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How to identify it
- Damage is the usual clue: around mid-June the outer 6 to 8 inches of a new shoot droops and turns yellow, and the shoot often breaks over or falls off, leaving a flat stub.[1][2]
- Split an infested shoot and you will find the pith hollowed into a tunnel 6 to 8 inches long, with a round exit hole near its base once the caterpillar has left.[1]
- The full-grown caterpillar is dirty white to gray and about 1/2 to 3/4 inch long, with a yellowish-brown head marked by a round blackish spot and a pale yellow shield behind the head.[1]
- The moth is small, with a wingspread of about 15 to 18 mm. Its forewings are coppery red crossed by two shiny gray bands, and its hindwings are gray-brown.[1][2]
Where it lives
It occurs across the northeastern United States and southern Canada, from Maine west to southern Manitoba and south through the Lake States to northern Ohio, Pennsylvania and New Jersey, broadly following the range of white pine.[1][2][3]
Biology and life cycle
Hosts are mainly pines. Eastern white and Scots pines are preferred, but jack, red, Austrian, pitch and mugo pines are also attacked, and occasionally white spruce and Douglas-fir.[1][2][3]
Moths emerge from late April to May, around the time pine buds break. They hide among the needles by day, and the females lay single eggs at night on the needle sheaths of several new shoots.[1][2][3]
Within two weeks the caterpillar hatches and bores into the shoot, mining down through the pith. Usually there is one caterpillar per shoot, though up to six have been found in heavy infestations.[1]
By mid-June the grown caterpillar turns back up the tunnel and cuts into the wood near its base, which weakens the shoot so wind snaps it. Between mid-June and early July it chews an exit hole, drops to the ground and spins a soil-covered cocoon in the litter or topsoil, where it spends the winter as a pupa.[1][2][3]
Damage and signs
- Both leaders and side shoots are attacked. Killed leaders leave crooks and forks, and when side shoots die the crown loses its shape; repeated attacks make trees bushy.[1][2]
- Young trees about 3 to 8 feet tall suffer most, although trees up to 30 feet can be attacked. It has been a serious pest of young jack pine in the Lake States and Ontario and of white, red and Scots pine plantations in New York and Pennsylvania.[1][2]
- Severe attacks do not kill trees. The main loss is on Christmas trees: affected trees are left with 2- to 4-inch leaders instead of the 8- to 12-inch leaders growers want, and their marketability suffers in the year of attack.[1][3]
Health risk
The forest sources treat it only as a pest of pine shoots and mention no risk to people.[1][2][3]
Control
Traps and physical control
Prune out and destroy wilted or yellowing shoots before the caterpillars leave them and drop to the ground (by mid-June to early July).[3][1]
Pesticides
Sprays are hard to time because moths emerge over a long period and the caterpillars are hidden inside shoots. If control is necessary, the USDA leaflet says to treat about the second week of May to kill caterpillars before they bore in, and to get current product advice from your state agricultural experiment station or county agricultural agent.[1]
Common questions
- Why are the new tips on my white pine drooping and turning yellow in June?
- In the Northeast that is the classic sign of the eastern pine shoot borer. A caterpillar inside the shoot has hollowed out the pith, and the shoot often breaks off at a flat stub. Look for a round exit hole near the base of the dead section.[1][2]
- Will the eastern pine shoot borer kill my pine?
- No. Natural Resources Canada says even severe attacks do not kill trees. The damage is to shape and growth, which matters most on Christmas trees and young plantation pines.[3][1]
- How do I control it on a few trees?
- Clip out and destroy the damaged shoots while the caterpillars are still inside, before they drop to the ground in early summer.[3]
Sources
- USDA Forest Service, “Eastern Pineshoot Borer, Forest Insect & Disease Leaflet 134 (L. F. Wilson, revised November 1978; scanned copy).” www.fs.usda.gov/foresthealth/docs/fidls/FIDL-134-EasternPineshootBorer.pdf (accessed 2026-11-10)
- USDA Forest Service, “Eastern Forest Insects, Miscellaneous Publication 1175 (W. L. Baker, 1972; scanned copy).” archive.org/details/easternforestins1175bake (accessed 2026-11-10)
- Natural Resources Canada, Canadian Forest Service, “Eastern pine shoot borer, Trees, insects and diseases of Canada's forests.” tidcf.nrcan.gc.ca/en/insects/factsheet/11035 (accessed 2026-11-10)
- iNaturalist, “Eucopina gloriola taxon page (order and family).” www.inaturalist.org/taxa/511568 (accessed 2026-11-10)