pyrethrins

Noun

pyrethrin (plural pyrethrins)

1. Any of a number of naturally occurring insecticides extracted from the pyrethrum plant; unusual in having a cyclopropane ring.
   • Ecoparasite control, with appropriate concentrations of carbaryl, malathion, or pyrethrin dusts, is permissible if the agent is applied externally to both test and control animals not less than seven days prior to the start of the test.1983, D. E. Kaukeinen, Vertebrate Pest Control and Management Materials, page 102