The compatibility of the entomopathogenic nematode, Steinernema feltiae, and chemical insecticides for the control of the South American leafminer, Liriomyza huidobrensis

The compatibility of infective juveniles (IJs) of entomopathogenic nematodes, Steinernema feltiae, and chemical insecticides to control larval stages of the South American leafminer, Liriomyza huidobrensis, was investigated. Initially the effect of direct IJ exposure to 5 insecticides (abamectin, deltamethrin, dimethoate, heptenophos and trichlorfon) for 24 hours was tested against Galleria mellonella in a standard sand tube bioassay. Trichlorfon and dimethoate did not reduce the nematodes ability to locate and infect G. mellonella larvae to an unacceptable level. However, nematode infectivity was significantly reduced following exposure to abamectin, deltamethrin and heptenophos. Secondly, IJ infectivity for L. huidobrensis in the presence of dry pesticide residues on foliage was tested. No significant detrimental effects on the level of control of L. huidobrensis was recorded when compared with the effect of nematodes applied to residue free foliage. The integration of these agents into a pest management programme is discussed.