The MGS Forum

Gardening in mediterranean climates => Pests and diseases => Topic started by: Chantal on June 25, 2011, 07:01:18 AM

Title: aphids on Cercis siliquastrum
Post by: Chantal on June 25, 2011, 07:01:18 AM
What can I do to get rid of the aphids on Cercis siliquastrum. I live in Montpellier (France) and I am not the only one here, to have problems with aphids on this tree and other shrubs of course.
My tree is very old, but flowering very freely in spring. The aphids arrive late, just after the leaves have grown. I don't particularly hate the aphids, what I don't like is the honeydew (I hope it is the right word in english) caused by the ants which are breeding the aphids.

Chantal
Montpellier (France)
Title: Re: aphids on Cercis siliquastrum
Post by: David Bracey on June 25, 2011, 08:36:16 PM
Chantal, you have two possibilities.  The first is to leave the aphids to get on with their lives and to hope that some predator such as lacewings, or ladybirds or something will come along and gobble them all up, or you give spray them with an aphicide such as deltamethrin which was discovered and patented in France.  It is very effective but being a synthetic pyrethroid it is very broad spectrum and will thus kill both good and bad insects.  Frankly if you spray the target only, there are plenty of areas left you predators to live and multiply without radically disturbing the ecology of the site. Bon choix. David
Title: Re: aphids on Cercis siliquastrum
Post by: Chantal on June 26, 2011, 01:24:16 PM
Thank you very much, David, for your answer.
I am sorry to tell you that, considering the width and heigth of the tree, it is an impossible task to spray everywhere. I will need a crane.
Perhaps, it is not so annoying, because, it happens each year and it flowers again each year.


Title: Re: aphids on Cercis siliquastrum
Post by: David Bracey on June 27, 2011, 08:04:08 AM
If it occurs every year  there shoud be a build-up of predators but as you know they generally arrive after the damage has been done.  I had C siliquastrum "Forest Pansy" - a super tree with leaves edged in purple -  in Uzes and each year it was attacked by a mysterious leafhopper and each year it was practically defoliated but each year it came back.  Result was a "little" tree.  Not very satisfactory.

Bisous David
Title: Re: aphids on Cercis siliquastrum
Post by: Chantal on July 02, 2011, 07:21:33 AM
Dear David,

Thank you for your answer.