Beetle Identification Question - Western Colorado

Asked July 10, 2013, 9:43 AM EDT

I have never senen these bugs (beetle?) before. They are prevalent this year on sunny dry hillsides with pinion and juniper in early July. They also like to hang out on driveways, the siding of the house and around the foundation and deck. Some seem to be in my Aspen trees in New Castle, Colorado. What are they? What are they eating?

Garfield County Colorado

1 Response

Those are nymphs of a stink bug of the genus Chlorochroa.

These are generalist feeders on many plants, sucking sap from stems, but do not seem to be very damaging.

The behavior you are seeing, massing on the sides of buildings, has been noted from to time in the past in Mesa County. I am unsure of the reason that this species moves to buildings. One possible cause is that they move to buiidings for the relatively higher humidity and lower temperatures present there, as aggregations of these stink bugs tend to occur during hot, dry spells.