Collapse of Insects
Researchers called the state of insect biodiversity worldwide ‹dreadful’ explaining in no uncertain terms that unless we change our ways of producing food insects will become extinct in a matter of decades.
Lepidoptera are insects that include butterflies and moths and Hymenoptera are insects that include bees and dung beetles, all of which are most at risk on land. Aquatic insects affected include dragonflies, damselflies, stoneflies, caddisflies and mayflies.
Overall, the total mass of insects is said to be falling by a shocking 2.5 percent a year. If this rate continues unchecked, insects could disappear within 100 years.
“It is very rapid. In ten years, you will have a quarter less, in 50 years only half left and in 100 years you will have none” study author Francisco Sánchez‐Bayo, at the University of Sydney, Australia, told The Guardian.
“Major insect decline occurred when agricultural practices shifted from traditional, low‐input farming style to the intensive, industrial scale production brought about by the Green Revolution.
The latter practices did not necessarily involve deforestation or habitat modification (e.g. grassland conversion, drainage of wetlands) but rather entailed the planting of genetically‐uniform monocultures, the recurrent use of synthetic fertilisers and pesticides, the removal of hedgerows and trees in order to facilitate mechanization, and the modification of surface waterways to improve irrigation and drainage.
Monocultures led to a great simplification of insect biodiversity among pollinators, insect natural enemies and nutrient recyclers, and created the suitable conditions for agricultural pests to flourish. A quarter of the reports indicate these agriculture‐related practices as the main driver of insect declines in both terrestrial and aquatic ecosystems.
Pesticides have caused the decline of moths in rural areas of the UK and pollinators in Italy. Broad-spectrum insecticides reduce the abundance and diversity of beneficial ground‐dwelling and foliage‐foraging insects. Systemic insecticides reduce populations of ladybirds and butterflies in gardens and nurseries and inflict multiple lethal and sublethal effects on bees and other arthropods.
Fungicides are not less damaging to insects, and synergism of a particular group of compounds (i.e. azoles) with insecticide toxicity is certainly involved in honey bee collapses.”B