(Leaf) Mining in NW Gwent

Quick stops at Bryn Bach Country Park and Waun y Pound helped slightly with rebalancing the eastern bias of leaf mine recording in VC35.  It was slim pickings, with just 13 species shared between the two sites.  Most were on Hawthorn, with a couple on Rowan, Oak and Willow.  Perhaps the biggest surprise was Phyllonorycter viminiella on introduced Osier.  Searches of several birch trees produced no moth mines, but an abundance of Sawfly blotches. 

I wonder whether the Micro fauna is limited by the number of host tree species that occur naturally in these areas; most of the trees/bushes at Bryn Bach were in obviously planted landscaping blocks.  Are the common miners of lowland Monmouthshire, such as Phyllonorycter coryli and Stigmella floslactella present on almost all Hazels in the Valleys in the way they are in the east?  More questions than answers from this brief visit.