Willow twigs and aphid eggs

Here are some views of Salix viminalis twigs and buds, showing the greyish hairs on the twigs and buds. The buds have just one outer bud-scale, and are flattened against the twig, as is characteristic of the genus.

In this closer view you can see the placement of the lenticels on the "shoulders" of the buds - perhaps a very useful place for them to be metabolically? It is also interesting to see the "lipped" appearance of the buds, which may, or may not, be somewhat characteristic of the species - they may have dried out a bit of course. And, is it genuinely S. viminalis?

The other thing is the three small horns on the leaf scar - the two outer ones are smaller and "sharper" and sometimes appear to have a circular scab just to the outside of the horn, and I am finding it difficult to interpret this pattern. One possibility is that the circular scab results from the abscission of a stipule - as suggested on this webpage. The horns would therefore perhaps be "now blocked off" veins? If so the two outer ancillary ones may join with the central main one to form the midrib of the leaf, but perhaps branching off again in the lower quarter or third of the blade. Or could they be for stipule venation?

Several of the twigs had aphid eggs on them, quite glossy black by now.

Here are two more eggs

This is a twig from one of the yellow-orange Crack-Willows, Salix fragilis, on the Southern side of the Ocean lake. The stipule scar is very obvious and the bud itself is quite solid-looking, almost thorn-like at this angle. So many of them seem quite sharply colour-banded.

This is another twig of Crack Willow, this time with one partly diseased bud, a not uncommon sight in my limited experience.

This is a Dogwood twig, showing the spiky opposite unscaled buds that look to me like "witch's fingers"

Ambling around Leybourne

At the first bend on the Ocean path, there was a small group of Long-tailed and Blue Tits, and luckily I spied a Chiff-Chaff in with them, mainly by its different movements. Wonderful. I saw several similar groups of Tits on my way around, but didn't see any sign of any other Chiff-Chaffs, or indeed that one again.

On the causeway I spied two Redwing, and quickly realised that I had already seen one earlier, flying over the water towards me and the small group of Tits, noting its pale face and chin.

A lovely sunny afternoon, and I tried to look for aphid eggs, but failed (almost) entirely. Right at the last minute, by the door to the toilet I did find an oval egg of some sort on Field Maple, quite likely an aphid egg.

However, despite this failure it was so interesting to see the aphids hanging from the Grey Willow over by the West Scrub. Probably dead individuals of Tuberolachnus salignus, the Giant Willow Aphid.

Adult aphids are supposed to remain active over the winter period, through January and February. There appeared to be wingless individuals attached to the twigs further along.

Incidentally, all aphids appear to have co-evolved with a bacterial partner, Buchnera aphidicola, that helps them cope with their plant phloem-sap sucking lifestyle. Aphids, being typical animals, have distinctly poor chemosynthetic ability. However their diet is very limited in amino-acid content, for example being largely (not entirely) limited to a few non-essential amino acids like Arginine in the Phloem sap. So how do aphids get the essential amino-acids they cannot synthesise, such as Trytophan for example? The bacteria embedded in their many thousands in huge mycetocytes (cells) in their bacteriosomes (organs) are very limited nowadays, as they rely for much of their structure and nutrition on their host aphids. But they CAN produce (for example) the essential amino-acid Tryptophan from the non-essential Arginine, which they do.  Buchnera over-produces the essential amino acids which are needed by its aphid host, but none of the non-essential amino acids, for which it depends on its aphid hosts, like most of its other nutrients. This partnership goes back possibly 180 - 250 million years. The bacteria in their bacteriocytes are passed by cellular migration across the ovaries into the developing embryos (or are expelled from bacteriocytes to migrate into eggs in the sexual stage?) or......

A quick whizz around a breezy access trail and reservoir

At nearly 4 pm I set off with Monty through the village to the start of the Access Trail, across Great Court, then down towards Victoria Lane, Malt Cottage and the Reservoir, then back along the River Bourne, the Green Lane to the Red Pond and then reversing our course back through Great Court to home, getting back towards 6 pm.

I found a Periphyllus aphid species on the Sycamore, Acer pseudoplatanus, on the Access Trail together with aestivating nymphs, and again on one of the trees just downstream of Goldhill Mill, together with a small midge species. On the English or Atinian Elm, Ulmus minor 'Atinia', there was evidence of a leaf-curling aphid, presumably originally caused by Eriosoma ulmi, but now apparently inhabited by a "normal" green aphid.

There were apparent fledgelings for the Greylag/Whiter Goose, and for another pair of Greylags on the reservoir. A small group of Goldfinches were in the tall hedge running South of the reservoir to the River Bourne. I saw one Swallow over the field to the East of the Bourneside bridge, and one Swift over the Acccess Trail. There were Blackcaps, Chiffchaffs, Robins and Blackbirds along the Green Lane section of the Access Trail. Woodpigeons and Chaffinches were everywhere.

On the bank of the reservoir, the trefoils were in good flower. On the way back along the Church footpath I checked the Bittercress on the side of the tarmac - and it was Hairy Bittercress of course, with only four stamens. There was also Green Alkanet and Common Fumitory along the same path.