Identification Summary: Small; uncommon; other than L. lustrans the only species in the East regularly with 2 submarginal cells, note that L. asteris may have 2 at times; completely black abdomen without any rim color and no hair also partially distinctive. There at least a few instances where L. anomalum has 3 instead of the usual 2 submarginals (sometimes with 2 on one side and 3 on the other).
Reprinted with permission from: Mitchell, T.B. 1960 Bees of the Eastern United States. North Carolina Agricultural Experiment Station Technical Bulletin No. 141.
FEMALE—Length 4.0—4.5 mm.; head and thorax dark olive green, abdomen piceous; pubescence short and inconspicuous, entirely pale, abdominal terga 4 and 5 largely bare; head slightly longer than broad; clypeus convex, projecting slightly below suborbital line, punctures rather deep and distinct, scattered and rather sparse, those on supraclypeal area fine and obscure; eyes slightly converging below; antennae much nearer each other than to eyes; cheeks subequal to eyes in width, shining below, hypostomal carinae parallel; punctures below ocelli fine and close but deep and distinct, becoming shallow and obscure on vertex, minute and indistinct on cheeks; scutum rather dull, with scattered, rather shallow punctures, these quite sparse in center of disc (much as in inconspicuus, fig. 99); scutellum closely punctate medially, very sparsely so on each side; pleura dull, finely rugosopunctate; dorsal area of propodeum finely striate, the striae not quite complete, lateral areas smooth and shining; wings hyaline, veins and stigma testaceous; tegulae testaceous; legs brownish, becoming somewhat more yellowish apically; abdominal terga smooth and somewhat shining, punctures exceedingly minute, sparse and obscure, apical margins rather broadly impressed, the more apical terga hyaline apically.
MALE—Length 3.5—4.0 mm.; head and thorax dark olive green, abdomen piceous; pubescence entirely pale, more copious on head and thorax than in female; length and breadth of head subequal; clypeus rather narrow, somewhat produced and convex; eyes strongly convergent below; antennae slightly nearer eyes than to each other, basal segment of flagellum subequal to pedicel, the following segments short, being only very slightly longer than broad, pale brownish; cheeks slightly narrower than eyes; punctures below ocelli very fine and close, but deep and distinct, becoming shallow and obscure on vertex and cheeks; scutum and scutellum somewhat shining, punctures scattered and irregular, rather sparse in center of discs; pleura somewhat shining, obscurely and closely punctate; dorsal area of propodeum finely striate, the striae nearly complete, lateral faces finely roughened but somewhat shining; wings hyaline, veins and stigma testaceous; tegulae pale ferruginous; basal segments of legs brownish, tarsal segments somewhat more yellowish; abdominal terga shining, minutely but quite closely and distinctly punctate except for the rather narrow apical margin of each tergum which is slightly depressed and entirely impunctate; sternum 5 very broadly incurved, median lobe of sternum 7 very narrow and elongate, parallel-sided; gonostylus of armature as shown (fig. 102), retrorse lobe rather short, narrowed apically, finely short pubescent.
DISTRIBUTION—Minnesota to New York, south to Alabama and Georgia; May to September.
FLOWER RECORDS—Ceanothus, Houstonia purpurea and Solidago. Robertson (1929) records anomalus on Aster, Capsella and Hypoxis.
This species differs from all of the other eastern species so far recorded in having but two submarginal cells in the front wing.
Retrieved from: Gibbs, J. 2010. Revision of the metallic species of Lasioglossum (Dialictus)in Canada (Hymenoptera, Halictidae, Halictini). Zootaxa; 2591, 66-69
Halictus anomalus Robertson, 1892: 272. ♀.
Lectotype. ♀ USA, Illinois, Carlinville, 19.v. (C. Robertson); [INHS: 179,603] by W.E. LaBerge. Examined.
Taxonomy. Robertson, 1902: Dialictus anomalus ♂, p. 48 (description); Michener, 1951: Lasioglossum
(Dialictus) anomalum, p. 1119 (catalogue); Mitchell, 1960: Dialictus anomalus ♀♂, p. 379 (redescription);
Krombein, 1967: Lasioglossum (Dialictus) anomalum, p. 462 (catalogue); Hurd, 1979: Dialictus anomalus, p.
1964 (catalogue); Moure & Hurd, 1987: Dialictus anomalus, p. 89 (catalogue).
Diagnosis. Lasioglossum anomalum and L. occidentale can be recognised by the absence of vein 1rs-m
resulting in only two submarginal cells (Fig. 2B). Some individuals of L. asteris also share this trait but are
easily distinguished by their parasitic characters (see L. asteris below). Lasioglossum anomalum has a green
head and mesosoma, a short face (length/width ratio = 0.95–1.00), faintly dusky wings and the apical half of
T2–T3 nearly impunctate. Lasioglossum occidentale has a blue head and mesosoma, a longer face (length/
width ratio = 1.00–1.05), pale, hyaline wings and, at most, the apical impressed margin of T2–T3 impunctate.
Redescription. FEMALE. Length 4.15–4.64 mm; head length 1.22–1.27 mm; head width 1.27–1.34 mm;
forewing length 3.05–3.23 mm.
Colouration. Head and mesosoma green with bluish reflections. Clypeus with apical half blackish brown,
basal half, and supraclypeal area brassy. Antenna dark brown, flagellum with ventral surface light brown, F8–
F10 with ventral surface orange. Mesoscutum with brassy reflections. Tegula reddish amber. Wing membrane
subhyaline, venation and pterostigma brownish amber. Metasoma dark brown, terga and sterna with apical
margins reddish to translucent yellowish brown.
Pubescence. Dull white. Sparse. Head and mesosoma with sparse woolly hairs (1 OD), longest on genal
beard, metanotum and mesopleuron (1.5–2.5 OD). Lower paraocular area without tomentum. Propodeum
with sparse plumose hairs on lateral and posterior surfaces (1–2 OD). Metasomal terga with sparse, fine setae.
T1 acarinarial fan small, widely spaced appressed hairs, not at all encircling the central area. Metasomal terga
without appressed tomentum.
Surface sculpture. Face imbricate, punctation strong. Clypeus polished, basal margin imbricate, punctation
moderately sparse (i=1–3d). Supraclypeal area with punctation sparse (i=1–2.5d). Lower paraocular area
punctation dense (i≤d). Antennocular area punctation moderately sparse (i=1–2d). Upper paraocular area and
frons reticulate-punctate. Ocellocular area punctate (i≤d). Gena and postgena imbricate. Mesoscutum imbricate,
punctation moderately coarse, moderately sparse between parapsidal lines (i=1–1.5d), close laterad of
parapsidal lines (i≤d), contiguous on anterolateral portion. Mesoscutellum polished, punctation similar to
mesoscutum, submedial punctation sparse (i=2–5d). Axilla punctate. Metanotum imbricate. Preëpisternum
and mesepisternum strongly imbricate/weakly rugulose between close punctures (i
Structure. Head wide (length/width ratio = 0.95–0.96). Eyes convergent below (UOD/LOD ratio = 1.25–
1.31). Clypeus ˝ below suborbital tangent, apicolateral margins convergent. Antennal sockets close (IAD/
OAD < 0.5). Frontal line carinate, ending 2 OD below median ocellus. Gena narrower than eye. Vein 1rs-m
absent. Inner metatibial spur pectinate with 3–4 teeth. Metapostnotum moderately elongate (MMR ratio =
1.26–1.35), posterior margin weakly angled onto posterior surface. Propodeum with oblique carina fine but
distinct, lateral carina nearly reaching dorsal margin.
MALE. Similar to female except for the usual secondary sexual characters and as follows. Length 4.15–
5.31 mm; head length 1.15–1.34 mm; head width 1.20–1.34 mm; forewing length 2.99–3.42 mm.
Colouration. Flagellum with ventral surface brown. Tarsi reddish brown.
Pubescence. Face not obscured by tomentum. S2–S3 with sparse, erect hairs (1–1.5 OD). S4–S5 apicolateral
portions with more dense erect hairs (1–1.5 OD).
Surface sculpture. Hypoepimeral area and mesepisternum punctation more distinct and coarser (i≤d).
Structure. Head wide to round (length/width ratio = 0.96–1.00). Eyes strongly convergent below (UOD/
LOD ratio = 1.52–1.57). Antennal sockets distant (IAD/OAD > 1.1). Frontal line carinate, ending 2.5 OD
below median ocellus. Pedicel longer than F1. F2 length 1.2–1.4X F1. F2–F10 short (length/width ratio =
1.09–1.25). Metapostnotum truncate (MMR ratio = 1.35–1.38), posterior margin weakly angled onto posterior
Terminalia. S7 with median lobe narrowly clavate, apex rounded. S8 with apicomedial margin strongly
convex. Genitalia as in Fig. 72D–E. Gonobase with ventral arms narrowly separated. Gonostylus small, dorsal
setae elongate. Retrorse lobes short and broad.
Range. Ontario west to Minnesota, south to Colorado, Indiana and Iowa
Extracted from Jason Gibbs. 2011. Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini.) Zootaxa.
Lasioglossum (Dialictus) anomalum (Robertson)
Halictus anomalus Robertson, 1892: 272. ♀.
Lectotype. ♀ USA, Illinois, Macoupin Co., Carlinville, 19.v.1891 (C. Robertson); [INHS: 11111] by W. E. LaBerge (in
Webb 1980). Examined.
Taxonomy. Robertson, 1902a: Dialictus anomalus ♂, p. 48 (description); Sandhouse, 1923: Dialictus anomalus, p. 193
(key); Michener, 1951: Lasioglossum (Dialictus) anomalum, p. 1119 (catalogue); Mitchell, 1960: Dialictus anomalus
♀♂, p. 379 (redescription, key); Krombein, 1967: Lasioglossum (Dialictus) anomalum, p. 462 (catalogue); Hurd, 1979:
Dialictus anomalus, p. 1964 (catalogue); Moure & Hurd, 1987: Dialictus anomalus, p. 89 (catalogue); Gibbs, 2010b:
Lasioglossum (Dialictus) anomalum ♀♂, p. 66 (redescription, key).
Diagnosis. Both sexes of L. anomalum can be recognised by the absence of vein 1rs-m resulting in two submarginal
cells. Some individuals of L. lionotum also have two submarginal cells but are easily distinguished by their parasitic characteristics
(see diagnosis for L. lionotum below). Lasioglossum anomalum are small, with mesoscutal punctures sparse
between parapsidal lines, mesepisternal with contiguous punctures, T2 impunctate on apical half (except along premarginal
line), and metasomal terga without tomentum. Male L. lionotum have the flagellomeres short (length/width ratio =
1.09–1.25), and gonostylus with elongate, medially directed hairs.
Range. Ontario west toColorado, south to Alabama. USA: AL, CO, CT, GA, IL, IN, IA, MA, MI, MN, MO, NC,
NE, NY, VT, WI. CANADA: ON.
DNA Barcode. Available. Multiple sequences.
Comments. Common. Gibbs (2010b) reported a less southerly range for L. anomalum but additional material has
since been identified from CUIC.
Lasioglossum anomalum is the type species for Dialictus.
Several individuals of L. anomalum with three submarginal cells in one or both wings have been examined (Gibbs
2010c), including one of the paratypes at INHS.