These Small Ermines’ caterpillars don’t leave any leaves on the plant

So people had to think of means to get rid of the pests. They use pesticides which, besides killing the caterpillars, contaminated the water and endangered many other wild animals. But the insects can get resistant against the poisons, so new ones must be found.

Another method is to spray pest caterpillars with a special bacterium called Bt infecting and killing them how it is done with gypsy moth outbreaks in North America. But this method causes problems, too. The bacterium kills caterpillars of nonpest moths and butterflies living in the same forests as well. Birds feeding on them will have problems to survive when all caterpillars die at once.

The best way to keep agricultural pests under control is to reestablish biological checks: parasites and predators. Farmers could introduce them to their fields and grow pest-resistant plants. Smaller fields with a greater diversity of crops also reduce pest outbreaks. Of course these methods are expensive and take some time - but the results are the best, especially in the long run.

In draining swamps, destroying woods and other natural living spaces we take away the butterflies’ basis of life. Pushing back feeding plants also has consequences for butterflies. Poisonous deposits from industry, households and traffic present another danger. Pesticides and insecticides used by farmers not only threaten butterflies but other animals and plants, too and contaminate the water.

Many butterflies and other insects are run over every day in the streets or puzzled by the lights of the cars.

However, humans are learning from their mistakes and do positive things as well. Besides trying to save particular living spaces, more and more attempts of reintroduction are made.

But there is still a whole lot more to do.