Birch trees are a beautiful addition to any landscape.
Unfortunately they can be 
susceptible to diseases
such as birch leafminor. The birch leafminor larvae causes damage to the tree by burrowing in to the birch tree leaves for nutrients. You can see signs of the larvae as small green spots on the leaves, these spots change to ugly brown patches after some time. Birch leafminer will rarely kill a tree but certainly weakens birch trees and they end up looking less attractive.
Birch LeafMiner Cycle
The Birch Leafminer Cycle Leafminer season in Calgary begins in late April to the end of May , small grayish grubs begin to feed on the birch leaves. During June or July larvae fall to the ground and begin to pupate. Adults, the small fly insects develop at this point and emerge a couple weeks later. In one season there can be as many as four generations of birch leafminer.
Treating Your Birch Tree
Effective treatment or control of birch leafminer can often be achieved through the use of systemic herbicides early on. Herbicides are less effective if the larvae are already inside the leaf. There is currently no effective biological treatment for the birch leafminer Spinosad is a relatively new insecticide and has shown good results when applied early. Unfortunately it is not available in Canada so Canadians are force to order it from the U.S. It is fast becoming the most popular choice as it has proven non-toxic to humans and animals. Be sure to apply this insecticide early on in spring at the first sign of infestation. Apply again in July during the beginning of the next generation of Birch leafminer.
Click here for more landscaping Calgary