Bioacoustics of Holocnemus caudatus

Redescription Male ( Granada , Trevélez, MHNG) MEASUREMENTS. Total length 5.5, carapace width 1.6. Distance PME–PME 110 µm; diameter PME 110 × 130 µm; distance PME–ALE 50 µm; diameter AME 70 µm; distance AME–AME 25 µm. Leg 1: 33.4 (9.7 + 0.8 + 8.8 + 12.1 + 2.0), tibia 2: 6.3, tibia 3: 4.7, tibia 4: 5.7; tibia 1 L/d: 49; femora 1–4 diameters: 0.32, 0.24, 0.21, 0.22. COLOR (in ethanol). Carapace ochre-yellow; ocular area, carapace pit and posterior median area light brown; sternum brown, with dark brown radial marks; legs ochre-yellow, without darker rings, with black lines on femora and (few) on tibiae; abdomen ochre-gray, with some dark marks dorsally and laterally; ventrally with distinct black median band, partly disrupted, with three parallel longitudinal marks behind gonopore. BODY. Habitus very similar to H. reini (cf. Fig. 7 ). Ocular area slightly raised. Deep thoracic pit and pair of shallow furrows diverging from pit toward posterior margin. Clypeus unmodified but rim more sclerotized than in female. Sternum wider than long (1.05/0.85), with distinct indentations between consecutive leg coxae and between coxae 4. Abdomen strongly elongated beyond spinnerets, dorsoposteriorly pointed. Gonopore with six epiandrous spigots ( Fig. 118 ); ALS with one widened spigot and one pointed spigot, PMS with two pointed spigots ( Fig. 125 ). CHELICERAE. As in Figs 97–98 , with pair of low proximal frontal humps and pair of frontal lateral apophyses, each with two large modified cone-shaped hairs ( Fig. 115 ); distance between tips of modified hairs: 320 µm; several ‘regular’ frontal hairs with small but distinct processes at basis; lateral stridulatory ridges very fine ( Fig. 113 ; distances between ridges proximally ~1.5 µm, distally ~4 µm), barely visible in dissecting microscope. PALPS. In general apparently indistinguishable from H. reini (cf. Figs 59–61 ); coxa with rounded retrolateral hump; trochanter barely modified; femur slightly curved towards dorsal, distally widened, with rounded ventral protrusion, proximally with prolateral stridulatory pick ( Fig. 116 ), with barely visible retrolateral transversal line, without retrolateral proximal process; femur-patella joints shifted toward prolateral side; tibia very large compared to femur, tibia-tarsus joints shifted toward retrolateral side; tarsus without macrotrichia; tarsal organ capsulate ( Fig. 121 ); procursus (cf. Figs 62–63 ) straight, few hairs slightly curved upwards; proximally on prolateral side with strong hump free of hairs, procursus tip with distinctive flat membranous element retrolaterally (arrow in Fig. 117 ) covering proximal part of ventral sclerite in retrolateral view, with dorsal transversal flap; genital bulb (cf. Figs 66–68 ) with simple basal sclerite connected to distal (main) sclerite, sperm duct opening in membranous area prolaterally at basis of distal sclerite; distal sclerite with one large apophysis (fold) and two smaller apophyses on prolateral side; with indistinct retrolateral parallel ridges. LEGS. Femur 1 with single row of ~23 ventral spines; without curved hairs; few vertical hairs ( Figs 119– 120 ); retrolateral trichobothrium of tibia 1 at 4%; prolateral trichobothrium absent on tibia 1, present on other leg tibiae; tarsal pseudosegments indistinct except 2–3 distally; tarsal organs capsulate, with round or slightly irregular rim ( Figs 122–123 ). Male (variation) Tibia 1 in 82 males : 6.8–9.9 (mean 8.5). Chelicerae maximum width (N = 43): 0.46–0.62 (mean 0.55); procursus length (N = 46): 0.86–1.00 (mean 0.92). Coloration of fresh specimens very similar to H. reini (cf. Figs 7–8 ), with distinct pattern on abdomen. Ventral dark band on abdomen variably distinct, section behind gonopore with 2–4 longitudinal bands. Female In general similar to male (cf. Fig. 8 ) but without spines on legs. Without stridulatory apparatus between carapace and abdomen; with fine cheliceral stridulatory ridges as in male ( Fig. 114 ; distances between ridges 3 µm). Tibia 1 in 103 females : 5.1–8.8 (mean 6.9). Epigynum as in Figs 101–106 and 127–128 , main epigynal plate triangular to semicircular, weakly protruding; only posteriorly laterally strongly sclerotized; with pair of variably distinct pockets (distance between pockets 0.32–0.35); internal sclerotized arc and median round structure variably visible in uncleared specimens; posterior epigynal plate large but simple; pair of low but distinct elevations in front of epigynum. Internal genitalia ( Figs 99–100 , 107–110 ) with triangular pore plates converging anteriorly, dorsal arc simple and slender, ventral arc laterally strongly widened, medially strong, with simple median pouch. Natural history The biology of this common Spanish spider has apparently been little studied. According to Wiehle (1933) it occupies similar habitats as H. hispanicus (i.e., wall niches, rock cavities, etc.). The domed web was described as having a surprisingly regular mesh; the size of the dome is similar to H. hispanicus (i.e., approximately 35–40 cm ), but the silk puffs are not as close together as in H. hispanicus . Females lay up to 50 eggs per egg-sac and produce up to three egg-sacs per season ( Wiehle 1933 ).