Geckobia circumdata, Machado & Gazêta & Pérez & Cunha & Giupponi, 2019

Machado, Ingrid B., Gazêta, Gilberto S., Pérez, José, Cunha, Rodolfo & Giupponi, Alessandro P. De L., 2019, Two new species of the genus Geckobia Mégnin, 1878 (Acariformes, Prostigmata, Pterygosomatidae) from Peru, Zootaxa 4657 (2), pp. 333-351 : 342-346

Geckobia circumdata n. sp.

( Figs. 20–38 )

Etymology: The specific epithet circumdata refers to the longitudinal folds positioned laterally, which contour the entire dorsal idiosoma of this species.

Type material: Peru, Arequipa, Cerro Verde , 19K 0219403, 8175454; 2345 m: J. Pérez col. (1 female, CAVAISC-ACA 1951). Collected from Phyllodactylus gerrhopygus .

Diagnosis. Idiosoma (179 x 300), wider than long, ellipsoid. Propodonotal shield with two anterolateral fragments and no concavity; wider than long with inverted trapezoid shape, not reaching concave anterior border of idiosoma; bearing 12 serrated setae. Eyes present. Longitudinal folds positioned laterally, contouring the entire dorsal idiosoma and fused to anogenital plate; serrated setae of variable length. Ventral idiosoma possessing transverse and longitudinal striae. Coxae I–II with 5 setae: 1a, 1b setiform, 2a, 2b, 2c serrated and coxae III–IV with 6 serrated setae: 3a, 3b, 4a, 4b, 4c, 4d; coxal formula: 2–3–2–4. Anal opening on dorsal idiosoma; genital opening terminal, visible on both sides of idiosoma. Anogenital valves with longitudinal to transverse striations. Gnathosoma with subquadrangular infracapitulum, with 1 pair of setae n. Trifurcate spine at base of palp claw and serrated palpal seta dT. Tarsi II–IV with 13 setae. Solenidion ω1 present on tarsi I–II and ft seta present only on tarsus I. Solenidion ω2 absent on tarsi I–IV.

Description of female. Measurements. Female holotype: idiosoma wider than long (length 270, width 300) ( Table 1), ellipsoid, small ( Figs. 20–21 ). Ventral idiosoma strongly hypertrichous, moreso than dorsal idiosoma ( Figs. 20–21 ).

Dorsal idiosoma. Dorsal idiosoma covered with well-defined striae and numerous plumose setae ( Fig. 20A ). Propodonotal shield wider than long (length 57, width 134), with two anterolateral fragments and no concavity ( Fig. 25 ). Propodonotal shield inverted-trapezoid shape, not reaching border of idiosoma; 12 serrated setae present (length 18–27) ( Fig. 25 ). Eyes present ( Fig. 25 ). Posterior edge of propodonotal shield surrounded by ripples, following propodonotal shield outline, striate cuticle with short serrated setae (length 6–8) ( Fig. 25 ). Opisthosomal setae, especially marginally and posteriorly, longer (length 31–57) than other dorsal setae ( Fig. 20A ). Longitudinal folds positioned laterally and contouring the entire idiosoma, with serrated setae of variable length (22–50) ( Fig. 20A ).

Ventral idiosoma. Ventral idiosoma covered by transverse and longitudinal striae. Coxae divided into two groups: coxae I–II and coxae III–IV. Fused coxae I–II with 5 setae: 1a, 1b setiform (length 13–37), 2a, 2b, 2c, serrated (length 14) ( Fig. 26 ). Fused coxae III–IV with 6 serrated setae: 3a, 3b and 4a, 4b, 4c, 4d (length 13–20). Anterior and posterior epimeral plates separated by narrow band of striated cuticle ( Fig. 26 ). Setae of coxae: 1a, 1b, 2a, 2b, 2c, 3a, 3b, 4a, 4b, 4c, 4d with the following formula: 2–3–2–4.

Ventral idiosoma covered by plumose setae, short to medium length 17–22 anteriorly, becoming longer posteriorly, length 47–57 ( Fig. 21 ).

Anogenital area. Genital and anal openings close together, defined by thickened sclerites. Plate skirts pair of folds in anogenital area. Anal opening dorsal, genital opening terminal. Anogenital valves overlapping, without striae ( Figs. 20 ). Setae ag1 (length 48), ag2 (length 57), ag3 (length 39), ag4 (length 34), ag5 (length 37), ag6 (length 36), ag7 (length 34), ag8 (length 31) and ag9 (length 19) on anogenital plate, anogenital plate with striae and six setae: g1 (length 21), g2 (length 17), g3 (length 10), g4 (length 20) g5 (length 18) and g6 (length 18) ( Fig. 20B ). Pair of setae ps1 (length 24) on dorsal idiosoma ( Fig. 20A ).

Gnathosoma . Gnathosoma (length 91) with subquadrangular infracapitulum, subcapitular setae n 31 long ( Fig. 22, 24 ). Palp (length 84), seta dF serrated, dG setiform and palp tibia with tow setiform setae l’T, l”T and serrated seta dT ( Fig. 22 ). Palp tarsus with phaneres ul’, ul”, acm and sul present and setiform ( Fig. 23 ). Trifurcate spine at the base of the palp claw. Chelicera (length 73) with fixed digit tri-toothed and mobile digit smooth and hook-shaped ( Fig. 22 ).

Legs. Length of legs I to IV, coxae–tarsi (length 161–224). Setae distribution by segment compatible with Geckobia species of Group 1 ( latasti group): tibiae I–IV (5-5-5-5) genua I–IV (0-0-0-0) femora I–IV (2-2-2-2) trochanters I–IV (1-1-1-1) ( Figs. 27–30 , Figs. 31–38 ). Solenidion ω1 present on tarsi I–II, solenidion ω2 absent on tarsi I–IV and ft seta present only on tarsus I. Setae of tarsi: tarsus I with 14 setae (ft, tc’, tc”, p’, p”, it’, it”, a’, a”, u’, u”, vs’, vs”, pl’) compatible with group A of Jack (1964), tarsus II with 13 setae (tc’, tc”, p’, p”, it’, it”, a’, a”, u’, u”, vs’, vs”, pl’), tarsus III with 13 setae (tc’, tc”, p’, p”, it’, it”, a’, a”, u’, u”, vs’, vs”, pl’) and tarsus IV with 13 setae (tc’, tc”, p’, p”, it’, it”, a’, a”, u’, u”, vs’, vs”, pl’), tarsal formula: tarsi I–IV (14(ω1)–13(ω1)–13–13) ( Figs. 27–30 ).

Male unknown.

Distribution: Peru, Cerro Verde, Andean highlands ( Fig. 39 ).

Differential diagnosis. Geckobia circumdata n. sp. differs from the other members of the latasti group by possessing: longitudinal folds laterally and contouring the entire idiosoma; a trifurcate spine at the base of the palp claw; g1–g6 and ag1–ag9 present; and 13 setae on tarsi II–IV ( Figs. 27–30 ).

Geckobia circumdata n. sp. and G. bataviensis share the same leg setal formula for I–IV (1-1-1-1) trochanters, genua I–IV (0-0-0-0) and tibiae I–IV (5-5-5-5); both belong to group A with regard to chaetotaxy of the tarsus I (with 14 setae); and both possess coxal field I with 2 setae (1a, 1b both setiform), coxal field III with 2 setae (3a, 3b both serrated), trochanter setae present and serrated, and ps1 present. However, G. circumdata n. sp. differs from G. bataviensis by possessing coxal field IV with 4 setae (4a, 4b, 4c and 4d); setae g1–g6 present and a serrated palpal seta dT and trifurcate spine at the base of the palp claw. For species with many specimens, such as G. latasti , G. tarentulae , G. hemidactyli and G. aureae , these character states are known not to vary intraspecifically, and thus support our hypothesis that our single specimen represents a unique species.

Figures

FIGURE 39. Distribution of Geckobia species in South America and the Caribbean, showing all localities reported to date. It does not include Geckobia species occurring in North America and other Central America countries: G. keegani, G. leonilae and G. bataviensis.

FIGURES 20–21. Geckobia circumdata n. sp., female. 20A, Idiosoma, dorsal view; 20B, Schematic drawing of anogenital area with setae insertion, dorsal view; 21, Idiosoma, ventral view.

FIGURES 22–24. Geckobia circumdata n. sp., female. 22, Gnathosoma, dorsal view; 23, Palp, ventral view; 24, Gnathobasal seta, ventral view.

FIGURES 25–26. Geckobia circumdata n. sp., female. 25, Propodonotal shield, dorsal view; 26, Coxae I–II and III–IV fused, ventral view.

FIGURES 27–30. Geckobia circumdata n. sp., female. Legs, postero-lateral view: 27, Leg 1; 28, Leg 2; 29, Leg 3; 30, Leg 4.

FIGURES 31–34. Geckobia circumdata n. sp., female. Tibiae, antero-lateral view: 31, Tibia 1; 32, Tibia 2; 33, Tibia 3; 34, Tibia 4.

FIGURES 35–38. Geckobia circumdata n. sp., female. Femur, dorsal view: 35, Femur 1; 36, Femur 2; 37, Femur 3; 38, Femur 4.