OSU Extension fact sheet HYG-2106 says boxelder and leaf-footed bugs enter mostly through gaps around doors, windows and roof soffits, and cause no structural or food damage. Crushing them can leave an odour and fecal stains. In Columbus, the reliable order is to seal the entries, vacuum the bugs inside and not crush them.
Key takeaways
- OSU’s HYG-2106 fact sheet names doors, windows and roof soffits as the main entries.
- These bugs cause no structural or food damage, according to the same fact sheet.
- Crushing them can leave an odour and fecal stains on curtains or walls.
- Seal first, vacuum the bugs inside, and use a residual only as a later step.
- Check the sealing again before the first warm autumn spell.
- Keep the vacuum bag sealed and out of the house.
Where do these bugs enter a Columbus house?
According to OSU’s fact sheet, they enter mostly through gaps around doors, windows and roof soffits. Small gaps at the corners of frames and the joints of soffit boards are the usual routes.
A door is often the largest route, because the threshold and the sweep wear with use and the gap grows. A window frame is the next most common route, particularly at the corners, where caulk shrinks and cracks. A light from inside on a bright day shows which gaps let light through.
The roof soffit is the third route, and the fact sheet names it directly. A soffit joint or a vent without a fine screen is open to the insects. The check covers each soffit section, each vent and the joints where the soffit meets the wall.
Do these bugs do any damage?
The OSU fact sheet says they cause no structural or food damage. Their effect is the number of bugs in the living space and the mess that crushing them makes.
This matters for how the problem is handled. A nuisance insect is dealt with by closing the route and clearing the bugs inside. It is not a structural problem, and a homeowner does not need to treat the building’s wood for it.
A homeowner who sees bugs inside may worry about food. The fact sheet describes no food damage, but the bugs should not be left to crawl over food surfaces, and any food left out should be covered.
Why vacuum instead of crushing?
Crushing a boxelder or leaf-footed bug can leave an odour and fecal stains on curtains and walls, according to the fact sheet. A vacuum removes the bugs without that mess.
A crushed bug leaves a fluid that stains light fabric and paint, and it leaves a smell that can linger in a room. The vacuum keeps the stain away from the surface and removes the insect from the room in one step.
The bag or canister should be emptied outdoors and sealed. A bug in a loose bag can climb out in a warm room, which defeats the vacuum.
When is a residual worth adding?
A residual is used where the bugs keep gathering after the gaps are closed. It is placed according to the label, usually on the sunny walls or along the foundation, and it is not a replacement for sealing.
A residual works on insects that touch or pass over the treated surface. It does not close a gap, so a bug entering through an untreated crack is not stopped by it. Sealing comes first for that reason.
The placement is recorded so the next check can see whether the residual is still working after rain and sun. A residual that has weathered away is replaced on the schedule the technician sets.
When should the work be done in Columbus?
The sealing is best finished before the first warm autumn days, usually in late summer or early autumn. A spring check looks at the screens and vents that winter may have damaged.
A sealing job done in August has not yet been tested by a warm October, so an autumn follow-up is useful. The follow-up looks at the same frames and joints and records any new gap.
Spring is the time to replace torn screens and check the vents, which ice and wind often damage. A torn screen in spring is an open route for the next autumn.
What can a homeowner do this week?
Walk the outside on a bright day with a flashlight, mark each door and window gap, check the soffit vents and vacuum the bugs inside without crushing them.
The walk takes under an hour for most houses. Hold the light on the outside of each frame and look for brightness on the inside. A piece of painter’s tape marks each spot, which makes the sealing quicker when the materials are ready.
Close the curtains in a room with bugs and wash any stained curtain. Those steps reduce the mess while the sealing is under way, and they make the next check easier to read.
Which parts of the house should a homeowner check first?
Start with the sunny faces, then the rest of the house. The sun drives the gathering, so the south and west walls are where the bugs are most often seen and where the sealing matters most.
On the south face, check every window and door frame, the siding joints at each corner and the vents in the soffit. Use a flashlight from inside on a bright day to see where light passes through the frame, and mark each spot with tape.
On the west face, check the same items and also the cable and pipe penetrations, which are often hidden behind a meter box or a bracket. The north and east faces get less sun, so the gathering is less common there, but a gap is still a gap.
How does a homeowner know the sealing has worked?
The sealing has worked when the bugs stop getting in through the same route across a warm season. A simple walk in the evening and a follow-up in autumn show whether it has.
Walk the house in the evening, after the sun has left the walls, and note any bug seen inside. A bug in a room that was sealed points to a gap that was missed. A bug in a room with no gap may have come in through a door opened on a warm day.
A follow-up visit in the next autumn compares the sightings with the previous year. If the number has fallen, the plan is working. If it has stayed the same, the gaps should be checked again.
How do Columbus houses of different ages get sealed?
Older houses have more movement in their frames and more joints in their masonry, and newer houses have fewer old gaps but still have joints at windows, doors and soffits. The sealing list is written for the building in front of the technician.
A brick house from the early twentieth century has window frames set in deep masonry. The gap is usually at the lintel or the sill, and the sealing material is chosen to suit the masonry. A frame that has moved over the decades may need a fitted trim as well as a sealant.
A ranch from the 1960s has long walls and many windows and doors. The sealing list is built around the frames and the door sweeps, and the soffit vents are checked for screens. A split-level has the same joints on both levels, and the walk covers both.
What should a homeowner expect from a sealing report?
A sealing report lists each gap by location, the material recommended, the date sealed and the date of the next check. It also states any gap the technician could not reach or could not seal without damage.
The report is most useful when each item can be found again. A gap at the south window of the front bedroom is clearer than a general note about the windows, and a homeowner can check it after the next season.
Where a gap cannot be sealed without damage, such as a historic frame that should not be cut, the report says so and recommends the least damaging alternative, such as a fitted screen on the vent or a trim over the joint.
What does a sealing walk cost a homeowner in time?
A sealing walk takes a few hours for an average house, and a follow-up takes less. The homeowner can plan the time around the autumn and book the technician early.
The outside walk takes the longest, especially on a house with two storeys or a steep roof. The inside check with the light is quicker, and the sealing itself depends on the number of gaps. A plan that splits the sealing across two weekends suits many households.
Booking early in the summer leaves room for a second visit if the first finds more gaps than expected. A late booking in October may find the warm spell has already started.
Frequently asked questions
Do boxelder bugs bite?
The OSU fact sheet does not describe a bite risk, and this guide does not add one. It describes them as a nuisance insect that does not damage the structure or food.
Why do they come in on warm winter days?
A warm day can bring insects out of wall voids and into a room. The bugs already in the house tend to appear this way until the entries are sealed.
Is spraying the outside wall enough?
It can act as a residual, but the sealing closes the route. A spray alone does not close a gap, so bugs can still enter through an untreated crack.
When is the best time to seal?
Before the first warm autumn days, ideally in late summer or early autumn. Sealing later still helps, but it does not reach the bugs already in the wall.
Are these bugs the same as stink bugs?
No. The OSU fact sheet on boxelder and leaf-footed bugs is separate from the fact sheet on brown marmorated stink bugs, which is covered in a separate guide and service on this site.
Can I use a shop vacuum on them safely?
Yes. Use the vacuum on the bugs and empty it outdoors into a sealed bag. Wear gloves if you need to move them by hand, and wash your hands afterwards.
What if I cannot reach a high soffit to seal it?
Ask the technician to check it from a ladder on the visit. The report records the soffit as reached or not reached, and a high section left unchecked is listed as a gap in the plan.
Sources
This guide is general information for Franklin County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.