Total Landscape Care Digital Magazine
Issue link: http://read.dmtmag.com/i/139414
PEST MONTH of the Grubs Japanese Beetle Grubs A s if the multitude of white grub species isn't enough for landscape professionals to deal with, the Japanese Beetle's larva or grub offers a complete second level of required attention and resources, says Dr. R. Chris Williamson. "I call that the beetle that gives you the double whammy," says the University of Wisconsin-Madison professor. "Not only do the grubs feed on roots of turfgrass and woody ornamental as well as herbaceous ornamental plants, but the adults cause feeding damage on more than 350 species of plant material." This sets the Japanese Beetle apart in the U.S., where the bug was first discovered in Riverton, New Jersey in 1916, and has slowly and surely spread west ever since. Today, some regions can have as many as eight significant species of the sluggish, thick-bodied beetle larvae known commonly as grubs, others very few, but "the most widespread" is the Japanese Beetle, says Dr. Williamson. "The grubs will just feed on whatever they can get their grimy little jaws on. They really don't discriminate," says the turfgrass and ornamental plants specialist. "With other white grub species, we don't really have a prob- lem per se with the adults." A mild, even debatable exception, he says, is the May/June Beetle, which will as an adult partake in "nominal" feeding on plant material. There are two basic management strategies to deal with the beetle, preventative and curative. Ideally you would choose the preventative one but for right now, you need to take a curative approach for those plant-loving adult Japanese Beetles. · Contact sprays applied to the actively feeding adults: "Japanese Beetles are very sun-loving, gregarious animals. In other words, they feed during the day, typically from 10 in the morning until 5 in the afternoon. They like the full sun," says Dr. Williamson. · A "systemic" approach, in which a soil drench or soil injection is applied. The insecticide is absorbed by the root tissues and translocated up into the leaf tissue, "so that when a beetle feeds upon that treated tree, it gets a lethal concentration of the insecticide," he says, "and then it's lights out." A preventative approach is based on a longstanding history of grub infestation. The preventative insecticide is applied so that when beetle eggs hatch, the larvae immediately begin to feed on it. "Most preventative products are going to provide 90 percent or greater control or efficacy," says Dr. Williamson. A curative approach, usually absent a longstanding history when more of a "wait-and-see" approach is being taken. Statistically, commercially-available curative products are less effective, he says. "As a landscape manager, for controlling grubs you have to decide: 'Do I want 90-percent control or do I want about 75-percent control?' That's not for me to decide; that's for the landscaper to decide." Grub Damage Photo credit: Dr. Dan Potter, University of Kentucky Arena® Insecticide: Outstanding control of grubs A rena® Insecticide from Valent Professional Products delivers superior curative control of white grubs in a single application. Unlike competing products, Arena doesn't need to be immediately watered-in, saving you time and labor. Providing the longest residual grub control on the market, Arena offers PestoftheMonth_TLC0713_PG.indd 44 preventive and curative white grub control, including European and Northern masked chafer, and Japanese beetles. Arena also controls a broad spectrum of other soil- and surfacefeeding insects like billbugs and Southern chinch bugs. Available in two formulations for maximum convenience and flexibility, Arena curatively takes care of grubs before foraging animals, such as skunks and raccoons, take care of your customers' lawns. For more information on Arena, visit www.valentpro.com/arena or contact your Valent territory manager. Information sponsored by Valent Professional Products 6/18/13 3:18 PM