Crotonia cophinaria ( Michael, 1908 )

Colloff, Matthew J., 2015, The Crotonia fauna of New Zealand revisited (Acari: Oribatida): taxonomy, phylogeny, ecological distribution and biogeography, Zootaxa 3947 (1), pp. 1-29 : 14-16

Crotonia cophinaria ( Michael, 1908)

( Figs. 6 , 7 e)

Nothrus cophinarius Michael, 1908 , p. 142, pl. 19, Figs. 13–16.

Acronothrus cophinarius (Mich.) :— Hammer 1966, p. 30, Fig. 38.

Crotonia cophinaria ( Mich., 1908) : Wallwork 1977b, p. 515, Figs. 1–5 . Crotonia cophinaria ( Michael, 1908) :— Luxton 1982, p. 247, Figs. 1 , 2 . Acronothrus brachyrostrum Hammer, 1966 :— Luxton 1982, p. 247.

Dimensions. Female length 1240 Μm, breadth 679 Μm (n = 1). Ratio of length of prodorsum to total length: 0.3. Female. Prodorsum: rostrum well-developed, with prominent naso; rostral setae (ro) 34 Μm long, spiniform, smooth ( Fig. 6 a). Lamellar setae (le) 218 Μm long, recurved, sparingly barbed, flagelliform apically. Lamellar apophyses 126 Μm long, diverging, almost as long as their mutual distance; extending anteriorly beyond apices of rostral setae. Interlamellar apophyses three times as long as broad; interlamellar setae (in) well-developed, 344 Μm long, flagelliform apically, smooth; extending beyond arc of lamellar setae. Prodorsal ridges extending two-thirds of the distance between interlamellar and lamellar apophyses. Diameter of bothridium 42 Μm. Anteriolateral ridge of bothridium elongated, broadly conical, with one lobed ridge ( Fig. 7 e). Inter-bothridial ridge very faint or absent; median field of muscle sigilla well-developed. Prodorsum porose.

Notogaster: ratio of length to breadth 1.55; broadest at level of setae e 2 ( Fig. 6 a). Dorsosejugal suture discrete, simple. With 13 pairs of notogastral setae; lateral ones smooth, caudal ones barbed. Pre-notogastral shield rectangular, separated from notogastral shield by transverse hyaline strip bearing setiform setae c 1 (57 Μm long). Apophyses of setae c 3 prominent, 29 Μm long, at least twice as long as broad; setae c 3 flagelliform apically, 258 Μm long, extending beyond bases of lamellar apophyses. Dorsal notogaster flat, almost at right angles to lateral notogastral plates, lateral margins more-or-less parallel, posterior region curved, acute. Notogastral shield porose, discrete, margins oval; bordered laterally by narrow strip of small tubercles extending posteriorly to between setae f 1 and f 2. Lateral hyaline strip (suprapleural scissure) relatively broad, well developed, bearing tubercles of setae cp, e 2 and f 1. Tubercles of setae f 2 short (17 Μm), projecting just beyond lateral margin. Seta f 2 curved, 52 Μm long; cp 103 Μm; e 2 86 Μm. Seta d 2 minute (22 Μm), setiform, bases of d 2 180 Μm apart. Opisthonotal gland gla slightly anterior of f 2. Caudal apophyseal cluster bilateral, separate: 93 Μm apart; caudal margin between them Ushaped. Caudal region elongate, V-shaped. Seta f 1 81 Μm long, barbed, their apophyses projecting laterally or posteriolaterally, well separated from those of h 1. Apophysis of seta h 2 126 Μm, 5 × length of that of h 1, diverging apically. Seta h 2 80 Μm long; apophyses of setae h 3 ventral to, and parallel of, those of h 1.

Venter: epimeres porose ( Fig. 6 b); epimeral setae smooth, spiniform, sub-equal 17–29 Μm long; formula 3-1-3- 3. Genital plates sub-circular; posterior margin straight posteriolateral margin straight, angled obtusely to posterior margin; each plate 218 Μm long, 132 Μm broad with eight setiform setae; two pairs of aggenital setae, subequal in length to genital setae. Anal plate 40 Μm broad, 293 Μm long with three spiniform setae on central and posterior half of anal plate; three pairs of adanal setae ad 2-3 setiform, ad 1 spiniform, longer and thicker than others. Ventral margin of notogaster surrounding anal plates V-shaped. Setae of p series smooth, curved, setiform, p 3 46 Μm, p 2 34 Μm, p 1 52 Μm, on short tubercles; setae p 1 separated by distance 3 × the width of their tubercles.

Material examined and locality data. One adult, litter of Olearia colensoi, Mount Wharite Ridge , 40°15'S 175°51'E, 885 m., coll. A.V. Spain, 29.x.1966.

Remarks. Crotonia cophinaria can be differentiated from other members of the genus based on the following combination of characters: 1) the elongated, broadly conical anteriolateral ridge of the bothridium, with one lobed ridge; 2) setae cp and e 2 are sub-equal in length and longer than c 1; 3) the curved, acute posterior region of the notogastral plate; 4) the very short setae d 2, their bases further apart than the distance between setae c 1; 5) the barbed setae f 2 and caudal setae; 6) the very long, prominent apophyses of setae h 2, five times the length of those of h 1 and diverging apically; 7) apophyses of setae f 1 are separated from those of h 1.

Crotonia cophinaria is morphologically most similar to Australian members of the Cophinaria species group: C. pyemaireneri Colloff, 2009 from Tasmania, C. momitoi Colloff & Perdomo, 2009 from Victoria and C. jethurmerae Lee 1985 from South Australia. These species share the barbed caudal setae of the h series and f 1, but C. jethurmerae and C. momitoi have much longer setae c 1 and C. momitoi has much longer setae d 2. Crotonia cophinaria differs from C. pyemaireneri in having strongly diverging apophyses of seta h 2, rather than strongly incurved ones; very short setae f 2 and cp, whereas in C. pyemaireneri these setae are longer than c 3. Differences between C. cophinaria , based on the supplementary description by Luxton (1982) and C. brachyrostrum have been detailed above (cf. Remarks section for C. brachyrostrum ).

Wallwork (1977b) redescribed C. cophinaria , designated a lectotype and commented on discrepancies between the description by Michael (1908), the supplementary description of Hammer (1966) and his own redescription. The same limitations apply to his redescription of C. cophinaria as to that of C. unguifera because of Michael’s use of Canada Balsam mountant (cf. Remarks section for that species above). Wallwork (1997b, his Fig. 1 ) illustrated the prodorsal setae much shorter and thicker than they really are, and the caudal setae are covered in the tritonymphal cerotegument and illustrated as smooth rather than barbed. The lectotype has lost both setae c 1. Wallwork (1977b) considered that Michael’s specimen from Maungakaretu may represent a subspecies. It differs from the lectotype in that the notogaster is entirely tuberculate, the lamellar apophyses are half as long as their mutual distance and the apophyses of setae h 1 are fused to the base of h 2.

Figures

FIGURE 1. Crotonia ramsayi sp. nov. holotype female; a) dorsal; b) ventral. Scale bar = 200 µm.

FIGURE 2. Lateral views of caudal clusters: a) Crotonia ramsayi sp. nov. paratype female; b) C. unguifera, female. Scale bar = 50 µm.

FIGURE 3. Crotonia unguifera (Michael, 1908), female; a) dorsal; b) ventral. Scale bar = 200 µm.

FIGURE 4. Crotonia caudalis (Hammer, 1966), female; a) dorsal; b) ventral. Scale bar = 200 µm.

FIGURE 5. Crotonia brachyrostrum (Hammer, 1966), female; a) dorsal; b) ventral. Scale bar = 200 µm.

FIGURE 6. Crotonia cophinaria (Michael, 1908), female; a) dorsal; b) ventral. Scale bar = 200 µm.

FIGURE 7. Details of bothridia of a) Crotonia ramsayi sp. nov.; b) Crotonia unguifera (Michael, 1908); c) Crotonia caudalis (Hammer, 1966); d) Crotonia brachyrostrum (Hammer, 1966); e) Crotonia cophinaria (Michael, 1908). Scale bars = 20 µm.