Centaurea is a genus of between 350 and 600 species of herbaceous thistle-like flowering plants in the family Asteraceae. Members of the genus are found only north of the equator, mostly in the Eastern Hemisphere; the Middle East and surrounding regions are particularly species-rich. In the western United States, yellow starthistles are an invasive species. Around the year 1850, seeds from the plant had arrived to the state of California. It is believed that those seeds came from South America.
Centaurea diffusa, also known as diffuse knapweed, white knapweed or tumble knapweed, is a member of the genus Centaurea in the family Asteraceae. This species is common throughout western North America but is not actually native to the North American continent, but to the eastern Mediterranean.
Centaurea solstitialis, yellow star-thistle, is a member of the family Asteraceae, native to the Mediterranean Basin region. The plant is also known as golden starthistle, yellow cockspur and St. Barnaby's thistle The plant is a thorny winter annual species in the knapweed genus.
Bruchidius villosus is a species of bean weevil known by the common names broom seed beetle and Scotch broom bruchid. This beetle is used as an agent of biological pest control against the noxious weed known as Scotch broom.
Exapion fuscirostre is a species of straight-snouted weevil known by the general common name Scotch broom seed weevil. It is used as an agent of biological pest control against the noxious weed known as Scotch broom.
Agapeta zoegana is a species of moth known as the sulphur knapweed moth and the yellow-winged knapweed root moth. It is used as an agent of biological pest control against noxious knapweeds, particularly spotted knapweed and diffuse knapweed.
Chaetorellia acrolophi is a species of tephritid fruit fly known as the knapweed peacock fly. It is used as an agent of biological pest control against noxious knapweeds, especially spotted knapweed.
Cyphocleonus achates is a species of true weevil known as the knapweed root weevil. It is native to southern Europe and the Mediterranean and is used as an agent of biological pest control against noxious knapweeds, especially spotted knapweed. It has recently been spotted in India.
Larinus minutus is a species of true weevil known as the lesser knapweed flower weevil. It is used as an agent of biological pest control against noxious knapweeds, especially diffuse knapweed and spotted knapweed.
Larinus obtusus is a species of true weevil known as the blunt knapweed flower weevil. It is used as an agent of biological pest control against noxious knapweeds, especially spotted knapweed.
Metzneria paucipunctella is a species of moth known as the spotted knapweed seed head moth. It is used as an agent of biological pest control against noxious knapweeds, particularly spotted knapweed.
Rhinocyllus conicus is a species of true weevil. It is best known as a controversial agent of biological pest control which has been used against noxious thistles in the genera Carduus, Cirsium, Onopordum, and Silybum.
Bangasternus orientalis is a species of true weevil known as the yellow starthistle bud weevil. It is used as an agent of biological pest control against the noxious weed yellow starthistle.
Chaetorellia australis is a species of tephritid fruit fly known as the yellow starthistle peacock fly. It is used as an agent of biological pest control against the noxious weed yellow starthistle.
Eustenopus villosus is a species of true weevil known as the yellow starthistle hairy weevil. It is used as an agent of biological pest control against the noxious weed yellow starthistle.
Larinus curtus is a species of true weevil known as the yellow starthistle flower weevil. It is native to Southern Italy, Southern Europe, the Middle East and the Caucasuses. It is used as an agent of biological pest control against the noxious weed yellow starthistle in the United States.
Centaurea virgata is a species of Centaurea. It is native to Western Asia. The subspecies C. virgata ssp. squarrosa is known as squarrose knapweed.
Urophora affinis is a species of tephritid or fruit flies in the genus Urophora of the family Tephritidae. It has been released in the United States and Canada as a biocontrol agent to control spotted knapweed. U. affinis became established in Montana in 1973.
Larinus planus is an insect of the Curculionidae family. They are oval shaped, dark brown or black, and about 5-10 millimeters long. While native to Europe, it is also common in North America. It feeds on floral buds, primarily of thistles, with the larvae stage being the most destructive to them. In North America, it has been used as a biocontrol agent. It is also known as Larinus carlinae.
Centaurea stoebe, the spotted knapweed or panicled knapweed, is a species of Centaurea native to eastern Europe. It is also an invasive species in the United States, and particularly widespread in dryer regions of the Pacific Northwest. This species along with Centaurea diffusa are the stereotypical "tumbleweed" of the West- breaking off at the top of the roots which facilitates its seeds spreading far and wide, but are not actually native to the North American continent, but to a similar dry climate in the Mediterranean.
