Bark beetle? in Pines
- Subject: Bark beetle? in Pines
- From: M* <m*@googlemail.com>
- Date: Sun, 1 Feb 2009 08:03:39 +0100
|
Dear Pamela
Is the beetle about 4mm long, with a black
head and throat and chestnut-brown wings and legs? Is the white resin exuding
from the tree in the shape of a volcano? If yes, your beetle could be
Tomicus destruens Woll. The hole is made by the beetle to provide a nuptial
chamber, and while the female creates a gallery in which to lay her eggs the
male expels the resin. The larvae that emerge from the gallery, which is always
built vertical to the trunk, feed on the fibre that channels the sap, eating
outwards from the gallery, ie horizontally. Of course, if they get all the way
round the trunk that is the end of the tree.
But don't despair.
We had about 50 pine trees, each
of which had at least 50 volcanos. As the trees were old
with thick bark, we scraped around each of the volcanos to lay bare the hole
into the chamber and into this we injected a neat insecticide
with a syringe. A laborious and dangerous job as the trees were very tall. But
it worked. In spite of the massive infestation, we didn't lose one of the
trees we treated. We DID lose two trees, which we found in a postmortem to have
been attacked by beetles (Orthotomicus erosus Woll) that don't leave a
volcano.
So, be grateful for the volcanos.
Assuming that you save your trees and are
interested in preventive measures, the best thing you can do is keep your trees
healthy and free of processionarias (the beetles like to attack old/sick
trees) and burn any prunings or fallen trees (the beetles are attracted by
the the smell).
Andrew Beith
Mallorca, Spain
|
- Next by Date: RE: The over enthusiastic gardener
- Next by thread: RE: Bark beetle? in Pines