Asemostera dianae, Rodrigues, Everton Nei Lopes & Brescovit, Antonio Domingos, 2012

Rodrigues, Everton Nei Lopes & Brescovit, Antonio Domingos, 2012, Linyphiid spiders of Peru: description of a new species, complementary descriptions and new distribution records (Araneae: Linyphiidae), Zootaxa 3506, pp. 77-86 : 78-80

Asemostera dianae new species

( Figures 1–7 )

Types. Holotype male from Peru, Madre de Dios, Zona Reservada Pakitza (bosque), 356 m a.s.l. (above sea level), 04.III.1991, D. Silva col., deposited in MUSM ENT 0 0 503897. Paratype female, same data as the holotype, deposited in MUSM ENT 0 0 508000. Paratypes, four males and seven females, same data as the holotype, deposited in MUSM ENT 0 0 508001. Paratypes, male and female from Peru, Cuzco, Acjanaco–Tres Cruces, 13.III.1991, D. Silva col., deposited in IBSP 162933.

Etymology. The specific name honors the arachnologist Diana Silva, collector of the type specimens series and curator of the arachnological collection of Museo de Historia Natural da Universidad Nacional Mayor de San Marcos, Lima, Peru.

Diagnosis. The male of Asemostera dianae new species resembles that of A. enkidu Miller, 2007 ( Miller, 2007: 173, figs. 124H, 127E, F, I) by the less developed radix ( Fig. 2 ), but differs by the following: shorter retrolateral tibial apophysis ( Fig. 1 ), less developed paracymbium, embolic membrane developed and enlarged ( Figs. 1, 2 ), tegulum with duct sinuous and not forming a loop ( Fig. 1 ), and embolus longer than A. enkidu ( Fig 2 ). The female of Asemostera dianae new species is closest to that of A. pallida ( Millidge, 1991) (see Miller, 2007: 173, figs. 124I, 128G, O, P) based on the presence of short copulatory ducts, fertilization ducts oriented mesally from posterior part of spermathecae, and epigynum with ventral plate scape, but differs by the less developed ventral plate scape, which does not surpass the posterior margin of epigynum ( Fig. 6 ), and more closely adjacent copulatory ducts ( Fig. 7 ).

Description. Male (Holotype, MUSM ENT 00503897): Total length 2.14. Carapace length 1.01, width 0.71. Clypeus height 0.23. Sternum length 0.50, width 0.50. Chelicerae length 0.29. Abdomen length 1.21, width 0.90, height 0.86. Leg formula IV/II/I/III; segment lengths (I/II/III/IV): femora 0.79/0.81/0.65/0.81; patellae 0.21/0.21/0.21/ 0.21; tibiae 0.67/0.65/0.52/0.67; metatarsi 0.58/0.60/0.50/0.65; tarsi 0.42/0.44/0.37/0.44; total 2.67/2.71/2.25/2.74. Palp (femur, patella, tibia, cymbium): 0.42/0.25/0.25/0.33. Coxa IV bases separated by more than the width of one (0.25) vs 0.16, respectively. Metatarsal trichobothria I–III present, IV absent; TmI 0.41. Tibial spine formula: 1-1-1-1. Eye diameters and interdistances: AME 0.06, ALE 0.07, PME and PLE 0.04; AME–ALE 0.04, PME–PLE 0.04, AME–AME 0.02, PME–PME 0.06. Eyes margined with black, especially AME. Clypeus glabrous. Carapace dark brown, narrowed anteriorly, longer than wide, setae present at ocular area. Chelicerae brown. Endites brownish. Labium dark brown. Sternum brown, borders dark brown; strongly truncate posteriorly ( Fig. 4 ). Chelicerae promargin with four teeth, retromargin with three teeth. Stridulatory striae ridged. Legs brown, covered with dark brown dots, except coxa pale brown. Pedicel with sternite and pleurites fused. Abdomen dark grey, longer than wide. Spinnerets dark grey. Palpal paracymbium U-shaped ( Fig. 1 ). Embolus long and embolic membrane well developed anteriorly ( Figs. 1, 2 ). Tegulum with sinuous margin and lightly sinuous duct, forming a long, gently sinuous curve. Tailpiece of radix absent. Retrolateral tibial apophysis hooked, sclerotized distally ( Figs. 1, 3 ), prolateral tibial apophysis projecting distally, pointed. Retrobasal cymbial groove sclerotized. Embolus flagelliform, long, slender and tapered at distal end ( Fig. 2 ). Anterior radical process ( Fig. 2 ), with apex near mid-length of embolus.

Female (Paratype, MUSM ENT 00508000): Total length 2.31. Carapace length 0.92, width 0.73. Clypeus height 0.18. Sternum length 0.48, width 0.48. Chelicerae length 0.29. Abdomen length 1.34, width 0.98, height 0.92. Leg formula IV/II/I/III; segment lengths (I/II/III/IV): femora 0.79/0.79/0.63/0.79; patellae 0.21/0.23/0.21/ 0.23; tibiae 0.65/0.63/0.50/0.65; metatarsi 0.58/0.60/0.50/0.65; tarsi 0.42/0.42/0.37/0.39; total 2.65/2.67/2.21/2.71. Palp (femur, patella, tibia, tarsi): 0.31/0.12/0.23/0.37. Metatarsal trichobothria as in holotype, except TmI 0.39. Tibial spine formula, clypeus texture, coloration of carapace, border of eyes, chelicerae, endites, labium, sternum (except border), abdomen, and spinnerets, truncation of sternum, distance between coxal bases, sclerites of pedicel, and cheliceral stridulatory striae and dentition as in holotype. Eye diameters and interdistances: AME 0.05, ALE 0.06, PME 0.04 and PLE 0.03; AME–ALE 0.04, PME–PLE 0.04, AME–AME 0.02, PME–PME 0.06. Eyes with dark borders. Carapace setae present at ocular area and behind eyes. Legs dark brown. Female palpal tarsus long and swollen ( Fig. 5 ). Epigynum with prominent ventral plate scape. Ventral plate large, wider than longer ( Fig. 6 ). Spermathecae round ( Fig. 7 ). Fertilization duct orientation mesal. Copulatory ducts longer, sinuous, and approaching each other medially ( Fig. 7 ). Dorsal plate large wider than longer ( Fig. 7 ).

Variation. Males (n=5): total length 2.1–2.31; carapace length 1.02–1.11. Females (n=5): total length 1.91–2.33; carapace length 0.81–0.88. The color pattern is quite variable from dark-brown to brown in carapace and abdomen dark-grey to grey in both sexes.

Material examined. PERU. Cuzco: Acjanaco–Tres Cruces, 13.III.1991, D. Silva col., 1Ƥ ( MUSM ENT 0503954); 6.III.1991, D. Silva col., 23, 2Ƥ ( MUSM ENT 00503974); Madre de Dios: Zona Reservada Pakitza (bosque), D. Silva col., 356m, 07.VII.1991, 43 ( MUSM ENT 00503909); 02.VII.1991, 23 ( MUSM ENT 00503965); 03.VII.1991, 13 ( MUSM ENT 00503966); 04.VII.1991, 13, 3Ƥ ( MUSM ENT 00503967); 13 ( MUSM ENT 00503973).

Distribution. Peru (Cuzco and Madre de Dios).

Figures

FIGURES 1 – 7. Asemostera dianae new species: (1, 2) Male palp: (1) ectal, (2) mesal, (3) tibia, dorsal. (4) Male carapace, ventral. (5) Female palpi. (6, 7) Epigynum: (6) ventral, (7) dorsal, cleared. (ARP: anterior radical process; CG: retrobasal cymbial groove; DP: dorsal plate; E: embolus; EM: embolic membrane; FD: fertilization duct; PTA: prolateral tibial apophysis; R: radix; RTA: retrolateral tibial apophysis; S: spermathecae; Sc: scape; SPT: suprategulum; ST: subtegulum; T: tegulum; VP: ventral plate). Scale lines: 0.25 mm.