Dry weather can turn nature on end: termites feeding on peony roots and ants chewing on corn.
University of Nebraska insect experts are seeing some unusual things this year.
Despite heavy rains in parts of Nebraska June 24 and 25, insects still are desperate for moisture, said James Kalisch, an NU Institute of Agriculture and Natural Resources entomology technologist. This year's bumper crop of thirsty bugs is busy seeking moisture in Nebraska's gardens, fields and even homes, and the worst may be yet to come, he said.
"We still have a whole summer ahead of us," Kalisch said. "We are going into the drier season."
Populations of some insects are higher as summer begins for several reasons, NU Entomologist David Keith said. Bugs emerged earlier than usual and survived in greater numbers due to the mild winter. Humidity-induced diseases and heavy rainfall that typically moderate insect numbers have been minimal this year.
Hot, dry conditions in parts of Nebraska have brought out insects seldom seen in these parts. Unusual occurrences this year include sightings of the southern corn leaf beetle, which damaged corn in southeastern Nebraska, and the cowpea aphid, which damaged alfalfa, Kalisch said. The beetles hadn't been reported in Nebraska since the 1930s and the aphids, while probably fairly common, haven't been reported as pests in the past.
Whiteflies, which attack squash, tomatoes, peppers and several ornamental plants, have been spotted in southeast Nebraska. The tiny, white-winged insects aren't usually observed in Nebraska until later in the season, he said.
Drought-stressed garden pants and crops are more susceptible to insect and mite attack, Kalisch said. Spider mites, aphids, chinch bugs and false chinch bugs are common pests that count on plants as food and moisture sources.
Landowners and gardeners should regularly examine gardens or crops for signs of pests for the rest of the summer. Examine leaves carefully, turning them over without greatly disturbing the plants. If bugs look unfamiliar, they can be taken to an NU Cooperative Extension office for proper identification, Kalisch said.
Once pests are identified, and if infestation levels seem threatening, be prepared to take control measures, he said.
Spider mites feed on fruit trees, many vegetables, ornamental plants, soybeans and grasses. Spider mite species vary in their responsiveness to commonly used miticides, Keith said. On ornamental plants, he recommends discouraging spider mites with a fine, cold water mist applied with strong pressure for several consecutive days.
In Nebraska, chinch bugs are found mostly in southeastern counties. These crop pests can damage wheat, turf grass, corn and grain sorghum. Chinch bugs moving from wheat to corn and sorghum are difficult to control, but spraying with an appropriate pesticide can provide short-term relief, he said.
False chinch bugs are found statewide, especially in central and western Nebraska. These small brown insects multiply on weeds, particularly mustards, in alfalfa fields, pivot corners and other areas along roadsides. Although they usually are considered household nuisance pests, because they invade buildings, they can occasionally damage gardens and crops, he said.
"Keep an eye on them," Keith said.
Keeping false chinch bugs out of homes might require several insecticide treatments around the outside of the house when they are active, he said.
Grasshoppers also may be common in Nebraska this year, Keith said. With appropriate insecticides, grasshoppers can be controlled while they are small, but not eliminated. Control grasshoppers in early stages, before they begin to invade home plantings and crops, by spraying waste areas with proper insecticides, he said. Mowing a 10- to 20-foot strip around a garden helps reduce grasshopper numbers, but don't expect a high degree of protection, Kalisch said.
"Grasshoppers like to hide in grasses," he said. "They are less likely to move across bare areas."
Keith doesn't expect a major grasshopper outbreak this summer, but numbers are likely to increase if the drought persists.
For further information about treating pests, consult NU Cooperative Extension Circular 96-1555, "Insect Pest Management Strategies for Yards and Gardens," available at a local cooperative Extension office.