Boxelder Bugs

Box Elder Bugs- 1st Instar- 12 font

Spring brings a common annoyance into our Springfield home.  We get really bugged by tiny red bugs, the size of a period on a 12 font document seem to be crawling silently everywhere.  They are most prominent on the brushed aluminum of my computer notebook.  Barb identified these as the first instar of the boxelder bug.

Boxelder bugs, Boisea trivittata are commonly seen true bugs.  The first instars we see are miniature versions of the adult.  Boxelder nymphs grow through molting with five nymphal stages (instars) before reaching the adult stage (imago).  They are wingless, gradually taking on the adult's characteristics and color with each molt.  Like pilots, when they hit the final stage, they get their wings.

5 Instars and adult- University of Rhode Island

True bugs are characterized by specialized mouth parts modified for piercing and sucking juices.  Although most attack plants, some like the assassin bug specialize in predating insects and caterpillars.  Another characteristic is the hardened proximal portion of the upper wing.  For those of us who are etymologically challenged, the easy thing to remember is that their wings overlap, unlike beetles whose wings fit together along the center of their backs.

University of Minnesota

Their primary breeding home is female boxelder trees, as well as maple and ash trees. They are sometimes called "garage bugs" for a good reason.  They tend to cluster in human structures to hibernate for the winter.  No nearby box elder trees?  No problem, as they are capable of flying up to two miles to find a nice place to spend the winter.

They do not cause significant plant damage and are primarily just an annoyance.  When squished they leave a tiny water soluble orange-red stain.  They do not have an odor but do have a bad tasting chemical that deters predators, allowing them to hang out in large clusters unmolested.

They are said to lay their eggs outside under bark and not in houses.  This is a little hard to believe considering the constant flow of 1st instars throughout our house.  In season there is always one crawling across the surface of my computer notebook.   With no nearby box elder, they may chose it because it is an Apple!

There are management suggestions from the University of Minnesota Extension.