Plebs salesi, Joseph & Framenau, 2012

Joseph, Mathew M. & Framenau, Volker W., 2012, Systematic review of a new orb-weaving spider genus (Araneae: Araneidae), with special reference to the Australasian-Pacific and South-East Asian fauna, Zoological Journal of the Linnean Society 166 (2), pp. 279-341 : 328-329

PLEBS SALESI SP. NOV.

SALE’ s GRASS ORB- WEAVER ( FIG. 32 )

Type: Holotype. ♂ from Papua New Guinea, Townsville drilling site, Mount Akric , Western Province, 5°10 ′ S, 141°9 ′ E, 23.xi.1996, M. Humphrey ( AM KS53471 ).

Other material examined: Only known from holotype male.

Diagnosis: Plebs salesi bears resemblances to P. bradleyi as both species have a macroseta on the pedipalp femur; however, the two species show striking differences in pedipalp morphology. Plebs salesi has a notch on the tegular protrusion, which is absent in P. bradleyi . The embolus in P. bradleyi is smooth and even; however, it is humped in P. salesi . The base of the terminal apophysis is less sinuous in P. salesi in comparison to P. bradleyi . The dorsal abdomen is marked by a distinct folium in P. salesi in contrast to the unique V-shaped pattern seen in P. bradleyi . The coxae IV of the male of P. salesi bear three setae on the ventral side in contrast to two setae in P. bradleyi .

Description

Male: Based on holotype. Carapace orange-brown ( Fig. 32A ); glabrous with the exception of sparse white setae mainly in cephalic area and in a wide band along lateral margins; one light brown bristle behind PE; fovea cross-shaped, longer than wide. Chelicerae yellow-brown, a band of dark pigmentation running along the dorsal surface reaching up to the mid-region; a few black setae mainly in the apical half. Sternum black, interspersed with orange-brown pigmentation; a sparse cover of brown bristles. Abdomen dorsally glabrous, with a sparse cover of white bristles; covered with off-white pigmentation, interspersed with a median greenish-brown folium; two prominent orange-brown sigillae mid-dorsally in the anterior half ( Fig. 32A ); venter with greenishbrown pigmentation ( Fig. 32B ); weakly covered with white setae and brown bristles. Spinnerets light brown. Legs orange-brown, weakly spined, more so on the patella and metatarsus. Coxae of leg IV with three stout setae ventrally. Pedipalps ( Fig. 32C–E ): apex of the median apophysis curved in and with two sclerotized apical tips, tegulum with a prominent notched apical protrusion; terminal apophysis with a sclerotized tip, base sinuous; embolus with sclerotized tip, base bulbous; conductor ovate; palpal femur with a macroseta.

Dimensions: total length (excluding chelicerae) 4.48. Carapace length 2.12, width 1.88, height 0.77. Eyes: AME 0.19, ALE 0.12, PME 0.15, PLE 0.12, AME–AME 0.12, AME–ALE 0.15, PME–PME 0.04, PME–PLE 0.25, PLE–ALE 0.02, MOQ width front 0.38, MOQ width back 0.35, MOQ length 0.35, eye group width 0.96. Sternum length 1.03, width 0.79. Abdomen length 2.61, width 1.94. Pedipalp: femur 0.30, patella + tibia 0.36, tarsus 0.97, total 1.63. Leg I: femur 2.91, patella + tibia 3.03, metatarsus 1.82, tarsus 0.79, total 8.55. Leg II: femur 2.18, patella + tibia 2.30, metatarsus 1.33, tarsus 0.73, total 6.54. Leg III: femur 1.52, patella + tibia 1.09, metatarsus 0.85, tarsus 0.42, total 3.88. Leg IV: femur 2.18, patella + tibia 1.88, metatarsus 1.21, tarsus 0.48, total 5.75.

Variation: only known from holotype male.

Female: Unknown.

Distribution: Only known from holotype, Papua New Guinea.

Etymology: The specific epithet is a patronym in honour of the late Rev. Fr. Francis Sales C.M.I., founder of Sacred Heart College, Thevara, Kochi, India.

Figures

Figure 32. Plebs salesi sp. nov. A–E, male holotype from Townsville drilling site, Mount Akric, Western Province, Papua New Guinea (AM KS53471). A, dorsal view; B, ventral view; C, pedipalp, ventral view; D, pedipalp, dorsal view; E, pedipalp, apicoventral view. Scale bar = 1.0 mm in A, B; 0.2 mm in C-E.