Saw Fly Alert

OLYMPUS DIGITAL CAMERAWe have been receiving reports of infestation of pine trees and pine shrubs such as Mugo Pine by Pine Sawfly  caterpillars.  They eat the needles and can be veracious feeders and strip the plants quickly.  This is also the time of the year when Spruce Sawfly are actively eating the tender new needles of several varieties of spruce trees such as Colorado, Black Hills and Norway Spruce.

If you notice new shoots without needles, or just stubs of needles, sawfly probably are or have been actively feeding on the new growth.  To stop the damage quickly, spray with an insecticide.  To kill the sawfly caterpillars more slowly, but with an organic product, try Bt spray, which is safe for humans, but infects caterpillars with a bacteria which eventually kills them.  This may not take effect quickly enough to prevent the loss of a large percentage of the needles.

The picture here shows healthy new growth that is just getting started.  These needles will soon be as long as the needles from last year’s growth.  If you notice the new growth with few needles or no needles – this is damage from the sawfly.

2 thoughts on “Saw Fly Alert”

  1. Deb and/or Leif,
    What should we be trimming the new maples flanking the front entry? We would like to achieve an arched entry of branches as we discussed last spring. They are growing vigorously and look very healthy.Thank you, Sharon and Bob

  2. Sharon & Bob… Good to hear from you. Give us a call at the office – we’ll set up a time when Leif can stop by and show you what to prune / what not to prune on these plants. He’ll be glad to stop by.


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