Leptothorax, Mayr, 1855

Seifert, Bernhard, 2023, Two new species of Formicoxenus Mayr 1855 and Leptothorax Mayr 1855 from Tibet (Hymenoptera: Formicidae), Soil Organisms 95 (2), pp. 129-142 : 132-133

publication ID	https://doi.org/ 10.25674/so95iss2id315
persistent identifier	https://treatment.plazi.org/id/03FAE936-FFC0-FA72-356A-FBFDFD41EA63
treatment provided by	Felipe
scientific name	Leptothorax
status

Treatment

Leptothorax View in CoL and Formicoxenus

Specimens of Leptothorax oceanicus were not available for investigation – I follow here the original description of Kuznetsov-Ugamsky (1928) and the re-description by Radchenko & Heinze (1997). The three socially parasitic Palaearctic Leptothorax species L. pacis , L. goesswaldi and L. kutteri have no workers.

1a Postpetiolar sternite with a well-developed acute spine ( Figs 7 View Figure 6–9 , 11 View Figure 10–13 , 15 View Figure 14–17 ). Head very narrow but with a broad frons, FRS/CW> 0.464. Eye small, EYE/CL <0.176. Genus Formicoxenus ...................... 2

1b Postpetiolar sternite in profile without a well developed spine, at most with small frontal denticle ( Figs 20 View Figure 19–21 , 32 View Figures 31–33 ). Head wider, frons narrower, eye larger, FRS/ CW <0.464, EYE/CL> 0.176. Genus Leptothorax ........ 4

2a Whole dorsum of head smooth and brilliantly shiny, sometimes frontal lobes and genae weakly longitudinally carinulate. Temperate to boreal zone of Palaearctic from Europe to Russian Far East ( Figs 6–9 View Figure 6–9 ) .......................................... ....... F. nitidulus

2a Whole dorsum of head matt, strongly longitudinally rugulose, the interspaces microreticulate (appearing at lower magnifications punctate) ...................................... 3 3a Setae on whole body very short (PnHL/CS <0.090), widening from base to apex ( Fig. 13 View Figure 10–13 ), apically fringed and in cross-section forming a tridentate star. Frons much broader, FRS/CW>0.533. Middle Asia, Inner Mongolia, Transbaikalia ( Figs 10–13 View Figure 10–13 ) ............................. F. sibiricus

3b Setae on whole body much longer (PnHL/ CS> 0.90), narrowing from base apex ( Fig. 17 View Figure 14–17 ), and in cross-section cylindrical. Frons much narrower, FRS/CW <0.533. North of Tibetan Plane ( Figs 14–17 View Figure 14–17 ) ................................................ F. gebaueri n.sp.

4a Anterior and posterior slopes of petiole node in lateral view almost linear, forming an acute angle and a sharp dorsal corner; subpetiolar lobe broad ( Fig. 18 View Figure 18 ). Anteromedian margin of clypeus without a notch. Erect setae on head and mesosoma sparse. Russian Far East ...................................................... L. oceanicus

4b Dorsum of petiole node in lateral view not forming a sharp, acute corner. Subpetiolar lobe small, dentiform or spiky ......................................................... 5

5a Scape and tibiae with numerous standing setae ( Figs 19–21 View Figure 19–21 ): Temperate to south arctic zone of whole Palaearctic................................................ L. acervorum

5b Scape and tibiae without standing setae, occasionally semierect pubescence hairs may be present ....................................................................... 6

6a Propodeal spines longer and frons narrower. With all measurements in mm, discriminant 14.66*CW-60.0*FRS+52.06*SPST-7.29> 2.6 [error 0 % in 6 specimens]. Asia Minor and Caucasus ( Figs 22–24) ..................................................... L. scamni

6b Propodeal spines shorter and frons wider. Discriminant <2.6 [error 0 % in 90 specimens]............ 7

7a Postocular distance smaller, scape relatively longer and head width on average larger. With all measurements in mm, discriminant 37.13*CW+46.90*SL-127.92* PoOc-12.72> 0.25 [error 0 % in 40 specimens]. Lateral vertex with pronounced longitudinal sculpture, reticular structures in comparison much less obvious. Temperate and submediterranean zone of Europe and Caucasus ( Figs 25–27) .............................................................. L. gredleri

7b Postocular distance larger, scape relatively shorter and head width on average smaller. Discriminant <0.25 [error 0 % in 50 specimens]. Lateral vertex with a more reticular sculpture................................................. 8 8a Frontal carinae not or only very slightly diverging frontad (FL/FR <1.025). Petiolerelativelylower ( PEH / PEL 0.803 ± 0.023) and in profile with a broader dorsal crest. Sculpture weaker. Temperate to south boreal zone of Palaearctic ( Figs 28–30 View Figures 28–30 )...................................................... L. muscorum

8b Frontal carinae notably diverging frontad (FL/ FR> 1.025). Petiole relatively higher (PEH/PEL 0.870 ± 0.021) and in profile with a narrow (but not acute) dorsal crest. Sculpture stronger. Tibetan Plane ( Figs 31–33 View Figures 31–33 ) ......................................... L. tibeticum n.sp.