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An Annotated Checklistand Keys to the Mosquitoes of Samoaand Tonga’
Shivaji Ramalingam2
ABSTRACT. An historicalreview is given of the work done on the mosquitoesof Samoaand Tonga A total of 15 speciesbelonging to the generaAedes, Culex, Coquillettidia and Toxorhynchites is known to occur in the area, 13 speciesin Samoaand 8 in Tonga. Information for each speciesis provided with respectto the original description,stages described, biology and distribution. Where necessary,a taxonomic discussionis provided. Keys for the identification of adults, male genitalia, pupaeand larvae are provided.
INTRODUCTION The islandsof Samoalie in the South Pacific between latitude 11O and 15OS. and longitude 168Oand 173OW. WesternSamoa consists of the two largeislands, Savaii and Upolu, with the two tiny islands,Manunu and Apolima, situatedin the narrow straitsbetween them. About 40 miles southeastis American Samoaconsisting of Tutuila, the Manua group, Rose and SwainsIslands. The islandsof the Kingdom of Tonga lie betweenlatitude 1So and 23O 30’ S. and longitude 173O and 177OW. There are about 150 islandsin the Kingdom, of which only 36 are inhabited, and the total land areais only 269 squaremiles. Three main groupsof islandsare recognizedfrom north to south, the Vavau, Haapai and Tongatabugroups. The southernmostgroup takesits name from the largestisland in the Kingdom, Tongatabu,on which is located Nuku’alofa, the capital of Tonga.
HISTORICAL SAMOA. The earliestrecorded mosquito collection from Samoawas made in November 1904 when J. F. Floyd collectedAedes (S.) aegypti in Apia (Howard, Dyar and Knab, 19 17:840). In 1913 Gruenbergdescribed Aedes (F. 1 samoanus (as Finlaya samoana) from severalfemales collected by K. Friederichs,the Government Zoologist in Apia. Friederichssent additional material to Theobald (19 14) who describedCulex (C.4 Samoaensisfrom a singlefemale and reported Aedes 6.) aegypti (as Stegomyia fasciata), Aedes (5.’ ) polynesiensis (asStegomyia pseudoscutellaris), Culex (C.) quinque- fasciatus (as Culex fatigans) and Mansonia fijiensis (asMansonia, i.e., Taeniorhynchus sp.). O’Connor (1923) was the first investigatorto obtain fundamental information on the mos- quitoesof Samoa and to study their relation to the transmissionof filariasis. He recorded for the
’ This investigationwas carried out when the author was at the Department of Zoology, Uni- versityof California, Los Angelesand wassupported by Public Health Servicetraining grant TI-AI-132, directed by Dr. John F. Kesseland formed a portion of a dissertationsubmitted in partial satisfactionof the requirementsfor the degreeof Doctor of Philosophyin Zoology at the University of California. 2Department of Parasitology,Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia. Mosquito Systemat first time Aedes (Aedimorphus) vexans ’ (as Ochlerotatus vexans) and Culex (C.) annulirostris (as Culex jepsoni) and collected another female of Culex (C.) samoaensis, a speciesnot encountered in any subsequentsurvey. By meansof studieson natural and experimentalinfections on the common man-biting mosquitoesO ’Connor demonstratedAedes 6s.) polynesiensis (as Stegomyia pseudoscutellaris) to be the vector of subperiodicBancroftian filariasis in Samoa,confirming the earlierfindings of Bahr (19 12) in Fiji. Buxton and Hopkins (1927) made extensivestudies on the arthropodsof medical importance in Samoa,with particular emphasison the bionomicsof mosquitoes. To the speciesthat were al- ready known from Samoa,they added Culex (C.) sitiens. Most of their work wasdone on Upolu, and someon Savaii. During and after the SecondWorld War, much emphasiswas placed in Samoaon the study of filariasisand the mosquitoesthat transmitted this disease.Byrd, St. Amant and Bromberg(1945) dissectedover 5700 mosquitoesfrom Tutuila, American Samoa,and confirmed the findings of O’Connor. Bohart and Ingram (1946)ticluded the Samoanmosquitoes in their publication, “Mosquitoesof Okinawa and islandsin the Central Pacific.” They describedthe known species and summarizedtheir bionomics. Most of their Samoanmaterial was from the U.S. National Museum, collectedprimarily by K. L. Knight, W. G. Reddick, E. E. Boyd and P. S. Rossiter. Jachowskiand Otto (1952, 1953, 1954) carriedout studiesin American Samoaon the bionomicsof polynesiensis and on the density of infection and the sitesof transmissionof filariasis. Marks (1957) describeda new species,Aedes (S.) upolensis, from material sent to her from WesternSamoa by T. E. Woodward. Among this material was a singleadult of Mansonia fijiensis (reported asMansonia sp.). Laird, duringhis studieson “Mosquitoesand freshwaterecology ” (1956), made severalcollections in Samoaand studied the habitatsof the immature stages.M. 0. T. Iyengar ( 1955, 1960) made a few collectionsin Samoaand listed the species.He alsostudied the extent of transmissionof filariasisin WesternSamoa (1954). Peterson(1956) gavean account of the introduction of two speciesof Toxorhynchites into American Samoafor the purposeof controllingAedes polynesiensis. Finally Belkin (1962), in his comprehensivework “Mosquitoesof the South Pacific,” describedin great detail the stagesof the known mosquitoes(11 species)and analyzedthe relationshipsof the mosquitoesin the region. He recorded 13 speciesas occurringin Samoaincluding a new species, Aedes (F. ) oceanicus. TONGA. Only incidental collectionsof mosquitoeshave been made in Tonga in the past. The earliestwere made some time prior to 1926 by C. L. Edwards,S. M. Lambert and G. H. E. Hopkins. Aedes (S.) tongae (as variegatus var. tongue) wasdescribed from this material by F. W. Edwards(1926). In 1953 Laird ( 1956) collectedin Nuku’alofa and recordedCulex (C. 1 yuinque- fasciatus (as Culex pipiens jbtigans), Culex (C.) annulirostris, Aedes (Aedimorphus) vexans (as vexans nocturnus) and Aedes (F.) oceanicus (as samoanus). Iyengar (1955, 1960) collected in Vavau and Nuku’alofa and listed 8 speciesfrom Tonga. The Medical Department of Tonga con- ducted a survey of the mosquitoesof Foa Island in the Haapaigroup (Halu and Haunga 1952) and listed speciesfrom Tonga, with severalquestionable identifications (1957). Finally Belkin (1962) describedin detail the 7 speciesthat were then known from Tonga up to the presenttime. Belkin (1962) believedthat, despiteearlier contributions,the mosquito fauna of both Samoa and Tonga was still poorly known. The author spent 6 months in Samoaand Tonga during 1963, studyingthe mosquito fauna of these areasand its relationshipto Bancroftianfilariasis. Partsof this study have been published(Ramalingam and Belkin, 1964, 1965; Ramalingam, 1966, 1968). Despitethe long delay, it is felt that the information obtained on the biology and distribution of eachspecies along with the keys would be useful to public health workersin the area. 300 MATERIAL Of the six months spent in the area, the months of February, March and July were spentin American Samoa; 1 April to 10 May in W. Samoaand 16 May to 29 June in Tonga. The islands visitedwere Tutuila,__. Upolu, Savaii,Tongatabu, Eua, Tofua, Matuku and Nomuka. Mosquitoes examined-fromthe Manua group and SwainsIsland were collected by Neal Spencer. A total of 368 collectionswas made for this study in Samoaand Tonga. Over 12,000 specimenswere pre- servedfor taxonomic studies,about equally divided between immature stagesarid adults and including485 individual rearingsfrom larvaeor pupae. Of the 12 speciesdefinitely known from the areaprior to this surveyall were found except Culex (C) samoaensis and Mansonia fijiensis. In addition 2 new endemic specieswere found, Aedes (F.) tutuilae and Aedes LS.)’ tabu (Ramalingamand Belkin, 1965). A speciesof Toxorhynchites introducedinto American Samoawas recovered and wasshown to have been misidentified in the past. The previouslyundescribed larva and pupa of Aedes (F.) samoanus were also discoveredand rearedindividually. Considerableadditional data on the bionomicsof immature stages(breeding sites,association with other species)and adults (biting activity) were obtained for nearly every speciescollected. Table I summarizesthe current information on the distribution of all 15 speciesdefinitely known to occur in the Samoa-Tongaarea, basedon this surveyas well as on previousrecords. In the following paragraphsthe mosquito fauna of eachisland group is discussedbriefly. MOSQUITO FAUNA OF SAMOA The known mosquito fauna of Samoaconsists of 13 speciesbelonging to the 4 genera,Culex, Aedes, Coquillettidia and Toxorhynchites. The genusCulex is representedby 4 species,only one of which, samoaensis,is endemic. Culex samoaensisis an exceedinglyrare specieswhich has been collected only twice and is now known by only 2 specimens(Belkin 1962:2 12). Despitecareful searchfor this speciesin suitablesituations no specimensof samoaensis were found during this survey. Culex quinquefasciatus is undoubtedly an introducedspecies, having arrivedin the South Pacific during the period of exploration, probably as breedingpopulations on sailingvessels. It is extremely common in and around the larger settlements in American Samoa and WesternSamoa. The other 2 species,annulirostris and sitiens, are probably indigenousin Samoa as in many other islandsin the South Pacific. Of the 2, sitiens is much more common in Samoa. The record of Mansonia fijiensis from Samoawas based on a singlemale from Moata’a swampon Upolu examined by Belkin ( 1962309). Theobald (19 14:37) reported the presenceof a speciesof Mansonia found by Friederichson Upolu but this material hasnever been located. Belkin (1962, lot. cit.) indicated the possibilitythat this may be a speciesdifferent from true fijiensis which is common in the Fiji Islands. Specialefforts were made to obtain this speciesin Moata’a swampbut no specimenswere found. Stone (1966) describedthis Mansonia asa new species,Coquillettidia (C) samoaensis, from 2 specimenscollected in the Manua group and from the singlemale from Moata swamp,Upolu. Aedes is the dominant mosquito genusin Samoaand is representedby 3 endemic or indigenous speciesin the Kochi Group of the subgenusFinlaya, 2 endemic or indigenousspecies of the Scutel- larisGroup and the introduced aegypti in the subgenusStegomyia and a representativeof the sub- genusAedimorphus, vexans, which may be indigenousor introduced. The speciesof the subgenera Finlaya and Stegomyia are breedersin containerhabitats, those of Finlaya primarily in the leaf axils Mosquito Systematics Vol. 8(3) 1976 301 of monocotyledonousplants (primarily Araceaeand Pandanaceae)and those of Stegomyia primarily in treeholes,plant parts on the ground (coconut shells,husks, spathes, etc.) and artificial containers. Toxorhynchites amboinensis was introduced into American Samoafor the control of Aedes (S.1polynesiensis and is now well establishedin Tutuila. Four other specieshave been reported from Samoain the past. Culex (C.) Zitoralis Bohart, 1946 wasreported by Iyengar (1955:33,46; 1960:77,101). Belkin (1962:27) regardedthis record asmost unlikely but consideredthe possibilitythat a relative of C (C.) roseni Belkin, 1962 could occurin Samoa. During this survey49 collectionswere made in seasiderockpools, the reported breedingsites of Zitoralis and only C. (C.) sitiens wasfound. It appearstherefore that the record of Zitoralisis erroneous. Another specieswhich should be dropped from the list of Samoanmos- quitoesis Tripteroides (T.) purpuratus (Edwards, 192 1). Belkin (1962:37,500) mentions 4 larvae of this specieslabelled American Samoa(Otto) and suggeststhat this material was erroneously labelledand that it actually came from Fiji wherepurpuratus is common. The other possibilitysug- gestedby Be&in that a relative of purpuratus may be presentin Samoamust be discardedsince in some 100 treehole collectionsduring this surveyno speciesof Tripteroides was found. Finally the report of the introduction of Toxorhynchites (T.) brevipalpis and T. splendens (Peterson 1956; Belkin 1962:37,53 1,533) should be clarified. Neither specieswas found during this surveyin Amer- ican Samoa. It is evident that one of the speciesintroduced was actually T. amboinensis (misidenti- fied assplendens). This speciesis now firmly establishedin Tutuila. On the other hand it appears that the introduction of brevipalpis wasnot successful(Ramalingam and Belkin, 1976). MOSQUITO FAUNA OF TONGA The known mosquito fauna of Tonga consistsof 8 speciesbelonging to the generaCuZex (3 species)and Aedes.(5 species). In the genusCulex, 2 speciesare probably indigenous,annulirostris and sitiens, and the third is the ubiquitousintroduced quinquefasciatus. In the genusAedes, the subgenusFinlaya is representedby an introduced species,oceanicus, of the Kochi Group, the sub- genusStegomyia by 2 endemic species,tabu and tongae, of the ScutellarisGroup and the introduced aegypti and finally the subgenusAedimorphus by vexans which wasprobably introduced by the natives. A redescriptionof the adult male and female of tongae wasmade by Huang (1972). There are recordsof 3 additional specieswhich are probably basedon either misidentifications: CuZex(C.) albinervis and Aedes (S.) horrescensreported by the Tonga Medical Department (1952, 1957) or an error in labelling,CuZex (C.) roseni (Belkin, 1962:204). The current knowledge of the mosquito fauna of Tonga is extremely fragmentaryas only a few of the more than 150 islandshave been surveyed. In view of the presenceof 2 endemic species of the ScutellarisGroup it is prdbablethat with more intensivesurveys additional endemic species will be found, particularly on the more remote and isolatedislands. CONSIDERATION OF SPECIES 1. Aedes (Finlaya) samoanus (Gruenberg) 19 13. Entomol. Rundschau30: 130-l 3 1 (asFinlaya samoana). Apia, Upolu Island, Samoa(BERLIN, destroyed?). STAGES DESCRIBED. M*, F, P*, L* (Stone and Bohart, 1944:212, M*, L; Marks, 1947:32, M, F, L; Belkin, 1962:379, M*, F; Ramalingam, 1965:P*, L*; Ramalingamand Belkin, 1976:P*, L*). 302 DI_SCUSSION.-This mosquito wasundoubtedly confusedin the past with the other members of the Kochi Group asit wasthe only speciesknown to occur in Samoaprior to 1962. In that year Belkin (1962) describeda new species,oceanicus, and a third speciesof the group, tutuilae, was describedfrom material cdllected&ring this survey(Ramalingam and Belkin, 1965). Associated rearingsof the immature stagesof samoanus were obtained for the first time during this surveybut their descriptionswere not publisheduntil this year (Ramalingamand.Belkin, 1976) although they were originally prepared more than 12 yearsago (Ramalingam, 1965). Previouspublished descrip- tions of the immature stages(P, L) actually pertain to A. oceanicus. Aedes samoanus can be readily distinguishedfrom oceanicus and tutuilae in all the stagesexcept for the femaleswhich resemble thoseof tutuilawery closelyand cannot be separatedfrom that specieswith certainty (Ramalingam and Belkin, 1965). BIOLOGY. In American Samoathe immature stagesof samoanus were found commonly in the leaf axils of Freycinetia sp., a forest creeperbelonging to the family Pandanaceae.In numerouscol- lectionsmade in the axils of taro (Colocasia) and screwpine(Pandanus sp) in American Samoa, samoanus wasnever recoveredand was found only once in the leaf axil of the giant taro (“ta’amu”, Alocasia indica). In WesternSamoa heavy breedingof samoanus occurredin the leaf axils of Freycinetia sp.aswell asin Pandanus. In one collection a singlelarva of samoanus was found in the leaf axil of giant taro. The difference in the 2 populationsof samoanus, as regardsthe choice of breedingplaces, is puzzling sincemorphologically the 2 populationsare very similar in all the stages.In American Samoano other speciesof mosquito breedsin the axils of Freycinetia and hencesamoanus did not occurin associationwith any other speciesof mosquito. In WesternSamoa samoanus occurredin the samecollection with oceanicus, tutuilae and polynesiensis, in the leaf axils of Pandanus. The adultsof samoanus are nocturnal in habit, becomingactive after sunsetand reachinga peak of activity at 11:00 p.m. They rest primarily outdoors and only a few were collectedin “fales” during the day. In American Samoa this mosquito is exceedinglyabundant in the interior villagesand in those coastalvillages that are closelysurrounded by virgin forest. In WesternSamoa, because of breeding in the leaf axils of Pandanus, samoanus is abundantin all villagesand especiallyin the interior. This is highly important in the epidemiologyof subperiodicBancroftian filariasis,since it has been shown that samoanus is an efficient vector of this disease(Ramalingam and Belkin, 1964; Ramalingam, 1968). DISTRIBUTION. WesternSamoa: Savaii (Aopo, Asau). Upolu (Afiamalu, Aleisa, Fagali’i, Lanuto’o, Luatuanu’u, Mafa Pass,Manunu, Moata’a Stream or Swamp, Solosolo,Tuanai, Vavau). American Samoa: Tutuila (Aasu, Amouli Ridge, Aoa, Aoloau, Iliili, Leloaloa, Mapusaga). Not known elsewhere. 2. Aedes (FinZaya) tutu&e Ramalingam and Belkin 1965. Am. Entomol. Inst., Contrib. 1(4):3-7. Aoloau, Tutuila, American Samoa(USNM). STAGES DESCRIBED. M*, F, P*, L* (Ramalingamand Belkin, 1965). BIOLOGY. Aedes tutuilae breedsalmost exclusivelyin the leaf axils of Pandanus. In Samoa,32 collectionswere made in the leaf axils of taro, 38 in Pandanus leaf axils and 6 in the leaf axils of Frey- cinetia sp. Each collection wasmade at a different location and generallyincluded severalplants. Thus the mosquito larvae and pupae of a collection came from many leaf axils and even from several plantsof the samespecies. They were obtained from the leaf axils of Pandanus in 24 collections, near sealevel on the coastto elevationsof 460 meters in the interior. Mosquito Systematics Vol. 8131 1976 303 The immature stagesof Aedes tutuilae occurredin associationwith the following species: oceanicus (in 16 collections),samoanus (4) and polynesiensis (2). In each of thesecollections the immature stageswere recoveredfrom more than one ax& therefore it is not known definitely if tutuilae is ever found in associationwith another speciesin the sameplant axil. As femalesof tutuilae cannot be differentiated with certainty from those of samoanus little can be saidabout their biting habits. Undoubtedly the adults are nocturnal asin the caseof samoanus. Severalunusually dark specimensof the samoanus/tutuiZae type were collected biting man on severaloccasions and it is probable that they were tutuilae. It is possiblethat the two speci- mensof Aedes (Finlaya) South Pacific species25 (UCLA) reported by Ramalingamand Belkin (1964) as beingnaturally infected with Wuchereria bancrofti were alsotutuilae as originally surmised. How- ever, this cannot be definitely determined and the relation of tutuilae to filariasisis uncertain. DISTRIBUTION. WesternSamoa: Savaii (Asau, Paia, Saleia). Upolu (Afiamalu, Manunu, Moata’a Swamp, Tuanai). American Samoa: Tutuila (Aasu, Aoloau, Fagasa,Fighter Strip, Masefau, Agriculture Farm). Manua Group (Ofu, Amouli Ridge). Not known elsewhere. 3. Aedes(Finlaya) oceanicusBelkin 1962. Mosq. South Pac. 377-379. Amouli, Tutuila, American Samoa(USNM). This specieswas con- fusedwith samoanus by workers prior to 1962 (seeunder samoanus). STAGES DESCRIBED. M*, F, P*, L* (Belkin, 1962). BIOLOGY. The immature stagesof oceanicus are found most frequently in the leaf axils of taro, giant taro and Pandanus. In Samoaespecially, extensive breeding takes place in the leaf axils of taro. On severaloccasions, nearly every plant examinedin a tar-opatch containednumerous im- mature stages.They were alsoplentiful in the leaf axils of Pandanus, but asPandanus is not culti- vated asmuch as tara, the leaf axils of the latter account for the major breedingsite of this species. In TutuiIa a few larvae were collectedin the leaf axils of pineappleand Neal Spenceralso found oceanicus in the leaf axils of the Sagopalm. Two collectionsof oceanicus, one eachfrom Tutuila and Upolu, were obtained from small holes in coconut trees. Two collectionsof this specieswere alsomade in rockholes;in both thesecases the rockholeswere in plantations,in partial shade;the water wasclear with a little organicdebris at the bottom. Finally 2 larvaeof oceanicus were re- corded from a collection in a coconut shell together with the immature stagesof polynesiensis. The collection immediately before this one wasmade in taro leaf axilsand it is possiblethat these 2 larvaewere accidentally carriedover from one collection to the other in the bulb of the pipette. Buxton and Hopkins (1927) observedthat the eggsof this speciesare laid in stringsjust abovethe water level in the leaf basesof Colocasia. Aedes oceanicus was found in associationwith the following speciesin collectionsof immature stages:Aedes tutuilae, A. samoanus, A. polynesiensis, A. tabu, A. tongae and Toxorhynchites am boinensis. The adults of oceanicus are crepuscularand nocturnal. Although they enter “fales” at night, their density there is very low when comparedto what one would expect from the profusion of breedingthat occursclose by. A. oceanicus doesnot rest in “fales” during the day and is not a vector of filariasis. 309 DISTRIBUTION. WesternSamoa: Savaii (Aopo, Asau, Paia, Saleia,Samauga, Sale ’aula). Upolu (Afkmalu, Aleisa, Mafa Pass,Malua, Manunu, Moata’a Stream or Swamp, Luatuanu’u, Solosold,hipa ’a, Tuanai, Vaiusu, Vavai). American Samoa: Tutuila (Aasu, Agriculture Farm, Alofau, Amalvia, Aoa, Aoloau, Amouli Ridge, Fagasa,Faleniu, Fagaalu,Fighter Strip, Laloaloa, __-- _--- .- _ ___ .___- _..- -_- ___ - .- Malaeloa,Mapusaga, Masemau, dlh Aoloau, Pavais, v&a). Manua Group (df$)l ?%&z~. Tonga: Tongatabu (Hofoa, Houma, Matahau, Pea,Tofua, Nuku’alofa, Havelu). Eua (Futu, Government Farm, Ohonua, Petani, ReichlemannEstate, Government Saw Mill, Tongamama’o). Matuku. Tofua. Also reported from Wallis Island and questionablyfrom Futuna Islands(Alofi) by Belkin (1962). 4. Aedes (Stegomyia) aegypti (Linnaeus) 1762. In Hasselquist,_-. Reise nach Palaestina,470 (as CuZex aegypti). Egypt (Neotype, BMNH). STAGES DESCRIBED. M*, F*, P*, L* (Carpenter and LaCasse,1955:261-262; Christophers, 1960; Belkin, 1962:442). BIOLOGY. The immature stageswere found only in artificial containers,the typical breeding sitesof aegypti in the South Pacific. In Tonga, aegypti was found breedingin associationonce each with A. tabu and C. quinquefasciatus. No aegypti wascollected in Tutuila during the surveyin 1963 but it wassubsequently repotted in PagoPago (Hitchcock, personalcommunications, 1969). In WesternSamoa and Tonga aegypti was collectedin the larger villagesand in the towns of Apia and Nuku’alofa where the adults were presentin a high enough density to be considereda nuisance. DISTRIBUTION. WesternSamoa: UpoZu (Apia, Aleisa). Tonga: Tongatabu (Nuku’alofa, Hogoa,Matahau). Haapai (Belkin, 1962). Reported widely from many other islandsin the South Pacific and throughout the tropical regionsof the world. 5. Aedes (Stegomyia) polynesiensis Marks 195 1. Ann. Trop. Med. Parasitol.45: 138. Ura, Taveuni, Fiji (BMNH). Prior to 195 1 this species wasreferred to aspseudoscutellaris. STAGES DESCRIBED. M*, F, P*, L* (Marks 1954:383, M*, F*; Rosenand Rozeboom, 1954: 531, L*; Belkin, 1962:466, M*, F, P*, L*). BIOLOGY. Sincepolynesiensis is the principal vector of subperiodicBancroftian filariasisand of Dengueover a wide areaof the South Pacific, it has attracted much notice. Severalworkers have studiedits biology, notably O’Connor (1923), Buxton and Hopkins (1927), Jachowski(1954), Bonnet and Chapman (1958), Ramalingam(1968) and Suzuki and Sone (1973). A very brief review of the biology is given below. Aedes polynesiensis is the predominant speciesin Samoaand the immature stageswere obtained in 55 collections. It showsa great deal of plasticity in the selectionof the breedingplaces and will breedin treeholes,rockholes, coconut shells,artificial containers,cocoa pods, bananastumps and leaves,crabholes and leaf axilsof Pandanus. In most of the breedingsites it occurredalone but on rare occasionsit was found breedingin associationwith Toxorhynchites amboinensis, CuZex quinque- fasciatus, C. sitiens, Aedes oceanicus, A. tutuilae and A. samoanus. Although the biting activity of polynesiensis is largely diurnal some femalesbite at night, both in “fales” and in the bush. Aedes polynesiensis is diurnally active, with two peaksof activity, a Mosquito Systematics 305 lesserone in the morning and a greaterone in the afternoon. It doesnot rest in housesexcept on rare occasions.Man is the principal host for polynesiensis although this specieswill also feed on pigs,horses and dogs. The seasonalperiodicity of polynesiensis showsthe speciesto be present throughout the year with a peak in March and its lowest density in September. DISTRIBUTION. WesternSamoa: Savaii (Aopo, Asau, Falealupo, Matavai, Saleia,Vaisala). Up& (Afiamalu, Aleisa, Faleolo, Mafa Pass,Malua, Manunu, Moata’a Stream or Swamp, Mulifanuai, Paepaeala,Puipa ’a, Satepuala,Solosolo, Vaiusu, Vavau). American Samoa: Tutuila (Aasu, Amouli, Amanave,Aoa, Aoloau, BreakersPoint, Coconut Point, Fagasa,Fagasa Pass, Fighter Strip, Futigo, Malaeloa,Masefau, Old Aoloau, PagoPago, Tafuna, Vatia). Uftl. Swains. Also occursin the following islandgroups or islandsin the South Pacific: Fiji, Horne, Wallis, EZZice,Tokelau, Cook (Northern and Southern),Austral, Marquesas, Tuamotu, Pitcairn, Society Islands. 6. Aedes(Stegomyia) upolensis Marks 1957. Ann. Trop Med. Parasitol.5 1: 5 l-57. Afiamalu, Upolu, Samoa(BMNH). STAGES DESCRIBED. M*, F, P*, L* (Marks, 1957:5 1, M*, F, P, L; Belkin, 1962:477, M*, F, P”, L”). DISCUSSION. Aedes (A.) upolensis can be distinguishedfrom polynesiensis, the only other member of the ScutellarisGroup in Samoa,by the following characters.(1) In the adults, the lower mesepimeralpatch of scalesis either missingor consistsof 3 or fewer scales.(2) The female hasa complete or almost complete subbasalband on tergite VII. (3) The male has stout specializedsetae on the claspetteof the genitalia. (4) The larvahas an incomplete saddle;prothoracic hair 13 is present;and the upper and lower pairsof gills are approximately equal in length. BIOLOGY. The immature stagesof upolensis were obtained in only 2 collections,one in a forest tree trunk at the edge of the rain forest in Tofuna, Tutuila and the other in a fern tree stump in Afiamalu, Upolu. Femaleswere alsoobtained in severalbiting collections. This speciescan be describedas a truly forest mosquito. The adults were obtained on severaloccasions, but alwaysin densebush. They do occur at the edgeof somevillages where the virgin forest bordersthe village. They feed readily on man and eggswere obtained from severalfemales. Like polynesiensis, this speciesis diurnal but becauseit is not abundantno opportunity aroseto make detailed observations on biting habits, restingplaces or even breedingsites. Aedes upolensis is a minor vector of Wuchereria bancrof ti. DISTRIBUTION. WesternSamoa: Savaii (Aopo). UpoZu (Afiamalu, Aleisa, Manunu, Solosolo). American Samoa: Tutuila (Aasu, Aoloau, Tofuna). Manua (islandnot specified,Belkin, 1962). 7. Aedes(Stegomyia) tongae Edwards 1926. Bull. Entomol. Res. 17: 103 (asAedes (Stegomyia) variegatus var. tongae). Haapai, Tonga (BMNH). STAGES DESCRIBED. M*, F (Edwards, 1926, M*, F; Marks, 1954, M*, F*; Belkin, 1962: 475, M*, F, the immature stagesof Belkin pertain to Aedes tabu; Huang, 1972:338, M*, F). 306 DISCUSSION. Until 1965 Aedes (S.) tongae wasthe only member of the ScutellarisGroup known from the islandsof Tonga. It had been raisedto full specificrank by Farner and Bohart (1945). A secondmember of the ScutellarisGroup wasdescribed from Tonga by Ramalingamand Belkin (1965). These studiesindicated that tongae wasactually restrictedto the Haapai and Vavau groupswhere it was the dominant species.It doesnot occur in the Tongatabugroup whereAedes tabu is the dominant form. Both speciesoccur in the Haapaigroup but only Aedes tongae is presentin the Vavau group. Aedes tongae resemblesAedes cooki Belkin, 1962 from Niue Island closelybut due to insufficient material it is not possibleto establishif cooki is in fact synonymous with tongae at this time. BIOLOGY. Ten collectionsof immature stagesof tongae were made in treeholes. These were mostly in coconut treesand included the large “tree wells” used for collectingrainwater for domes- tic purposes. One of the treeholeswas in a fern tree and another in a rotting papayastump. The organiccontent of the latter wasvery high, resultingin a foul odor. Three collectionswere obtained from coconut shellsand 3 from the leaf axils of Pandanus. Aedes tongae was found to breed in as- sociationwith Aedes h!S.)’ tabu in 3 collectionsfrom treeholesand with Aedes (F.) oceanicus in 2 collectionsfrom the leaf axils of Pandanus. Nothing is known about the bionomicsof the adults except that the femalesbite during the day. As it is the dominant member of the ScutellarisGroup in the Vavau and Haapai groupsit probably actsas the vector of filariasisin theseareas. DISTRIBUTION. Tonga: Haapai group (Matuku, Tofua). Vavau Group (Vavau). Not known elsewhere. 8. Aedes(Stegomyia) tabu Ramalingamand Belkin 1965. Am. Entomol. Inst., Contrib. l(4): l-3. Eua Island, Tonga (USNM). STAGES DESCRIBED. M*, F, P, L (Ramalingamand Belkin, 1965). DISCUSSION. Prior to 1965 this specieswas not separatedfrom tongae by Edwards(1932: 165); Taylor (1934:20); Farner and Bohart (1945:44-45); Marks (1954:352); Iyengar (1955129; 1960:60); Laird (1956:80); Stone, Knight and Starcke(1959); Belkin (1962:475-476) and Stone (1963:129). BIOLOGY. The breedingplaces of Aedes tabu in order of importance are: (1) treeholes, (2) artificial containers,(3) coconut shellsand spathesand (4) leaf axils of taro. As most of the islandsin Tonga are elevatedcoral islandsor coral atolls , rockholesare very scarce. Thus a breed- ing placeof some importance to membersof the ScutellarisGroup in the Society Islands,Samoa and Fiji is of little consequencehere. The hairy form of tabu wasobtained in 4 collections,2 in treeholesand 2 in artificial containers. Aedes tabu wasfound to breed in the leaf axils of taro in 9 collectionsbut wasnot recoveredfrom the leaf axils of Pandanus. A. tongae, on the other hand, wasfound in the leaf axils of Pandanus, among other plants, but never in taro. All the breeding placesof tabu were situatedin partial or deep shade. The water rangedfrom clear to very turbid, the latter being more frequent in the caseof treeholes. Aedes tabu was found to breed in associa- tion with the following species:Aedes aegypti (l), Aedes tongae (3), Aedes oceanicus (9), Culex (C.1 annulirostris (1) and Culex (C.) quinquefasciatus (2). Aedes tabu is a semidomesticspecies but it is primarily a bush mosquito that bites out-of-doorsand doesnot rest in housesduring the day. It is most abundant in plantationsbut alsooccurs in shadyareas in villages. Mosquito Systemat~es Vol. 8(3) 1976 307 DISTRIBUTION. Tonga: Tongatabu (Havelu, Hofoa, Houma, Matahau, Nuku’alofa, Tofoa). Eua (Government Farm, Chonua, Petani, ReichlemannEstate, Government Saw Mill). Matuku. Tofua. Not known elsewhere. 9. Aedes(Aedimorphus) vexans vexans (Meigen) 1830. Syst. Beschr.Zweifl. Insekt. 6:241; near Berlin, Germany (MNHP). DISCUSSION. This specieswas referred to in the past asAedes (Aedimorphus) vexans (Edwards,1924:372, 1932: 170-l 71; Buxton and Hopkins, 1927:9 l-95; Taylor, 1934:20; Paine, 1935, 1943:22-23; Lee, 1944:72; Knight, Bohart and Bohart, 1944:35-36; and Perry 1946) and asAedes (Aedimorphus) vexans nocturnus (Bohart and Ingram, 1946: 15-l 7; Knight and Hull, 1953:460-463; Iyengar, 1955:30; Laird, 1956; Rageau, 1958:3-4; Stone, Knight and Starcke, 1959). Belkin (1962:427) treated it asA. nocturnus and Reinert (1973) synonymizednocturnus with vexans vexans. STAGES DESCRIBED. M*, F, P*, L* (Bohart and Ingram, 1946: 15, M*, F, P*, L*; Yama- guti and LaCasse,1950:73, M*, F*, L*; Knight and Hull, 1953:460, M*, F, L; Belkin, 1962:427, M*, F, P*, L*; Reinert, 1973:66, M*, F*, P*, L*). BIOLOGY. Six collectionswere made of vexans in American Samoa,Western Samoa and Tonga, all in shallowground pools, often with a lot of grassand other vegetation. The speciesdid not occur in large numbers. The adults are nocturnally active and will occasionallybite man. Four femalesof vexans were collectedindoors in Tongatabu. DISTRIBUTION. WesternSamoa: Savaii (Aasu). Upolu (Apia, Manunu, Paepaeala). Ameri- can Samoa: Tutuila (Malaeloa). Olosega. Tonga: Tongatabu (Hofoa, Tofoa). Tofua. Widely distributed in the South Pacific, and Eurasiaand North America. I 0. Culex (Culex) pipiensquinquefasciatus Say 1823. Acad. Nat. Sci. Phila., J. 3: 10. New Orleans,LA, U.S.A. (NE). DISCUSSION. This specieswas introduced into the South Pacific during the daysof the sail- ing ships. Known in the Commonwealth and Europe asCulex pipiens fatigans (Wiedemann). STAGES DESCRIBED. M*, F*, P*, L* (Belkin, 1962:195, M*, F, P*, L*; Eram, 1967: 192, M*, F*, P*, L*). BIOLOGY. This speciesbreeds in polluted to relatively clean watersin cement drains,cisterns and other artificial containers. Femalesare nocturnally active and will rest in housesduring the day. It is not important as a vector of filariasisin the South Pacific. _’ DISTRIBUTION. WesternSamoa: Upolu (Afiamalu, Apia, Asau, Manunu, Satepuala,Solo- solo, Vaiusu, Fagali’i). American Samoa: Tutuila (Aoloau, BreakersPoint, Fagaalu,Fagatogo, Futigo, Leloaloa, Mapusaga,Pago Pago, Tofuna, Malaeloa). Tonga: Tongatabu (Havelu, Hofoa, Matahau,Nuku ’alofa). Widely distributed elsewherein the South Pacific and throughout the tropical, subtropical and warm temperate regionsof the world. 308 Il. Culex (Culex) annulirostrisSkuse 1889. Linn. Sot. N. S. W., Proc. 2(3): 1737-1738. Blue Mountainsand Berowra,New South Wales, Australia(MM). STAGES DESCRIBED. M*, F, P*, L* (Knight and Hurlbut, 1949:30, M*, F, P, L*; Bohart, 195780, M*,_F, L*; Belkin, 1962:207, M*, F, I’*, L*). BIOLOGY. In Samoaand Tonga this specieswas most frequently collectedin ground pools and severaltimes in large artificial containers. The latter resembledground pools sincethey con- tained considerableamounts of mud and organicdebris. This specieswas found more frequently in Upolu, Savaii,Tongatabu and Eua than in Tutuila. Culex annulirosfris occurredin association with Aedespolynesiensis and with Aedes tabu in artificial containers. It wasalso associated once with Aedes vexans vexans and severaltimes with Culex quinquefasciatus. ?Zz&x’ &zuh&ris is a seriouspest mosquito in the Solomonsand in the New Hebrides.%is is not the casein Samoaand Tonga where it bites man only occasionally. DISTRIBUTION. WesternSamoa: Savaii (Falealupo, Sasina,Vaisala). Upolu (Apia, Faleolo, Mulifanuai, Paepaeala,Satepuala). American Samoa: Tu tuila (FagasaPass, Fatatogo, Futigo). Tonga: Tongatabu (Hofoa, Matahau,Nuku ’alofa, Pea,Tonga College). Eua (Ohoniva, Reichlemann Estate,Tongamamao). Nomuka. Tofua. - Widely distributed elsewherein the Pacific and in the Indomalayan region. 12. Culex (Culex) sitiensWiedemann 1828. Aussereurop.Zweifl. Insekt. 1:542. Sumatra (ZMC). STAGES DESCRIBED. M*, F*, P*, L* (Bohart and Ingram, 1946: 18, M*, L*; Yamaguti and LaCasse,1950:30, M*, F*, L*; Belkin, 1962:205-206, M*, F, P*, LT). BIOLOGY. This specieswas especially abundant in Tutuila and was collected only occasion- . ally in Upolu. It has been reported from Tongatabuin the past (Iyengar, 1960; Belkin, 1962) but only a singleaberrant female was collectedduring this survey. The immature stageswere collected many times in shallow rockpoolsclose to the seaand once in a coconut shell. The water tempera- ture in thesepools rose considerablyduring the afternoon owing to direct exposureto the sun. The salinity in the pools varied considerablyand sometimesapproached that of seawater. C. sitiens was found in associationwith A. polynesiensis severaltimes. DISTRIBUTION. WesternSamoa: Upolu (Manunu, Solosolo). American Samoa: Tutuila (Alofau, BreakersPoint, Laloae, Laulii). Tonga: Tongatabu (Havelu, Hofoa, Matahau, Nuku’alofa). This speciesis widely distributed in the South Pacific and occursin the Ethiopian and Oriental Regions. 13. Culex (Culex) samoaensisEdwards 1914. Entomologist 47: 36-37. Apia, Samoa(BMNH). STAGES DESCRIBED. F (Edwards, 1914:36; Belkin, 1962:2 11-212). Mosquito Systematics VOL. 8(3) 1976 309 I BIOLOGY. Only 3 femalesare known of this species,2 of thesecollected in a latrine. Rare. DISTRIBUTION. WesternSamoa: Upolu (Apia). Not known elsewhere. 14. Coquillettidia(Coquillettidia) samoaensisStone 1966. Entomol. Sot. Wash.,Proc. 68:33 l-333. Tau Island, Manua Group, American Samoa(USNM). DISCUSSION. Belkin (1962:309) examined a singlemale from Upolu and provisionallyincluded it with fij’iensis. Stone (1966) obtained 2 additional specimensfrom the Manua group and described them asa new species. Not collectedduring the survey. STAGES DESCRIBED. M*, F (Stone, 1966:331). BIOLOGY. A very rare species.Only 3 adults obtained so far from the localitiesindicated. DISTRIBUTION. WesternSamoa: Upolu (Moata’a Stream). American Samoa: Manua Group: Tau Island. Not known elsewhere. I5. Toxorhynchites(Toxorhynchites) amboinensis (Doleschall) 1857. Natuurkd. Tijdschr. Ned.-Ind. 14:381-382. Amboina, Moluccas,Indonesia (NMW). DISCUSSION. This specieswas introduced into American Samoain 1955 mistakenly assplendens for the purposeof controlling Aedes poZynesiensis(Peterson, 1956). As in most other speciesof Tox- orhynchites there is marked sexualdimorphism in the adults of amboinensis. This hasundoubtedly led to misidentificationsof the malesand femalesas two different species.The female of amboinensis resemblessplendens quite closely,actually inornatus even more. The male, on the other hand, is super- ficially quite similar to that of brevipazpisexcept for the dark scaletuft of abdominal segmentVIII. STAGES DESCRIBED. M*, F*, P*, L* (Doleschall, 1857:381, adults;Banks, 1906, M*, F*; Ramalingam,1965, P*, L*; Steffan, 1968: 150,310, M*, F*, P*, L*). BIOLOGY. Immature stagesof amboinensis were found on Tutuila in leaf axils of Colocasia, Alocasia and Pandanus, in treeholes,a bamboo stump and a rockhole. The principal breedingsites for this speciesare the leaf axils of Colocasia. Adult femaleswere collected twice, on one occasion restingon a tree trunk and on anotherjust after oviposition. Oviposition took place around 1200 hrs. on an overcastday in a large cavity filled with water on a fallen tree trunk. The female was ob- servedto move up and down (dance) over the treehole water a distanceof about 0.6 m, startingfrom a height of about 1 m and graduallyapproaching the water surface. When the movementscame to about 10 cm the female would strike the water surfaceand deposit an egg. DISTRIBUTION. American Samoa: Tutuila (Aasu, Agriculture Farm, Aoloau, Masefau,Tofuna, Vatia, Fighter Strip). Occursnaturally in SoutheastAsia; introduced and establishedin Hawaii and from there to Samoa. 310 KEYS TO THE MOSQUITOES OF SAMOA AND TONGA There are no publishedkeys to the mosquitoesof Samoaand Tonga. The only availablere- cent keys are those of Belkin (1962) and theseinclude the entire mosquito fauna of the South Pacific. Keys to the adults, pupae and larvaeof the mosquitoesof Samoaand Tonga are given below. ADULTS Toxorhynchites 1. Proboscisrigid, apicalhalf sharplyrecurved and narrower than the basalhalf; scutellum rounded posteriorly;very large,brilliantly colored species(Toxorhynchites) ...... *...... amboinensis Proboscisnot rigid, apicalhalf not sharplyrecurved and about equal in width to basal _-half;scutellum trilobed posteriorly ...... 2 2(l)* Postspiracularbristles absent ...... 3 Postspiracularbristles present (Cedes) ...... 7 Coquillettidia 3~2). Dark scalingof abdomenpurplish violet, light scalingdeep golden (Coquillettidia) ...... samoaensis Dark scalingof abdomenbrown or blackish,light scalingwhitish or yellow (Culex) . . 4 Culex 4(3 ). Labium without distinct complete median light ring; tarsi without distinct basallight markings; 1 or more mesepimeralbristles present ...... quinquefasciatus Labium with a distinct complete light ring; tarsi with distinct basallight markings; lower mesepimeralbristles absent ...... 5 5(4). Abdominal tergitesII-VI without any indication of transversebasal pale bands,only indistinct lateral pale spotspresent ...... samoaensis One or more of abdominal tergitesII-VI with more or lesscomplete transversebasal palebands ...... 6 6(5). Foretibia with a line of small pale spotson anterior surfaeealong dorsalrow of ...... bristles...... annulirostris Foretibia without any pale spotson anterior surfacealong dorsalrows of bristles ...... sitiens Aedes Wing with conspicuouspattern of dark and light spotsor areas(Finlaya) ...... 8 Wing without any pattern of dark and light spotsor areas,largely dark scaled,some- times with small basallight spot or some scatteredpale scales...... 9 Wing predominantly dark, baseof vein C largely dark; no accessorysubcostal pale area on vein C ...... 1 ...... oceanicus Wing predominantly light, baseof vein C largely light; accessorysubcostal pale area frequently developedon vein C ...... samoanus,tutuilae Mosquito Systematics Vol. 8(3) 1976 311 9(7). No silvery white scaleson mesonotum, pleuron or legs (Aedimorphus) ...... vexans vexans Conspicuous silvery white scaleson mesonotum, pleuron and legs (Stegomyia) . . . . .10 lO(9). Mesonotum with lyre-shaped silvery markings; clypeus with a pair of patches of sil- very scales ...... aegypti Mesonotum with conspicuous narrow median longitudinal line of silvery scales and a supraalar silvery line on each side; clypeus without silvery markings (Scutellaris Group; key to females only, for males use key to genitalia) ...... 11 1 l( 10). Lower mesepimeral area without silvery scales or at most with 3 scales . . . . . trpolensis Lower mesepimeral area with a conspicuous patch of many silvery scales ...... 12 12( 11). Abdominal tergite VII usually with a complete or dotted transverse dorsal silvery band connecting lateral silvery markings; one or more additional tergitcs usually with complete or dotted transverse silvery bands ...... tabu Abdominal tergite VII with lateral silvery markings not connected by complete or dotted transverse dorsal bands; other tergites usually at most with a few light scales dorsally in middle but without distinct bands ...... 13 13(12). Abdominal tergites usually without pale scalesdorsally suggestingtransverse bands; hind tarsal segment 4 usually silvery for 0.67 or more ...... polynesiensis Abdominal tergites usually with some pale scalesdorsally suggestingtransverse bands; hind tarsal segment 4 silvery for about 0.5 ...... tongae MALE GENITALIA Toxorhynchites 1. Segments VII and VIII with dense lateral tufts of long linear scales:tergite IX long (Toxorhynchitcs) ...... arnboinensis Segments VII and VIII without dense lateral tufts of long linear scales;tergite IX varied but never long ...... , ...... 2 2(l). Proctiger strongly developed, paraproct with a transverse crown of numerous apical spines, denticles or spicules, nearly always more than 6 and usually very conspic- uous; sidepiece with subapical lobe bearing specialized setae; phallosome complex (Ciclexb ...... 3 Proctiger variously developed, paraproct if distinct usually with not more than 5 spines projecting tcrgally: sidepiece without subapical lobe; phallosome simple ...... 5 3w. Inner division of phallosome simple, entirely sternal and sharply bent laterad to form a large acute spine ...... quinquefasciatus Inner division of phallosome complex, with at least some denticles projecting tergally on apex ...... 4 4(3). Basal sternal process of proctiger not devclop=tl or inconspicuous, very short or mod- erately long but weak and poorly pigmented . . . . _ ...... annulirostris Basal sternal process of proctiger very conq%cIIous, lon g, curved and darkly pigmented...... sitiens 322 Coquillettidia 5(2). Paraproctwith at least 3 distinct spines(Coquillettidia) ...... samoaensis Paraproctusually with at most 1 distinct spine(Aedes) ...... 6 Aedes 6(5). Aedaguswithout teeth (Finlaya) ...... 7 Aedaguswith severalapical teeth on each side ...... 9 7(6X Specializedbasal mesa1 seta hairlike, slender,smoothly curved,at most slightly flat& tened distally ...... samoanus Specializedbasal mesa1 seta not hairlike, distinctly flattened, expanded,widened or angledbeforeapex ...... _...... 8 8(7). Sidepiecewith postmediancentral mesa1patch a densegroup of long, pointed, apically curved hairs;a row of 3 to 5 hairs with very broad bladelike or spoonlike apical expansions,extending from the specializedbasal mesa1 seta distad ...... tutuiZae Sidepiecewith postmediancentral mesa1patch absentor with only a few hairs;row of specializedhairs absent ...... oceanicus 9(6). Clasperirregular in shape;spiniform arisingfrom a distinct preapicallobe (Aedi- morphus) ...... vexansvexans Claspermore regularin form; spiniform arisingapically (Stegomyia) ...... 10 lO(9). Ninth tergite deeply emarginatein the middle and with very largebroadly triangular lateral lobes ...... aegypti Ninth tergite rounded, truncate or produced into a lobe in the middle and with very small ventrolaterallobes ...... 11 1l(10). Claspettewith lateral or sternolateralhairs extending almost to point of attachment of lobe to sidepiece ...... polynesiensis Claspettewith lateral or sternolateralhairs extending only about halfway to point of attachment of lobe to sidepiece ...... 12 12(11). Claspettelong, apicalhairs about aslong as lobe ...... upolensis Claspetteshort, apicalhairs only slightly more than half length of lobe ...... 13 13(12). Apical hairs of claspetteextending basadto about 0.25 of entire claspette;average length of specializedsetae 0.046 mm ...... tongae Apical hairs of claspetteextending basadto about 0.34 of entire claspette;average length of specializedsetae 0.053 mm ...... tabu PUPAE Coquillettidia 1. Hair 4-C absent,all cephalothoracichairs very small: trumpet without pinna, apex specializedfor piercingplant tissue ...... samoaensis Hair 4-C alwayspresent, some of the cephalothoracichairs usually moderately to very strongly developed;trumpet with pinna ...... 2 Mosquito Systematics Vol. 8(3) 1976 313 Toxorhynchites 2(l). Anal segmentwith conspicuousbranched cereal hair (1-X) ...... amboinensis Anal segmentwithout any cerealhair (1-X) ...... 3 3(2). Hair g-VIII usually removed distinctly cephaladfrom caudolateralangle on sternal surface;paddle usually with both hairs 1,2-Ppresent; hair l-IX usually present, alwaysa simple bristle(Culex) ...... 4 Hair g-VIII usually at caudolateralangle; paddle with only hair 1-P present;hair l-IX irregularwhen present(Cedes) ...... 6 Culex 4(3)* Hair 5-IV usually at least 5-branched;6-V,VI usually at least4-branched. . .annuZirostris Hair 5-IV usually double or triple; 6-V,VI usually 2- or 3-branched ...... 5 5(4). Hairs 6-V,VI markedly strongerthan 6-W, usually double ...... sitiens Hairs 6-V,VI not markedly strongerthan 6-IV, double or triple ..... quinquefasciatus Aedes 6(3 ). Paddle marginswith long fringe of filamentoushairlike spicules(Scutellaris Group) . . 7 Paddle marginswithout spiculesor with short or indistinct spicules ...... 10 7(6). Hair l-11 primarily branchedonly and with at least 5 branches ...... 8 Hair l-11 secondarilybranched or with only 3,4 simple branches...... 9 g(7). Hair 10-C usually double; hairs 5-11and 5-IV alsousually double ...... tongae Hair 10-C with 3 or more branches;hairs 5-11and 5-IV usually unbranched...... tabu 9(7). Hairs 9-VI,VII heavy, with barbsor branches ...... polynesiensis Hairs 9-VI,VII slender,smooth and single ...... upolensis 1O(6). Hair 1-C of the sameorder of magnitude ashairs 2,3-C, smalleror at most 1.5 as long ...... 11 Hair 1-C at least twice aslong ashairs 2,3-C; 2-11distinctly mesadof hair 3-11(Kochi Group)...... 12 1 l( 10). Hair 2-VI distinctly laterad of hair l-VI ...... aegypti Hair 2-VI mesador at level of hair I-VI (Aedimorphus) ...... vexansvexans 12( 10). Mesonotum with severalclear, unpigmentedspots; trumpet dark brown and in sharp contrast with the rest of the cephalothorax ...... tutuilae Mesonotum with one pair of clear, unpigmentedspots; trumpet samecolor as cephalothorax ...... 13 13(12). Metanotum without clear, unpigmentedspots ...... samoanus Metanotum with a pair of clear, unpigmentedspots ...... oceanicus LARVAE Toxorhynchites 1. Each mouthbrush composedat most of 10 stout rods; abdominalhairs in groupsof 3-5 on common basaltubercles (Toxorhynchites) ...... amboinensis 314 Each mouthbrush composedof at least 30 slenderfilaments; abdominal hairs not on commontubercles ...... 2 Coquillettidia 2(l). Valves of siphon serrated,about aslong asbody of siphon, adaptedfor piercing plant tissues(Coquillettidia) ...... samoaensis Valves of siphon not serrated,much shorterthan body of siphon ...... 6 3~) Siphon with at least 2 pairs of hair tufts, exclusiveof preapicaldorsal hairs (Culex). . .4 %phon with only 1 pair of hair tufts, exclusiveof preapicaldorsal hairs (Aedes) . . . . .6 Culex 4(3X Head hair 1-C markedly flattened, its apex rounded or irregular ...... sitiens Head hair 1-Cvery slenderor moderately thickened, its apex acuminateor filamen- tous ...... 5 S(4). Head hair 1-C thickened, not filamentous distally, usuallyvery strongly pigmented*...... annulirostris Head hair 1-C very slender,distal part filamentous,sometimes basal part somewhat broadened,usually very lightly pigmented ...... quinquefasciiztus Aedes 6(3). Ventral brush of anal segmentwith 2 or more detachedunpaired proximal hairs not on grid or boss(Aedimorphus) ...... vexansvexans Ventral brush of anal segmentwith all hairspaired and all on grid or boss ...... 7 7(6). Caudal border of anal saddlewith very long marginalspicules; siphon usually spiculate; comb scalesin large patch (Finlaya) ...... 8 Caudal border of anal saddlewith short marginalspicules or none; siphon without dis- tinct spicules;comb scalesin a singlerow (Stegomyia) ...... 10 8(7). Head hair 4-C with 2-4 branches,6-C usually double or triple; spiculesof siphon very sparse ...... oceanicus Head hair 4-C with more than 6 branches;6-C with 4 or more branches;siphon uniform- ly coveredwith spicules ...... 9 9(8). Head hair 4-C with 7-l 1 branches,6-C with 4-6 branches;siphon moderately pilose, spiculessimple ...... tutuilae Head hair 4-C with 14-22 branches,6-C with 9-l 2 branches;siphon strongly pilose, spiculeswith 2-4 branches ...... samoanus 1O(7). Ventral brush with 5 pairs of hairs;comb scaleswith short basaldenticles . . . . aegypti Ventral brushwith 4 pairs of hairs;comb scaleswithout basaldenticles ...... 11 1l(10). Anal segmentwith saddleincomplete, broadly or narrowly interrupted ventrally ...... upolensis Anal ‘segmentwith complete saddle ...... 12 12(11). Hair4a-Xsingle ...... tab u Hair 4a-X double or triple ...... 13 Mosquito Sys-tematics Vol. 8(3) 1976 315 13( 12). Hair 5-M usuallydouble ...... tongae Hair 5-M usually single ...... polynesiensis ACKNOWLEDGMENTS I am deeply grateful to Dr. J. N. Belkin for his encouragementand guidancethroughout the period of thesestudies and for his critical readingof this manuscript. I have pleasurein thanking Dr. J. F. Kesselfor his guidanceand for his generousfinancial support, which made it possiblefor me to spendsix months in the South Pacific, collectingmaterial. I would especiallylike to thank the following: Dr. R. Kaufmann, Mr. H. Bumshock and Mr. Neal Spencer,in American Samoa;Dr. J. C. Thieme and Mr. P. Rasmussenin WesternSamoa: and Dr. S. Tapa and Mr. Kaufman (alias Tavi) in Tonga. My thanks go to SipaiaFatuesi, Fola Sone and PinayaMao, who accompaniedme on all the collecting trips and assistedme in variousways in American Samoa,Western Samoa and Tonga, respectively. REFERENCES Bahr,P. H. 1912. Filariasisand elephantiasisin Fiji. Lond. Sch. Trop. Med., J., Supl. 1 192 p. (Res. Mem. 1, 1). Banks,C. S. 1906. A list of Philippine Culicidae with descriptionsof some new species. Philipp. J. Sci. 1:977-1005. Belkin, J. N. 1962. Mosquitoesof the South Pacific (Diptera, Culicidae). Berkeley, Univ. Calif. Press. 2 vol. Bohart, R. M. 1957. Diptera:Culicidae. InsectsMicronesia 12( 1). 85 p. Bohart, R. 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Mimeographeddocument, WHO/FIL/73: 115, WHO/VBC/73-443. 15 p. Taylor, F. H. 1934. A check list of the Culicidaeof the Australianregion. Syd. Univ., Sch. Public Health Trop. Med., Serv. Publ. 1. 24 p. Theobald, F. V. 1914. A new mosquito from Samoa. Entomologist 47:36-37. Tonga, Medical Dept. 1957. List of mosquitoesof Tonga. Unpublishedcommunications to J. F. Kessel. Yamaguti, S. and W. J. LaCasse. 1950. Mosquito fauna of Guam. Hq. 8th Army, Off. Surg., APO 343. 101 p. TABLE 1. Recordsof Mosquitoesfrom Individual Islands in Samoaand Tonga 328 TABLE I: RECORDS OF MOSQUITOES FROM INDIVIDUAL ISLANDS IN SAMOA AND TONCA _TONGA SAMOA / I WESTERN AMERICA . MOSQUITO SPECIES . I AEDES I I . Finlaya I 1. samoanus l **o I I Stegomyia COQUILLETTIDIA 14. samoaensis TOXORHYNCHITES Toxorhynchites i 15. amboinensis I + + Recorded in present survey only. 0 Recorded in other surveys only. 0 Recorded in present and other surveys.