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......
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......
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