Ulyxes theoclymenus, Shaw, 2014

Shaw, Matthew D., 2014, Ulyxes, a new Australopapuan mite genus associated with arboreal nests (Acari: Laelapidae), Zootaxa 3878 (3), pp. 261-290 : 283

Ulyxes theoclymenus sp. nov.

( Figs 47–51 )

Specimen examined. 1 holotype female, May River , West Sepik province, 3 Jun 1963, P. Temple coll., ex Lorius lory det A. C. Zeigler, BBM-NG 22634. Holotype in BBM.

Description of female (n=1). Dorsum. Dorsal shield 890 x 630, with 39 paired setae and eight unpaired Jx setae at ca. level of J4, spread longitudinally between J5 and mid J3–4 ( Fig. 47 ). Podonotal j1 58, j2 70, z1 38, z3 72. Discal setae shorter e.g. j6 36. Marginal setae r2 65, r3 75, r4 68, r5, S1 80, S2 77, S3 76, S4 82, S5 79, J5 51 Z5 77. Fine reticulations over opisthonotal and lateral portions of shield. Discal portion of podonotum glabrous. Z5 smooth. Distinctive gland pore posterolaterad px2, set in subcircular lacuna ca. 20 wide.

Gnathosoma . Epistome a shallow, smoothly-rounded lobe ( Fig. 49 ). Corniculi protrude 28. Hypostomal setae: h1 61, h2 41, h3 83, capitular seta 54. Fixed and movable digits are scoop-shaped, with teeth borne on both lateral edges of movable digit ( Fig. 48 ). Movable digit 70 long with two strong teeth borne on antiaxial edge of digit which do not oppose any teeth in fixed digit, although they shear against undulating antiaxial edge of fixed digit. In addition another strong tooth borne on paraxial edge of movable digit shears against three triangular teeth on paraxial edge of fixed digit. Cheliceral seta not discernible. Second cheliceral segment 188, first cheliceral segment 85. Six deutosternal rows of 8–14 denticles, flanked by single pair of lateral lines at ca. level of Q7 ( Fig. 50 ). Palp genu al1 with rounded, unexpanded tip. Palp genu al2 strongly spatulate. Lateral arms of malae lengthened with fimbriae extending past tip of corniculi. Fimbriae tips not expanded.

Venter. Tritosternum with base 51 long to suture. Lacinae separate 10 above suture. Lacinae free for 118. Sternal shield 155 wide, 120 deep, anterior edge straight, lacking excavations, posterior edge straight. St1 68, st2 72, st3 75. Shield 240 long, extends posteriorly to within 1µm of anal shield. Genito-ventral shield broad, 62 between st5, maximum width 285, between level of Zv1 and Jv1 ( Fig. 51 ). Longitudinal striae narrowly border genito-ventral shield, falling short of Jv1. Serially-regular, broadly transverse striae in 7–8 rows, 5–6 rows at or below level of Zv1. Post-stigmatal plate with median and posterior pore-like structures connected by narrow gutter. Exopodal IV a slender rim, 10 wide, without ridges. Primary metapodal platelet oval 62 x 13, secondary (inner) metapodal platelet 28 x 8. Paragenital platelet present. Opisthogaster hypertrichous with ca. 24 pairs of setae (excluding Zv1, Jv1–2). Anal shield 118 long by 137 wide at cribral pores. Maximum width 148. Para-anal setae 46. Cribrum in 3 closely-appressed rows.

Legs. Leg setation holotrichous as defined by Evans (1963), genu IV with a single pl seta, proximally positioned. Eight setae are modified as apically bifid; femur I ad1, femur I pd2, femur I ad3, femur II ad1, femur II pd2, femur III ad1, femur IV ad1 and femur IV ad2. Pretarsal opercula concealed in this unique specimen. Ambulacra I borne on apical stalk, 16 long. Leg segment lengths as in Table 4 .

Etymology. Theoclymenus was a diviner who read the auspices of birds.

Remarks. The dentition of the movable digit is highly conservative throughout the Laelapidae so U. theoclymenus is remarkable in having a third tooth that has arisen de novo, creating an additional, paraxial, shearing plane. This tooth contacts complementary teeth that have developed, or shifted, on the fixed digit. Other Ulyxes spp are like most other Laelapidae in that adjacent teeth on a given digit are spaced closely along a proximal-distal axis. I tentatively suggest this species may be a predator merely because of the relatively strong dentition and the relative size of the digits ( Table 2 ).

Ulyxes theoclymenus is similar to U. euryclea however it differs in its unique dentition, broader genitoventral shield, its moderately well-developed apical stalk on tarsus I, and lacking an apically bifid seta on trochanter IV.

Figures

FIGURES 47–51. Ulyxes theoclymenus holotype female. 47, dorsal shield, unpaired Jx setae indicated by x’s, scale = 200 µm; 48, chelicera, axial-ventrolateral view, scale = 50 µm; 49, epistome, scale = 50 µm; 50, gnathosoma, scale = 50 µm; 51, ventral idiosoma, suture (s) marking top of tritosternal base, exo- and endopodal shields shown on LHS only, scale = 200 µm.