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Research work on individual groups of animals in the collection can only
be as good as the material it is based on.
- A few battered specimens from a limited number of sites are less valuable
than a truly representative sample of the species as it occurs in nature.
- Specimens do not outlive their usefulness as they become older: in
fact, they become more valuable as:
- reference specimens of completed studies;
- representing populations from habitats that have been so altered
that the species no longer exists there;
A lot of time may be required, therefore, to curate (care for and work
on) older specimens.
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Preparation
Preparing individual insects for study is a very exacting process, because
it is essential to have all the important features visible.
For instance, moths are usually pinned with the wings spread. This requires
the specimen to be:
- relaxed (softened)
- carefully pinned out on a setting board
- labelled
- transferred to a storage container.
A competent insect preparator working with small moths could probably deal
with only about 100 in a day.
The smallest insects:
- may be "double-mounted" on strips of plastazote foam using tiny pins;
- glued on card points;
- may be mounted on glass slides for study under the microscope, a lengthy
process involving a sequence of chemical treatments and careful manipulation.
Perhaps as few as 8-10 permanent slides can be prepared by one person
in a working day.
Because insects in collections tend to deteriorate, they must be protected
from anything that can reduce their scientific value.
- Soft specimens and those in bulk storage are:
- "pickled" in 70% ethanol and thus prevented from decomposing;
- kept in a darkened room to reduce phytochemical changes.
- For pinned specimens the environment is controlled:
- to prevent excessive humidity and temperature fluctuations (which
leads to the growth of fungal mould);
- to reduce ultraviolet radiation (which causes photochemical changes,
e.g., decolouration).
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Sorting
The second part of curation is sorting, or "systematics-in-the-tray".
Specialists:
- examine the specimens
- name them (usually on a new label)
- rearrange the specimens into systematic groups - usually by species,
gender, and place of origin.
This process makes a vast store of information available on ecology, distribution,
and geographic variation.
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