Crotonia blacki, Colloff, Matthew J. & Perdomo, Giselle, 2009

Colloff, Matthew J. & Perdomo, Giselle, 2009, New species of Crotonia (Acari: Oribatida: Camisiidae) from Nothofagus and Eucalyptus forests in Victoria, Australia, with a redescription of the fossil species Crotonia ramus (Womersley, 1957), Zootaxa 2217, pp. 1-36 : 16-23

publication ID	https://doi.org/ 10.5281/zenodo.189961
DOI	https://doi.org/10.5281/zenodo.6225402
persistent identifier	https://treatment.plazi.org/id/03FEC052-FFF8-DC6A-569F-5CD0FC3C0E4B
treatment provided by	Plazi
scientific name	Crotonia blacki
status	sp. nov.

Treatment

Crotonia blacki View in CoL sp. nov.

( Figs. 8–12 View FIGURE 8 View FIGURE 9 , 15 View FIGURE 15 , 17–19 View FIGURE 17 View FIGURE 18 View FIGURE 19 )

Dimensions. Holotype female length 1344, breadth 585; paratype male length 1203 breadth 508; Paratype female from Mt. Donna Buang length 1323, breadth 553. Mean ratio of length of prodorsum to total length: 0.33 (both sexes). Larva length 343, breadth 132; protonymph length 751, breadth 300; tritonymph length 998, breadth 512. Ratio of length of prodorsum to total length: larva 0.37; protonymph 0.4; tritonymph 0.4.

Female. Prodorsum: rostrum well-developed, with prominent naso; rostral setae (ro) straight, smooth, 62 ( Fig. 8 View FIGURE 8 a). Lamellar setae (le) 305, recurved, smooth, flagelliform. Lamellar apophyses 125, incurved, two thirds as long as their mutual distance; extending anteriorly almost as far as tubercles of rostral setae. Interlamellar apophyses as long as broad; interlamellar setae (in) 345, flagelliform, smooth, extending anteriorly at least as far as apices of rostral setae. Diameter of each bothridium 47, with short, broad spine with subsidiary, elongate, spiniform lath laterally. Bothridial membrane reticulate with sub-hexagonal cells medially; sensilla containing vesicular structures ( Fig. 18 View FIGURE 18 b). Prodorsal ridges extending two thirds of the distance between interlamellar and lamellar apophyses. With well-developed posterior inter-bothridial ridge consisting of straight, transverse ridge indented medially and connected laterally to obtusely-angled straight ridges. Cuticle posterior of ridge smooth. Median field of muscle sigilla present. Prodorsum porose.

Subcapitulum: with three setae on gena: setae a 24; m 1 7; m 2 7. Oral setae or 1 bifurcate, barbed bilaterally; or 2 and or 3 spiniform, subequal, 23 ( Fig. 15 View FIGURE 15 d).

Notogaster: ratio of length to breadth 1.6; broadest between setae cp and e 2 ( Fig. 8 View FIGURE 8 a). Dorsosejugal suture simple, discrete. With 13 pairs of notogastral setae; those of caudal series barbed, others smooth. Porose prenotogastral shield bearing short setiform setae c 1 (56) and separated from notogastral shield by transverse hyaline strip. Apophyses of setae c 3 20, only slightly longer than broad; setae c 3 205, flagelliform, longest of notogastral setae, extending as far as bases of setae cp. Notogastral shield discrete, porose; bordered laterally by two narrow strips of small tubercles extending posteriorly as far as caudal apophyses and curving medially. Setae d 2 setiform, 45. Caudal cluster similar to male, apophyses of setae h 2 parallel or slightly diverging apically. Caudal region with sparse tubercles, becoming denser on lateral notogastral plates. Lateral hyaline strip (suprapleural scissure) well developed, up to 35 broad; setiform setae cp and e 2 both 95, f 2 62. Tubercles of setae f 2 squat, not projecting beyond lateral margin. Opisthosomal gland opening positioned at level anterior of f 2. Flagelliform, proximally-barbed setae f 1 95, their apophyses projecting anteriolaterally, directly adjacent to those of h 1. Flagelliform, proximally-barbed setae h 1 ca. 115, their apophyses projecting posteriolaterally. Setae h 2 140, flagelliform, proximally-barbed; their apophyses relatively short, 62, two thirds of their mutual distance; caudal margin between them an inverted U-shape. Apophyses of setae h 3 positioned ventrally between apophyses of f 1 and h 1 when viewed dorsally.

Ve n t e r: epimeres porose ( Fig. 9 View FIGURE 9 a); epimeral setae smooth, spiniform, formula 3-1-3-3; setae 3c on welldeveloped tubercles. Genital plates sub-circular. Each plate 198 long, 124 broad with eight stout, spiniform setae. Ventral margin of notogaster surrounding anal plates V-shaped, notched. Anal plate 50 broad, 285 long, with 3 pairs of anal setae located on median part of plate; anal setae subequal in length to adanal setae. Setae of p series smooth, flagelliform, p 3 37, p 2 40, p 1 50, curved, on short tubercles; setae p 1 separated by distance at least three times the width of their tubercles ( Fig. 9 View FIGURE 9 a), located adjacent to caudal margin.

Lateral view: Caudal margin more or less perpendicular to notogastral shield ( Fig. 17 View FIGURE 17 b); distance between dorsal and ventral surface ca. 405. Apophyses of setae f 1, h 1 and h 2 parallel, directed posteriodorsally; those of h 3 positioned ventral of those of h 2, directed posteriorly. Apophyses of setae p 1 positioned most dorsally on caudal region, then p 2, then p 3. Distance between apophyses of p 1 and that of h 3 214.

Male. Prodorsum: rostrum well-developed, with prominent naso; rostral setae (ro) straight, smooth, 37 ( Fig. 8 View FIGURE 8 b). Lamellar setae (le) 280, recurved, smooth, flagelliform. Lamellar apophyses 90, half as long as their mutual distance; extending anteriorly almost as far as base of naso. Interlamellar apophyses as long as broad; interlamellar setae (in) 275, flagelliform, smooth, extending anteriorly as far as apices of rostral setae. Prodorsal ridges extending three quarters of the distance between interlamellar and lamellar apophyses. With well-developed posterior inter-bothridial ridge consisting of straight, transverse ridge indented medially and connected laterally to obtusely-angled straight ridges. Cuticle posterior of ridge smooth. Median field of muscle sigilla present. Prodorsum porose.

Notogaster: ratio of length to breadth 1.6; broadest at level of setae e 2 ( Fig. 8 View FIGURE 8 a). Dorsosejugal suture simple, discrete. With 13 pairs of notogastral setae; those of caudal series barbed, others smooth. Porose prenotogastral shield bearing short setiform setae c 1, 62, and separated from notogastral shield by transverse hyaline strip. Apophyses of setae c 3 30, only slightly longer than broad; setae c 3 150, flagelliform, longest of notogastral setae, extending as far as bases of setae cp. Notogastral shield discrete, smooth, porose; bordered laterally by two narrow strips of small tubercles extending posteriorly as far as caudal apophyses and curving medially. Setae d 2 setiform, 45. Caudal cluster similar to male, apophyses of setae h 2 parallel or diverging converging apically. Caudal region with sparse tubercles, becoming denser on lateral notogastral plates. Lateral hyaline strip (suprapleural scissure) well developed, up to 30 broad; setiform setae cp 74, e 2 100, f 2 85. Tubercles of setae f 2 squat, not projecting beyond lateral margin. Opisthosomal gland opening positioned at level anterior of f 2. Flagelliform, proximally-barbed setae f 1 90, their apophyses projecting posteriolaterally, directly adjacent to those of h 1. Flagelliform, proximally-barbed setae h 1 ca. 95. Setae h 2 112, flagelliform, proximally-barbed; their apophyses relatively short, 60, less than the distance between them, parallel or converging apically, caudal margin between them an inverted U-shape. Apophyses of setae h 3 positioned ventral of f 1 when viewed dorsally.

Ve n t e r: epimeres porose ( Fig. 9 View FIGURE 9 a); epimeral setae smooth, spiniform, formula 3-1-3-3; setae 3c on welldeveloped tubercles. Genital plates sub-circular. Each plate 180 long, 100 broad with eight stout, spiniform setae. Ventral margin of notogaster surrounding anal plates V-shaped, notched. Anal plate 50 broad, 280 long, with 3 pairs of anal setae located on median part of plate; anal setae subequal in length to adanal setae. Setae of p series smooth, flagelliform, p 3 43, p 2 40, p 1 75, curved, on short tubercles; setae p 1 separated by distance at least three times the width of their tubercles ( Fig. 9 View FIGURE 9 a), located adjacent to caudal margin.

Larva. Prodorsum: rostral setae (ro) on short naso, curved ventrally. Lamellar apophyses conical, extending anteriorly as far as apical curve of rostral setae. Prodorsal plate punctate, surrounded by unsclerotised striate cuticle. Interlamellar setae (in) short, setiform, covered in bacilliform cerotegument. Sensillus represented by a setiform seta. Bothridium absent. Prodorsal ridges extending from sensillar setae three quarters of the distance to base of lamellar apophyses. With diagonal ridges posterior of sensillar setae, connected by narrow transverse ridge medially. Median field of muscle sigilla present ( Fig. 10 a).

Notogaster: ratio of length to breadth 1.6; broadest at base of apophyses of setae c 3 ( Fig. 10 a). Dorsosejugal suture marked by series of diagonal striae. With 13 pairs of notogastral setae, all smooth. Each seta c 1 24, situated at lateral end of oval porose sclerite. Setae d 2 25, not on sclerite. Apophyses of lateral setae prominent tubular extensions of ovoid porose sclerites. Apophyses of setae c 3 37, longest of lateral series, projecting anteriolaterally. Lateral setae flagelliform, c 3 60, cp 84, e 2 55, f 2 30, f 1 48, h 1 67. Setae h 1 stout, incurved, pointed; their apophyses conical, 40. Notogastral microsculpture a series of transverse lines of sparse tubercles centrally and anteriorly, interspersed by striate unsclerotised cuticle.

Ven t er: epimeres porose, with unsclerotised, longitudinally-striate, median integument diverging laterally and becoming transverse posterior of epimeral plates IV. Epimeral setae smooth, spiniform, subequal; formula 2-1-2. Setae h 2 41, markedly shorter than h 1, on ventrally-positioned apophyses posteriolateral of anal plate; h 3, 38, anteriolateral of h 2 ( Fig. 10 b).

Protonymph. Prodorsum: rostrum with squat naso; rostral setae (ro) 20 curved, smooth ( Fig. 11 View FIGURE 11 a). Lamellar setae (le) 124 recurved, smooth. Lamellar apophyses 32, a third as long as their mutual distance; extending anteriorly almost as far as apices of rostral setae. Interlamellar setae (in) 140, flagelliform, smooth; extending anteriorly beyond apices of rostral setae. Prodorsal ridges extending about half the distance between interlamellar and lamellar apophyses. Bothridium as in adult, with broad spiniform projection extending anteriolaterally. With well-developed, acute, V-shaped inter-bothridial ridge. Median field of muscle sigilla present. Prodorsum porose; cuticle posterior of interbothridial ridge striate, unsclerotised.

Notogaster: ratio of length to breadth 1.63; broadest at base of apophyses of setae c 3 ( Fig. 11 View FIGURE 11 a). Dorsosejugal suture marked by series of diagonal and transverse striae. With 13 pairs of notogastral setae, all smooth. Each seta c 1, 36, situated at lateral end of oval porose sclerite. Setae d 2 25, not on sclerite. Apophyses of lateral setae prominent tubular extensions of ovoid porose sclerites; those of setae c 3 36, the longest of the lateral series. Lateral setae flagelliform, c 3 192, cp 155, e 2 145, f 2 135, f 1 184, h 1 97. Setae h 2 stout, divergent, 68, pointed; their apophyses conical, 65. Notogaster with transverse lines of sparse tubercles anteriorly, becoming longitudinal posteriorly, interspersed by striate unsclerotised cuticle.

Ven t er: epimeres porose ( Fig. 11 View FIGURE 11 b), with median unsclerotised longitudinally striate integument, diverging laterally and becoming transverse posterior of genital plates. Epimeral setae smooth, spiniform, some with bacilliform cerotegument, formula 3-1-3-3; setae 3c longer than others, on well-developed tubercle. Genital plates elongate, ovoid; each plate 39 long 13 broad with one setiform seta. Anal plate 116 long, 22 broad; three pairs of stout, setiform setae in p series; p 1 longer than others, on prominent apophysis; setae h 3 posteriolateral of these.

Tritonymph. Prodorsum: rostrum with squat naso; rostral setae (ro) 41 straight, spiniform, smooth ( Fig. 12 View FIGURE 12 a). Lamellar setae (le) 267 recurved, smooth. Lamellar apophyses 77, half as long as their mutual distance; extending anteriorly almost as far as apices of rostral setae. Interlamellar setae (in) 263, flagelliform, smooth; extending anteriorly beyond apices of rostral setae. Prodorsal ridges, with tubercles laterally, extending two thirds of the distance between interlamellar and lamellar apophyses. Bothridium as in adult, with broad, subconical projection extending anteriolaterally. With well-developed V-shaped inter-bothridial ridge. Median field of muscle sigilla present. Prodorsum porose; cuticle posterior of interbothridial ridge tuberculate, interspersed by striate unsclerotised cuticle.

Notogaster: ratio of length to breadth 1.88; broadest at base of apophyses of setae e 2 ( Fig. 12 View FIGURE 12 b). Dorsosejugal suture discrete, transverse. With 13 pairs of smooth notogastral setae. Each seta c 1 66, situated at lateral end of oval porose sclerite. Setae d 2 63, not on sclerite. Apophyses of lateral setae prominent tubular extensions of ovoid porose sclerites; those of setae c 3 36, the longest of the lateral series. Lateral setae flagelliform, c 3 411, cp 384, e 2 329, f 2 378, f 1, 450, h 1 466. Setae h 2 stout, spiniform, slightly diverging apically, 98, pointed; their apophyses conical, 137. Notogaster with transverse lines of densely-packed tubercles anteriorly, becoming longitudinal posteriorly, interspersed by striate unsclerotised cuticle.

Ven t er: epimeres porose ( Fig. 12 View FIGURE 12 b), with median unsclerotised longitudinally striate integument, diverging laterally and becoming transverse posterior of genital plates. Epimeral setae smooth, spiniform, some with bacilliform cerotegument, formula 3-1-3-3; setae 3c longer than others, on well-developed tubercle. Genital plates elongate, ovoid; each plate 110 long 30 broad with six setiform setae covered in bacilliform cerotegument. Anal plate 260 long, 38 broad; three pairs of stout, setiform, adanal setae; subequal in length. Setae p 1 longer than others, on prominent apophysis; setae h 3 posteriolateral of these.

Material Examined and Locality Data. Holotype female, sieved litter, Eucalyptus forest, near summit of Mount Donna Buang, ca. 6 km NNW of Warburton, 37°42'25"S 145°40'43"E, 1240 m, coll. D. Black, 27.v.1990. Two paratype females, two paratype males, litter, wet sclerophyll forest, 1050 m, Mt. Donna Buang, Yarra Ranges National Park, Victoria, 37°42’S, 145°41’E, coll. R.W. Taylor & R.J. Bartell, 5.xi.1970 ( ANIC Berlesate no. 299). Two paratype females, one paratype male, sieved litter, Eucalyptus forest, 860 m, 4 km SE of Toolangi State Forest, Victoria, 37°32'39"S 145°31'38"E, 820 m, coll. D. Black, 15.i.1990. One paratype female, moss on trunk of Sassafras ( Atherosperma moschatum ), cool temperate rainforest, 1077 m, Errinundra Saddle, Errinundra National Park, Victoria, 37°19’18”S 148°51’11”E, 1030 m, coll. M.J. Colloff, 30.v.2009 ( ANIC Berlesate sample no. 4016). One paratype male, litter under tree, Cobb Hill, 14 km southeast of Bonang, Goonmirk Range, Victoria, 37°17’56”S 148°50’20”E, 1144 m, coll. J.E. & N. Lawrence, 24.xi.1985 ( ANIC Berlesate no. 1045). Two paratype females, litter, in riparian zone, coastal Angophora and Eucalyptus forest, Quarry Beach, Mallacoota, 149°44'2"E, 37°35'18"S, 20 m, coll. J. Bloszyk & S. Konwerski, 3.viii.2007 (CRO-006). One paratype female, litter from tree fern, coastal Angophora and Eucalyptus forest, Quarry Beach, Mallacoota, 149°44'2"E 37°35'18"S, 20 m, coll. J. Bloszyk & S. Konwerski, 3.viii.2007 (CRO-010).

Other Material: one tritonymph, ANIC Berlesate no. 299. One larva, five protonymphs, three tritonymphs, ANIC Berlesate sample no. 4016.

Holotype and four paratypes from Mt Donna Buang deposited in Department of Entomology, Museum Victoria, Melbourne. Remaining paratypes in Australian National Insect Collection, CSIRO Entomology, Canberra.

Etymology. This species is named after its collector, Dr Dennis Black (Department of Environmental Management and Ecology, La Trobe University, Wodonga).

Remarks. The association of the male and the female of Crotonia blacki sp. nov. is based on the following shared characters: 1) the morphology of the caudal apophyseal cluster and its barbed, flagelliform setae f 1, h 1 and h 3; 2) the short lamellar apophyses; 3) the concordant relative dimensions of the non-caudal notogastral setae (c 3> e 2> f 2 = c p> c 1> d 2) and 4) the angled shape of the interbothridial ridge. The association of the immatures with the adults is based upon samples from Errinundra National Park, which contains only this species and C. momitoi sp. nov., the differences between the immatures of which have been mentioned above. In particular, the immatures of C. blacki sp. nov., like the adults, have relatively short apophyses of setae h 2 and a characteristic broad, sub-conical bothridial projection ( Fig. 15 View FIGURE 15 ). In the larva, the bothridia are absent, and the sensilla are setiform. This arrangement differs from other larvae of Crotonia spp., for example those illustrated by Łochyńska (2008b, 2008c), which shows bothridia smaller and less distinct than the adult version and with globose sensilla.

Crotonia blacki View in CoL sp. nov. is a member of the Cophinaria species group ( Wallwork, 1977; Luxton, 1982; Colloff, 2009b). It differs from all other species in the genus by the following combination of characters: 1) the apophyses of setae h 2 are very short - less than twice the length of those of f 1 and h 1; 2) with flagelliform, proximally-barbed caudal setae; 3) setae c 1, cp and f 2 are short, smooth and subequal; 4) the lamellar apophyses extend only as far as bases of rostral setae; 5) with narrow lateral strips of small tubercles on the porose notogastral shield; 6) the interbothridial ridge consist of three straight elements, the lateral ones angled obtusely from the transverse medial one. Crotonia blacki View in CoL sp. nov. is morphologically most similar to C. momitoi View in CoL sp. nov. (see remarks section for C. momitoi View in CoL sp. nov. above)