Total corn acreage is up across many states this year, thanks to a favorable price outlook. The potential down side is some growers may struggle to manage additional acres effectively, giving pests such as spider mites an opportunity to flourish this summer.



"Mites aren't as consistent year-to-year like weeds, so you have to stay on top of them," notes Greg Hudec, Bayer CropScience technical service representative.



That means scouting for the two major spider mite species: Banks grass mite and two-spotted spider mite. Both of these commonly feed on corn throughout states, including Colorado, Kansas, Nebraska, Oklahoma and Texas.



Beneficial insects such as lacewing, thrips, predatory mites and bigeyed bugs often can keep low infestations of spider mites in corn in check. However, if hot, dry temperatures prevail, mite populations can quickly build.



"If last week you didn't see many mites, but this week you're seeing dime-sized colonies, it's time to treat," Hudec says.



One product, Oberon miticide/insecticide is very effective against all stages of mite development, including eggs and adults. In addition, the product controls whitefly and psyllid species. Also, because it is an integrated pest management-friendly compound, Oberon allows beneficial insects to continue working.



"Oberon leaves the beneficial populations in the field," John Quillin says. "That's an added plus." Quillin, with Pan Handle Ag Consulting, Dalhart, Texas, scouts corn and cotton fields in the northwest corner of the Texas panhandle and into New Mexico.



Unlike most other products, Oberon is a flexible treatment option that growers can use as a preventive or even, if necessary, as a rescue treatment.



"In most areas, I recommend that growers hold onto their money and treat only if they see populations starting to build," Hudec says. "But in some areas of the Panhandle, where growers fight mites constantly, I recommend that growers use Oberon as a preventive." In these latter scenarios, Hudec says growers can reduce their costs by banding Oberon over their corn rows.



He adds that mite infestations usually begin on the lower portions of corn plants and move upward as numbers increase. Spider mite infestations that reach the ear leaf are most damaging.



While yield losses from spider mites are difficult to document, Colorado State University reports that losses as high as 40 percent for silage (dry matter) have been documented in that state. Average losses typically are lower. A CSU study at Rocky Ford reported that untreated spider mite losses in corn ranged from 6 percent to 48 percent, with an 18-year average of 21 percent.



Rainfast once it dries on the leaf surface, Oberon provides consistent mite control for up to 30 days and many trials show even longer control, says Jon Mixson, Bayer CropScience product manager.



Because it shows no cross-resistance to other miticides in the marketplace, Oberon is an attractive option to help growers, pest control advisers and crop consultants manage potential resistance issues.



Oberon is also quick acting, adds Dale Deshane, Supervised Controlled Services, Inc., Kern County, Calif. "Within four to five days of application, the adult mites were dead," he says, recalling the 2006 season. "It saved our tail in a lot of fields."