Christian Krupke and John Obermeyer
- Western rootworm adults have been spotted in west central Indiana.
- Beetles should not be a concern until fields are pollinating.
- Late planted/replanted fields could be a “trap crop” for beetles and egg laying.
Western corn rootworm beetles are beginning their annual emergence from the soil in Indiana. The male beetles are generally first to emerge and feed for several days until females begin emerging a few days later. Females mate, then feed and disperse, sometimes over long distances.
After emerging, beetles will begin to feed on corn leaves if pollen is not available. Leaf feeding damage is of no economic importance. However, pollinating plants with high beetle populations could suffer economic losses from the beetles clipping silks prior to the completion of pollination. Pest managers should watch their fields for this type of feeding activity when pollination begins.
Adult beetles survive for several weeks and are consistently attracted to pollen sources throughout their lifespan. Therefore, late-planted fields are particularly susceptible to silk-clipping. Fields with uneven growth and/or replanting may be more vulnerable than most. These delayed areas should be closely watched for silk clipping. For rootworm beetle control products, see Extension Publication E-219-W, Corn Insect Control Recommendations - 2013, which can be viewed at <http://extension.entm.purdue.edu/publications/E-219.pdf>.
A lonely male western corn rootworm beetle
Source : purdue.edu