Life Cycle of Black Widow Spider
Black widow mating occurs in springtime into early summer. In some cases, black widow females consume males after mating, feeding on them as sources of nutrients needed for egg fertilization. Female black widow spiders can produce several egg sacs in summer months. These sacs are tightly woven, silken cups and are protected fiercely by the female until they hatch.
Egg sacs are white, tan or gray in color and have a paper-like texture. They may be pear-shaped or globular. Each egg sac contains hundreds of eggs, from which hundreds of spiderlings emerge. However, only a handful of these young survive, as black widows are cannibalistic during the early stages of their lives.
Surviving spiderlings undergo molting stages known as instars. Many spiderlings overwinter as immatures, and then they mature fully the following spring. Although the expected lifespan of black widow spiders is one year, some specimens have been known to live up three years.