Cold Weather and Insects

Did the cold weather have an impact on insect pest?

By: Sheldon D. Barker, County Director

We saw some extremely cold weather in the first three months of 2014. Thus the question, “Did the cold weather have an impact on insect pests?” Well, the answer, that depends.

Many insects have survival methods for extreme cold.  While the cold may have affected some pest, others may have survived. Scott Stewart, IPM Extension Specialist with UT Extension and other Extension Entomologist have written on this and they conclude, “It depends on the bug.”

While the Sequatchie Valley and surrounding mountains saw temperatures below zero, many insects can survive much colder temperatures. Many insects overwinter by hiding from the cold. For example, Japanese beetles overwinter as larvae in the soil. They simply burrow deeper to avoid the cold.

Fire Ants require persistent cold temperatures to be affected. According to Karen Vail, Extension Urban Entomologist at the University of Tennessee, we have not experienced the continuous cold temperatures needed to cause widespread death of fire ant colonies. Fire ants have massive mounds, and to be impacted by the cold the ground has to freeze as deep as their nest.

What about mosquitoes? Well, Alaska is known for its mosquitoes, which says a lot for this hardy pest.

We also have several invasive pest that can cause problems besides fire ants. The brown marmorated stink bug, an invasive pest from Asia, now well established in the Knoxville and Nashville area, is well established in Pennsylvania, Virginia, Delaware and other surrounding states. It is also moving north from these states, thus the brown marmorated stink bug seems to do well in the cold. According to Dr. Stewart hot summers may negatively affect the spread of this pest in the South.

The Hemlock Woolly Adelgid, a forest pest that is of serious concern in Eastern Tennessee, effects the Eastern Hemlock. “The lethal temperature for the woolly adelgid is minus 4 or 5 degrees Fahrenheit,” said Richard S. Cowles, a scientist with the Connecticut Agricultural Experiment Station. Temperatures in parts of the area did fall below this level, however we will just have to wait and see.

For the most part many of the common pest we see around our homes and gardens will be around this summer, so be ready!