Western Bean Cutworm Flight Increases, Scouting More Difficult Post-Whorl

by | Aug 3, 2022 | Indiana Agriculture News, News Feed

Scouting late-whorl corn for western bean cutworm egg masses. Photo courtesy of Purdue Extension.

The western bean cutworm (WBC) trapping season continues, and after a slow start, moth flights have increased slightly in many northern Indiana county traps this summer.

With hot temperatures continuing, egg development and hatch will happen in less than a week after they are first placed by females. This will give little time for egg scouting, and unfortunately larval scouting is far more difficult, time-consuming and less reliable. In other words, some larvae have hatched and have already infested corn whorls, leaf axils, and/or ears – control is very difficult at this point and those just looking for egg masses beginning now will likely be underestimating the population.

Here is a video you may find helpful in scouting corn post-whorl:

Pre-tassel corn is preferred by egg-laying females. Research conducted at the University of Nebraska has shown that larvae survive best in late whorl stage corn. This is likely because this synchronizes their development with the onset of pollen shed, and pollen is a key, high-protein food source for young larvae before they move into corn ears.

Here is a video that you may find helpful in scouting whorl stage corn:

Written by: Christian Krupke and John Obermeyer

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