Galumnella baleensis Ermilov, Sidorchuk and Rybalov

Ermilov, Sergey G., Sidorchuk, Ekaterina A. & Rybalov, Leonid B., 2010, New species of oribatid mites of the superfamily Galumnoidea (Acari: Oribatida) from Ethiopia, Zootaxa 2646, pp. 43-62 : 56-59

Galumnella baleensis Ermilov, Sidorchuk and Rybalov sp. nov.

( Figs. 44 –62)

Material examined. Holotype and four paratypes were obtained from the Ethiopia, 6º38'N, 39º43'E, 1883 m above sea level, Bale Mountains National Park, Harenna Forest, in soil, collected by L. B. Rybalov, 23.11.2009.

Type deposition. The holotype and two paratypes are deposited in the collection of the Zoological Institute of the Russian Academy of Sciences, St. Petersburg, Russia; two paratypes are in the personal collection of the first author.

Etymology. The species is named after the Ethiopian Bale Mountains National Park.

Diagnosis. With character states of Galumnella that were proposed by Berlese (1916), and summarized by Balogh and Balogh (1992). The new species is characterized by the small size of body, 315–328 × 225–246; surface of body with very small foveolae; rostrum pointed; rostral and lamellar setae thin, smooth; sensilli long, with head asymmetrically dilated, barbed; notogaster with minute setae and setal alveoli; one pair of pores developed dorso-laterally; oblong postanal area porosa present; legs monodactylous.

Description. Measurements. Small species, body length 315 (holotype), 315–328 (paratypes); body width 225 (holotype), 225–246 (paratypes).

Integument. Body color brown. Surface of body foveolate; foveolae very small (less than one micrometer).

Prodorsum ( Figs. 44, 46–49 ). Rostrum conical, pointed in dorsal view. Sublamellar line well developed. Rostral and lamellar setae 16 – 20, thin, smooth; sometimes rostral setae slightly longer than lamellar setae. Sensilli long (69–77), with head dilated on one side; head with one or two large barbs and one or three small barbs on tip. Interlamellar setae absent (only their alveoli present). Exobothridial setae not observed.

Notogaster ( Figs. 44 , 51, 52 ). Nine pairs of notogastral setae minute or dorsal setae absent (only alveoli present). Setae (or alveoli) c and lyrifissures ia on pteromorpha not observed. One pair of small pores developed dorso-laterally.

Anogenital region ( Figs. 45 , 53–55 ). Oblong, small (12 × 4) postanal area porosa (Ap) present. Two pairs of anal setae, three pairs of adanal setae, one pair of aggenital setae, six pairs of genital setae short, 2–6, thin, smooth. Anterior parts of genital plates with three setae; one plate in one specimen was with two setae ( Fig. 54 ). Lyrifissures iad not observed. Ovipositor ( Fig. 56 ) elongate, narrow (114–118 × 41). Length of lobes 49– 53, length of cylindrical distal part 65. Setae smooth, ψ1 ≈ τ1 (28) longer than ψ2 ≈ τ a ≈ τ b ≈ τ c (12). Setae k short, 4.

Epimeral region ( Fig. 45 ). Epimeral setae short (4–6), thin, smooth. Epimeral setal formula 1–0–3–3; setae 3c and 4c located laterally.

Gnathosoma ( Figs. 57–59 ). Subcapitulum slightly longer than wide: 61 × 53. Hypostomal setae thin, smooth; setae a (10–12) longer than m, h (6–8). Palp (length 53) with setation 0–2–1–3–9(+1ω). All setae (except on tarsus) barbed. Chelicera (length 102) with weakly developed few blunt teeth on fixed and movable digits.

Legs ( Figs. 25–28 ). All legs monodactylous. Formulas of leg setation and solenidia: I (1–4–3–4–20) [1–2– 2], II (1–4–3–4–15) [1–1–2], III (1–2–1–3–15) [1–1–0], IV (1–2–2–3–12) [0–1–0]; setation of legs same as that of former species. Almost all setae well barbed; some ventral setae of tarsi and tibiae with long cilia. Solenidia ω1 and ω2 on tarsi II, straight or weakly curved, rod-like. Other solenidia rather long, setiform.

Distribution. At present, this species is only known from Ethiopia.

Remarks. Galumnella baleensis sp. nov. is most similar to G. p a r a d o x a Berlese, 1916 (from Somalia) (see Berlese 1916; Mahunka 1992a; Balogh and Balogh 2002), but the latter has blunt-ended rostrum in dorsal view; rostral and lamellar setae absent; sensilli lanceolate, with thin, pointed tips, smooth; alveoli of notogastral setae (la, lm, lp, h 3) located differently.

Keys with distinctive morphological characters of species within Galumnella were published earlier (see Mahunka 1992b; Aoki and Hu, 1993; Balogh and Balogh 2002).

Galumnella baleensis sp. nov. belongs to the Galumnella species group with one pair of dorso-lateral notogastral pores. Only two species with this diagnostic feature were known as yet: the type species, G. paradoxa , and G. i n d i c a Balakrishnan, 1989 (see Balakrishnan 1989). A diagnostic key to the three known species of Galumnella with one pair of notogastral pores is presented below.

Figures

FIGURES 44 – 49. Galumnella baleensis sp. nov.: 44 — dorsal view, 45 — ventral view, legs removed, 46 — rostrum, 47 – 49 — sensilli. Scale bar (44 – 45) 100 μm, scale bar (46 – 49) 50 μm.

FIGURES 50 – 52. Galumnella baleensis sp. nov.: 50 — lateral view of prodorsum, 51 — pteromorpha, 52 — caudal view. Scale bar (50 – 51) 50 μm, scale bar (52) 100 μm.

FIGURES 53 – 56. Galumnella baleensis sp. nov.: 53 — genital plate, right, 54 — genital plate, left, 55 — anal plate, right, 56 — ovipositor. Scale bar (53 – 55) 20 μm, scale bar (56) 50 μm.

FIGURES 57 – 59. Galumnella baleensis sp. nov.: 57 — subcapitulum, without rutelli, 58 — palp, 59 — chelicera. Scale bar 20 μm.

FIGURES 25 – 27. Taeniogalumna behanae sp. nov.: 25 — dorsal view, right pteromorpha partly removed, 26 — ventral view, right pteromorpha partly removed, legs removed, 27 — sensillus. Scale bar (25, 26) 100 μm, scale bar (27) 20 μm.

FIGURES 28 – 30. Taeniogalumna behanae sp. nov.: 28 — dorso-lateral view of prodorsum, 29 — pteromorpha, 30 — caudal view. Scale bar (28, 29) 50 μm, scale bar (30) 100 μm.