Why Insects Are Important
Insects are very fertile. And their influence on the nature is, of course, enormous. Let us talk about their beneficial influence.
The most important function of insects is pollination of flowering plants. Flowering plants are the main source of food and moisture for the majority of insects. At the same time, most of the flowering plants (that is, those with cross-pollination) depend of insects-pollinators.
All bright, noticeable-from-a-distance plants are “advertisements”, by means of which plants attract insects. Insects are also attracted by plants’ aroma.
In the corolla of a flower in the middle, there is a pistil; around it there are stamens; the ends of the stamens (anthers) contain pollen. For a cross-pollination plant to bring fruit, it has to be pollinated: the pollen of one flower has to be brought to the stigma (the upper part of the pistil) of another one. It is insects visiting flowers that ensure such pollination.
Insects come to flowers for collecting pollen (some beetles, many hymenopterans) or for the sake of sweet nectar (flies, butterflies, many hymenopterans).
Sometimes insects use corollas of flowers as an asylum or come inside a flower cluster for placing there their young. All kinds of insects’ visits are used by plants for pollination.
Many plants reproduce only thanks to pollination by insects. And we — gather harvests!
* * *
Honeybees, silkworm moths and Chinese oak silkmoths, Indian lac insects and cochineal insects — these are examples of semi-domesticated insects, bred by man for the sake of products obtained from them.
Let us recall how much good man receives from the honeybee! Honey, propolis, beeswax…
Caterpillars of the silkworm moth produce silk when they build cocoons; from this silk gentle silk fabric is made.
Another insect — the Chinese oak silkmoth — also produces thread — even stronger one.
A very valuable product — shellac — is produced by Indian lac insects living on certain kinds of trees in South East Asia. Wax-like substances secreted by them have very good insulating qualities and are widely used in radio engineering.
In the same way, mealybugs produce dye.
Many insects are important for soil formation: they are destroyers of fallen leaves, dead wood, dung.
For instance, there was the following interesting case in Australia. Some pastures suffered from large amount of cow feces that accumulated and prevented growth of grass. It turned out that in Australia there were no dung beetles. When dung beetles were introduced, it helped to decompose quickly the feces and to increase of the crop capacity of the fields.
Apart from everything described above — let us remember about the esthetical role of butterflies, moths, dragonflies, and other insects that beautify our nature!