During the past few weeks my staff and I have received quite a few calls from people asking about a couple of annoying insects. Since many homeowners in our area may encounter these pests, this may be a good time to share some interesting and helpful information.

The insects in the spotlight this week are the Asian lady beetle and the boxelder bug. Both of these insects have similar habits during this time of the year. They congregate on the side of a house in search of places to hibernate. Even though neither of them are doing any damage to the houses or nearby plants, they can be very annoying and most of those calling our office want to do something to get rid of them.

Asian lady beetles are close relatives to the lady beetles that we all know and admire. They feed almost entirely on aphids, and since aphids are so harmful to plants both of these beetles can be classified as beneficial insects.

The native lady beetle is easily recognized by its bright red body with 9-12 distinct black spots. Although it has the same body shape and size, the Asian lady beetle varies in color from bright red to pale orange, and the spots can vary from none to more than twenty.

The major characteristic that sets these beetles apart is their method of hibernation. The native lady beetle hibernates in small groups, usually under logs or behind the bark on trees. The Asian lady beetles group together, usually by the thousands, and seek warm secluded areas to hibernate such as under the warm side of homes.

These beetles use visual or physical cues to find suitable over wintering sites. Once the beetles arrive at the site they seek cracks that allow them to get behind the warm siding on the house. They also use chemical cues to locate the specific crevice they want to use The source of these chemical cues may be beetle feces from the previous winter, the odor of beetles that died at the site, or an attractant pheromone placed there by earlier arriving beetles. These factors may help to explain why beetles seem to pick the same sites over and over year after year.

What is frustrating to homeowners is that in addition to leaving a stain on the side of the house, many of these beetles will find their way into the house. People become annoyed when beetles begin dropping from the ceiling onto the family dinner table or onto people as they sleep or watch television.

Since there are so many of them many people think the beetles are feeding and reproducing in their homes. Of course, this isn't true. The beetles feed mostly on aphids and they lay their eggs on the same plants where they find the aphids. They are simply seeking shelter to escape the harsh winter weather.

Pesticide treatments provide little control for these beetles. It is difficult to treat enough areas outside to effectively prevent the beetles from finding access points into the house. Inside treatments may kill some beetles, but thousands of others will take their place.

Since the beetles are actually beneficial we encourage you to just vacuum them up and release them a distance from your house. Some people report good results by placing a woman's knee-high stocking into the vacuum's extension hose, securing it with a rubber band, and putting the hose attachment back on. This allows you to trap the beetles inside the stocking, which then conveniently closes up at the end with the rubber band when you remove it. If you prefer you can simply tie a knot in the end of the stocking and throw in the garbage.

For more information about Asian lady beetles please check out the web site http://www.ces.ncsu.edu/depts/ent/notes/Other/goodpest/note107.html

Boxelder bugs are oblong and are about ½ inch long. They have 3 red stripes on their middle body part, the leathery parts of the wings are outlined in red, and the eyes are red. The remainder of the insect is dark gray or black.

The boxelder bug is found throughout North Carolina and instead of being beneficial it does feed on plants. In addition to boxelder trees, this insect also feeds on apple, ash, buckeye, cactus, geranium, grape, honeysuckle, lilac, linden, oak, peach, plum, strawberry, and tulip. Alder, maple and boxelder trees are most often infested but are seldom injured. Fruit trees and strawberries have occasionally had fruits damaged.

Although boxelder bugs are associated with shade trees, this insect is more commonly a household pest. In fall, boxelder bugs tend to congregate on buildings and enter cracks and crevices to over winter just as does the Asian lady beetle. They do not bite people or harm the house, but their presence is a nuisance. On warm winter days, the insects become active and move about in and on buildings and continue to aggravate the homeowner.

Just like the Asian lady beetle, many of these boxelder bugs will find their way into the house which can be very annoying to people. These insects can also be easily swept up or vacuumed up. The woman's knee-high stocking trick also works very well with this insect, but once collected these insects should be thrown in the garbage instead of released back into the environment.

Many of the commonly used garden pesticides such as malathion are very effective as outdoor treatments for this insect. The pesticide can be applied to the ground or plants where the insects are congregating, or directly to the crevices where they are entering the house. However, these treatments tend to be temporary and usually do not totally prevent additional insects from seeking hibernating areas in attractive places.

Additional information about boxelder bugs can be found at the website http://www.ces.ncsu.edu/depts/ent/notes/O&T/houseplants/ort040e/ort040e.htm

Although winter will soon be here the climate in Robeson County is mild enough that we will face problems with insects almost any time of the year. If you need information about specific insects, or need an insect identified, please call my office at 671-3276.

E-mail address: Everett_Davis@ncsu.edu

Mailing Address:
P. O. Box 2280
Lumberton, NC 28359-2280

Phone: 910-671-3276
Fax: 910-671-6278

Date Created 11/19/02