Thursday, 30 July 2015

The canal side at Braunston

The morning was gloomy but the weather forecast was for a bright afternoon. Throwing caution to the winds I decided to have a mooch along the banks of the Oxford Canal at Braunston, only about four miles away. Sure enough, the sun did its bit, breaking though at around noon and encouraging me to cast a clout.

The Oxford Canal at Braunston, Northants.
30 July, 2015

The usual colourful array of boats was present, some moored beside the bank but, this being the holiday season, many more heading both north and south. The occupants, seeing my net, all advised me regarding the best stretches of the canal to see butterflies but I didn't disillusion them by pointing out that my prey was simply flies.

If you don't mind a highly poisonous boat...
Braunston, Northants. 30 July, 2015

I was encouraged to see Wild Hemlock on the bank but, though it was only a boat, I did see a few of hemlock's relatives further on.

Orthops campestris is patterned in green and brown.
Braunston, Northants. 30 July, 2015
One of those relatives was Wild Angelica, Angelica sylvestris. (The Garden Angelica, Angelica archangelica, is the species occasionally cultivated for its petioles, which are candied and used in cakes, etc.)

The umbels (flower heads) had many green and brown bugs scurrying about; all were Orthops campestris. The usual food-plant of this little (3-4 mm) mirid bug is the closely related Wild Parsnip.

The blotch-mine of Phytomyza angelicae.
Braunston, Northants.  30 July, 2015

The leaves of the Angelica bore a blotch-mine caused by a fly, Phytomyza angelicae. As is usually the case, the insect seems to cause the host-plant little damage.

On a nearby leaf was a Sponge Fly, Sisyra nigra. It is a fly I've not seen before, largely because I do little waterside recording. The larvae are specialist feeders on freshwater sponges and are therefore most often seen beside still or very slow-moving water. Foolishly I failed to photograph it.

Orthops kalmii has no green coloration.
Braunston, Northants. 30 July, 2015

Another relative of Wild Angelica is Upright Hedge-parsley, Torilis japonica. This common annual was present all along the towpath although it is by no means water-dependent. It too was being visited by a bug, Orthops kalmii. Although superficially much like Liocoris tripustulatus, the latter is nearly always found on nettles. 

Marsh Woundwort beside the canal.
Braunston, Northants. 30 July, 2015

Of course, insect visitors or not, the flowers were interesting in their own right. Marsh Woundwort, Stachys palustris, was present in abundance. It is very similar to the very common Hedge Woundwort, Stachys sylvatica, but lacks its unpleasant odour.

Meadowsweet provides a background for Great
Water Dock. Braunston, Northants.  30 July, 2015

Great Water Dock, Rumex hydrolapathum, was present too. The flowers are unimpressive but the sheer size of the leaves has quite an impact. Several interesting insects are associated with this plant but to reach out was to risk life and limb - or at least, risk a wet foot. Here, as elsewhere, it grows among Meadowsweet, Filipendula ulmaria, with its froth of cream-white flowers.

Meadowsweet leaves disfigured by the galls of
Dasineura ulmaria. Braunston, Northants.  30 July, 2015

Meadowsweet had its share of problems too, but these galls of Dasineura ulmaria, are unsightly rather than particularly harmful.


Gipsywort,  interesting rather than
spectacular. Braunston, Northants.
30 July, 2015

The dock was sometimes growing among tangled masses of Gipsywort, Lycopus europaeus. This rather unexciting plant is, like Marsh Woundwort, a member of the mint family and, dull though it may be, it attracts its fair share of insects.

The neat little flowers of Skullcap beside the canal at
Braunston, Northants. 30 July, 2015

Yet another member of the mint family, Lamiaceae, was Skullcap, Scutellaria galericulata. This plant is common throughout the canal system in the county and is worth stooping to in order to see its rather attractive flowers.

Birch Sawfly, Croesus septentrionalis, on alder leaf.
Braunston, Northants. 30 July, 2015

Alder, Alnus glutinosa, is happiest in wet conditions. Here, in places, the branches hung out across the water where dozens of larvae of the Birch Sawfly, Croesus septentrionalis, lived a rather precarious existence, skeletonising some of the leaves. Birch and alders are, of course, closely related.

Nettle-tap larva beside the canal at Braunston, Northants.
30 July, 2015

Another larva, this time a moth (Moth and sawfly larvae? Its all about counting the legs.) was feeding on a nettle. It is a Nettle-tap, Anthophila fabriciana, the adults of which are extremely common on this plant. The larvae seem not often to be photographed. 

What is the collective noun for hoverflies?
Braunston, Northants. 30 July, 2015
Thistles are always worth checking. Here a Creeping Thistle, Cirsium arvense, is getting plenty of attention. On the far right is the abundant Marmalade Fly, Episyrphus balteatus, and with it (centre) is a female Syrphus ribesii together with, far left, Syrphus vitripennis. It is fortunate that the Syrphus species are females as the males, in some cases, cannot be identified without dissection. 

I could go on with more flowers, leaf mines and butterflies but to end, a moth. This is the Yellow Shell, Camptogramma bilineata. It is not a distinctly marked specimen but the key points are all there.

Yellow Shell beside the Oxford Canal at Braunston, Northants.  30 July, 2015


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