St. John's wort

      In Nova Scotia, Hypericum perforatum occurs mainly in localized areas including roadsides, pastures, cranberry and blueberry fields.

      Two insects, Chrysolina quadrigemina and Chrysolina hyperici, were introduced in 1969 with C. hyperici becoming the dominant species (Jensen et al., 2002). A third insect, Aplocera plagiata, was also released and caused significant defoliation in the initial season; however it was not detected in subsequent surveys (Sampson and MacSween, 1992). A fourth insect, Aphis chloris, was released in 1991 and had spread significantly from release sites (Sampson and MacSween, 1992).
St. John's wort with Chrysolina hyperici: G. Sampson 2003 St. John's wort: S. Crozier 2004 St. John's wort with Chrysolina hyperici: S. Crozier 2004 St. John's wort with Chrysolina hyperici: S. Crozier 2004 St. John's wort showing perforated leaves: S. Crozier 2004

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Prepared by S. Crozier and M.G. Sampson, 2005