They are small, often inconspicuous and often well camouflaged. Therefore, insects are often overlooked, even though they represent the largest group in the animal kingdom. They also play an important role in Zurich Zoo, especially as food.
The zoo feeds about two tons of insects a year, including crickets, grasshoppers and fruit flies, it announced Wednesday. Clients include chameleons, anteaters, toucans and squirrel monkeys.
The zoo also displays various insects in the Exotarium, including stick insects that look like a branch, or the walking leaf, which is hardly distinguishable from real leaves.
Insect biodiversity is declining worldwide. The reasons for this are: habitat loss, pesticides, diseases, introduced species and climate change. In Switzerland, almost 60 percent of insects are threatened, according to the zoo.
200 million insects per person
Insects are harmful and useful at the same time. Some insects, such as the desert locust, which destroys entire crops in large swarms in a few days, are feared pests. Others are important benefits. Insects pollinate two-thirds of major crops and 80% of wild plants.
Over one million insect species have been described to date. However, researchers even speculate as many as five million. Experts estimate that there are 200 million insects for every human being in the world.
They inhabit all continents, come in many shapes and colors and range in size from a tiny 0.14 millimeter to an impressive 33 centimetres. Insects always have three pairs of legs, which distinguishes them from spiders, mites, ticks, woodlice, or millipedes.
Wintering with different strategies
Insects are cold-blooded and are therefore not active in cold weather. In the spring they fall into a cold torpor. Some protect themselves from frost with some kind of antifreeze, others warm each other, like bees.
Hornets, for example, have developed other strategies. In these, only the queens survive, who then lay their eggs in the spring. Some moths like birds and migrate south. Example of this is the Admiral.
