Mushrooms Fight Back - They Release a Natural Slug Repellant
Researchers at Humboldt State University found that when
slugs bite mushrooms, the mushrooms fight back by synthesizing
distasteful chemicals. This study started when the researchers were
collecting wild mushrooms in the coastal rain forests of the Pacific
Northwest. They noticed that some mushroom species had small bite
marks on their caps. It looked like these mushrooms had been tasted
and rejected by the giant banana slug, Ariolimax columbianus. To
find out why some mushrooms are eaten and others are not, they
studied the "sweetbread mushroom," Clitopilus prunulus. Slugs were
observed to briefly taste this mushroom before feeding on other
Like the name implies, the sweetbread mushroom is a highly
edible species found in North America and Europe and it is usually
cooked before human consumption. In a recent article, William Wood
and coworkers described how tissue disruption of raw mushrooms, like
that caused by munching slugs, released a slug repellant [Biochem.
Syst. and Ecol., 29, 531 (2001)]. A comparison of the volatile
chemicals in crushed and uncrushed mushrooms showed a 19-fold
increase of one chemical, 1-octen-3-ol. In laboratory tests, banana
slugs refused to eat lettuce that had been treated with similar
quantities of this chemical. This chemical is not found in mushrooms
commonly eaten by banana slugs.
To humans, 1-octen-3-ol, has a typical mushroom-like odor.
This chemical has been identified from many other species of
mushrooms, so its slug antifeedant activity may be wide spread in
nature. In mushrooms this chemical is biosynthesized from linoleic
acid. Besides repelling slugs, 1-octen-3-ol may protect mushrooms
from microbes trying to invade a wound inflicted by the slugs, since
it has also been shown to have antibacterial activity.
For further information contact:
Professor William F. Wood Phone (707) 826-3109
Department of Chemistry FAX (707) 826-3279
Humboldt State University E-Mail chem@...
Arcata, CA 95521, USA
More by Dr. Wood on mushroom odors at: