On the Old World Species of the GenusStethorusWeise (Coleoptera, Coccinellidae)

Abstract

The genusStethorusWeise is of special interest on account of its cosmopolitan distribution and the habit of its species of feeding mainly on mites, some of which are pests of crops, including fruit trees. Its relationship with other members of the tribe Scymniniis also of importance, as it was separated by Dobrzhansky in 1924 into a distinct tribe called Stethorini, which, however, was regarded by Korschefsky (1931) as synonymous with Scymnini. The material on which the present study is based came mainly from the Old World. Much of it had been submitted to the Commonwealth Institute of Entomology for identification, and I am grateful to Dr. W. J. Hall and Dr. T. H. C. Taylor, of this Institute, for giving me facilities and help. The remainder of the material studied was in the collection of the British Museum. I am indebted to Mr. N. D. Riley for procuring, on my behalf, certain type specimens from abroad for examination.