Square-bashing in Scotland - first results

I have previously written about 'parataxonomy' as a way of improving geographic coverage in less well-supported recording schemes. Whilst on field trips I retain a wide range of insects across many Orders for relevant schemes as a matter of course. The two schemes that benefit most are craneflies and fungus gnats, but I also hold on to specimens for many other Diptera schemes. In addition, I retain specimens for several beetle schemes, Neuroptera and Hemiptera, all of which are effectively by-catch whilst sweeping for flies.

This year, I headed to Scotland on 25 May and focussed on the north and west coasts, which are relatively under-recorded. I got home on 18th June after covering well over 2000 miles. I've still to send samples to many of the recording schemes but have passed on my gnats and craneflies. Results from the gnat sample came back just six days later! Goodness knows how he did it, but Peter Chandler worked through the 92 packets of gnats in less than a week! The resulting records comprised nearly 1,000 new records:

Family	Records
Bolitophilidae	19
Diadocidiidae	7
Drosophilidae	5
Keroplatidae	112
Mycetophilidae	841
Sciaridae	2

The majority of the species were relatively well-known but there were a few that were considered noteworthy and one species new to Britain. So, it looks like my efforts were worthwhile. Breaking down the list into frequency of occurrence it is clear that there is a vast amount still to do. Of the 160 species recorded, all but a handful were seen on fewer than 10 occasions (figure 1). Bearing in mind that a lot of western Scotland is comparatively uniform coverage of Birch woodland with deep stream gullies, I suspect that many of the species I found will be much more widespread than records suggest. There is a lot more to do, and I suspect a repeat trip at the same time of year would yield far more. Change the dates a little bit and the differences are likely to be even more pronounced.

Figure 1. Numbers of records against the species list for gnats and related families recorded from western and northern Scotland in May-June 2018

The trip was extremely hard work, often meaning that I worked into the early hours of the morning - sorting samples and attending to the UK Hoverflies Facebook page. My target group (hoverflies) was extremely thin on the ground, but I do have a massive sample of Empids and Dolichopodids plus numerous packages of Cantharidae (Coleoptera), Hemiptera and Neuroptera. There are also lots of pinned Chrysomelidae, Elateridae and Curculionidae (Coleoptera) and numerous Symphyta (Sawflies) to identify. I will probably do a fair block of these samples but inevitably some will go directly to their respective recording schemes. I hope that they all make a useful contribution but the real big hits are inevitably the gnats and craneflies. The results encourage me to go back! Perhaps others will think about developing as parataxonomists too!