Goldenrod Galls

Solidago and Euthamia are two plant genera commonly called goldenrods. They host a number of gall-making insects. These insects have not been collected into a single document online, though someone started to do so on bugguide a few years ago.

This journal entry is my attempt to catalog all the gall-making insects on goldenrods. This is probably never going to be an exhaustive 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. This definition is a little wishy-washy, and could include other stem-borers and leafminers, for example, if one really wants to split hairs, but I have excluded those creatures for now. This is not an identification guide for all insect residents of goldenrod galls; many times the current resident(s) of a gall are not the original gall-makers! In some types of galls parasitoids and inquilines are more commonly reared than the gall-maker.

This entry was motivated by my observation in summer 2019 that many identifications of Rhopalomyia solidaginis summer galls were probably misidentified on iNaturalist. I think the computer vision was partly to blame for this; it likely got a little aggressive and started suggesting R. solidaginis for diverse images. This included identifications on observations of normal rosettes from plants from a variety of families (Asparagaceae to Campanulaceae) with no evidence of an insect or gall even being present. People also may have been unaware of the great diversity of gall-midges and other gall-makers on these genera, selecting R. solidaginis by default for any leafy gall on a goldenrod.

That said, many 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.

Charley Eiseman has a great series on his blog about goldenrod rosette bud galls:

The above-mentioned bugguide page is here:

Emily S. Damstra has good illustrations of seven gall-makers on S. altissima:

Much of this information comes from the published work of Netta Dorchin (see full reference list at bottom).

() = 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.

bolded entries are the most commonly observed

Gall-making insects on Euthamia ("goldentops", "grass-leaved goldenrods")

gall-making insect host gall gall description representative images sources
Asphondylia pseudorosa E. graminifolia bud
Vegetative bud galls are usually formed at the apex, but can also be found on lateral buds. The outer leaves are broadened, the innermost leaves form the gall-chamber, which is lined with white mycelium. The innermost leaves eventually turn black. Unlike in R. lobata galls, spongy tissue does not form, and each bud gall contains only one larva.

Capitulum bud galls form later in the season. These are difficult to distinguish from normal, developing capitula, though they do not flower, and instead house the developing larva. These are also lined with white mycelium.

Leaf-snap galls are pictured in Dorchin et al. (2015) but not mentioned in the text. They appear to be formed at 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 ones. He attributed these galls to "Asphondylia monacha", which is a name he used to refer to what are now several distinct Asphondylia species.
See Figs. 15-17 in Dorchin et al. (2015) Dorchin et al. (2015)
Asteromyia euthamiae Euthamia leaf spot
(stem spot)
Black blisters on leaves (and rarely on stems?). The blisters are lined with a white mycelium. There are several generations per year. photo of Asteromyia carbonifera galls on Euthamia leaves by cassi saari
photo by cassi saari (@bouteloua) (CC BY-NC 4.0)
photo of Asteromyia euthamiae galls on a Euthamia leaf by Ethan Maitra
photo by Ethan Maitra (@astrobirder)(CC BY-NC 4.0)
photo of Asteromyia euthamiae galls on Euthamia stems by Ethan Maitra
photo by Ethan Maitra (@astrobirder)(CC BY-NC 4.0)
Stireman et al. (2010)
Dasineura carbonaria E. graminifolia bud Shoot tip bud galls, formed by several variously-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 may be 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. A monogenous species, as is Dasineura folliculi: the offspring of a single female is all of one sex, though multiple oviposition events from multiple mothers can occur on a single host bud, giving rise to mixed-sex composite galls. Because most galls house larvae of a single sex, though, individual galls may be called "male" or "female". I do not know if male and female galls differ morphologically. The name "carbonaria" implies a blackened structure, but this is misleading. The flies have this name because these midges were initially mistakenly assigned to the galls of Asteromia carbonifera.

D. carbonaria gall on the terminal bud of a Euthamia, photo by Michael K. Oliver
photo by Michael K. Oliver (@peakaytea)(CC BY-NC 4.0)

more photos in Dorchin et al. (2007) (paywalled)

Dorchin et al. (2007), Dorchin et al. (2009b)
Epiblema desertana E. graminifolia stem Very narrow stem swellings. Larvae overwinter in the gall. See Miller (1963) for a photo (pg. 67, Fig. 3d) Miller (1963)
Lasioptera cylindrigallae E. graminifolia stem Very, very narrow stem swellings. Gagne 2017
Rhopalomyia lobata E. graminifolia bud Multi-chambered galls in 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, 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. R. lobata galls on lateral buds of Euthamia photo by Jason Michael Crockwell
photo by Jason Michael Crockwell (@berkshirenaturalist)(CC BY-NC-ND 4.0)
R. lobata galls clustered and fused at the apical buds of Euthamia photo by Christian Grenier
photo by Christian Grenier (@krisskinou) (CC0 1.0)
Dorchin et al. (2009)
Rhopalomyia pedicellata E. graminifolia variable 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 shot of R. pedicellata gallphoto by Ethan Maitra (@astrobirder)(CC BY-NC 4.0)
context shot of R. pedicellata gallsphoto by Sara Rall (@srall)(CC BY-NC 4.0)
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. This minor difference in gall shape correlates with differences in insect morphology. My note: I wonder how these two species diverged when they are found on the same hosts in roughly the same geographic range? context shot of many R. fusiformae galls
photo by Ethan Maitra (@astrobirder )(CC BY-NC 4.0)
Dorchin et al. (2009)
Galeopsomyia haemon E. graminifolia gall-within-a-gall This Hymenopteran 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 A. solidaginis, A. rosulata, and A. pseudorosa bud galls. Beatriz Moisset posted a photo of these galls in A. solidaginis leaf-snap galls here Dorchin et al. (2015)

Gall-making insects on Solidago (most other "goldenrods")

gall-making insect host gall gall description representative image sources
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 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 on S. uliginosa, but rarely found there on other host species. S. uliginosa-derived adults were smaller in size as well. The authors speculate that these might represent a separate species (but distinct from the S. uliginosa-galling Asphondylia entity below).
spring generation A. monacha bud gallspring generation
A. monacha bud gall clustersummer generation gall cluster
photo by Tom Norton (@tsn)(CC BY-NC 4.0)
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 the leaves are very young) to make a single chamber lined with white mycelium. Unlike those produced by A. solidaginis, this species' leaf-snap galls are often located very near the plant apex, giving rise to a gradient of gall morphology, 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. These galls are smaller and flatter than those formed by R. solidaginis on S. rugosa, and are composed of fewer leaves. Unlike those of R. solidaginis, this species' galls contain a single chamber.
See Fig. 11-14 in Dorchin et al. (2015) for images of leaf snap and terminal bud galls by this species.
An observation of a gradient of A. rosulata galls, from leaf-snap galls to a bud gall, on Solidago rugosa by Ashley M Bradfordbud gall and leaf-snap galls on Solidago in subsect. Venosae in TN
photo by Ashley M Bradford (@ashley_bradford) (CC BY-NC 4.0)
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. See Fig. 19-20 in Dorchin et al. (2015) for images of terminal bud galls by this species. 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 while the leaves are very young) to make a single chamber lined with white mycelium.

Mid-Late 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 mycelia. 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 fly: Camptoneuromyia adhesa sometimes emerges from snap-galls like these.
A. solidaginis leaf snap galls photo by Lena Struweleaf snap galls
photo by Lena Struwe (@vilseskog ) (CC BY-NC 4.0)
A. solidaginis bud gall photo by Timothy Freybud gall
photo by Timothy Frey (@calconey)(CC BY-NC 4.0)
Dorchin et al. (2015)
Felt (1907)
Asphondylia sp.1 (S. bicolor-galler) S. bicolor 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. sempervirens-galler". One insect from an S. uliginosa rosette gall also sorted into this clade, while others from that host species sorted into A. monacha. S. bicolor galler gall imagegall cluster on S. bicolor
See also Fig. 6 in Dorchin et al. (2015).
Dorchin et al. (2015)
Asphondylia sp.1 (S. sempervirens-galler) S. sempervirens 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.
Dorchin et al. (2015)
Asphondylia sp.1 (S. uliginosa-galler) S. uliginosa bud See comments for A. "S. sempervirens-galler" and A. "S. bicolor-galler". Distinct, at least, from A. monacha, though that species also forms rosette bud galls on S. uliginosa Dorchin et al. (2015)
Asphondylia sp. 2 S. nemoralis leaf snap Leaf snap galls observed rarely on this species, but insect responsible is unknown Dorchin et al. (2015)
Asphondylia sp.2 S. tortifolia* bud A. rosulata-like galls in October, but insect unknown Dorchin et al. (2015)
Asphondylia sp.2 S. patula bud Aggregated bud galls with mini-rosettes, like those made by A. monacha, have been observed on this species, but the insect remains unknown. Could be A. monacha, or another gall-maker. These observations of bud galls on S. patula may or may not be the same galls referred to by Dorchin et al. (2015):; Dorchin et al. (2015)
Asphondylia sp.2 S. odora bud Aggregated 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. My note: on iNaturalist, Alvin Diamond (@adiamond) has observed galls in Alabama on S. odora that resemble R. solidaginis bud galls on S. altissima. These may or may not be the same S. odora galls Dorchin et al. (2015) refer to. Dorchin et al. (2015), this iNat observation
Asteralobia solidaginis S. pacifica
(east Asia)
Gagne 2017
Asteromyia carbonifera Solidago leaf spot Black blisters on leaves, lined internally with a white mycelium. Lots of interesting evolutionary biology research has been done in this system, particularly in the lab of John Stireman at Wright State University, that I look forward to diving into. Different lineages of A. carbonifera induce differently-shaped galls. The fungus that comprises the mycelium that lines the interior of these galls is Botryosphaeria dothidea. photo by Matt Parr of Asteromyia carbonifera gall on Solidago leafphoto by Matt Parr (@ginsengandsoon) (CC BY-NC-SA 4.0)
photo of Asteromyia carbonifera gall on Solidago leaf by Ethan Maitra
photo by Ethan Maitra (@astrobirder)(CC BY-NC 4.0)
photo of Asteromyia carbonifera galls on Solidago leaf by Chuck Sexton
photo by Chuck Sexton (@gcwarbler)(CC BY-NC 4.0)
Stireman et al. (2010)
Asteromyia modesta Solidago,
leaf spot Leaf blisters. Probably polyphyletic as currently circumscribed, with two distinct clades, one of which is itself polyphyletic with the recognition of A. tumifica. Both clades included some individuals that made galls on Solidago. "Galls" might be an overstatement; the larvae reside in cryptic pockets of leaf tissue that may be purple but are often nearly the same green color as the surrounding leaf tissue. The chambers are lined with a thin mycelium. Charley Eiseman (@ceiseman) accidentally reared this midge from a leaf with more prominent leaf-mines, and photographed both the blister and the midge. Stireman et al. (2010)
Bug Tracks post
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, so perhaps this insect taxon will be folded into a revised concept of A. modesta in the future. John van der Linden has a photo of a gall identified as this fly by Raymond Gagné here. Stireman et al. (2010)
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, sometimes deforming the leaves somewhat) on the more-distal portions of the gall leaves. A monogenous species, as is Dasineura carbonaria: the offspring of a single female is all of one sex, though multiple oviposition events from multiple mothers can occur on a single host bud, giving rise to mixed-sex composite galls. Because most galls house larvae of a single sex, though, individual galls may be called "male" or "female". I do not know if male and female galls differ morphologically. D. folliculi bud gallon S. gigantea - I am unsure of this identification, but it does resemble photos of such galls in the cited literature. Dorchin et al. (2007), Dorchin et al. (2009b)
Dasineura virgaureae S. virgaurea
Gagne 2017
Epiblema scudderiana S. altissima, Solidago spp.
Heterotheca subaxillaris
stem Narrowly cylindrical-ellipsoid stem-swelling galls. Sometimes irregularly shaped. Two holes. One small one near the top and close to a leaf axil. This is the entry hole. Another hole gets larger through the season. This is the frass-ejection and eventual exit hole. This" bung hole" is blocked with caterpillar-derived material that fits the hole closely and resembles a train wheel. Univoltine; larvae overwinter in the gall. Before winter, the caterpillar spins a silk funnel that guides the emerging moth to the exit hole. Branches often proliferate at or above the gall. But see also Lasioptera galls. photo by David of Epiblema scudderiana gall on Solidago stemphoto by David (@davidenrique) (CC BY-NC-SA 4.0)
Miller (1963); Miller (1976)Brown et al. (1983)
Eurosta 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 explaining that earlier authors have confused the host-species for E. elsa and E. comma; they attempt to correct the record by assigning E. elsa to S. juncea and E. comma to S. rugosa. Modern databases (according to ITIS) synonymize E. elsa with E. comma. photos and illustrations in Novak & Foote (1980) (paywalled) 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 upwards and is mostly above-ground at maturity. Like those of E. comma, the galls resemble peanuts somewhat. Ming (1989) includes E. conspurcata and E. reticulata in synonymy with this species. My note: Are S. juncea and S. sempervirens really hosting the same fly species? photos and illustrations in Novak & Foote (1980) (paywalled) bugguide, Arthr. Fl., Sutton & Steck (2005)
Eurosta fenestra ? rhizome Sutton & Steck (2005) say that this is also a member of the E. comma species complex. They mention that it's probably never actually been found in FL, despite earlier reports, which were due to misidentifications of E. floridensis or other members of the E. comma species complex. photos and illustrations in Novak & Foote (1980) (paywalled) Sutton & Steck (2005)
Eurosta floridensis S. fistulosa rhizome Galls are similar to those made by E. comma and E. fenestra. Arth. Fl., Sutton & Steck (2005)
Eurosta lateralis S. chapmanii stem Similar to 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., FL, at least recently. Sutton & Steck (2005) state that it may be critically endangered. They give S. odora as the host, but that was before S. chapmanii was segregated from that species. 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)
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. There is a great wealth of literature on the evolutionary dynamics at play in this system. Briefly, gall diameter seems to be under the control of the insect's genetics, not the host plant's. 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 bird predators. 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 selection at play during this process. The galls are so frequent on S. altissima in the mid-Atlantic, that the presence of galls has been suggested as a character for distinguishing S. altissima plants from S. canadensis, although S. canadensis can also be (rarely?) a host for this fly. E. solidaginis stem gallon S. altissima Bucknell Solidago Gall Website, Moffatt et al. (2019), Stoltzfus (1989)
Eutreta hespera Solidago sp. rhizome Reared once from rhizomes of an unknown Solidago species near Custer, SD, but the flies have been collected from the Dakotas westward, through much of western NA. Stoltzfus (1974)
Eutreta noveboracensis S. altissima,
(S. rugosa)
(Solidago spp.)
rhizome Larvae bore through rhizomes and above-ground stems, inducing galls. 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 probably does not make galls on Solidago, instead associating with Stachytarpheta branches. bugguide, Stoltzfus (1974)
Galeopsomyia haemon Solidago sp. gall-within-a-gall This Hymenopteran 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 A. solidaginis, A. rosulata, and A. pseudorosa bud galls. Beatriz Moisset posted a photo of these galls in A. solidaginis leaf-snap galls here Dorchin et al. (2015)
Gnorimoschema gallaeasterella S. flexicaulis
(S. caesia)
Eurybia divaricata
Doellingeria umbellata
probably others
stem Stem galls similar to those of S. gallaesolidaginis, but with brown bung holes (? - implied in Miller (1963)). Need to find a print copy of Miller (2000) to read more about this genus. Judd (1962) could not find any galls on S. caesia despite there being large numbers of these plants adjacent to and within the S. flexicaulis site with many galls. I think it's likely that the initial report of galls from S. caesia may be in error since these two Solidago species were frequently confused/lumped early on. Then again, the Eurybia and Doellingeria host reports suggest a wider range of acceptable hosts. Nazari & Landry (2012)
Judd (1962)
Gnorimoschema gallaesolidaginis S. altissima,
S. canadensis
stem Ellipsoid (wider than those of Epiblema) stem galls with a characteristic white exit bung-hole. Miller (1963) mentions that there are other species in this genus that make galls on other Solidago species. His monograph on them (2000) lists eight species, most of which are on Solidago. 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 see G. jocelynae for more. Need to find a print copy of Miller (2000) to read more about this genus. photo of Gnorimoschema gallaesolidaginis spindle gall on Solidago stem by Colin D Jones
photo by Colin D Jones (@colindjones) (CC BY-NC 4.0)
Miller (1963)
Heard & Kitts (2012)
Nazari & Landry (2012)
Gnorimoschema gallaespeciosum (S. speciosa)
(S. jejunifolia)
(S. rigidiuscula)
stem? Mentioned in passing in Nazari & Landry (2012). Need to find a print copy of Miller (2000) to read more about this genus. Type specimen is from Ramsey Co., MN, which is out-of-range for S. speciosa in the new, strict sense. The host is probably S. jejunifolia and/or S. rigidiuscula. This gall has the bung-hole located just above the middle of the gall - unlike its relatives. Nazari & Landry (2012)
Gnorimoschema gibsonella S. rigida,
(Symphyotrichum pilosum)
stem S. rigida for the type. Nazari & Landry (2012) cite Miller (2000) for additional host. Need to find a print copy of Miller (2000) to read more about this genus. Nazari & Landry (2012)
Gnorimoschema jocelynae S. gigantea stem 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 only difference is in the bung hole coloration - which was determined by the adult's ancestral host species, not its current host species in Miller (2000), however, Nason et al. (2002) points out that these exit hole characteristics could be idiosyncratic to particular plants and Miller's N was only 3 for this experiment. Need to find a print copy of Miller (2000) to read more about this genus. Works after Nason et al. (2002) tend to refer to these moths as G. gallaesolidaginis, gigantea host-race. Nazari & Landry (2012)
Gnorimoschema salinaris S. sempervirens,
S. missouriensis
S. juncea
other members in this species group
stem S. gigantea is also a host according to one MI record in Nazari & Landry (2012), but this might be G. gallaesolidaginis / G. jocelynae. Need to find a print copy of Miller (2000) to read more about this genus. Nazari & Landry (2012)
Janetiella inquilina Solidago sp. aka Oligotrophus inquilinus Felt 1908; on "S. canadensis" which, at the time, could have referred to several species in subsection Triplinerviae. Gagne 2017
Lasioptera solidaginis Solidago stem Irregular, elongate stem-swelling galls. Makes a small exit hole on the side of the gall. But see also Epliblema galls. bugguide
Lestodiplosis carolinae S. canadensis (presum. sensu lato) rosette bud gall - maybe this is a synonym of R. carolina(e), itself a synonym of R. solidaginis? Asheville, NC Gagne 2017
Lestodiplosis rugosae Solidago sp. New York Gagne 2017
Lestodiplosis triangularis Solidago sp. leaf New York Gagne 2017
Procecidochares anthracina S. californica bud bud galls cluster on stem near where the stem emerges from rhizomes. Usually buried in humus, but not truly subterranean. Univoltine, unlike P. atra. Goeden & Teerink (1997)
Procecidochares atra S. altissima,
S. gigantea,
S. rugosa,
S. nemoralis
(Erigeron canadensis),
(Aster** sp.)
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 artichokes 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, remaining somewhat 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 have typically flattened and grown away from the gall, no longer giving the gall an artichoke-like appearance. (My note: At this stage, these galls, particularly the terminal ones, can superficially resemble those of Rhopalomyia solidaginis and Asphondylia solidaginis. However, these midge-induced galls have distinct chambers. 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).
P. atra bud gallssummer generation gall cluster on S. altissima
P. atra bud gall vertical sectionsummer generation, vertical section through terminal bud gall
P. atra bud gallssummer generation gall cluster on S. altissima
wikipedia, iNat obs, bugguide, Philips and Smith (1998), Aldrich (1929) for S. nemoralis record
Procecidochares minuta (Solidago) 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". I think this species is known to produce galls on a number of composite host species. I'm not sure this record is a correctly identified Solidago. Wasbauer (1972)
Procecidochares polita (S. virgata)
(S. chrysopsis)
(((S. sempervirens)))
(((S. mexicana)))
bud? stem?
Reared from Solidago sp. "small, roundish galls" by Girault (1913) in VA. Reported from galls of Solidago sp. by Johnson (1910). However, Aldrich (1929) says 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) attributes "Solidago stricta" stem galls collected in Dade County, FL to this 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, FL area (Sutton & Steck 2005) and Falls Church, VA 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 MA to FL. 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. It could be all or some members of the S. sempervirens-S. mexicana complex, which are in the same subsection as S. virgata and S. chrysopsis. Wasbauer (1972) includes some records from "S. stricta" galls as well.
Aldrich (1929), Ibrahim (1980), Goeden & Norrbom (2001), Sutton & Steck (2005)
Rhopalomyia anthophila S. altissima capitulum Capitulum (flower-head) galls among the inflorescence of the host. Cylindrical, or like a truncated cone. Fuzzy and whitish. Inner chamber conical with thin walls. photo of an isolated R. anthophila gall
photo by Kevin Keegan (@kevinliam)(public domain)context shot of many R. anthophila galls
among S. altissima capitula
macro image of R. anthophila galls by Dan Mullen
photo by Dan Mullen (CC BY-NC-ND 2.0)
Dorchin et al. (2009)
Rhopalomyia bulbula S. juncea 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 from Felt (1917)
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 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.

My side note: In the upper Great Lakes region there are leafy galls on S. gigantea that more closely resemble those made by R. solidaginis.
R. capitata spring bud gall
spring generation
R. capitata bud gallsummer generation
R. capitata bud gall, vertical sectionsummer generation bud gall, vertically sectioned
photo by hallm (@hallm) (CC BY-NC 4.0)
R. capitata bud gall in MNsummer generation bud gall, from above, in MN
photo by Miriam Kniaz (@miriamkniaz) (CC BY-NC 4.0)
Dorchin et al. (2009)
Rhopalomyia clarkei S. rugosa,
S. altissima
leaf out-growth
stem out-growth
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. (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, or else different presentations on different host species.) See Figs. 62-65 of Dorchin et al. (2009) for additional images of these galls at various stages of development on S. rugosa and S. altissima.
R. clarkei leaf gall photo by Will Van Hemessen
photo by Will Van Hemessen (@wdvanhem) (CC BY-NC 4.0)
Dorchin et al. (2009)
Rhopalomyia cruziana (S. spathulata),
(S. velutina)
capitulum? From an unknown gall from an unidentified Solidago species growing in the Santa Cruz mountains in California. Dorchin (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)
Rhopalomyia 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 this is really S. juncea. Dorchin et al. (2009)
Rhopalomyia guttata S. bicolor capitulum Hidden among normal-looking inflorescence pedicels of neighboring 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 than ungalled ones. Unlike R. anthophila galls, these retain the capitulum's pedicel. Dorchin et al. (2009)
Rhopalomyia 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. R. hirtipes bud gall photo by catherineklatt
photo by Catherine Klatt (@catherineklatt)(CC BY-NC 4.0)
R. hirtipes bud gall photo by Charles and Kathy Appell showing the plant flowering from lateral buds under the gall.
not always arresting growth
photo by Charles and Kathy Appell (@charleshappell) (CC BY-NC 4.0)
Dorchin et al. (2009)
Rhopalomyia 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 follicularis galls. Conjecture that these R. clarkei-like galls might be the real galls occupied by this species. Perhaps Felt (the original describer) confused D. follicularis galls with R. capitata galls, and then concluded that R. inquisitor was an "inquilines" 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 (@srall). See Figs. 66-67 in Dorchin et al. (2009) for reference images. Dorchin et al. (2009)
Rhopalomyia racemicola S. altissima,
(S. fistulosa)

Green, bristly, onion-shaped capitulum galls, sometimes found in aggregations. Galls on S. fistulosa were tentatively identified as this species by Raymond Gagné . The illustration in Felt (1915) by L. H. Joutel looks suspiciously like Schizomyia racemicola, but
I can find no other published images of these galls.

Illustration of galls of Rhopalomyia racemicola on an unidentified Solidago by L. H. Joutel in Felt's 1913(1915) 29th Report of the State Entolomogist
Illustration by L. H. Joutel in Felt (1915)
Dorchin et al. (2009), Felt (1915)
Rhopalomyia solidaginis S. altissima,
S. canadensis,
S. rugosa,
((S. odora))
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.
Alvin Diamond (@adiamond) has observed similar galls on S. odora in Alabama; I'm not sure whether these are the galls that Dorchin (2015) refers to and suspects an Asphondylia midge of making (see Asphondylia entries above) or if this is a distinct entity.
See Figs. 70, 72 in Dorchin et al. (2009) for images of spring generation galls. R. solidaginis bud gall vertical sectionsummer generation
R. solidaginis bud gall vertical sectionsummer generation, vertical section
Dorchin et al. (2009)
Rhopalomyia 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)
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. Might be responsible for the gall in this observation: Dorchin et al. (2009)
Schizomyia racemicola Solidago 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. S. racemicola gall on S. ulmifoliaon S. ulmifolia
S. racemicola gall on S. altissimaon S. altissima
Tephritis 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)

Some records of Trupanea infesting goldenrod flower-heads, but do they form galls?

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

Foote & Blanc (1963) refer to 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.
***probably refers to Symphyotrichum species now, not Aster sensu lato.

1These entries are for insects that induced galls that resembled those of A. 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 entries may represent infestation by known Asphondylia midges, A. monacha and A. solidaginis in particular, on occasional/accidental host species. I myself have observed Asphondylia-like galls on S. patula. They may also represent unrelated gall-making organisms.

Unexpected / Interesting goldenrod gall observations

Rhopalomyia solidaginis-like bud gall on Solidago chapmanii:

Asphondylia monacha-like bud gall on Solidago leavenworthii:

bud-gall on Solidago sp. (?) in Kansas:

Asphondylia monacha-like bud galls on Solidago sempervirens:
(probably the same bud-galler discovered by Charley Eiseman here:
and in the above table as: "Asphondylia sp. (S. sempervirens-galler)"

bud-gall on Solidago juncea (?):

tiny bud-galls on Solidago ulmifolia (?) in IL:

Asphondylia-like bud galls on southeastern USA Solidago sp., possibly A. monacha on S. erecta:

Rhopalomyia fusiformae on Euthamia graminifolia sort of far from Ithaca, NY:

Asphondylia monacha-like bud gall cluster on Solidago sp. in VA:

Asphondylia monacha-like bud gall cluster on Solidago altissima (?) in NJ:
...or very, very large R. solidaginis galls, I guess. More-typical looking examples of R. solidaginis in immediate vicinity:
Could also be R. capitata but on an atypical host species (host is definitely not S. gigantea), and the gall is not flat-topped.
A similar situation in N IL:

Asphondylia solidaginis-like leaf deformities (and maybe a snap-gall?) on Solidago sp. in MS:

A very tightly-wound Asphondylia solidaginis-like gall:

Is this Asphondylia rosulata on Solidago rugosa?

not Procecidochares atra, looks kind of like Dasineura, but lateral galls present in addition to terminal gall, on S. altissima in OH:

Dasineura-like leaf deformities in spring in TX:

A strange bud gall on Solidago in CT:

A bud gall on Solidago way out-of-range in Washington State:

Rhopalomyia anthophila-like gall chamber, but not on the inflorescence, in MI:

Rhopalomyia solidaginis-like bud galls in appearance, but on S. gigantea in MN:
and in MA:

Asphondylia-like bud galls on S. rigida (?) in IL:

bud gall on Solidago ptarmicoides in Ontario:

Rhopalomyia capitata on a Solidago species that is not S. gigantea:


Aldrich (1929):

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):
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,[539:TLHAPS]2.0.CO;2

Dorchin et al. (2009):

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

Heard & Kitts (2012):

Ibrahim (1980):

Felt, E. P. (1915):

Felt, E. P. (1917):
Felt, E.P. Key to American Insect Galls. New York State Museum Bulletin 200.

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):

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.

Miller (1963):

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

Moffat et al. (2019):

Philips and Smith (1998):

Phillips (1923):

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. (2010):

Stoltzfus (1974):

Stoltzfus (1989):

Sutton & Steck (2005):

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

All unattributed photos are my own.

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 8 months 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 8 months 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 8 months 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 8 months 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 8 months ago (Flag)

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

Posted by kimberlietx 8 months ago (Flag)

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

Posted by ddennism 8 months ago (Flag)

GoBotany is my goto botanical source in New England. New England Solidagos can be found here:
And then there is the Goldenrod group called Euthamia:
And then Oligoneuron:
If you get stumped, you can go to the Plant Share section and ask the botanist.
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 7 months ago (Flag)

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:

Posted by ddennism 6 months ago (Flag)

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

Posted by vilseskog 5 months ago (Flag)

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

Posted by wdvanhem 5 months ago (Flag)

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 4 months ago (Flag)

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 4 months ago (Flag)

@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 4 months ago (Flag)

@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 4 months ago (Flag)

@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:
1. The presence/absence and shape of basal leaves.
2. The texture of the undersides of mid-stem leaves. (hairs in focus if possible)
3. 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:

1. 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.

2. 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 4 months ago (Flag)

@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 4 months ago (Flag)

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 4 months ago (Flag)

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