Black Willow Aphids, we believe

Subject:  Interesting bug
Geographic location of the bug:  Michigan
Date: 08/20/2018
Time: 11:03 PM EDT
Your letter to the bugman:  Hello bugman!
Can you tell me what this bug is? We seem to have an infestation outside and I am a bit worried about our small children and pets. Can you help me?   Thanks for your time in advance!
How you want your letter signed:  Megan O’Dell

Black Willow Aphid

Dear Megan,
Your image lacks critical clarity, but we were convinced these were Giant Aphids in the subfamily Lachninae, though BugGuide does not picture any individuals with the bright orange tubercles on the individuals in your image.  We then located an image of the Black Willow Aphid,
Pterocomma salicis, on Influential Points where it states:  “The black willow bark aphid forms dense colonies on two-year-old twigs and wands of willow (Salix spp.). It is usually attended by ants. Apterous males and oviparae occur in October-November. It is widely distributed in Europe and Asia and has been introduced into North America.”  The Black Willow Aphid is also pictured on BugGuide.  We believe that is a correct ID.  Do you have a nearby willow tree?

Thank you very much for getting back to me. It was hard to get a good picture of the bugs up close.  Sorry 🙁
We do have two huge willow trees.  Are they a danger to the trees?  I have never seen them in any previous years and I have been here my whole life.  I worry if they are eating away at the trees, the trunks are probably 4ft in diameter and would crush our house.
Thank you again for the advise and information!
Megan O’Dell
Hi again Megan,
Aphids feed by sucking fluids from plants, generally on the tender tips of branches, so they will not be eating the trunks of your trees.


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BugMan aka Daniel Marlos has been identifying bugs since 1999. is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

1 thought on “Black Willow Aphids, we believe”

  1. Have circles of peeled bark around the lower base branch (up to 4′ or so) on some of the black willows around a stream. Sometimes just one horizontal circle of peeled bark, and sometimes several of the perfectly horizontal peeled circles close together on the bark from ground up to about 4′. What is it? How can I kill it. Live in central Colorado.


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