Female box elder tree
This past October, box elder insects fed off the female box elder tree located less than five feet from our house. The tree seemed to produce a bumper crop of seed pods this year, and the insects were overwhelming, both for us and our neighbor. The bugs numbered in the thousands and came in through our sliding glass window and skylights. Even now, when the weather is mild, the bugs still congregate on the exterior of the house. We used insecticidal soap but were infested with the bugs for weeks. A similar scenario next year would be intolerable, and we note that the extension service recommends the removal of such trees if they grow near the house. Given the size and location of the tree, the price to remove it is high: $2,500 is the estimate we've received. Before we go ahead with the tree removal, we wanted to check with you again to see if there is any other effective alternative. We don't see caulking and sealing as feasible to prevent the entry of the bugs, given their overwhelming presence. We've lived here 19 years and have seen the insects before but never in this volume. Is this year's experience aberrational, or could we see a big infestation again next year? If the tree is not removed, is it possible that the tree pod seeds will spread through our community? Thanks for your response.
Montgomery County Maryland
The populations of insects can vary dramatically from year to year, associated with weather conditions. Box elder bugs is one of those species whose fluctuations are noticed distressingly by humans. Be assured that just because you had hordes of box elder bugs last year, does not mean that this will continue unabated in the future. In fact, it may never happen again in the same numbers.
This is a native tree and is apt to appear anywhere, whether your tree is removed or not. One should be removed when young if it pops up in a problematic spot.
Because the bugs congregate on the trunks, that is a good place to spray them and hit a large number at once. Here is our website publication, which includes some tips for management: http://extension.umd.edu/sites/default/files/_images/programs/hgic/Publications/HG%2010_2Boxelder_Bu...