[when on S. canadensis]:
"5- to 15-mm diam. when larvae mature, nonmarginal galls round to elliptical, but marginal galls lunate…Color variable: yellow, gray, buff, or purple with a pink center and ringed with white. Strikingly different-colored galls sometimes appear on the same leaf. Circular galls usually contain more than 1 larva but marginal galls typically contain only 1."

[when on S. juncea]:
"circular, about 3-4 mm diam. with only 1 larva/gall. Color dark gray with white or yellow margin becoming dull black or brownish when larva is mature."

[Also lists the following host records for this species, verified by both host and insect identification: verbatim name [current name]: Solidago angusta [S. petiolaris var. angusta], S. arguta, S. caesia, S. californica, S. canadensis [S. canadensis, S. altissima, and presumably other very close relatives], S. chadonnetii [S. rigidiuscula], S. concinna [S. missouriensis var. extraria], S. confinis, S. curtisii, S. delicatula, S. dumetorum [S. gigantea?], S. elliotii [S. latissimifolia], S. erecta, S. fistulosa, S. gigantea, S. juncea, S. missouriensis [S. missouriensis var. missouriensis], S. mollis, S. nemoralis, S. rigida, S. rugosa, S. sempervirens [S. mexicana, based on location], S. sparsiflora [S. velutina], S. speciosa [S. rigidiuscula], S. squarrosa]

[Also lists the following probable host records for this species, based on records of leaf spot galls. Without a definitive insect ID, it is possible, though unlikely, that these could represent other Asteromyia species, namely, A. modesta : S. angusta [S. petiolaris var. wardii, based on location], S. mollis [S. radula, based on location], S. sempervirens [S. sempervirens s.s., based on location], S. bicolor, S. bootii [S. arguta var. bootii], S. buckleyi, S. multiradiata, S. confinis [or possibly refers to S. spectabilis/guiradonis], S. decumbens [S. gutinosa], S. odora, S. ohioensis, S. pinetorum, S. roanensis]

Asteromyia carbonifera (Osten Sacken) is a multivoltine species which produces a blister leaf gall on Solidago rugosa.

Leaf blister gall. Galls contain a symbiotic fungus that apparently is not eaten by the larva. The fungus turns hard and black and becomes incorporated with the plant tissue as the larva matures. This species is found on most goldenrods and is widely distributed across North America. As the season progresses, galls develop on leaves progressively farther up the stem. The color of the galls is characteristic of the host species. The size is variable also, 5-15 mm in diameter on S canadensis with one to several larvae, 3-4 mm in diam on S juncea with one larva. Hosts: most species of Solidago.