Physiology of digestion in mango weevil, Sternochetus gravis (Fabr.) (Curculionidae : Coleoptera)
Keywords:
Sternochetus gravis, hydrogen-ion concentration, digestive enzyme, amylase, maltase, lactase, lipase and invertase.Abstract
Sternochetus gravis has been proved to be a serious pest of mango fruit in Manipur. The insect during both of its larval and adult stages feed on the fruit pulp where the entire life cycle is completed. Certain physiological parameters of the pest and its food have been revealed significant interaction between them. The hydrogen-ion concentration has been observed to vary from 3.2 to 6.5 in the unripe and ripe fruit pulp and 4.5 to 6.2 in the larval and adult gut respectively. The qualitative estimation of digestive enzymes has revealed the presence of almost all the enzymes in the insect gut namely amylase, maltase, lactase, lipase and invertase to digest the different components of its food. Thus, the pest is host specific and is well adapted both physiologically as well as morphologically inside the growing food.