Lasioglossum (Dialictus) leucocomum (Lovell)

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216: 130-131

publication ID

http://doi.org/ 10.5281/zenodo.1049595

publication LSID

lsid:zoobank.org:pub:B5AF6DF4-D3A7-4942-A94F-CC051D8074CF

persistent identifier

http://treatment.plazi.org/id/9A5987DB-A797-FF35-0A97-8C1BFEF60395

treatment provided by

Plazi

scientific name

Lasioglossum (Dialictus) leucocomum (Lovell)
status

 

Lasioglossum (Dialictus) leucocomum (Lovell)  

Halictus pilosus   var. leucocomus Lovell, 1908: 37   . Ƥ.

Lectotype. Ƥ USA, Maine, Waldoboro, 28.v. 1905 (J.H. Lovell); [ NMNH: 71569] designated herein. Examined. Dialictus otsegoensis Mitchell, 1960: 440   . 3. [new synonymy]

Holotype. 3 USA, Michigan, Ostego Co., 7–24.vii. 1955 (R.R. Dreisbach); [ NCSU]. Examined.

Taxonomy. Krombein, 1967: Lasioglossum (Dialictus) otsegoense   , p. 465 (catalogue); Dialictus otsegoensis   , p. 1969 (catalogue); Moure & Hurd, 1987: Dialictus otsegoensis   , p. 118 (catalogue); Gibbs, 2010 b: Lasioglossum (Dialictus) leucocomum   Ƥ, p. 175 (redescription, key).

Diagnosis. Female L. leucocomum   can be recognised by the following diagnostic combination: head elongate (length/width ratio = 1.03–1.06), clypeus with apicolateral margins strongly convergent, supraclypeal area relatively short (0.65–0.86 X clypeal length), mesoscutal punctures contiguous, metapostnotum rugoso-carinulate, and metasomal terga metallic with dense yellowish tomentum. They are most similar to L. pilosum   and L. succinipenne   . Female L. pilosum   have the apicolateral margins of the clypeus subparallel. Female L. succinipenne   have the supraclypeal area relatively long (0.80–0.90 X clypeal length) and dense whitish tomentum on the metasomal terga.

Male L. leucocomum   can be recognized by the combination of head elongate, clypeus yellow distally, mesoscutal punctures dense but distinctly separated medially, metasomal terga metallic. They are most similar to L. pilosum   which have the mesoscutal punctures contiguous medially.

MALE. Similar to female except for the usual secondary sexual characters and as follows. Length 4.25–5.13 mm; head length 1.32–1.63 mm; head width 1.22–1.45 mm; forewing length 3.44–3.75 mm.

Colouration. Labrum yellow. Mandible yellow. Clypeus distal margin yellow. Flagellum with ventral surface orange. Legs brown, except bases and apices of tibiae and tarsi yellow.

Pubescence. Moderately dense. Face below eye emargination with tomentum partially obscuring surface, dense on lower paraocular area. T 1 acarinarial area with sparse fan of appressed hairs. T 1 dorsolaterally, T 2 –T 3 basolaterally and T 4 basally with sparse tomentum. S 2 –S 3 entirely and S 4 –S 5 laterally with posteriorly directed hairs (1–1.5 OD).

Surface sculpture. Clypeal punctation moderately dense (i= 1–2 d). Mesoscutal punctures distinctly separated medially (i=d). Mesepisternum reticulate-rugulose. Propodeum with dorsolateral slope and lateral and posterior surfaces rugulose. Metasomal terga punctation deep, distinct.

Structure. Head very elongate (length/width ratio = 1.08–1.12). Eyes convergent below (UOD/LOD ratio = 1.43– 1.52). Clypeus 2 / 3 below suborbital tangent, apicolateral margins subparallel. Antennal sockets distant (IAD/OAD = 1.0). Frontal line carinate, ending 2 OD below median ocellus. Pedicel subequal to F 1. F 2 length 1.6–1.8 X F 1. F 2 –F 10 moderately elongate (length/width ratio = 1.38–1.63). Metapostnotum truncate (MMR ratio = 1.25–1.33), posterior margin weakly angled onto posterior propodeal surface.

Terminalia   . Not examined.

Range. Nova Scotia, Maine west to Minnesota, south to Appalachian mountains of North Carolina. USA: CT, IN, MA, ME, MI, MN, NC, NH, NJ, NY, WI. CANADA: NB, NS, ON, PE.

Additional material examined. USA: NORTH CAROLINA: 1 Ƥ 5.viii. 1957 (W.R. Richards); [ CNC].

DNA Barcode. Available. Multiple haplotypes.

Comments. Common.

Until recently, L. leucocomum   had never been considered more than a subspecies of L. pilosum   ( Gibbs 2010 b). Attempts to separate the males of L. pilosum   and L. leucocomum   using DNA barcoding have consistently failed to produce L. leucocomum   sequences. Morphological study of L. pilosum   s. l., however, has revealed variability in mesoscutal puncture density. It is now believed, based on geographical patterns of co-occurence with females, that the males with sparser punctures are actually L. leucocomum   . The holotype of D. otsegoense   , considered by Gibbs (2010 b) to be a junior synonym of L. pilosum   , is of this form.

The name-bearing type has lectotype labels from both Mitchell and Covell. No publication by either of these authors could be found that makes a valid lectotype designation. Lasioglossum leucocomum   was recently resurrected from synonymy with L. pilosum   by Gibbs (2010 b). To maintain stability of usage, the specimen indicated above is designated as the lectotype.

NMNH

Smithsonian Institution, National Museum of Natural History

NCSU

North Carolina State University Insect Museum

CNC

Canadian National Collection of Insects, Arachnids, and Nematodes

DNA

Department of Natural Resources, Environment, The Arts and Sport

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Hymenoptera

Family

Halictidae

Genus

Lasioglossum

Loc

Lasioglossum (Dialictus) leucocomum (Lovell)

Gibbs, Jason 2011
2011
Loc

Halictus pilosus

Lovell 1908: 37
1908