Crotonia valdivia, Colloff, Matthew J., 2009

Colloff, Matthew J., 2009, Species-group concepts and biogeography of the genus Crotonia (Acari: Oribatida: Crotoniidae), with new species from South and Central America, Zootaxa 2081, pp. 1-30 : 10-11

Crotonia valdivia sp. nov.

( Fig. 6 )

Dimensions: Holotype female length 1510; breadth 717; paratype female length 1434; breadth 691; mean ratio of length of prodorsum to total length: 0.3.

Female. Prodorsum: rostrum prominent, 42 long, 87 broad; rostral setae 62, straight, smooth ( Fig. 6 a). Lamellar setae recurved, 330, very sparsely barbed, stout proximally. Lamellar apophyses extending anteriorly beyond rostrum but behind apices of rostral setae; length 133, slightly more than half their mutual distance. Interlamellar apophyses twice as long as broad; interlamellar setae stout proximally, flagelliform distally, smooth; ca. 423, extending anteriorly beyond apex of arch of lamellar setae. Shallow curved prodorsal ridges extending less than half the distance between interlamellar and lamellar apophyses. Posterior interbothridial ridge with medial alveolar field present, with plaques and flat tubercles posterior of it. Sensillus globular, enclosed in bothridium, with veined microsculptural covering. Prodorsal microsculpture tuberculate.

Notogaster: ratio of length to breadth 1.5; broadest at seta e 2 ( Fig. 6 a). Dorsosejugal suture complex, with diffuse medial margin with smooth, rectangular pre-notogastral shield and waisted, concave lateral margins adjacent to setae c 3. Notogastral shield discrete, smooth, with two lateral strips of plaques and diffuse porose microsculpture. With 13 pairs of notogastral setae; all smooth. Setae of c series short, setiform, tubercles of c 1 and c 3 squat, no longer than broad, positioned on hyaline lenses of cuticle just anterior to margin of dorsal shield, some distance posterior of dorsosejugal suture. Elongated less sclerotised region present anterior of setae c 1. Distance between tubercles c 3 and c 1 and both c 1 132 and 190 respectively. Lateral hyaline strips present bearing tubercles of setae cp, e 2 and f 2. Setae d 2 short, setiform, on alveloli. Tubercles of setae f 2 not prominent, subequal to other tubercles of other lateral notogastral setae. With gla positioned immediately anterior of f 2. Setae f 1 and the h series on short, clustered apophyses; those of f 1 directed laterally and upward, those of h 1 laterally, subequal in length to f 1; apophyses of h 2 longer than others, parallel, directed posteriorly, their mutual distance about three times their length; caudal margin between them straight, transverse. Apophyses of setae h 3 positioned ventrally between those of h 1 and h 2, subequal in length to those of h 1. Caudal microsculpture with small, scattered foveolae, otherwise smooth.

Ve n t e r: Setae h on mentum smooth, setiform, long. Epimera smooth, porose ( Fig. 6 b); epimeral setae smooth, spiniform, minute, formula 3-1-3-3; seta 3c on large tubercle on anterior margin of epimere. Ventral margin of notogaster surrounding anal plates acutely U-shaped; genital plates sub-circular; posteriolateral margin of genital plates concave; posterior margin straight, transverse. Each genital plate 250 long, 150 broad, with nine thin spiniform setae with basal cerotegument. Aggenital setae subequal in length to genital setae. Anal plate 66 broad, 423 long; anal setae minute (15), positioned closely together on anterior half of anal plate. Adanal setae plus p 2 and p 3 subequal, spiniform; p 1 slightly longer, on short tubercles, ca. 50 apart.

Material examined and locality data. Type material: holotype female and paratype female, ex. litter in Valdivian temperate rainforest, 580 m, Bosque de Fray Jorge National Park, Limar Province, Chile, coll. N. Platnick and O. Franke, 5th January 1985; ex. R. A. Norton collection (RAN 86-18). Types deposited in Canadian National Collection of Insects, Arachnids and Nematodes, Ottawa, Ontario.

Etymology. The specific name, valdivia , refers to Valdivian relict temperate rainforest where this species was found.

Remarks. This species can be distinguished from other members of the genus based on the following combination of characters: 1) caudal apophyses short, in two lateral clusters, but with h 2 longer than others, parallel; caudal margin between them inverted, flat U- shaped; 2) c 1 and c 3 short, subequal; 3) dorsosejugal suture diffuse, complex, with oblong, smooth pre-notogastral shield anterior of setae c 1; 4) centrodorsal region of notogastral shield smooth.

Superficially, this species seems to have the characteristics of the Obtecta species-group in that the caudal apophyses are clustered medially, like those of C. flagellata with which it shares the elliptical shape of the hysterosoma and notogastral shield. However, in both the description of C. flagellata by Balogh & Csiszár (1963) and the supplementary description by Wallwork (1977a) , it appears that the apophyses of setae h 1, and not h 2, are the ones pointing directly posteriorly and those of h 2 are positioned ventral to them, pointing posteriolaterally. Crotonia valdivia sp. nov. differs from C. flagellata in having short setae of the c series, whereas in C. flagellata setae c 1 extend well beyond the apices of the interlamellar apophyses, c 3 are curved and prominent and cp extend as far as the tubercles of d 2. In fact, apart from the shorter apophyses of setae h 2 (only about twice the length of the others), C. valdivia sp. nov. has more shared characters with members of the Cophinaria species-group than the Obtecta group. These include curved, flattened, apically-converging lamellar apophyses rather than straight, tubular, apically-diverging ones; the presence of a transbothridial ridge; the notogastral shield with lateral bands of cuticle with different microsculpture from the centrodorsal region; porose (rather than tuberculate) epimeral and perigenital microsculpture and the bases of setae p 1 positioned very close together.

Figures

FIGURE 6. Crotonia valdivia sp. nov. holotype female a) dorsal; b) ventral; c) caudal apophyses; d) detail of microsculpture of lateral notogastral shield; e) setae of the c and d series.