INSTITUTE, PUSA, FOR 1919-20 105 



(ii) A few Culicoides adults (exceedingly minute 

 species), 



(Hi) One Ceratopogon adult and a fairly large number 



of Ceratopogon larvae, and 

 (iv) Innumerable larvae of Culicoides (which could be 



seen with difficulty with the naked eye) along 



with the larvae of Syrphidae, of Psychoda and of 



a species of acalyptrate fly. 



" Young stages of the sand-fly could nowhere be found. 

 Some Culicoides and Ceratopogon adults were bred out. 



' The Culicoides larvae could never be found in the loose 

 debris within the hole but they lodged themselves in the 

 fungi and other vegetation that had overgrown the inner 

 walls of the hole. The position, shape and depth of the 

 hole afforded ready protection against wind and rain, the 

 source of blood, their food-supply, being probably a large 

 gecko which was found inhabiting it (some of the 

 Phlebotomus adults were frequently noticed gorged with 

 blood)." 



Mr. H. N. Sharma, Entomological Assistant, submits the 

 following report on his work during the year : — 



" On the Imperial Pathological Entomologist receiving 

 orders to investigate Culicifuges for the Military Depart- 

 ment, I was directed by him accordingly first to make an 

 inquiry by practical tests into official or other well-known 

 preparations and then into any other substances which 

 might suggest themselves as possibly helpful in securing the 

 ultimate object of the inquiry. This object was to obtain 

 a preparation absolutely effective against mosquitos for a 

 period of not less than three hours. 



"According to the above directions the work was 

 arranged under the following heads : — 



" (i) Severe practical tests of preparation in official or 

 general use; 16 preparations were tested against hungry 

 Armigeres obturoans, in cages containing not less than 100 

 females. Three grams of solid or 1\ com. of liquid prepara- 

 tions, covering the hand and the forearm up to an inch 



