Neonicotinoid

A neonicotinoid is a chemical compound that is similar in makeup to nicotine. Neonicotinoids are a commonly used pesticide in farming. Farmers spray these chemical compounds onto crops, or the chemicals are added to plant seeds so the chemicals seep into a growing plant. Research indicates that neonicotinoids are a threat to pollinators, such as honeybees. Some research suggests that neonicotinoids are also harmful to humans. Because of these problems, some people want to end the use of neonicotinoids as pesticides. Nevertheless, proponents believe that neonicotinoids are not as harmful to beneficial insects as other threats, and that neonicotinoids help grow enough crops to feed the population.

Background

Farming has helped humans survive and thrive for thousands of years. During that time, people have developed new tools, methods, and chemical treatments that have increased crop yields. During the early twentieth century, people used advances in chemistry and technology to develop new tools and treatments for farming. Farmers began using chemicals to reduce the number of pests that ate their crops. Early chemical pesticides included arsenic and cyanide. Farmers stopped using these pesticides because they were not very effective and were extremely toxic. Scientists developed a second generation of chemical pesticides in the early to mid-twentieth century. These pesticides included a chemical called dichlorodiphenyltrichloroethane (DDT).

DDT quickly became the most important chemical pesticide in the world. By the 1950s, DDT was being used in numerous countries, especially in the United States. Farmers saw DDT as a miracle-like chemical that prevent pest problems for many crops. Nevertheless, scientists and activists soon realized that DDT was also highly toxic. It was killing off insect populations and birds. These creatures make up an important part of the food chain, as many other organisms rely on them for food. With many insects and birds dying off, other animals were also unable to survive. In 1962, an activist named Rachel Carson published a book called Silent Spring. In the book, Carson identified the problems that DDT caused and encouraged people to stop using the pesticide. Thanks in large part to Carson’s work, the US government stopped the use of DDT as an insecticide, expect in some special circumstances, in the 1970s. After DDT was banned, scientists began developing new chemical pesticides. One group of pesticides that scientists developed after the ban of DDT was the neonicotinoid group.

Overview

Neonicotinoids are chemical compounds used to kill insects that are harmful to agricultural crops. Scientists developed neonicotinoids in the 1980s and 1990s. They created these chemicals because farmers wanted to use pesticides that were toxic to insects without being as harmful to other creatures. Neonicotinoids are much more toxic to invertebrates, such as insects, than to vertebrates, such as humans and other mammals. Some examples of neonicotinoids include acetamiprid, clothianidin, dinotefuran, imidacloprid, nitenpyram, thiocloprid, and thiamethoxam.

One way that farmers use neonicotinoids is by spraying the chemicals onto crops. The neonicotinoid sprayed onto the plant can then be absorbed into the plant, including into its pollen and nectar. Another way people use neonicotinoids is by applying them to seeds. As a plant grows, the plant contains the chemical inside it. Neonicotinoids that are applied to crop plants can also spread. For example, the chemicals inside the plants can enter ground water that the plants are growing in. The ground water can be used by nearby weeds or other plants; then, those nearby plants become contaminated with the neonicotinoids as well.

Neonicotinoids affect insects and other organisms by disrupting signals sent in the central nervous system (CNS). Neonicotinoids are often used against sucking insects, such as aphids. They are also useful against some leaf-chewing insects. When the insects consume parts of the plant, they ingest the neonicotinoid that is inside the plant. Then the neonicotinoid disrupts communication between the insect’s brain and the rest of its body, eventually causing death.

The scientists who created neonicotinoids did so because they wanted to create an insecticide to specifically target to the harmful insects farmers wanted to kill. Scientists created neonicotinoids so that they were chemically related to nicotine, which had been used a pesticide in the past. Scientists developed neonicotinoids so that they would be systematic. That means that chemicals would be inside the plants. Scientists wanted to create pesticides that stayed inside the plant because only insects that were consuming the plants would be those exposed to the chemical.

For these reasons, many people believed neonicotinoids were relatively safe for many beneficial insects, such as honeybees. However, over time, scientists have found evidence that prolonged exposure to neonicotinoids can be toxic for honeybees and other beneficial insects. Studies on the effects of neonicotinoids on bee populations suggest that neonicotinoids can be deadly to bees after prolonged exposure. Furthermore, scientists found that neonicotinoids make reproduction more difficult for bees, which further decreases populations.

In the twenty-first century, scientists have observed that honeybee populations around the world were declining. One culprit for the decline was colony collapse disorder (CCD). CCD is a phenomenon that happens when a large group of worker bees—the bees that make up most of the hive—suddenly become confused and leave a colony. When too many worker bees leave a colony, the colony collapses and the queen dies. This problem greatly concerned scientists because of the role honeybees play in food production. One-third of food produced in the United States relies on the honeybee population.

Neonicotinoids are popular among chemical companies and are sold in many consumer insecticide products. Chemical companies use various forms of these chemicals in many different products. Some environmentalists and consumer advocates have accused some of the larger chemical companies of denying facts about neonicotinoids because they want to sell more of them. Many of these companies argue that honeybee populations are affected by other problems, including mites that attack the bees, more than they are affected by neonicotinoids. However, bees are exposed to neonicotinoids in many different ways. Bees and other pollinators can then ingest the neonicotinoid through the pollen and nectar that has been contaminated. They can also be exposed by these chemicals in the air.

Bibliography

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King, Anthony. “What You Need to Know about Neonicotinoids.” Royal Society of Chemistry, 24 Mar. 2018. www.chemistryworld.com/news/what-you-need-to-know-about-neonicotinoids/3008816.article. Accessed 1 April 2019.

“Neonicotinoid Pesticides.” National Collaborating Centre for Environmental Health, 5 Jun. 2018. www.ncceh.ca/environmental-health-in-canada/health-agency-projects/neonicotinoid-pesticides. Accessed 2 Apr. 2019.

“Neonicotinoids and Bees.” Xerces Society for Invertebrate Conservation. xerces.org/neonicotinoids-and-bees/. Accessed 2 Apr. 2019.

Oder, Tom. “Neonicotinoids: What Home Gardeners Need to Know.” Mother Nature Network, 15 Aug. 2017, www.mnn.com/your-home/organic-farming-gardening/stories/neonicotinoids-what-home-gardeners-need-to-know. Accessed 2 Apr. 2019.

“The Story of Silent Spring.” NRDC, 13 Aug. 2015. www.nrdc.org/stories/story-silent-spring. Accessed 2 Apr. 2019.

“What Is a Neonicotinoid?” Insects in the City, Texas A&M Agrilife Extension. citybugs.tamu.edu/factsheets/ipm/what-is-a-neonicotinoid/. Accessed 2 Apr. 2019.