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Celypha arbutella (Lepidoptera: Tortricidae) -
a new micromoth for Essex (and England?)
CHRIS GIBSON
1 Dove House Cottage. Oakley Road. Dovercourt, Essex CO 12 5DR
In the morning of 8 August 1997, I was
examining the contents of the previous night's
MV moth trap in our garden at Dovercourt
(TM 226 304), and came across an unfamiliar,
small but distinctive tortricoid moth. It had an
overall gingery-purple appearance, broken by
metallic blue striae which were easily visible
to the naked eye. Reference to Bradley,
Tremewan & Smith suggested it was
Olethreutes arbutella, although this
identification was rapidly demoted to
provisional when I noted its distribution -
'mainly a northern mountain species' from the
Scottish Highlands and Islands - and food
plant Arctostaphylos uva-ursi (bearberry), not
a native plant in lowland Britain.
The specimen was retained, and passed to
Brian Goodey who concurred as to its
apparent identity, and thence to K. R. Tuck at
the Natural History Museum, London.
Eventually word came back - it was indeed the
species we had suggested, although with a
newer name Argyroploce arbutella.
Subsequently, its name has mutated yet again,
to Celypha arbutella.
The distribution of the moth and its restriction
to montane habitats poses several questions
about its appearance in Dovercourt, notably
how did it arrive there? There are perhaps
three main possibilities. Firstly, its food plant
is grown as an ornamental garden plant,
although not widely so in Essex. Could it have
emerged from garden stock? Certainly we
have never grown bearberry. and a general
search of the neighbourhood failed to reveal
any. A factor possibly in favour of
horticultural origin is the late date of the
record - according to the literature, the normal
flight period of C. arbutella is May and June.
Secondly, we are situated within 5km of
Harwich International Port, where ships dock
from, amongst others, Scandinavian ports. The
moth is known to occur in Scandinavia, so it is
conceivable that it was a ship-assisted
immigrant.
A third and most interesting possibility is that
it was a natural, wind-blown vagrant from
Scandinavia, although it is not reported as a
dispersive species. Reference to my moth
trapping log indicated that for the night in
question, and indeed for at least the previous
four nights, the wind was north-easterly, on
three of those nights blowing strongly, with
minimum temperatures of 14 to 170C.
However, there was absolutely no indication
of associated Scandinavian migrant moths at
the same lime. Indeed, the only immigrant
moths noted were a very few silver Y
Autographa gamma and a strong influx of
diamond-back moths Plutella xylostella from
6 August.
The only previous English records, both
unconfirmed, arc from the north of the
country. Given that its food plant occurs
locally in the northern uplands of England, it
would perhaps not be surprising if the C.
arbutella was resident in the Lake District or
Pennines. But whatever the source of the
present record, it represents the first record for
Essex, and possibly also the first for England.
After now five years' trapping in our garden
and a list in excess of 700 lepidoptera species,
it is our least expected moth so far - proof, if
any were needed, that a moth trapper's
expectation of the unexpected can prove to be
fully justified.
Essex Naturalist (New Series) 16 (1999)