Social Aggregation and Gregarious Behaviour in Hoppers of Locusta Migratoria Migratorioides (R. & F.) 1)

SOCIAL AGGREGATION AND GREGARIOUS BEHAVIOUR IN HOPPERS OF LOCUSTA MIGRATORIA MIGRATORIOIDES (R. & F.) 1) by PEGGY E. ELLIS (Anti-Locust Research Centre, London and Department of Zoology, University College, London) (With 10 figs) (Rec. 24-1-1953) INTRODUCTION The nymphs or hoppers of the African Migratory Locust Locusta migra- toria migratorioides (R. & F.). vary considerably in morphology, colour and behaviour. A good deal of this variation is related to the degree to which the hoppers are crowded (FAURE, 1932), although other factors may play a part (GUNN & HUNTER-JONES, 1952). As there are so few accounts of the behaviour of this