Formica dusmeti EMERY, 1909

Seifert, Bernhard, 2021, A taxonomic revision of the Palaearctic members of the Formica rufa group (Hymenoptera: Formicidae) - the famous mound-building red wood ants, Myrmecological News 31, pp. 133-179 : 170-171

Formica dusmeti EMERY, 1909

Formica rufa ssp. dusmeti EMERY, 1909 [conception of TINAUT & MARTINEZ-IBANEZ (1998)]

The original description reports as type locality and collector: “Peñalosa in Spanien; 3 Exemplare wurden mir von Herrn Dusmet mitgeteilt.” According to TINAUT & MARTINEZ-IBANEZ (1998), there is obviously a misspelling of the site as the two worker specimens in the Dusmet collection in MNCN Madrid bear labels indicating “Peñalara” as the collecting site. Furthermore, TINAUT & MARTIN- EZ-IBANEZ (1998) quoted F. dusmeti to be frequent at Peñalara ( Sierra de Peñalara ) but to be absent from Peñalosa and surrounding areas in the province of Cordoba .

All material examined. Numeric phenotypical data were recorded in three samples with seven workers from Spain. For details, see SI1, SI2, and SI3.

Geographical range. According to TINAUT & MARTINEZ-IBANEZ (1998) and ESPADALER & GOMEZ (2000) restricted to Iberia with main occurrence in the northern part of the Peninsula. The altitude of seven sites was 1573 ± 261 m, which is higher than in Formica frontalis .

Diagnosis of worker ( Tab. 5, key). Medium-sized, mean and maximum CS 1706 and 2074 µm. Head elongated, CL / CW 1750 1.113. Clypeal structure as in Formica truncorum . Scape very long and slender, SL / CS 1750 1.001, SL / Smax 1750 11.08. Petiole scale narrow, PeW / CS 1750 0.438. Eyes without or with only short microsetae, EyeHL 1750 14 µm. Dorsal plane of scape completely without setae, nSc 1750 0.0. Setae number on each place of the body strongly reduced, clearly smaller than in Formica frontalis , nCH 1750 0.0, nGu 1750 0.0, nPn 1750 0.3, nMes 1750 2.4, nPr 1750 0.8, nMet 1750 0.4; when present, setae are short or of medium length, GuHL 1750 156 µm, mPnHL 1750 18µm, MetHL 1750 28µm. Typical pigmentation in medium-sized to large workers: whole head, mesosoma, petiole, and frontal part of first gaster segment light or- ange brown.

Diagnosis of gyne. Unknown to me.

Taxonomic comments and clustering results. I maintain here the concept of TINAUT & MAR- TINEZ-IBANEZ (1998), who separated Formica dusmeti and Formica frontalis workers based on strong differences in setae numbers on pronotum, hind margin, and underside of head. This is basically confirmed by the data given in Table 5. Using these data, the first principal component provided a clear separation of seven F. dusmeti and 25 F. frontalis workers. However, the sample size is low, and considering the extreme intraspecific variation of pilosity data known in several species of the Formica rufa group, a thorough morphometric and genetic study is desired. Xavier Espadaler (pers. comm. July 2020) commented that some Portuguese and West Spanish populations of F. dusmeti and F. frontalis appeared to be intermediate in pilosity data.

Biology. TINAUT & MARTINEZ-IBANEZ (1998) report as main habitat conifer woodland, but it has also been found in open situations under large rocks and stone plates. Alates were observed between 14 June and 4 August.