Red wigglers (Eisenia foetida) are one of the most popular worms to use in composting systems. In part, this is due to their rapid reproduction rate.
When red wrigglers mate, they produce small, yellow sacs called cocoons. Sexually mature wrigglers can produce between two and four cocoons a week. The cocoons take between four and a half and 11 weeks to hatch. On average, three hatchlings emerge from each cocoon.
Age of Maturity
Red wigglers reach the age of maturity at approximately 3 months old. According to the City of Euless' worm composting page, once red wigglers have matured they will develop a "bulbous gland about one-third of the way down its body called the clitellum." Once the clitellum appears, the wiggler is able to reproduce.
Rate of Reproduction
Though it takes two red wigglers to mate, each wiggler will produce its own cocoon. Assuming an average of three cocoons a week, with an average of three hatchlings per cocoon, one wiggler can produce approximately 468 hatchlings per year. As the hatchlings mature, they will produce cocoons of their own, rapidly increasing the wiggler population.
Climate Control and Reproduction
Cold weather can delay sexual maturity in red wigglers. According to Vermicoast, for optimum reproduction rates, soil should be kept at 65 to 80 degrees Fahrenheit and "moist to the touch, but not dripping."