Halted by Worms
 |
| Click here to see the entire Calvin & Hobbes cartoon |
The
gardener's best friend, the earthworm, is great at protecting leaves from being
chomped by slugs, suggests research in BioMed Central's open access journal BMC
Ecology. Although they lurk in the soil, they seem to protect the plants
above ground. Increasing plant diversity also decreases the amount of damage
slugs do to individual plants.
Spanish
slugs (Arion vulgaris) are among the top 100 worst alien species in
Europe and are considered a pest almost everywhere. A team of scientists from
the University of Natural Resources and Life Sciences Vienna investigated what effect
the presence of earthworms and plant diversity would have on the amount of
damage these slugs caused.
Using
large incubators to simulate grassland environments the researchers could
regulate the diversity of plant species and time the introduction of earthworms
and slugs. They found that the presence of worms increased nitrogen content of
plants and reduced the number of leaves damaged due to slugs by 60%. Yet when
they compared leaf area damaged the researchers found slugs also ate 40% less
at high plant diversity than at low.
Explaining
their results Dr Johann Zaller, who led the study, said, "Our results
suggest that two processes might be going on. Firstly, earthworms improved the
plant's ability to protect itself against slugs perhaps through the build-up of
nitrogen-containing toxic compounds. "Secondly, even though these slugs are generalists they prefer widely available food and in high diverse ecosystems slugs eat less in total because they have to switch their diets more often since plants of the same species are less available.
"Therefore gardeners are to help protect earthworms by increasing plant diversity in the garden in order to keep slug damage low. In order to elucidate the mechanisms behind these complex interactions, all parts of an ecosystem need to be investigated."
Story Source:
The
above story is reprinted from materials provided by BioMed
Central Limited.
Note: Materials may be edited for content and length. For further
information, please contact the source cited above.
Journal Reference:
1. Johann G Zaller, Myriam Parth, Ilona Szunyogh,
Ines Semmelrock, Susanne Sochurek, Marcia Pinheiro, Thomas Frank and Thomas
Drapela. Herbivory of an invasive slug is affected by earthworms and
the composition of plant communities. BMC Ecology, 2013 (in
press) [link]
Need to cite this story in your essay, paper, or report? Use one
of the following formats:
APA
MLA
MLA
BioMed Central Limited (2013, May 12). Invasion of the slugs;
Halted by worms.ScienceDaily. Retrieved May 13, 2013, from
http://www.sciencedaily.com/releases/2013/05/130512201613.htm
