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Purple loosestrife, is a well-known and well-documented invasive plant species, which has spread with prolific abundance throughout North America. Its invasiveness has lead to countless loss of habitat for wetland species in terms of loss of biodiversity with population densities that exclude native plant flora as well as excluding nesting waterfowl. Purple loosestrife is also presenting a challenge to agriculture as dense stands are rapidly invading into pastures, blocking drainage and irrigation canals and sloughs, moving away from traditional wetlands into ever increasingly drier habitats. Three insect species are being utilized throughout North America for the control of this invasive species. The chrysomelid loosestrife beetles, Galerucella pusilla and G. calmariensis have been introduced and established in Truro, Nova Scotia in the mid 1990’s on the flood plains with promising results. Further rearing and distribution would serve to limit spread of this weed over time and to reduce population densities where it occurs.
Both these beetles act as defoliators which act to strip foliage and buds from plants so completely that root reserves are depleted and winter mortality occurs. Surveys in 2004 have found that G. calmariensis has become the dominant species in Nova Scotia. 3000 beetles were reared and released in Nova Scotia in the summer of 2004. The third species, Hylobius transoversovittatus a weevil, is being recommended for release in areas where the Galerucella sp. are limited by moisture. This weevil has experienced success in the United States but because of its physiology does not distribute well on its own and must rely on human intervention to spread from site to site.
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