Pyrethrum refers to several Old World plants of the genus
ChrysanthemumChrysanthemums, often called mums or chrysanths, are of the genus constituting approximately 30 species of perennial flowering plants in the family Asteraceae which is native to Asia and northeastern Europe.-Etymology:...
(e.g.,
C. coccineum) which are cultivated as ornamentals for their showy
flowerA flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
heads. Pyrethrum is also the name of a natural
insecticideAn insecticide is a pesticide used against insects. They include ovicides and larvicides used against the eggs and larvae of insects respectively. Insecticides are used in agriculture, medicine, industry and the household. The use of insecticides is believed to be one of the major factors behind...
made from the dried flower heads of
C. cinerariifolium and
C. coccineum.
Description
Some members of the
Chrysanthemum genus, such as the following two, are placed in the
TanacetumTanacetum is a genus of about 160 species of flowering plant in the family Asteraceae, native to many regions of the Northern Hemisphere.Common names include Tansy , Costmary , and Feverfew ; several other species are also known as tansies.Tanacetum species...
genus instead by some botanists. Both genera are members of the daisy (or aster) family,
AsteraceaeThe Asteraceae or Compositae , is an exceedingly large and widespread family of vascular plants. The group has more than 22,750 currently accepted species, spread across 1620 genera and 12 subfamilies...
. They are all
perennial plantA perennial plant or simply perennial is a plant that lives for more than two years. The term is often used to differentiate a plant from shorter lived annuals and biennials. The term is sometimes misused by commercial gardeners or horticulturalists to describe only herbaceous perennials...
s with a daisy-like appearance and
whiteWhite is a color, the perception of which is evoked by light that stimulates all three types of color sensitive cone cells in the human eye in nearly equal amounts and with high brightness compared to the surroundings. A white visual stimulation will be void of hue and grayness.White light can be...
petalPetals are modified leaves that surround the reproductive parts of flowers. They often are brightly colored or unusually shaped to attract pollinators. Together, all of the petals of a flower are called a corolla. Petals are usually accompanied by another set of special leaves called sepals lying...
s.
- T. cinerariifolium is called the Dalmatian chrysanthemum, denoting its origin in that region of the Balkans (Dalmatia
Dalmatia is a historical region on the eastern coast of the Adriatic Sea. It stretches from the island of Rab in the northwest to the Bay of Kotor in the southeast. The hinterland, the Dalmatian Zagora, ranges from fifty kilometers in width in the north to just a few kilometers in the south....
). It looks more like the common daisy than other pyrethrums. Its flowers, typically white with a yellow center, grow from numerous fairly rigid stems. Plants have blue-green leaves and grow to between 45 to 60 cm in height. The plant is economically important as a natural source of insecticideAn insecticide is a pesticide used against insects. They include ovicides and larvicides used against the eggs and larvae of insects respectively. Insecticides are used in agriculture, medicine, industry and the household. The use of insecticides is believed to be one of the major factors behind...
. The flowers are pulverized and the active components, called pyrethrinThe pyrethrins are a pair of natural organic compounds that have potent insecticidal activity. Pyrethrins are neurotoxins that attack the nervous systems of all insects. When present in amounts not fatal to insects, they still appear to have an insect repellent effect. Pyrethrins are gradually...
s, contained in the seed cases, are extracted and sold in the form of an oleoresin. This is applied as a suspension in water or oil, or as a powder. Pyrethrins attack the nervous systems of all insectInsects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s, and inhibit female mosquitoMosquitoes are members of a family of nematocerid flies: the Culicidae . The word Mosquito is from the Spanish and Portuguese for little fly...
es from biting. When present in amounts less than those fatal to insects, they still appear to have an insect repellentAn insect repellent is a substance applied to skin, clothing, or other surfaces which discourages insects from landing or climbing on that surface. There are also insect repellent products available based on sound production, particularly ultrasound...
effect. They are harmful to fishFish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
, but are far less toxic to mammalMammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s and birdBirds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s than many synthetic insecticides and are not persistent, being biodegradableBiodegradation or biotic degradation or biotic decomposition is the chemical dissolution of materials by bacteria or other biological means...
and also breaking downChemical decomposition, analysis or breakdown is the separation of a chemical compound into elements or simpler compounds. It is sometimes defined as the exact opposite of a chemical synthesis. Chemical decomposition is often an undesired chemical reaction...
easily on exposure to light. They are considered to be amongst the safest insecticides for use around foodFood is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals...
. KenyaKenya , officially known as the Republic of Kenya, is a country in East Africa that lies on the equator, with the Indian Ocean to its south-east...
produced 90% (over 6,000 tonneThe tonne, known as the metric ton in the US , often put pleonastically as "metric tonne" to avoid confusion with ton, is a metric system unit of mass equal to 1000 kilograms. The tonne is not an International System of Units unit, but is accepted for use with the SI...
s) of the world's pyrethrum in 1998, called py for short. Production in TanzaniaThe United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state...
and EcuadorEcuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
is also significant.
- C. coccineum, the Persian chrysanthemum, is a perennial plant native to Caucasus
The Caucasus, also Caucas or Caucasia , is a geopolitical region at the border of Europe and Asia, and situated between the Black and the Caspian sea...
and looks somewhat like a daisyThe Asteraceae or Compositae , is an exceedingly large and widespread family of vascular plants. The group has more than 22,750 currently accepted species, spread across 1620 genera and 12 subfamilies...
. It produces large white, pink or red flowers. The leaves resemble those of fernA fern is any one of a group of about 12,000 species of plants belonging to the botanical group known as Pteridophyta. Unlike mosses, they have xylem and phloem . They have stems, leaves, and roots like other vascular plants...
s, and the plant grows to between 30 and 60 cm in height. The flowering period is June to July in temperate climates (Northern hemisphere). C. coccineum also contains insecticidal pyrethrum substances, but it is a poor source compared to C. cinerariifolium.
- Other species such as C. balsamita and C. marshalli also contain insecticidal substances, but are less effective than the two species mentioned above.
Sprays
Pyrethrum was used for centuries as an
insecticideAn insecticide is a pesticide used against insects. They include ovicides and larvicides used against the eggs and larvae of insects respectively. Insecticides are used in agriculture, medicine, industry and the household. The use of insecticides is believed to be one of the major factors behind...
, and as a lice remedy in the
Middle EastThe Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East...
(
PersianIran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...
powderPersian powder is a Plant toxin insecticide powder, also called "Persian Pellitory" and Insect powder.-Biological pest control:Persian powder is a green pesticide that has been used for centuries for the biological pest extermination of household insects, garden pests, and agricultural pests...
, also known as "Persian pellitory"). It was sold worldwide under the brand Zacherlin by Austrian industrialist
J. ZacherlJohann Zacherl was an Austrian inventor, industrialist and manufacturer. Johann Zacherl made a fortune in the late 19th century by selling dried flower heads of Chrysanthenum cinerariifolum as an insecticide.- Biography :...
.
The flowers should be dried and then crushed and mixed with water. It should be noted that though the pesticide is organic, it can still be harmful to humans.
- Pyrethroid
A pyrethroid is an organic compound similar to the natural pyrethrins produced by the flowers of pyrethrums . Pyrethroids now constitute a major commercial household insecticides...
s are synthetic insecticides based on natural pyrethrum ( pyrethrinThe pyrethrins are a pair of natural organic compounds that have potent insecticidal activity. Pyrethrins are neurotoxins that attack the nervous systems of all insects. When present in amounts not fatal to insects, they still appear to have an insect repellent effect. Pyrethrins are gradually...
s ); one common example is permethrinPermethrin is a common synthetic chemical, widely used as an insecticide, acaricide, and insect repellent. It belongs to the family of synthetic chemicals called pyrethroids and functions as a neurotoxin, affecting neuron membranes by prolonging sodium channel activation. It is not known to...
. A common formulation of pyrethrin is in preparations containing the synthetic chemical piperonyl butoxidePiperonyl butoxide is an organic compound used as pesticide synergist, especially for pyrethroids and rotenone. It does not by itself have pesticidal properties. However, when added to insecticide mixtures, typically pyrethrin, pyrethroid, and carbamate insecticides, their potency is increased...
: this has the effect of enhancing the toxicity to insects and speeding the effects when compared with pyrethrins used alone. These formulations are known as synergized pyrethrins.
Companion planting
Because of the natural insecticidal properties of the pyrethrums, they are used as companion plants, to repel pest insects from nearby crops and
ornamental plantOrnamental plants are plants that are grown for decorative purposes in gardens and landscape design projects, as house plants, for cut flowers and specimen display...
s. They are thought to repel
aphidAphids, also known as plant lice and in Britain and the Commonwealth as greenflies, blackflies or whiteflies, are small sap sucking insects, and members of the superfamily Aphidoidea. Aphids are among the most destructive insect pests on cultivated plants in temperate regions...
s, bed bugs (
Cimex lectularius),
leafhopperLeafhopper is a common name applied to any species from the family Cicadellidae. Leafhoppers, colloquially known as hoppers, are minute plant-feeding insects in the superfamily Membracoidea in the order Hemiptera...
s,
spider miteSpider mites are members of the Acari family Tetranychidae, which includes about 1,200 species. They generally live on the under sides of leaves of plants, where they may spin protective silk webs, and they can cause damage by puncturing the plant cells to feed...
s, harlequin bugs,
tickTicks are small arachnids in the order Ixodida, along with mites, constitute the subclass Acarina. Ticks are ectoparasites , living by hematophagy on the blood of mammals, birds, and sometimes reptiles and amphibians...
s, pickleworms and imported
cabbage wormThe term cabbage worm is primarily used for any of four kinds of lepidopteran whose larvae feed on cabbages and other cole crops. Host plants include broccoli, cauliflower, Brussels sprouts, collards, kale, mustard greens, turnip greens, radishes, turnips, rutabagas and kohlrabi...
s, among others that are in gardens and farms. For example, they are planted among broccoli plants for protection from several common insect pests.
Common names
Common names for
Chrysanthemum cinerariifolium include:
- Pyrethrum
- Pyrethrum daisy
- Dalmatian pyrethrum
- Dalmatian chrysanthemum
- Dalmatian insect flower
- Dalmatian pellitory
Pellitory may refer to:*Anacyclus pyrethrum or pellitory, a plant containing an oil once used for toothaches and facial neuralgia*Achillea ptarmica or European pellitory, bastard pellitory, or wild pellitory*Parietaria debilis...
- Big daisy
Common names for
Chrysanthemum coccineum include:
- Pyrethrum
- Pyrethrum daisy
- Painted daisy
- Persian chrysanthemum
- Persian insect flower
- Persian pellitory
Pellitory may refer to:*Anacyclus pyrethrum or pellitory, a plant containing an oil once used for toothaches and facial neuralgia*Achillea ptarmica or European pellitory, bastard pellitory, or wild pellitory*Parietaria debilis...
- Caucasian insect powder plant
See also
- Chrysanthemum
Chrysanthemums, often called mums or chrysanths, are of the genus constituting approximately 30 species of perennial flowering plants in the family Asteraceae which is native to Asia and northeastern Europe.-Etymology:...
- List of companion plants
Category: Plant toxin insecticides
External links
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