This pest can be responsible for the premature browning of birch trees. The larvae feed on the inner green tissues of the leaf, causing a discoloured spot.
Feeding over several weeks causes the blemish to take on a blister-like appearance and can destroy much of the leaf. Heavy attacks repeated over several
years will cause stress, making the tree more susceptible to other problems. Since 1990, populations of a tiny wasp which selectively attacks the most
damaging birch leaf mining pest have developed and drastically reduced the problem in the Edmonton area.
The following tips will help you maintain a healthy birch tree that will be more resistant to any birch leaf miner attack:
- - Roots of birch trees need a cool, moist, shady location. proper site selection is crucial for a long, healthy existence.
- - Fertilizing is best done in early spring at the onset of the growing season. Lawn fertilizer applications around the tree may be sufficient.
- - Prune (June to July) any dead wood and remove the smaller of any branches that rub one another.
- - During the growing season, provide water during prolonged drought conditions. Thoroughly soak the area under and around the tree at least once a week if there is little rainfall.
- - To reduce the risk of mechanical damage from lawn mowers, weed eaters etc., do not have any sod immediately surrounding the tree trunk.