Mugo Pine Shrub- Worm Investation - Ask Extension
Good morning,
My 5 year old mugo pine shrub was invested with light green worms approx. 3/4 " in length. Each worm emerged from a shiny black round s...
Knowledgebase
Mugo Pine Shrub- Worm Investation #402327
Asked May 25, 2017, 10:09 AM EDT
Good morning,
My 5 year old mugo pine shrub was invested with light green worms approx. 3/4 " in length. Each worm emerged from a shiny black round speck about the size of a pin head or a bit larger. I've attached a photo of the little critters. We decided to remove the shrub fearing that the critters would spread to other plants and shrubs in our yard. What is this? What caused it? How harmful and was it treatable?
Diane, Minneapolis,MN- Seward neighborhood.
Diane, Minneapolis,MN- Seward neighborhood.
Hennepin County Minnesota
Expert Response
There are pine sawfly larvae. They feed on last year's needles and usually can be removed with a blast of water from a hose. They are short-term feeders - about 2 weeks - and only have one hatching per year (some insects like aphids have several generations per season). There are different kinds of sawflies that can affect other plants, but they can be hosed off as well. No need to remove the plant. Here is an excellent Extension publication about sawflies: http://www.extension.umn.edu/garden/insects/find/sawflies/. Scroll down to the Management section and you'll see different options for control. Again, blasting the insects with water or using insecticidal soap will help manage the populations (note: insecticidal soap will not harm pollinators).
Julie,
Thank you for your prompt reply and detailed answers!
Your fellow gardner,
Diane
Thank you for your prompt reply and detailed answers!
Your fellow gardner,
Diane
