Masteria downeyi ( Chickering, 1966 )

Passanha, Victor & Brescovit, Antonio D., 2018, On the Neotropical spider Subfamily Masteriinae (Araneae, Dipluridae), Zootaxa 4463 (1), pp. 1-73 : 25-27

Masteria downeyi ( Chickering, 1966)

( Figs 14, 29F, 32)

Accola downeyi Chickering, 1966: 158 , figs 1–5.

Masteria downeyi: Brignoli, 1983: 126 .

Type. COSTA RICA. ♂ holotype, Turrialba (9°54’0”N; 83°41’0”W), Cartago, 25.VII-15.VIII.1965, A.M. Chickering leg., deposited in MCZ, examined)

Additional material examined. COSTA RICA. Guanacaste: Tilarán (10°26’0”N; 85°24’ 0”W), 1♂, 14.VII.1966, S. Peck leg. ( AMNH); Cato, 1♂, 22.VII.1957, E. Dixon leg. ( AMNH); Quepos: Manuel Antonio National Park (9°22’32”N; 84°8’9”W), 1 immature, Charles & M. Goodnight leg. ( AMNH) ; PANAMA. Chiriqui: Tierras Altas, El Volcán (8°46’12”N; 82°37’48”W), 1♀, 14.VIII.1950, A. M. Chickering leg. ( MCZ 140 ); Cerro Punta (8°51’0”N; 82°34’0”W), 1♀, 04.III.1936, W. J. Gertsch leg. ( AMNH).

Diagnosis. Males of Masteria downeyi are similar to those of M. colombiensis , M. lewisi , M. yacambu n. sp., M. amarumayu n. sp., M. mutum n. sp. and M. aguaruna n. sp. in the palpal bulb piriform ( Fig. 14B). They differ from M. colombiensis , M. yacambu n. sp., M. amarumayu n. sp. and M. mutum n. sp. in having a group of thick and elongated setae medially on the palpal tibia ( Fig. 14D), from M. lewisi in the long embolus, and from M. aguaruna n. sp. in the cylindrical embolus tip ( Fig. 14C) and short BS ( Figs 14E, 29F). Females differ from those of the other species of the genus in having bilobed spermathecae, with the ectal lobe very small and the ental one globose ( Fig. 14F).

Description. Male ( Costa Rica, Guanacaste, Tilaran, AMNH). Color: Carapace in dorsal view yellowish and in ventral view slightly lighter, legs yellowish and abdomen whitish. Total length, 3.50. Carapace 1.75 long, 1.28 wide. Abdomen 1.75 long. Fovea 0.07. Clypeus 0.03. Ocular tubercle 0.20 long, 0.26 wide. Eyes: six, posterior row recurved ( Fig. 14A). AME absent, ALE 0.14, PME 0.06, PLE 0.11. Basal segment of chelicerae with 11 prolateral teeth, and 10 smaller mesobasal teeth. Labium 0.18 long, 0.32 wide. Sternum 0.81 wide, 0.84 long. Palp: femur 1.05/ patella 0.57/ tibia 1.00/ tarsus 0.50/ total 3.12; Legs I: femur 1.46/ patella 0.59/ tibia 1.37/ metatarsus 0.90/ tarsus 0.81/ total 5.13; II: 1.21/ 0.59/ 0.96/ 0.87/ 0.68/ 4.31; III: 1.15/ 0.53/ 0.90/ 0.96/ 0.78/ 4.32; IV: 1.59/ 0.65/ 1.40/ 1.25/ 0.87/ 5.76; Leg formula 4123; Spination: Legs I: tibia v1-1 -1, p1-3ap, metatarsus p1b; II: tibia v1-1 - 1ap, p1, metatarsus v1-1 -1, p1; III: patella v1-1, r1, tibia v1-1 -2ap, r1-1-1, metatarsus v1-1 -3ap, p2-1, r1; IV: patella p1, r1, tibia d1, v1-1 -1-3ap, p1-1, r1-1-1, metatarsus v1-2 -1-3ap, p1-1-1, r1. Tibia I: P1 a rounded projected spur, P2 a strong spine slightly below other two processes and P3 two spines on the same base. Metatarsus I with flattened basal spine and basal depression associated with prolateral processes of tibia I ( Figs 14E, 29E). Palpal tibia twice length of cymbium with group of 15–20 thick and elongated setae on retrolateral medial area ( Fig. 14D). Cymbium as long as wide with four apical spines. Palpal bulb piriform with short embolus, half length of tegulum, with slight curvature ( Fig. 14B–C). PLS: basal, medial and apical 0.64, 0.52, 0.52 long. Medial and apical segments of female posterior lateral spinnerets were missing due to specimen damage.

Female (MCZ-140). Color: Carapace orange, legs and abdomen yellowish. Total length 4.51. Carapace 2.22 long, 1.82 wide. Abdomen 2.29 long. Fovea 0.10. Clypeus 0.06. Ocular tubercle 0.22 long, 0.34 wide. Eyes: six, posterior row recurved. AME absent, ALE 0.15, PME 0.08, PLE 0.12. Basal segment of chelicerae with 11 prolateral teeth, and 10 smaller mesobasal teeth. Labium 0.32 long, 0.47 wide. Sternum 1.00 wide, 1.07 long. Palp: femur 1.31/ patella 0.69/ tibia 1.16/ tarsus 1.13/ total 4.29; Legs I: femur 1.87/ patella 0.88/ tibia 1.63/ metatarsus 1.22/ tarsus 1.00/ total 6.60; II: 1.54/ 0.88/ 1.16/ 1.04/ 0.84/ 5.46; III: 1.47/ 0.75/ 1.16/ 1.19/ 0.79/ 5.36; IV: 1.91/ 0.88/ 1.72/ 1.57/ 0.84/ 6.92; Leg formula 4123; Spination: palp: tibia v1, tarsus v1 b; Legs I: metatarsus v1 ap; II: metatarsus v1-1 -1, p1; III: patella p1-1, r1, tibia v1-1 -1-3ap, p1-1, r1-1, metatarsus d1, v2-2 -3ap, p1-1, r1; IV: patella r1, tibia v1-1 -1-3ap, p1-1, r1-1-1, metatarsus v2-2 -3ap, p1-1, r1-1. Palpal claw with 15 teeth. PLS: basal 1.15, medial and apical lost. Spermathecae bilobed, with ental lobe on a wide glandular region ( Fig. 14F).

Variation. 2 males: total length 3.50–4.00. 3 females: total length: 3.90–4.51.

Distribution. Costa Rica and Panama ( Fig. 32).