Calapnita bidayuh, 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 : 19-22

Calapnita bidayuh sp. nov. Figs 16–17 , 55–59 , 65–71

Diagnosis. Distinguished from most other species of phyllicola group (except C. bankirai , C. phyllicola , C. semengoh ) by shape of appendix (widely curved with two ventral tines; Fig. 57 ), by male palpal tarsal organ on cylindrical process of tarsus ( Fig. 66 ), by serrated edge of embolus, and by drop-shaped pore plates ( Fig. 59 ); from closest known relatives ( C. bankirai , C. phyllicola , C. semengoh ) by distal spine-like process on procursus ( Figs 55 , 67–68 ); from C. bankirai also by dorsal flap at tip of procursus ( Fig. 55–56 ); from C. phyllicola also by presence of split hairs dorsally on procursus ( Figs 55 , 67–69 ); from C. semengoh also by much shorter palpal segments and external female genitalia. Females of C. bidayuh and C. bankirai may not be distinguishable externally, but the pore plates of C. bidayuh are slightly farther apart ( Fig. 59 ).

Etymology. Bidayuh is the collective name for several indigenous groups found in southern Sarawak and northern West Kalimantan; noun in apposition.

Material examined. Holotype. MALAYSIA-BORNEO: ♂, ZFMK ( Ar 15991), Sarawak, near Kapit, forest along river (1.937– 1.944°N, 112.904– 112.910°E), 80–120 m a.s.l., underside of leaf, 20.vii.2014 (B.A. Huber, S.B. Huber).

Other material. MALAYSIA-BORNEO: 4♂ 4♀, ZFMK (Ar 15992–93), and 1♂ 1♀, SMK, same data as holotype; 2♂ 2♀ in absolute ethanol , ZFMK (Bor 187), same data .

Description. Male (holotype).

MEASUREMENTS. Total body length 4.6, carapace width 0.8. Leg 1: 33.2 (7.8 + 0.3 + 8.0 + 15.2 + 1.9), tibia 2: 5.7, tibia 3: 3.4, tibia 4: 5.2; tibia 1 L/d: 107. Distance PME-PME 250 µm, diameter PME 80 µm, distance PME- ALE ~30 µm; no trace of AME.

COLOR. Entire animal mostly pale whitish to yellowish, sternum whitish, patellae and tibia-metatarsus joints with short brown rings.

BODY. Habitus as in Fig. 16 ; ocular area barely elevated, each triad on very low hump ( Fig. 65 ); carapace without median furrow; clypeus unmodified; sternum as wide as long (0.50), unmodified.

CHELICERAE. As in C. phyllicola (cf. fig. 172 in Huber 2011), with pair of simple apophyses near lamellae and pair of indistinct lateral humps proximally; without modified hairs; without stridulatory ridges.

PALPS. In general very similar to C. phyllicola (cf. figs 170–171 in Huber 2011); proximal segments apparently indistinguishable; procursus with two split hairs dorsally and with distinctive distal spine-like process ( Figs 55–56 , 67–69 ); appendix barely distinguishable from C. phyllicola ( Fig. 57 ).

LEGS. Without spines and curved hairs; few vertical hairs; retrolateral trichobothrium on tibia 1 at 2.5%; prolateral trichobothrium absent on tibia 1, present on other tibiae; tarsus 1 pseudosegments very indistinct, only distally a few visible in dissecting microscope.

Male (variation). Tibia 1 in 5 other males: 7.7–8.3 (mean 7.9).

Female. In general similar to male; eye triads at same distance as in male. Tibia 1 in 5 females: 5.8–6.9 (mean 6.5). Epigynum strongly folded ( Fig. 71 ), apparently similar to C. phyllicola but without transversal sclerotized folds ( Fig. 58 ); with simple short posterior ‘knob’; internal genitalia as in Fig. 59 , with pair of membranous ‘sacs’. Natural history. The species seems to prefer palm leaves, but such leaves were rare at the type locality, resulting in apparently low abundances. Egg-sacs contained 6– 11 eggs and had at least proximally up to three eggs per diameter.

Distribution. Known from type locality in Sarawak only ( Fig. 282 ).

Figures

FIGURE 282. Known distribution of the Calapnita phyllicola group, part 2 (cf. Fig. 281). Note that all western specimens of C. phyllicola are assigned tentatively.

FIGURES 13 – 19. Live specimens, Calapnita phyllicola group. 13 – 15. C. phyllicola Deeleman-Reinhold, ♂♂ from Bako and Ulu Dong, ♀ with parasitized egg-sac from Gunung Liang. 16 – 17. C. bidayuh sp. nov., ♂♂ from Kapit. 18. C. bankirai sp. nov., ♂ (with mite; arrow) from Niah. 19. C. semengoh Huber, ♂ from Semengoh.

FIGURES 55 – 64. Calapnita bidayuh sp. nov. (55 – 59; ZFMK, Ar 15992 – 93) and C. bankirai sp. nov. (60 – 64; ZFMK, Ar 15995). 55 – 56, 60 – 61. Left procursi, prolateral and retrolateral views (arrows point at split hairs). 57, 62. Left bulbal appendices, prolateral views. 58, 63. Epigyna, ventral views. 59, 64. Cleared female genitalia, dorsal views (arrows point at membranous sacs). Scale lines 0.3 mm.

FIGURES 65 – 71. Calapnita bidayuh sp. nov., SEM micrographs (ZFMK, Ar 15992 – 93). 65. Male prosoma, frontal view. 66. Male palpal tarsal organ. 67 – 68. Right procursus tip, retrolatero-ventral and retrolateral views (arrows point at distal spine-like process). 69. Split hair on procursus. 70. Tips of right appendix and embolus, retrolateral view. 71. Epigynum, ventral view. a, appendix; e, embolus. Scale lines: 10 µm (66, 69), 100 µm (65, 67, 68, 70, 71).