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APPENDIX B.
ANNUAL REPORT OF THE WORK OF THE MALARIA BUREAU.
For the year 1932. By
R. B. Jackson, M.D., D.P.H.. Malariologist.
Staff.
The staff consisted of the Malariologist, Assistant to Malario logist, four probationer inspectors, one clerk and four coolies.
Work carried out during the year.
This was included under the following headings :
(a) General mosquito survey of the Colony and New Terri- ories in order to determine what species existed, their life histories, and, as far as possible, their identifications in the larval and adult stages.
(b) A general investigation of malaria and other mosquito-
borne diseases.
(c) The catching of mosquitoes frequenting habitations, their identification, and, the dissections of such Anophelines as were found, for malarial infection.
(d) Investigations as to the prevalence of malaria in certain areas and the conditions under which it was existing, with a view to its abolition.
(e) Local mosquito surveys for the abatement of mosquito
nuisance.
(f) The teaching of mosquitology and the instruction of the probationers in this and other matters bearing on
he subject.
(g) Co-operation with Government Departments, the Mili- tary, Naval and Air Forces, public companies and private individuals in the investigation and eradication of malaria.
(a) INVESTIGATION OF SPECIES AND THEIR LIFE HISTORIES. Anophelines.
The number and species of the various larvae examined are given in Table V: Table VI gives the number and species of the imagines obtained from pupae collected, and from pupae obtained from the larger larvae. As in 1930 and 1931, the larvae of A.
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When
maculatus were by far the most frequently met with. sought for, these can be obtained in large numbers throughout the seasons, and adults can be hatched out in the Laboratory at all times. This mosquito does not figure prominently in night or day ra ches as will be seen on reference to Tables VII, VIII, and ÏX; outdoor searches made near its breeding places have not been successful so far in obtaining any. Its larvae were occasionally found in unusual places, in water in a discarded Lucket, and in concrete basins. They were found in polluted streams, in one instance, a few inches below a dead frog in an advanced sate of decomposition. In December sixteen larvae of A. maculatus, and nineteen of A. minimus were found in a brick and cement tank on the site of the former Taikco Sanator- ium. A seepage from a rock was trickling into the tank. The site is approximately 1,200 feet above sea level, one mile as the crow flies from the nearest habitation and two and a half miles by road. No one had been living there for two years so that approximately to human dwellings would not appear to be es- sential to the existence of A. maculatus or A, minimus. Ravine streams met with on the Tytam path, over half a mile from human habitations have been selected for future investigations as to what species can be me. with in such situations. At Repulse Bay, cattle, horses, and pigs are absent, yet larvae of A. maculatus and A. Minimus can be found, so that such animals
ould not appear to be necessary for these Anophelines.
Larvae of A. hyrcanus were the next most commonly met with. The adults were not obtained in large numbers either in day collections or in night catches except when the night catch- ing was done near a swampy area as will be mentioned later. It may be that this mosquito generally leaves soon after it has fed, and so would not be numerous in day collections. This matter requires further investigation. From the results of searches made in a swampy area this mosquito would appear to have special times for breeding.
Larvae of A. minimus were obtained in greatest abundance after the rains in rocky bedded boulder strewn streams, especially in the neighbourhood of the hills. They were also found in irrigation ditches. They have been found in such streams and ditches in highly cultiva ed, thickly populated areas, where a good deal of pollution should find its way into these water courses. These larvae do not thrive so well in captivity as do those of A. maculatus and A. hyrcanus, and adults are not so easily obtained from them. The larvae are not often found alone being mostly associated with either A. maculatus or A. hyrcanus or both, very cften only one or two larvae were met with in a considerable length of stream or ditch where numerous larvae of the other varieties were found. During the rainy season whilst good num- bers of the adults were being captured with the ovaries in an advanced stage of development, very few larvae could be found in the saine area. These mosquitoes can be obtained during the
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