Influence of Adjuvants on Cuticular Penetration and Metabolism of Aminocarb Following Topical Application of Matacil® 180F Formulations to Spruce Budworm

Three mixtures, AID-585, AS-7N, and AA-3409, were prepared by mixing Matacil^® 180F (a commercial formulation of aminocarb) with a light oil (insecticide diluent, ID 585), a heavy oil (Sunspray^® 7N) or a surfactant (Atlox^® 3409F)/water, respectively. The mixtures were fortified with ¹⁴C-ring labeled aminocarb and were topically applied to fifth instar larvae of the spruce budworm. Penetration rates and depletion of the external residues were determined by ¹⁴C-assay. The amount of aminocarb penetrated into the insects was determined by macerating them and extracting with ethyl acetate. The parent material and its metabolites present in the external rinses and in the extracts were determined by thin-layer-chromatography and a liquid scintillation counter. Penetration rates of aminocarb in the three mixtures varied according to the type of adjuvants present in them. The increasing order of penetration was AID-585 > AS-7N > AA-3409. The metabolites found, in decreasing order of concentration, were 4-methylamino, 4-amino, and 4-methylformamido aminocarbs. Trace levels of 4-formamido aminocarb, and 4-dimethylamino and 4-methylamino 3-methylphenols, were tentatively identified. The amount of aminocarb and its metabolites found varied according to the type of adjuvants and the rate of penetration.