Broad-spectrum insecticides

Haloisoxazolylureas have acardicidal and insecticidal properties 76JAP(K)7659858 and isoxazoles with a phosphorothiolate functionality are broad spectrum insecticides <80USP4212861, 78USP4104375, 78JAP(K)7825566>. 

Neonicotinoids are potent broad-spectrum insecticides that exhibit contact, stomach and systemic activity. Acetamiprid, imidacloprid, nitenpyram, thiamethoxam and thiacloprid are representatives of the neonicotinoid insecticides (Figure 1). The mechanism of action is similar to that of nicotine, acting on the central nervous system causing irreversible blocking of postsynaptic nicotinic acetylcholine receptors (nAChR). Neonicotinoid insecticides are often categorized as antagonists of the... 

Toxaphene (chlorinated camphene, 67 to 69% chlorine) is a broad-spectrum insecticide, which was formerly one of the most heavily used agricultural chemicals on a global scale, especially... 

Not surprisingly, considering their highly efficacious and broad-spectrum insecticidal activity, SPs are highly toxic to honeybees and other nontarget arthropods. High levels of toxicity to aquatic arthropods have been reported [5]. Although of relatively low toxicity to birds, fish are also sensitive, probably because of a less... 

A newer class of insecticides is the pyrethroids. These are synthetic derivatives of pyrethrins, which are natural extracts from chrysanthemums. Pyrethroids have been developed to be more stable (and thus more effective as insecticides) than the pyrethrins, which are particularly instable in light. Pyrethroids are frequently used as broad-spectrum insecticides. They have high insect toxicity, but lower mammalian toxicity than their organophosphate or carbamate counterparts. Pyrethroids are still limited in effectiveness due to their environmental lability, their high cost, and their potential for resistance development. 

The discovery in the early years of the 20 century that certain phosphate esters possess mammahan toxicity and insecticidal properties heightened interest in this class of compounds, both in agriculmre and as potential agents in chemical warfare. Parathion became the practical choice as a broad-spectrum insecticide because of its greater stability and lower mammalian toxicity compared to its P=0 analogue, paraoxon . 

One of the symmetrical IJ,N -thlobiscarbamates, 15,N -thiobismethomyl or LARVIN, is currently under development as a new, broad spectrum insecticide (22,23). This compound was... 

At Bhopal they were manufacturing SEVIN, also called carbaryl, a broad-spectrum insecticide that was and still is used on many crops throughout the world. The reaction steps to manufacture SEVDSf are shown in Figure 10-16. 

F. Colliot, K.A. Kukorowski, D. Hawkins and D.A. Roberts, Fipronil a new soil and foliar broad spectrum insecticide , in Brighton Crop Protection Conference - Pests and Diseases, 1992 , British Crop Protection Council, Farnham, UK, 1992, Vol. 1, pp. 29-34. 

Chlorpyrifos (73) is the only phosphate of importance containing a pyridine ring. Partial hydrolysis of 2,6-dichloropyridine, followed by peroxide mediated chlorination, gives the required 3,5,6-trichloropyridin-2-ol intermediate (66MI10700, 67USP3355456). The phosphate is a broad spectrum insecticide with some vapour activity. 

Whenever applied, IPM practices have consistendy resulted in decreases in insecticide applications of 50 to 90% over conventional spray programs. By encouraging natural enemies, IPM practices markedly decrease the rigor of natural selection by pesticides that is responsible for resistance. Natural enemy preservation also prevents the great fluctuations and suiges in insect pest populations observed after the injudicious use of broad-spectrum insecticides. Under the IPM concept, insecticides are generally used when other practices are inadequate and the pest population reaches the economic threshold. In order to make the IPM concept effective, insecticides must be used as selectively as possible, with minimal disturbance to all other elements of the ecosystem. Thus IPM practices are essentially blueprints for the proper use of insecticides in insect pest control. 

Synthetic Pyrethroid Insecticides. Elucidation of the chemical structures of the naturally occurring pyrethrum esters, their rapid and selective insecticidal action, and their high cost stimulated the search for effective synthetic derivatives (13,17,21). Since the 1940s, structural optimization has produced an array of broad-spectrum insecticides with activity 10- to 20-fold greater than other types of insecticides, and with extended residual action. These synthetic pyrethroids have become one of the most important classes of insecticides with world annual production estimated at 6000 t (21). 

Endosulfan [115-29-7] (36) is the adduct of hexachlorocyclopentadiene and l,4-dihydroxy-2-butene which reacts subsequently with SOCl to produce 6>7>8>9>10>10-hexachloro-l,5,5, 6,9,9 -hexahydro-6>9-methano-2,4,3-benzodioxathiepin-3-oxide. The technical product is a brownish solid (mp 70— 100°C, vp 1.3 mPa at 30°C) which consists of about four parts of a-isomer (mp 108°C, cis with regard to the sulfite group) and one part of the p-isomer (mp 206°C, trans with regard to the sulfite group). The a-isomer, which is somewhat more insecticidal, is slowly converted to the more stable p-isomer at high temperature, and both isomers are oxidized slowly to endosulfan sulfate [1031-07-8] (mp 181°C). In acid media, both isomers form endosulfan diol [2157-19-9] (mp 203°C). The rat LDc-s are 43, 18 (oral) and 130, 74 (dermal) mg/kg. Endosulfan is a broad-spectrum insecticide for vegetables, fruits, and row crops. Unlike the other cyclodiene insecticides, it is biodegradable by hydrolysis at the sulfite ester bonds. 

Carbaryl [65-25-2], 1-naphthyl ZV-methylcarbamate (111) (mp 142°C, d 1.232 g/cm3, vp 0.67 Pa at 20°C), is ca 95% pure as the technical grade and is soluble in water to 120 mg/L. Carbaryl has a rat oral LD5Q of 540 mg/kg and a dermal LD50 of >2000 mg/kg. It is a broad-spectrum insecticide registered on more than 100 crops. Carbaryl is rapidly detoxified and eliminated in animal urine and is neither concentrated in fat nor secreted in the butterfat of milk, thus it is favored for application to food crops. 

Fenitrothion is a broad-spectrum insecticide effective against a number of insects. It has been widely used in Australia for locust control. In January 2002, nine workers were hospitalized in Melbourne, Australia, as the result of exposure to fenitrothion.8 The incident occured when a forklift ran over and punctured three cans of the insecticide. Symptoms reported included irritated skin, stinging eyes, and nausea. According to an official at the scene, fenitrothion works its way into the eyes, armpits, and up the nose. Because of the applications for which it is used, residential and dietary exposures to fenitrothion are considered to be negligible in the U.S. 

Malathion, also known by the generic name carbophos (0,0-dimethyl phosphorodithioate or diethyl mercaptosuccinate), is one of the very popular, short-lived broad-spectrum insecticides for application to nearly all fruits, vegetables, field crops, dairy livestock, and household insects. 

Uses nonsystemic, broad-spectrum insecticide used to control the spruce budworm in forests and also as molluscicide. 

The most intensive effort to use pheromones in insect management has been in Australia, where an attract-and-kill strategy has been developed for protecting stone fruit crops. Historically, the Oriental fruit moth, Grapholita molesta Busck, was the major stone fruit pest, and heavy insecticide applications kept both this moth and, coincidentally, the Carpophilus beetles at acceptable levels. However, the widespread adoption of pheromone-based mating disruption for G. molesta control released the Carpophilus beetles from insecticide pressure, and these beetles, Ca. davidsoni in particular, became the dominant stone fruit pests (James et al., 1994). Late applications of broad-spectrum insecticides often... 

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