Revision of the Nearctic species of the Lasioglossum (Dialictus) gemmatum species complex (Hymenoptera: Halictidae)
Bibliographic record
Abstract
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.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.004 | 0.001 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.001 | 0.002 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".