TIMING INSECTICIDE APPLICATIONS FOR MANAGING EUROPEAN CORN-BORER (LEPIDOPTERA, PYRALIDAE) INFESTATIONS IN POTATO

European corn borer, Ostrinia nubilalis (Hubner), management using ins ecticides was investigated in Irish potato, Solanum tuberosum L, in ea stern North Carolina. Additionally, activity of corn borer larvae on u ntreated 'Kennebec' potato plants was evaluated. Corn borer larvae pro duced new tunnels at the same rate throughout their development and ul timately produced 4.7 +/- 0.4 (mean +/- SEM) tunnels per plant per lar va. Thus, for any given corn borer infestation level, estimates of dam age to the crop will increase as the season progresses. Application ti ming of carbofuran, methamidophos and esfenvalerate were evaluated for control of corn borer damage in 'Atlantic' potato. The type and rate of insecticide and the level of corn borer damage at the time of appli cation affected the level of damage at the end of the season. The grea test reduction in damage occurred when the insecticide was applied whe n many neonates were observed penetrating the plant. A single applicat ion of either carbofuran (1.12 kg a.i. ha(-1)) or methamidophos (0.84 or 1.12 kg a.i. ha(-1)) when approximate to 20-40% of the stems are da maged in early May should improve European corn borer management in po tato. Copyright (C) 1995 Elsevier Science Ltd.