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Pinons: Profile of the top two killers
BLACK STAIN ROOT DISEASE
Q. What is it A vascular disease causes extensive black staining and damages the sapwood. Bark beetles tend to follow this disease and kill the tree. Q. What are the symptoms? A. Yellowing and browning of needles
Old needles drop
prematurely, crown appears thin
Resin may seep
along trunk
Abnormally small
cones
Bands of
jet-black wood at root collar and at roots
Q.
How does it spread?
A. Through root grafts and root contacts, and by insects that carry the spores. Affected trees are usually in a group.
Q.
What are the treatment options?
A. Plant junipers, spruce or true firs in areas with the disease.
Trenching between
trees may stop root-to-root spread if the trees on the other side
of the trench are disease-free.
"ENGRAVER" IPS BEETLE
Q. What
is it?
A. Ips are small, dark-colored bark beetles about the size of an uncooked rice grain. They frequently attack damaged or stressed trees. The ongoing drought is putting significant stress on trees and is considered the underlying reason for the major increase in ips populations.
Q. What
are the symptoms?
A. Pitch tubes (multiple small, popcorn-shaped masses of pitch scattered up and down the trunk that oozed out where beetles entered the tree. These are usually rusty red in color but yellow with time.
Frass, or boring
dust that resembles fine sawdust (usually rusty red in color but
can be lighter) that collects in bark crevices, branch crotches,
and on the ground around the base of the tree.
Fading of foliage
from green to straw-color, later turning red and then brown.
Blue-gray
staining of sapwood under the bark by bluestain fungi introduced
by the beetles.
Woodpeckers
chipping away the bark to get at the beetles beneath – does not
always occur.
Live ips adults,
larvae, and/or pupae and their galleries (tunneling) between the
bark and outer wood. Adults are black, callow (immature) adults
are tan to brown, larvae are white w/brown heads, and pupae are
white.
Q.
How does it spread?
Ips kill piñon by mass-attacking a tree, where they tunnel beneath the bark. There they mate, lay eggs, and the resulting larvae tunnel between the bark and wood. A new generation of beetles emerge to fly and infest new trees.
Q.
What are the treatment options?
Direct control measures usually involve identifying currently infested trees, then preparing them for treatment by felling, limbing, and cutting the trunks into lengths that can be easily handled.
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