A typically variable spring weather pattern has enveloped much of the corn-growing region so far this growing season. The temperature ups and downs in association with multiple cold front passages has resulted in rather variable four inch soil temperatures both locally and across the entire corn-growing region. Accumulated four inch soil temperature measurements are important when it comes to predicting the first corn rootworm hatch. Accumulated soil temperatures are running about on pace or slightly ahead of last year (depending on where you are) and the highest accumulated growing degree days to date are located in southwest Kansas and central Illinois. Some fields in these geographies are likely to see their first corn rootworm hatch risks issued by next week (May 18-22). Additional initial corn rootworm hatch risks are then likely to spread north as accumulations continue to increase especially by late May (after Memorial Day) and into early June. Growers across southern Kansas and also into central and eastern Illinois should prepare to scout for newly-hatched corn rootworm larvae in the coming week or so, with additional scouting recommended further north into the I-80 corridor by late May and into early June.