Polymorphic diversity in salivary and haemolymph proteins and digestive physiology of assassin bug Rhynocoris marginatus (Fab.) (Het., Reduviidae)

Rhynocoris marginatus (Fab.) occurs in three morphs viz. (i) niger (black connexivum) (ii) sanguineous (red connexivum) and (iii) nigrosanguineous (black and red banded connexivum). The salivary protein (mug/mg wet weight of salivary gland complex), and haemolymph protein (mug/100 mul) were higher in niger morph than in nigrosanguineous and sanguineous morphs. Endopeptidase (trypsin) activity of homogenate of salivary gland complex (SGC) of niger morph was also higher. It was significantly lower in the sanguineous morph. Endopeptidase activity was found to be uniformly meagre in the anterior midgut (AMG) and in the posterior midgut (PMG) in all the three morphs. The exopeptidase (aminopeptidase) activity was also found to be negligible in SGC in all the three morphs. Niger morph showed a significantly higher activity of exopeptidase in AMG and PMG than the other two morphs.