The consequences of human activity and the importance of insect population in global ecosystems
Photo by Amanda Slater (Flickr)
by Nidhiyaa Anagananthan
According to the first global review, the insect population has fallen by 40 percent overall with one-third of the species endangered. This could lead to the collapse of many ecosystems and the repercussion are heavy.
While there is moderate public awareness of decline in mammals and birds, insects are commonly underrepresented in biodiversity analyses. Decline in insect species is twice as high as vertebrates, implying that animals that rely on insects as a food source are also at risk which could lead to shifts in ecosystems.
The biodiversity of insects is at risk due to the growth of human civilization as stated by a review of 73 reports on insect population and its causes across the world. The number of insect species has fallen by 40 per cent overall including many specialist species and generalist species affecting various ecosystems.
“If we don’t stop it entire ecosystems will collapse due to starvation,” says the main author, Francisco Sanchez Bayo, a researcher at University of Sydney, Australia. The decrease in insect population reduces food sources for birds and other mammals. Humanity itself relies on plant pollination with about 75 percent of flowering plants being pollinated by insects. Decomposers and dung beetles are important for the removal of waste and the natural process of decomposition.
There is compelling evidence showing that agricultural expansion, use of chemical fertilizers, pesticides and deforestation are the main forces behind insect and arthropod population decline. Other factors include climate change, especially in a tropical climate with large insect habitats.
However, only a small proportion of studies suggest climate change as a cause with the main reasons being habitat change and pollution, all consequences of human activities. Habitat change is caused by the development of industries, expansion of cities and farming lands. As the human population grows, demand for agricultural goods raises, which in turn increases the need for pesticides and chemical fertilizers to prevent infestation of crops.
“No insects equals no food, equals no people,” says Dino Martins, an entomologist at Kenya’s Moala Research Center while stressing on the importance of insects for the ecosystem. The severity of the situation can be misjudged due to the lack of knowledge and representation. While there is an abundance of studies based in Europe and parts of America, there is still very little knowledge about insect species in other parts of the world. But ultimately, action needs to be taken to protect wildlife and reduce human impact on the environment or the consequences could be catastrophic.
