Lasius flavus (Fabricius, 1782)

Boudinot, Brendon E., Borowiec, Marek L. & Prebus, Matthew M., 2022, Phylogeny, evolution, and classification of the ant genus Lasius, the tribe Lasiini and the subfamily Formicinae (Hymenoptera: Formicidae), Systematic Entomology 47, pp. 113-151 : 138

4. Species group of flavus (= Cautolasius part 1/2)

( Figs 8G , 9G )

Constituent species (8): Nearctic (3): brevicornis [e], fallax Wilson [e], humilis [e]; Palaearctic (5): alienoflavus Bingham [e], elevatus Bharti and Gul [e], flavus * [e], myops Forel [e], talpa Wilson [e].

Distribution: Holarctic.

Identification: Among species groups of the flavus clade, most similar to those of carniolicus , nearcticus , and umbratus in having relatively small eyes (vs pallitarsis ), stocky mesosomata and shorter scapes (vs atopus ), and unreduced palpomere count (vs claviger group). At present, not collectively distinguishable from nearcticus group; otherwise, identifiable as follows: clypeus broad relative to head width (vs narrow, carniolicus group); eyes small, with <35 ommatidia excepting L. alienoflavus and L. flavus , which lack standing setae on head underside (vs with> 35 ommatidia and head underside with distinct, standing setae, umbratus group). No key is available to specifically separate all of the species of the flavus group as here constituted; the three Nearctic species are keyed in Wilson (1955), with brevicornis as ‘ flavus ’; the two Western European species, L. flavus and L. myops , are keyed by Seifert (2018); the three species from the Himalayas, L. alienoflavus , L. elevatus , and L. talpa are keyed by Bharti & Gul (2013) and Collingwood (1982), and the easternmost Asian population(s) of L. talpa are keyed for North Korea by Radchenko (2005b) and Japan by ( Yamauchi, 1979).

Notes: This group corresponds to the former subgenus Cautolasius , in part. The inclusion of L. alienoflavus , L. elevatus , L. fallax , L. humilis , and L. talpa is provisional. Wilson (1955) accepted the placement of L. humilis in the former subgenus Chthonolasius as proposed by Emery (1925) without stated justification; we observe that this species has very small eyes and lacks standing setae on the ventral head surface, matching the polythetic diagnoses of the flavus and nearcticus groups. Likewise, the species L. elevatus also has very small eyes and lacks postgenal bridge setation, although it was unplaced to subgenus in its original description ( Bharti & Gul, 2013). Molecular data should be generated for all species of this group, their relationships relative to the nearcticus group tested, and a critical reanalysis of phenotypic traits conducted.

Figures

Fig. 8. Gross phenotypic synopsis of the extant species groups of Lasius, plus two phenotypically similar fossil species; all images in full-face view; scale bars = 0.5 mm. (A) Lasius brunneus (CASENT0280440); (B) Lasius fuliginosus (CASENT0179898); (C) Lasius nr. niger (CASENT0106128); (D) Lasius nr. atopus (CASENT0234858); (E) Lasius carniolicus (CASENT0280471); (F) Lasius claviger (CASENT0103542); (G) Lasius brevicornis (CASENT0280456); (H) Lasius nearcticus (CASENT0104774); (I) Lasius pallitarsis (CASENT0005405); (J) Lasius aphidicola (CASENT0280468); (K) †Lasius schiefferdeckeri (MNHNB25217); (L) †Kyromyrma neffi (AMNH-NJ1029). (Image credits: D = the authors; AntWeb: A = Will Ericson; B = Erin Prado; C = Michael Branstetter; E, G, J = Shannon Hartman; F, H = April Nobile; I = unknown; K = Vincent Perrichot; L = Dave Grimaldi & Vincent Perrichot.)

Fig. 9. Gross phenotypic synopsis of the species groups of Lasius, plus two phenotypically similar fossil species; all images in profile view; scale bars = 1.0 mm; scale bar unavailable for K. (A) Lasius brunneus (CASENT0280440); (B) Lasius fuliginosus (CASENT0179898); (C) Lasius nr. niger (CASENT0106128); (D) Lasius nr. atopus (CASENT0234858); (E) Lasius carniolicus (CASENT0280471); (F) Lasius claviger (CASENT0103542); (G) Lasius brevicornis (CASENT0280456); (H) Lasius nearcticus (CASENT0104774); (I) Lasius pallitarsis (CASENT0005405); (J) Lasius aphidicola (CASENT0280468); (K) †Lasius schiefferdeckeri (HJF013); (L) †Kyromyrma neffi (AMNH-NJ1029). (Image credits: D = the authors; AntWeb: A = Will Ericson; B = Erin Prado; C = Michael Branstetter; E, G, J = Shannon Hartman; F, H = April Nobile; I = unknown; K = Vincent Perrichot; L = Dave Grimaldi & Vincent Perrichot.)