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)Dichlorodiphenyldichloroethane: An organochlorine insecticide that is slightly irritating to the skin. (From Merck Index, 11th ed, p482)Dichlorodiphenyl Dichloroethylene: An organochlorine pesticide, it is the ethylene metabolite of DDT.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.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.Pesticide Residues: Pesticides or their breakdown products remaining in the environment following their normal use or accidental contamination.Dieldrin: An organochlorine insecticide whose use has been cancelled or suspended in the United States. It has been used to control locusts, tropical disease vectors, in termite control by direct soil injection, and non-food seed and plant treatment. (From HSDB)Mosquito Control: The reduction or regulation of the population of mosquitoes through chemical, biological, or other means.Anopheles: A genus of mosquitoes (CULICIDAE) that are known vectors of MALARIA.