Grain Sorghum maturity ranges from milk to near harvest. Some fields may have already been harvested. The primary insect pests in post bloom sorghum is stink bugs, headworms and aphids.
Stink bugs and headworms can cause economic losses until hard dough. Once the seed is at hard dough, these pests are no longer an issue.
The economic threshold for headworms ranges from 0.15 to 1 large worm (> 0.5 inch) per head. For medium worms (0.25-0.5 inch) the ET ranges 0.8 to 2 per head. The threshold for treating stink bugs is from 0.5 to 0.85 per head. (0.75-1.25 if treating by air).
Many fields were treated for Sugarcane aphids 2-4 weeks ago and may see a resurgence in numbers. Keep a watchful eye as these aphids can produce excessive amounts of honeydew causing problems for harvesting equipment.
Fields with low populations can be beneficial in maintaining high numbers of aphid predators. Lady beetles, lacewing and syrphid fly larvae can help keep the aphid population in check and spread to adjacent fields to help with their aphids as well.