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The fate of residues of five insecticides (chlorpyrifos methyl, fenthion, methidathion, parathion methyl, and quinalphos) from the treatment on vine to the production of wine was studied. The influence of clarifying agents (bentonite, charcoal, potassium caseinate, gelatin, polyvinylpolypyrrolidone, and colloidal silicon dioxide) on residue concentrations in wine was also studied. The insecticide residues on grapes showed high decay rates after treatment, with first-order kinetics and half-lives ranging from 0.97 to 3.27 days. Grape processing into wine caused considerable residue reduction (>80%) for chlorpyrifos methyl, parathion methyl, and quinalphos, moderate reduction (co. 50%) for methidathion, and almost no reduction for fenthion. The wine-making technique (with or without maceration) had the same influence on the residue concentrations in wine. The clarifying agents tested showed no or moderate influence on the residue contents in wine with the exception of charcoal, which allowed complete or almost complete elimination of insecticide residues.

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The fate of Primicarb (I) residue on field and greenhouse lettuce was studied. The parent compound was quickly transformed into its N-methyl-N-formyl (11) and N-demethyl (111) analogues. Five days after treatment, another metabolite, N-demethylphenol (VI), was determined, though in low amounts. These metabolites were rapidly degraded, and 10 days after application of Pirimicarb, only I11 was detected, showing a very low residue. The very rapid decay rate of Pirimicarb into its metabolites should indicate that volatilization does not represent the primary means of loss of I in plants and that the aphicide action could also be ascribed to its metabolic products. Though the microclimatic conditions were different in the two experiments, the degradative kinetics were similar in both cases, because in the field relative humidity and wind speed, compensating for each other, determined a tendency to evaporation analogous to that occurring in the greenhouse.Aphids are among the most important pests in the cultivation of lettuce. Of the numerous insecticides on sale, Pirimicarb, 2-(dimethylamino)-5,6-dimethylpyrimidin-4yl dimethylcarbamate (I) (Figure l ) , is one of the few to possess selective action against aphids but not against their natural predators.Pirimicarb is rapidly lost in plants after spraying, mainly by volatilization but also by photochemical and metabolic degradation. The major degradative products are the carbamate-containing metabolites I1 (2-[(methylformyl)amin0]-5,6-dimethylpyrimidin-4-y1 dimethylcarbamate) and I11 (2-methylamino-5,6-dimethylpyrimidin-