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.

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

Posted on May 1, 2024 10:58 PM by matthewvosper