JJ-CR 蜘蛛俠－AT資訊站

大陸人真是非常之牛!

蜘蛛網的那題似乎被他們找到原文出處

題目:

Many organisms convey false signals to mislead their prey or predators.Some orb-weaving

spiders build conspicuous structures on webs called decorations. Web decorations and spider

colorations are both suggested to be important signals involved in interactions between spiders

and other organisms. There are several hypotheses about the functions of signaling by decorations,

among which prey attraction had received much support, but empirical evidence regarding predator

defense is controversial. In this study, we conducted field experiments to investigate the effects of

spider decoration and coloration on insect interception rates of webs built by Argiope aemula and to

evaluate whether presence of decorations may decrease predation risk of spiders. Decorated webs with

spiders present had the highest prey interception rate, followed by undecorated webs with spiders,

and then undecorated webs without spiders. Such results indicated that decorations of Argiope spiders

functioned as visual lures, and so did spiders’ bright body colorations. In the field, almost all wasp

attack events occurred on medium-sized spiders rather than on large ones. Moreover, medium-sized

Arg. aemula on decorated webs received far more attacks than those on undecorated webs. Results

of this study thus show that the signals conveyed by decorations can visually lure prey but at the cost

of an increased predation risk.

牛大們找到的原文:

predation pressure of medium-sized Arg. aemula spiders is
much higher than that of large individuals. When Arg. aemula
spiders are very small, they build webs deep within the vegetations.
Previous studies showed that the predatory wasps were
not generalist predators but searched for prey of a specific size
range (Elgar and Jebb 1998). So, the observed higher magnitude
of attacks on medium-sized Arg. aemula indicates that
spiders of this size class are preferred prey of wasps in our
study site. Our field census showed that all size classes of
Arg. aemula exhibited a similar building frequency of decorated
webs. Because decorating the webs greatly increases
the prey intake of spiders, the high frequency of decoration
building in medium-sized Arg. aemula might reflect their strategy
to maximize prey intake to speed up the growth rate, even
at the cost of increased predation risk.
Because large Arg.
aemula are rarely attacked by wasps, if juvenile spiders develop
quickly and grow into a certain size as soon as possible, they
could shorten the vulnerable period.