Pictures from the Hainault website:
![](https://lh3.googleusercontent.com/blogger_img_proxy/AEn0k_uzbbnK9wwqNsw2t0mhXJog6aITnpnoEVyZMa_eBt6DVJGaaszngCyvU7JtNgwqtBydCV2gfjAGXPxQ5Nh33LETTlMMaNv50XCKfbNGvGHzf32XQoAaj8ieooG5w8ucIteWtwXKQOf9AcsM=s0-d)
Aculus leionotus, a sort of uneven blister above, erineum beneath. Looks very like what I saw today.
![](https://lh3.googleusercontent.com/blogger_img_proxy/AEn0k_swQYsLSA9csKq2fZjOOVUHxHFQuu-HcCLac0RqOuBTLP6ulFpe3FRkAsqoZSKAcl6555_F7va-xQZP7z5h0e6fU97oW8Z76a0aHoSB2c1dfibKYpQ4-A=s0-d)
Circular blister on both sides of the leaf. Anisostephus betulinus.
![](https://lh3.googleusercontent.com/blogger_img_proxy/AEn0k_vn3Ap2puCixZFC20wK-wL3tkM-jMlou7vfFshOmv0kqFYwUTCrt6UnWOnN5y7QbTsA8NF5jrSkr6obzjr0hYWLDAuNf7nV1F0DLrptpWNms2inNItGx0Y=s0-d)
Silver birch hemispherical gall. Cecidophyopsis betulae.
![](https://lh3.googleusercontent.com/blogger_img_proxy/AEn0k_uxAdeRjzVngwcECU7aS-I0k6fM39ERhSWJCj4YU7hikP9UVse4w619BzeqSeeUbIQtZtABoXaA9bFJxOMFEy1_EM0uaJN4EDONUZZymQTwTKwkJUhgHORmgA=s0-d)
The hairs of the erineum are described a reddish-brown. However I am seeing tufts of white in a similiar situation, could this be just as it develops? Aculus leionotus. I have also seen this, but both species cannot be A. leionotus.
Aculus leionotus, a sort of uneven blister above, erineum beneath. Looks very like what I saw today.
Circular blister on both sides of the leaf. Anisostephus betulinus.
Silver birch hemispherical gall. Cecidophyopsis betulae.
The hairs of the erineum are described a reddish-brown. However I am seeing tufts of white in a similiar situation, could this be just as it develops? Aculus leionotus. I have also seen this, but both species cannot be A. leionotus.