Editing Jacobaea vulgaris (section)

==Ecological importance==
Although the plant is often unwanted by landowners because of its toxic effect for cattle and horses, and because it is considered a [[weed]] by many, it provides a great deal of [[nectar]] for [[pollinators]]. It was rated in the top 10 for most nectar production (nectar per unit cover per year) in a [[UK]] plants survey conducted by the AgriLand project which is supported by the UK Insect Pollinators Initiative.<ref name=Pollinators>{{cite web |title=Which flowers are the best source of nectar? |date=2014-10-15 |publisher=Conservation Grade |url=http://www.conservationgrade.org/2014/10/which_flowers_best_source_nectar/ |access-date=2017-10-18 |archive-date=2019-12-14 |archive-url=https://web.archive.org/web/20191214024659/http://www.conservationgrade.org/2014/10/which_flowers_best_source_nectar/ |url-status=dead }}</ref> It also was the top producer of nectar sugar in another study in Britain, with a production per floral unit of (2921 ± 448μg).<ref>{{cite journal |last1=Hicks|first1=D. M. |last2=Ouvrard|first2=P. |last3=Baldock|first3=K. C. R. |title=Food for Pollinators: Quantifying the Nectar and Pollen Resources of Urban Flower Meadows |journal=PLOS ONE |volume=11 |issue=6 |pages=e0158117 |date=2016 |doi=10.1371/journal.pone.0158117 |pmid=27341588 |pmc=4920406 |bibcode=2016PLoSO..1158117H |doi-access=free}}</ref>

[[File:Eristalis tenax and flowers.jpg|thumb|[[Eristalis tenax|Drone fly]] on ragwort]]
[[File:Senecio jacobaea - Le Sénécon jacobée - Jakobs-Greiskraut - Jacobskuiskruid - 3.JPG|thumb|''Jacobaea vulgaris'']]
In the United Kingdom, where the plant is native, ragwort provides a home and food source to at least 77 insect species. Thirty of these species of invertebrate use ragwort exclusively as their food source<ref name=buglife>{{cite web |title=Ragwort Fact File |url=http://www.buglife.org.uk/conservation/currentprojects/Habitats+Action/Ragwort/ragwortfactfile |access-date=2012-03-31 |archive-url=https://web.archive.org/web/20120514042802/http://www.buglife.org.uk/conservation/currentprojects/Habitats+Action/Ragwort/ragwortfactfile |archive-date=2012-05-14 |url-status=dead}}</ref> and there are another 22 species where ragwort forms a significant part of their diet.

English Nature identifies a further 117 species that use ragwort as a nectar source whilst travelling between feeding and breeding sites, or between metapopulations.<ref name=buglife/> These consist mainly of solitary bees, hoverflies, moths, and butterflies such as the small copper butterfly (''[[Lycaena phlaeas]]''). Pollen is collected by solitary bees.<ref>{{cite journal |last1=Wood|first1=Thomas J. |last2=Holland|first2=John M. |last3=Goulson|first3=Dave |title=Providing foraging resources for solitary bees on farmland: current schemes for pollinators benefit a limited suite of species |journal=Journal of Applied Ecology |volume=54 |pages=323–333 |date=2016 |doi=10.1111/1365-2664.12718 |url=http://sro.sussex.ac.uk/60867/3/Pollen%20insights%20FINAL%20DRAFT%2006.04.2016.pdf}}</ref>

Besides the fact that ragwort is very attractive to such a vast array of insects, some of these are very rare indeed. Of the 30 species that specifically feed on ragwort alone, seven are officially deemed [[British nature conservation statuses|nationally scarce]]. A further three species are on the [[IUCN Red List]]. In short, ragwort is an exclusive food source for ten rare or threatened insect species, including the [[cinnabar moth]] (''Tyria jacobaeae''),<ref>{{cite web |title=Common caterpillars: A simple guide | url=http://www.countrylife.co.uk/nature/a-simple-guide-to-10-common-caterpillars-72350 |publisher=countrylife.co.uk |access-date=20 July 2017 |date=7 June 2017}}</ref> the picture winged fly (''Campiglossa malaris''), the scarce clouded knot horn moth (''[[Homoeosoma nimbella]]''), and the Sussex emerald moth (''[[Thalera fimbrialis]]'').<ref name=buglife/> The Sussex Emerald has been labelled a Priority Species in the [[United Kingdom Biodiversity Action Plan]]. A priority species is one which is "scarce, threatened and declining".<ref name="ukbap">{{cite web |publisher=Butterfly Conservation |date=2007 |title=The United Kingdom Biodiversity Action Plan - moths |url=http://www.butterfly-conservation.org/uploads/The%20UK%20Biodiversity%20Action%20Plan%20-%20BC%20website%20draft%2020071.pdf |archive-url=https://web.archive.org/web/20120507201500/http://www.butterfly-conservation.org/uploads/The%20UK%20Biodiversity%20Action%20Plan%20-%20BC%20website%20draft%2020071.pdf |archive-date=2012-05-07}}</ref> The remainder of the ten threatened species include three species of leaf beetle, another picture-winged fly, and three micro moths. All of these species are Nationally Scarce B, with one leaf beetle categorised as Nationally Scarce A.<ref name=buglife/>

The most common of those species that are totally reliant on ragwort for their survival is the cinnabar moth. The cinnabar is a United Kingdom Biodiversity Action Plan Species, its status described as "common and widespread, but rapidly declining".<ref name="ukbap"/>