Mixturatulla ozwini, Bernard, Ernest C., 2016

Bernard, Ernest C., 2016, Two new genera and five new species of Tullbergiidae (Collembola) from the southern Appalachian Mountains of North America, with redescription of Tullbergia clavata Mills, Zootaxa 4162 (3), pp. 451-478 : 461-464

Mixturatulla ozwini n. sp.

Figs 6 , 7

Material examined. Holotype female on slide, North Carolina, Swain County, Great Smoky Mountains National Park ( GSMNP), Ravensford area , leaf litter in mixed deciduous upland forest, near pitfall 35, N669200.106, E722181.572, 30 October 2001, E.C. Bernard and T. Goodrich, colls . Paratypes: three females on slides, four specimens in ethanol, same data as holotype; two females on slides, 9 in ethanol , same data as holotype except near pitfall 31, N669255.908, E722135.776; 17 specimens in ethanol , same data as holotype except floodplain forest near pitfalls 15 and 17, N668461.484 E720196.354; two females on slides, five in ethanol, North Carolina, Swain County, GSMNP, Ravensford area , floodplain forest, near pitfall 13, N668491.940, E720265.304, 22 August 2001, P. Jennings & T. Goodrich, colls.; one female , Tennessee, Cumberland County, Obed Wild and Scenic River, Potters Ford , sandy soil on river bank, tall perennials, sample 7.186AF, 36° 04.372N, 84° 54.119W, elev. 213 m, 5 June 2007, A. Fjellberg, coll.

Description. White. Length of adult females 566‒802 µm (n = 11, mean = 705 µm). Antenna length (62‒65 µm) shorter than head length (87‒93 µm), length ratio of Ant I:II:III:IV as 1:1.5:1.9:2.0. Pseudocellus shape Type III (crescentic) usually with two arms, occasionally one rectangular block or three arms ( Figs 7 D, E), formula 11/ 010/11111. Pseudopores absent. Anal spines short, stout, length about 0.6× that of hind unguis.

Granules on dorsum of head of variable size (diameter 1.3‒2.3 µm, mean 1.8 µm), evenly distributed, generally appearing round. Thoracic nota and Abd. I‒II with mid-dorsal band of 5‒7 longitudinal rows of large granules (diameter 1.9‒2.4 µm, mean 2.2 µm) flanked by similar granules not in distinct rows; subdorsal fields with smaller granules ( Fig. 7 D). Abd. III‒V granulation similar to that of Abd. I but large mid-dorsal granules not in distinct longitudinal rows; on Abd. IV‒V large granules not closely packed ( Fig. 7 F). Posterior region of all segments except pronotum and Abd. V‒VI with 3‒5 distinct transverse rows of granules similar in shape, size and density to those in medial regions ( Figs 7 D, E); posterior margin of Abd. V with weak and partial transverse bands of granules ( Fig. 7 F). Sixth abdominal segment with two fields of very large and strongly elevated tubercles (3.2‒5.6 µm, mean 4.5 µm), one field proximal, the other just anterior to anal spines; tubercles of proximal field tending to coalesce at their bases ( Figs 7 F, G). Abd. III and IV ventrally granulated, without smooth areas.

Labial palpus ( Fig. 6 E) with papillae A‒E, papilla spines A and B stout, rounded at tip; C‒E pointed, similar; guard setae a1 and b1 minute, conical; b2, b4, d3, e1 and e2 long and slender; papilla H and guard setae h1 and h2 present, normal; other guard setae not seen; six proximal setae, four basolateral setae, four basomedian setae. Outer lobe of maxilla with one sublobal hair. Mandible with four blunt apical teeth. Labral formula 5-4-2; two prelabral setae. Postantennal organ ( Figs 6 F, 7A‒C) elongate, in shallow trench, mainly with two or three rows of bacilliform vesicles often irregularly arranged; anterior row usually entire, with 32‒35 vesicles; posterior row of 27‒30 vesicles interrupted laterally by expansion in exterior half to field of about 20‒25 globular vesicles; PAO with three guard setae along posterior edge.

Ant. I with 7 setae, Ant. II with 11 setae. Sense organ of Ant. III with two converging sense clubs and two minute, clavate or weakly bilobed sensory rods partially covered by cuticular lobes; three proximal guard setae ( Fig. 6 G). Ventral sense club with offset basal stalk ( Fig. 6 H). All Ant. III setae pointed. Dorsal side of Ant. IV ( Fig. 6 G) with 10 arcuate sensilla, one proximal sensillum thicker than others; microsensillum rod-like, in shallow groove; subapical organite clavate, slightly bifid at tip, rising from cup-like depression; apical bulb spherical. Most longer dorsal and lateral setae of Ant. IV thin but sensilliform with blunt tips. Ventrally, Ant. IV with thick, tapering subapical sensillum and several sensilliform setae of various lengths ( Fig. 6 H); poorly defined ventral sensory field composed of mix of about 9 pointed or blunt setae surrounding larger sensilliform seta.

All leg setae pointed. Trochanter with 4 setae, femur with 9 setae. Tibiotarsal setal number 12, A and B setal whorls of six setae each ( Fig. 6 I). Unguis stout, without teeth or tunica-like expansion; unguiculus pointed, minute.

Dorsally, cephalic setae sd4, oc2, g3 and p5 macrosetae, other setae on head dorsum short mesosetae ( Fig. 6 A). Seta v2 present, v1 absent. Six setae between posterior cephalic pseudocelli, p1 slightly longer than p2. Medial seta anterior to and same size as a0. Pronotum with 8 setae. Mesonotum and metanotum ( Fig. 6 B) with m-row consisting of m1, m4 and m5; setae a2, a4 and p5 macrosetae; p3 longer than p1 but shorter than p5. Abdominal segments I, IV and V without m-setae, m4 present on Abd. II and III, length similar to that of p3. Setae a2, p3 and p5 longer than other setae on Abd. III and IV; a4 slightly longer than or equal to a3 on Abd. I‒III, long on Abd IV ( Fig. 6 B). On Abd. IV p2 displaced slightly anteriorly, shorter than p1. On Abd. V setae p1 and p2 absent ( Fig. 6 C), sensilliform seta p3 tapering ( Fig. 7 E inset); a2, a4 and p5 macrosetae. Abd. VI with two unpaired medial setae (Fig. 3C).

Ventrally, head with three pairs of medial setae. Mesosternum and metasternum each with two setae. Ventral tube with 4+4 setae on valves and 2+2 setae on base. Abdominal sternal setae usually variable and irregularly arranged. Sternum of Abd. II with 6 a-setae, m-setae m0 and m3 or m1 and m3, and 6 p-setae ( Fig. 6 D). Sternum of Abd. III similar but a-row with 10 setae. Arrangement of setae on Abd. IV sternum variable and usually irregular; a0 and m0 present, absent or one seta shifted to median. Sternum of Abd. V with five setae surrounding the genital aperture and two setae, occasionally three setae arranged asymmetrically, on the anterior lip. Sternum of Abd. VI with complete setal complement.

Etymology. This distinctive new species is named in honor of the noted pharmacologist Dr. Charles Ozwin Rutledge, whose family are generous benefactors of Great Smoky Mountains National Park.

Remarks. Mixturatulla ozwini n. sp. differs from nearly all other Tullbergiidae in lacking pseudocelli on the metanotum. It shares this character with Ameritulla clavata n. comb. and Psammophorura miniclavata n. sp., but M. ozwini n. sp. possesses pseudocelli on Abd. I‒V, whereas A. clavata and P. miniclavata lack them on Abd. I and III. Tubercle size and arrangement on Abd. VI also differ markedly. In M. ozwini n. sp. the dorsal tubercles are strongly erumpent, of irregular shape and up to twice as wide as the granulations on A. clavata , which are round and clearly separated. Finally, the PAOs of the three species differ markedly in number and arrangement of the vesicles.

Mixturatulla ozwini n. sp. bears some resemblance to Tullbergia silvicola Folsom, 1932 . The latter species has a PAO with two rows expanding into multiple rows toward the exterior end, and Abd. VI has rows of enlarged granules, although they are not coalescent as in M. ozwini n. sp. The two species differ markedly in several characters. In M. ozwini n. sp. the labial palp has blunt papillae A and B; In T. silvicola all labial palp papillae are pointed (unpublished).

Figures

FIGURE 6. Mixturatulla ozwini n. gen., n. sp. A) Head, dorsal view. B) Thorax and Abd. I ‒ IV, dorsal view. C) Abdominal segments V and VI, dorsal view. D). Abdominal segments II ‒ VI, ventral view. E) Labial palp. F) Postantennal organ. G) Third and fourth antennal segments, dorsal view. H) Third and fourth antennal segments, ventral view. I) Middle leg. Scales: A, 50 µm; B ‒ D, 50 µm; E, 10 µm; F ‒ I, 10 µm.

FIGURE 7. Mixturatulla ozwini n. gen., n. sp. A ‒ C) Postantennal organs. D) Posterior of Th. III and Abd. I, dorsal side, showing mid-dorsal rows of granules. E) Second and third abdominal segments, showing posterior transverse rows of granules. F) Granulation of Abd. V and VI. Inset: seta p 3 of Abd. V. G) Optical sagittal cross-section of Abd. VI. Scales: A ‒ C, 10 µm; D ‒ F, 50 µm; G, 20 µm.