We’ve had an early drought and more recent rains that has resulted in the emergence of volunteer wheat in some double-cropped soybean fields.  This happened widely in 2007, and these conditions resulted in a huge fall generation of Hessian flies and an even larger spring generation that devastated some fields.  It that year, some folks actually kept stand of volunteer wheat which served as a nursery for Hessian flies.  The moral of the story is to control volunteer wheat NOW to prevent the start of Hessian flies.  Also remember that the earliest recommended planting date for wheat is October 15th.  September planted wheat will be at much higher risk of attack from Hessian flies, fall armyworms, and fall infestations of aphids that transmit barley yellow dwarf virus.