Insects and Humans

One section of the exhibition is devoted to insect species that are harmful from the human point of view. The most well-known and troublesome crop pests belong to many insect orders and families. They are most often beetles, moths and Hymenoptera, less often flies or Orthoptera (including the migratory locust, now rarely encountered in Poland).

Another category of pests are storage pests – insects that feed on food and textile products of natural origin, as well as on stuffed animal specimens kept in homes and museums. Most of these insects come from tropical and subtropical countries.

Blood-sucking species that transmit diseases, especially in tropical countries, have a particularly notorious reputation among insects. The exhibition presents not only the vectors of Chagas disease (the bugs Triatoma infestans and Rhodnius prolixus), malaria (mosquitoes of the genus Anopheles) and African sleeping sickness (the tsetse fly), but also offers interesting details about their biology and the course of the diseases they transmit.

The second section of the exhibition is devoted to beneficial insects. Many predatory and parasitic species are our allies in the fight against plant pests. A huge number of carrion-feeding and coprophagous species, beetles and flies, take part in the processing of organic matter in nature. An equally numerous host of Hymenoptera, flies and moths pollinates the flowers of crop plants.

Some insect species are used by humans directly. Besides the widely known honeybee and silkworm, these include, among others, species that yield shellac, natural dyes or tannins: the lac insect Laccifer lacca, the Polish cochineal Pophyrophora polonica, cochineal and some gall wasps of the family Cynipidae.

The third section presents selected topics in entomology – adaptations, ways of life, sizes and coloration. Regular insect migrations are particularly remarkable; among the most persistent travellers are some butterflies, especially the American species Danaus plexippus. Apart from butterflies, mass migrations are also undertaken by some dragonflies, grasshoppers, certain flies, beetles and Hymenoptera.

We usually notice the disparity in size between the largest and smallest mammals – whales and shrews. Among insects, however, the disparity between the largest modern species (some stick insects, beetles) and the smallest (Hymenoptera of the family Mymaridae, beetles of the family Ptiliidae) is almost threefold greater. One of the most striking features of insects is their magnificent coloration. The colours admired especially in diurnal butterflies and beetles are most often caused by the refraction of light passing through a suitably shaped outer layer of chitin. Scales covering various parts of the insect's body often take part in this. Less often, coloration is caused by the presence of pigments.

The shape and patterns on insect bodies are often cryptic (camouflaging) or, on the contrary, deter attackers. Other insects resemble in colour species that are poisonous or armed with dangerous weapons, such as a sting, and are thus avoided by predators. This phenomenon is called mimicry and is very common among insects. Another interesting and frequent feature of these animals is dimorphism. It is most often linked to sex. Sometimes the differences in appearance between male and female are so great that it is hard to believe they belong to the same species. Occasionally dimorphism is seasonal, with differences occurring between successive generations. An example is the Map butterfly (Araschnia levana), common in our country, whose spring generation differs greatly in colouring from the summer generation.

These are only a small number of the phenomena with which insects surprise us. Some of them are difficult to show in museum display cases, away from the insects' natural environment. Many can be observed by ourselves during excursions "into nature", and even without leaving home it is enough to look around – insects are everywhere.