Effect of bioresmethrin on mitochondrial ultrastructure and oxidative phosphorylation in the flight muscles of Chrysomya albiceps (Wied.) (Diptera: Calliphoridae)

The sublethal effect of bioresmethrin on the ultrastructure, oxidation and phosphorylation of flight muscle mitochondria in the blow fly Chrysomya albiceps which survived treatment of newly formed pupae (0-day old) with 10 micrograms/pupa (LD30) was studied. The ultrastructure of the flight muscle mitochondria was severely deteriorated by treatment with bioresmethrin. The deterioration included disalignment and sometimes destruction of the cristae and vacuolation of mitochondria. The oxidation rate was decreased in treated flies, although the P/O ratio was increased. The present study may indicate that bioresmethrin is neither an uncoupler nor a direct inhibitor of oxidative phosphorylation but may have functioned as an inhibitor of the oxidation rate.