Insecticide resistant cotton aphids were indicated to be present in New Mexico cotton fields in 1991. Studies continued in 1992 indicated a lower level of resistance to some insecticides. Bidrin^®, Furadan^®, Lannate^®, Lorsban^®, Monitor^®, and Orthenc^® were the most effective products. Various tank mixes with each other and with various pyrethroids were also effective at higher rates. The numbered compound TD-2231 4OWP was also very effective at a Tate of 1.13 pound (lb) formulation (form)/acre (a). Bioneem^®, nicotine sulfate, Sunspray^®, and insecticidal and laundry soaps were ineffective at the rates and methods tested.

Sidedress application of Temik^® 15G in late season at 7.5 lb form/a resulted in the lowest accumulation of "aphid days" and a significantly (P ò 0.05) higher lint yield. However, no yield benefit was obtained with a 10 lb/a rate in the same test.