Cockroaches are often said to resist everything, and even survive a nuclear attack. "Insects have long been considered adaptable, very resistant, able to survive despite the activity of man. But they are dying out, "observes entomologist Jean-François Silvain. After the publication of a study on the
decline in insect populations published Sunday in the journal Biological Conservation, the president of the Foundation for Biodiversity Research (FRB) details the potentially catastrophic consequences of the disappearance of insects for our life on Earth.
"We live in a world of insects: their biomass is much larger than that of men," says Jean-François Silvain. "Apart from the sea, insects have colonized all terrestrial environments, and the diversity of their mode of exploitation of the environment means that they have essential functions in ecosystems." Fewer insects, or extinctions of species, would cause disruption on our planet.
A whole disrupted food chain
Insects are the food of many other species. Their decline would affect many animals. "The birds would have problems feeding, as well as bats, small insectivorous mammals like shrews and frogs. This insect deficit partly explains the bird population falls already observed in France ", says Jean-François Silvain.
A land without flowers or fruits?
The other key role of insects is pollination, which is not confined to bees alone. "Very many plants are pollinated not by the wind, but by bees, Diptera (flies, mosquitoes …),
hymenoptera (bees, wasps, ants, hornets …),
lepidopterans (butterflies) or
beetles (beetles, ladybugs, cockchafers …), "explains the entomologist. Fewer insects would mean that some plants would not be pollinated enough, which could rob the planet of flowers and fruits, and even some vegetables. Other crops could be affected because "insects are aids to agriculture". The diversity of our diet would be affected.
A pile of organic waste (dung, corpses, dead leaves …)
Insects are also essential to remove a lot of rubbish. "They are decomposers of organic waste, some provide some of the decomposition of dead leaves, others attack the corpses. There are also the dung beetles, among the beetles: without them, our peerages would be only fields of cow dung, "warns Jean-François Silvain. The flocks that feed the men would thus be deprived of a space to graze. "Moreover, when cattle were introduced to Australia, it was then realized that it was necessary to introduce coprophages! "
"Insects are key, even if you do not see them. If this downward trend is confirmed, we will see major food and health problems, "says the president of the FRB.