Refine
Document Type
- Article (2)
- Part of Periodical (1)
Language
- English (3)
Has Fulltext
- yes (3) (remove)
Is part of the Bibliography
- no (3)
Keywords
- Apoidea (3) (remove)
The Lasioglossum (Dialictus) gemmatum species complex, also known as the L. tegulare species group and the L. parvum species complex, is a very common, widespread, diverse, and recognisable lineage of sweat bees, containing 22 previously described species and several known undescribed species. The species were recently revised for the eastern Nearctic region and the Greater Antilles, but remain poorly known in the western Nearctic along with most other L. (Dialictus). These characteristics make it a prime candidate for revision in ongoing taxonomic work on the western Nearctic L. (Dialictus). Here we present the results of this revision, including 10 new species descriptions, one new synonymy, a preliminary phylogeny, and keys to known Nearctic species. Species of the eastern Nearctic and a few primarily Neotropical species which can occur in the Nearctic are also included. We report that the L. (D.) gemmatum species complex is likely a monophyletic group arising from the L. (D.) comulum group, but that the enlarged tegula has arisen independently in at least two other L. (Dialictus) lineages, and it contains multiple cases of allopatric speciation. The following species are described as new: Lasioglossum (Dialictus) angelicum sp. nov., L. (D.) deludens sp. nov., L. (D.) diabolicum sp. nov., L. (D.) eremum sp. nov., L. (D.) gloriosum sp. nov., L. (D.) indagator sp. nov., L. (D.) holzenthali sp. nov., L. (D.) magnitegula sp. nov., L. (D.) profundum sp. nov., and L. (D.) rufodeludens sp. nov. Previously undescribed males of L. (D.) perparvum (Ellis, 1914) and L. (D.) pseudotegulare (Cockerell, 1896) and the female of L. (D.) gaudiale (Sandhouse, 1924) are diagnosed and figured for the first time. Lasioglossum (Dialictus) hunteri (Crawford, 1932) is a new subjective junior synonym of L. (D.) ellisiae (Sandhouse, 1924). Pre-2022 specimen records of L. (D.) hunteri and L. (D.) tegulariforme (Crawford, 1907) are attributable to a heterogeneous mix of species, and records of L. (D.) perparvum are likely attributable to L. (D.) deludens.
Lasioglossum is a large genus of halictid bees with high species diversity in morphologically rather cryptic species groups. With more than 1900 described species, the taxonomy of the genus is complex and largely unresolved in many regions. For practical reasons, systematic reviews are restricted in scope either geographically or to particular species groups. In this study we focus on the subgenus Dialictus of the genus Lasioglossum from the Yucatán Peninsula in Mexico. In previous studies we identified members of the genus as important pollinators of cash crops in the region, and genetic analyses suggested the existence of seven molecular taxonomic units (mOTU). Based on additional morphological differences, we here describe these mOTUs as novel species, Lasioglossum (Dialictus) yucatanense Landaverde-González sp. nov., L. (D.) paxtoni Landaverde-González sp. nov., L. (D.) ameshoferi Landaverde-González sp. nov., L. (D.) aureoviride Landaverde-González & Husemann sp. nov., L. (D.) paralepidii Gardner sp. nov., L. (D.) milpa Landaverde-González sp. nov. and L. (D.) nanotegula Landaverde-González & Husemann sp. nov., and provide keys and images to assist in their identification.
Sweat bees in the subgenus Lasioglossum (Dialictus) are one of the most diverse and abundant bee taxa, and a critically important component of bee biodiversity. Yet, the most basic taxonomic knowledge of these bees is lacking in many regions. As a step towards a better understanding of the L. (Dialictus) of the western Nearctic region, a revision of the ‘red-tailed’ L. (Dialictus) species was completed. Thirty-six species were revised, 20 of which are described as new, and two names are treated as junior subjective synonyms. Descriptions, figures, distribution maps, floral hosts, and keys to species for females and males are provided. The following 20 species are described as new: Lasioglossum (Dialictus) arenisaltans sp. nov., L. (D.) argammon sp. nov., L. (D.) austerum sp. nov., L. (D.) cactorum sp. nov., L. (D.) cembrilacus sp. nov., L. (D.) clastipedion sp. nov., L. (D.) clavicorne sp. nov., L. (D.) decorum sp. nov., L. (D.) festinum sp. nov., L. (D.) imbriumbrae sp. nov., L. (D.) julipile sp. nov., L. (D.) lilianae sp. nov., L. (D.) meteorum sp. nov., L. (D.) miltolepoides sp. nov., L. (D.) minckleyi sp. nov., L. (D.) perditum sp. nov., L. (D.) rufornatum sp. nov., L. (D. ) spivakae sp. nov., L. (D.) tessellatosum sp. nov., and L. (D.) torrens sp. nov. Previously unknown males of L. (D.) clematisellum (Cockerell, 1904), L. (D.) droegei Gibbs, 2009, L. (D.) kunzei (Cockerell, 1898), and L. (D.) pallidellum (Ellis, 1914) are described and figured for the first time. Lasioglossum (Dialictus) clarissimum (Ellis, 1914) (= Halictus clarissimus Ellis, 1914) and L. (D.) perexiguum (Sandhouse, 1924) (= Halictus (Chloralictus) perexiguus Sandhouse, 1924) are new subjective junior synonyms of L. mesillense (Cockerell, 1898) (= Halictus nymphalis var. mesillensis Cockerell, 1898). A lectotype specimen is newly designated for L. mesillense, for which the location of the type material has not previously been known. The following five new records for Mexico are reported: L. clematisellum, L. droegei, L. eophilus (Ellis, 1914), L. kunzei, and L. pallidellum.