Laboratory toxicity of insecticides to workers of Trigona spinipes (F., 1793) (Hymenoptera, Apidae)

The laboratory LD₅₀ values of organophosphate, carbamate, organochlorine (including cyclodienes) and pyrethroid insecticides were determined for workers of Trigana spinipes (F., 1793). Determinations used topical application techniques from which dose-morality was derived using Bliss' method (1935). In order of decreasing toxicity the LD₅₀ values for workers, in µg/bee were as follows: heptachlor, 0.0168; dieldrin, 0·0289; cypermethrin, 0·0704; permethrin, 0·0724; parathion, 0·0956; lindane, 0·1331; methomyl, 0·1402; dicrotophos, 0.1685; endosulfan, 0.2097; malathion, 0.2649; acephate, 0.4234; carbaryl, 0.7472; fenvalerate, 1·0880. The insecticides tested were highly toxic to T. spinipes.