Territoriality and Mating Behavior of Sphex pensylvanicus L (Hymenoptera: Sphecidae)

10 Pages·1998·3.6 MB·English

by  F E Kurczewski

J.HYM.RES.
Vol.7(1),1998,pp.74-83
Territorialityand Mating BehaviorofSphexpensylvanicusL.
(Hymenoptera: Sphecidae)
FrankE.Kurczewski
EnvironmentalandForestBiology,StateUniversityofNewYorkCollegeofEnvironmental
ScienceandForestry,Syracuse,NewYork13210-2778,USA
—
Abstract. DailyobservationsweremadeonnineindividuallymarkedmalesofSphexpensyl-
vanicusinupstateNewYorkduring25July-8August1982.Malesoccupiedterritoriesonornear
agrateatopastormsewerdraininwhich12femalesnested.Theyobtainedhoneydewatamaple
treeandsleptandfedonwhitesweetclovergrowingonanearbyhillside.Thefollowingmain-
tenanceandreproductiveactivitiesofmalesweredefined:(1)perchingatstations,(2)swivelling,
(3)cleaning,(4)wingraising,(5)defecating,(6)spontaneousflights,(7)feedingflights,(8)pounc-
ingonconspecificmales,(9)pursuitflights,(10)grappling,(11)trailingconspecificfemales,(12)
claspingconspecificfemales,and(13)copulation.Aggressiveinteractionsbetweenterritorialcon-
specificmalesoccupiedmoretimethanallothermaintenanceandreproductiveactivitiescom-
bined.
Almost nothing was known about the nesting may extend for several weeks in
behaviorofmalesolitarywaspsuntilLin's certain species of Sphecidae (Hager and
(1963)studyofmaleterritorialityinSplie- Kurczewski 1986, Kurczewski 1997), cop-
ciusspeciosus(Drury),thecicadakiller.Re- ulations in most species take place only
centinterestinmalebehaviorsurfacedfol- duringthefirstweekortwo.Themajority
lowingtherevivalofDarwin's(1859)sex- ofcontactsbetweenmalesandfemalesdo
ual selection theory, especially as cham- not end insuccessful copulation(O'Neill
pioned by Trivers (1972) and his 1979). Once females are actively nesting,
contemporaries.Theactivitiesofmalesol- they rebuff all attempted matings by
itarywaspsareprimarilyaimedatobtain- males(EvansandO'Neill1988).Therela-
ingmatings.Malesfeedonnectar,reston tive low fecundity of the females may
plants or inburrows, orbask in the sun mean that they actually gain little from
whennotinpursuitoffemales(Evansand additionalmatings(O'Neill 1985).Alcock
O'Neill 1988). Males of most species of etal.(1978)addressthecostsandbenefits
Sphecidae are free from parental duties associated with multiple matings in spe-
and their reproductive success is solely ciesofaculeateHymenoptera.
determined by the number of eggs they Territoriality, as defined by spacing,
fertilize. In other words, males of most maintenance of stations, and aggressive
speciescontributelittlemorethangenesto encounters between conspecific males,
theiroffspring. doesnotoccurinallsphecidwasps(Hag-
Malesolitarywaspstendtoemergebe- erandKurczewski1985).But,itcanbeex-
forethefemales,aphenomenonknownas aggerated in some species (Minkiewicz
protandry (Evans 1966). Circumstantial 1934, Lin 1963, Evans and O'Neill 1988).
evidence suggests that females of most Malesmayestablishstationsorterritories
diggerwaspsmateonlyonceduringtheir nearprominentlandmarksontheground
lifetime (Alcock et al. 1978). Although (Astata,Minkiewicz1934;Tachysphex,Kur-
Volume7,Number1,1998 75
czewski 1966) or emergence holes {Splie- chronologically sequenced and described
ciiis, Lin 1963), or they may scent mark individual male behaviors, especially
plants to attractfemalestoasite (Philan- thoseconnectedwithspacing,aggression,
thus, EvansandO'Neill 1988).Theestab- and copulation, and attributed possible
lishment and maintenance of stations or significancetothem,therebyaddingtothe
territories clearly facilitates mating be- overallknowledgeofmalebehaviorinthe
tween resident males and females in the familySphecidae.
vicinity(Alcocketal. 1978). METHODS
Studiesonthebehaviorofmalesolitary
waspslagfarbehindthoseonfemalenest- MalesofS.pensylvanicuswereobserved
ing behavior (Evans 1966, Alcock et al. onadailybasis,weatherpermitting,from
1978, EvansandO'Neill 1988). Malesoli- 25Julyto8August1982from0730to2100
tarywaspsareoftensmaller,shorterlived, hrs(EDT). Thestudyareawasexamined
anddonotmaintainanestmakingthem beforeandafterthesedatesandtherewas
more inconspicuous to the average ob- no sign of male activity. One must as-
server(Kurczewski1966,HagerandKur- sume, therefore, that the males had not
czewski1985).AmongthespeciesofSphe- emerged before 25 July and either had
cinae (R. Bohart and Menke 1963, 1976), diedorlefttheareaafter8August. Nine
manyofthestudiesonmalebehaviorin- maleseachwerecolor-codedbyplacinga
volve thegenusAmmophila (Turner1912, dropofTester'smodelpaintontheirme-
Baerends 1941, G. Bohart and Knowlton soscutum with a tiny paint brush from
1953,Olberg1959,Powell1964,Hagerand which had been removed most of the
Kurczewski 1985). Little is known about hairs. The activities of these males were
territorialityandmalebehaviorinthege- observedandrecordedatornearastorm
nusSphexincludingthenearcticS.pensyl- sewergrateforatotalof62.5hrsduring
vauicusLinnaeus,theGreatBlackWaspof 10 ofthe 15 days that they were in evi-
JohnBartram(Rau1944).RigleyandHays dence. The individual life spans of the
(1977) noted dominance, grappling, and nine males was only 10-14 days, with
attemptedcopulationinafewmalesofS. three males living an entire two-weeks-
peiisi/lvanicus. Gillaspy (1962) described long period. I similarlymarked all 12 fe-
matingbehaviorinthenearcticS. tepane- malesfromthisaggregationthusyielding
cus Saussure. Janvier (1928) noted perch- asecondarysexratioof3:2infavoroffe-
ingandgrapplingintheneotropicalS.la- males. One male and one female each
treillei Lepeletier. Surprisingly, nothingis were collected before individually mark-
known of male behavior in a common ing them and placed as voucher speci-
nuesa)r(cBtircocskpmecainens,19S8.0)i.chneutiioneus (Linnae- mUneinvsersiintythoefiNnseewctYmourskeCuomlleogfetohfeESntvait-e
Mypaperpresentsnewandinteresting ronmentalScienceandForestry,Syracuse,
informationonthebehaviorofmalesofS. NewYork.
pensi/lvanicus and provides a verbal out- Territoriality in this species facilitated
line of the mating system employed by simultaneous observation of all nine
thisspecies.Theliteratureonreproductive males;however,sometimewasallocated
behavior in sphecids is depauperate and toobservecertainfocalmalesmoreexten-
observationssuchasthosereportedherein sively during fixed observation periods.
areneeded torectify thissituation.Terri- Individualmalebehaviorsweredescribed
torialityand matingbehaviorinthisspe- andchronologicallysequenced.Particular
cieswereobservedconcurrentwithanin- emphasiswasplacedonreproductivebe-
vestigationonthesequentialdailyactivi- havioras itoccurred neara stormsewer
ties of the females (Kurczewski 1997). 1 drain in which the females nested. Less
76 JournalofHymenopteraResearch
emphasis was placed on male mainte- alitbrieflyonorenteredthroughopenings
nancebehaviorssuchasfeeding,sleeping, inthesewergrate,butthenquicklyexited
and basking in the sun that took place andflewtosleepingroosts.Malesdidnot
awayfromthissite. maintainstationsatornearthegratedur-
EMERGENCEANDLOCATIONOF ingthistime.Theydidnotmakeextensive
STUDY andintricateflightsforthepurposeofori-
entationtotheimmediateenvironsasdid
Both males and femalesemerged from the provisioning females (Kurczewski
soilnearabrokentileatthebottomofthe 1997).
sewerdrainsituated inanasphaltdrive- MALEACTIVITY
way beside the Marcellus Senior High
School, Marcellus, Onondaga County, ThefollowingactivitiesofmaleS.pen-
New York. Three males emerged on 25 sylvanicusweredelineated:(1)perchingat
July1982,twodaysbeforethefirstfemale stations, (2) swivelling, (3) cleaning, (4)
appeared.Theemergencesoftheothersix wingraising, (5)defecating,(6)spontane-
malesshortlythereafter(27-31July 1982) ousflights, (7)feedingflights, (8)pounc-
were interspersed among those of early ing on conspecific males, (9) pursuit
emerging females. Behavior that repre- flights,(10)grappling,(11)trailingconspe-
sented aspects of territoriality such as cific females, (12)claspingconspecificfe-
spacing,maintainingstations,andaggres- males,and(13)copulation.Definitionand
sion between conspecific males was fo- significance of these activities are as fol-
cusedona70 X 70cmgrateatopthe70 lows: —
cm-deepdraininwhichthefemalesnest- (1)Perchingatstations. Malesperched
veidsi(tFeidg.am1,apKluerctzreeews1k3im1s99o7u)t.hMofaltehessaelws-o hoinnodrlengesarotuhtestsreewtecrhegdratyeetwitrhaimsiedd-aanndd
erdraininordertoobtainhoneydew,and wingsfoldedflatonthedorsum.Theype-
s(lwehpitteansdwefeetdcaltovaers)ta5n5dmofaMewlaiylot(uFsig.alb2a, briooddyicaflrlyommsoivdeedtothseiidre.hWehaidleorpearnctheirnigo,r
Kurczewski1997).Bothmalesandfemales malesmovedtheirantennaeorheldthem
fed on the flowers ofotherplantspecies still inan upward and outward attitude.
nearbybutnotasfrequentlyasattheflo- Theforelegswereeither"fishhooked"me-
rets of white sweet clover, probably be- diallyorheldbackwardbeneaththebody,
cause thisspecieswasmoreabundant in raised above the substrate, and moved
thevicinity(Kurczewski1997). back and forth slowly or in short rapid
Theninemaleslefttheirsleepingroosts bursts. Positioningbycertainmalesclose
onwhitesweetcloverdailyonwarmsun- tothegrateopeningsgavethemadecided
ny days, occasionally fed on nectar or advantage over males stationed farther
baskedinthesun,andthenmadelowcir- awaywithrespecttoaccesstoenteringor
cling or figure-8 flights over the sewer exitingfemales.Thesemalessubsequently
grate as early as 0828-0837 hrs (EDT) at obtained more claspings and copulations
an air temperature as low as 16°C. They thanmalesstationedfartherfromthesew-
stationed themselvesonand/ornearthe ergrate(seebelow).
grate from0845 to 1643hrs, and onceas Following emergence and through the
late as 1818 hrs, at air temperatures of first week of nesting, males maintained
16.5-26°C. Males interrupted this territo- stationsnearthefemalenestingsite.Males
rialactivitytofeedontheflowersofMel- spentmuchtimeatapreferredsiteorsta-
ilotusalbafrom1125to1800hrsatairtem- tion; however, most males maintained
peratures of 23-26°C. They circled the severalstationsincloseproximitymoving
draininflightbetween1819and2019hrs. from onetoanotherthroughout theday.
Volume7,Number1,1998 77
—
On27July1982,fivemalesperchedatsta- (2) Swivelling. Males often moved or
tionsonornearthesewergrate. Twoof turnedtheirentirebodytofaceinaslight-
the males occupied oppositeends of the lydifferentdirection.Thismovementwas
grate,beingonly50-70cmapart.Theoth- made so smoothly that the wasps ap-
erthreemaleswerelocatednearthegrate pearedtobeonaswivel.Swivellingwas,
altesscatrhdainnal1 pmoinftrsomofthtehetwcoompmaasless,.eTahceh Cthhearnegfoere,inavarnatmaigfeicagtrioounndofbpyerccehritnagi.n
malesnearthegratewerenotallowedto malesmayhaveensuredthattheywould
approachthemalesonthegrateanycloser notmissviewingfemalesapproachingor
thanthiswithoutbeingchasedaway.On exitingthedrai—n.
thefollowingday, fouradditional,newly (3)Cleaning. Malesfrequentlycleaned
egrmaetregleedssmtahlaens1tomokfruopmstthaetioolnsdenremaarletsh.e tmhoeuitrhpaanrttesnnwaiet,h cthoempfooruelnedgs,eyaensd, tahenidr
Nstianteionmsalweisthninowadmiaaimnettaeirneodf2onmeforrommotrhee Wwiinnggsanadndabadbodmionmaelnclweiatnhintghfeolhlionwdeledg6s3.
grate. The two males stationed on the flightsduringwhichamalepursued an-
grate and a third male nearest the grate other male, female, orother insect. Only
perchedattheirstationsforperiodsof20- five times did a male land from such a
150 min (x = 37.9 min, n = 37 observa- flight without cleaning. Cleaning of the
tions),exceptforchasingawayconspecific antennae, eyes, and mouthpartsoccurred
males, females, and other insects, and seeminglyspontaneouslywithorwithout
making periodic flights with no discern- thepresenceofan—otherinsect.
ible function. The six most peripherally (4)Wingraising. Malesperchingatsta-
situatedmales,ontheotherhand,perched tionsoftenheldthewingsoutwardatan
for an averageofonly3.8 (<l-7)min (n angleorraised and flicked thewingsre-
= 41)and then flew away for 1-71 (x = peatedly.Theformerbehaviorwasnotob-
32.4,n=41)minbeforereturning.Inoth- served tobe associated with any specific
erwords,thethreemalesnearestthegrate incident. Sixty-one times wing flicking
spent most of their time on or near it was associated with the appearance ofa
whereas thesix malespositioned periph- conspecific male, female, or other insect.
eral to the grate occupied most of their Aftertheintruderpassedby,theperched
timeawayfromit. male either lowered the wings onto the
Thetwomalesperchingonthegrateof- dorsumorcleanedthewingswiththehin-
tenapproachedtowithin30cmofonean- dlegsandthenloweredthem.Raisingand
otherwithoutanyapparentsignofinter- flickingthewingsfollowedbywingclean-
ference between them. When one of the ing invariably followed the pursuit in
males flew away to feed, the othermale flight of another male and landing (see
encroached on his territory oftentempo- above).Thetwomalesstationedonly50-
rarilyappropriatingsomeofthestations. 70 cm apart on the grate often wing
Suchreplacementimpliesthatmalescom- flickeduponvisiblemovementoftheoth-
pete for stations, the defense of which er. Raising and flicking the wings may
Tclheearlsyparceipnrgesednitsstaancfeorofmaofbotuetrri1tormialibtey-. htoavfleyraseptrheissebnetheadviaonriwnatsentpieornfomromveedmuesnut-
tween most territorial conspecific males allyattheappearanceofanothermale,fe-
probably diminished theamount and in- male,orotheri—nsect.
tensity of aggressive interactionbetween (5)Defecati)ig. Thetwomalesstationed
them and thereby increased their chance onthesewergrateforlongperiodsoftime
for successful copulation but 1 have no periodically discharged a viscous liquid
concreteevidencetosubstantiatethis. from theanustoadistanceof 10-20cm.
78 JournalofHymenopteraResearch
Often, this fluid was squirted in two or one another. Thisbehaviormayhavere-
three directions by the wasp moving his inforcedthespacing—ofindividualmales.
a2.b1(,d6)onmS=epon7n8tt)aomnaienosu,hsgahflmtilagyhltesd.im—fafeEdrveeenratysahn1og-rl8et.b(xrie=f sqtuae(t9ni)tolnPysurfnsleueaiwrtafttlhioegthhtfsee.rmamlaMelaelnseessftliyminangignstcialtoiesnefirntego-
falwigahytforfomnohisdisstcaetrinoin,blteurfnuendct1i8o0n°,dainredctrley- tthheeyseawpeprrogarcatheedortaotonceliogsehlbyo.riTnwgomawlaesspisf
turned along the same route to resume stationedonthegrateperiodicallychased
paemrechtienrg.inSulecnhgtflhigahntdswoefroenloyfte1n-2lessesctdhua-n mouosreorpefriigpuhreer-a8llfyliglhotcsa,te1d-2mamlesabionvesitnhue-
raTashtei3oy-n6,wmbeurtaenodcucssaesuviaeolrnlaaylllsmyeactdohneedyswinienreddiufarfsaetrlieoonnntg., tsgphrieorsuaenldff,lliiggthhottss,di3ts-rtAaannmscefhsoirgomhfe.d3C-oi5nnttmoi.nausSocuoesmnedpiunrog-f
sometimesopposite,directionsfromasta- suitflightssometimeslastedforaslongas
tion.Possiblefunctionsoftheseflightsin- 1.5 min. Regardless of the form of the
clude movinginto cooler strata ofair to flight,asmanyasfourorfivemalespar-
reducebody temperature or surveillance ticipated ina singlechasewith distances
oftheimmediateareaanditsoccupants. of20-30cmseparatingindividualsintan-
Other flights made by males were dem. After several seconds, such flights
slower,moredeliberate,andlongerindis- brokeup into pairsofmalesorthree in-
tance and duration. They were more or dividuals involved in chases. Flights ter-
leersesdsttrhaeighstaminelignreo,uonfdt,enwreerpeeat1e-d2lymcovi-n tmhieniarterdeswpehcetinvethestpaatritoincsipoanntsorretnueranredthteo
lengthorlonger,andinvariablylastedfor grate.Somechasesinvolvingtwoorthree
more thana second ortwo. Someflights malescontinuedintoandoutofthesewer
tooktheformofrepetitiveshortdistance drain.Physicalcontactoccurredonlyrare-
figure8's.Thelongerflightspossiblyfunc- lybetweenmalesinpursuitofoneanoth-
tioninhelpinglocate—receptivefemales. er.Insuchcasesonewaspgraspedanoth-
(7) Feeding flights. Periodically, males er,bothfelltotheground,theygrappled
temporarilylefttheirperchesandflewto for several seconds, separated, and then
anearbymapletreewheretheyobtained flewtorespectivestations.
honeydew or to a stand of white sweet Inadditiontochasingconspecificmales
clover from which they gathered nectar. andfemales,territorialmalesalsopursued
Asmanyassixmalesweresimultaneous- dragonflies, moths, butterflies, horseflies,
ly seen in the maple tree or feeding on and otherwaspsandbees. The initiation
Melilotus alba from late morning to early of chasing depended entirely upon the
evening. Flowers of other plant species visible presence of another insect, es-
nearbysuchasQueenAnne'slaceorwild pecially a conspecific. When other males
carrot,goldenrod,yarrow,andwhiteclo- were in the vicinity, males left their sta-
verwerevisitedlessfrequentlyfor—nectar. tions,tookflight,andwereair-bornecon-
(8)Pouncingonconspecificmales. When tinuouslyuntilthevisitors(s)leftthearea.
males at adjacent stations moved closer Thesightofanon-provisioningfemaleen-
than30cmapart,oneofthemoftenmade teringorexiting throughthesewergrate
ashortpouncingflightattheotherwasp. oftenincitedmalesstationednearbytoact
Thelatterfrequentlyflewoutofreachof aggressivelytowardoneanotherandthis
theformerand thensometimeswaspur- frequently led topursuitflights.Bychas-
sued in a low, sinuous flight for a short ingothermalesoutoftheimmediatearea,
distance.Lesscommonlythetwoindivid- males stationed on or near the grate
uals,aftermakingcontact,grappledwith would have more mating opportunities
Volume7,Number1,1998 79
availabletothem.Suchmales,infact,did of adjacent males. One to several males
obtain more copulations with females pursuedsuchanincomingfemale,imme-
than males situated on the periphery of diately bringing them into close contact
the aggregation. Where all males were with one another. They briefly grappled
viewed simultaneously, the three males witheachother,onechasedanotheraway,
perching on or near the grate obtained andthevictorcontinuedtopursuethefe-
eight (67%) of the 12 observed matings male in flight. Spacing, an expression of
while the six males positioned farther territorialityinmalesmaintainingstations
away gained only four (33%). The three nearfemalenests,wasclearlyestablished
waspsstationedonornearthegratedrove throughboutsofgrappling.Suchpremier
away all other males and permitted fe- positions often facilitated successful cop-
males to freely fly into the nesting area. ulation(seeabove). —
However, copulations were successful (11)Trailingconspecificfemales. During
only with females exiting through open- the height of male activity the trailing
ings in the grate. Copulations with fe- and/orpursuitofconspecificfemaleswas
males entering the sewer drain were in- secondarytochasingothermales.Infact,
variablyunsuccess—ful. manyfemaleswereallowedintothenest-
(10) Grappling. When two males ap- ingareaandpermittedtolandwithoutbe-
proached towithin30cmofoneanother ing chased orcontacted by males. None-
theyleaptateachother,heldoneanother theless, some non-provisioning females
in a venter to venter position with the flying near but not entering the sewer
glergasp,plainndgobictcuwrirtehd itnhebomtahndainbtelreiso.r-aSnutceh- gdriastteanwceerseopfu1rs^uemdbayftteerrrwithoirciahlmtahelemsafloer
riorandanterior-posteriorbodypositions. returnedtohisstation.Inaddition,males
Grapplinginvariablyensued whenares- stationedonthegratesometimesfollowed
ident male pounced upon an intruding femalesinflightintoandoutofthesewer
male flying low near the grate. Such drain and often interfered with females
wasps either separated in flight and re- making orientation flights. Orienting fe-
turned to their respective stations or fell males werepounced upon, bumped, and
to the ground, making a buzzing noise, jostled inmid-airbeforethey flewaway.
andcontinuedgrappling.Malesstationed However, males did not pursue females
ngerxatpptloedonfeora2n-o2t0he(rxo=n1o1r.8n,enar=th1e3)grsaetce, wfrhoomsethoeridernatian.tiAonttfelmigphttssbtyoomkatlhesemtoacwoany-
separated,andflewtorespectivestations. tactfemalesinflightprobablyservedasa
One male stationed on the grate twice preludetomating,butothermalesinthe
grappledwithanddroveawayalargerin- vicinity constantly disrupted copulation
truderfromaperipheralstation.Onthree efforts. —
occasions two or three grappling males (12) Clasping conspecific females. Males
fell throughopeningsinthesewergrate, clasped femalesby flyingonto theirdor-
disappearedfromview,andresurfacedin sum and holdingthemwiththelegs. Fe-
tandem flight3-5seclater. Afterexiting, malessograspedweredeprivedoftheuse
thethreegrapplingmalesresumedgrasp- of their wings and either plummeted
wtihniegthomnatenhdeiabnlleogetssh.earnBidonuctfoslingtohiftnuagebrdoapvbpeiltitinhngeggewrviaettnhe d3l0aowwncn,mw2at^rodm2tomfrthooemrgtrghloeiugdnredadtef.ornoStmuochhaeicgnlheatassrpbeoydf
tuopoktop3la^cemwiinthhienigahts.ceMnudicnhggsrpaiprapllifnlgigohct-s wmaaskpisngraolbluezdzionvgersosuenvderaaslthteimfeesmalwehialte-
curred when non-provisioning females tempted to escape. Sometimes the male
flewintotheareaby-passingthestations was dorsum down, still retaining his
80 JournalofHymenopteraResearch
grasp ofthe female which was also dor- antennae. This behaviorseemingly aided
sumdownwithherlegs dangling in the in keeping her acquiesced. When the fe-
air. One pair remained clasped together male became restless, she sporadically
for3minas they continually rolled over produced a buzzing sound. In order to
andtwistedonthegroundwhilemaking contacthergenitalia,themalerubbedthe
a constant buzzing sound. They eventu- sides ofhis abdomen against the under-
allyseparatedbutthemaleclaspedthefe- sideofthefemale'sabdomen.Themale's
male again and repeated his attempted abdomenhadtobetelescopedandthefe-
copulationforanadditional 1.5min. Un- male'sabdomen mildly contracted toex-
successfulcopulationintheformofclasp- ecutecoupling.Thelasthalfofhisabdo-
i=ng,18.h7o,wNeve=r,14u)suseacl.lyFollalsotewdinognlaytt5e-m4p5te(dx mfeemnalhea'dstaobbdeotmweisntedtunrenaerdlys45o°meawndhatth.e
copulation, males cleaned the sides of Once coupling was achieved, periodic
their abdomen alternately with the hin- soundproductionceased.Therewassome
dlegs and their eyes, antennae, and rhythmicabdominalmovementfromboth
mouthparts alternately with the forelegs. participantsduringcopulation.
Clasping of females by males preceded Males and females remained coupled
matingbutmostsuchengagementsnever foranaverageof5.1 (R = 2.5-14.0, N =
wenttocompletion. 12)min.Followinganapparentlysuccess-
(13) Copulation.—Twelve of 29 (41%) fulcopulation, thefemalefeeblyattempt-
pairingsthatbeganasclaspingculminat- ed to release herself from the male by
edinseveralminutes-longmatings.Gen- slowlymovingherlegsandantennaeand
iitnaglsictuhantiodniswsaolsvendotafatecrhi5evseecd-4inmi17np(axir=- tthweisfteimngalheertrhieedadtoibnraenakarlco.oIsnesboymwealcaksiensg,
47.8 sec) of clasping. The twelve appar- on the substrate dragging the attached
ently successful matings were observed male behind. Coupling, separation, and
between 1021 and 1231 hrsduring27-31 recoupling of male and female occurred
July 1982. Thisperiod, whenmaleswere uptothreetimesincertainpairs.Thear-
2-6 and females only 1-4 days old, rep- rivalofothermalesor,rarely,femalesof-
resented thepinnacleofreproductiveac- ten led to disruption of mating and, al-
tivity insofar as frequency of claspings mostinvariably,todissolutionofthepair-
and copulations. Attempted copulations ing.Twice,intrudingfemalesenteringthe
were sparse before and after this time. mixledtogenitalicseparationandcessa-
Matingswerenotseenduringthesecond tionofmating. Seventimesanintruding
weekofamale'slife. malemountedthefirstmalewhilehewas
Successful copulation proceeded mating, dislodgedhim, anddisjoinedthe
throughasequenceofbehaviors.Malesal- coupling. Recouplingbytheoriginalpair
waysmounted femalesdorsal sideup in wassometimesachievedaftersuchadis-
ahead abovehead position. Usually, the ruption.
maleremainedontopwiththefemaleon Once,asmanyasthreemalesattempted
thebottom.However,sometimesthemale tocopulatewithasinglefemale,thepar-
was on his side or, rarely, on his back ticipantsbeingstacked inapileatopone
holding the female ventral side up with another.Thepileofbodieskeptfallingto
herlegsdanglingintheair.Regardlessof one side, but the pedestal male retained
orientation,themaleretainedhisgraspof his grasp of the female and the other
the female by using his legs to grip her malestheirgrasptooneanother.Whether
wings,body,andlegs. the pile remained uprightorfell ontoits
Inthebeginningstagesofcopulation,a sidemadenodifferenceintherespective
malestrokedafemale'santennaewithhis positioningofthemales,probablybecause
Volume7,Number1,1998 81
the pedestal male was holdingthebases mainderofthemalesandthefirstfemales.
ofthefemale'swingswithhisforelegsand Theearlyemergingmalesweremoresuc-
adinfinitum. After35sec,theuppermost cessfulinestablishingstationsnearthefe-
maleflewawayforafewsecondsonlyto malenestingsitethanlateremergentsand
returnand rejointhepile. Inhisabsence, this eventually resulted in a higher pro-
the remaining two males each tried to portionofmatingsfortheseindividuals.
makegenitaliccontactwiththefemaleby RigleyandHays(1977)noteda"domi-
fencing for prime positionwith theends nance order" among malesofSphexpcn-
oftheirabdomens. Sound productionoc- sylvanicus for about a week during the
curred on and off during the entire at- "latter part" of July before the females
tempted copulation. After 4 min of re- startedprovisioning.Onemalepositioned
maining together, the participants sepa- himself nearer the female burrows than
ratedandflewawaywithoutsuccessfully twoothermales,continuallychasedthem
mating. — from the area, occasionally caught and
Maleactivitysummary. Theactivitiesof grappled with them, and temporarily
fourfocal malesstationed onornearthe drovethemaway. The"dominant" male
gratewere observed and recorded for30 "solicited" females at their burrow en-
min-long periods at air temperatures of trances by repeatedly flicking his wings,
23-24°Cbetween1015and1553hrson29- flewafterfemalesastheyexitedtheiren-
31July1982forthepurposeofsummariz- trances, clasped them in flight, disap-
ing and ranking them. Of the combined pearedfromview,andthenreturned2-5
120 min spent by these males, 67 (56%) min later to resume perching near the
minwereutilizedforflying,chasing,and nests.
grappling, 43 (36%) min for perching, Behaviorofmalesphecidwaspsispre-
swivelling, cleaning, wing raising, and dominantly directed toward obtaining
defecating, 6 (5%) min for clasping and matings (Hager and Kurczewski 1985,
copulating,and4(3%)minforfeedingon Evans and O'Neill 1988). Males ofmany
honeydewandtheflowersofwhitesweet diggerwaspspeciesmaintainterritoriesor
clover.Thelargeproportionoftimespent perchesnearfemalenestsinordertogain
air-borne by these males coincided with a reproductive advantage (Lin 1963,
thepresenceofconspecificmalesand fe- O'Neill 1979, Evans and O'Neill 1988).
males in the area. Ninety percent of the Copulatoryattemptsnearnestingsitesun-
time(60/67min)usedforflying,chasing, derline the importance of territories or
and grappling by males stationed on or perchestofacilitatemating (Alcocketal.
near the sewer grate included the intru- 1978).InSphexpcnsylvanicus,femalesoften
sionofconspecificmalesstationednearby. nest aggregatorily in one area (Reinhard
DISCUSSION p1e9r2s9., oFbrsi.s)c.hM1a9l3e8,sReisgtlaeblyisahndstaHtaiyonss1n9e7a7,r
Male solitary wasps often emerge one thefemalenests,thetwosexesarecontin-
or a few days before the females (Evans uallybroughtintocontactwithoneanoth-
1966). This trend, known as protandry, er,andmatingisexpedited.
and an overall shorter flight season syn- Male territoriality, as defined by spac-
chronizemaleactivity withfemaleemer- ing, maintenance of stations or perches,
gence (Evans and O'Neill 1988). Early and aggressionbetweenconspecifics,has
emergenceofmalesgivesthemanoppor- beendemonstratedforanumberofsphe-
tunity to mate with unmated, recently cids (Lin 1963, Evans 1966, Kurczewski
emergedfemales(Bulmer1983).One-third 1966, Alcock et al. 1978, O'Neill 1979,
ofthe malesofSphexpensylvatiicus that I Evans and O'Neill 1988, Hastings 1989).
studiedemerged twodaysbeforethe re- Applying this definition to Sphex pcnsyl-
82 JuuRNAi,or-HymenopteraResearch
imiiicus, territorialityclearlyisoperational frequently in AmmophUa and Sphex. Two
among themales (Rigleyand Hays 1977, ormoremalesattemptingtomatewitha
pers.obs.)-Inthisspeciesspacingandsta- single female and, in the process, disen-
tion maintenance and defense may func- gagingtheinitialcouplingappearstobea
tioninretiucingconflictbetweenconspe- commonstrategy inbothgenera. Insuch
cificmalesandpromotingsuccessfulcop- acaseanintrudingmaleniaybenefitim-
ulation. mediately or later via successful copula-
Althoughmatingistheultimategoalof tionwiththedisjoinedfemale(Hagerand
male digger wasps, aggressive interac- Kurczewski 1985).
tionsbetweenconspecificsareclearly the ACKNOWLEDGMENTS
most conspicuous activities of territorial
males (Evans and O'Neill 1988). More 1amgratefultoM.G.Spoffordforassistanceinthe
tlSophnhagcnxo9bp0sc%nesriv/olafvtnitiiohienciiptseirmdieuodrsipinengnvtoalbvytehdmreaaelgegdsraeyso--f amfianendldu.stc1wrtiohpatan.knoBn.y].mHoaugser,reKv.ieMw.erOs'Nefiolrl,imL.prS.ovVliinegtsttrhae,
siveactivitiesconnectedwithterritoriality. LITERATURECITED
Mflailghetss,ugsreadppmlionsgtwoifththainsdtipmuersiuninmgaoktihnegr AlcocLk.,KJi.r,kEe.ndMal.l,BaDr.roWw.s,PyGl.e,GoTr.dhL.,PLo.ndJ.erH,ubabnadrdF,.
males, and vigorously defendingstations G. Zalom. 1978.Theecologyandevolutionof
against conspecifics. Males of Sphcx pcn- male reproductive behaviour in the bees and
sSaivo/almivleaanbimlcauelsetsuit,mileiinzfefodarcot,ncllcayosnpasibinosgtuetnatn5ld%y imogfanttoihrneegi.dr Baered2wn9rad3iss-ep,3ns2t.6iG.Z.eorouUPn.^\g;1idc9en4l1r.lGouFrnoaurbitlwpetiVsl'ap/nue'zuUAniiunguisiivctiie'irfihhiiahSliit'ceainicmtypue6ns4d-:
females flying into the area in order to trif.Jur.TijiticliriftiwrEiitcinokigic84:68-275.
pursue other males. However, if a male Bohart,G.E.andG.F.Knowlton.1953.Notesonmat-
swteaprseatncedtssiottniosmoewaminutdchhencetoringmseypetochniaftiaccgogurmleadslsbeiesv,eusiehnde- BoharciSteno,grc,uiseRt.pyr(MeDo.yafhWplairbnKoodhvmii)Ans..giotSPno.rincncMcg5ec5tn:aikinleidio.gVsnl1eoO9sf6lt3.it.nhegAEinnrteSocpmloahslcsoxigfipicrcaoa-l-
for locating and contacting females tionoftheSphecinaewitharevisionofthenearc-
st(iiOom'CniNoslepaiuorllflianmt1a9ic7loo9enn).faiignnudraSftpeihmocanxleanptdconsrtyehllavattainovifecuopftohseiir-s Boharocmttiifoc,nltih.soRepg.eUyWncoMii3r.v0el:esdra:9son1ifAd-ty1tGA8heo2.enf.eStrC.riaiclMbieeRfsneovkSricensem.iloinP1p.u9hb7Ulr6nio.icnaviStenpirihoscnicasitntydmioWSfEapCnshatpelo-s--
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