Insecticides are pesticides used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. Acaricides, which kill mites and ticks, are not strictly insecticides, but are usually classified together with insecticides. The major use of Insecticides is agriculture, but they are also used in home and garden, industrial buildings, vector control and control of insect parasites of animals and humans. Insecticides are claimed to be a major factor behind the increase in the 20th-century's agricultural productivity. Nearly all insecticides have the potential to significantly alter ecosystems; many are toxic to humans and/or animals; some become concentrated as they spread along the food chain.
Imidacloprid is a systemic insecticide belonging to a class of chemicals called the neonicotinoids which act on the central nervous system of insects. The chemical works by interfering with the transmission of stimuli in the insect nervous system. Specifically, it causes a blockage of the nicotinergic neuronal pathway. By blocking nicotinic acetylcholine receptors, imidacloprid prevents acetylcholine from transmitting impulses between nerves, resulting in the insect's paralysis and eventual death. It is effective on contact and via stomach action. Because imidacloprid binds much more strongly to insect neuron receptors than to mammal neuron receptors, this insecticide is more toxic to insects than to mammals.
Pesticides vary in their effects on bees. Contact pesticides are usually sprayed on plants and can kill bees when they crawl over sprayed surfaces of plants or other areas around it. Systemic pesticides, on the other hand, are usually incorporated into the soil or onto seeds and move up into the stem, leaves, nectar, and pollen of plants.
Fipronil is a broad-spectrum insecticide that belongs to the phenylpyrazole chemical family. Fipronil disrupts the insect central nervous system by blocking the ligand-gated ion channel of the GABAA receptor and glutamate-gated chloride (GluCl) channels. This causes hyperexcitation of contaminated insects' nerves and muscles. Fipronil's specificity towards insects is believed to be due to its greater binding affinity for the GABAA receptors of insects than to those of mammals, and for its action on GluCl channels, which do not exist in mammals. As of 2017, there does not appear to be significant resistance among fleas to fipronil.
The Cape honey bee or Cape bee is a southern South African subspecies of the western honey bee. They play a major role in South African agriculture and the economy of the Western Cape by pollinating crops and producing honey in the Western Cape region of South Africa. The species is endemic to the Western Cape region of South Africa on the coastal side of the Cape Fold mountain range.
Bees can suffer serious effects from toxic chemicals in their environments. These include various synthetic chemicals, particularly insecticides, as well as a variety of naturally occurring chemicals from plants, such as ethanol resulting from the fermentation of organic materials. Bee intoxication can result from exposure to ethanol from fermented nectar, ripe fruits, and manmade and natural chemicals in the environment.
Nosema ceranae is a microsporidian, a small, unicellular parasite that mainly affects Apis cerana, the Asiatic honey bee. Along with Nosema apis, it causes the disease nosemosis, the most widespread of the diseases of adult honey bees. N. ceranae can remain dormant as a long-lived spore which is resistant to temperature extremes and dehydration. This fungus has been shown to act in a synergistic fashion with diverse insecticides such as fipronil or neonicotinoids, by increasing the toxicity of pesticides for bees, leading to higher bee mortality. It may thus play an indirect role in colony collapse disorder. In addition, the interaction between fipronil and N. ceranae induces changes in male physiology leading to sterility.
Neonicotinoids are a class of neuro-active insecticides chemically similar to nicotine, developed by scientists at Shell and Bayer in the 1980s.
Nitenpyram is a chemical frequently used as an insecticide in agriculture and veterinary medicine. The compound is an insect neurotoxin belonging to the class of neonicotinoids which works by blocking neural signaling of the central nervous system. It does so by binding irreversibly to the nicotinic acetylcholine receptor (nACHr) causing a stop of the flow of ions in the postsynaptic membrane of neurons leading to paralysis and death. Nitenpyram is highly selective towards the variation of the nACHr which insects possess, and has seen extensive use in targeted, insecticide applications.
Clothianidin is an insecticide developed by Takeda Chemical Industries and Bayer AG. Similar to thiamethoxam and imidacloprid, it is a neonicotinoid. Neonicotinoids are a class of insecticides that are chemically similar to nicotine, which has been used as a pesticide since the late 1700s. Clothianidin and other neonicotinoids act on the central nervous system of insects as an agonist of nAChR, the same receptor as acetylcholine, the neurotransmitter that stimulates and activating post-synaptic acetylcholine receptors but not inhibiting AChE. Clothianidin and other neonicotinoids were developed to last longer than nicotine, which is more toxic and which breaks down too quickly in the environment.
The western honey bee or European honey bee is the most common of the 7–12 species of honey bees worldwide. The genus name Apis is Latin for "bee", and mellifera is the Latin for "honey-bearing" or "honey carrying", referring to the species' production of honey.
Colony collapse disorder (CCD) is an abnormal phenomenon that occurs when the majority of worker bees in a honey bee colony disappear, leaving behind a queen, plenty of food, and a few nurse bees to care for the remaining immature bees. While such disappearances have occurred sporadically throughout the history of apiculture, and have been known by various names, the syndrome was renamed colony collapse disorder in early 2007 in conjunction with a drastic rise in reports of disappearances of western honey bee colonies in North America. Beekeepers in most European countries had observed a similar phenomenon since 1998, especially in Southern and Western Europe; the Northern Ireland Assembly received reports of a decline greater than 50%. The phenomenon became more global when it affected some Asian and African countries as well. From 1990 to 2021, the United Nation’s FAO calculated that the worldwide number of honeybee colonies increased 47%, reaching 102 million.
Acetamiprid is an organic compound with the chemical formula C10H11ClN4. It is an odorless neonicotinoid insecticide produced under the trade names Assail, and Chipco by Aventis CropSciences. It is systemic and intended to control sucking insects (Thysanoptera, Hemiptera, mainly aphids) on crops such as leafy vegetables, citrus fruits, pome fruits, grapes, cotton, cole crops, and ornamental plants. It is also a key pesticide in commercial cherry farming due to its effectiveness against the larvae of the cherry fruit fly.
Thiamethoxam is the ISO common name for a mixture of cis-trans isomers used as a systemic insecticide of the neonicotinoid class. It has a broad spectrum of activity against many types of insects and can be used as a seed dressing.
Carbophenothion also known as Stauffer R 1303 as for the manufacturer, Stauffer Chemical, is an organophosphorus chemical compound. It was used as a pesticide for citrus fruits under the name of Trithion. Carbophenothion was used as an insecticide and acaricide. Although not used anymore it is still a restricted use pesticide in the United States. The chemical is identified in the US as an extremely hazardous substance according to the Emergency Planning and Community Right-to-Know Act.
Triazofos is a chemical compound used in acaricides, insecticides, and nematicides.
Jeffery Stuart Pettis is an American-born biologist and entomologist known for his extensive research on honeybee behavior. He is currently head of Apimondia. He was the research leader at the United States Department of Agriculture's Beltsville Bee Laboratory (BBL). His research has led to significant breakthroughs in understanding and managing CCD, a primary cause of North American bee population decline. He is also known for discovering with Dennis vanEngelsdorp, then at Pennsylvania State University, the ability of bees to detect pesticides and harmful fungi in collected pollen and subsequently quarantine the harmful substances from the rest of the hive. His research has also studied the synergistic effects of Imidacloprid on bees, an insecticide derived from nicotine which has been shown to contribute to CCD.
Sulfoxaflor, also marketed as Isoclast, is a systemic insecticide that acts as an insect neurotoxin. A pyridine and a trifluoromethyl compound, it is a member of a class of chemicals called sulfoximines, which act on the central nervous system of insects.
9-Oxodecenoic acid (9-oxo-2(E)-decenoic acid, also called 9-ODA) is an unsaturated ketocarboxylic or fatty acid and a pheromone secreted by the queen bee of the honeybee species Apis mellifera. It functions as a sex attractant that stimulates the olfactory receptors of male drones. Additionally, this acid plays a crucial role in regulating the colony's social structure; it inhibits the development of ovaries in worker bees, which are sterile females. However, its inhibitory effect on the worker bees' ovaries is only fully effective when combined with another pheromone, 9-hydroxydecenoic acid. When the queen bee is removed from the hive, the worker bees initiate the construction of new queen cells and the previously inhibited drones develop functional ovaries. The exact biological mechanisms through which 9-oxodecenoic acid and related substances influence these processes are not fully understood, but they are thought to affect the nervous system in some way.
