Pseudopygmephorellus mazandaranicus Katlav and Hajiqanbar

Katlav, Alihan, Hajiqanbar, Hamidreza & Talebi, Ali Asghar, 2015, Pseudopygmephorellus mazandaranicus sp. nov. (Acari: Heterostigmata: Pygmephoridae), phoretic on scarabaeid dung beetles (Coleoptera: Scarabaeidae) from Iran, Zootaxa 3919 (1), pp. 100-110 : 101-108

Pseudopygmephorellus mazandaranicus Katlav and Hajiqanbar sp. nov.

Diagnosis. The phoretic female of the new species is characterized by having: two claws on tarsus IV; posterior margin of the prodorsum nearly straight; setiform epimeral setae 1 a, 1 b, 2 a, 2 c; setae v 1 situated posterior to the level of setae v 2; reduced apodemes 5; setiform TaII tc' (slender and tapering); setiform and pointed FeIV v’.

Description. Female. Length of idiosoma 212 (194–229), maximum width (measured on widest part of segment C) 128 (119–135).

Gnathosoma ( Figs. 1–2 ). Length of gnathosoma 20 (18–20), width 24 (22–25). Gnathosomal capsule rounded sub-trapezoid in dorsal aspect, slightly wider than long, dorsally with one pair of pointed and smooth cheliceral setae ch 1 5 (4–6) and a weak longitudinal dorsal median apodeme in its anterior half (hardly discernible in some specimens), ventrally with one pair of pointed subcapitular setae su 4 (4–4); palpi dorsally with a pair of smooth and pointed setae dGe 11 (9–11) and a pair of smooth and needle-like setae dFe 6 (5–6), dGe nearly twice longer than dFe; tibiotarsus with single solenidion ventrally (barely visible in some specimens) and a terminal claw; chelicerae inconspicuous; pharyngeal system ( Fig. 3 ) including three striated pumps: pump 1 smallest and bowlike, pump 2 well developed and subcylindrical, pump 3 inverted cordate.

Idiosomal dorsum ( Fig. 4 ). Anterior part of idiosoma overlapping posterior part of gnathosoma like a collar. All dorsal shields smooth, in a few specimens each tergite is posteriorly sparsely ornamented with barely visible small dimples; all dorsal setae slightly barbed and moderately blunt-ending, except smooth, attenuate and pointed setae v 1 and smooth and needle-like setae v 2; prodorsal shield (PrS) ( Figs. 4 and 15) broad flask-shaped, narrower and concave in its anterolateral margins, with one pair of thin-stemmed capitate trichobothria (sc 1) and three pairs of setae v 1 17 (17–18), v 2 16 (16–16) and sc 2 39 (37–39), v 1 slightly longer v 2, both shorter than seta sc 2; ovoid stigmata located anterolaterally on prodorsum, associated with conspicuous atria; all cupuli (ia, im, and ih) evident, rounded; on tergite C c 2 39 (36–39) slightly longer than c 1 33 (29–33); setae d 37 (32–36) on tergite D barely reaching the base of f 43 (38–42) on tergite EF; tergite EF with barely visible small dimples, setae e 19 (17–21) barely exceeding the posterior margin of tergite EF, setae f approximately 2.2 times longer than e; on tergite H setae h 1 43 (38–43) more than 3.5 times longer than setae h 2 12 (9–11). Distance between setae: v 1– v 1 11 (11–14), v 1– v 2 17 (15–17), v 2– v 2 38 (34–39), sc 2– sc 2 49 (44–48), c 1– c 1 38 (34–39), c 1− c 2 24 (22–24), c 2− c 2 83 (76–85), d–d 48 (46–53), e–e 60 (54–62), e–f 7 (5–7), f–f 51 (46–53), h 1– h 1 40 (38–45), h 2– h 2 51 (48–56), h 1– h 2 6 (5–7).

Idiosomal venter ( Fig. 5 ). Ventral plates distinctly smooth; all propodosomal apodemes (ap1, ap2, appr and apsej) fully developed; ap1 reaching to presternal apodeme (appr), forming well scelerotized Y-shape juncture with appr; ap2 uniting with appr, with moderately thickened and arched lateral ends; sejugal apodeme (apsej) uniting to appr, medially forming a tiny protuberance; ap3 thickened and well sclerotized; ap4 partly developed, extending beyond seta 3 c; both ap4 and ap5 joined with poststernal apodeme (appo); ap5 reduced to a lateral fragment; all epimeral setae smooth and pointed except setae 1 c and 1 b which are moderately barbed and pointed; coxisternal plate I with three pairs of setae 1 a 11 (9–12), 1 b 14 (13–16) and 1 c 12 (11–13), setae 1 b obviously longest on the plate, setae 1 c situated adjacent to ap1; coxisternal plate II with two pairs of subequal setae 2 a 13 (11–13) and 2 c 12 (12–13); coxisternal plate III with three pairs of setae 3 a 14 (12–13), 3 b 15 (14–16) and 3 c 13 (12–13), coxisternal plate IV with three pairs of setae 4 a 13 (11–13), 4 b 15 (13–14) and 4 c 18 (16 – 19); 4 c longest among epimeral setae; posterolateral margins of poststernal plate weakly convex and undulated; posterior margin of aggenital plate weakly concave medially; anterior genital sclerite (ags) small and mushroom-like, posterior genital sclerite (pgs) tiny and oval; pseudanal plate (PS) with three pairs of setae ps 1 12 (12–13), ps 2 13 (12–13) and ps 3 16 (16–17), seta ps 3 weakly barbed and blunt ending, setae ps 1 and ps 2 somewhat delicate and needle-like, close together.

Legs ( Figs. 6–10 ). Leg I 71 (67 – 72) ( Fig. 6 ): thicker and shorter than other legs with a massive sickle-like claw opposed to a thick counterpiece (forming clasper-like structure); setal formula (solenidia in parentheses): Tr1-Fe4- Ge3-TiTa17(ω 1, ω 2, φ 1, φ 2). Tibiotarsus: all solenidia including ω 1 6 (5–6), ω 2 3 (3–3), φ 1 5 (5–5) and φ 2 3 (3–3) finger-shaped; ω 2 and φ 2 tiny and subequal; φ 1 slightly shorter, but wider than ω 1 ( Fig. 8 a); eupathidia ft’, ft”, tc’, tc” and p’ moderately blunt-ending; setae d, l’ and l” barbed and pointed, l’ 28 (27 – 30) 1.5 times as long as l” 18 (18 – 20); remaining tibiotarsal setae smooth and pointed; ft’ slightly longer than ft”; setae p’, pv’, pv” and tc’ subequal; v” and pl’ whipped and subequal; v’ shortest on tibiotarsus. Genu: l’ and l” moderately barbed, l’ longer than l”; v’ smooth and pointed, shortest on genu. Femur: seta d hooked; l” nearly twice longer than l’; l’ slightly curved and blunt-ending. Trochanter: seta v’ slightly barbed and pointed.

Leg II 89 (87 – 92) ( Fig. 7 ): setal formula: Tr1-Fe3-Ge2-Ti4(φ)-Ta6(ω). Tarsus: dorso-distally with a sclerotized cone-like protrusion; solenidion ω 6 (6–6), finger-shaped; pv’, pv”, pl” and tc’ barbed and pointed; tc” slender, smooth and pointed; u’ moderately blunt-ending. Tibia: solenidion φ 2 (2–2) very small and hard to discern, situated in a shallow depression; v’ and l’ barbed, pointed and subequal; d smooth and pointed; v” attenuated and pointed, longest on tibia. Genu: l’ barbed and pointed, reaching base of tarsal solenidion; seta v’ pointed and slightly barbed. Femur: d barbed and blunt-ending, seta l’ smooth, stiff and blunt-ending, v” slightly barbed and pointed, subequal to d. Trochanter: v’ indistinctly slightly barbed and pointed.

Leg III 88 (86 – 92) ( Fig. 9 ): setal formula: Tr1-Fe2-Ge2-Ti4(φ) -Ta6. Tarsus: pv’ and pv” smooth and subequal; tc’ moderately barbed, subequal to smooth tc”; tc” slightly longer than pointed pl”; u’ somewhat blunt-ending and shortest on tarsus. Tibia: solenidion φ 2 (2–2) very small and hard to discern, situated in shallow depression; all setae pointed and moderately barbed; setae l’, v’ and v” subequal, slightly longer than d. Genu: setae l’ and v’ little barbed, pointed and subequal. Femur: v’ pointed and moderately barbed; d barbed and blunt-ending, longer than v’. Trochanter: v’ barbed and pointed.

Leg IV 112 (107 – 115) ( Fig. 10 ): Longer than other legs; setal formula: Tr1-Fe2-Ge1-Ti4-Ta6. Tarsus: all setae moderately barbed and pointed except seta pl” which is considerably stiff and blunt-ending; setae tc’ and pv’ subequal, slightly longer than subequal setae tc” and pv”. Tibia: solenidion φ not seen; v” barbed and with rather blunt apex; other tibial setae moderately barbed and pointed; d longest on the tibia. Genu: v’ barbed and pointed. Femur: v’ moderately barbed and pointed, d barbed and indistinctly blunt-ending, longer than v’. Trochanter: v’ barbed and pointed.

Male and larva unknown.

Differential diagnosis. The new species is most similar to P. szekessyi ( Mahunka, 1970) but differs from it in some characters as follows: in P. mazandaranicus sp. nov., solenidia on TiTaI (ω 1, ω 2, φ 1 and φ 2) and TaII (ω) much shorter than those in P. szekessyi (6 vs 10, 3 vs 7, 5 vs 8, 3 vs 6 and 6 vs 8, respectively) ( Fig. 8 b); all ventral and dorsal idiosomal tergites somewhat smooth (all ventral and dorsal idiosomal tergites densely ornamented with tiny dimples in P. szekessyi ); posterior margin of tergite EF with barely visible small dimples (posterior margin of tergite EF with prominent densely-dimpled microsculpture in P. szekessyi ); anterior genital sclerite (ags) small and mushroom-like, posterior genital sclerite (pgs) tiny and oval (ags small, much narrower anteriorly, forming arrowhead-like habitus, pgs larger, ellipsoidal, posteriorly with a tiny rounded protuberance in P. szekessyi ); ap5 considerably reduced (ap5 well developed in P. szekessyi ); seta TaII tc ' seta-like, with pointed apex (seta TaII tc ' thickened, somewhat pilose, with blunt apex in P. szekessyi ); seta FeII l’ rod-like and distinctly blunt-ending (seta FeII l’ seta-like and distinctly pointed in P. szekessyi ); setae TrI v ', TrII v ' and TrIV v ' distinctly pointed (setae TrI v ', TrII v ' and TrIV v ' somewhat blunt-ending in P. szekessyi ); seta FeIV v’ seta-like and distinctly pointed (seta FeIV v’ rod-like and distinctly blunt-ending in P. szekessyi ); seta TaIV pl" almost 1/3 as long as seta TaIV tc' (seta TaIV pl" approximately more than half as long as seta TaIV tc' in P. szekessyi ); seta TrI v' almost twice as long as seta FeI l' (setae TrI v' and FeI l ' subequal in P. szekessyi ).

Type material. Female holotype AK-20130318-H and more than 180 paratypes, as three colonies (each including more than 60 females), attaching firmly on soft membranes between head and pronotum (cervical membrane) and between pronotum and elytra of three specimens of the beetle Onthophagus sp. ( Coleoptera : Scarabaeidae ) ( Figs. 11–12 ). Host beetles were collected directly by forceps from cow-pads in Dohezar Forest, Tonekabon town, west of Mazandaran Province, northern Iran, (36°39′ N, 50°40′ E, altitude 578 m a.s.l.), 18 March 2013, leg. Alihan Katlav.

Additional material. Twelve females as two small colonies (one including 6 females and the other 7 females) attaching firmly to the first abdominal sternite near third coxae of two specimens of the beetle Aphodius varians Duftschmid, 1805 ( Coleoptera : Scarabaeidae ) ( Figs. 13–14 ) collected directly by forceps from cow-pads in Kzemkela village, Abbas abad, west of Mazandaran Province, northern Iran, (36°41′ N, 51°05′ E, altitude 9 m a.s.l.), 18 March 2013, leg. Alihan Katlav. Two extra females under elytra, on abdominal tergites of single specimen of the beetle Aphodius depressus (Kugelann, 1792) , same collection data as holotype.

Etymology. The specific epithet refers to the locality of the origin (Mazandaran province), a large district in Northern Iran.

Remarks. One of the 60 slide-mounted specimens, associated with A. depressus , had a setiform sc 1 (Fig. 16), however, the remaining characters were exactly the same. This anomaly could be a case of neoteny as larvae of other species have a setiform sc 1 (Evert E. Lindquist, personal communications) or may also be an implication for the phenomenon “atavism” in which an individual remarkably represent the tendency to revert to ancestral phenotypical features ( Le Page 2007). These features reappear in some individuals after several generations of absence ( Liu et al. 2009). Alternatively, this specimen could represent another species, but we refrain from considering this option with just one likely aberrant specimen.

FIGURES 15–16. Pseudopygmephorellus mazandaranicus Katlav and Hajiqanbar sp. nov. (female): 15. Prodorsum with capitate and bothridial shape of sc 1; 16. Prodorsum with setiform appearance of sc 1.

Figures

FIGURE 4. Pseudopygmephorellus mazandaranicus Katlav and Hajiqanbar sp. nov. (female): dorsum of the body. Scale bar 50 µm.

FIGURE 5. Pseudopygmephorellus mazandaranicus Katlav and Hajiqanbar sp. nov. (female): venter of the body. Scale bar 50 µm.

FIGURES 1 – 3. Pseudopygmephorellus mazandaranicus Katlav and Hajiqanbar sp. nov. (female): 1. Gnathosoma, dorsal view; 2. Gnathosoma, ventral view; 3. Pharyngeal system. Scale bar 10 µm.

FIGURES 6 – 8. Pseudopygmephorellus mazandaranicus Katlav and Hajiqanbar sp. nov. (female): 6 – 7. Legs I – II respectively. Scale bar 20 µm; 8. Comparison of length of solenidia in two close species: a. P. mazandaranicus sp. nov, b. P. szekessyi (Mahunka, 1970). Scale bar 10 µm.

FIGURES 9 – 10. Pseudopygmephorellus mazandaranicus Katlav and Hajiqanbar sp. nov. (female): 9 – 10. Legs III – IV respectively. Scale bar 20 µm.

FIGURES 11 – 14. Pseudopygmephorellus mazandaranicus Katlav and Hajiqanbar sp. nov and the beetle hosts: 11. Onthophagus sp. (Col., Scarabaeidae); 12. Colony of mite on cervical membrane and between pronotum and elytra of Onthophagus sp.; 13. Aphodius varians Duftschmid, 1805 (Col., Scarabaeidae); 14. Colony of mite on first abdominal sternite (near third coxa) of the beetle Aphodius varians.