The methods of despatching insects from one country to another for biological control purposes have often left much to be desired. When insects are sent as pupae or cocoons, they are generally packed in damp wood-wool or sphagnum moss to absorb vibration, from which it is often difficult to remove either the insects or any undesirable fellow travellers.

The ideal insect container should be strong, light in weight, small enough for ease of handling, yet able to hold large numbers of individuals without excessive crowding.