Lasius bombycina, Seifert, Bernhard & Galkowski, Christophe, 2016

Seifert, Bernhard & Galkowski, Christophe, 2016, The Westpalaearctic Lasius paralienus complex (Hymenoptera: Formicidae) contains three species, Zootaxa 4132 (1) : -

Description of Lasius bombycina sp.nov.

Etymology. The species epithet refers to the rich, whitish pubescence giving the cuticular surface a silky appearance.

Type material. See in section 2.2." Type Material".

Description of worker caste. Figs. 10–12 . Numeric data given in the following description are primary data (without removal of allometric variance) of 50 measured individuals.

Rather large compared to related species, CS 893 ± 68 [744,1076] µm. Basic morphology not different from other members of the Lasius alienus group. Head moderately elongated, with convex sides and straight posterior margin of vertex, CL/CW 1.077 ± 0.017 [1.043,1.112]. Scape rather short: SL/CS 0.970 ± 0.018 [0.932,1.008]. Eye medium-sized and moderately distant from posterior margin of head: EYE/CS 0.238 ± 0.007 [0.223,0.253], PoOc/ CL 0.239 ± 0.008 [0.224,0.257]. Antennal socket situated rather close to posterior clypeal margin: dCLAn/CS 4.34 ± 0.35 [3.75,5.07]%. Masticatory border of mandibles with 8-9 teeth. Maxillary palps with six segments and comparably short: MP6/CS 0.160 ± 0.009 [0.143,0.176]. Pubescence on whole body surfaces very dense and whitish, sqPDCL 3.42 ±0.23 [3.05,3.98]. Mean length of pubescence hairs between frontal carinae 33.9 ± 2.38 [29.9,35.8] µm. Pilosity compared to next related species long. Eyes with rather many microsetae of 23.1 ± 1.98 [18,25] µm length (these unusually long microsetae are perhaps diagnostic but this was not thoroughly checked).

Dorsal plane of scape with no or very few standing setae: nSc 0.55 ± 0.63 [0.0,2.5]. Genae with very few erect setae: nGen 1.10 ± 0.80 [0.0,3.0]. Underside of head and hind margin of vertex with rather numerous standing setae: nGu 3.34 ± 1.34 [1.5,8.5], nOcc 12.30 ± 2.66 [4.5,18.0]. Extensor profile of hind tibia with few and metapleuron below level of propodeal stigma with rather many erect to suberect setae: nHT 3.15 ± 1.77 [0.5,8.5], nSt 4.13 ± 1.32 [1.5,7.5]. Setae on pronotum long: PnHL/CS 0.161 ± 0.011 [0.137,0.201]. Whole body concolorous medium to blackish brown; mandibles, scapes and sometimes tibiae lighter reddish or yellowish brown. Mesosoma in lateral view with a rather low and more convex propodeal dome. Petiole scale low, in frontal view with convex sides which strongly converge towards the rather narrow dorsal crest which is slightly emarginate to straight.

Comments. For the geographic distribution see section 4.4. The main habitats are different kinds of xerothermous grassland, but in Turkey this species was also found in an urban garden. It frequently builds more hidden soil nests but in the steppes of the Neusiedler See region conspicuous soil mounds overgrown by herbs were observed which seems to be a difference to L. paralienus . Over the whole range, alates are observed inside the nests or swarming rather late: 9 September ± 26 d [1 August – 21 October] n=7. Oviposition of foundresses usually does not start before the next spring and workers develop until July. Gynes are on average larger than in alienus and psammophilus . In a laboratory nest, a founding gyne reared 26 workers without feeding ( Andrasfalvy 1961; named by Andrasfalvy " Lasius alienus ", recent determination as L. bombycina sp. nov. by geographic indication, swarming time and verbal description). Above-ground foraging was observed on the soil surface, in the herb layer and on bushes. There is trophobiosis with subterranean and epigaean Aphidae and tending of Lycaenidae caterpilars (Plebeijus sephirus, Plebeijus argus). Lasius bombycina is zoophagous on small invertebrates.

Figures

FIGURE 10. Head of the holotype of L. bombycina sp. nov. in dorsal view.

FIGURE 11. Mesosoma of the holotype of L. bombycina sp. nov. in lateral view.

FIGURE 12. Hind tibia of the holotype of L. bombycina sp. nov. seen in the plane of flexion.