Étude des cellules neurosécrétrices cérébrales non associées à la pars intercerebralis chez la larve d’Aeshna cyanea (Müller) (Anisoptera: Aeshnidae)

Five types of neurosecretory cells are found in the brain of A. cyanea outside the pars intercerebralis. There arc in the anterior part of the protocerebrum: 2 pairs of A-cells and 2 or 3 pairs of B-cells, both in paramedial position, 4 other A-cells in mediodorsal position. In the posterior part of the protocerebrum; 4 or 5 pairs of C-cells in lateral position, in the tritocerebrum: 2 pairs of B-cells. No neurosecretory cell can be observed in the deutocerebrum. Except for the lateral C-cells which cannot be recognized until the end of the larval development, the other cells can be detected histologically already on the fourth instar.