Thursday 28 November 2019

First foray into mines

Hi all
Spotted these at Beaconsfield Service Station
First of all are they Mines and if they are what can you tell me about them
Iain


1 comment:

  1. Hello Iain,

    Yes, there are some Lepidoptera mines on the leaves you show. The first and most important thing by far is to correctly identify the food-plant. Without that basic knowledge you won't get far at all with mines.

    The leaves you show look to me like Hazel. If that's correct then there are only three "corridor" miners to choose between: Bucculatrix demaryella, Stigmella floslactella and Stigmella microtheriella. Bucculatrix species only make a short mine in their earliest instars and then leave it to feed externally until fully grown, so that narrows down the choice on your leaves even further to just the two Stigmella species. To separate them you need a clearer view of the frass (caterpillar poo) inside the mine which unfortunately your images don't show well enough. To get such an image you need to have a light source behind the leaf. The easiest way is to collect the leaf and photograph it at home. I tape them to the inside of a window and take an image looking out with the flash off.

    It is not always just the general pattern of the mine and the frass which you need to see. Sometimes you'll need to find which side of the leaf the egg has been laid (they're usually visible with a hand lens) or maybe you'll need an active mine with a caterpillar present.

    There are other types of mine too, blotches within which species such as the Parornix, Phyllonorycters and the like feed. In fact on your lowest leaf there's a triangular-shaped blotch in the centre not far from the leaf stem and that looks to me as though it might have been an early mine of Parornix devoniella.

    Have a look at the invaluable UK Leafmines web-site:
    http://www.leafmines.co.uk/index.htm
    Click on "Mine Guide" and read the introduction which will explain things better than I can here.

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