Tuesday, 22 March 2011

Keep learning

Over the years, as experience builds up, you make a series of 'rules' which help you reach an identification. Until yesterday, one of my rules was "If you see a bee which is less than 20mm long, then it isn't one of the social bees". Applying this rule, I leaned towards one of the Andrena solitary bees for this specimen: 

But it didn't match any of the images that I could find in the usual places. When I asked for help, back came "It's a Honeybee". Blinded by assumption (and not helped by the fact that this was roughly 60% - 70% as big as I would normally see), I had excluded the obvious. Factor in the fact that Honeybees have become very rare in our area, and the mistake is easy to make.

Assume nothing.

Moving swiftly on......

This Eristalis tenax hoverfly has the very dark colouring that we expect to see in early specimens. The summer generation of many of our hoverflies is much brighter due to the higher temperatures. This female will have mated at the end of last year and has managed to successfully shelter in some nook or cranny through the -17 degrees that we endured in December:

Female Eristalis tenax
The Willow catkins opened last Thursday (17th) and insects have been busy nectaring and gathering pollen ever since. This queen Bombus lucorum bumblebee found the pollen quickly enough:

Queen Bombus lucorum
She is now gathering enough pollen to feed the first few workers from her nest, and she will spend the rest of the year laying more eggs to sustain the nest and produce drones and queens for next year's generation. A few of the new queens actually become workers for a while at the end of the season, gathering pollen alongside the last of the workers.

With the early willow pollen season being so short, no time is wasted before the willow-dependent moths appear. This is the first Common Quaker - Orthosia cerasi - of the year:

Common Quaker - Orthosia cerasi
The Common Quaker is readily identified by the large, rounded, 'kidney mark' which has a pale, thin, outline which matches the colour of the thick band near the trailing edge of the wing. 


Gill said...

Fantastic shots of the bee - and yes, I can certainly see why you thought it was an Andrena.

I'm intrigued by the statement "have been busy nectaring and gathering pollen" - I didn't realise catkins had nectar as well as pollen, at least on the male flowers. I've seen one white-tailed bumble queen, two buff-tips (one dead) and one red-tailed so far this year.

It's amazing what two or three days of warm sun can do!

The Weaver of Grass said...

Your willow catkins are open well before ours Stuart - the hazel are well on though. Good to see bees around in force again.

Emma Springfield said...

Spring is definitely on its way. Nature keeps us on our toes with what we see as little oddities. It is one of the ways we continue to learn.

Caroline Gill said...

I think we are a bit ahead of you, Stuart. The bees have been very active. When should we expect to see males, I wonder?

I hope the painting is going well. I am just planning an impasto Tawny Owl (oil), but it will doubtless take me weeks to execute!

Stuart said...

Gill, both male and female flowers of willow produce nectar. I'll see if I can get a shot of the smaller flies that can be seen feeding at the base of the stamens.

Weaver, I'd expect catkins to generally be a little later near the east coast. The weather there is influenced more by the North Sea, whereas we get the gulf stream. Individual specimens vary, though. There are are also some willow species that flower much later, after the leaves. These tend not to be as important for nectaring or pollen as the early species because there are plenty of alternative sources by then.

Emma, yes indeed. I reckon a day without learning something is a day wasted.

Caroline, my current project is a pair of Boletus mushrooms on the forest floor. I like the planning part almost as much as the painting part.