Cheiroseius mesae, Rueda-Ramírez, Diana, Varela, Amanda & De Moraes, Gilberto J., 2016

Rueda-Ramírez, Diana, Varela, Amanda & De Moraes, Gilberto J., 2016, Soil mites of the families Ascidae, Blattisociidae and Melicharidae (Acari: Mesostigmata) from mountainous areas of Colombia, Zootaxa 4127 (3), pp. 493-514 : 504-506

Cheiroseius mesae sp. nov.

( Figs 20–28 )

Specimens examined. Holotype and a three paratype females from soil of a fragment of Andean forest ( pH 3.8– 4.3; organic matter 37–82%; humidity 47–70%; soil temperature 9–12°C); collected by D. Rueda-Ramirez in August and October, 2010, deposited at ESALQ-USP; a paratype with same collection data deposited at MJHN- PUJ.

Diagnosis. Anterior region of epistome with three distally denticulate projections (in some specimens at least one projection non-denticulate); deutosternum with eight transverse lines, of which the first smooth and the others with progressively larger number of denticles; dorsal shield covering the idiosoma and extending ventrolaterally, with a network of ridges and depressions and with 39 pairs of setae; a pair of metapodal plates; a pair of elongate platelets between genital and ventrianal shields; ventrianal shield with four pairs of setae in addition to circumanal setae (Jv 1, Jv 5, Zv 1 and Zv 3 and Zv 5 on unsclerotised cuticle); peritreme wide extending anteriorly to the bases of j 1, with post-stigmatic extension narrower than pre-stigmatic section; peritrematic plate wide, fused to dorsal shield at level of s 1.

Description (Female, three specimens measured).

Gnathosoma. Movable cheliceral digit with two teeth, 77 (77–78) long; fixed digit 81 (80–82) long, with a short ridge bearing 10–12 fine denticles matching interval between teeth of movable digit, with setiform pilus dentilis and subterminal notch matching apex of movable digit; dorsal and paraxial lyrifissure and dorsal seta distinct ( Fig. 20 ). Numbers of setae on palp trochanter–tarsus: 2, 5, 6, 14, 15; palp tarsal apotele bifurcate; palp trochanter seta av much longer than the pv seta of the same segment. Anterior region of epistome with three projections slightly wider at the base, all distally denticulate (in some specimens at least one projection nondenticulate); median projection slightly longer ( Fig. 21 ). Deutosternal region ( Fig. 22 ) without delimiting lateral lines and with eight transverse lines, the first of which (most distal) smooth, the second with 22 denticles and other lines with progressively larger number of denticles; the last with about 35 denticles; most basal line w-shaped. Internal malae distinctly separated from each other, covered with tiny spines giving the appearance of crenulate margins. Corniculi horn-shaped, with a ventro-longitudinal carina, about twice as long as basal width. Seta h 3 slightly mesad of h 1 and well anteriad of h 2. Setal measurements: h 1 64 (63–65), h 2 41 (40–43), h 3 48 (47–49), pc 46 (44–48), palp trochanter av 80 (77–82), palp trochanter pv 37 (36–39); setae aciculate and smooth.

Dorsal idiosoma ( Fig. 23 ). Dorsal shield entire, covering the idiosoma and extending ventrolaterally, with a network of ridges and depressions; 515 (480–533) long and 342 (330–361) wide. Podonotal region with 22 pairs of setae, one pair of lyrifissures and four pairs of pores. Opisthonotal region with 17 pairs of setae (one specimen with R 1 on unsclerotised cuticle, and thus with 16 pairs of setae on the opisthonotal region of the shield), three pairs of lyrrifisures and a pair of pores. Setal measurements j 1 39 (38–40), j 2 44 (42–48), j 3 45 (44–47), j 4 41 (40–42), j 5 41 (40–42), j 6 44 (43–45), J 1 46 (45–47), J 2 46 (45–47), J 3 47 (45–48), J 4 45 (43–46), J 5 16 (16–17), z 1 25 (24– 25), z 2 41 (40–42), z 3 39 (37–40), z 4 45 (43–47), z 5 27 (26–29), z 6 44 (42–45), Z 1 47 (45–48), Z 2 46 (45–48), Z 3 45 (42–47), Z 4 43 (42–44), Z 5 50 (47–52), s 1 20 (19–20), s 2 34 (32–35), s 3 40 (38–42), s 4 45 (44–45), s 5 46 (44– 50), s 6 47 (45–48), S 1 43 (41–45), S 2 47 (46–48), S 3 44 (43–45), S 4 45 (44–45), S 5 48 (46–50), r 2 20 (20–21), r 3 25 (25–26), r 4 38 (37–40), r 5 27 (26–28), R 1 27, R 2 32 (31–33), R 3 37 (36–37); setae stout and smooth, most of which inserted on tubercles.

Ventral idiosoma ( Fig. 24 ). Line separating the base from the remaining of tritosternum indistinct. Whole tritosternum 189 (181–193) long; separated laciniae corresponding to 50% of total length of tritosternum, pilose. Pre-sternal platelets absent. Sternal shield smooth except for a reticulate, elongate anteromedian area, 113 (110–115) long and 94 (88–100) wide at level between coxae III and IV, with three pairs of setae and two pairs of lyrifissures; distances st 1– st 3 103 (100–109), st 2– st 2 66 (62–70). Fourth pair of sternal setae (st 4) and third pair of sternal lyrifissures (iv 3) on metasternal plates. Genital shield smooth, posterior margin slightly convex; 129 (124–134) long and 76 (75–78) wide at the widest level; distance st 5– st 5 68 (65–70). Lyrifissure iv 5 on unsclerotised cuticle, posterolaterad of st 5. One pair of ovoid metapodal plates. Ventrianal shield subtriangular, reticulate; 165 (162–170) long and 238 (234–245) wide; with four pairs of setae (Jv 2– Jv 4, Zv 2) in addition to circumanal setae and a large pore anteromesad of Jv 4; para-anal setae inserted behind posterior margin of anal opening; the latter small, about 1/8 of shield length, 18 (18–19) long. Unsclerotised cuticle around ventrianal shield with five pairs of setae (Jv 1, Jv 5, Zv 1, Zv 3 and Zv 5), a pair of transversely elongate platelet, three pairs of lyrifissures and a pair of pores. Anterior section of endopodal plate fused with sternal shield; section between coxae II–III and III–IV reduced to two elongate V-shaped platelets. Exopodal plate distinct around coxa III with triangular sections between coxae II–III and III–IV, connected by a narrow bridge. Peritrematic plate wide, fused anteriorly with dorsal shield at level of s 1 and with exopodal shield at level of coxa IV, with a pore and a pair of lyrifissures behind each stigma. Peritreme wide, extending anteriorly to the bases of j 1, almost meeting anterior end of each other; with post-stigmatic extension narrower than pre-stigmatic section. Setal measurements: st 1 21 (20– 22), st 2 26 (25–27), st 3 27 (26–27), st 4 24 (23–25), st 5 28 (25–30). Jv 1 26 (25–27), Jv 2 42 (41–44), Jv 3 40 (37– 45), Jv 4 28 (25–30), Jv 5 41 (39–43), Zv 1 19 (17–20), Zv 2 29 (27–32), Zv 3 22 (20–23), Zv 5 40 (37–42), para-anal 25 (22–28), post-anal 23 (21–25); setae stout and smooth.

Spermathecal apparatus. Induction pore apparently between coxae III and IV; infundibulum ovoid to subtriangular (about 13 long); tubulus string-like; distinct section about 75 long ( Fig. 25 ).

Legs. Lengths: I: 574 (560–588); II: 415 (410–356); III: 398 (380–401); IV: 534 (530–551).–Setation (legs I– IV): coxae: 2, 2, 2, 1; trochanters: 6, 5, 5, 5; femora: 12, 11, 6, 6; genua: 13, 10, 8, 9; tibiae: 13, 10, 8, 10; tarsi: I not counted, 18, 18, 18. Leg I with small pretarsi and claw. Legs II–IV with a pair of strongly sclerotised claws, median section of pulvilli acute and paradactyli acuminate. Setae al 2 (ca. 50) and pl 2 of tarsus II (ca. 70), ad 2 and pd 2 of tarsus III (ca. 65), and ad 2 of tarsus IV (ca. 85) longer than other setae of the same segment and distally curved ( Fig. 26–28 ).

Etymology. This species is named after Nora Cristina Mesa Cobo , eminent Colombian acarologist.

Remarks. This new species is most similar to Cheiroseius trispinosus Karg, 1981 described from Venezuela by having post-stigmatic extension of the peritreme, ventrianal shield with four pairs of setae in addition to circumanal setae, and similar size (530–550 long and 340–350 wide in C. trispinosus ). However, the sternal shield of C. trispinosus does not have a median reticulate area and its setae Z 5 (75) and J 4 (70) are much longer than in the species here described.

Figures

FIGURES 20 – 25. Cheiroseius mesae sp. nov. Female. 20. Chelicera; 21. Epistome; 22. Hypostome and proximal palp segments; 23. Dorsal idiosoma; 24. Ventral idiosoma; 25. Spermathecal apparatus.

FIGURES 26 – 28. Cheiroseius mesae sp. nov. Female. 26. Tarsus II; 27. Tarsus III; 28. Tarsus IV.