Field tests were conducted in 1978 at Phoenix, AZ, to evaluate a feeding adjuvant, the nuclear polyhedrosis virus (NPV) from the alfalfa looper, Autographa californica (Speyer), and the HD-l strain of Bacillus thuringiensis Berliner in controlling Heliothis virescens (F.) in cotton. When cotton that was planted on a normal planting date (Apr. 21) was treated with the virus + a feeding adjuvant or virus + B. thuringiensis + the adjuvant, the percentage of squares and bolls damaged by Heliothis and the number of larvae in the fruiting forms were reduced 38–50 compared to numbers in untreated cotton. However, this reduction did not affect the yield of seed cotton. When cotton, planted late (June 26) to maximize tobacco budworm damage, was treated on a 5-, to 7-day schedule, yields of seed cotton in untreated plots, plots treated with virus alone, plots treated with virus + adjuvant, and plots treated with virus + B. thuringiensis + adjuvant were 332, 774, 1066, and 1427 kg/ha, respectively. Treatment with the virus + B. thuringiensis + adjuvant resulted in the boll damage never exceeding 5% and square damage never over 10%. In another late-planted area, the percentage of squares damaged by Heliothis in untreated plots, plots treated with B. thuringiesis alone, and plots treated with B. thuringiensis + adjuvant was 44.5, 18.3, and 8.8, respectively. The yield of seed cotton was 32% greater in cotton treated with the B. thuringiensis + adjuvant compared to the yield in cotton treated with the bacterium alone. Of Heliothis eggs examined during the tests, 89–98% were H. virescens , and the remainder were H. zea (Boddie).