M 154
The major part of stream clearing was done by labour supplied by the Engineering staff and under their supervision.
By the end of March the area represented by the 2′′ circle on the map (corresponding to 440 yards on the flat) was under larval control. Streams B2, B3, C, D, E had been dealt with in their entire length and stream A as far as the 3" circle (corresponding to 660 yards on the flat). On the 30th of March, in order to enable oiling to be carried out up to the 3" limits, clearing and ditching was asked for, commencing with stream F, as A. jeyporiensis which formed the majority of the morning catches in the Camp were found to be breeding in grassy seepage areas on its banks.
On the 10th of April 300 Anophelines were caught in the coolie lines; on the 19th 290 were caught. Five A. jeyporiensis were found to have sporozoites in the salivary glands. On the 20th April clearing and ditching up to the area of the 3" circle was again asked for; this was started on 21st April.
The area within the 3" circle was brought under larval control in June, but Anophelines continued to be captured in large numbers in the Camp, by far the most numerous being A. jeyporiensis.
Larval surveys done by the staff of the Bureau and collections made by the Resident Medical Officer failed to find larvae of A. jeyporiensis in any great numbers in the area between the 3" and 4" circles. From researches made on the Island it was ascertained that hill streams did not harbour the larvae of A. jeyporiensis to any great extent. Larvae of A. hyrcanus were found in rice fields on all occasions when they were sought for. Larvae of A. minimus and A. maculatus were found in the streams and irrigation ditches but until control of the cultivation had been obtained, and clearing of the streams had been done, oiling operations could not be undertaken for the destruction of such larvae.
A. jeyporiensis was found breeding in the fallow terraced rice fields just outside the 4" boundary at Pineapple Pass, at the foot of stream H, and later on in similar situations along stream I on the right bank of the Shing Mun below the P.W.D. Dam. Previous to the cutting of the second rice crop the Chinese cultivators make a few simple drains which remove the water from the plots. Temporary drainage of the rice fields on these lines was asked for; this was done and permanent drainage was afterwards put in. Permanent work was also done in the area between these places although no larvae of A. jeyporiensis had been reported, and no drainage had been asked for. More breeding places of A. jeyporiensis were found in rice swamps on the left bank of the Shing Mun between the P.W.D. Dam and Pineapple Pass in connection with streams L, M, N,
- M 154
The major part of stream clearing was done by labour sup- plied by the Engineering staff and under their supervision.
By the end of March the area represented by the 2′′ circle on the map (corresponding to 440 yards on the flat) was under larval control. Streams B2, B3, C. D. E. had been dealt with in their entire length and stream A as far as the 3" circle (cor- responding to 660 yards on the flat). On the 30th of March, in order to enable oiling to be carried out up to the 3" limits, clearing and ditching was asked for, commencing with stream F, as A. jeyporiensis which formed the majority of the morn- ing catches in the Camp were found to be breeding in grassy seepage areas on its banks.
On the 10th of April 300 Anophelines were caught in the coolie lines; on the 19th 290 were caught. Five A. jeyporiensis were found to have sporozoites in the salivary glands. On the 20th April clearing and ditching up to the area of the 3" circle was again asked for this was started on 21st April.
The area within the 3" circle was brought under larval control in June, but Anophelines continued to be captured in large numbers in the Camp, by far the most numerous being A. jeyporiensis.
Larval surveys done by the staff of the Bureau and collec- tions made by the Resident Medical Officer failed to find larvae of A. jeyporiensis in any great numbers in the area between the 3" and 4" circles. From researches made on the Island it was ascertained that hill streams did not harbour the larvae of A. jeyporiensis to any great extent. Larvae of A. hyrcanus were found in rice fields on all occasions when they were sought for. Larvae of A. minimus and A. maculatus were found in the streams and irrigation ditches but until control of the culti- vation had been obtained, and clearing of the streams had been done, oiling operations could not be undertaken for the destruc- tion of such larvae.
A. jeyporiensis was found breeding in the fallow terraced rice fields just outside the 4" boundary at Pineapple Pass, at the foot of stream H, and later on in similar situations along stream I on the right bank of the Shing Mun below the P.W.D. Dam. Previous to the cutting of the second rice crop the Chinese cultivators make a few simple drains which remove the water from the plots. Temporary drainage of the rice fields. on these lines was asked for this was done and permanent drainage was afterwards put in. Permanent work was also done in the area between these places although no larvae of A. jeyporiensis had been reported, and no drainage had been asked for. More breeding places of A. jeyporiensis were found in rice swamps on the left bank of the Shing Mun between the P.W.D. Dam and Pineapple Pass in connection with steams L, M, N,
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