Halictidae

1
Halictidae

• A guide to their Identification in Eastern North
  America

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Acknowledgements

• This presentation has been put together by a
  consortium of North American bee biologists
• This presentation has developed over many years
  and the original web picture acknowledgements
  were lost, if you see one of your pictures let us
  know and we will add your picture credit
• Correspondence can be sent to Sam Droege at
  sdroege_at_usgs.gov

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Format

• Each Genus has an information page followed by a
  page of illustrations and a map of the
  distribution of Eastern North American species
  western populations of Eastern species are shown,
  but the Western species are not mapped.
• The number of Eastern species are listed at the
  top of the page

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Halictidae Groups of Genera

• Agapostemon 4 species
• Augochlora pura - 1
• Augochlorella - 3
• Augochloropsis - 3

• Halictus 6
• Lasioglossum 115 or so
• Sphecodes 34 or so
• Dieunomia - 3
• Nomia - 2
• Dufourea - 3

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Agapostemon

• Larger than the other bright green halictids
• Has a prominent raised line or carina that
  circles the OUTSIDE of the rear face of the
  propodeum
• Males with alternating bands of black and yellow
  on the abdomen
• Common in fields, much less common in urban areas
• A. virescens is usually the most common and
  females easy to identify because of its black
  abdomen (the others are green)
• Males and green females take some practice to
  differentiate due to often subtle differences
• Similar genera Augochlora, Augochlorella,
  Augochloropsis

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Agapostemon 4 Biggest of the green bees
Female
Common Fields
Male
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Augochlora pura

• Common, particularly in wooded regions, nests in
  decaying logs
• Shape and color (all black) of the tip of the
  females mandibles is distinctive
• Rim of S4 in the males is straight across unlike
  the concave or emarginate shape of S4 in
  Augochlorella, its most common look-alike
• Clipped tip of the marginal cell is useful when
  processing many specimens, but Augochloropsis
  also has this feature
• Similar genera Augochlorella, Augochloropsis,
  Agapostemon

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Augochlora pura Woodlands and edges
Common, trimmed tip of marginal cell
Male
Female
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Augochlorella

• Usually the most common bright green bee
• A. aurata, the most common, but care must be
  taken to pull out the other 2 species where their
  ranges overlap
• The smallest of all the green Halictids
• Males have a concave S4 rim
• Tip of marginal cell lays directly on the rim, a
  good character for sorting out the common green
  bees
• Similar genera Augochlora, Augochloropsis,
  Agapostemon

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Augochlorella In Every Field - 3
Way Abundant!
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Augochloropsis

• Regular, but usually the least common of the
  bright green bees
• Some species and individuals can take on distinct
  blue/purple metallic overtones
• A. metallica is the most common, but recent
  genetic analyses indicate that there is more than
  one species involved
• The non-oval tegula is distinctive and easy to
  see
• The band of straight hairs (fimbria) fringing the
  rims of the tergites is usually distinctive in
  most specimens, but can be very sparse in some
• Tip of marginal cell is trimmed similar to
  Augochlora pura
• Similar genera Agapostemon, Augochlorella,
  Augochlora

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Augochloropsis Least Common - 3 Green Bee
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Halictus

• Some of the most common bees, usually associated
  with fields
• The large headed H. ligatus and its look-alike H.
  poeyi have distinct projections on their lower
  cheeks that makes identification easy
• Because H. confusus is a dull metallic green
  rather than black or brown it is often confused
  with Lasioglossum species in the Dialictus group
• Told from Lasioglossum by having all of the
  crossveins of the submarginal cells being the
  same thickness and having the short, thick,
  white, appressed hairs that lie on the surface of
  the abdomen originating on the RIM of the
  tergites rather than from the base
• Similar genera Lasioglossum

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Halictus Every Open Place - 6
Abundant
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Lasioglossum

• Overall the most common group of bees encountered
  when using bowl traps, because they are very
  small they are often netted at relatively lower
  numbers
• Many of the most common species are only 4-6mm in
  size
• All species have at least the outermost crossvein
  in the outer submarginal cell thinner or weaker
  than the other veins unfortunately, in males
  this character is much less clear
• Told from Halictus by the weakened crossvein(s)
  of the submarginal cells and having the short,
  thick, white, appressed hairs that lie on the
  surface of the abdomen originating on the BASE of
  the tergites rather than from the rim, often this
  results in a band of white hairs emerging from
  UNDERNEATH the rim of the preceding segment
• Some species, however, lack these appressed hairs
  completely
• This group is being revised and several species
  changes will be made over the coming years
• Similar genera Halictus

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Lasioglossum Groups

• There are several groups within Lasioglossum
  that, in the past, have, at times, been given
  genera status
• Sensu strictu Very large, Black, one weakened
  crossvein
• Evylaeus Black, 2 weakened crossveins
• Dialictus Blue, green, gold, 2 weakened
  crossveins, identification to species often
  difficult
• Paralictus Blue or green, parasitic, 2 weakened
  crossveins
• Sphecodogastra Black, Oenothera specialists,
  sparse scopal hairs
• Hemihalictus 2 submarginal cells

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Lasioglossum - 115
Abundant, many species, everywhere, difficult ids
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You too can see weak veins OK maybe not In
this male only the last vein is weakened and its
hard to detect
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Some Black Lasioglossums
Evylaeus Group
Evylaeus Group
Sensu Strictu Group
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Sphecodes

• All species are regular but uncommon and
  parasitic on other Halictid species
• While the females do not have pollen carrying
  hairs per se, their rear legs contain a fair
  amount of short hair which upon very close
  inspection often contain small short spines along
  the length of the tibia
• Almost all of the females are characterized by a
  red to orange-red abdomen, however, many males
  are entirely black, but can be told by heavy
  surface sculpturing and widely spaced antennae
• None of the species have the small, thick, white,
  appressed hairs found in Halictus and
  Lasioglossum
• All wing veins are the same thickness (strong) in
  a similar way to Halictus
• Identification to species is difficult and
  several taxonomic issues at the species level
  remain unresolved
• This group is being revised and several species
  changes will be made over the coming years
• Similar genera Lasioglossum, Halictus

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Sphecodes 34 - Lasioglossum parasite
ALMOST all with red red abdomen
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Dufourea

• Extremely uncommon group of species in the East
• The low placement of the antennae on the face is
  distinctive, particularly in conjunction with the
  wide clypeus
• Has a pre-episternal groove, which most other
  species lack but unfortunately is often difficult
  to see
• Similar genera Halictus

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Dufourea - 3
Uncommon plant specialists
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Dieunomia

• Uncommon to rare group of summer and fall species
• Very large, the size of bumblebees
• Often specialists on composites such as
  sunflowers and almost always associated with
  sandy soils
• The arched basal vein so prominent in most of the
  other genera of Halictids is weak to absent
• Males have greatly modified legs with flanges and
  extensions to the normal tibia shape,
  consequently, often mistaken for wasps
• Females have non-oval tegulae and often have
  scopal hairs on the underside of their abdomen in
  addition to those on their legs
• Similar genera Andrena, Melitta

25
Dieunomia - 3
Sand specialists, large uncommon, composites
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Nomia

• Uncommon to rare group of species in the East
• The mother-of-pearl band along the rims of the
  tergal segments is distinctive
• Some males have expanded and flanged tibiae
  similar to Dieunomia
• Similar genera None

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Nomia Pearl Rims - 2
Southern, uncommon
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Resources

• Species lists, Identification Guides, and Maps
  for genera and species are available at
• http//www.discoverlife.org/20/q?searchApoidea
• A guide to the genera of the bees of Canada is
  available at
• http//www.biology.ualberta.ca/bsc/ejournal/pgs_03
  /pgs_03.html
• Mitchells 1960s books on the bees of the
  Eastern United States is available as a series of
  pdf files at
• http//insectmuseum.org/easternBees.php
• A slightly out of date guide to the
  identification of the genera of ALL of North and
  Central America is available at
• http//www.knoxcellars.com/Merchant5/merchant.mvc?
  ScreenPRODStore_CodeKCNPProduct_CodeBGNACate
  gory_CodeBL