Red-shouldered bugs

Question:

Can you identify the "bug" I have enclosed and tell me how to control it? It is coming over the wall from my neighbor's yard into my yard. Is there something I can spray to stop it?

Marilyn M.
Rio Rancho

Answer:

The insect you sent by mail was easily identified by its black color and red-orange markings on its "shoulders". Thank you for the sample and for sending it so that it arrived in good condition.

Your insect is the red-shouldered bug (a relative of the boxelder bug and often called boxelder bug). This is a true bug (in the order Hemiptera). Other things we call "bugs" should usually be called by the more general term "insect" (except spiders and other non-insects).

The red-shouldered bug and the boxelder bug are usually considered nuisance insects rather than economically damaging or medically important pests. Since they will often invade homes, they are an extreme nuisance. They can cause some "spotting" on walls, upholstery and other indoor fabrics. They may overwinter in the attics of homes or in the void between ceilings and flat roofs. As the weather warms, they leave their overwintering sites to return to the trees on which they feed. They are often confused in this process and enter homes through light fixtures and electrical outlets instead of going back outside. They then fly towards the light and accumulate in windows where they are observed in large numbers. Indoors the solution to the problem is to vacuum them from windows and other places where they are found. Don't forget to remove the vacuum bag or otherwise discard the bugs outside before returning the vacuum sweeper to the closet!

The red-shouldered bugs are more difficult to manage outside. The red-shouldered bug prefers to feed on the goldenrain tree and chinaberry tree, but may also be found on althea (rose-of-sharon), arbor vitae, Western soapberry trees, boxelder trees and some fruit trees. The early stage nymphs are bright red with black legs and no wings. Later stages of the nymph begin to develop wing pads and more adult appearance. The earlier stages are easier to control with insecticides. Insecticides containing carbaryl, cyfluthrin, malathion, permethrin, rotenone, pyrethrin and some others have been shown effective in controlling red-shouldered bugs. Some of these are labeled for use outside on the host plants and some can be used outside as perimeter treatments to prevent the adults from entering your house. There are a few that may be used indoors if necessary. Be sure to use them in an appropriate manner that is consistent with the directions on the product label. Some of the products are available only to professional pest control professionals who may be called to apply products to protect your home and landscape. Other products may be purchased and applied by homeowners. Products labeled for outdoor use should not be used indoors for obvious safety reasons. Before purchasing a product, read the label to be sure it is made for controlling red-shouldered bug in the environment in which you will use it. However, since the bugs do little damage to the host plants and do not carry human diseases, you may choose to use only a vacuum to eliminate them from indoors locations and a strong jet of water to wash them from walls and plants.

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Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email: desertblooms@nmsu.edu, office: 505-865-7340, ext. 113.

For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms and the NMSU Horticulture Publications page.

Send gardening questions to Southwest Yard and Garden - Attn: Dr. Marisa Thompson at desertblooms@nmsu.edu, or at the Desert Blooms Facebook.

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