The Effects of Diflubenzuron on the Cuticle and on Hemolymphatic Ecdysteroids of Fifth Instar Nymphs of the Desert Locust, Schistocerca Gregaria (Orthoptera: Acrididae)

The effect of diflubenzuron (DFB), a benzoylphenyl urea insecticide, on the cuticle in newly molted fifth-instar nymphs of Schistocerca gregaria was examined. While there was an increase in dry weight of the cuticle in untreated nymphs, DFB treated nymphs had a reduced cuticle dry weight, with significant reductions in chitin levels. In a second series of experiments, DFB significantly reduced (p < 0.05) ecdysteroid titers in the hemolymph during nymphal development, leading to disruption of molting.