Comparisons of gut carbohydrolase activity patterns in Reticulitermes flavipes and Coptotermes formosanus (Isoptera: Rhinotermitidae) workers and soldiers.

摘要

Cellulolytic and xylanolytic gut carbohydrolases were compared in Coptotermes formosanus (Shiraki) and Reticulitermes flavipes (Kollar). Endoglucanase activity was mainly localized in the foregut and hindgut of both species, reflecting both endogenous and symbiont enzyme origins. beta -glucosidase activity was found throughout the gut in both species, but was most prevalent in the midgut and hindgut. beta -xylosidase activity was mostly restricted to the hindgut and was lowest in the foregut in both species. Exoglucanase and xylanase activities were almost entirely confined to the hindgut in both species. C. formosanus workers had a more active array of gut carbohydrolases, particularly exoglucanase and beta -glucosidase, than R. flavipes. This increased activity may be associated with increased metabolic demands that result from larger foraging ranges and greater soldier ratios for C. formosanus colonies. Soldier carbohydrolase activities in both of these species were generally lower than worker carbohydrolase activities, which is consistent with solders being incapable of direct wood feeding. C. formosanus soldier carbohydrolase activities were especially low, presumably due to reduced gut size to make room in the soldier abdomen for an enlarged frontal gland. These findings enhance our understanding of termite sociobiology by illustrating caste-associated differences in nutritional physiology between two pest species.