Insect view of orb spider body colorations

Abstract

Visual signals are important cues involved in the interactions between orb web spiders and their insect prey and predators, and body coloration is a commonly seen visual signal of orb web spiders. Realizing how spider colorations are viewed by insects interacting with these spiders plays a key role while studying functions and underlying mechanisms of these visual signals. Besides, because of the recent advancement of analytical methods and equipment, researchers are beginning to explore the functioning of orb web spider visual signals in the dim light condition. In this chapter, I will describe methodologies quantifying how colorations are viewed from the eyes of insects. The functions and potential selection factors shaping the design of orb web spider visual signals will also be discussed based upon empirical evidence accumulated so far. All these issues will be addressed in diurnal as well as nocturnal context. The chromatic properties of bright body parts of orb web spiders from a wide array of taxa resemble that of food resource diurnal and nocturnal insects are searching for, and therefore, these traits serve as visual lure to enhance foraging success of spiders. Brightly colored orb web spiders from several families exhibit both high- and low-contrast body parts, and such coloration pattern seems to reflect a trade-off between pressures of prey attraction and predator avoidance.