Shiny blue death fly

Just a quick post on a productive spot of moth trapping this week. The week went out on Wednesday night, more out of a sense that I hadn't done much mothing this year than expecting much to turn up. The forecast was for a clear night with temperatures dropping to around 5 degrees, but in the end I think it stayed a bit warmer, which resulted in a pretty good haul. By far the best moths were a brace of Dotted Chestnuts, a formerly very rare moth in the county which seems to be increasing in numbers a bit, but I'd still only seen twice before.

Dotted Chestnut

Almost as good was my first Frosted Green for the garden, and with a supporting case of Powdered Quaker, Streamer, Clouded Drab (5), Common and Small Quakers and another brindled beauty, I was very glad I decided to put the trap out.

Frosted Green

The only other notable bit of wildlife I came across this week came the morning before, when I stopped off on the cycle to work to check a patch of Alexanders that I'd been keeping an eye on for a while. In the warm morning sun it was buzzing with flies, mainly Calliphora species, but with a hoverfly or two, and one slightly different looking "bluebottle" which had a really rich blue sheen to the abdomen and a yellowish face. I vaguely recognised it as C-something mort-something, which with the aid of the internet and my photos was later clarified to Cynomya mortuorum, a reasonably common and widespread species with the slightly gruesome habit of laying its eggs in carrion. Apparently it sometimes has the common name of "fly of the dead" which sounds pretty sinister, I prefer my version :).

Cynomya mortuorum - the shiny blue death fly

An unusual hoverfly

A lot of hoverflies pretend to be something else; Eristalis tenax looks like a honey-bee, Chrysotoxum species look like social wasps, and Volucella zonaria and inanis do a pretty good hornet impression. On Saturday I found a hoverfly that didn't look much like a hoverfly, but didn't really look like much else either. The Brachyopa genus of hoverflies is represented by four species in the UK, none of which I'd seen before this weekend, and all of which are notoriously tricky to identify, so when I saw one on the garden hedge I quickly ran inside to grab a pot, passing/throwing the baby to my wife on the way past.

Fortunately the fly was still there, and even better, obligingly stayed still long enough to be wrangled into the pot. With that achieved, all I had to do was work out which species it was. The scutellum was clearly all yellow, so that narrowed it down to two species, and after a lot of faffing, several escape attempts and a lot of blurry photos, I managed to get a good enough shot of the antennae to see the pit on the inside of the 3rd segment (I said they were tricky!) This was large enough to clinch the identification as Brachyopa scutellaris, the commonest UK species, but still by no means common. The fly was released unharmed, and unsurprisingly didn't hang around for any nice photos after a day in a glass tube!

The unhoverfly like Brachyopa scutellaris

After that the rest of the weekend passed without much incident, although I did get the moth-trap out on Sunday night, and amongst the usual common quakers and hebrew characters was a magnificently furry brindled beauty, with some of the most impressive antennae of any moth.



I had the luxury of an extra day off this week, and managed to get some free time to go and explore the nearby blackthorn which is in full flower, and attracting a decent variety of insects. My first small tortoiseshell of the year was very nice to see, along with a brace of peacocks and a single Brimstone skipping past on the breeze. The hoverfly contingent was dominated, as always this year, by Eristalis pertinax, with a single Melanostoma scalare the only other species I saw, although there were also a fair few Bee-flies on the wing, which are kind of honorary hoverflies in my mind.

Small Tortoiseshell

Eristalis pertinax

Melanostoma scalare

Bee-fly

More hanging around sallows

After a nice long Easter break it was back to work yesterday and today, but that came with the consolation of being able to check out the sallow on the heath, which has come nicely into flower. I was hoping for another new hoverfly, perhaps a Cheilosia grossa, but the only hoverflies to be seen were a solitary Parasyrphus punctulatus and a Melanostoma scalare, both common spring species.

Melanostoma scalare

There were a few more bees buzzing around, possibly more able to fly in the chilly air with their furry coats, including a lovely female Andrena praecox, the small sallow bee. As the name suggests this is a specialist on sallows, the females will only collect pollen from this one tree, they are oligolectic to use the technical term.

Andrena praecox - a nicely distinctive bee

On Thursday there was also a larger Andrena on a catkin, which I think might be a female A.bimaculata. I've not seen it before, and I briefly dismissed it as another honey bee, before thankfully deciding to give it a second look. They look very similar to a number of other Andrena species though, and I'm not quite sure that it's not an Andrena trimmerana, unfortunately I don't think the key characteristics are visible in my photos. In an attempt to clinch an ID I went back to the sallow today with Rosie, armed with our nets, but there weren't any female bees around to catch. We did bag a couple of male Andrenas though, which might fortuitously be one each of bimaculata and trimmerana, we'll take a look under a microscope to check. (Edit - I've now had the ID of the female confirmed as bimaculata, and the males were indeed one of each - very efficient netting!)

Andrena bimaculata

Elsewhere on the heath things are pretty quiet, as there aren't many other sources of nectar or pollen around. The fences did attract a good number of basking flies, including a single Eudasyphora cyanella, a species I'd never heard of before this year before seeing some photos on the UK Diptera facebook group. Once you know to look for the black and white markings at the top of the thorax, they're actually quite distinctive.

Eudasyphora cyanella

The gardens are buzzing with bumblebees, including the first Red-tails I've seen this year, and on a daisy a single dimunitive male Andrena bicolor was taking a rest. These are one of the easier male Andrenas to identify, with the combination of their small size, spindly build and black hairs on the face making them quite distinctive.

Andrena bicolor