“I’ve been reading the newsletters you sent to me since I started raising my ANC worms sometime September last year. I am happy that I’ve learned a lot of things about raising worms except one thing, there average life span. Do they reach one year or two years or five years?” ~ Joselito
Hi Joselito – that’s a good question.
While I don’t have any specific information for African Nightcrawlers (Eudrilus eugeniae), I was able to dig up some info for worms in general, including our good friend the Red Worm (Eisenia fetida).
According to Edwards and Bohlen (1996), there tends to be a big difference in the lifespan of worms living in their natural habitat vs those living in protected cultures – such as the inhabitants of a worm bin. This makes sense given all the various natural and human created hazards that can occur in the ‘wild’.
Composting worms such as Red Worms living in an outdoor manure pile may have to contend with predation, lack of moisture, freezing temperatures in the winter, and loss of habitat (manure often gets taken away and spread on fields). Those living in a worm bin certainly can face their fair share of hazards as well (particularly if the owner of the bin is new to vermicomposting), but in general they live a more protected, stable live.
Edwards and Bohlen suggest (based on the research of others) that wild worms typically only live for a few months, while those in captivity can live as long as 4-8 years (or more). According to one study, E. fetida was found to survive for 4 1/2 years, while another (soil-living) species lived more than 10 years!
Not sure if I really answered your question, Joselito – but hopefully you now at least have a few new factoids to share at your next dinner party! 😉