Diplotemnus balcanicus (Redikorzev, 1928)

Gogshelidze, Mariam & Novák, János, 2024, First record of the family Atemnidae (Pseudoscorpiones) from Armenia, Caucasiana 3, pp. 257-262 : 257-262

Diplotemnus balcanicus (Redikorzev, 1928)

Material examined.

Armenia • 1 ♂ (ZFMK-TIS- 97516); Ararat valley, Angel’s Canyon, near the town Vedi ; 39 ° 56 ' 52.8 " N, 44 ° 44 ' 27.6 " E; 1025 m a. s. l.; sifted leaf litter; 14 - May. 2022; leg: Astrin J .

Short description.

Carapace and tergites yellowish-brown, pedipalps dark reddish-brown. Setae on body and palps apically dentate.

Carapace (Fig. 2 A ). 1.37 x longer than wide, strongly granulated with two transverse furrows. Two pairs of eyes are present, with one pair of preocular setae. Four setae at the anterior and ten on the posterior margin of the carapace. Lyrifissures: two pairs at the anterior, one pair at the medial, and one pair at the posterior disk.

Chelicera. 2.02 x longer than broad, with five setae on hand; one seta on the movable finger; serrula exterior with 18 blades; galea not visible (broken); curved teeth at the base of galea present; fixed finger with three small teeth at the marginal end.

Coxae. Pedipalpal coxae with 8 setae; setation of pedal coxae: coxa I: 8, coxa II: 8, coxa III: 7 (9) and coxa IV 12 setae.

Pedipalp (Fig. 2 B ). Robust and strongly granulated; femur 2.91 x, patella 2.06 x, chela 2.55 x, hand with pedicel 2.61 x longer than broad. Chelal movable finger shorter than hand without pedicel. Venom apparatus only in fixed finger. Fixed chelal finger with thirty-two, movable finger with thirty-two cusped teeth.

Abdomen. Chaetotaxy of tergites I-XI: 6: 6: 4: 5: 6: 5: 5: 5: 5: 5: 4. On the anal cone two short setae visible. Lyrifissures on half of the tergites III-XI: 2: 2: 2: 2: 2: 2: 2: 2: 4; sternal chaetotaxy: III-XI: 6: 8: (?): 6: 6: 6: 7: 6: 5; sternal lyrifissures (on half-tergites): III-XI: 2: 2: 2: 2: 2: 2: 2: 4: 2.

Legs. Leg I: trochanter 1.25 x, femur 1.71 x, patella 2.78 x, tibia 3.46 x, tarsus 5.08 x times longer than broad; leg IV (Fig. 2 C ): trochanter 1.67 x, femoropatella 3.13 x, tibia 4.11 x, tarsus 3.97 x times longer than broad; one submedial tactile seta (broken) on tarsus IV, somewhat proximal to the middle of the article (Fig. 3 ).

Dimensions (in mm). Body – 3.27; Carapace – 1.09 / 0.80 (1.37 x); Chelicera – 0.24 / 0.11 (2.20 x); Cheliceral movable finger 0.22; Pedipalp: Femur – 0.89 / 0.30 (2.91 x); Patella – 0.80 / 0.39 (2.06 x); Chela – 1.34 / 0.52 (2.55 x); Hand with pedicel – 1.37; Chelal movable finger – 0.44; Leg I: trochanter – 0.17 / 0.14 (1.25 x); femur – 0.25 / 0.15 (1.71 x); patella – 0.47 / 0.17 (2.78 x); tibia – 0.39 / 0.11 (3.46 x); tarsus – 0.39 / 0.07 (5.08 x). Leg IV: trochanter – 0.29 / 0.17 (1.67 x); femur + patella – 0.87 / 0.28 (3.13 x); tibia – 0.75 / 0.18 (4.11 x); tarsus – 0.45 / 0.11 (3.97 x).

Notes.

Besides Diplotemnus balcanicus , two other species of the family Atemnidae are known in the neighboring countries: Atemnus politus (Simon, 1878) from Azerbaijan, Georgia, Iran, and Turkey, and A. syriacus (Beier, 1955) from Turkey ( WPC 2024). Genus Diplotemnus differs from Atemnus by the following morphological characteristics: a granulated carapace with two distinctive transverse furrows, the presence of two corneate eyes, and having the trichobothrium of leg IV tarsus near the middle of the article (it is basal in Atemnus ).

Diplotemnus balcanicus can be distinguished from the other two Diplotemnus species of Europe and Asia by the following characters: the number of preocular seta ( D. pieperi Helversen, 1965 has three preocular seta, whereas D. balcanicus only has one), and the smaller body size ( D. egregius Beier, 1959 pedipalpal femur 1.45–1.65 mm and pedipalpal patella 1.45–1.55 mm in length, whereas in the newly found D. balcanicus specimen these measurements range from 0.99–1.25 and 1.08–1.21 mm) ( Beier, 1959; Helversen, 1965; Novák and Harvey, 2015; Krajčovičová et al. 2021).

The Armenian specimen is smaller than the Slovakian specimen rediscovered in 2019 (body length: Armenian specimen – 3.27 mm, Slovakian specimen – 3.75 mm; palpal femur: Armenian specimen – 0.89 mm, Slovakian specimen – 1.25 mm; leg IV femur + patella: Armenian specimen – 0.87 mm, Slovakian specimen – 1.20 mm) ( Krajčovičová et al. 2021). This difference can be attributed to geographical distance and intraspecific variation. In a 2015 publication, Novák and Harvey proposed several species as junior synonyms of Diplotemnus balcanicus (Redikorzev, 1928) . In the original descriptions of the synonymized species, the body dimensions have high variability ( Novák and Harvey 2015). Recently synonymized Diplotemnus lindbergi ( Beier, 1960) , distributed in Afghanistan, is the closest to the Armenian specimen in body measurements, as the holotype dimensions are as follows: body length 3.5 mm; carapace length 0.88 mm; pedipalpal femur L / W 0.70 / 0.27 mm; and chelal movable finger length 0.51 mm ( Beier, 1960).

Considering the above-mentioned distinctive characters between the studied specimen and other atemnid taxa, coupled with great interspecific variation and the huge geographical area of D. balcanicus , the newly recorded specimen in Armenia can be attributed to D. balcanicus , adding further information on the dimensional variation of the species.

Figures

Figure 2. The studied male specimen of Diplotemnus balcanicus. A: Entire body, dorsal view; B: Right chela, lateral view; C: Righ Leg IV, lateral view.

Figure 3. Right leg IV Telotarsus, lateral view. The arrow is pointing at submedial tactile seta.