Andy Michel
Our trap counts of Western bean cutworm (WBC) adults have been on the rise during the last week, and will likely increase until the end of July. Just like in previous years, our hotspots for western bean cutworm activity are in NW and NE Ohio. Based on these counts, we would recommend growers scout for the presence of any WBC egg masses. We know that females prefer to lay eggs in corn that has not tasseled, so those fields should take priority. Egg masses are laid on the uppermost 1-2 leaves, especially those that remain in the vertical position. Scout 10 plants in 10 locations. Egg masses contain 25-75 eggs and start out white, then tan and then turn purple. Once eggs turn purple, egg hatch will occur within 24 hours. Treatment is recommended when 5% or more plants have egg masses. Although we have yet to see economic populations of WBC, we do have a fair amount of pre-tassel corn that is at risk. See fact sheet http://ohioline.osu.edu/ent-fact/pdf/0040.pdf for more information.
Source : osu.edu