DALLAS White grubs may be a less ferocious enemy of Texans striving for the picture perfect yard in North Texas this year. Flights of the June beetle, the adult stage of the white grub, were both earlier and lighter than normal this year, according to Texas A&M entomologists.
“Mating flights of June beetles (the adult stage of white grubs) were unusually early and short this year,” says Dr. Robert Crocker, research entomologist at the Texas A&M Research and Extension Center in Dallas. “We had substantial flights following our rainy spell in early June. But then they sort of fizzled out. Now’s the time to treat before the end of July for best control of white grubs,” he said.
“This year is different because we have more time than usual to make our applications,” said Dr. Mike Merchant, urban entomologist with the Texas Agricultural Extension Service. “The grubs are still small. If people apply pesticides for grubs now, they’ll have a better chance of success.”
Merchant warns everyone not to spray for an insect they don’t have. Make sure grubs are indeed a problem before spraying. Otherwise, pesticide applications are a waste of time and money, not to mention added potential environmental damage should it run off into sewers and streams.
The Extension Service recommends checking for grubs by digging small holes, three to four inches deep, in several parts of your yard. “Grubs found now should be in the small stage, less than the length of your thumbnail with a head about the size of a BB,” said Merchant.
“Look for C-shaped, whitish, worm-like insects in the grass root zone. Treat if you have more than four or five grubs per square foot of turf.
“Not all brown spots in lawns are caused by insects. Lack of water and some turfgrass diseases also cause dead spots.” To be sure, Merchant suggests tugging at the grass in the brown area. “If the grass pulls out with no roots attached, or if you can lift entire sections of turf from the soil, you may have grubs.”
White grubs hatch from the eggs of June beetles, which in our area normally emerge as you might guess in June. Approximately four to six weeks after the major mating flight is the best time to treat. Gardeners who wait too long to treat, after Aug. 1 this year, risk battling the older and more pesticide-tolerant grubs.
A fact sheet on white grub control in turfgrass is available through the Internet at http://entowww.tamu.edu/extension/lawn.html.
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