Pay close attention to the mill date on your feed. The adult female grain weevil lays an average of 4 eggs per day and may live for four to five months (producing 250-400 eggs). A single generation can be completed in around 28 days. At 80 to 86 degrees F, 75- to 90-percent relative humidity, eggs hatch in grain with a moisture content of 13.5 to 19.6 percent in 3 days. The larvae feed inside the grain kernel for an average of 18 days. The pupal stage lasts an average of 6 days (5-16 range). The new adult will remain in the seed for 3 to 4 days while it's cuticle hardens and matures. The life cycle is about 30 to 40 days during the summer, and 123 to 148 days during the winter, depending on temperature.
Any chance you can stuff half of that into a deep freezer to put the breeding cycle of these pests on hold?