As many crops are close to harvest, normally, treatment for insect pests may not make sense. However, drought conditions in the eastern half of the state have worsened in recent weeks, which is favorable for both chewing and sucking insect pests.
There are still a lot of peanuts in the ground and those close to maturity should be harvested as suitable. If producers are in a situation with high caterpillar counts in the field, then peanuts may be treated with a low-cost synthetic pyrethroid. Note that it takes between 10 to 14 days for spider mites to flare up after chemical applications. If a grower is over a month away from harvest, they shouldn’t risk a spray treatment with synthetic pyrethroids. For late-planted peanuts, there are other caterpillar control materials (insect growth regulators, spinetoram etc.) that can be safely used under this dry environment.
Overall Moth Counts From Pheromone Traps (AL)
|Species||Trap Initiation (Locations)||Total Numbers (16 loc.)||Change in Numbers||Trend Over Two Weeks|
|Beet Armyworm||May (16)||701||+179||25% increase|
|Fall Armyworm||May (16)||309||+143||46% increase|
|Cabbage Looper||May (16)||352||+83||23% increase|
|Soybean Looper||May (16)||246||+135||55% increase|
|Corn Earworm||May (16)||61||+20||33% increase|
|Tobacco Budworm||May (16)||65||+5||8% increase|
|Lesser Cornstalk Borer||May (16)||4,680||+1,030||22% increase|
|Squash Vine Borer||May (16)||953||+269||28% increase|
|Yellowstriped Armworm||Aug (8)||5|
|Southern Armyworm||Aug (8)||9|
|European Corn Borer (ECB-IA)||Aug (8)||0|
|European Corn Borer (ECB-NY)||Aug (8)||0|
Overall moth captures from sticky wing pheromone traps is shown in the table above. Insects showing the largest increase in terms of number and percent change include beet armyworms, fall armyworms, and soybean looper. Excessive dry conditions are also favorable for lesser cornstalk borer (LCB), a major pest in peanuts that can cause reduced yield and quality.
Although we do not monitor moths of the velvetbean caterpillar using sticky traps, there is high activity of moths and caterpillars in peanut fields in southeast Alabama, along with a significant number of loopers that make the peanut plants look grazed. Most caterpillars may feed on the stem terminals and not threaten the whole plant with defoliation. Lack of treatment for caterpillars may make the harvesting unsightly and problematic for some peanut growers, so plan ahead.
In vegetables, squash vine borer also seem to be favored by drought, although it has a restricted host range and may not bother many growers in north Alabama that experience fewer moth generations. Armyworm larvae should be abundant on vegetable crops around this time of year, often mixed with the loopers and fruitworms.
We added a few traps for insect pest species, like the yellowstriped armyworm, southern armyworm, and European corn borer, late in the season upon request from hemp producers in Alabama. For this reason, the moth numbers in the table are preliminary and do not indicate season-long moth activity. If hemp producers are having fire ant and other caterpillar issues, consult Managing Fire Ants in Hemp for a full list of approved products. For a deeper conversation about hemp IPM, please contact Dr. Katelyn Kesheimer.
Additional IPM Resources
Additional details about pest monitoring and scouting can be found on the Integrated Pest Management page of the Alabama Extension website. For further information, contact your county Extension commercial horticulture agent. To receive timely pest alerts, subscribe to the Alabama IPM Communicator Newsletter.