Neolobogynium sorae Saito 2022, sp. nov.
Creators: name: Saito, Hajime
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Mesostigmata
Diplogyniidae
Neolobogynium
Neolobogynium sorae

description: Neolobogynium sorae sp. nov.
(Figs 1–6)
Materials examined. Holotype: female, Miyagaoka, Chūō-ku, Sapporo-shi, Hokkaidō (43.0533°N, 141.3127°E), 30 m alt., 5 July 2020, S. Yamamoto leg., ex Hololepta amurensis Reitter, 1879 (Coleoptera: Histeridae). Paratypes: five males and 11 females, data as same as the holotype; one male and one female, Kawabata, Yuni-chō, Yūbarigun, Hokkaidō (42.8946°N, 141.9261°E), 132 m alt., 27 June 2020, H. Saito leg., ex Syntelia histeroides Lewis, 1882 (Coleoptera: Synteliidae); four males and four females, Honbetsuhonsawa-chō, Mikasa-shi, Hokkaidō (43.2764°N, 141.9693°E), 136 m alt., 8 July 2020, H. Saito leg., ex H. amurensis. Holotype, nine male paratypes and 15 female paratypes will be deposited in Systematic Entomology, Hokkaido University, Hokkaido, Japan (SEHU). One male paratype and one female paratype will be deposited in National Museum of Nature and Science, Tokyo, Japan.
Diagnosis (adults). Both sexes with long, barb-tipped setae on dorsum. Female with four pairs of medio-laterals: z3, z6, Z2 and Z4. In male, s4 is also prolonged, so that, five pairs of long setae present on dorsal shield. Other setae including Z5 with simple pointed tips.
Description of female (Figs 1–4; 16 specimens measured). Dorsal idiosoma (Fig. 1). Dorsal shield 737– 810 µm long, 547–614 µm wide, length/width 1.26–1.39.
Shape oval, weakly depressed in anterior part and with short posterior notch. 42 pairs and one unpaired setae present in total. Podonotum with 23 pairs of setae and unpaired seta (j2): five dorso-central (j1, j3–j6), one additional setae between dorso-central and medio-lateral (jx1), five mediolateral (z1–z3, z5, z6), six lateral (s1–s6), five and one additional marginal (r2–r6, rx1). Opisthonotum with 19 pairs of setae: five dorso-central (J1–J5), five medio-lateral (Z1–Z5), four lateral (S1–S3, S5), five marginal (R1–R5). Four mediolateral (z3, z6, Z2, Z4) setae the stoutest and longest with barbed tip. Marginal setae (r2–r6, rx, R1–R5) a little stout but short. Setae S5 and Z5 both long and as stout as four long medio-lateral setae, Z5 longer than S5. Other setae fine and short or vestigial. Many small pores arranged on whole dorsal shield almost symmetrically. Eleven pairs of lyrifissures present: between setae z5–j6, s2–r2, z6–r6, S1–R1, S3– R4, J3–Z4, J4–Z5 and J2–Z2, nearby setae z3, J1 and Z1. Anterior parts of the lyrifissures nearby z3 projected upward. A weak transverse line located middle area but not reaching to the margins. Entirely covered in polygon-shaped ornamentation.
Ventral idiosoma (Fig. 2A–C). Sternal shield (Fig. 2A) 54–65 µm long in the midline, 311–338 µm wide between ends of postero-lateral prolongations, length/width 0.168 – 0.206, anteriorly rectangular with postero-lateral prolongations and rounded anterior edges; shield folded along anterior and lateral margins; one pair of thin, triangular projections extending from beneath lateral margins; anterior margin narrowly concave, posterior margin deeply and broadly concave. Three pairs of simple setae (st1 18–25 µm, st2 31–38 µm, st3 20–26 µm), two pairs of lyrifissures and one pair of small pores on sternal shield; st1 just behind the anterior margin, anterior lyrifissures stp1 lateral to st1, st2 posterior to stp1, posterior lyrifissures stp2 and st3 at the beginning of postero-lateral projections. One pair of metasternal shields free from sternal shield, with alveolus of st4 and pore-like stp3. Metasternal shields covered mostly by latigynal shields and partially by sternal shield (Fig. 2A). Latigynal shields harp shaped, with two pairs of simple setae along lateral margin and one pair of small pores centrally. Mesogynal shield (Fig. 2B) about 1/3 length of latigynal shield, antero-laterally covered by latigynal shields. One pair of vaginal sclerites (Fig. 2A) beneath latigynal shields; anterior ends more strongly sclerotized, bow-shaped; one pair of short spines projecting antero-laterally from midpoint; membranous tissue connecting sclerites at posterior ends. Ventri-anal shield (Fig. 2B) covering most of the ventral side, not extending to posterior margin, and only barely fused to exopodal-peritrematal shield. Stigmata located between coxae III and IV; peritremes bent inward between coxae II and III, extending beyond the coxae I. Two pairs of pores and two pairs of lyrifissures present along the peritremes. Ventri-anal shield posterior to latigynal shields with six pairs of setae (JV1 10–19 µm, JV2 15–23 µm, JV3 28–38 µm, JV5 19–26 µm, ZV2 9–17µm, ZV3 23–31 µm), five to six small pores, two pairs of pores (bigger than small pores), anus, and one pair of large lyrifissures present: line connecting insertion of JV1 and JV2 parallel to axis, ZV2 external to this line, other three setae (ZV3, JV3, JV5) aligned along posterior edges of ventri-anal shield, large lyrifissures close to anus and JV5. Ventri-marginal shields slightly covered internal lateral margins by ventri-anal shield, widely meeting each other posterior to anus. Five pairs of lyrifissures and one pair of setae present on ventri-marginal shields. Ornamentation of ventral shields similar to that of dorsal shield and entirely covered in polygon-shaped ornamentations but polygonal elements very long on marginal shields and on ventri-anal shield surrounding coxae. No ornamentation on mesogynal shield. Tritosternum (Fig. 2C) extending from under anterior notch of sternal shield, with two pilose laciniae fused for approximately two thirds their length.
Gnathosoma (Figs 2D, 3A–D). Tectum (Fig. 2D) sharply pointed forward with one pair of lateral projections, many transverse lines (about 15 to 20 central rows and about five pairs of lateral rows), and ventral keel. Hypostome (Fig. 3A) with three pairs of setae in oblique line, one pair of gnathosomal setae with three to four distinct denticles, one pair of corniculi and hypostomal processes, and three pairs and one continuous, nearly transverse lines: corniculi stout and slightly curved inward with rounded tips, hypostomal processes weakly sclerotized. Deutosternum not clearly distinguished, but three denticulate rows present. One pair of long membranous hypopharyngeal processes projected forward and triangular epipharynx or hypopharynx visible dorsal to these processes. One pair of additional styli dorsal to hypostomal processes visible in some specimens (perhaps originating from hypostomal processes but can’t be observed clearly). Trochanter of palp (Fig. 3B) with two ventral setae; femur with five setae, of which d3 is the stoutest, longest, and barbed on two sides; genu with seven setae, ventral seta (v) barbed; tibia (Fig. 3B, C) with fourteen simple setae and one slightly barbed dorsal seta; tarsus with fifteen simple setae and two-tined apotele. Fixed digits of chelicerae (Fig. 3D) with internal pore (pilus dentilis) and about nine teeth: the most proximal large tooth situated in a different row. Movable digits with about eight teeth and ventral excrescences: one comb-like and two to three brush-like excrescences projecting inward. One membranous projection arising from base of movable digit, but difficult to see.
Legs (Figs 3E, F, 4). Leg I (Fig. 3E, F) antenniform and without claws. Legs II–IV (Fig. 4) each with one pair of claws on end of tarsus. Leg chaetotaxy is shown in Table 1. Most setae simple or slightly barbed, but some setae characteristic in shape (e.g., pd1 of genua III and IV very long with brushed tips similar to dorsal long setae, av1 of genu and tarsus II stout with apparent denticles, seta ad1 and pd1 of each tarsus of legs II–IV thin spatulate).
Description of male (Figs 5, 6; 9 specimens measured).
Dorsal idiosoma (Fig. 5). 709–842 µm long, 560–646 µm wide, long/wide 1.24–1.36. Dorsal characteristics almost same as female except for setae s4; s4 prolonged and with barbed tips just like the four pairs of long setae of female.
Ventral idiosoma (Fig. 6A). Central area covered by one holoventral shield, opisthogaster similar to female. Sternogenital region with six pairs of setae, three pairs of lyrifissures, and two pairs of small pores: position of anterior three pairs of setae (st1–st3) and two pairs of lyrifissures similar to that of female in position: third pair of lyrifissures stp3 and setae st4 located at base of projections extending between coxae II and III; the other two setae on intercoxal area of leg III, and line between these two setae parallel to axis. Genital opening located at anterior margin of holoventral shield, surrounded by membrane; two-branched clawlike excrescence projected under membrane, with each end of excrescence two-tined and sclerotized.
Gnathosoma (Fig. 6B–D). Corniculi with pointed tips; sclerotization weaker but more strongly curved than female. Tectum triangular with anterior end rounded, without lateral projections. One pair of styli dorsal to hypostomal processes larger than that of female. Chelicerae longer than female. Ventral side of movable digits with two wall-like, thin extensions; external extension wide and large. Two excrescences projecting from base of movable digits and fit the indentation between the two extensions; stout excrescence with grooved ventral side, another fine excrescence project-ed inward, with ventral side densely pilose.
Legs. Similar to female.
Etymology. This species is named in honor of the curiosity of Ms. Sora Yamamoto, who provided samples of mites.
Remarks. This species shows an obvious sexual dimorphism on the dorsal shield. The dorsal seta s4 is long with a barbed tip in males, while in females it is simple and short. However, in females the sockets of s4 are noticeably larger than those of the other short setae. In females, each metasternal shield bears the third lyrifissure and vestige of seta st4. These are so reduced that the lyrifissures are porelike and, in some specimens, the external one (stp3 or alveolus of st4) is incomplete or absent. Comparing sternal regions of both sexes, the lyrifissure between coxae II and III of male seems to be homologous to the metasternal pores the of female. The tips of each tarsus of legs II–IV have two spatulate setae ad1 and pd1, which are similar in shape to each other. Removing claw from tarsus makes it easier to recognize these setae.
description: Published as part of Saito, Hajime, 2022, A New Species of Neolobogynium and New Records of Lobogynium sudhiri of the Mite Family Diplogyniidae (Acari: Mesostigmata: Trigynaspida) Phoretic on Some Beetles (Coleoptera: Histeridae, Synteliidae, and Geotrupidae) from Japan, pp. 329-340 in Species Diversity 27 (2) on pages 331-337, DOI: 10.12782/specdiv.27.329, http://zenodo.org/record/7522744