Volume VII SEPTEMBER, 1920 No. 1 



ON A NEW POLYEMBRYONIC ENCYRTID (CHAL- 



CIDOIDEA) COPIDOSOMA TORTRICIS SP. N. BRED 



FROM THE STRAWBERRY TORTRIX MOTH. 



By JAMES WATERSTON, B.D., B.Sc. 



(Published by permission of the Trustees of the British Museum.) 

 (With 5 text-figs.) 



During the course of investigations into the life history of the Straw- 

 berry Tortrix (Oxygrapha comariana Z.) in 1918 and 1919, of which 

 the results appear elsewhere (p. 6), Mr F. R. Petherbridge reared a 

 small chalcid in numbers and was good enough to send me some of his 

 material for study. With the hymenoptera there were fortunately en- 

 closed two of the irregularly swollen dried skins of the hosts whose 

 remarkable appearance (Fig. 1) at once suggested a polyembryonic 



Fig. 1. Larva of Oxygrapha comariana Z., showing the characteristic swellings produced 

 by the pupation of Copidosoma tortricis Wtrst. with holes of emergence of the parasite. 



method of reproduction on the part of the parasite. Although Mr 

 Petherbridge could supply no direct evidence on this point he had made 

 the significant note that as many as 35 of these parasites might emerge 

 from one larva. 



Having dissected and thoroughly examined both sexes of the chalcid 

 I came to the conclusion that it should be assigned to the genus 

 Copidosoma Ratz. but neither the named material in the British Museum 

 collection — at present in an unsatisfactory state — nor a study of Mayr's 

 Monograph of the European Encyrtidae enabled me to determine the 

 species. Recently I have submitted both dried specimens and various 

 preparations of the Copidosoma to my friend Prof. F. Silvestri who, 

 however, can suggest no definite name for the insect though he knows 

 Ann. Biol, vn 1 



