Bioacoustics of Nerudia trigo

( FIGS 1E , 22–24 ) Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: 2D2F4A08-7C18-4ED6-8894-FE391F17E6C6 . Diagnosis: Easily distinguished from known congeners by male chelicerae ( Fig. 22G, H ; without frontal apophyses, with patches of strong hairs); also by shapes of procursus ( Fig. 22A–C ; similar to N. guirnalda , but without prolateral–ventral ridge proximally), by bulbal processes ( Fig. 22D–F ; ventral apophysis distally slender, curved towards ventral, same length as embolar process), and by epigynum and female internal genitalia ( Figs 22I , 23 ; epigynal plate with short but wide posterior indentation, laterally strongly sclerotized; internal genitalia with indistinct ‘receptacle’. Type material: ARGENTINA – Salta : • ♂ holotype ; between Alemanía and Cafayate; 25.7023° S , 65.7022° W ; 1340 m a.s.l. ; 23 Mar. 2019 ; B. A. Huber and M. A. Izquierdo leg.; LABRE-Ar 589 • 1 ♂, 2 ♀♀ , paratypes ; same data as holotype; ZFMK Ar 23894 . Other material examined: ARGENTINA – Salta : • 10 ♀♀ , 2 juvs, in pure ethanol ( one female used for SEM; three female prosomata used for molecular study); same data as holotype; ZFMK Arg 206 • 3 ♂♂; same data as holotype ; LABRE-Ar 539 • 1 ♂; ~ 1 km SW Alemanía ; 25.6300° S , 65.6180° W ; 1210 m a.s.l. ; 23 Mar. 2019 ; B. A. Huber and M. A. Izquierdo leg.; ZFMK Ar 23895 • 1 ♀ , in pure ethanol; same data as preceding; ZFMK Arg 202 • 2 ♀♀ , 1 juv. , in pure ethanol; same data as preceding; LABRE-Ar 550 . Etymology: The species epithet trigo (Spanish for ‘wheat’) is taken from Pablo Neruda’s poem ‘Cien sonetos de amor’; noun in apposition. Description Male ( holotype ). Measurements: Total body length 1.70, carapace width 0.77. Distance PME–PME 80 µm; diameter PME 65 µm; distance PME–ALE 20 µm; distance AME–AME 20 µm; diameter AME 50 µm. Leg 1: 7.50 (2.10 + 0.30 + 1.95 + 2.40 + 0.75), tibia 2: 1.80, tibia 3: 1.60, tibia 4: 2.10; tibia 1 L/d: 22. Colour (in ethanol): Prosoma and legs mostly pale ochre-yellow; darker ochre Y-mark behind ocular area; legs without dark rings; abdomen monochromous pale grey. Body: Habitus as in N. poma (cf. Fig. 1B ). Ocular area barely raised. Carapace with indistinct thoracic groove. Clypeus unmodified. Sternum wider than long (0.54/0.42), with pair of distinct anterior processes near coxae 1. Abdomen globular. Chelicerae: As in Figure 22G, H ; with large patch of strong hairs on each side; without frontal processes; stridulatory files on low lateral protrusions. Palps: Similar to N. colina (cf. Fig. 4 ); proximal segments apparently identical to N. colina ; femur length/width 2.08; tibia length/width 1.10; procursus simple, in lateral view slightly directed towards dorsal, similar to N. colina but without subdistal ventral sclerite and slightly wider ( Fig. 22A–C ); genital bulb similar to N. colina but ventral apophysis less strongly curved towards ventral ( Fig. 22D–F ). Legs: Without spines and curved hairs; apparently few vertical hairs; retrolateral trichobothrium of tibia 1 at 63%; prolateral trichobothrium absent on tibia 1; tarsus 1 with seven to eight pseudosegments, distally distinct. Variation (male): Tibia 1 in three other males from type locality: 1.71, 1.72, 1.83. The male from 1 km SW Alemanía has apparently identical chelicerae and pedipalps but is smaller: tibia 1: 1.40; carapace width: 0.63; chelicerae maximum width: 240 µm. Female: In general, similar to male ( Fig. 1E ) but sternum without pair of anterior humps. Tibia 1 in four females : 1.46, 1.47, 1.65, 1.85. Epigynum ( Fig. 23 ) anterior plate roughly rectangular, weakly protruding, with short but wide posterior indentation; posterior plate large, simple. Internal genitalia ( Figs 22I , 23B– D ) simple, with indistinct ‘receptacle’. Distribution: Known only from two neighbouring localities in Salta , Argentina ( Fig. 3 ). Natural history: At the type locality, the spiders were found in small cavities or shelters composed of large rocks in a dry ravine. They were sitting relatively exposed on the ceiling of the cavities and were easy to collect as they barely moved. Several females carried egg-sacs that were consistently reddish, flattened, and contained approximately 15– 18 eggs . Near Alemanía , the single pair was found close together on the underside of a large rock. The spiders barely moved at disturbance. They shared the microhabitat with a tiny undescribed species of Modisiminae .