Well, it is officially fall and cool weather has begun to move in. With cooler nights and shorter days trees are beginning to show the full spectrum of Mother Nature’s color palette. Just as the plants can “sense” that the season is changing, so can the many insects that feed and live on those plants. Like most creatures, insects want to find a warm, toasty place to stay over winter … aka … your house!
As plants go dormant for the winter, they undergo many physiological changes. Photosynthesis slows down, nutrient up-take grinds to a halt, and leaves begin to fall to the ground. Insects can sense these physiological changes in the plants and know that it is time to find a warm place to hide. As their habitat and food sources begin to dwindle, many insects will look for alternative food sources and cracks and crevices to hide in. Some insects will be so few in numbers that you might not ever know that they are there. As for others, swarms of hundreds and even thousands will be noticeable. In the Southeast, there are three common pests that tend to rear their heads in the fall and again in the spring as the days begin to get warmer: the multicolored Asian lady beetle, a few species of stink bugs, and a new pest, the kudzu bug.
In general, lady beetles, also known as lady bugs, are native predatory insects that consume high numbers of pest insects such as aphids, some scale insects, and many other damaging insects that harm our ornamental and agricultural plants. Lady beetles can reduce damaging insects to low numbers and are even used as bio control agents for many pests. While the multicolored Asian lady beetles are also predatory insects that can help control some damaging insect populations, they come with a few bad habits. These lady beetles seem to have a gift for finding even the smallest cracks and crevices in a home and then making their way indoors. While the bugs do not eat wood, fabric or human food, they do come with a few bad characteristics. When threatened (mostly by a human that is trying to smash them) the lady beetle can exude foul smelling, yellow fluids that can permanently stain walls and cause an unpleasant odor, and, though uncommon, the lady beetle can bite. Fortunately, the bite is nothing more than a pinch and will not cause lasting pain.
Stink bugs are a common sight during the summer months when we are trying to prevent them from destroying our tomatoes and other vegetables in our garden. Unfortunately, they can be a common home pest in the fall. Just like the multicolored Asian lady beetle, they will begin to look for a place to overwinter. They also seem to be good at finding crevices in the home and making their way indoors. When on plants, these pests are what we refer to as “sucking” pests. They have a straw like mouthpart that pierces leaves and fruit and sucks sap from plants. Being plant eaters, stink bugs do not eat humans or human foods. Although they are not known to bite often, they have been reported to occasionally pierce the skin, most likely trying to find food.
The last bug is a new pest to our area. The kudzu bug, also known as the bean plataspid, is a green and brown, square-ish shaped insect about the size of a pencil eraser. Don’t be fooled by its name, this insect is not a good one. While, as its name implies, the kudzu bug does eat kudzu, it has been found on over 100 other plants, both in agricultural fields and at home. While studies have shown the kudzu bug to reduce kudzu by 30 percent, this insect can also reduce yield by as much as 25 percent in its second favorite food, soybean. This is a potential problem for many farmers across the country. Kudzu bugs are commonly found in the fall near areas of high kudzu concentration, which seems to be everywhere. As soybeans and kudzu begin to die out and go dormant for the winter, kudzu bugs will begin to search for other food sources. Like many other fall invaders, kudzu bugs are attracted to white and other similarly light colors. They have been reported to cover white garage doors and walls of homes across our area. If squished, the kudzu bug can emit a strong, potent smell and leave a small orange stain; therefore, squishing is not advised as a control method. While they are not known to bite, the problem with this insect will be its numbers. And, being a new pest, the population is expected to grow largely over the next three to five years.
Fortunately for the home owner, control methods for these three pests are the same. Chemical control can be effective but preventing the insects from entering a structure is critical. The most effective way to prevent entry is finding and sealing cracks and crevices on the outside of buildings, especially around doors and windows. If you do have an invasion, a quick and way easy to remove these pests is with a vacuum. Simply use a wet-dry vacuum (the bugs might cause your house vacuum to smell) to vacuum the insects up and then immediately dump the contents into a bucket of soapy water and dispose. For more information on fall invaders and other plant and pest problems, contact your local Extension Office.
Hunter McBrayer is an agent with the Marshall County Cooperative Extension System.