Halocosa Azarkina & Trilikauskas, 2019

Wang, Lu-Yu, Irfan, Muhammad, Marusik, Yuri M. & Zhang, Zhi-Sheng, 2024, Review of the wolf spider genus Halocosa Azarkina & Trilikauskas, 2019 from China (Araneae, Lycosidae), ZooKeys 1218, pp. 99-111 : 99-111

Halocosa Azarkina & Trilikauskas, 2019

Type species.

Lycosa cereipes L. Koch, 1878 from Turkmenistan.

Diagnosis.

This genus resembles Xerolycosa Dahl, 1908 , another genus within subfamily Evippinae . Species of both genera lack a transverse depression on the carapace (Fig. 2 A, B ), tibia I and II with three pairs of ventral spines (Fig. 2 E, F ), and male palps with a bifid terminal apophysis (Fig. 2 G, H ). Halocosa can be distinguished by the presence of three retromarginal cheliceral teeth in Halocosa (Fig. 2 C, D ; vs. with two teeth in Xerolycosa ); embolus lacking accompanied membrane (Fig. 2 C, D ; vs. present in Xerolycosa ); strong or small tegular sclerite, bifid terminal apophysis (anterior arm strong and sclerotized, posterior arm thin and membranous) in Halocosa (Figs 3 A, B , 4 C – F , 5 , 6 A, B , 7 E, F , 8 ; vs. both are membranous in Xerolycosa ); wide square or rectangular septum covering whole atrium in Halocosa (vs. pear-shaped, partly covering atrium in Xerolycosa ); slit-like copulatory openings, presence of accessory tube-like glands in Halocosa (Figs 3 C, D , 4 G, H , 6 C, D , 7 G, H ; vs. glands absent in Xerolycosa ).

Description.

Medium sized (6.4–13.21) ( Azarkina and Trilikauskas 2019) light colored. Carapace dirty brown with pattern formed by yellowish spots: butterfly like spot around fovea, pair of bean-shaped spots posteriorly from eye field and three pairs of marginal round spots; sternum brown; dorsum of abdomen with variegated pattern formed by numerous paired and unpaired spots on dirty brown background, venter uniformly yellow. Carapace very low (length / height ratio c. 4), furrow between cephalic and thoracic parts absent. Chelicera with three pro- and three retromarginal teeth. Leg formula: 4123 or 4132. Femora I – IV with three dorsal spines, patella with one dorsal, tibia and metatarsi III and IV with two dorsal spines (not indicated in tables). Within the intraspecific, the dorsal spines on tibia and metatarsus can be strong or weak, almost indistinguishable from large setae.

Palp with droplet-shaped cymbium, subtegulum (St) small, placed on prolateral side; tegulum large, going rather high on prolateral side with long ridge (Tr) on prolateral side that hold and hide part of embolus (Em); retrolateral part of tegulum with extension directed anteriorly, terminating by conductor, median part with tegular sclerite (TS); seminal duct thin, with “ sharp ” loop (Sl) on prolateral half; median apophysis located closer to retrolateral part of tegulum, without extensions, inner side of median apophysis with kind of pocket (or furrow) (MA), that holds tip of embolus and seems to serve as functional conductor; in retrolateral view median apophysis concave; embolic division with large sharply pointed terminal apophysis (TA) accompanied by membranous subterminal apophysis (SA); embolus long whip-like, smoothly rounded, slightly bent near tip, making almost whole circle, partly hidden by tegular ridge and median apophysis, base of embolus located in position of 2 o’clock.

Epigyne relatively small, one-fifth the width of the abdomen, densely covered with white setae to such extent that adult female could be considered as juvenile, especially in the field; fovea / atrium absent, totally covered with rectangular septum, septal stem absent, copulatory openings located in anterior part of epigynal plate, open into deep bulge which turns to wide, weakly sclerotized duct going straight down, near epigastral fold this duct turns up into strongly sclerotized, partly twisted, duct terminating by more or less clavate spermatheca; heavily sclerotized part of duct with finger-like or clavate accessorial gland (Ag).

Relationships.

Azarkina and Trilikauskas (2019) placed this genus in Lycosinae due to “ the latero-median origin of the embolus that is situated in a shallow and wide depression ”. This placement appears to be incorrect. All Lycosinae have palea (lacking in Halocosa ), the median apophysis originates prolaterally and stretches horizontally (vs. originates retrolaterally and stretches parallel to cymbium axis), and the septum is not covered with setae (with exception of Arctosa ) (vs. covered with setae). In addition, the carapace in Halocosa is very low, 3–4 times longer than high in comparison to Lycosinae (c. 2.4 longer than wide). To the best of our knowledge, the copulatory organs of this genus, as well as the flattened carapace, fit well with those known in Evippinae . Therefore, we consider Halocosa in Evippinae .

Composition.

Two species: H. cereipes (L. Koch, 1878) and H. hatanensis ( Urita, Tang & Song, 1993) .

Biology.

Halocosa cereipes is a dweller of saline places. It was collected around salt lakes ( Iran, Azerbaijan, around the Aral Sea), and on the low seashore in the Crimea (personal data). The same habitats were reported by Azarkina and Trilikauskas (2019). Numerous spots on the carapace and abdomen, and leg annulation make the spiders very cryptic, and invisible if they are not moving.

Distribution.

From southern Ukraine to western Inner Mongolia, south to Iran ( Azarkina and Trilikauskas 2019; Nentwig et al. 2021). In China, known from Xinjiang, Ningxia, Qinghai and Inner Mongolia (present paper).

Figures

Figure 2. Halocosa spp. A, C, E, G Halocosa cereipes (L. Koch, 1878) B, D, F, H Halocosa hatanensis (Urita, Tang & Song, 1993) A, B carapace, lateral view C, D chelicerae, ventral view E, F tibia of leg I, ventral view G, H terminal apophysis and embolus, ventral view.

Figure 3. Halocosa cereipes (L. Koch, 1878) A left male palp, ventral view B same, retrolateral view C epigyne, ventral view D vulva, dorsal view.

Figure 4. Halocosa cereipes (L. Koch, 1878) A male habitus, dorsal view B female habitus, dorsal view C left male palp, bulb, ventral view D same, retrolateral view E left male palp, ventral view F same, retrolateral view G epigyne, ventral view H vulva, dorsal view.

Figure 5. Halocosa cereipes (L. Koch, 1878) A left male pedipalp, bulb, ventral view B same, retrolateral view C median apophysis and conductor, retrolateral view D embolic base, ventral view E median apophysis, ventral view F tegular sclerite, ventral view.

Figure 6. Halocosa hatanensis (Urita, Tang & Song, 1993) A left male pedipalp, ventral view B same, retrolateral view C epigyne, ventral view D same, dorsal view. Abbreviations: CO = copulatory opening; Co = conductor; Em = embolus; FD = fertilization duct; HS = head of spermatheca; MA = median apophysis; Se = septum; SS = stalk of spermatheca; St = subtegulum; TA = terminal apophysis; Te = tegulum; Ts = tegular sclerite.

Figure 7. Halocosa hatanensis (Urita, Tang & Song, 1993) A male habitus, dorsal view B female habitus, dorsal view C left male palp, bulb, ventral view D same, retrolateral view E left male palp, ventral view F same, retrolateral view G epigyne, ventral view H vulva, dorsal view.

Figure 8. Halocosa hatanensis (Urita, Tang & Song, 1993) A left male pedipalp, bulb, ventral view B same, retrolateral view C median apophysis, ventral view D median apophysis and conductor, retrolateral view.