subsoil water-level will fall and water will not stay long in the beds of streams
and drains. But even in this case it would be an. improvement if some attention
were paid to avoiding collections of water in drains and natural stream beds.
Whatever is done to the Mopad area itself the adjacent part of the Maneru
in its present condition will always remain a serious menace to the health not only
of the Mopad tract but also of the villages on the other bank. It is doubtful
whether either of the alternatives mentioned for improving the Mopad tract will
affect the Maneru river to any serious extent, for the Manneru is the natural
drain for this part of the country, and after the onset of the south-west monsoon
will always tend to have water in it, and so will breed anophelines at the most
dangerous time of the year from July to January. The only remedy seems to be
to canalize it, but this may be not only expensive initially, but may have to be
done after every heavy monsoon, because the Maneru receives the spill water of
the reservoir. Perhaps it would be possible to arrange that the overflow of the
Maneru at this time is regulated in such a way as to prevent damage to the
drainage canal.
7. Recommendations.—The main problem is to diminish the anopheline
population between July and January. As is evident from the discussion the
permanent remedy is the reduction of the number of breeding places by one of the
two following plans:—
(a) by reverting to dry crop irrigation and by canalizing the Maneru
from the dam to just below Kambaladinne.
(b) by combining draining of the area and minor filling up of depressions
with wet crop irrigation, and by canalizing the Maneru.
We think that the problem is essentially an engineering one and that before
any action is taken that an Engineer be asked to give his opinion after a survey
of his own if sufficient data are not to hand. Such an opinion should include a
forecast of the effect on the Maneru of reverting to dry crop irrigation, for we
have assumed that doing so would not much diminish pools in the Maneru
between July and January. Our assumption may not be correct, in which case
reverting to dry crop irrigation alone would effectively diminish breeding places
throughout the Mopad and Maneru areas.
We doubt if any temporary anti-larval measures in the Maneru would
succeed. Jumbo grass would make oiling ineffective. Poisons such as Paris
green are not suitable for use here where there is a slight flow.
Minor measures have been indicated in the first report, and of these the
most important is the effective treatment of the people. Trees seem to be lack-
ing in most parts of the Mopad area. Tree-planting would probably assist in
keeping streams, canals and drains well aligned and in diminishing water-logging.
FIRST REPORT ON MALARIA IN UDAYAGIRI (APRIL 1926)
BY LIEUT.-COL. H. H. KING, I.M.S.
AND
CIVIL ASSISTANT SURGEON K. V. KRISHNAN.
Institution of the survey. —On the completion of a survey in Mopad, Dr. K. V .
Krishnan visited Udayagiri and Duttalur in early April at the request of the
Health Officer, Nellore, who had reported the presence of a severe epidemic of
malaria. Dr. Krishnan did all the field work and has helped in the writing of
this report.