American Heritage® Dictionary of the English Language, Fourth Edition
- n. Either of two viscous liquid esters, C21H28O3 or C22H28O5, that are extracted from pyrethrum flowers and used as insecticides.
Century Dictionary and Cyclopedia
- n. A resinous compound found in pellitory resin from the root of Anacyclus Pyrethrum.
- n. chemistry Any of a number of naturally occurring insecticides extracted from the pyrethrum plant; unusual in having a cyclopropane ring.
GNU Webster's 1913
- n. (Chem.) A substance resembling, and isomeric with, ordinary camphor, and extracted from the essential oil of feverfew; -- called also
- pyrethr(um) + -in. (American Heritage® Dictionary of the English Language, Fourth Edition)
“Pyrethroid Pesticides were developed as a synthetic version of the naturally occurring pesticide pyrethrin, which is found in chrysanthemums.”
“Hackett says the problem is a long-acting insecticide called pyrethrin, also called permethrin.”
“These effects are due to "pyrethrin" contained in the plant, which is an acid fixed resin; also there are present a second resin, and a yellow, acrid oil, whilst the root contains inulin, tannin, and other substances.”
“The best products for elimination of fleas outdoors are formulations that contain a knockdown material such as pyrethrin or permethrin plus an insect growth regulator (pyriproxyfen or methoprene) to inhibit larval maturation.”
“A natural insecticide, "pyrethrin" is judged as the most effective and least harmful insecticide to mammals,”
“The recommended treatment is pyrethrin, used when leaves first show damage.”
“Load up your portable tanks with as much pyrethrin as necessary, spray liberally in the general direction of the GOP caucus nest, and stop asking for advice from ..”
“Piperonyl butoxide (a chemical used with pyrethrin and similar pesticides to kill wasps, ants, fleas and ticks, lice and other pests) was found in 52% of homes.”
“Still, keep Raid away from kitty: Cats' livers can't process pyrethrin fast enough to keep from, you know, dying.”
“Piperonyl Butoxide or N-Octyl Bicycloheptene Dicarboximide Not poisons on their own, these so-called pesticide synergists block the enzyme that breaks down pyrethrin in insects.”
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