Update on Intense Flights of Black Cutworm Moths

May 7, 1999
During the last week of April, reports of intense captures (nine or more moths caught over a 1- to 2-day period) of black cutworm moths were numerous in many counties of the state. For the period of April 23 through 29, intense flights occurred in the following counties: Champaign (4/28), Clark (4/23), Clinton (4/24), Douglas (4/29), Effingham (4/28), Fayette (4/25­ 4/28), Hancock (4/23 and 4/28), Knox (4/24), Logan (4/23), Macon (4/26), McHenry (4/28), McLean (4/27), Montgomery (4/24 and 4/26), Morgan (4/23 and 4/27), Shelby (4/28), and Stark (4/24). The following cooperators were organized by Len Dobbins, FMC Corporation, and provided the information on black cutworm flight activity: WLS Flying (Montgomery County), Bo Jac Seeds (Logan County), Hennings Feed and Fertilizer (Shelby County), PC Ltd. Cerro Gordo (Macon County), Ehler Bros. Thomasboro (Champaign County), Hughes Seed Farm (McHenry County), Mowers Plus (Stark County), Agri Pride FS (Clinton County), Woolsey Bros. (Fayette County), Effingham Equity (Effingham and Douglas counties), UAP Jacksonville (Morgan County), Hancock Service Co. (Hancock County), and Leroy Fertilizer (McLean County).

The distribution of cooperators who reported intense flights of cutworms during late April suggests that central Illinois producers should be vigilant in their scouting efforts of seedling-stage corn plants. A reminder: Cornfields at or below the 4-leaf stage of development are most susceptible to cutting and potential economic losses. Don't wait for cutting to show up before you begin monitoring cornfields for black cutworms. Pinhole leaf feeding is the best early indicator of potential cutworm problems. Even though your county may not have been listed so far this spring in our newsletter, don't assume that cornfields in your area are not at risk. Our list of cooperators is not exhaustive. Our best advice is to "ground-truth" the cutworm risk in each cornfield under your management. In last week's Bulletin we provided a list of projected cutting dates based on earlier intense flights this season. Cutting of plants in some southern and southwestern counties is expected to begin as early as May 9. We'll provide new projected cutting dates for the most recent intense flights in next week's issue. Stay tuned as the black cutworm season unfolds.

If you've experienced low numbers of black cutworm moths in your pheromone trap(s) this season, you may not be alone. Dale Baird, Crop Systems Educator, Rockford Extension Center, reported that Scentry Biologicals indicated they had sent him a "bad batch" of pheromone lures. So if you ordered your pheromone lures from this company, you may want to confirm that your specific lot number contained functioning lures. Please let us know if any confirmed cases of black cutworm injury are occurring in your area of the state. We'll pass along your observations in future issues of the Bulletin.--Mike Gray

Author: Mike Gray