This family of (garden) pests has worn out its welcome

Russ Ottens/University of Georgia/Bugwood.org

Adult Japanese beetles feed on more than 300 plants and are fond of Japanese maples, crape myrtles, fruit trees and roses.

Three days.

That's the limit that family should visit. By the end of three days, you all had fun, still love each other and are sad to leave. Compare that with a seven-day trip. By then, your mother-in-law is giving you parenting advice, your sister is painting the bathroom sink with toothpaste and it's obvious no one knows how to turn off a light or shut the front door.

I love my family, but you can sleep on an inflated mattress for only so long. You can sleep under a ticking ceiling fan for only so long. And you need your own bathroom, folks. The three-day rule is not merely recommended, it will save lives.

If only we could convince other things of the three-day rule. For instance, Japanese beetles. Here's an uninvited guest that arrived in New Jersey around 1916. Not only has it clearly overstayed its visit, it's branching out. Since that time, it has sent relatives all the way to the Midwest and as far south as Tennessee, Georgia and South Carolina.

And like any large family, they're eating everything along the way without asking or offering to pay.

The immature stage of the Japanese beetle is a white grub. All beetles are white grubs, so the only way to identify a white grub as a Japanese beetle is by the pattern of hair on its business end.

That would be the anus. And, yes, it's gross. The grubs feed mostly on turf roots. To date, I'm not aware of any white grub problems in Lowcountry lawns. They're out there, but not in high enough numbers to cause a problem.

White grub damage makes turf look water-stressed in August/September. This is also when mole cricket feeding peaks. To verify grub damage, tug on the dying turf and it'll come right up. The grubs will be underneath. Mole crickets will need to be flushed out with soapy water (2 ounces of dish soap per gallon of water).

Japanese beetle adults are just as much a problem as the grubs. The adults feed on more than 300 plants. They're not picky but do have their favorites: Japanese maples, crape myrtles, fruit trees and roses. And they aren't bashful. As many as 30 or more will gather on leaves in the middle of the day and strip the foliage. The veins are left behind, giving the damage a distinct lacy look. The adult grubs prefer plants in full sun on warm days, June through Labor Day. Peak emergence is July Fourth. They'll even eat flowers and fruit. Ungrateful pigs!

In some parts of the country, control starts with the white grubs, using insecticides. One noninsecticide control is a bacterium that causes milky spore disease in Japanese beetle grubs only. However, it takes two to four years to become effective and must be applied communitywide. Even then, research indicates inconsistent results. It is not considered a homeowner product. Since I don't see white grubs as a problem, I don't see this as a viable method of control.

Controlling the adults is more effective. First off, they don't like magnolia, redbud, dogwood or holly. These are potential substitutes that would significantly reduce the need for control. However, to protect susceptible plants, insecticides such as Talstar, Sevin, Tempo and Merit can be used. Be aware of spraying flowering plants because it can harm honeybees. In these cases, spraying during the evening is recommended.

Perhaps you've seen the lure traps that contain pheromones to attract beetles. You end up with a satisfying bag of dead beetles. Problem is, this is not an effective means of control. In fact, it can attract more of them! Some sources recommend placing traps 200 feet from target plants, but many suggest the actual number of beetles it controls is still insignificant.

It's obvious that getting Japanese beetles to leave isn't as easy as sabotaging your air conditioner or cracking open a water pipe. Not that I've done that. But if nothing else works, just start hanging around the TV in your underwear. Nothing stays long after that.

Tony Bertauski is a horticulture instructor at Trident Technical College. To give feedback or request specific column topics, e-mail Tony at tony.bertauski@tridenttech.edu.