Can you help me identify this disease: Is it Pine needle scale (Phenacaspis pinifoliae)? (The yellow colour of the needles is the natural colour of this pine :Pinus sylvestris 'Wolting Gold' in winter.) What would be the appropriate treatment? We cannot buy any insecticide in Ontario. Will it kill the plant? Thanks
It sure looks like it. As for treatment, here is what the Missouri Botanical Garden recommends: Properly timed dormant oil spray. A very effective control is to use a dormant oil spray in late March or early April, before new growth begins. The oil coats the scales, preventing oxygen intake so the insects suffocate. Dormant oil sprays are nontoxic to humans, birds, and pets, but must be applied at the right time to be effective and prevent damage to the plant.
Thanks for your help Sundrop. Any idea that late March time frame pertains to what weather Zone? I am in USDA Zone 4-5; Canadian Zone 5b.
Missouri roughly encompasses hardiness zones 5b to 7b, see http://www.gardeningknowhow.com/wp-content/uploads/2004/10/missouri_map_lg.gif, so late March there could probably correspond to the middle or late April where you live. Anyhow, I believe what is important is that you do it shortly before new growth starts.
