Somehow it is easier to worry about wolves, sea turtles and white rhinoceroses that are dying than to feel remorse over the fading insects.
But the loss of insects is a serious threat – one that can trigger a "catastrophic collapse of Earth's ecosystems" – says the new study.
Research, the first global review of this type, looked at 73 historical reports of insect declines around the world and found that the total weight of all insects on planets drops by 2.5% per year.
If this trend persists, the Earth may not have any insects at all by 2119.
"In ten years you will have a quarter less, 50 years only by half, and you will not be in 100 years," said The Guardian Francisco Sanchez-Bayo, co-author of research and researcher at the University of Sydney.
This is a big problem because insects are a source of food for countless species of birds, fish and mammals. Pollinators, such as bees and butterflies, also play a key role in the production of fruits, vegetables and nuts.
Insects will die 8 times faster than mammals, birds and reptiles
Sanchez-Bayo and his co-authors focused on the analysis of insects in Europe and North America. They assess that 41% of insect species are in a fall, 31% are at risk (according to criteria set by the International Union for Conservation of Nature), and 10% die out.
This rate of extinction is eight times faster than the observed rate of extinction of mammals, birds and reptiles.
The study suggested that bee species in the UK, Denmark and North America have been very successful – bumblebees, honeybees and wild bees are falling. In the United States, the number of honeybee colonies fell from 6 million in 1947 to 2.5 million just six decades later.
Moths and butterflies also disappear in Europe and the United States. Only in the years 2000-2009 the United Kingdom lost 58% of butterfly species on agricultural land.
Dragonflies, mayflies and beetles also seem to die out.
Looking at all animal populations around the world (not only insects), according to a study from 2017, it seems that Earth is undergoing a "biological annihilation" process. This analysis estimated that "up to 50% of the number of animals that once shared the Earth with us has already disappeared."
This rapid decline in biodiversity in the world is sometimes called the "sixth extinction" because for the sixth time in the history of life on Earth the planet's fauna experienced a significant decline in numbers.
In the past, mass extinction was caused by the appearance of ice ages or asteroid collisions. This massive extinction, however, results from human activity – deforestation, mining and carbon dioxide emissions that contribute to global warming.
"Because insects account for about two-thirds of all terrestrial species on Earth, the above trends confirm that the sixth large-extinct event has a profound impact on the life forms on our planet," the authors wrote.
Read more:Scientists say we are witnessing the sixth massive extinction of the planet – and "biological annihilation" is the latest sign
"Catastrophic consequences for … survival of humanity"
The study emphasized that insects are "essential for the proper functioning of all ecosystems" as a food source, crop pollinators, pest controllers and soil nutrient reclaimers.
"If you can not stop the loss of insect species, it will have disastrous consequences both for the planet's ecosystems and for the survival of humanity," said Sanchez-Bayo, The Guardian.
The significant declines in insect populations are therefore threatening the production of food, wood and fibers that determine the survival of humanity, according to Timothy Schalyter, a professor of entomology at the State University of Louisiana.
"Pollinators reduce the risk for 35% of our global food supply, which is why European countries require protection and restoration of pollinator habitats," said Business Insider.
Schaufter added that insects are also important food resources for many birds, fish and other vertebrates that would disappear if they had a source of food.
"Insects are often vilified, or at least their significant contribution to ecosystem efficiency and the provision of ecosystem services is undervalued," said Schowalter. "In short, if the insects and other arthropods fall, our survival would be at risk."
This is not the first time scientists have focused on declining insect populations.
In 2017, the survey showed that 75% of German flying insects have disappeared since the 1990s. Other recent studies have shown that the total biomass of arthropods – creatures such as insects, spiders and lobsters that have legs connected but no spine – has been diverted in Puerto Rico since the 1970s.
Pesticides, fertilizers and intensive land use in agriculture are the main reasons for this decline.
"In general, the systematic, widespread and often unnecessary use of pesticides on agricultural land and pastures over the past 60 years has had a negative impact on most organisms, from insects to birds and bats," the authors of the new study wrote.
They added: "The conclusion is clear: if we do not change our ways of producing food, the insects as a whole will follow the path of extinction in a few decades."
Sanchez-Bayo told The Guardian that he think insecticides, such as neonicotinoids and fipronil, are particularly harmful.
"They sterilize the soil, killing all the larvae," he said.
Temperature changes due to climate change also play a role in insect deaths, although this is not a major factor.
"Until now, declines have been more related to changes in land use, especially with agricultural intensification, forest fragmentation and urban development, than changes in temperature," said Schowalter.