Slides Information Pine Wilt Nematode Megan Kennelly Kansas State University

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

Image from Jon Appel, Kansas Dept of Agriculture

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

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

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

Beetle overwinters in pine trees -start emerge ~ May 1st. female male Images from: http://www.extension.iastate.edu/Publications/SUL9.pdf

*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: http://www.extension.iastate.edu/Publications/SUL9.pdf Beetles feed in healthy trees Nematodes are inside the trachea (breathing tubes) of the beetle. Beetle carries up to ~80,000 nematodes

*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: http://www.extension.iastate.edu/Publications/SUL9.pdf Feeding phase Nematodes leave beetles and enter tree through feeding wounds. Nemas eat plant cells, and tree dies

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)

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

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

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

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