Nests of yellowjacket wasp, Vespula germanica F., were collected, from which comb pieces were selected with last stage larvae (n ≥ 35), that were later maintained at 25°C and ~50% RH in absence of light. Laboratory assays were conducted to determine the LC50 of commercial formulations of abamectin (applied in a range from 6.8 to 0.84 mg L-1), Bacillus thuringiensis (640-5.1 mg L-1), fipronil (1,000-1 mg L-1), methoxyfenozide (9,600-60 mg L-1), spinosad (106-0.11 mg L-1), and triflumuron (24,000-2.4 mg L-1). Each larva was fed 1,5 mL of insecticide solution (30% honey solution mixed with the commercial formulations, and a control was fed with only 30% honey solution). The symptoms of the neurotoxic insecticides previous to death were body paralysis and cuticle darkening within the first 72 h; triflumuron was effective, but because of its form of action its symptoms took longer to appear (incomplete ecdysis, and/or partial rupture of the cuticle). The LC50 were determined by Probit analyses, were: spinosad, 0.29 mg L-1; abamectin, 1.40 mg L-1; fipronil, 3.34 mg L-1, and triflumuron, 11.83 mg L-1. Bacillus thuringiensis had no lethal effect on larvae in the range of concentrations evaluated. With methoxyfenozide, mortality was obtained only when using the highest concentration (9,600 mg L-1).