Goldenrod Galls

I can't find a single resource online with all these gall-formers in one place, so here are my notes. This is not an exhaustive list, but I'm striving to include as many as I can. Right now, many observations on iNaturalist of Rhopalomyia solidaginis are probably actually other bud-galling species, because I think people are unaware of the great diversity of gall-midges and other gall-formers. However, many of those observations don't really match any of these known ones, either. I think there are quite a few out there to be discovered.
Charley Eiseman has a great series on his blog about goldenrod rosette bud galls:

() = uncertainty in the literature about whether this is a host species, or a note that it more rarely/conditionally serves as a host.

(()) = host not mentioned in literature, but I suspect there might be some iNat observations of this species serving as a host.

gall-forming insect host gall gall description sources
Procecidochares atra S. altissima,
S. gigantea,
S. rugosa,
(Erigeron canadensis),
(Aster sp.)
bud Spring Generation: Large stem galls in base of host containing several larvae.

Summer Generation: Lateral (sometimes also terminal?) bud galls that look like artichokes initially, and eventually open as fly matures. Gall chamber is large and not sealed; somewhat open at the distal end. Each gall has only one larva, unlike in spring generation. Probably has many other hosts, including some outside Solidago.
wikipedia, iNat obs, bugguide, Philips and Smith (1998)
Eurosta comma S. juncea,
S. missouriensis,
(S. rugosa)
rhizome Swellings on rhizomes very near soil line. Sometimes peanut-like in outline. S. rugosa was reported as a host for E. elsa (Phillips 1923, Novak & Foote (1980)), which modern sources synonymize with this taxon. bugguide, Cedar Creek (2000), Novak & Foote (1980)
Eurosta cribrata S. juncea,
S. sempervirens
rhizome "Crown Gall" that begins basically at the soil line (or just under), but grows up and is mostly above-ground at maturity. Like that of E. comma, galls resemble peanuts somewhat. Are the two host-species really hosting the same species? bugguide, Arthr. Fl.
Eurosta floridensis S. fistulosa rhizome Similar to E. comma. Arth. Fl.
Eurosta lateralis S. chapmanii stem Similar to E. solidaginis. Only known from Brevard Co., FL, at least recently Arth. Fl.
Eurosta solidaginis S. altissima,
S. gigantea,
(S. canadensis),
(S. rugosa)
stem round, nearly spherical stem galls. Exterior vestiture depends on host species; hairy in S. altissima (presumably also hairy in S. canadensis and S. rugosa), smooth and shiny in S. gigantea Bucknell solidago gall website, Moffatt et al. (2019) Stoltzfus (1989)
Eutreta hesperis Solidago root source differentiates between rhizome and root galls Stoltzfus (1974)
Eutreta noveboracensis S. altissima,
(S. rugosa)
rhizome bores through rhizomes, (sometimes?) making galls bugguide, Stoltzfus (1974)
Gnorimoschema gallaesolidaginis S. altissima,
S. canadensis
stem ellipsoid stem galls with a characteristic white exit bung Miller (1963)
Epliblema scudderiana S. altissima stem narrowly cylindrical-ellipsoid stem galls. But see also Lasioptera Miller (1963)
Epiblema desertana E. graminifolia stem very narrow stem galls. But see also Lasioptera(?) Miller (1963)
Asphondylia monacha S. juncea,
S. erecta,
S. uliginosa,
S. altissima
bud Early Spring Generation (only observed on S. altissima): Bud galls directly off of rhizomes at soil line, wider and harder than normal buds, single chamber lined with white mycelium. Or, slightly later, bud galls at the tip of longer sprouts that still appear stunted and thickened.

Summer Generation (S. juncea, S. erecta, S. uliginosa and NOT S. altissima): Much more conspicuous apical rosette bud galls, lined with mycelium, 15-30 rosette-units, forming a spherical single structure at the shoot apex. Occasionally found on lateral buds on S. uliginosa, rarely found there on other species.
Dorchin et al. (2015)
Asphondylia pseudorosa E. graminifolia bud Vegetative bud galls usually at apex, but also on lateral buds; Rigid base with dramatically wider leaves than normal, giving the whole structure the appearance of a rosebud. The internal chamber is lined with a white mycelium; inflorescence bud galls are also formed, later in the season. They are difficult to distinguish from normal inflorescence buds. Dorchin et al. (2015)
Asphondylia silva S. caesia bud Very small, single-chambered bud galls at shoot tips. Several very short leaves press together to form a single, mycelium-lined chamber. Dorchin et al. (2015)
Asphondylia rosulata S. rugosa,
(S. gigantea)
leaf snap
Spring-Early Summer: Snap Galls (both hosts): Multiple leaves appear joined together at a blistering point (actually the leaves are "glued" together when very young) to make a single chamber lined with white mycelium. Unlike in A. solidaginis, the galled leaves are often located nearer the plant apex, giving rise to a gradient of snap to bud galls.

Mid-Late Summer: Bud galls (only S. rugosa) on apical buds only, with a single, conical chamber in the middle that is lined with white mycelium. These galls are smaller and flatter than those formed by R. solidaginis, and are composed of fewer leaves.
Dorchin et al. (2015)
Asphondylia solidaginis S. altissima,
(S. gigantea)
leaf snap
Spring-Early Summer: Snap Galls (both hosts): multiple leaves appear joined together at a blistering point (actually the leaves are glued together when very young) to make a single chamber lined with white mycelium.

Mid-Late Summer: Bud galls (only S. altissima) on apical or axillary buds of S. altissima (3-5 cm in diameter), with a single, conical chamber in the middle that is lined with white mycelium. Unlike in Rhopalomyia solidaginis galls, the central chamber is visible without dissection, and the gall walls are lined with thick white mycelia. The rosettes are also smaller in size, and flatter (not tufted).
Dorchin et al. (2015)
Asphondylia sp. (S. bicolor galler) S. bicolor bud S. monacha-like galls (and insects) that are distinct from A. monacha according to molecular phylogeny. Could be the same species as A. sp. "S. sempervirens galler". One S. uliginosa rosette gall adult also sorted into this clade, while others sorted into S. monacha. Dorchin et al. (2015)
Asphondylia sp. (S. sempervirens galler) S. sempervirens bud S. monacha-like galls (and insects) that are distinct from A. monacha according to molecular phylogeny. Could be the same species as A. sp. "S. bicolor galler". One S. uliginosa rosette gall adult also sorted into this clade, while others sorted into S. monacha. Dorchin et al. (2015)
Asphondylia sp. (S. uliginosa galler) S. uliginosa bud See comments for A. "sempervirens galler" and A. "bicolor galler". Distinct, at least, from A. monacha, though that species also forms rosette bud galls on S. uliginosa Dorchin et al. (2015)
unknown, but Asphondylia suspected S. nemoralis leaf snap Leaf-snap galls observed rarely, but insect unknown Dorchin et al. (2015)
unknown, but Asphondylia suspected S. tortifolia* bud A. rosulata-like galls in October, but insect unknown Dorchin et al. (2015)
unknown, but Asphondylia suspected S. patula bud Aggregated bud galls like those of A. monacha known, but insect unknown. Could be A. monacha, or another gall-maker. Dorchin et al. (2015)
unknown, but Asphondylia suspected S. odora bud Aggregated bud galls like those of A. monacha known, but insects unknown. Could be A. monacha, or another insect. A. Diamond has observed galls in Alabama on S. odora that closely resemble R. solidaginis galls on S. altissima. These may or may not be the same galls Dorchin (2015) is referring to. Dorchin et al. (2015), iNat observation
Dasineura carbonaria E. graminifolia bud Shoot tip bud galls, loose, with twisted and/or inrolled leaves Dorchin et al. (2007)
Dasineura folliculi S. rugosa,
S. gigantea
bud Shoot tip bud galls that resemble other bud galls, but are looser and show evidence of feeding (yellowish spots) on the distal portions of the gall leaves Dorchin et al. (2007)
Rhopalomyia bulbula S. juncea bud Only a spring generation is known, but the insect is presumably multivoltine;
Spring Generation: Clustered on rhizomes, at bases of spring shoots. Gall resembles a bud, with acute apex and base. Surface smooth and white, green where exposed to light. Single chambered.
Dorchin et al. (2009)
Rhopalomyia capitata S. gigantea,
S. leavenworthii,
(S. altissima),
((S. canadensis))
bud Spring Generation: Few (1-8) conical chambers surrounded by disorganized small leaves, sheathed (initially at least, sometimes loosening) by several wide leaves. Distinctly more conspicuous than R. solidaginis spring galls.

Summer Generation: apical bud gall with many small leaves of uniform length in the middle, surrounding many (6-20) closed larval chambers. Wide leaves also sheath these galls. The small leaves give the overall gall complex a flat-topped appearance.
Dorchin et al. (2009)
Rhopalomyia anthophila S. altissima capitulum Capitulum galls among the inflorescence. Cylindrical, or like a truncated cone. Fuzzy and whitish. Inner chamber conical with thin walls. Dorchin et al. (2009)
Rhopalomyia lobata E. graminifolia bud Multi-chambered galls in apical and lateral buds. Start as 1 cm globular swellings in shoot tips or clusters around the shoot tips. Several leaves surround the spongy mass at the gall base, which grows to 6 cm. Eventually the leaves loosen and the whitish tissue reveals 5-35 larval chambers. The leaves continue beyond the gall, thinning towards the apex. Dorchin et al. (2009)
Rhopalomyia hirtipes S. juncea bud Fleshy bud galls at shoot apex, but shoots often arrested when very short. Gall initially has a tapered tip, but this disappears with growth, the whole gall becoming ovoid and reminiscent of a potato. Spongy and usually multi-chambered. Dorchin et al. (2009)
Rhopalomyia solidaginis S. altissima,
S. canadensis,
S. rugosa,
((S. odora))
bud Spring Generation: Inconspicuous, shoot tip bud galls, often stunting the shoot.

Summer generation: each of multiple (2-5) chambers is surrounded by a group of very short and narrow leaves, which in turn are surrounded by longer and wider leaves to form a distinct subunit within the gall. The whole complex makes a conspicuous rosette.
A. Diamond has observed similar galls on S. odora; I'm not sure if these are the galls that Dorchin (2015) refers to, and suspects an Asphondylia of making. At least superficially, they resemble R. solidaginis galls moreso than Asphondylia monacha galls.
Dorchin et al. (2009)
Rhopalomyia thompsoni S. altissima bud Spring Generation: Solitary or clustered, bulbous, fleshy masses with 1-8 chambers each. Start on rhizomes but become apparent above ground by emergence in early May.

Second Generation: Brownish, globular multi-chambered swellings of the rhizomes that stay underground until late September when they become apparent above the soil surface for adult emergence.
Dorchin et al. (2009)
Rhopalomyia guttata S. bicolor capitulum Among normal-looking inflorescence pedicels among other capitula. Capitula galls are conical-cylindrical, droplet-shaped, smooth, white-to-green or sometimes red. Tapering apically. Galled capitula are wider and harder to the touch. Unlike R. anthophila galls, these retain pedicels. Dorchin et al. (2009)
Rhopalomyia racemicola S. altissima,
(S. fistulosa)
capitulum Green, bristly, onion-shaped capitulum galls, sometimes in aggregations. Galls on S. fistulosa tenatively identified as this species. Dorchin et al. (2009)
Rhopalomyia sp. (S. fistulosa stem galler) S. fistulosa stem Aggregated stem galls, each gall a hairy grayish oval, with a single chamber each. The whole aggregate commonly has a star-like structure. They appear most similar to R. racemicola galls. Dorchin et al. (2009)
Rhopalomyia pedicellata E. graminifolia variable Off of stems, leaves, or inflorescences. Delicate, slender gall with a single chamber. Green to purplish-red with longitudinal ridges, tapered at both ends. Proximal end has a long, slender stalk ('pedicel') that attaches to the rest of the plant. Two generations per year at least. Dorchin et al. (2009)
Rhopalomyia fusiformae E. graminifolia,
E. tenuifolia
variable Same as those of R. pedicellata, but without a pedicel, often lacking even some of the bottom tapering section, appearing as though welded to the host tissue Dorchin et al. (2009)
Rhopalomyia clarkei S. rugosa,
S. altissima
vascular outgrowth Small, conical, single-chambered. Usually on abaxial leaf surface, but can also appear on adaxial surface or on stems. When on leaves, attached at a major vein. Green to yellow-green and covered with hairs. Very young galls with a tuft of hair at base. Multivoltine. Less frequent on S. altissima. Dorchin et al. (2009)
Rhopalomyia gina S. juncea vascular outgrowth Like R. clarkei galls, but usually on upper side of leaf and with a corresponding scar or little tail on other side. Hairless. Dorchin et al. (2009)
Rhopalomyia inquisitor S. gigantea vascular outgrowth Originally described as an inquiline in R. capitata galls, but this could not be replicated. R. clarkei-like galls (except smooth) on S. gigantea, though, particularly from R. clarkei-like galls within Dasineura follicularis galls on S. gigantea, might be the real galls of this species. Maybe Felt confused D. follicularis galls with R. capitata, and then found these "inquilines" that way? However, Dorchin et al. (2009) were unable to rear any adults from these R. clarkei-like galls, so the galls of R. inquisitor remain unknown. Dorchin et al. (2009)
Rhopalomyia cruziana (S. spathulata),
(S. velutina)
capitulum? From an unknown Solidago from Santa Cruz mountains in California. Gall probably from a capitulum gall, based on adult insect similarities, but gall itself unknown. Dorchin et al. (2009)
Asteromyia euthamiae Euthamia leaf spot Black spots on leaves Stiremann et al. (2010)
Asteromyia tumifica Solidago stem Spongy outgrowth that partially or wholly encircles a stem. Can be very low on stem. Nested within one of two A. modesta clades, rendering that clade paraphyletic. Stiremann et al. (2010)
Asteromyia modesta Solidago,
leaf spot Leaf blisters. Possibly polyphyletic, with two distinct clades, one of which is itself polyphyletic with the recognition of A. tumifica. Both clades include some individuals that make galls on Solidago. Stiremann et al. (2010)
Asteromyia carbonifera Solidago leaf spot Black spots on leaves Stiremann et al. (2010)
Lasioptera solidaginis Solidago stem Irregular, elongate stem-swelling galls. Makes a small exit hole on the side of the gall. But see also Epliblema moths. bugguide
Schizomyia racemicola Solidago capitulum Greenish-purplish onion-shaped capitulum galls alongside normal capitula in the inflorescence. Gall exterior is smooth. Gall-maker larva exits gall as a larva and pupates elsewhere. bugguide

Trupanea might infest goldenrod flower-heads, but do they form galls?

*observed in Maryland (??)
**I think this Conyza species is probably C. canadensis, which is back in Erigeron now.

Arth. Fl. = Arthropods of Florida website by Florida State Museum of Entomology:
Bucknell University Eurosta biology page:
Cedar Creek Ecosystem Science Reserve (2000):
Dorchin et al. (2007):
Dorchin et al. (2009):
Dorchin et al. (2015):
Moffat et al. (2019):
Philips and Smith (1998):
Phillips (1923):
Stiremann (2010):
Stoltzfus (1989):

Posted by ddennism ddennism, October 08, 2019 06:53



Another really wonderful journal entry, Dennis! Thanks for all of the work in putting these together.

Posted by sambiology 7 days ago (Flag)

@sambiology - Thanks. It's a work-in-progress, and might not be as helpful for you down in Texas. Most of the research I can find on these Solidago gallers is centered in the northeast and mid-Atlantic.

Posted by ddennism 7 days ago (Flag)

It's a darn good start for Texas, too! We can always add and adapt. And I'm happy to investigate what I find down here. Bookmarking this page for future reference. Also, Daniel did you find this when you were looking? It's one of the other pages I have bookmarked.

Posted by kimberlietx 7 days ago (Flag)

BTW, my biggest issue is being able to ID the goldenrod to species. @sambiology swears he's going to write up a journal post, but I haven't seen it yet. ;)

Posted by kimberlietx 7 days ago (Flag)

Haha! Yeah, one of these days I may even wrestle with Solidago ID's.. One of these days... ;)
Texas is loaded with Solidago!

Posted by sambiology 7 days ago (Flag)

Well, if I can tackle Rubus, you can do at least one... ;)

Posted by kimberlietx 7 days ago (Flag)

Yes, @kimberlietx - that bugguide page is really great, but it's missing some of the most common gallers.

Posted by ddennism 7 days ago (Flag)

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