European Pine Sawfly
We have an infestation of what appears to be Neodiprion sertifer on our mugo pines here at our office in Albany. How common are these pests in the Northwest, and what is the best control? Thank you, Bill Marshall, Landscape Construction Manager, Stutzman Services
Linn County Oregon
I am not aware of the European Sawfly being here in the western US, so you are probably looking at one of our native sawflied.
I have certainly seen sawfly outbreaks on our native Valley ponderosa pine in the past, although not frequently and not recently. They were also short lived. They are alarming to people because they can strip off the needles pretty well. But because they eat the old needles and not the new needles, I have not seen them be all that destructive. The p pine can survive just fine on its new growth of needles.
Now the situation might be quite different in landscapes, since the aesthetics and growth and survival count. I will include links to the PNW handbook as it relates to ornamentals, including some control measures. I will pass this on to colleagues as a heads up (we like to know if we are seeing lone events or build ups) and will get back to you if I learn anything new or significant.
Also, you can follow up by email at email@example.com if you need to.