The Effect of Wind Exposure on the Web Characteristics of a Tetragnathid Orb Spider

Abstract

Studies on spiders in their natural habitats are necessary for determining the full range of plasticity in their web-building behaviour. Plasticity in web design is hypothesised to be important for spiders building in habitats where environmental conditions cause considerable web damage. Here we compared web characteristics of the orb spider Metellina mengei (Araneae, Tetragnathidae) in two different forest habitats differing in their wind exposure. We found a notable lack of differences in web geometry, orientation and inclination between webs built along an exposed forest edge and those built inside the forest, despite marked differences in wind speed. This suggests that M. mengei did not exhibit web-building plasticity in response to wind in the field, contrasting with the findings of laboratory studies on other species of orb spiders. Instead, differences in prey capture and wind damage trade-offs between habitats may provide an explanation for our results, indicating that different species employ different strategies to cope with environmental constraints.

A comparison of morphology and web geometry between hypogean and epigean species of Metellina orb spiders (family Tetragnathidae)

“…Not much is known on the ecology and behaviour of its members either, although some studies have been conducted on mating and web-building behaviour in the common European species M. segmentata (Clerck, 1757) and M. mengei (Blackwall, 1870) (Prenter et al 1994;Bridge et al 2000;Hesselberg 2017, 2018). Metellina species are known to prefer dark and humid places to build their orb webs, although M. mengei can be found both in the dark interior, in clearings and at the edge of forests (Tew and Hesselberg 2017). At least two species, M. merianae (Scopoli, 1763) from Europe and the Middle East and M. villiersi (Denis, 1955) from Guinea are found in caves and classified as troglophiles (Hesselberg et al 2019).…”

Orb-weaving spiders are fewer but larger and catch more prey in lit bridge panels from a natural artificial light experiment

“…The lower radius (R l ) was calculated by subtracting R u from D v . All measurements were taken from the center of the web (see Tew & Hesselberg, 2017). The overall web capture area was then calculated from the Ellipse-Hub equation (Herberstein & Tso, 2000):…”

High contrast yellow mosaic patterns are prey attractants for orb‐weaving spiders

“…They are sit-and-wait foragers that rely on a range of strategies to acquire prey. These strategies include modifying the architecture of the web in response to fluctuating prey availability (Blamires, 2010;Blamires, Martens, & Kasumovic, 2018;Heiling & Herberstein, 2000;Sandoval, 1994;Schneider & Vollrath, 1998), and exploiting different sensory channels to attract prey to the vicinity of the web, for instance by adding odours (Henneken, Goodger, Jones, & Elgar, 2017), colours (Craig, Weber, & Bernard, 1996;Hsiung, Justyn, Blackledge, & Shawkey, 2017), silken decorations (Tan et al, 2010;Walter & Elgar, 2012;Yeh, Blamires, Liao, & Tso, 2015) or prey remains (Bjorkman-Chiswell et al, 2004;Tan & Li, 2009) to their webs, as well as conspicuous colour patterns on the body (Peng, Blamires, Agnarsson, Lin, & Tso, 2013;Tso, Lin, & Yang, 2004). There is remarkable variation in the colour patterns of web-building spiders, and the commonly seen yellow or orange mosaic pattern on the ventral surface of orb-weaver spiders can serve as visual lures to enhance foraging success (Blamires et al, 2011;Chuang, Yang, & Tso, 2007;Liao, Liao, Blamires, & Tso, 2019;Tso, Liao, & Huang, 2007;Tso, Tai, Ku, Kuo, & Yang, 2002; see also White & Kemp, 2015 for a review).…”