Plebs mitratus ( Simon, 1895 )

Paul, Jimmy, Sankaran, Pradeep M., Joseph, Mathew M. & Sebastian, Pothalil A., 2016, The male of the orb-weaving spider Plebs mitratus (Simon, 1895) and a redescription of the female (Araneae, Araneidae), Zootaxa 4179 (1), pp. 103-106 : 103-106

publication ID	https://doi.org/ 10.11646/zootaxa.4179.1.4
publication LSID	lsid:zoobank.org:pub:CD3911CC-3950-44C0-B53D-1C2225DA79E9
DOI	https://doi.org/10.5281/zenodo.6081494
persistent identifier	https://treatment.plazi.org/id/DA05255F-8600-FFC4-EDAE-43D7FE95C27F
treatment provided by	Plazi
scientific name	Plebs mitratus ( Simon, 1895 )
status

Treatment

Plebs mitratus ( Simon, 1895) View in CoL

( Figs 1A–B View FIGURE 1 A – C , 2A–L View FIGURE 2 A – L )

Araneus mitratus Simon, 1895: 805 (description of ♀).

Araneus mitratus Bonnet, 1955: 545 .

Araneus mitratus Sherriffs, 1918: 60 , 63–64 (description of ♀ and immature Ƌ). Araneus mitratus Sherriffs, 1919: 241 –242, 244 (description of ♀ and immature Ƌ). Plebs mitratus Joseph & Framenau, 2012: 333 View in CoL , Figs. 34A–F (neotype designation, (WAMT109510); description of ♀).

Material examined. India: Kerala: Idukki, Nayamakkadu Shola near Eravikulam National Park , 10o08'57.54''N , 77o04'56.69''E, 1875 m, M.S. Pradeep leg., 22 March 2015, from web among shrubs, by hand, 2♂, 9♀ ( ADSH 912710 View Materials A); Wayanad, near Heart Lake in Chembra peak , 11o32'45.18''N, 76o05'03.97''E, 1140m, Jimmy Paul leg., 30 July 2015, from web among shrubs, by hand, 1 ♂ ( ADSH 912710 View Materials B); Idukki, Anamudi Shola National Park , 10°11'58.75''N, 77°11'30.11''E, 1740 m, Mathew M. Joseph leg., 25 August 2015, from web among shrubs, by hand,1♂ (ADSH912710C).

Diagnosis. Plebs mitratus is most similar to P. eburnus (Keyserling, 1886) but can be separated from the latter by the following combination of characters. In males, embolic tip directed at twelve o’clock position in ventral view whereas in P. eburnus , embolic tip directed at two o’clock ( Fig. 2A View FIGURE 2 A – L ), conductor wider than P. eburnus in ventral view ( Fig. 2A View FIGURE 2 A – L ), two ventral stout setae on each coxa IV whereas in most P. eburnus each coxa IV bears three ventral setae ( Fig. 2L View FIGURE 2 A – L ). In females, scape with basal wrinkles whereas in P. eburnus the entire scape wrinkled and medially wide epigynum which in P. eburnus widest at posteriorly (compare Figs 2A–C View FIGURE 2 A – L with Joseph & Framenau 2012: figs. 4A, D, 8A, E). Females of P. mitratus can be separated from the females of P. himalayaensis , the only Indian congener, by less wrinkled and straight scape whereas the scape in P. himalayaensis strongly wrinkled with median kink (compare Fig. 2C View FIGURE 2 A – L with Tikader & Bal 1981: figs. 108–109 and Tikader 1982: figs. 445–446).

Description. Male (ADSH912710A). Carapace pear-shaped. Fovea cross–shaped. Single bristle behind each PLE. Chelicerae with four promarginal and three retromarginal teeth. Abdomen subtriangular, with less prominent humeral humps than that of females, with inconspicuous ventral inverted U-shaped white pattern and with paired conspicuous white spots antero-lateral to the spinnerets. Leg I with coxal spur and corresponding femoral groove on leg II; coxae of leg IV ventrally with paired stout setae; leg formula 1>2>4>3. Pedipalp ( Figs 2A–B View FIGURE 2 A – L ). Cymbium with a baso-prolateral spur ( Fig. 2A View FIGURE 2 A – L ). Paracymbium simple, retrolaterally curved, lying in close contact with subtegulum ( Figs 2A–B View FIGURE 2 A – L ). Tegulum with prominent tegular protrusion ( Figs 2A–B View FIGURE 2 A – L ). Median apophysis massive with bulbous basal arch, distal half cup-shaped with two apical tips ( Fig. 2A View FIGURE 2 A – L ). Radix with dorsally visible apical part ( Fig.2B View FIGURE 2 A – L ). Terminal apophysis with a sinuous base and an unsclerotized tip ( Fig. 2A View FIGURE 2 A – L ). Embolus with medio-prolateral protrusion, with sclerotized tip directed at twelve o’ clock position in ventral view ( Fig.2A View FIGURE 2 A – L ). Paramedian apophysis with spatula-like tip ( Fig. 2A View FIGURE 2 A – L ). Conductor broad, ovate with sclerotized tip ( Fig. 2A View FIGURE 2 A – L ).

Dimensions: Total length 5.22. Carapace length 2.44, width 2.07. Eye diameter: ALE 0.10, AME 0.13, PLE 0.11, PME 0.13. Eye interdistances: AME–AME 0.16, AME–ALE 0.21, PME–PME 0.12, PME–PLE 0.38, PLE–ALE 0.03. Abdomen length 2.78, width 2.27. Pedipalp: femur 0.43, patella + tibia 0.44, tarsus 0.97, total 1.84. Leg I: femur 2.76, patella + tibia 3.17, metatarsus 1.65, tarsus 0.83, total 8.41. Leg II: femur 2.29, patella + tibia 2.66, metatarsus 1.60, tarsus 0.79, total 7.34. Leg III: femur 1.50, patella + tibia 1.43, metatarsus 0.85, tarsus 0.55, total 4.33. Leg IV: femur 2.13, patella + tibia 2.22, metatarsus 1.51, tarsus 0.69, total 6.55.

Variation (range): TL 4.98–5.52; CL 2.26–2.44; CW 2.04–2.21; AL 2.72–3.07; AW 2.03–2.27; N =3.

Female (ADSH912710A). In most details like male except the followings: brown bristle behind each PLE absent. Fovea Y- shaped. Cheliceral promarginal teeth equally spaced. Abdomen subtriangular with prominent humeral humps and conspicuous ventral inverted U-shaped white pattern and with paired white spots antero-lateral to spinnerets. Leg formula 1>4>2>3. Genitalia ( Figs 2C–G View FIGURE 2 A – L ): Epigymum medially wide composed of paired elongated lateral plates and a posterior oval plate, all remained fused antero-medially ( Fig. 2C View FIGURE 2 A – L ). Scape elongated, straight, with conspicuous wrinkles basally ( Fig. 2F View FIGURE 2 A – L ), wide at base ( Fig. 2C View FIGURE 2 A – L ). Copulatory openings medium-sized, crescent-like, medially placed ( Fig. 2C View FIGURE 2 A – L ). Copulatory ducts sclerotized. Spermathecae reniform, confronting each other in dorsal view ( Figs 2D, G View FIGURE 2 A – L ). Fertilization ducts short, originate apically to copulatory ducts ( Figs 2D–E, G View FIGURE 2 A – L ).

Dimensions: Total length 7.87. Carapace length 2.94, width 2.73. Eye diameter: ALE 0.12, AME 0.15, PME 0.14, PLE 0.12. Eye interdistances: AME–AME 0.18, AME–ALE 0.48, PME–PME 0.14, PME–PLE 0.59, PLE–ALE 0.07. Abdomen length 4.93, width 3.93. Palp: femur 0.92, patella + tibia 1.06, tarsus 1.13, total 3.11. Leg I: femur 3.56, patella + tibia 4.18, metatarsus 2.40, tarsus 0.93, total 11.07. Leg II: femur 3.07, patella + tibia 3.45, metatarsus 2.18, tarsus 0.93, total 9.63. Leg III: femur 1.94, patella + tibia 1.91, metatarsus 1.19, tarsus 0.70, total 5.74. Leg IV: femur 3.23, patella + tibia 3.39, metatarsus 2.32, tarsus 0.85, total 9.79.

Variation (range): TL 6.33–7.87; CL 2.37–2.94; CW 2.28–2.73; AL 3.81–4.93; AW 2.74–3.93; N =9.

Remarks. All examined specimens were collected from three different sites of tropical montane wet temperate forests (Shola forests) ( Fig. 1C View FIGURE 1 A – C ). Specimens from these three Shola forests showed considerable variation in body pattern, colouration and aspects of male and female genitalia (see Figs 2A, D, H, J–K View FIGURE 2 A – L ). Male palp of specimen from Chembra peak exhibits variations from the described specimen by the following aspects (characters): shape of the conductor, size and orientation of tegular protrusion and shape and orientation of unsclerotized angular tip of terminal apophysis ( Figs 2A, H View FIGURE 2 A – L ). Even specimens from the same Shola forest (Nayamakkadu Shola) revealed intraspecific variations ( Figs 2D, J– K View FIGURE 2 A – L ). A mating plug was also observed in five of the nine female specimens collected from the Nayamakkadu Shola ( Fig. 2I View FIGURE 2 A – L ). The plug, which was formed of an amorphous material (secretory plug), was found to be inserted in the copulatory openings (right or left or both) and in the clefts between the lateral and median plates and extended posteriorly to cover the entire area of the median plate. A mating plug was clearly visible in the right copulatory opening and in the left cleft of P. eburnus , although Joseph & Framenau (2012) had not mentioned its occurrence in the genus ( Joseph & Framenau 2012; fig. 4D).

ADSH	Arachnology Division, Sacred Heart College

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Taxonomy

Kingdom	Animalia
Phylum	Arthropoda
Class	Arachnida
Order	Araneae
Family	Araneidae
Genus	Plebs