Le Contrôle endocrinien de la diapause imaginale des femelles de Tetrix undulata (Sowerby, 1806) (Orthoptere, Tetrigidae)

Abstract

Imaginal diapause, which is a syndrome-like pseudoallatectomy, is terminated by implantation of active CA (corpora allata). When CA of dispausing females of Tetrix undulata (2 weeks old) are implanted in females also in diapause, vitellogenesis occurs. The same results are observed when CC-(corpora cardiaca) CA (under same conditions) are implanted or when the allatocardiac nerves are cut. But when the complex “brain-CC-CA” is implanted, no vitellogenesis is observed in oocytes. These experiments suggest that CA in diapausing females are inhibited by the brain by a nervous pathway. The cauterization of the pars intercerebralis area brings about vitellogenesis. These experiments suggest that the brain is the place of an inhibitory center which acts by a nervous pathway on the CA of diapausing females. When CA are implanted from females on the first day after the adult molt, or when the allatocardiac nerves are severed on the same day, the oocytes stay the same length as in the sham operation. Connection between the brain and CA are necessary in the beginning of adult life.