Stridulation and associated behaviour in certain orthoptera. 3. The influence of the gonads

Abstract

1. 1. Extirpation of testes and accessory glands in males of the acridid grasshoppers C. parallelus and O. viridulus did not alter their stridulation nor the behaviour associated with it; however, time spent in copulation was considerably increased and it is suggested that this may be due to the fact that in normal males the emptying of the spermatophore is the stimulus for the cessation of copulation. 2. 2. Injections of crustacean eyestalk hormone, found to inhibit ovarian development in honeybees, was without effect on ovarian tissue in the grasshoppers used. 3. 3. Removal of ovaries and accessory glands in female C. parallelus in the “responsive state” resulted in the disappearance of this condition in from 24–48 hours. The responsive state was reinduced in several castrated females by injection of blood from females in the responsive state. 4. 4. The responsive state was not terminated by cutting the ventral nerve cord in the abdominal region in normal females. 5. 5. Inhibition of the responsive state in females by copulation only occurs after the passage of sperm into the receptaculum seminis; this inhibition is not mediated by the central nervous system, consequent on mechanical stimulation of the receptaculum seminis, and is probably due to some chemical factor associated with the sperm.