Saturday, 30 May 2015

Two unusual mines

I do most of my mine recording in autumn, focussed on Stigmella and Phyllonorycter, and haven't really bothered with spring Eriocrania mines on birch before.  This is a difficult genus to identify as adults, but the larvae each have distinctive characters so identifying tenanted mines is reasonably accurate.  So far I had seen three species this year: unimaculella (new for Carms) at Cnwc y Llwyn, sangii (dark grey larvae) in the Eastern Cleddau Valley, and semipurpurella at Mynydd Mawr.  Yesterday I looked at the E unimaculella colony in our wood, where the mines are large and the larvae have left, and noticed several much smaller mines which are still tenanted.  These have a long section of linear frass at the start and pale-headed larvae, which couples with their rather late season to indicate E salopiella.

Eriocrania salopiella (left) and E unimaculella (right),
the unimaculella were identified 2 weeks ago when tenanted

A couple of days ago George emailed me a photo of the mines of Incurvaria pectinea in a Hazel leaf from Monmouthshire.  I had this species in the back of my mind as we walked up along the edge of our field, with Bea hiding among the hazels of the grown-out boundary hedge and trying to jump out at me.  To my surprise I noticed one Hazel leaf with 5 roundish, tenanted mines on it.  They do appear to be early instar I. pectinea larvae rather than any species of beetle/sawfly illustrated on the Leafmines website.  If so, this is a new moth for Carmarthenshire.

5 comments:

  1. The larvae (dark head and midline) look just like those I saw in VC35 last week, and those leaves also had cut-outs (used to make the portable case in which they feed on the ground after the mining phase) which confirmed them as Incurvaria.

    I also noticed pectinea mines on hazel at Castell Coch on my day off yesterday. I guess it's reasonably safe to record them as this species rather than any other Incurvaria if on Hazel. I masculella has been recorded on Hazel in mainland Europe but not in the UK as far as I know. I'm not quite sure what I oehlmanniella feeds on - books say Bilberry but I've seen adults in limestone districts with none of this plant.

    Like you I've never done much with spring mines - I must try and do better with the birch-feeding Eriocranias!

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  2. I like these informative posts of yours, Sam - please keep it up as it helps us all improve our `moth knowledge`. I`ll be doing a catch-up post (or posts) on Monday (when it`s supposed to be wet!). I had Argyresthia trifasciata - beaten off cypress - this afternoon; a certain record (have just checked the specimen). It`s not the other cupress job (cupresella).

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  3. That's the first VC44 record of Argyresthia trifasciata. By coincidence, Nick Felstead had it new to VC35 this week as well.

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  4. Thanks Sam. I`ve been looking for this moth for several seasons as I am confident that I had it back in 2006 - though I certainly cannot claim that earlier record, without specimen or photo. I was n`t bothering with micros back then, but clearly recall a little three-striped job that I beat (with Blair`s shoulder-knot caterpillars) from my garden Lawson cypress (not leylandii). The tree was cut down in early 2007.

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  5. PS - I`ll post a photo of it on the blog on Monday.

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