Trachytes axe, Kontschán, Jenő & Starý, Josef, 2012

Kontschán, Jenő & Starý, Josef, 2012, New Uropodina (Acari: Mesostigmata) from California, USA, Zootaxa 3210, pp. 26-38 : 31-34

Trachytes axe sp. nov.

(Figs 15–25)

Material examined. Holotype. Female ( HNHM, in alcohol), USA, California, Del Norte County , Jedediah Smith State Park , 1 April 1992, 41o50’ N, 124 o W, coniferous forest , under Tsuga heterophylla , sample of litter and soil, K. Horner coll. Paratypes. One female on slide ( HNHM); same data as for holotype.

Description. Female. Length of idiosoma 600–610 µ m, width 410–420 µ m (n=2). Idiosoma pear-shaped.

Dorsal idiosoma ( Fig. 15 ). Vertex without wide and ribbed lateral section. Marginal and dorsal shields fused anteriorly. Pygidial shield wide and oval, placed between posterior margin of dorsal shield and anterior margin of postdorsal shield. All setae on dorsal, marginal, and postdorsal shields smooth, robust and ca. 33–42 μm long. Surface of dorsal idiosoma covered by large, oval pits.

Ventral idiosoma ( Fig. 16 ). Sternal setae short, smooth, and needle-like. St1 situated near the anterior margin of sternal shield, St2 and St3 near anterior margin of genital shield, their length ca. 5–6 μm. St4 ca. 6 μm long, placed at level of central area of coxae III, St5 ca. 7 μm long, situated on adgenital platelets, St6 placed near basal margin of genital shield, ca. 7 μm long. Sternal shield anterior to genital shield without ornamentation, but bearing a strongly sclerotised π-shaped line near its anterior margin. Several oval pits situated posterior to genital shield. Ventral and inguinal shields not fused laterally, covered by oval pits, bearing long (ca. 36–40 μm) needle-like setae. Setae X4 (ca. 44–45 μm) situated on small platelets in membranous cuticle. First pair of adanal setae present, short (ca. 9–10 μm), second pair of adanal setae absent, postanal seta robust, ca. 20 μm long. Genital shield axe-shaped, wider basally than apically (2.5:1), very narrow at level of St4. Anterior margin of genital shield straight, its surface covered by oval pits on basal area. Adgenital platelets present. Genital shield situated between coxae III and IV ( Fig. 17 ). Peritremes long and straight, situated near coxae III. Tritosternum ( Fig. 18 ) with wide base, tritosternal laciniae divided into three branches.

Gnathosoma ( Fig. 18 ). Corniculi horn-shaped, internal malae longer than corniculi, smooth. Hypostomal setae h1 long (ca. 48 μm) and smooth, h2 short (ca. 21 μm) and smooth, h3 similar in shape to h1, ca. 40 μm long, h4 marginally serrate and ca. 11 μm long. Chelicerae with long sharp apical process on fixed digit, two lateral sensory organs situated on fixed digit, movable digit shorter than fixed digit and bearing one tooth. Epistome marginally serrate ( Fig. 19 ). Palps with smooth setae ( Fig. 21 ).

Legs. Leg I with small ambulacral claws ( Fig. 22 ), surface of legs I and II covered by small oval pits, setae on leg I smooth and needle-like, other legs bearing smooth and marginally serrate setae ( Figs 23–25 ).

Etymology. The name of the new species refers to the shape of the female genital shield.

Notes. Only one Trachytes species has a similar axe-shaped genital shield in the female and lacks wide and ribbed lateral sections on the vertex – the European species, T. welbourni Moraza, 1989 . In T. welbourni , however, the inguinal and sternal shields are fused, whereas in these shields are separated from each other in the new species.

Figures

FIGURES 15 – 20. Trachytes axe sp. nov., holotype, female. 15. Body in dorsal view; 16. Body in ventral view; 17. Intercoxal area; 18. Tritosternum and ventral view of gnathosoma; 19. Epistome; 20. Chelicera.

FIGURES 21 – 25. Trachytes axe sp. nov., holotype, female. 21. Palp; 22. Leg I; 23. Leg II; 24. Leg III; 25. Leg IV (All legs and palp in lateral view).