William F. Lyon
The earthworm has many enemies, including mites, ants, centipedes, earwigs, nematodes, fly larvae, termites, springtails, sowbugs, snails, slugs, millipedes, spiders, birds, rats, mice, moles, gophers, toads and snakes. The best method to avoid problems is to not "overfeed" your earthworms. Earthworms are not good large-scale garbage disposal subjects. Before earthworms can use garbage, it must be decomposed by bacteria in order to be ingested and digested. Excess feeding will sour, creating acid conditions and attract several kinds of undesirable mites, insects, etc.
Small, brown mites occasionally infest worm beds by the millions. Although live, healthy worms are not harmed; the injured or dead ones are eaten. These mites can become so populated that most of the food is eaten in one night. After wetting the bed, mites swarm to the surface, often covering the entire bed.
Red mites are parasites that suck earthworm blood while they are attached. They also pierce and suck fluid from earthworm egg capsules.
Water earthworm beds heavily (do not flood). Mites, insects and other pests will move to the top of the bed. Use a torch (hand-held propane, butane or equivalent) to burn or scorch the bed top. Repeat procedure every two to three days if needed. Earthworms are not damaged.
Place watermelon or cantaloupe rind or potato slices on the bed. Mites and insects will accumulate in large clusters on the rind and slices due to the food sweetness. Rinds, slices or peels can then be removed and dropped in water or buried elsewhere.
The use of calcium carbonate used in beds can prevent mite, insect and pest buildup. Maintaining a near neutral or basic condition prevents the acid conditions necessary for various pests to live and reproduce.
An excellent treatment for mites is to use crushed limestone (calcium carbonate) to relieve the acid condition. Use limestone dust such as used on football or baseball fields. Do not use slaked lime or any type of "hot" lime, quicklime or agricultural lime. Dolomitic limestone will work well.
Another method is to lightly dust the top of the soil with sulfur to kill mites; this will not injure worms. However, in time the bed may become acidic, reducing earthworm populations.
Control the white nematode with calcium carbonate to control acidity. Turning and aerating the bedding will help.
Reduce the rate of feeding and apply sufficient water to prevent heating. Larvae or maggots of the house fly are found in beds where the protein content of feed is too high and when heavy feeding causes the bed to become too hot.
Various mole poison baits and traps will reduce moles burrowing through outdoor beds and stop them from eating earthworms. Some feel that caster oil plants grown beside beds keep moles away.
Mice and rats occasionally raid earthworm beds. Control rodents with permanent bait stations around beds. Rodent baits have given control. Screens can also keep rats, mice and other pests out of earthworm beds.
For more specific practices of controlling earthworm enemies, contact:
Smith's Worms
All educational programs conducted by Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race, color, creed, religion, sexual orientation, national origin, gender, age, disability or Vietnam-era veteran status.
Keith L. Smith, Associate Vice President for Ag. Adm. and Director, OSU Extension.
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