Plebs rosemaryae, Joseph & Framenau, 2012, 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: 324-328

publication ID

http://doi.org/ 10.1111/j.1096-3642.2012.00845.x

persistent identifier

http://treatment.plazi.org/id/EB7687FC-FFB8-854B-7488-FBD5FF26E6EA

treatment provided by

Marcus

scientific name

Plebs rosemaryae
status

SP. NOV.

PLEBS ROSEMARYAE   SP. NOV.

ROSEMARY’ s GRASS ORB- WEAVER ( FIGS 29–31 View Figure 29 View Figure 30 View Figure 31 )

Types: Holotype. ♂ from Queensland ( Australia), Chujeba Peak , 7 km south-west of Redlynch, 16°56 ′ S, 145°39 ′ E, 14–16.xii.1989, G. Monteith & G. Thompson, 1000 m asl ( QM S88992 View Materials ) GoogleMaps   . Paratypes. ♂, data as holotype ( QM S41583 View Materials ) GoogleMaps   ; ♀ from Queensland, Mount Edith, Lamb Range , 17°06 ′ S, 145°38 ′ E, 11.x.1982, G. Monteith, D. Yeates & G. Thompson ( QM S84232 View Materials ) GoogleMaps   .

Other material examined: Sixteen males, 57 females, and 24 juveniles from 29 records (Appendix S1).

Diagnosis: Based on somatic characters and overall morphology of the pedipalp, P. rosemaryae   males bear strong resemblances to P. arletteae   . However, there are subtle differences in the pedipalp morphology, which differentiate the two species. For instance, the apical tips of the median apophysis are comparatively smaller in P. rosemaryae   than in P. arletteae   (compare Figs 24A View Figure 24 and 13A View Figure 13 ). Females of P. rosemaryae   have an epigynal scape that is convoluted at the base similarly to those of P. cyphoxis   and P. opacus   . However, the scape of P. rosemaryae   differs from that of P. cyphoxis   in the incidence of a single curve at its base ( Fig. 30E, F View Figure 30 ) in all observed specimens as opposed to multiple convolutions in P. cyphoxis   ( Fig. 19E View Figure 19 ). Additionally, the scape of P. cyphoxis   has a wrinkled texture along its entire length and tapers gradually towards the distal end, whereas in P. rosemaryae   , the scape is generally smooth in appearance and tapers rather abruptly towards the distal end (compare Figs 19E View Figure 19 and 30E, F View Figure 30 ). The major difference in the scape morphology between P. rosemaryae   and P. opacus   is in the degree of the basal curvature. It is sharp and prominent in P. rosemaryae   ( Fig. 30E, F View Figure 30 ) in comparison to a shallower curve in P. opacus   ( Fig. 24E View Figure 24 ). Further, in P. rosemaryae   , the scape has an abrupt tapering towards the apex in contrast to the gradual tapering observed in P. opacus   (compare Figs 30E, F View Figure 30 and 24E View Figure 24 ).

Description

Male: Based on holotype. Carapace light orangebrown, patches of dark pigmentation along the lateral margins and a central patch of dark pigmentation covering the entire length of fovea ( Fig. 29A View Figure 29 ); carapace glabrous; two light brown bristles behind PE; fovea cross-shaped, longer than wide. Chelicerae yellow-brown, a small band of dark pigmentation at the proximal dorsal surface; a few black setae mainly in the apical half. Sternum orange-brown, with scattered dark pigmentation; a weak cover of brown bristles. Abdomen dorsally glabrous, a very weak cover of white setae; covered with off-white pigmentation, interspersed with a greenish-brown folium ( Fig. 29A View Figure 29 ); venter with greenish-brown pigmentation ( Fig. 29B View Figure 29 ); a weak cover of white setae. Spinnerets light brown, posterior lateral spinnerets extending beyond abdomen. Legs orange-brown, weakly spined, more spination on patella and metatarsus. Coxa of leg IV with three stout setae ventrally. Leg formula 1> 2> 4> 3. Pedipalps ( Fig. 30A–C View Figure 30 ): apex of the median apophysis curved towards cymbium and with two sclerotized apical tips, base sinuous; tegulum with a prominent apical protrusion; terminal apophysis with sinuous base and a marginally sclerotized tip; embolus bulbous at the base; conductor ovate.

Dimensions: total length (excluding chelicerae) 4.18. Carapace length 2.0, width 1.7, height 0.58.

Eyes: AME 0.19, ALE 0.15, PME 0.17, PLE 0.12, AME–AME 0.08, AME–ALE 0.08, PME–PME 0.02, PME–PLE 0.19, PLE–ALE 0.02, MOQ width front 0.38, MOQ width back 0.35, MOQ length 0.31, eye group width 0.81. Sternum length 0.97, width 0.73. Abdomen length 2.55, width 1.39. Pedipalp: femur 0.30, patella + tibia 0.48, tarsus 0.79, total 1.57. Leg I: femur 2.79, patella + tibia 3.03, metatarsus 2.18, tarsus 0.61, total 8.61. Leg II: femur 2.42, patella + tibia 2.55, metatarsus 1.82, tarsus 0.61, total 7.4. Leg III: femur 1.39, patella + tibia 1.21, metatarsus 0.67, tarsus 0.48, total 3.75. Leg IV: femur 2.12, patella + tibia 1.94, metatarsus 1.52, tarsus 0.61, total 6.19.

Variation (range): TL 4.18–5.45; CL 1.33–2.42; CW 1.70–1.94; AL 2.24–3.39; AW 1.39–1.82; N = 6.

Female: Based on paratype from Mount Edith, Lamb Range, QM S84232 View Materials . Carapace as male, but fovea Y-shaped ( Fig. 29C View Figure 29 ). Chelicerae and sternum as male. Abdomen with general coloration as male ( Fig. 29C View Figure 29 ); humeral humps present; venter as male ( Fig. 29D View Figure 29 ); the area enclosing the inverted ‘U’ pattern with brown bristles. Spinnerets light brown. Legs orange-brown with black annulations; weakly spined. Leg formula 1> 2> 4> 3. Epigyne scape elongated, convoluted at the base. ( Fig. 30E, F View Figure 30 ): spermathecae elongate ovoid ( Fig. 30D View Figure 30 ).

Dimensions: total length (excluding chelicerae) 6.30. Carapace length 2.18, width 1.70, height 0.77. Eyes: AME 0.19, ALE 0.12, PME 0.15, PLE 0.12, AME–AME 0.12, AME–ALE 0.17, PME–PME 0.06, PME–PLE 0.29, PLE–ALE 0.02, MOQ width front 0.44, MOQ width back 0.38, MOQ length 0.44, eye group width 1.15. Sternum length 1.15, width 0.91. Abdomen length 5.15, width 2.91. Palp: femur 0.73, patella + tibia 0.85, tarsus 0.73, total 2.31. Leg I: femur 3.03, patella + tibia 3.64, metatarsus 2.42, tarsus 0.79, total 9.88. Leg II: femur 2.91, patella + tibia 3.03, metatarsus 2.06, tarsus 0.67, total 8.67. Leg III: femur 1.33, patella + tibia 1.52, metatarsus 1.03, tarsus 0.61, total 4.49. Leg IV: femur 2.55, patella + tibia 3.03, metatarsus 2.06, tarsus 0.67, total 8.31.

Variation (range): TL 5.88–7.09; CL 1.70–2.30; CW 1.82–2.30; AL 3.82–5.27; AW 2.12–3.94; N = 6. Within the overall general colour pattern, slight variations are evident ranging from a lighter ( Fig. 29F View Figure 29 ) to a darker abdominal folium ( Fig. 29C, E View Figure 29 ).

Distribution: Norfolk Island, Queensland ( Fig. 31 View Figure 31 ).

Life history and habitat preferences: Most mature spiders were collected from October to December, although there are some records from January, April, and July. Plebs rosemaryae   appears to be a higher elevation forest species with most records from altitudes above 800 m.

Etymology: The specific epithet is a matronym in honour of the senior author’s spouse Rosemary Antony.

QM

Queensland Museum

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae

Family

Araneidae

Genus

Plebs