Metatarsonemus badurkani Karmakar & Mondal, 2021

Mondal, Priyankar & Karmakar, Krishna, 2021, First record of Metatarsonemus (Acari: Tarsonemidae) from India with description of two new species, Zootaxa 4942 (2), pp. 229-251 : 230-238

Metatarsonemus badurkani Karmakar & Mondal sp. nov.

( Figs.1–12 ; 30–34 )

Diagnosis: Adult of both sexes: Sensory cluster on tibia I incomplete, missing ϕ1. Setae pl” absent on tarsus II. Female: Setae v1 usually shorter than setae sc 2 in length; setae c2 slightly shorter or subequal to c1. Ventral surface of podosoma with a conjunct of several fissures: a pair of angulate fissures near base of coxisternal setae 1a; a pair of curved fissures anterolaterad to the bases of coxisternal setae 2a, in part parallel with apodeme 2; a pair of Y-shaped fissures near bases of coxisternal setae 3b, in part superimposed over apodeme 4; and a small subcircular unpaired fissure at posterior end of poststernal apodeme; tc” more than two times longer than v’Ti on leg IV, both setae smooth; apodeme 3 with proximal end shaped as crescent moon. Male: Setae v1 shorter than sc1 and sc2; setae c1 and c2 of a similar length, d slightly shorter; apodeme 5 conspicuous; solenidion ω much larger and more swollen on tarsus II than on tarsus I, approximately 2 times longer than greatest width of tarsus II; tibial tactile setae not longer than femorogenu on leg IV; l’G, v’G and v’Ti serrate.

Adult female (10 specimens measured).

Gnathosoma: subcircular, length 28 (27–30), maximum width 26 (27–31). Seta dgs 9 (9–10) and vgs 5 (4–5), both smooth; seta pp absent. Palpus short with 2 small subterminal setae and few dentate structures apically. Pharynx fusiform, 19 (17–20) long and 7 (6–8) wide at widest level, almost one third width of gnathosomal capsule.

Idiosoma ( Figs.1 , 2 ): length 183 (180–190), maximum width 114 (111–125) at level of c1. Dorsum: Prodorsal shield covering entire gnathosoma with two small acute “bat ear” shaped projections apically and a convex posterior margin. Stigma located on lateral margin of prodorsal shield, slightly closer to bases of v1 than sc1. Bothridial seta sc1 globose and spiny, located ventrolaterally closer to base of sc 2 than v1. Dorsal plates with margins perpendicularly striate. Length of setae: v1 22 (19–24), sc1 11 (10–13), sc2 25 (22–27), c1 20 (20–23), c2 18 (16–19), d 16 (14–16), e 9 (7–9), f 16 (14–17), h 11 (10–12). All setae slender and serrated except sc2. Distances between setae: v1–v1 25 (23–26), sc2–sc2 51 (49–52), v1–sc2 26 (25–27), c1–c1 47 (45–50) c2–c2 74 (71–76), c1–c2 32 (30–34), d–d 31 (28–32), f–f 18 (17–21), e–f 8 (6–9), h–h 24 (22–26). Dorsal plates ornamented with tiny punctations. Venter: coxisternal setae 1a 6 (5–6), near middle of apodemes 1 and at level of point of fusion of apodemes 1 and prosternal apodeme; 2a 13 (13–14) close to distal end of apodemes 2; 3a 17 (16–18) near anterior end of apodemes 3; 3b 10 (9–10) near posterior end of apodemes 4; all setae smooth; setae 1b and 2b vestigial, only pits visible. Apodemes 1 conspicuous with angular projections at base of gnathosoma, widened diagonally, converging posteriorly to fuse with anterior end of prosternal apodeme.Apodemes 2 short, not fused with prosternal apodeme. The latter conspicuous from point of fusion with apodemes 1 with two subsequent nodes in region between apodemes 1 and apodemes 2, interrupted just after level of proximal end of apodemes 2, diffuse and widened from this point before meeting convex sejugal apodeme. Sejugal apodeme conspicuous through entire length. Apodemes 3 extending diagonally from anterior end of trochanter III to about longitudinal level of insertion of 3a with proximal end crescent moon shaped; apodemes 4 conspicuously united to middle region of poststernal apodeme from which it extends diagonally up to base of seta 3b. Poststernal apodeme conspicuous with two medial nodes at equidistance from both ends, bifurcate anteriorly. Coxisternal plates smooth. A pair of angulate fissures near base of coxisternal setae 1a; a pair of curved fissures 15–16 long anterolaterad bases of coxisternal setae 2a, in part parallel with apodemes 2; a pair of Y-shaped fissures 24–26 long near bases of coxisternal setae 3b, in part superimposed over apodeme 4; a small subcircular unpaired fissure 2 long at posterior end of poststernal apodeme. Tegula 9 (8–10) long and 13 (12–14) wide at level of lower margin of coxa 4; posterior margin rounded, resembles a vase with raised and rounded edge. With a pair of ridges 8–9 long flanking near about middle of tegula from both sides. Seta ps slender 7 (7–8), serrate.

Legs ( Figs. 3–6 ): lengths (femur to tarsus): leg I 51 (48–55), leg II 44 (42–49), leg III 44 (43–52), leg IV 38 (36– 40). Number of setae (solenidia in parentheses) on femur, genu, tibia and tarsus, respectively: leg I: 4-4-6(1)+8(1), leg II: 3-3-4-5(1), leg III: 1+3-4-5, leg IV: 1+1-1+1. Solenidion ω of tibiotarsus I 5 (5–6) long, stout and clavate. Sensory cluster of tibia I incomplete, solenidion φ1 missing; solenidion φ2 2, stout, capitate; famulus k 3, inserted at same level. Seta d of tibia I 28 (26–30) long, smooth. Solenidion ω of tarsus II proximal, 5 (4–5) long, stout, clavate; seta pl” absent. Seta d of tibia II 9 (9–11) long, smooth. Femur I and II with ventral flanges. Femorogenu IV 25 (24–28); tibiotarsus IV 13 (10–15). Lengths of setae of leg IV: v’F 9 (8–10), v’G 14 (13–15), v’Ti 28 (26–29) and tc” 60 (57–65); all setae smooth.

Adult male (5 specimens measured).

Gnathosoma: subcircular, length 24 (22–26), maximum width 22 (22–25). Setae dgs 9 (8–10) and seta vgs 6 (6–7), both smooth; seta pp absent. Palpus short with 2 small subterminal setae and few dentate structures apically. Pharynx fusiform, 15 (16–18) long and 6 (6–7) wide at widest region, near about one third width of gnathosomal capsule.

Idiosoma ( Figs.7 , 8 ): length 127 (123–135), maximum width 78 (75–83). Dorsum: Prodorsal shield trapezoidal, anterior margin convex. Length of setae: v1 22 (20–22), v2 21 (20–23), sc1 31 (28–32), sc2 24 (23–25), c1 26 (24– 27), c2 26 (25–27), d 25 (25–26), f 24 (23–24). All setae setiform, thickened and serrate. Distances between setae: v1–v1 12 (11–13), v2–v2 23 (21–24), v1–v2 11 (10–13), sc1–sc1 27 (25–30), sc2–sc2 37 (36–41), sc1–sc2 5 (5–6) v2–sc2 12 (10–13), c1–c1 64 (60–66), c 2 –c 2 72 (69–75), c1–c2 30 (28–32), d–d 40 (37–42), f–f 22 (20–24). Seta c1 closer to d than c2. Dorsal plates ornamented with tiny punctations. Venter: coxisternal setae 1a 5 (4–6) long, near middle of apodemes 1 and at level of point of fusion of apodemes 1 and prosternal apodeme; 2a 9 (8–10) located near centre of upper half of coxisternal plate 2; 3a 22 (21–23), near anterior end of apodemes 3; 3b 18 (16–19), near anterior end of distal half of apodemes 4; all setae smooth; setae 1b and 2b vestigial, only pits visible. Apodemes 1 conspicuous, converging posteriorly to fuse with anterior end of prosternal apodeme. The latter interrupted in region where it would fuse with apodemes 2, continuing behind for a short distance to narrowly fuse with sejugal apodeme. The latter is conspicuous, almost straight and uninterrupted throughout. Apodemes 3, 4, and poststernal apodeme conspicuous, connected to each other anteriorly by transversal lines, which together make a slightly concave shape anteriorly. Apodeme 5 split conspicuously at the level of setae 3b and extends posteriorly to distal end of coxisternal plates 4. Coxisternal plates 1–4 with faint to coarse punctations.

Legs ( Figs. 9–12 ): length (femur to tarsus): leg I 48 (47–53), leg II 46 (43–50), leg III 48 (46–53), leg IV 55 (52–59). Number of setae (solenidia in parentheses) on femur, genu, tibia and tarsus: leg I: 4-4-6(1)-9(1), leg II: 3- 3-4-5(1), leg III: 1-3-4-5, leg IV: 1-3-1(1)-3 Solenidion ω of tarsus I 4 (4–5), stout, clavate. Sensory cluster of tibia I incomplete, solenidion φ1 absent; solenidion φ2 2 clavate; famulus k 3 (2–3) rod like, inserted in transverse line with φ2. Seta d of tibia I 24 (20–25), smooth. Solenidion ω of tarsus II proximal, 10 (9–11) long, stout, wider mediad. Seta d of tibia II 12 (11–13), smooth. Seta v’ of trochanter IV 10 (9–11), smooth; femorogenu IV, 38 (36–42) long and 20 (18–22) wide at v’F level, without flange, posterior margin convex and anterior margin slightly concave at distal third. Setae v’F 7 (6–18), smooth; v’G 16 (15–18), l”G 17 (16–21) serrate; tibia IV 14 (12–17), solenidion φ 7 (6–8), bacilliform, v’Ti 30 (29–35), serrate; tarsus IV 4 (4–5), tc” 3, pv” 5 (5–6) and u’ 6 (5–7). Claw well developed, stout, unciform, 9 (8–11) long, 3 (3–4) wide basally.

Differential diagnosis: This new species is most similar to Metatarsonemus megasolenidii Lofego & Ochoa, 2005 having an incomplete sensory cluster on tibia I, pl” absent on tarsus II, coxisternal fissures next to 3b posteriorly bifurcate, small subcircular fissure on posterior end of poststernal apodeme and the male with solenidion on tarsus II long (more than 10 μm). Females of these two species differ by the shape and size of tergite D (more than 60 long with uniformly convex posterior margin in M. badurkani vs less than 50 long with convex posterior margin medially in M. megasolenidii ), length of ventral setae 3a (16-18 vs 8-15), anterior end of apodemes 3 (crescent moon in M. badurkani vs blunt in M. megasolenidii ), texture of leg setae on femur genu and tibia I (all smooth in M. badurkani vs presence of few barbed setae in M. megasolenidii ), texture of seta v’Ti and tc” on leg IV (smooth in M. badurkani vs serrate in M. megasolenidii ), length of tc” (57–65 in M. badurkani vs 24–30 in M. megasolenidii ). Males of M. badurkani differ from M. megasolenidii by longer prodorsal setae v2 (20–23 vs 12–15), sc1 (28–32 vs 18–23), c1 (21–27 vs 14–22) and f (23–24 vs 11–16), longer ventral seta 3a (21–23 vs 11–16) and 3b (16–19 vs 10–14), division of apodeme 5 (split conspicuously at the level of setae 3b in M. badurkani vs split slightly at the end of coxisternal plates 4 in M. megasolenidii ).

Type material: Holotype female, male; 8 paratype females and 5 paratype males, from leaves of Ziziphus jujubae and Piper betle, Maslandapur (22°50’52”N; 88°45’31”E; 9m MSL), State of West Bengal, 01/II/2020, P. Mondal; 6 paratype female and 2 paratype males, from leaves of Lagerstroemia speciosa, Jaguli (22°55’46”N; 88°32’57”E; 8m MSL), State of West Bengal, 10/IV/2020, K. Karmakar.

Etymology: The specific epithet badurkani derived from the Bengali words Badur meaning bat (Chiroptera) and kan meaning ear which together refers to the bat-ear like angular projections (fig. 32) of the anterior prodorsal shield.

Figures

FIGURE 1. Metatarsonemus badurkani n.sp., (female). Dorsal surface.

FIGURE 2. Metatarsonemus badurkani n.sp., (female).Ventral surface.

FIGURES 3–6. Legs of Metatarsonemus badurkani n.sp., (female). 3.—leg I, 4.—leg II, 5.—leg III, 6.—leg IV.

FIGURE 7. Metatarsonemus badurkani n.sp., (male). Dorsal surface.

FIGURE 8. Metatarsonemus badurkani n.sp., (male). Ventral surface.

FIGURES 9–12. Legs of Metatarsonemus badurkani n.sp., (male). 9—leg I, 10—leg II, 11—leg III, 12—leg IV.

FIGURES 30–34. Metatarsonemus badurkani n.sp., 30.—Female dorsal surface, 31.—Female ventral surface, 32.—Female anterior part, 33.—Male dorsal surface, 34. Male ventral surface.