Scout now for silk clipping!

Insects like adult Corn Rootworm and Japanese Beetles can interfere with pollination by feeding on corn silks. Most corn is or will be pollinating soon so get out now and scout for silk clipping!

A rescue treatment with an insecticide is recommended if the following thresholds are observed:Japanese Beetles

• Silks are being clipped within ½ inch throughout the field
• 3 or more beetles per ear (consideration for less if silk clipping is occurring under drought and heat stress)
• Pollination is ongoing/less than 50% complete

*Reference: http://bulletin.ipm.illinois.edu/?tag=economic-thresholds
Corn Rootworm Adults

Commercial hybrid production fields

• Average of 20 beetles per plant, or
• Silks clipped back with ½ inch of husk prior to 50% pollen shed

Inbreds (seed production fields)

• Fields under drought or heat stress with 1 to 3 beetles per plant feeding on green silks
• Fields with optimum moisture and moderate temperatures and 5 beetles per plant feeding on green silks

*Reference: Culy, Edwards & Cornelius. 1992. Journal of Economic Entomology 85: 2440-2446.
Photo: Purdue University