Cosmochthonius foliatus Subías, 1982

Seniczak, Stanisław, Penttinen, Ritva & Seniczak, Anna, 2011, The ontogeny of morphological traits in three European species of Cosmochthonius Berlese, 1910 (Acari: Oribatida: Cosmochthoniidae), Zootaxa 3034, pp. 1-31 : 12-17

Cosmochthonius foliatus Subías, 1982 ( Figs 8 B, 9B, 10B. 11, 12, 13A, 14–16)

Cosmochthonius foliatus: Ruiz and Subías 1984 ; Minguez and Subías 1986; Ruiz et al. 1986, 1991; Arillo et al. 1988; Pérez- Iñigo 1988; Pérez-Iñigo, Jr 1990; Gil et al.1991; Subías 2004, 2011; Penttinen and Gordeeva 2009. Cosmochthonius lanatus: Sergienko 1987, 1994 .

Diagnosis. Adult small (279–325 µm), light brown. Seta c 3 hardly reaching seta cp, and inserted on lateral border of plate Na (Figs 11, 12). Setae of e - and f -series with 23–25 pairs of cilia, and 22–24 pairs, respectively ( Table 2 ). Cerotegument thick, with small holes (seen in SEM; Penttinen & Gordeeva 2005); cuticle with shallow, rounded and sub-equal foveae (Fig. 12). Cerotegumental collar present. Genital plate with 10 pair of setae, six pairs inserted on inner border of genital plate ( Fig. 13 A). Formulae of leg setae and solenidia, and number of claws as in C. reticulatus .

Juveniles similar to those of C. reticulatus , but setae of e - and f -series with more cilia (larva 10–11 pairs, nymphs 19–23 pairs) than in C. reticulatus .

Description of larva and tritonymph: Shape of larva ( Figs 14 , 15 A), prodorsal setae, bothridium, and sensillus as in C. reticulatus . Gastronotal setae similar to those of C. reticulatus , but hypertrophied setae with 10–11 pairs of cilia. Cupules ia, im, ip and ih located as in C. reticulatus .

Shape of body, setae, bothridium and sensillus of tritonymph ( Figs 15 B, 16) as in C. reticulatus , but hypertrophied setae with 19–23 pairs of cilia ( Figs 8 B, 16). Setae p 1 and h -series bushy, p 1 and h 1 thicker than h 2 and h 3 ( Fig. 10 B). Cupules ia, im, ip, ih, ips and iad located as in C. reticulatus . Ontogenetic transformations of C. foliatus , and shape of tibia and tarsus I, solenidia φ and ω, and famulus ε as in C. ponticus (see Seniczak & Seniczak 2009a).

FIGURE 9. Fragment of plates Na and Nm 1, scale bars 10 μm. (A) Cosmochthonius reticulatus ; (B) C. foliatus ; (C) C. ugamaensis ; (D) C. ponticus .

Distribution and ecology: Cosmochthonius foliatus is a Mediterranean occidental species ( Subías 2004, 2011). It is considered common in the western Mediterranean ( Gil et al. 1991, Penttinen & Gordeeva 2009), but was also found in oak litter ( Quercus pubescens Willd. ) in the Ukraine. Pérez-Iñigo jr. (1990) considred this species xerophilous; it was found in sandy soil covered with herbs ( Pérez-Iñigo & Peña 1995). We found this species rather abundant (102 indiv. per 500 cm 3) in cypress litter in coastal Santa Susana (Costa Brava, North-East Spain, N41°37.26’, E2°43.24’, 4 m a. s. l.), where juveniles comprised 38.2% of the population.

Figure 11. Cosmochthonius foliatus , adult. (A) Notogaster with cerotegument, scale bar 50 μm; (B) fragment of pygidium.

Figure 12. Cosmochthonius foliatus , adult. (A) Notogaster, cerotegument removed, scale bar 50 μm; (B) fragment of pygidium.

Figures

FIGURE 8. Hypertrophied setae of tritonymph, scale bars 50 μm. (A) Cosmochthonius reticulatus; (B) C. foliatus.

FIGURE 10. Posterior margin of gastronotum, scale bar 20 μm. (A) Cosmochthonius reticulatus; (B) C. foliatus; (C) C. ugamaensis; (D) C. ponticus.

FIGURE 13. Anogenital region of adult, scale bars 50 μm, legs partially drawn. (A) Cosmochthonius foliatus; (B) C. ugamaensis.

FIGURE 14. Cosmochthonius foliatus, larva, dorsal aspect, legs partially drawn, scale bar 50 μm.

FIGURE 15. Cosmochthonius foliatus, legs partially drawn, scale bars 50 μm. (A) Anal region of larva; (B) anogenital region of tritonymph.