There’s nothing “chinchy” about chinch bugs! At least, they’re not stingy when it comes to expending energy in attacking St. Augustine grass. In fact, while not significantly injuring any other lawn grasses, the chinch bug ranks as Florida’s most serious St. Augustine pest.
Chinch bug control often can be accomplished with minimal use of chemicals. Studies show that improper mowing and over fertilization invite chinch bug attack, while good management practices reduce the need for pesticides.
Rapid growth in combination with improper care causes St. Augustine lawns to develop excessive thatch, a thick, spongy mat of runners and undecomposed clippings which provide an excellent habitat for chinch bugs.
St. Augustine should be mowed to a height of three to three-and-a-half inches every five to seven days/if the lawn is not mowed often enough to avoid thatch buildup, clippings should be mowed to a height of three to three-and-a-half inches every five to seven day. If the lawn is not mowed often enough to avoid thatch buildup, clipping should be removed with a grass catcher, or by raking, sweeping, or vacuuming the yard. If thatch reaches a serious level, it may require mechanical removal through vertical mowing or power raking.
It’s true that prolonged periods of drought can encourage chinch bug invasion. The key is to water enough to keep the grass healthy, but not growing excessively. Whenever you notice grass leaves curling or showing a bluish-gray color, water immediately, but do not water again until the lawn shows early signs of need.
The type and amount of fertilizer also influences grass growth. Growth rate and chinch bug problems can be reduced when minimum applications of slow release nitrogen are substituted for frequent doses of water soluble inorganic nitrogen.
In addition to good cultural practices, you may find some valuable allies in beneficial insects that prey on chinch bugs. The most prominent of these are the black big-eyed bug and predacious earwig. Populations of these benefactors can be encouraged by limited pesticide use.
Even if you follow these suggestions chinch bugs may attack. Inspect your St. Augustine lawn frequently for signs of damage. As they feed, chinch bugs cause yellowish to brownish patches in the grass. Such symptoms also may result from other factors. It’s essential to identify the true cause.
If you suspect chinch bugs damage, part the grass in the declining. Yellowish areas, not dead, brown spots and look for the pests on the soil surface. Immature chinch bugs are tiny red critters with a shite band across the back. The adults are about one-fifth of an inch long-black, with white wings.
If chinch bugs are found, start control measure promptly. Several chemicals are effective. Some can be applied as liquids with a lawn-type hose attachment sprayer, or pressurized sprayer, there are granular products on the market that can be applied with drop-type spreaders.
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 10 foot buffer zone around each. A few days later, check for effective control. If damage is widespread, the entire yard may have to be treated.
For more information on chinch bug control contact the Gulf County Extension Service at 639-3200 or visit our website: http://gulf.ifas.ufl.edu or www.http://edis.ifas.ufl.edu and see Publication ENY 325.