Methiocarb is a carbamate pesticide with insecticidal, molluscicidal, acaricidal, and bird repellant properties.^1,2,3,4,5It inhibits acetylcholinesterase (AChE) activity and is toxic to the western flower thrip (F. occidentalis; IC₅₀= 2.1 μM; LC₅₀= 3.26 ppm).²Methiocarb is also toxic to the land snailM. obstructa(LD₅₀= 27.4 μg/snail) and the citrus miteA. pelekassi, inducing 94% mortality when used at a concentration of 0.5 ppm.^1,3It reduces the seasonal percentages of cotton bolls infested with pink bollworm (P. gossypiella) to 4%, compared with 65% infestation in untreated controls, when applied to cotton fields at a concentration of 1.86 lb/acre.⁵Methiocarb reduces damage to grapes by song birds when applied to vineyards at a concentration of 2.5 lbs AI per 100 gal water per acre.⁴It is an estrogen receptor α (ERα) and ERβ agonist (EC₂₀s = 19.87 and 20.24 μM, respectively) and an androgen receptor antagonist (IC₅₀= 13.89 μM) in cell-based reporter assays.⁶It is toxic to juvenile rainbow trout (O. mykiss) and guppies (P. reticulata) with LC₅₀values of 0.8 and 1.48 mg/L, respectively, at 48 hours of exposure.⁷Formulations containing methiocarb have been used in the agricultural control of pests.

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