By WAYNE BECKER AgriLife Extension Agent
I have heard the comment made that this cold weather should, at least, help minimize the insect problem next year. That may be true…but before you get your hopes up; you should know some of the facts.
Despite very cold temperatures recently, it is probable that many insects will survive and will be poised and ready to impact landscapes and crops this coming Spring and Summer.
Many factors influence the ability of insects to survive the winter. According to Loretta Ortiz-Ribbing, Ph.D., Extension Specialist for Crop Systems in Illinois, the individual nature and life cycle of each insect determines it’s susceptibility. Predicting the influence of cold weather on insects is nearly impossible. Too many factors like pest biology, temperature, food availability, and moisture make predicting insect demise impossible. Some insects have skills that help them to avoid temperature extremes, like burrowing deeper into the soil or buffering themselves inside plants.
Some migrate.
Insects that are unable to avoid cold weather have two mechanisms for surviving its effects. The first is that insects are cold-blooded and do not regulate their own temperature. The other mechanism insects have for tolerating cold weather is to go into a state of hibernation. Insects stop moving when they are cold, and as long as they don't freeze solid, most can wait until temperatures warm back up and then continue doing whatever they were doing.
Finally, in some cases, the cold does hamper the survival of insects. The bad news is that insects that are affected by the cold often have a very fast reproduction rate, so the few that do live will bring the population back to sustainable levels quickly.
If insects do become a problem for you, you can do something to control them. Learn about the biology of pests you frequently encounter, learn how to monitor for them, evaluate pest densities throughout the year, and make treatment decisions based on established treatment thresholds where available.
Cold Stress on Cattle
Wind, cold, mud, rain, and snow all take their toll on cattle. The more stressful the weather, the more energy is required just for maintenance purposes. When cattle are cold nearly all the systems of the body are stressed. Muscles shiver, the heart beats faster, breathing becomes deeper, urine flow is increased and energy expenditures are increased, resulting in heat production. This results in an increase in the cow’s requirements for energy.
Cattle do best with mild temperatures. When the weather is either too hot or too cold, stress sets in. For cold weather feeding requirements, the wind chill should be factored in, as well as other factors such as if the cattle are wet. In general, studies have indicated that for every one degree below the critical temperature (60 °F when wet; 32-45 °F with Dry Fall to Winter coat; 19 °F with Dry, mid-Winter Coat) a cow’s energy requirement (TDN) increases 1 percent. It is also estimated that for every ten degrees below the critical temperature the digestibility of the ration decreases by 1 percent. This means that when the temperature drops below the critical temperature the cattle need to be fed better. More and/or better hay usually needs to be fed.
