Loricaseius lepontinus Plumari & Mašán, 2014, sp. nov.
Creators: name: Plumari, Massimo
name: Mašán, Peter
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Mesostigmata
Eviphididae
Loricaseius
Loricaseius lepontinus

description: Loricaseius lepontinus sp. nov.
(Figs 1–31)
Material examined. Holotype, female: ITALY, Piemonte, Verbano-Cusio-Ossola Province, Alpe Veglia–Devero Nature Park, Baceno, Alpe Devero, 1,600 m a.s.l., 26 July, 2008, M. Plumari coll., habitat with Larix decidua, Rhododendron ferrugineum and Vaccinium sp., litter (MSNM; Iv81). Paratypes, same data as in holotype: 14 females, 8 males, 10 deutonymphs (MSNM; Iv82 – Iv86); 133 females, 157 males, 168 deutonymphs (LSSCMC); 8 females, 7 males, 8 deutonymphs (IZSAS).
Supplements to generic description. Female (Figs 1–10, 26, 27, 28–31; 10 specimens measured). Dorsal idiosoma (Fig. 1). Idiosoma dorsally convex, 440 ± 9 (425–450) long and 310 ± 11 (290–325) wide. Distance between setae j2, 77 ± 2 (75–80), longer than distance between setae j3, 71 ± 3 (68–78); setae j2 parallel to anterior margin of idiosoma, setae z 2 in lateral position on anterolateral margins of dorsal shield (not well discernible in unpressed specimens); ventrally displaced setae j1 and z1 shorter, subequal in length (10–13); other dorsal setae only slightly differing in length: j 2 29–33, j 5 31–36, z 5 24–27, J1 38–42, J3 36–40, J 5 28–32, Z 5 25–28, r2–r5 37–41, S4– S5 41–45. Twenty-two pairs of pore-like structures barely discernible, except two pairs larger, hypertrophied and adjacent to setae z2 and Z4 (Fig. 1), and one pair of lyrifissures situated on ventral extension of shield, near setae z1 (Fig. 2).
Ventral idiosoma (Figs 2–6, 28–31). Distance between inner margins of coxae II 46 ± 3 (40–50) long. Sternal shield 70 ± 5 (60–75) long and 51 ± 2 (48–55) wide, slightly concave on anterior medial margin, with anterolateral corners pointed; medial posterior margin slightly to strongly concave (seeming bilobed), posterolateral corners rounded; surface delicately ornamented with irregular polygonal pattern; sternal setae subequal in length (13–16; Figs 2, 5). Metasternal platelets generally present, metasternal setae st 4 13–15 long, and together with metasternal lyrifissures inserted on metasternal platelets or less commonly on soft integument (Figs 2, 6). Epigynal shield 110 ± 7 (100–113) long and 52 ± 2 (50–55) wide, with anterior tapering projection having one or two small tips, ornamented with irregular polygonal pattern, more pronounced in its posterior half; genital setae 13–15 long, located on small and well sclerotized promontories of shield, along its posterolateral margins (Figs 2, 3). Peritrematal shields 61 ± 2 (58–65) wide, width at level of stigma about one-fifth of width of idiosoma at its widest point; posterior margins varying from weakly to strongly curved inwards along inner corner, and with outer corner pronounced (Figs 2–4); with two small gland pores behind stigmata (excluding slightly larger post-stigmatic gland pore), a gland pore along posterior outline of outer margin, a slit-like lyrifissure at level of coxae II and a small gland pore within peritreme; with some sculptural lines on surface (Fig. 2). Anal shield wider than long, 76 ± 5 (70–85) long and 97 ± 3 (93–100) wide; post-anal seta 23–25 long and adanal setae 19–21 long; with some sculptural lines on surface, more strongly sclerotized in lateral portions of shield (Figs 2, 3). Ventral opisthosoma with ten pairs of setae, Jv4–Jv 5 31–34, Zv 3 23–26, R 3 25–27, R 4 26–30, and with at least six pairs of lyrifissures, excluding adgenital pair and gland pores close to coxae IV, pores on strongly sclerotized skin of mature female specimens not discernible (Figs 2, 3). Area of strongly sclerotized skin surrounding anal shield (in mature females), covering approximately posterior half of ventral opisthosoma, capturing setae Jv2–Jv5, Zv3, R1, R3 and R4, and most opisthogastric lyrifissures; setae Jv1, genital lyrifissures and other two pairs of pore-like structures on soft integument; setae Zv2 on soft integument, situated very close to anterior margin of area strongly sclerotized, or into this area; anterolateral extensions fused with dorsal shield (with boundary visible), but not fused with peritrematal shields, gradually tapering toward to anterior tip, closely abutting inner margin of peritrematal shields about at level of stigma and ending about at level of marginal setae r3; tuberculo-striated pattern of ornamentation with tubercles arranged to form regular polygons, expanded to a narrow strip of dorsal shield along its posterolateral margins and grading into dorsal punctate-reticulate pattern (Figs 2, 28–29). In immature specimens, all ventral and marginal posterior setae and pore-like structures placed on soft integument (Figs 3, 30–31).
Gnathosoma (Figs 7–10). Hypostomal and palpcoxal setae uniform (h 1 26–28, h 2 31–33, h 3 15–17 long, pc 11–13; Fig. 8). Epistome usually without denticles between central projection and lateral prongs (Fig. 10). Cheliceral teeth coarse, stout, subequal in size (Fig. 7).
Legs. Paradactyli about one and a half as long as claws (Fig. 27). Tarsus I with nine apical sinuous sensory setae clearly longer than other tarsal setae, a characteristic falcate-mucronate seta having subdistal part slightly flattened and widened, and six specialized blunt-peg type sensilla (Fig. 27).
Male (Figs 11–17; 10 specimens measured). Dorsal idiosoma (Fig. 11). Idiosoma dorsally more convex than in female, with barely pronounced hump at the level of the posterior third (observable in lateral view), 386 ± 4 (380–395) long and 274 ± 6 (265–280) wide. Distance between setae j2, 70 ± 3 (66–73), approximately equal to distance between setae j3, 69 ± 2 (66–71). Setae j1 and z1 subequal in length (11–13 long), setae J3 (19–22), J5 (6–8) and Z5 (11–13) relatively much shorter than in female (J 1 30–33 long, not subequal in length to J3 as in female), J5 shortest, slightly thickened, spine-like; other dorsal shield setae subequal in length. Dorsal pore-like structures as in female.
Ventral idiosoma (Figs 12–14). Distance between inner margins of coxae II 42 ± 2 (40–45) long. Sterno-genital shield 134 ± 3 (130–140) long and 48 ± 2 (45–51) wide, with anterior margin concave medially, anterolateral corners pointed, posterior margin from widely rounded to undulating, very weakly ornamented with irregular polygons; sternal setae st1–st5 subequal in length (11–16; Figs 12, 14). Peritrematal shields 59 ± 3 (55–65) wide, width at level of stigma about one-fifth of width of idiosoma at its widest point, as in female; posterior margin along the inner corner, less strongly curved inwards than in female, outer corner rounded, less pronounced than in female; lyrifissures and gland pores as in female (Figs 12, 13). Anal shield 66 ± 2 (63–70) long and 82 ± 4 (79–91) wide, weakly ornamented with irregular polygons (Fig. 12); post-anal seta 22–24 long and adanal setae 16–18 long. Ventral opisthosoma with nine pairs of setae; setae with length slightly increasing posteriorly, Jv5 longest (17–20); dorsal pore-like structures as in female (Fig. 12).
Gnathosoma (Figs 15–17). Length of hypostomal and palpcoxal setae as follows: h 1 22–24, h 2 29–31, h 3 13–15 and pc 10–12 (Fig. 16). Epistome with denticles of variable number and size between central projection and lateral prongs (Fig. 15). Cheliceral teeth coarse, stout, subequal in size, as in female; spermatodactyl sinuous, distally pointed (Fig. 17).
Legs. As in female.
Deutonymph (Figs 18–25; 20 specimens measured, 10 FDN and 10 MDN). Dorsal idiosoma (Fig. 18). Idiosoma dorsally more convex than in adult female, with barely pronounced hump at the level of the posterior third (observable in lateral view), as in adult male; in FDN 373 ± 6 (360–378) long and 273 ± 4 (268–280) wide, in MDN 356 ± 6 (350–370) long and 266 ± 6 (255–275) wide. Distance between setae j2, in FDN 66 ± 2 (63–69), in MDN 64 ± 2 (60–66), approximately equal to or slightly greater than distance between setae j3, in FDN 70 ± 1 (69–71), in MDN 68 ± 2 (64–69). Setae j1 and z1 subequal in length (10–13); J1 (29–34) longest dorsocentral setae, longer than J3 (17–21); J5 (15–17) and Z5 (12–14) subequal in length, J5 not modified as in male, setiform; other setae subequal in length. Dorsal pore-like structures as in adults.
Ventral idiosoma (Figs 19, 20, 22). Distance between inner margins of coxae II 46 ± 5 (38–53) long in FDN, 49 ± 4 (40–53) long in MDN. Sternal shield 130 ± 3 (126–133) long and 48 ± 2 (46–53) wide in FDN, 126 ± 2 (121–128) long and 49 ± 2 (45–51) wide in MDN; with anterior margin concave, widely rounded anterior angles, pointed anterolateral corners, undulating lateral margins, posterior margin from bluntly tapering to irregularly truncate and fragmented, same as in female and male deutonymphs (Fig. 22), ending between coxae IV; surface with weak polygonal ornamentation on most of shield and with lines of stronger sclerotization close to posterior end; second pair of lyrifissures situated on incisions of lateral margins of sternal shield, surrounded by slightly more sclerotized skin (Fig. 19). Endopodal platelets II-III and III-IV interconnected and connected to endopodal platelets I-II by very constricted ends (Fig. 19). Peritrematal shields width about one-third of width of adult shields, in FDN 21 ± 1 (19–23) wide, in MDN 20 ± 1 (19–21) wide; distance from lateral margins of dorsal shield about equal to width of shields; posterior margin weakly curved inwards near to outer corner; with some sculptural lines on surface and a gland pore along posterior outline of outer margin, as in adults; small pore within peritreme of adults apparently absent (Fig. 19). Anal shield wider than long, 62 ± 2 (60–65) long and 76 ± 2 (73–79) wide in FDN, 58 ± 3 (53–63) long and 73 ± 2 (70–76) wide in MDN; weakly ornamented with irregular polygons (Figs 19, 20); post-anal seta 22–26 long and adanal setae 15–17 long. Ventral opisthosoma with ten pairs of setae in female deutonymph (Fig. 19) and with nine pairs of setae in male deutonymph (setae Jv3 missing in male deutonymph; Fig. 20); setae similar as in male, Jv5 longest (16–19); opisthosomal pores not discernible, a pair of very small platelets present in position very close to posterior margin of coxae IV (Fig. 19).
Gnathosoma (Figs 21, 23–25). Length of hypostomal and palpcoxal setae as follows: h 1 21–23, h 2 25–27, h 3 11–13 and pc 9–11; deutosternal groove with five or six transverse rows of denticles (Figs 24, 25). Epistome with no or few small denticles between central projection and lateral prongs (Fig. 21). Cheliceral teeth coarse, stout; proximal tooth on movable digit with rounded outline, without sharp edges; fixed digit with a very small accessory tooth close to terminal hook (Fig. 23).
Legs. Tarsus I as in adults.
Etymology. The species is named after the type locality, Lepontine Alps.
Notes. The species newly described here shows strong sexual dimorphism of some secondary sexual characters, as it is also found in various genera of Eviphididae, including Alloseius, Crassicheles, Neocrassicheles, Thinoseius, and Uroiphis. In the case of Loricaseius, the dorsal shield of female eviphidids possess coarse punctate-reticulate sculpture and uniform posterior setae, compared with the male’s unornamented, smooth surface, and shortened posterior setae J3, J5, Z5, and slightly thickened J5. Ventrally, setae Jv3 are absent in the male and male deutonymph, but present in females, allowing deutonymphs to be sexed. In males, the post-stigmatic sections of the peritrematal shields are not so well expanded posteriorly as in the female, and they reach to or slightly beyond the posterior margins of coxae IV, while the peritrematal shields in the female are longer and reaching well beyond the posteriormost coxae, very close to the metapodal shields. There are also differences in the anal shield, which is subtriangular in the female but subcircular in the male. Specific secondary sclerotization of circum-anal and lateromarginal soft integument was detected only in mature females. Besides setae Jv3, some further but minor sexual dimorphism was present in deutonymphs in regards to the size of the body and its shields, with female deutonymphs slightly larger than male deutonymphs.
All specimens of Loricaseius lepontinus were collected from a sample of plant debris and they were found together with some specimens of Eviphis ostrinus (C. L. Koch), an eviphidid mite having ecological plasticity, but that could be considered an edaphic detriticole species (Mašán & Halliday 2010). Loricaseius lepontinus thereby appears to be an edaphic species with non-phoretic deutonymphs and free-living in litter substrates.
description: Published as part of Plumari, Massimo & Mašán, Peter, 2014, Loricaseius lepontinus gen. nov., sp. nov., a new genus and species of eviphidid mite from the Italian Alps (Acari: Mesostigmata), with an updated key to European genera of the family Eviphididae, pp. 1-22 in Zootaxa 3802 (1) on pages 11-18, DOI: 10.11646/zootaxa.3802.1.1, http://zenodo.org/record/286093