{ ^M20 192)5 A 



PROCEEDINGS V^ 



GENERAL MEETINGS FOR SCIENTIFIC BUSINESS 



ZOOLOGICAL SOCIETY OF LONDON 



PAPERS. 



15. The Life-History and Habits of two Parasites of Blow- 

 flies. By A. M. Altson. With an Introduction by 

 Prof. H. Maxwell Lefkoy, F.Z.S.* 



[Received March 29,'l920 : Read April 1.3, 1920.] 



(Text-figures 1-20.) 



Index. 



Page 



A Short Account of the Start of the Work 196 



Breeding Methods 198 



Life-Historjf and Habits of Alysia manducator Panz. and Hosts 199 



Life-History and Habits oi' .Nasotiia brevicornis Ashm. and Hosts ... 216 



Super-parasitism, or Accidental Secondavj^ Parasitism 230 



Refrigerating Experiment 240 



Conclusions upon the Economic Importance of A. vianducator 



Panz. and N. brevicornis Ashm 241 



Summarj' 242 



Acknowledgments 248 



References 243 



Introduction. 



This paper deals with part of the work initiated after a visit 

 to Australia, wdiere the lack of any means of control of tiie Sheep 

 Blow-flies is painfully evident. As some of these i^robably came 

 from England, it seemed desirable to study the natural checks 



* Communicated b}' Prof. Lefeot. 



Proc. Zool. Soc— 1920, No. XY. U 



