Each female constructs 5 to 15 egg balls, each of which contains 200 to 900 eggs. Young spiders emerge from the ball in 10 to 30 days. They are cannibalistic at this stage. Only a few nymphs from each egg mass survive. They require 2 to 3 months to develop into adults.
Older adults die the same summer or autumn after laying eggs.
The new generation of adults survives through the winter. Outdoors and in outbuildings, caution must be used to avoid being bitten. In fields of fruit or vegetable crops where these spiders are known to be a problem, gloves should be worn as a safeguard against being bitten. Black widow spiders can also be killed with pesticidal sprays.