Eresus lavrosii Mcheidze, 1997

Seropian, Armen, Bulbulashvili, Natalia, Makharadze, Giorgi & Kovács, Gábor, 2025, From burrows to spotlight: first description of the female of Eresus lavrosii Mcheidze, 1997 (Araneae, Eresidae), with notes on the natural history, Caucasiana 4, pp. 1-14 : 1-14

Eresus lavrosii Mcheidze, 1997

Figs 2 A – D , 3 A – G , 4 A – G

Eresus lavrosiae Mcheidze 1997: 48, figs 28–29 (♂).

Eresus lavrosiae : Zamani et al. 2020: 564 , figs 15–22, 28–29, 34 (♂).

Material examined.

GEORGIA • Kiketi ; 1 ♀; N 41.6389 °, E 44.6457 °; 1088 m a. s. l.; edge of deciduous forest, meadow; leg. Bulbulashvili N.; 23 May 2021; CaBOL-ID 1010321 . • Tetrobi Managed Reserve ; 1 ♂ (subadult); N 41.5843 °, E 43.3965 °; 2004 m a. s. l.; edge of coniferous forest, meadow; leg. Bulbulashvili N.; 15 Oct. 2022; CaBOL-ID 1035445 . • Udzo Monastery , Kojori; 1 ♂; N 41.6758 °, E 44.7009 °; 1406 m a. s. l.; forest edge, meadow; leg. Makharadze G.; 27 May 2024; CaBOL-ID 1037403 ( BGE_00657_E 11 ) . • 1 ♂; 29 Apr. 2024; CaBOL-ID 1037402 ( BGE_00657_E 10 ) .

Diagnosis.

Females of E. lavrosii are similar to those of E. moravicus Řezáč, 2008 by a pars cephalica covered with dense short yellow hair and a uniformly black abdomen. They can be distinguished from E. moravicus by femora I – IV ventrally and sternum with yellow and off-white macrosetae (vs. completely black) (Figs 3 D , 4 F – G ; cf. Kovács et al. 2015: fig. 1 C; personal communication with Gábor Kovács), shorter and wider epigyne, significantly wider and more extensive median lobe (Fig. 2 A, C ), more globular anterior sections of copulatory ducts (vs. more oval-shaped), longer epigyne fissures with almost straight anterior tips (vs. shorter and strongly bent (Fig. 2 B, D ; cf. Kovács et al. 2015, fig. 5. C – D), and yellow setae not reaching the middle line of pars cephalica (Fig. 4 D ) (vs. closing in the middle line, Kovács et al. 2015, fig. 1 C; Kovács et al. 2010, fig. 2 E).

Description.

Total length 14.21. Carapace 7.25 long, 5.38 wide. Carapace: dark red-brown in alcohol; black in live specimen; pars cephalica and pars thoracica nearly equally wide; pars cephalica elevated, anteriorly covered with dense yellow setae. Chelicerae with dense yellow setae, covering ca. ½ of cheliceral length. Legs dark brown, with a thin yellow ring of setae at joints. Fe I ventrally with yellow macrosetae. Leg measurements are given in Table 1 . Epigyne and vulva as in Figs 2 A – D : median lobe subtrapezoidal; epigynal fissures (EF) anteriorly and posteriorly diverging; anterior section of copulatory ducts (ACS) oval, closely situated; spermathecae (S) broad and convoluted, forming numerous small lobes, slightly extending further laterally than ASC.

Male. See Mcheidze (1997); Zamani et al. (2020); see “ Note ” below. Habitus as in Fig. 4 C . Bulbus as in Figs 2 E – G .

Habitat.

This species is found at altitudes ranging from ca. 800 to 2300 m a. s. l (1), occurring on the woodland edges, forest clearings, and temperate grasslands.

Distribution.

Georgia, Türkiye, Armenia, Iran ( WSC 2025), and Azerbaijan (1). This is the first record from Azerbaijan.

Phenology.

The copulation of E. lavrosii generally takes place in the second half of spring, when the mean weekly maximum air temperature is around 16 ° C. The earliest males appear in late February, and the latest in early June (1 s).

Note.

Several photographs on iNaturalist show males from southern populations originating in Armenia, Azerbaijan, and Türkiye with a reduced abdominal pattern of different degrees, starting from the posterior edge (see the Reference column in 1). This phenomenon was also observed in Latrodectus tredecimguttatus (Rossi, 1790) from the Southern Caucasus, where adult females are characterized by partial or complete abdominal pattern reduction (personal observation by AS).

Barcoding.

We obtained two identical COI sequences (658 bp) from a male and a female specimen collected in the same burrow (CaBOL-IDs 1037402 and 1037403 (BOLD: AEE 3321), p - distance 0 %). These sequences perfectly match those of E. lavrosiae from Turkey (BOLD: AEE 3321, p - distance 0 %), thus confirming the female's identity.

Figures

Figure 2. Copulatory organs of Eresus lavrosii, Udzo, Kojori (A, C – female, epigyne, ventral view; B, D – vulva, dorsal view; E – male, bulbus, prolateral view; F – ditto, ventral view; G – ditto, retrolateral view). Scale bars = 0.3 mm (A – D); 0.25 mm (E – G).

Figure 3. Live specimens of Eresus lavrosii (A – juvenile, frontal view, Tetrobi Managed Reserve, 15 October 2022; B – subadult female, ditto; captive-reared on 27 March 2023; C – juvenile, frontal view, Telovani, 29 April 2019; D – adult female, ditto, Kojori, 12 May 2019, arrows indicating the characteristic macrosetae on the venter of Fe I). Abbreviations: Fe – femur.

Figure 4. A – intact burrow of Eresus lavrosii, subadult female, Kiketi, 29 April 2024; B – same burrow with a “ lid ” raised exposing the entrance to the underground retreat zone, arrow indicating the prey remains at the burrow entrance; C – adult male, live specimen, dorsal view, Kojori, 29 April 2024; D – adult female, dorsal view, Kojori, 27 May 2024; E – ditto, lateral view; F – ditto, ventral view; G – ditto, arrows indicating the characteristic macrosetae on the venter of Fe I – IV and the SCP. Abbreviations: Fe – femur, SCP – secretion mating plug.