Pyrethrum, Tanacetum

Natural pyrethrins, insecticidal ingredients occurring in the flowers of Tanacetum cinerariaefolium (also known as Chrysanthemum cinerariaefolium or Pyrethrum cinerariaefolium), have been modified for higher stability in the environment as well as better biological performance for more than 40 years, and consequently more than 30 synthetic pyrethroids have been marketed and used worldwide for controlling indoor and agricultural pest insects [1,2]. 

Tanacetum parthenium (L.) Schultz Bip. is the official Latin name for the member of the Compositae family which is more commonly referred to as feverfew [6]. The plant had previously been classified as Chrysanthemum parthenium (L.) Bernh., so the latter name is strictly speaking no longer correct. Other old classifications for feverfew are Leucanthemum parthenium (L.) Gren. Godron or Pyrethrum parthenium (L.) Sm. 

Pyrethrum refers to the oleoresin extracted from the dried flowers of Tanacetum cinerariaefolium (Asteraceae) and is the source of the pyrethrins, chrysanthemates and pyrethrates. Among the natural pyrethrins, those incorporating the alcohol pyrethrolone, namely pyrethrins 1 and II (Fig. 9), are the most abundant and account for most of the insecticidal activity. The pyrethrins are recommended for control of a wide range of insects and mites on fruit, vegetables, field crops, ornamentals, glasshouse crops and house plants, as well as in public health, stored products, animal houses and on domestic and farm animals. Pyrethrins are sold in a wide variety of formulations, under many different trade names by a large number of different manufacturers. 

The pyrethrins are valuable insecticidal components of pyrethrum flowers, Chrysanthemum cinerariaefolium (= Tanacetum cinerariifolium) (Compositae/Asteraceae). The flowers are harvested just before they are fully expanded, and usually processed to an extract. Pyrethrum cultivation is conducted in East Africa, especially Kenya, and more recently in Ecuador and Australia. The natural pyrethrins are used as a constituent of insect sprays for household use and as post-harvest insecticides, having a rapid action on the nervous system of insects, whilst being biodegradable and non-toxic to mammals, though they are toxic to fish and amphibians. This biodegradation, initiated by air and light, means few insects develop resistance to the pyrethrins, but it does limit the lifetime of the insecticide under normal conditions to just a few hours. 

Kalmia latifolia, Leucothoe grayana, L. spp., Rhododendron spp. (Ericaceae) in honey from Rhododendron-feeding bees Tanacetum (Chrysanthemum) cinerariifolium (pyrethrum) (Asteraceae) Leopold Ruzicka (Croatia/Switzerland, Nobel Prize, 1939, Chemistry, polymethylenes terpenes) Tanacetum (Chrysanthemum) cinerariifolium (pyrethrum) (Asteraceae)... 

The pyrethrum daisies Chrysanthemum (=Tanacetum) cinerariifolium and C. cocci neum contain several compounds that kill insect pests on contact. You can purchase this insecticide in several forms The dried flqwer heads are called pyrethtum, while the extmeted active ingredients are called pyrethrin. (Pyrethroids are synthetic versions of the insecticide that are even more toxic to insects.)... 

The Dalmatian insect powder, as its name imphes, was prepared from the dried, crushed blooms of the Dalmatian insect-flower (Tanacetum cinerarUfoli-um, syn. Chrysanthemum cinerariifolium, Pyrethrum cinerariifolium) (Fig. 8.23). 

On the other hand the Armenian, Persian and Caucasian insect powder was obtained from the Caucasian insect-flower (Tanacetum coccineum, syn. Chrysanthemum coccineum, Pyrethrum roseum, Pyrethrum carneum), native to the Caucasus. 

Synonyms Chrysanthemum tanacetum Vis., Chrysanthemum vulgare (L.) Bemh., Pyrethrum vulgare (L.) Boiss., Tanacetum... 

Pyrethrins (such as 96 and 97, Fig. 19.21 and 19.22) are of special interest because of their insecticidal properties and ecomonic importance (Mabry and Gill, 1979). These compounds are isolated from the genus Chrysanthemum (sometimes segregated as species of Pyrethrum, or transferred to the genus Tanacetum). Several species are cultivated and the flowers harvested and extracted with lipid solvents (such as petroleum ether) to yield a crude p3n-ethrin fraction. 

Generally, sesquiterpenes are less volatile than monoterpenes. Among the sesquiterpenes, the sesquiterpene lactones are widely distributed in terrestrial and marine organisms and are well known for their wide variety of biological activities. The anti-inflammatory activities of some medicinal plants are due to presence of one or more sesquiterpene lactones [89]. Parthenolide is responsible for the majority of the medicinal characteristics of this traditional herbal remedy. This sesquiterpene lactone can be found in several species, including Chrysanthemum parthenium, Leucanthemum parthenium, Pyrethrum parthenium, and Tanacetum parthenium [90]. 

Pyrethrins. Although phytochemicals from a wide variety of chemical families (alkaloids, terpenes, furanocoumarins, polyacetylenes, unsaturated amides, and others) have been shown to possess insecticidal properties, only one group, the pyrethrins, has achieved major commercial success. The recognized insecticidal activity of pyrethrum (dried and powdered flowers of Tanacetum coccineum (Persian insect flower) and Tanacetum cinerari-... 

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