WSU Extension


Armillaria root rot 
Bacterial canker 
Black knot 
Brown rot blossom blight and fruit rot 
Crown gall 
Cytospora canker 
Dead bud 
Gumming (Gummosis) 
Leaf spot 
Little cherry 
Mottle leaf 
Necrotic rusty mottle 
Powdery mildew 
Prunus necrotic ringspot 
Shothole (Coryneum blight) 
Verticillium wilt 
Witches'-broom (Cherry leaf curl) 
Apple-and-thorn skeletonizer 
Black cherry aphid 
Brown marmorated stink bug 
Cherry bark tortrix 
Cherry fruit fly 
Cutworms and armyworms 
Peachtree borer 
Pear slug (Cherry slug) 
San Jose scale 
Shothole borer 
Spider mites 
Spotted wing Drosophila (SWD) 

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Caption: Frass tubes from Cherry bark tortrix activity
Photo by: T.A. Murray
Cherry : Cherry bark tortrix
(revision date: 3/10/2017)

The cherry bark tortrix (CBT) is a pest of most woody ornamental trees and shrubs in the family Rosaceae. CBT attacks Prunus (cherry, plum and peach), Malus (apple, crabapple), Pyrus (pear), Crataegus (hawthorn), Sorbus (mountain ash), Cydonia (quince), Pyracantha (firethorn) and Photinia. CBT has one generation per year and a prolonged flight period from April until September. All life stages occur within the host tree except for the eggs and adults. Eggs are laid singly on the bark surface. Hatching larvae penetrate the bark through openings (natural and mechanical wounds) and feed on the living tissue of the tree's bark. Graft unions of ornamental trees are preferred sites for attack. Larvae do not penetrate the hard wood of the tree. During feeding, CBT larvae construct a frass tube consisting of fecal pellets and webbing. The frass tube is the location for pupation once CBT has completed the larval stage. Frass tubes are an excellent indication of CBT infestations and susceptible trees should be regularly monitored for frass tubes.
Management Options

Non-Chemical Management
  • Avoid any mechanical injuries or large pruning cuts.
  • Conserve parasitic wasps and other predators by reducing pesticide usage. Do not make unnecessary pesticide applications to the trunk of the tree unless CBT is your target.
  • Do not purchase susceptible trees. Mount Fuji Oriental and Weeping (or Higan) Flowering cherries are very susceptible to CBT attack.
Select non-chemical management options as your first choice!

Chemical Management

Only use pesticides for large infestations. For best results, apply in mid-September to early October when temperatures are warm and conditions are dry. Treat only infested areas, such as the trunk or graft union. Do not treat the canopy. Drench the frass tubes with a low-pressure spray until run-off. Mix only small amounts of pesticides, very little mixed material is needed to control CBT. Less than one liter of mixed product is more than enough to treat most highly infested trees. Esfenvalerate is toxic to bees. Do not apply products containing esfenvalerate on or near blooming plants. To minimize risk to bees, apply in the evening after bees have stopped foraging for the day.

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.
  • Monterey Bug Buster II
    Active ingredient: esfenvalerate  |  EPA reg no: 1021-1778-54705
  • This list may not include all products registered for this use.

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Caption: Frass tubes from Cherry bark tortrix activity
Photo by: T.A. Murray
Caption: Frass tubes from Cherry bark tortrix activity
Photo by: T.A. Murray
Caption: Cherry bark tortrix damage
Photo by: T.A. Murray