FAQ Compost Worm -
Frequently asked Questions about the earthworms
Eisenia fetida und Eisenia andrei
Translation and Copyright:
Klaus Valentin, natuga - Natur und Garten http://www.natuga.de
The english version will be completed soon.
Do compost worms also eat normal earth or only rotting organic material?
Although the compost worms Eisenia foetida and Eisenia andrei are not commonly found in mineral grounds, scientific investigations show that they also eat mineral earth. However, they select an organic enriched fraction from the bulk soil (approximately by a factor 2), which is also typical for soil dwelling worms. Therefore, compost worms can also be used to clean contaminated mineral grounds.
References
Roel H. L. J. Fleuren, Tjalling Jager,Willem Roelofs, Arthur C. De Groot, Rob Baerselman and Willie J.G. M. Peijnenburg (2003) Pedobiologia 47, 670-675, Feeding behaviour of Eisenia andrei in two different field contaminated soils
Bolton, P. J., Phillipson, J. (1976) Oecologia 23, 225�245, Burrowing, feeding, egestion and energy budgets of Allolobophora rosea (Savigny)(Lumbricidae).
Can compost worms be used for decontamination of mineral soils?
Yes, because they eat mineral soils too. Experiments were done with the harbour sludge of Rotterdam.
Eisenia andrei is commonly used in standard toxcicity tests (OECD 1984) and in bioassays for contaminated soils (Cortet et al. 1999).
References
Roel H. L. J. Fleuren, Tjalling Jager, Willem Roelofs, Arthur C. De Groot, Rob Baerselman and Willie J.G. M. Peijnenburg (2003) Pedobiologia 47, 670-675, Feeding behaviour of Eisenia andrei in two different field contaminated soils
Cortet, J., Gomot-De Vauflery, A., Poinsot-Balaguer, N., Gomot,
L., Texier, C., Cluzeau, D. (1999) The use of invertebrate
soil fauna in monitoring pollutant effects. European
Journal of Soil Biology, 35, 115�134.
How long will the material ingested by the compost worm be in his gut?
In adult compost worms (Eisenia andrei) appr. 3 to 4 hours, in juvenile worms appr. 11 to 13 hours. The scientists expected the opposite (a longer retention time for adult worms).
For Eisenia foetida 2.5 h werde measured at 25 �C, independent from the weight or the length of the worm. At 18 �C the retention time was appr. 3.5 h.
Lumbricus terrestris showes a retention time of 20 h.
Other worm species 11 to 13 h (Lumbricus festivus, Lumbricus rubellus, Allolobophora caliginosa).
References
Roel H. L. J. Fleuren, Tjalling Jager, Willem Roelofs, Arthur C. De Groot, Rob Baerselman and Willie J.G. M. Peijnenburg (2003) Pedobiologia 47, 670-675, Feeding behaviour of Eisenia andrei in two different field contaminated soils
Parle (1963) Journal of General Microbiology 31, 1�11
Hartenstein, F, Hartenstein, E., Hartenstein, R. (1981) Gut load and transit time in the earthworm Eisenia fetida. Pedobiologia 22, 5�20
Hendriksen, N. B. (1991) Gut load and food-retention time in the earthworm Lumbricus festivus and L. castaneus: A field study. Biology and Fertility of Soils 11, 170�173
Piearce, T. G. (1978) Gut contents of some lumbricid earthworms. Pedobiologia 18, 153�157
How do compost worms muliply?
Like all earthworms, compost worms have female and male gender organs (hermaphrodite). If they pair off, the genitals come mutually to narrow contact. These are localized in the wide rings (clitellum) of adult worms. This ring walks in the course of the next days on and on to the back and is shored up, in the end, so that a yellowish cocoon originates which has the form a lemon. After a certain time, out of this small mites are slipping.
References
Jorge Dominguez, Alberto Velando, Manuel Aira and Fernando Monroy (2003) Pedobiologia 47, 530-534, Uniparental reproduction of Eisenia fetida and E. andrei (Oligochaeta: Lumbricidae): evidence of selfinsemination
How often does a conception take place with the mating of compost worms?
It comes to 61% of the matings to the transfer of sperm. Of it a mutual transfer of sperm takes place in 88.2% of the cases, in 9.8% the transfer occurred only in one direction. Merely in one case a selfconception occurred.
References
Jorge Dominguez, Alberto Velando, Manuel Aira and Fernando Monroy (2003) Pedobiologia 47, 530-534, Uniparental reproduction of Eisenia fetida and E. andrei (Oligochaeta: Lumbricidae): evidence of selfinsemination
Is a self-fertilization also possible with compost worms?
Although reported very often with earthworms, a self-sperm transfer could be clearly documented in 2003 for the first time. This occurs very seldom and was observed with Eisenia foetida. Selfconception is an extreme form of inbreeding. The genetic diversity is lowered what normally leads to a reduction in fitness of the species. For this reason mechanisms of self-incompatibility have been developed in many species.
References
Jorge Dominguez, Alberto Velando, Manuel Aira and Fernando Monroy (2003) Pedobiologia 47, 530-534, Uniparental reproduction of Eisenia fetida and E. andrei (Oligochaeta: Lumbricidae): evidence of selfinsemination
Jarne, P., Charlesworth, D. (1993) The evolution of the selfing rate in functionally hermaphrodite plants and animals. Annual Review of Ecology and Systematics 24, 441-466
Which compost worm multiplies faster? Eisenia foetida or Eisenia andrei?
Scientific investigations from the year 2003 showed that Eisenia andrei multiplies much faster under the elective conditions of the study. The percentage of the worms, that produced cocoons was substantially higher (33% compared with 3.5%). Also the number of the produced cocoons was higher with Eisenia andrei, likewise the slip rate of the mites from the cocoons. The life ability of the cocoons was possibly equally high with both species.
References
Jorge Dominguez, Alberto Velando, Manuel Aira and Fernando Monroy (2003) Pedobiologia 47, 530-534, Uniparental reproduction of Eisenia fetida and E. andrei (Oligochaeta: Lumbricidae): evidence of selfinsemination
What do eat compost worms?
Fungi are probably a primary source of food for many earthworm species. Rotting material from plants, which is richly colonized with it, is the most popular "meal" for th worms.
References
Edwards, C. A., Fletcher, K. E. (1988) Interactions between earthworms and microorganisms in organic-matter breakdown. Agriculture, Ecosystems and Environment, 24, 235-247
Flack, F. M., Hartenstein, R. (1984) Growth of the earthworm Eisenia foetida on microorganisms and cellulose. Soil Biology and Biochemistry 16, 491-495
Morgan, M. H. (1998) The role of microorganisms in the nutrition of Eisenia foetida. In: Edwards, C. A., Neuhauser, E. F. (eds) Earthworms in waste and environmental management. SPB Academic Publisher, The Hague, pp. 71-82
Schönholzer, F., Hahn, D., Zeyer, J. (1999) Origin and fate of fungi and bacteria in the gut of L. terrestris L. studied by image analysis. FEMS Microbiology Ecology 28, 235-248
Slows the composting process down because the fungi in the compost are eaten by the worms?
On the contrary, in the general, it is even accelerated. More diverse fungal communities inhabited earthworm-processed
substrates than were found in fresh substrates.
This, although it is generally believed that fungal hyphae are destroyed and may be a preferred food source for earthworms.
Worms probably accelerate the composting process by both grazing and dispersal, and indirectly by their effects on the substrate (comminution, burrowing and casting).
References
Václav Pizil and Alena Nováková (2003) Interactions between microfungi and Eisenia andrei (Oligochaeta) during cattle manure vermicomposting. Pedobiologia 47, 895-899
Brown, G. G. (1995) How do earthworms affect microfloral and faunal community diversity? Plant and Soil 170, 209-231
Schönholzer, F., Hahn, D., Zeyer, J. (1999) Origin and fate of fungi and bacteria in the gut of L. terrestris L. studied by image analysis. FEMS Microbiology Ecology 28, 235-248
Can earthworms nibble at living roots?
No! The earthworms to which also the compost worms belong, attack no living roots. They live on the dead plant material colonized richly with micro-organisms. In addition, they have no tools (teeth, grater plates or other things) by which they could nibble at roots. The earthworm in the flowerpot or plant patch does not harm the plants.
Are certain fungi preferred by earthworms as food?
Earthworms can make a good distinction between the different kinds of fungi. Lumbricus terrestris prefers Fusarium oxysporum and Mucor hiemalis, other tested mushrooms are only sometimes eaten or are avoided even completely. In case of the compost worm Eisenia foetida it was shown, that the black melanine containing fungus C. cladosporioides was the most attractive in contrast to Aspergillus niger which was the least attractive. For Eisenia andrei still no investigations were done.
References
Cooke, A. (1983) The effect of fungi on food selection by Lumbricus terrestris L. In: Satchell, J. E. (ed) Earthworm ecology from Darwin to vermiculture. Chapman and Hall, Marfenina, O. E., Ishchenko, I. A. (1997) Earthworms preference for microscopic fungi. Izvestiya Akademii Nauk, Seriya Biologicheskaya 4, 504-506 [in Russian]
Does a quicker worm composting take place if the plant leftovers are inoculated with certain fungi before?
This is possible, however, for the normal leisure gardener too exaggeratedly and also not necessary. Investigations proved, that a previous addition of A. flavus accelerates the growth of Eisenia andrei. Mucor sp. should accelerate the growth with five other earthworms. Nevertheless, with Eisenia andrei M. circinelloides shows the opposite effect.
References
Václav Pizil and Alena Nováková (2003) Interactions between microfungi and Eisenia andrei (Oligochaeta) during cattle manure vermicomposting. Pedobiologia 47, 895-899
Bonkowski, M., Griffiths, B. S., Ritz, K. (2002) Food preferences of earthworms for soil fungi. Pedobiologia 44, 666-676
Which role play composting worms besides the use as humus producer, fish bait and animal food?
The compost worms Eisenia fetida and Eisenia andrei play an important role in the ecotoxicological assessment of compounds in soil and are the recommended OECD earthworm test
species. This species has been used to examine the relative
toxicity and predict the short and long-term effects of toxic
substances on earthworm populations in field soil. The composting worm (Eisenia fetida) is representative
of three other species of earthworms (Allolobophora
tuberculata, Eudrilus eugenia, and Perionyx excavus). For Eisenia fetida a very large toxicological literature database is existing.
References
Robidoux et al. (1999) Acute Toxicity of 2,4,6-Trinitrotoluene in Earthworm ( Eisenia andrei), Ecotoxicology and Environmental Safety 44, 311-321
For which toxiticy test compost worms were applicated?
The compost worms Eisenia foetida und Eisenia andrei were applicated in soil invertebrate toxicity tests to assess the risk of contamination.
One example is the contamination of soil by energetic substances (TNT, RDX, HMX) to assess the ecological risk of a munitions manufacturing plant. TNT-spiked forest soil was lethal to oligochaetes (Eisenia fetida) at 150 mg/kg. A sublethal effect (i.e., weight loss) was observed at lower concentrations.
Other examples include heavy metals, polycyclic aromatic hydrocarbons and carbamate pesticides.
Carbaryl (1-naphthyl-N-methyl carbamate), a commonly used carbamate, kills earthworms rapidly.
E. andrei and Eisenia fetida seem to be exceptions as they have a high lethal threshold to this pesticide (Stenersen et al., 1992). However, enzyme activities showed changes at very low concentrations of carbaryl (12mg/kg soil). In cultivated soils concentrations from 232 to 525 mg kg/soils were found (WHO, 1994).
References
Robidoux et al. (1999) Acute Toxicity of 2,4,6-Trinitrotoluene in Earthworm ( Eisenia andrei), Ecotoxicology and Environmental Safety 44, 311-321
D. Ribera, J.F. Narbonne, C. Arnaud, M. Saint-Denis (2001) Soil Biology & Biochemistry 33, 1123-1130. Biochemical responses of the earthworm Eisenia fetida andrei exposed to
contaminated artificial soil, effects of carbaryl
Stenersen, J., Brekke, E., Engelstad, F., 1992. Earthworms for toxicity testing; species differences in response towards cholinesterase inhibiting insecticides. Soil Biology & Biochemistry 24, 1761-1764.
WHO, 1994. IPCS Environmental Health Criteria 153: Carbaryl. World Health Organization, Geneva.
The FAQ Compost Worm will be completed continously.
