March 28, 2019

Lichen and Air Pollution in Hamilton, Ontario

The Hamilton Naturalists' Club and Environment Club did a study to test air quality in different parts of Hamilton using lichen:

"Testing both ash and maple trees, McMaster professor George Sorger found that there existed a relationship between two common lichen species (Physcia millegrana and Candelaria concolor) and sulphur dioxide and nitrogen dioxide levels. Areas with a high lichen presence have better air quality than those with a low presence."

"Hamilton residents can help by planting native trees in their yards, as the greatest opportunity to increase the urban tree canopy is through private property. The low lichen diversity and abundance in urban areas also indicate the need to prioritize public transit and reduce exhaust emissions along high-travelled roadways. Lichen diversity should also be assessed and monitored in Hamilton over time to track changes in our airshed."

Identification tips in the Appendix.

Posted on March 28, 2019 01:22 by upupa-epops upupa-epops | 0 comments | Leave a comment

January 20, 2019

Random Notes on Hoverfly Identification

Sphaerophoria in Eastern North America

Males with incomplete thorax stripe:

Females with incomplete thorax stripe:

Males with full thorax stripe (I think only S. philanthus identifiable):

Females with full thorax stripe (I think only S. bifurcata identifiable):

Separating similar yellow-banded Syrphini

Eupeodes subgenus Metasyrphus, Syrphus, Epistrophe, others (Didea, Meliscaeva)

It's hard

Eupeodes latifasciatus on the east coast is an exception not always having black margins (, and Syrphus opinator on the west coast is an exception having black margins (

Some things from BugGuide comments on Epistrophe:
Yellow spots at base of abdomen widen toward margin (always narrow toward margin in Syrphus maybe?)
Edges of yellow bands on abdomen straight rather than curving (except usually a black point in the centre of the first band)
Edges of abdomen very fuzzy
Yellow on abdomen dull/mottled rather than bright yellow (also there is a "dark morph" with grey/brown bands)

Identifying Syrphus
S. torvus

S. ribesii
How do you tell if the wing has hairs?

S. knabi

S. vitripennis

S. opinator
Lots of sad unresolved conversations:

Scaeva vs Eupeodes subgenus Eupeodes

These have very similar abdomen patterns. Are they separated by head shape?

E. volucris

S. pyrastri (now S. affinis I think?)
Probably I can go through these links later and weed out some redundant ones...

Lapposyrphus, Dasysyrphus also similar.


Allograpta in North America

Neotropical Allograpta

List of Neotropical species of each subgenus and locations from Mengual et al.:
A. obliqua group
aeruginosifrons (Brazil)
annulipes (Colombia, Ecuador, Peru, Brazil, Bolivia)
aperta (Surinam, Guyana)
bilineella (Colombia)
browni (Ecuador)
exotica (central US south to Argentina)
falcata (Colombia, Venezuela)
hastata (Peru, Brazil)
hortensis (Peru, Chile, Argentina)
insularis (Puerto Rico)
limbata (West Indies, Brazil)
neotropica (Colombia, Ecuador, Brazil, Argentina) -
obliqua (Canada south to Argentina)
piurana (Peru, Chile)
pulchra (Chile, Easter Island)
radiata (Florida, West Indies)
robinsoniana (Juan Fernandez Island)
splendens (Galapagos)
tectiforma (Ecuador)
teligera (Ecuador, Brazil)
trilimbata (Mexico)

Mengual, Ruiz, Rojo, Stahls, & Thompson. A conspectus of the flower fly genus Allograpta (Diptera: Syrphidae) with description of a new subgenus and species. 2009.


O. pumilus/callidus group has a unique pattern:

Big thesis on Ocyptamus: (some abdomen diagrams on page 160)

Some places to search for specimen photos: (Go to letter "O") (search for "Baccha")

Paper with lots of diagrams, also in references looks like there may be more:

Posted on January 20, 2019 20:28 by upupa-epops upupa-epops | 1 comments | Leave a comment

January 10, 2019

Toxomerus watsoni confusion

I've noticed that many Toxomerus observations, especially in Mexico, are being identified as Toxomerus watsoni:
However, I've tried looking through all the papers I can find, and can't find any way to separate T. watsoni from similar species like T. duplicatus without a microscope.

I put all the similar individuals like that with simple abdomen patterns under one observation field so I can compare them here:

After doing this, I noticed that many of the individuals that are identified as T. watsoni look a bit different from unidentified individuals.
For example, these two are both males but they look different:

The one that is called "T. watsoni" has a thinner, tubular abdomen, the dark bands are mostly black, and the last abdomen segment has a different pattern.
The other one has a flat, wide, abdomen, the dark bands are lighter grey, and the last abdomen segment has just a black dot.
I see similar differences in females, although the abdomen structure is less different:

But I don't know if that's still not enough to identify them to species.

Other similar groups within the "T. cf. duplicatus" group

1. Ones identified as T. watsoni have a consistent look
- Orange centre of abdomen sections, pair of commas, blue/silver between with black borders
- Long thin abdomen

2. Orange bands, pairs of commas, shiny blue stripes with little or not black borders (thinner)

3. Orange or yellow bands, little or no commas, blue/shiny stripes with little or no black borders

4. Orange or yellow bands, no commas, blue stripes with black borders

Most have dark ring near end of hind femur, but in some it's faint or not there.
Ones in Florida vary between groups 2 and 3:
What species is this?


I've been trying to make a list of species that fall into the general group of simple band patterns:

T. brevifacies
T. buscki
T. corbis/planiventris?
T. difficilis
T. duplicatus
T. ecuadoreus
T. idalius
T. minutus?
T. norma
T. papaveroi
T. paraduplicatus
T. pinchinchae
T. productus
T. puellus
T. steatogaster
T. taenius
T. watsoni

Posted on January 10, 2019 23:34 by upupa-epops upupa-epops | 1 comments | Leave a comment

January 08, 2019

Rough Identification Guide to Slug Genera of Ontario (In Progress)

Guide to Superfamilies

When trying to identify a slug, here are some characteristics you should try to notice (in roughly this order of importance):
1. How much of the body is covered by the mantle
2. Location of breathing hole (pneumostome) on the right side of the slug, relative to the mantle
3. Shape (e.g. is there a keel/ridge on the tail behind the mantle or is it round)
4. Texture, especially on the mantle
5. Size
6. Colour and pattern (e.g. orange, brown, plain, mottled, stripes along the sides)
7. Mucus colour

By far the most common genera to see are Arion and Deroceras. Double-check if you think it is not one of those two. Also note that it is often difficult to determine species of slugs without dissection.

This guide only includes genera that I know to be in Ontario. It is unclear for sure what genera and species are present - hopefully iNaturalist can help improve our knowledge. I'd appreciate any suggestions or critique.

Superfamily Parmacelloidea

Has a strong keel running all the way from the mantle to the tail
Pneumostome toward back of mantle
Mantle can look like it has two different sections
Mostly plain colouration with little pattern
- 2 genera in Ontario (Milax, Tandonia) in one family

Superfamily Limacoidea

Rounded tail (no keel) except sometimes at very end of tail
Pneumostome toward back of mantle
Mantle texture often with circular ridges resembling fingerprint
Can have plain, mottled, or striped pattern
- 5 genera (Lehmannia, Limacus, Limax, Deroceras, Boetgerilla) in three families

Superfamily Arionoidea

Pneumostome usually either halfway along or toward front of mantle
If the mantle covers most of the slug (i.e. not just the front half, or it looks like it has no mantle), then it is in this superfamily
Pattern often striped, but can be plain or mottled
- At least 4 genera (Arion, Megapallifera, Pallifera, Philomycus) in at least two families

Guide to Genera of Superfamily Parmacelloidea

Guide to Genera of Superfamily Limacoidea

Guide to Genera of Superfamily Arionoidea

Posted on January 08, 2019 01:05 by upupa-epops upupa-epops | 0 comments | Leave a comment

January 07, 2019

List of Slug Species of Canada

From Identifying Land Snails and Slugs in Canada.
Does anyone know if there is a checklist of species for Ontario? Sometimes it is unclear from the book whether or not a species is in Ontario, but when it is I've marked them with an asterisk (*). Probably/Possibly in Ontario are marked with (~). Unknown/Unclear are hopefully marked with (?). There are quite a few species only in BC. Please let me know if you have any questons.

Superfamily Parmacelloidea

Family Milacidae

Genus Milax
- Milax gagates ~

Superfamily Limacoidea

Family Limacidae

Genus Lehmannia
- Lehmannia marginata
- Lehmannia valentiana *

Genus Limacus
- Limacus flavus ~

Genus Limax
- Limax maximus *

Family Agriolimacidae

Genus Deroceras
- Deroceras agreste *
- Deroceras hesperium ?
- Deroceras laeve ?
- Deroceras panormitanum *
- Deroceras reticulatum *

Family Boettgerillidae

Genus Boettgerilla
- Boettgerilla pallens *

Superfamily Arionoidea

Family Arionidae

Genus Arion
- Arion intermedius *
Subgenus Arion (ater group)
- Arion ater
- Arion lusitanicus *
- Arion rufus
Subgenus Carinarion (fasciatus group)
- Arion circumscriptus *
- Arion fasciatus *
- Arion silvaticus *
Subgenus Kobelita (hortensis group)
- Arion distinctus *
- Arion hortensis ?
Subgenus Mesarion (subfuscus group)
- Arion subfuscus *

Family Anadenidae

Genus Prophysaon
- Prophysaon andersonii
- Prophysaon coeruleum
- Prophysaon foliolatum
- Prophysaon vanattae

Genus Kootenaia
- Kootenaia burkei

Family Ariolimacidae

Genus Ariolimax
- Ariolimax columbianus

Genus Magnipelta
- Magnipelta mycophaga

Family Binneyidae

Genus Hemphillia
- Hemphillia camelus
- Hemphillia dromedarius
- Hemphillia glandulosa

Family Philomycidae

Genus Megapallifera
- Megapallifera mutabilis ?

Genus Pallifera
- Pallifera fosteri ?
- Pallifera dorsalis ?

Genus Philomycus
- Philomycus batchi ?
- Philomycus carolinianus ?
- Philomycus flexuolaris ?
- Philomycus togatus ?

Posted on January 07, 2019 21:52 by upupa-epops upupa-epops | 0 comments | Leave a comment

May 27, 2018

Random Toxomerus Stuff

Common Name Suggestions?

T. pulchellus -- Bean-spotted Calligrapher
T. virgulatus -- Club-shaped Calligrapher (the markings sort of look like playing cards clubs? Maybe?)
T. dispar -- Variable Calligrapher (I'm curious why Skevington et al. chose "Dark-sided"... could be helpful)
T. vertebratus -- Backbone Calligrapher / Chilean Calligrapher?
T. arcifer -- Hook-backed/Hook-shaped Calligrapher
T. pictus -- Tiger Calligrapher
T. mosaicus -- Mosaic Calligrapher
T. mutuus -- Mexican Calligrapher (or Mexican Banded Calligrapher)
T. floralis -- Common Calligrapher / Variable Calligrapher
T. crockeri -- Galapagos Calligrapher
T. duplicatus -- Common Banded Calligrapher (then make T. verticalis to American Banded Calligrapher)
T. basalis -- Sundew Calligrapher


Index to Toxomerus Species Diagrams

[Draft] List of species that have abdomen diagrams or images available (I don't think I will ever have time to complete this, but I think it would be helpful).

Bold: Found on iNaturalist
Italic: Maybe found on iNat? Not confirmed.


T. aeolus -- Hull 1943 fig. 46 / Thompson 1981 fig. 84
T. arcifer -- Thompson fig. 75
T. aurulentus -- Thompson fig. 88
T. boscii -- Hull
T. difficilis -- Thompson fig. 87
T. dispar -- Thompson fig. 91
T. geminatus -- Hull / Vockeroth
T. floralis -- Thompson fig. 92
T. jussiaeae -- BugGuide
T. luna -- Thompson fig. 71
T. maculatus -- Thompson fig. 77
T. marginatus -- Hull fig. 28
T. multipunctatus -- Thompson fig. 76
T. nasutus -- Hull
T. occidentalis
T. parvulus??
T. pictus -- Thompson fig. 78
T. politus -- Hull fig. 3 / Thompson fig. 85
T. puellus -- Thompson fig. 89
T. pulchellus -- Hull fig. 74
T. una -- Thompson fig. 83
T. valdesi -- Thompson fig. 86
T. vertebratus
T. verticalis -- Thompson fig. 73
T. virgulatus
T. veve -- Thompson fig. 72
T. watsoni -- Thompson fig. 90



Hull 1943:
Thompson 1981:

For resolving synonyms:

See bottom of page here for more resources:

Please let me know if you find any errors or any species not on this list!

Posted on May 27, 2018 20:59 by upupa-epops upupa-epops | 2 comments | Leave a comment

May 19, 2018

Canadian "Unknown" Observations

I have just finished going through all the "Unknown" observations for Canada:

When I started there were over 90 pages. There are quite a few I reviewed and skipped because I had no idea what to do for them (9 pages, if someone else is able to go through them that would be awesome), but other than those they are all done. I know other people go through the unknowns as well so I'm not sure how much was my doing... Also currently more are added at a rate of 1-2 pages per day, so if it continues to be ignored they will build up again pretty soon.

The vast majority of the observations were plants, also lots of fungi, lichen, and miscellaneous marine seaweed/algae/goop stuff.
There were quite a few where multiple species were put in one observation, and some where one individual was spread over multiple observations. An uncommon but weird thing is where a person opts of of community IDs, but doesn't add an ID themselves so the observation is stuck as "Unknown" forever.

There were also quite a few observations in 2016 for water bodies. Some examples:
I'm not really sure what to do for these. I marked some of them "Plants" for trees and grass in the background, but there aren't plants visible in every photo so I think that was a mistake. "No evidence of organism" isn't exactly true either though...

Anyway I thought it would be good to get this out there. There are still thousands of unknowns for the rest of the world to work through...

Posted on May 19, 2018 19:09 by upupa-epops upupa-epops | 1 comments | Leave a comment

March 25, 2018

Identifying Toxomerus Hoverflies

Toxomerus is a distinctive genus of hover flies in the subfamily Syrphinae restricted to the Americas. It is a large genus, with 100-150 species described and probably many more undiscovered in the tropics. However, there are only a few species in North America. They are distinguished from other hover flies by their relatively small size, an indent in the back of their eyes, and unique abdomen markings.

(work in progress)

Toxomerus in Canada and the United States

NOT Toxomerus
The most similar and often confused genus is Allograpta, which is of a similar size but lacks the pointed indent in the back of the eyes and has a distinctly different abdomen pattern.

Female A. obliqua. Note the leaf-shaped spots near the end of the abdomen and the pair of vertical lines between them. These markings are found in both North American species of this genus.

Another genus sometimes mistaken is Sphaerophoria.


In northeastern North America, there are 3 species of Toxomerus: T. marginatus, T geminatus, and T. politus

Margined Calligrapher (Toxomerus marginatus)

Margined Calligrapher is the most common species in North America. It is distinguished by having a thin pale line margin around the abdomen, which prevents any of the dark patterning from reaching the edge. It is smaller than the other common species. The abdomen pattern is composed of two sections of repeated bow-shaped dark areas surrounding a pale area, within which is a pair of comma-shaped dark markings. They have pale yellow legs, usually with little or no dark areas (especially on the femurs). The scutellum usually has a pale edge and a darker centre, which fade gradually into each other. Often it is entirely pale yellow.
This species is probably the most variable of the Toxomerus, but all of the above should stay true.

A fairly typical T. marginatus

This one has stronger black areas

This one has darker light areas

This one has paler dark areas

This one has reduced dark areas

View of legs and margin

It is possible, but rare, for there to be no dark or no pale areas left. That should give you a good idea of their variability. Other species are also variable, but the common species don't vary to the same extent. According to BugGuide, the colouration is based on the temperature that the pupa was exposed to. If it is cold, darker colours will develop, and if it is hot, paler colours will result.
Here's a cool photo showing one just before coming out of its pupa:

More photos:

Eastern Calligrapher (Toxomerus geminatus)

The Eastern Calligrapher is also a very common species in the east. When comparing it with Margined Calligrapher, the most obvious difference is that every aspect of the abdomen pattern is sharper and more pointed, with zig-zagged edges. Other distinguishing features are that the hind femurs will have a black ring around them, and the scutellum has a very dark centre with a yellow edge, and a sharp distinct line between the two (rather than gradual like in Margined Calligrapher).

A darker individual

Males are more tubular and their pattern is more obscured, but still visible

A pale individual

Darker with black in areas it usually isn't

Much less jagged than usual with black missing from some spots it's usually present

Maize Calligrapher (Toxomerus politus)

Maize Calligrapher is a larger distinctive hover fly with a unique pattern, although sometimes it is confused with the Marmalade Hoverfly (Episyrphus balteatus) from Europe. It is much less common than the previous two species. It has a unique T-shaped pattern which should separate it from any other Toxomerus. In addition to that, it has a pale scutellum with a diffuse darker centre and pale legs, similar to Margined Calligrapher. The line in the centre of the scutum tends to be paler and more distinct than in other species.

This species might have a unique abdomen pattern from any other species in the genus, and it ranges all the way down to Argentina.

West Coast

On the west coast of North America, there are only 2 species of Toxomerus: T. marginatus and T. occidentalis.

Western Calligrapher (Toxomerus occidentalis)

This species is in nearly all ways identical to Eastern Calligrapher, but is easy to separate by range. You can see a map here:
A vagrant of either species outside of its range would probably be impossible to identify without a microscope (see Vockeroth, 382).


In the southeastern United States, there are at least 4 species, with the number increasing as you get closer to Florida. In addition to the three eastern species mentioned above, Thin-lined (or Bosc's?) Calligrapher is also common.

Thin-lined Calligrapher (Toxomerus boscii)

This species is less well known than the previous species, since it is restricted to the southeastern states. Its abdomen pattern is sort of halfway between that of Margined and Eastern Calligrapher, and is unique in having separated pairs of vertical lines on either side. It is usually reddish in colour, as opposed to the orange of Margined Calligrapher or yellow of Eastern or Western Calligraphers, although they can all vary. The main identifying features used on BugGuide are that "the yellow stripe on the mesonotum [along the side of the thorax above the wings] is not very thick and the hind femur has a black ring."

Florida has at least 10 species, some of which may be found in neighbouring states.
The list of species confirmed for Florida, from BugGuide, is: T. arcifer, T. boscii, T. corbis, T. dispar, T. floralis, T. jussiaeae, T. geminatus, T. parvulus, T. politus and T. marginatus
Many of these species come from the West Indies area, which has many more species.

Any photos of these species are only tentatively identified because the species in Florida are not very well known and there may be more species that haven't been confirmed for Florida.

Orange-backed Calligrapher (Toxomerus jussiaeae)

Has pattern similar to Margined Calligrapher, but the dark pattern reach the edge of the abdomen. The abdomen appear rounder and more egg-shaped, the dark bars are thinner and straighter, and the consecutive dark curved lines do not reach up to and touch the next set up. All photos I have seen so far show an entirely pale scutellum, with only a slightly dark centre.

Toxomerus jussiaeae?

More photos here:

Banded Calligrapher (Toxomerus verticalis)

This species has a relatively simple pattern, with repeated black and blue bands horizontal connected by a thin vertical black stripe.

Toxomerus verticalis?

More photos here:

Black-backed Calligrapher (Toxomerus parvulus)

There are photos of specimens here:
and here:
Although they seem to contradict each other, so one of them may be misidentified?
There is a diagram of the abdomen here (fig. 72), which matches the second link:

Florida and Dark-sided Calligraphers (Toxomerus floralis, dispar, and arcifer)

As far as I can tell, these hover flies are very similar to Margined Calligrapher, except without the margin. Thompson in "The Flower Flies of the West Indies" talks a lot about how dispar and floralis are inseparable. They are very variable like Margined.

Some more images here:

More here:
and here:
And a couple here:

Hopefully summarizing what I understand this way will help us figure more out.

Bow-shaped Calligrapher (Toxomerus arcifer)

If it is possible to separate T. arcifer, it would probably be by the pattern on the base of the abdomen:

T. arcifer?

Notice the backwards pointing light-coloured pair of hooks, as compared to the straight pale bands in the previous photos. These are visible in diagrams of the abdomen in this species and not others (figs. 75a-75c, compare 91a-92):

A couple more images here:


This individual does not match any of the abdomen diagrams or identified photos I have seen. There is a similar individual here:

Since they are in Florida, I would assume it is one of the 10 species listed on BugGuide, but I think I have found images or diagrams of all of them and it doesn't seem to match.


I have not seen any photographed Toxomerus officially identified as T. corbis, but I am wondering if the observations listed here may be this species:
If so, this species is similar to T. watsoni from Mexico, with a mostly orange-abdomen. It has uncurved horizontal bands of black and blue, similar to T. verticalis, but it also has the pairs of comma-shaped markings in the centre like T. jussieae and other species.

A couple supposed specimens:

Toxomerus corbis?

Toxomerus in Central and South America

There are some websites or papers I have found that have photos or diagrams of many Toxomerus species, which may be helpful for identifying species further south. Based on old papers, the genus name used to be Mesogramma, which makes searching even more difficult than it already is.

Searching this database for the genus "Mesogramma" and "Mesograpta" results in photos of some species: (faster, same database:
There are quite a few photos of different species here:
More photos (I wonder if some of these may be misindentified):
And here (again, I wonder if some are misidentified):
And here:
A few species:
A small number of photos lower down (sort by letter "T" first):
Searching for genus "Mesogramma" and "Toxomerus" gets a few images here (unfortunately many images don't work):
Also here (sort by Toxomerus and limit to specimens with images only):

There are many abdomen diagrams here, but they are liable to be outdated:

Here is a filter for all the interesting Toxomerus that we still need to figure out:,126532,58752,146632,466380

Tips for species I have look into:

Clicking on the observations below each photo may yield more information about that species.

T. politus is relatively easy to ID and ranges from Canada all the way to Argentina. Tips for neotropical ID here: The most similar species is T. aeolus.

People in Mexico seem to be pretty comfortable identifying Watson's Calligrapher (Toxomerus watsoni), but I don't know yet what the similar species in the area might be.

Many species look very similar to T. cf. duplicatus, with this simple pattern of horizontal bars and a pair of comma-shaped dots on a plain background. It is probably not possible to identify most of them to species.
More here:

T. pulchellus seems to have a unique abdomen pattern, so it might be identifiable regardless of location. However, personally I would like to somehow first be confident that there are no similar species to eliminate. See:
"Toxomerus pulchellus is easily recognized by the characteristic abdominal pattern in the female ... yellow with black bean-shaped spots on 3rd, 4th and 5th tergite" (Dumbardon-Martial, pg. 415)

T. pulchellus

T. pictus looks very similar to T. geminatus (which might be restricted to the US and Canada?) but can actually be separated by the length of the sharp black points on the abdomen, I think? As far as I can tell, T. croesus is the only species that looks the same, and Borges & Couri 2009 seems to suggest it is only found in southern Brazil.

T. pictus?
More here:

T. virgulatus might have a unique abdomen pattern?

T. virgulatus

T. lacrymosus and musicus have a very unique pattern, but seem identical to each other and are inseparable as far as I can tell.

T. lacrymosus/musicus
More here:

T. vertebratus seems to have a unique abdomen pattern. Good photo here:

T. vertebratus

T. saphiridiceps seems to have a unique abdomen pattern.

T. saphiridiceps

T. crockeri might be the only species on the Galapagos?

Other Resources

BugGuide page for Toxomerus:

Common names are suggestions from this list, and aren't set in stone:

Vockeroth. The Flower Flies of the Subfamily Syrphinae of Canada, Alaska, and Greenland. 1992:

Upcoming Field Guide to the Syrphidae of Northeastern North America:

Key to the Genera of Nearctic Syrphidae:

Metz & Thompson. A revision of the larger species of Toxomerus. 2001:

Thompson, Chris. The Flower Flies of the West Indies. 1981:

Hull. The Genus Mesogramma. 1943:

Borges & Couri. Revision of Toxomerus from Brazil. 2009:

Illustrated key for the genera of Syrphinae (Diptera, Syrphidae) of occurrence in the South of Brazil:

This website is helpful for finding taxonomic synonyms:

Gerdes. Notes on Types of Toxomerus. 1975.
Gerdes. A New Species of Ecuadorean Toxomerus. 1974.
Gerdes CF. (1974) Toxomerus (Diptera: Syrphidae) of Ecuador. Masters thesis, Western Illinois University, 135 pp. (has only the same abdomen diagrams as the above two papers but descriptions of many species)

Harbach. A New Species of Toxomerus from Brazil, with Notes on Three Related Species. 1984.

Image of T. apegiensis (from Reemer and Rotheray, 2009).

Quite a few great image, most not identified past genus unfortunately:

Dumbardon-Martial. Pollen feeding in the larva of Toxomerus pulchellus. 2016.

Mengual. Black-tie dress code: two new species of the genus Toxomerus. 2011.

Thompson & Thompson. A new Toxomerus species from Chile. 2006.

Thompson, Vockeroth, Sedman. A Catalogue of the Americas South of the United States: Family
Syrphidae. 1976. (just a list of all the Toxomerus species)

Reemer. A second survey of Surinam Syrphidae: introduction and Syrphinae. 2010. (comments and photos of specimens of a number of species)

No images but some descriptions and helpful information:
Marín-Armijos et al. Checklist of the flower flies of Ecuador. 2017.

Hull. New species of Mesogramma. 1951.
Hull. New Species of Syrphidæ From the Neotropical Region. 1942.


Draft index to abdomen diagrams:

Photo list of species identified on iNat:

Observation field for Toxomerus that are currently unidentifiable:

I have also made a Flickr gallery which has quite a few Toxomerus photos:
There are a lot of great photos on Flickr which haven't been added to iNat.

I would appreciate any corrections or suggestions for improving this guide. Thanks!

Posted on March 25, 2018 21:05 by upupa-epops upupa-epops | 10 comments | Leave a comment