Distribution of digestive enzymes in the gut of American cockroach, Periplaneta americana (L.)

Adult male and female cockroaches, Periplaneta americana (L.) were assayed for the presence of digestive enzymes in the fore-, midand hindgut regions. Activities of αamylase, β-amylase, γ-amylase, proteinase and lipase were detected in the three gut regions except for the absence of γamylase and lipase in female hindgut. The presence of these enzymes partly explains the polyphagous feeding habit of P. americana, enabling the insect species to digest a wide variety of food substances. In some instances, significant differences in enzyme activities were observed between sexes and among gut regions. Generally, enzyme activity was highest in the midgut followed by the foreand hindgut in descending order. Despite this trend, a considerable level of proteinase and male lipase was observed in the hindgut suggesting that it might be necessary to give extra attention to hindgut activities in future studies.