EFFECTIVE USE OF CHEMIGATION TECHNOLOGY FOR MANAGING SOYBEAN INSECT PESTS, WITH NOTES ON GEOCORIS-PUNCTIPES (SAY)

Field studies were conducted to evaluate the potential of chemigation as a management tool for soybean insects. Applications of chlorpyrifos (Lorsban 4E), cypermethrin (Ammo 2.5), esfenvalerate (Asana .66 XL), and thiodicarb (Larvin 3.2) significantly reduced populations of velve tbean caterpillar, Antirarsia gemmatalis Hubner, 48 h after treatment in all tests. All chemigated insecticides performed at least as well a s chlorpyrifos applied with a high clearance sprayer. Esfenvalerate co nsistently reduced larval populations by >97%. Thiodicarb and esfenval erate were the only chemigated insecticides that provided >90% velvetb ean caterpillar reduction 7 d after treatment in all tests. Management of the threecornered alfalfa hopper, Spissistilus festinus (Say), usi ng chemigation was sporadic in each test, with no one insecticide trea tment providing consistent population reduction. Plots chemigated with methomyl (Lannate 1.8L) and thiodicarb to manage velvetbean caterpill ar populations appeared to offer favorable habitat for the lygaeid pre dator Geocoris punctipes (Say). Thiodicarb offers growers an effective management tool for the velvetbean caterpillar while not adversely im pacting G. punctipes populations.