AND COLLEGE, PUSA, FOR 1915-16 83- 



Mosquitos. 



The Mosquito Campaign was continued on the Pusa 

 Estate with considerable success, the reduction in numbers 

 of mosquitos prevalent during the year being in marked 

 contrast to the experience of previous years. Breeding- 

 places were sought out and dealt with, either by filling in 

 (hollows in trees, small puddles, etc.), removal (tin cans, 

 pots, etc., holding rain-water), oiling (large semi-permanent 

 pools) or the introduction of larvivorous fish (more or 

 less permanent pools, wells, etc.). Pieces of bamboo-stem, 

 filled with water, were also placed out in trees and in other 

 likely situations to serve as traps for oviposition of Stego- 

 myia, and regularly emptied out and replaced. The follow- 

 ing were the principal species found breeding on the Estate 

 during the year, viz., Anopheles fuliginosus, A. culicifacies, 

 A. rossi, Culex fatigans, C. gelidus, C. sitiens, Wied 

 (microannulatus, Theo), T oeniorhynchus tenax, Stegomyia 

 scutellaris, S. sugens and S. gubernatoris. Pseudograbha- 

 mia maculata, not previously noted at Pusa, was also found 

 and reared during the progress of this work. 



Eleven coloured plates, showing life-histories of mosqui- 

 tos, were sent to press during the year and will be available 

 shortly, and other plates were completed. 



Mr. S. K. Sen carried out a series of experiments on the 

 role of blood in the development of eggs in mosquitos, the 

 species dealt with being Stegomyia scutellaris for the most 

 part. This inquiry was still in progress at the close of the 

 year but a preliminary report on the results attained has 

 been written up ; meanwhile, it may be noted here that, as 

 regards S. scutellaris, it has been found that this species 

 (l)*may oviposit without having fed on blood, (2) may 

 deposit as many as three batches of eggs after only one meal 

 of blood, (3) a single fertilization will suffice for several 

 batches of eggs. 



The collection of mosquitos was rearranged and put m 

 order during the year. 



