Effect of selected pesticides on the vitality and virulence of the entomopathogenic nematode Steinernema feltiae (Nematoda: Steinernematidae)

Abstract

The survival and infectivity of infective juveniles of the entomopathogenic nematode Steinernema feltiae (Rhab- ditida: Steinernematidae) were determined after being exposed to 8 insecticides (a.i. kinoprene, lufenuron, methomyl, metoxyfenozide, oxamyl, piperonyl-butoxide, pyriproxyfen, tebufenozide), 7 acaricides (a.i. azocyclo- tin, clofentezin, diafenthiuron, etoxazole, fenbutatinoxide, fenpyroximate, tebufenpyrad) and 4 fungicides (a.i. captan, fenhexamid, kresoxim-methyl, nuarimol) under laboratory conditions. S. feltiae was tolerant to all tested insecticides and fungicides, mortality during 72 hours varied from 2.26% to 18.68 % and from 7.04% to 8.86%, respectively. Acaricides with a.i. fenpyroximate and tebufenpyrad considerably influenced the S. feltiae ability to infect larvae of Tenebrio molitor. Tebufenpyrad caused 95% and fenpyroximate 85% reduction in S. feltiae virulence. These results suggest that S. feltiae can be applied in combination with all tested pesticides except the acaricides with a.i. tebufenpyrad and fenpyroximate.