Response of Cotton Arthropod Populations in Cotton to Various Dosages of Aldicarb Applied in the Furrow at Planting Time

Arthropod populations found in cotton treated with aldicarb were compared to those found in cotton treated with dimethoate and an untreated check from 1981 through 1983. Populations of the bollworm, Heliothis zea (Boddie), and tobacco budworm, H. virescens (F.), were low during all 3 years of the test, and the use of aldicarb did not result in increased damage. The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), was the main cotton pest found during all 3 years of the test. All aldicarb treatments suppressed tarnished plant bug populations, although the high dose (1.13 kg [AI]/ha) gave the most consistent control for a 7- or 8-week period after planting. Control, mainly of the tarnished plant bug, resulted in a higher squaring rate and an increase in numbers of bolls in the insecticide treatments. Yield of seed cotton was significantly higher in the plots receiving the dimethoate and high and medium (0.56 kg [AI]/ha) dosages of aldicarb, compared to the untreated check in 2 years of the study. Some suppression of big-eyed bugs, Geocoris spp., populations occurred in 2 years of the test. However, populations of several other beneficial arthropods were not affected.