The chemical acceleration of the maturation process and its hormonal control in the male of the desert locust

Abstract

The gregarious male of the desert locust shows a characteristic colour change during adult life; it is light brown and pink when immature, and bright yellow when mature. A mature, yellow male is able to accelerate the maturation process of young locusts by secreting a volatile substance which is produced in the epidermis and transmitted to the recipients by olfaction through the antennae and by contact over the body surface. The presence of this lipophilic substance is indicated by a vibration reaction, in which antennae, palpi and hind femora take part (Loher 1959). The volatile material can be extracted and preserved in oil and fat solvents. Extirpation and implantation of the corpora allata have demonstrated that in the male these endocrine glands are in control of sexual maturation and some associated processes, such as the production of the epidermal secretory substance, the colour change, the development of the accessory glands and the acceleration of maturation which results from wounding. The possibilities of combined action between the corpora allata and the epidermal secretory substance are discussed.