Wheat sowing dates

Yesterday I saw someone hauling seed wheat. Looks like we will see more wheat in the area than last year. Checked on Planting dates in the IL Agronomy Handbook. In my area, fly free dates are Oct 2 to 9th. This is based on average first date of frost. Waiting till the fly free date was an old practice to avoid Hessian Fly infestations. Now-a-days some varieties are resistant to hessian fly. Still a good reason to wait is that the aphids that cause barley yellow dwarf in wheat are active in early planted fields. Yields do decline a bit within 10 days of the fly free date, so timely planting is important. Thanks to U of I for the information.