1. Non-Susceptibility of Earthworm Eisenia fetida to the Rhabditid Nematode Phasmarhabditis hermaphrodita , a Biocontrol Agent of Slugs.
- Author
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De Nardo, Elizabeth A. B., Sindermann, Anne B., Grewal, Sukhbir K., and Grewal, Parwinder S.
- Subjects
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EISENIA foetida , *EARTHWORMS , *NEMATODES , *ORGANISMS , *PHYSIOLOGICAL control systems - Abstract
The rhabditid nematode Phasmarhabditis hermaphrodita is a lethal parasite for slugs that is sold commercially in Europe under the trade name Nemaslug™. We evaluated the effects of P. hermaphrodita on the earthworm Eisenia fetida ( Savigny ). Adults of E. fetida were exposed in one-liter glass beakers to P. hermaphrodita at three concentrations (1×, 10× and 50× of the field recommended rate of 3×10 9 billion nematodes/ha) during a 14-day period in an artificial soil substrate. The average body weight, burrowing behavior, mortality and other clinical signals of the earthworms were recorded at 0, 7, and 14 days after exposure to the treatments. In addition, injured earthworms (posterior ends removed) were exposed to the 10× field recommended rate of the commercial formulation. Neither intact nor injured E. fetida showed susceptibility to the slug-parasitic nematode P. hermaphrodita during the 14 days of exposure even at concentrations 10 and 50 times higher than the label dose. However, the worms in the attenuated control (autoclaved formulation) had higher mortality and lost less weight compared to the other treatments. Under the conditions of the test, we conclude that the use of the commercially available strain of P. hermaphrodita is safe to E. fetida . [ABSTRACT FROM AUTHOR]
- Published
- 2004
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