Malathion: A wide spectrum aliphatic organophosphate insecticide widely used for both domestic and commercial agricultural purposes.Insecticides: Pesticides designed to control insects that are harmful to man. The insects may be directly harmful, as those acting as disease vectors, or indirectly harmful, as destroyers of crops, food products, or textile fabrics.Insecticide Resistance: The development by insects of resistance to insecticides.Lice Infestations: Parasitic attack or subsistence on the skin by members of the order Phthiraptera, especially on humans by Pediculus humanus of the family Pediculidae. The hair of the head, eyelashes, and pubis is a frequent site of infestation. (From Dorland, 28th ed; Stedman, 26th ed)Parathion: A highly toxic cholinesterase inhibitor that is used as an acaricide and as an insecticide.Propoxur: A carbamate insecticide.Permethrin: A pyrethroid insecticide commonly used in the treatment of LICE INFESTATIONS and SCABIES.Pediculus: Lice of the genus Pediculus, family Pediculidae. Pediculus humanus corporus is the human body louse and Pediculus humanus capitis is the human head louse.ThiomalatesForensic Sciences: Disciplines that apply sciences to law. Forensic sciences include a wide range of disciplines, such as FORENSIC TOXICOLOGY; FORENSIC ANTHROPOLOGY; FORENSIC MEDICINE; FORENSIC DENTISTRY; and others.Methyl Parathion: The methyl homolog of parathion. An effective, but highly toxic, organothiophosphate insecticide and cholinesterase inhibitor.Pesticides: Chemicals used to destroy pests of any sort. The concept includes fungicides (FUNGICIDES, INDUSTRIAL); INSECTICIDES; RODENTICIDES; etc.Organothiophosphorus Compounds: Compounds containing carbon-phosphorus bonds in which the phosphorus component is also bonded to one or more sulfur atoms. Many of these compounds function as CHOLINERGIC AGENTS and as INSECTICIDES.Organothiophosphates: Carbon-containing thiophosphoric acid derivatives. Included under this heading are compounds that have carbon bound to either SULFUR atom, or the OXYGEN atom of the SPO3 core structure.Organophosphorus Compounds: Organic compounds that contain phosphorus as an integral part of the molecule. Included under this heading is broad array of synthetic compounds that are used as PESTICIDES and DRUGS.Lepidium: A plant genus of the family BRASSICACEAE growing in Peru mountains. It is the source of maca root.Scalp DermatosesDimethoate: An organothiophosphorus cholinesterase inhibitor that is used as a systemic and contact insecticide.DDT: A polychlorinated pesticide that is resistant to destruction by light and oxidation. Its unusual stability has resulted in difficulties in residue removal from water, soil, and foodstuffs. This substance may reasonably be anticipated to be a carcinogen: Fourth Annual Report on Carcinogens (NTP-85-002, 1985). (From Merck Index, 11th ed)Fenitrothion: An organothiophosphate cholinesterase inhibitor that is used as an insecticide.Mosquito Control: The reduction or regulation of the population of mosquitoes through chemical, biological, or other means.Lethal Dose 50: The dose amount of poisonous or toxic substance or dose of ionizing radiation required to kill 50% of the tested population.Organophosphate Poisoning: Poisoning due to exposure to ORGANOPHOSPHORUS COMPOUNDS, such as ORGANOPHOSPHATES; ORGANOTHIOPHOSPHATES; and ORGANOTHIOPHOSPHONATES.Diazinon: A cholinesterase inhibitor that is used as an organothiophosphorus insecticide.Culex: A genus of mosquitoes (CULICIDAE) commonly found in tropical regions. Species of this genus are vectors for ST. LOUIS ENCEPHALITIS as well as many other diseases of man and domestic and wild animals.Piperonyl Butoxide: An insecticide synergist, especially for pyrethroids and ROTENONE.Anopheles: A genus of mosquitoes (CULICIDAE) that are known vectors of MALARIA.Pyrethrins: The active insecticidal constituent of CHRYSANTHEMUM CINERARIIFOLIUM flowers. Pyrethrin I is the pyretholone ester of chrysanthemummonocarboxylic acid and pyrethrin II is the pyretholone ester of chrysanthemumdicarboxylic acid monomethyl ester.