They show up early and arrive hungry, which is good news for cotton producers in the Southeast and low-spray areas of the Mid-South.
These often underappreciated guests are beneficials, or “good” bugs, that attack aphids, the worm complex, spider mites and a variety of other unwanted pests.
Veteran entomologist, Ron Smith, with Auburn University, believes beneficials still play a significant role in the Southeast. He points out that because the plant bug is not a dominant pest early in the season, farmers in this region can utilize beneficials until about the third week of bloom, which occurs around July 20.
“This is the time that our stink bug pressure starts,” Smith says. “And that is by far the most dominant pest in the Southeast, including Alabama. Once we start spraying for stink bugs, the beneficials are taken out of the picture.
“However, if we can get through the moth flight before we have to treat for stink bugs, then the beneficial insects play a key role,” he adds. “The insect control gene technology is very good, but it’s not perfect. If you have beneficials in the fields in addition to the technology, you will have fewer surviving escapes in terms of eggs and small caterpillars.”
Fire Ants In The Spotlight
In the past, most of the focus has been on big-eyed bugs and minute pirate bugs, Smith says. But, in recent years, more appreciation is being given to fire ants, which are suppressing caterpillar numbers.
“In many areas of the Southeast, seeing wall-to-wall no-till production is not uncommon,” Smith says. “More fire ants are present in reduced-tillage systems, and they are searching the plant every day in multiple numbers. A small caterpillar doesn’t stand a chance where there are fire ants crawling all over the plant. The worms are feeding on or inside white blooms, and that’s where the fire ants are foraging.”
As Smith alluded to earlier, many areas of the Mid-South, particularly the Delta area, are not able to take advantage of beneficials as much as the Southeast does because of the plant bug situation.
“In the Delta, it is difficult to realize the full effects of beneficials because it is such a high-spray environment for tarnished plant bugs,” says Angus Catchot, Extension entomologist with Mississippi State University. “Once we start spraying for this pest, we diminish our beneficial populations.
“However, in the hills where we are in a low-spray environment, beneficials do a fantastic job of keeping aphid numbers below economic threshold levels and bollworms and tobacco budworms numbers down on non-Bt cotton,” he adds.
The main beneficial that farmers rely on in the hills is the fire ant, Catchot says. Other “good” bugs include larvae and adult lady beetles, lacewings and a number of parasitic wasps that parasitize caterpillar larvae.
Gus Lorenz, Extension entomologist with the University of Arkansas Division of Agriculture, says that unless the state’s farmers have to make disruptive sprays for thrips or spider mites early in the season, then the beneficial insects help keep bollworm/budworm populations down.
“Also, predators like lady beetles help us with aphids and spider mites,” Lorenz says. “Minute pirate bugs, lacewings, nabids and other predators that feed on a wide array of pests like aphids, spider mites and worms are probably the most important natural enemies we have in the system.”
The Arkansas entomologist adds that spiders have a big impact at times, and fire ants can be beneficial in cotton and soybean fields, particularly in south Arkansas.
The bottom line is that beneficials can effectively demolish cotton’s “bad guys,” depending on the early season spray environment and the pest spectrum that is present at the time.
Contact Carroll at (901) 767-4020 or firstname.lastname@example.org.