Spider identification

Eggs and egg sacs

Egg development in spiders is greatly affected by temperature, but some approximations can be made for time of development. After egg deposition, the eggs inside the protective egg sac are typically round, white, individual entities that roll around like little ping pong balls inside a bag. Within a few days, the spider develops. After about 1 week, legs can be seen, and within about 2 weeks, the spiderling hatches from the egg. At this point, the spiderlings are usually unpigmented, unable to move around easily, and live off nutrients in the yolk from their egg. This stage is the first instar; all spider species undergo their first instar completely inside the egg sac. About 3 weeks after egg deposition, the spiderlings complete their first molt inside the egg sac and enter the second instar. Now the spiderlings have acquired some pigment (except for those species that are naturally pale such as the yellow sac spiders), are mobile, and are preparing to exit the egg sac. One can usually determine when spiderlings are in the second instar and are preparing to emerge quite easily because the darker pigment of older spiderlings is visible through the silk of the sac.