Mercy landlord or good lodgers? The form of interaction between Argyrodes fissifrons and Cyrtophora.
The interactions between different species of spiders are usually described as competition, predation, or parasitism. Mutualistic interactions involving different species of spiders have rarely been reported. In this study, I examined the nature of interactions between the kleptoparasitic spiders, Argyrodes fissifrons, and their Cyrtophora host spiders. The body coloration of A. fissifrons is very conspicuous, while that of the Cyrtophora hosts is dark brown. Previous studies showed that conspicuous body colorations of spiders may function as visual lure to prey. In this study I tested whether the conspicuous body coloration of A. fissifrons functioned as a visual lure to attract prey to the webs of Cytophora hosts, and consequently benefited the hosts. I performed a field experiment in the summer of 2009, in which the presence of kleptoparasites was manipulated and prey catching rates of host webs were monitored by infrared video cameras. The presence of A. fissifrons increased the prey catching rates of Cyrtophora webs, no matter the host spiders were present or not. The result of this field experiment indicates that presence of A. fissifrons is beneficial to Cyrtophora hosts and the interactions between these two spiders might be mutualistic. In this summer, I tested whether the bright body coloration of A. fissifrons played an important role in this interaction by manipulating the chromatic properties of A. fissifrons in a field experiment. The bright body parts of A. fissifrons were covered by dark paint and the effect of such treatment on host webs’ prey interception rate and foraging of Cyrtophora hosts was monitored by infrared video cameras. The field experiment was completed but several hundred hours' video footages await further processing. The results of these two field experiments will help reveal whether there is a mutualistic interaction between Cyrtophora hosts and A. fissifrons mediated through conspicuous colors of the latter.
Updated: Mar-10-2014 01:22:51 (Taiwan, GMT+08:00).