Friday, 5 May 2017

Lombardy Poplars

The Black Poplar, Populus nigra, has always been rare in Northamptonshire and, according to the Forestry Commission, is the most endangered native timber tree in Britain. Yet earlier today, in Byfield, I photographed several specimens. Of course, there is a catch...
Lombardy Poplars edging the Brightwell Playing Field, Byfield.
5 May, 2017
I did indeed photograph Black Poplars but they were specimens of Populus nigra 'Italica', commonly known as the Lombardy Poplar. This fastigiate form is hardy, easy to grow and quite architectural; rare it is not and must rate as one of the most recognisable trees in Britain.
For insects and other organisms the fact that it is just a form of  the 'real thing' is of no consequence, so when I strolled over to take a closer look I was not surprised to find some poplar-loving creatures present. In several places the petioles (leaf stalks) were twisted into a helix of two or three turns.
These curiously coiled petioles on poplar are the work of the aphid'
Pemphigus spyrothecae. Byfield, 5 May, 2017

This was the work of an aphid, Pemphigus spyrothecae. It is common in southern England and I have located it elsewhere in Northamptonshire. The aphids could not be seen and will not emerge from these swollen tissues until around August.
A couple of Yellow-barred Long-horn moths, Nemophora degeerella, were on the foliage but took to the wing as soon as I raised my camera. This was a pity since the males, with the antennae 3-4 times the length of the wings, are a remarkable sight. However they are common and I often see them in the nearby pocket park, so I may have an opportunity of photographing one later.
The edge of one poplar leaf blade was rolled under and the tissues were reddish. This is the work of another aphid, Thecabius affinis, one of the numerous species to have a secondary host forming part of its life-cycle. In this case it can be one of several buttercup species.
Also on poplar, the gall caused by Thecabius affinis.
Byfield, Northants. 5 May, 2017
A trio of beetles completed my quick survey. All proved to be of the same species, Phratora laticollis. This is very common on poplars and seems particularly abundant hereabouts as it turns up regularly on poplars in the vicinity including aspen trees, Populus tremula, in the pocket park. It is a smart, glossy beetle with blue-green iridescence, but I have not included a picture as this colouring failed to show in my photographs.
Poplars and their hybrids, like their close relatives, willow species, play host to a wide range of insects and a close look is generally rewarding - if you are a naturalist.

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