Horticulture/Senecio

Senecio is a genus of the daisy family (Family ../Asteraceae/) that includes ragworts and groundsels. Though of late the genus has been reviewed and split up, it still contains a vast number of species (about 1,500) of extremely wide form including leaf succulents, stem and tuber succulents, annuals, perennials, aquatic forms, climbers, shrubs and small trees. Some species produce natural pesticides (especially alkaloids) to deter or even kill animals that would eat them.

Description
The flower heads are normally rayed, completely yellow, and the heads are borne in branched clusters.

Species

 * ../Senecio vulgaris/, Common Groundsel
 * ../Senecio jacobaea/, Tansy Ragwort

Pests and diseases
../Rusts/ ../Viruses/ ../Maggots/ ../Flea Beetles/ ../Caterpillars/
 * ../Puccinia lagenophorae/
 * ../Alfalfa Mosaic Virus/
 * ../Beet Western Yellows Virus/ (BWYV, syn. Beet mild yellowing luteovirus or BMYV)
 * ../Potato Virus Y/
 * Leafminer: ../Phytomyza senecionis/
 * Leafminer: ../Phytomyza ovatus/
 * Tansy seedfly: ../Pegohylemia seneciella/
 * Ragwort Flea Beetle: ../Longitarsus jacobaea/ has been introduced in New Zealand as a biocontrol for ../Senecio jacobaea/.
 * ../Longitarsus ganglbaueri/
 * list of Lepidoptera which feed on Senecio.
 * ../Cochylis atricapitana/
 * ../Phycitodes maritima/
 * ../Phycitodes saxicolais/
 * Saltmarsh Caterpillar: ../Estigmene acrea/
 * Cinnabar moth: ../Tyria jacobaeae/ absorbs alkaloids from the plant and become distasteful to predators, a fact advertised by the black and yellow warning colours. The red and black, day-flying adult moth is also distasteful to many potential predators. The moth is used as a biocontrol for ../Senecio jacobaea/ in countries in which it has been introduced and become a problem, like New Zealand and the western United States.