Influence of Planting Date and Row Width on Abundance of Velvetbean Caterpillars (Lepidoptera: Noctuidae) and Southern Green Stink Bugs (Heteroptera: Pentatomidae) in Soybean

Abstract

The influence of soybean planting date and row width on seasonal abundance of velvetbean caterpillars, Anticarsia gemmatalts Hubner, and southern green stink bugs, Nezara viridula (L.), was examined in large field plots during 1987-1988. Late-season populations of velvet bean caterpillars were more abundant in ‘Braxton’ soybeans planted in early June than in early May. They also were more numerous in narrow rows (45 cm) than in wide rows (90 cm), regardless of velvet bean caterpillar population density or sampling date. Southern green stink bugs were more numerous from July to mid-August in soybeans planted in early May than in soybeans planted in mid-Mayor early June. In late September to mid-October, when peak numbers were observed, there were more stink bugs in the narrow-row plantings than in the wide-row plantings. Several planting date, row spacing, and sampling date interactions were noted and are discussed. The canopy closure index (space left open between rows) was higher in the later plantings and wide rows, whereas plant height was higher in the earlier plantings and about the same for both row widths. Plot yields varied among planting dates between years but were higher in narrow rows both years.