Augochlorella

Distinguished from the closely related genus Augochlora by three microscopic characters: pointed (not squared) tip of the marginal cell, orthogonal (not oblique) epistomal sulcus, and absence of a strong basal lobe on the inner metatibial spur. Externally, Augochlorella species are virtually identical to Augochlora and Augochloropsis; definitive identification to genus requires specimen examination under a microscope.

Nests constructed in underground burrows in well-drained soils, typically in flat or sloped bare ground. Found in fields and wooded locations across a wide variety of habitats. Nest burrows range 5–25 cm deep depending on soil moisture. Augochlorella aurata has been documented in longleaf pine savannas, where it responds positively to prescribed fire regimes that create open ground and increased floral resources.

New World distribution from northern Argentina to southern Canada, with highest abundance in Neotropical regions. Only a few species reach the temperate Nearctic; Augochlorella striata (synonym of A. aurata) occurs further north than any other member of tribe Augochlorini. Augochlorella aurata is one of the most common bees in eastern North America.

Augochlorella aurata active from April through September in parts of its range. Queens initiate nest construction mid-April, completing by early May. Pollen ball construction occurs from second week of May through mid-August. Workers begin nest expansion mid-June.

Generalist pollinators. Documented floral visits include Apocynum cannabinum, Erigeron strigosus, Pycnanthemum tenuifolium, Solidago odora, Euthamia graminifolia, wild roses, goldenrod, dogbane, fleabane, and mountain mint. Augochlorella aurata is an important pollinator of stone fruits, pome fruits, alfalfa, sunflower, pepper, strawberry, tomato, and watermelon.

Eusocial or solitary depending on population and environmental conditions. Eusocial nests: foundress produces initial brood of 1–2 female workers, then switches to male-biased brood (though female-biased broods occur less commonly). Workers are mostly sterile and slightly smaller than queens. Brood cells average around 3 per female; maximum nest size approximately 12 cells. Mean offspring per nest: 14–15. Two-week period of inactivity typically follows first egg-laying bout. Some cells reused, though most are used only once.

Flexible social organization determined by growing season length: more often solitary at high altitudes, high latitudes, or where growing season is shorter; more often social where growing season exceeds threshold duration. Maritime Canadian populations show reduced brood production duration, fewer workers per nest, and fewer reproductive individuals. Nest foundresses may produce mixtures of workers and reproductively capable offspring in response to local conditions. Augochlorella aurata and A. persimilis sometimes nest in mixed aggregations. Typical flight distance for A. aurata: 60–210 m.

Important generalist pollinators in natural and agricultural ecosystems. Augochlorella aurata is among the most frequently observed bees in longleaf pine forest studies, responding positively to prescribed fire management. Wild bee populations increase in areas with available wildflowers and nesting habitat. Serve as prey for generalist predators including birds, asilid flies, and spiders.

Valuable pollinator for commercial fruit and vegetable farming including stone fruits, pome fruits, alfalfa, sunflower, pepper, strawberry, tomato, and watermelon. Important for maintaining healthy urban gardens and parks. Subject of research on fire management effects on pollinator communities. Sometimes mistaken for cuckoo wasps by observers due to metallic coloration.

• AugochloraExtremely similar metallic green appearance; distinguished microscopically by squared (not pointed) marginal cell tip, oblique epistomal sulcus, and presence of strong basal lobe on inner metatibial spur. Augochlora pura frequently brassy, coppery, or bronze rather than green.
• AugochloropsisVirtually identical external morphology; requires microscopic examination for definitive separation. All three genera in tribe Augochlorini (Augochlora, Augochlorella, Augochloropsis) are easily confused without specimen analysis.
• AgapostemonAlso metallic green Halictidae; males have banded black and yellow abdomen (not metallic), females often hairier. More widespread and easily recognized than Augochlorini genera.
• Cuckoo wasps (Chrysididae)Similar metallic coloration frequently causes misidentification. Distinguished by behavior: cuckoo wasps seldom visit flowers, move with quick jerky motions, and lack pollen-collecting scopae on hind legs. Sweat bees are common on flowers, move more directly, and females carry pollen.

• Halictidae
• sweat bees
• Augochlorini
• metallic bees
• eusocial
• generalist pollinators
• agricultural pollinators
• fire ecology
• North America
• Neotropical

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Augochlorella aurata bee - Entomology Today
• Augochlorella sweat bee on Venus flytrap flower - Entomology Today
• Augochlorella Archives - Entomology Today
• Augochlorella aurata Archives - Entomology Today
• Bug Eric: Metallica
• Study Shows How Prescribed Burns Benefit Bees
• A review of the bee genus Augochlorella (Hymenoptera: Halictidae: Augochlorini)