Sensitivity of <I>Meloidogyne incognita</I> and <I>Rotylenchulus reniformis</I> to Abamectin


  • T. R. Faske
  • J. L. Starr


abamectin, avermectin, LD50, Lycopersicon esculentum, Meloidogyne incognita, nematicide, Rotylenchulus reniformis, reniform nematode, root-knot nematode, seed treatment, tomato.


Avermectins are macrocyclic lactones produced by Streptomyces avermitilis. Abamectin is a blend of B1a and B1b avermectins that is being used as a seed treatment to control plant-parasitic nematodes on cotton and some vegetable crops. No LD50 values, data on nematode recovery following brief exposure, or effects of sublethal concentrations on infectivity of the plant-parasitic nematodes Meloidogyne incognita or Rotylenchulus reniformis are available. Using an assay of nematode mobility, LD50 values of 1.56 æg/ml and 32.9 æg/ml were calculated based on 2 hr exposure for M. incognita and R. reniformis, respectively. There was no recovery of either nematode after exposure for 1 hr. Mortality of M. incognita continued to increase following a 1 hr exposure, whereas R. reniformis mortality remained unchanged at 24 hr after the nematodes were removed from the abamectin solution. Sublethal concentrations of 1.56 to 0.39 æg/ml for M. incognita and 32.9 to 8.2 æg/ml for R. reniformis reduced infectivity of each nematode on tomato roots. The toxicity of abamectin to these nematodes was comparable to that of aldicarb.