Diario del proyecto UK Hoverflies (Syrphidae)

01 de mayo de 2024

State of the Syrphs - 1-May-2024

We have lift-off! (bzzzz.....)

It's been quite a month on the hoverfly front. Last month I predicted we might get 2,500-3,000 new uploads in April (the previous record for April being 1,824). We actually had nearly 3,800! Only July and August last year have ever had more. Nearly 1,200 of these were observed during the four days of the City Nature Challenge (CNC). The identification window for the CNC ends on Sunday. More comments on that below.

I'm not going to predict next month! May is an exciting one for species diversity (read all about it on What to look out for: May!). But it will be interesting to see how it compares to the last time there was an early CNC, 2020, when the number of observations in May was actually fewer than in April.

With such numbers it is remarkable how well we have kept up!

Provisionally 78 species were recorded, smashing the previous April record of 60 from 2022. Highlights include Neoascia interrupta, Anasimyia interpuncta, Cheilosia ranunculi and Epistrophella euchroma/Meligramma euchromum

The link to iRecord appears to have got back to normal, so we can go back to normal routine.


It is indeed the first month since September that the NeedsID pile has grown - but not by as much as it might have done - up by 12.7%. Only 8 genera decreased (small ones, and not by much), 28 were up and 35 were unchanged. Here's the breakdown by tribe, and the breakdown of Syrphini by genera:

The biggest % climbers (with >50 obs to start with) were: Syrphus (+114%), Melanostoma (+55%), Epistrophe (+41%), Helophilus (+30%), Platycheirus (+24%),Sphaerophoria (+22%), Meliscaeva (+15%), and Eristalis (+13%). In addition to those mentioned last month the following genera also now have >100 observations needing ID: Epistrophe (106), Sphaerophoria (104).

The total proportion of observations that are research grade has fallen slightly to 88%. Just over two thirds of observations uploaded in April are research grade already, including just under half of those posted during CNC.


Somehow we managed to maintain an extremely high level of annotation.

Obscured locations

These continue to bobble around the 4-5% mark. If you used obscured locations to preserve privacy or for whatever reason, and you haven't already given thought to using Pinned Locations instead, NBN encourage you to consider it. Observations with obscured locations cannot be used by the Hoverfly Recording Scheme.

Hope you all have a great May!

All data compiled on 30th April

Publicado el mayo 1, 2024 10:58 TARDE por matthewvosper matthewvosper | 0 comentarios | Deja un comentario

18 de abril de 2024

Current transfer issues to iRecord, helping HRS - please read.

Hello everyone,

Roger Morris noticed a sharp drop in iNat observations coming through to iRecord in April. Having investigated a bit, this seems to have to do with a technical change in the way iNat is linking to images. This has been interpreted by the bridge as a form of editing of these old observations, and caused a large amount of information traffic between iNat and iRecord that has clogged the system and caused significant delays in the transfer of new observations.

The result is that Roger has received fewer than 1/3 of the observations he should have so far this month, and there is a fair likelihood that a large number of observations are going to be dumped on him all at once at some point in the future - just as things are getting really busy anyway.

I suggest that for the next few months we generally hold back on the following activities to avoid exacerbating the issue: 1) annotating pre-2024 research grade observations. 2) making pre-2024 observations research grade.

Instead we could focus on 1) Annotating and identifying 2024 observations as they come in LINK 2) Annotating observations of any age that are still in the Needs ID pile (only sex annotations required now) LINK 3) Identifying observations of any age that are stuck at subtribe or above to finer levels LINK.

This is more than enough for us to get on with :-)

Publicado el abril 18, 2024 08:19 MAÑANA por matthewvosper matthewvosper | 4 comentarios | Deja un comentario

14 de abril de 2024

State of the Syrphs - Pre-CNC update and strategising

Hello all,

With the ides of April behind us, and despite the weather, it looks like my estimate of 2500-3000 observations this month will be too low. We are already approaching 1500 and the City Nature Challenge looms! It starts on April 26th. Last year the period of the City Nature Challenge saw more than 1300 hoverfly observations uploaded.

For those not familiar with the City Nature Challenge you can read all about it here. It includes four days of observing (26th-29th) and nearly a week more to upload and identify things. For the purposes of the City Nature Challenge it is important that as many observations as possible are identified by May 5th. You can use this link to identify these observations specifically. If you would like to help this intensive ID effort you might want to familiarise yourself with how to identify some of the top 10 species from last year, which accounted for well over 500 observations:

  1. Epistrophe eligans
  2. Eristalis pertinax
  3. Episyrphus balteatus
  4. Myathropa florea
  5. Melanostoma scalare
  6. Helophilus pendulus
  7. Syrphus ribesii
  8. Platycheirus albimanus
  9. Rhingia campestris
  10. Leucozona lucorum

All the best!

Publicado el abril 14, 2024 10:10 TARDE por matthewvosper matthewvosper | 0 comentarios | Deja un comentario

01 de abril de 2024

State of the Syrphs - 1-Apr-2024

Hello Syrphers!

It has been wet, hasn't it? Just a little bit. Ah well.

What to look out for...

April is lift-off month for hoverflies - check out which hoverflies are at their peak, and which are getting going in this month's 'What to look out for', which contains advice on getting identifiable pictures of the difficult 'black jobs' that form a significant part of the fauna at this time of year. (Bear in mind that species will appear earlier in the south and later in the north).

Keeping up with New Observations

Despite the weather, an awful lot of hoverflies have been uploaded (for March anyway)! This continues the trend of 2024 - so far well over three times as many hoverflies have been uploaded as in any previous year. Some of that is certain users uploading plenty of photos from previous years, but there has also been a significant increase in real time observations, easily more than twice as many as any previous year.

I don't expect that to continue - it is relatively easy to double or treble the small numbers at the start of the year. Nevertheless we have more than kept up with the influx and so the NeedsID pile continues to diminish. 87% of this month's new observations are RG already. Don't forget the handy URLs here which can help us keep up!

What would we need to do to keep up with observation numbers in April? One complicating factor is that this year much more of the City Nature Challenge (CNC) period is in April - so just comparing to last April (when all of the upload period fell in May) won't work. (Last time CNC was mostly in April - 2020 - there were more observations in April than May!) Last year there were nearly 2500 hoverfly uploads from April 1st to the end of the CNC. Based on the increase so far this year it doesn't seem inconceivable that there could be 2500-3000 in April this year. I worked out that on average an observation needs about 1.5 IDs additional IDs to reach RG (i.e. additional to the observer's ID), so that's up to 150 IDs per day on average between all identifiers to keep the pile the same size. In reality they will not be spread evenly - there will be a big surge in the week from Fri 26th. It will be interesting to see if April is the month the NeedsID pile starts to get bigger again...


I suggested last month that we try to get the NeedsID pile below 8500 (half of what it peaked at last year). With a bit of a late activity over the weekend we have achieved that!

8 genera have increased (but not by much), with 30 unchanged and 33 down. The biggest fallers (with >50 obs to start with) are Pipiza (-85%), Neoascia (-76%), Eumerus (-66%), Xanthogramma (-65%), Syrphus (-56%), Melanostoma (-54%), Parhelophilus (-49%), Eupeodes (-43%), Epistrophe (-38%), Meliscaeva (-38%), Rhingia (-28%), Platycheirus (-26%), Chrysogaster (20%), Merodon (-20%), and Helophilus (-11%): Those are some serious numbers, so well done for your contributions. The neediest genera now (those with >100 observations) are Eristalis (1176), Platycheirus (1021), Cheilosia (595), Melanostoma (419), Eupeodes (364), Helophilus (198), Chrysotoxum (121), Xylota (113), and Syrphus (108). May I make a personal plea on behalf of Eristalis? It's my favourite genus, but I've already identified everything still needing ID in the UK so I can't do any more, and the numbers haven't moved much since new year. Anyone fancy having a go?

Another thing that is worth noting is that an increasing proportion of the NeedsID pile is not even ID'd to genus - currently 40%. This includes nearly 50% of Syrphini languishing at tribe. Identifying these is a great exercise for beginners because you don't have the pressure of making things research grade. The following rather messy pie chart shows you the whole NeedsID pile divided by genera. (Probably won't be readable on the app - but the big blue block is 'No Genus yet')

And here is how we did it. You can see just how many more IDs have been added over the winter compared to previous years, and it really is impressive :)


It's also been a very successful month on the annotations front. Sex annotations over 95% for the first time.

Obscured locations

Unfortunately we had quite a high proportion of obscured locations this month. I wonder if more observation has taken place close to people's homes due to the relatively poor weather. Observations with obscured locations cannot be used by the Hoverfly Recording Scheme. An alternative that avoids this problem is 'Pinned Locations'.

Finally, Happy Easter to you all, and Happy Syrphing for April!

All data compiled on 31-Mar-2024

Publicado el abril 1, 2024 08:27 MAÑANA por matthewvosper matthewvosper | 2 comentarios | Deja un comentario

01 de marzo de 2024

State of the Syrphs - 1-Mar-2024

Hello Everyone!

A happy Spring to you all!

What to look out for:

All of the What to look out for articles are now available on the project journal, including the March edition. This is the month hoverflies just start to pick up. One early riser, Melangyna quadrimaculata is best seen this month, and the article suggests how to give yourself the best chance of seeing it, and photographing it identifiably. There are a few other species getting going too :)


A little piece of information I picked up recently, courtesy of @rkl: When a record becomes research grade and is sent to the hoverfly recording scheme subsequent changes made in iNaturalist are still sent through until the record is confirmed in the iRecord system used by HRS. Only once HRS have confirmed the record do changes made in iNat have no further effect. So do not despair if you find a new record that is already research grade but hasn't been annotated! Add the sex and life stage as quick as you can, and you might still be in time. (This includes if the ID is wrong - add a correcting ID and the observation will be withdrawn from iRecord until it becomes research grade again).

Anyway, we've just had our best ever month for keeping up with sex annotations, bravo! Just a smidge short of 90%. And life stage annotations remain very high.

Also, two thirds of all UK hoverfly observations now have a sex annotation.


Last month I suggested that we aim to get the total number of observations needing ID down to 8500 (half of last year's peak), and we're not doing too badly towards that. March is really the last month of the off-season (although things are just starting to pick up). With a bit of a push we might just make it!

Remember the handy URLs here that can help you find what you want to identify and annotate, and keep up with new observations.

Here's the usual breakdown of the NeedsID pile by tribe, and deeper dive into the largest tribe, Syrphini. Syrphini is reducing fast, but Melanostomini, Bacchini, Eristalini and Rhingiini remain stubbornly similar in size.

7 genera have increased slightly, 28 are unchanged and 35 have fallen in numbers needing ID. The month's biggest % fallers (that had >50obs to start with) are: Eupeodes (-55%), Xylota (-46%), Xanthogramma (-13%), Chrysogaster (-12%), Helophilus (-12%), Parhelophilus (-12%) and Eristalis (-11%).

If you are new to identifying, a good way to get started is by identifying observations that are stuck at higher levels - bringing down the ID to genus, or species if you know it. This is less pressure than making things research grade. A third of all observations needing ID have not yet been identified to Genus; you can find them using the link on the URLs page

The neediest genera now (those with >100 obs needing ID) are: Platycheirus (1373), Eristalis (1186), Melanostoma (978), Eupeodes (635), Cheilosia (597), Syrphus (249), Helophilus (223), Xylota (120), and Neoascia (105). Hark at that! Eupeodes down to 4th! You may want to consider learning these genera, to make a bigger difference with your effort. The most accessable are probably Eristalis, Melanostoma, Syrphus, Helophilus and Xylota. See the resources page!

Have a great March!

All data compiled on 29-Feb-2024

Publicado el marzo 1, 2024 12:15 MAÑANA por matthewvosper matthewvosper | 0 comentarios | Deja un comentario

08 de febrero de 2024

What to look out for: October to February

The 'off season' for hoverflies really begins toward the end of October and continues into early March. (see the end for a list of species still above 10%opa in October). Using data from NBN atlas and excluding those marked 'larva', only 2% of all hoverfly records occur in the months Nov-Feb. Nevertheless, that is some. I do not believe any species achieve 10%opa from November to January, the only species to do so in February is Melangyna quadrimaculata - see March's article for information about that.

Some 46 species have records from January (I excluded larvae from the search but I can't guarantee that none of the results are 'undeclared larvae!'). It must be said though that you are considerably more likely to see adult hoverflies in the winter in the south.

The most likely species to see are Eristalis tenax, Eristalis pertinax, Eristalinus aeneus (near the coast), Episyrphus balteatus, Meliscaeva auricollis, and Melanostoma species. These may actually overwinter as adults. I have personally seen Eristalis tenax and Episyrphus balteatus on New Year's Day before!

It is worth therefore looking for hoverflies basking in sunlight on mild winter days. It may be possible to attract them by spraying foliage with a solution of sugar in water. In late winter, catkins (especially Salix) and early flowering Prunus species may be useful hunting grounds.

Another way to see hoverflies in winter is by looking for their larvae...

Larvae can most easily be found by searching through leaf litter. In the winter most larvae will be in a state of diapause (a sort of hibernation, if you will). Diapause often involves a change from bright to dull colours (green larvae often go brown). There is a separate project specifically for UK hoverfly larvae that also feeds into the HRS. Rotheray's guide to larvae is still very useful and can be found here. Many larvae can be identified to genus, and some even to species.

The following species remain over 10%opa in October
Didea fasciata 14%opa
Eristalis abusiva 12%opa, E. pertinax 20%opa, E. tenax 34%opa
Eupeodes luniger 22%opa
Helophilus pendulus 17%opa
Melanostoma scalare 11%opa
Neoascia podagrica 21%opa
Platycheirus albimanus 21%opa, P. manicatus 10%opa, P. scutatus 11%opa
Sericomyia silentis 16%opa, S. superbiens 15%opa
Syrphus ribesii 14%opa, Syrphus torvus 22%opa
Xanthandrus comtus 13%opa

Publicado el febrero 8, 2024 10:06 MAÑANA por matthewvosper matthewvosper | 0 comentarios | Deja un comentario

What to look out for: September

[For explanations and definitions see here. Almost all of the data here is derived from NBN Atlas and the species information from Steven Falk's Flickr and the HRS website]

Things really wind down in September. Only three species peak in this month, although plenty of summer species will hang around for a while - in fact a further 94 species remain above 10%opa in September, and they are listed at the end.

September is the best month to see....


Callicera spinolae (73,-80%)

A rare treat. Females can be easily distinguished from the similar C. aurata by their all-orange femora. Both sexes have dull black hind margins to the tergites, and relatively conspicuous bands of pale hairs on the tergite hind margins.

This hoverfly appears from nowhere in September and can be seen into October, often on Ivy. Larvae live in tree rot holes. It has expanded out of its previous stomping ground in East Anglia and now occupies an area east of a line from Brighton to Rutland. Falk's pics

Didea fasciata (34,-45%)

This species has been building for a long time (it first surpassed 10%opa in April!) but it peaks now. It can be seen on a wide range of flowers, including ivy. A view of the pale halteres is crucial. Falk's pics

Other species that peak in September [species in square brackets usually require microscopy to identify]:

Helophilus pendulus (0,-24%)

The following species remain above 10%opa in September

- those still over 50%opa highlighted in bold.

Pipizinae Heringia vitripennis 25%opa
Pipiza lugubris 17%opa
Triglyphus primus 11%opa
Eristalinae Callicera aurata 14%opa
Cheilosia bergenstammi 24%opa, C. caerulescens 20%opa, C. cynocephala 19%opa, C. griseiventris 10%opa, C. impressa 26%opa, C. latifrons 34%opa, C. longula 18%opa, C. mutabilis 17%opa, C. pagana 16%opa, C. scutellata 34%opa, C. soror 51%opa, C. vernalis 33%opa, C. velutina 13%opa
Eristalinus aeneus 17%opa
Eristalis abusiva 65%opa, E. arbustorum 52%opa, E. cryptarum 38%opa, E. horticola 40%opa, E. intricaria 16%opa, E. nemorum 32%opa, E. pertinax 57%opa, E. rupium 18%opa, E. tenax 73%opa
Eumerus funeralis 25%opa, E. strigatus 17%opa
Ferdinandea cuprea 42%opa, F. ruficornis 27%opa
Helophilus hybridus 52%opa, H. trivittatus 32%opa
Lejogaster metallina 13%opa
Lejops vittatus 22%opa
Myathropa florea 34%opa
Neoascia geniculata 14%opa, N. interrupta 11%opa, N. podagrica 51%opa
Rhingia rostrata 57%opa
Riponnensia splendens 21%opa
Sericomyia silentis 60%opa, S. superbiens 95%opa
Sphegina clunipes 10%opa
Syritta pipiens 32%opa
Volucella inanis 17%opa, V. zonaria 33%opa
Xylota florum 12%opa, X. segnis 23%opa, X. sylvarum 16%opa
Syrphinae Baccha elongata 25%opa
Chrysotoxum arcuatum 33%opa
Dasysyrphus albostriatus 33%opa, D. tricinctus 27%opa
Didea alneti 25%opa
Epistrophe grossulariae 34%opa
Episyrphus balteatus 27%opa
Eriozona syrphoides 14%opa
Eupeodes bucculatus 50%opa, E. corollae 11%opa, E. latifasciatus 49%opa, E. luniger 71%opa, E. nielseni 13%opa, E. nitens 21%opa
Leucozona glaucia 33%opa
Megasyrphus erraticus 22%opa
Melangyna arctica 11%opa, M. barbifrons 13%opa, M. compositarum 14%opa, M. labiatarum 15%opa, M. umbellatarum 22%opa
Melanostoma mellinum 31%opa, M. scalare 41%opa
Meliscaeva cinctella 36%opa
Parasyrphus lineola 18%opa
Platycheirus albimanus 62%opa, P. clypeatus 15%opa, P. europaeus 11%opa, P. manicatus 14%opa, P. peltatus 38%opa, P. scutatus 52%opa, P. sticticus 10%opa
Pyrophaena granditarsus 38%opa
Scaeva selenitica 25%opa, S. pyrastri 12%opa
Sphaerophoria batava 10%opa, S. loewi 25%opa, S. rueppellii 11%opa, S. scripta 24%opa, S. virgata 14%opa
Syrphus ribesii 71%opa, S. torvus 54%opa, S. vitripennis 60%opa
Xanthandrus comtus 25%opa
Xanthogramma pedissequum 11%opa

Publicado el febrero 8, 2024 10:02 MAÑANA por matthewvosper matthewvosper | 0 comentarios | Deja un comentario

What to look out for: August

[For explanations and definitions see here. Almost all of the data here is derived from NBN Atlas and the species information from Steven Falk's Flickr and the HRS website]

This is the last of the big months for hoverflies. Many species that peaked in previous months are still busily buzzing around, but the number of species at peak this month is a fair bit lower, at 41. The number reaching 10%opa for the first time is a big fat 0 (although there is one species waiting for September - I'll keep you in suspense!).

August is the best month to see....

...Cheilosia soror (45,-44%)

One of the three Cheilosia with fungus-feeding larvae - subgenus Eucartosyrphus - and the only one with orange antennae. Females of the subgenus are easily identified by the pale tip to the scutellum, so female soror is easy to determine by the combination 'pale-tipped scurellum + orange antennae'. Males are more challenging to identify. Be sure to get the best possible pictures of the eyes (not hairy), bristles on the scutum, the leg and antennae colour. Hairs under the hind femur also help with males.

This is the only Cheilosia that remains above 50%opa in September, and it can be seen on hogweed and later, ivy. Common as far north in England as the Wash, although uncommon in the south west peninsula and Wales. Scattered records as far north as Newcastle. Larvae have apparently been bred from truffles, but other fungi may well be used. Falk's pics


...Meligramma guttata (76,-100%)

This rare Meligramma has more the appearance of a Melangyna. It is most easily identified from females which have yellow stripes along the side of the scutum (like Sphaerophoria), and two yellow dust spots (often merged into one large spot) on the back of the scutum, in front of the scutellum. Males are harder to identify, but both sexes have particularly small markings on T2, and very little yellow on the hind margins of T4 and 5. The markings are more 'bar-shaped' than triangular, unlike Meligramma trianguliferum.

The species is widespread across Great Britain, but there are hotspots between Nottingham and the Yorkshire Dales, around County Durham and Tyneside, and the central belt of Scotland. Falk's pics


...Neoascia podagrica (7,-98%)

One of three Neoascia with clouded crosveins in the wing. It can be tentatively distinguished from the other two by not having oblique markings on T2, and not having markings on T4. But the best way to make sure is a clear picture of the underside of the thorax, showing the area in front of the hind coxae: no mean feat in such a small fly.

It is ubiquitous everywhere. The larvae live in wet manure and compost, or around the edge of ponds. The adults can be found with a sweeping net, but they do regularly visit low-growing flowers. Falk's pics


...Platycheirus peltatus (22,-96%)

As usual with Platycheirus the male front leg is key. Males in the peltatus-group of species are notable for their large paddle-shaped forebasitarsi. peltatus itself is larger than the other two, (amplus and neilseni) with larger markings on T2 A front view of the shape and hair tufts of the*middle* tibia is also valuable in distinguishing these.

Ubiquitous everywhere in Great Britain. Damp grassy areas and hedgrows.

...Sericomyia superbiens (27,-68%)

A hairy bumble-bee mimic, most similar to Mallota cimbiciformis - but the radial wing vein is straight. It is also similar to the oxycanthae form of the Spring-flying Matsumyia berberina, but the wings have a cloud.

Occurs north and west of a straight line from Weymouth to Scarborough, with an outpost in Norfolk. Visits flowers. Larvae are unknown, but probably develop in wet mud.

Also look out for Didea fasciata this month, which is very close to its peak - be sure to get a shot of the pale halteres!

The following species were discussed in July's 'First month you may find', but they peak now:

Triglyphus primus (59,-100%)

The following species were discussed in June's 'First month you may find', but they peak now:

Eristalis rupium (38,-71%)

The following species were discussed in May's 'First month you may find', but they peak now:

Cheilosia impressa (25,-81%)

Other species that peak in August [species in square brackets usually require microscopy to identify]:

Callicera aurata (67,-40%)
[C. carbonaria (79,-100%), C. cynocephala (71,-100%), C. latifrons (43,-100%), C. mutabilis (63,-100%), C. vulpina (47,-93%)
Dasysyrphus albostriatus (20,+53%), D. tricinctus (24,-45%)
Episyrphus balteatus (0,+45%)
Eriozona syrphoides (40,-64%)
Eristalis arbustorum (3,-41%), E. pertinax (1,+57%), E. tenax (1,+91%)
[Eumerus funeralis (34,-96%), E. strigatus (30,-99%)]
Eupeodes latifasciatus (19,-55%), E. luniger (8,0%)
Ferdinandea ruficornis (65,-100%)
Helophilus hybridus (16,-63%), H. trivittatus (17,-18%)
Leucozona glaucia (11,-33%)
Melangyna umbellatarum (35,-61%)
Meliscaeva cinctella (12,-49%)
Myathropa florea (4,+174%)
Paragus albifrons (85,-100%)
Pelecocera caledonica (92,-100%)
Rhingia rostrata (32,+32%)
Scaeva albomaculata (100,-100%), S. selenitica (37,-9%)
Sericomyia silentis (3,-48%)
[Syrphus vitripennis (6,-99%)]
Volucella inanis (18,+309%), V. zonaria (16,+1034%)

Publicado el febrero 8, 2024 09:53 MAÑANA por matthewvosper matthewvosper | 0 comentarios | Deja un comentario

What to look out for: July

[For explanations and definitions see here. Almost all of the data here is derived from NBN Atlas and the species information from Steven Falk's Flickr and the HRS website]

Another big month for hoverflies. For the first time in the year, more species are past their peak than not - but many of those species are still around in good numbers. 71 species peak this month, but only 3 reach 10%opa for the first time. The 84 species that peaked last month are still around, of course!

July is the best month to see....

...Anasimyia lunulata (46,-98%)

This Anasimyia is very similar to A interpuncta, a clear view of the markings on T3-4 (especially at the sides), and a side view of the face profile will help to separate them. Its distribution has apparently been decreasing, and records from the last ten years are restricted to Devon/Cornwall and Wales, especially the north west and Anglesey. There are early 21st century records from around Godalming and Norfolk. It is a species of bogland, perhaps associated with sphagnum mosses and bog-bean. Falk's pics


...Cheilosia proxima (21,-97%)

In general with Cheilosia it really is a case of 'the more angles the better'! With proxima the underside of the abdomen should be heavily dusted, it is also useful to capture the bristles on the scutellum, the side profile of the face and the colours of the legs - but that view of the underside of the abdomen is particularly valuable.

The larvae are known to develop in the rosettes of marsh thistle, but Falk states that it is likely they also develop in other thistles, since this is also a common species in dry grassland where marsh thistle is not present. Falk's pics. A ubiquitous species, only becoming somewhat rarer north of Dundee.


...Pyrophaena granditarsus (7,-93%) and P. rosarum (15,-90%)

Very distinctively marked species - still regarded as Platycheirus by many. Male P. granditarsus have remarkable hooked modifications of both the front and middle tarsi. These species are ubiquitous in distribution. They are found in wet grassland and often hover around tall vegetation such as rushes and reeds, and it may be productive to look for them on the stems. They visit a wide range of flowers.

...Paragus haemorrhous (18,-97%) and Paragus tibialis (70,-100%)

So it's a bit ambitious to put these here, but given how common P. haemorrhous is, I think it's worth it. These are tiny flies: only males are really distinguishable. Firstly though, especially if you are near the Thames estuary/North sea coast of Kent, it is worth getting a very good picture of the eyes - vertical bands of hair in the eyes indicate the critically endangered P albifrons. If there are no bands of eye hairs, males can be distinguished from the underside of the abdomen, by the size of the genitals, and the shape of the pregenital sternites. (Although tibialis should only be encountered in the south from Lyme Regis to London, it has been recorded in western Wales.)

The following species were discussed in June's 'First month you may find', but they peak now:

Cheilosia scutellata (36,-77%), Chrysogaster cemiteriorum (29,-90%), Lejops vittatus (67,-100%)

The following species were discussed in May's 'First month you may find', but they peak now:

Chrysotoxum elegans (51,-97%), Eupeodes bucculatus (63,-100%), Eupeodes nitens (69,-100%), Lejogaster tarsata (36,-97%), Parhelophilus consimilis (55,-100%), Parhelophilus versicolor (33,-100%)

The following species were discussed in April's 'First month you may find', but they peak now:

Neoascia interrupta (56,-96%)

The following species were discussed in March's 'First month you may find', but they peak now:

Eristalinus aeneus (30,-51%), Syrphus torvus (13,-68%)

Other species that peak in July [species in square brackets usually require microscopy to identify]:

Blera fallax (77,-100%)
Cheilosia illustrata (7,-29%), [C ahenea (95,-100%), C. longula (50,-100%), C. velutina (76,-100%), C. vernalis (21,-100%)]
Chrysogaster solstitialis (12,-52%)
Chrysotoxum bicinctum (10,-31%), C. festivum (27,+63%), C. verralli (46,+23%)
Didea alneti (87,-100%)
Epistrophe grossulariae (13,-8%)
Eristalinus sepulchralis (14,-67%)
Eristalis horticola (10,-56%), E. intricaria (6,-43%), E. nemorum (9,-24%)
Eupeodes corollae (6,+39%)
Helophilus groenlandicus (100,-100%)
Heringia senilis (92,-100%)
Leucozona laternaria (25,-56%)
Megasyrphus erraticus (58,-88%)
Melangyna sexguttata (=compositarum) (49,-94%)
Melanogaster aerosa (58,-100%)
Melanostoma mellinum (3,-88%)
[Myolepta dubia (71,-74%), M. potens (92,-100%)]
[Neoascia geniculata (39,-98%), N. tenur (5,-99%)]
Parasyrphus lineola (57,-73%)
Pelecocera tricincta (66,-55%)
Pipiza lugubris (68,-93%)
Pipizella maculipennis (90,-100%)
Platycheirus albimanus (1,-71%), P. aurolateralis (88,-100%), P. clypeatus (8,-99%), P. nielseni (37,-100%), P. occultus (29,-99%)
Scaeva pyrastri (7,+18%)
Sphaerophoria loewi (85,-100%), S. rueppellii (44,-64%), S. scripta (5,+25%), [S. fatarum (58,-96%), S. interrupta (14,-98%), S taeniata (65,-100%)]
Syritta pipiens (2,-37%)
Syrphus ribesii (3,-38%)
Volucella pellucens (4,+78%)
Xanthandrus comtus (41,-69%)
Xanthogramma stackelbergi (71,-15%)
Xylota florum (48,-95%), X. sylvarum (17,-41%), X. tarda (68,-100%)

July may be the first month you see...


...Triglyphus primus (59,-100%)

46%opa in July. A Pipizine notable because the abdomen is dominanted by T2+3, with T4 hardly visible. A view of the face will help clarify that it is a Pipizine, not a Cheilosia. The upper-outer cross vein meets the marginal at an acute angle, like in Pipiza, Heringia and Neocnemodon. The legs are partly pale, and not thickened.

This small species is associated with waste ground and urban brownfield sites as well as other thermophyllic environments like dry meadows and heathland. The larvae appear to be specific predators of the Mugwort Gall Aphid (Cryptosiphum artemisiae) that forms galls on Common Mugwort (Artemisia vulgaris). So look out for this plant! T. primus occurs in England south of York and through the Midlands, becoming rarer south west of a line from Worcester to Brighton.

Other species exceeding 10% of peak abundance (%opa) for the first time in July are [species in square brackets usually require microscopy to identify]:

Sericomyia superbiens (27,-68%) 19%opa
Volucella inanis (18,+309%) 52%opa

Publicado el febrero 8, 2024 07:30 MAÑANA por matthewvosper matthewvosper | 0 comentarios | Deja un comentario

What to look out for: June

[For explanations and definitions see here. Almost all of the data here is derived from NBN Atlas and the species information from Steven Falk's Flickr and the HRS website]

More species peak in June than any other month (81), but only 30 are exceeding 10% of peak abundance for the first time. It's a good time for flower feeders. Remember, hoverflies like open flowers with easily accessible nectar. Umbellifers (esp. Apiaceae) and asters are particularly popular: small flat flowers in preference to deep tubular or bell-shaped ones. Having said that - don't forget to keep an eye on low vegetation, tree trunks etc.

June is the best month to see....

...Didea intermedia (65,-83%)

Didea species are distinctive due to the dipped radial vein and the rather angry-looking abdomen markings - strongly angled spots on T2. D intermedia is distinguished from the other common species fasciata by the black haltere knob - so do your best to get a clear view of the side under the wing. The rare D alneti usually has broken bands on T3-4 with a greenish colour, and no markings on T5 (the others have a complete bands on T3-4 and little markings in the front corners of T5). D intermedia and alneti have face stripes (alneti less so) which fasciata usually lacks. The female frons of Didea sports a bold black inverted Y marking: this falls short of the lunule in intermedia but usually reaches the lunule in the others. The scutellum of intermedia is a slightly characteristic pale colour with a dark rim.

This species' larvae are associated with pine aphids, and it is rarely found far from conifers. Its distribution is blotchy throughout England, but its real stronghold is in the Cairngorms and Highlands. Falk's pics

...Doros profuges (77,-66%)

A distinctive, large and spectacular wasp mimic - but very elusive. It is believed to have a very short flight period in early June (late May). Larvae are believed to be associated with black ants - or the aphids they attend. The related (and even rarer) continental species D destillatorius was observed apparently ovipositing on a moss-covered oak at about head height, near an ant trackway up the tree. It is known from the central part of southern England, northern Lancashire and the Isle of Mull - but its elusiveness means it could easily be undetected elsewhere. Falk's pics


...Anasimyia contracta (28,-79%), Eurimyia lineata (21,-83%) and Anasimyia transfuga (47,-98%)

These three are recognisable as Helophilines by the striped scutum, bend in the radial vein and unspotted eyes. They can be distinguished from others by the elongate bodies, abdomen pattern and orange antennae. To distinguish from each other one needs a picture of the face ideally in side profile (extended forwards into a snout in Eurimyia, and slightly extended in some Anasimyia), the shape of the second abdominal segment seen from above (try and get it with the wings open), and the pattern on T3-4 including the sides.

They can be found around wetlands and ponds with emergent vegetation to trap rotting material. E lineata is abundant everywhere, A. contracta appears to be missing in the north of Scotland, and A transfuga seems to be missing north of Yorkshire. Falk's pics


...Epistrophe diaphana (59,-96%)

One of two Epistrophe with black antennae, but unlike E. grossluariae the bands are pinched forwards at the margins like a Syrphus. It can be distinguished from Syrphus by the shinier scutum and yellower frons - not black at the front (especially obvious in females), also T5 is usually completely yellow (only yellow at the front and back edge in Syrphus).

The behaviour of this species is like other Syrphines and the larvae eat aphids. It is found in England as far north as Yorkshire, and is extending its range northward. Falk's pics


...Trichopsomyia flavitarsis (26,-99%)

A Pipizine hoverfly with the upper-outer cross vein joining the radial vein at a near right angle like a Pipizella (always get the wing venation with Pipizines!) The legs are much yellower than any Pipizella however. It has two spots on the abdomen like a Pipiza. T lucida has been recorded once in the UK - but the wing venation is different, and the abdominal spots are larger.

It is a species of wetlands/boggy areas. The larvae attack larvae of the psyllid Livia junci which make striking galls on rushes. T. flavitarsis is abundant throughout Great Britain. Falk's pics


...Sphegina clunipes (20,-100%)* and *Sphegina sibirica (35,-92%)

Your best bet for getting identifiable pictures of Sphegina is to get very clear pictures of the wing venation, the feet (contrastingly black in sibirica) and the abdomen of a male from the side (the genital capsule of clunipes has a very prominent 'spike' pointing forwards on each side.) This is a challenge with such tiny, delicate flies.

S clunipes is one of the commonest hoverflies with no iNatUK observations. It is found everywhere in Great Britain, but sibirica is uncommon in England south and east of a bent line from Bournemouth to Birmingham to Hull. These species like lush vegetation in and around woods. They prefer shade - but less so in Scotland - and the larvae are associated with sap runs. Falk writes that adults can often be found nectaring on Fool's Watercress and Lesser Water-Parsnip. Falk's pics


...Xylota jakutorum (29,-91%), Xylota xanthocnema (59,-87%)

Xylota species are usually observed running around on broad leaves: they are not often seen on flowers. Useful characters include the abdomen markings, the colour hind tibia from the side (the view from above can be deceptive because yellow hairs can mask the black colour of the apical part), the dust spots on the female frons and the shape of the abdomen (from above). xanthocnema is restricted to England and Wales, jakutorum occurs north of a bent line from Bournemouth to Birmingham to Hull.

...Eristalis cryptarum (66,-94%)

Only found in association with bogs on Dartmoor. A distinctive reddish appearance for an Eristalis and mostly orange legs. Falk's pics

...Eumerus sabulonum (51,-100%)

The easiest Eumerus to identify because the sides of T2 are reddish. This is a strongly coastal species, appearing on the west coast of Britain from Portsmouth to Glasgow, especially Wales. Larvae may be associated with Sheep's-bit (Jasione montana) Falk's pics

...Eumerus ornatus (51,-97%)

This Eumerus requires a very clear picture of the position of the ocellar triangle on the vertex. It occurs mainly in certral and southern England, but extends into south and north Wales and up the coast to the Peak district, and in the east to Lincolnshire. It is associated with meadowsweet (Filipendula ulmaria) Falk's pics

...Mallota cimbiciformis (56,-92%)

A furry bumblebee mimic in the tribe Eristalini, subtribe Helophilina, so the radial vein is strongy bent but the marginal cell is open. The scutum is densely golden haired, the black abdomen is sparsely white haired. The wing has a central cloud. This is another species whose larvae are associated with water-filled rot holes in mature deciduous broadleaved trees. It is most concentrated it the south of England, but there are scattered records as far north as Montrose. It does not seem to occur in Wales, however. Falk's pics

The following species were discussed in May's's 'First month you may find', but they peak now:

Brachypalpoides lentus (36,-79%), Chrysotoxum arcuatum (22,-81%), Chrysotoxum cautum (34,-53%), Eupeodes nielseni (73,-100%), Hammerschmidtia ferruginea (74,-100%), Lejogaster metallina (12,-96%), Microdon analis (70,-84%), Microdon devius (52,-100%), Parhelophilus frutetorum (37,-93%), Pipiza austriaca (40,-92%), and a summary of various *Platycheirus

The following species were discussed in April's's 'First month you may find', but they peak now:

Parasyrphus annulatus (71,-100%)

Other species that peak in June [species in square brackets usually require microscopy to identify]:

Pipizinae [Heringia brevidens (90,-100%), H. (75,-100%), H. vitripennis (69,-93%)]
[Pipiza fasciata (74,-100%)]
[Pipizella viduata (17,-99%), Pipizella virens (42,-98%)]
Microdontinae [Microdon mutabilis (50,-94%), M. myrmicae (63,-62%)]
Eristalinae Chalcosyrphus nemorum (23,-80%)
[Cheilosia ahenea (95,-100%), C. sahlbergi (92,-100%), C. vicina (47,-100%)]
Chrysogaster virescens (41,-100%)
[Melanogaster hirtella (9,-97%)]
Merodon equestris (10,169%)
Orthonevra intermedia (93,-100%), O. nobilis (32,-90%)
Pelecocera scaevoides (64,-100%)
Sericomyia lappona (23,-77%)
Riponnensia splendens (26,-70%)
[Sphegina. elegans (33,-94%), S. verecunda (36,-99%)]
Tropidia scita (15,-71%)
Volucella bombylans (5,-42%), V. inflata (31,-38%)
Syrphinae Chrysotoxum octomaculatum (87,-100%), C. vernale (85,-72%)
[Dasysyrphus friuliensis (80,-100%), D. neovenustus (87,-68%), D. pinastri (60,-91%)]
Eupeodes lundbecki (93,-100%)
Lapposyrphus lapponicus (79,-82%)
Melangyna ericarum (90,-100%), Melangyna labiatarum (43,-61%)
Meliscaeva auricollis (15,63%)
Paragus albifrons (85,-100%)
Parasyrphus vittiger (48,-97%)
Platycheirus amplus (83,-100%), P. angustatus (14,-99%) P. europaeus (40,-100%), P. fulviventris (29,-97%), P. immarginatus (48,-100%) P. melanopsis (82,-100%), P. perpallidus (57,-100%), P. podagratus (46,-100%), P ramsarensis (40,-100%), P scambus (31,-96%), P. scutatus (14,-84%)
[Sphaerophoria batava (53,-100%), S. philanthus (22,-100%), S. potentillae (87,-100%), S virgata (69,-100%)]
Xanthogramma pedissequum (18,26%)
Xylota segnis (4,-43%)

June may be the first month you see...

...Eristalis rupium (38,-71%)

61%opa in June. An Eristalis with a distinct wing cloud (usually linear in males, like E horticola but the spots are pointy not rounded; quadrate in females). The hind metatarsus is yellow, unlike any other Eristalis except the distinctive E cryptarum which has almost entirely orange legs, and only occurs on Dartmoor. E rupium's stronghold is in Scotland and the very north of England, but it's range extends down the east coast as far as the Humber estuary, and down the Pennines to the Peak Distict. It is also fairly abundant in Wales, especially the northwest. Falk's pics

...Lejops vittatus (67,-100%)

72%opa in June. A Helophiline distinguished from the similar Anasimyia species by black, rather than orange andtennae, but in any case with a distinctive 'dashed' abdomen pattern. It's range is very limited: it occurs in coastal areas from Kent to Norfolk, and around the Severn estuary - venturing further inland on the Somerset Levels. It occurs in somewhat brackish waters - e.g. coastal grazing marsh - where the bases of sea clubrush (Scirpus maritimus) are normally submerged. The association with this plant is strong and the adults are said to be sluggish - not flying a lot - so searching and sweeping clubrush is the best way to find it. Falk's pics

...Chrysogaster cemiteriorum (29,-90%)

36%opa in June. This species has pale yellow wing bases and brownish antennae but the best feature if you can get it, is the strongly dusted proepimeron (side of the thoax just above the front coxae) - an image low to the side focussed on the area above the front leg is needed. It occurs throughout England and Wales to the south of Scotland, and also in the north of Scotland. Wetland, wet meadow and forest margins are the places to look, often found on umbellifers.

...Cheilosia scutellata (36,-77%)

53%opa in June. Several Cheilosia (including particularly this one) are helped by an image of the face knob from directly above - so try to get a shot of it down between the antennae to show whether it is pointed or rounded, narrow or broad. This is one of three UK Cheilosia in the subgenus Eucartosyrphus: their larvae feed in fungi (in this case members of Boletus), and they can be distinguished from other subgenera by the fact that the females have a pale tip to the scutellum. Common in England and Wales, but patchy in the very north of England and in Scotland. Falk's pics

Other species exceeding 10% of peak abundance (%opa) for the first time in June are [species in square brackets usually require microscopy to identify]:

Pipizinae Pipizella maculipennis (90,-100%) 25%opa
Eristalinae Blera fallax (77,-100%) 56%opa
Callicera aurata (67,-40%) 64%opa
[Cheilosia cynocephala (71,-100%) 25%opa, C. (50,-100%) 35%opa, C. velutina (76,-100%) 13%opa]
Chrysogaster solstitialis (12,-52%) 67%opa
Helophilus trivittatus (17,-18%) 45%opa
Pelecocera tricincta (66,-55%) 76%opa
Volucella pellucens (4,+78%) 89%opa, V. zonaria (16,+1034%) 17%opa
Xylota florum (48,-95%) 76%opa
Syrphinae Chrysotoxum bicinctum (10,-31%) 83%opa, C. festivum (27,+63%) 62%opa, Chrysotoxum verralli (46,+23%) 29%opa
Didea alneti (87,-100%) 50%opa
Epistrophe grossulariae (13,-8%) 39%opa
Eriozona syrphoides (40,-64%) 14%opa
Leucozona glaucia (11,-33%) 12%opa, L. laternaria (25,-56%) 54%opa
Melangyna umbellatarum (35,-61%) 34%opa
Meligramma guttatum (76,-100%) 38%opa
Paragus tibialis (70,-100%) 45%opa
Scaeva pyrastri (7,+18%) 40%opa
Sphaerophoria loewi (85,-100%) 75%opa
Xanthogramma stackelbergi (71,-15%) 67%opa

Publicado el febrero 8, 2024 12:02 MAÑANA por matthewvosper matthewvosper | 0 comentarios | Deja un comentario