Sorghum maturity ranges from bloom to soft dough stage. We continue to watch fields for the sugarcane aphid but our attention is turning toward Stink bugs and headworms.
I produced a short video last year demonstrating how to check sorghum for stink bugs and headworms, provided below.
When we scout sorghum after bloom, we check 5-10 places in each field and take 3-5 samples with a beat bucket. Each sample will be 10 heads. This allows you to determine the number of insects per head. Continue to monitor stink bugs and headworms until hard dough.
Sugarcane aphid populations have declined in many fields due in part to the high numbers of predator insects. Keep and eye on the aphids, especially if you have to treat for stink bugs or headworms. A pyrethroid insecticide has the potential to reduce the number of beneficial insects and increase the reproductive rate of aphids.
Cotton fields are in early to mid-bloom and have 6-9 nodes above white flower. We are looking for Verde Plant Bugs and Stink Bugs in cotton fields. Scout for Verde plant bugs with a beat bucket or drop cloth. Using a 5-gallon bucket, beat one plant around in the bucket 5-7 times and check what insects are dislodged into the bucket. Treat for Verde plant bugs when populations exceed 15 bugs per 100 plants.
Once a field has bolls which are 1-inch in diameter, inspect 20, one-inch bolls from 5 spots per field. Open the boll by pressing on the sides and inspect the inside for evidence of feeding. Treat the field when more than 20% of 1-inch bolls have evidence of internal feeding.
Stink bugs will be the primary insect pest in soybeans until maturity. We are finding all of the important species of stink bugs in area fields. Some of these fields have exceeded threshold in the past week, requiring treatment. Treat stink bugs when numbers exceed 36/100 sweeps, or 24/100 sweeps for Red-Banded Stink bugs.