Influence of planting date and insecticide treatment on insect pest abundance and damage in dryland cotton

Objectives of this study were to measure the influence of planting date and insecticidal control on pest abundance and damage in dryland cotton. 'Paymaster 145' cotton was planted in late April, late May (which is the recommended delayed uniform planting date for management of the boll weevil, Anthonomus grandis grandis Boheman), and late June for 4 yr from 1986 to 1989 in the northern Texas Rolling Plains. Subplots within each planting date were no insecticide treatment, and treatment with aldicarb at planting and application of an appropriate insecticide when a pest attained its damage threshold. Insects sampled were thrips (including the western flower thrips, Frankliniella occidentalis [Pergande]); cotton fleahopper, Pseudatomoscelis seriatus (Reuter); bollworm, Helicoverpa zea (Boddie); cotton aphid, Aphis gossypii Glover; and boll weevil. Thrips densities were highest in cotton planted in late April; densities were reduced by aldicarb treatments in late April and late May cotton but not in late June cotton. Highest densities of cotton fleahoppers occurred in cotton planted in late May; densities were reduced by aldicarb treatments in late May and late June cotton but not in late April cotton. Densities of overwintered boll weevils were highest in April-planted cotton and lowest in June-planted cotton. Boll weevil damage during the growing season was lowest in cotton planted in late May, and insecticides applied for boll weevil control during the growing season suppressed damage for all planting dates. Bollworm densities were not influenced by planting date or by insecticide treatment. Cotton aphid densities were highest in cotton planted in late June. Delayed uniform planting for boll weevil management does not adversely affect damage by the other important cotton pests in dryland cotton in the northern Texas Rolling Plains. Planting in late May reduces damage caused by thrips, cotton aphids, and boll weevils