Susceptibility of the South American Leafminer Liriomyza huidobrensis (Blanch) to Some Insecticides

O. KARADJOVA
Plant Protection Institute, BG-2230 Kostinbrod, Bulgaria

Abstract

KARADJOVA, O., 2001. Susceptibility of the South American leafminer (Liriomyza huidobrensis Blanch) to some insecticides. Bulg. J. Agric. Sci., 7: 279-284

The South American Leafminer Liriomyza huidobrensis (Blanch) was established for the first time in Bulgaria in 1996. Laboratory studies were conducted to determine the comparative age-specific efficacy of selected insecticides against larvae and adult of L. huidobrensis. The adults of L. huidobrensis react with normal susceptibility to thiocyclam and to the combination chlorpyriphos + cypermethrin. The estimated resistance ratios at LC95 level were 1.3 and 2.1 fold respectively. A moderate resistance ratio was established to acephate and bifenthrin whose values were 3.89 and 4.4 fold. The highest level of resistance was observed to methomyl (6.5 fold) and dimethoate (7.7 fold). Cyromazine, abamectin and imidacloprid had a high efficacy (100%) against L. huidobrensis immature stages. Dimethoate, acephate, methomyl and bifenthrin were ineffective against larvae and pupae of the South American leafminer.

Key words: Liriomyza huidobrensis, insecticides, South American leafminer