This is a large hymenopteran characterized by striking sexual dimorphism and a robust body measuring between 25 and 30 millimeters in length, making it one of the most imposing native pollinators within its range. Adult females exhibit a predominantly shiny black integument, featuring dark wings with prominent blue or violet metallic iridescence. Their most defining diagnostic feature is the presence of bright ferruginous-red or orange hair bands on the lateral margins of the metasoma, particularly visible on the first few abdominal segments. In contrast, males display a completely different appearance, being covered in dense, velvety greenish-yellow or golden pubescence, with conspicuously larger compound eyes adapted for detecting potential mates during flight. Both sexes possess strong, heavy mandibles specially adapted for chewing and boring through tough plant fibers.

Geographical distribution: Native to the southern cone of South America, this species occupies a wide geographic range that encompasses central and northern Argentina, southern and southeastern Brazil (with significant populations in states such as Rio Grande do Sul, Santa Catarina, Paraná, and São Paulo), all of Uruguay, and extensive regions of Paraguay. In recent decades, it has successfully established breeding populations in the central valley of Chile, where it was first documented around 2013 in the Santiago Metropolitan Region. Since then, it has expanded rapidly northward and southward due to high ecological plasticity, human-mediated transport, and its strong flight capacity, now being recognized as an exotic species undergoing active range expansion.

Habitat: Prefers temperate, transitional, and subtropical biomes, showing an exceptional ability to adapt to human-modified landscapes. It is commonly found in urban gardens, public parks, agricultural orchards, forest edges, and disturbed scrublands, generally avoiding closed, dense rainforests where sunlight is limited. Its presence is highly dependent on a continuous supply of diverse floral resources and, crucially, the availability of suitable nesting substrates such as dry deadwood, decaying logs, wooden fence posts, and untreated structural timber in residential or agricultural buildings.

Feeding: Exhibits highly polylectic foraging behavior, feeding on a vast taxonomic array of flowering plants to gather pollen and nectar. It is well-known for its proficiency in buzz pollination (sonication), a specialized behavior in which the bee clutches the flower and rapidly vibrates its indirect flight muscles, creating a loud, high-pitched buzz that efficiently releases pollen from the poricidal anthers of plants in families like Solanaceae (such as wild tomatoes and eggplants) and Fabaceae. When faced with flowers containing deep corolla tubes that are inaccessible to its tongue, it frequently acts as a "nectar robber," using its robust mouthparts to pierce the outer base of the corolla to extract nectar without pollinating the plant.

Behavior: Leads a predominantly solitary lifestyle, with peak activity restricted to the warmer spring and summer months, followed by winter diapause in adult stages. While females spend most of their active hours foraging and constructing nesting tunnels, males show highly territorial and patrolling behaviors. They establish vantage points near active floral patches or nest sites, performing hover-flights and aggressively chasing away competing males, other insects, or even small birds that enter their defended airspace. Their flight is characterized by high speed, agility, and a deep, resonant buzz that is easily recognized.

Reproduction: The reproductive cycle begins in early spring with complex aerial courtship displays followed by mating. Once fertilized, the female assumes the sole responsibility of constructing a secure environment for her offspring. Utilizing her powerful mandibles, she excavates longitudinal tunnels deep within dry wood, which can extend for several inches. Inside these galleries, she builds individual linear cells. For each cell, she collects pollen and nectar, mixing them into a moist, compact mass known as "bee bread." She lays a single, exceptionally large egg on this provision and then seals the cell with a circular partition made of chewed wood dust mixed with her salivary secretions. This sequence is repeated until the tunnel is filled. The larvae develop independently, pupate within their sealed chambers, and emerge as fully formed adults.

Conservation status: Currently classified as Not Evaluated (NE) on the global IUCN Red List of Threatened Species, as it remains common and widespread throughout its native distribution. In its native habitat, it is considered a species of Least Concern due to its high ecological resilience and positive adaptation to urbanization. Conversely, in areas where it has been introduced, particularly in central Chile, it is monitored as an invasive exotic species. In these non-native environments, it is studied for its potential negative impacts, including competition for food and nesting sites with native bees, and minor damage to wooden structures.