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Are Box Elder Bugs Temporary Pests?

Every fall we can count on swarms of box elder bugs blanketing homes throughout the metro. Conversations revolve around ideas ranging from “burn the place down” to “don’t worry – they are just temporary.” Well, which is it? I know what the science says, but I bribed my family with ice cream to run an experiment of our own. If we did nothing, would box elder bugs be temporary pests?

Adult Box Elder bug

Fall Box Elder Bug Behavior

Fall is the time for Box Elder Bugs to make their presence known. Some people are aware of them at other points in the year (which we will get to shortly), but fall is their heyday. This is the time of year when these insects go into overwintering mode.

In the autumn, Box Elder bugs will swarm homes looking to take part in the wonderful shelter we have built for ourselves to survive winter. People will experience them:

  • coating sunny walls of homes (usually south and west facing)
  • flying around outside
  • crawling and flying indoors
  • landing on persons and belongings for no good reason
  • attracting predatory wasps

This swarming is typically short-lived and may last a few days to a few weeks depending on weather patterns. While the active swarming is temporary, the question of whether this is the last of them remains.

What happened at my house? South and west walls blanketed. Younger kids had conniptions in the early morning hours and later evening hours, Box Elder bugs everywhere.

Winter Occurrences

After the fall swarms, some people do not experience box elder bugs again until the next fall. This group of people includes situations where:

  • active control measures (physical removal, exclusion, barrier treatments, etc.) were in place
  • the number of surviving box elder bugs is below noticeable thresholds (thresholds vary greatly from one person to the next)
  • Luck kept the overwintering Box Elder bugs from crossing paths with the human occupants

For those that had swarms, but were not lucky and did not have adequate control measures in place for the swarms, box elder bugs may pop up from time to time or continuously throughout the winter. These box elder bugs are typically confused by the warmth inside of the home either from central heating or other heat sources radiating into their overwintering spots and making them believe spring has arrived. These interrupted bugs will wander and fly towards the heat source ending up inside homes and businesses where they are as confused as you are.

What happened at my house? We definitely had weekly sightings. There were several stretches of multiple bugs per day. I spent a lot of time responding to hollering kids. I hauled a lot of them out with tissue.

Box Elder bug nymph with developing wings

Spring Box Elder Bug Activity

In the spring, Box elder bugs can be seen:

  • coming out of the woodwork inside structures
  • blanketing exterior walls while sun bathing
  • moving around on mulch and trees

Of course, the Box Elder bug will always be observed in its natural habitat on and around box elder trees (though this isn’t the only tree they live on and around). The thing that annoys people is when they deal with not only the reverse of what they experienced in the fall but also get to deal with the confused ones coming indoors which occurs during the winter. The masses from the fall come back though typically in lower total numbers at a time and a bit more strung out over time.

What happened at my house? All of the above. They were in the bathtub, on the plants, in the trees, on the play set, and in our curly hair.

Summer Box Elder Bugs

Summer time is when it is easiest to forget about Box Elder Bugs. For the most part, they will be out and about in their preferred feeding and breeding grounds around the Box Elder and other preferred trees. The summertime is the best time to make preparations for and against the coming fall invasion. Populations can be reduced, harborage sites can be adjusted or removed, and exclusion and barriers can be established ahead of the fall push.

Where were they at my house? Lounging on our deck and patio furniture, landing in our food even though they can’t eat it, napping in our beds, and pretty much anywhere we had landscaping they wanted to explore.

Making Box Elder Bugs Temporary

As an experiment, I did nothing last year to reduce Box Elder bug numbers or access into my home. I didn’t even complain when the kids propped the door open allowing them free access. I wanted to see just how temporary they are. The result of the experiment was my wife and kids telling me that their sanity would be temporary if we went down this path again. I will gladly be utilizing the expertise from Rove Pest Control for my future Box Elder bug invaders to ensure a happy home.