Arrhopalites persicus, Vargovitsh & Kahrarian, 2020

Vargovitsh, Robert S. & Kahrarian, Morteza, 2020, A new species of Arrhopalites Börner, 1906 (Collembola, Symphypleona, Arrhopalitidae) from Iran with an updated key to A. diversus group of species, Zootaxa 4759 (3), pp. 338-350 : 339-343

Arrhopalites persicus sp. nov.

Figs 1–36 , Tables 1–3

Diagnosis. Body white or very slightly pigmented, up to 0.8 mm long. Setae of head dorsum slightly spine-like. Antenna 1.2–1.3× of head; Ant IV not subdivided, with 12 whorls of setae. Claw I with tiny inner tooth and short narrow tunica along distal third of outer margin; claw II and III with well-developed inner tooth and broad tunica. Empodium I with tiny corner tooth, apical filament slightly overtopping claws tip; empodium II and III without tooth, shorter (III) or reaching (II) the tip of corresponding claw. Tibiotarsi I–III with 40, 40, 41 setae; seta FSa on ti-biotarsus III absent. Tenaculum with 1 seta. Manubrium with 5+5 setae. Dens with 3, 2, 1, 1 simple anterior setae; posterior side with 11 setae, 5 of which are strongly spine-like. Mucro with 30–40 teeth on each posterior lamella and with swollen globular tip. Trichobothria ABC form an angle about 90–110 o and AB> BC. Seta 3 of central dorsal complex as short bent sensillum. Sixth abdominal segment with 5+5 cuticular spines; circumanal setae long and broadened; appendices anales smooth and acuminate distally.

Type material. Holotype: female, soil and leaf litter under oak trees ( Q. infectoria veneris ), Kal Kushk Village (N 33°59’19.2”, E 47°11’22.0”, elev. 1516 m), Osmanevand area, Kermanshah County, Kermanshah, Iran, 13.xii.2013, M. Kahrarian leg.

Paratypes: 1 female, same data as in holotype . 8 females, 1 juv., soil and leaf litter under oak trees ( Q. infectoria veneris ), Qader Mazd Village (N 34°0’15.6”, E 47°12’9.4”, elev. 1682 m), Osmanevand area, Kermanshah County, Kermanshah, Iran, 13.xii.2013, M. Kahrarian leg. 1 female, soil and leaf litter under oak trees ( Q. infectoria veneris ), Cheshmeh Sorkh Village (N 33°59’15.5”, E 47°16’37.8”, elev. 1937 m), Osmanevand area, Kermanshah County, Kermanshah, Iran, 20.xii.2013, M. Kahrarian leg.

Holotype (slide 25-6) and 11 paratypes (slides 25-7, 27-1, 27-2, 27-3, 27-4, 27-5, 27-7, 27-9, 27-10, 27-11, 29-5) are deposited in the collection of the Schmalhausen Institute of Zoology, National Academy of Sciences of Ukraine, Kiev.

Description. Female: Body length up to about 0.8 mm, habitus as in Fig. 21 , white or with slight diffuse traces of pigmentation.

Head ( Figs 1 , 22 ). Eyes 1+1, about 4 μm in diameter, unpigmented, sometimes hardly noticeable. Clypeal area: row a: 4 + axial + 4 setae, rows b, c, d and e with 5+5 setae each, row f with 6+6 setae, median region M with 3 setae (marked with oval in Fig. 1 ). Interantennal area: row α: 2+2, row β: 1 + axial + 1. Dorsal area (rows A to D): axial seta present in rows A, B and C; 6(5)+1+6(5) dorsal setae (13 or 11 in total) usually slightly thickened ( Figs 1, 5 , 22 ). Chaetotaxy of the head posterior side as in Fig. 1 (dotted lines).

Chaetotaxy of mouth region. Labrum ( Fig. 1 ): labral / prelabral chaetotaxy: 4 5 5 / 6.

Labium: submentum with 4 setae, mentum with 5 setae; labial palp ( Figs 3 , 24 ) with 4 proximal setae, 5 papillae (A, B, C, D, E) with deeply inserted setae and with 12 associated guard setae (a1, b1-4, d1-3, e1-4 of which b1 and b2 are blunt and thickened) and 3 hypostomal setae (H, h1, h2) one of which is distinctly curved. Maxilla as in Fig. 25 . Apical seta of the maxillary outer lobe ( Fig. 2 ) with short and thin subparallel branch at the base, sublobal plate with three sublobal hairs. Oral fold with 2 setae.

Antenna ( Figs 4 , 23 ) short, about 1.3× of head. Mean length ratio of antennal segments I: II: III: IV = 1: 2.1: 2.8: 5.3 (1: 2.4: 3.1: 5.6 in holotype). Ant I with 7 setae, p as microseta (3.6 μm). Ant II with 14 setae one of which is more than 2× longer than others. Ant III subbasally moderately swollen, with following chaetotaxy: 17 simple setae of which Api and Ape especially thin, 2 sense rods in shallow pits (4.4 μm in holotype) and Aai as small (3 μm in holotype) bent and blunt sensillum ( Fig. 23 ). Ant IV short and undivided, bears 12 densely settled whorls of setae without clear empty spaces between them ( Fig. 4 ).

Legs. Foreleg ( Figs 13 , 16 , 28 ): precoxae 1, 2 and coxa with 1, 0, 1 setae respectively ( Fig. 16 ). Trochanter with 3 anterior and 1 posterior setae. Femur with 12 setae, a4 turned perpendicularly to the longitudinal axis of the segment, p3 as microseta. Tibiotarsus with 40 setae: whorls I–II with 7, whorls III–IV with 8, whorl V with 7 (sometimes 6) setae and region F with 3 primary setae (e, ae, pe). Pretarsus with 1 anterior and 1 posterior setulae. Foot complex ( Fig. 28 ). Claw: with short narrow tunica along distal third of outer margin (sometimes unnoticable); with tiny inner tooth, about 5× shorter than tibiotarsus. Empodium: thin, with hardly noticeable tiny corner tooth or without, 1.1–1.2× shorter than claw; tip of empodial filament overtopping tip of claw.

Mid leg ( Figs 14 , 16 , 29 ): precoxae 1 and 2 with 1, 1 setae respectively, precoxal process present, coxa with 3 setae and microsensillum ( Fig. 16 ). Trochanter with 4 setae including 2 simple anterior and 1 posterior setae and anterior trochanteral organ. Femur with 13 setae, 1 posterior as microseta. Tibiotarsus with 40 setae: distal whorl I with 7, whorls II–IV with 8, whorl V with 6 setae, basal region F with 3 FP setae. Foot complex ( Fig. 29 ). Claw: with well-developed tunica, distinct inner tooth, 4.7–5.5× shorter than tibiotarsus (5.1 in holotype). Empodium: broader than in foreleg, without corner tooth, 1.3–1.7× (1.5 in holotype) shorter than claw; tip of empodial filament visually not reaching or almost reaching tip of claw.

Hind leg ( Figs 15 , 16 , 30 ): precoxae 1 and 2 with 1, 1 setae respectively, process on precoxa 1 present, coxa with 3 setae and microsensillum ( Fig. 16 ). Trochanter with 4 setae: anterior trochanteral organ, 2 anterior and 1 posterior simple setae. Femur with 12 setae, 2 posterior ones as microsetae. Tibiotarsus with 41 setae: whorl I–IV with 8, whorl V with 6 setae, region F with 3 primary setae FP present and secondary seta FSa absent. Foot complex ( Fig. 30 ). Claw: with broad tunica, with distinct inner tooth, 5.4–6.3× shorter than tibiotarsus (6.3 in holotype). Empodium: broad, corner tooth absent, 1.5–2.1× shorter than claw; tip of empodial filament not reaching tip of claw.

Mean lengths ratio of tibiotarsi I: II: III = 1: 1: 1.3 (same as in holotype). Tibiotarsus I about 2× shorter than head.

Ventral tube ( Fig. 16 ) with 1+1 subapical microsetae.

Tenaculum ( Fig. 18 ): each ramus with 3 teeth and a basal process; anterior lobe with 1 apical seta.

Furca ( Figs 17 , 31 ). Manubrium with 5+5 posterior setae. Dens with 18 setae (7 anterior and 11 posterior). 3, 2, 1, 1 thin setae on anterior side, Ia – not modified ( Fig. 10 ). Posterior side with 5 distinctly spine-like setae: Ie ( Fig. 11 ), Ii and Ipe–IIIpe. Mucro densely serrated with 30–40 teeth on each lateral lamella, with globular apex ( Fig. 31 ). Dens 1.3–1.7× as long as mucro (1.5 in holotype).

Great abdomen ( Figs 16 , 26, 27 ). Segments Th II and III bearing single short and bent sensillum in row a ( Fig. 34 ) and 3 setae in row m with m1 ( Figs 6 , 35 ) about as long as setae of posterior complex ( Figs 7 , 36 ). Abd I bears single row with 5 setae. Trichobothrial complex ( Figs 16 , 26 ): ABC form about right or a little obtuse angle (91°–111°) and AB is 1.3–1.9× longer than BC (1.5 in holotype); seta a stronger and longer than others of complex; seta p is located approximately at the level of trichobothrium B; seta b1 lies on line BC, closer to C; microseta c1 (4.5–6.8 μm) lies in front of trichobothrium C and seta c2 —below C. Posterior lateral complex with 6 setae in two rows and furca base complex with 8 setae in two rows, neosminthuroid seta absent. Central dorsal complex with usual setae 1 and 2 and curved sensillum 3 ( Fig. 27 ). Posterior dorsal complex with 21–25 relatively short setae ( Figs 7 , 36 ) arranged in 3 longitudinal rows, the longest of which (among the most posterior setae of rows dI–dIII) = 20–29 μm (24 μm in holotype) and is somewhat shorter or subequal to hind claw ( Table 2). Ventral complex with 2 setae.

Small abdomen. Fifth abdominal segment ( Fig. 19 ) with 2 setae and trichobothrium D in row a, and 2 setae in row p. Genital field usually with 3+3 microsetae along anterior margin of genital opening.

Sixth abdominal segment ( Figs 19 , 32 ) with 5+5 cuticular spines: 3+3 on dorsal valve and 2+2 on each of lateral valves; s2 and s3 on dorsal valve usually larger than others ( Table 1). Dorsal valve with 11 + 2 axial + 11 setae. Each of lateral valves bears 18 setae. Circumanal row with 5+1+5 modified setae (ms1, mps1–mps3 and mpi1–mpi2): long (the longest = 40–81 μm, that is about 2–3× longer than posterior setae of great abdomen), broadened but without distinct lamellation or basal serration ( Figs 8, 9 ). Appendices anales ( Figs 12 , 33 ) (18–37 μm) smooth and apically acuminate; sitting on globular basal papilla. However, under highest magnification in dorso-lateral position few hardly noticeable toothlets on apex were observed ( Fig. 33 ). In total, normally 60 setae and 10 cuticular spines on Abd VI are present.

Male not seen.

Variability. Two cases of teratology were observed: in two females (paratypes: slide 27-3 and 27-10) seta ms1 distinctly bifurcated and in one female (paratype: slide 27-9) claw of left hind leg bears two inner teeth.

Bionomy and distribution. Specimens of Arrhopalites persicus sp. nov. were sampled from three sites in western Iran ( Fig. 20 ) from upper soil layer and litter under oak trees.

Etymology. The species name is an adjective derived from Persia, the Latin name pertaining to Iran.

Figures

FIGURES 1–12. Arrhopalites persicus sp. nov.: 1, chaetotaxy of head; 2, maxillary outer lobe; 3, chaetotaxy of labial palp; 4, chaetotaxy of antenna; 5–11, shape of setae: 5, seta of head vertex; 6, m1 of mesothorax; 7, dIII-1 of great abdomen; 8, ms1 of Abd VI; 9, mps3 of abd VI; 10, Ia of dens; 11, Ie of dens; 12, appendices anales.

FIGURES 13–15. Arrhopalites persicus sp. nov.: 13, chaetotaxy of foreleg; 14, chaetotaxy of mid leg; 15, chaetotaxy of hind leg.

FIGURES 16–19. Arrhopalites persicus sp. nov.: 16, chaetotaxy of great abdomen; 17, chaetotaxy of furca; 18, tenaculum; 19, chaetotaxy of small abdomen.

FIGURES 20–25. Arrhopalites persicus sp. nov.: 20, type localities on map of Iran: blue mark—Kal Kushk, red mark—Qader Mazd, green mark—Cheshmeh Sorkh; 21, habitus of mounted female; 22, fragment of head dorsum; 23, chaetotaxy of antennal III organ; 24, labial palps; 25, maxillae heads.

FIGURES 26–31. Arrhopalites persicus sp. nov.: 26, chaetotaxy of trichobothrial complex; 27, chaetotaxy of central dorsal complex with seta 3 as sensilla; 28–30, foot complex: 28, foreleg; 29, mid leg; 30, hindleg; 31, mucro.

FIGURES 32–36. Arrhopalites persicus sp. nov.: 32, dorsal valve of female Abd VI with broadened circumanal setae and 3+3 cuticular spines; 33, appendices anales with enlarged apex; 34–36, setae of great abdomen: 34, sensilla a of mesothorax; 35, dorsal seta m1 of mesothorax; 36, setae of posterior dorsal complex.