Crotonia yeatesi, Colloff, Matthew J., 2010

Colloff, Matthew J., 2010, The Gondwanan relict oribatid genus Crotonia (Acari: Oribatida: Crotoniidae) from rainforests in Queensland and Northern New South Wales: new species show a mixed pattern of short-range and long-range endemism, Zootaxa 2649, pp. 1-51 : 27-30

Crotonia yeatesi sp. nov.

(Figs. 10, 18j, 21)

Dimensions: holotype female length 1460, breadth 717. Ratio of length of prodorsum to total body length: 0.32 (holotype).

Description of female. Prodorsum: ratio of length to breadth 1.13. Rostrum with squat naso, barely projecting beyond rostrum; lateral edges concave; rostral seta 52, straight, spiniform, smooth (Fig. 10a). Lamellar seta 258, recurved, smooth. Lamellar apophyses 147, parallel, broadening basally to three times their apical breadth, slightly more than three quarters as long as their mutual distance; extending anteriorly as far as apices of rostral setae. Interlamellar apophyses very large (52 long, 30 broad); interlamellar seta 370, flagelliform, smooth; extending anteriorly as far as apex of curve of lamellar setae. Prodorsal ridges long, well-developed, curved medially, extending anteriorly almost three quarters of the distance between bases of interlamellar and lamellar apophyses. Diameter of bothridium 45; auriculate ridge of bothridium a broad, Dshaped structure with an anterior invaginated ridge; hexagonal reticulations of operculum with welldeveloped concentric ridges and with point of origin near lateral margin ( Fig. 18 j). Inter-bothridial ridge a well-developed, shallow, straight ridge, angled laterally, with median invagination. Median field of muscle sigilla present. Prodorsal microsculpture smooth, porose.

Notogaster: ratio of length of notogaster to breadth of notogastral shield 1.42; notogastral shield broadest at level of bases of setae e 2 (Fig. 10a); ratio of width of shield to entire notogastral width 0.84; margins of notogastral shield convex, sub-hexagonal. Dorsosejugal suture well-defined, with discrete ridge interrupted medially by field of small tubercles. Lyrifissure ia 37 long, positioned immediately lateral of seta c 3. With 14 pairs of smooth notogastral setae. Pre-notogastral shield separated from notogastral shield by narrow transverse hyaline strip, and bearing short, stout, setiform setae c 3 (118) on short, squat tubercles and thin, setiform, short setae c 1 and c 2 (33) emerging from alveoli on posterior margin. Notogastral shield with narrow lateral strips of small tubercles extending anteriorly along transverse margin and broadening, becoming more extensive in caudal region posterior of setae f 2. Notogastral margin between setae f 2 and f 1 straight, sloping diagonally. Lateral hyaline strip (suprapleural scissure) wide, bearing well-developed tubercles of short, stout, setiform setae cp and e 2 (both ca. 75). Seta d 2 thin, 30, setiform; mutual distance (192) slightly less than that between setae c 2. Straight, spiniform seta f 2 (80) on prominent conical tubercle projecting beyond margin of notogastral shield. Opisthosomal gland opening gla positioned anteriomedial of setae f 2. Caudal apophyses bilobed, originating directly from caudal margin; no caudal stalk present. Apophysis of h 2 straight, slightly inflexed, short (70), though longer than others, half as long as their mutual distance, caudal margin between them transverse. Apophysis of h 1 (37) emerging dorsolaterally from base of that of h 2; apophysis of f 1 (39) projecting dorsolaterally, slightly separated from, and anterior of, that of h 1. Apophysis of seta h 3 positioned ventral of h 1. Caudal setae smooth, short, straight, spiniform; f 1 and h 1 subequal in length (77), h 2 88, h 3 55.

Ve n t e r: epimeral microsculpture smooth, porose (Fig. 10b); epimeral setae smooth, thin, spiniform, subequal, formula 3-1-3-3; ca. 30–42 long; seta 3c spiniform, on well-developed tubercle. With lcs narrow, straight, forming an obtuse angle (ca. 130°) with pcs. Anteriolateral margin of adanal plate with a narrow, shallow indentation. Genital plates sub-circular; posterior margin transverse; posteriolateral margins straight, diverging. Perigenital region smooth, porose. Each genital plate 215 long, 146 broad, with eight setiform setae, subequal in length (35); two pairs of aggenital setae, subequal in length to genital setae. Anal plate narrow (52 broad), 393 long, with three very short (10) setae on central region of plate; three pairs of spiniform adanal setae, ad 2-3 slightly shorter than spiniform ad 1 (31); distance between ad 2 and ad 3 half that between ad 2 and ad 1. Ventral margin of notogaster surrounding anal plates straight, V-shaped. Setae of p series spaced equidistantly, setiform, p 2 and p3 subequal in length (52); p 1 long, flagelliform (160). Tubercles of p 1 well-developed, cylindrical, separated by distance equal to their width.

Lateral view: Caudal margin slightly inflated, contiguous with notogastral shield (Fig. 10c); dorsal and ventral surfaces convex, not parallel, distance between them ca. 645 perpendicular of seta e 2, narrowing anteriorly. Apophysis of seta f 2 projecting well above dorsal margin. Apophysis of seta f 1 pointing dorsally, those of h 1 pointing posteriodorsally, those of h 2 only slightly longer than those of h 1, positioned ventral of them; those of h 3 positioned ventral of h 2, pointing ventrolaterally. Caudal cluster positioned below level of notogastral shield. Apophyses of setae of p 2 and p 3 much closer together than p 1 and p 2. Pleuraspis with sparse tubercles dorsally.

FIGURE 10. Crotonia yeatesi sp. nov. holotype female a) dorsal; b) ventral; c) lateral; d) seta f 2.

Material examined. Holotype female, QM S26053 , moss on trees and rocks, open woodland, Nothofagus Mountain , 12 km north of Woodenbong, New South Wales, 28°17'S 152°37'E, coll. G.B. Monteith, D.K. Yeates & D. Cook, 26.ix.1982. Holotype deposited in the Queensland Museum, Brisbane.

Etymology. The species is named in honour of my colleague, Dr David Yeates (Australian National Insect Collection, CSIRO Ecosystem Sciences), in recognition of his research contribution to the phylogeny, systematics and biogeography of Australian insects.

Remarks. Crotonia yeatesi differs from all other Crotonia spp. by the following combination of characters: 1) notogastral margin between setae f 2 and f 1 straight, sloping diagonally; 2) narrow lateral strips of small tubercles extending anteriorly along transverse margin of notogastral shield and broadening in caudal region posterior of setae f 2; 3) short caudal apophyses, broadly-spaced, with transverse caudal margin between them; h 2 no more than twice the length of h 1; 4) Straight, spiniform setae f 2 (80) on prominent conical tubercles projecting beyond margin of notogastral shield; 5) short, stout, setiform setae c 3 (118) on short, squat tubercles and thin, setiform, short setae c 1 and c 2 (33) emerging from alveoli on posterior margin; 6) minute anal setae on central region of anal plates; 7) lateral ridge of bothridium in the form of a broad, D-shaped projection with an anterior invaginated ridge.

Crotonia yeatesi is not especially morphologically similar to any other species in the genus, particularly in relation to the shape of the posterior part of the notogaster. The shared character states with C. weiri are mentioned above under the remarks section for this species.

Figures

FIGURE 18. Details of bothridia of a) Crotonia sterigma sp. nov.; b) Crotonia borbora Luxton, 1987; c) Crotonia brisbanensis sp. nov.; d) Crotonia maculata sp. nov.; e) Crotonia capistrata Luxton, 1987; f) Crotonia ardala Luxton, 1987; g) Crotonia monteithi sp. nov.; h) Crotonia daviesae sp. nov.; i) Crotonia weiri sp. nov.; j) Crotonia yeatesi sp. nov.; k) Crotonia cameroni sp. nov.; l) Crotonia eungella sp. nov. m) Crotonia queenslandiae sp. nov.; n) Crotonia seemani sp. nov.; o) Crotonia raveni sp. nov.