Sensitivity of Meloidogyne incognita and Rotylenchulus reniformis to Abamectin

T. R. Faske, J. L. Starr

Abstract


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.

Keywords


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

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