18

SUPPLEMENT TO THE ANNUAL REPORT OF THE

anopheline were biting even in the day time. The anophelines caught were as
follows:—

      Culicifacies was the commonest of the malaria-carrying anophelines. Females
were commoner than males. Zygotes were found in 5 out of 50 dissected
mosquitoes and in one of these (a culicifacies specimen) sporozites were also found.
The zygote rate 10 per cent for culicifacies and fuliginosus combined, is extra-
ordinarily high and accounts for the severity of the epidemic. It looks as if
culicifacies is the chief malaria-carrier with fuliginosus a less important one simply
because of its smaller numbers.

Anopheline breeding places.—Streams from the mountains surround the main
village and enter large tanks, from these run irrigation channels to fields most of
which are dry, but a few of which are wet puddy fields. In and about Udayagiri,
and near the main irrigation channel draining the tanks are numerous wells. In
the whole area particularly near the tank bund are many pools of water in
depression, most of which are natural and some of which are borrow pits. Larvæ
were easily obtained and bred out from all these sources. The ease of breeding out
was in great contrast with the trouble at Mopad, and this though Mopad is only
30 miles away and though the expedition was in Mopad at an earlier and generally
cooler time of the year. It appeared to be cooler in Udayagiri in April than in
Mopad in March. Unfortunately temperature records are not available. The
species and numbers of anophelines bred out from larvæ are given below:—

      Fuliginosus, listoni and jamesi were all found in and near the main village
only. Fuliginosus and jamesi were obtained from wells. Jamesi was found in
only one well where it was breeding freely. Listoni was found in a grassy pool
formed by an overflow from the drinking-water conduit and in an adjoining
drainage stream. The main carrier culicifacies was obtained from every source in
abundance except from paddy fields and pools where only a few could be obtained
—rossi were much more common in these.

      Thus we see that the important breeding places are wells, irrigation canals,
tanks and streams. Where all provided anophelines so freely it is difficult to
apportion relative importance. The wells were mainly kutcha step wells with earth
bunds. Probably they play one of the most important parts in producing malaria