We have talked about corn leaf diseases and foliar fungicides in this space recently but we need to watch out for insects also. Some of the important insects that might “bug” us are discussed below:
• Corn rootworm beetles larvae attack the roots during June and early July and the adult beetles clip the silks and may interfere in the pollination process during July and early August. Watch out for these insects if you are growing GMO corn where the trait has failed or the non-GMO corn if you have not used insecticide.
• Japanese beetles have copper and green color and eat the green silks as well as leaf tissue. Adult may be found during July and August.
• European corn borer larvae are dirty white to tan with dark spots and a dark brown to black head. Young larvae feed on the leaves. Before tasseling the larvae feed deep inside the leaf whorl and produce shot holes. They lay egg masses underside of the leaves.
• Corn leaf aphids are found on the tassels before they emerge from the leaf whorl. They remove moisture and nutrients from the leaves and tassels and secrete sticky honey dew. They are more of a problem during the stress periods.
• Corn earworm larvae may feed in the whorl, on silks or inside developing ears. Larvae may tunnel through the developing silks, interfere with pollination and destroy kernels at the tips. They are cannibalistic and only one worm is found per ear.
• Western bean cutworms are dark brown to tan and have two dark brown stripes behind the head. After mating, the females lay their eggs on top surface of the corn leaves. Unlike corn earworm, more the one may be found per ear. Walking is good for you and the crop, so keep scouting.