Western Conifer Seed Bug

The Western Conifer Seed Bug, *Leptoglossus occidentalis*, belongs to the family Coreidae (leaf-footed bugs) and is characterized by its robust, elongated body measuring 16-20 mm, exhibiting a mottled reddish-brown coloration that aids in camouflage among conifer cones and bark. A diagnostic feature is the distinct white, zigzagging band visible across the hemelytra when the wings are folded, and leaf-like expansions (flares) on the hind tibiae. Its incomplete metamorphosis involves three stages: egg, nymph (five instars), and adult; eggs are typically laid in rows on conifer needles, hatching within 10-14 days, with nymphal development spanning 4-6 weeks through successive molts. Adults can live for several months, with a single generation per year, and exhibit a remarkable tolerance for cold temperatures, which facilitates their overwintering success.

This species primarily exhibits diurnal activity during its feeding and reproductive periods, foraging on developing conifer seeds, particularly those of pines, Douglas fir, and hemlocks, which they access using their piercing-sucking mouthparts. While not social in the strict sense, large aggregations can form during fall invasion events as they seek overwintering sites. They are known for their strong flight capabilities, often accompanied by a distinctive loud buzzing sound, especially when agitated or flying indoors. When threatened, *L. occidentalis* emits a defensive pheromone, a pungent, pine-like odor produced from thoracic glands, which can be off-putting to predators and homeowners alike, though they pose no direct public health threat or structural damage to homes.