RSPB Tudeley car park

Doing my RSPB car-park duty, I found a quiet Andrena male on a hawthorn leaf in the woodland fringe around the car park, and some of the pictures are shown below. At first glance it could have been Andrena nitida, and although it didn't fit the draft Andrena key on the BWARS website, it did fit the Falk book, and I still think that's the right ID.

Note the apparently darker hairs along the inside margin of the eye, which is mentioned in the Falk book. 

 

The characteristics of Andrena nitida include the foxy red thorax hairs, white moustache with some dark hairs, white underside hairs and whitish or pale brown leg hairs, together with the shiny dorsal surface to the abdomen. There was also another individual, possibly of the same species, on one of the branches:

Sunny Cliffe on Good Friday - Eupeodes luniger

Superfast access (but not on BT!)

Yes I meant a superfast visit to the access trail - sadly I was not referring to my broadband access supplied by BT. A very quick visit to the groups of blackthorns along the access trail in cold breezy conditions gave me almost entirely bumblebees today. This Southern Vestal Cuckoo Bumblebee, Bombus vestalis, was clearly demonstrating its habit of holding its wings close together. Its host, Bombus terrestris, always seems to hold its wings significantly further apart, and out an angle, like a fighter jet, and this is generally the quickest way to spot the difference (either that, or the obvious long body and white tail on vestalis usually leads me to my normal snap conclusion).

Eristalis intricarius on the Access Trail

Moving along the outside of the blackthorn alongside the path, on the Hadlow Estate side, seemed to be a good strategy for getting close to the bees and flies on the blossom, without having to kink my neck up too much.

On the second group of blackthorn (including the bunch by the start of the nature trail) I found a decent view of the Yellow Legged Burrowing Bee, Andrena flavipes.

At the third major group of blackthorns there was a suspicious looking bee, and sure enough it turned out to be my first sighting of the bee mimic Eristalis intricarius! I was really pleased to see this at last, and all the features checked out.

The humeri were clearly visible, the upper outer cross-vein was not re-entrant, the R4+5 vein was deeply looped, and the lower and upper outer cross veins were running in a smooth curve more or less continuously parallel to the rear wing margin, so this keyed out at Eristalini.

The two anterior veins R1 and R2+3 are joined into a short common vein before they reach the wing tip, and the scutellum is yellowish or brownish rather than black, so that puts it into the genus Eristalis.

No really obvious central black stripe down face, but maybe a smudgy version of one. The front two legs have partly or wholly dark tarsi, the sides of the thorax are not dusted at all and its obviously furry, very much like a bumblebee. This should make it either Eristalis intricarius or Eristalis anthophorinus. Side of the thorax definitely very black, and squamae possibly a bit darkened, so should be the known UK species Eristalis intricarius as opposed to the European species anthophorinus.

Just to be safe, the basal part of the tibiae is clearly and obviously pale. If the tibiae were dark I should instead have been looking at the other common bumble bee mimic, Merodon equestris, the large bulb fly.

This one was a male, the more variable gender in this species!

On the same group of blackthorns several honeybees, Apis mellifera were working away, easily identified by their hairy eyes.

And then there was I think an Andrena

And then I came across a Southern Vestal Cuckoo Bumblebee, Bombus vestalis.

This is my first bluebell for the year - at the moment the bluebells look as though they are about two weeks ahead of normal years!

The access trail is just wonderful

Dr. Beverley Glover from the Plant Sciences Department in Cambridge suggests that the surface of petals has multifaceted functions. There appear to be projecting cells or groups of cells - these can be extremely useful perhaps for insect feet to grip onto, or for the light to be concentrated - this may make the petals look brighter, or perhaps rather more importantly the increased radiative energy input could warm the petals up - there is certainly evidence that bumblebees prefer warmer flowers.

Warmer nectar could also be important for bees searching for food on cold mornings - they have to warm themselves up, they may not want to have warm up the nectar they are drinking as well!

Flowers appear to have had such surface projections from an early stage in evolution. Flowers that don't have them, appear to have secondarily lost them.

Of course sallows don't seem to have these issues - they do not have petals, so clearly they do not have these projections? However they certainly seem to smell delicious at close range. They also attract huge amounts of insects, in conditions that may not always be the warmest! Here is a Bombus terrestris that is enjoying the sallow catkins along the outward path of the access trail at about 6 in the evening.

The Buff-tailed Bumblebee, Bombus terrestris, was accompanied by numbers of Bombus vestalis, the Southern Cuckoo Bumblebee. Here you can see the white tail and the yellow edges at the boundary of the tail, contrasting somewhat with the true orange of the front thoracic band. This looks like mimicry of the buff tail of the Buff Tailed Bumblebee!

The yellow at the tail is not always clear - hopefully this bee is still B. vestalis!

This is a better and therefore more reassuring shot, of the same bee. You can see the yellow edge to the white tail more easily at this angle. Note also the shiny thorax, easily seen in this photo.

Here is a close-up of the antenna - 12 segments altogether, rather than 13, shows it to be a female

Also on the sallow were one or two relatively small black bees - female flower bees, Anthophora plumipes. I haven't seen these on Sallow before, but there were plenty of males by this tree, but at ground level, nectaring off the Ground Ivy, Glechoma hederacea.

However when I looked at these photos of one of the other apparently small black bees there was clearly a bit of a red-tail, so realistically that led me to either Bombus lapidarius or Bombus ruderarius. I looked as closely as I could and the hind leg on the left looks as though any hairs on the rear tibia were black, not red, so that pointed to the commoner species, Bombus lapidarius. On the right hand wing you can also just see the pale cross bar in the small cell (first submarginal cell) at the front of the wing.

Yet more interest on the access trail

There were a few more Drone Flies on the Access Trail this evening and I think this rather more brightly coloured one was Eristalis arbostorum. Particularly the face appeared fairly well dusted white over the front surface, with only a slightly darker central smudge. The hind metatarsi were swollen to the width of the hind tibia, which were yellow at the base, dark at the apex, as also were the mid-tibia.

The thorax wasn't too furry, and the sides of the thorax below the wings were pale rather than black. I couldn't see the stigma on the wing clearly, but it seemed to be relatively small and unextended.

At the first Sallow on the outward path to Victoria Lane I found Anthophora longipes (several males and a likely female) on the Ground Ivy, Glechoma hederacea on the ground of the rabbit burrows, and many probable Bombus terrestris on the sallow catkins, together with its cuckoo parasite, Bombus vestalis, confirmed (probably) on ispot.