The Bionomics of South African Insects. 831 



These results are tolerably decisive ; but it would have 

 been more satisfactory if the experiments had been con- 

 tinued for a much longer period and controlled by others 

 in which different forms of food were employed. In this 

 way a convincing test of the wholesome qualities of the 

 larvae would have been supplied. In other experiments, 

 again, it would have been desirable to offer a wide choice, 

 and ascertain if there are any marked preferences. 



Mr. G. A. K. Marshall has also observed one of the 

 HisteridcV, Histcr caffcr (Erichs.), eating a far larger beetle 

 than itself, the Scarabasid Onitis alexis. He has also 

 observed the same beetle devouring Aphodii. 



On July 19, 1898, I observed a large Elaterid {Corym- 

 hitcs virens ^) eating the larva3 of Vanessa nrticcV on a 

 nettle beside the mountain road (GOOO feet) from Leukerbad 

 to the Gemmi Pass, Valais. The specimens are now in the 

 Hope Department. 



C. Predctceous Diptcra. 



It is convenient to bring together the numerous records 

 of the attacks of Asilid/B upon insects into a tabular 

 statement. In its preparation I have received the kindest 

 help and co-operation from Colonel Yerbury, Colonel 

 Bingham, Mr. G. A. K. IMarshall, Mr. A. H. Hamm, and 

 Dr. Chapman. 



