Pselaphochernes scorpioides (Hermann, 1804)

Gogshelidze, Mariam & Novak, Janos, 2023, The first record of Pselaphochernes scorpioides (Hermann, 1804) from Georgia, Caucasus (Arachnida: Pseudoscorpiones), Caucasiana 2, pp. 299-303 : 299

Pselaphochernes scorpioides (Hermann, 1804)

Material examined.

GEORGIA • 1♀ (ISUIZ-Pseud-243); western Georgia, Adjara region, Kintrishi National Park ; 41°44 ’38.0” N, 42°05 ’02.0” E; 1264 m a.s.l.; Malaise trap; 1 Jun. - 15 Jun. 2018; leg. CaBOL team .

A short description of the specimen.

Carapace (Fig. 2A): 1.07 times longer than broad; Surface granulated, with clavate setae; On the anterior margin 6, on the posterior margin 6 setae; Eyes or eyespots absent; Two trasverse furrows present 4 pairs of lyrifissures: 2 pair on anterior margin, 1 pair in posterior margin. Chelicera (Fig. 2B): Galea with 4 branches, 2 of them broken; Serrula exterior with 17 lamellae; Five setae on hand: b, sb and es dentate; Rallum with 3 blades; Coxal chaetotaxy: on pedipalpal coxa 16, coxa I with 13-14, coxa II: 18, coxa III: 21 and coxa IV: 26 setae. Pedipalps (Fig. 2E): Surface granulated, with clavate and long dentate setae on each segment; Femur 2.66 times, patella 1.97 times longer than broad; Fixed chelal finger with 45 and movable finger with 37 small cusped teeth (Fig. 2D); On the external side of chela, 7 accessory teeth on fixed and 2 on movable finger; On the internal side, fixed finger with 5 and movable finger with 2 accessory teeth. Abdomen: Tergal chaetotaxy I - XI: 1L5P1M: 1L5P1M: 1L5P0M: 1L6P1M: 1L6P1M: 1L6P1M: 1L5P1M: 1L5P1M: 1L3P1M: 1L2P1M: 8; Last tergite with two long tactile setae (one of them broken); Anal cone with 2 dorsal and 2 ventral setae; Sternal chaetotaxy IV-XI: 4:8:(?):12:12:18:18:12:8; Female genital atrium with a T-shaped spermatheca. Legs: One tactile seta at the middle of tarsus of leg lV (Fig. 2C) (broken, only its base is visible); Claws simple, arolium shorter than claws. Dimension (in mm): Body - 1.51; Carapace - 0.57/0.53 (1.07x); chelicera - 0.20/0.09 (2.37x); movable cheliceral finger - 0.13; Pedipalp: Femur - 0.50/0.21 (2.41x); patella - 0.46/0.23 (1.99x); chela - 0.94; chelal movable finger - 0.45; hand with pedicel - 0.47/0.31; hand without pedicel - 0.42. Leg I: femur - 0.13/0.07 (1.84x); patella - 0.19/0.7 (2.63x); tibia - 0.19/0.05 (3.61x); tarsus - 0.23/0.03 (7.23x); Leg IV: femur - 0.14/0.10 (1.37x); patella - 0.34/0.08 (4.20x); tibia - 0.36/0.06 (5.51x); tarsus - 0.27/0.05 (5.05x).

Remarks.

Kintrishi National Park, the place of the new species record, is unique with its climate, plant and animal diversity. Here are presented Colchic relict forests with evergreen undergrowth ( Dieterich 2018). Previously, five pseudoscorpion species were recorded from this area: Neobisium crassifemoratum (Beier, 1928); N. fuscimanum (C.L. Koch, 1843); N. sylvaticum (C.L. Koch, 1835); N. labinskyi Beier, 1937; and N. validum (L. Koch, 1873) ( Kvavadze et al. 2008). Besides Psealaphochernes , four other chernetid genera are present in Georgia, namely, Allochernes , Chernes , Dendrochernes , and Lamprochernes (WPC 2023). The genus Pselaphochernes can be distinguished from all other chernetid genera based on the following combination of characters: having a T-shaped spermatheca; a rallum with 3 blades; the long tactile seta of pedal tarsus IV situated medially; and the posterolateral corner of coxa IV normal (Nassirkhani, 2018).

Though the characters of our specimen fit very well with other descriptions of Pselaphochernes scorpioides ( Beier 1963; Nassirkhani 2018), we have found some slight differences that might be within intraspecific variation. Our specimen differed from the specimens described by Nassirkhani (2018) in having only 4 pairs of lyrifissures on the carapace, while the Iranian specimens did have 5 pairs. The new specimen differed from Beier's redescription ( Beier 1963) in having 7 external accessory teeth on the fixed finger and 5 on the movable one (8 and 6 in Beier's redescription, respectively). Additionally, the new Georgian specimen has a lower femur length/width ratio (2.41x) compared to the descriptions of Beier (1963) and Nassirkhani (2018) (2.5-2.6x and 2.5-2.83x, respectively), but it is still within the range given by Christophoryová and Jablonski (2017) (2.27-2.95). In the Caucasus, the only other known species of the genus is P. lacertosus (L. Koch, 1873), which differs from P. scorpioides in having a shorter chelal finger than its chelal hand without pedicel ( Beier 1932; Beier 1963). Based on the known area of the species, the occurrence of P. lacertosus (WPC 2023) in Georgia is also possible.

The preferred habitat type of the newly recorded species, Pselapochernes scorpioides , is heaps with decomposing materials ( Beier 1955, 1961, 1963, 1966; Ressl and Beier 1958; Ressl 1970). However, it was also collected from leaf litter, bird and ant nests, dead wood, tree hollows, decaying wood, under tree bark, and using malaise traps ( Christophoryová 2010, 2013; Kaňuchová et al. 2016), therefore showing a diverse range of habitat preferences.

Phoresy on dipterans was observed in the case of P. scorpioides ( Graham-Smith 1916; Weygoldt 1969; Muchmore 1971; Jones 1978; Cuthbertson 1982; Hete ová and Christophoryová 2022; Jurgová et al. 2019). This provides possible ways of trapping the specimen in the malaise trap, which is primarily used for collecting flying insects.

Our knowledge of the pseudoscorpion fauna of Georgia and other parts of the Caucasus is far from complete. With the new finding of P. scorpioides , the number of pseudoscorpion species known from the country has increased to 54. The genus Pselaphochernes is also new to the fauna of Georgia. The new finding clearly shows the need for further investigations of the Georgian pseudoscorpion fauna.