Abstract
The ovicidal and adulticidal activity of formamidines, including chlordimeform (CDF) and its metabolites, and monoamine oxidase (MAO) inhibitors against eggs of the Kanzawa spider mite, Tetranychus kanzawai, and adults of a mite predator of house fly eggs, Macrocheles muscadomesticae and cheese mite, Tyrophagus putrescentiae, were examined. Of the compounds tested, CDF and demethylchlordimeform (DMCDF) were significantly toxic to eggs and adults. Ovicidal activity of CDF against susceptible strains was better than that of DMCDF, but the adulticidal activity of CDF was almost identical to that of DMCDF. It is the characteristic property of formamidines that poisoning symptoms are slow to appear. Furthermore, a marked variation in susceptibility of M. muscadomesticae and T. putrescentiae for formamidines was apparent; the former was much more sensitive than the latter. The MAO inhibitors, nialamid, iproniazid and tranylcypromine, did not show any ovicidal or adulticidal effects. The ovicidal activity of CDF and DMCDF was synergized by SKF-525A, sesamex and piperonyl butoxide (pb), but that of H-20013 was slightly synergized by sesamex and pb.
