     |
 |
Tree
and Shrub Problems - Moths |
Adult gypsy moths don’t
cause much harm to trees but caterpillars (the immature form of
the moth) are another story. Like most caterpillars, gypsy moth
caterpillars are ‘eating machines’ whose consume as
much as they can, as quickly as they can before they become adults.
This caterpillar feeding period lasts seven to ten weeks. Unfortunately
for homeowners, gypsy moth caterpillars primarily feed on the leaves
of many types of trees and shrubs. 
Gypsy moths are capable of feeding on over 500 different species of trees and plants, but they have a particular fondness for oak trees. Although gypsy moths can exist at relatively low population levels for years at a time, sometimes their populations explode. This occurs for various reasons (favorable weather conditions or a lack of predators, for example). This rapid swelling of population size is called an "outbreak". Since a single gypsy moth caterpillar can consume 11 square feet or more of vegetation during its lifetime, the presence of thousands or even millions of caterpillars can severely affect trees. During large outbreaks, trees are virtually stripped of their leaves by hungry caterpillars within a few days. Defoliated trees are left looking as they would in deep winter with bare, leafless branches.
Weakened trees and shrubs, especially those in urban settings, are more susceptible to attack by opportunistic diseases and organisms such as armillaria root rot and two-lined chestnut borers. In addition, the tree’s growth rate is impaired, which affects its chances for survival during the following years. If a tree loses more than 50% of its leaves (for any reason) for more than two years in a row, it will certainly be weakened and may not survive. |
Although
most trees will re-grow new leaves (refoliate) before summer’s
end, the energy used to accomplish regrowth stresses the tree
and drains its reserves.| © 2008 Ace Landscaping Services Inc. All rights reserved. |