FROM THE FIELD: Summer Time = Grub Time

With the heat and intensity of summer stress, the last thing your customers’ lawns want to deal with is an insect infestation. But this is exactly the time for Midwest and Northeast lawn care companies to be concerned.

If you can survive the initial diagnosis and resolve the problem successfully, then the good news is you have a tremendous opportunity to sell a preventive grub application for the following year.
 
Ultimately, as with any turf pest, the key to success and customer satisfaction is understanding the pest you’re battling and how to best control it.

BEETLE MANIA. Grubs are infant beetles. More technically speaking, grubs are beetle larvae, most commonly Japanese beetle larvae. If left unchecked, these small, white, turf-chewing insects will grow into different types of beetles.
 
Most importantly, their feeding habits make them the most destructive pest of cool-season and transition turf. Grub-infested lawns show patches of wilted, dead or dying turf during spring and fall as the grubs feed on the turf roots. But the telltale sign of a grub population is often the presence of various birds and mammals feeding on these pests below the soil’s surface.
 
Grubs are best controlled preventively since a curative plan often includes turf replacement or renovation work as well. There are  a few preventive grub control products on the market. Be sure to understand the product you choose to use. Some insecticides require a little extra time to get set up in the soil, while others come with certain irrigation recommendations.
 
Regardless of the product, preventive applications should be made anywhere from late May or early June through early July. Many lawn companies target July 4 as their deadline for having all preventive grub control products applied.
 
Grubs that have overwintered from the previous year are generally too large to control in the early spring, so they will pupate into beetles in June. The females  will then lay their eggs back in the soil in early to mid-July. Those beetles are not your control target – the first instar (smallest) grubs that hatch from the eggs and soon begin feeding on turf roots are your focus. Control becomes more challenging as the grubs feed and grow, hence the importance of a well-timed preventive application.

PROBLEMS PERSIST? If you make a preventive application and still experience grub problems, the problem most likely comes from the following:

• The application was made too early or too late. Apply too early and risk breakdown before the first instar grubs begin feeding. Apply too late, and the grubs have grown too large to control with the preventive products.
• Lack of irrigation. Again, grubs feed just below the surface, so any product applied for preventive control must be watered into the soil to ensure the grubs contact it.
• Excessive thatch levels. Even with sufficient irrigation, too much thatch will tie up the insecticide, keeping it from the soil. If you uncover this problem when a breakthrough occurs, look at aeration as another upsell opportunity.

Again, finding grubs on a customer’s property isn’t cause for gloom and doom. If a preventive application was not made, then obviously successful curative control is the key to protect the turf from damage. And while grubs used to be such hard-to-control pests, this is no longer the case. The preventive products on the market today will get the job done.

J.B. Toorish and Brian Kelley are part of LESCO’s Tech Services Department. They can be reached at techguys@lesco.com or at 800/321-5325 ext. 3150 to answer technical questions.