Goldenrod Galls

Solidago and Euthamia are two plant genera commonly called goldenrods. They host a number of gall-making insects.

This is an attempt to catalog all the gall-making insects on goldenrods. This is probably never going to be a complete list, but I'm striving to include as many as I can find. I'm defining "gall" as a structure primarily composed of plant tissue that is induced by a resident insect and is not otherwise produced by the plant. This definition is a little wishy-washy, and could include other stem-borers and leafminers, for example, but I have excluded those creatures for now. This is not an identification guide for all insect residents of goldenrod galls. In fact, often the current residents of a gall are not the original gall-makers! In some galls, parasitoids and inquilines are more commonly reared than the initial gall-maker.

This entry was motivated by my observation in summer 2019 that many identifications of Rhopalomyia solidaginis summer galls were misidentified on iNaturalist. I think the computer vision algorithm was partly to blame for this; it was aggressively suggesting R. solidaginis as an identification for diverse input images. These included images of other galls, but even extended to images of normal plant structures, especially rosettes of leaves, with no evidence of an insect present. Users also may have been unaware of the great diversity of gall-midges and other gall-makers on goldenrods, selecting R. solidaginis by default for any leafy gall.

Several iNaturalist observations of galls on Solidago and Euthamia don't seem to match those of any known species of gall-maker. There may be quite a few out there to be discovered.

Much of the information on this page comes from the published work of Netta Dorchin and coworkers (see full reference list at end).

Related Resources

Quick guide to identifying leaf-bunching galls on goldenrods:

Quick guide to identifying stem-swelling galls on goldenrods:

Beatriz Moisset's bugguide page on goldenrod galls:

Emily S. Damstra's beautiful scientific illustrations of goldenrods and their associated insects:

Warren Abrahamson's website at Bucknell University reviews his lab's comprehensive research on the evolutionary dynamics of the Eurosta solidaginis system, including a particularly useful goldenrod identification chart for the mid-Atlantic area:

Charley Eiseman's BugTracks blog entries about goldenrod galls:

gallformers.org entries for galls on Solidago and Euthamia:

Catalog of Goldenrod Galls

() = uncertainty in the literature about whether this is a host species, or a note that it more rarely, conditionally, or "accidentally" serves as a host, or a species name included to account for a taxonomic change
(()) = host not mentioned in the literature, but I suspect there might be some observations of this species serving as a host on the internet.

insect host description and notes representative images sources
galls on Euthamia:
Asphondylia Larvae of this gall midge genus develop in chambers composed of modified plant tissue with an inner fungal lining. For several species the walls of the chambers are made of leaf tissue that has the appearance of being glued together, forming either a rigid cone at the site of a bud or a "spot-welded" blister between two leaves. Others develop within modified flower-heads. There are often several generations per year. The organ and host species may vary through the year. Dorchin et al. (2015)
A. pseudorosa E. graminifolia,
((E. caroliniana)),
((E. leptocephala))
bud-rosette,
capitula,
leaf-snap
Several different gall types per year, always on Euthamia. The most apparent are the bud-rosette galls formed usually on apical buds. These feature a single rosette with broadened outer leaves surrounding appressed inner leaves, the innermost much shorter, forming a single, rigid cone. This conical insect chamber is lined with white mycelium. After the insect leaves or dies the innermost leaves turn black and wither, leaving only the outer, broadened rosette leaves. Before this happens, the gall resembles a green rose flower. Unlike in R. lobata galls, also found on Euthamia buds, spongy white tissue does not form, and each bud gall contains only one inner larval chamber. A second gall type forms later in the season in developing flower head (capitulum) buds. These are difficult to distinguish from normally developing capitula, though they do not flower, and instead house the developing larva. These are also lined with white mycelium. A third type, leaf-snap galls, are pictured in Dorchin et al. (2015) but not mentioned in the text. They appear to be formed near the terminal bud, and are presumably also lined with fungus. Felt (1907) raised Camptoneuromyia flavescens, another cecidomyiid, probably from these galls - specifically the flower-head type. He attributed these galls to "Asphondylia monacha", which is a name he used to refer to what are now known as several distinct Asphondylia species. photo of Asphondylia pseurorosa gall on Euthamia lateral shoot
photo by Brad Walker
(CC BY-NC 4.0) photo of Asphondylia pseurorosa gall on Euthamia terminal shoot
photo by Daniel McClosky
(CC BY 4.0)
Dorchin et al. (2015)
Asteromyia Larvae of this gall midge genus usually develop in flat blisters between the faces of a single leaf. The galls are composed of discolored plant tissue with a brittle inner fungal lining. There are often several generations per year.
A. euthamiae Euthamia sp. leaf spot
(stem spot)
Black blisters on leaves (less-frequently on stems). The blisters are lined with white mycelium. There are several generations per year. Photo of Asteromyia euthamiae galls on Euthamia leaves
photo by cassi saari
(CC BY-NC 4.0)
Photo (2) of Asteromyia euthamiae galls on Euthamia leaves
photo by Sequoia Janirella Wrens
(CC BY-NC 4.0)
Stireman et al. (2010)
Dasineura This large genus of gall midges includes species with diverse life histories and gall forms. The species known from North American goldenrods make deformed and swollen terminal shoot buds with clustered and blistered leaves. The orange larvae develop between the leaves, but exit the gall and pupate in the soil. The shoot sometimes recovers and grows beyond the gall, leaving a deformed section of stem with very short internodes.
D. carbonaria E. graminifolia bud Shoot tip bud galls, formed by several adherent and contorted leaves. Circular discolored feeding spots are often visible, and these may also contribute bumps and wrinkles to the gall. The gall itself is green to purple in color. The galls are not sealed; the larvae freely come and go to feed on the leaves, finally exiting to the soil to pupate.
The name "carbonaria" implies a blackened structure, but this is misleading. This midge species has this name because it was mistakenly assigned to the galls made by Asteromyia carbonifera, which are frequently blackened.
Photo of a D. carbonaria gall on the terminal bud of Euthamia
photo by Michael K. Oliver
(CC BY-NC 4.0)
Photo (2) of a D. carbonaria gall on the terminal bud of Euthamia
photo by Jeff Skrentny
(CC BY-NC 4.0)
Dorchin et al. (2007),
Dorchin et al. (2009b)
Epiblema Larvae of this moth genus (at least those that form goldenrod galls) bore into stems, where they initiate narrow swellings.
E. desertana E. graminifolia stem Very narrow stem swellings. Larvae overwinter in the gall. photo of Epiblema desertana gall on Euthamia
photo by Daniel McClosky
(CC BY 4.0)
See also Miller (1963) for reference photo (pg. 67, Fig. 3d)
Miller (1963)
Miller (1976)
Lasioptera Members of this gall midge genus have a variety of life histories, but most form stem galls. Gagné & Jaschhof (2017)
L. cylindrigallae E. graminifolia stem narrow stem swellings Gagné & Jaschhof (2017)
Galeopsomyia in Eulophidae, a family of chalcidoid wasps
G. haemon Asteraceae endogall This wasp induces the plant to produce dark, grayish spherical structures within Asphondylia galls, each of which contains a wasp larva. Dorchin et al. (2015) found these galls within galls made by A. solidaginis, A. rosulata, and A. pseudorosa, mostly in leaf-snap galls. photo of Galeopsomyia haemon galls within a Asphondylia solidaginis leaf-snap gall
photo by Beatriz Moisset
(CC BY-SA 4.0)
Dorchin et al. (2015)
Rhopalomyia Gall midges that can induce a variety of galls on a variety of hosts, but those on goldenrods tend to induce the plant to form small insect chambers with soft walls. These chambers may be hidden by a large, spongy mass of plant tissue and/or clusters of leaves, or they may occur unobscured, protruding directly from stems and leaves. Dorchin et al. (2009)
R. fusiformae E. graminifolia,
E. caroliniana
inflorescence, mostly Very similar to the galls formed by R. pedicellata, but without a pedicel, often lacking even some of the bottom tapering section, appearing as though welded to the host tissue. This is a minor difference in gall shape, but it correlates with differences in insect morphology. Galls occur on stems, leaves, and inflorescences. context shot of many R. fusiformae galls
photo by Don Sutherland
CC BY-NC 4.0
Dorchin et al. (2009)
R. lobata E. graminifolia bud Multi-chambered galls on apical and lateral buds. They start as 1 cm globular swellings within shoot tips or clustered around the shoot tips. Several leaves surround the spongy mass at the gall base. Eventually the leaves loosen and the whitish tissue reveals many larval chambers. The leaves extend beyond the gall, thinning towards the apex. Photo of R. lobata galls on lateral buds of Euthamia
photo by Jason Michael Crockwell
CC BY-NC-ND 4.0
Photo (2) of R. lobata galls on lateral buds of Euthamia
photo by Christian Grenier
CC0 1.0
Dorchin et al. (2009)
R. pedicellata E. graminifolia inflorescence, mostly Pod-like structures attached to stems, leaves, and/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. Close up of R. pedicellata gall on Euthamia
photo by Sequoia Janirella Wrens
CC BY-NC 4.0
Context shot of R. pedicellata galls on Euthamia
photo by Sara Rall
CC BY-NC 4.0
Dorchin et al. (2009)
galls on Solidago:
Asphondylia Larvae of this gall midge genus develop in chambers composed of modified plant tissue with an inner fungal lining. For several species the walls of the chambers are made of leaf tissue that has the appearance of being glued together, forming either a rigid cone at the site of a bud or a "spot-welded" blister between two leaves. Others develop within modified flower-heads. There are often several generations per year. The organ and host species may vary through the year. Dorchin et al. (2015)
A. 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 the soil line: Wider and harder than normal buds, single chamber lined with white mycelium. Or, slightly later in the season, bud galls at the tip of longer sprouts, stunting them and making them slightly thickened.
Summer Generation (on S. juncea, S. erecta, S. uliginosa, but not S. altissima): Much more conspicuous apical rosette bud galls, lined with mycelium, 15-30 rosette-units, forming a spherical gall complex at the shoot apex. Occasionally found on lateral buds of S. uliginosa, but rarely found there on other host species. S. uliginosa-derived adults were smaller in size as well. The authors speculated that these might represent a separate species (but also distinct from the S. uliginosa-galling Asphondylia below).
photo of spring generation A. monacha bud gall
early spring gall
photo by Daniel McClosky
(CC BY 4.0)
A. monacha bud gall cluster
summer bud gall
photo by Sequoia Janirella Wrens
(CC BY-NC 4.0)
Dorchin et al. (2015)
A. rosulata S. rugosa, S. gigantea,(S. uliginosa), (S. altissima), ((S. ulmifolia)) leaf snap,
bud
Spring-Early Summer: Leaf Snap galls (either hosts): Multiple leaves appear joined together at a single blister (actually the leaves are "glued" together when the leaves are still developing) to make a single chamber lined with white mycelium. Unlike those produced by A. solidaginis, these galls are often located very near the plant apex, giving rise to a gradient in forms from leaf snap to bud galls. This gradient is visible in the example observation.
Mid-Late Summer: Bud galls (only on S. rugosa) and only on apical buds. A single, conical chamber in the middle of a rosette of leaves. The chamber is lined with white mycelium.
Photo of a gradient of A. rosulata galls, from leaf-snap galls to a bud gall, on Solidago rugosa
bud gall and leaf-snap galls on Solidago in subsect. Venosae in Tennessee.
photo by Ashley M Bradford
(CC BY-NC 4.0)
Photo of A. rosulata leaf-snap gall on Solidago rugosa
leaf-snap gall on S. rugosa in Pennsylvania
photo by Daniel McClosky
(CC BY 4.0)
Dorchin et al. (2015)
A. silva S. caesia bud Small, single-chambered bud galls at shoot tips. Several very short leaves press together to form a single, mycelium-lined chamber. photo of an A. silva gall on Solidago caesia
gall on S. caesia in Pennsylvania
photo by Daniel McClosky
(CC BY 4.0)
Dorchin et al. (2015)
A. solidaginis S. altissima, S. gigantea bud Spring-Summer: Leaf-snap galls (either host): Multiple leaves appear joined together at a blistering point (actually the leaves are "glued" together while the leaves are developing) to make a single chamber lined with white mycelium.
Summer: Bud galls (only on S. altissima) on apical and/or axillary buds (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 not obscured by the surrounding modified leaves; it is visible without dissection. The gall walls are lined with thick white mycelium. The surrounding rosette of bunched leaves is also smaller in size, and flatter (not tufted). R. solidaginis bud galls usually contain several chambers per gall; those of A. solidaginis contain a single chamber. Another cecidomyiid, Camptoneuromyia adhesa, sometimes emerges from snap-galls like these.
A. solidaginis leaf snap galls photo by Lena Struwe
leaf snap galls
photo by Lena Struwe
(CC BY-NC 4.0)
A. solidaginis bud gall photo by Timothy Frey
bud gall
photo by Timothy Frey
(CC BY-NC 4.0)
A. solidaginis leaf snap gall with pupal exuviae
leaf snap gall with protruding pupal exuviae
photo by Vitaly Charny
(CC BY-NC 4.0)
Dorchin et al. (2015)
Felt (1907)
A. sp.1 "S. bicolor-galler" S. bicolor rosette A. monacha-like galls (and insects) that are distinct from A. monacha according to a molecular phylogenetic analysis. Could be the same species as A. sp. "S. sempervirens galler". One insect from a S. uliginosa rosette gall also sorted into this clade, while others from that host species sorted into A. monacha photo of a dense, A. monacha-like gall on Solidago bicolor gall on S. bicolor
photo by Daniel McClosky
(CC BY 4.0)
See also Fig. 6 in Dorchin et al. (2015).
Dorchin et al. (2015)
A. sp.1 "S. sempervirens-galler" S. sempervirens, ((S. mexicana)) bud A. monacha-like galls (and insects) that are distinct from A. monacha according to a molecular phylogenetic analysis. 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 A. monacha. Unlike A. monacha, this species also makes lateral bud galls.
See Charley Eiseman's (@ceiseman) blog post for a photo by Noah Charney of this gall, along with details of its discovery and insects reared from it.
See also Fig. 5 in Dorchin et al. (2015) for a photo of these terminal bud galls.
photo of an A. monacha-like gall on Solidago sempervirens gall on S. sempervirens
photo by Sara Rall
(CC BY 4.0)
Dorchin et al. (2015)
A. sp.1 "S. uliginosa-galler" S. uliginosa rosette See comments for A.  sp. "S. sempervirens galler" and A. sp. "S. bicolor galler". Distinct, at least, from A. monacha, though that species also forms rosette bud galls on S. uliginosa. Dorchin et al. (2015)
A. sp.2 S. nemoralis leaf snap Leaf snap galls similar to those made by Asphondylia species are observed rarely on this species, but the agent responsible is unknown. Dorchin et al. (2015)
A. sp.2 S. tortifolia° bud A. rosulata-like galls have been observed in October, but the agent responsible is unknown. Dorchin et al. (2015)
A. pumila S. patula bud Aggregated bud galls with mini-rosettes, like those made by A. monacha, have been observed on this species, but as of 2015 the insect remained unknown. These have since been attributed by Plakidas (2018) to a new species, Asphondylia pumila presumably on morphological grounds. The alternative hypothesis alluded to in Dorchin et al. (2015), that these galls are simply an expansion of the host-range of A. monacha (or another Asphondylia species), was not directly addressed.
My notes: These three observations of bud galls on S. patula were found in close vicinity to typical A. monacha galls on their typical host, S. juncea.
Photo of aggregated bud galls on S. patula
Aggregated bud galls atop S. patula
photo by Daniel McClosky
(CC BY 4.0)
Dorchin et al. (2015), Plakidas (2018)
A. sp.2 S. odora bud Bud galls like those made by A. monacha have been observed on this species, but the insect remains unknown. Could be A. monacha, or another insect. Dorchin et al. (2015) , this observation
A. sp.2 S. chapmanii bud Bud galls like those made by A. monacha have been observed on this species, but the insect remains unknown. Could be A. monacha, or another insect. Perhaps conspecific with the one on S. odora, a closely-related host. gallformers unknown inducer page
A. sp.2 S. rigida, S. ptarmicoides bud Bud galls like those made by A. monacha have been observed on this species, but the insect remains unknown. Could be A. monacha, or another insect. I'm grouping those occurring on hosts in Solidago subsect. Ptarmicoidei here. gallformers unknown inducer page
A. sp.2 S. ulmifolia bud Bud galls roughly like those made by A. rosulata have been observed on this species, but the insect remains unknown. They have a distinctive appearance with narrower rosette leaves. gallformers unknown inducer page
Asteralobia
A. solidaginis S. pacifica bud East Asia.
Moved to Schizomyia solidaginis in Elsayed et al. (2018)
Gagné & Jaschhof (2017)
Elsayed et al. (2018)
Asteromyia Larvae of this gall midge genus usually develop in flat blisters between the faces of a single leaf. The galls are composed of discolored plant tissue with a brittle inner fungal lining. There are often several generations per year.
A. carbonifera Solidago leaf spot Black or black-and-white blisters on leaves, lined internally with white mycelium. Interesting evolutionary biology research has been done in this system, particularly in the lab of John Stireman at Wright State University. Different lineages of A. carbonifera induce differently-shaped galls. Some are black, some black-and-white, and some have raised white cushions. The fungus that lines the interior of these galls is Botryosphaeria dothidea. Photo by Asteromyia carbonifera gall on Solidago leaf
photo by Matt Parr
(CC BY-NC-SA 4.0)
Photo of Asteromyia carbonifera gall on Solidago leaf
photo by Sequoia Janirella Wrens
(CC BY-NC 4.0)
Photo of Asteromyia carbonifera galls on Solidago leaf
photo by Ryan (iNat user: brick1083)
(CC BY-NC 4.0)
Stireman et al. (2010)
bugguide
A. modesta Solidago, Erigeron, Conyza°°, Grindelia, Symphyotrichum leaf spot Leaf blisters. The larvae reside in cryptic pockets of leaf tissue that may be purple but are often the same green color as the surrounding leaf tissue.
The species is probably polyphyletic as currently circumscribed, with two distinct clades. One clade is itself polyphyletic if A. tumifica is separated from A. modesta. Both clades include some individuals sampled from galls on Solidago. Charley Eiseman accidentally reared this midge from a leaf with more prominent leaf-mines, and photographed both the blister and the midge.
Photo of Asteromyia modesta gall on Doellingeria leaf
on Doellingeria umbellata
photo by Charley Eiseman
(CC BY-NC 4.0)
Stireman et al. (2010)
Bug Tracks blog post
A  tumifica Solidago stem Spongy outgrowth that partially or wholly encircles a stem. Sometimes very low on stem.
Nested within one of two A. modesta clades, rendering that clade paraphyletic. Perhaps this insect taxon will be folded into a revised concept of A. modesta in the future, or perhaps that taxon will be split up.
Photo posted to bugguide here by John van der Linden, identified by Raymond Gagné
Photo of an A. tumifica gall
photo by Tom Murray
(CC BY-NC 4.0)
Stireman et al. (2010)
Dasineura Species in this large genus of gall midges have diverse life histories and gall forms. The species known from North American goldenrods make deformed and swollen terminal shoot buds with clustered and blistered leaves. The orange larvae develop between the leaves, but exit the gall and pupate in the soil. The shoot sometimes recovers and grows beyond the gall, leaving a deformed section of stem with very short internodes.
D. folliculi S. rugosa, S. gigantea, ((S. altissima)), ((S. canadensis)), ((S. caesia)) bud Shoot tip bud galls that resemble other bud galls, but are looser and show evidence of feeding (yellowish spots, sometimes deforming the leaves somewhat) on the more-distal portions of the gall leaves. The galls may be hairy or smooth depending on the host species. The larvae exit the galls to pupate in the soil. Dasineura larvae are orange. Similar, but smaller and white-colored larvae present in galls may be Macrolabis americana, an inquiline. Photo of a D. folliculi bud gall
on S. rugosa in Pennsylvania
photo by Daniel McClosky
(CC BY 4.0)
Photo of a D. folliculi bud gall
on S. gigantea
photo by David (iNat user: davidenrique)
(CC BY-NC-SA 4.0)
Dorchin et al. (2006),
Dorchin et al. (2007),
Dorchin et al. (2009b)
D. virgaeaureae S. virgaurea variable? Eurasia. There are several descriptions of the galls caused by this midge. Galls in shoot tips, capitula, leaf rolls, and swollen flower buds have all been ascribed to this fly. Dorchin et al. (2006)
Epiblema Larvae of this moth genus (at least those making goldenrod galls) bore into stems, where they initiate narrow swellings in which they overwinter. These structures might not be strictly considered galls by some; they lie somewhere on the continuum of gall formation to herbivory-responsive growth. Miller (1976) referred to them as "rudimentary galls".
E. scudderiana S. altissima, S. canadensis, S. gigantea, S. juncea, S. ulmifolia, S. nemoralis,((Heterotheca subaxillaris)), ((Symphyotrichum ericoides)) stem Narrowly ellipsoid stem-swelling galls. Sometimes irregularly shaped, often with vertical scars. Univoltine; the larvae enter the stems as late instars and overwinter in the gall. Before winter, the caterpillar spins a silk funnel that guides the emerging adult moth to the exit hole, which is plugged with a wagon wheel-shaped bung. Branches often proliferate at or above the gall. photo of Epiblema scudderiana gall on Solidago stem
on Solidago stem
Photo by Reiner Jakubowski
(CC BY-NC 4.0)
Miller (1963),
Miller (1976),
Brown et al. (1983)
Eurosta Most (all except E. latifrons?) of these Tephritid fruit flies develop in bulbous galls on stems of Solidago species, usually at least partially underground (rhizomes). However, the most commonly observed species develops on above-ground stems.
E. comma (S. juncea, S. missouriensis, S. rugosa) rhizome Swellings on rhizomes very near soil line. Sometimes peanut-like in outline. Steyskal & Foote (1977) give a reasonable rationale for earlier authors' confusion of the hosts of E. elsa and E. comma; they assign E. elsa to S. juncea and E. comma to S. rugosa. Current databases (e.g. ITIS) synonymize E. elsa with E. cribata. photo of Eurosta comma gall on Solidago juncea rhizome
photo by Daniel McClosky
(CC BY 4.0)
bugguide, Cedar Creek (2000), Novak & Foote (1980)
E. cribata S. juncea, S. sempervirens rhizome "Crown Gall" that begins near the soil line (or just under), but grows upwards and is mostly above-ground at maturity. Like those of E. comma, the galls resemble peanuts somewhat. Ming (1989) included E. conspurcata and E. reticulata in synonymy with this species. photos and illustrations in Novak & Foote (1980) (paywalled) bugguide, Arthr. Fl., Sutton & Steck (2005)
E. fenestra ? rhizome According to Sutton & Steck (2005) this is also a member of the E. comma species complex. They mention that it has likely never been found in Florida, despite earlier reports, which were misidentifications of E. floridensis or other members of the E. comma species complex. photos and illustrations in Novak & Foote (1980) (paywalled) Sutton & Steck (2005)
E. floridensis S. fistulosa rhizome Galls are similar to those made by E. comma and E. fenestra. Arth. Fl., Sutton & Steck (2005)
E. lateralis S. chapmanii stem Similar to the common "ball galls" made by E. solidaginis, but the gall radius is much smaller (Foster, 1934, as "E. nicholsoni", later realized to be synonymous with E. lateralis by Foote (1964)). Another synonym: E. donysa. Only known from Brevard Co., Florida, at least recently. It may be critically endangered (Sutton & Steck (2005)), or even extinct. They give S. odora as the host, but the host is presumably S. chapmanii based on location, which was not regularly segregated from S. odora then. They point out a very old record by Wiedemann (1830) also possibly of this species in the "Indien" (sic) River area of Florida. Foster (1934) points to galls found "near Titusville", "near Malabar", and "from 5.5 miles southwest of Indian River" all near the coast. Arth. Fl., Sutton & Steck (2005)
[E. latifrons] Solidago sp. ? Sutton et al. (2002) speculate that this fly probably develops from undiscovered galls on Solidago. Sutton et al. (2002)
E. solidaginis S. altissima, S. gigantea, (S. canadensis), (S. rugosa) stem Nearly spherical galls, made on the aboveground stem, rather than on the rhizome like most of the rest of the goldenrod-galling members of this genus. The exterior vestiture of the gall depends on the identity of the host species. They are hairy when on S. altissima (presumably also when on S. canadensis and S. rugosa), but smooth and shiny when on S. gigantea. There is a great wealth of literature on the evolution of this system. Gall diameter is a function of the genes of the insect, not the host plant. Insects that produce galls with larger diameters are more likely to survive attack by parasitic wasps, whose ovipositors are unable to penetrate the thicker galls. However, larger galls are more attractive to birds, which eat the larvae in winter. There is also interesting research on host-species specialization by different populations of this fly (on S. altissima vs. on S. gigantea), and the divergent selective pressures at play. The galls are so frequent on S. altissima in the mid-Atlantic that the presence of galls has been suggested as an identification aide for distinguishing S. altissima from S. canadensis, although some sources suggest that S. canadensis can also (rarely?) host this fly. photo of E. solidaginis stem gall on Solidago altissima
on S. altissima
photo by Daniel McClosky
(CC BY 4.0)
photo of E. solidaginis stem gall on Solidago gigantea
on S. gigantea
photo by iNat user: auroradj29
(CC BY-NC 4.0)
Bucknell University Solidago Gall Website, Moffatt et al. (2019), Stoltzfus (1989)
Eutreta Tephritid fruit flies whose larvae bore through stems, usually inducing galls. They have a variety of hosts in Asteraceae and Verbenaceae.
Eutreta hespera Solidago sp. rhizome Reared once from rhizomes of "a goldenrod" near Custer, South Dakota. The adult flies have been collected along streams and grassy slopes from the Dakotas westward, throughout much of western North America. Stoltzfus (1974)
Eutreta novaeboracensis *S. rugosa, (S. spp.) rhizome, stem Larvae bore through both rhizomes and above-ground stems, inducing galls as swellings of those organs. The stem-borers emerge earlier than the rhizome-borers (and are bivoltine rather than univoltine), so these two groups might represent cryptic sister species. Stem-galls can be found near the ground, sometimes described as crown galls. "Eutreta sparsa" is sometimes attributed to these and other galls on North American Astereae, but this is actually a South American species that does not make galls on Solidago rhizomes, instead associating with Stachytarpheta (Verbenaceae) branches. drawing of Eutreta novaeboracensis galls on the rhizomes of Solidago altissima
drawing by Millett T. Thompson (1907)
(public domain)
bugguide, Stoltzfus (1974), Thompson (1907)
Galeopsomyia in Eulophidae, a family of chalcidoid wasps
G. haemon Asteraceae endogall This wasp induces the plant to produce dark, grayish spherical structures within Asphondylia galls, each of which contains a wasp larva. Dorchin et al. (2015) found these galls most frequently within leaf snap galls, but also found them in bud galls made by A. solidaginis, A. rosulata, and A. pseudorosa. photo of Galeopsomyia haemon galls within a Asphondylia solidaginis leaf-snap gall
photo by Beatriz Moisset
(CC BY-SA 4.0)
photo of Galeopsomyia haemon galls within an Asphondylia solidaginis bud gall
photo by iNat user @jennimartin
(CC BY-NC 4.0)
Dorchin et al. (2015)
Gnorimoschema Larvae of some members of this large moth genus develop within stem swellings on goldenrods. Several species have been described from goldenrods, but not all are universally accepted as distinct. The larvae bore into the shoot apex and then travel down the center of the stem. Deformed, stubbier leaves at the shoot apex give a clue to the presence of the larva before it begins to make its gall. The larvae then backtrack upwards, where they induce a stem swelling with a large internal cavity. There is one larva per gall. Before spinning a cocoon they bore an adult exit hole. This hole is variably capped with plant- and/or insect-derived substances. Miller (2000) gave evidence that these "bung hole" structures were diagnostic of particular species, arguing that differences in their construction were not merely consequences of different host goldenrod building material, but were intrinsic to the species of insect. Whether all the species in his monograph on the group are distinct enough to warrant their own names (particularly in the case of G. jocelynae) remains debated, but with some support from molecular phylogenies (Nason et al. 2002). Miller gave species names with neuter suffixes, but I don't know which form is correct according to nomenclatural rules so I will follow the suffixes present in online checklists and more recent literature instead.
G. gallaeasteriella S. flexicaulis, Symphyotrichum saggitifolium, (Solidago caesia, S. uliginosa, Eurybia divaricata, and perhaps many others) stem No bung is formed; the adult exit hole is difficult to see because it is capped with plant epidermal tissue instead. It is located in the top third of the gall, like most other goldenrod Gnorimoschema galls, but unlike those of the otherwise very similar G. gallaespeciosum, which are instead formed near the gall equator.
This species might be conspecific with G. gallaediplopappum, a moth with unknown gall biology (Miller 2000).
Unlike other Gnorimoschema species, the leaves at the shoot apex may not be deformed by the presence of the larva, but the shoot itself may have its growth arrested.
Are all these different host reports really referring to the same species of moth? They are all basically woodland Astereae, but I can't help but wonder whether there have been some mistakes in host identification. Miller (2000) reported that he could only find these galls on Symphyotrichum saggitifolium. From these he reared adults that matched Kellicot's (the original species authority). Judd (1962) could not find any galls on S. caesia despite there being large numbers of these plants adjacent to and within a S. flexicaulis site with many galls. Busck (1911) considered the problem of host identification, and concluded that the species may simply have a wide host range. His "S. latifolia" is our S. flexicaulis; his Aster corymbosus apparently refers to E. divaricata. I still can't help but wonder whether all these hosts might really be misidentified plants in the Symphyotrichium cordifolium species complex (which includes S. saggitifolium), which are variable and difficult to identify in the absence of flowers.
woodcut of gall by D. S. Kellicott (1878)
woodcut of gall by D. S. Kellicott (1878)
Gnorimoschema gall on Solidago caesia
Gnorimoschema gall on S. caesia
photo by Rob Curtis
(CC BY-NC-SA 4.0)
Nazari & Landry (2012), Miller (2000), Judd (1962), Kellicott (1878), Busck (1911)
G. gallaesolidaginis S. altissima, S. canadensis, (S. gigantea) stem Probably the most common Gnorimoschema moth that forms galls on goldenrods. These are ellipsoid stem galls with an exit hole stuffed with characteristically light-colored "bung". The bung tissue is essentially flush with the surrounding plant tissue, which forms a slightly raised ring around the hole. The galls are wider than those made by Epiblema moths. Miller (1963) mentioned that there are other species in this genus that make galls on other Solidago species. His later monograph on them (2000) listed eight species, most of which have been reported from Solidago species. Later, Heard & Kitts (2012) compared G. gallaesolidaginis on S. altissima and S. gigantea. Nason et al. (2002) considered this to either contain a single differentiating species (into semispecies) onto the two respective host-groups (S. altissima/canadensis and S. gigantea), or two barely-isolated cryptic species, in which case G. jocelynae is the species name for the group that feeds on S. gigantea. photo of Gnorimoschema gallaesolidaginis spindle gall on dead Solidago stem
photo by Daniel McClosky
(CC BY 4.0)
photo of Gnorimoschema gallaesolidaginis spindle gall on living Solidago stem
photo by Sarah Scharf
(CC BY-NC 4.0)
Miller (1963), Heard & Kitts (2012), Nazari & Landry (2012)
G. gallaespeciosum (S. speciosa, S. jejunifolia, S. rigidiuscula, S. pallida) stem Elliptical stem galls similar to those of G. gallaesolidaginis, but differing in exit hole placement nearer the equator and the lack of bung tissue (instead being capped with plant epidermis). Reported from S. speciosa, but the type specimen is from Ramsey Co., MN, which is out-of-range for S. speciosa in the new, strict sense. The host is more likely S. rigidiuscula, a goldenrod species segregated from S. speciosa in the broad sense. S. pallida and S. jejunifolia were also segregated from *S. speciosa, so they, too, are provisionally included here as a potential hosts. Miller (2000)
G. gibsoniella S. rigida, Symphyotrichum pilosum stem S. rigida was reported as the host plant for the type collection, but Miller (2000) reared these from galls on Symphyotrichum pilosum stems. The initial description by Busck here notes that it forms galls just above the ground, and Miller also noted this, mentioning that he only found them after mowing tall grass. Nazari & Landry (2012), Busck (1915)
G. jocelynae S. gigantea stem Very similar to galls by G. gallaesolidaginis, but with dark bungs that are recessed into the exit hole. The bung material is not flush with the surrounding plant epidermis. This is the name Miller (2000) gave to the host-race derived from G. gallaesolidaginis, when that species established a cryptic sister species on S. gigantea (Nason et al. 2002). The main visible difference is in the bung coloration. Miller performed larva transplant experiments to confirm that bung colors were a function of the larvae's parental host species, not their current host species. However, Nason et al. (2002) point out that these exit hole characteristics could be idiosyncratic to particular plants; Miller only examined three specimens for each reciprocal experiment. I wonder whether the larva transplant experiments might have a different interpretation than Miller's: The bung material could reflect the host species that the larva spent most of its life feeding on, which in his experiments would be the plant with the donor-gall, not the plant with the receiver-gall. Works after Nason et al. (2002) refer to these moths as "G. gallaesolidaginis, gigantea host-race". photo of Gnorimoschema spindle gall on Solidago gigantea stem
Gnorimoschema gall on S. gigantea
photo by iNat user rangerrich
(CC BY-NC 4.0)
Nazari & Landry (2012)
G. salinaris S. sempervirens, S. missouriensis, S. juncea, (S. gigantea, S. ulmifolia) stem Differences from G. gallaesolidaginis galls: (1) bung material is dark brown to black in color, (2) galls tend to be lower on the stem, (3) the interior surface of the bung (not visible from outside) is cushioned by layers of spongy silk material, (4) different host species. The original description, by Busck, noted that the insects were reared from galls similar to those of G. gallaesolidaginis, but occurring on S. sempervirens. Miller (2000) associated this species with additional hosts inland: the S. juncea species complex. He referred to these plants as "S. juncea/missouriensis", but based on the locations of his collections, he was almost certainly only collecting galls from S. juncea. Nazari & Landry (2012) list S. gigantea as a host according to one Michigan record, but this might be G. gallaesolidaginis/G. jocelynae. Miller (2000) attributed some galls on S. ulmifolia to this species, but noted that these were rare and only found at one site with abundant galls on S. juncea. Miller may have been following a taxonomic treatment of the three main host species that does not match the current circumscriptions of these species. Some of his statements, particularly that S. sempervirens and S. juncea hybridize, sound a little strange, and he seems to imply that these three species are closely related. Both molecular- and morphology-informed phylogenies imply otherwise. I wonder whether some of Miller's hosts might have been S. uliginosa or other species. However, all reported hosts do have smooth stems in common.
Miller (2000) noted that some of the adult characteristics that Busck said differentiated this species from G. gallaesolidaginis were not as consistent as Busck claimed. He instead focused more on the gall characters (host plant ID and bung characters), and presented evidence that this species makes galls closer to the ground, and with a more variable shape in outline, ranging from elliptical to pear-shaped. The gall shape begins perfectly vertically-symmetric in the ultimately pear-shaped galls, becoming asymmetric only with age. The bung itself is dark in color, like that of G. jocelynae, and surrounded by a ring of tissue that may be slightly raised. The bung tissue is flush with this ring, like in G. gallaesolidaginis and unlike in G. jocelynae.
photo of Gnorimoschema spindle gall on Solidago juncea stem
Gnorimoschema gall on S. juncea
photo by Daniel McClosky
(CC BY 4.0)
Nazari & Landry (2012), Miller (2000), Busck (1911)
Janetiella I can't find much on these. Gagné & Jaschhof (2017) call the genus a "diverse assemblage".
J. inquilina Solidago sp. ? aka Oligotrophus inquilinus Felt 1908; on "S. canadensis", which, at the time, could have referred to several species in Solidago subsection Triplinerviae. I presume that these are inquilines, from the name. Gagné & Jaschhof (2017)
Lasioptera Members of this gall midge genus have a variety of life histories, but most form stem galls. Gagné & Jaschhof (2017)
L. solidaginis Solidago stem Irregular, elongated stem-swelling galls. "Knotty" in appearance according to Felt (but so many of the galls are mismatched in that work). See this observation by M.J. Hatfield on bugguide, verified by Gagné and also here bugguide, Gagné & Jaschhof (2017)
Lestodiplosis Larvae of this gall midge genus are usually predators of other cecidomyiid larvae, but some have been reported to be gall formers, maybe in error. Gagné & Jaschhof (2017) give the following species from Solidago galls, but are not claiming that they are the gall-makers. Gagné & Jaschhof (2017)
L. carolinae S. canadensis (presumably sensu lato) bud Reported by Felt to be the initiator of the gall, but given the life history of others in the genus, more likely a predatory species. Found in a rosette bud gall on "S. canadensis". Maybe this is a synonym of Rhopalomyia carolina(e), itself a synonym of R. solidaginis? Found in Asheville, NC Gagné & Jaschhof (2017)
L. rugosae Solidago sp. New York Gagné & Jaschhof (2017)
L. triangularis Solidago sp. leaf New York Gagné & Jaschhof (2017)
Procecidochares
P. anthracina (S. californica) bud Bud galls cluster on stems near where they emerge from rhizomes. Usually buried in humus, but not truly subterranean. Univoltine, unlike P. atra. Reported from "S. velutina" in California - these plants are now in the segregate species, S. californica, according to John Semple's website. Goeden & Teerink (1997)
P. atra S. altissima, S. gigantea, S. canadensis, S. erecta, S. nemoralis, S. odora, S. rugosa, S. speciosa, Symphyotrichum drummondii bud Spring Generation: Large stem galls at the base of the host plant, each containing several larvae.

Summer Generation: Lateral bud galls that look like Brussels sprouts initially, and eventually open as the fly matures. The terminal bud is also sometimes galled, but usually in addition to lateral galls. (My observation: When the terminal bud is galled, it is often much larger than the accompanying lateral galls.) The gall chamber is large and not sealed, much larger than the fly larva or pupa, and is slightly open at the distal end. The chamber has the appearance of being inset into the stem somewhat, although the surrounding tissue may not technically be derived from the stem, but rather from other plant tissues. At maturity, the rosette of leaves surrounding the gall typically flatten and grow away from the gall, giving the gall a more rosette-like appearance.

(My note: At this stage, these galls, particularly the terminal ones, can superficially resemble those of Rhopalomyia solidaginis and Asphondylia solidaginis. However, those midge-induced galls have distinct chambers formed by one or few young leaves. The midge gall chambers are cryptic, translucent conical structures set atop the host stem rather than appearing hollowed-out within stem-like tissue.) Each gall has only one larva, unlike in the spring generation.

This species probably has many other hosts, including some outside Solidago, although some researchers have speculated that there may be cryptic host-races within P. atra, some of which may have fully speciated (Philips & Smith 1998).
photo of spring Procecidochares atra gall

photo of spring Procecidochares atra gall, cut open
Spring Generation gall
photos by Daniel McClosky
(CC BY 4.0)
photo of Procecidochares atra galls
Summer Generation galls
photo by Jason Dombroskie
(CC BY-NC 4.0)
another photo of Procecidochares atra galls
photo by Yann Kemper
(CC0)
vertical section  of Procecidochares atra gall
summer generation, vertical section through terminal bud gall
photo by Daniel McClosky
(CC BY 4.0)
Wikipedia, iNat obs, bugguide, Philips & Smith (1998), Eiseman (2024) for host records
P. minuta (Solidago), Astereae stem Recorded from a stem gall on Solidago californica in Wasbauer (1972): "C. D. A. 1 In stem gall; CALIFORNIA: Palomar Mt., San Diego Co., IX-19-1964, E. D. Algert". This species is known to produce galls on a number of composite host species, including rabbitbrushes. I'm not sure this record is from a correctly identified host plant; rabbitbrushes can look vaguely like goldenrods before blooming. Wasbauer (1972)
P. polita (S. virgata, S. chrysopsis), (((S. sempervirens))),(((S. mexicana))) ? Reared from Solidago sp. "small, roundish galls" by Girault (1913) in Virginia. Reported from galls of Solidago sp. by Johnson (1910). However, Aldrich (1929) wrote that accounts of this species being reared from Solidago galls are in error, and actually refer to P. atra due to some nomenclatural confusion at the time in the literature.
Much later, Ibrahim (1980) attributed "Solidago stricta" stem galls collected in Dade County, Florida to P. polita. At that time, "Solidago stricta" would have referred to what is now known as S. virgata or possibly S. chrysopsis at that location (see John Semple's website for details). There are older records for collections in the Jacksonville area (Sutton & Steck 2005) and the Falls Church, Virginia area (Aldrich 1929). Sutton & Steck (2005) caution that many details in Ibrahim (1980) are inaccurate and repeat known mistakes from earlier literature, though they don't mention the P. polita record specifically.
The adult flies are apparently easily distinguished from P. atra by having entirely yellow legs rather than having black femora and coxae. Goeden & Norrbom (2001) say it's distributed along the east coast, from Massachusetts to Florida. None of these post-1929 sources describe the gall.
This fly seems to be restricted to the east coast of the USA, so its host plant, if it is a Solidago species, is probably a coastal species. Wasbauer (1972) includes some records from "S. stricta" galls as well.
Aldrich (1929), Ibrahim (1980), Goeden & Norrbom (2001), Sutton & Steck (2005)
Rhopalomyia Gall midges that can induce a variety of galls on a variety of hosts, but those on goldenrods tend to induce the plant to form small insect chambers with soft walls. These chambers may be hidden by a large, spongy mass of plant tissue and/or clusters of leaves, or they may occur unobscured, protruding directly from stems and leaves. Dorchin et al. (2009)
R. anthophila S. altissima capitulum Capitulum (flower-head) galls among the flowers of the host. Cylindrical, or like a truncated cone. Fuzzy and whitish. Inner chamber conical, resembling the shape of other Rhopalomyia insect chambers, with thin walls. Photo of an isolated R. anthophila gall on the inflorescence of Solidago altissima
photo by Kevin Keegan
(CC0)
macro image of a R. anthophila gall
photo by Dan Mullen
(CC BY-NC-ND 2.0)
cluster of R. anthophila galls, some with persisting pupal exuviae
a highly-galled flowering stem; several galls have persisting pupal exuviae
photo by Karen Yukich
(CC BY-NC 4.0)
Dorchin et al. (2009)
R. bulbula S. juncea rhizome bud Only a spring generation is known, but the insect is presumably multivoltine;
Spring Generation: "Clustered on rhizomes, at the bases of spring shoots. The gall resembles a bud, with acute apex and base. Surface is smooth and white, with green stripes where exposed to light." Single chambered.
photograph of R. bulbula gall from Felt (1917)
photo by E. P. Felt (1917)
Dorchin et al. (2009), Felt (1917)
R. capitata S. gigantea, S. leavenworthii, (S. rugosa), ((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 uniformly-small leaves give the overall gall complex a flat-topped appearance. Whereas tufts of leaves that comprise the summer generation gall complex formed by R. solidaginis form discernible mini-rosettes, each surrounding a larval chamber, in R. capitata the gall leaves are not obviously so-organized, perhaps as a consequence of there being many more chambers.

Stireman et al. (2005) demonstrated that Rhopalomyia leaf-bunching gall midges sorted into two well-separated clades, one from specimens raised from S. altissima galls and the second from specimens reared from S. gigantea and S. leavenworthii galls. Dorchin et al. (2009) resurrected the name R. capitata for the latter clade, and described some morphological differences from R. solidaginis sensu stricto.

Note: The separation between the two may not be this clean. In the upper Great Lakes region there are leafy galls on S. gigantea that more closely resemble those made by R. solidaginis. Eiseman (2024) recently reared flies identified to this species (ID by morphology by Raymond Gagné) from single-chambered R. solidaginis-like galls on S. rugosa - a new host for R. capitata. Some of these galls terminated short axial shoots.
photo of R. capitata spring generation bud gall
spring generation
photo by Daniel McClosky
(CC BY 4.0)
photo of typical summer generation R. capitata bud gall
summer generation
photo by iNat user mamiles
(CC BY-NC-ND 4.0)
Stireman et al. (2005), Dorchin et al. (2009), Eiseman (2024)
R. clarkei S. rugosa, S. altissima leaf outgrowth Small, conical, single-chambered. Usually on lower leaf surface, but can also appear on upper 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.
(My observation: There are several gall observations on iNaturalist that fit this description, and are currently identified as R. clarkei, but they do not all closely resemble one another. They may represent different stages of development, different presentations on different host species, or misidentifications with some other gall-maker.)
Photo of a R. clarkei leaf gall
photo by Adam Kranz
(CC0 1.0)
Photo of a R. clarkei leaf gall
photo by Sara Scharf
(CC BY-NC 4.0)
macro photo of a brown R. clarkei leaf gall
photo by Ann McKenzie
(CC BY-NC 4.0)
Dorchin et al. (2009)
R. cruziana ((S. californica)) capitulum? From an unknown gall from an unidentified Solidago species growing in the Santa Cruz mountains in California. The host species to the left is my speculation based on the ranges of Solidago species native to this region. Dorchin et al. (2009) infers that the gall is probably a capitulum gall because the adult insects closely resemble other capitulum-gallers in this genus. Dorchin et al. (2009)
R. gina S. juncea leaf outgrowth Like R. clarkei galls, but usually on upper side of leaf and with a corresponding scar or little tail on the opposite side. Hairless, probably reflecting the vestiture of the host plant. See Figs. 68-69 in Dorchin et al. (2009) for images.
My note: Fig. 69 shows a leaf with what might be pubescence on the abaxial surface (in addition to the normal cilia at the leaf margin), which makes me wonder whether the host plant is correctly ID'd as S. juncea.
Dorchin et al. (2009)
R. guttata S. bicolor capitulum Forms teardrop shaped galls that retain the capitulum-pedicel. Difficult to find among regular flower-heads. Dorchin et al. (2009)
R. hirtipes S. juncea bud Forms fleshy bud galls at the shoot apex, often arresting shoot growth while the plant is still very short. Gall initially has a tapered tip, but this disappears with growth. The whole gall eventually becomes ovoid and reminiscent of a potato. Spongy and usually multi-chambered. See also R. thompsoni for a similar gall that appears earlier in the season and mostly underground. Photo of an opened R. hirtipes bud gall
photo by Marie-Ève Garon-Labrecque
(CC BY-NC 4.0)
Photo of a R. hirtipes bud gall
photo by Catherine Klatt
(CC BY-SA 4.0)
R. hirtipes bud gall photo showing the plant flowering from lateral buds under the gall
not always arresting growth
photo by Charles and Kathy Appell
(CC BY-NC 4.0)
Dorchin et al. (2009)
R. inquisitor S. gigantea leaf outgrowth? Originally described as an inquiline in R. capitata galls, but this could not be replicated by Dorchin et al. (2009). The did notice R. clarkei-like galls (except smooth-surfaced) on S. gigantea, though, particularly on leaves from within Dasineura folliculi galls, and conjectured that these R. clarkei-like galls might be the real galls occupied by this species. Perhaps Felt (original description) confused D. folliculi galls with R. capitata galls, and then concluded that R. inquisitor was an "inquiline" that way? However, Dorchin et al. (2009) were unable to rear any adults from these R. clarkei-like galls on S. gigantea, so the galls where R. inquisitor resides remain unclear. An example of these galls is probably shown here: by Sara Rall. Close up of Rhopalomyia galls on Solidago gigantea leaves
photo by Daniel McClosky
(CC BY 4.0)
Photo of R. inquisitor galls, maybe, on S. gigantea leaves
click to zoom to see small leaf-outgrowths. Leaf clustering may be caused by D. folliculi. Host plant is S. gigantea.
photo by Sara Rall
(CC BY-NC 4.0)
See also Figs. 66-67 in Dorchin et al. (2009) for reference images.
Dorchin et al. (2009)
R. racemicola (S. altissima, S. fistulosa) capitulum Green, bristly, onion-shaped capitulum galls, sometimes found in aggregations. A collection of galls on S. fistulosa was tentatively attributed to this species by Raymond Gagné . Gagné (1971) described the history of confusion around the causal agent of these galls, and assigned to Schizomyia the galls containing bright orange larvae (which chew a hole through the gall as larvae to pupate elsewhere; originally described as Cecidomyia racemicola by Osten Sacken). Felt (1907) reared adults from similar galls on "S. canadensis" (probably S. altissima) racemes in North Carolina. These adult flies do belong in Rhopalomyia, according to Gagné (1971) and Dorchin et al. (2009); Gagné (1971) considered their larva and gall therefore unknown.

Dorchin et al. (2009) tentatively ascribe the bristly, aggregated onion-shaped galls on the stems of S. fistulosa as well as whatever the true galls Felt (1907) originally reared the species from (his description in 1915 is of S. racemicola galls) to R. racemicola.
Felt (1907), Gagné (1971), Dorchin et al. (2009)
R. solidaginis *S. altissima, S. canadensis, S. rugosa bud Spring Generation: Inconspicuous, shoot tip rosette bud-galls, often stunting the shoot. Unlike the later generation, these typically enclose a single, white, conical gall-chamber, but sometimes several gall-chambers are connected longitudinally.
Summer generation: Each of multiple (2-5) chambers is surrounded by a group of very short and narrow leaves, which are in turn surrounded by longer and wider leaves to form a distinct rosette-subunit within the gall complex. The whole complex itself forms a conspicuous mass of leaves. This is a very common gall in the mid-Atlantic states. See R. capitata for more.
photo of Rhopalomyia solidaginis bud gall on Solidago shoot apex
summer generation
photo by Brad Walker
(CC BY-NC 4.0)
photo of dug-up spring generation bud gall on Solidago altissima
spring generation
photo by Daniel McClosky
(CC BY 4.0)
vertical section through R. solidaginis summer generation bud gall on Solidago altissima
summer generation, vertical section
photo by Daniel McClosky
(CC BY-NC 4.0)
See also Figs. 70, 72 in Dorchin et al. (2009) for images of spring generation galls.
Stireman et al. (2005); Dorchin et al. (2009)
R. thompsoni S. altissima, (S. juncea), (S. rugosa) rhizome bud Spring Generation: Solitary or clustered, bulbous, fleshy masses with 1-8 chambers each. Start on rhizomes (underground) but become apparent above ground by emergence time 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. Both galls and adults resemble R. hirtipes. Dorchin et al. (2009) could only find galls that reared adults similar to the type of R. thompsoni from galls from S. atissima, but Felt had listed the other two species as hosts.
Dorchin et al. (2009)
R. sp. (S. fistulosa-stem-galler) S. fistulosa stem Aggregated stem galls, each gall a hairy grayish oval, with a single chamber each. The aggregate commonly has a star-like structure. They appear most similar to R. racemicola galls. Might be responsible for the gall in this observation. Dorchin et al. (2009)
Schizomyia Gagné & Jaschhof (2017)
S. racemicola Solidago spp. capitulum Greenish-purplish onion-shaped capitulum galls alongside normal capitula in the inflorescence. Gall exterior is smooth. Gall-maker larva is bright red-orange. It exits the gall as a larva and pupates elsewhere. photo of S. racemicola gall on S. ulmifolia
on S. ulmifolia
photo by Daniel McClosky
(CC BY 4.0)
photo of S. racemicola gall on S. altissima
on S. altissima
photo by Daniel McClosky
(CC BY 4.0)
bugguide
S. solidaginis S pacifica See Asteralobia solidaginis entry. bugguide
Tephritis
T. pura S. gigantea
S. altissima
stem "[in May and June]...puparia were taken from often indistinct apical stem swellings in Solidago gigantea... and, possibly S. canadensis [my note: probably S. altissima this far south]... from which the adults emerged in the laboratory in June-July of the same year." - later mentions another record of S. altissima serving as a host in the midwest Sutton et al. (2002)
T. webbi Solidago sp. capitulum "M. F. Canova states that the specimen was taken from a gall in the flowerhead of goldenrod." Sycan Glen, OR. The adult insects closely resemble T. michiganiensis and T. pura, neither of which have known host species (at least by 1951). Quisenberry (1951)

There are some records of Trupanea spp. infesting goldenrod flower-heads, but do they form galls?

Wasbauer (1973) gives a secondary record for galls of Aciurina bigeloviae on Solidago, but this species probably doesn't regularly gall Solidago (?)

Foote & Blanc (1963) ascribe a collection of galls on Solidago in Inyo Co., CA to A. ferruginea, but this fly typically galls rabbit-brushes. Maybe a mistaken host ID?

See also Aster Yellows phytoplasma, which can induce phyllody in Solidago.

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

1These entries are for insects that induce galls resembling those of Asphondylia monacha, but were found on other host Solidago species, and were divergent phylogenetically.
2These entries are for the un-studied (to my knowledge) insects that induce Asphondylia-like galls on other host Solidago species. These are known only from the appearance of galls on these goldenrods; the midges themselves have been neither reared nor described. These may be the work of known Asphondylia midges, A. monacha and A. solidaginis in particular, on occasional/accidental host species. They may also represent unrelated gall-making organisms.

Unexpected / Interesting goldenrod gall observations

Asphondylia-like bud galls on southeastern USA Solidago sp.
https://www.inaturalist.org/observations/33794356
https://www.inaturalist.org/observations/34156586
https://www.inaturalist.org/observations/17063696
https://www.inaturalist.org/observations/31258368
https://www.inaturalist.org/observations/31420378
https://www.inaturalist.org/observations/89391537
https://www.inaturalist.org/observations/41637825
https://www.inaturalist.org/observations/42327854
https://www.inaturalist.org/observations/58255409

Leaf deformation (and maybe a snap-gall?) on Solidago sp. in MS:
https://www.inaturalist.org/observations/12472658

A bud gall on Solidago way out-of-range in Washington State:
https://www.inaturalist.org/observations/13619060

Rhopalomyia solidaginis-like bud gall in appearance, but on S. gigantea in MN/WI:
https://www.inaturalist.org/observations/57784622

P. atra on unidentified southern goldenrod species:
https://www.inaturalist.org/observations/61521973



References


Aldrich (1929):
https://repository.si.edu/bitstream/handle/10088/15820/1/USNMP-76_2799_1929.pdf

Arth. Fl. = Arthropods of Florida website by Florida State Museum of Entomology:
http://www.fsca-dpi.org/Diptera/Families/Tephritidae/Species/Eurosta/eurosta_cribrata.htm

Bucknell University Eurosta biology page:
http://www.projects.bucknell.edu/solidago/main.html

Cedar Creek Ecosystem Science Reserve (2000):
http://cedarcreek.umn.edu/insects/029061n.html

Dorchin et al. (2006):
Dorchin, N., Scott, E. R., Abrahamson, W. G. (2006) First Record of Macrolabis (Diptera: Cecidomyiidae) in America: A new inquiline species from Dasineura folliculi galls on goldenrods. Systematics 99(4): 656-661.

Dorchin et al. (2007):
Netta Dorchin, Carolyn E. Clarkin, Eric R. Scott, Michael P. Luongo, Warren G. Abrahamson, Taxonomy, Life History, and Population Sex Ratios of North American Dasineura (Diptera: Cecidomyiidae) on Goldenrods (Asteraceae), Annals of the Entomological Society of America, Volume 100, Issue 4, 1 July 2007, Pages 539–548, https://doi.org/10.1603/0013-8746(2007)100[539:TLHAPS]2.0.CO;2

Dorchin et al. (2009):
https://www.mapress.com/j/zt/article/view/zootaxa.2152.1.1

Dorchin et al. (2009b):
Dorchin, N., Scott, E. R., Clarkin, C. E., Luongo, M. P., Jordan, S. and Abrahamson, W. G. (2009) Behavioural, ecological and genetic evidence confirm the occurrence of host‐associated differentiation in goldenrod gall‐midges. Journal of Evolutionary Biology, 22: 729-739. doi:10.1111/j.1420-9101.2009.01696.x

Dorchin et al. (2015):
Dorchin, N., Joy, J. B., Hilke, L. K., Wise, M. J., Abrahamson, W. G. (2015) Taxonomy and phylogeny of the Asphondylia species (Diptera: Cecidomyiidae) of North American goldenrods: challenging morphology, complex host associations, and cryptic speciation. Zoological Journal of the Linnean Society, 174: 265-304. doi:10.1111/zoj.12234
https://academic.oup.com/zoolinnean/article/174/2/265/2449766

Eiseman (2024):
Eiseman, C. S. (2024) Procecidochares atra Loew (Tephritidae) and Rhopalomyia capitata Felt (Cecidomyiidae) (Diptera) reared from single-chambered rosette galls on rough-stemmed goldenrod (Asteraceae: Solidago rugosa Mill.). Proceedings of the Entomological Society of Washington 125 (2): 273-277. https://doi.org/10.4289/0013-8797.125.2.273

Elsayed et al. (2018):
Elsayed, A. K., Yukawa, J., Tokuda, M. (2018) A taxonomic revision and molecular phylogeny of the eastern Palearctic species of the genera Schizomyia Kieffer and Asteralobia Kovalev (Diptera, Cecidomyiidae, Asphondyliini), with descriptions of five new species of Schizomyia from Japan. Zookeys 808: 123-160.

Heard & Kitts (2012):
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.726.1531&rep=rep1&type=pdf

Ibrahim (1980):
https://ufdcimages.uflib.ufl.edu/AA/00/02/97/95/00001/AA00029795_00001.pdf

Felt, E. P. (1915):
http://www.nysm.nysed.gov/staff-publications/29th-report-state-entomologist-injurious-and-other-ins

Felt, E. P. (1917):
Felt, E.P. Key to American Insect Galls. New York State Museum Bulletin 200.
https://www.biodiversitylibrary.org/item/35191

Foote (1964):
Foote, R. H. (1964) A new synonym in the genus Eurosta (Diptera: Tephritidae). Proceedings of the Entomological Society of Washington 66 (1): 61.

Foote, R. H., Blanc, F. L., and Norrbom, A. L. (1993) Handbook of the Fruit Flies (Diptera: Tephritidae) of America North of Mexico

Goeden & Teerink (1997):
https://www.biodiversitylibrary.org/part/55666#/summary

Goeden & Norrbom (2001) Life history and description of adults and immature stages of Procecidochares blanci, n. sp. (Diptera: Tephritidae) on Isocoma acradenia (E. Greene) E. Greene (Asteraceae) in Southern California. Proceedings of the Entomological Society of Washington 103 (3-4): 517-540.

Kellicott, D. S. (1878) A new gall moth and notes on larvae of other gall moths. The Canadian Entomologist 10(11): 202-204.

Miller (1963):
https://kb.osu.edu/bitstream/handle/1811/4921/V63N02_065.pdf

Miller (1976):
https://www.biodiversitylibrary.org/page/41135216#page/58/mode/1up

Ming (1989): Thesis, referenced in Foote et al. (1993)

Moffat et al. (2019):
https://link.springer.com/article/10.1007/s10682-018-9966-z

Philips and Smith (1998):
https://www.biodiversitylibrary.org/part/13377#/summary

Phillips (1923): https://www.jstor.org/stable/pdf/25003994.pdf

Plakidas, J. D. (2018):
https://www.researchgate.net/publication/330204246_Asphondylia_pumila_n_sp

Steyskal & Foote (1977):
Steyskal, G. C. and Foote, R. H. (1977) Revisionary notes on North American Tephritidae (Diptera), with keys and descriptions of new species. Proceedings of the Entomological Society of Washington 79 (1): 146-155.

Stireman et al. (2005):
Stireman, J. O., Nason, J. D., Heard, S. B. (2005) Host-associated genetic differentiation in phytophagous insects: General phenomenon or isolated exceptions? Evidence from a goldenrod-insect community. Evolution 59 (12): 2573-2587. https://doi.org/10.1554/05-222.1

Stireman et al. (2010):
https://doi.org/10.1016/j.ympev.2009.09.010

Stoltzfus (1974):
https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=6120&context=rtd

Stoltzfus (1989):
https://scholarworks.uni.edu/cgi/viewcontent.cgi?article=1587&context=jias

Sutton et al. (2002)
Suton, B. D., Steck, G. J., DeFoe, D. (2002) New recoods of Tephritidae (Diptera) from Great Smoky Mountains National Park - II. Insecta Mundi 16 (1-3), pp. 1-8.

Sutton & Steck (2005):
http://journals.fcla.edu/mundi/article/viewFile/25075/24406

Thompson (1907):
Thompson, M. T. (1907) Three galls made by cyclorrhaphous flies. Psyche 14: 71-74.

Quisenberry (1951):
Quisenberry, B. F. (1951) A Study of the Genus Tephritis Latreille in the Nearctic Region North of Mexico (Diptera: Tephritidae). Journal of the Kansas Entomological Society, Vol. 24, No. 2 (Apr., 1951), pp. 56-72

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

Comments

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

Posted by sambiology almost 5 years ago

@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 almost 5 years ago

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 https://bugguide.net/node/view/324012 when you were looking? It's one of the other pages I have bookmarked.

Posted by kimberlietx almost 5 years ago

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 almost 5 years ago

Haha! Yeah, one of these days I may even wrestle with Solidago ID's.. One of these days... ;)
Texas is loaded with Solidago!
http://bonap.net/Napa/TaxonMaps/Genus/County/Solidago

Posted by sambiology almost 5 years ago

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

Posted by kimberlietx almost 5 years ago

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

Posted by ddennism almost 5 years ago

GoBotany is my goto botanical source in New England. New England Solidagos can be found here: https://gobotany.nativeplanttrust.org/genus/solidago/
And then there is the Goldenrod group called Euthamia: https://gobotany.nativeplanttrust.org/genus/euthamia/
And then Oligoneuron: https://gobotany.nativeplanttrust.org/genus/oligoneuron/
If you get stumped, you can go to the Plant Share section and ask the botanist. https://gobotany.nativeplanttrust.org/plantshare/
Of course, I don't know what other species might be found in Texas or Florida. I haven't mastered, them all, but each year I get a little better.

Posted by chaffeemonell almost 5 years ago

Thanks for the identification links, Chaffee.

Just to clarify for others: in this entry I'm following iNat's taxonomic scheme and lumping Oligoneuron in with Solidago. GoBotany and Wikipedia separate Oligoneuron. I haven't found literature on gall-forming insects on hosts in Oligoneuron (= Solidago sect. Ptarmicoidei), but there is an iNat observation of a bud-gall on S. rigida here: https://www.inaturalist.org/observations/32639920.

Posted by ddennism almost 5 years ago

This is great, thank you for doing this! /Lena Struwe

Posted by vilseskog almost 5 years ago

This is excellent! I'm going to pay more attention to these now.

Posted by wdvanhem over 4 years ago

Très beau travail. Merci pour avoir collecté tous ces renseignements. La saison qui arrive, je vais ouvrir l'œil pour observer de nouvelles galles. Mon seul problème est que je ne parle pas anglais et que les traducteurs sont peu efficaces.

Vous pouvez utiliser toutes mes photos pour illustrer votre article.

Encore bravo pour votre travail

Posted by krisskinou over 4 years ago

This guide is great! I'm looking forwards to seeing it filled out more if you can find more info. I also wonder if making a visual guide to these based on shape might be doable... if I ever get good at art I might give it a try

Posted by mws over 4 years ago

@mws thank you! Right now I'm still in the collection phase. Hopefully I can organize it into a more useful form by the season next year. The information on these insects is very scattered!

Posted by ddennism over 4 years ago

@ddennism is there anything that an amateur entomologist such as myself could do to help you make the guide? Maybe certain things to look for when making observations of goldenrod galls?

Posted by mws over 4 years ago

@mws - Yeah, slice 'em vertically sometimes! Or at least, with leaf-bunch galls, try to peel back some leaves to get a better idea of where the internal insect chambers are. Are they on top of the stem? Within the stem? Are they translucent and pliable? Hard, opaque and conical? Do the insects instead reside in inrolled leaves or blisters?

Take careful photos of the host plant. Particularly with Solidago, getting photos or otherwise noting:

The presence/absence and shape of basal leaves.
The texture of the undersides of mid-stem leaves. (hairs in focus if possible)
The size and shape of the phyllaries, (the green bracts that surround each flower-head; phyllaries are to flower-heads what sepals are to flowers.)

These make it easier for someone to identify the plant to species-level.

And if you want to get really crazy:

Look for galls that develop in the spring. This is difficult because it's hard to identify goldenrods before they bloom. But there are several spring- and early-summer generations of gall-formers for which there are very few - zero observations and photos. In some cases the spring generation is only inferred and has never been documented. Sometimes early season galls look very different from flowering-season galls. If you know of a local goldenrod colony, try looking for stunted stems around May.

Dig around the bases of Solidago juncea plants and look for underground galls (always near the surface, so far as is known). This species in particular seems to have a bunch of rhizome gallers, in several genera, most of which are basically un-photographed as far as I can tell.

What are some features of a guide that you would find most helpful?

Posted by ddennism over 4 years ago

@ddennism So take a pocket knife with me and get cross-sections when possible, search rhizomes, look for spring galls, and get species-level IDs for the host plant. That sounds doable to me! I think a makeshift key would be very helpful for this guide. Not something very complex, just something along the lines of "if your gall is shaped like this, check this section. These x species are your options. Here's how to tell apart the species with the same gall shape." But maybe I'm just a really picture-focused person.

Posted by mws over 4 years ago

Very nice work! Also bookmarking this page except, yes, IDing goldenrod in the first place is a real challenge for me.

Posted by ashley_bradford over 4 years ago

What a masterpiece of work! I'm sure we will all benefit from this!!!

Posted by ken-potter over 3 years ago

I literally have this post bookmarked for reference. Fantastic stuff.

Posted by wdvanhem over 3 years ago

Thank you for these resources. I shared them with my brother who is a goldenrod rod enthusiast from a different angle. He creates goldenrod gall art. You can check out some of his work at http://dparkerparkerosa.com/3dshow/GRod/Class_Presentation.pdf.

Posted by primada over 3 years ago

Very useful list.

Posted by beartracker about 3 years ago

Very nice! Thank you!

Posted by ken-potter about 3 years ago

wow! Anyway that this is downloadable for future reference?

Posted by skrentnyjeff about 3 years ago

Thanks, Jeff - I might move it somewhere more permanent in the future when I feel like it's more complete. For now, the iNaturalist journal entry URLs seem to be pretty stable.

Posted by ddennism about 3 years ago

thank you for sharing...

Posted by skrentnyjeff about 3 years ago

Thank you, very helpful!

Posted by annikaml almost 3 years ago

Thank you!

Posted by beartracker almost 3 years ago

This is so interesting for a budding botanist! Thank you!

Posted by bbuzas about 2 years ago

Are you aware of any published references to Procecidochares atra using Solidago gigantea? Or any unpublished rearing records from that host?

Posted by ceiseman about 1 year ago

@ceiseman - No, I think I must have grabbed that from the bugguide page when I was first putting together notes, which I see now is unsourced.

I have seen many P. atra-like galls on Solidago gigantea, but I have never reared them. I assume these common galls were the basis for the bugguide page author's claim. I'll put that host in parenthesis now. Thanks!

People who are reading along should look at Charley and Julia's more-rigorous and better-cited summary of the situation with Procecidochares atra and P. polita here:
http://doi.org/10.4289/0013-8797.124.3.564

Posted by ddennism about 1 year ago

Thanks. Evidently that came from Netta Dorchin's comment here: https://bugguide.net/node/view/443421/bgimage
I don't think I've ever personally seen one on S. gigantea, but I did find one example on BugGuide which was opened to remove any doubt that it's Procecidochares: https://bugguide.net/node/view/857056/bgimage
I have a short note in press that is a small contribution to our knowledge of goldenrod rosette galls (a little investigation in my yard that follows up on the discussion of P. atra galls in that Nantucket paper). Stay tuned!

Posted by ceiseman about 1 year ago

Now published:
Eiseman, Charles S. 2024. Procecidochares atra Loew (Tephritidae) and Rhopalomyia capitata Felt (Cecidomyiidae) (Diptera) reared from single-chambered rosette galls on rough-stemmed goldenrod (Asteraceae: Solidago rugosa). Proceedings of the Entomological Society of Washington 125(2) [2023]: 273–277.
...in case you missed it in the rather long email I just sent to my leafminer list.

Posted by ceiseman 8 months ago

I did miss it! Thank you!

Posted by ddennism 8 months ago

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