By DANA TIMS/Lincoln Chronicle
YACHATS — Joanne Kittel could only stand and watch recently as Sitka spruce needles rained down onto the driveway of her forested property on the edge of Cape Perpetua just south of Yachats.
“I knew that aphids were causing the problem because I’ve had them before,” Kittel told Lincoln Chronicle. “But nothing like this. It’s a pretty helpless feeling.”
She’s not alone in reporting significant visual damage from Sitka spruce aphids, a long-established exotic and invasive species along the West Coast, including Oregon.
In fact, state and local officials have received enough reports of dead and dying spruce needles that they have scheduled a public meeting next month in Yachats to discuss the tiny insect that is mostly responsible for defoliating Sitka spruce in and around Yachats. But well before the meeting begins at 9 a.m. July 11 in the Yachats Commons, they want the public to know that spruce aphids are far more of a nuisance than a real threat to most coastal trees.
“Trees affected by spruce aphids present an eyesore that looks worse than it is,” said Dan Stark, forester agent with Oregon State University’s extension service in Lincoln County. “But it’s certainly fair for people to be concerned and I have definitely received some calls recently from folks asking ‘What’s happening to my tree’?”
Any damage now being seen, he said, was actually inflicted in late February and early March, when aphid populations increase dramatically.
The insects, which can be either winged or wingless and as small as a grain of rice, feed on the sap of older spruce needles, causing them to fade or turn yellow, triggering the fall of those needles between May and June each year.
When damage is finally apparent, the aphids have usually already dispersed to other trees, Stark said.
Any actual tree mortality that ensues, however, is usually due to a variety of factors beyond just the presence of aphids, he said. Trees may have been planted too closely together, destabilizing their roots, or may be having a hard time surviving in poor soils.
If a property owner has a prized spruce that appears to be endangered, chemical agents can be applied to help control future aphid development, Stark said.
But even then, he noted, there can be drawbacks to that approach.
“Aphids have natural predators, which always help control their numbers,” Stark said. “But when you spray with something, you’re also spraying all the other beneficial insects in the area. You do risk getting rid of those things, as well.”
In addition, aphids aren’t known to feed on new needles, meaning a lack of back-to-back outbreaks of aphids will be sufficient to enable most mature trees to continue to thrive just fine.
And based on prior years’ experience, consecutive outbreaks are not common, Christine Buhl, an Oregon Department of Forestry entomologist, said in a news release.
“We don’t typically see back-to-back outbreaks in the same areas, but because outbreaks often occur after a particularly warmer than usual winter or when we don’t get a late cold snap, it is possible that we will eventually see more outbreaks one after the other.”
In Kittel’s case, however, she is seeing for the first time this year some evidence that aphids have been feeding not just on the older needles they traditionally prefer, but on her trees’ new growth, as well.
“For the first time in the 38 years I’ve lived here, this is the first time I’ve seen this,” she said. “At this point, I just have no idea if any of the trees will end up dying.”
She also offered her own prescription for how to fix the problem.
“All we need are a couple of good hard freezes this winter,” Kittel said. “We haven’t really had one in a good, long time. If we get a couple of those, aphid numbers will fall way down and my trees will be in great shape again.”
Doors open at 8:30 a.m. for the July 11 informational session at Yachats Commons. For more information and to RSVP, contact Stark at dan.stark@oregonstate.edu.
- Dana Tims is an Oregon freelance writer who contributes regularly to Lincoln Chronicle and can be reached at DanaTims24@gmail.com
I don’t think we are paying enough attention to this as a major fire risk especially during with July 4th right around the corner, seasonal winds and drought conditions. I hope that fire agencies in the county is paying attention and mobilizing resources for worst case scenarios. The sap, tinder dry stripped branches and sticky needle litter of thousands of trees should be a huge concern.