Little
understood and unique amongst the British moths, the
China mark moths (of the Pyralidae family) live
underwater during their immature stages. During July
and August, these small, light coloured moths are 'on
the wing' and active during warm summer evenings along
the waters edge.
Still
water and plenty of floating leaves are the ideal habitat
for these moths. Their eggs are generally laid on the
underside of floating leaves. Once hatched the young
larva tend to mine into the leaves for both shelter
and nourishment.Wave a net through waterside vegetation,
especially still water, at this time of year and you
could catch any one of five different species.
- Brown china mark (Elophila nymphaeata).
The largest of the china moths with a wing span between
25 and 33mm. Common throughout Britain it prefers stagnant
or slow moving water.. It particularly likes living
in habitats where there are floating leaves such as
pondweed, water-lily or frogbit. The larva will make
a small oval and flat case from pieces of floating leaves.
The pupal cocoon is attached to plant stems or leaves
both below and above the water surface.
- Ringed china mark (Paraponyx stratiotata).
Slightly smaller than the brown,wing span being 22 to
28mm, the female ringed china mark is larger than the
paler male. Both the sexes fly freely during dusk but
the female is less easily disturbed during the day.
This species is again widely spread but becomes much
more common further south. The ringed china mark is
seldom found north of Yorkshire and Lancashire. The
larva makes a much more open shelter than the brown
and its cocoon is always found on submerged stems. The
larva is a specialist feeder concentrating predominantly
on pondweeds, canadian waterweed and hornwort.
- Beautiful china mark (Paraponyx stagnata).
Very similar in size, 20 to 25mm, to the ringed china
mark, this species is commonly found along the banks
of rivers and lakes. This species tends to fly low over
the water surface and it can travel a fair distance
from it's breeding grounds. The young larva will mine
into and feed on mainly bur-reed and occassionally water
lily before making a case out of leaf pieces. Its cocoon
can be found attached to submerged or partially submerged
leaves.
- Small china mark (Cataclysta lemnata).
Smaller than the previous species (18mm-24mm), the small
china mark is associated, as you would expect from it's
Latin name, with duckweed.There is a big difference
between the male and female of the species with males
having a wing span of 18-19mm and the females wingspan
usually between 22 and 24mm. It is usually found in
and around ponds and small bodies of water with ample
duckweed. The larva will build a case from the duckweed
fronds and the cocoon, found just below the water surface,
is often covered with fronds.
- False caddis fly (Acentria nivea). The
smallest of the china moths. The female usually only
have immature wings and they rarely leave the water.
It will be the males that are seen flying and swarming
around the waters edge. Mating takes place at the waters
surface. The larva will make loose cases from plant
species and the cocoon is found attached to submerged
stems.
Of
course, like so many other species, global transport has
introduced a number of the remaining 10 or so species
into Britain. These species are thought to have first
started appearing in 1967 when Parapoynx obscuralis
was first discovered at a nursery in Hemel Hempstead.
It is thought that they were brought into Britain in a
cargo of water weeds from Maryland USA.
But it wasn't
really until the 1970's that many exotic china marks were
imported, predominately through the gardening trade. A
number of these species seem to have been imported, unintentionally,
from the Far East but others, such as Oligostigma polydectalis,
could have originated in Australia.
Fortunately, it
doesn't appear as though these exotics are having any
effect on our native china moth species. And that means
we can enjoy their presence here in the UK. Indeed, it
adds enjoyment to the study of this family of moths which
is still relatively little understood.
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