Calapnita dayak, Bernhard A. Huber, 2017

Bernhard A. Huber, 2017, Revision and cladistic analysis of the Southeast Asian leaf-dwelling spider genus Calapnita Simon (Araneae, Pholcidae), Zootaxa 4219 (1), pp. 1-63 : 39

Calapnita dayak sp. nov. Figs 164–171

“ Calapnita vermiformis ” (misidentification; only specimens listed below): Deeleman-Reinhold 1986b: 212. Huber 2011: 48.

Diagnosis. Distinguished from most species of vermiformis group (except C. bugis ) by wide obtuse tip of ventral flap of procursus ( Fig. 164 ); from most (except C. bario ) also by long and slender palpal tibia (tibia length/width>2.5; Fig. 286 ); from several species also by very small proximal part of bipartite cheliceral apophyses ( Fig. 168 ), by narrow and distinct epigynal ‘knob’ ( Fig. 170 ), and by oval pore plates converging anteriorly and very close together ( Fig. 171 ).

Etymology. Dayak is a loose term for over 200 riverine and hill-dwelling ethnic subgroups located principally in the interior of Borneo; noun in apposition.

Material examined. Holotype. INDONESIA-BORNEO: ♂, RMNH ( ARA 17814), Central Kalimantan, Tumbang Tahai (2.033°S, 113.583°E), primary marshy forest, from leaves, 3/ 13.ix.1985 (S. Djojosudharmo).

Other material. INDONESIA-BORNEO: 1♂ 1♀, RMNH ( ARA 17424), same data as holotype . 1♂ 1♀, RMNH ( ARA 17421), Central Kalimantan, Kaharian (2.033°S, 113.667°E), swampy primary forest, in foliage, 2– 16.ix.1985 (S. Djojosudharmo) . 1♂ 1♀, RMNH ( ARA 17427), Central Kalimantan, 40 km NW Palangkaraya [~ 1.96°S, 113.75°E?], secondary forest, from leaves, ix.1985 (S. Djojosudharmo).

Assigned tentatively. INDONESIA-BORNEO: 1♂ 1♀, ZFMK (Ar 5330), East Kalimantan, Balikpapan [~ 1.25°S, 116.833°E], primary forest, 20.vii.1982 (Murphy, 11872 part).

Description. Male (holotype)

MEASUREMENTS. Total body length 3.5, carapace width 0.5. Leg 1: 25.4 (6.5 + 0.3 + 5.5 + 10.9 + 2.2), tibia 2: 4.2, tibia 3: 2.6, tibia 4: 4.7; tibia 1 L/d: 110. Distance PME-PME 160 µm, diameter PME 70 µm, distance PME- ALE ~30 µm; no trace of AME.

COLOR. Entire animal pale gray to whitish, legs slightly yellowish with brown patellae and tibia-metatarsus joints.

BODY. Habitus as in close congeners (cf. Figs 122, 124 ); ocular area barely elevated, each triad on very low hump; carapace without median furrow; clypeus unmodified; sternum as wide as long (0.40), unmodified.

CHELICERAE. As in Figs 168–169 , apophyses near lamellae bipartite with small proximal part, with pair of barely visible lateral processes; without modified hairs; without stridulatory ridges.

PALPS. In general similar to C. vermiformis (cf. figs 139 and 140 in Huber 2011); trochanter apophysis as in Fig. 167 ; femur as in Fig. 166 , distal process at 50% of femur length; tibia very slender ( Fig. 286 ), length/diameter 0.44/0.15; procursus as in Figs 164–165 , with simple ventro-distal flat sclerite; bulb length 0.30; embolus length 0.58; embolus tip with distinct fringes.

LEGS. Without spines and curved hairs; few vertical hairs; trichobothria on tibia 1 and tarsus 1 pseudosegments not seen.

Male (variation). Tibia 1 in 2 other males: 5.5, 6.1. The male from East Kalimantan shares the distinctively slender palpal tibia but is significantly larger and therefore assigned tentatively (tibia 1 missing; palpal tibia length/ diameter 0.59/0.18; bulb length 0.38; embolus length 0.80).

Female. In general similar to male, also eye triads at same distance. Tibia 1 in 3 females: 5.5, 5.6, 5.8. Epigynum as in Fig. 170 , weakly sclerotized triangular plate with small and slender anterior ‘knob’; internal genitalia as in Fig. 171 , longer than wide, with oval pore plates close together.

Distribution. Known from Central Kalimantan and (specimens assigned tentatively) East Kalimantan ( Fig. 283 ).

Figures

FIGURE 283. Known distribution of the Calapnita vermiformis group, part 1 (cf. Fig. 284). The Java record of C. lawangan is based on specimens assigned tentatively.

FIGURES 156 – 171. Calapnita magaseng sp. nov. (156 – 163; ZFMK, Ar 16027) and C. dayak sp. nov. (164 – 171; ♂: RMNH, ARA 17421; ♀: RMNH, ARA 17424, 17427). 156 – 157, 164 – 165. Left procursi, prolateral and retrolateral views. 158, 166. Left palpal femora, prolateral views. 159, 167. Left palpal trochanters, retrolateral views. 160 – 161, 168 – 169. Right male chelicerae, frontal and lateral views. 162, 170. Epigyna, ventral views. 163, 171. Cleared female genitalia, dorsal views. Scale lines: 0.3 mm.

FIGURES 285 – 288. Interspecific variation in proportions (285 – 286) and absolute sizes (287 – 288) of selected characters in the Calapnita vermiformis group. These graphs are based on measurements of holotypes and ignore intraspecific variation. The graphs show the conspicuous but largely continuous interspecific variation in some male genital characters.

FIGURES 120 – 127. Live specimens, Calapnita vermiformis group. 120 – 121. C. bario sp. nov., ♂ and ♀ with egg-sac from Bario. 122 – 123. C. magaseng sp. nov., ♂ and ♀ with egg-sac from Mount Penrissen. 124 – 125. C. saluang Huber, ♂ from Berastagi and ♀ with egg-sac from Phanom Bencha. 126 – 127. C. vermiformis Simon, ♂♂ from Mount Isarog and Mount Banahaw.