UK Hoverflies (Syrphidae)'s Journal

Hello everyone,

Hope the hovers have come out for you in the recent warm weather!

There are two things I'd like to tell you about. One is 'Annotation Sunday' as suggested in this forum post. The basic jist is that some people are challenging themselves to add 25 or more annotations to observations each Sunday. As far as UK hoverflies are concerned, determining the sex is quite easy in most genera, and it's a great activity for beginners to get familiar with the variety of hoverflies. Information about how to determine the sex of a hoverfly can be found here. You can use the links on the URLs page to find all the UK hoverflies needing sex annotations. (Life stage annotations are all but done, and life stage should not be added to pre-2024 observations please due to this problem).

Secondly, October will mark the start of what I refer to as 'identification season', (when it's easier to do IDs than make observations!). I'd like to suggest that we use October to tackle the observations that have not yet been identified to Genus - there are just over 3000 of these. Again, a link to all of these observations can be found on the URLs page. This is another great activity for beginners, because you're not so often making observations research grade, which takes a little pressure off. Many observations in this category will be impossible to identify further: Here's what to do in that situation. Resources for identifying hoverflies can be found here. You'll be pleased to hear that the third edition of the very accessible WildGuide to hoverflies is now available!

It doesn't matter how many or how few you do, so long as it's fun! And you don't have to know the species: if you can move something from family to subfamily, or from tribe to genus or whatever, that's great.

My plan after October is to suggest particular genera to focus on each month. So this will set us up well for that!

All the best.

Hello! Time for our monthly data frenzy, and it's been another fun one.

September is really the last month of hoverfly season: here's what to look out for. Keep your eyes on the ivy. If you are anywhere near East Anglia it would be awesome to get some more Callicera spinolae observations on iNatUK!

Observations

We have now exceeded 100,000 hoverfly observations on iNatUK! Whoop!

And for the first time the number of hoverflies uploaded in August is greater than in July... so another record - over 6000 for the first time.

However this is partly due to a significant number of old observations being uploaded. The number of hoverflies actually observed in August also went up compared to July for the first time, but the number is still slightly lower than July last year.

In 2024 we have already easily exceeded the total number of observations uploaded in any previous year

We recorded a provisional 103 species: highlights including Eristalis abusiva, Pipiza luteitarsis, Brachypalpoides lentus, Epistrophe diaphana, Sphaerophoria rueppellii and a smattering of Eriozona syrphoides

Identifications

We have also delivered another record month for identifications:

Despite that, the NeedsID pile has grown by nearly 1000. Some of you may remember a few months ago I created a method to predict the size of the needs ID pile in the past from the number of IDs and observations. That was verified by correctly matching the data from this project as it came in. Well this month, for the first time, that method failed completely! By that prediction, the number of IDs we added should have been enough to reduce the NeedsID pile slightly. I don't have an explanation for why our IDs have not translated into Research Grade observations at the normal rate: answers on a postcard!

Below is the usual breakdown of the NeedsID pile according to tribe, and the deep dive into the tribe Syrphini. Something that I think is worth noting is that the reduction in the NeedsID pile compared to this time last year is due almost entirely to the huge reduction in Syrphini that we acheived over the winter, and that we have kept on top of. The other tribes have grown back to the same size as last year.

36 genera increased their number needing ID, with 28 unchanged and 7 down. The genera with the biggest % increases (which had >50 obs to start with) are: Sphaerophoria (+59%), Xanthogramma (+38%), Syrphus (+25%), Neoascia (+24%), Rhingia (+17%), Eristalis (+15%), Melangyna (+13%), Meliscaeva (+13%), and Cheilosia (+11%). The increases in Eristalis and Cheilosia from a high base are particularly noteworthy - Cheilosia has leapfrogged Melanostoma to become the third neediest genus. The neediest genera are Eristalis (1940), Platycheirus (1628), Cheilosia (994), Melanostoma (986), and Eupeodes (569).

Annotations

We haven't kept up with annotations quite as well as some previous months, but we're still doing great really.

Obscured Locations

The use of obscured locations dropped to the lowest proportion we've seen for a major month - just 2.3%. That means more usable data for the recording scheme :)

AOB

Usually the NeedsID pile increases for the last time in September, but I do wonder if this year it might go down - that would be cool. If we want to achieve anything like we did last winter we'll have to deal with the neediest genera listed above. I'll be having a think about what events we can do and what resources might help us tackle them. Happy to hear ideas.

If you are new to IDing, or want to get started, a great way to do that is to sort observations at a high level into the right genus - you can use the URL here, and of course feel free to tag in any of the major identifiers of UK hoverflies if you want to discuss an ID. That's particularly helpful at the start of autumn because it will help us tackle particular genera later in the winter.

Happy Autumn syrphing!

(All data collected on 31st Aug 2024)

Hello everyone,

Welcome to the summer holidays! There's been a big bump in observations at the end of this month, unsurprisingly. We'll see how August goes. Here's what to look out for in August.

 Observations

July set another record for the number of observations uploaded.

We recorded a provisional 102 species. Highlights included Callicera aurata, Sphaerophoria interrupta, Eristalis similis, a couple of Platycheirus angustatus, Chrysogaster cemiteriorum and Pelecocera tricincta.

 Identifications

We have also delivered a record number of IDs this month.

Despite that, the NeedsID pile has grown considerably. I'm not sure why that should be because we have actually made more IDs per new observation than last month when it grew much less. But hey-ho, the NeedsID pile is still much lower than it was this time last year - the first full month of this project. Here are the usual breakdowns by tribe and the deep dive into Syrphini. For the first time these can show 13 months so from now on we can directly compare where we are this year to the same time last year!

The biggest climbers (with >50obs to start with) were Syrphus (+34%), Melanostoma (+26%), Chrysotoxum (+24%), Xylota (+20%), and Neoascia (+18%). Eristalis increased by 13% which is a lot from a high base - enough to easily reclaim the 'neediest' spot from Platycheirus. The top 5 neediest genera at the moment are Eristalis (1692), Platycheirus (1576), Melanostoma (916), Cheilosia (897), and Eupeodes (545).

 Annotations

As far as annotations go we're a bit down on where we have been recently, but still way up on the 10-20% that was normal before the project.

 Obscured observations

Just over 3% of observations this month had obscured locations, which is quite good. Click here for why this setting poses difficulties for recording schemes and NBN's recommended alternative.

Thanks everyone, it's great to see more and more people chipping in with IDs and annotations for others. There have been people who have not been able to do as much this month (including myself), but others have more than taken up the slack.

Enjoy the summer!

Matt

All data collected on 31st July 2024

Well, well, the tournament is over, and so is the little excursion that several of us have indulged in!

In total during the tournament over 113,000 annotations were added to European observations! Unsurprisingly in the last few rounds the biggest beneficiaries of our efforts have been teams that played against England, with Switzerland receiving 4200, the Netherlands just over 6000 and Spain 6800. France also muscled into the middle with just over 5400 annotations added.

Here are the graphs showing the change during the tournament:

Overall in the tournament the biggest beneficiary was Germany, which received 14,171 annotations, followed by France with 13,332, Denmark with 11,682, and Spain with 9,994.

For the participating nations outside the UK we have increased the proportion with a sex annotation from 27% to 42%, and with a life stage annotation from 26% to 50%. Fabulous work.

[A quick reminder, please do not add life stage annotations to UK observations from before 2022 for reasons discussed elsewhere.]

Well done everyone who participated!

So here we are! It was almost exactly a year ago that we made this project active in an attempt to create a team for the curation of iNatUK Hoverflies and to improve the data quality going through to HRS. We now have over 100 members, some have joined for the information, and some - with varying degrees of experience - have become really active participants in the task above. That's all great. Thanks to everyone who has joined, read, participated in, used or enjoyed anything in this group :).

I don't want to make this an annual review though - it is about the transition from June to July as usual. But now all the graphs have 12 months of data so...

Annotations and the Euro 24 Annotatathon Tour

One of the most immediate impacts of the project was to vastly increase the proportion of observations receiving sex and life stage annotations. Before the project these were less than 20%. Quite a few people got on board with this straight away as something they could do. This is the last time you will see that initial impact in the graph below (I'm only going to keep 13 months of data on these graphs). We maintained our high proportions this month: here are the proportions of new observations that received annotations before the end of the month.

And the total proportion of all UK hoverflies annotated with sex continues to grow, and is now over 75% for the first time:

You can see there the huge impact of the original 'Annotatathon' event back in November. (Please remember that a few hundred old observations have been left deliberately unannotated with life stage because they cause problems for HRS - please do not add life stage annotations to any remaining pre-2022 observations)

As a bit of a side-hustle, during the Euro 24 football tournament it was suggested that we annotate observations during the matches from whichever countries are playing. During the tournament so far I think we've added about 60,000 annotations! I've been posting updates here - the next update will be after the round of 16. For participating European countries outside the UK the proportion of observations with an annotation has increased from 27% to 35% for sex, and from 26% to 43% for life stage. Some smaller countries have been fully completed.

Observations

5500+ observations were uploaded in June: the most ever in a month. They provisionally included 113 species, matching last month's record. Here are some species to look out for in July.

June's highlights include: Microdon devius, Pelecocera tricincta, Sphegina elegans and S. sibirica, Mallota cimbiciformis, Pipizella viduata, Epistrophe diaphana and a flurry of Myolepta dubia.

(note these are the species uploaded during the month, not necessarily observed during the month)

Identifications

Incredibly, the increase in the NeedsID pile is again just a few hundred, despite the increase in observations. For two weeks in early June we absolutely smashed any previous record for IDs - nearly 3500 a week! This is testament to those who do a regular bit on new records each day, and some people I notice taking first steps into the world of identifying - all adding up.

35 genera are up, 31 unchanged and 5 down.

If you are interested in helping with identifications, don't feel you need to do it alone - you can always tag in myself or another of the top UK identifiers if you want someone to check what you think. A safe way to get started is to try identifying things that don't yet have a species ID - that way your ID does not make it research grade. Gradually, and with a few mistakes, you will gain confidence. You can find a URL for this task here. Clearly someone has been doing this, because the number stuck above genus has decreased by 5% this month! Well done you :)

Here is the breakdown by tribe, and the deeper dive into Syrphini as usual:

Obscured Locations

Another thing we have tried to do over the last year is spread the word that using obscured locations for privacy settings causes problems for recording schemes (not just the hoverfly scheme). NBN recommend pinned locations as an alternative. The proportion of obscured locations in June was below 3% for the first time since December (when total numbers were smaller and therefore proportions more random). I don't know the reason for that - whether some people have changed their settings or whether it is random variation.

So finally, thanks to all of you who have engaged with this project in whatever way. I think we've made a difference both to people on iNat, and hopefully also to the recording scheme as they field the iNat data that goes through to them. I want to give a particular shout-out to @rkl who has recently done a great job feeding back whenever HRS have corrected a mistaken ID fed through from iNat.

Happy Syrphing for July!

All data collected on 30th June 2024

Updated 03-Jul-2024

Hello all,

The first round of group games is over, and it's been quite fun seeing familiar names pop up on observations all over Europe when people are obviously watching the same games! Given that this activity is not core to our purpose as a project - which is for the UK , I don't want to create lots of posts about it (although it gives us all a chance to practice adding annotations - which is a core activity), so I'll just update this post again after each round of group games, the round of 16, and the end of the tournament.

Remember - you don't have to watch the football to join in!

End of first round of group games:

We've added life stage annotations to more than 6% of all non-UK European hoverflies! and sex annotations to 2%, Very cool! (I think it's fair to assume that the jumps are down almost entirely to us!) In particular some of the smaller countries have been greatly affected. I think the biggest total number of annotations added has been to Denmark, while the biggest proportional changes have gone to Serbia (Obviously some of us were watching the England-Serbia match!) You can see the difference in the darker coloured parts of the bars.

End of second round of group games:

Well over 50,000 sex and life stage annotations have been added to European observations since the start of the Euros. I can't say how many are due to us, but it is an increase of 18.5% compared to the number of annotations pre-tournament. And that's for the whole of Europe not just participating countries. Wow. (Participating countries account for 87% of European observations)

4% of all non-UK European hoverflies have received a sex annotation, and 13% have received a life stage annotation.

It may be a little more challenging to choose which country to annotate in this third round of games since matches are being played simultaneously. It looks like Austria, the Netherlands and Poland could particularly do with a little bit of love. Hosts Germany got the biggest numerical increase this time round with nearly 5000 annotations added. Switzerland, France and Belgium also saw nearly or more than 3000. Proportionally, Georgia and Romania did well.

(Note that I've collected these data at the end of each day for the teams that played that day)

End of Group Stage

Since more teams have been playing each day, fewer days in total, and with matches being played simultaneously, it's not surprising that fewer annotations (13500) have been added in the last round of group games. Nevertheless Germany still racked up an impressive 5800+ annotations added. Proportionally, Croatia, Slovakia and Slovenia did the best. Countries needing the most annotations are still Austria, Denmark, France, Germany, Italy, the Netherlands, Poland, Portugal and Spain. Poland are now out of the tournament - though don't let that stop you if you fancy that challenge (I will continue to update all countries). I think I'll update at the end of the round of 16 as well as the end of the tournament.

During the group stage, 7% of non-UK European hoverflies have received a sex annotation, and 15% a life stage annotation.

After Round of 16

We've added more than 15,000 annotations during the round of 16 - for participating countries excluding the UK we've annotated 10% or all observations with sex, and 20% of all observations with life stage, which I think is quite spectacular!

Italy got the most attention this time with nearly 3000 annotations added - which is just as well given they've crashed out! Turkey did the best proportionally. Of the countries remaining in the tournament it's the Netherlands who need the most love (proportionally).

Here are the graphs

Hi all,

With the Euros about to start I did wonder about taking a continental excursion...

Now I don't wish to detract from the good work we are doing with UK hoverflies, but it did occur to me that I'm likely to end up watching a goodly number of matches without necessarily being engrossed by them... and my laptop will be handy. I think I might set about doing some annotating in the countries that are playing - perhaps swapping at half time!

Anyway, feel free to join me. As you can see below, most of Europe is still at the levels of annotation that the UK was before this project got underway. In fact, after the success of November's annotatathon and our subsequent activities, more than half of European hoverflies with life stage annotations are now in the UK! (and just under half of those with sex annotations). There aren't really any additional confusing things for annotations in the rest of Europe compared to the UK, and it's a great opportunity to learn if you are new to this.

Adding annotations is a great way for beginners to see the diversity of hoverflies. It's fairly simple, you can even avoid the few tricky genera completely by sticking to the subfamily Syrphinae. Here's how to do it. (Of course you don't need to be watching the football!).

You can use the links from the Useful URLs post, but just change the country.

Here are the participants in the Euros, showing first the percentage of hoverflies with annotations, and secondly the absolute numbers of annotations compared to the total number of hoverfly observations in each country (in green):

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 :-)