Unlike flowering plants, bracken ferns do not release any
odour signals to attract the enemies of their attackers for their own benefit
They dominated the earth for 200 million years and numerous
different species can still be found all over the world: mosses, horsetails and
ferns. Researchers from the Max Planck Institute for Chemical Ecology in Jena,
Germany, have now found out that bracken ferns (Pteridium aquilinum) do not
release any volatiles when they are attacked − unlike many of the now dominant
and evolutionary younger flowering plants. Such an emission of volatile
compounds may attract the pest insects’ enemies, such as ichneumon wasps or
predatory bugs, that parasitise herbivores. Nevertheless, volatile emission
could be also elicited in fern fronds, if they had been treated with plant
hormone jasmonic acid. Jasomonic acid induces the synthesis of volatile
substances in flowering plants. This suggests that ferns can in principle
mobilise this kind of defense reaction. However, they do not use this indirect
defense to fend off herbivores.