Thursday, 11 March 2021


Be On the Look-Out for ... three uncommon species found in all three of our counties which may well be under-recorded because of the time of year at which they fly.  Please let us know if you see them!

Small Eggar Eriogaster lanestris
This smart-looking moth is active now and with luck should be flying until late-April.  It is a declining species associated with blackthorn and hawthorn hedgerows and does come to light.  Its main population is in the south-west of the UK but that colony stretches into parts of Berks & Oxon.  A smaller population exists in East Anglia and that one reaches west as far as the very northern tip of Bucks, particularly around Olney and Lavendon where it was last seen in 2020.  

Small Eggar, March 2018

Mottled Grey Colostygia multistrigaria   
In contrast to the one above, Mottled Grey isn't that inspiring to look at, being a boring grey geometrid!  This is another species very much in decline in our area and it now has a marked western distribution in the UK.  However, there have been a few post-millennium records from all three of our counties so it is quite likely still out there somewhere in west Berks & Oxon or at sites in the Chilterns.  So far as I'm aware the last records for Bucks were in 2013 from the Ivinghoe hills and a site near Bradenham.  Again, it comes to light and should be active now into the second half of April.  EDIT :  A possible confusion species is the Early-Tooth-striped Trichopteryx carpinata which is more widespread locally and should start flying in April.  They are easily separated by checking the antennae (female Mottled Grey illustrated below, male Mottled Grey has antennae which are even more obviously feathered; Early Tooth-striped male and female have simple antennae).  

Mottled Grey, April 2013

Northern Drab Orthosia opima
Not really a 'northern' moth at all, Northern Drab is a much-declined species mainly of southern England which should start flying very soon and will go on into May.  Once again it is found in very small numbers in all three of our counties, mainly associated with large areas of chalk grassland across the Chilterns, such as at Aston Rowant in Oxon.  The last record for Bucks was, I believe, in 2018 from the Ivinghoe hills where it should still be present.  As with the other moths above, it does come readily to light. 

Northern Drab, April 2018

1 comment:

  1. Very helpful post Dave! I've been planning to try Aston Rowant for the latter two, but sadly can't get out there at the moment, hopefully soon.


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