Identification Summary: Most of what had been called this species recently has actually been L. atlanticum; L. admirandum has an open T1 fan; for now this species, and L. perspicuum, L. paradmirandum, and L. viridatum are currently considered indistinguishable and are refered to collectively as L. viridatum group.
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 5-5.5 mm.; head and thorax dull green or greenish-blue, abdomen dark, with metallic reflections; pubescence very short and thin, entirely pale; head slightly broader than long; clypeus slightly convex, rather broad, projecting about one-half below suborbital line; supraclypeal area considerably broader than long, much shorter than clypeus; eyes convergent below; lateral ocelli very slightly nearer eyes than to each other; cheeks subequal to eyes in width; face below ocelli somewhat shining, punctures very minute, close but obscure, vertex laterally more shining, punctures obscure; cheeks above shining, very minutely and obscurely punctate, shining and finely roughened below; hypostomal carinae sub- parallel; lower half of face somewhat shining, punctures minute and obscure, rather close, those on supraclypeal area somewhat more distinct, but very minute, well separated; upper margin of clypeus nearly impunctate, with a few subapical, scattered, fine punctures visible; scutum and scutellum rather dull, punctures very fine, well separated in center of disc (somewhat closer than in rohweri, fig. 99), becoming quite close laterally; pleura somewhat shining, more or less rugose above and anteriorly, smoother but dull posteriorly; dorsal area of propodeum regularly and completely striate, lateral faces smooth and shining; wings whitish-hyaline, veins and stigma yellowish; tegulae yellowish-hyaline; legs brownish-testaceous, becoming somewhat more yellowish apically; abdomen shining, punctures exceedingly minute and obscure, hardly visible, terga narrowly impressed apically, this area yellowish-hyaline, the more apical terga thinly clothed with pale tomentum.
DISTRIBUTION—Minnesota to Nova Scotia, south to Louisiana and Florida; March to September.
FLOWER RECORDS—Agastache, Althaea, Antennaria, Anthemis, Apocynum, Asclepias, Aster, Baptisict, Barbarea, Brassica, Ceanothus, Cirsium, Claytonia, Daucus, Erynglum, Fagopyrum, Gladiolus, Gypsophila, Helenium, Hydrangea, Hypericum, Isopappus, Koellia, Leucothoe, Lotus, Malus, Medicago, Melilotus, Nepeta, Oxypolis, Paeonict, Pastinaca, Phaseolus, Plantago, Polygonum, Potentilla, Prunus, Ptilimnium, Pycnctnthemum, Pyraeanthca, Raphanus, Robinia, Rorippa, Rosa, Rubus, Rudbeckia, Salix, Salvia, Senecio, Solidago, Splraea, Symplocos, Taraxacum, Trifolium, Vaccinium, Vernonia, Viburnum and Vicia.
This species is subject to a considerable range of variation which does not appear to have any relation to distribution. The type specimen (U.S.N.M. No. 26405) is 5 mm. in length, but this varies from 4 to 6 mm. in the long series of specimens at hand. The pleura in the type are subrugose anteriorly, becoming smooth and finely tessellate posteriorly. In other specimens the pleura are sometimes quite shiny, sometimes finely striate, and in others densely tessellate. The third and fourth abdominal terga are covered with yellowish tomentum in the type, this not completely hiding the surface. In others these plates may be more densely tomentose, or may be nearly bare, and the apical margins may be bright yellow or rather dark. The type is quite blue in color, but numerous specimens in the series at hand agree in this respect.
There is a possibility that two or more species compose this complex. Discovery of the male or males and some knowledge of the biology may give an answer.
Retrieved from: Gibbs, J. 2010. Revision of the metallic species of Lasioglossum (Dialictus)in Canada (Hymenoptera, Halictidae, Halictini). Zootaxa; 2591, 52-56
Halictus (Chloralictus) admirandus Sandhouse, 1924: 14. ♀.
Holotype. ♀ USA, Woods Hole, Massachusetts (E. Cattell), [NMNH: 26405]. Examined.
Dialictus perspicuus Knerer and Atwood, 1966a: 883. ♀ ♂. [new synonymy]
Holotype. ♀ CANADA, Ontario, Iona, Elgin Co., 15.ix.1963 on Solidago, (G. Knerer); [ROM: 83647]. Examined.
Taxonomy. Michener, 1951: Lasioglossum (Chloralictus) admirandum p. 1111 (catalogue); Mitchell, 1960:
Dialictus admirandus ♀, p. 377 (redescription); Krombein, 1967: Lasioglossum (Dialictus) admirandum, p.
462 (catalogue); Hurd, 1979: Dialictus admirandus, p. 1963, D. perspicuus, p. 1970 (catalogue); Moure &
Hurd, 1987: Dialictus admirandus, p. 88, D. perspicuus, p. 121 (catalogue).
Diagnosis. Females of L. admirandum can be recognised by the diagnostic combination of a moderately
elongate head (length/width ratio = 0.95–1.01), densely tessellate mesoscutum with sparse punctures on centre
of disc (i=1–3d), pale translucent brownish yellow tegula, weakly rugulose mesepisternum, incomplete
rugae on metapostnotum, T1 acarinarial fan incomplete dorsally and metasomal terga polished, brown, with
distinct punctures throughout and T3–T4 with abundant tomentum. Females of this species are most similar to
L. paradmirandum and L. sagax. Female L. paradmirandum have the mesepisternum tessellate and declivitous
portions of T1 distinctly coriarious. Female L. sagax have the apical half of T2 nearly impunctate.
Males of L. admirandum are similar to females but have longer heads (length/width ratio = 1.01–1.04)
and may be further distinguished by a yellow band on the apex of the clypeus, abundant tomentum on face
obscuring surface, elongate flagellomeres (length/width ratio = 1.57–1.82), extensive yellow on tibial apices
and bases, and apical impressed areas of metasomal terga impunctate. Males of this species are most similar to
L. sagax which differ in having the mesoscutum moderately polished due to weak microsculpture.
Redescription. FEMALE. Length 5.00–6.50 mm; head length 1.51–1.63 mm; head width 1.55–1.69 mm;
forewing length 3.97–4.45 mm.
Colouration. Head and mesosoma bluish green to blue. Clypeus with apical half blackish brown. Antenna
dark brown, flagellum with ventral surface reddish brown. Mesoscutum golden green. Tegula brownish yellow
to pale yellow. Wing membrane subhyaline, venation and pterostigma pale brownish yellow. Legs brown,
medio- and distitarsi reddish brown. Metasoma dark brown, terga and sterna with apical margins translucent
Pubescence. Dull white. Moderately dense. Head and mesosoma with moderately sparse woolly hairs (1–
2 OD), longest on genal beard, metanotum and mesopleuron (2–2.5 OD). Lower paraocular area and gena
with sparse tomentum not obscuring surface. Propodeum with plumose hairs on lateral and posterior surfaces
(2–2.5 OD). Metasomal terga with moderately sparse, fine setae. T1 acarinarial fan with wide dorsal opening,
equal to width of lateral hair patches. T2 with basolateral and T3–T5 with moderately dense tomentum partially
obscuring surface. T2 apicolateral and T3–T4 apical margins with weak fringes.
Surface sculpture. Face weakly imbricate, punctation moderately strong. Clypeus with apical half polished,
punctation moderately sparse (i=1–3d). Supraclypeal area with punctation moderately dense (i=1–2d),
medial line punctate. Lower paraocular area punctation dense (i≤d). Antennocular area punctation moderately
dense (i=1–1.5d). Upper paraocular area and frons reticulate-punctate. Ocellocular area minutely punctate
(i≤d). Gena lineolate. Postgena polished, weakly lineolate. Mesoscutum imbricate-tessellate, punctation moderately
coarse and deep, sparse between parapsidal lines (i=1–3d), dense laterad of parapsidal line (i≤d), and
punctate-reticulate on anterolateral portions. Mesoscutellum weakly imbricate, submedial punctation moderately
sparse (i=1–2d). Axilla punctate. Metanotum ruguloso-imbricate. Preëpisternum weakly rugulose.
Hypoepimeral area imbricate. Mesepisternum dorsal half weakly ruguloso-imbricate, ventral half imbricate,
obscurely punctate. Metepisternum with dorsal third rugoso-striate, ventral portion imbricate. Metapostnotum
incompletely rugoso-striate, posterior margin imbricate. Propodeum with dorsolateral slope and lateralsurface weakly ruguloso-imbricate, posterior surface ruguloso-tessellate. Metasomal terga highly polished,
very weakly coriarious, punctation on basal halves moderately dense (i=1–1.5d), sparse on apical halves
Structure. Head wide to round (length/width ratio = 0.95–1.01). Eyes convergent below (UOD/LOD ratio
= 1.27). Clypeus 2/3 below suborbital tangent, apicolateral margins convergent. Antennal sockets close (IAD/
OAD < 0.5). Frontal line carinate, ending 2.5 OD below median ocellus. Gena narrower than eye. Inner metatibial
spur pectinate with 4 teeth. Metapostnotum moderately elongate (MMR ratio = 1.25), posterior margin
weakly angled onto posterior surface. Propodeum with oblique carina very weak, lateral carina weak, not
reaching dorsal margin.
MALE. Similar to female except for the usual secondary sexual characters and as follows. Length 5.00–
6.10 mm; head length 1.45–1.63 mm; head width 1.44–1.55 mm; forewing length 3.54–3.90 mm.
Colouration. Labrum yellow. Mandible yellow, apex red, base blackish brown. Clypeus distal margin yellow.
Flagellum with ventral surface reddish brown. Legs brown, protibia (sometimes all tibiae) yellow except
anterior and posterior surface with brown patch; mesotibia yellow except outer surface mostly brown; metatibial
base, apex and dorsal surface yellow; tarsi yellow.
Pubescence. Face below eye emargination moderately dense partially obscuring surface. Lower paraocular
area with dense tomentum obscuring surface. S3 apicolateral and S4–S5 lateral portions with moderately
dense plumose hairs (1–1.5 OD).
Surface sculpture. Clypeal punctation moderately dense (i=1–1.5d). Metanotum rugose. Mesepisternum
dorsal half rugoso-reticulate. Metapostnotum completely rugoso-striate. Propodeum with dorsolateral slope
rugose, lateral surface rugulose. Metasomal terga apical impressed areas impunctate.
Structure. Head moderately elongate (length/width ratio = 1.01–1.04). Eyes strongly convergent below
(UOD/LOD ratio = 1.50–1.54). Antennal sockets distant (IAD/OAD > 1.1). Frontal line carinate, ending <2
OD below median ocellus. Pedicel shorter than F1. F2 length 1.8–2.0X F1. F2–F10 elongate (length/width
ratio = 1.57–1.82). Metapostnotum moderately elongate (MMR ratio = 1.21–1.23), posterior margin weakly
angled onto posterior surface.
Terminalia. S7 with median lobe clavate, apex rounded (Fig. 64F). S8 with apicomedial margin convex
(Fig. 64F); genitalia as in Fig. 64D–E. Gonobase with ventral arms widely separated. Gonostylus small, dorsal
setae elongate. Retrorse lobes elongate, attenuated and recurved apically.
Range. Ontario south to Maryland, west to Saskatchewan, Minnesota