Range extension of Doleschallia tongana (Nymphalidae) to the Samoan archipelago, with notes on its life history and ecology

3 Pages·2000·1.7 MB·English

by  Robert P Cook

JournaloftheLepidopterists'Society
54(1),2000,33-35
RANGE EXTENSION OF DOLESCHALLIA TONGANA (NYMPHALIDAE) TO THE SAMOAN
ARCHIPELAGO, WITH NOTES ON ITS LIFE HISTORYAND ECOLOGY
RobertR Cook1
U.S. NationalParkService,NationalParkofAmericanSamoa,PagoPago,AMERICAN SAMOA96799
AND
DonVargo
AmericanSamoaCommunityCollege,LandGrantProgram,PagoPago,AMERICAN SAMOA96799
ABSTRACT. AdultsandlarvaeofthenymphalidbutterflyDoleschalliatonganavomanaFruhst.wererecentlydocumentedforthefirsttime
intheSamoanarchipelago,ontheislandofTutuila,AmericanSamoa.DistributedfromMelanesiatowesternPolynesia,thisspeciesconsistsof
severalsub-species,withD. t. voinanaendemictoFiji.TheestablishmentofthisspeciesonTutuilaislikelytheresultofnaturaldispersalby
adult(s)blownfromFiji,thoughthesuccessofthiscolonizationwasmadepossibleonlyastheresultofhumanintroductionofthehostplants
GraptophyllumpictumandPseuderanthemumcarruthersii (Acanthaceae).
ThenymphalidbutterflyDoleschalliatongana Hop- dorsallyandprominent cream colored stripes running
kins is distributed through Melanesia eastward to longitudinally, locateddorso-laterallyandventro-later-
western Polynesia. Formerlyconsidered a subspecies ally Each body segment had seven prominent black
ofD. bisaltide, D. tonganawas elevatedto full species spines, with numerous smaller secondary spines. The
status by Parsons (1999). Based on a review of Do- base of each primary spine was pale metallic blue.
leschallia specimens, Parsons (1999) determinedthat From a distance, the most prominent features ofthe
D. bisaltide extended from India eastward to New caterpillar are the black ground color with metallic
Guinea, andthat further eastward, specimens consid- blue spots, andthepairoflightparallelstripesrunning
ered to be subspecies ofD. bisaltide were in fact, D. longitudinallyon each side.
tongana. D. tongana consists ofabout six sub-species, OnOctober6, 1997, severalunidentifiedcaterpillars
and is reported from the Bismarck Archipelago; the (Fig. 1) were independently observed by DV feeding
Solomons; NewCaledonia; the NewHebrides; Tonga; onaPseuderathemumcarruthersii (Seem.) Guillaumin
Fiji; and Samoa (Parsons 1999). At the eastern end of (Acanthaceae) on the campus of American Samoa
thespecies'range,D.t. vomana Fruhst. isendemictoa Community College located in the Malaeimi Valley.
numberofislandsinFiji(Robinson 1975) andD.t. ton- Severalwere collectedand adults reared. These speci-
gana Hopkins is endemicto anumberofislands in the mens were compared with that from April 1997, and
Tongangroup (Hopkins 1927, Miller& Miller 1993). allwere tentativelyidentified as Doleschallia bisaltide.
TheinclusionofSamoainthis species'rangebyPar- Assignment to the sub-species vomana was subse-
sons (1999) appears to be based on a misreading of quentlymadebyDr. Jacqueline Miller, Allyn Museum
Hopkins (1927). In his account ofDoleschallia, Par- of Entomology, Florida Museum of Natural History.
sons (1999) makes referenceto aSamoanspecimen of Based on the revised taxonomy (Parsons 1999) these
D. bisaltide, citing Hopkins (1927). However, while specimens would now be assigned to D. tongana vo-
the principal focus ofHopkins (1927) was Samoa, he mana.
onlyreportedDoleschallia from Tonga. Thus, priorto Since these initial records, the occurrence oflarvae
the observations reported here, there have been no onthehostplants orobservations ofadultsinflighthas
records ofDoleschallia from the Samoan Archipelago become more frequent. Two additional adult speci-
(Swezy 1921, Hopkins 1927, Comstock 1966, Kami & mens were collected in the Tafuna section ofTutuila
Miller 1998). (12 February 1998, 23 May 1998; Fig. 2) and Do-
On9April 1997, anunidentifiedcaterpillarwascol- leschallia larvae can nowbe found throughout the in-
lectedbyRPC movingacross abroadexpanse ofside- habited areas ofTutuila. Three adults have been de-
walk in an urbanized section of the village of Pago posited at the Allyn Museum ofEntomology, Florida
Pago, island ofTutuila, American Samoa. It pupated MuseumofNatural History(AccessionNumber 1998-
on 11 April andemergedon 18April. Justpriortopu- 12). Consideringthat the records are distributed tem-
pation,thecaterpillarmeasuredca. 50mminlength. It porally and spatially (from Tula on the east end to
possessed a black ground color with light speckling Fagamaloonthewestend, adistanceof30km) andin-
*Presentaddress:U.S.NationalParkService,CapeCodNational clude both adult and larval forms, it appears that a
Seashore,Wellfleet,Massachusetts02667. breedingpopulation has become established on Tutu-
34 Journalofthe Lepidopterists' Society
Fic. 1. Mature larvae ofDoleschallia tongana vomana Fruhst
feeding on Pseuderanthemum camruthersii, Mapusaga, Tutuila
AmericanSamoa.PhotobyDonVargo.
FlG. 2. Dorsal andventralviewoffemaleDoleschalliatongana
vomana Fruhst,collected23 May1998,Tafuna,Tutuila, American
Samoa. Allyn MuseumofEntomology, FloridaMuseumofNatural
ila. This seems to be a recent occurrence, as this is a HistoryAccession 1998-12.PhotosbyJacqueline Miller.
large, conspicuous species, readilyobserved andiden-
tifiedon diewing (once initiallyidentifiedin hand).
Priortotheobservations reportedhere, neitherone rina sp. (Robinson 1975). Whilethere are no accounts
ofus had observed the species on Tutuila. While one ofhostplants ofD. tongana fromTonga, G. insularum
ofus (RPC) hadonlybeenmakingobservationsonTu- is anative species ofAcanthacaeae there (aswell as in
tuila since 1996, the other (DV) has been observing Fiji) (Whistlerpers. comm.), andpresumablyservesas
and collectingbutterflies on Tutuila since 1988. Hop- the hostplant. OnTutuila, larvae ofD.t. vomanahave
kins (1927) spent two years in Samoa and Comstock been observed feeding on Pseuderanthemum car-
(1966) spent fourmonths (June to October) collecting ruthersii (syn. P. reticulatum) andGraptophyllumpic-
on Tutuila without encountering this species. In the tum. These two plant species are native to Melanesia
Samoan Archipelago, Doleschallia presently is only andAsia-Malaysiarespectively
known from Tutuila. We have spent many days afield With the exception ofDicliptera samoensis Seem,
in the Manu'aislands ofAmerican Samoawithout ob- endemic to Upolu and Savaii (in the independent na-
servingit. We have not observediton Upolu or Savaii tion ofSamoa) there are no native Acanthaceae in the
either, but time spent afield on these islands has been Samoan archipelago. All are European introductions
verylimited. (primarily in the 20th century) and arrived either as
ExistingdataonthehostplantsofDoleschallia indi- weeds (7 species) or ornamentals (21 species)
cate the genus feeds primarily on members of the (Whistler 1992, 1994, 1995, pers. comm.). OnTutuila,
FamilyAcanthaceae, with Moraceae ofminor impor- P. carruthersii and G. pictum are widespread orna-
tance to some species (Parsons 1999). Doleschallia in mentalplantings.
New Guinea feed principally on Graptophyllum pic- Doleschallia occursinprimaryandsecondaryforest,
tumT (Parsons 1991), andPseuderanthemumvariable although accounts suggest it prefers forest edge or
is the principal host plant ofD. bisaltide in Australia clearings rather than deep forest. D. bisaltide is re-
(McCubbin 1971, D'Abrera 1978, Common &Water- ported from rain forest (Common and Waterhouse
house 1972). Host plants recorded forD. tongana in- 1972) and "open spaces on the outskirts of jungle
clude Graptophyllum pictum on Manus and New patches" (McCubbin 1971). In New Guinea, D. ton-
Britain (Parsons 1999), Pseuderanthemum sp. on New gana occurs in marginal secondary forest, especially
Caledonia (Holloway & Peters 1976), and, in Fiji, along creeks (Parsons 1999) and in New Caledonia it
Graptophyllum insularum (A. Gray) A.C. Smith, G. prefers rich primary forest but is often seen on low
pictum, Pseuderanthemum laxifolium A. Gray, Arto- vegetationinthe sun (Holloway&Peters 1976). How-
carpusaltilis Parkinson,A. integraThunb., andEryth- ever, its occurrence on ornamental hedges ofG. pic-
Volume 54, Number 1 35
turn (Parsons 1999), suggest an ability to utilize hu- Y. Millerforconfirmingthespecificidentificationofourspecimens,
man-modified habitats as well. On Tutuila, observa- forprovidingidentificationtosub-species,andforhercriticalreview
ofthisnote.
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