the second toPL,butexcludingtheanteroventralpro-
funicularsegment. cess.
LF3 Length of third funicular segment: maxi- PPL Postpetiolelength:lengthofthepostpetiole,
mummeasurablelengthofthethirdfunicular measuredinlateralview,fromtheanterior
segment. peduncle(ofthepostpetiole)tothepointof
WF2 Widthofsecondfunicularsegment. contactwiththe fourthabdominal tergum,
FL Profemur length: length of the profemur, excluding the pretergite (see Ward 1985,
measured along its long axis in posterior figure4).
view(seeWard1985,figure3). DPWDorsalpetiolarwidth:maximumwidthofthe
FW oPfrotfheemuprrowfiedmtuh:r,mamxeaismuurmedmefarsuormabtlheewsiadmteh MPWpMeitinoilem,ummeapestuiroeladriwniddtohr:samlivniiewm.umwidthof
view as FL, at right angles to the line of thepetiole,measuredindorsalview,anterior
measurementofFL. toDPW.
DPL Diagonallengthofthepropodeum:lengthof PPW Dorsalpostpetiolarwidth:maximumwidth
the propodeum, measured in lateral view ofthepostpetiole,measureindorsalview.
along a diagonal line drawn from the LHT Lengthofmetatibia:maximummeasurable
"metapleural"lobetothemetanotalgroove lengthofmetatibia,excludingtheproximal
(seeWard1985,figure2). partofthearticulationwhichisreceivedinto
BF Length ofthe basal (=dorsal) face ofthe thedistalendofthemetafemur(seeWard
propodeum,measuredinlateralviewfrom 1989,figure5).
the metanotal groove to the point on the CI Cephalicindex:HW/HL
surface ofthe propodeum which is maxi- 01 Ocularindex:EW/EL
mally distant fromthe diagonal propodeal REL Relativeeyelength:EL/HL
line. REL2Relativeeyelength,usingHW:EL/HW
DF Length of the declivitous face of the 001 Oculo-ocellarindex:OOD/OD
propodeum,measuredinlateralviewfrom VI Vertexwidthindex:VW/HW
the "metapleural" lobetothe pointon the FCI Frontalcarinalindex:MFC/HW
surface ofthe propodeum which is maxi- FCI2 Frontalcarinalindex,usingASD:MFC/ASD
mally distant from the diagonal propodeal ASI Antennalscleriteindex:ASD/ASO
line. SI Scapeindex:SL/HW
MP Depthofmetanotalgroove("mesopropodeal SI2 Scapeindex,usingEL:SL/EL
impression"),measuredinlateralviewfrom FLI Funicularlengthindex:(LF2+LF3)/WF2
thebottomofthemetanotalgroovetoaline FI Profemurindex:FW/FL
drawn across the dorsal surface of the PD1 Propodealindex:BF/DF
mesonotumandpropodeum. MPI Metanotalindex:MP/HW
NI Petiolenodeindex:PND/PL
Volume2,Number1,1993 121
PLI Petiolelengthindex:PH/PL
PLI2 Petiolelengthindex,usingPPL:PPL/PL CladisticAnalysis
PWI Petiolewidthindex:DPW/PL
PWI2 Petiolewidthindex,usingPPW:DPW/PPW A setof47 characters, representingthe most
PWI3 Petiole width index, using MPW: MPW/ discreteorquantifiabledifferencesamongspecies
DPW orgroupsofspeciesintheP.ferrugineusgroup,
PWI4 Petiole width index, using LHT: DPW/ was used forphylogenetic analysis. Twenty of
LHT thesecharacterswereworker-based(11 ofthese
PPWI Postpetiolewidthindex:PPW/PPL manifestedthesameconditionsinqueens),8were
queen-based,and 19weretakenfrommalemor-
OtherConventions phology,primarilymalegenitalia. Thecharacters
andcharacterstatesareasfollows:
OtherterminologyfollowstheusageinWard
(1989). Notethatdescriptionsofsurfacesculpture 1. Worker, median clypeal lobe (0) laterally
andintegumentreflectanceapplytoobservations roundedorsubangulate,(1)laterallywithsharp
madeundersoftlight,withanopaque(Mylar)filter anglesorteeth(Figs. 10, 11).
placedbetweenthespecimensandsourceofillumi- 2. Workerandqueen, frontal carinae (0)rela-
nation. Palpformulareferstothenumberofmax- tivelywellseparated,medianlobesofanten-
illary palp segments followedby the numberof nalscleriteslessexposed(Figs.12-19,32),(1)
labialpalpsegments;5p4,3indicatesacondition closelyadjacentandmedianlobesofantennal
intermediatebetween5,3and4,3,i.e.partialfusion scleritesmoreexposed(Figs. 10, 11,32).
ofthefourthandfifthmaxillarypalpsegments. 3. Workerandqueen,palpformula(0)5,3,(1)
Listingofsynonymyundereachspeciesisre- 4,3.
strictedtocitationoftheoriginaldescriptions(with 4. Worker,head(0)broader,relativetoHL,DPL
jfuulnliorrefseyrneonnceymgsi)veanndfonrewallnopmreenvcilouastluyraplrcoopmobsie-d DanPdLPLa,nd(1P)LnaornroHwWer;(Fsieges.re3g6r-e3s8s)i.onsofHL,
nations. Forecologistsamoreusefulsummaryof 5. Worker,scape(0)short,relativetoHL. (1)
nameusageisofferedinTable 1,whichindicates longer;regressionofSLonHLlyingabove
thecorrespondencesbetweenthenamesappearing thatofotherspecies.
inthebiologicalliteratureonacacia-antsandthe 6. Worker,conspicuouspit-likeimpressionon
currentlyvalidscientificnames. Thereaderwill midlineofhead(0)absent.(1)present.
appreciate that there has been considerable 7. Worker,petiole( )shortrelativetopostpetiole.
misidentificationoftheseants. PLI2 0.77,(1)longerrelativetopostpetiole,
Inthelistsofmaterialexaminedofeachspecies, PLI2<0.77.
I have cited only locality and collector ("c.u." 8. Workerandqueen,petiole(0)withoutawell
signifiescollectorunknown),withthesourcecol- differentiatedanteriorpeduncle, i.e. weakly
lectionslistedtogetheratthebeginning.Additional constrictedindorsalviewandwithlittleorno
localityinformationissometimesprovidedinsquare inflectionoftheanteriorfaceofthepetiolein
brackets,tofacilitatelocationofthecollectingsite. lateralprofile(Figs.22,23),(1)withawell
Considerableeffortwasexpendedtodeterminethe differentiatedpeduncle(Figs.20,21,24-29).
coordinates(latitudeandlongitude)ofeachcollect- 9. Worker and queen, petiole, dorsal view,
ingsite,andthiswasthenusedinconjunctionwith angulateposterolateralcorners(0)absent,(1)
the public domain software program Versamap moderatelydeveloped,precededbyconvexor
(version 1.20) to plot the distributions of each sinuatesides(e.g.Figs,20,27),(2)verypromi-
species(Figs.67-72). nent,precededbymoreorlessstraightsides
(Fig.24).
10. Worker and queen, petiole (0) shorter and
higher,workerPLI 0.71,queenPLI 0.64,
122 JournalofHymenopteraResearch
(1)moreslender,workerPLI<0.72.queen HLlyingabovethatofotherspecies.
PLI<0.64. 27. Queen, metatibia (0) short, relative to HL,
11. Worker,DPWrelativetoHW(0)narrow,(1) LHT/HL<0.62,(1)longer,LHT/HL>0.66.
12. WbDroPorakWdeerro,,npH(l2o)Wtvo(eFfriygP.Wb4Ir1o)3a.db;ysHeeWrelgyriensgsiionn(o0)f 28. Ql31ou)ne.geenr,;mseeteatriebgiraes(s0i)osnhoortf,LreHlTatiovnetHoHWW,(Fi(g1.)
13. ouWfpoprFeikrge.lre3fa9tn.(d1q)uleoewne,rprliogthtof(2P)WlIow4ebryleHftWrelgyiionng, 29. MHa0W.l9e6,<(0hr.ee9ag6rd,e(s(s10i))obnrnoaoarfdreHorwL,erCo,InCH0I.W904.l8ay2ni-dn0/g.o9br4eHlaoWnwd
in(0)centerandlowerright(1)upperleft(3) thatofotherspecies).
14. Wloowrekrerl,eftporsetgpieotni,oloef(F0i)g.br4o0a.d,PPWI>1.30, 30. 0M.a3l5e,,asncdapreegirnedsesxio(nSIo)f(S0L)0o.n22H-0W.3l0y.in(g1)a0b.o2v9e-
15. rW(eo1lr)aknteiavrrer,loymwe,ltoaPntgPi;bWisIeae(10r.)e0gs0hr-oe1rs.ts3,i0r.oenlaotfivLeHtToHoLn,H(1L) 31. tlMhoaanltge,o,fSsIoc2tahp0ee.r4l3se-pne0gc.ti5he6,s,.reSlLat/iHvLeto0E.2L2,an(d1)HL(0)
(Fig.30). shorter, SI2 0.33-0.43, SL/HL 0.21 (and
16. Workerandqueen,headsculpture(0)densely regressionofSLonHLlyingbelowthatof
punctulate,subopaquetosublucid,atleaston otherspecies). HW
upperthirdofhead,(1)densely punctulate. 32. Male,compoundeyelength,relativeto
o(mpaatqtuee)., (3) punctulate-coriarious, opaque 0(0.)49l-o0n.g5,8,RaEnLd2re0g.r5e6s-s0i.o6n3,of(1E)LshoonrtHerW,RlEyiLn2g
17. Worker and queen, propodeum, posterolat- belowthatofotherspecies.
eralportions(0)sublucid.withoutoverlying 33. Male,petiole(0)lessslender.PLI>0.45,(1)
roupgauqluoe-,puwnictthatreuguscluol-pptuunrcet,at(e1)scsuulppotupraeq.ueto PmoHreansdleDndPerW,PoLnIL<H0T.50l,yianngdbreelgorwestshioosnesooff
18. Workerandqueen,petiolarnode(0)lacking otherspecies.
conspicuous suberect pubescence, (1) with 34. Male,sterniteIX,posteriormargin(0)con-
suchpubescence. vex,(1)withamoderateconcavity,lessthan
19. Workerandqueen,standingpilosityonexter- semicircular(Fig.54),(2)withadeep,semi-
nalfacesoftibiae(0)present,(1)absent. circularconcavity(Fig.55).
20. Workerandqueen,headandgaster(0)yel- 35. Male, paramere, lateral view, posterodorsal
low-toorange-brown,(1)reddish-brownto extremity(O) rounded, (1) angulate or ex-
mediumordarkbrown,(2)verydarkbrownto panded.
black (excluding mandibles, clypeus and 36. Male, paramere, lateral view, posterodorsal
21. sQcuaepeen),.siHzeW(0)small,HW 0.85,(1)medium jeexcttrienmgitcyau(d0a)d,noatspirnojFeicgtsi.n5g6c,a5u7d.ad.(1)pro-
tolarge, 0.85. 37. Male, paramere, lateral view, posterodorsal
22. Queen,headshape,foragivenLHT(0)elon- extremity (0) not developed as a lobe-like
gate,(1)lesselongate,(2)broad(seeFig.52). protrusion,whosemesialfaceisasaucer-like
23. QHuWeen<,0p.e7t1i,o(l1e)(l0o)nsgheorr,t,PrLe/laHtiWvet0o.7H1.W,PL/ 38. cMoanlcea,viptayr,a(me1r)es,odlaetveerlalopveidew(,Figpso.st6e1r-o6d6o)r.sal
24. Queen,petiole(0)short,relativetoHL,(1) extremity(0)wellseparatedfrommesiodorsal
25. Qlounegeenr,:sreeegrreesgsrieosnsioofnPoHfPonLHonWHlLyi(nFgigi.n46()0.) alonbae,rr(o1w)cslpoasceetboemtewseieondoirtsaanldltohbee,leonbecl(oFsiignsg.
upper(1)middle(2)lowerregion,inFig.47. 58,61-66).
26. Queen,petiole,dorsalview(0)narrow,rela- 39. Male,paramere,digitiformmesiodorsallobe
tivetoHL,(2)broader;regressionofDPWon (0)absent,(1)present,slender,directedposte-
Volume2,Number1,1993 123
riorlyorposterodorsally(Figs.56-60,63-65), weakridgeorcarina, (2) with acentral el-
(2)present,stubby,directedmoreorlessdor- evatedarea,delimitedposteroventrallybya
sally(Figs.61,62). stronglamellatecarina.
40. Male,paramere,mesialfaceofposterodorsal 46. Male, aedeagus, external face, afore-men-
extremity(0) simpleinform,notexpanded tionedcarina(ifpresent)(0)well separated
mesially, (1) expanded mesially, partly ob- fromthetoothedposteriormargin,(1)running
scuringthemesialdorsoventralridgeinposte- close to and more orless parallel with the
riorview. toothedposteriormarginbutseparatedbya
41. Male,aedeagus,posteriormargin(0)entire, deepgroove,(2)convergingposterodorsally
notmediallypointed,(1)toothed,andmedi- withthetoothedposteriormargin.
allypointed. 47. Male,aedeagus,posteroventralextremity(0)
42. Male, aedeagus, posterior margin (0) bent broadlyrounded,(1)subangulate,(2)angulate
posterolaterally,(1)bentanterolateral^,(2) withatooth-likeprotrusion.
bentanterolaterallybutwiththemedialpoint
redirectedposteriorly.
43. Male,aedeagus,laterallybentportionofpos- ThedatasetwasanalyzedusingFairis'Hennig86
teriormargin(0)continuouswiththemargin program.Characters12,13and16wereconsidered
oftheposterodorsalextremity.!1)discontinu- unordered. AsanoutgroupIchosePseudomyrmex
ouswithmarginofposterodorsalextremity fervidus (F. Smith), a Central American species
(elevated laterally),thetwoconnectedbya whichsharesanumberof(mostlyworker)features
gradualslope,(2)discontinuouswithmargin incommonwiththeP.ferrugineusgroup:5,3palp
ofposterodorsalextremity,elevatedlaterally, formula,similarmandibulardentition,welldevel-
andseparatedby atrenchantrise (posterior oped metanotal groove, abundant pilosity on
view)fromtheposterodorsalextremity. mesosoma dorsum, relatively small eyes, and a
44. Male, aedeagus, plate-like expansion of similarhabituswithrespecttosizeandcolor. Ina
posterodorsalextremity(0)absent,(1)mod- few instances the outgroup species spanned the
eratelydeveloped,(2)stronglydeveloped. phenotypicgapbetweentwodiscretestatesinthe
45. Male,aedeagus,externalface(0)withouta ingroup; it wasthencoded as unknown forthat
large,centralelevatedarea,(1)withacentral character. Inadditiontoseekingthemostparsimo-
elevatedarea,delimitedposteroventrallybya nioustreefortheentiredataset(rootedwiththe
outgroup),Ialsocomparedthecladogramsbased
onthreesubsets,derivedfromtheworker,queen,
and male characters sets, respectively. Forthis
secondanalysisthequeencharactersetincluded
theeightcharactersassessedonlyinqueens(21-28)
plusthosemanifestedidenticallyinworkersand
queens (2, 3. 8-10, 13, 16-20), foratotal of 19
characters.
124 JournalofHymenopteraResearch
Figs. 1-9. Pseudomyrmexworkers,lateralviewofmesonotum,propodeumandpetiole,withpilosityshownin
outline;Figs.4and5includeafrontalviewofworkerhead.1,P.boopis(CostaRica);2,P.ita(CostaRica):3,P.
kuenckeli(CostaRica);4,P.hesperius(Mexico,paratype);5.P.opaciceps(Guatemala,paratype);6,P.gracilis
(Mexico);7.P.nigropilosus(CostaRica);8.P.reconditus(Nicaragua,holotype);9,P.simulans(Panama).
Volume2,Number1,1993 125
mm
1
Figs. 10-19. Pseudomyrmexferrugineusgroup,workers,full-facedorsal(=frontal)viewofheadwithpilosity
showninoutline(exceptonmandibles);Fig.19includesalateralviewofhead.10,P.satanicus(Panama);11.P.
spinicola(CostaRica);12,P.peperi(Guatemala);13,P.nigrocinctus(CostaRica);14,P.particeps(CostaRica,
holotype); 15.P.mixtecus(Mexico,holotype);16,P.flavicornis(Nicaragua);17,P.veheficus(Mexico); 18,P.
ferrugineus(Mexico);19.P.janzeni(Mexico,holotype).
126 JournalofHymenopteraResearch
-V~
mm
1
Figs. 20-29. Pseudomyrmexferrugineusgroup, workers,dorsal view ofpetiole paired with lateral viewof
mesonotum,propodeum,petioleand,inFig.28,postpetiole.Standingpilosityshowninoutline.20,P.satanicus;
21,P.spinicola;22,P.nigrocinctus;23,P.particeps;24,P.peperi;25,P.flavicornis;26,P.mixtecus;27,P.
ferrugineus;28,P.veneficus;29,P.janzeni.ThesearethesameindividualsillustratedinFigs.10-19.