Inhibition of Phenoloxidase Activity Delays Development inBactrocera dorsalis(Diptera: Tephritidae)

Abstract

Abstract Phenoloxidase (PO) is a multicopper enzyme, which plays an important role in melanin synthesis. PO is necessary for defense against intruding microorganisms and parasites, and is important in wound healing and cuticle pigmentation. As a specific inhibitor of PO, kojic acid (KA) is commonly used to characterize the functional properties of PO. In this study, we investigated the effect of KA on PO activity during the development of the oriental fruit fly, Bactrocera dorsalis, which is a destructive pest of many horticultural crops. After feeding on a KA-containing artificial diet, the larval and pupal developmental periods were significantly prolonged. In addition, the larvae did not grow to normal size and rates of pupation and emergence were decreased when B. dorsalis larvae had been fed with KA-containing diet for 6 days. Compared to the control, PO activities from whole bodies of B. dorsalis were inhibited, so did in larval cuticles. Consistent with these, kinetic analysis showed that the catal...