River birch aphids

Asked May 29, 2016, 6:52 PM EDT

What systemic insecticide do you recommend to treat my 3 year old river birch tree? The leaves on the younger branches are full of aphids and their eggs. There was also a 1/4 inch red and black caterpillar on one twig.

Anne Arundel County Maryland insect id

1 Response

We hear about this often as it is common in our area.
Sounds confusing, but this is the work of the witch hazel gall aphid, which has a complicated life cycle.
We don't generally suggest treatment, as beneficial insects help to control it. It would be too late to do anything now anyway.
Here is a publication on River Birch, which includes information about this insect.
https://extension.umd.edu/sites/default/files/_images/programs/hgic/Publications/HG58_IPM_Birch.pdf
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