Abstract
Yellow toadflax, L. vulgaris, is a herbaceous perennial native to Europe and northern Asia, which arrived with the first European colonists to eastern North America in the mid-1700s. Beginning in the mid-1800s, it quickly spread throughout temperate North America, where it is now an invader of cultivated lands and pastures, particularly on the Canadian Prairies. Although there have been no new biological control agents released against L. vulgaris in Canada since 1997, a brief status report on all existing biological control insects is given for the period 2000-12, including any changes in taxonomic nomenclature that have occurred. This chapter presents information on the weed status in Canada, followed by a comprehensive background on previous studies, review of the application of biological control in these programmes, an evaluation of the biological control efforts and future needs in research or implementation activities.