The silent collapse of the insect kingdom

The bees are not alone. A series of studies reveals a severe damage to insect populations in the world due to human activity. The collapse of the insect kingdom could cause severe damage to the ecosystem and the food production system

Racheli Vox, Angle - Science and Environment News Agency

At the opening of the first film in the "Men in Black" series, released in 1997, the camera follows the dramatic journey of a flying insect for several minutes. The insect flies swiftly through the night sky, buzzing as it passes between various landscape routes, until it reaches the vicinity of a lighted desert road, where it evades various vehicles by the skin of its teeth - until it is suddenly crushed against the windshield of a moving (and full of aliens) car.

The phenomenon of the dead flying insects on the windshield, which was nicknamed "The windshield phenomenon", may not sound particularly important, and even positive for those who do not like insects; But she is the one who focused the world's attention on another, much more significant phenomenon - that quietly, almost without us noticing, the insects are disappearing from the world in huge numbers.

Admittedly, encountering a bug indoors is something most people would be happy to pass up, and it usually involves screeching and a frantic search for a shoe; But the phenomenon that is happening today is nothing less than a widespread disaster, which is collapsing the kingdom of insects in the world and in Israel. The habitats of insects in nature are disappearing due to human actions, and damage to their critical function in nature can cause the collapse of entire ecosystems and have a significant impact on the lives of humans. In other words - we will still miss the insect on the windshield.

The center of nature's pie

Today, no less than a million species of insects are known to science, among them 12 thousand species of ants, almost 20 thousand species of bees and close to 400 thousand species of beetles. Entomologists estimate that there are millions of other species in the world that we don't know about. "People don't understand that they exist thanks to insects," says Dr. Moshe Gish from the Department of Natural Resources and Environmental Management at the University of Haifa. "Insects are at the center of the file of nature around us, without them there is nothing." Gish explains that all terrestrial ecosystems depend on insects. "If there are no insects, or if there is a drastic decrease in their quantity and diversity, ecosystems will simply collapse - and the human race will be in a very serious problem," he says.

One of the main functions of the insects is pollination of flowers, an essential process without which the plant is unable to produce fruits and seeds. Pollination is mainly carried out by bees, as well as by other insects such as butterflies, flies and beetles. A large part of the crops grown by man depend on pollination by insects, so damage to insects means damage to our food.

In addition, the insects function as nature's "recycling factory": insects decompose animal corpses, and the products of these decomposition are used as natural fertilizer for plants. Without the insects, areas will be filled with corpses and plants will not receive sufficient nutrition.

Beyond that, insects are an important link in the food web, because they are a critical link in the transfer of energy from plants to animals. When insects digest plants, they turn them into protein, from which they build their bodies - therefore they serve as an important source of quality protein for many animals, including birds, reptiles and amphibians. That is, damage to the prevalence of insects will also damage their predators and predator-predators, and may reverberate across the entire food web.

One of the main functions of insects is pollination of flowers. Photo: Hayley Harman, Unsplash

are also disappearing in Israel

In a study published in 2017 by the Association of Insect Enthusiasts from Germany, which caused an uproar upon its publication, a decrease of no less than 76 percent was revealed in the various insect populations in the country's nature reserves in the past 27 years. A subsequent study found that beetle populations in the Netherlands dropped by 72 percent, and moth populations by 54 percent. American researchers have discovered that the population of the royal damselfly, the well-known orange butterfly, has decreased by 90 percent in the last 20 years - a massive loss of 900 million butterflies. The damage to the honey bee and wild bees is also dramatic, and has been studied intensively in recent years. All over the world, both a decrease in the variety of existing insect species, with the extinction of many species, and a decrease in the number of individuals in each species are observed.

In Israel, so far no comprehensive study has been conducted on the prevalence of the insects, like the one done in Germany, but there is no doubt that the insect populations here are also severely affected. "There is a general impression of people who work in the field that the trend they see in the world, of a general decrease in diversity and prevalence, is also true in Israel," says Dr. Neta Dorchin from the Steinhardt School of Zoology and Museum of Nature at Tel Aviv University.

The insects in Israel are disappearing for the same reasons that also exterminate their counterparts in the world, the main of which is the loss of habitats. According to Dorchin, the most affected habitats in Israel are the humid habitats. "To begin with, there are very few humid habitats in Israel, and their sensitivity is higher," she says. In recent decades, large water beetles, certain dragonflies as well as insects from the bryomyel series have disappeared from the humid habitats in Israel.

Insects may be significantly affected even when their habitats are not completely destroyed. When habitats are cut off, for example due to a road being paved through them, the total area of ​​the habitat does not change significantly, but certain species will not be able to move between the different parts of the area, and therefore their habitat will be dramatically reduced - which may cause the extinction of a species. The habitat may also be damaged by human disturbances, such as light pollution at night.

Agricultural pesticides also harm insects. Such damage may occur when the spray cloud flows from the fields into the environment, killing both insects that are not agricultural pests, and even beneficial species that serve as natural exterminators for agricultural pests (natural enemies). Insecticides that affect the plant systemically may also harm harmless insects, such as wild bees that feed on nectar that may contain a variety of pesticides (these later flow into honey, as an Israeli study found last year).

Another offensive factor is invasive species: animals or plants that have been spread as a result of human activity to an area outside of their natural range, and have managed to survive there and even thrive there, while suppressing the native species. For example, the small fire ant, which is a nuisance for humans because of its painful bites and is harmful to agriculture, severely damages populations of ants of other species as well as populations of other insects.

Another reason for the decline in the numbers of insects is climate change: droughts in Israel (in the northeast of Israel in the last 5 years, with an emphasis on the Kinneret basin) are becoming more and more common in recent years, the amounts of rain are decreasing, and the rains appear in a sub-optimal pattern of few rain events where large amounts of rain fall. The insects, like the entire ecosystem, are also affected by this change.

"Insect preservation is not on the list of priorities"

The general public occasionally notices the disappearance of insects of prominent species, such as fireflies and bees. However, many other species that we do not encounter every day are also disappearing at a dizzying rate - many of them from the group of pollinators.

The insect species that do not suffer at all from the disaster that befalls the insect world are precisely the ones that we would wish for a mass disappearance: the species that accompany humans, the same insects that roam our homes and obtain an endless supply of resources from us. These parasitic and disease-spreading species are expected to continue to thrive as man's presence in the world continues to increase.

Other insect species that survive well are harmful invasive species, such as the disease-spreading Asian tiger mosquito that has become very established in Israel, the American cockroach that has spread from the African continent (despite what its name suggests) to all corners of the globe because of humans, or the red palm weevil, which severely damages palm trees in Israel and around the world .

So what can be done to protect the insects and stop the disaster that is happening nowadays? "Humans should just stop destroying the environment," says Dorchin. "We need to mark unique habitats and preserve them before they disappear." Gish adds that it is necessary to devote more thought to insects as part of the conservation efforts that are being carried out today. "Conservation of insects is almost not at all on the list of priorities," he says.

Gish also emphasizes that the unnecessary use of pesticides must be reduced, as well as making it clear to the public how significant insects are for our existence. "People need to understand that they may not want the cockroach in the kitchen, but outside insects are a good and very important thing," he concludes.