Friday, 22 September 2017

God bless the hogweed...

...and all who sail in her.
I visited Woodford Halse earlier today for a much-needed tonsorial operation in the form of a Number 4 back and sides.  My return to Daventry was via back roads and, on a whim,  I stopped to examine the Hogweed, Heracleum sphondylium, still flowering in some profusion at the roadside.
Hogweed is one of the most familiar of our roadside plants. Near Woodford
 Halse, Northants. 22 September, 2017

For entomologists it is an extremely important plant, the broad umbels each acting as a dinner table for insects of several orders. In fact around fifty of the plant's visitors contain the words heraclei or heraclea in their specific epithets [Ref 1]. We take hogweed for granted yet, apart from these attendant insects it is of interest in other ways. For example, in the early years of the 20th Century experiments were conducted to extract sugar from the stems. They were not effective with 40 pounds of stems only yielding about one pound of sugar[Ref 2]. Nevertheless it is a very nutritious plant once fed to pigs, hence the common name, and in winter the young 'spears' may be cooked like broccoli.
Its close relative, the infamous Giant Hogweed, Heracleum mantegazzianum, is well-known for causing photo-dermatitis when handled, making the skin extremely sensitive to light and resulting in damage similar to burns and sometimes causing serious scarring. What is less well-known is that similar, though less severe, damage can result from handling hogweed. As children we would use the hollow stems of this plant as peashooters as an alternative to Cow Parsley. How we got away without damaged lips is a mystery.
A few other plants were in flower including dandelion. It is well known as a diuretic with one of its of names being Piss-in-the-bed (in French Pis-en-lit) but this does not bother its numerous insect visitors such as this bee, delightful in its creamy fur tippet. Bees aren't my field but I suspect it is an Ashy Mining Bee, Andrena cineraria. 

There cannot be a scintilla of doubt about the identity of pair of insects I observed mating in the grass nearby. Roesel's Bush-cricket, Metrioptera roeselii was, until the early 20th Century found only in small regions of south-east England but in recent decades it has spread rapidly to become rather common further north and west. The U-shaped creamy border to the thorax is very distinctive. It is sometimes called Rousel's Bush-cricket.

Roesel's Bush-crickets in copula. Near Woodford Halse, Northants.
22 September, 2017
Crickets belong to an order of insects called the Orthoptera. It is a very large order but the only other member I found today was a Meadow Grasshopper, Chorthippus parallelus. With the disappearance of meadows across Britain it is, although still common, far less widespread than it was prior to World War Two.

So, what started off as a brief pause guided by impulse (and the need to eat my packed lunch) turned out to be a very productive stop of an hour or so. Oh dear, yet more incineration of midnight oil beckons as I begin to identify my specimens.


1.  Wright, J (2016) A Natural History of the Hedgerow   Profile Books, London.

2. Harley, M (2016) Wonderful Weeds   Papadakis Books

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