Petrobia (Petrobia) tabarjalensis Mirza & Kamran & Alatawi 2023, sp. nov.
Creators: name: Mirza, Jawwad Hassan
name: Kamran, Muhammad
name: Alatawi, Fahad Jaber
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Trombidiformes
Tetranychidae
Petrobia
Petrobia tabarjalensis

description: Petrobia (Petrobia) tabarjalensis sp. nov.
Diagnosis. Females with stylophore anteriorly indented, propodosoma medially with regular longitudinal striations, leg tibiae I with 12 tactile setae, leg I shorter than body, setae f 1 surpassing the bases of setae f 2, setae f 1 -f 2 and h 1 appear on tiny bulges.
Description
Female (n = 7): Length of body (v 2 –h 1) 410 (402‒434), including gnathosoma 520 (502‒ 519); width (c 3 –c 3) 338 (330‒354); length of legs (from trochanter to distal end of tarsus): leg I 380 (375‒380); leg II 238 (237‒240); leg III 257 (255‒260), leg IV 305 (299‒315); leg I/ v2–h1:0.92.
Dorsum. (Figure 11a,b) Propodosomal shield defined by weak longitudinal regular striations, two pairs of eyes; lateral idiosoma with longitudinal striations, opisthosomal striae fine, transverse medially between setae c 1 –h 1, except submedially changing to v-shaped striation pattern posterior to setae d 1 and e 2 (Figure 11a). Dorsal setae lanceolate, serrate, slightly expanded distally (Figure 11b), shorter than the longitudinal distance between the setae next in line, except setae f 1 extending beyond the bases of f 2 and setae f 2 reaching the bases of h 1-2, setae f 1, f 2 and h 1 appear to be present on very tiny bulges. Lengths of dorsal setae v 2 38 (36‒38), sc 1 34 (33‒35), sc 2 34 (32‒37), c 1 36 (32‒36), c 2 33 (30‒34), c 3 33 (30‒ 34), d 1 29 (25‒30), d 2 28 (27‒31), e 1 31 (30‒32), e 2 38 (36‒39), f 1 34 (32‒36), f 2 33 (31‒34), h 1 36 (32‒35). Distances between dorsal setae: v 2 –v 2 61 (60‒65), sc 1 –sc 1 162 (160‒166), sc 2 –sc 2 235 (228‒240), c 1 –c 1 125 (120‒128), d 1 –d 1 100 (92–107), e 1 – e 1 62 (58–64), f 1 –f 1 45 (42‒46), h 1 –h 1 35 (32–36), c 1 –d 1 52 (50‒57), d 1 – e 1 55 (52‒59), e 1 –f 1 55 (50‒55), f 1 –h 1 55 (51‒54).
Venter. (Figures 12, 13) Area between setae 1a–3a with transverse striae, 3a–4a with longitudinal striae, posterior opisthosoma with transverse striae, anterior of genitoanal area with longitudinal striae (Figure 12). Lengths of setae: la 52 (50‒54), 1b 61 (60–65), 1c 26 (24‒29), 2b 44 (42‒47), 2c 25 (22‒28), 3a 44 (43‒49), 3b 29 (24‒29), 4a 52 (52‒54), 4b 29 (26‒29), one pair of aggenital setae (ag), two pairs of genital setae (g 1 ‒g 2) and three pairs of anal setae (ps 1‒3) (Figure 13). Spermatheca with very elongated sacculus, 18 (17–18) (Figure 13).
Gnathosoma. (Figures 14, 15) Ventral infracapitulum with one pair of adoral setae or 3 (2‒4) and one pair of subcapitular setae m 36 (34‒39). Palp five-segmented, palp tarsus with one solenidion, three eupathidia and three simple setae; palp tibia with three setae and one entire claw distally, palp genu and palp femur each with one serrated seta (Figure 14). Peritremes with elongate anastomosed ends (Figure 15).
Legs. (Figures 16–19) Leg I shorter than body length. Leg segment setal formula as follows: coxae 2-2-1-1; trochanters 1-1-1-1; femora 8-5-3-3; genua 5-5-3-3; tibiae 13(1φ)- 9-8-8; tarsi 12 (2dup)-11 (1dup)-11 (1dup)-11 (1dup). Tarsus I and IV with solenidia Iω ′ 74 (72‒74), Iω ″ 66 (66‒68), IIω ″ 41 (40‒42), IIIω ′ 36 (34‒36), IVω ′ 38 (34‒39) and tibia I with Iφ 1 31 (30‒33). Most leg setae narrowly lanceolate, barbed; setae at tips of tarsi slender, smooth. Empodia I–IV with true claws pad-like, two-thirds the length of empodial claws bearing two rows of ventrally directed hairs (Figures 16–19).
Etymology. The specific epithet is derived from the type locality where the new species was collected (tabarjalensis = Tabarjal, Saudi Arabia).
Type materials. One holotype and six paratype females, Chrozophora sp. (Euphorbiaceae), Tabarjal, Jouf, 30.53192°N, 38.23592°E, 27 May 2022, coll. H.M.S. Mushtaq.
Remarks
The new species belongs to the subgenus Petrobia (Petrobia) and is morphologically closer to P. (P.) pseudotetranychina Auger and Flechtmann (Tunisia) based on the following combination of characters: femur III–IV and genu III–IV each with three setae, dorsal setae short and spatulate to lanceolate and shorter than longitudinal intervals between them, dorsal striation smooth; striae between setae c 1 –d 1 transverse, setae f 1 longer than f 1 -f 2, leg tibiae III–IV each with eight setae. The new species differs from P. (P.) pseudotetranychina by shape of stylophore (indented vs rounded), striation pattern medially on propodosoma (regular longitudinal vs broken longitudinal), and anterior to genital region (longitudinal vs irregular), length of leg I (obviously shorter vs slightly longer than body), and number of setae on tarsus I (12 (2dup) vs 14 (2 dup)). The new species also differs from P. (P.) arabica sp. nov. based on number of setae on leg femur I–II (8–5 vs 6–6), and on leg tibiae III–IV (8–8 vs 5–5), shape of palp tibial claw (entirely intact vs bifid), and length of setae f 1 (reaching f 2 vs shorter than f 1 -f 2).
description: Published as part of Mirza, Jawwad Hassan, Kamran, Muhammad & Alatawi, Fahad Jaber, 2023, Two new species of the subgenus Petrobia (Petrobia) Müller from Saudi Arabia, pp. 1178-1191 in Journal of Natural History 57 (21 - 24) on pages 1185-1189, DOI: 10.1080/00222933.2023.2238947, http://zenodo.org/record/8270909