Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Giant Willow Aphid - Tuberolachnus salignus

Giant Willow Aphid - Tuberolachnus salignus
Riverbanks Zoo, Columbia, Richland County, South Carolina, USA
November 17, 2004
Note, I originally thought this might be a true bug nymph, but we've since identified it as a Giant Willow Aphid.

I found this bug crawling on a fence at the Riverbanks Zoo. I coaxed it onto a lighter colored sign. The body length was about 6mm. Is it a bug nymph? I didn't see anything similar while browsing the BugGuide True Bug images.

Giant Bark Aphid
I believe that this is Longistigma caryae.

Giant Willow Aphid?
I never thought about the aphids. I looked up images of the Giant Bark Aphid and they didn't look quite right to me. However, I came across the Giant Willow Aphid. See this image and also this page.

I've seen two latin names listed, Pterochlorus viminalis and Tuberolachnus salignus. I'm not yet sure if those are two distinct aphids with the same common name or synonomous names.

Giant Willow Aphid
At Troy's suggestion I contacted Dr. Tilly Collins, who studies these aphids. She graciously provided the ID as Tuberolachnus salignus and noted that Pterochlorus viminalis is not a valid species in her references. She also stated that the Northern Virginia Ecology page I linked above cotains several errors, including the images and its description of the aphid's reproduction. She says the Giant Willow Aphid is "genetically incompatible with sexual reproduction and reproduces parthenogenetically year-round."