Ponderosa pines are dying throughout the valley where I live here in Eastern Oregon. I have about 100 on my farm and many are hundreds of years old and are dying. I've done basal trunk drenching with Dinotefuran twice a year for a couple of years and it doesn't seem to be helping. I'm wondering about "soil injection" and looking for recommendations on what type of devise and how effective it is. I've also considered trunk injections but have concerns about doing it repeatedly, etc. Any advise would be helpful.
Black pineleaf scale Oregon
- Thread starter Skookum
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ossa
New Member
I don't really have an answer to your question. I also have tried both soil infection and basal trunk sprays with dinotefuran, but I'm not sure if either works. The branches that broke off this winter from high up my 150 foot Jeffrey pine were loaded with black pineleaf scale - and I did spray the tree twice with dinotefuran last year. The trunk is about 3 feet in diameter, so I only sprayed the dinotefuran in the fissures in the bark- the bark is probably 4 inches thick at the base so I saw little point to applying it to the whole surface, I doubt much would translocate into the circulatory system through all that bark.
Have you had any luck with any treatments for black pineleaf scale? It's decimating the forest near my home. I've been spraying the lower branches and the smaller trees with horticultural oil/neem oil mixture and it has helped, but I can only reach about 3o feet up the trees.
Have you had any luck with any treatments for black pineleaf scale? It's decimating the forest near my home. I've been spraying the lower branches and the smaller trees with horticultural oil/neem oil mixture and it has helped, but I can only reach about 3o feet up the trees.
Jason Douglas
ArboristSite Guru
Are drought and bark beetles also problematic in this area? That could help explain lack of control.
Dinotefuron is an excellent scale killer but it's residual is far shorter than most neonics, around 50 days or so. Try a soil soak or injection at crawler emergence followed by some light waterings to help improve translocation if dry soil. Contact local universities for GDD emergence time for crawlers.
An alternative may be using an insect growth regulator rather than a conventional insecticide
Parasitic wasp releases may be beneficial as a supplement as well.
Dinotefuron is an excellent scale killer but it's residual is far shorter than most neonics, around 50 days or so. Try a soil soak or injection at crawler emergence followed by some light waterings to help improve translocation if dry soil. Contact local universities for GDD emergence time for crawlers.
An alternative may be using an insect growth regulator rather than a conventional insecticide
Parasitic wasp releases may be beneficial as a supplement as well.
ossa
New Member
Jason, I have already tried soil injection and basal trunk sprays but neither has worked. One could easily spend a hundred dollars on dinotefuran trying to save a single tall ponderosa or jeffrey pine and some people have hundreds on their lots. California is emerging from the worst drought in 600 years. The forests of the Sierra Nevada have been decimated by drought and bark beetle, and in my area thousands of acres have been lost due to black pineleaf scale alone. The local trees are mostly dead - they've been dying for the last 5 years- with needles completely covered with scale and then a few western pine beetles or ips come along and finish them off. The primary cause of the mortality is the drought ( which is now "over" for the moment) the secondary cause is black pineleaf scale ( in my geographic area anyway) and various beetles (jeffrey pine beetle, western pine beetle, and ips) are the tertiary cause of death ( but they are the ones that usually get blamed!)
As to the parasitic wasp release- I don't have any of those. Do you? No one does. There is no breeding program for the parasitoid wasps that prey on black pineleaf scale. I asked the Forest Service entomologists about this and they practically laughed out loud.
Jason Douglas
ArboristSite Guru
Crappy.
Has the Dino been applied when it's hot and dry out? That's about all I can come up with.
Sounds like introducing/augmenting other parasites and predators may not be in the fed/state budget. They're still air bombing gypsey moths with Bt or mating hormones around here...maybe a similiar approach could work out west
Has the Dino been applied when it's hot and dry out? That's about all I can come up with.
Sounds like introducing/augmenting other parasites and predators may not be in the fed/state budget. They're still air bombing gypsey moths with Bt or mating hormones around here...maybe a similiar approach could work out west
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