Knowledgebase
What is this little bug that I am finding all around inside my house this fall? #431203
Asked October 13, 2017, 2:19 PM EDT
For the last month or so I've seen an increasing number of little bugs in my house. I'll attach pictures. They started showing up in my Colorado house in early fall. They don't seem to eat anything or do anything, they're not drawn to fruit or the pantry or the bedroom or anything. They just seem to hang out on walls, bookshelves, vents, counters, etc. They're small (~1/4") and not armored. I've squished a bunch of them and they sometimes leave a slight reddish stain.
I looked around on the Colorado State University insect pages (http://extension.colostate.edu/topic-areas/insects/?target=publications#household) and couldn't find anything matching it.
Mine are too small and spindly to be a conifer seed bug.
Mine are just brown / grey / tan colors, and smaller than a boxelder bug.
Those were the closest things I could find to a match -- neither seemed right. Maybe they're a smaller, less brightly-colored species related to boxelders... Not sure.
Who is this bug? And what can I do to get them to leave my house? They are not a swarm or thick anywhere, but there are lots of them scattered around the house and you can usually find 10 in a room if you go looking. I haven't seen anywhere that they're particularly dense and I can't tell where they're coming from.
Thanks!
Larimer County Colorado
Expert Response
It is some kind of plant feeding bug (order Hemiptera), but I am unsure as to what species it is or even what family (either Lygaeidae, Rhopalidae, or Miridae). Regardless it is strictly a nuisance invader of the home that develops on some outdoor plant and whose presence indoors is incidental and temporary. (And harmless, other than the nuisance.)
That being said, it is not one of the half dozen or so "true bugs" that commonly enter homes. Likely there occurrence indoors is a "one of" type of event involving an established insect that for whatever reason was particularly abundant around your home this year and made its presence known. But, alternatively it could be a new type of insect in the state that has the nuisance invading habit.
If you can get a sample to CSU we can work on getting it identified as long as the insects are in good shape (not crushed). They can either be dropped off at the Larimer County Extension office (on 1525 Blue Spruce Drive in Fort Collins) and they can bring it by or it can be brought directly to campus at the Department of Bioagricultural Sciences and Pest Management in the Plant Sciences Building. Indicate it is to go to Whitney Cranshaw and leave and email for a response.
I am interested in figuring out what it is since it is a new one for me as something found indoors.
These insects are native to the eastern U.S. and apparently have been moved into Colorado. Previously this was not in the CSU collection, but this year we have 3 reports, including yours. They are of negligible importance in terms of plant damage, feeding on seeds of various plants. We think this one feeds on seeds of russian olive, among other plants.
The issue with this insect is that it is one of a handful that tend to move into homes as a nuisance invader. such as happened in your case. indoors they do not bite, feed on anything, or reproduce.
