Lasioglossum

Curtis, 1833

sweat bees, furrow bees

Species Guides

75

Lasioglossum is the largest of bees, containing over 1,800 described worldwide. These sweat bees exhibit extraordinary diversity in size, coloration, and social , ranging from solitary to primitively eusocial, kleptoparasitic, and socially parasitic species. Most species nest in the ground, though some utilize rotten logs. The genus is divided into two informal series based on forewing venation: Lasioglossum (strong-veined) and Hemihalictus (weak-veined).

Lasioglossum quebecense by (c) Zachary Dankowicz, some rights reserved (CC BY), uploaded by Zachary Dankowicz. Used under a CC-BY license.Lasioglossum imitatum by (c) Zachary Dankowicz, some rights reserved (CC BY), uploaded by Zachary Dankowicz. Used under a CC-BY license.Lasioglossum lionotum by (c) Cole Shoemaker, some rights reserved (CC BY), uploaded by Cole Shoemaker. Used under a CC-BY license.

Pronunciation

How to pronounce Lasioglossum: //ˌlæsi.oʊˈɡlɒsəm//

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

Identification

Identification to level is extremely difficult and requires specialized taxonomic expertise. The is characterized by features of the Halictidae combined with specific traits of the subgenus or species group. Bowl traps frequently capture numerous Lasioglossum specimens, often disproportionately to their abundance on flowers. Subgeneric classification remains controversial among experts.

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Habitat

Most nest in soil, excavating burrows in clay, sand, or loam. Some species nest in resembling ' housing estates' with many individual burrows clustered together. A minority nest in rotten logs or other decaying wood. Found in diverse environments from prairies and meadows to forest edges and urban areas.

Distribution

Worldwide distribution with on every continent except Antarctica. Particularly diverse in North America, Europe, and Australia. The subgenus Dialictus is especially abundant and commonly collected in North America.

Seasonality

Activity periods vary by and region. Many species are active from spring through late summer. In temperate regions, some species emerge in mid-April with males typically appearing before females.

Diet

Most are polylectic () foragers, collecting pollen and nectar from diverse floral sources. Some species are oligolectic, specializing on particular plant or . of many species are attracted to human sweat for salts and minerals.

Host Associations

  • Nomada - Nomad bees parasitize Lasioglossum nests, laying in
  • Sphecodes - Blood bees are kleptoparasites of Lasioglossum and other halictids
  • Halictoxenos borealis - Strepsipteran that manipulates to facilitate larval release

Life Cycle

Nests are excavated by females, with provisioned with pollen and nectar before laying. Some are solitary with each female founding her own nest. Others are communal, sharing nest entrances while maintaining separate cells. Primitively eusocial species produce small numbers of that assist in provisioning. Colony sizes range from a single with fewer than four workers to large colonies exceeding 400 workers lasting five or six years.

Behavior

Social is extraordinarily variable across . Some species exhibit solitary nesting, others primitive eusociality with division of labor, and some are social or kleptoparasites. Males often patrol nesting seeking females. Some species are . Parasitized individuals show altered flower-visiting behavior, such as curling the against leaves to facilitate parasite larval release.

Ecological Role

Important of wild plants and crops. In agricultural systems, wild Lasioglossum contribute significantly to crop pollination services, though a small subset of common species provides most of this service. The represents a major component of biodiversity and serves as a model system for studying the evolution of social in insects.

Human Relevance

Contribute to crop pollination with economic value estimated at over $3,251 per hectare in some systems. Frequently encountered by humans due to attraction to sweat; generally harmless though females can sting if handled roughly. Important subjects for scientific research on social evolution and . Often overrepresented in bowl trap , complicating bee monitoring efforts.

Similar Taxa

  • HalictusAlso sweat bees in Halictidae; Halictus are generally medium-sized with brown or black coloration and pale abdominal banding, lacking the metallic coloration common in many Lasioglossum
  • AgapostemonRelated halictid sweat bees with brilliant metallic green or blue coloration; Agapostemon are generally larger and more uniformly metallic than most Lasioglossum
  • SyrphidaeHover flies frequently mistaken for sweat bees; flies have single pair of wings, short , and different structure

Misconceptions

Despite the name 'sweat bee,' these insects do not bite or sting aggressively; they seek sweat for minerals and salts. The common use of bowl traps in monitoring has created a misconception that Lasioglossum abundance in traps reflects their true abundance on flowers, when trap catches often poorly represent actual foraging .

More Details

Taxonomic challenges

Lasioglossum, particularly subgenus Dialictus, represents one of the greatest challenges in . identification requires examination of microscopic characters, and many species remain undescribed or poorly characterized.

Social evolution model system

The exhibits the full range of social organization found in bees, from solitary to complex eusociality, making it invaluable for studying the evolutionary origins and transitions of social .

Subgeneric classification

The is divided into two informal series (Lasioglossum and Hemihalictus) and numerous subgenera including Dialictus, Evylaeus, and others. Subgeneric classification remains controversial with ongoing disagreement about the number and boundaries of subgenera.

Sources and further reading