FOR RELEASE THE WEEK OF MAY 3, 1999:
What are these elongated gray weevils that are crawling on my sidewalk?
If they’re about a half-inch long, they’re probably adult bluegrass billbugs–and trouble, says Bob Stoltz, University of Idaho extension entomologist. Adult billbugs come out in April and May to lay eggs in the lawn. By summer, the larvae hatch and begin feeding on grass roots.
"They can be devastating," says Stoltz. "One larva per square foot can cause a lot of damage." Irregular brown patches often start as hot spots, then spread across the lawn.
It’s not easy for insecticides to reach the underground larvae, so Stoltz recommends a two-pronged approach: targeting first the adults, then the larvae about four to six weeks later. To kill the adults before they lay eggs, spray the lawn with a registered insecticide such as Sevin, Dursban or diazinon. To destroy the larvae once they’ve hatched, apply the same insecticides and immediately water them in to push the chemical past the crowns and thatch.
Don’t ignore this pest, Stoltz says. "It generally gets worse." If you’d rather not use lawn chemicals, try controlling the larvae with Heterorhabditis beneficial nematodes.
For photos of billbugs and their damage, click onto the University of Idaho’s Southern Idaho Insect Guide web site, www.uidaho.edu/so-id/entomology.
We love homegrown sweet corn but ours never seems to do well. What are the keys to successful backyard corn production in Idaho?
Generally speaking, sweet corn is not too difficult to grow, but there are a few things gardeners must do to ensure good production, says Darrell Bolz, University of Idaho extension educator.
Match your variety to your growing season and plant in blocks, rather than single rows, to ensure adequate pollination. Delay planting until soil temperatures reach 50-55 degrees. A warm-season crop, sweet corn needs heat to germinate and launch its growth; seedlings that don’t get it can be yellow and sickly looking.
To reach its growth potential and to produce full ears of corn, sweet corn demands adequate phosphorus, potassium and especially nitrogen. Plants also require a fair amount of water and should never be allowed to dry out. It’s particularly critical to keep sweet corn moist during silking, when heat and drought can impair pollination.
Finally, to prevent corn earworms from burrowing into ears at silking, apply either 5 percent Sevin dust or 5 percent malathion dust directly to the silks. Or, add a few drops of mineral oil to the tips of the ears when the silks dry. Once safely inside the ears, this No. 1 pest of sweet corn escapes further control efforts.
I’ve been trying to decrease my fat intake by buying low-fat and fat-free cake, cookies and muffins. But rather than lose weight, I’ve gained seven pounds in three months! Why is this happening?
Just because a product is low-fat or fat-free doesn’t mean it’s calorie-free, says Martha Raidl, University of Idaho extension nutrition specialist. "In fact, the calorie difference between the reduced fat and regular products is often minimal," she says. "Unfortunately, many people assume they can eat as much as they want of a fat-free product and not gain weight. They’ll eat a whole box of fat-free cookies or several pieces of fat-free cake in one day."
Raidl says a healthier approach is to follow the Food Guide Pyramid and eat more whole grains–bread, rice, pasta and cereal–as well as more fruits, vegetables, and low-fat meat and dairy products. "Eating these foods provides a diet low in fat and high in fiber, phytochemicals and antioxidants that may prevent heart disease and certain cancers," she says. By comparison, many reduced-fat snacks contain low levels of vitamins and minerals.
This spring, I discovered that some of my rose canes had turned dark purple–not at the ends but in the middle. I assumed it was winterkill and pruned below them. Now my neighbor tells me it could have been something else. What was it?
In 1996, University of Idaho extension plant pathologist Krishna Mohan identified a never-before-reported rose disease right in Idaho’s Treasure Valley. He has since confirmed the presence of what he calls "bacterial cane blight of roses" in rose bushes in Boise, Fruitland, Emmett and Blackfoot but suspects the disease is far more widespread.
Unlike winterkill and cane borer symptoms, which begin at the exposed ends of rose canes, bacterial cane blight lesions start near buds, then spread in both directions up and down the canes. "Instead of the normal green color of healthy canes, the affected areas turn dark purple to black," says Mohan. Everything from very limited sections to the entire cane may be involved. Under microscopic examination, the moist, reddish- to dark-brown tissue beneath the lesions reveals profuse amounts of Pseudomonas syringae bacteria.
You were right to prune below the diseased canes, Mohan says. That should be done as soon as the gardener first notices symptoms–whether in spring, summer or fall–to prevent the blight from progressing to adjacent canes or killing the entire bush. He recommends cutting at least 4 to 6 inches beneath the blighted sections and sterilizing pruning shears with a 10 percent bleach solution between cuts and plants. Discard--don’t compost--the diseased cuttings.
In the fall, after the leaves have dropped and any remaining blighted sections have been cut out, spray the plants with a copper-based fungicide like Bordeaux mixture or Kocide 2000, Mohan says. Copper-based sprays aren’t recommended for roses in leaf.