Voi!. 6(4)
Mosquito Systematics
A PICTORIAL
KEY
TO
1976
THE MOSQUITO
SEYCHELLES
343
LARVAE
OF THE
Eugene J. Gerberg and Ross H. Arnett, Jr.*
The Seychelles are a group of predominantly grani tic islands lying in the Indian Ocean approximately
1,000 miles east of the African coast and 2,000 miles southwest of Sri Lanka. The remoteness of the
Seychelles from mainland biota limits the number of species that can populate these islands. This same
remoteness also has prevented their thorough study by biologists prior to the influx of tourists. The
destruction of the natural ecosystem on the islands is a great biological loss.
Most likely the islands were formed from a crest or ridge of land left behind when India and Africa
separated during the drifting of these continents. These are the only granitic oceanic islands in the world.
The question remains: Does any part of the present day biota represent the continental species that
remained on the islands during drifting, or were the islands submerged? The speciesnow inhabiting the
islands are of three possible types: archaic remains of the continental biota; 2) invasions from India
or Madagascar (which species from which area?), or 3) autochthonous. The following list of mosquito
species are tentatively evaluated in this manner.
Mattingly and Brown (1955) reviewed the mosquitoes of Seychelles including historical references, and
listed 13 species from the Seychelles proper. The following species were collected by the authors during
the period of 8-15 August 1974 on the islands of Mahe and Praslin. The geographical distribution of the
species is given in brackets after the name. This is as recorded in Stone, Knight, and Starcke, 1959.
Aedes albocephalus (Theo.) [Tropical Africa; Madagascar] Mahe: Northpoint,
pond; Victoria Botanical Gardens 11 Aug 74, in rock pool.
10 Aug 74, in swampy
Cedes ulbopictus (Skuse) [Oriental Region; Australia; New Guinea, Mariana IsI.; Hawaii; Japan; French
Somaliland; Madagascar] Mahe: San Souci, 9 Aug 74 in rockhole; Victoria Botanical Gardens, 11 Aug
74 in leaf axil.
Cedes Zumbrechti van Someren [Autochthonous].
Mahe: Port Glaud, 12 Aug 74 in crab hole.
A&es vigilax vunsomerenue Mattingly and Brown [Autochthonous; typical subspecies: Coasts of
Australia, New Guinea, New Hebrides, New Galedonia, Indonesia, Thailand, Vietnam, Formosa,
and ? Malaya]. Mahe: Port Glaud, 12 Aug 74 in brackish water rock hole.
Culex futiguns Weid. [Gosmotropical]. Mahe: Victoria Botanical Gardens, 11 Aug 74, in rock pool.
C&x
simpsoni Theo. [Ethiopian Region]. Mahe: Rochon Dam, Filter Plant, 9 Aug 74, at edge of dam;
Northpoint, 10 Aug 74 in swampy pond.
Culex stellutus van Someren [Autochthonous].
Mahe: St. Louis Hill,
13 Aug 74 in tire.
Urunotuenia browni Mattingly [Autochthonous]. Praslin: Vallee de Mai, 14 Aug 74, in fallen rachis of
coca-de-mer; Mahe: Victoria Botanical Garden, 11 Aug 74, in leaf axil.
Urunotaeniu nepenthes (Theo.) [Seychelles and Madagascar]. Mahe: Sans Souci, 9 Aug 74, in flower
bracts of Nepenthes sp. Note: the species of the pitcher-plant family NEPENTHACEAEare distributed
from Madagascar to Sri Lanka, Burma, Malaya, northern tip of Australia to New Galedonia which
shows the close relationship between Madagascar and the Indo-Malayan region.
Urunotueniu punduni (Theo.) [Seychelles and Madagascar]. Mahe: Victoria Botanical Gardens,
11 Aug 74, in leaf axil; Praslin: Vallee de Mai, 14 Aug 74, in fallen rachis of Cocode-Mer.
In summary, 1 speciesis cosmotropical; 2 also occur in Africa; 4 are found in the Indo-Malayan region;
and 3 are autochthonous. Obviously no satisfactory conclusions can be drawn from these data as to the
origin of the Seychelles fauna.
The pictorial key to the larvae includes 12 of the 14 speciesreported the Seychelles. Not included in the
key are: Culex scottii Theo. [autochthonous] and Culex wigglesworthi Edw. [known from Central Africa,
but not Madagascar]. The larva of C. scottii is unknown and C. wigglesworthi has been reportedonly once
from Praslin. C. wigglesworthi would key to C. simpsoni, from which it can bedifferentiated by the comb
scales.
lB~~~~~~~
RESEARCHINSTITUTE OF AMERICA, 13.30 Dillon
Heights Ave., Baltimore,
MD 21228.
344
The authors are greatly indebted to Dr. David G. Reynolds and Mr. Vidot of the Medical and Health
Department. Their assistance and guidance made our collecting possible as well as pleasant. The
hospitality and graciousness at the pension of Madam M. Georges made our stay in Mahe very pleasant.
REFERENCES
MATTINGLY,
P. F. and E. S. BROWN. 1955. The mosquitoes (Diptera: Culicidae) of the Seychelles. Bull. Entom. Res. 46: 69-110.
LAMBRECHT, FRANK L. 1971. Notes on the ecology of Seychelles mosquitoes. Bull. Entom. Res. 60: 513-532.
STONE,r\l.AS, klC;tl
1’01.. 6, 3.58 ],I,.
I K. 1..ilIlt! ~r.ARRCKF.,
1IEI.I.E.
1939. ;I 4\‘11o])tt( (:tt;liog 01 t/It* n~ovluittxx\oi
thrwwrld. Thorna? Say Foundation.
345
VoZ. B(4) 1976
Mosquito Systematics
PICTORIAL
LARVAE
KEY TO THE MOSQUITO
OF THE SEYCHELLES
Eugene J. Gerberg
& Ross H. Arnett, Jr.
SIPHON
cylindrical or spindleshaped, not attenuated at tip
SIPHON attenuated, with
sclerotized saw-toothed
projection at tip
I
I
I
SIPHON with single pair of subventral setae
I
SIPHON
with
more numerous
subventral
,
1
setae
a
Mansonia
uniformis
,
MAXILLARY
incomplete
SUTURE
absent or
MAXILLARY
SUTURE
posterior ten torial pit
’
Culex
reaching
Aedes
Urano taen ia
I
THORAX
AND-ABDOMEN
many stellate hairs. SIPHON
many long spines
THORAX
AND ABDOMEN
, single hairs
,
wrth
with
with
,
I
LATERAL SETAE fine, pale.
COMB AND PECTIN SCALES
denticulate
1,ATERAL SETAE OF ABDOMEN
long, stout, dark. COMB AND
PECTIN scales fringed
I
Uranotaenia
hrowni
Uranotaenia
I
pandan
Urano taenia
nepenthes
?J
,
346
Culex
I
t
THORAX
AND ABDOMEN
stellate hairs
SETAE single, branched, not stellate
with
I
I
SIPHON 7 X long as wide. HEAD
SET;ZE l-2 blanches
1
SIPHON not more than 5 X long as
wid(b.
HEAD
SETAE
many
branched
Culex stellatus
Culex jatigans
Aedes
SIPHON
I
cylindrical and pale
SIPHON
1
not cylindrical
I
t
VENTRAL BRUSH with tufts
outside barred area
VENTRAL
b
BRUSH of
1
VENTRAL
BRUSH with
no tufts outside
barred area
I
1
VENTRAL BRUSH of
single setae
Aedes lambrechti
Aedes aegypti
I
HEAD SETAE 5 & 6 many branched,
SIPHON 2-3 X long as broad. ‘I‘UFT
of 4-6 branches
Aedes albocephalus
Aedes albopictus
I
HEAD SETAE 5 & 6 single
SIPHON short, TUFT of
IO- 15 branches
Aedes rligilax vansomerenae