Neurosecretion in the frontal ganglion of Achoea janata Linn. and Philosamia ricini (Hutt.) (Lepidoptera).

The cytomorphology of the neurosecretory cells in the frontal ganglion of two Lepidopterous insects, Achoea janata and Philosamia ricini have been studied using PF, PARF and PAVB techniques. In the frontal ganglion of both the insects conspicuous 2 to 3 oval A-cells, staining deep purple and a number of B-cells staining green have been clearly observed. The A-cells have been observed to be located either in the centre or close to the root of the recurrent nerve or to the frontal ganglion connective. Both the A and B types of cells show a distinct cyclic change during larval development. The endocrine nature of frontal ganglion is clearly demonstrated.