[From PARASITOLOGY, Vol. XII, No. 3, 28 Septembeb, 1920.] \ 



[All Sights reserved] \ 



ON THE LIFE HISTORY OF BUCENTES (SIPHON A) 

 GENICULATA (DIPTERA: TACHINIDAE), PARASITE OF 

 TIPULA PALUDOSA (DIPTERA) AND OTHER SPECIES^. 



By JOHN RENNIE, D.Sc. 



AND 



CHRISTINA H. SUTHERLAND, M.A., B.Sc, Carnegie Scholar. 



{From the Laboratory of Parasitology, University of Aberdeen.) 



(With Plate XIV.) 



The Dipterous Family, Tachinidae, comprises a very large number of species 

 whose larvae live as parasites within other insects, particularly in their larval 

 forms. 



Bucentes (Siphona) geniculata, one of the Tachinidae whose larvae are 

 considered in the following paper, is a small ordinary looking fly, blackish in 

 colour and showing a somewhat greyish abdomen, with prominent abdominal 

 bristles. The labium is long and slender, sharply geniculated about the middle 

 of its length, and folded like a clasp knife under the head when not in use^. 



In a former paper (1912) one of us has recorded the occurrence of the larva 

 of this species as a parasite in the body cavity of Tipula larvae. It is probably 

 not confined to one host species. In one collection of Tipula larvae, a pro- 

 portion of which yielded the parasite, the majority of the survivors, on 

 hatching, proved to be Tipula oleracea. In most instances, however, we have 

 found the infected insects to be T. paludosa. 



Since the original observation in 1912, we have found this larva regularly 

 every year, and consequently regard it as a normal parasite of Tipula. Other 

 observers record it from Mamestra brassicae and a related species, Siphona 

 cristata, is reported by Roubaud (1906) to occur in Tipula gigantea. 



OCCURRENCE AND DISTRIBUTION OF THE ADULT FLY. 



From an examination of records relating to the adult insect, kindly sub- 

 mitted to us by the entomologists in charge at the British Museum and the 

 Royal Scottish Museum, we find the fly is widely distributed throughout 



' This work has been carried out with the aid of Grants from the Board of Agriculture for 

 Scotland, to whom we desire to evp-ess our thanks. 



• A full description of the structure and habits of the adult fly is reserved for a further paper 



