[Effect of experimental interventions provoking the start of molting on the secretory activity of cerebral glands of Lithobius forficatus L. (Myriapoda Chilopoda)].

In Lithobius forficatus, the removal of the two antennae or of 10-15 walking legs and the ecdysteroid supply induces ecdysis. The effects of these experiments has been studied on the secretory cycle of the cerebral glands; it must be reminded that these neurohaemal organs exert a moderating role on moulting. The removal of the antennae leads to injuries in some of the protocerebral neurosecretory cell axonal endings. Correlatively, a slight decrease can be observed in the glandular activity. The removal of the walking legs disturbs the secretory activity of the cerebral glands, whereas the axonal endings do not present injuries. It seems that the removal does not act-through the protocerebral neurosecretory cells. After ecdysteroid supply, the axonal endings are intact and the glandular activity is not affected. Ecdysteroids seem to stimulate the metabolism via the pars intercerebralis. These reported results show that moulting can be induced by various pathways. Moreover, the cerebral glands are not the only organs exercing a role in the control of moulting; complexe interactions exist between endocrine centres, the nervous system and environmental factors.