Nematodes of many different species infect pine trees. Root nematodes are a microscopic worm which lives in soil, however, they are not in any way related to the well-known earthworm. Pine tree root nematodes may have infested your tree if you note that the tree is growing poorly and yellowing on the needles. Branches of the tree may also die, or in cases of extreme root nematode infestation the entire tree turns brown and dies off. These evidences of root nematodes may be the only indication that they are present as even on close examination you are unlikely to view these microscopic worms.
Root nematodes prefer sandy loam soils that have lots of moisture.
The good news is that on thier own, these pests can only move a few inches each year. The bad news is that due to their size, they are easily carried from their original infestation through rain, wind, soil, water or infested tools. Pine tree root nematodes feed on the plant roots which stunt growth and damage roots. When the roots become damaged so that they can no longer provide sufficient nutrients for the growth of the tree you will begin to see the yellowing and browning of the tree,, along with eventual die off of branches or the entire tree if left untreated. However, many problems of both soil and the root system can cause similar problems, so don t just assume that you have root nematode infestation.