Arachnologische Mitteilungen 55

Life history of Zorocrates guerrerensis 47 lation) was observed in Petri dishes (diameter 90 mm, height 50 mm) under laboratory conditions (room temperature and a natural photoperiod). A white, moistened filter paper was placed into the Petri dish to provide a substratum suitable for spider locomotion, to improve contrast during videotaping and to allow the spiders to remain hydrated. An adult female was placed into the Petri dish 2 h before the trial to allow her to habituate to the new surroundings and to deposit silk and pheromones. After introducing a male, the spiders’ behavi- our was recorded for 15 min, using a digital Panasonic NV- GS400 video camera. Such a 15 min period was enough for all observed copulations to be completed. The females were paired with randomly chosen males. All but one mated female was paired in one more trial to determine whether females are monandrous or polyandrous (one female had produced an egg sac before the second trial began). Seventeen copulations were observed and analysed. La- tency (the time between introducing the male and the first physical contact), courtship and copulation duration were re- corded. Numbers of insertions and of side shifts were coun- ted. Behaviour of mating spiders was recorded. The moment when a male climbed onto a female was designated as the beginning of copulation, and the moment when the spiders physically separated as the end of copulation (Stratton et al. 1996). After copulation, each female was placed back in their plastic tube where later on they constructed their egg sacs. The production of egg sacs, the process of egg laying, hatching and postembryonic development inside the egg sacs were not investigated. The software NCSS 2007 (Hintze 2006) was used to test the normality of continuous variables (all data were normally distributed) and to calculate descriptive statistics of the fol- lowing variables: latency, courtship and copulation duration, number and duration of palpal insertions and hematodochal expansions, delay between copulation and egg sac production and number of offspring. Of the descriptive statistics, means (x) and standard errors (SE) were calculated.The first and se- cond copulations were compared using a Paired t-test. Vou- cher specimens have been deposited in the National Museum, Prague (N o s P6A-6468 and P6d-14/2017). Results The life cycle of Z. guerrerensis lasted a year. Spiders under- went up to 12 instars; on average, the instar duration was 42.4 days (SE = 10.82) (Tab. 1). Males reached adulthood in the 10th (n = 1) or 11th (n = 3) instar, females in the 10th (n = 2), 11th (n = 4) or 12th (n = 3) instar.The between-instar growth factor was approximately constant (Tab. 1).The following in- stars were about 20.0 % (SE = 3.88) larger than the previous ones; the relative growths had a descending tendency (Tab. 1). Adult males were about 11.7 % smaller than females. Pre-mating interactions between males and females star- ted quite rapidly; the first contact occurred 28 s (SE = 34) after introducing the male into the arena with a female.Males touched the tibia or head region of the females with its first pair of legs. Females located the introduced males, raised its first or two first pairs of legs and held them either parallel to each other (Fig. 1) or at an angle of 30-60 degrees. Further contact was tactile. Males tapped (using their front legs) the patellae and tibiae of the female’s front legs and also her ca- rapace, and the femora and tibiae of the female’s third and fourth legs (Fig. 2). On the average, the tactile interactions lasted for 123 s (SE = 146). During this courtship, the males waggled several times with their opisthosoma up and down and climbed onto females.When the male prosoma was abo- ve the female carapace, the females performed on average 5.5 (SE = 2.43) very vigorous jerks forwards using their third and fourth pairs of legs (the front legs were still raised) but their tarsi did not change their position, standing still on the same place. All tested females (n = 9) were receptive. Then, males mounted the females (Fig. 3) so that the male’s prosoma was above that of the female, but the spiders were facing in oppo- site directions. Once the males reached the copulatory position [“Posi- tion II” after Gerhardt & Kästner (1941) or “Type 3” after Foelix (2011)], they immediately inserted one palp equilate- rally. The palp was inserted between the third and fourth leg of the females (Fig. 4). Just before insertion, the males briefly scraped the epigyne using rapid movements of their palps.The haematodocha was expanded (and leg spines erected) imme- diately after the palp was inserted (Fig. 5); during the palpal insertion, only one haematodochal expansion occurred.Males left their palps close to the epigyne (but not in direct contact with it) for some time after the haematodocha had collapsed and the spines returned to their original position (Fig. 6 and the supplementary video file).Males switched sides only once, thus each palp (right and left) was used only once. In four out of 17 copulations, the so-called ‘flubs’ were observed: males inserted their palps, but the haematodocha never expanded in full and males usually used the other palp. Such unsuccessful Tab. 1: Summary of the ontogenetic development of Zorocrates guerrerensis . Carapace lengths, percentage of growth in carapace length during moults and duration of each instar given separately for males (n = 4) and females (n = 9). Means and standard errors (in parentheses) are provided. Instar 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. Carapace length (mm) ( 1.0 (0.06) 1.2 (0.10) 1.4 (0.07) 1.7 (0.20) 1.9 (0.27) 2.4 (0.22) 2.9 (0.22) 3.4 (0.39) 4.2 (0.52) 5.1 (0.49) 5.5 (0.34) – Carapace length (mm) ) 1.0 (0.08) 1.2 (0.13) 1.5 (0.17) 1.8 (0.21) 2.2 (0.28) 2.6 (0.22) 3.3 (0.26) 3.9 (0.35) 4.5 (0.45) 5.2 (0.52) 6.0 (0.50) 6.4 (0.35) Relative growth (%) ( – 21.6 (4.36) 22.2 (7.96) 20.2 (8.11) 18.8 (3.02) 21.8 (5.90) 20.3 (3.98) 20.6 (4.49) 20.3 (6.46) 22.3 (6.46) 10.3 (4.38) – Relative growth (%) ) – 26.5 (9.47) 20.8 (6.95) 18.4 (6.08) 20.1 (5.56) 22.3 (7.87) 19.1 (3.48) 24.3 (7.25) 18.1 (3.80) 16.8 (6.43) 19.5 (5.74) 12.7 (4.42) Duration (days) ( ? ? ? 40.0 (5.488) 33.5 (4.04) 36.0 (2.71) 38.0 (4.16) 45.0 (15.78) 54.0 (11.22) 68.3 (4.51) – – Duration (days) ) ? ? ? 37.9 (2.09) 36.2 (4.09) 38.0 (8.12) 34.8 (3.38) 46.1 (12.47) 50.1 (7.29) 48.6 (12.04) 46.0 (15.39) –