Ectoparasite control

Sources. Amibaz, a topical miticide, is used in flea collars and for ectoparasite control in swine. 

Rotenone-containing iasecticides have been used as dusts of ground roots, dispersible powders, and emulsive extracts. Their principal uses have been for appHcation to edible produce just prior to harvest and for the control of animal ectoparasites and cattle gmbs. 

Lindane is used predominately as a seed dressing and soil insecticide, for the control of ectoparasites of humans and domestic animals, for the control of locusts and grasshoppers, and as a residual spray to control the Anopheles vectors of malaria. Because of its relatively high volatility it is useful to control wood-boring insects of timber, fmit trees, and ornamental plants. The mode of action is not well understood but is thought to be competitive blocking of the y-aminobutyric acid (GABA) transmitter of synaptic nerve transmission. 

Vinyl Phosphates. Dichlorvos [62-73-7] 0,0-dimethyl 0-(2,2-dichloroviayl) phosphate, (CH20)2P(0)0CH=CCl2 (bp 140°C at 27 kPa, d 1.314, vp 1.6 Pa at 20°C), is soluble ia water to about 10 g/L. The half-hfe ia water is 8 h. The rat oral LD qS are 80, 56 mg/kg. Dichlorvos is used ia aerosols and sugar baits to control flies and mosquitoes. Slow release formulations have been used ia plastic strips and pet collars to control animal ectoparasites. 

HCH, sometimes misleadingly termed benzene hexachloride (BHC), exists in a number of different isomeric forms of which the gamma isomer has valuable insecticidal properties. These were discovered during the 1940s, and HCH came to be widely used as an insecticide to control crop pests and certain ectoparasites of farm animals after the Second World War. Crude technical BHC, a mixture of isomers, was the first form of HCH to be marketed. In time, it was largely replaced by a refined product called lindane, containing 99% or more of the insecticidal gamma isomer. 

The first commercially available HCH insecticide sometimes misleadingly called benzene hexachloride (BHC) was a mixture of isomers, principally alpha HCH (65-70%), beta HCH (7-10%), and gamma HCH (14-15%). Most of the insecticidal activity was due to the gamma isomer (Figure 5.1), a purified preparation of which (>99% pure) was marketed as lindane. In Western countries, technical HCH was quickly replaced by lindane, but in some other countries (e.g., China) the technical product, which is cheaper and easier to produce, has continued to be used. HCH has been used as a seed dressing, a crop spray, and a dip to control ectoparasites of farm animals. It has also been used to treat timber against wood-boring insects. 

Copper sulfate is used to control protozoan fish ectoparasites including Ichthyopthirius, Tri-chodina, and Costia. The effectiveness of the treatment diminishes with increasing total alkalinity and total hardness of the water (Straus and Tucker 1993). Copper compounds now used to control protozoan parasites of cultured red drum (Sciaenops ocellatus) include copper sulfate, copper sulfate plus citric acid, and chelated copper compounds (forms of copper bound by sequestering agents, such as ethanolamine) chelated copper compounds are considered less toxic to fish than copper sulfate and at least as effective in controlling parasites (Peppard etal. 1991). 

Copper discharges to the global biosphere are due primarily to human activities, especially mining, smelting, and refining copper and the treatment and recycling of municipal and industrial wastes. Some copper compounds, especially copper sulfate, also contribute to environmental copper burdens because they are widely and intensively used in confined geographic areas to control nuisance species of aquatic plants and invertebrates, diseases of terrestrial crop plants, and ectoparasites of fish and livestock. 

Uses Contact and stomach insecticide used to control mosquito larvae, house flies, ectoparasites on cattie, sheep, and goats recommended for use in dairy barns. Effective against a wide variety of pests in fieid, forage, fruit, and vegetabie crops. Methoxychior is aiso used to controi househoid and industriai pests (Worthing and Hance, 1991). 

Kirst HA, Creemer LC, Naylor SA, Pugh PT, Snyder DE, Winkle JR, Lowe L, Rothwell JT, Sparks TC, Worden TV. (2002) Evaluation and development of spinosyns to control ectoparasites on cattle and sheep. Curr Topics Med Chem 2 675-699. 

Rotenone and the rotenoids (Figure 2) have long been used as Insecticides and plscicides (fish poisons). By the early 1950 s more than 7 million pounds of Legumlnosae roots (Perris, Lonchocarpus, and Tephrosia spp.) containing these insecticides were imported annually into the United States. In 1972, about 1.5 million pounds of the roots were used in the United States for pest control in the home and garden markets and to control ectoparasites on animals (10). 

In veterinary medicine, the control of ectoparasites is of great importance due to their effects on livestock profitability and the health status of animals. Infestations on livestock can cause intense irritation leading to poor condition, weight loss, reduced milk yield, and hide or fleece damage. Furthermore, many species of acari are responsible for transmission of diseases to the host animals themselves or act as vectors of a number of diseases to humans [6]. 

The control of lice, mites and warbleflies continues to be achieved by the older agents. The selection pressure that caused resistance in cattle ticks and sheep blowfly has not been encountered by these other ectoparasites since their less frequent incidence has required less insecticide/acaricide usage. In addition to the OPs, rotenone (92) (the active principle of derris), an uncoupler of oxidative phosphorylation, continues to be used to combat mange. 

---