European Corn Borer - Ostrinia nubilalis         Ronald Smith, Auburn University, www.ipmimages.org      Clemson University, USDA Cooperative Extension Slide                                                                                            Series, www.ipmimages.org HOSTS: Beans, Corn, peppers, rhubarb. DESCRIPTION: Adults are pale yellow moths, 1 inch long, with dark bands on their wings. Larvae are pink/grey with brown heads and are about 1/2 to 1 inch long. LIFE CYCLE: This pest overwinters as a full-grown caterpillar in plant debris. Pupation occurs in the spring. Moths lay eggs which hatch in 10 days. The young borers enter plant tissue, feed for 2-3 weeks, then pupate. There are 2 generations per year. CONTROLS: Traps: Blacklight traps catch male and female moths; pheromone traps catch only the males. Both traps are most effective as indicators of population levels. Mechanical: Use floating row covers, being sure to remove them when plants bloom so that pollination is not hindered. (Remay has been shown to be the most effective type of floating row cover for these types of pests.) Biological: Scout your plants every 2 to 3 days; apply BtK in granular or ES (emulsifiable suspension) form if 20% of leaves have "shot holes" in them, being particularly attentive to the undersides of the leaves. (BtK is most effective on small larvae, 1/4 to 3/4 inch long, in their first instar.) See Bacillus thuringiensis. FOR CORN: Spray directly to leaf whorls, and to silks after they have wilted. Apply Dipel (Bt) at 1 lb/A or Xentari at 1.5 lb/A. For late plantings, apply Xentari once at tassel; hand apply a corn oil/Bt mix directly to corn silks. Apply any of the various horticultural oils to ear tips 4 - 5 days after the silks wilt to discourage worms already present. See Bacillus thuringiensis. Botanical: Spray ryania or rotenone/pyrethrin in the evening.
Missoula County Extension Office; Missoula, Montana 59808 - Updated for 2006