Question by Charity W.
We have a small property with a very large dam in Victoria, near Yackandandah. There are some old willow trees which we believe have an aphid problem, after reading about all the signs, like the honeydew sap dripping from the leaves. We would like to treat the trees to stop aphids, but not sure what to use that is environmentally safe. There are several large trees to be treated, near water, which is used for stock and domestic and also has native fish in it. Do you have any suggestions? Thank you.
Sarah's answer
Hi Charity,
Giant willow aphid is a recent pest spreading around the world with sometimes devastating effects. Not only the sap sucking harms the tree, but also the honeydew is sticky and attracts wasps and sooty mildew, which is unsightly and can prevent the plant from photosynthesising.
As your trees are so close to an aquatic environment, it can limit the options for treating this problem. As it is a relatively new pest and is listed as a Priority Insect Pest in your State, I would suggest you contact your local government agriculture biosecurity department to seek the most recent and best advice for dealing with this problem in the safest way possible for your livestock and waterways.
All the best with it.
Cheers Sarah
