Courtship, Mating and Agonistic Behaviour inPisaura mirabilis(Clerck, 1757)*

Abstract

After a short review of the literature, beginning with the discovery of the nuptial gift of the nursery-web spider Pisaura mirabilis (Clerck, 1757) in 1884 by Van Hasselt, the courtship, mating, agonistic behaviour, and peaceful coexistence of a female with two males in a planted terrarium are described (Table 1). Details of the normal mating process with a wrapped fly of different sizes are given (Figs. 3–10). Copulations occurred during both day and night. Eyesight seems to be of little importance for recognition of sexes and the gift, apart from perceiving movements. Mating variations using a freshly caught unwrapped fly (Lucilia) (Figs. 11–12), a small fly (one Drosophila), a wrapped substitute (heather blossom, Fig. 13) and even without any gift (Figs. 14–15, 23) are shown (Table 4). Males can even perform successfully with females with prey or egg sacs and on nursery webs. Agonistic behaviour, gift robbery, disturbance of mating by a rival, a threesome with one female and two males, but also peaceful male-male encounters are described and illustrated (Figs. 16–23, Table 3). Intersexual aggression and sexual cannibalism are demonstrated and discussed. The so-called “feigning death” of males (Fig. 8) is considered as an evolutionarily stable trick of the male to maintain contact with the female within the dense layer of the herbaceous stratum if she suddenly runs away after a disturbance, or simply for recovering the gift. This behaviour also occurs when two males share one gift (Fig. 22) and try to copulate with each other (Fig. 19). The benefits and disadvantages of the different kinds of gifts, evolution of the gift, its functions and the degree of cannibalism are discussed. Comparisons with the mating behaviour of related Pisauridae and Trechaleidae species using gifts and silk in courtship are made, and suggestions for further research are given.