Chinch bugs have gotten off to an early start in local St. Augustinegrass lawns this year.
This tiny insect prefers St. Augustinegrass and rarely bothers our other lawn grass species. If you have a St. Augustinegrass yard, you need to know how to recognize their damage.
Many people misdiagnose the problem because they are not looking for something as small as chinch bugs.
Adult chinch bugs are about 1/10 of an inch in length and are black with white wings.
Nymphs (immature stage) are reddish with a white band across the back and are about 1/20 of an inch in length after hatching. Nymphs become black as they mature.
Because drought stress can promote chinch bug problems, irrigate with ½ to ¾ of an inch of water when the lawn begins to show signs of water need. Don’t irrigate again until wilting begins to occur. Visit http://edis.ifas.ufl.edu/lh025 for details on lawn irrigation.
The kind and amount of fertilizer affects grass growth and chinch bug activity.
You can reduce grass growth rate and possible chinch bug problems simply by using minimum applications of a slow release nitrogen fertilizer as compared to frequent doses of a water soluble nitrogen fertilizer. One to two applications of a slow release lawn fertilizer per year may be sufficient to produce an attractive St. Augustine lawn.
By limiting insecticide use, you can encourage valuable beneficial insects that will help battle chinch bugs. The black big-eyed bug and the earwig are great allies. These two insects consume large numbers of chinch bugs.
During spring through fall, inspect your St. Augustine lawn frequently for signs of chinch bug damage. As they feed, chinch bugs quickly cause yellowish to brownish patches in the grass. Because other factors may cause similar symptoms, it’s important to identify the true cause.
If chinch bugs are found, start control measures promptly. Many lawn insecticides list chinch bugs on their label. It’s best to use a product that can be applied in a hose end sprayer verses a granular application when targeting chinch bugs. Always read and follow label directions before using any pesticide.
To avoid unnecessary environmental contamination and a reduction in beneficial insects, early spot treatments can be applied while infestations are still small. Treat the off-color areas and about a ten-foot buffer zone around each. A few days later, check for effective control. If damage is widespread, the entire yard may need to be treated.
Visit http://edis.ifas.ufl.edu/topic_southern_chinch_bug for more information on chinch bugs.
Larry Williams, UF/IFAS Extension Agent, Okaloosa County, April 26, 2017