-
- In order to manage ...
- what am I doing anyways? (timber vs. wilderness)
- what have I got? (ID/ diagnostics)
- when is it likely to attack? (susceptibility over rotation of stand)
- do I need to worry? (hazard & risk)
- ID vs Diagnose
- ID
- positive ID
- signs are present, unique and recognizable
- typically this means the bug
- diagnosis
- determine the cause based on evidence (symptoms)
- follow a logical / analytical process
- 1) gather evidence
- host species
- location
- symptoms (& hopefully signs)
- 2) apply method/ logic to determine cause(s)
- exhaustive & nonsystematic
- consider each possibility
- dichotomous key
- previously constructed
- series of questions
- if this - go to 2
- if not - go to 5
- "old school", also OK for a novice
- but, what if you can't answer the first question?
- differential diagnosis
- i.e. based on evidence at hand (host, location & S&S)
- make a short list ... then eliminate/ confirm
- e.g. Douglas-fir, S slope, Fraser Canyon; crown is red
- therefore "whole tree is failing"
- possibilities (short list)
- root disease (black stain, phellinus, armillaria)
- drought
- bark beetle (Douglas-fir beetle)
- defoliator (IDW, IDT)
- differentiate (elim./ confirm)
- if root disease then ...
- if drought ...
- if bark beetle then ...
- etc.
- Timing is Important
- age specific?
- plantation pest (cutworm, conifer seedling weevil)
- saplings (terminal weevil)
- mature (bark beetles)
- range of ages (defoliators, Warren's root collar weevil, adelgids)
- steady state or outbreaks
- Warren's root collar weevil vs. bark beetle
- balsam woolly adelgid vs. defoliator
- outbreak cycle
- steady state, endemic level
- building (incipient)
- outbreak
- collapse
- Hazard & Risk
- Hazard
- consequence
- likely damage due to outbreak
- Risk
- chance
- liklihood for outbreak to occur
- Mgmt decision
- moderate hazard but low risk?
- low hazard but high risk?
- Know Your Enemy
- study biology to find 'weaknesses'
- host specificity
- life cycle
- host responses
- development over time
- long term (good forestry)
- "good forestry"
- mixed species
- age class mosaic in watershed, "mimic natural disturbance"
- maintain vigour (thinnings & proper spp.)
- maintain old forest structure & legacies (biodiversity, maximize your "P")
- short term (kick some frass)
- launch an offensive
- "harvest early"
- remove pine before MPB does
- beetle proof
- rehab (IWS)
- sanitation logging (get the green)
- spot treat (too small to log)
- chemical warfare
- spray (Btk, NPV, insecticide)
- timing in outbreak
- timing in season
- mating disruption
- lure & trap (kairomones & agrr. pheromones)
- repel (verbenone)
- tree breeding (IWS)
- passive agressive
- delay treatment (JS or planting)
- restrict certain species (e.g. Ss or B)
- salvage (get what you can after the fact)
- shorter rotations (bark beetle)
- "do nothing"
- too expensive to treat ($$ > benefits)
- other resource more valued
- wait and see if it even happens (i.e. low risk)
- can live with losses (i.e. low hazard)
