The bollworm flight overall this year has been low, slow and a trickle flight. Moth traps indicate that we have an increase in moth activity in spots and this is occurring later in the season than normal. Bollworm can be a significant pest of cotton and soybeans, particularly late soybeans that are just flowering during the flight. As such, the large 2021 wheat crop that was planted to double crop soybeans in June and July will need to be monitored. Wide row soybeans are especially attractive to moths.
In cotton, we need to be vigilant in scouting the two-gene cottons like Bollgard II as sometimes treatment is warranted for bollworm, and fall armyworm may also be present in Bollgard 2 cotton. The diamide products are the “go to” if treatment is required. Due to the outbreak of fall armyworms, diamide supplies may be tight. The three-gene technologies should still be scouted for bollworm infestations but it is unusual for a treatment threshold to be reached. As a reminder, treatment for bollworm could potentially be needed for 14-18 days (350 DD60s) after cotton has reached cutout, and in later cotton, this would include anytime through the end of August and first few days of September.
With the potential for an excellent soybean crop in many areas in Tennessee, we need to be mindful of insect pests in soybean that can sneak in and cost us yield. Please see this link to Dr. Stewart’s blog about bollworm in cotton and soybean for more details: