OBSERVATIONS ON THE BIOLOGY OF SOME SOUTH AFRICAN ACRIDIDAE (ORTHOPTERA)

FROM December 1934 until January 1936 a study was made of the biology of a few species of local ACRIDIDAE in South Africa, particular attention being paid to the duration of the instars and the external morphology of the nymphs. The object of this study was to make a preliminary contribution to the knowledge of South African ACRIDIDAE and it is my intention that these studies be continued. Very few descriptions of the nymphal stages of South African ACRIDIDAE were found in the literature and it appears that there is a need for systematic descriptions on which the identification of nymphal stages can be based. During 1935 I was enabled to pursue my studies with the aid of a University Research Scholarship from the Research Grant Board, which I wish gratefully to acknowledge. I also wish to express my sincere appreciation of the continual advice and encouragement given me by Dr. N. F. Paterson and Professor C. J. van der Horst of the Witwatersrand University. Thanks are also due to Dr. Hesse of the South African Museum for kindly identifying specimens and to Dr. B. P. Uvarov for valuable assistance in this connection. The adult males and females and the nymphal instars of the species studied were collected chiefly in the grounds of the University, Milner Park, Johannes- burg, and most of them, unless otherwise stated, were found associated in the same area. The following is a list of the species of ACRIDIDAE collected at various times in the grounds of the University.