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(Coleoptera, Diptera, Hymenoptera and Lepidoptera)
by
Brian Pitkin, Willem Ellis, Colin Plant and Rob Edmunds
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PLANTS
AND THE LAW
All
wild animals and plants are given some protection. Under
the Wildlife
and Countryside Act, 1981, which covers Britain, it
is illegal to dig up any wild plant without permission from
the owner or occupier of its habitat. Some very rare plants
are totally protected by the Act, and removal of any part
of them is an offence. If required for further study or
identification, wild flowers known to be common or plentiful
in the locality may be picked; but in general, wild flowers
should be left for the enjoyment of other people. Equivalent
provisions for Northern Ireland are contained within the
Wildlife
(Northern Ireland) Order 1985 and the Nature
Conservation and Amenity Lands (Northern Ireland) Order
1985. Where a host plant is protected under any of the
above provisions, this is noted in the keys to mines
A
Code
of Conduct for the conservation and enjoyment of wild
plants, giving further details of the Act, including the
list of protected species, is available from the Botanical
Society of Britiain & Ireland (BSBI).
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COLLECTING
MINES
Dipterous
miners are recorded throughout the British Isles. Mines
may be sought wherever their host plant or plants grow.
Some mines are very obvious and will be easily discovered
e.g. those of Phytomyza
ilicis on Holly (Ilex)
and Pegomya species on Docks and Sorrels (Rumex)
and Knotgrasses (Polygonum),
others are difficult to find without a thorough and extensive
search e.g. those on grasses and sedges
On
discovering a leaf mine, you should endeavour to identify
its host plant in situ, preferably by reference to
a field guide. British wild flowers may be identified using
either one of the numerous published floras such as Stace (2010) New Flora of the British Isles and Francis
Rose's 'The Wild Flower Key British Isles-N.W.Europe with
keys to plants not in flower' first published by Frederick
Warne in 1981 and reissued in 1991 or online at www.botanicalkeys.co.uk/flora/content/SEARCH.ASP.
It is usually easier to identify flowering plants when in
flower. Unfortunately not all mines occur when the host
plant is in flower, so it may be neccessary to visit the
site again to re-examine a host plant. However, The Vegetative Key to the British Flora by John Poland and Eric Clement [published in 2009 by the BSBI] is also very useful. There is a downloadable list of additional publications by the BSBI.
If
possible take a photograph or digital image of the host
plant in situ. Where it legal to do so, remove mined
leaves and stems avoiding unneccessary damage to the host
plant. Transfer the mined leaves and stems to a polythene
bag in which you have placed a sheet of white paper to absorb
excessive moisture. If you have been unable to identify
the host plant, collect a flowering stem and some undamaged
leaves and place them in the polythene bag with the mined
stems or leaves for later examination. If you have been
able to identify the host plant make a note of the its identity.
Write collection data, such as the name of the host plant,
location, date of collection, using a pencil on a slip of
paper and place this inside the bag. Keep the bagged mines
out of sunlight to avoid overheating.
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IMAGING
MINES
Host
plants and mines may be photographed using either a film
or digital camera. The later are preferable because of their
immediacy. My earliest images were taken using a Nikon F801
with a 60 mm macro lens on Kodachrome 25 ASA slide transparency
film which were subsequently scanned using a Canon Canoscan
2700F. I now use a Nikon D80 with a 60mm macro lens. However, any digital camera with the ability
to capture images of 3 Megapixels or more and a zoom lens
allowing at least 1:1 image to subject ratio is suitable.
Whether
film or digital, your resulting images will provide you
with a permanent record of the host plant's and mine's appearances
when fresh, when it is usually easier to observe the larva
or larvae and frass inside the mine.
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REARING
On
return to your base, carefully remove the mined leaves and/or
stems you have collected from the polythene bag and photograph
or digitally image them on a white background and, if possible,
on a back-lit sheet of glass. Transmitted light passing through
the mine will often reveal detail not apparent using reflected
light. Document your images carefully.
Any
unoccupied mines, once photographed or digitally imaged, should
be pressed using a plant press. Remember to document them.
Return any occupied mines to the polythene bag, seal it and
keep it out of the sunlight in a cool place to await the emergence
of the miners (adults or larvae) or any parasitoids. If the
mines are incomplete when collected you may wish to take further
photographs of the mines as they develope.
Species
pupating within the leaf, e.g Chromatomyia species,
will usually emerge within a couple of weeks. The pupae of
species which pupate externally can be carefully transfered
to a small plastic box lined with white paper using a fine
moistened paint brush. The white paper will enable you to
observe the puparia more easily. Some miners emerge from the
puparium within a week or two, but others with only a single
generation per year or towards the end of the year will overwinter.
The later are usually very difficult to rear out!
Leaves
and stems with empty mines, if not decomposing, should be
pressed and retained.
Brian Elliot (2007) published a short paper on rearing leaf miners (http://www.leafmines.co.uk/pdfs/news2.pdf).
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PRESERVING
MINES
Pressed
mines should be mounted on archive quality herbarium sheets,
documented and stored in a dry place. The collections of mines
at the Natural History Museum are mounted on folded A4 paper
using white gummed paper strips. Data is printed on the outside
of the folder. The folders are stored flat in card boxes in
steel cupboards.
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PRESERVING
ADULT FLIES
Adult
flies may be preserved by pinning them using micro pins or
by gluing them to a card mount or directly to a pin.....
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DISSECTING
ADULT FLIES
In
order to identify adult flies it is usually neccessary to
remove the abdomen and dissect the genitalia for slide mounting
(see https://mothdissection.co.uk/guides.php for methods).
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SLIDE-MOUNTING
Larvae,
pupae, adults and dissected genitalia may be slide-mounted.....
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IDENTIFYING
ADULT FLIES
There
are some keys for the identification of British flies published
as Handbooks by the Royal
Entomological Society of London, although they are all
considerably out of date:
d'Assis Fonseca, E.C.M., 1978. Dolichopodidae.
Freeman,
P., 1983. Sciarid flies (Sciaridae).
Smith,
K.G.V., 1989. An introduction to the immature stages of British
flies. Diptera larvae, with notes on Eggs, puparia and pupae.
Spencer,
K.A., 1972. Agromyzidae.
White,
I.M., 1988. Tephritidae.
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