Members of the family Apidae are commonly known as honey bees, bumble bees, carpenter bees, long-horned bees, squash bees, digger bees, cuckoo bees, stingless bees, and orchid bees. One hundred eighteen (118) species of apid bees have been recorded in Pennsylvania [1]. Of these species, only two (Apis mellifera – the European honey bee, and Anthophora villosula) are not native to North America (indicated by an asterisk; *). This family contains five species of conservation concern in Pennsylvania: Bombus affinis – the rusty patched bumble bee (endangered), Bombus fervidus – the yellow bumble bee (declining), Bombus pensylvanicus – the American bumble bee (declining), Bombus terricola – the yellow banded bumble bee (declining), and Epeoloides pilosulus (rare within its range since the 1960s) (indicated by orange text). Worldwide, this family has over 5,920 species described [2].

General identifying morphological characters include:

  • Three submarginal cells on the forewing
  • Long tongue length
  • Small to very large size
  • Wide range of colors and patterns
  • Many species are covered in hairs and have structures on their hind legs for carrying pollen, resin, and/or oils

Nesting habitats

Bees in this family have a wide range of nesting habits. Solitary species often nest in tunnels that they dig in the ground or construct in wood. Others nest in cavities, including honey bees and bumble bees, with honey bees typically preferring trees/buildings while bumble bees prefer underground spaces or dense clumps of vegetation. 


Most species in this family are solitary or semi-social. Carpenter bees (Ceratina and Xylocopa spp.) may be solitary or exhibit cooperative breeding with a weak social structure. A few groups are primitively eusocial (most species of bumble bees, Bombus spp.) or fully eusocial (honey bees, Apis spp.). 

Other behavioral or biological traits

Apidae is one of the most diverse 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, while others are broad generalists that collect pollen from many different types of plants. 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 apid 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 Anthophora — 5 species

Anthophora (Anthophora) villosula Smith, 1854 *

Anthophora (Clisodon) terminalis Cresson, 1869

Anthophora (Lophanthophora) ursina Cresson, 1869

Anthophora (Melea) abrupta Say, 1837

Anthophora (Melea) bomboides Kirby, 1837

Genus Apis — 1 species

Apis (Apis) mellifera mellifera (L., 1758) *

Genus Bombus — 18 species

Bombus (Bombias) auricomus (Robertson, 1903)

Bombus (Bombus) affinis Cresson, 1863

Bombus (Bombus) terricola Kirby, 1837

Bombus (Cullumanobombus) griseocollis (DeGeer, 1773)

Bombus (Cullumanobombus) rufocinctus Cresson, 1863

Bombus (Psithyrus) ashtoni (Cresson, 1864)

Bombus (Psithyrus) citrinus (Smith, 1854)

Bombus (Psithyrus) insularis (Smith, 1861)

Bombus (Psithyrus) fernaldae (Franklin, 1911)

Bombus (Pyrobombus) perplexus Cresson, 1863

Bombus (Pyrobombus) bimaculatus Cresson, 1863

Bombus (Pyrobombus) impatiens Cresson, 1863

Bombus (Pyrobombus) ternarius Say, 1837

Bombus (Pyrobombus) sandersoni Franklin, 1913

Bombus (Pyrobombus) vagans vagans Smith, 1854

Bombus (Subterraneobombus) borealis Kirby, 1837

Bombus (Thoracobombus) fervidus (F., 1798)

Bombus (Thoracobombus) pensylvanicus (DeGeer, 1773)

Genus Ceratina — 5 species

Ceratina (Zadontomerus) calcarata Robertson, 1900

Ceratina (Zadontomerus) dupla Say, 1837

Ceratina (Zadontomerus) floridana Mitchell, 1962

Ceratina (Zadontomerus) mikmaqi Rehan & Sheffield, 2011

Ceratina (Zadontomerus) strenua Smith, 1879

Genus Epeoloides — 1 species

Epeoloides pilosulus (Cresson, 1878)

Genus Epeolus — 6 species

Epeolus americanus (Cresson, 1878)

Epeolus autumnalis Robertson, 1902

Epeolus bifasciatus Cresson, 1864

Epeolus lectoides Robertson, 1901

Epeolus pusillus Cresson, 1864

Epeolus scutellaris Say, 1824

Genus Eucera — 6 species

Eucera (Cemolobus) ipomoeae (Robertson, 1891)

Eucera (Peponapis) pruinosa (Say, 1837)

Eucera (Synhalonia) atriventris (Smith, 1854)

Eucera (Synhaloniadubitata (Cresson, 1878)

Eucera (Synhaloniahamata (Bradley, 1942)

Eucera (Synhaloniarosae (Robertson, 1900)

Genus Habropoda — 1 species

Habropoda laboriosa (F., 1804)

Genus Holcopasites — 2 species

Holcopasites calliopsidis calliopsidis (Linsley, 1943)

Holcopasites illinoiensis (Robertson, 1891)

Genus Melecta — 1 species

Melecta (Melecta) pacifica Cresson, 1878

Genus Melissodes — 16 species

Melissodes (Apomelissodes) apicatus Lovell & Cockerell, 1906

Melissodes (Apomelissodes) fimbriatus Cresson, 1878

Melissodes (Eumelissodes) agilis Cresson, 1878

Melissodes (Eumelissodes) boltoniae Robertson, 1905

Melissodes (Eumelissodes) denticulatus Smith, 1854

Melissodes (Eumelissodes) dentiventris Smith, 1854

Melissodes (Eumelissodes) druriellus (Kirby, 1802)

Melissodes (Eumelissodes) fumosus LaBerge, 1961

Melissodes (Eumelissodes) illatus Lovell & Cockerell, 1906

Melissodes (Eumelissodes) niveus Robertson, 1895

Melissodes (Eumelissodes) subillatus LaBerge, 1961

Melissodes (Eumelissodes) trinodis Robertson, 1901

Melissodes (Heliomelissodes) desponsus Smith, 1854

Melissodes (Melissodes) bimaculatus bimaculatus (Lepeletier, 1825)

Melissodes (Melissodescommunis communis Cresson, 1878

Melissodes (Melissodestepaneca Cresson, 1878

Genus Melitoma — 1 species

Melitoma taurea (Say, 1837)

Genus Nomada — 39 species

Nomada affabilis Cresson, 1878

Nomada articulata Smith, 1854

Nomada australis Mitchell, 1962

Nomada rubicunda Olivier, 1812

Nomada placida Cresson, 1863

Nomada armatella Cockerell, 1903

Nomada bethunei Cockerell, 1903

Nomada ceanothi Cockerell, 1907

Nomada composita Mitchell, 1962

Nomada cressonii Robertson, 1893

Nomada denticulata Robertson, 1902

Nomada depressa Cresson, 1863

Nomada fragariae Mitchell, 1962

Nomada gracilis Cresson, 1863

Nomada illinoensis Robertson, 1900

Nomada imbricata Smith, 1854

Nomada integerrima Dalla Torre, 1896

Nomada lehighensis Cockerell, 1903

Nomada luteola Olivier, 1812

Nomada luteoloides Robertson, 1895

Nomada obliterata Cresson, 1863

Nomada parva Robertson, 1900

Nomada pygmaea Cresson, 1863

Nomada sayi Robertson, 1893

Nomada skinneri Cockerell, 1908

Nomada sulphurata Smith, 1854

Nomada ulsterensis Mitchell, 1962

Nomada valida Smith, 1854

Nomada vicina Cresson, 1863

Nomada xanthura Cockerell, 1908

Nomada bella Cresson, 1863

Nomada cuneata (Robertson, 1903)

Nomada lepida Cresson, 1863

Nomada maculata Cresson, 1863

Nomada ovata (Robertson, 1903)

Nomada perplexa Cresson, 1863

Nomada superba Cresson, 1863

Nomada fervida Smith, 1854

Nomada tiftonensis Cockerell, 1903

Genus Ptilothrix — 1 species

Ptilothrix bombiformis (Cresson, 1878)

Genus Svastra — 2 species

Svastra (Anthedonia) compta (Cresson, 1878)

Svastra (Epimelissodes) obliqua caliginosa (Cresson, 1878)

Genus Triepeolus — 12 species

Triepeolus atripes Mitchell, 1962

Triepeolus concavus (Cresson, 1878)

Triepeolus donatus (Smith, 1854)

Triepeolus helianthi (Robertson, 1897)

Triepeolus lunatus (Say, 1824)

Triepeolus nevadensis (Cresson, 1878)

Triepeolus pectoralis (Robertson, 1897)

Triepeolus quadrifasciatus atlanticus Mitchell, 1962

Triepeolus remigatus (F., 1804)

Triepeolus rhododontus Cockerell, 1921

Triepeolus rugosus Mitchell, 1962

Triepeolus simplex Robertson, 1903

Genus Xylocopa — 1 species

Xylocopa (Xylocopoides) virginica virginica (L., 1771)

Additional information about species in this family is available at:


  1. 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.
  2. Ascher JS, Pickering J (2020) Discover Life bee species guide and world checklist (Hymenoptera: Apoidea: Anthophila).

Photo Credit
USGS Bee Inventory and Monitoring Lab

How to Cite this Webpage
Kilpatrick SK, López-Uribe MM (2020) Apidae.

Updated 29 June 2020