White birch

Description:

This Betula Papyrifera Marsh, commonly known as white birch, is located in the south facing front yard of a house on 52 st. Olds AB. The tree is approximately 30 ft. tall, with a 20 ft. canopy. It is positioned 10 ft. north of the paved side walk, and 15 ft away from the foundation of the house, and growing in the lawn. The soil in this area is well drained and sandy. The tree receives full sun most of the day, it has no other trees within 30 ft. of it, and it is partially sheltered from the north wind by the house. This white birch has a dead crown possibly from a previous years snow damage. There are scattered small pecked holes along its trunk, from woodpeckers foraging for food. And approximately 75% of the foliage bears the scars from leafminer larvae (Fenusa Pumila). Although hard to notice during autumn, as the changing colours hide the already damaged leaves, on a closer look, the remaining leaves have been hollowed out, and contain spots of papery thin almost see-through dead tissue where the leafminer larvae have lived. The birch Leafminer is a type of sawfly, The adult fly lays her eggs inside a slit in the leaf, in early May. (they can lay several batches per year) The caterpillar-like larvae then mature inside the leaf for 8 to 12 days before they emerge as mature adults.

Habitat:

White birch can grow in a variety of soils, but prefers full sun and adequate water. It is a medium sized tree, the bark on mature trees is white with blackened speckles, and the younger growth is a reddish brown. The leaf is an egg-shape, with dull light green colour on top and a slightly hairy underneath.

Notes:

Chemical sprays have no effect on this pest, as the larvae are inside of the leaves. Keep your birch tree well watered, birch health depends largely on the amount of available water. There is an inject able biological pesticide (Acecaps, or TreeAzin) that has shown promise in reducing the leafminer. For large scale outbreaks, two types of sting less, parasitic wasps have been used to control the leafeminer, ( Lathrolestes nigricollis and Grypocentrus albipes) Both of these were used in the 1990s in Alberta. I have also been told that you can boil rhubarb leaves in water, and pore the resulting 'tea' (once cooled) on the ground above the infected trees roots. The poison derived from the rhubarb is absorbed by the tree, and supposedly makes the leaves inedible to the leafminor larva. This would have to be performed in ealier spring, before the lava become a significant problem. ( I do not however, have any proof of this method being effective) Refferences: http://www.ontree.ca/treatment-for-birch... https://www.nrcan.gc.ca/forests/fire-ins... http://www1.agric.gov.ab.ca/$department/...