slide information pine wilt nematode megan kennelly kansas state university
TRANSCRIPT
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
Beetle overwinters in pine trees
-start emerge ~ May 1st.
female male
Images 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 season
Beetles feed in healthy trees
Nematodes are inside the trachea (breathing tubes) of the beetle.Beetle carries up to ~80,000 nematodes
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Egg-laying phase
Feeding 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
Nematodes 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 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