What is pitch tubes?

How to recognise a pitch tube

Look on the trunk for crumbly or tube-like lumps of resin, often cream, pink or white, about the size of a pea or a little larger, with a tiny entry hole at the center. Fresh ones are soft and sticky; old ones harden and turn gray. Boring dust may collect in bark crevices below them (see frass).

A pitch tube is not the same as a resin streak from a broken branch or an old wound. The hole in the middle, and the pattern of several tubes at about the same height, are what separate an attack from ordinary sap flow.

Why it matters in Northern Nevada

Pines that are short of water are the usual targets, and the foothills and the Tahoe Basin have plenty of them after dry years. A healthy pine can flush a beetle out with resin; a stressed one often cannot. Needles that fade from the top down, along with pitch tubes, point toward a tree in trouble. The USDA Forest Service tracks bark beetle activity in Nevada pines in its annual forest health report.

Many tubes does not mean a dead tree, and no tubes does not mean a healthy one. Read it alongside the rest of the tree, as described in bark beetles in pines.

What an arborist does about it

The arborist finds the tubes, checks how high and how many, looks at the needles and the base of the trunk, and decides whether the tree is alive, declining or dead. The practical question for the owner is what to do with the tree: keep and watch it, prune out dead limbs, or take it down if it stands over a house, driveway or power line. Battle Born does not spray or treat trees; our part is identification and the pruning or removal call. See removing dead pines after bark beetles.

A useful habit is to note the date and height of what you see. An arborist asked to look at a pine can then tell whether the attack is new, how far up the trunk it reaches, and whether nearby pines show the same marks.