Trisetacus campnodus causes yellowing and stunting of Scotch pine needles. The mites colonize the needle base beneath the sheath. This area becomes necrotic and brown, at times calloused, and eventually the needles turn yellow and stunted, often distorted. Infested pine trees are chlorotic and generally appear unthrifty. This mite species was collected in Washington State.

[pg. 90]

[Trisetacus] campnodus attacks pine needle bases under the needle sheath typically causing chlorosis, stunting, and distortion of the needles.

[Note: Quote taken from abstract; did not access full article.]