THE CONTROL OF REPRODUCTION IN DIPLOPTERA PUNCTATA (BLATTARIA)

Abstract

In females of the viviparous cockroach Diploptera, mated shortly after emergence, ovulation was observed 9 to 10 days later. During egg maturation the corpora allata became active as judged by the histological criterion of increased cytoplasmic content of the gland cells. When allatectomy was performed after mating it prevented the deposition of yolk in the oocytes. This demonstrates that active corpora allata are necessary for egg maturation. It was noted that mating is essential for a normal rate of egg growth since in virgins egg maturation was delayed, and in some females it did not take place within 5 months. From this it seems that in virgins the corpora allata are restrained. Severance of the corpora allata from the brain in virgins results in the persistent activity of these glands and leads to the maturation of successive batches of eggs. It appears that the brain exerts an inhibitory action upon the corpora allata and that mating stimuli counteract this inhibition. Moreover, the stimuli resulting from parturition are able to counteract this inhibition also and thus elicit egg maturation. Sensory receptors in the genital apparatus receive the stimuli of mating or parturition; both are transmitted to the corpora allata via the ventral nerve cord and the brain. An artificial spermatophore was deposited in the bursa copulatrix in an attempt to simulate the mechanical aspect of the mating act. Egg maturation followed.