杏吧原创

BARK beetles sniff out their favourite trees, according to a team of
researchers at Simon Fraser University in British Columbia. The researchers hope
to use the beetles鈥� sense of smell to reduce the damage to forests that they
cause. Bark beetle infestations cost North America鈥檚 foresters billions of
dollars a year.

Dezene Huber, of the department of biological sciences, has shown that
mountain pine beetles (Dendroctonus ponderosae) and Douglas fir beetles
(D. pseudotsugae) can smell the volatile chemicals that the trees give off. The
beetles are attracted by the smell of their favourite trees and repelled by the
scents generated by others.

In the past, scientists looking for ways to control bark beetles have studied
the pheromones that prompt breeding adults to congregate. But Huber is one of
the first to examine the effects of the tree鈥檚 own scent. Huber鈥檚 colleague,
Regine Gries, identified the chemicals that give each species of tree its unique
smell. 鈥淲e are currently mostly interested in a set of fairly simple aldehydes
and alcohols,鈥� says Huber.

Field trials last summer indicated significant potential for protecting firs
by masking their scent with chemicals from other tree species, such as alder.
Small devices containing the false scent were fastened to the firs鈥� trunks.
鈥淲hat we want to do,鈥� Huber says, 鈥渋s disguise certain trees so the beetles will
bypass them and head elsewhere.鈥�

Huber sees potential for treating whole forests. During an infestation, a
鈥減ush-pull鈥� strategy could be employed using a scent to repel beetles from
valuable trees while laying false trails to attract them into areas that are due
for logging.