Home lawns & gardens news:
|
Mild Winter, Spring Means Lots of BugsBy Bonnie Coblentz MISSISSIPPI STATE -- Last winter's mild temperatures not only were easy on Mississippi people, but the state's insects as well. The lack of a sustained deep freeze, together with the warm, relatively dry spring has resulted in favorable breeding and growing conditions for many insect pests. Dr. James Jarratt, Mississippi State University extension entomologist, said typical Mississippi winters don't do widespread harm to insect populations. "About 90 percent of Mississippi winters don't hurt insect populations," Jarratt said. "We have a temperate climate and the insects have defense mechanisms that prevent most widespread effects, unless we have an unusually cold winter." Dr. Blake Layton, Mississippi State University extension cotton entomology specialist, said a mild winter set the stage for a tough year for the cotton crop. "Not all insects are susceptible to winter kill," Layton said. "A lot of them seem to have antifreeze in their blood, and Mississippi winters are often not cold enough to rid fields of overwintering pests." Among the cotton pests affected only by severe, sustained freezes are the tobacco budworm and bollworm. However, the boll weevil, cottons No. 1 pest, is susceptible to winter kill. "Historically, after severe winters there were big reductions in overwinter boll weevil populations the next year," Layton said. "We can look at boll weevils and temperature and basically predict if we'll have a severe boll weevil problem that year." Boll weevils begin to die off when temperature at their overwintering site is sustained at 10 degrees, Layton said. Temperature at MSU dropped below 32 degrees Fahrenheit only 40 days this winter, Layton said, compared to 83 days the winter of 1995-96. Only four days had temperatures below 15 degrees, and it never dropped below 10 degrees. "That's a pretty good indication we had a mild winter from a boll weevil standpoint," Layton said. "There should be a good survival rate of overwinter boll weevils this year." For the rest of the insect population, summer numbers should be average, Jarratt said. In Mississippi, that means the usual annoyingly high number of pests. But while the winter did not harm insect populations, what can affect them is a cold, damp spring that delays their development, or a hot, dry summer that stresses them. "Hot and dry weather is the worst kind of weather for insects," Jarratt said. "It dries up many of their breeding grounds and insects have to work harder to survive." But regardless of the weather, insect pests manage to survive. The best people can do is to try to prevent them from being a personal problem. This involves staying away from areas where they thrive and using insect repellant when outdoors. Released:
May 12, 1997 |
|
|
