Stalk borer migration out of brome grass into adjacent corn should be underway in southern and central Iowa. Fields that had stand loss last year in the border rows should be scouted for this insect. If you are uncertain about the occurrence of stalk borers in brome grass, look for dead grass inflorescences (blasted, pale seed heads). These plants have young larvae tunneling in the grass stem. See last week's newsletter, pages 98-99, for details on scouting.

Stalk borer degree days (base 41°F) January 1 through June 15, 1997.

Top number shows degree days. Bottom number shows expected date for 10 percent migration.