Curation

Killing

I have an aversion to killing anything without a purpose. Therefore, I try to kill as few beetles as possible and only kill voucher specimens for my collection, or specimens which I cannot identify live. Having a reference collection of beetles is a valuable tool in species identification, and justifies taking specimens.

Beetles can either be killed by placing them directly in a killing fluid such as 70-100% ethanol, propylene glycol or ethylene glycol (antifreeze). Remember that antifreeze will stain specimens and may make species identification more difficult. Beetles can also be killed in the field by placing them in water (salt water to aid preservation) with a drop of washing-up liquid to break the surface tension. Beetles may also be killed using ethyl acetate: a piece of cotton wool should be placed in the base of a collecting bottle, to which a drop of ethyl acetate is added. The fumes will quickly kill beetles. Alternatively, beetles can be frozen live either in a killing fluid or 'dry'.

Storing

Once dead, if you are not planning to mount beetles immediately, they should be stored in a freezer. Beetles are best stored in 70% ethanol in the freezer.

Drying & Mounting

Before mounting beetles, they may need to be relaxed in order to make sure that legs can be positioned correctly. To do this, plunge beetles into warm-hot water containing detergent - the stronger the better (Decon 90 is the best). This will also help clean beetles and help prevent the build up of fatty deposits on the specimen. The best way to clean dirty beetles (like dung beetles) is to place them, along with warm water and detergent into a commercially-available sonic jewellery cleaner for ten minutes.

As a rough guide, beetles more than 1cm long should be direct-pinned and beetles less than 1cm long should be either card-mounted or point-mounted using commercially-available insect cards. Direct-pinned beetles should be pinned through the front of the right elytron using the smallest pin possible to minimise damage to the specimen. A range of plastic-headed pins from size 0-2 (available from entomological suppliers) are usually ok for the British fauna. Pinned beetles should be pinned to blocks of polystyrene or such-like, covered with a sheet of kitchen roll. Beetles should be pinned right down onto the kitchen roll and polystyrene to aid with positioning. The kitchen roll also soaks up any excess seepage from specimens during drying.

Carded/pointed beetles should be glued to the cards using conservation-grade PVA glue. Point-mounting is best, as it allows you to view the underside of the beetle, where many identification characters are located. The card you use should be acid free to ensure longevity. Stainless steel pins are used for card/point mounts and the card/point should be at a defined distance from the top of the pin, using the highest setting on a mounting block. These specimens must then be dried thoroughly, otherwise they will go mouldy.  If you don't have an insect drying cupboard, popping them in your airing cupboard for a week should do the job!

A home-made drying cupboard consisting of a modified bedroom cabinet, lined with cooking foil, 
containing a wardrobe heater

Locality labels (acid-free card) should be added under the card/point. The convention at the Hope Entomological Collections, Oxford University Museum of Natural History is:

Font: Times New Roman, black, bold, 3.5pt

Page layout (A4): x 8 columns, column spacing 0.5mm. format page margins to 1cm

Paper: acid-free, 160g/m²

Locality names: taken from OS Landranger map series (1:50 000). If the site name is not on the map, use the nearest name to the site as well as the site name.

Label format: maximum of 6 lines per label, use a second label if required.

     COUNTRY: Vice County (VC No.)

     Locality

     NGR, Date(s) collected (Roman numerals for month)

     Collecting info. (or on new label)

     Collector(s)

Another label can be added with habitat information e.g.

     sheep grazed pasture

     sandy soils

     dung baited PF trap

Curating

Beetles should be stored in purpose-made (or hand-made) storage cabinets or boxes. These are available from entomological suppliers and vary in price and quality dramatically! All collections should be checked regularly for pests such as the museum beetle Anthrenus spp. which can destroy entire collections in no time at all. If any evidence of damage is discovered, drawers/boxes should be wrapped in plastic bags and frozen for more than 2 weeks. Dried specimens must be kept in low humidity to prevent them going mouldy.

Many thanks to Darren Mann from the Hope Entomological Collections in the University of Oxford Museum of Natural History for teaching me how to curate beetles. All the information above comes from his years of experience as an entomologist.