COMMON STALK BORER
Identification & Incidence:
Common stalk borer (CSB) over winters in egg stage on various plants especially
grassy weeds. Eggs hatch in May or June and larvae develop on their host plants
moving to corn when host plant is killed or too small for the larva. Larvae are
marked with white and purple-brown stripes. They are about 1-1/2 inches in length
when full grown. Sampling: Sample 20 plants in 5 places recording damaged
plants. Record larval size, stage of larval development and location of stalk
borer larva in the plant. Economic Threshold: Rescue treatment may be necessary
when 3% or more of the stand is being damaged and before the larvae have burrowed
deep into the plants. Management Options: Good weed control will reduce
the incidence of stalk borer. See chart for insecticides
labeled for CSB.
Corn,
Soybean, Wheat, and Alfalfa Field GuideBulletin 827