HISTOLOGY AND BIOGENIC AMINES LOCALIZATION OF SALIVARY GLAND OF THE ADULT RED PALM WEEVIL, RHYNCHOPHORUS FERRUGINEUS (COLEOPTERA: DRYOPHTHORIDAE)

Abstract

This study describes the histology and biogenic amines
localization of salivary glands of the adult Red Palm Weevil
(RPW), Rhynchophorus ferrugineus. The observation were done
by using light microscopy of Zeiss Image Analyzer with Axio
Vision software and Zeiss Axioscope with iSolutionlite software.
The histology involves staining procedures of haematoxylin and
eosin staining method while the immunohistochemistry analysis
involves serotonin and dopamine of the biogenic amines. The
salivary gland of the RPW adult is a single tubular gland. The
single gland lies dorsally on the alimentary tract of the insect that
begins in the head and extends through the thorax into the
abdomen. The reservoir region is located in the mid to fore region
of the gland, while the secretary region is found in the mid to rear 

part of the gland. The reservoir region of the RPW tubular gland
seems to probably secrete only water and ions but do not secrete
enzymes. The distribution of biogenic amines suggest that
dopamine mainly stimulates the production of water-based saliva
in the secretory cells of the reservoir region, while serotonin
stimulates the production of protein-rich saliva in the secretory
cells of the secretory region.