Early in my career one bug stood out as the most hardy insect and most difficult to exterminate, the boxelder bug. In the dead of winter I would check exterior rodent stations around commercial structures and very often I would find large collections of boxelders hiding behind and under the stations. With 3 feet of snow on the ground and frigid temperatures these bugs were doing their best to ‘over winter’ using the rat stations as protection. Even with the cold they were still moving and on some bright and warmer days they would actually venture out and sun themselves for a couple of hours. Insect sprays at the time were ineffective and we would power spray around homes but not kill very many bugs. We knew that soap and water worked well so we would fill our large professional spray tanks with the sudsy mix and our manager had us use the chemical name for soap on the service receipts. R-COO-Na + H2O or potash was what we were instructed to write and I never felt good about that. I guess this mega company didn’t want to be seen as using a home remedy or perhaps wanted to justify the cost with a big fancy scientific word.
Boxelders are most prevalent in the early spring and fall but can be a nuisance throughout the summer season as well. At times the numbers grow so large that they can be in every square foot of a lawn or garden and found soaking up the sun by the thousands on the side of a home. Generally speaking it is always the south and west sides as these get the warmest rays.
Boxelders are a small bug about 1/2 inch long and adults can be distinguished by the 3 red lines on 
their abdomen. Nymphs are most often completely red and fill in with black as they grow. The young bugs lack wings but the adults have overlapping wings outlined in red to form an ‘x’ when folded. Eggs are laid on plant leaves and are completely red. These bugs feed on many plants but especially love the seed pod of the female boxelder tree. Although they do little damage and only wander inside occasionally the sheer number of them prompt many people to try their hand at spraying this bug but they usually have poor results.
What to spray
Until recently most pesticides were pretty ineffective and the mainstay of boxelder control was soap and water. The problem with this approach is that you need to get it directly on the bug for it to work. If you are in your garden or working around the home you can fill a sprits bottle with 30% soap and 70% water and spray them as you see them. For larger problems that need more volume you can use the soaping feature on your pressure washer. The same ratio in a 5 gallon bucket will go along way and you can spray to your hearts delight.
Insecticides such as Bifen or Cyfluthrin (Tempo wettable powder) can work well but don’t be surprised if they do not die right away. Remember I told you they were hardy. If the bugs are getting inside the Tempo is an excellent choice but also look to seal up where they are getting in. Smashing a boxelder can sometimes leave a red stain so try and avoid that. For best results you should use a backpack sprayer or power spray rig to get maximum coverage. Since most folks don’t have this kind of equipment stored behind the garage, you might consider a pest control company for the job at this time. (Just watch your service ticket)
Other than chemical control you can always take down the female boxelder tree if it is on your property. This is the most permanent solution and chances are you won’t get them back next spring unless there is another tree nearby.
In the world of bugs few are as hard to kill as the boxelder, it’s like a fighter in the 10th round that won’t go down even though he’s being hit directly. Today’s formulations and pest control products have eliminated most of this but nothing I know of gives you a good immediate ‘knock down.’ Just remember that in pest control the most important ingredient is common sense so let your treatment work and don’t over do it. Now, go get em champ!
