You’re a mean one Mr. Chinch

No one likes to see patches of yellow turf on their course. But when you do see that dreaded straw color emerge, there’s a chance chinch bugs are behind it. Chinch bugs may be small, but they can cause serious damage to lawns and golf courses. And once the turf dies, it takes a long time to bounce back.

There are different management approaches to handling the hairy chinch bug of the North and the southern chinch bug of the South, which feeds primarily on St. Augustinegrass. But wherever you work and whatever your turf, catching chinch bugs early is crucial to preventing a serious outbreak.

We spoke to some chinch bug experts who shared with us five surprising facts that will give you the upper hand over the dreaded warm-season pest.
 

1. Chinch bugs can be confused with other small predatory insects

Overall, chinch bugs are easily distinguished from other turf pests. But some insects – such as false chinch bugs, minute pirate bugs and big-eyed bugs – often have been mistaken for chinch bugs.

The big-eyed bug “is a common predatory insect in turf, about the same size as a chinch bug,” explains Mike Merchant, Ph.D., an urban entomologist with Texas A&M AgriLife Extension Service, in Dallas.

Big-eyed bugs can be distinguished from chinch bugs by their bulging eyes and more rounded body, compared to a chinch bug, whose eyes are small and body is long and narrow. The biggest difference between big-eyed bugs and chinch bugs, Merchant says, is that big-eyed bugs are beneficial insects to have on grass while chinch bugs aren’t.

Eileen Buss, Ph.D., a chinch bug expert at the University of Florida, recalls one lawn maintenance worker in Florida mistook little black beetles for chinch bugs. “Then he mentioned he needed to get his eyes checked,” she says. “I now remind applicators that their best monitoring tools are their eyes.”
 

2. They like nitrogen

Using proper amounts of water and nitrogen is crucial, says Scott Ferguson, Ph.D., owner of Atlantic Turf and Ornamental Consulting in Vero Beach, Fla. “If you have proper amounts of water and fertilizer, your turf can withstand a fair amount of chinch bug feeding and you won’t even see visible damage,” he says.

Understand that fertilizing equates to giving chinch bugs better food, Buss warns. So it’s important that nitrogen be used in moderation. Although nitrogen helps grass grow and stay green, she says, “it can also help more chinch bugs survive, develop faster, and the females can lay more eggs.”

Overfertilizing leads to “all kinds of problems – because excess nitrogen favors the development of insects and diseases,” Ferguson says.

Damage is first evident in areas of drought- and heat-stressed turf. Superintendents should ensure turf gets adequate amounts of moisture, their irrigation systems are functioning properly and water is being distributed evenly, Ferguson says.

Chinch bug damage tends to be worse in hot and dry turf areas and stresses the importance of sensible irrigation practices, Buss says. An adequate amount of water, she says, “can help mask turf damage or help turf tolerate more chinch bugs before damage becomes significant.”
 

3. Southern chinch bugs can be resistant to pyrethroids

Pyrethroids alone may control chinch bugs, or they may not. It depends on the genetics of the local chinch bug population. Northern species are easily controlled by pyrethroids, but pyrethroid effectiveness on southern chinch bugs isn’t guaranteed.

While northern species are easily controlled by pyrethroids, southern chinch bugs “vary in their susceptibility to pyrethroids on St. Augustinegrass,” Buss says.

While pyrethroid resistance among southern chinch bugs remains, it’s substantially lower than it was five to 10 years ago. And many professionals have found that tank mixtures of pyrethroids and neonicotinoids gives them good control.

Neonicotinoids such as Arena, Meridian and Merit “are very effective against chinch bugs,” Ferguson says. “This class of insecticide works very well and gives very good control of chinch bugs.”

When a pyrethroid and neonicotinoid are used together, Ferguson says, the pyrethroid will give “a quick knockdown” of chinch bugs while the neonicotinoid will kick in and create longer residual control.

“One line of thought is that the combination is not a good idea, because the mixture is selecting for insecticide resistance in chinch bugs to both classes of chemistry simultaneously,” Ferguson says. “So mixing a pyrethroid and a neonic is a good idea on one end and not such a good idea on another end.”
 

4. The flotation method of control works

Inserting into the ground a coffee can with the top and bottom cut off may sound archaic, but even after decades of being practiced, this simple method still is the best way to count the chinch bugs in your turf and gauge the density of chinch bug populations, entomologists say.

Pound the can into the turf just far enough so it will hold water, then put water in it and use a probe to stir up the grass at the bottom of the water column. “It’s the easiest way to find them. These insects float right to the top,” says Danny Kline, an entomologist at Penn State University.

In Pennsylvania and the Mid-Atlantic, tall fescues abound. Since hairy chinch bugs are drawn to them, the flotation method is a useful tool in catching chinch bugs early.

“They tend to attack fescues most of all – mostly the older fescues,” Kline says. “They’ll come out in the spring when temperatures average in the fifties, and the easiest way to find them is to use the flotation method.”

It’s especially helpful in spotting young nymphs, and when you see between 15 and 20 of them per square foot, it’s time to make a first application, he says.

Merchant says the flotation method was popular 25 years ago when he launched his career, and it’s still reliable today.

If you don’t see chinch bugs at first, “keep sampling,” Kline says. “Keep using that flotation method, and if you have them, treat them with pyrethroids.”

Buss says other methods can be used to find southern chinch bugs as well. The easiest and fastest method is to part the grass near yellowed areas and look at the soil surface and thatch, she says. She also suggests using a Dustbuster or hand-held vacuum to suck up any chinch bugs near damaged areas.
 

5. Timing applications for hairy chinch bugs is easier than timing applications for southern chinch bugs

That’s because northern chinch bugs tend to have more synchronized life cycles. The southern chinch bug, however, “has multiple overlapping generations each year,” making timing more difficult, Buss says. “Eggs laid inside leaf sheaths are physically protected from insecticides and hatch about seven to 10 days after being laid.” She adds that since southern adult chinch bugs fly only in extreme heat, populations may not move around much and inbreed.

While progress has been made in chinch bug control, further advances are needed. Buss, for one, says she would like to see new tools for chinch bug control make it to market.

While different strains of insect-pathogenic fungi have shown positive results in laboratory testing, she says, “…new chemistry that could be used in a rotation program would help turfgrass managers delay the development of insecticide resistance.”