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Monthly Archives: May 2012

The making of the Autokatcher

Be warned: Using an Autokatcher involves some risk of damage to your vehicle, some risk of causing accidents for other road users (especially on horseback), and possibly other risks.

My inspiration for making an Autokatcher was this photo and this text. First, I bought a pair of steel roof-bars from the RAC (£64.99 including delivery). Then I found a local metalworking outfit that could make up an iron frame to my specification. John Sayer at JGS Metalwork & Son made a really nice job of it for £40. They’ll happily take further orders and can have frames delivered by post/courier. Finally, B&S Entomological Services made up the net for me for £34.45 including delivery, and again would be happy to take further orders.

The frame is made from 3mm thick iron, 17mm wide. There are two pieces to the frame: (i) a straight bottom piece which is the same length as the roof-bar (1120mm), and (ii) a top piece with a semicircular curve and lugs at each end for fixing to the roof-bar.

Plans for the Autokatcher frame

The two pieces of the frame are bolted onto the roof-bar at each end. I also got JGS to drill two holes in my roof-bar.

Detail showing the bolt fixing both pieces of the frame to the roof-bar. These are 10mm nuts: conveniently the same size as the nuts for fixing the roof-bar onto the roof.

The net was designed by B&S Entomological Services to my dimensions and is absolutely perfect! The toe of the net is attached by velcro and it was quite easy to peel it of, poot up the beetles and reattach it.

The Autokatcher net

I’d been worried that something would break but having given it a test run at up to 30-ish mph it all seems perfectly robust. It could probably withstand a lot higher speeds but I think I only need to go fast enough to billow the net out and so there’s nothing to be gained by driving faster than about 30.

Scaring horses is known to be an issue with Autokatchers (read here!) and that’s probably only one of several potential misadventures that await. I’m still debating whether to use the Autokatcher on the public roads – it seems like a guaranteed way to get pulled over by the police!

I think it would reveal a lot about our fauna if British coleopterists started using Autokatchers. It would certainly add to the body of knowledge from flight interception traps and light traps about which species actually take to the wing. But more interestingly to me, there is the potential to record those species which, when they’re not dispersing by flight, spend all their time in very inaccessible habitats: high in the tree canopy; deep inside veteran trees; or underground in mammal burrows, at tree roots or in truffles.

Maiden voyage of the Autokatcher!

I received the custom-made Autokatcher net from B&S Entomological Services during the week, in time to give the Autokatcher its maiden voyage around Parham Park during the first Pan-species Listers’ Field Meeting on Friday. I’ve just put the meagre haul of eight beetles that I caught on the first spin under the microscope and, incredibly, the first one I look at is Litargus balteatus (Mycetophagidae). A first for Sussex and a new beetle for me!

The Autokatcher

Colin Welch summarised the status and distribution of this beetle in a 2009 paper. 14 specimens were found in Sherwood Forest in 1907. It wasn’t seen again until 1982 when 3 were found in Leicestershire, followed by one in Norfolk in 2003, another one in Norfolk and one in Cambs in 2007, one in Huntingdonshire and one in Dorset in 2008. The first Irish record was of one in Co. Armagh in 2010. No doubt there have been a few other records as yet unpublished. It’s a non-native species from North America and despite a slow start, it seems to be spreading in Britain now.

The test run of the Autokatcher was a complete success and I’ll post full details soon for anyone else who fancies getting one. But meantime here’s some footage of the maiden voyage!

Welch, R.C. (2009). Litargus balteatus Le Conte (Mycetophagidae) outdoors in Cambridgeshire (Vice County 31, Hunts.). The Coleopterist, 18, 130.


A non-native endemic!

I love seeing a beetle in the field and not having a clue what it is, other than the certainty that it is something I’ve never seen before! Graeme Lyons found this amazing weevil at Parham Park, West Sussex on Friday …

The Fern Weevil Syagrius intrudens playing dead

After a suitable amount of colourful language, I suggested Graeme googled for an image of Syagrius intrudens – and it’s a match, subsequently confirmed under the microscope. With another few minutes’ work with the sweep-net targeting bracken, we had recorded four individuals. But we were left wondering how it could be that Syagrius intrudens has no conservation status when none of the 18 assembled pan-species listers had ever seen it before?!

Syagrius intrudens is definitely a rare species, previously known from six sites: Co. Dublin (Dublin Botanical Gardens), West Cornwall (Tregithy Woods area), East Sussex (Leonard’s Lee), East Kent (Hothfield Common), Glamorgan (Bridgend) and Guernsey (Fermain Bay). As a flightless species, it must be getting around with the help of gardeners moving fern plants around.

Syagrius is an Australian genus with 8 species known from the coastal plain between Sydney and Brisbane. As a non-native species in Britain it is ruled out from inclusion in the Red Data list but Syagrius intrudens has never been recorded away from Britain, Ireland and the Channel Islands, and Parham Park becomes the seventh known site for the species in the world! As Theodoor Heijermann and Mike Morris have already written, we should surely be giving this fabulous weevil some conservation status in Britain. It may never be discovered in its native range, and could even be extinct in Australia?

A day on Salisbury Plain

Dave Gibbs and I had three days’ fieldwork together recently in Somerset, Dorset and Wiltshire. For two days we took a drenching and struggled to find any but the most ordinary invertebrates. And then on Friday 11th May we had a dry day with just enough sun to get a few butterflies on the wing. Our survey site proved to be a very interesting place on a south-facing, rabbit-grazed slope of Salisbury Plain with a very friable, chalky soil. Two new beetles for me: Ptomaphagus varicornis (Leiodidae) is a rare species (RDBK) which to the best of my knowledge has only been recorded from Surrey and Wiltshire in the last 40 years; and Stenus ochropus (Staphylinidae) which has no conservation status but must be fairly rare and has not been recorded from Wiltshire before (Darby, 2009). Dotted Bee-fly is always a superb thing to see, and I even had to stop work briefly to admire one basking on my sieving equipment!

Dotted Bee-fly Bombylius discolor

I also suction-sampled Geomyza breviseta (Opomyzidae), a Nationally Scarce fly mining grass leaves. Other scarcities on the day included the longhorn beetle Phytoecia cylindrica on Cow-parsley, the weevil Trachyphloeus aristatus*, the bee Osmia bicolor, a probable Hedge Rustic caterpillar**, the weevil Limobius borealis on Meadow Crane’s-bill, and Dingy Skipper. A single worker of the ant Stenamma debile s.s. looks like a good distributional record.

Couldn’t help but notice some big birds too …

Great Bustards

* previously determined as Trachyphloeus asperatus, re-determined and corrected on this webpage 7.vii.2012.
** Dave reared this and it was a Feathered Gothic.

Dogging in Bedfordshire

Today Jo and I have been to see the Prairie Dogs which roam wild and free in Bedfordshire. Although they would only peep nervously from their holes at first, they soon emerged to feed and gave really good views in the sunshine. There seem to be just three animals here on a sandy abandoned arable field off Gypsy Lane, Broom, near Biggleswade. I don’t know where they’ve come from but there used to be at least 6 Prairie Dogs at this wildlife attraction near Bedford which closed in 2010.

Pretty sure they are Black-tailed Prairie Dog Cynomys ludovicianus.

It could be a scene from the prairies ... but for the oilseed rape field.

Nearby, a few miles up the A1, we dropped in to look for Firebugs Pyrrhocoris apterus at some dilapidated glasshouses in Beeston: a site which I heard about from this blog. We only saw two, both adults and both walking on the tarmac track where it passes between glasshouses on either side. Jo saw them at the Surrey colony soon after they were discovered in 1996 so it was high time I caught up!

Firebug Pyrrhocoris apterus