Diario de matthewvosper

Australian hoverflies are a fascinating bunch. The fauna are dominated by the subfamily Eristalinae, there are only just over 30 from the subfamily Syrphinae.

There seem to be a few other species on iNat in Australia that are either undescribed or just not yet known from Australia. There are also a couple of genera where there are significant taxonomic difficulties.

As always when I create something like this I want to stress that I claim no expertise; I simply enjoy learning and investigating these things, and I hope it is worth sharing what I have found. Please let me know of any corrections that need to be made.

Most of the images in the slides below are by @reiner, other observers are credited where their photos appear. Thanks to everyone who has made their pictures available. It's been great engaging with these hoverflies that I can't get close to myself, and the iNat community observing them, from the other side of the world. I was especially delighted when my first response to a request for a photo actually began with the word "G'day" !

Anyway, the slides below include a key to the genera (or some groups of genera) that should help narrow down what you need to look at, and each genus is listed in alphabetical order and treated in one or two slides.

I have based the list of species on those said to be present in Australia in Thompson and Vockeroth's Catalog of the Diptera of Australasia and Oceania, and the Atlas of Living Australia. In a few places there are difficulties, or interesting iNat observations that suggest the presence of species not on the usual lists: I've given some of my own thoughts in those cases, but it should be clear that they are simply my thoughts.

The genus Melangyna (subgenus Austrosyrphus) poses particular difficulties and I have declined to try and indicate how to identify the six listed species. Instead I have given an indication of the diversity of the genus. I hope to do a separate journal post on this group at some point. I have taken a similar approach to Asarkina and Citrogramma.

So here it is: hope it's of some use.

Species or genera discussed [square brackets indicate doubtful presence, or near-Australian species mentioned], (Parentheses give extra informatrion):
Allobaccha monobia, A. siphanticida, [A. amphithoe, possible others]
Allograpta alamaculata, A. australe, A. notiale, A. terraenovae, [possible something else]
Asarkina (only A. ericetarum is listed for Australia but...)
Asiobaccha bicolor, A. notofasciata
Betasyrphus serarius
Citrogramma (C. australe and C. notiale are the two listed species for Australia)
Dideopsis aegrota
Episyrphus glaber, E oliviae, E viridaureus
Eupeodes confrater
Ischiodon scutellaris
Melangyna (Austrosyrphus) (the six species listed for Australia are M. ambusta, M. collata, M. damastor, M. jacksoni, M. sellenyi, and M. viridiceps)
Melanostoma apicale
Paragus crenulatus, P. politus, [P. villipennis]
Simosyrphus grandicornis
Sphaerophoria macrogaster
Xanthandrus agrolas

Toward the end of last year I've tried to deal with the European Sphaerophoria observations. I've added sex and life stage annotations to almost all of them except mating pairs, which I have marked with the observation field 'copulating'. Hopefully now the phenology graphs on the genus taxon page are more meaningful (especially because the 'no annotation' plot on the sex phenology graph basically corresponds to 'mating season').

I've also been rolling out the observation field 'Sphaerophoria identifiable group', which was created by @upupa-epops for North American species, but he kindly added some categories for Europe. The main aim of this really is to try and make it possible to find the things that aren't S scripta! The rules I've followed for each value are:

'cf. S scripta': for males that I suspect of being more elongate but can't properly judge the length: for females with a scripta-like marking on T5 (well separated bars terminating in distinct inward-angled longitudinal wedges).
'interrupta group': for specimens I suspect of being a spotted species, primarily interrupta, fatarum or philantha, especially if there is a strong face stripe (the spots being well formed rather than looking like darkened bands)
'Complete lateral scutum stripes': for specimens that have complete lateral stripes on the scutum but seem to not be scripta or interrupta-group
'"cleoae" pattern': for females exhibiting cleoae characteristics regardless of species (terminal tergites/sternites fused into rings, bands broken in the lateral third).

I have also added the observation field 'cf' to several observations, especially if I suspect interrupta s.s. (broad spots and strong face stripe), or taeniata (very bright; female T5 short with quite straight bars narrowly joined or nearly so by an 'isthmus' in the middle)

Highlights included iNat's first S estebani (quite probably the first live photo of that species!), and the second S loewii

"cleoae" I find quite interesting. Almost all of these I assume to be S scripta, but there is one definate S rueppellii and one probable S taeniata. I don't know how much is known about the "cleoae" phenomenon in Europe.

The genus Lucilia is very difficult to identify from photographs (as are many other genera of blow flies). But the greenbottles are also very commonly observed, and there is a tendency to overidentify certain species (I'm looking at you sericata...). Most people I know are surprised to discover that there are eight species of greenbottle known just from the UK. There are a further three species in the rest of Europe. As a result of this perfect storm, Lucilia observations on iNaturalist are, frankly, a bit of a mess.

The presentation below should give an idea of what it is necessary to photograph in order to have the best chance of getting identifiable pictures. To spell it out:
 1) The bristles on the top of the thorax
 2) The base of the wing from the front (not the top)
 3) The bristles on the middle tibia (the best angle is to look toward the front of the side of the thorax from just a position just back of the middle leg.
 4) The space between the eyes (frons).

The key below is primed for use with photographs but, even so, identification will frequently be impossible. Hopefully it will raise awareness and increase people's confidence to tackle the huge and tangled backlog of observations on iNaturalist.

Which brings me to... Africa! As far as I can tell there is only one additional species of Lucilia in Africa: Lucilia infernalis. This species is immediately distinctive because of the extensive and dark infuscation on the leading half of the wing. I do not know much else about it except that it is widespread in the Afrotropical region, but a picture of it can be seen in Figure 5 of this paper. This is more likely to be confused with certain species of Chrysomya - particularly C laxifrons. Chrysomya can be distinguished by the black margins of the tergites, and the wing infuscation is much better defined in those species that have it. I cannot confidently give a list of which European species may also be present in Africa - I know that L cuprina and L. sericata are widespread on the continent, but others may also be present especially in the north. I believe that only those two species are present in Arabia, so there is little risk of Asian species impinging on East Africa.

The Key below covers the European species and also gives information about how to distinguish 'True greenbottles' from lookalikes. Species found in the UK are underlined. The usual caveat applies: I've made this for my own learning and hopefully for the benefit of others, I believe it to be accurate and based on sound sources carefully considered - but I am not an expert, and Calliphoridae are even outside of my normal activities, so bear that in mind.

The species covered are: Lucilia ampullacea, bufonivora, caesar, cuprina, illustris, magnicornis, pilosiventris, regalis, richardsi, sericata and silvarum.

In addition to the Millipede Key I've also been working on a Centipede Key - so here it is! As with the millipedes, the strategy is to deploy the most obvious features first, and where possible to include a number of different features, and in addition to try and follow the taxonomy step by step from the broader IDs down to species level, enabling the finest possible ID to be given - this is often not possible, but an attempt has been made. These two strategies can sometimes conflict, so compromises have to be made.

To my tremendous surprise I have ended up keying out every British species, although it will not allow the confident identification of every species in every combination of habitat and leg count: the Geophilus flavus/seurati/osquidatum group is particularly knotty (there are also a couple more species of very doubtful presence in the UK that I have ignored such as Schendyla monoeci). There are a few species that key out in two or even three places (L. borealis). I have tried to use features that might just be visible in a high quality macro photograph from above or the side - very rarely have I included a ventral feature. It is worth noting however that in practice most photographs will not be identifiable to species, especially in Cryptops.

I have not illustrated this key - I might add some pics at some time later, but there isn't much available. However there are pictures of the vast majority of British species on the website of the British Myriapod and Isopod Group www.bmig.org.uk/checklist/centipede-checklist which can be used to help interpret the key. The key also draws heavily on information in Tony Barber's AIDGAP guide.

After the key are a couple of charts illustrating the trunk length of Geophilomorph species and the antennal length of Lithobiomorph species.

British Geophilomorpha by Number of Leg Pairs

Colours represent families: Green = Geophilidae, Red = Lintotaeniidae, Pale yellow = Schendylidae, Purple = Mecistocephalidae, Grey = Dignathodontidae, Golden brown = Himantariidae,

British Lithobiomorpha by Number of Antennal Articles:

Colours in header row represent subgenera: Cyan = Lithobius (Monotarsobius), Purple = Lithobius (Sigibius) [Myriatrix] or Lithobius (Polybothrus) [Chilobase], Yellow = Lamyctes (Lamyctes), Green = Lamyctes (Metalamyctes), Red = Lithobius (Lithobius)

Colours in the body represent tergite projections: Red (Lithobius) and Black (Lamyctes) = No tergite projections, Yellow = T7, 9, 11 and 13, Green = T9, 11 and 13, Blue = T11 and 13 but pale blue are those variable or ambiguous species that usually have T11 and 13 only but may also have T9 (borealis) or may lack projections of T11 and even occasionally T13 (lapidicola)

So here's something I've been working at on-and-off for a while as a bit of a learning exercise. This is my best attempt at a key to the Millipedes of the British Isles from Photographs on iNat. The strategy is in line with other keys I have done for hoverflies: photographs don't give you the opportunity to choose which features you look at, and are often short on detail, so the key tries to deploy the most obvious features first, and where possible to include a number of different features. In addition, for iNat purposes it is helpful to try and follow the taxonomy step by step from the broader IDs down to species level, enabling the finest possible ID to be given - this is often not possible, but an attempt has been made. These two strategies can sometimes conflict, so compromises have to be made.

Of course certain species simply cannot be identified without microscopic treatment and therefore the key sometimes ends at a higher level (where it is not obvious I have listed the possible taxa in a footnote marked e.g. '(1)'). I have tried to use features that might just be visible in a high quality macro photograph.

I have not illustrated this key - I might add some pics at some time later, but there isn't much available. However there are pictures of the vast majority of British species on the website of the British Myriapod and Isopod Group www.bmig.org.uk/checklist/millipede-checklist which can be used to help interpret the key.

(1) Family Haplodesmidae or Poratia digitata
(2) Genera Anthogona, Anamastigona or Turdulisoma
(3) Genera Boreoiulus or Archiboreoiulus
(4) Genera Choneiulus or Nopoiulus
(5) Cylindroiulus britannicus, latestriatus or parisiorum
(6) Genera Haplopodoiulus or Allajulus, or Cylindroiulus dahli or sagittarius

For me the origins of this little escapade can be traced back to the time I was involved with implementing the taxonomy of Platycheirus on iNat a while ago and discovered the intriguing New Zealand subgenus-raised-to-genus Eocheilosia. I learned a little more about the genus some time later through a series of conversations with @steve_kerr to whom I am grateful for showing me descriptions of the species I hadn't yet found. I realised that there weren't too many other Bacchines or Melanostomines in the wider region and thought it could be expanded a bit. So here we are.

I have produced a separate key for the Eocheilosia not only because it is by far the largest genus in the region, but also because the difficulties of that genus are so particularly acute. Be sure to read the introductory slides. I should say that that particular key must be taken with a whole mouthful of salt!! I think of it more as a way of beginning to feel around the genus - any ID should be checked with the original descriptions which are almost all linked to in the Powerpoint (bearing in mind that in Eocheilosia there are as many known undescribed species as there are described species!!)

Species included:

BACCHINI
Baccha maculata
Eocheilosia antipoda, captalis, clarkei, cunninghami, fulvipes, harrisi, howesii, huttoni, leptospermi, lignudus, myersii, notata, ronana
Platycheirus albimanus, stegnus

MELANOSTOMINI
Melanostoma apicale, atrum, fasciatum, fumivenosum, polynesiotes, univittatum
Xanthandrus agrolas, bergmani, bicinctus, orientalis

Happy Christmas to our Antipodean friends!

I've been trying this out over the last few days and it seems to work for me. Suggestions for improvement are welcome.

There are not a huge number of these flies and they seem to mostly be large, distinctlive and charismatic.

I'd like to extend this further to the wider region but there's a just a couple of descriptions I can't get hold of - hopefully I'll do that at some point.

The 18 species covered are as follows:

Subtribe CRIORHININA
Malometasternum rufocaudatum
Deineches fulva, D hackeri, D nudiventris

Subtribe TEMNOSTOMINA
Odyneromyia illucens, O iridescens, O spadix, O transparens

Subtribe TROPIDIINA
Orthoprosopa (Orthoprosopa) grisea
Orthoprosopa (Paratropidia) bilineata, O (P) multicolor
Syritta hackeri, S luteinervis, S orientalis

Subtribe XYLOTINA
Chalcosyrphus (Hardyimyia) elongata
Chalcosyrphus (Neploneura) pleuralis, C (N) victoriensis
Xylota flavitarsis

It is best to interpret these keys with sight of quality pictures such as the excellent resource by Steve Falk

In constructing this I have used information from the helpful Book 'Britain's Hoverflies' by Ball and Morris, the key in 'Hoverflies of Northwest Europe' by M.P. van Veen and Steve Falk above.

Some of these species are genuinely impossible to ID from a photo, but I hope that this key might enable more of them to reach a finer level of ID. The female of P. aurolateralis is unknown

For an overview of how the taxonomic groupings used by the UK Hoverfly Recording Scheme relate to the taxa available on iNat see here. For the key to males see here.

Note that the distinctive rosarum and granditarsus have departed for Genus Pyrophaena.

This key is intended to be as useful as possible when IDing from photos, but this will frequently be impossible. Used with a little circumspection I hope it is at least helpful. Be especially aware that it is often difficult in photographs to tell the difference between grey and pale yellow spots. I am very happy to be informed of any errors.

Females:

It is best to interpret these keys with sight of quality pictures such as the excellent resource by Steve Falk

In constructing this I have used information from the helpful Book 'Britain's Hoverflies' by Ball and Morris, the key in 'Hoverflies of Northwest Europe' by M.P. van Veen and Steve Falk above.

Some of these species are next to impossible to ID from a photo, but I hope that this key might enable more of them to reach a finer level of ID.

For an overview of how the taxonomic groupings used by the UK Hoverfly Recording Scheme relate to the taxa available on iNat see here

Note that the distinctive rosarum and granditarsus have departed for Genus Pyrophaena.

This key is intended to be as useful as possible when IDing from photos, but this will frequently be impossible. Used with a little circumspection I hope it is at least helpful. I am very happy to be informed of any errors.

Males:

The Genus Platycheirus is a very large, nearly cosmopolitan genus of small elongate hoverflies typified by males with distinctive modifications to the shape and/or bristles of parts of the front leg. The fact that it is such a large genus means that it has been subdivided. Traditionally the subdivisions have been based on the morphology of these male forelegs.

In the UK, for the purposes of the National Hoverfly Recording Scheme, the genus has been split up into 'groups'. This is not a taxonomic statement, but one of convenience for recording by grouping similar looking species together. Of course it is often the case that 'looking similar' does have taxonomic significance, and most of the UK groups do indeed align with more widely used taxonomic units. The exception, as we shall see, is the albimanus-group.

The UK groups are:
albimanus-group: inc. albimanus, ambiguus, discimanus, sticticus
manicatus-group: inc. manicatus, tarsalis, melanopsis
peltatus-group: inc. peltatus, nielseni, amplus
scutatus-group: inc. scutatus, aurolateralis, splendidus
clypeatus-group: inc. clypeatus, angustatus, europaeus, fulviventris, immarginatus, occultus, perpallidus, podagratus, ramsarensis, scambus
(Note that Subgenus Pyrophaena i.e P. granditarsus + rosarum is considered a full genus in iNat, not part of Platycheirus at all)

Apart from the UK albimanus-group, all of the above mentioned groups have equivalents in iNat such that if you have a species identified as one of those UK groups it is fine to ID them as 'Section P peltatus', 'Section P manicatus', 'Complex P. clypeatus', or 'Complex P. scutatus' respectively.

The UK albimanus group however, which depends on the whitish or bronzish abdominal markings (as opposed to yellow in other species) could not be reconciled with a wider taxonomy from the literature. It is handy for recording convenience in the UK - but breaks down quickly under the weight of overseas species, and is not taxonomically meaningful anyway. 'Section P. albimanus' in iNat is a completely different concept. In fact 'Section P. albimanus' in iNat includes 'Complexes clypeatus and scutatus' (Which is why we had to use Sections and Complexes to implement these groups). In addition, two species of the UK albimanus group are not in 'Section P. albimanus' (P ambiguus and discimanus). Here is how it looks:

Genus Platycheirus
---Subgenus Pachysphyria (inc. ambiguus - this whole Subgenus is characterised by a curled apical bristle on the male forefemur)
---Subgenus Platycheirus (inc. everything except ambiguus)
------Section P peltatus (same as the UK group)
------Section P manicatus (=UK group + discimanus)
------Section P albimanus (=albimanus, sticticus and the two complexes mentioned below)
---------Complex P scutatus (same as UK group)
---------Complex P clypeatus (same as UK group)

Another way to look at this is:
If you know the UK group you can give it the same ID on iNat unless there is a possibility that it is ambiguus or discimanus.
If you have an ID from iNat, the UK group will be the same unless the ID is albimanus-group and the spots are not grey, or the ID is manicatus-group and the spots are grey (but the latter case is unlikely to occur in practice).

I hope that makes some sense. I have intended to put out a key to help with this, but it will have to wait. Maybe not long...