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PACIFIC SCIENCE, Vol. VI, April, 1952 
but hover-fly larvae (Syrphidae) were some- 
times present. 
The species was troublesome in the shade 
of abandbned buildings and at the jungle’s 
edge throughout the day, especially so in the 
late afternoon. On one occasion numerous 
A. hreinli together with a few Aides quasi- 
sciitellaris were noticed biting two domestic 
cats resting in the shade of a wall at midday. 
Culex (Culex) annulirostris Skuse, 1889, 
Linn. Soc. N. S. Wales, Proc. 13: 1737. 
Collections were made from 26 larval habi- 
tats, 16 of these being the ground pools 
utilized by Anopheles farauti. C. annulirostris 
was recorded from water in 44-gallon drums 
four times: once alone, twice in association 
with developmental stages of Aides quasi- 
scutellaris, and once with both this species 
and Anopheles farauti. Larvae were also found 
with those of A. quasiscutellaris in the flour 
drum indoors previously mentioned. The 
other larval habitats noted were truck tyres 
(twice), an exposed wheelbarrow holding a 
few inches of rain water (the midday temper- 
ature of which was recorded as 40°C.), a pool 
on the steel tray of an abandoned truck, and 
water held in the folds of a self-sealing rubber 
petrol tank. In the latter cases larval Chirono- 
midae were the only other arthropods present. 
C annulirostris was the most abundant and 
most troublesome mosquito during the 
earlier part of the evening. Adults of both 
sexes were attracted in large numbers to 
lighted huts. They were also collected during 
the day, together with Anopheles farauti, by 
sweeping the vegetation bordering ground 
pools. 
DISTRIBUTION 
Four of the seven mosquito species now 
listed Trom Nissan are common to the Solo- 
mon Islands and the Bismarck Archipelago: 
Anopheles farauti occurs throughout both 
island chains (Lee and Woodhill, 1944; Bel- 
kin et al., 1945; Laird, 1946^); Aides carmenti 
is common to the Solomons (Edwards, 1924; 
Paine and Edwards, 1929), New Ireland 
(Edwards, 1925), and New Britain (Laird, 
1946); Armigeres hreinli is known from the 
Solomons (Paine and Edwards, 1929) and 
New Britain (Laird, 1946); and Culex annuU- 
rostris occurs throughout the South Pacific. 
C. annulirostris is widespread in the Solomons 
(Edwards, 1924) and has been collected in 
New Britain (Laird, 1946). 
Of the other three species, one is indi- 
genous but closely related to a species found 
in both island groups, one has not been re- 
corded with certainty from the Solomons, and 
one does not occur in the Bismarck Archi- 
pelago. Lee (1945) states that Tripteroides 
nissanensis is closely allied to T. quasiornata 
(Taylor), which occurs in the Solomons (Bel- 
kin, 1945) and New Britain (Hill, 1925; 
Laird, 1946). Aides quasiscutellaris occurs 
throughout the Solomons (Earner and Bo- 
hart, 1945), but in the Bismarck Archipelago 
its place is taken by Aides scutellaris (Walker) 
(Stone and Earner, 1945; Stone, 1947). Aides 
kochi is a common mosquito in the Bismarcks 
where it is known from New Ireland (Taylor, 
1934) and New Britain (Hill, 1925; Laird, 
1946). There is no certain record of this 
species from the Solomons, and Marks (1947) 
states that Nissan is probably near its eastern 
limit. 
MEDICAL SIGNIFICANCE 
Malaria: Anopheles farauti is the principal 
vector of Plasmodium in the Solomons (Perry, 
1945) and an important vector in the Bis- 
marck Archipelago (Heydon, in Lee and 
Woodhill, 1944). 
Filariasis: Anopheles farauti is claimed to be 
the most important vector of Wuchereria 
bancrofti in the Solomons (Anon., 1944). 
Aides kochi (Marks, 1947) and Culex annuliro- 
stris (Anon., 1944) may also act as vectors for 
this parasite. 
SUMMARY AND CONCLUSIONS 
The mosquito control measures practised 
on Nissan Island throughout the period of 
