Eisenia fetida and Eisenia Andrei are the proper Latin names of the worms commonly known as red wigglers. The 2 species are anatomically identical but cannot breed to create hybrids (J. Dominguez et al. 2004). Eisenia Andrei are said to be sometimes darker pigmented than Eisenia fetida, this isn’t necessarily a reliable identifier between the 2 species and is irrelevant for our needs in composting.
Red wigglers have some distinctive features that can help identify them.
- The clitellum on an adult begins at segment 25 or more commonly 26
- The clitellum covers 6-8 segments
- They always have a striped banding between segments (sometimes less distinctive than other times)
- Red wigglers have a lighter coloured tail than head, ranging from yellow to almost orange.
- fully grown adults are between 2 and 4 inches (5-10cm)
- If in the wild they will be found in leaf litter or manure and compost piles, never in soil
- When handled or frightened they exude a yellow smelly fluid (fetid smell)
Eisenia fetida and Eisenia Andrei are an ideal worm for beginning composters
- They have a wide temperature tolerance 35-85F (2-30C)
- They tolerate moderate handling
- Red wigglers reproduce quickly
- Red wigglers generally stay in a bin well
- They tolerate high population densities
- They compost quickly and have large appetites.
There are a few drawbacks:
- They’re size is limited to smaller than most want for bait.
- Their small size makes more work in extracting worms from compost
All in all true red wigglers are an excellent choice for beginner composters. Knowing how to identify that you’ve received the correct species when ordering may save you some grief.
A special thank you to The Little Worm Farm for allowing use of the photograph in this post.