Jumping spiders are common arachnids found across diverse habitats worldwide, from tropical forests to temperate regions. These fascinating creatures are known for their exceptional eyesight and unique hunting strategy, which involves stalking and pouncing on prey rather than relying on webs for capture. Like other spiders, jumping spiders reproduce by laying eggs, but the eggs themselves are typically encased within a protective structure crafted by the female.
Identifying the Egg Sac
When searching for jumping spider eggs, one is most likely to encounter the egg sac, a delicate yet resilient structure spun from silk. These sacs are typically white or off-white, sometimes appearing with a creamy yellow or yellowish-brown hue. The shape can vary, often described as a small, flattened disc, a lens shape, or a somewhat irregular, fluffy mass. Its texture is soft and papery.
Jumping spider egg sacs are generally quite small, usually only a few millimeters in diameter, often compared to the size of a pea or smaller than a quarter. For instance, the egg sac of a Phidippus audax can be about 9 mm (3/8 inch) in diameter. The individual eggs within the sac are tiny and translucent, rarely seen without disturbing the protective silk. An infertile sac might appear lighter in color or more yellow, and may not maintain its typical round shape.
Common Nesting Sites and Maternal Care
Female jumping spiders select hidden, protected locations for their egg sacs. These sites often include crevices, the undersides of leaves, inside curled leaves, or within sheltered corners of homes. They may also be found under rocks or within the female’s silken retreat, which serves as a shelter for molting, resting, and egg laying.
A defining characteristic of jumping spider reproduction is the female’s dedicated maternal care. The mother spider typically remains with or near her egg sac, actively guarding it against potential threats until the spiderlings emerge. This attentive behavior, often observed as she perches protectively over the silk sac, can be a key indicator of its presence.
Life Cycle of the Eggs
Once laid within the silk sac, jumping spider eggs undergo an incubation period before hatching. The incubation period varies depending on environmental conditions like temperature and humidity, typically ranging from one to four weeks.
Following incubation, tiny spiderlings hatch from the eggs while still inside the protective sac. These spiderlings resemble miniature versions of adult jumping spiders. They often remain within the sac or in close proximity to their mother for a short period, typically the first few weeks of their lives, before they disperse to begin independent foraging. A single egg sac can contain a variable number of eggs, ranging from a few dozen to several hundred. Females are also capable of producing multiple egg sacs over time.