You may have heard the saying, "If you don't like the weather in Florida, just wait a minute." This quip has never held more true than it has this year.
We had a prolonged cold, wet winter followed by two months of high temperatures and drought. It was early July before we started seeing our "normal" summer weather pattern: warm muggy days and afternoon showers.
As I predicted, the abnormally cold winter we experienced really put a dent in certain insect populations. In years past, chinch bug activity was in full swing by early May. This year it was early July before any serious level of chinch bug population was detected in this area. The preemptive use of the insecticide "Aloft" that I applied to your lawns back in May has held off chinch bug activity up to this point. I will continue to monitor your turf, keeping my eyes peeled for signs of this destructive pest.
Many other insect species that are pests on shrubs and trees also took a real hit this winter. Aphids, mealybugs, scale, thrips, and mite populations, just to name a few, all showed up in spring and early summer in much lighter numbers than "normal." Too bad for them, but good for your landscapes!
Some insect pests, however, weren't hampered by the cold winter. Two turf pests in particular, the tropical sod webworm and the army worm, have shown up this early summer in higher than "normal" numbers. These two worm pests along with a fungal disease known as "gray leaf spot" on St. Augustine turf have kept us very busy the last four weeks. The sod webworm and the army worm both feed on the grass blades. The army worm will chew on the edges of the grass, giving the blades a notched appearance. The sod webworm, a nocturnal feeder, chews on the green in the center of the grass blade, leaving a clear membrane of plant tissue. Both worms hide in the thatch layer of a lawn during the heat of the day, making them hard to spot. The damage these two pests incur, however, is not difficult to notice. Turf damaged by these worms can show up in very small patches, or patches
ten feet in diameter or greater. These patches of worm activity appear as though the grass has been mowed. If left unchecked, damaged turf will turn yellowish-brown in color.
Other indicators of worm activity that I look for as I scout your turf are the presence of adult moths roosting in the grass. I also look for certain wasp species that fly at ground level feeding on worms. Finally, I'll be looking for birds on the ground that might be searching for a meal. Fortunately, turf that has been damaged by worms usually recovers fairly quickly once an insecticide application has been made.
The St. Augustine fungus known as "gray leaf spot" is more prevalent so far this summer than in years past. This disease appears as olive green to brown water-soaked dots that are smaller than a pin head. These dots will turn gray in color and elongate. If left unchecked, this disease will turn the entire leaf blade brown, killing patches of turf. This disease thrives in warm weather accompanied by high relative humidity. The wet stretch of weather we got in early July really got this fungal pathogen cranking. Proper water and nitrogen management along with timely fungicide applications are the best tools available for keeping this turf disease at manageable levels. Florida's warm, humid summers will have me continually monitoring your lawn for "gray leaf spot" and other fungal diseases.
My next scheduled turf fertilizer application will begin in mid-September for Manatee County clients, and October 1st for Sarasota County clients. Please feel free to call or email our office at any time with comments, questions or concerns. Thank you and have a great summer!
--Ken G. Kiger, Licensed Horticulturalist / Pesticide Applicator
Michael A. Gilkey, Inc. Landscape Maintenance Division
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