Aedes vigilax in Fiji— Burnett 
391 
are reasons for accepting this one. There is no 
doubt that the species was firmly established in 
Fiji in 1958, and the soil of the area which I 
was shown in June of that year was saline. 
A. vigilax is the only species likely to breed 
here in large numbers, except for the easily 
distinguishable Culex sitiens Wied, or possibly 
C. annulirostris Skuse. The origin of the plague 
of mosquitos at the airport buildings was not 
likely to have been within a mile of these build- 
ings because surface water is kept to a minimum 
within this radius by drainage and unavoidable 
collections of water are inspected regularly. It 
is characteristic of A. vigilax that it may be a 
serious pest for up to 5 mi. from its breeding 
place. There is in fact only one other mosquito 
in Fiji at all likely to be a pest in daylight in 
the middle of the large bare expanse of the 
airfield, and this is A. aegypti, which could con- 
ceivably breed undetected in water collections 
near the buildings themselves. It would, how- 
ever, be recognised by even the least competent 
mosquito inspector. There is no doubt that there 
was a mosquito nuisance at Nandi in October, 
1957, and it is very likely that this was due to 
A . vigilax, but whether it had really been estab- 
lished since the previous May is more doubtful, 
because reports of a plague at this time are not 
supported by any written confirmation. The 
year 1957 was unusually dry in Fiji and serious 
breeding of any other species would be most 
unlikely in this area at this time. In any event 
the October, 1957, report from Nandi precedes 
by several months reports of A. vigilax from 
elsewhere. 
STATUS OF A. vigilax IN EARLY 1959 
The plague of A. vigilax in the southeast of 
Viti Levu early in 1958 was brought to a sud- 
den end in April, when over 40 ■ in. of rain 
fell and there were extensive floods. Dense 
masses of larvae were seen being washed out to 
sea by the rising Rewa River. Surprisingly, the 
insect has not reappeared as a pest in the wet 
southeastern zone although there have been some 
unusually high tides which have left brackish 
pools above normal high water. A few larvae 
were found in the Rewa delta in January, 1959, 
but these were washed away by floods. In the 
dry zone of the island A. vigilax has persisted, 
notably In the Mba delta, in the general vicinity 
of Lautoka (in small numbers) , and near Nandi, 
where it greatly increased in numbers at the 
start of the rains in November, 1958 (Fig. 1). 
It also Infests the islands to leeward, e.g., Malolo, 
where it arrived before May, 1958, when the 
island was visited In response to a request for 
help from the islanders. In October, A. vigilax 
was still on Malolo and had reached the Ma- 
manutha Group to the north. It was not found 
to the windward of Viti Levu until January, 
1959, when it was found breeding on Makongai 
(Fig. 1). It may be assumed that the species is 
well established and will become a pest again 
in the wet zone when a suitable combination of 
conditions arises once more. In Fiji the habits 
of the insect closely resemble its habits in 
Australia. 
On August 27, 1958, four adult female A. 
vigilax were recovered from an aircraft which 
had been sprayed on landing at Nandi airport 
after a flight from Tontouta, New Caledonia. 
They were fresh and had almost certainly been 
alive at the time of spraying. 
A. vigilax as A vector of fijian 
Wuchereria bancroftii AND 
Diroftlaria immitis 
A. vigilax from both New Caledonia (Iyen- 
gar and Menon, 1956) and Sydney (Backhouse 
and Woodhill, 1956) have been shown to be 
highly efficient laboratory vectors of the New 
Caledonian strain of nonperiodic bancroftial 
filariasis, and it was feared that it would be 
equally hospitable to the Fijian strain of the 
same filar i a . The results of various feeding tests 
are given in Table 1. The mosquitos, aged 2-6 
days, were given a single blood meal on the 
infective subject and were at once isolated in 
3" X 1 " glass tubes containing a strip of filter 
paper and closed with mosquito gauze. A drop 
of sugar solution was placed each morning on 
the strip of filter paper and in the afternoon a 
drop of distilled water was added. For the last- 
three feeds some A, pseudoscutellaris (Theo.), 
which is an important vector in Fiji, were in- 
cluded as a check. The three Insects dissected 
immediately after the first feed had been killed. 
