Acuclavella sheari, Richart, Casey H. & Hedin, Marshal, 2013

Richart, Casey H. & Hedin, Marshal, 2013, Three new species in the harvestmen genus Acuclavella (Opiliones, Dyspnoi, Ischyropsalidoidea), including description of male Acuclavella quattuor Shear, 1986, ZooKeys 311, pp. 19-68 : 48-52

Acuclavella sheari sp. n. Figure 9 and 10, Appendix VIII: Figure 1, Figure 2

Type material.

Male holotype (AMNH) and female paratypes (AMNH; CAS, CASENT9039225; UWBM) from Burgdorf Road 12.4 miles northwest of Warren Wagon Rd, tributary of Fall Creek, Payette National Forest, Idaho County, Idaho; two male paratypes (CAS, CASENT9039217; UWBM, ID0016/5360) from Burgdorf Road 16.6 miles northwest of Warren Wagon Road; otherwise as previous (Appendix I).

Etymology.

The specific epithet honors Dr. William A. Shear, eminent milliped and opilionid taxonomist. His influence has been important to the authors’ aspirations to be systematic biologists, and we thank him sincerely, and with pleasure.

Diagnosis.

Generally reduced dimensions overall. Males with one pair of scutal spines on area II only; scutal spines ≤ 0.50 mm, distance from ventral edge of eye to tip of ocularium ≤ 0.60 mm distinguishes it from other males with single pair of spines. Females lack scutal spines. Diagnosed from spine-less Acuclavella shoshone (Shear, 1986 sensu stricto) females by having palpal femora ≤ 0.88 mm, leg II tarsi ≤ 3.92 mm, leg II femora ≤ 2.75 mm.

Description.

Description of male. Body arched and convex dorsally (Figure 9); sides broader posteriorly. Nearly all of body heavily sclerotized black or dark brown, with densely scattered hemispherical warts which irregularly house short setae apically or posteriorly; bilobed warts sporadic in holotype. Total length 3.90 mm (n=3, 3.68-4.06 mm), carapace length 1.24 mm (n=4, 1.15-1.32 mm), carapace width 2.34 mm (n=3, 2.31-2.36 mm); length of fused tergites I-V 2.26 mm (n=4, 2.16-2.31 mm), scutum length 2.61 mm (n=3, 2.32-2.81 mm), scutum width 2.60 mm (n=3, 2.55-2.63 mm).

Eye tubercle at anterior edge of carapace, hemispherical warts cover entirety of ocular spine, prolonged into an acute spine standing 0.67 mm above the surface of the carapace (n=3, 0.64-0.70 mm), 0.53 mm (n=4, 0.48-0.60 mm) from the ventral edge of the eye to the tip of the tubercle, eye spine less acute than in other species of Acuclavella . Eyes dark brown to brown, located basally on tubercle. Surface of carapace evenly curved, posterior margin arcuate. Metapeltidial paramedian sensory cones raised into sharp, acute spines standing 0.21 mm (n=4, 0.17-0.24 mm) above surface of the carapace, curving slightly towards the midline, lacking warty microsculpture, shiny; lateral to spines, clusters of warts form tubercles, missing in paratype (UWBM).

All scutal tergites with pairs of paramedian tubercles; relatively short, pointed spines on area II only. Fused tergite I with paramedian tubercles as raised mounds, relatively tall but not spike-like, standing 0.125 mm above the surrounding scute (n =4, all 0.125), these adorned with warts; lateral to these, two additional raised mounds become smaller away from the midline, these lacking in holotype. Paramedian tubercles of area II form acute spine 0.39 mm above the scutum surface (n=4, 0.34-0.43 mm), curved slightly posteriad; lateral to these are raised tubercles adorned with warts. Fused tergites III, IV, and V with paramedian tubercles in the form of raised mound adorned with warts; lateral to these, area III with 2 or 3 additional pairs of tubercles, area IV with 1 or 2 additional tubercles, area V with 0 or 2 additional tubercles; these tend to diminish in size away from the midline and posteriorly across tergites. Area III tubercle height above tergite 0.081 mm (n=4, 0.075-0.10 mm); area IV tubercle height 0.075 mm (all 0.075 mm). Free tergites without discernable tubercles, or tubercles occur in single pairs as small warty mounds.

Abdominal sternites with infrequent setae; warty sculpturing strongest laterally and on posterior margin; sternites brown, dark brown, or black. Sclerotized areas of genital operculum relatively setose. Prosomal sternum (n=1) wider than long: length 0.19 mm, width 0.29 mm; dark brown; without setae. Labium weakly to well-sclerotized, wider than long (n=3):, length 0.09 mm (0.08-0.10 mm), width 0.16 mm (0.13-0.19 mm), light brown to dark brown, darkness commensurate to sclerotization, without setae. All coxae with endites. Palpal endites setose, light brown, dark brown, or black. Leg II endite bearing 2 setae, other leg endites unadorned. Horn-shaped process of epistome decurved, projecting 0.34 mm from sulcus.

Chelicerae light brown, dark brown, or black; lighter individuals with article I darker dorsally, article II with darker, more sclerotized striations on prolateral and retrolateral surfaces (Figure 10). Article I length 1.11 mm (n=3, 1.00-1.18 mm), width 0.39 mm (0.36-0.42 mm), article II length 1.21 mm (1.12-1.27 mm), width 0.40 mm (all 0.40 mm), article III length 0.54 mm (0.52-0.56 mm). Dorsal surface of article I with raised, glandular area dense with setae. Palpal coxae pale-brown, light brown, or black, with 2 or 1 (UWBM) seta-bearing tubercles. Palpal measurements given in Table 6. Trochanter (Figure 10) pale-brown or dark brown, with 2 (CAS), 3 (holotype), or 4 (UWBM) seta-bearing tubercles; these reduced on later individual; femur pale-brown, brown, or dark brown; patella pale-brown or brown, with (CAS) or without a diffuse dark band on middle third, without darkened tubercle distally, bearing small setae and microtrichia distally; tibiae pale brown or white (holotype), with scattered setae and dense microtrichia; tarsus pale-brown or white (holotype), darkening to brown distally. Claw rudiment very small to absent.

Leg measurements given in Table 6. Microsculpture of femora, patellae, and tibiae scattered, distally elevated scales, bilobed scales not observed; scales subtend setae, occasionally housing seta apically. Trochanters, femora, patellae, tibiae black, or in holotype, trochanters light brown, femora, patellae, and tibiae brown; metatarsi of leg III proximal one-third to one-quarter brown or black; leg IV with proximal half black or brown; proximal end of metatarsi on legs I and II black or brown, remaining metatarsal areas pale brown or brown; all tarsi pale brown or brown, darkening distally. Scaled microsculpture subequal to darkened areas, remainder with setae and microtrichia. False leg articulations not observed. Leg claws single, black, not toothed, evenly curved.

Penis length 2.94 mm (n=1); glans plate 0.31 mm, scattered small setae; stylus 0.13 mm, slightly spirally twisted and decurved.

Description of female. Similar to male, differing in dimensions, secondary sexual characteristics, and dorsal armature. Total length 4.25 mm (n=3; 4.05-4.65 mm); carapace length 1.325 mm (n=4, 1.05-1.45 mm), width 2.62 mm (n=3, 2.35-3.05 mm); scutum length 3.03 (n=3, 2.90-3.25 mm), width 3.23 mm (n=3, 2.85-3.55 mm); fused tergites I-V length in midline 2.81 mm (n=4, 2.20-3.10 mm).

Eye tubercle height above surface of carapace 0.67 mm (n=3, 0.56-0.73 mm), distance from ventral surface of eye to tip of spine 0.54 mm (n=4, 0.46-0.60 mm). Eye color brown or gray. Metapeltidial spine 0.11 mm (n=4, 0.08-0.15 mm), curving slightly posteriad and towards the midline, lateral to these spines clusters of warts form tubercles.

Dorsal armature lacking. Dorsal adornment generally with median tubercles as raised mounds adorned with warts, decreasing in size away from midline and posteriorly across tergites. Two lateral pairs of warts on areas III and IV, area V with median pair of tubercles barely discernable, two pairs of lateral tubercles, or shallowly raised mounds adorned with warts. Free tergites with tubercles in the form of clusters of warts, or without discernable tubercles. Paramedian tubercles heights above the surface of the tergite (n=4): of area I 0.07 mm (0.05-0.08 mm); area II 0.10 mm (0.08-0.15 mm); area III 0.06 mm (0.05-0.08 mm); area IV 0.05 mm (0.03-0.08 mm).

Sternites brown, black, or light brown. Prosomal sternum (n=1) length: 0.26 mm, width 0.31 mm; light brown, without setae. Labium wider (0.13, 0.17, 0.16 mm) than long (0.08, 0.09, 0.08 mm); light brown or pale brown. Palpal endites brown or pale brown. Endites of leg II adorned with two or one (CAS) setae.

Chelicerae article I length 0.98 mm (n =3, 0.92-1.06 mm), width 0.41 mm (0.37-0.44 mm); article II length 1.31 mm (1.14-1.40 mm), width 0.43 mm (0.40-0.46 mm); article III length 0.57 mm (0.52-0.62 mm). Article I without raised glandular mound (Figure 10). Article I darker dorsally, chelicerae light brown or black with areas of dark brown. Palpus dimensions in Table 6; coxae light brown, dark brown, or white, with two seta-bearing tubercles; trochanters light brown, dark brown, or white, with three (AMNH) or four (CAS, UWBM) seta-bearing tubercles; femora and patella pale brown, brown, or white, patella without both distal tubercles and diffuse bands; tibiae white or pale-brown; tarsus white or pale-brown, fading to brown distally. Claw rudiment very small (AMNH, UWBM), or absent.

Leg measurements given in Table 6. Leg trochanters brown, black, or pale-brown; femora, patellae, and tibiae dark brown, back, or pale brown; metatarsi of legs III with proximal third brown, black, or pale-brown; leg IV metatarsi with proximal half brown, black, or pale-brown; proximal end of legs I and II metatarsi brown, black, or pale-brown; remaining metatarsal areas pale-brown, brown, or white; tarsi pale brown or white, darkening distally.

Ovipositor length 0.82 mm, width 0.46 mm (n=1); otherwise as Acuclavella makah .

Distribution and habitat.

Known from north-facing, horizontal band of Abies grandis forest above south shore of Salmon River. This habitat is mainly roadless, though intersected by FS 592 and Burgdorf Road in Payette National Forest, Idaho County, Idaho. Adults collected in June and September. Abies grandis , Pseudotsuga menziesii , and Picea engelmannii associated canopy cover; collected under woody debris adjacent to headwater streams.