Geckobia andina, 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 : 335-339

Geckobia andina n. sp.

( Figs. 1–19 )

Etymology: The specific epithet andina derives from the region where the specimen was collected—the Andean highlands.

Type material: Peru, Arequipa, Cerro Verde , 19K 0219403, 8175454; 2345 m: J. Pérez col. (1 female, CAVAISC-ACA 1950). Collected from Phyllodactylus gerrhopygus .

Diagnosis. Idiosoma (186 x 342), wider than long, ellipsoid. Propodonotal shield bifurcated posteriorly and with fragmented anterolateral projections; wider than long, not reaching concave anterior border of idiosoma; bearing 16 serrated setae. Eyes present. Weakly defined opisthosomal plate, ellipsoid, encompassing genitoanal region. Ventral idiosoma more hypertrichous than dorsal idiosoma; possessing transverse and longitudinal striae. Coxae I–II with 4 setae: 1a, 1b setiform, 2a, 2b serrated and coxae III–IV with 7 serrated setae: 3a, 3b, 4a, 4b, 4c, 4d, 4e; coxal formula: 2–2–2–5. Anterior and posterior epimeral plates separated by striated cuticle. Anal opening on dorsal idiosoma; genital opening terminal, visible on both sides of idiosoma. Anogenital valves with longitudinal to transverse striations, with g1, g2 and g3 setae present on the anogenital plate. Gnathosoma with subquadrangular infracapitulum, with 1 pair of setae n; with 5 setae on palp tibia, being v”T setiform seta twice length of article. Leg IV slightly longer than others. 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 275, width 342) ( Table 1), ellipsoid, small ( Figs. 1–2 ). Ventral idiosoma more hypertrichous than dorsal idiosoma ( Figs. 8–11 , Fig. 7 ).

Dorsal idiosoma. Soft cuticle of dorsal idiosoma with coarse transverse striae and numerous plumose setae ( Fig. 1A ). Propodonotal shield bifurcated posteriorly, with anterolateral projections; these fragmented ( Fig. 6 ); propodonotal shield wider than long (length 562, width 175), not reaching border of idiosoma; 16 serrated setae present (length 17–27) ( Fig. 6 ). Eyes present, located on either side of first pair of propodonotal shield fragments, above ocular setae (length 27) ( Fig. 6 ). Posterior edge of propodonotal shield surrounded by striae following propodonotal L—length / W—width

shield outline, soft cuticle with serrated setae varying in length 12–23 ( Figs. 1 , 6 ). Antero-lateral setae shorter than postero lateral setae (length 19–54) ( Fig. 1A ). Opisthosomal plate weakly defined, ellipsoid, encompassing genitoanal region (length 9–24) ( Fig.1 ).

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 4 setae: 1a, 1b setiform (length 18–20) and 2a, 2b, serrated (length 15–18) ( Fig. 7 ). Fused coxae III–IV with 7 serrated setae: 3a, 3b and 4a, 4b, 4c, 4d, 4e (length 18–25) ( Fig. 7 ). Anterior and posterior epimeral plates separated by narrow band of striated cuticle ( Fig. 7 ). Setae of coxae: 1a, 1b, 2a, 2b, 3a, 3b, 4a, 4b, 4c, 4d, 4e, with the following formula: 2–2–2–5.

Ventral idiosoma covered by plumose setae, 18–28 long. These setae longer in posterior part, 38–54 long ( Fig. 2 ).

Anogenital area. Genital and anal openings close together, defined by thickened C-shaped sclerites. Anal opening dorsal, genital opening terminal, visible on both sides of idiosoma. Anogenital valves with longitudinal to transverse striations ( Figs. 1–2 ). Setae g1 (length 19), g2 (length 26) and g3 (length 22) present on anogenital plate ( Fig. 1B ). Anogenital plate with striae ( Fig. 1A ).

Gnathosoma . Gnathosoma (length 90) with subquadrangular infracapitulum bearing pair of subcapitular setae n (length 45) ( Fig. 5 ). Palp (length 75), with serrated seta dF on palpal femur, setiform seta dG on palp genu and setiform setae l’T, l”T, v’T, v’’T and dT on palp tibia ( Figs. 3–4 ). Palp tarsus with phaneres ul’, ul”, acm and sul present, setiform, and five times greater than length of article ( Fig. 4 ). Chelicera (length 78) with fixed digit threetoothed and mobile digit smooth and hook-shaped ( Fig. 3 ). Hypostome contoured laterally by short, upward-facing peritremes ( Fig. 3 ).

Legs. Length of legs I to IV, coxae–tarsi (length 188–229). Leg IV longer than others ( Figs. 8–11 ). 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 (3-2-2-2) trochanters I–IV (1-1-1-1) ( Figs. 8–11 , Figs. 12–19 ). 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 10 setae (tc’, tc”, p’, p”, a’, a”, u’, u”, vs’, vs”), tarsus III with 10 setae (tc’, tc”, p’, p”, it’, it”, a’, a”, u’, u”) and tarsus IV with 10 setae (tc’, tc”, p’, p”, it’, it”, u’, u”, vs’, vs”), tarsal formula: tarsi I–IV (14(ω1)–10(ω1)–10–10) ( Figs. 8–11 ).

Male unknown.

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

Differential diagnosis. Geckobia andina n. sp. differs from the other members of the latasti group by possessing a weakly defined ellipsoid opisthosomal plate that encompasses the genitoanal region, and palp phaneres ul’, ul”, acm and sul present ( Figs. 3–4 ), all setiform and five times greater than the length of the article.

Geckobia andina n. sp. is morphologically most similar to G. bataviensis . Geckobia andina n. sp. and G. bataviensis share the same leg setal formula—tibiae I–IV (5-5-5-5) genua I–IV (0-0-0-0) femora I–IV (3-2-2-2) trochanters I–IV (1-1-1-1)—a basally bifurcated propodonotal shield, and only g1, g2 and g3 setae present on the anogenital plate. Furthermore, both species belong to group A with regard to chaetotaxy of tarsus I (with 14 setae) and coxae I–II with 4 setae (1a, 1b both setiform, and 2a, 2b serrated). However, the new species differs from G. bataviensis by having coxal field IV with 5 setae (4a, 4b, 4c, 4d and 4e), a weakly defined ellipsoid opisthosomal plate that encompasses the genitoanal region, and five setae on the palp tibia of which seta v”T is twice the length of article. For species with many specimens, such as G. latasti , G. tarentulae , G. hemidactyli and G. aureae , among others, 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 1–2. Geckobia andina n. sp., female. 1A, Idiosoma, dorsal view; 1B, Schematic drawing of anogenital area with setae insertion, dorsal view; 2, Idiosoma, ventral view.

FIGURES 3–5. Geckobia andina n. sp., female. 3, Gnathosoma, dorsal view; 4, Palp, ventral view; 5, Gnathobasal seta, ventral view.

FIGURES 6–7. Geckobia andina n. sp., female. 6, Propodonotal shield, dorsal view; 7, Coxae I–II and III–IV fused, ventral view.

FIGURES 8–11. Geckobia andina n. sp., female. Legs, postero-lateral view: 8, Leg 1; 9, Leg 2; 10, Leg 3; 11, Leg 4.

FIGURES 12–15. Geckobia andina n. sp., female. Tibiae, antero-lateral view: 12, Tibia 1; 13, Tibia 2; 14, Tibia 3; 15, Tibia 4.

FIGURES 16–19. Geckobia andina n. sp., female. Femur, dorsal view: 16, Femur 1; 17, Femur 2; 18, Femur 3; 19, Femur 4.