Island Life

I nipped out today with a specific leafminer target. Given my rank amateur approach to leafmining, most of my finds have generally been a case of looking at and finding mines on whatever trees I come across and then trying to work out what they are - rather than looking for a specific target on a specific host. Anyway today, the host was Aspen. I nipped over to Croft Hill where there are a couple of decent stands, and noted that there were plenty of golden yellow leaves still on the trees ....

But actually, I had no intention of looking into the foliage. Instead, I was intent on looking through the masses of fallen leaves ....

It seemed like looking for a needle in a haystack initially, but I soon spotted what I was after ....

If you look carefully, you'll see that amongst the numerous yellowed leaves with signs of decay is one with a distinct green flush - a so-called green island. Before long I was finding lots of them.

What you may also have noticed on the above closer shots, at that right at the base of the green island, right between the mid-rib and a vein and into the petiole is a mine.

This is the mine of Ectoedemia argyropeza, and happily as you can hopefully see in the above at least one of the several leaves I brought home was tenanted. The early part of the mine actually causes a gall in the stem and petiole, and some of the mines that seemed to have been vacated may just have the larva in the petiole where they retreat in the day. Apparently.

This species is thought to be parthenogenetic in the UK, which perhaps explains the wholly daft vernacular 'Virgin Pygmy'.

As you can see here, I got lucky with one leaf having two mines.

There are some very complicated scientific explanations for how leafminer larvae create these green islands, which remain photosynthetically active, using bacteria. Like this one.

This is a new species for me. There are very similar mines to look for created by closely related Ectoedemia spp. on hybrid Black Poplar (E. hannoverella, no VC55 records) and on either White Poplar & Grey Poplar (E. turbidella, one VC55 record of a gen detted adult to light).