I returned home on Sunday night from a four-day entomological expedition to The Mullet, County Mayo. Thanks to Dave Allen for including me in the team for this trip and thanks to The Heritage Council (Ireland) for financial assistance. After a 5-hour drive from Belfast, we arrived on Thursday in a land of machair grassland, lakes and hay meadows. Relatively few entomologists have worked this part of the world but it is already known as the only area in Ireland for the click beetle Selatosomus melancholicus, and a stronghold for the sand wasp Ammophila sabulosa, otherwise known in Ireland only from The Raven, Co. Wexford. What else awaits discovery out there?
I have been to The Mullet once before, on a similar expedition in late June 2007. On that occasion, resident naturalist Dave Suddaby guided us to a couple of the best spots for the click beetle, only to find the dunes littered with their corpses. This is a beetle which emerges in considerable numbers but doesn’t live for very long. I was, quite frankly, gutted. Fingers were crossed that the earlier dates of this year’s trip (7 – 10 June) and the late spring would give us a better chance of seeing them alive.
The first one I found at Annagh dunes on 7th in pouring rain … was dead. But then Sudds found a live one, and there was rejoicing.
We eventually tallied 21 dead click beetles to 4 live ones. This beetle does not occur in Britain, and in France it is restricted to the Alps and Pyrenees. Whether the population on The Mullet is native, or an ancient introduction is unclear – but either explanation is pretty mind-boggling.
Despite the rain, sand wasps were still out and about, hunting caterpillars.
We endured some terrible weather for the first couple of days though it did blow in a summer plumaged Long-tailed Skua. The wind and rain eased on Friday evening and Saturday was a beautiful sunny day. Sudds found a Great Yellow Bumblebee Bombus distinguendus on Red Clover in the garden of our B&B (Léim Siar, highly recommended), which was to be the first of many. Though I never succeeded in photographing any of them!
We worked some meadows near Termoncarragh Lough, with more Bombus distinguendus, and a fly-past from a pair of Chough. A Marsh Pug here was probably the best macro-moth discovery of the trip. Roy Anderson decided to try sieving one of the hay-ricks which turned out to be seething with Atomaria, ptiliids and all manner of other beetles. Bells started ringing in my head about the hay-rick beetle fauna – there are several species which were seemingly common in the days before combine-harvesters and silage but are now extinct or vanishingly rare. Maybe they could survive out in west Mayo, where Corncrakes and Great Yellow Bumblebees also cling on? Well I filled my pooter with a lot of LBJs but it will need several winter days at the microscope before I know what I’ve caught!
We ended the day listening to Corncrakes after dusk in beautifully still conditions.
Sunday’s fieldwork plans were mucked up by a slow puncture on Dave’s truck but when we did collect the moth traps, there were still very few moths. I was pleased to see an adult Pod Lover Hadena perplexa capsophila and Red-shanked Carder Bee Bombus ruderarius before we set off back.
Just after breakfast I grabbed some photos of a bumblebee in the garden of our B&B. At the time I thought it might be one of the cuckoos (formerly in genus Psithyrus) as it looked quite shiny. On examining the photos back home I thought it was probably a Shrill Carder Bee Bombus sylvarum, which would be a good find. However, Mike Edwards reckons it is just a worn individual of one of the brown carder bees (pascuorum or muscorum) and that the apparent black hair-band across the thorax is just a bald patch.
Last stop before I was dropped at the airport was Cullentra Lough, a beautiful little lough just off the main A4 road east of Fivemiletown at H 476 474. It’s a good spot for Irish Damselfly Coenagrion lunulatum (and the only place I’ve ever seen it). We found just the one on this visit after checking through loads of Common Blues Enallagma, Variables Coenagrion pulchellum and Azures C. puella.
Another fine day on Salisbury Plain on Thursday with Dave Gibbs. Added a few more scarce insects to our list from the first visit, including the red-tailed cuckoo-bee Bombus rupestris, and the weevil Protapion filirostre (a new beetle for me). The suction sampler also turned up another individual of Ptomaphagus varicornis, the Red Data Book beetle I recorded here on 11th May, and this time I was able to show it to Dave in the field. With Knapweed Broomrapes pushing skywards, Small Blues on the wing, and a Quail quick-lick-licking from a nearby field, it reminded me of a few happy weeks surveying invertebrates on Salisbury Plain in 1997, my first job after finishing my PhD.
A surprise record from 11th May was a single individual of Rhinusa collina, a weevil which develops on Common Toadflax Linaria vulgaris. This is a Nationally Scarce (Na) species with a single previous Wiltshire record. I hadn’t even noticed any Linaria on 11th May but on Thursday, we made a specific search for the plant and eventually found a small patch of a few sprigs up to about 5 inches high within an area of about two square feet. The first sprig I looked at had four elongate cylindrical weevils on it of a species I’d never seen before! My first thought was Baris but I soon found a match in Mecinus janthinus, Nationally Scarce (Na) and another one new to Wiltshire. I suction sampled the entire population of the host plant, which only took a few seconds, and produced one more Mecinus janthinus, three Rhinusa collina, two Rhinusa linariae (Nationally Scarce (Na); one previous Wiltshire record) and the pollen beetle Brachypterolus linariae.
I don’t know whether anyone else has come to the same conclusion but I think the way to find both the two scarce Rhinusa species is to look at Linaria when it is just a mere few inches high. By the time it is in flower, all I ever find is the common one, Rhinusa antirrhini. My dates for the three species are as follows:
- linariae (Na) 17th May to 5th June
- collina (Na) 31st May to 2nd June
- antirrhini (Common) 9th July to 14th September
So if anyone is out and about now and sees Linaria, it would be interesting to know which weevils you find. As Thursday’s observations show, even a tiny patch of the plant can support the scarce species.
The suction sampler is turning up a lot of interesting beetles for me but, unexpectedly, the flies in the suction samples have been very interesting too. There are a few species with very reduced wings that are clearly adapted to a life on foot. But there are also some species which look perfectly capable of flying off but choose a ground-hugging way of life, running about in the bottom of the tray and seeming reluctant to even climb up the walls to escape. Amongst Thursday’s samples Dave has already identified two Nationally Scarce species, Geomyza apicalis and Geomyza breviseta, with more specimens still to be looked at. I guess these flies would be recorded more often if more dipterists used suction samplers – they’re probably not so scarce, just very good at eluding capture by nets!