"Returning from a walk with the dog I was struck by a mass of bizarre fire orange fungus tentacles covering all the stems of some low lying juniper bushed in our driveway. This is the first time I have seen it in 21 years of living here with the same juniper bushes."
Observation by Shona Thorne:
Returning from a walk with the dog I was struck by a mass of bizarre fire orange fungus tentacles covering all the stems of some low lying juniper bushed in our driveway. Within 2 days the majority of it had shriveled or was in the process of shriveling into small orange specs all over the branches. I did an internet search and believe that it is Cedar-apple rust is or the disease caused by the fungus Gymnosporangium juniperi-virginianae. I am not sure how common it is but I do know that this is the first time I have seen it in 21 years of living here with the same juniper bushes. We do have a couple of crab apple trees nearby which makes sense but it seems it will adversely affect the fruit. I did find this article form 2021 saying it had been spotted in Windsor, Ontario https://www.cbc.ca/news/canada/windsor/apple-cedar-rust-spotted-windsor-1.6018200. Last year a large black bear got most of the end of season fruit when he came in and cleaned up all the trees. Does anyone know if the fungus adversely effects bears?
Follow Up (May 24, 2022):
I will ask Brendan (the Source Tree service) for sure but in the meantime have asked my neighbor – he has been a trapper and logger for >50 years, and another friend who has worked as a logger for over 30 years – neither have seen anything like this before and both have worked with and amongst cedar extensively.
Comment by plant pathologist Dr. Jay Pscheidt, Oregon State University:
Let’s start with some general observations. Cedar-apple rust has never been reported in Alaska, British Columbia or the PNW. That is a technicality in that the specific species of Gymnosporangium virginiana has not been seen on native plants. I have no records on gardens for this fungus either. BUT we do have plenty of other Gymnosporanium species that have a similar life cycle going from a conifer to a roseaceous host. Alaska has only one reported – G. nelconii - while BC has 8 different ones reported on Juniper. One of the alternate hosts is Serviceberry where the fruit are deformed by the fungus. I suspect that if a bear depended on service berry during a particular time of year that it might have an effect. But I think I have been told that bears are very omnivorous and would just look for something else to eat. Even if a bear were to eat a berry with rust it would not be harmed. These are plant parasites and not animal pathogens.That is about as far as I am prepared to go with bears and rusts. I hope that helps a little. Here is a little more reading that might be useful as well: https://pnwhandbooks.org/plantdisease/host-disease/serviceberry-amelanchier-spp-rust