30
The adults exhibit considerable powers of passing through long
periods of drought.
Mysorhynchus barbirostris.-Is found breeding in grassy pools
and drains. In one case the larv of this species were seen in pro-
fusion in some foul water in a tea-house drain along with the larv
of P. rossi.
The adults do not appear to fly to any great distance, as will
be seen in the section on flight. The adults also disappear very quick-
ly after the drying up of their breeding places.
Nyssorhynchus fuliginosus.-Is found in some parts of the district
where there are larger pools of weed-covered water, but never in very
large numbers.
FLIGHT OF ANOPHELES.
Very often in the Duars we have found anopheles in consider-
able numbers in spite of the fact that the nearest breeding places
were a considerable distance away. Houses and lines on high bluffs,
for example, are almost invariably infested with anopheles, though
breeding places in such cases are nearly always several hundred
yards away. It seems certain that M. listoni and N. theobaldi habi-
tually traverse distances up to a quarter of a mile, and in the case of
N. theobaldi we have seen an instance where it seems certain that
adults were traversing nearly double this distance to reach a bunga-
low on a steep bluff.
It has often been taken for granted that the flight of anopheles
is a " random " one, but all evidence is in favour of its being purpos-
ive. That anopheles exercise very intelligent action in attempt-
ing to gain an entrance to rooms and mosquito-nets is very evident to
one who notes their behaviour when frustrated; and their attrac-
tion by light often in very large numbers has been demonstrated
by us on several occasions. It is not at all surprising then that they
should direct their flight purposely towards light and sounds in a
bungalow, line, or bazaar, rather than be dependent on random