Foundation treatments and grub check

By John Fulton         

[May 29, 2007]  It's about that time once again when the lowly cricket makes a real nuisance of itself in your home. Add to this a large number of ants, and an ounce of prevention goes a long way. The best offense is a good defense, and that means putting down a preventive foundation treatment.

A foundation treatment entails spraying the foundation of the house and the adjacent foot or two of soil with permethrin or bifenthrin insecticide. This treatment creates a chemical barrier that the insects crawl through when trying to enter your home. If they don't die on the outside, they are very short-lived on the inside. You can expect the chemical treatment to last for three to four weeks. Both of these chemicals are used on a wide range of plants, so should present no problems to flowers, shrubs or turf.

Once crickets are on the inside, there are few effective options, and none that will do a good job over a period of time. These options include spraying individual insects or small areas with an aerosol product containing pyrethrins, spraying baseboard areas with an aerosol containing permethrin, or a fly swatter.

Foundation sprays are also effective against ants, spiders, elm leaf beetles and other nuisance pests, so the benefits are several for applying these treatments. The addition of ant bait stations in the house should aid your control efforts against ants. With the bait stations, try not to spray anything indoors for about a week. This allows the poison bait to get back to a nest.

Grub check

The first indicator of grub numbers to come is the number of adults. Right now we are starting to have the June bugs out and laying eggs. There are actually three types of grubs that can be found in turf areas. These would be larvae of the Japanese beetle, the June bug and the green June bug. All of these insects cycle annually, and the green June bug is not really a turf pest, but rather is found in areas with high organic matter, such as compost piles and flower beds.

Don't pull the trigger and treat for grubs at this time. We are about a month early. I usually say to treat at Logan County Fair time. I know that the insects don't know what time it is, but people do. By timing treatments around the fair, it provides an easily remembered "marker" for us. Most publications indicate early August as the time to assess grub numbers and apply treatments if warranted. Most turfs in good condition can stand eight or so grubs per square foot without damage becoming noticeable.

Looking at adult numbers right now just gives us a very rough idea of how many adults there are to lay eggs. By waiting another month, we give the eggs time to hatch to a stage where they can be counted and controls would be effective. Many controls are not timed at "first sight" but rather at "complete hatch." Controls applied when the first actual grub is seen can be a month or so ahead of the last egg hatching. In this case we want to allow for a complete hatch to assess numbers and, if needed, apply one grub control treatment. Even the products for early application should be applied close to this August time period. A good example is the product Oftanol. It was promoted at first as a product that could be applied in May for grub control. It worked well a few seasons, and then the microbes that break the chemical down began to build up to the point where it also had to be applied in the August time frame.

[Text from file received from John Fulton, University of Illinois Extension, Logan County Unit]