Friday 9 May 2014

Emperlings and Eriocranias

My Emperor Moth eggs from Barton Hartshorn, Bucks (see "Empressive!", 25th April) emerged last night so I now have 50+ hungry mouths to feed until the end of June.  I've decided to give them hawthorn as one of our garden bushes needs trimming back so this will kill two birds with one stone.  They seem to have taken to it with gusto.

Newly-emerged Emperor Moth larvae, Westcott 9th May 

In my experience the Eriocrania species micro-moths which feed on birch, all of which are reasonably common, rarely seem to end up in light traps as adults and the best way to gain records for them is to look for leaf-mines.  Now is the time to do so (indeed it may already be too late for some) and during a quick search near Greatmoor, Bucks today active mines of Eriocrania sangii and Eriocrania semipurpurella were not difficult to find.  E.sangii is perhaps the easiest to recognize because the larvae are almost black.  See http://www.leafmines.co.uk/html/mine-guide/birch.htm

Mine of Eriocrania sangii on birch, Greatmoor 9th May

Dave Wilton

2 comments:

  1. what do you do with your Emperor eggs? Baste them in a microwave to get them to hatch early? My females are just finishing off egg laying.

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  2. Maybe things happen differently in Herefordshire! Of course, as my eggs this time came from a wild female who came to the trap (in a new 10k square, so at least something has been achieved this year), I don't know over what period she'd disposed of her other eggs, or indeed if she had any left when I released her. The eggs laid on my egg-box were as ever left entirely alone indoors until they hatched, which took the usual 14-16 days (14 in this case). No microwaves involved!

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