Effects of Aldicarb on the Behavior of Heterodera schachtii and Meloidogyne javanica


  • A. Hough
  • I. J. Thomason


The toxic effects of sublethal concentrations ofaldicarb were studied on eggs and second-stage larvae and males of Heterodera schachtii and second-stage larvae only of Meloidogynejavanica in a quartz sand substrate. Aldicarb was more toxic to eggs of H. schachtii than to those of M.javanica. Complete suppression of hatching occurred between 0.48 and 4.8 [mu]g/ml aldicarb for H. schachtii whereas 100% inhibition of hatch of M. javanica occurred between 4.8 and 48.0 [mu]g/ml. M.javanica hatch was stimulated at 0.48 [mu]g/ml aldicarb. Migration of second-stage larvae of H. schachtii and M. javanica in sand columns was inhibited under continuous exposure to 1 [mu]g/ml aldicarb. Infection of sugarbeet and tomato seedlings by larvae was inhibited at 1 [mu]g/ml. H. schachtii males failed to migrate toward nubile females at 0.01 [mu]g/ml aid icarb. This was partially confirmed in a field study in which adding aldicarb to soil resulted in fewer females being fertilized. Key Words: cyst nematode, root-knot nematode, nematicide, hatching, movement, sex attractant, infectivity, systemic action, mode of action.