fNSTlTUTE AND COLLEGE, PUSA, FOR 1911-12. 75 



enable observations to be carried on with a facility un- 

 obtainable at any existing laboratory known to me, with 

 the possible exception of Coonoor and Madras. 



The work of the section has been largely concerned with 

 mosquitos, and the life-histories of eighteen species of 

 Pusa mosquitos have now been worked out. Special 

 attention has been paid to the genus Stegomyia and allied 

 forms, and a five weeks' course of instruction has been given 

 to medical officers deputed to the " Stegomyia-survey "' in 

 connexion Avith the possible future importation of yellow 

 fever. Seven officers attended the course. The most inter- 

 esting point discovered regarding Stegomyia life-histories 

 is that during cold and dry weather the two commoner 

 species at Pusa {S. scutellaris and S. thomsoni) survive 

 normally as dry eggs and not as active, hibernating, or 

 sestivating adults. This has an important bearing on the 

 practical question of checking the increase of Stegomyia. 



Investigations have been begun on general mosquito 

 bionomics, the main heads being the influence of tempera- 

 ture on mosquitos ; methods of colouring or otherwise mark- 

 ing mosquitos in order to study their movements, and the 

 range and rate of flight under natural conditions; sexual 

 reactions of mosquitos; new larvicides; the food, feeding, 

 and digestion of mosquito-larvse ; fish and other enemies of 

 mosquito-larvas. The difficult question of the breeding- 

 places and habits of Phlehotomus has been taken up. A 

 possible association with Termites may prove of importance. 



Si7nulium-ii\iQ?>tQdi streams at Simla were examined 

 with a view to finding methods of decreasing the numbers 

 of the fly, but local conditions are such that no cheap method 

 seems apj^licable. The life-history of the Crab-louse (P. 

 inguinalis) was worked out (apparently for the first time), 

 and its curious habits studied. 



Other subjects which received attention are the para- 

 sites of Tabanus albimedius and of Monofhlebus stebbingi 

 var. octocaudata, the nature of the attraction of citronella 

 oil for fruit flies of the genus Dasyneura, the life-history 

 of Celyphidw and improvements in mosquito-traps. The 



