The sweet corn variety plots at Pinney Purdue provide a good chance to observe sweet corn insects. In late July I observed two caterpillars that surprised me. The first was European Corn Borer (ECB), in the tassel where they are often found (Figures 1 & 2). It was a surprise because I have seen many fewer of these in the sweet corn plots in recent years. I understand from the entomologists that it is due to the widespread use of Bt field corn that has resulted in much lower populations of ECB. The week of Aug. 19 I observed an ECB egg mass on a flag leaf and a young larva on the ear (Figures 3 & 4). The second late July observation was a corn earworm (CEW)–the insect itself is not surprising, but it was in the tassel! (Figures 5-8). I have previously only seen them in ears. The[Read More…]

We have begun our state-wide trapping and monitoring program for corn earworm (Figure 1). The latest trap catch information can be found here. Traps have been placed at each of the eight Purdue Agricultural Centers throughout the state. Trap catches at the reporting farms are already in the double digits. Please refer to E-31 to learn more about corn earworm identification and management. Management and insecticide sprays target the eggs that are laid, preferably on fresh corn silk. If no field corn in the area is silking, which is true for most this year, use a threshold of 1-3 moths per night per pheromone trap. You only need to spray your sweet corn if it has silk present. When field corn begins to silk and green silk is present the threshold increases to 10 moths per night. Eggs are laid individually on developing silk. They hatch within 2-5 days and[Read More…]