Q.
My Italian cypress started to lose their color and then die. Upon inspection of
the trunk, I saw borers in them. Borers seemed to take place within two months
or so and killed a few mature trees. I treated them with Bayer Tree and Shrub
Insect Control but wanted to know if there is anything else I can do to help
save them.
My Italian cypress started to lose their color and then die. Upon inspection of
the trunk, I saw borers in them. Borers seemed to take place within two months
or so and killed a few mature trees. I treated them with Bayer Tree and Shrub
Insect Control but wanted to know if there is anything else I can do to help
save them.
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| Borer damage found in Italian cypress trunk |
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| Bora damage found in another Italian cypress trunk |
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| Suspected board damage found in Italian Cypress |
A.
Damage from borers or boring insects is typically a slower progression than a
couple of months unless the plants are small. You are right, the progression in
many plants is a change in color from a vibrant green to a dull, gray green
color as the limb and leaves are dying from a lack of water.
Damage from borers or boring insects is typically a slower progression than a
couple of months unless the plants are small. You are right, the progression in
many plants is a change in color from a vibrant green to a dull, gray green
color as the limb and leaves are dying from a lack of water.
My guess is borer damage to your
trees started before this year. Internal damage to the trunk from borers can be
present for several years before enough damage has accumulated to result in the
death of older trees. If trees are growing vigorously, they can recover from
light borer damage on an annual basis.
trees started before this year. Internal damage to the trunk from borers can be
present for several years before enough damage has accumulated to result in the
death of older trees. If trees are growing vigorously, they can recover from
light borer damage on an annual basis.
This color change due to damage starts
in midsummer when air temperatures begin to heat up and plants require more
water. Damage from boring insects begins in mid-spring (March) but get
progressively more intense as these insects become larger and more voracious
feeders. By midsummer (June and later) internal
damage to limbs and the trunk can be extensive, unrecoverable by the plant, and
the supply of water from the roots is cut off.
in midsummer when air temperatures begin to heat up and plants require more
water. Damage from boring insects begins in mid-spring (March) but get
progressively more intense as these insects become larger and more voracious
feeders. By midsummer (June and later) internal
damage to limbs and the trunk can be extensive, unrecoverable by the plant, and
the supply of water from the roots is cut off.
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| Homeowners have this product available for borer control containing Imidacloprid in the active ingredients. It comes in other names as well. It is always best to check the active ingredients to make sure. Apply it late spring after any flowering has occured to avaid possible problems with honeybees. This chemical has been implicated, not proven, in colony collapse of honeybees. The safest way to apply it in our environment is a soil drench. Always read the label before applying any chemical. |
You chose the correct insecticide to
use but it was probably applied too late. The best time to control boring
insects with these types of insecticides is in mid spring when they first
become active.
use but it was probably applied too late. The best time to control boring
insects with these types of insecticides is in mid spring when they first
become active.
Consider using pesticides as a last
resort because they can be a bit like “whack-a-mole” and contribute to other
pest problems. Death of boring insects can happen in a few days when systemic
insecticides are applied as a liquid drench to the soil.
resort because they can be a bit like “whack-a-mole” and contribute to other
pest problems. Death of boring insects can happen in a few days when systemic
insecticides are applied as a liquid drench to the soil.