May 7, 2009
Early cutting has begun in some of the early planted corn and sweet corn in the county. Damage may be more widespread in a spring like 2009, where wet field conditions have allowed for weed growth to grow without tillage or spraying taking place. One tool available for predicting cutting date is at http://www.isws.illinois.edu/warm/pestdata/sqlchoose1.asp?plc= You can select black cutworm from the list of pests, click on a town, and enter an intense moth capture date to get an estimated date of first cutting. From data available, the first estimated date of black cutworm damage would be May 14. That's not to say lower numbers of moths came through prior to the intense capture time, which happened to be April 4 in Piatt County.
Early damage appears as pinhole feeding in leaves, and this occurs when larvae are not yet big enough to actually cut plants. The next stage is usually cutting leaf tips or upper portions of plants, but other types of cutworms will have similar damage and these other cutworms are mainly leaf feeders. Finally with black cutworms, cut plants will appear. Finding the cutworms is important so correct identification can be made. Descriptions can be found at this website http://ipm.illinois.edu/bulletin/pastpest/articles/200204c.html .
Watch fields, especially those with good egg-laying sites provided by early weed growth. Treatments are justified when 3-5% plant cutting is occurring. Listed products include most of the pyrethroids, and Lorsban.