The black cutworm, Agrotis ipsilon (Hufnagel), damages various cultivated crops and is also occasionally a serious pest of turfgrass, especially on golf courses. Essential oils have potential as alternative control agents for insect pests. Sixteen essential oils (anise, camphor, cinnamon, citronella, clove, fennel, geranium, lavender, lemongrass, linseed, neem, peppermint, pine, thyme, turpentine and tea saponin) and paraffin oil were assessed in the laboratory and the green house for their efficacy against black cutworm larvae. Treatment of potted perennial ryegrass with anise, cinnamon, neem, paraffin or turpentine reduced black cutworm damage in a greenhouse trial. Neem oil (2000 ppm) reduced growth of black cutworms feeding on treated clippings within 3 and 5 days. Treatment of perennial ryegrass in pots resulted in 100, 100 and 46% mortality of black cutworm at 4000, 2000 and 1000 ppm, respectively. Weight of survivors at the 1000 ppm rate was 5 fold less than weight of comparably-aged controls.