Impacts Of Defoliation

Question 1

How is monitoring done?

Answer 1

Indirect observation: public

Annual overview: aerial 1:100,000 can trigger a ground check

Intensive traps to survey population in order to make predictions.

Question 2

What are beatings?

Answer 2

A method of ground survey where tarp is laid under tree and tree is beat

Question 3

Predictive vs population survey ***

Answer 3

Predictive (survey predicts next years population. Must be confirmed with another survey before spraying)

Population survey: population is checked after treatment to assess spray efficacy.

Question 4

Long term management practice

Answer 4

Annual survey (aerial and pheremone traps)

Mix species and age classes at the landscape level (not stand)

Maintain wildlife trees to keep a healthy bird population

Research

Question 5

Short term reactional practices

Answer 5

• predictive and pop survey
• foliage protection (spray early targeting l4, accept multiple years), more of an option later in the outbreak.
• maximum kill by attacking l5 stage late in season and earlier in the outbreak. Sacrifices years foliage for max efficacy.

Question 6

At what stage in an outbreak would you spray btk?***

Answer 6

You would spray early in the outbreak of you were trying to kil the pest.

If you were spraying late in the outbreak you would likely be spraying to save the tree, early in the season.

Question 7

Why is btk host specific?

Answer 7

Btk and NPV is only active in alkaline situations, such as the gut of a caterpillar.

Paralyzed midgut

Question 8

What is different about NPV?

Answer 8

Very species specific. Different NPVs for different hosts, very expensive to raise.

Takes 5-8 weeks to kill and far better at killing as well as being infective.

Liquefies caterpillars

Question 9

What are the main impact of defoliators?

Answer 9

Growth and volume loss ( -50% during 2-3 year recovery )

Stress and complexes ( stress make tree more susceptible to other pathogens such as IDx-IBx, DRA )

Top kill

Mortality (IDM gypsy moth, IDT tussock moth, IDL hemlock looper, IDH black headed budworm)

Non timber impacts: aesthetic, watershed, human health, cone and seeds, wildlife

Trade restriction (IDM)

Question 10

What is mating disruption

Answer 10

Sex pheremones releases everywhere, overpowering females directional signals.

Males pheremone detectors are overloaded. Contact between males can pass on this confusion.

Non poisonous, cannot be built a tolerance for.