Birch Aphids

[eaa]

Our large weeping birch tree is dropping leaves as if it were autumn and has many aphids on the branches. Tree is approx. 60' tall. How should we treat the aphid problem? Can we do it ourselves? (Spraying the leaves is problematic due to size.) Can we treat it this time of year? (July) Thank you in advance for any advice you can give!

 

[Ekka]

Sounds like it could be a seasonal problem, the tree could be slightly stressed with the summer.

So ensure tree is getting sufficient water, preferably have mulch around it but not up to the trunk, organic fertilizer is always good beneath the mulch.

Due to the size of the tree you can forget about sprays which only leaves systemmic insecticides to do the work. It would be good to have natural biological controls, ladybugs etc feed on aphids. Ants are also bad news, if they're in the tree that's not a help, lightly band the trunk with adhesive tape so the ants cant travel up and down the tree, change it every few days, like masking tape applied sticky side out.

Now the danger of using chemicals is that the good bugs also get killed and the bugs themselves can build up resisitance to the chemical. So it's important to get the health and vigor of the tree into shape.

You can purchase a range of insecticides from the local nursery etc, I would suggest the application method be via soil treatment and watering in. The roots will take up the chemical. Follow directions carefully.

Some brands/names etc off hand are Talstar, Metasystox-R®. Try not to do tree injection ... why wound the tree. Remember that roots can travel further than the drip line.

There are natural alternatives but only as a foliar spray, once again, due to size you'll have to go with the soil application method.

Good luck

 

[darkstar]

climb to top of tree with garden hose attached to sprayer with dawn dishwashing liquid in it.... thourghly soap entire tree . especially underside of leaves .....re soap in one week ... works great with aphids for me but its hard to do with a big tree ....

 

[treeman45246]

More information on the aphid. The damage is primarily cosmetic, and does not threaten the health of the tree.
http://64.233.167.104/search?q=cach...O17.PDF+"hamamelistes+spinosus"&hl=en&start=8
Dropping leaves is typical of birch, tulip poplar, and other water-loving trees this time of year. As the soil dries out, the tree loses its least efficient leaves and supports the others with the remaining moisture.

 

[Chucky]

EAA, I don't want to come off as alarmist, but from your description it sounds like you have a very mature European White Birch, not a River Birch. White Birches are not really water-loving trees like a River Birch, nor are they very tolerant to drought. They are fairly suseptible to aphids, and especially as your Birch has about reached its age limit, severe defoliation by aphids will weaken the defenses of the tree to the extent where more aggressive pests, such as the Bronze Birch Borer, will quickly colonize the tree and kill it. The soaping method suggested by Darkstar is effective, but do you really want to climb a 60' Birch? I agree with EKKA in that watering, fertilizing, and mulching is very important, expecially mulching to protect the tree's roots from the Sun's drying out the roots. Very important in White Birches as they're not accustomed to a lot of heat. But realize that in an overmature tree there sometimes is little to do to prevent death, no matter how much you treat it. If the tree is especially dear to you, consult a certified arborist to inspect it.

 

[kgbtechie]

I had a problem with aphids on my Honey Locust, extremely annoying problem. We finally went here: http://www.buglogical.com/ and got a bag full of ladybugs and lacewings every year. They love them aphids and got rid of them in not too long of time. I have asthma, and not only cannot have the spraying in my yard, but if affects me when others spray. The past few years the government has been heliocopter spraying long island in NY due to problems with Mosquitoes and the west nile virus-bad news no matter how safe they say it is. If their natural predator will eat them, why not give them a try first

 

[eaa]

Thank you to all for your advice. Now we just need to choose course of action: the "natural" approach certainly appeals to me, so we'll try that first - ladybugs and mulching roots. I did consult a local tree-care person who will charge $200-250 to come "inject" the tree - he recommended doing that now and again in the winter. I surely appreciate all the input we received in response to my inquiry. Thanks again for a great resource!