Bioacoustics of Artema nephilit

Natural history The spiders were found both in natural habitats such as caves, deep crevices, and under boulders, as well as in man-made habitats such as buildings, under low culverts, and artificial caves. In caves, the spiders built irregular webs (not clearly dome-shaped webs) near the ground, under stones, in crevices, and on the cave ceiling. The spiders seemed to avoid the deeper, dark parts of the visited caves. In a large cave survey we conducted in Israel ( Aharon 2016 ), we found A. nephilit sp. nov. in caves especially along the Jordan Rift Valley, in a very hot and arid zone with low mean annual precipitation ( 50–150 mm ). Only a few specimens were found outside the Jordan Rift Valley, in caves in areas with higher mean annual precipitation ( 400–650 mm ) in a more mesic habitat. These findings suggest that the species is more abundant in xeric, hot and dry caves rather than in humid caves nearby. The spiders were always found on the east or south slopes that are dryer than the west and north slopes and thus seem to be adapted to arid conditions ( Aharon 2016 ). We examined more than 40 caves in Israel ; 19 caves were inhabited by A. nephilit sp. nov. , and most of these caves were dry. Some specimens were also found in hot, humid caves, but the species was never found in wet caves. In caves in southern Israel , where food abundance was low, we could not observe prey items. In a cave situated in the Golan Heights, in the north of Israel , where the annual precipitation is higher, we recorded remnants of isopods, tenebrionid beetles, small scorpions, and a spider. In the south of Israel , in a basement of the Eilat Field School, we observed remnants of adult males that had probably been killed by females (that were seen nearby), while in a cave in Nahal Perat, east of Jerusalem , we observed the predation of an adult male A. nephilit sp. nov. by Holocnemus pluchei (Scopoli, 1763) . Penultimate instar juveniles collected from caves in southern Israel (Arubatayim, Sedom, and Malcham) and reared independently in Bonn, Germany and Midreshet Ben-Gurion, Israel , molted to adult almost simultaneously after an unusually long period of 9–10 months ( September 2013 to July 2014 ) ( 4 ♂♂ and 1 ♀ molted in Midreshet Ben-Gurion; 3 ♂♂ in Bonn). This simultaneous timing suggests that the long period is not an artifact caused by the food regime or differences from natural conditions, but rather reflects an intrinsic growth and maturation period. A mating sequence was observed on 10 Jan. 2015 (in Bonn, Germany ). Male from Israel , Sedom Cave; collected penultimate in September 2013 ; molted to adult in July 2014 . Female from Israel , Mount Berenice; collected penultimate in September 2013 ; molted to adult in September 2014 . Previous trials (with various males and females) performed in daylight had resulted in no male reaction when placed into the female’s web. Trials under red light resulted in male courtship, but the females, who had not recently fed, attacked the males. Two days after being fed with crickets, the female above finally accepted the male. Time specification shown as hr:min. 0:00 Male is gently transferred to female web. 0: 12 Male approaches female, bounces slightly and touches silk lines with front legs; female directs herself towards male, vibrates slightly a few times. 0: 16 Male touches female legs and approaches further ( Fig. 9 ); female remains mostly still. 0:17 Final approach; male lowers palps below body ( Fig. 10 ); searches for about 20 sec for correct position on female, apparently by searching for correct alignment of chelicerae relative to epigynum ( Fig. 11 ); female abdomen is pushed backwards. 0:18 As soon as chelicerae are correctly placed (locked?) at epigynum, palps are rotated 180° around longitudinal axis (procursus moving outward and forward; Fig. 12 ); insertion of palps, start of copulation; female releases legs from silk, pulls all legs above body and is moved by male to perpendicular final mating position. 0:19–1:02 No major movements, only very slight jerks of male body, usually every 6–8 seconds, rarely with shorter (4 sec) or longer (10 sec) intervals; no rhythmic palpal movements; no female movements; no female stridulation; asymmetric insertion of palps, consistent over entire copulation (left palp more deeply inserted than right palp; Fig. 13 ). 1:02 Sudden separation, apparently initiated by male. 1:02–1: 12 Female remains motionless; male cleans palps for about 10 min ( Fig. 14 ), then also motionless. 1:18 End of observation. About 24 weeks later, this female produced an egg-sac. After another two weeks (i.e., beginning of August 2015 ), about 40 spiderlings emerged; two weeks later again they molted for the first time. In July 2017 , i.e., almost two years after eclosion, most remaining specimens (about 15) molted to adults.

Description Male ( holotype ) MEASUREMENTS. Total body length 7.0, carapace width 3.1. Leg 1: 48.4 (11.9 + 1.4 + 13.9 + 18.3 + 2.9), tibia 2: 10.2, tibia 3: 8.0, tibia 4: 10.9; tibia 1 L/d: 35. Distance PME–PME 190 μm, diameter PME 190 μm, distance PME–ALE 90 μm, distance AME–AME 50 μm, diameter AME 170 μm. COLOR. Carapace pale to light beige, with dark gray median band. Clypeus with wide light brown band (as in Figs 4 , 9–14 , 35 ). Legs pale yellow to light ochre with dark rings on femora subdistally, patellae + tibiae proximally, and tibiae subdistally, tips of femora and tibiae whitish; sternum pale, with narrow light brown margins. Abdomen light brown with white and dark dots forming stripes from dorsal to lateral side (as in Figs 51–52 ). BODY. Ocular area slightly elevated. Carapace with median pit and distinctive posterior furrow. Clypeus unmodified. Sternum wider than long (2.3/1.5). Chelicerae as in Figs 42–44 and as in Figs 67–69 , with frontal row of ~20 modified (cone-shaped) hairs on each side that splits distally, with outer branch ending at tip of process, inner branch ending at tip of median projection; with indistinct small field of stridulatory ridges laterally (as in Fig. 70 ). Abdomen globose and high; gonopore with four epiandrous spigots. PALPS. As in Figs 36–38 . Coxa unmodified. Trochanter with short ventral projection. Femur with short, somewhat pointed retrolateral process proximally; ventral membranous area proximally bordered on both sides by sclerotized ridges; femur-patella hinges close together dorsally. Patella very short. Procursus with proximal dorsal process and weakly developed ventral pocket; with distal dorsal notch on prolateral margin (as in Fig. 40 ). Bulb with two processes close to membranous embolus (processes a and b, as in Fig. 40 ), process c (as in Fig. 40 ) strongly projecting prolaterally, and indistinct projection on ventral side of bulb (as in Figs 39 , 64–65 ). Area between processes b and c modified with granular surface (as in Fig. 66 ). LEGS.Without spines;with long curved hairs, especially on tibiae and metatarsi; retrolateral trichobothrium on tibia 1 at 8%; prolateral trichobothrium present on all tibiae; pseudosegmentation not visible. Male (variation) Tibia 1 in 14 other males: 9.2–20.6 (mean 14.4). Color pattern on abdomen varies from distinctive stripes consisting of black and white dots on pale to brown-ochre background to pale without any pattern (cf. females, Figs 52–53 ); leg color varies from light brown to ochre; ocular area usually light brown to ochre; median band on carapace sometimes reaches posterior margin of ocular area, forming short v-shaped mark. Cheliceral modified hairs vary slightly in numbers. Gonopore with variable number of epiandrous spigots (4–6) ( Fig. 63 ). Female In general similar to male; tibia 1 in 26 females : 8.0–16.5 (mean 12.5); several females with light brown carapace margins and subtle brown stripes on ocular area. Stridulatory files laterally on chelicerae more distinct than in males ( Fig. 71 ). Epigynum almost twice as wide as long, semi-circular, posterior margin almost straight, gently undulating; epigynal plate consisting of two sclerotized lateral areas that appear swollen posteriorly, pale median area, and dark median sclerite anteriorly (variably large and variably distinct) ( Figs 45–50 ); pair of projections anterior to epigynum (AEP) visible ( Fig. 48 ) but not prominent as in A. bunkpurugu (cf. Huber & Kwapong 2013 : figs 49, 53–54).