Preparing insects

The preparation of Insects does not require particularly complicated equipment, a few pairs of tweezers are enough, entomological pins, a small brush, entomological glue and a few other accessories that we shall see later.

We shall examine the preparation of a Coleopteran and a Lepidopteran, among the groups generally most collected and studied.

If the insect to be prepared is dry, it must be softened by placing it in a “humid chamber”: any airtight plastic container, on the bottom of which we will have placed some absorbent paper or a small sponge moistened with water, on top of which we lay the specimen for as long as is needed for it to soften; generally one day is enough, but for larger specimens more time is sometimes required.

An entomological pin of a size suited to the dimensions of the beetle is then taken and inserted perpendicularly into the right elytron, leaving it projecting above by about 1-1.5 cm.

After placing the beetle on a polystyrene board or a setting surface, the legs and antennae are positioned with the help of fine-pointed tweezers, fixing them at the sides with a series of pins; once it has dried, the side pins are removed and it is ready to be placed in the collection.

Smaller beetles are generally prepared by gluing them onto special cards with a drop of entomological glue. After softening the insect, it is placed with its legs spread on the card on which the glue has been put; with the help of a small brush and tweezers the antennae and the little legs are positioned, taking care not to let them project beyond the card.

When the specimen is dry, it is useful to use a special spacer so as to have all the cards at the same height.

For Lepidoptera, one proceeds by placing the envelope containing the dry specimen in the “humid chamber”. After inserting the entomological pin in the centre of the thorax, the butterfly is placed on a special setting board, taking care to insert the body in the central groove; on the side boards we will previously have fixed two strips of parchment paper of a width suited to the size of the wings.

With the wings placed under the two strips, one begins on one side; the vein of the upper wing is gripped with the tweezers or a sharp pin until its lower edge forms a right angle with the groove of the setting board.

In the same way the hindwing is raised until its upper margin is almost completely covered by the forewing; then, pulling the paper strip slightly, glass-headed pins are stuck in around the wings to keep them from moving.

The same procedure is followed on the other side, and the specimen is left to dry for a few days, after which, once the paper strips have been carefully removed, it can be placed in the collection.

It is important to place under each insect specimen a label with the collecting data, where available (collecting locality, altitude, date etc); in this way anyone who comes to study the species in question will have as much information as possible available.