Skip to Main navigation Skip to Left navigation Skip to Main content Skip to Footer

University of Minnesota Extension
www.extension.umn.edu
612-624-1222

Extension > Garden > Diagnose a problem > What's wrong with my plant? > Evergreen Trees and Shrubs > Pine > Resin or sticky substance on shoots

Print Icon Email Icon Share Icon

Pine > Shoots/Branch Tips > Resin or sticky substance on shoots

1 of 5
  • Diplodia shoot blight 1
  • Diplodia shoot blight 2
  • Diplodia shoot blight 3

Diplodia shoot blight
Diplodia pinea

  • New needles are brown, short and often glued together with resin
  • Cankers are resin coated flattened areas on branches
  • Needles and branch beyond canker turn brown and dies
  • Tiny, black, pimple-like fungal structures on dead needles and pine cones
  • Infected shoots and dead branches occur throughout the tree but most commonly in lower canopy
  • Cankers and dead needles can appear rapidly after wounding from hail, drought or other stress
  • Olive to dark brown streaking in sapwood below cankers
  • Common on Austrian, red and Scots pine
  • More information on Diplodia shoot blight...
2 of 5
  • White pine weevil 1
  • White pine weevil 2
  • White pine weevil 3

White pine weevil
Pissodes strobi

  • Terminal leader dead or dying, curled into a shepherd's crook
  • Branches in whorls near the top may also wilt and die
  • Repeated attacks can leave trees looking bushy
  • Drops of sap from feeding wounds on terminal shoots in early spring
  • Prefers Eastern white pine but will also infest jack pine and Norway and blue spruce
  • Small, ¼ inch long, white, grub-like larvae feed under bark from June to August
  • Adult weevils ¼ inch long, dark with tan and white mottling; has conspicuous snout
  • More information on White pine weevil...
3 of 5
  • Zimmerman pine moth 1
  • Zimmerman pine moth 2
  • Zimmerman pine moth 3

Zimmerman pine moth
Dioryctria zimmermani

  • Dead terminal leader and shoots are common
  • Larvae feed at branch whorls and a base of shoots
  • Pitch mixed with reddish frass just below feeding sites
  • Affected shoots turn brown and may break off
  • Larvae are dark pinkish-green, about ¾ - 1 inch long
4 of 5
  • Pine tortoise scale 1
  • Pine tortoise scale 2
  • Pine tortoise scale 3

Pine tortoise scale
Toumeyella parvicornis

  • Moderate feeding can cause needles to yellow and become shortened
  • Heavy infestations can cause shoots and branches to die back
  • Feeding produces honeydew which can cause sooty mold
  • Individual scales are reddish-brown, helmet-shaped and up to ¼ inch long when mature
  • More information on Pine tortoise scale...
5 of 5
  • Red pine shoot moth 1
  • Red pine shoot moth 2
  • Red pine shoot moth 3

Red pine shoot moth
Dioryctria resinosella

  • Small pitch mass at point of entry
  • Infested shoots turn red to brown
  • Tree become flat-topped after several years of feeding
  • Favors red pine, particularly on dry, sandy sites
  • Larvae have dark head with body that varies from blackish to reddish-purple on top and white to green underneath
  • More information on Red pine shoot moth...

Don't see what you're looking for?

  • © Regents of the University of Minnesota. All rights reserved.
  • The University of Minnesota is an equal opportunity educator and employer. Privacy