THE ROLE OF THE CORPORA ALLATA IN THE ADULT MALE CRICKET (GRYLLUS-CAMPESTRIS AND GRYLLUS-BIMACULATUS) IN THE DEVELOPMENT AND EXPRESSION OF ITS AGONISTIC BEHAVIOR

We examined the role played by the corpora allata, paired glands which secrete juvenile hormone, in regulating male agonistic and sexual beh aviours in the field cricket species Gryllus campestris and Gryllus bi maculatus. G. bimaculatus males began to exhibit their typical agonist ic behaviour approx. 10-14 days after their adult moult. Application o f juvenile hormone to newly moulted males did not precociously induce agonistic behaviour. Removing the corpora allata from newly moulted ma les had no effect on their subsequent agonistic behaviour, Allatectomi zed animals of both species fought with the same success, duration and intensity as controls. Therefore, neither the corpora allata nor its product, juvenile hormone III, are critically important in regulating male agonistic behaviour, Moreover, allatectomized males of both speci es were capable of copulating with females and transferring normal-loo king spermatophores, Allatectomized G. bimaculatus males were able to mate even when they had to compete with control males. The identity of the factors that are important for the expression of sexual and agoni stic behaviours in the adult male cricket remains unknown, but it is n ot JH III.