Yesterday – the blue spruce in cemetery has turned brown instead of blue. All the needles on the tips are gone!!
A previously healthy tree.
What to do ? Internet says “Saw Fly” & to spray with soap and pyrethium ? Your advice please with MANY THANKS.
It is difficult to accurately diagnose the problem you are describing so, I would suggest you take a closer look at the tree to see if you can find some of the markers to it being infested with sawfly. These include – the presence of webs between the needles, damage starts at the top of the tree and radiates downward, looks like the tree has been burned and the presence of actual sawfly larvae (caterpillars) feeding on the needles.
Sawflies can be identified at this developmental (caterpillar) stage by – having 3 sets of true legs at the front, 5 or more prolegs (stumpy) extending down the length of the body, a round button like head (often a different colour to the body), waxy skin with no noticeable hairs, they usually curl defensively overlapping their bodies when threatened and depending on their age can range in length between 10-40mm.
Whether or not you determine this is indeed a sawfly infestation, I would suggest you contact the cemetery management to have the tree professionally looked at and treated if necessary, as it is not advisable to take on this job yourself.
Hope this is helpful.