Key To Diagnosing Common Pine Problems

Natural Fall Needle Drop

The oldest needles (near trunk) turn yellow or brown throughout the tree; these needles are shed in the fall of the year; all pine species naturally drop older needles.

Freeze Damage

Needles show symptoms of brown flecking and partial or complete dieback, needles being the only part affected initially; symptoms usually appear on the new needles, or are localized on the southside of the tree; young trees tend to show more damage; all pine species are susceptible; symptoms may develop from spring to fall.

Dothistroma Needle Blight

Pine needles dying with the needles being the only part of tree affected; symptoms generally showing up in the summer or fall. Needles develop yellow or tan spots which turn into brown or reddish bands; needles die from the bands outward; the needle base remains green. This disease affects both young and old needles throughout the tree; susceptible hosts include Austrian, ponderosa and mugho pines.

Sphaeropsis Tip Blight (Formerly Diplodia Tip Blight)

Pine needles, twigs and branches dying irregularly within tree. Dieback of current year's shoots accompanied with resin soaked infected tissue; black fruiting bodies develop on the base of the dead needles and pine cones; susceptible hosts include red, Austrian, and Scotch pines; symptoms usually show up in the spring or fall.

Fusiform Rust

Elongated swellings occur along branches; orange blisters may be present on the galls during the spring; susceptible hosts include Austrian, loblolly and slash pines.

Western Gall Rust

Circular swellings on branches and on trunk; orange blisters may be present on the galls during the spring; susceptible hosts include Austrian, lodgepole, ponderosa and Scotch pines.

Sapsucker Damage

Pine branches or trunks with circular holes present occurring in horizontal rings or vertical lines forming a distinct pattern; sap flow coming from the holes; damage may occur year around; all pine species are susceptible

Bark/Wood Boring Beetles

Pine branches or trunk with circular holes present not in distinct lines or rows; beetle larvae tunnels present under the bark; usually a problem in older mature trees; all pine species are susceptible

Pine Tip Moth

Current years candles (new growth) dieback; new growth hollow inside; brown to orange larvae up to 3/8" long on/or inside the new shoots; webbing may be present on the needles; susceptible hosts include Austrian Scotch, Virginia and red pines; symptoms may develop spring through falL

Pine Wilt Nematode

Needles turn completely brown; tree dies rapidly; affected branches become brittle due to the lack of resin flow; symptoms generally develop in the late summer or early fall; susceptible hosts include Austrian, Japanese red , Japanese black and Scotch pines. ( No control available. Remove infected tree as soon as possible. )

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ADDITIONAL INFORMATION