The colour and size of the migratory locust changes according to its phase and its age. "Gregarious larvae" have a yellow to orange covering with black spots. "Solitary larvae" are green or brown. The "gregarious adult" is brownish with yellow, the latter colour becoming more intense and extensive on maturation. The "solitary adult" is brown with varying extent of green colour depending on the colour of the vegetation. "Gregarious adults" vary in size between 40 and 60 mm according to the sex. They are smaller than the solitary adults.