This is a public-interest archive. Personal data is pseudonymized and retained under GDPR Article 89.

Friendly worms or killer worms???

Nan Sterman said:


Very unsettling article in the Los Angeles Time today about damage
being done by red wigglers in the northern forests of the US.

Not red wigglers, Nan. The article specifically states Lumbricus terrestris, commonly known as the nightcrawler, here in Michigan, the Canadian nightcrawler, in Canada, dew worms, in the south, lob worms, and probably other names in other regions. Lumbricus rubellus has fewer common names that I am aware of, but redworm is certainly one of them. Some of the worms I have seen here in Michigan baitshops that they call leaf worms are Lumbricus rubellus.

Most people who use the term red wiggler are usually referring to Eisenia fetida which is a composting worm. Of the many articles I have read recently about worms removing of the thick duff layer of slowly decomposing leaves, none so far has mentioned Eisenia fetida. Other common names for this worm include manure worm, brandling, tiger worm. This worm is said to be epigeic, that is, is lives in the litter layer. It is not a soil dweller, but lives in environments where there is a lot of decomposing material, such as manure piles, compost heaps, and, under bark of dead trees. It is this species of worm that is most commonly used in worm composting systems because it processes a great deal of organic material, reproduces quickly in favorable environments, tolerates a wide range of temperatures and environmental conditions, and does not invest much energy in constructing and maintaining burrow systems.

Of course, I am concerned about this wide swath of publicity that Cindy Hale and others are giving to the phenomenon that they are finding. I don't dispute that Lumbricus terrestris removes leaves from forests. I have videotaped LT on rainy nights foraging for food, tails in their burrows, anterior end weaving around seeking a piece of dead grass, a piece of bark, a dead leaf, grasping ahold of it, then drawing it towards its burrow. In fact, nightcrawlers are known to create middens, or piles of leaves and twigs around the entrance to their burrows. Where there once was a 6 inch layer of leaves covering the ground, there may end up small piles of leaves every 14-16 inches or so. Push aside the pile and you will find the worm's burrow, which may extend several feet down into the soil. The worm brings subsoil minerals up from the deeper layers and mixes them with organic materials from the surface, performing functions of aeration, mixing, making channels that direct water deeper into the soil.

I myself love the thick leaf layer of beech-maple woods. Nothing delights me more than going for a walk in the spring in such a woods, finding the early hepatica present while snow is still there, and later, hillsides just blanketed with trilleum. It is this environment that Ms. Hale says is disappearing because of the worms that possibly escaped from fishermen and women who dumped their bait containers. I think I would be distressed to see my favorite woods denuded because of worm activity.

But it isn't all worms that are causing this. Most people think that a worm is a worm is a worm. Seeing such an article can make them think that having a home worm bin and letting some of those worms get out may not be so benign after all. Whereas they've been feeling good about taking responsibility for their own wastes by maintaining a colony of Eisenia fetida in a controlled environment, then using the vermicompost in their gardens thereby avoid using chemical fertilizers, and having healthier plants, to boot, they begin to question whether they're doing the right thing.

There is no question that earthworms do many good things for our soils. Sometimes the changes they bring about can be perceived as good, sometimes, bad. I think this points out our need for becoming more acquainted with the fact that different kinds of worms have different jobs to do. And the more precise one can be in identifying which worm is doing what, the more understanding people can have about what is going on, so they can make better decisions about how their own behavior affects our planet.

I share this in the spirit of Doreen's comments asking for more tips and information.

Mary Appelhof
_______________________________________________
gardenwriters mailing list
gardenwriters@lists.ibiblio.org
http://lists.ibiblio.org/mailman/listinfo/gardenwriters

GWL has searchable archives at:
http://www.hort.net/lists/gardenwriters

Send photos for GWL to gwlphotos@hort.net to be posted
at: http://www.hort.net/lists/gwlphotos

Post gardening questions/threads to
"Organic-Gardening" <organic-gardening@lists.ibiblio.org>

For GWL website and Wiki, go to
http://www.ibiblio.org/gardenwriters

Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index