Orb webs evolved primarily to capture prey, though they also have other functions. Recently, it has been argued that the orb web does not work as a functional unit, but instead some sections or components have presumably been shaped by selection to increase capture success of large prey (relative to the spider size). Changes in these components (e.g., an increase capture area) presumably compromise the design and function of other components (e.g., density of adhesive threads). In this study, we explore the changes in the design of orb webs throughout the ontogeny of two orb-weaving spiders of the genus Leucauge: L. mariana (Taczanowski, 1881) and L. argyra (Walckenaer, 1841). Small nymphs of both species construct webs with a relatively larger capture area and higher density of adhesive spiral loops compared to webs of larger individuals. In addition, small nymphs of L. argyra construct webs with more radii. These features probably increase the probability of capturing large prey. Some web features show different trade-offs in the two species. For instance, the number of adhesive threads increases with capture area in webs of L. mariana, but decreases in L. argyra. The density of adhesive threads in webs of both species decreases as the area of the web increases, but decreases faster in L. argyra. Thus, small nymphs are capable of optimizing different structural components of the web to increase the probability of capturing large prey, but the trade-offs between web features vary between species.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 45 • No. 2