Shoot and Tip Insects Flashcards
Primary Impacts?
Not much. Not mortality. Generally pests of younger trees, Christmas trees, nursery plantations. Growth/stem deformities.
Manage for the growth/form of tree.
Quality and quantity of wood.
Where are they found?
The leader (tip) (apical meristem) of the tree.
Shoots
Twigs
Branches
Biology: How many generation per year do white pine weevil have?
One.
Where do WPW overwinter?
Adults hibernate under the tree in the duff layer.
Sperm remains viable after winter. Females don’t need to mate again.
How mobile are WPW?
Great fliers. Quite mobile.
Where do female WPW lay their eggs?
At the leader, then she makes her way down, chewing out cavities and laying more eggs. Seals the cavities with excrement over the eggs.
Where do WPW larvae develop?
They start to develop in the leader in “feeding rings” going down the tree.
They pupate in “Chip cocoons.” And destroy the phloem tissue.
Where do WPW new adults feed in the fall?
July/August adults feed on the lateral branches.
WPW damage?
Reduce tree height 40-60% and tree/stem deformities: compression wood, knots, etc
What are some ways to manage WPW?
Sampling: scout for infested leaders, typically target smaller trees
Chemical Control: insecticide to the leaders in spring or sometimes fall
Mechanical and Biological Control: not heavily practiced, but dead leaders can be trimmed off. Biological control with parasitoid wasps in burlap sacks
Silvicultural Control: plant under hardwood over story like oak, and release white pine 20-30 years later once straight and tall. Remover over story once pines are 15-20ft tall
-essentially grow them tall and fast, since WPW targets younger, smaller trees. Shade also helps prevent WPW (they like sunny areas)
-remove some of overstory or branches near ground to reduce moisture
-plant very dense and then thin trees that have weevils
White pine weevil can also be found on ?
White spruce
