Friday, 9 October 2015

Frustration - then a surprise

Chris and I were tied down by jobs all morning but sun shone from a clear blue sky. With a free afternoon I was looking forward to a visit to Kentle Wood or Newnham Windmill. But it was not to be.

As Chris was off to Byfield for a meeting the world was my oyster and I set off for Kentle Wood. I had managed about five hundred yards before frustratingly, threatening clouds gathered and, as on 8th October, prospects were not good. Time for Plan B!

Where the A361 joins the A45 a moderately complex junction exists. An 'island' of land, with grasses, herbs and shrubs exists and there the hand of man has never set foot - or only occasionally - and I'd had an eye on it for some time. It was easy to reach and I set off, virtually going back home in the process.

Stefen Hill is an area of attractive houses, with plenty of open space. I guess the area was developed when the land was relatively cheap. Here the horror of Leyland Cypress hedges has been replaced by the lovely blue-green of Lawson's Cypress, Chamaecyparis lawsoniana. An inappropriate name as the prefix 'chamae' means 'low' but, given a chance, these trees will reach a towering 140 feet.

Lawson's Cypess, Stefen Hill, Daventry.
8 October, 2015

Despite being a hybrid the Leyland Cypress does carry a few cones; Lawson's Cypress bears huge numbers and, whereas the former is very limited in terms of wildlife the latter can receive many visitors. I decided to investigate.

Juniper Shieldbug, from Lawson's Cypress. Stefen Hill,
Daventry. 8 October, 2015

The very first sweep of my net yielded the nymph of a Juniper Shieldbug,  Cyphostethus tristriatus. Once a great rarity, restricted to juniper shrubs in Surrey and adjacent counties, it began sometime in the 1960's to colonise Lawson's Cypress trees in local gardens. Soon it was spreading rapidly, but this seems to be the first record from the Daventry area.

Duller, but rather more interesting, were nymphs of a groundbug, Orsillus depressus. It was unknown in Britain until the late 1980's but has also spread quickly. It appears to be confined in Britain to Leyland's Cypress.

I was also surprised to capture two specimens of the picture-winged fly, Tephritis formosa, not because it is rare - it is quite common - but not usually associated with cypress trees. One specimen could have been a stray - but two? It is normally associated with sow thistles, but there were no obvious specimens nearby.

Red Admiral, Vanessa atalanta on ivy. Daventry
8 October, 2015

Ivy was in flower and, when the sun broke through, it received visitors including this Red Admiral (the butterfly, not a Russian naval officer). Hoverflies were also feeding but I didn't attempt to secure any.

I was intrigued by the mottled colours assumed by Sycamore, Acer pseudoplatanus, leaves. The white spots are, according to books, caused by powdery mildew, but these look quite different and I suspect a Rhytisma species.

I guess a species of Rhytisma is the culprit here too. The best known is Rhytisma acerinum. well- known as the cause of Tar-spot, but related species may cause different discolorations.

I pressed on to my traffic-island target and received a surprise. It quickly became obvious that the area was remarkably rich in species. At this late time in the year expectations were low, but I realised that this patch would not only need a close examination now, but merits further visits. 

A patch of Oxeye Daisies, Chrysanthemum leucanthemum, was in bloom but, although the sun deigned to make an occasional appearance, it had no insect visitors.

Wormwood Pug, swept from ragwort. Roadside at
Daventry, Northants. 8 October, 2015

Oxford Ragwort was also in bloom, and from it I swept this caterpillar. It is the Wormwood Pug, Eupithecia absinthiata. It will feed on a wide range of plants, obviously including wormwoods, Artemesia species, but ragworts are frequently chosen.
Long-winged Coneheads were common on roadside
vegetation. Daventry, Northants. 8 October, 2015

Finally, before the tolerance of my readers is too strained, I would mention this Long-winged Conehead, Conocephalus discolor. Though obviously related to grasshoppers, they display several differences. This is a female, and her long ovipositor to the left is very obvious. Three dark spurs beneath the hind legs confirmed the identification. I needed to bring it home to confirm the species and it had failed to survive the experience.

So, with fifty or so flies to sort through (all microscope jobs) I made my way home, resolved to pay another visit next spring.

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