Augochlora

Smith, 1853

green sweat bees

Species Guides

Augochlora aurifera(Auriferous Green Sweat Bee)
Augochlora azteca(Aztec Sweat Bee)
Augochlora pura(Pure Green Sweat Bee)

Augochlora is a of small, metallic sweat bees in the Halictidae, comprising approximately 127 valid distributed from southern Canada to Argentina. The genus exhibits remarkable social flexibility, with most species showing facultative eusociality while at least one species, Augochlora pura, is exclusively solitary. Members nest primarily in decaying wood, though some species utilize soil. The genus is divided into three subgenera: Augochlora s. str., Oxystoglossella (formerly Oxystoglossa), and the extinct Electraugochlora known from Miocene Dominican amber.

Augochlora pura by (c) Katja Schulz, some rights reserved (CC BY), uploaded by Katja Schulz. Used under a CC-BY license.

Augochlora by (c) Francisco Farriols Sarabia, some rights reserved (CC BY), uploaded by Francisco Farriols Sarabia. Used under a CC-BY license.

Augochlora pura mosieri by (c) Eridan Xharahi, some rights reserved (CC BY), uploaded by Eridan Xharahi. Used under a CC-BY license.

Pronunciation

How to pronounce Augochlora: //aʊˈɡɒklɔːrə//

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

Identification

Distinguished from other metallic green halictid (Agapostemon, Augochlorella, Augochloropsis) primarily by microscopic examination of morphological characters. Augochlora differs from Augochlorella and Augochloropsis in subtle genitalic and exoskeletal features not visible to the naked . From Agapostemon, Augochlora differs in having the entire body metallic (versus Agapostemon males with banded black-and-yellow ) and less dense . Behavioral cues are unreliable for genus-level identification. Cuckoo wasps (Chrysididae) can be separated by their quick, jerky movements, lack of pollen-collecting structures, and absence from flowers.

Images

Appearance

Small to moderate-sized bees with slender, andreniform bodies and long . All exhibit metallic coloration, most commonly greenish-blue, though some tropical species display blue, red, purple, or black hues. Augochlora pura frequently appears brassy, coppery, or bronze. Females possess scopae—brushes of pollen-collecting hairs—on the hind legs. Subgenera differ subtly in : Augochlora s. str. has a transverse basal elevation on the and bidentate ; Oxystoglossella males have long setae on the outer lobe of the gonostylus and light yellow basitarsus, while females have appressed setae on the pseudopygidial area and a smaller preapical tooth, with less iridescent blue coloration.

Habitat

Primarily forest-dwelling; nests in rotting wood, decaying logs, and stumps. Some nest in soil banks. Avoids very dry areas. Subgenus Augochlora s. str. specializes in wood-cavity nesting; Oxystoglossella species nest in soil. Artificial substrates such as plaster are accepted in laboratory conditions.

Distribution

Widespread in the Western Hemisphere from southern Canada through the United States, Mesoamerica, the Caribbean islands, and throughout South America to Argentina. Approximately 40 occur in Mesoamerica, with the majority in the Neotropics; only a few species reach the United States. Atlantic biome association prominent for many southern temperate species.

Seasonality

seasons are long, with multi-voltine producing multiple annually. Augochlora pura has been observed from April to September in eastern North America. Activity patterns vary by latitude and elevation across the broad geographic range.

Diet

Females provision nests with pollen and nectar collected from diverse flowering plants. Augochlora pura has been recorded visiting over 40 plant from 20 . Augochlora esox collects pollen from six plant families. , particularly females, are attracted to sodium chloride and have been observed collecting sweat from human skin and other mammals for electrolytes.

Life Cycle

Development from to requires approximately 30 days. Nests contain multiple provisioned with pollen balls, each receiving a single egg. Larvae consume provisions, pupate within cells, and emerge as adults. Male production is delayed to second or subsequent in eusocial .

Behavior

Social varies by : most exhibit facultative eusociality with solitary nest initiation by a foundress female followed by an eusocial phase with 1-3 first- daughter . Augochlora pura is exclusively solitary. In eusocial colonies, foundresses monopolize , remain in the nest, and initiate social interactions; daughters perform construction, pollen collection, and guarding. Nest architecture includes supported by pillars or clustered within cavities, lined with waxy secretions from the for moisture and protection. Division of labor indexes range 0.32-0.76.

Ecological Role

of diverse flowering plants in forest . Contribute to pollen and nectar transfer in both natural and agricultural settings. Their broad floral visitation patterns support pollination services.

Human Relevance

Occasionally encountered lapping sweat from human skin, particularly on hot days; poses minimal sting risk due to solitary nature and docile temperament. Used in scientific research on social evolution, brain development, and sampling methodology validation. Featured in entomological outreach and education collections.

Similar Taxa

Augochlorella-level distinction requires microscopic examination; both share metallic green coloration, tribe Augochlorini, and similar size. Augochlorella are more commonly referenced in eastern North American studies but morphologically convergent.
AugochloropsisThird in tribe Augochlorini; virtually identical in appearance to Augochlora, requiring dissection and microscopic examination of genitalia and exoskeletal microstructure for reliable separation.
AgapostemonMetallic green halictid ; males have distinctly banded black-and-yellow (versus entirely metallic in Augochlora), and females are generally hairier. Both genera frequent flowers and nest in soil or wood.
Chrysididae (cuckoo wasps)Non- with similar metallic coloration; distinguished by jerky rapid movement, absence of pollen-collecting structures, lack of scopae, and minimal flower visitation. Wasps seek other insects' nests rather than constructing their own.

More Details

Social Polymorphism

The exhibits exceptional social flexibility. Facultative eusociality—where solitary and eusocial strategies coexist within —is common across both extant subgenera. The exclusively solitary of Augochlora pura represents a derived loss of sociality, accompanied by reduced neural investment in mushroom body calyces compared to social relatives.

Subgeneric Classification

Three subgenera recognized: Augochlora s. str. (97 , wood-nesting), Oxystoglossella (32 species, soil-nesting; formerly Oxystoglossa), and Electraugochlora (extinct, Miocene Dominican amber). Traditional separation by nesting substrate and social is not fully reliable; an enigmatic species shares characteristics of both extant subgenera.

Research Significance

Augochlora pura serves as a model organism for studying the evolutionary loss of sociality and associated neural changes. Mark-recapture studies including Augochlora pura have validated that aerial netting more accurately reflects abundance than pan traps, contributing to improved monitoring protocols.