Hello everyone,

Hope you've had some chance to enjoy nature this month, wherever you've been. It's been a great month. We seem to have had a bumper spring for iNat hoverflies, which seems to be improving the diversity of what is recorded compared to previous years.

Fantastically, we have passed 100 members this month. Thanks to everyone who has gotten stuck in and made it feel like a team effort to improve our hoverfly data for the benefit of the national recording scheme. If you are new, please be sure to read this key article about how to make your observations as useful as possible to the national recording schemes (because much of the advice there does not just apply to hoverflies).

Updates

I have tweaked the URLs in the Useful URLs post. The links for adding sex and life stage annotations now include Research Grade. Originally they didn't because it seemed more important to focus on observations that were yet to go through to HRS, rather than observations that had already gone through. But now that pile is basically done, and we only need to keep up with new observations as they come in, and deal with the old RG ones.

I have also added a new URL, "Pre-Mavericks", which allows you to find the observations where there is a disgreement that is potentially one ID from resolution (depending on which way it needs to go!). It deploys the Pre-maverick project by @jeanphilippeb, which you can also use for other taxa you are interested in.

Observations

Another record month for observations with just over 4000 posted (the previous record for May being 2854 last year). In terms of diversity, we have provisionally recorded 113 species, more than any previous month! Highlights include: Cheilosia lasiopa, Pocota personata, Brachyopa pilosa, Criorhina asilica, Dasysyrphus venustus s.s., Pipiza luteitarsis, and a smattering of P. austriaca

In June, more species are at their peak than any other month of the year, so have a good one! Here's what to look out for in June.

A history of the NeedsID Pile

We are approaching the point where we will have a whole year's worth of data from this project. One thing that's bugged me for a while is the inability to compare what we have acheived to previous years when there was no project. You cannot get from iNat how many observations needed ID at a point in the past. Anyhow, one very dull evening I had a crack at estimating the size of the NeedsID pile in times past. Starting from Jan 2018 (before which only 0.5% of observations were posted) I used the number of observations posted and IDs made each month, coupled with the average number of IDs that UK hoverflies have needed to reach Research Grade (which is 2.45 if you're interested!) to estimate the change in the NeedsID pile each month, eventually I reached the recent months for which we have real data and tuned the single unknown constant until they matched (gory details at the end). I think the graph below must be accurate enough to tell a true-ish story - maybe I'll be able to improve it once we have some real data from the upward curve. But see what you make of it, I definitely think we've made a difference!

Identifications

Despite the record numbers of observations, the NeedsID pile has grown this month by only a few hundred. It looks like we have a really good chance of keeping it well below last year's peak. It's been especially cool to see members of this group stepping up and starting to try a few IDs for other people.

Here's the usual breakdown of the tribes, and the deep dive into Syrphini.

Only 7 genera have decreased, with 21 unchanged and 43 increased. It's nice to see though that the number stuck at higher levels has actually decreased by more than 5%. The biggest climbers (with >50 obs to start with) are, Chrysotoxum (+19%), Eupeodes (+18%), Helophilus (+16%), Rhingia (+16%), Xylota (+16%), Cheilosia (+15%), Melangyna (+15%), Meliscaeva (+13%), Platycheirus (+13%), and Sphaerophoria (+12%). Platycheirus is the runaway train here, leapfrogging Eristalis to become the neediest genus with nearly 1500 observations needing ID. Cheilosia is also rising much from a very high base. Just over 70% of observations posted in May are already Research Grade.

Annotations

We have maintained a high level of annotation. Great job!

Obscured locations

Obscured locations remain at about 4.5%. Observations with obscured coordinates cannot be used by the hoverfly recording scheme (and most other recording schemes). For an alternative way to address privacy, recommended by NBN, see here.

Right, that's all! Happy Syrphing for June!

All data compiled on 31st May

 
 
 
 
[Gory details
The average number of IDs per research grade observation was calculated as the total number of IDs made on RG observations posted before the end of 2023 divided by the total number of such observations. The time limit was intended to keep out more recent observations for which the numbers will still be changing more. Call it A. It turns out that for UK hoverflies A=2.45. (This includes the original poster's ID).
The number of observations needing ID at the start of 2018 was assumed to be as small as possible given the number of IDs and observations before that time, assuming that A=2.45 and all observations had an ID on upload (no unknowns). Any error from those assumptions shouldn't matter because all the numbers are so small at that point. Given these assumptions the maximum possible number of RG observations at the start of 2018 is [ IDs(Pre2018)-Obs(2018) ]/(A-1), where the subtractions account for the observers' initial IDs.
Therefore the starting point, NeedsID(Jan 2018) = Obs(Pre2018) - [ IDs(Pre2018)-Obs(2018) ]/(A-1).
Each month the NeedsID pile changes by Obs(Month) - K.[ IDs(Month)-Obs(Month) ]/(A-1) where K is a fudge factor multiplying the maximum possible number of RG observations from that month (0 < K < 1) to account for the fact that we don't in fact make the maximum possible number of RG observations per ID. This is the number that was scaled to match the true data from recent months. K=0.913, which suggests that on average we make just over 90% of the number of research grade observations possible with the number of IDs we use. This is assumed to have always been constant.
]

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.

Identifications

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.

Annotations

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

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 :-)

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!

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...

Identifications

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 :)

Annotations

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

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 :)

Annotations

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.

Identifications

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

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

[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....

*TOP TARGET*

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

 
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

[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

*TOP TARGET*

...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

*TOP TARGET*

...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

*TOP TARGET*

...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%)

[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

*TOP TARGET*

...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.

*TOP TARGET*

...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...

*TOP TARGET*

...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