M 142
thus obtained either by pulling or digging up the plants. In the Po Kong Survey one Inspector reported that he obtained them by the simple device of scraping plants with his dipping pan. It is not easy to rear the adults from the larvae and so obtain male specimens. In Malaya in 1927, males of these species, as well as other mosquitoes were obtained by the Malariologist in the early morning hours, from railway carriages which had been standing the previous night in the neighbourhood of swamps.
A species of Culicoides found on C. fatigans was identified by Dr. Edwards as Culicoides anophelis (Edw.) and a Chrysops caught biting at Shing Mun at 4 p.m. in the month of May, was identified by him as Chrysops mlokosiewiczi (Big.). Larvae and adults of A. pattoni were received from Dr. Hoeppli, Peiping Union Medical College on behalf of Dr. L. C. Feng. Larval specimens and mosquitoes were sent to Professor E. W. Walch, Batavia, to Dr. P. F. Russell, Bureau of Science, Manila, to Captain Barraud, Malaria Survey of India, Kasauli and to Dr. L. C. Feng. Mosquito specimens, slides of mounted larvae and of mosquito dissections were given to Dr. Sien, Canton, slides of mosquito dissections to Dr. Kandasamy, Penang, and slides of larvae to Major Stewart, Stanley.
A collection of fishes and insects which prey on mosquito larvae is being made.
(b) Malaria.
From the results of the 1933 dissections it will be seen that the important carriers are A. minimus and A. jeyporiensis.
The infection rates in these mosquitoes were low in the first quarter of the year, rose in the second, remained high in the third and fourth quarters, declining towards the end of the year.
A. maculatus and A. hyrcanus were found infected at Shing Mun Camp under what must be considered exceptional circumstances.
Investigations made at Pokfulam during the year as to the pathogenicity of A. maculatus confirmed the results obtained in 1932 and point to A. maculatus being of no great importance in comparison with A. minimus and A. jeyporiensis.
As to A. hyrcanus further research is required in localities remote from the hills (where it is likely to be unaccompanied to any extent by the important carriers) to ascertain its harmfulness under such conditions.
Records obtained from the R. A. M. C. authorities indicated as formerly a much higher incidence for the second half of the year, being 104 fresh cases out of a total of 113 amongst British Troops. The figures for Lai Chi Kok Gaol (male) which is close