Arachnologische Mitteilungen 55

Life history of Zorocrates guerrerensis 49 Fertilised females were allowed to construct up to four egg sacs under laboratory conditions.The first egg-sac was const- ructed in 31.9 days (SE = 12.26, n = 9) after the first mating. From each egg sac, on average 42 spiderlings (SE = 17.8, n = 17) emerged after about a two-month period (x = 60.6 days, SE = 21.23, n = 16) of incubation. Discussion We observed the growth during a year and details of the re- productive behaviour of Z. guerrerensis , a Mexican cribellate spider from the family Zoropsidae. Reaching adulthood by Z. guerrerensis after 9-11 moults outside the egg sac is compara- ble with two other studied zoropsids, Tengella perfuga Dahl, 1901 and T. radiata (Kulczyński, 1909), reaching adulthood in 11-12 and 8-9 moults, respectively (Barrantes & Madri- gal-Brenes 2008, Mallis & Miller 2017). The between-instar growth factor of Z. guerrerensis was approximately constant, contrary to T. radiata and T. perfuga , in which Barrantes & Madrigal-Brenes (2008) and Mallis & Miller (2017) obser- ved some fluctuations in the growth factor in several instars. The observed decreasing tendency in the growth factor was caused by some individuals that needed more moults to reach maturity.Those should have also grown less during their early instars. Males displayed the courtship of “Level I”, i.e. the direct contact with the female (Platnick 1971). Communication between males and females was (beside an expected olfactory way) largely tactile. No visual or acoustic communication was recorded. Tactile communication was observed also in T. per- fuga by Mallis & Miller (2017: video S2), but the difference was in the ‘receptivity signal’ (acceptance of the male and al- lowing it to assume a copulatory position). The ‘receptivity signal’ of the Z. guerrerensis female was in precise contacts by legs I and II, whereas the T. perfuga female had their front legs stretched at the moment when the male was climbing onto it (Mallis & Miller 2017: video S5). The ‘receptivity signal’ of Z. guerrerensis was rather similar to that of the wolf spider Arctosa ( Tricca ) lutetiana (Simon, 1876) (Dolejš et al. 2010). In T. perfuga , Mallis & Miller (2017: video S3) observed that males spun the so-called ‘bridal veil’ [the silk deposited across the female’s carapace and legs; also a common part of court- ship in certain Xysticus species (Platnick 1971)] prior to co- pulation. No such behaviour was observed in Z. guerrerensis ; instead, females were jerking with their whole bodies when males were climbing onto them. A possible explanation of such behaviour occurring just prior the copulation could be that it was the female’s last chance to chase away a male that for some reason would not be an ideal partner. The copulatory position of Z. guerrerensis resembled that of wolf spiders and T. perfuga , but differed from the copulati- on position of T. radiata , in which spiders were orientated to- wards each other by their ventral sides (Barrantes 2008).The males of Z. guerrerensis inserted their palps between the third and fourth legs of the females. Such a position corresponds to what can also be seen in videos about T. perfuga (Mallis & Miller 2017). However, it differs from the position obser- ved in wolf spiders in which males insert their palps behind the females’ fourth legs (e.g., Montgomery 1903, Dolejš et al. 2010, 2012, Foelix 2011). Unfortunately, we are not aware of any literature dealing with this difference among various families. Thus, any conclusions about the sense, function or mechanical limitations of different ways of palpal insertions would be too preliminary now. The pattern of copulation of Z. guerrerensis with a single insertion of each palp and a single expansion of haematodo- cha is a frequent one not only among the lycosoids but also in the unrelated cribellate genera Amaurobius and Titanoeca (Stratton et al. 1996). However, in both Tengella species, re- peated insertions of the same palp were observed (Barrantes 2008, Mallis & Miller 2017). The second difference is in the duration of haematodochal expansion in relation to that of palpal insertion. In wolf spiders and the zoropsid T. radiata , almost the whole duration of palpal insertion is composed of the haematodochal expansion (Barrantes 2008, Dolejš et al. 2010, 2012). The males of Z. guerrerensis , however, switched Tab. 2: Comparison of behavioural components of mating virgin and on- ce-mated females of Zorocrates guerrerensis . Means and standard errors (in parentheses) are given. Behaviour Copulation of virgin females (n = 9) Copulation of mated females (n = 8) P value (Paired t-test) Courtship (s) 83.9 (121.46) 166.5 (167.47) 0.4393 First expansion of haematodocha (s) 19.6 (3.50) 16.7 (6.58) 0.1780 First palpal insertion (s) 91.9 (62.92) 98.4 (21.75) 0.9366 Second expansion of haematodocha (s) 23.0 (2.83) 22.5 (7.69) 0.4627 Second palpal insertion (s) 112.8 (46.77) 121.8 (61.03) 0.9660 Total copulation duration (s) 246.6 (53.13) 390.1 (133.75) 0.0515 Fig. 7: Sperm web of Zorocrates guerrerensis spun in a plastic tube