22
SUPPLEMENT TO THE ANNUAL . REPORT OF THE
Both spleen and parasite rates particularly the latter are rather high than one
would expect. The explanation is that many of the Duttalur adults have been to
Udayagiri for several days at a time, e.g., for the revenue jamabandi which was on
at the time of the survey. Thus some of the adults probably got infected in
Udayagiri. This is an illustration of the necessity for choosing as healthy as
possible a town for administrative headquarters for the sake not only of local
inhabitants but also of villagers in the district.
Adult mosquitoes.—Culicines abounded. The number and species of ano
-
p h e l i n e s c a u g h t a r e a s f o l l o w s : —
A. culicifacies.
A. rossi.
Male.
Female. Total.
Mal e.
Female.
Tot al .
Number caught ...
...
...
2
2
4
30
18
48
Number dissected ... ...
...
2
2
...
...
...
Percentage malaria positive
...
Nil.
Nil.
The only malaria carrying anopheline found was A. culimtacies. It is
interesting to note how few adults were found here while only 10 miles west in
Udayagiri they were swarming. The importance of local variations affecting
adult anophelines is obvious. It will be remembered that in Mopad the carrier
anophelines were also scarce.
Breeding places.—Streams, irrigation canals, tanks and wells were the chief
sources of anopheline larvæ. Pools and borrow pits in most parts had dried up.
Larvae from all sources were bred out with the following results.
TABLE IV.—Species according to (A) village and (B) breeding place.
Name of village.
Culicifacies. Faliginosns. Stephensi.
Jamesi.
Rossi.
Duttalur
...
16
2
1
...
28
Kammavaripalem
...
...
3
. . .
. . .
33
14
Kattakindepalli ...
10
...
...
...
18
Lakshmipuram
...
...
6
...
2
...
13
Nature of breeding place.
Streams
...
15
...
...
...
25
Irrigation canals
...
...
12
2
. . .
. . .
25
Tanks
...
...
..
7
. . .
. . .
. . .
21
Wells ...
...
...
...
1
...
3
33
2
It is evident that culicifacies was found mostly in streams and irrigation
canals. The streams were hill streams which empty themselves into tanks. The
canals being kutcha and shallow, spread out into pools and formed ideal breeding
places for culicifacies. Fuliginosus was found in an irrigation canal. Stephensi
and jamesi were caught from wells—all the jamesi from a single well.
We see that the important breeding places during April are the hill streams,
irrigation canals and tanks. But as in the other reports it is difficult to estimate
the relative importance of breeding places from this survey alone. An autumn
visit is necessary.
Recommendations.—These are on the same lines as for Udayagiri because the
types of breeding places are the same except that wells play a minor part here.
Conclusion.—From this brief summary it is obvious that unlike Mopad and
Udayagiri, Duttalur does not suffer severely from malaria. The three reports
serve to illustrate the extreme importance of local conditions. Climatically and
in type of country Mopad and Duttalur are the same, but the former has the
special conditions described of wet crops high sub-soil water level and so on
accompanied by severe malaria, while Duttalur would appear to be on the same
level with regard to conditions and malaria as the control dry crop villages near
Mopad. So the survey of Dattalur tends to confirm the conclusion reached in the
report on Mopad that wet crop irrigation is mainly responsible for the more
severe malaria in Mopad. A comparison of Duttalur with Udayagiri illustrates
the severity of malaria that may be produced mainly by variations in climate
given certain favourable local conditions.