Our earliest planted corn has tasseled and silking at this time. I’m seeing stink bugs move into corn as wheat is being harvested. Stink bugs can cause the greatest amount of damage when the ear first pollinates. With piercing mouthparts, they feed through the husk and damage kernels. Their feeding injury usually deforms ears into a C or boomerang shape. The ears do not develop properly and may be more susceptible to infection by diseases. Here is a hatch out of brown stink bugs I found on a leaf this week.
1st Instar – Brown Stink Bug
We usually see southern green, green, and brown stink bugs. Each of these species have similar behavior at hatching. They tend to remain clustered on the egg mass unless disturbed. They do not feed on plant tissue at first instar. Immature brown stink bugs are yellow to tan, with brown spots down the middle of the abdomen.
1st Instar – Brown Stink Bug
Adult – Brown Stink Bug
Threshold
UGA Extension Grain Entomologist Dr. David Buntin says, “Treat during the ear elongation / tassel state (VT) if 1 stink bug per 2 plants is present. During pollination to blister stages (R1 – R2), control is warranted if populations reach 1 bug per plant. Use pyrethroid insecticides if southern green and green stink bugs are prevalent. If brown stink bugs are present, a high rate of bifinthrein will provide about 75-90%.”
Thomas County Ag 