The sorghum midge Contarinia sorghicola (Coquillet) (Diptera Cecidomyiidae) is a severe sorghum pest in the State of São Paulo, Brazil, and the aphid Rhopa-losiphum maidis (Fitch) (Hemiptera Aphididae) is commonly found in the crop. The interaction among varieties of different cycles and resistance, planted in successive dates in relation to the damage done by sorghum midge and the size of the aphid population were studied in 1967-1968. The planting season for sorghum in the State of São Paulo goes from October to January. The plantings were made on XI-3-1967, XI-23-1967, XII-13-1967, and I-2-1968. The different responses of the varieties in relation to the sorghum midge damage were evident. Varieties AF-28 and AF-117 were resistant and Sumac and B. Leoti were moderately resistant. These last two varieties are early flowering and had low damage in the first plantings but had as much damage as the susceptible varieties in the last plantings. The interaction between varieties and planting season was significant. In general the sorghum midge infestation was low in the first flowering plots and increased thereafter whereas the aphid infestation was high in the first flow-erings and decreased thereafter. The response of the varieties to the aphid was studied protecting the heads of five plants per replication of each variety of each planting date, with a non treated paper bag and grading the aphid population afterwards. The varieties AF-28, AF-37, and AF-117 all with open type panicles were resistant to the aphid whereas the other varieties with compact type of head were susceptible or moderately resistant. There was independence between the resistance against the aphid and the sorghum midge. Varieties AF-28 and AF-117 were resistant to both insects. Variety AF-37 was susceptible to the midge and resistant to the aphid. Variety Sumac was moderately resistant to the midge and susceptible to the aphid and varieties Double Dwarf Feterita and M 35-1 were susceptible to both insects.