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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Evergreen Trees and Shrubs > Pine > Distorted or deformed needles

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Pine > Needles > Distorted or deformed needles

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  • Growth regulator herbicide damage 1
  • Growth regulator herbicide damage 2
  • Growth regulator herbicide damage 3

Growth regulator herbicide damage
(e.g. 2,4D or MCPP)

  • Shoots may wilt or curl
  • Needles stunted, twisted or misshapen but remain green
  • If damage is severe, needles turn brown and fall off, branches may die
  • Symptoms occur a few days to several weeks after herbicide application
  • Dead or dying weeds expressing similar symptoms may be present nearby
  • More information on Growth regulator herbicide damage...
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  • European pine sawfly 1
  • European pine sawfly 2
  • European pine sawfly 3

European pine sawfly
Neodiprion sertifer

  • Larva feed only on old (last year's) needles
  • Needles chewed on by young larvae become discolored and straw-like
  • Larvae feed in colonies, feeding on one branch at time
  • Active from May to June; one generation per year
  • Feeds particularly on mugo, Scots, red and jack pines
  • Larvae have shiny, black heads, grey, green body with dark green stripes; they are ¾ - 1 inch long when fully grown
  • More information on European pine sawfly...
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  • Redheaded pine sawfly 1
  • Redheaded pine sawfly 2
  • Redheaded pine sawfly 3

Redheaded pine sawfly
Neodiprion lecontei

  • Larvae feed on both old (last year's) and new needles
  • Larvae feed in colonies, feeding one branch at a time
  • Feeding by young larvae leave needles dry and straw-like
  • Active between mid-June and late July and again from mid-August and late September; two generations occur per year (primarily in southern MN)
  • Prefers young pine (5 - 20 foot tall); many species of pines are attacked, especially red and jack pines
  • Larvae are ¾ to 1 inch long when fully grown; they are yellow with rows of black spots and reddish brown head
  • More information on Redheaded pine sawfly...
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  • Introduced pine sawfly 1
  • Introduced pine sawfly 2
  • Introduced pine sawfly 3

Introduced pine sawfly
Diprion similes

  • Missing needles on old (last year's) needles; can also feed on new growth
  • Needles chewed on by young larvae become discolored and straw-like
  • Larvae feed in colonies, feeding on one branch at a time
  • Active from late May/early June to early July and again from late July through early September; two generations per year
  • Prefers white pine; will also feed on Scots, jack and red pine
  • Larvae grow to ¾ - 1 inch in length; Larvae have black heads, a yellow-green body with a black double stripe and many yellow and black spots
  • More information on Introduced pine sawfly...
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  • Sawflies 1
  • Sawflies 2
  • Sawflies 3

Misc. sawflies
(jack, red and white pine sawflies)

  • Missing needles
  • Needles may be completely consumed, partially eaten or become straw-like from feeding
  • Larvae feed gregariously (i.e. in nonsocial groups), on new or old needle growth
  • Larvae 1 inch long or less, green or yellowish-green with spots or stripes
  • Different pine species favored by different sawflies but most pine are susceptible
  • More information on Sawflies...

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