Second generation Phyllonorycter coryli and Phyllonorycter nicellii on Hazel.

 

Now we are into September we should be seeing the second generation mines of these two Phyllonorycters. 

I do not intend to try to rear any of these larvae or pupae through to adults as they will be going into diapause and it will be many months before they are supposed to emerge as adults next summer.  

There are plenty of fresh-looking mines of Phyllonorycter coryli, so I am assuming these will all be second generation, and there seem to be even more than I found of the first generation. 

This is a closer view of this leaf. Interesting to speculate what is eating the larger holes in these hazel leaves. It looks like earlier caterpillar damage!

A closer view of two P. coryli mines on a different leaf, the further or upper one being already contracted, has folded the leaf over quite sharply.  

However in contrast I found no obviously fresh mines of Phyllonorycter nicelli, so no direct evidence of a second generation in this species. However I did fine one apparently mature mine still tenanted with a pupa, so this could have been second generation. 

To compensate there is a new arrival on the scene, the mines of a Stigmella species are now very commonly found on the leaves. I am going to assume that this is most likely to be Stigmella floslactella, as the other is said to be a narrow mine.

This is a closer view of the same mine.

The following day I found these feeding marks on a separate couple of leaves reasonably close together  on a hazel bush along the knights wood path. Maybe this is the one of the tracks of two Coleophora larvae, perhaps the result of just one adult female's egg-laying efforts?

This photograph was taken of the upper surface, but the presence of the feeding holes on the underside in each of the mined areas was confirmed later using a hand lens. 

This is a closer view:

This is a useful link about leafminers, from Eakring birds.   

http://www.eakringbirds.com/mothimagescasebearers.htm