Variation and possible function of egg sac coloration in spiders

Egg sac construction and camouflage behaviors of Deinopis cf. cylindracea (Araneae: Deinopidae)

“…The brown color and spherical shape of egg sacs recorded in D. cf. cylindracea have also been observed in other Deinopis and Menneus species (Baum 1937;Coddington 2005;Coddington et al 2012;Barrantes et al 2013Barrantes et al , 2014 and may be a conserved trait at the family level (Coddington et al 2012).…”

“…; species that can perceive UV wavelengths would likely be able to distinguish between brown egg sacs with low and high UV chroma. In contrast, silk of the egg sacs of spiders in Uloboridae, (the sister family of Deinopidae) such as Zosis geniculata (Olivier, 1789), have low UV reflectance and high red reflectance (Barrantes et al 2013). High red reflectance of egg sacs has presumably evolved within these families to reduce the visual contrast of the egg sacs against the background, as they blend in with the surrounding structures of similar coloration.…”

“…Their outer layer is often the hardest one and has a very compact consistency. Occasionally it is concealed in debris, a behavior that has presumably evolved to reduce the visibility of egg sacs to natural enemies (Barrantes 2007;Barrantes et al 2013) The egg sac coloration varies widely among spider species; however, there is no information on the pigments responsible for different colors or their roles in camouflage (Barrantes et al 2013). The effectiveness of camouflage depends on the color, shape, decoration, oviposition substrates, and specifically the contrast of the outer layer of egg sac against the visual background (Craig 2003;Bauer et al 2019).…”

Spider Parental Care and Awe-Inspiring Egg Sac (Cocoon)

“…Other sparassids, the Delana cancerides (Walckenaer, 1837) (Sparassidae), for example, produces creamish white egg sac (diameter 19-22 mm) which turns dull brown color camouflaging with pseudostems in banana agroecosystem may reduce conspicuousness [18]. Studies have shown that spectral characteristics of the egg sac reduce conspicuousness against the background and low environmental light available may help to camouflage [44]. Nephila clavipes (Linnaeus, 1767) (Araneidae) constructs a golden yellow egg sac 2.5 to 3 cm in diameter consisting of several hundred eggs [45].…”

Fine Structural Characteristics of the Chorionic Microspheres on the Egg Surface of the Orb Web Spider Trichonephila clavata

“…Most spiders wrap their eggs in cocoon silk derived from the tubuliform silk gland (Foelix 2011). The cocoon silk is known to protect the eggs from predators and parasites (Austin 1985), reduce the predator's perception of the background (Barrantes 2013), decrease desiccation during a long overwintering period (Hieber 1992), and regulate the temperature (Hieber 1985). Some species, such as Theridiidae and Lycosidae, build their cocoon as a compact "eggcase", while others like T. edulis use a loose "eggpad" (Grim and Slobodchikoff 1982;Humphrey 1995).…”