Editing Pyrethrum (section)

===Sprays===
Pyrethrum has been used for centuries as an [[insecticide]],<ref>''Bioaromatica'' [https://web.archive.org/web/20100324061424/http://www.aromatica.hr/eng/page.asp?id=buhac&sub=buhac3 The history of pyrethrum]</ref> and as a lice remedy in the [[Middle East]] ([[Persian powder]], also known as "Persian pellitory"). It was sold worldwide under the brand [[Zacherlin]] by Austrian industrialist [[Johann Zacherl|J. Zacherl]].<ref name="US Patent">{{US patent reference| number = 308172|issue-date=November 18, 1884| inventor = Johann Zacherl| title =Pyrethrum Soap}}</ref>  It is one of the most commonly used non-synthetic insecticides allowed in certified organic agriculture.<ref>[http://www.colostate.edu/Depts/CoopExt/4DMG/VegFruit/organic.htm Some Pesticides Permitted in Organic Gardening], by Laura Pickett Pottorff, Colorado State University Cooperative Extension, January 5, 2010.</ref>

The flowers should be dried and then crushed and mixed with water.
* [[Pyrethroid]]s are synthetic insecticides based on natural pyrethrum ([[pyrethrin]]s); one common example is [[permethrin]]. Pyrethrins are often sold in preparations that also contain the synthetic chemical [[piperonyl butoxide]], which enhances the [[toxic]]ity to insects and is faster acting compared with pyrethrins used alone. These formulations are known as ''synergized pyrethrins''.