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BOXELDER BUG

Michael G. Waldvogel and S. Bambara, Extension Entomologists


CAUTION: This information was developed for North Carolina and may not apply to other areas.


Boxelder Bug, Boisea trivittata (Say), Rhopalidae, HEMIPTERA

General Information adult box elder bug

Boxelder bugs are elliptical and about 0.5 inch long. The thorax has 3 red stripes; the leathery parts of the wings are outlined in red; and the eyes are red. The remainder of the insect is dark gray or black. Initially eggs are light yellow, but darken to rusty red. Each has a distinct cap. Nymphs are conspicuously bright red; older nymphs have dark gray wing pads. The head, legs and antennae are gray. 


Biology

The boxelder bug is found throughout North Carolina. Besides boxelder tree seeds, this insect has been recorded as feeding on apple, ash, buckeye, cactus, geranium, grape, honeysuckle, lilac, linden, oak, peach, plum, spirea, strawberry, and tulip. Alder, maple and boxelder trees are most often infested but trees are seldom injured. Fruit trees and strawberries have occasionally had fruits damaged. Although boxelder bugs are associated with shade trees, this insect is more commonly a household pest. In fall, boxelder bugs tend to congregate on buildings and enter cracks and crevices to overwinter. They do not bite people or harm goods, but their presence is a nuisance. On warm winter days, the insects become active and move about in and on buildings and cause concern for the homedweller.

mass of box elder bug nymphs  on tree base Adult boxelder bugs emerge from their overwintering shelters in March and early April and feed for about 2 weeks before mating. These insects prefer sunny areas and, therefore, are found most abundantly on trees in a southern exposure and on sides of buildings facing south. Eggs are deposited in masses of 10 or 11 eggs usually in bark crevices. Each female deposits about 230 eggs. The eggs hatch in about 2 weeks. Development of the six nymphal stages takes 50 to 70 days. The boxelder bug population increases rapidly from middle July to early September. Two generations are produced each year. The insects seek overwintering places in September and October. Only the adults survive the winter.

Boxelder bugs have unusual feeding preferences. Because these insects feed primarily on boxelder and maple seeds, the insects are found on the ground beneath female trees in the early summer before the seeds start to develop. The bugs move into the trees once seeds begin to form. These insects are cannibalistic, particularly when the victim is molting, and they have been reported to feed on other dead or dying insects. 


Control

In the Home - Boxelder bugs are easily swept up or vacuumed up. If pesticide application is preferred, the following chemicals are among those available. Pesticide applications must target areas where the insects tend to be found. Applications in the Fall around windows and doors may reduce the number of boxelder entering the home. Outside the Home - Malathion loses its effectiveness below 65° F. Be sure to use the lower rates listed when applying pesticides to green plants.
 
Table 1: Pesticides for Use Against Boxelder Bugs INDOORS
Pesticide (Trade Name) Formulation Amount per Unit of Water
*cyfluthrin (Bayer Advanced) Ready-to-Use or Concentrate As directed by label of concentrate formulation
*bifenthrin (Ortho Home Defense) Ready-to-Use  
*tralomethrin (Spectracide Bug Stop) Ready-to-Use  

  
Table 2: Pesticides for Use Against Boxelder Bugs OUTDOORS (above 65 F)
Pesticide (Trade Name) Formulation Amount per Unit of Water
acephate (Orthene)  75 % soluble powder  1 pound per 100 gallons of water
carbaryl* (Sevin) 50% wettable powder 2 pounds per 100 gallons of water
cyfluthrin (Tempo 20) 20% wettable powder 9 tablespoons per 100 gallons of water
*cyfluthrin (Multi-Insect Killer)  0.75% concentrate or 0.003% premix 
cyfluthrin (Tempo 2) 24.3 % emulsifiable concentrate  1.5 fluid ounces per 100 gallons of water
*malathion  50 to 57% emulsifiable concentrate 3 tablespoons per quart (Don't spray this high rate on plants. Use 3 teaspoons per gallon of water for plants.)
* Suitable for home use. Some houseplant spray mixtures should also give adequate suppression.

Recommendations of specific chemicals are based upon information on the manufacturer's label and performance in a limited number of trials. Because environmental conditions and methods of application by growers may vary widely, performance of the chemical will not always conform to the safety and pest control standards indicated by experimental data.

Recommendations for the use of chemicals are included in this publication as a convenience to the reader. The use of brand names and any mention or listing of commercial products or services in this publication does not imply endorsement by the North Carolina Cooperative Extension Service nor discrimination against similar products or services not mentioned. Individuals who use chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage and examine a current product label before applying any chemical. For assistance, contact your county North Carolina Cooperative Extension Service agent.


Other Resources

For assistance with a specific problem, contact your local North Carolina Cooperative Extension Service personnel.

Published by North Carolina Cooperative Extension Service

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Last update to information: 2005
Web page last reviewed January, 2011 by webperson