• Worm densities are high in pockets of the Coastal Plain and widespread across the Blacklands.
SOYBEAN LOOPER has two prolegs and one anal proleg (2 + 1).
Corn earworm is still not very abundant overall in soybeans across the state. That is unless you are one of the growers who have them!
Densities are high in pockets of the Coastal Plain and widespread across the Blacklands.
The threshold for flowering soybeans is unknown. However, based on data gathered from one of my students last year, I feel comfortable increasing the threshold for flowering soybeans three times above that for soybeans with pods.
Consult the online threshold calculator for corn earworm, located at this website. Unfortunately, the calculator does not include the plant’s ability to compensate for the feeding done by a very few caterpillars.
Therefore, our thresholds remains constant for corn earworm with prices anywhere above $10 per bushel. Please input $10 per bushel as the price of soybeans when using this calculator (see this post for more of the logic behind this).
In addition, wide areas across the Blacklands are seeing various mixes of earworm, soybean looper, and beet armyworm. Be sure to check all your varieties, as some are preferred over others.
It is especially important to scout behind soybeans that have already been treated with an insecticide this season.
Next, I will post new information on what chemicals are working for these pests. For now, remember to avoid using a pyrethroid alone for corn earworm (just a reminder, bifenthrin is a pyrethroid). Belt, Steward and Tracer are good alternative options.
In addition to these chemicals, Intrepid manages loopers and beet armyworm well, but is weak on corn earworm.
For a look at research trials showing insecticide efficacy for corn earworm, beet armyworm and loopers in soybeans, visit http://www.nccrops.com/2012/08/16/insecticide-efficacy-for-corn-earworm-beet-armyworm-and-looper-in-soybean/.