It is with much concern that I write this letter to the editor in response to the recent media publications regarding the recent forest tent caterpillar outbreak.
There has been some controversy about using pesticide to control this outbreak. I, as well as many others in the arboriculture/tree care industry do not recommend the practice of applying pesticides for cosmetic purposes. I admit that the caterpillars are not appealing but they generally are short lived and do not affect the health of established trees.
The trees may lose the majority of their leaves and will use stored energy to produce a new flush of leaves. A well maintained tree will be able to do this with little or no effect to the health of the tree. The practice of using pesticides greatly reduces the health of the landscape, in particular by killing the natural predator species. The 'friendly fly' or 'large flesh fly' Sarcophagi aldrichi is a parasitoid of the tent caterpillar that can be inadvertently destroyed as well. These natural predators are very important for the natural control of the tent caterpillars.
Pesticide use effects the balance of all species that make up the biodiversity of the landscape. This includes bees, butterflies, small mammals, birds, aquatic life and much more. The beneficial insects will bounce back from pesticide use much slower than the species being targeted.
There are non-toxic actions that can be taken by home or business owners such as spraying the caterpillars off the trees with a jet of water, removing them by hand or with a vacuum. After defoliation the trees can be given some additional nutrient to aid in the new flush of leaves. Apply a light application of a balanced organic fertilizer or mulch along the drip line of the tree. Watering regularly and deeply to ensure the tree is properly hydrated is essential. The presence of egg bands which resemble spongy brownish masses can be easily detected and removed from the branches in the fall after the leaves have dropped.
Let's not panic and do something that will tip the balance of nature and have long lasting negative effects in our environment. Practice some tolerance and have faith that Mother Nature has the best defence. Spend the money you save not buying pesticide but to purchase and plant a tree that will provide healthy benefits for generations to come.
Brenda Slade
ISA Certified Arborist
TreeWise Management Ltd.
Prince George
