Tuesday, 25 November 2014

Of this and that...

In the high summer it is easy to assemble enough material to write a blog. Something on flowers? No problem; there are plenty about. Hoverflies? It wouldn't take long to get a few interesting species on camera. But late November...

Last night was the first real frost of the year and the car roofs wore a white crust. On the other hand there was barely a cloud in the sky and under the increasing warmth of the climbing sun the frost was fleeing.

I had to go into Daventry and the sunshine prompted me to walk. Where fence panels were facing the sun a thin cloud of steam was rising and on dry areas flies were gathering to dispel the torpidity brought on by the cold night.

Male Calliphora on a fence in Daventry.
 24 November, 2014
There were at least a dozen concentrated in a particularly favourable spot. All were Calliphora species, i.e. blow flies. I took a close look but didn't attempt to capture one. My best guess is Calliphora vicina; all but one were males. The photograph shows one of these males and it can be seen that the large red-brown compound eyes are almost touching.This is known as the holoptic situation.

A female, probably of the same species.
Same fence; same date

The second picture shows the only female I saw. Here it can be seen that there is a significant gap between the eyes. This is the dichoptic state. Given a spell of warm sunshine it is not unusual for these flies to be seen in the depths of winter. Not all flies have this form of sexual dimorphism but it is common among the 'higher' flies.

I was rather  surprised to see Viburnum rhytidophyllum in flower in a garden (and annoyed not to have taken more care with my photograph). Viburnum tinus is in flower everywhere but to find the so-called Wrinkled Viburnum to be in bloom was a surprise.

Its common name is well justified, for the leaves are very wrinkled, making identification easy. Despite its Chinese origins it finds the British climate to its liking and is sometimes found established in the wild.

Web of Amaurobius similis in a hedge. Daventry.
24 November, 2014
Nearby a neatly clipped hedge of 'Leylandii' (yes, it is a good hedging plant if kept under control) was covered in spider webs. Their grey appearance and the apparently haphazard construction showed that they were the work of Amaurobius similis. This very common spider has an almost identical sibling species called Amaurobius fenestralis. Now 'fenestralis' ought to be the one found around our window frames but perversely it is nearly always A.similis whereas A. fenestralis is usually found under loose bark in woodlands. Why can't nomenclature be appropriate! In both cases the spider's retreat is a tunnel-like structure near the middle of the web and it is clearly shown in the photograph.

Ivy in flower, Badby Road West, Daventry
24 November, 2014

Ivy, as is often the case, was in flower and in fruit on the same plant and, as the sun gathered it's strength, a few flies were imbibing the copious nectar.

Ivy (Hedera helix) does not describe a
helix as it climbs a tree. Byfield churchyard.
28 November, 2014

Regarding inappropriate names, Ivy is another case in point. Its Latin name is Hedera helix, and the specific name suggests that the plant describes a helix as it ascends a tree. I have never seen Ivy climbing in this way.

Harlequin Ladybird on ivy fruit. Badby Road West,
Daventry, 24 November, 2014

Anyway, back to ivy and its fruit. The berries were quite plump but some way short of being ripe. They will ripen through January and February, doing much to sustain birds through the winter. 

The ladybird, in this case a Harlequin  Ladybird,  Harmonia axyridis, was one of dozens out enjoying the sun and, worryingly, it was the only species I saw.

So, as I stated, a bit of this and that.

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