NZAC: Caring for (curating) NZAC
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.
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
- transferred to a storage container.
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).
The second part of curation is sorting, or "systematics-in-the-tray".
- examine the specimens
- name them (usually on a new label)
- rearrange the specimens into systematic groups - usually by species, gender, and place of origin.