Calapnita dinagat, 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 : 49

Calapnita dinagat sp. nov. Figs 131 , 236–244

Diagnosis. Distinguished from other species of vermiformis group by shape of procursus (bifid ventral flap and distinctive prolateral process, Figs 236–238 ) and by additional ventral process close to distal ventral process on male palpal femur (arrow in Fig. 240 ). From most species also by small pedipalps ( Figs 287–288 ). From C. bario and C. bariengi also by distal cheliceral apophyses clearly bipartite ( Fig. 241 ); from several species also by dark male sternum and by oval pore plates in transversal orientation ( Fig. 244 ).

Etymology. The species name is derived from the type locality; noun in apposition.

Material examined. Holotype. PHILIPPINES: ♂, ZFMK (Ar 16052), Dinagat Island , near Libjo , Paragua Forest , ‘site 1’ (10.222°N, 125.553°E), 130 m a.s.l., forest at brook, on leaf, 20.ii.2014 (B.A. Huber, P.N. Banaag).

Other material. PHILIPPINES: 2♂ 5♀ 2 juvs, ZFMK (Ar 16053), same data as holotype ; 2 juvs in absolute ethanol, ZFMK (Phi 233), same data .

Description. Male (holotype)

MEASUREMENTS. Total body length 5.5, carapace width 0.75. Leg 1: 31.5 (8.0 + 0.3 + 7.1 + 13.6 + 2.5), tibia 2: 5.5, tibia 3: 3.4, tibia 4: 6.1; tibia 1 L/d: 118. Distance PME-PME 200 µm, diameter PME 90 µm, distance PME- ALE ~30 µm; no trace of AME.

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

BODY. Habitus as in Fig. 131 ; ocular area barely elevated, each triad on very low hump; carapace without median furrow; clypeus unmodified; sternum as wide as long (0.48), unmodified.

CHELICERAE. As in Figs 241–242 , with pair of bipartite apophyses near lamellae, pair of lateral processes; without modified hairs; without stridulatory ridges.

PALPS. In general similar to C. vermiformis (cf. figs 139 and 140 in Huber 2011) but much smaller; trochanter apophysis as in Fig. 239 ; femur as in Fig. 240 , distal process at 24% of femur length; tibia length/diameter 0.43/ 0.27; procursus as in Figs 236–238 , with conical semitransparent prolateral process, with flat bifid ventro-distal sclerite; bulb length 0.29; embolus length 0.35.

LEGS. Without spines and curved hairs; few vertical hairs; retrolateral trichobothrium on tibia 1 at 2%; prolateral trichobothrium absent on tibia 1, present on other tibiae; tarsus 1 pseudosegments not seen in dissecting microscope.

Male (variation). Tibiae 1 missing in other males.

Female. In general similar to male but sternum whitish; eye triads slightly closer together (distance PME-PME 190 µm). Tibia 1 in 4 females: 5.2, 5.2, 5.6, 5.7. Epigynum as in Fig. 243 , weakly sclerotized with wide anterior ‘knob’; internal genitalia as in Fig. 244 , with oval pore plates far apart.

Natural history. One male had an ectoparasitic mite on its prosoma ( Fig. 131 ; cf. C. bankirai above). Such mites are not rare in spiders (e.g., Welbourn & Young 1988) but have rarely been reported for Pholcidae .

Distribution. Known from type locality on Dinagat Island only ( Fig. 284 ).

Figures

FIGURE 284. Known distribution of the Calapnita vermiformis group, part 2 (cf. Fig. 283).

FIGURES 128 – 133. Live specimens, Calapnita vermiformis group. 128. C. loksado sp. nov., ♂ from Loksado. 129 – 130. C. bohol sp. nov., ♂ and ♀ with egg-sac from near Loboc. 131. C. dinagat sp. nov., ♂ (with mite; arrow) from near Libjo. 132 – 133. C. nunezae sp. nov., ♀ with egg-sac, and ♂ and ♀ at night from Katibawasan.

FIGURES 236 – 253. Calapnita dinagat sp. nov. (236 – 244; ZFMK, Ar 16053) and C. mae sp. nov. (245 – 253; ZFMK, Ar 16056). 236 – 238, 245 – 247. Left procursi, prolateral, dorsal, and retrolateral views (arrow points at distinctive ridge on ventrodistal sclerite). 239, 251. Left palpal trochanters, retrolateral views. 240, 248. Left palpal femora, prolateral views (arrow points at additional ventral process). 241 – 242, 249 – 250. Right male chelicerae, frontal and lateral views. 243, 252. Epigyna, ventral views. 244, 253. 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.