Abstract
Newly moulted 3rd and 4th instar nymphs of the desert locust were treated with precocene II (50 μg cm
-2). The precocious differentiation of adults was accompanied by delay of moulting and absence of colouration characterizing sexual maturity. The dry weight and protein content of the cuticle of the treated insects were decreased. The colour of the integument was altered by treatment with prococene II to green accompanied by reduction of the black pattern at the subsequent moult. The ovaries of the precocious adult females did not reveal the vitellogenic stage, while in the normal looking females vitellogenesis started early.