Are you finding little black bugs with red lines, about ½ inch long, inside your house or outside on the foundations or sunny walls? Do you have an invasion of these insects nearly every spring and again in fall? If so, chances are you have a female boxelder tree in your yard or nearby. Box elder bugs, as they are called, feed on the seeds and foliage of female trees, and to a lesser extent, on ash and maple. In fall, the bugs move to protected sites where they can overwinter, such as inside or under you house. Boxelder bugs you find in spring are those which survived the winter, perhaps in your house, and will soon die of “old age”. In fall, you can probably expect another invasion of the next generation of boxelder bugs.
The good news, is that they cause little or no damage to the trees, so tree protection is not needed. You already know the bad news, that the bugs are a nuisance. However, they will not reproduce in the house, nor will they feed on plants or furnishings indoors. They will soon die of old age. Inside the house, you can vacuum them up periodically, and those that escape will soon die off. Reduce the numbers that will enter your house in fall by caulking cracks, mending screens, and attaching "sweep strips" to the bottom of doors. These efforts will keep other insects out as well.
Outside, you can vacuum them with a shop vacuum for a non-toxic method of control. You can also spray them with insecticidal soap that contains pyrethrin. Insecticidal soap is simply a highly refined soap, and is a good least-toxic option. Formulations containing are even more effective. Malathion or long-residual insecticides applied to foundations and around doors and windows can also be used to manage the outdoor congregations. In fall, you can probably expect another invasion, and can use the same management methods.
For long-term indoor and outdoor control, a clear latex paint containing microencapsulated chlorpyrifos, an effective insecticide that kills most insects and spiders, can be painted around doors, window frames, baseboards, and threshholds. The insecticide remains in the latex base until an insect or spider crawls over the surface; because the active ingredient is contained inside polymers, which are dissolved by the enzymes in the mucus on insects’ feet, according to the manufacturer, the insecticide is absorbed directly into the insect and children and pets are not exposed to the insecticide or it’s vapors. The product can remain effective 2-5 years indoors, and 1-2 years outdoors. This can provide a least-toxic alternative. I know of only one source for this product; Marketing Labs Inc., in Ackron, Ohio, at 800/366- 5595. For outdoor use only, a similar product containing microencapsulated diazinon is locally available; you mix the diazinon with latex paint yourself.
If you have a severe problem with boxelder bugs every year, and feel you just don't want to tolerate them, you may want to consider removal of the female box elder trees. Male trees do not attract these bugs, and when boxelder trees are planted, males should be selected. You can distinguish between male and female trees in spring and fall: In spring, both have blossoms, but blossoms of male trees are corymbs (upright, small, with a branching effect similar to that of an umbrella); blossoms of female trees are racemes (long and slender, hanging down). In fall, only the female trees produce seeds, the type called samara or keys, similar in appearance to the paired “whirlybird” seeds of maple. The clusters of seeds on female trees remain attached in winter.
Conifer Seed Bugs
Conifer seed bugs (Leptooglossus species), known also as leaffoooted bugs due to their enlarged hind legs, feed on seeds of a variety of plants, including dogwood and pines. These insects are most common around areas of coniferous forest.
Similar to the boxelder bug, conifer seed bugs often migrate into homes during early fall in search of overwintering shelter. Although they do not occur in large aggregations, their large size and appearance can cause alarm. They do have a slight odor, however, they do not bite nor reproduce indoors.
Chemical Controls are not recommended. Sealing homes in the late summer may reduce infestations
References:
Cranshaw, W., M. Brewer, S. Armbrust, and S. Lajeunesse. 1994.
Household Insects of the
Rocky Mountain Region. Extension Publication 557A, Montana State University, Bozeman, Montana. 90 pp.
Pacific Northwest Insect Control Handbooks. 1997. Extension Services of Oregon State University. Corvallis, OR 97331-0817.
Ware, G.W. 1988. Complete Guide to Pest Control With and Without Chemicals. Second Edition. Thomson Publications, Fresno CA 93791. 304 pp.
Written by Sherry Lajeunesse, Extension Urban Pest Management Specialist. Sept., 1997
Categories: Boxelder bugs, Conifer Seed Bugs
Date: 11/26/2001