Mountain Pine Beetle

Question 1

How does blue stain fungus create better food for larvae?

Answer 1

Enhances nitrogen saturation in affected wood.

Question 2

What are critical beetle success factors?

Answer 2

Finding the right tree - older and or stressed

Signal pheremones between species to orchestrate a mass attack

Blue stain fungus that infects tree upon first bite - vectored by beetle maxillae

Timing of emergence and maturation

Varied dispersal behaviour spreading risk

Question 3

Host defences to beetles?

Answer 3

Primary resin ducts (constituent) and

secondary resin ducts - traumatic (conversion of other tissue to resin ducts) more fluid, free flowing, more toxins.

Question 4

Sink tree vs source tree?

Answer 4

Less than 25 cm beetles reduced survival in winter - sink

Over 25 cm tree beetles increased winter survival - source

Question 5

What are the age thresholds for beetle attack

Answer 5

0-40: too small

40-80: most resistant

80+: most susceptible. Old and right size

Question 6

What are the critical pheremones produce by pine beetle?

Answer 6

Aggregation and anti aggregation

Question 7

How many eggs to a brood? How long to hatch?

Answer 7

60-80 eggs per beetle, two weeks to hatch

Question 8

How many larval stages ?

How frost hardy are the stages

Answer 8

L1-L4. From L4 to pupa to adult

Egg very low

L1 and l2 med

L3 l4 high

Pupa low

Question 9

What is important to beetle lifecycle timing.

Answer 9

Life cycle should be timed for larvae to be in l3 and l4 stage through the coldest part of winter. Larvae shut down during most frost hardy stage to overwinter but l1 and l2 will continue developing to synchronize population.

Question 10

Green attack?

Answer 10

Current Attack. Can only be detected from ground by examining pitch tubes. This is the most important stage for us to know about but can’t be seen from air.

Question 11

Red attack?

Answer 11

One year after initial attack, tree has died and turns red. Beetles already gone. Does not do managers any good.

Question 12

Grey attack?

Answer 12

Two - three years after initial attack. Window of higher fire hazard

Question 13

What do beetles do to survive winter?

Answer 13

Produce glycerol, a slow increase in concentration in response to phenological cues.

Glycerol can allow beetles to survive up to -40. -20 at the beginning of winter and end of winter as it is still accumulating glycerol or breaking it down respectively.

Question 14

What do larvae do when they wake up from winter stasis?

Answer 14

Resume feeding -> pupate -> teneral adult which continues maturation feeding to form flight muscles and mycangia (grooves in mouthparts).

Question 15

What does the tree die of

Answer 15

Shut down of vascular system. Blockage of water

Phloem is eventually girdled, shutting down the sugar transportation system of the tree.

Question 16

What time period are bark beetles flying at? Why are the attacks so successful?

Answer 16

A temperature indicator cues beetles to wake up and fly all in about a 10 - 12 day period. Beetles are synced to temp for emergence.

When beetles are out in mass numbers, pheremones are much more effective. Since it is dry, stressed trees also have a reduced ability to pitch out and defend against invasion.

Question 17

How is beetle flight syncronized ?

Answer 17

Beetles wake up at a set temperature

Syncronized with seasons to fly at driest time of year where flight is improved and trees are stressed.

Question 18

How and when does pine beetle dissipate

Answer 18

• flight timed for late July - early August depending on temperature
• 70 % long dist 30 % short dist
• 2.5 % above canopy by convection
• fly downwind until they detect suitable kairomone ( if wind above 7k beetles won’t fly.)
• if it’s bright and warm out beetles will keep flying

Question 19

At a landscape level what pattern does bark beetle make?

Answer 19

Salt and pepper effect

Question 20

Where do most beetles fly?

Answer 20

Between the brush and the lower canopy of forests

Question 21

How are kairomone And pheremone interconnected?

Answer 21

Kairomones (attract pioneer)

Pheremones (mass attack) where pioneers attract mates.

Question 22

How to treat beetle infested logs

Answer 22

Cut into 2 foot lengths to dry them out

Or burn them

Or mill them

Question 23

What do beetles make pheremones for?

Answer 23

Mass attack

Anti aggregation.

Question 24

What is maturation feeding?

Answer 24

When young adults feed on spores of blue stain fungus. Enhances sexual maturation.