IDT Douglas Fir Tussock

Question 1

What are the characteristics of Fd tussock outbreaks?

Answer 1

Fast (2-4 years) and furious (extreme damage to trees and high risk to human health)

Question 2

What is the main short term treatment

Answer 2

Spray treetops with NPV or BTK or both. Target treetops from helicopter.

BTK - 3 sprays due to short active life

NPV - will multiply and probably one spray. Early in the morning for tussock

Question 3

What do eggs look like??

Answer 3

HAIRY MASS on a cocoon

OW as eggs

Question 4

When do larva hatch

What happens after?

Answer 4

May/June

L1 Larva move up the tree and to the tips of branches for wind dispersal.

Young new foliage preferred in early stage, as they mature older foliage is accessible. Kill tree.

Pupate in late July

Question 5

What is unique about the female moth?

Answer 5

Flightless. Pheremones very important to attract mate.

Question 6

Signs and Symptoms larva

Answer 6

Larva - Hairs radiating from red dots. 4 tufts in anterior region, long hairy tuft on posterior segment.

Question 7

Signs and symptoms male

Answer 7

Adult - Drab grey male. Extremely hard to identify for non expert.

Female - Wingless

Question 8

Symptoms tree and landscape

Answer 8

Heavy defoliation at top of tree, to a lesser extent on the outer branch tips. Burnt red appearance

Top kill

Landscape: valley bottom, distinct patch pattern, coalesce in outbreak.

Question 9

Hosts and Range

Answer 9

Interior BC (cow country) range forest interface. Valley bottoms where it is warmest. Fd(Bg, Py, Lw, Sx)

IDW on the other hand will be found in the mid range of elevations