Editing Hypericum perforatum (section)

=== Role as a herbivore food source ===
Though ''Hypericum perforatum'' is generally avoided by mammalian herbivores, a number of insects are dependent on it and its close relatives as a food source. ''[[Chrysolina quadrigemina]]'' and ''[[Chrysolina hyperici|C. hyperici]]'' are two beetle species that feed on plants from the genus ''Hypericum'', including ''H. perforatum''. ''Chrysolina quadrigemina'' can be colored metallic blue, purple, green, or bronze and is better adapted to warm and dry climates; ''Chrysolina hyperici'' is consistently smaller, metallic green, and tends to live in areas with wetter and cooler conditions.<ref name="CanadaAg">{{cite journal |last1=Harris |first1=P. |last2=Peschkin |first2=D. P. |title=Biological Control of St. Johns-Wort |journal=Canada Agriculture |date=1974 |volume=19 |issue=1 |pages=13–15 |url=https://archive.org/details/canadaagricultur191cana/page/13 |publisher=Canada Department of Agriculture |location=Ottawa, Canada}}</ref> Another ''Hyericum'' specialist beetle is ''[[Agrilus hyperici]]'', the St John's wort root borer, whose [[larva]]e feed on the roots of ''H. perforatum'' while the adults feed on the foliage.<ref>{{cite book |editor1-last=Copping |editor1-first=L.G. |title=The manual of biocontrol agents: a world compendium |date=2004 |publisher=British Crop Protection Council |location=Alton, Hampshire, United Kingdom |isbn=1-901396-35-5 |pages=270–271 |edition=Third |url=https://archive.org/details/manualofbiocontr0000unse/page/270 |access-date=2 August 2023}}</ref>

A moth, ''[[Treble-bar|Aplocera plagiata]]'', feeds heavily upon the leaves of ''H. perforatum'' as a caterpillar and is commonly known as the common St John's wort inchworm. As adults, they are a small moth with gray wings and dark gray bands.<ref name="FSControl">{{cite book |last1=Winston |first1=Rachel |last2=Randall |first2=Carol Bell |last3=Schwarzländer |first3=Mark |last4=Reardon |first4=Richard |title=Biology and Biological Control of Common St. Johnswort |date=2010 |publisher=U.S. Dept. of Agriculture, Forest Service, FHTET |location=Morgantown, West Virginia |url=https://archive.org/details/CAT31080043 |access-date=2 August 2023}}</ref> Another moth that feeds upon ''H. perforatum'' is ''[[Euspilapteryx auroguttella]]''. Their caterpillars start by mining the inside of the leaves and later roll the leaves into cigar shapes to feed in greater safety.<ref>{{cite web|url=http://www.bladmineerders.nl/minersf/lepidopteramin/euspilapteryx/auroguttella/auroguttella.htm|title=bladmineerders.nl|author=|date=|website=bladmineerders.nl|accessdate=18 January 2019|archive-url=https://web.archive.org/web/20160304204132/http://www.bladmineerders.nl/minersf/lepidopteramin/euspilapteryx/auroguttella/auroguttella.htm|archive-date=4 March 2016|url-status=dead}}</ref><ref name="Practical">{{cite book |last1=Shield |first1=Richard |title=Practical Hints Respecting Moths and Butterflies, With Notices of Their Localities : Forming a Calendar of Entomological Operations Throughout the Year, in Pursuit of Lepidoptera |date=1856 |publisher=John Van Voorst |location=London |pages=7, 42, 59, 83, 101 |url=https://archive.org/details/practicalhintsre00shie/page/7 |access-date=10 August 2023}}</ref> ''[[Agonopterix hypericella]]'' is another small ({{convert|17|mm|abbr=on}}) gray moth that exclusively feeds upon ''Hypericum''.<ref>{{cite web |title=Agonopterix hypericella (Insecta: Lepidoptera: Depressariidae) |url=http://www2.nrm.se/en/svenska_fjarilar/a/agonopterix_hypericella.html |website=Svenska Fjärilar |publisher=Naturhistoriska Riksmuseet |access-date=10 August 2023}}</ref><ref name="Practical" />

''Zeuxidiplosis giardi'', the common St. Johnswort gall [[midge]], is a small ({{convert|3|mm|abbr=on}}) fly that eats ''H. perforatum'' while developing. The larvae feed upon leaf buds, which causes the plant to form a round growth called a [[gall]] where the developing insect can feed, is protected, and [[pupa]]tes into a mature adult.<ref name="FSControl" />