82 REPORT OF THE AGRICULTURAL RESEARCH 



the fish have been transferred to large pucca tanks. This 

 seems to be owing to the attacks of the larvae of large 

 Dytiscid water-beetles which are common here, and which 

 destroy the young fry and even the adult fish. It is prob- 

 able that the native Haplochilus is, under Indian condi- 

 tions, at least as effective a larva-destroyer. 



With regard to sand-flies (Phlebotomus) the life- 

 histories of Phlebotomus papatasii, P. argentipes, and P. 

 minutus have been worked at. 



Attention was mainly directed to P. minutus, which is 

 the commonest species at Pusa, and a large amount of 

 time has been spent in the difficult task of discovering 

 natural breeding places. The preliminary results of this 

 enquiry were presented in a paper read at the Malaria 

 Conference at Madras. 



By combining these results with those obtained in a 

 series of experiments on the predilections of the larva and 

 of the fly for various foods and for different hosts, it ap- 

 peared probable that there was some connection between 

 the fly and the wall-lizards or Geckos commonly found on 

 tree-trunks and the walls of bungalows. Subsequent ob- 

 servations have shown that this supposition is correct, and 

 that there is undoubtedly a close connection at several 

 points between these reptiles and P. minutus. In a paper 

 contributed to the " Indian Journal of Medical Research " 

 I have put forward the view that the " real " hosts of this 

 sand-fly are lizards, and that the connection with man may 

 be of a secondary nature. 



Attention has lately been directed to the hosts attacked 

 by P. argentipes, as little is known of the biting habits of 

 this species, but no very definite results have yet been 

 obtained. P. papatasii will be most easily investigated in 

 the Punjab or North- West Frontier Province, where it is 

 far commoner than at Pusa. The results obtained through 

 the excellent work of Professor Newstead and Captain 

 Marett in Malta will probably be found applicable to India, 

 and can be taken as a basis for further investigation of the 

 habits of this species. 



