There is nothing to suggest that the insects consider their behaviour. When insects do something that looks reasonable, it is due to the innate, appropriate behaviours – that are built into their nervous system – that are triggered under certain conditions in response to certain environmental influences. Most of our knowledge about the storage pests’ biology and behaviour derives from laboratory tests, where the results are indicative only. The fact is that local populations of any given species can develop their own characters.

Due to short average insect lifetime, the individual insect will probably not adapt to changes. Any adjustments will be the result of natural selection. Individuals that have qualities that fit the available conditions best survive and have the most offspring. An example of such an adaptation to changing conditions through natural selection is that many insect populations have developed resistance to one or more of the toxins with which we treat their habitats. The individual only has very limited opportunities to change behaviour during its lifetime. However, there are examples where insects have learned to stay away from places where they are exposed to unpleasant experiences.

The Look and Behaviour of pests

Most of the pests that occur in food are insects. This is probably obvious. Today about 1 million species of insects are known and it is estimated that there are still many millions of unknown species of insects. Insects are by far that group of animals with the most members.

Some knowledge on the insects’ appearance and build is useful to be able to tell them apart and to know which insects are occasionally found in food. It is also quite useful to know something about insect behaviour. When trying to prevent or control pests, it is important to be able to make qualified guesses on the insect behaviour under certain circumstances. In most cases prevention and control is all about creating conditions for pests in which they do not thrive.