Members of the family Halictidae are commonly known as sweat bees. One hundred ten (110) species of halictid bees have been recorded in Pennsylvania [1]. Of these species, only three (Halictus tectus, Lasioglossum leucozonium, and Lasioglossum zonulum) are not native to North America (indicated by an asterisk; *). Worldwide, this family has over 4,470 species described [2].

General identifying morphological characters include:
- A strongly curved basal vein in the forewing
- A pair of grooves on their face (one below each antenna)
- Short tongue length
- Small to medium size
- Wide range of colors and patterns, but may appear wasp-like, nearly hairless, and often have black, brown, or metallic coloration (green, bronze, blue)
Nesting habitats
Bees in this family nest in burrows they dig in the ground or, less commonly, in decaying wood.
Sociality
Species of bees in this family may be solitary, communal, semi-social, or primitively eusocial (having less ridged social structures than fully eusocial bees). The level of sociality within a species can also vary based on the climate, season, and the location of their nest.
Other behavioral or biological traits
Halictidae is one of the most diverse bee families, in terms of behavior and biological traits. Even closely related species or groups of species can be very different! Notably, some species are specialists that only collect pollen from certain plant species, Most bees in this family store food for their young in their own nests, but others are social parasites or cleptoparasites. Parasitic bees invade and lay their eggs in the nest of another bee species. Either the adult parasite or their larva kills the host’s young in the nest. Then, the parasite’s larva eats the food that the host stored. In this way, social parasites and cleptoparasites take advantage of the other species’ efforts to build a nest and collect food.
Species list
A checklist of halictid bees recorded in Pennsylvania is presented below. For each species, we list the counties, date ranges, and the most recent years they have been collected or observed in the openly-accessible checklist [see 1].
Genus Agapostemon — 4 species
Agapostemon (Agapostemon) sericeus (Förster, 1771)
Agapostemon (Agapostemon) splendens (Lepeletier, 1841)
Agapostemon (Agapostemon) texanus Cresson, 1872
Agapostemon (Agapostemon) virescens (F., 1775)
Genus Augochlora — 1 species
Augochlora (Augochlora) pura pura (Say, 1837)
Genus Augochlorella — 2 species
Augochlorella aurata (Smith, 1853)
Augochlorella persimilis (Viereck, 1910)
Genus Augochloropsis — 2 species
Augochloropsis (Paraugochloropsis) metallica fulgida (Smith, 1853)
Augochloropsis (Paraugochloropsis) metallica sensu lato (F., 1793)
Augochloropsis (Paraugochloropsis) sumptuosa (Smith, 1853)
Genus Dieunomia — 1 species
Dieunomia (Dieunomia) heteropoda heteropoda (Say, 1824)
Genus Halictus — 5 species
Halictus (Nealictus) parallelus Say, 1837
Halictus (Odontalictus) ligatus Say, 1837
Halictus (Protohalictus) rubicundus (Christ, 1791)
Halictus (Seladonia) confusus confusus Smith, 1853
Halictus (Vestitohalictus) tectus Radoszkowski, 1876 *
Genus Lasioglossum — 72 species
Lasioglossum (Dialictus) albipenne (Robertson, 1890)
Lasioglossum (Dialictus) anomalum (Robertson, 1892)
Lasioglossum (Dialictus) bruneri (Crawford, 1902)
Lasioglossum (Dialictus) callidum (Sandhouse, 1924)
Lasioglossum (Dialictus) cattellae (Ellis, 1913)
Lasioglossum (Dialictus) cephalotes (Dalla Torre, 1896)
Lasioglossum (Dialictus) coeruleum (Robertson, 1893)
Lasioglossum (Dialictus) coreopsis (Robertson, 1902)
Lasioglossum (Dialictus) cressonii (Robertson, 1890)
Lasioglossum (Dialictus) dreisbachi (Mitchell, 1960)
Lasioglossum (Dialictus) georgeickworti Gibbs, 2011
Lasioglossum (Dialictus) gotham Gibbs, 2011
Lasioglossum (Dialictus) heterognathus (Mitchell, 1960)
Lasioglossum (Dialictus) hitchensi Gibbs, 2012
Lasioglossum (Dialictus) illinoense (Robertson, 1892)
Lasioglossum (Dialictus) imitatum (Smith, 1853)
Lasioglossum (Dialictus) izawsum Gibbs, 2011
Lasioglossum (Dialictus) katherineae Gibbs, 2011
Lasioglossum (Dialictus) laevissimum (Smith, 1853)
Lasioglossum (Dialictus) lineatulum (Crawford, 1906)
Lasioglossum (Dialictus) marinum (Crawford, 1904)
Lasioglossum (Dialictus) nigroviride (Graenicher, 1911)
Lasioglossum (Dialictus) oceanicum (Cockerell, 1916)
Lasioglossum (Dialictus) perpunctatum (Ellis, 1913)
Lasioglossum (Dialictus) rozeni Gibbs, 2011
Lasioglossum (Dialictus) simplex (Robertson, 1901)
Lasioglossum (Dialictus) smilacinae (Robertson, 1897)
Lasioglossum (Dialictus) timothyi Gibbs, 2010
Lasioglossum (Dialictus) trigeminum Gibbs, 2011
Lasioglossum (Dialictus) versans (Lovell, 1905)
Lasioglossum (Dialictus) versatum (Robertson, 1902)
Lasioglossum (Dialictus) weemsi (Mitchell, 1960)
Lasioglossum (Dialictus) zephyrus (Smith, 1853)
Lasioglossum (Dialictus) lionotus (Sandhouse, 1923)
Lasioglossum (Dialictus) leucocomus (Lovell, 1908)
Lasioglossum (Dialictus) pilosum (Smith, 1853)
Lasioglossum (Dialictus) pruinosum (Robertson, 1892)
Lasioglossum (Dialictus) michiganense (Mitchell, 1960)
Lasioglossum (Dialictus) platyparium (Robertson, 1895)
Lasioglossum (Dialictus) ellisiae (Sandhouse, 1924)
Lasioglossum (Dialictus) tegulare (Robertson, 1890)
Lasioglossum (Dialictus) abanci (Crawford, 1932)
Lasioglossum (Dialictus) admirandum (Sandhouse, 1924)
Lasioglossum (Dialictus) apocyni (Mitchell, 1960)
Lasioglossum (Dialictus) atwoodi Gibbs, 2010
Lasioglossum (Dialictus) ephialtum Gibbs, 2010
Lasioglossum (Dialictus) oblongum (Lovell, 1905)
Lasioglossum (Dialictus) obscurum (Robertson, 1892)
Lasioglossum (Dialictus) paradmirandum (Knerer & Atwood, 1966)
Lasioglossum (Dialictus) planatum (Lovell, 1905)
Lasioglossum (Dialictus) subviridatum (Cockerell, 1938)
Lasioglossum (Dialictus) taylorae Gibbs, 2010
Lasioglossum (Dialictus) viridatum (Lovell, 1905)
Lasioglossum (Evylaeus) cinctipes (Provancher, 1888)
Lasioglossum (Hemihalictus) birkmanni (Crawford, 1906)
Lasioglossum (Hemihalictus) foxii (Robertson, 1895)
Lasioglossum (Hemihalictus) inconditum (Cockerell, 1916)
Lasioglossum (Hemihalictus) macoupinense (Robertson, 1895)
Lasioglossum (Hemihalictus) nelumbonis (Robertson, 1890)
Lasioglossum (Hemihalictus) pectinatum (Robertson, 1890)
Lasioglossum (Hemihalictus) pectorale (Smith, 1853)
Lasioglossum (Lasioglossum) athabascense (Sandhouse, 1933)
Lasioglossum (Lasioglossum) coriaceum (Smith, 1853)
Lasioglossum (Lasioglossum) fuscipenne (Smith, 1853)
Lasioglossum (Lasioglossum) acuminatum McGinley, 1986
Lasioglossum (Lasioglossum) forbesii (Robertson, 1890)
Lasioglossum (Leuchalictus) leucozonium (Schrenk, 1781) *
Lasioglossum (Leuchalictus) zonulum (Smith, 1848) *
Lasioglossum (Sphecodogastra) truncatum (Robertson, 1901)
Lasioglossum (Sphecodogastra) comagenense (Knerer & Atwood, 1964)
Lasioglossum (Sphecodogastra) quebecense (Crawford, 1907)
Lasioglossum (Sphecodogastra) oenotherae (Stevens, 1920)
Genus Nomia — 1 species
Nomia (Acunomia) nortoni Cresson 1868
Genus Sphecodes — 22 species
Sphecodes confertus Say, 1837
Sphecodes clematidis Robertson, 1897
Sphecodes dichrous Smith, 1853
Sphecodes heraclei heraclei Robertson, 1897
Sphecodes minor Robertson, 1898
Sphecodes prosphorus Lovell & Cockerell, 1907
Sphecodes solonis Graenicher, 1911
Sphecodes antennariae Robertson, 1891
Sphecodes atlantis Mitchell, 1956
Sphecodes autumnalis Mitchell, 1956
Sphecodes banksii Lovell, 1909
Sphecodes coronus Mitchell, 1956
Sphecodes cressonii (Robertson, 1903)
Sphecodes galerus Lovell & Cockerell, 1907
Sphecodes illinoensis (Robertson, 1903)
Sphecodes levis Lovell & Cockerell, 1907
Sphecodes mandibularis Cresson, 1872
Sphecodes pimpinellae Robertson, 1900
Sphecodes smilacinae Robertson, 1897
Sphecodes townesi Mitchell, 1956
Sphecodes aroniae Mitchell, 1960
Sphecodes ranunculi Robertson, 1897
Additional information about species in this family is available at:
References
- Kilpatrick SK, Gibbs J, Mikulas MM, Spichiger S-E, Ostiguy N, Biddinger DJ, López-Uribe MM (2020) An updated checklist of the bees (Hymenoptera, Apoidea, Anthophila) of Pennsylvania, United States of America. Journal of Hymenoptera Research 77: 1–86. https://doi.org/10.3897/jhr.77.49622
- Ascher JS, Pickering J (2020) Discover Life bee species guide and world checklist (Hymenoptera: Apoidea: Anthophila). http://www.discoverlife.org/mp/20q?guide=Apoidea_species
Photo Credit
Insects Unlocked (Genus Nomia) & USGS Bee Inventory and Monitoring Lab (other genera)
How to Cite this Webpage
Kilpatrick SK, López-Uribe MM (2020) Halictidae. http://lopezuribelab.com/halictidae/
Updated 29 June 2020