Boisea rubrolineata

(Barber, 1926)

Western Boxelder Bug

Boisea rubrolineata, the western boxelder , is a scentless plant bug native to western North America, ranging west of the Continental Divide. This is a herbivore primarily associated with boxelder maple (Acer negundo), feeding on both pollen from staminate trees and seeds from pistillate trees. Distinguished from its eastern counterpart B. trivittata by prominent red on the , it exhibits complex -mediated including and foraging. The species undergoes and seeks sheltered sites in autumn, often becoming a nuisance pest when entering human structures.

Boisea rubrolineata by (c) dloarie, some rights reserved (CC BY), uploaded by dloarie. Used under a CC-BY license.

Boisea rubrolineata by (c) Trevor Van Loon, some rights reserved (CC BY), uploaded by Trevor Van Loon. Used under a CC-BY license.

Pronunciation

How to pronounce Boisea rubrolineata: //ˈboʊsiə ˌruːbroʊlɪˈneɪtə//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from the eastern boxelder (Boisea trivittata) by prominent red on the . The bold red and gray coloration is aposematic. Unlike stink bugs (Pentatomidae) and leaf-footed bugs (Coreidae), lacks defensive . Nymphs identifiable by black legs, short wing pads, and exposed red . found west of the Continental Divide; eastern occurs east of Rocky Mountains.

Images

Habitat

Associated with boxelder maple (Acer negundo) trees, including both pollen-bearing staminate trees early in the season and pistillate trees with maturing samaras (seed pods) midseason. Congregates on warm, sunlit surfaces prior to . Overwinters in sheltered including under bark, in woodpiles, rock formations, fallen leaves, tree crevices, and human structures.

Distribution

Western North America, west of the Continental Divide. Native to this region; distinct from eastern counterpart B. trivittata which occurs east of the Rocky Mountains.

Seasonality

Active during growing season; forms in midsummer on trees with maturing seeds. Clusters on warm sunlit surfaces in autumn prior to . Overwinters in , with emerging in early spring. One to three per year depending on geographic location.

Diet

herbivore feeding on boxelder maple (Acer negundo). Consumes pollen from staminate inflorescences early in season and seeds (samaras) from pistillate inflorescences midseason. Described as a seed .

Host Associations

Acer negundo - primary Boxelder maple; provides pollen from staminate trees and seeds from pistillate trees

Life Cycle

Undergoes incomplete (simple) . laid on tree bark, leaves, or ground; each female produces 200-300 eggs. Nymphs hatch and feed on plant material, passing through instars with progressively elongating wing pads. Fifth-instar nymphs present in midsummer. emerge and may enter reproductive for winter. One to three per year depending on latitude and climate.

Behavior

Forms large on pistillate trees bearing maturing seeds. Uses for host foraging and intraspecific communication. Attracted to host plant volatiles including phenylacetonitrile, 2-phenethyl acetate, and 2-phenylethanol. 2-Phenylethanol serves as context-specific semiochemical: aggregation in midsummer for females, males, and fifth-instar nymphs (originating from of seed-feeding individuals and male abdominal gland), and male-produced sex-attractant pheromone in early spring upon from (originating from male ventral abdominal gland). Clusters on warm sunlit surfaces before . -capable disperse to overwintering sites in autumn.

Ecological Role

seed of boxelder maple. Serves as for tachinid flies and as prey for various predators including green anole lizards (though aposematic coloration and chemical defenses deter ). Contributes to nutrient cycling through feeding activities and fecal deposition.

Human Relevance

Considered a nuisance pest when aggregating on building exteriors and entering structures to overwinter. Does not bite, sting, or reproduce indoors; does not damage structures or belongings. Can stain fabrics and walls if crushed. Often transported inadvertently in firewood. Subject of research due to association with brown marmorated stink bug (preyed upon by native Astata unicolor alongside stink bugs).

Similar Taxa

Boisea trivittataEastern boxelder ; occurs east of Rocky Mountains; lacks prominent red corial present in B. rubrolineata
Jadera haematolomaRed-shouldered bug; similar red and black coloration but different body shape and associations (goldenrain tree)
Leptoglossus occidentalisWestern conifer seed bug; similar autumn aggregating and nuisance pest status, but larger with leaf-like expansions on hind legs, different trees (conifers)

Misconceptions

Often confused with stink bugs due to autumn aggregating , but lacks and defensive odor. Sometimes mistaken for kissing bugs (Triatoma) by homeowners, but is harmless and does not feed on blood. The name 'Democrat ' in some regions reflects political folklore rather than biological reality.

More Details

Semiochemical ecology

One of the most thoroughly studied aspects of B. rubrolineata is its sophisticated use of . The responds to a five-component synthetic blend (hexanol, pentyl acetate, phenylacetonitrile, 2-phenethyl acetate, and trans-nerolidol) for location, with phenylacetonitrile alone effective as an attractant. The context-dependent use of 2-phenylethanol as both and represents a notable case of chemical communication plasticity in true bugs.

Parasite associations

Documented for the trypanosomatid Leptomonas podlipaevi, described as a new based on specimens from B. rubrolineata. This kinetoplastid parasite represents one of few documented associations for this insect species.

Taxonomic history

Formerly placed in Leptocoris; transferred to Boisea based on subsequent taxonomic revision. Both were previously treated as under Leptocoris in older literature.