Earthworms are amazingly beneficial

Published 6:15 am Tuesday, May 1, 2018

Since I enjoy an occasional fishing trip and dabble with a garden, I thought I knew a fair bit about worms. Little did I realize what amazingly beneficial little guys they are. The two most common worms we have in our area are the nightcrawler and the redworm. The nightcrawler is the larger of the two and can be 11 inches long and thick as a pencil.

Earthworms can be found in any moist, rich soil. Nightcrawlers build permanent vertical tunnels that can be 4 feet in depth, while redworms only build horizontal temporary tunnels in the top 10 to 12 inches of soil. Redworms tend hang out in decomposing organic matter, while nightcrawlers are usually found in pure soil.

The earthworm body is reddish brown and divided into ring-like segments. The head is the narrow, pointed end, while the tail end is more fat and blunt. The only other noticeable features are swollen sections along the body, which are sex organs. Worms have bristles on their underside that provides traction for movement through the soil, and if you pick one up you may feel these. Earthworms cannot see or hear, but are very sensitive to light and vibrations.

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Their lifestyle consists mostly of tunneling and eating decaying organic matter. As they eat they also ingest large amounts of soil, and it is estimated an earthworm can eat and discard its own weight in food and soil each day. This digestion of organic matter and spreading it underground greatly enriches the soil, while the tunneling improves aeration and drainage.

Earthworms are hermaphroditic, having both male and female sex organs. The eggs of one individual must be fertilized by the sperm of another. When mating, two earthworms are bound together by sticky mucus while each transfers sperm to a receptacle of the other. After mating they both form a cocoon of sorts, which is then shed off. As worm sheds its cocoon, its own eggs are mixed with sperm obtained from the other worm. The cocoon is finally discarded into the soil with the now fertilized eggs inside. Baby worms emerge about four weeks later, reach adulthood in 60 to 90 days, and attain full growth in about one year.

One scientist estimated that one acre of soil may contain 63,000 earthworms, which in a year’s time may bring 18 tons of soil to the surface and in 20 years create a new 3-inch layer. No one argues about the tremendous virtue of worms to our soil and ecosystem.

Worms are consumed by many birds and animals and provide humans with fish bait. They can be found on the soil surface on rainy summer nights or dug out of compost piles. Some fishermen use vibration to drive worms to the surface by sawing on small trees out in the woods with an old handsaw.

Steve Roark is a retired area forester from Tazewell, Tennessee.