Crotonia daviesae, 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 : 22-25

Crotonia daviesae sp. nov.

( Figs. 8 , 17 b, 18h, 20, 21)

Dimensions: holotype female length 1382, breadth 691. Paratypes: females (n = 17): mean length 1391 (range 1311–1477); mean breadth 689 (range 616–751); males (n = 19): mean length 1155 (range 1058– 1225); mean breadth 537 (range 490–569). Ratio of length of prodorsum to total body length: 0.32 (holotype).

Description of female. Prodorsum: ratio of length to breadth 1.0. Rostrum with prominent naso, projecting well beyond rostrum, lateral edges concave; rostral seta 53, straight, spiniform, smooth ( Fig. 8 a). Lamellar seta 260, recurved, smooth. Lamellar apophyses 153, slightly curved medially, broadening basally, three quarters as long as their mutual distance; extending anteriorly beyond apices of rostral setae. Interlamellar apophyses twice as long as broad; interlamellar seta 390, flagelliform, smooth; extending anteriorly as far as apex of curve of lamellar setae. Prodorsal ridges well-developed, strongly curved medially, extending anteriorly half the distance between bases of interlamellar and lamellar apophyses. Diameter of bothridium 55; auriculate ridge of bothridium a blunt, bi-lobed projection; hexagonal reticulations of operculum lacking concentric ridges and with point of origin near lateral margin ( Fig. 18 h). Inter-bothridial ridge well-developed, straight, transverse, curved anteriolaterally at margins, with a slight median invagination. Median field of muscle sigilla present. Prodorsal microsculpture smooth, porose.

Notogaster: ratio of length of notogaster to breadth of notogastral shield 1.39; notogastral shield broadest at level of bases of setae e 2 ( Fig. 8 a); ratio of width of shield to entire notogastral width 0.82; lateral margins of shield oval, sub-circular. Dorsosejugal suture well-defined, with discrete ridge. Region posterior of apophyses of setae c 3 very slightly concave; lyrifissure ia immediately posterior of concavity. With 14 pairs of smooth notogastral setae. Pre-notogastral shield separated from notogastral shield by narrow transverse hyaline strip, bearing short cylindrical apophysis (22 long) of long, stout, flagelliform seta c 3 (334); thin, flagelliform seta c 1 (144) and c 2 (195) emerging from alveoli on posterior margin. Notogastral shield slightly convex, tapering to U-shape anterior of caudal apophyses; opisthosoma inflated. Notogastral shield bordered laterally by relatively narrow strips of small tubercles, fusing and becoming dense and extensive in caudal region. Lateral hyaline strip (suprapleural scissure) wide, bearing tubercles of setiform setae cp and e 2 (both ca. 110) Seta d 2 thin, 62, setiform; mutual distance (185) two thirds of that between setae c 2. Recurved seta f 2 (70) on conical tubercles projecting beyond margin of notogastral shield. Opisthosomal gland opening gla positioned anteriomedial of setae f 2. Caudal apophyses bi-lobed, originating directly from caudal margin; no caudal stalk present. Apophyses of h 2 long, parallel (142), only slightly longer than their mutual distance; caudal margin between them transverse. Apophyses of h 1 (45) emerging dorsolaterally from bases of those of h 2; apophyses of f 1 (39) projecting posteriolaterally, adjacent to those of h 1. Apophysis of seta h 3 positioned between h 1 and f 1 ventrally. Caudal setae sparsely barbed, recurved, flagelliform apically; f 1, h 1 h 2 and subequal in length (117–130), h 3 102.

Ven te r: epimeral microsculpture smooth, porose ( Fig. 8 b); epimeral setae smooth, spiniform, subequal, formula 3-1-3-3; ca. 32–45 long; 4a longer than others (61); seta 3c on well-developed tubercle. Epimeral plates I with sharp projections posteriolaterally. With lcs broad, curved, forming an obtuse angle (ca. 130°) with pcs. Anteriolateral margin of adanal plate lacking indentation. Genital plates sub-circular; posterior margin transverse. Perigenital region strongly and densely tuberculate. Each genital plate 193 long, 135 broad, with eight setiform setae, subequal in length (45); two pairs of aggenital setae, subequal in length to genital setae. Anal plate narrow (58 broad), 354 long, with three short (39) setae on central region of plate; three pairs of spiniform adanal setae, ad 1-3 spiniform, sub-equal (52); distance between ad 2 and ad 3 a third of that between ad 1 and ad 2. Ventral margin of notogaster surrounding anal plates curved, U-shaped. Setae of p series setiform, p 1 145, p 2 103, p 3 71. Tubercles of p 1 longer than broad, separated by distance sub-equal to their length.

Lateral view: Caudal margin perpendicular to notogastral shield ( Fig. 8 c); dorsal and ventral surfaces convex, not parallel, distance between them ca. 396 perpendicular of seta f 2, narrowing anteriorly. Apophyses of setae f 1 and h 1 pointing posteriodorsally, those of h 2 about three times the length of h 1, more-or-less horizontal, pointing posteriorly; those of h 3 positioned ventral of h 1 on caudal margin, pointing ventrolaterally. Caudal cluster positioned slightly below level of notogastral shield. Apophysis of seta p 1 at junction of caudal margin and ventral surface; p series equidistantly spaced. Pleuraspis covered in dense tubercles.

Caudal view: Opisthosoma rhomboid in cross section, with lateral invaginations along dorsal part of pleuraspis ( Fig. 17 b). Caudal apophyses in paired clusters, originating at points slightly below level of notogastral plate, each cluster consisting of all four apophyses. Semi-circular ridge present dorsal of p series. Tubercles of caudal region concentrated ventrally and laterally of caudal apophyses, becoming sparse ventrally; with smooth median region.

Material examined. Holotype female, paratypes: eight females, eight males, QM S26071 , litter, complex notophyll vine forest, Tallawallal, Binna Burra, Lamington National Park, Queensland, 28°12'S 153°10'E, coll. V.T. Davies, J. Gallon & D. Court, 18.v.1983. Paratypes: two females, four males, QM S26056 , litter, closed forest, Gold Creek Reservoir, Brookfield, Queensland, 27°30'S 152°55'E, 135 m., coll. V.T. Davies and R.J. Raven, 23.vi.1980. Two paratype females, QM S26068 , rainforest, O Reilly’s, Lamington National Park, Queensland, 28°14'S 153°08'E, coll. G.B. Monteith, R.J. Raven and D.K. Yeates, 15.xii.1981. Paratype female, QM S26072 , moss, rainforest, Binna Burra, Tallawallal, Lamington National Park, Queensland, 28°12'S 153°10'E, coll. V.T. Davies J. Gallon & D. Court, 18.v.1983. Paratypes: one female, five males, QM S26073 , pitfall trap, simple notophyll vine forest, Nagarigoon, Lamington National Park, Queensland, 28°12' S 15310'E, coll. R.J. Raven & V.T. Davies, 30.iii–4.iv.1976. Paratypes: two females, one male, leaf litter, forest floor, O’Reilly’s, Lamington National Park (28°19'S, 153°05'E), Queensland, coll. M.J. Colloff and D.E. Walter, 18.x.1994. Paratype male, canopy fogging, subtropical rainforest (complex notophyll vine forest), Wishing Tree Track, O’Reilly’s Rainforest Retreat, Green Mountains, 28°14'03"S, 153°08'16"E, ca. 900 m., coll. R.L. Kitching, 1989–1991 (Lam 89–91 #F III). Holotype and paratypes from QM samples deposited in the Queensland Museum, Brisbane; other paratypes from O’Reilly’s deposited in the Australian National Insect Collection, CSIRO Ecosystem Sciences, Canberra.

Etymology. This species is named in honour of its collector, Dr Valerie Davies (Queensland Museum), in recognition of her contribution to Australian arachnology.

Remarks. Crotonia daviesae differs from all from all other Crotonia spp. by the following combination of characters: 1) the dense, tuberculate pattern on the lateral and caudal regions of the notogastral plate, the pleuraspis and the perigenital and adanal regions; 2) long, thin, flagelliform, setae c 1 and slightly longer setae c 2; 3) bothridium with blunt, bi-lobed projection laterally; 4) caudal setae sparsely barbed; 5) distance between ad 2 and ad 3 a third of that between ad 1 and ad 2; 6) seta 4a half as long again as other epimeral setae.

Crotonia daviesae is morphologically most similar to the members of the Capistrata species-group from Victoria described by Colloff & Perdomo, 2009 ( C. alpina , C. cornuta and C. victoriae ). It shares with C. cornuta the sharp projections on the margins of epimeral plates. In addition to the cuticular tubercles and barbed caudal setae, it differs in having markedly shorter setae cp and e 2. Crotonia daviesae shares with C. alpina the dense tubercles in the caudal region of the notogastral plate but they are not as extensive in the lateral and anterior regions, and it has far shorter setae d 2, cp and e 2. Crotonia daviesae shares with C. victoriae the relative lengths of setae d 2, e 2 and f 2, but differs in having much shorter apophyses of setae c 3 and longer, thinner setae c 1 and c 2 spaced equidistantly, whereas in C. victoriae c 1 and c 2 are close together. In C. daviesae cp and e 2 are subequal in length and the apophyses of setae f 1 and h 1 are adjacent. In C. victoriae e 2 is almost twice as long as cp and the apophyses of setae f 1 and h 1 are separate.

Figures

FIGURE 8. Crotonia daviesae sp. nov. holotype female a) dorsal; b) ventral; c) lateral.

FIGURE 17. Caudal regions of a) Crotonia raveni sp. nov.; b) Crotonia daviesae sp. nov.

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.