The Value of Christmas Trees

"...there is no reason why the joy associated with the Christmas evergreen may not be a means of arousing in the minds of children an appreciation of the beauty and usefulness of trees; and keen appreciation of the beauty and usefulness of trees is a long stop toward the will to plant and care for them (Arthur Sowder, US Forest Service, 1949)."

Monday, August 15, 2011

Cinara Aphids

Cinara aphids are some of the largest aphids in the world.
I can't believe I've never had a post just on Cinara aphids! Now is the time the people are starting to think about them. I talked to 2 or 3 growers last week who asked the same question -- is it too early to treat for Cinara aphids and keep them out of my go-to-market trees? Sadly, there isn't an easy answer to that question.

I talked with only one grower so far that has seen Cinaras in his trees this fall. Mostly they aren't seen until they show up in someone's home. Many people now treat preventatively for the pests, using Talstar or Wisdom which are both bifenthrin products in late September or October. But now is still a good time to treat for elongate hemlock scales with Asana and Dimethoate. And if you know Cinaras are in your trees now, should you wait until October or go ahead and spray?

The question that we don't have an answer to is how quickly do these aphids move into new areas. Some individual aphids have wings, allowing them to fly into trees. However, they aren't very good fliers. Basically all they can do is get up in the air and allow the wind to carry them places. They don't direct their flight like a fly or a bee.

A winged individual. 
Once they are in suitable locations, they lay live young, so their numbers can quickly rebound. However, most of the pesticides that people are using will last several weeks on trees. Therefore it would seem unlikely for Cinaras to move into trees treated in mid-August by mid-November, though the possibility exists. It would depend on each grower's concerns about the pest and how they are applying their materials. Spraying with a mistblower may allow quicker build-up again, while using a high pressure sprayer and getting good coverage will more likely take care of the problem from now until harvest.

One reason to go ahead and treat now is that most of the aphids are still higher up in the tree where they are more easily controlled. As it gets colder, it seems that the aphids move to the lower branches, making it harder to get a chemical to them, and certainly with a mistblower.

When Cinara aphids are on the trunk of the tree, it is harder for a mistblower to reach them.
No matter if you treat now or wait, there is a new product on the market for pest control in Christmas trees including Cinara aphids. Sniper, which is a 25% bifenthrin product, is now labeled for Christmas trees. It should be cheaper than Talstar. Click here for the label and msds sheets.

And what about the Cinara eggs? I've only seen them once in all my nearly 23 years working in the industry!

Cinara aphid eggs found in Ashe County about 10 years ago.
In the literature, different Cinara species only lay eggs infrequently. So basically, growers are fighting a live aphid that can reproduce very quickly. And if anyone does see these eggs, please give me a call. I'd love to see them again!

Whenever you are in your trees this fall, be sure to look closer if wasps or yellow jackets are interested in your trees. It could well be Cinara aphids. This typically happens during warm, dry days in the fall when the wasps are especially active. Beat the foliage of a few of these trees to see if aphids fall out.

Wasps are attracted to the sweet honey dew that aphids secrete.
You sometimes find Cinaras when you are beating the foliage to find other pests.
Also be sure that the folks tagging and harvesting your trees can recognize the aphids and their characteristic purple smear.

If you do end up with problems with Cinara aphids on harvested trees, remember these links for information. If you have a retail-lot, you might want to make a few printed copies of the last link in case of problems.


I am always happy to speak with your customers about this pest problem should the need arise.

15 comments:

  1. Our Christmas Tree, frasier fur from NC, is infested with thses aphids. My estimation is we have vacuumed up between 300-500 of these little devils. We sprayed under the tree with our home pest spray so the ones that fall off do eventually die but it looks so nasty. Tonight we sprayed the tree interior area with a water and Dawn detergent mix to try and get rid of more of them. We could also clusters of them in all different sizes on the lower branches. I have a house full of company coming for a week starting next week with a 2 year old. Any suggestions?
    Thank you for your help.
    Vickie in bug land SC

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  2. Were from Miami, FL and purchased a tree form the local tents that go up for the holidays. They are from Delaware I believe. Just our luck , it was infested with aphids. They were crawling all over our house, I mean everywhere! We had to dismantle the tree and return it for a refund.

    Truly wish the tree farmers would keep a better eye out for these. Seems most have become so passive on this problem. I'm sure they will think different next year as there were a TON of folks returning trees!

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  3. We are from Elora, Ontario Canada. We had an unbelievable investation on our tree. Spent an entire week cleaning up after them. The last live young that I have noticed died just two days before Christmas. The Nursery owner wanted to replace my tree with another same variety. Like I wanted to bring another host tree into my house. Where's the consumer information to warn about this from the selling merchants.

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  4. I have a huge tree that we bought from NC at a farm we always go to. It's infested with these, and the sap is dripping from every branch all over my ornaments, ruining my floor, and I don't know what to do. I'm trying to spot spray with an insecticidal soap, but there are just too many, and having to dodge my ornaments. I also have to keep a fence around the tree to keep the animals away from the pesticide and drinking the water. I don't like having to spray it in the house with little kids around either. I feel like I need to pull the tree down and give up. I'm devastated 2 weeks before Christmas about this. Not sure if I took it outside if we could hose it down with water and soap, or is it even worth it? We can't return it for a refund, the place is in the mountains 4 hours away. Wondering what the chances are if I remove the tree and buy a new one locally here in Georgia, already cut, that it too will have aphids. What a nightmare.

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  5. Man...Sounds like this is the year to aphids. I have a tree (white pine) purchased and fresh cut locally in the Knoxville, TN area. When we were in the field we noticed we got a couple small black bug on us when cutting the tree, but as my husband kept saying, "it is outside, there are bugs". Not knowing about the aphids we took the tree home and decorated it. Well 2 weeks later I have tree crawling with aphids, ornaments and lights COVERED in sap and honeydew and have already had to replace the tree skirt. I cleaned up hundreds of dead ones/discarded eggs last night. I grew up with fresh white pines and have NEVER seen anything like this. Sprayed the tree with a water/Dawn mixture and hoping to keep them under control for 12 more days. This was our first Christmas in a new home and this has been really horrible to deal with. I am hoping my ornaments will survive. I REALLY wish the tree farmer would have said something or looked closer at the tree. Now that I know what to look for it is obvious the tree was COVERED in these creatures, even in the field.

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  6. I'm in MA and we went for a 12' Fraser Fir this year. It cost us a fortune and I can't wait to take it down. We, for the first time ever, have these little pests. The vacuum has become a permanent fixture in our living room. I have not tried spraying the tree with the water/Dawn mixture but I'm going to give it a try. The tree was up and decorated for a couple of weeks before we started noticing the aphids. We, like the rest of you, don't want to invest the time in dismantling the tree only to redecorate it. I'm hopeful that we can make it through the holidays without the problem getting worse.

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  7. I purchased our frazier fur in Milwaukee, WI and put it up three weeks ago, but wasn't able to decorate it until Sunday, December 16th. Woke up Monday morning with these little pest everywhere throughout the living room, dining room, bathroom and kitchen. I'm on vacation from work, and spend all day yesterday and today combatting these little jerks. They say don't give up on a real tree, as this is very unlikely to happen twice in a lifetime...I guarantee it won't happen twice as I will hit the after-Christmas sales for an artificial tree. This is nuts!!! Two days straight and who know how much longer with this war!!!

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  8. We are in Niagara Region, Ontario and purchased a Frasier Fir from our local Home Depot back the first week of December. Saw a tick looking insect the other night, squished it and looked around, didn't see anything else. Last night before bed (Dec 26) my husband called me down thinking our dog had ticks - a bunch of these black bugs all under the tree. Took a closer look - tons of them, as well as a huge amount of pale shell looking things all collected on the skirt. I just shook the skirt out 2 nights previous and didn't notice anything - but it looked like dandruff all over the skirt last night. Threw the tree (lights and all) out on the front lawn in the middle of a snow storm and spent the next 3 hours sanitizing our living room and using a steam cleaner to clean the floors. This is our last real tree - going the artifical route after this - horrid experience! So disgusted!

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  9. We're in Northern Virginia. Just before Christmas, I left the presents under our Fraser Fir while my husband loaded the kids into the car and we left to spend the holidays in Chicago. When we arrived back home last night, the kids ran to the tree to open the presents "Santa" had left. All the presents were covered with what initially looked like specs of dirt. Upon closer inspection, I was horrified (and the kids grossed out)to discover these were actually bugs! What should have been a joyous celebration turned into me shaking out each gift and the kids barely willing to touch the presents to unwrap them. Although, I told the kids we could always donate the presents, they managed to get over it as we moved the presents away from the tree. Now comes the disgusting job of dismantling this tree, knowing that it's full of bugs!

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  10. I live in northern British Columbia and I have these aphids on the spruce tree in my yard and it is slowly dying, any suggestions on what I can use to get rid of them? We tried soap and water but it didn't work

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  11. We live in North Carolina (Raleigh) and have always had a fresh tree for Christmas but was unaware of these bugs until I saw these black spots on the floor which I thought was lint. Then I saw some of them move and after looking them up online, realized they were aphids. I guess tree growers are supposed to spray for these during the growing season so not sure what happened here but I have vacuumed up hundreds of them already. I wonder when they will stop appearing! With Christmas being a week away, we are going to stick it out and most likely take the tree down sooner than we usually do unless they stop appearing!

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  12. Addendum to my previous post -- the tree guy is going to come and set off a bug bomb tomorrow so hopefully that will help.

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  15. No matter how clean you keep your grow room, you will at some stage get mites/aphids on your plants!
    Hopefully this quick guide will help you control the bugs safely.

    How do bugs get on the plant in the first place? - The eggs can be in the soil you use... you can inadvertently carry the bugs in on your clothes, hands, shoes etc after being in the garden... other houseplants bought from garden centres are often crawling with them... or even your old dog could carry them in... Suffice to say that there are several ways for bugs to get into your home and find their way to your grow room!

    There are two main bugs that invade our grow rooms, the first and most common is the Spider Mite...

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