% feeding spiders
Larger-sized orb-weavers: Argiope bruennichi Aculepeira ceropegia Araneus diadematus Larinioides cornutus Neoscona arabesca Nephila clavata Nephila maculata
This paper Nyffeler (1982) Nyffeler (1982) Nyffeler (1982) Culin & Yeargan (1982) Miyashita (2005) Miyashita (2005)
Overall mean ± SE
25.9 ± 6.4
Overall mean ± SE
7.3 ± 3.2
Nyffeler (1982) Nyffeler et al. (1994) Nyffeler et al. (1994) Culin & Yeargan (1982) LeSar & Unzicker (1978) Nyffeler et al. (1994)
Mean value for surveys at different times of the day.
Tab. 2. Feeding frequency (= no. spiders feeding x 100%/no. spiders encountered) of various species of orb-weaving spiders in the field (based on literature data).
<10% (see reviews by Nyffeler & Breene 1990; Nyffeler & al. 1994; Nyffeler & Sunderland 2003). Evidently, the large orb-webs of A. bruennichi function as very effective insect traps (i. e. high foraging success).
Taxonomic composition of the catch
The overall composition of A. bruennichi's diet observed in this study (Tab. 3) parallels that found by other workers, although diet may vary in detail (see Becker 1982; Pasquet 1984; Malt 1996a; Prokop 2006). Large-sized Hymeno- ptera and Orthoptera made up the bulk of the spider catch (approx. 90% of total prey biomass)(Tab. 3). Such a predominantly insectivorous foraging pat- tern is typical for the vast majority of orb-weaving spider species (see Nyf- feler 1999), though there are some exceptions (Nyffeler & Symondson 2001). Members of the genus Argiope are very cannibalistic and regularly terminate copulations by aggressively attacking the male (Sasaki & Iwahashi 1995; Her- berstein & al. 2005; Schneider & al. 2005, 2006). Experiments by Fromhage & al. (2003), however, have shown that the additional food intake due to sexual
Prey catch of Argiope bruennichi