[Some effects of a growth inhibitor, Diflubenzuron, on a crab Carcinus mediterraneus (Czerniavsky)].

The effects of Diflubenzuron (N-4-chlorophenylamino carbonyl 2-6-difluorobenzamide) were tested, on a common crab of the Languedocian coasting ponds: Carcinus mediterraneus (Czerniavsky). Seawater was contaminated at two concentrations: 0.2 and 0.02 ppm. This insecticide enhances the mortality with increasing concentrations and causes a mortality at molting that, perhaps, results of alterations in the formation of the new exoskeleton. These effects on the cuticle look like those found in contaminated insects: the absence of resorption of the old integument is added to malformations in the synthesis of the new exocuticle.