Male mate-locating behavior in two Australian butterflies, Anaphaeis java teutonia (Fabricius) (Pieridae) and Acraea andromacha andromacha (Fabricius) (Nymphalidae)

7 Pages·1996·5 MB·English

by  John Alcock

JournalofResearchontheLepidoptera L2:l-7, 1903
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Male Mate-Locating Behavior in Two*^^^^^ian Buttei
m
Anaphaeisjava teutonia (Fabricius) (Pieri<
andromacha andromacha (Fabricius) (Nymphalidae)
John Alcock
DepartmentofZoology,ArizonaStateUniversity,Tempe,AZ85287-1501
AbstractScramblecompetitionforaccesstoemergingvirginfemalesthat
are moderatelytohighlyaggregatedcharacterizes male matingtacticsin
some populations of two Australian butterflies, Anaphaeisjava teutonia
(Pierinae) andAcraea andromachaandromacha (Acraeinae).
KeyWords: Anaphaeis, Acraea, mating strategy
Introduction
I present notes on the mating systems of two Australian butterflies,
Anaphaeisjava teutonia (Fabricius) andAcraea andromachaandromacha (Fab-
ricius), as a contribution to the natural history ofthese species. The male
matingtacticsofneitherbutterflyhasbeen previouslydescribed (Common
&: Waterhouse, 1982), although Hawkeswood (1991) reports commonly
encounteringmatingpairs ofA. andromachaon alarvalfoodplant,Passiflora
suberosa.
Anaphaeisjava teutonia
The mating behavior ofthis species was first observed on 23 and 25July
1993 in Kalbarri National Park about 5 km south of Kalbarri, Western
Australia. Several dozen maleswere flyingin ashallowrockygorgewithin a
few hundred meters of the coastline. Much of the activity was centered
aroundasingle causticbush {Sarcostemmaaustrale,Asclepiadaceae). Certain
stemsoftheshrubwerelinedwithatotalof29pupaeandemptypupalcases
ofthe butterfly.
At 1500 hrs on 23July, 17malesand 3femaleswere flyingaroundorwere
perchedinorneartheshrub,includingtwopairsincopula. Unmatedmales
flewseveralmetersoutandbackfromtheplant,someinspectingthemating
pairs closely, others courting (unsuccessfully) a single, apparently freshly
eclosed, female perched in the area. This female was not receptive; she
elevated her abdomen, and spread and fluttered herwings in response to
courtship attempts.
At 1000 hrs on 25 July, 8 males and 2 apparently recently eclosed but
unpaired females were present in and around the shrub; later that day at
1330 hrs, 15 males and 5 females were found in or near this one plant,
includingfourpairsincopulaonstemsofthecausticbush.Allmatingmales
seen on both days possessed extremelywornwings (Fig. 1). Two males had
been captured and killed in a spiderweb in the caustic shrub.
Papersubmitted 25May 1995; revisedmanuscriptaccepted 17November 1995.
2 J. Res. Lepid.
Fig. 1.AverywornmalecopulatingwithafreshlyeclosedfemaleofAnaphaeisjava
at a site within Kalbarri National Park, Western Australia.
32:1-7, 1993 3
Onanothercaustic shrubin the samegeneralareaIfoundfourpupalcases
incloseproximitytooneanother,withonefreshadultfemaleperchedinthe
plantand three flyingmales nearby.
This species was also observed on 14 September 1993 atYampire Gorge,
KarajiniNationalPark,WesternAustralia.Onthisdayat0830hrs,therewere
two copulatingpairsin adead,leaflessshrub (whichwas not S. austmle) less
thanameterhigh.About12unmatedmalesflewinandaroundtheplanton
whosedeadstemswereaggregated 106pupaeandopenedpupalcases.Asat
the Kalbarri site, copulating pairs were approached by patrolling males,
which courted them (Fig. 2).
Acraeaandromachaandromacha
This species was observed on 22 and 23 September at Windjana Gorge
National Park,WesternAustraliain aflatplain ofshorterdrygrass roughly
m m
135 X35 surroundedbyatallersavannah (Fig. 3) The male butterflies
.
wereflyinglowoverthegrassesinwhichwerescatterednumerouslastinstar
larvae and pupae suspended from dried grass stalks. Over two mornings,
recordsweremade ofthe substrate onwhich 20 matingpairswere perched;
17 (85%) were found on astem next to a castpupal cuticle, indicating that
maleswerematingprimarilyorexclusivelywithfreshlyemergedindividuals
(Fig. 4).
At0900on23September, themeandistancebetweenonecopulatingpair
m
anditsnearestneighboringpairwas6.2+4.2 for 11 differentdyads. Thus,
emerging,receptivefemaleswerepresentinmoderatelyhighdensitywithin
the short grass patch.
Two solitary females that had recently eclosed were observed until con-
tacted bypatrollingmales in 7 and 13 min respectively. The males courted
theperchedfemalesinflightbybuffetingtheirwingsforabriefperiod,with
copulation following.
In both cases, I carefully separated the male from the female within one
min ofthe onsetofcopulation, and then returned the female to herperch.
FemaleAwasnotapproachedbyamaleuntil40minhadelapsed.Thefemale
rejectedhispersistentcourtshipbytwistingherabdomenawayfromhisand
byopeningand closingherwings. However, femaleAwas seen mating 2 hr
after her firstcopulation was experimentally terminated.
FemaleBwascourtedsixtimes (presumablybydifferentmales) inthefirst
30 min after she was separated from her first partner; she rejected all six
suitors butwas seen coupledwith a male 60 min later.
Searching males also courted copulating pairs (n = 3 records) as well as
freshly eclosed males (n = 3) and even a pupa (n = 1), in addition to the
unreceptive, experimentallyunpaired females.
Discussion
Males ofboth species were seen searching for and mating with recently
eclosedfemales. Malesofthe pierineAnaphaeisjavafocused theirsearchon
4 / Res.Lepid.
Fig. 2. Unmated malesofAnaphaeisjavacourting acopulatingfemaleat Karajina
National Park, Western Australia. Notethe line of pupal cases belowthe
adult butterflies.
32:1-7, 1993 5
Fig. 3. The short grass plain that lies within taller grasses in the open savannah-
eucalyptus woodland at Windjana National Park, Western Australia.
Fig. 4. A pairof Acraea andromachaon adried grass stem; the pupal case ofthe
freshly eclosed female appears between the two butterflies.
6 J. Res. Lepid.
plantswherelarge numbersofpupaewereclusteredtogether. Theseplants
were not the larval foodplant, which are caper trees, Capparis (Hay et al.,
1993) butratherleaflessshrubswithconsiderableopenstemspaceonwhich
,
to pupate.
MalesofAcraeaandromachapatrolledaregionwhereeclosingfemaleswere
more diffusely distributed than in Anaphaeisjava. Nevertheless, the density
offemaleswasmuch greaterin theshortgrassareathan in thesurrounding
savannah. In this species, pupation and eclosion also took place on a
substrate (dried grasses) other than the larvalfoodplant,which is reported
to be Passijloraspp. (Hawkesworth, 1991).
Malebehaviorinbothspeciesisconsistentwiththeexpectationthatmales
will focus theirmate-searchingatsiteswhere eclosingfemales are relatively
denselydistributed (Rutwoski, 1991).AsRutowski (1991) pointsout,female
butterflies typically become receptive as they eclose or soon thereafter,
judgingfromthe raritywithwhichvirginfemalesarefoundin thefield. The
receptivity offreshly emerged females clearly applies to the two Australian
specieswhosebehaviorisdescribedhere.Underthesecircumstances,sexual
selectionfavorsmalesthatcanlocateplacescontaininghigherthanaverage
numbers ofeclosingfemales. Pupae are denselyclustered inAnaphaeisjava
and moderatelyaggregatedin Acraea andromacha, afairlyunusual phenom-
enon in butterflies thatmaybe adefensive phenomenon linked to distaste-
fulness in these species. In any event, the existence of pupal clusters
concentrates freshly emerged females in small areas, enabling males to
search economicallyfor mates in these places.
Males are also predicted to time theirmate-locating behavior to coincide
withtheperiodswhenfemaleeclosionismostlikelytooccur.Theabundance
ofpatrollingmalesoiAcraeaandromachain theearlymorningatWind]anais
consistent with the report that most males in a laboratory population
emerged in the very early morning, with females following a little later
(Hawkesworth, 1991).
Although territorial behavior has been reported for many butterflies
(reviewed in Rutowski, 1991), neither species observed here exhibited
territoriality. The limiteddurationofmyobservations means, however, that
I cannotrule out the possibility thatsome males defended pupae thatwere
onthevergeofeclosing,ashasbeenseeninafewbutterflies (Bellinger, 1954;
Elgar8cPierce,1988).However,malesthatfoundfemalesofAcraeaandromacha
thathadbeenexperimentallyseparatedfrom theirpartnersearlyincopula-
tion did notremain with them. Moreover, the dominant mode ofbehavior
for both Australian species clearly was nonaggressive patrolling. The rela-
tively large number ofindividuals searching for mates within a small area,
particularly in the case of Anaphaeis java, may have contributed to this
outcome, inasmuch as the costs ofrepelling intruders from an area even a
meter or two square would probably have been substantial.
The importance of finding freshly-eclosed females before rival males
almostcertainlyfavorspatrollingflightoverperchandwaiting. Undersome
conditions,malesofbothspeciesclearlyengageinscramblecompetitionfor
32:1-7, 1993 7
access to eclosing females. Whether males have alternative mate-locating
tacticsremainstobedocumented,althoughobservationsoiAcraeaandromacha
males at hilltops (Rutowski, pers. obs.) stronglysuggest that they do.
Acknowledgements. I thankMichael F. Brabyforproviding assistance with the litera-
ture search and Ronald L. Rutowksi forhiscomments on the manuscript.
Literature Cited
Bellinger,P.F. 1954.Attractionofzebramalesbyfemalepupae. Lepid.Soc.8:102.
J.
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Sydney. 434 pp.
Elgar, M.A. & N.E. Pierce. 1988. Mating success and fecundity in an ant-tended
lycaenidbutterfly. InT.H. Glutton-Brock (ed.).Reproductivesuccess:studiesof
individualvariationincontrastingbreedingsystems.UniversityofChicagoPress,
Chicago. 538 pp.
Hay, R.W., T.F. Houston, A.A.E. Williams, 8c M.R. Williams. 1993. Bring back the
butterflies. WesternAustralian Museum, Perth. 72 pp.
Rutowski, R.L. 1991. The evolution ofmale mate-locating behavior in butterflies.
Amer. Nat. 138:1121-1139.