Egg sac construction by folding dead leaves in Pozonia nigroventris and Micrathena sp. (Araneae: Araneidae)

Possible functional significance of spigot placement on the spinnerets of spiders

“…They seem to be slightly sticky when they emerge, because some lines in egg sacs are covered with liquid (Kullmann 1975 on an araneid, a mimetid and a deinopid; Stern & Kullmann 1981 on a theridiid), and they very frequently adhere at least weakly to each other, even though the spider only briefly dabs her abdomen to the egg sac during construction; the dabs are not accompanied by short pauses, as when piriform discs are produced (Kullmann 1961;Gheysens et al 2005;Moya et al 2010). It thus appears that piriform silk is not used to hold sticky cylindrical gland lines together; this is consistent with morphology, as the cylindrical gland spigots are downstream with respect to the piriform gland spigots (Fig.…”

HowMicrathena duodecimspinosa(Araneae: Araneidae) uses the elasticity of her dragline to hide her egg sac

“…Spiders' defenses against these dangers include physical protection by covering the eggs with silk (e.g., Gheysens et al 2005) or with other materials such as leaves or soil (Austin 1985;Moya et al 2010;Suter et al 2011). This note describes a hitherto undescribed technique that the araneid Micrathena duodecimspinosa (O. P. Cambridge, 1890), used to insert a package containing her eggs into the leaf litter on the forest floor, and that resembles the behavior of the congeneric Micrathena sp.…”

“…This note describes a hitherto undescribed technique that the araneid Micrathena duodecimspinosa (O. P. Cambridge, 1890), used to insert a package containing her eggs into the leaf litter on the forest floor, and that resembles the behavior of the congeneric Micrathena sp. (Moya et al 2010).…”

“…as they lowered their egg sacs (also wrapped in dead leaves) into the leaf litter (Moya et al 2010). That study speculated that these manipulations of egg sacs serve to insert them deeper into the leaf litter.…”

Variation and possible function of egg sac coloration in spiders

“…Some spiders (e.g., lycosids and pisaurids), attach the egg sacs to their chelicerae or spinnerets until the spiderlings emerge (Foelix 2011). Other spiders camouflage the egg sacs with silk stabilimenta (Herberstein et al 2000;Eberhard 2003), pieces of debris (Barrantes 2007), or wrap egg sacs in a leaf (Moya et al, 2010) to protect eggs against parasites and predators.…”