Friday, 31 October 2014

Late-flowering Hogweed

What a remarkable autumn! Penultimate day of October and Hogweed is still flowering in profusion.
Hogweed in flower at the edge of Daventry.
30 October, 2014

Hogweed, Heracleum sphondylium, is doing particularly well on roadside verges. It will have been cut back hard during routine maintenance, so it received what gardeners know as the "Chelsea chop". When plantsmen plan to show, at Chelsea, a plant which is likely to bloom too early, they will cut it hard back. It will then flower again and, if the timing is right, it will be at its best for the Show. 

Inevitably the flowers were attracting flies and, equally inevitably, the Common Dung-fly, Scathophaga stercoraria, was there. This insect breeds in dung but it is among the most ubiquitous of our flies and, outside the breeding season, is likely to turn up almost anywhere.

Hedge Woundwort beside the A361 near
Daventry, Northants. 30 October, 2014

Hogweed was by no means the only plant in flower. Hedge Woundwort, Stachys sylvatica, was also in bloom. This striking member of the Mint Family is quite rich in nectar and receives many visits from bees, but I saw none today. Like most members of the family (thyme, lavender, sage, etc) the leaves are strongly scented but in this case the odour is an unpleasant one. I was happy to look and not touch.

In the same family is White Dead-nettle. It is so common that I was inclined to ignore it, but then I noticed that some of the leaves were damaged.

Amauromyza labiatarum mining White
Dead-nettle. Roadside verge near
Daventry.  30 October, 2014
The culprit was an Agromyzid fly, Amauromyza labiatarum. It is a fly whose work I often encounter and certainly I noted it back in Byfield. Referring to Kenneth Spencer's book on the Agromyzidae family I read: "All Agromyzidae are exclusively phytophagous ...(the larvae)...frequently forming a characteristic feeding track or mine." The flies themselves are tricky to identify, it often being necessary to remove the genitalia of the adult for microscopic examination. Fortunately the mines are distinctive and  usually confined to one or a few closely related plants.

Other plants - brambles, Mouse-ear Chickweed - were in flower but my eye was  next attracted to fruit.

Spindle, Euonymus europaeus, in a roadside hedge.
Daventry. 30 October, 2014

The sealing-wax pink fruit of Spindle, Euonymus europaeus, were adorning the roadside hedgerow, splitting open to reveal their orange contents. The seeds are enclosed in an orange sheath, making them very striking. Although Spindle is a native species, these shrubs had clearly been planted by a thoughtful landowner. Excellent!
Coprinus comatus on a grassy verge.
Daventry, Northants. 30 October, 2014

On an area of disturbed earth a quite different organism was in fruit. This was Lawyer's Wig, aka Shaggy Ink Cap, Coprinus comatus. The word 'coprinus' means living on dung, but it is more often found on organic-rich soil and dung is by no means a requirement. Not only is it very common in Britain, it is found world-wide, even as far as New Zealand. The fruiting heads are deliquescent, dissolving to an inky fluid after a day or so, but when young and firm they are edible and delicious.

Mesembrina meridiana aka Noon Fly on railings.
Daventry, Northants. 30 October, 2014

On a white-painted rail a Noon Fly, Mesembrina meridiana, was loafing. With its glossy black body and orange wing-bases this is a striking and easily-identifiable insect. It is quite closely related to the House Fly; its larvae live in cattle droppings.

Throughout the walk ladybirds kept blundering into my head. There were hundreds of them about, and all but one was a Harlequin Ladybird, Harmonia axyridis. The one exception was a 7-spot Ladybird. On the previous day I had recorded a Kidney-spot Ladybird, Chilocorus renipistulatus, but overwhelmingly it has been Harlequins. Very worrying. For those not aware of the situation, the Harlequin Ladybird only arrived in Britain a couple of decades ago. It eats the larvae of other ladybirds and is surely now the commonest of these beetles in Britain.

Larva of Harlequin Ladybird on Cherry Laurel.
Edge of Daventry, Northants.  30 October, 2014

A few Harlequin larvae were around but this late in the year most had pupated. This larva appears to be fully grown and is probably about to settle down and begin the pupation process.

Finally, for those who hoped to escape without another photograph of a leaf miner...hard luck!

Emmetia marginea mining a bramble leaf near
Daventry, Northants.  30 October, 2014

This, mining a bramble leaf, is Emmetia marginea, a moth with the odd name of Bordered Carl. Sometimes called Coptotriche marginea, this is a member of the the small family - in Britain at least - the Tischeriidae. It is widespread but I don't often come across it.

So, another mixed bag, together with numerous flies which I still have to get under the microscope. For me, a good day.

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