var. crassisetosus, Niedbała, Wojciech & Dabert, Miroslawa, 2013

Niedbała, Wojciech & Dabert, Miroslawa, 2013, Madeira’s ptyctimous mites (Acari, Oribatida), Zootaxa 3664 (4), pp. 571-585 : 576

Steganacarus (Steganacarus) crassisetosus (Willmann, 1939)

( Figs. 2A–G )

Steganacarus applicatum (Sell.) var. crassisetosus n. var. Willmann, 1939

Measurements of specimen from Balcoes, Madeira. Prodorsum: length 379, height 192, width 288; setae of prodorsum: sensillum 101, interlamellar 177, lamellar 126, rostral 76, exobothridial 30; notogaster: length 818, height 566, width 555, setae of notogaster: c1 185, c1 / c1 – d1 =1.0, h 1 106, p 1 91; genitoaggenital plates: 227 × 192, anaoadanal plates: 268 × 172.

Diagnosis. Large species. Colour brown. Integumental body sculpture slightly areolate. Prodorsum with distinct median crista; median and lateral fields very long; lateral carinae absent; sensilla long, thick covered with spines, sickle-shaped; interlamellar and lamellar setae resemble gastronotic setae covered with small spines, rostral setae long, rough, curved sagittally, in> le> ro> ex. Notogaster with flattened setae covered with spines, setae h1 and p1 located perpendicularly to the surface of notogaster, the remaining setae procumbent; setae h1 and p1 considerably thicker and shorter, about the half of length of procumbent setae; setae c1 = c1 – d1; setae c3 near the anterior margin, c1 further away and c 2 in the most distant position; vestigial setae f1 posteriorly of setae h1; two pairs of lyrifissures ia and im. Ventral region: h> h – h; genitoaggenital plates with setal formula: 6(4+2): 3; anoadanal plate with four setae at proximal margin which diminish towards the anterior margin, setae ad 3 very short, spiniform, an / not =0.3. Chaetome of legs complete, setad d on femora I slightly remote from anterior margin.

Comparison. Willmann (1939) has particularly emphasised one character differentiating crassisetosus from the main form applicatus ( Fig. 2H – M ), that is short, thick and perpendicular setae h1 and p1 much shorter than the others; in applicatus the length of these setae is similar to that of the other ones. Moreover, Willmann claims that the size of crassisetosus is larger, however, in view of great variation in the size of phthiracaroid mites individuals, this feature should be treated with caution. There are two main morphological features differing S. (S.) applicatus and S. (S.) crassisetosus ; the perpendicular setae h1 and p 1 in S. (S.) crassisetosus are thick and shorter (h1: e1 = 0.55) than procumbent setae, while in S. (S.) applicatus , the setae h1 and p1 are of the same thickness and similar length (h1, e1 = 0.85) as procumbent setae. Rostral setae in S. (S.) crassisetosus are long, rough, curved sagittally but rostral setae in S. (S.) applicatus are shorter, spiniform and diriged forward. Steganacarus (S.) crassisetosus is also similar to S. (S.) carusoi (Bernini & Avanzati, 1989) (Western Palaearctic species, reported from the Maghrebian and Atlanto-Mediterranean region). These species have perpendicular setae h1 and p1 and rostral setae of similar length directed inward but S. (S.) carusoi has shorter lamellar setae, perpendicular setae h1 and p1 of the same length as the other procumbent setae, setae c1 of notogaster situated slightly nearer to anterior border than c3 setae and setae ad 3 in distal half are rugose or covered with small spines (versus shorter perpendicular setae than procumbent setae, greater distance of c1 setae from anterior border and small, spiniform ad3 setae in S. (S.) crassisetosus ).

Figures

FIGURE 2 A – M. A – G. Steganacarus (Steganacarus) crassisetosus (Willmann, 1939): A, prodorsum, dorsal view; B, prodorsum, lateral view; C, mentum of subcapitulum; D, genitoaggenital plate; E, anal and adanal setae; F, lateral view of opisthosoma, G, trochanter and femur I. H – M. Steganacarus (Steganacarus) applicatus (Sellnick, 1920) (specimen from Poland): H, prodorsum, dorsal view; I, prodorsum, lateral view; J, genitoaggenital plate; K, anoadanal plate; L, femur I; M, lateral view of opisthosoma.