Vermicompost 101 — Worm Life Cycle

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Early drawing of Eisenia fetida (source).

Many of us dissected worms in biology class and most have used them for fishing bait, but few know much about the lives of Eisenia fetida. Called “red wrigglers” by composters or “panfish” or “trout worms” by others, they belong to the Lumbricidae family of earthworms and are the only worms you should consider using in a compost bin. I did try this once with other types of worms, but it failed and we came home to find escaped worms all over the floor.

Reproduction

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Red Wriggler and cocoon (source).

Worms are hermaphroditic, that is, they are both male and female, however, they do require a partner for reproduction. Adult worms line up their clitella (the light-colored band near their front third; some call these worms “banded” worms because of this ring) with their partner’s genital openings and exchange sperm. Shortly after mating, the worms start laying about two cocoons per week. These little, whitish-yellow, blob-shaped cocoons typically hold three to six worms each and are found near the soil’s surface. They are formed from mucus secreted from the worm, which hardens around deposited reproductive material. The developing worms eat a nutritional “egg sac” during their gestation. The “egg stage” ends after about three weeks and the cocoon turns maroon. One to three weeks later, the juvenile worms emerge.

Life Cycle

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Close-up of worm showing clitella and bristles (source).

Worms are only a half an inch long and less than a sixteenth of an inch thick when they hatch. They spend a month or two as juveniles. As they mature, they develop the clitella band around their bodies about a third of the way down from their mouth. Once the ring is fully developed and turns orange, they can start mating.

Aside from reproduction, worms spend most of their lives eating half their body weight each day and moving through soil using an undulating motion and tiny bristles that help them grip the tunnel walls.

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The local 389 union of sanitation workers group photo (source).

I found no consensus on the red wriggler’s lifespan. Estimates vary from two to six years. This makes sense, as it would be difficult to identify individual worms and track them over their lifetime.

References:

Red Wriggler Supply
Uncle Jim’s Worm Farm
DenGarden
City of Euless, Texas
Encyclopedia Britanica


This is one article in a series of posts about vermicompost, or using worms in compost systems. Follow this link to see all posts in this series.

Check out these other resources:
Sustainable Table
Red Worm Composting
Composting Junkie
DIY Natural
Worm Composting HQ
City of Euless, Texas

 


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