Myrmica gebaueri

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Myrmica gebaueri
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Myrmicini
Genus: Myrmica
Species group: tibetana
Species complex: tibetana
Species: M. gebaueri
Binomial name
Myrmica gebaueri
Seifert, Schultz, Ritz & Ritz, 2018

Myrmica gebaueri holotype F9.jpg

Myrmica gebaueri holotype F8.jpg

Found on montane to subalpine grassland, usually pastures. Nests in soil, under stones or in grass tussocks. Polygynous.

Identification

The separation of Myrmica gebaueri and M. tibetana is most difficult and a safe discrimination on the worker individual level is only possible by the multivariate analyses described by Seifert et al. (2018). Compared to M. tibetana, M. gebaueri shows smaller eyes and longer and more diverging propodeal spines. A parsimonious morphometric method allows a determination on nest sample level if two or three workers per sample are measured. We simplified the species delimitation procedure by using absolute linear measurements and by reducing the number of characters for the condition that the error at nest sample level was zero. We emphasize at this point that the measuring instructions for each character have to be considered. The extracted morphometric method requires five minutes working time in a mounted specimen. With all measurements recorded in mm, a linear discriminant function

D(3) = 62.835 EYE + 44.41 SPBA - 50.213 SP - 15.713

resulted in an error of 0% on the nest sample level. Samples with D(3) < 0 are classified as Myrmica gebaueri, those above this threshold as M. tibetana. The error on the worker individual level was 5.6% in 126 specimens.

The easy separation from Myrmica bactriana, the three species of the M. smythiesii complex (Myrmica fortior, Myrmica smythiesii, Myrmica wittmeri) and from Myrmica tenuispina has been treated in the section considering possible synonymies in Seifert et al. (2018).

Distribution

NE Tibet between 35.5 and 38.0° N and 99.8 and 102.8° E, in altitudes of 2900 - 3500 m.

Latitudinal Distribution Pattern

Latitudinal Range: 38.038° to 35.541°.

 
North
Temperate
North
Subtropical
Tropical South
Subtropical
South
Temperate

Distribution based on Regional Taxon Lists

Oriental Region: Tibet (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.
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Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.
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Biology

Castes

Seifert et al. 2018. Holotype petiole, lateral view.
Seifert et al. 2018. Holotype left scape, caudodorsal view.

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

  • gebaueri. Myrmica gebaueri Seifert et al., 2018: 105, figs. 7-11 (w.) TIBET.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

Most similar to Myrmica tibetana. One of the smallest species of the genus (CS 918 μm). Head with a weakly concave to straight posterior margin and strongly convex sides (Fig. 7) and rather elongated (CL / CW 1.129). Postocular distance rather low (PoOc / CL 0.410). Frontal lobes broad and significantly diverging (FL / CS 0.482, FL / FR 1.190), their lateral outline more angulate than convex, usually forming an angle ± 110°, frontal carinae merging with the rugae that surround antennal sockets. Eyes with few microsetae and rather small (EYE / CS 0.191), distinctly smaller than in Myrmica tibetana (EYE / CS 0.205). Clypeus in dorsal view of head produced, its anterior margin more angulate than curved, forming an angle of 115 - 125°. Scape moderately long (SL / CS 0.794), with a slender, evenly curved basal part which performs a total bend of ± 35° when viewed in the frontal or caudal standard viewing positions (SVP f or c in Seifert & al. 2014; Fig. 11 does not show a fully caudal aspect). Dorsal profile of mesosoma with a strongly convex promesonotal part, a strong metanotal depression and a convex dorsal part of propodeum (Fig. 9). Propodeal spines acute and short but on average longer than in Myrmica tibetana (SP / CS 0.179 but 0.155 in the latter), spine axis in lateral view deviating from longitudinal mesosomal axis by 35 - 45°. Spines slightly diverging (Fig. 8): distance of spine base usually smaller than distance of tips (SPBA / CS 0.271, SPTI / CS 0.284) – in Myrmica tibetana there is usually no divergence of spines (SPBA / CS 0.282, SPTI / CS 0.263). Central height of propodeal lobe only slightly larger than equal-level height of subspinal excavation (MetL / CS 0.226, MetSp 0.200). Petiole rather low (PEH / CS 0.323) and in lateral view with a concave anterior profile, a rounded dorsum of node and a slightly concave to almost straight caudodorsal profile (Fig. 10). Petiole in dorsal view with rather straight sides, slightly diverging caudad, its width about 65% of postpetiolar width. Setae are present on all dorsal parts of body and rather long (PPHL / CS 0.206). Vertex moderately strong longitudinally rugose, posterior vertex reticulate; about 16 - 23 rather linear rugae are found between the most approximated parts of frontal carinae. Mesosoma and waist with a weak sculpture in terms of genus Myrmica, larger surface areas may be smooth. Dorsum of promesonotum as a rule reticulate-rugose, meso- and metapleuron longitudinally carinulate. Dorsal propodeum weakly carinulate-rugulose, substantial parts of its surface often completely smooth. Dorsum of petiole reticulate-rugulose, central dorsum of postpetiole at lower magnification always appearing smooth and shining, a delicate microreticulum becomes visible at larger magnifications. Whole body usually rather uniformly medium brown with a weak yellowish component and sometimes with a lighter mesosoma.

Type Material

Etymology

Named after the German naturalist Axel Gebauer who made several expeditions to the Tibetan Plateau and was the first to collect this species in 1992.

References