L-1830

Boxelder bugs and other closely related insects are found throughout most of Texas and feed on several kinds of trees. In the fall they enter houses to find shelter for the winter and become a nuisance to many homeowners. Control measures include removing host trees, eliminating hiding places, sealing the house and applying insecticide.

Description

Boxelder bugs are about 1/2-inch long and 1/3-inch wide. They are dark brownish-gray to black with distinctive red markings. These rather flat bugs have three red lines running lengthwise on the pronotum (area behind the head). The wings are folded over each other and lie flat on the back. Red lines mark the lateral margins of wings and run obliquely across at about midwing.

The young or nymphs of boxelder bugs resemble the adults in shape but are smaller and wingless. Nymphs are solid bright red and develop black markings and wings as they mature.

Another insect, Jadera haematoloma (no common name), is often confused with the boxelder bug. It, too, is found throughout Texas and greatly resembles the boxelder bug in size, shape, and color. This insect is a beautiful bluish to smoky black color and has bright red eyes and stripes along the sides of the head and pronotum. The nymphs somewhat resemble those of boxelder bugs. Little is known about the habits of J. haematoloma, but in many instances it is found in much greater numbers than boxelder bugs.

Biology and Habits

Adult boxelder bugs deposit eggs in cracks and crevices of tree bark in the spring when buds open. In about two weeks the eggs hatch into nymphs which grow larger and develop into adults during the summer. There may be two or more generations per year in Texas .

In the fall, adults and large nymphs congregate on the bark of boxelder trees and other hosts and then begin a migration to find a place to spend the winter. They usually move by walking although adults can and will fly. Only adults overwinter. They commonly hide in small cracks and crevices in walls, door and window casings, around foundations, and in stone walls, as well as in tree holes and large accumulations of debris. Adults come out of hiding and appear on light or white painted surfaces during warm days of winter or early spring. Apparently the development of Jadera haematoloma is similar to that of the boxelder bug.

Boxelder bugs and related species create pest problems when, during their migrations, they enter homes to overwinter. These insects become a nuisance as they crawl or fly in rooms. They are plant feeders and do not feed on structures, food products, cloth, humans, or pet animals. The bugs may stain curtains, paper and similar furnishings with fecal spots. These insects produce little or no odor when crushed.

Host Plants

Boxelder bugs feed primarily on seeds of female boxelder trees. Minor hosts include plum, cherry, apple, peach, grape, chinaberry, western soapberry, ash and maple. Fruits of these plants may be damaged by boxelder bugs. Young fruit is scarred or dimpled by their feeding. Mature fruit is quite often fed upon after it falls to the ground. These alternate host plants are not likely to be the source of migrating bugs.

Jadera haematoloma has been found on a number of hosts, but the role these plants play in this bug's development is uncertain. Hosts include arborvitae, chinaberry, western soapberry, ash, cotton, grain sorghum, and bluebonnets.

These bugs should not be considered damaging to the host plants. Although they suck plant juices while feeding, they are seldom abundant enough to harm trees .

Control

Since the boxelder tree is the chief source of food for the boxelder bug, removal of the female or seedbearing trees might be beneficial. If boxelder trees are important in the landscape, select only male trees. Eliminate hiding places such as piles of rocks, boards, leaves, and general debris close to the house. Repair and close places where bugs can enter the house, such as cracks around doors and windows and in the foundation. Rake leaves, weeds, and grass from a strip 6 to 10 feet wide around the foundation, particularly on the south and west sides of the structure. Such a barrier strip reduces the congregation of boxelder bugs near the foundation.

If host-tree removal is not desirable and exclusion techniques are not successful, insecticide applications may become necessary. Treatments should be applied to young, exposed bugs found on host trees in the spring and early summer. At this time of year insecticides are most successful in reducing insect numbers and preventing indoor migration. Applications should thoroughly cover trunk, limbs, and foliage. Sprays can also be applied to hibernation areas such as foliage and trunks of trees, building foundations, fences, sides of houses, and other outside areas where the bugs congregate .

Control indoors is difficult because the bugs are often scattered throughout the house. Spray directly on the bugs or on surfaces where they may crawl. Dust formulations are often more effective when treating cracks, crevices, and other concealed areas. Use products containing the insecticides listed in Table 1. For more information on pest control and pesticide products, see Extension publication B-1373 Home and Landscape Pests.

When applications on tall trees or large areas require extensive spraying and specialized equipment, employ the services of a local pest control firm.

Insecticide label clearances are subject to change and changes may have occurred since this publication was printed. The pesticide USER is always responsible for the effects of pesticide residues on plants or household goods, as well as problems that could arise from contamination of neighboring property or plants. Always read and follow carefully the instructions on the container label.

The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Cooperative Extension Service is implied.

Educational programs conducted by the Texas Agricultural Extension Service are open to all people without regard to race, color, sex, disability, religion, age or national origin.

Issued in furtherance of Cooperative Extension Work in Agriculture and Home Economics, Acts of Congress of May 8, 1914, as amended, and June 30, 1914, in cooperation with the United States Department of Agriculture. Zerle L. Carpenter, Director, Texas Agricultural Extension Service, The Texas A&M University System.

20M--8-85, Revision

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Last modified: January 22, 1997 by Edgar Cross