Boxelder Bug

Taxonomy

Domain	Eukarya
Kingdom	Animalia
Phylum	Arthropoda
Subphylum	Hexapoda
Class	Insecta
Subclass	Pterygota
Infraclass	Neoptera
Superorder	Paraneoptera
Order	Hemiptera
Suborder	Heteroptera
Infraorder	Pentatomomorpha
Superfamily	Coreoidea
Family	Rhopalidae
Subfamily	Serinethinae
Genus	Boisea

Scientific Name

Boisea trivittata

Scientific Name Synonyms

Leptocoris trivittata

Leptocoris trivitattus

Common Name

boxelder bug

Compiled by Whitney Cranshaw, Colorado State University:

Boisea (= Leptocoris) trivittata (Say)
Hemiptera: Rhopalidae

Hosts

Boxelder, sometimes silver maple

Damage and Diagnosis

Nymphs and adults usually feed on sap from seeds, flowers and leaves, but cause little damage to trees. Occasionally they feed on developing fruits, such as apples, and can produce puckered 'catface' injuries to these plants.

The major "damage" from these insects is their appearance in nuisance numbers on the windows and porches of homes. This is occurs most often in the spring and fall. Boxelder bugs are brownish-black, about 1/2 inch long, with three red lines on the head, and a bright red abdomen beneath the wings. The nymphs, which do not survive winter, are sometimes called "red bugs" because their bright body coloration is not covered by the wings.

Life History and Habits

Boxelder bugs overwinter in the adult stage in protected sites, often including homes. They emerge in midspring and lay eggs near fallen seeds of boxelder, ash, and silver maple. The first generation nymphs feed on these seeds, as well fruit trees, various low growing plants and, occasionally, dead insects. They become full-grown in early summer.

A second generation occurs during late summer. Eggs are laid almost entirely on boxelder, particularly seeds produced by female trees. The nymphs develop on these seeds often into October, if weather permits. After frosts, boxelder bugs move to winter shelter, during which time homes are invaded. Boxelder bugs can move hundreds of yards from boxelder trees.

It is commonly noted that some buildings are repeatedly infested by large numbers of boxelder bugs, while others are much less commonly infested. It is unclear why there can be such differences. Surface texture of buildings and, in particular, direct sun exposure seem to be important. Also there is a noticeable odor that the insects produce so that there may be an aggregation pheromone produced.

Boxelder bug eggs.

Boxelder bug nymph.

Similar Species

Another common black and red bug that may be confused with the boxlder bug is the small milkweed bug, Lygaeus kalmii Stal. L. kalmii belongs to the seed bug family (Lygaeidae).

Management

Only adult stages survive the winter and many nymphs which fail to complete development are killed by early frosts or shorter growing seasons.

Boxelder bugs do not require controls for protection of trees. However, treatments are often made to reduce nuisance movements into homes. Boxelder bugs are quite resistant to most insecticides with the pyrethroids being among the more effective.

The information herein is supplied with the understanding that no discrimination is intended and that listing of commercial products, necessary to this guide, implies no endorsement by the authors or the Extension Services of Nebraska, Colorado, Wyoming or Montana. Criticism of products or equipment not listed is neither implied nor intended. Due to constantly changing labels, laws and regulations, the Extension Services can assume no liability for the suggested use of chemicals contained herein. Pesticides must be applied legally complying with all label directions and precautions on the pesticide container and any supplemental labeling and rules of state and federal pesticide regulatory agencies. State rules and regulations and special pesticide use allowances may vary from state to state: contact your State Department of Agriculture for the rules, regulations and allowances applicable in your state and locality.