M 117
(a) Investigation of Species & Their Life Histories.
Anophelines.
4. The number and species of the various Anopheline larvae examined are given in Table I. Table II gives the number and species of the imagines obtained from pupae collected, and from pupae obtained from the larger larvae.
5. A. maculatus. In addition to its usual breeding places in hill streams, seepages, and ditches, in the month of May the larvae were found in the sumps of the Aqueduct which runs into Aberdeen Reservoir. They were obtained in numbers from streams receiving the washings from cow byres and the drainage from manure dumps. A few were occasionally collected from fallow rice fields, and also from the water in rice cultivation in the months of October and November.
6. Malarial infections in midguts and salivary glands were met with in the adults dissected, and larval filaria were also encountered. A comparatively large number of adults were obtained from the Shing Mun Camp, and from the cow byres and pigsties at the village of Wo Li Hop.
7. Unsuccessful searches were made for these mosquitoes amidst boulders in streams and hollows in the banks.
8. A. minimus. From observations made on various streams, it would appear that in some, the larvae can be found throughout the seasons unless soon after heavy downpours. In other streams they were not found during the five months May-September, and in some of these they were present only in small numbers, but in the remainder, towards the beginning and end of the year, they were almost as numerous as the larvae of A. maculatus. They were also met with in streams polluted by the drainage from cow byres. They were sometimes found in fallow rice fields, and sometimes in rice cultivation during October and November.
9. As in previous years, this Anopheline was found to be an important carrier of malaria, and harboured larval filaria.
10. A. hyrcanus. The larvae were obtained in small numbers in collections made in rice fields at Shek O during the period June-September. A marked increase took place in November, previous to the cutting of the second crop; they were numerous in collections made in November and December from pools in the rice stubble. Numbers were collected from fallow rice fields in various surveys.
11. Malarial infections were met with in this mosquito, also larval filaria.