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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Evergreen Trees and Shrubs > Yew > Blackened needles

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Yew > Needles > Blackened needles

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  • Image: Sooty mold 1
  • Image: Sooty mold 2
  • Image: Sooty mold 3

Sooty mold

  • Black, brown, or gray soot-like covering on leaf surfaces, or twigs
  • Sticky, shiny secretions on leaves from sap-sucking insects (aphids, leaf hoppers, psyllids, etc.)
  • Insects or signs of insect damage (distorted, pin-prick feeding marks, etc.) may be seen on leaves above the worst affected moldy areas
  • More information on Sooty mold
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  • Image: Fletcher scale 1
  • Image: Fletcher scale 2
  • Image: Fletcher scale 3

Fletcher scale
Parthenolecanium fletcheri

  • Heavily infested foliage turns yellow, becomes thin as needles drop prematurely
  • Honeydew is covered with sooty mold on branches, twigs and needles
  • Small (1/4 inch), round, brown scales at bases of needles
  • More information on Fletcher scale
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Taxus mealybug
Dysmicoccus wistariae

  • Heavily infested branches cause foliage to thin
  • Also covered with sticky honeydew and sooty mold
  • Mealybugs are covered with white waxy secretions, up to approximately ¼ inch long
  • Damage occurs in late spring

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