The role of the corpora allata in the adult male cricket (Gryllus campestris and Gryllus bimaculatus) in the development and expression of its agonistic behaviour

We examined the role played by the corpora allata, paired glands which secrete juvenile hormone, in regulating male agonistic and sexual behaviours in the field cricket species Gryllus campestris and Gryllus bimaculatus. G. bimaculatus males began to exhibit their typical agonistic behaviour approx. 10–14 days after their adult moult. Application of juvenile hormone to newly moulted males did not precociously induce agonistic behaviour. Removing the corpora allata from newly moulted males had no effect on their subsequent agonistic behaviour. Allatectomized 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, allactectomized males of both species were capable of copulating with females and transferring normal-looking 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 agonistic behaviours in the adult male cricket remains unknown, but it is not JH III.