Control of the Tobacco Aphid .Mvzus nicotianae Blackman (Homoptera: Aphididae) with Two Formulations of Acephate Chemical control ofthe tobacco aphid Myzus nicotianae Blackman was tested at the field, in Vera Cruz and Santa Cruz do Sul, RS. Two formulations ofacephate, Orthene 750-WP, and Orthene 50G-granulated, were tested with the dosages of 0.5 and 1.0 kg/ha, for the first formulation, and of 20, 30, and 40 kg/ha, for the second. Treatments were distributed in a completely randomized block design. In the first experiment, the granulated formulation was applied preventively, when seedlings were transplanted. In the second experiment, the granulated formulation was applied at the beginning ofM nicotianae infestation. The best control was obtained with the two dosages of Orthene 750, with 100% efficiency from 4 to 21 days after application, and 93% at the 30th day. The Orthene 50G was efficient (ca. 80%), only when applied with high dosages, at the beginning of the infestation period. KEY WORDS: Insecta, /vívzus nicotianae, tobacco, chemical control. RESUMODois ensaios de controle químico do pulgo do fumo Myzus nicotianae Blackman, foram conduzidos em lavouras de fumo tipo Virgínia, em Vera Cruz e Santa Cruz do Sul, RS. O delineamento utilizado foi o de quatro blocos completos ao acaso incluindo duas fonnulações de acefato: pó molhável, com 750gde i.a./kg(Orthene 750) e granulado, com 50gde i.a./kg (Orthene 50G) a primeira formulação foi utilizada em duas dosagens (0,5 e 1,0 kgfha) e a segunda em três dosagens (20, 30 e 40 kg/ha), totalizando, com unia testemunha, seis tratamentos. No primeiro ensaio, o granulado foi aplicado preventivarnente, por ocasião do Recebido em 25/11/93. Aceito em 03/03/95.