Warren's Root Collar Weevil

Question 1

For reference on Warren’s Root Collar Weevil, please see the SEDA –> http://www.forest-insects.umn.edu/pdfs/2009/09McCullochBCJEM10.pdf

Answer 1

:)

Question 2

What is the three letter code for Warren’s Root Collar Weevil?

Answer 2

IWW

Question 3

What kind of site does IWW like?

Answer 3

Moist, shady, deep duff, coarse textured soil.

High hazard for the Interior - particularly SBS and ICH wetter subzones.

Question 4

What species does IWW eat?

Answer 4

Mostly lodgepole pine, some spruce too.

Question 5

When is a lodgepole pine susceptible to attack?

Answer 5

At 5 years up until it is mature, attack starts when the sapling is a metre tall.

Question 6

How much of British Columbia’s forest stands are currently dealing with IWW?

Answer 6

20% (on average) of British Columbia’s Pine stands have IWW

Question 7

What is the % of trees within a stand that are attacked if IWW is present?

Answer 7

40-80% of susceptible species may be attacked

Question 8

What does the life cycle of IWW look like?

Answer 8

Eggs are laid in summer.

Question 9

How long do the Larva stay in the duff?

Answer 9

Larva overwinter for two years in the duff while eating roots.

Question 10

How long does an adult IWW survive?

Answer 10

Flightless adults survive for five more years.

Question 11

How does logging affect IWW outbreaks?

Answer 11

IWW moves out of the cutblock into surrounding timber and comes back once regen has hit 2 cm DBH or 1 m height.

Question 12

Describe the signs of IWW.

Answer 12

Signs: 2cm long white grub larva, dark grey flecked adults with long snouts. (like tiny elephants)

Question 13

Describe the symptoms of IWW

Answer 13

Symptoms: chlorotic foliage, leaning, root and root collar girdling, and ‘kitty litter’ (pitch mixed with frass and soil) caused by larval feeding.

Question 14

In what pattern does IWW attack an area?

Answer 14

From outside to inside.

Question 15

How does IWW damage young trees (5-20yrs)?

Answer 15

Root collar girdling. A young tree is ok with one or two larvae but any more will cause it to die a horrible death.

Question 16

How does MPB relate to IWW?

Answer 16

Damage is greater from IWW when the area is next to beetle kill stands.

Question 17

How does IWW damage older trees?

Answer 17

It moves to the primary roots, girdling these instead. Damage creates susceptibility to things such as drought, MPB, and root diseases like tomentosus or armillaria.

Question 18

How would you manage for IWW?

Answer 18

Survey for signs through examining roots and include adjacent pine stands in your cutblock.

Question 19

How might site prep help manage for IWW?

Answer 19

You can use site prep like burning, disc trenching or mounding to reduce the duff layer.

Question 20

What precautions might you take when it comes time to plant?

Answer 20

When planting, delay for 2-3 years since the weevil lives in stumps, plant more to compensate for loss, or fill plant with anything but pine please.

Question 21

How would you manage for IWW at the Free-to-Grow/Juvenile Spacing stage?

Answer 21

Check for signs and symptoms. Any tree with IWW is not FG.

Delay spacing until 20 years or more.

Question 22

In a test, what are some key terms about IWW that can help you?

Answer 22

Interior pine, duff layer, kitty litter, root collar young - death, roots on old - reduces growth, survey, delay plant, delay spacing, , IWW not FG.