Dynamics of the neurosecretory cells of the brain of Amsacta collaris Hampson (Lepidoptera: Artiidae) during post embryonic development.

A comprehensive account of the dynamics of the neurosecretory cells of the brain of Amsacta collaris Hampson, during post embryonic development has been given using largely PARF, as well as PF and PAVB techniques in whole mounts sections. On the basis of staining properties the neurosecretory cells have been distinguished into principal A, B and C types. These cell types have been further classified into A-1, A-2, A-3, and A-4; B-1, B-2, and C-1, C-2 subtypes. Occurrence of paired medial, lateral, optic, posterior, ventral and tritocerebral groups containing different types of cells in the brain of Amsacta collaris in specific development stages have been reported. It has been observed that in the 1st instar larvae, there is no distinction of subtypes of cells. The distinction of cells into respective subtypes starts from 2nd instar and onward. The number of cells are minimum in the 1st instar, which increases upto the sixth instar larva, and remain almost constant in the prepupa, and diapausing pupa. The maximum number of cells have been observed in the adult individuals. In addition to number and distribution, the secretory activity of different types of cells during post embryonic development have also been described.