Slide InformationPine Wilt NematodeMegan KennellyKansas State University

First found in Kansas in 1979

Pine wood nematode

Pine WiltPhoto by Judy OMara

Image from Jon Appel, Kansas Dept of Agriculture

Pine wilt hostsCommon on Scots

Also starting to see it on Austrian pine, and Mugo

Drought stressBeetles 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.femalemaleImages from:http://www.extension.iastate.edu/Publications/SUL9.pdf

May 1 : adult beetles emerge*Lay eggs, (prefer drought stressed/dying)*Nematodes enter tree and feed on bluestain fungi.Lay eggs all seasonBeetles feed in healthy trees

Nematodes are inside the trachea (breathing tubes) of the beetle.Beetle carries up to ~80,000 nematodesImages from: http://www.extension.iastate.edu/Publications/SUL9.pdf

Egg-laying phaseFeeding 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 continuesNematodes leave beetles and enter tree through feeding wounds.

Nemas eat plant cells, and tree dies

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

The nematode in the treeOnce 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 cant 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 WiltTree removal before April 1 Reduces nematode and pine sawyer numbersDont leave stumpsRoot removal not necessaryDont 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

InjectionsNot 100% effectiveNo curative activityCarefully evaluate tree beforehandProper techniqueRepeat every 2 yearsExpensive