Dysaphis spec.
on Crataegus

Crataegus monogyna, Belgium, Antwerp, Wilrijk; © Chris Snyers
notes
Some five Dysaphis species live on hawthorn as their primary host plant, and cause there deep red blister-like leaf galls. They have different Apiaceae species as secondary host; morphological differences between the aphids do exist, but they are minimal.
references
Redfern & Shirley (2011a).
Last modified 1.x.2018