Last week I had a run on phone calls and office visits with clients wanting me to identify these red and black insects.
If you know me, I am an animal science person by trade, but this particular insect is easy to ID. I label box elders as nuisance insects. Box elders can cause some damage to certain tree and items, but their main issue for many is as a household pest.
I will be sharing information from a Georgia Center for Urban Agriculture article done by Dr. Jim Howell, UGA Entomologist and submitted by a former co-work of mine, Randy Drinkard.
From talking to my clients, many are not actually seeing box elders inside the home, but are seeing them in clusters on the outside of the dwelling. I am guessing if you see them in clusters, you are seeing them on the south or west side of the home or building. They will get more protection on these areas and are getting more sunlight for warmth.
Box elders are slate grey in color with three red stripes behind the head and red lines on the wings. The rear margin of wing is red in appearance too along with a red abdomen. The eyes are red also. An adult box elder will be about one half inch long. The young nymphs are red in color, but the heads are darker. If you see a box elder, you should not miss identifying them down the road.
As I previously stated, I studied animal science in college, but at times I think I would have loved to be an entomologist too.
Box elders like most insects have a very interesting life cycle. At the end of the summer and into early fall, box elder adults and large nymphs will start looking for a place to overwinter. They will overwinter in any crack or opening. This can be a wall, window casing, rock piles foundations of a structure, hollows or holes in trees.
Prior to this overwintering site search, you may see a good number of the insects banding up on the bark of box elder trees or other host trees. What has happened recently is that on our warm winter days, the box elders have temporary came out of overwintering sites. This is way you are seeing large numbers in clusters. Folks are seeing them on those south or west side of houses and may even be seeing them on surfaces that are white or at least light in color.
There is that chance you could be seeing them on the inside of the house right now in good numbers too. This means you need to make sure every window is secure, screens do not have holes in them and things are caulked properly. It may be where a door sweep my help or weather strip cracks and crevices.
In a few weeks, box elders will come out of the overwintering sites and will start to feed. The feeding will go for about two weeks and then the mating season will begin. The female box elders will lay eggs in protected areas near host plants. Even though the insects are associated with box elder trees, they will feed on apple, ash, buck eye, maple, plum, cherry , peach, grape and ornamentals according to the Georgia Center for Urban Agriculture. You can get a second generation of box elders from new adults that may lay eggs in July.
All in all, box elders will do little damage to host plants. They can suck sap from leaves and twigs and can feed on seeds of box elder and maples, but the damage is normally small. The main nuisance is the invasion of a home. If stepped on or crushed, box elder can send off a foul odor and the fecal material can stain items in the house like wallpaper or curtains.
The best thing to do is to not let the insects get in the house in the first place. This means making your house more insect proof. I gave some ideas a few paragraphs prior. Once inside, your best option is to use the vacuum cleaner or sweep them up. If you think you have been aiding the overwintering with a rock pile or some other source, simply removal of the site may stop the nuisance. You may choose to treat a cluster of the insects on the outside of the home with an insecticide labeled for this pest.
Make sure you research to make sure that product will not stain the siding of your home before you spray. It is up to the person to read the label for effective and proper use of any product. For more information contact Gordon County extension or email firstname.lastname@example.org.