1. Slides Information Pine Wilt Nematode Megan Kennelly
Kansas State University

2. Pine Wilt First found in Kansas in 1979 Pine wood nematode
Photo by Judy O’Mara

3. Image from Jon Appel, Kansas Dept of Agriculture

4. Pine wilt hosts Common on Scots
Also starting to see it on Austrian pine, and Mugo
Drought stress
Beetles prefer to lay eggs where resin flow is reduced

5. Pine Wilt: Symptoms Rapid wilt/death. Needles yellow then brown.
Lack resin. Branches dry, brittle. They snap rather than bend

6. Image from: http://www.extension.iastate.edu/Publications/SUL9.pdf

7. Beetle overwinters in pine trees
-start emerge ~ May 1st.
female
male
Images from:

8. *Lay eggs, (prefer drought stressed/dying)
*Nematodes enter tree and feed on bluestain fungi.
Lay eggs all season
May 1 : adult beetles emerge
Images from:
Beetles feed in healthy trees
Nematodes are inside the trachea (breathing tubes) of the beetle.
Beetle carries up to ~80,000 nematodes

9. *Larvae feed in cambium layer, then burrow deeper into the tree
Egg-laying phase
*Beetle larvae develop in the tree.
*Larvae feed in cambium layer, then burrow deeper into the tree
*Larvae turn to pupae
*Nematodes are attracted to pupae
*Pupae emerge as adults, and the cycle continues
Image from:
Feeding phase
Nematodes leave beetles and enter tree through feeding wounds.
Nemas eat plant cells, and tree dies

10. The nematode in the tree
Once in the tree, the nematode spreads around in resin ducts. Feeds on resin cells (healthy trees) or blue-stain fungi (in dead trees)
When food is running out, nematode seeks out the beetle. Nematodes produce 4th stage larvae which hitch a ride with the beetle. This larva is a “dispersal” stage, tolerates drying. (dauer larvae)

11. Nematode can’t spread by itself: it needs the beetle
Beetle can fly several miles
We can also spread nematode and beetle in nursery stock, firewood

12. Sanitation is Critical Component in Controlling Pine Wilt
Tree removal before April 1
Reduces nematode and
pine sawyer numbers
Don’t leave stumps
Root removal not necessary
Don’t stack wood.
Chip or burn dead trees.
Sanitation must be coordinated effort.
Pine sawyers strong fliers

13. Two new products for pine wilt
Greyhound and Pinetect
Both are 2% Abamectin
Contact companies (Rainbow Tree Care, Arborsystems) for more information
Need to be applied by trained treecare professionals

14. Injections Not 100% effective No curative activity
Carefully evaluate tree beforehand
Proper technique
Repeat every 2 years
Expensive