On June ll, 1993, 2,000 Galerucella pusilla and G. calmariensis were released at this site in southern Ontario. The core area was, virtual monoculture of purple loosestrife with plants over 2m tall covering >5,000 square meters. Over the last 4 years the insect populations have exploded, completely suppressing seed output, and reducing purple loosestrife biomass from over 2,000g to less than 20g per square meter. In 1996, purple loosestrife plants were about knee high and native plants such as cattails have flourished (see picture taken 1996). Purple loosestrife is severely damaged throughout the entire core area (5,000 square meters) and beetles have spread several kilometers from the site. The Galerucella beetles produced 3-5 generations before this damage became obvious. Many releases at other sites across the continent were made more recently (within the last 2-3 years) and not enough time has passed to allow insect populations to build-up to damaging levels. While this example is the most spectacular so far, it is anticipated that many sites will develop similar profiles in the near future. The reductions in purple loosestrife biomass and the return of the native cattails demonstrate the potential of biological weed control as a management tool. It is anticipated that purple loostrife can be controlled over large areas within the next decade.	One year earlier, two species of leaf-eating beetles were released on this site and became established in 1994
	By 1995, the leaf-eating beetles defoliated nearly all the loosestrife
	In 1996, the purple loostrife biomass was reduced by over 90% and native plants were starting to rebound

The introduction of these biocontrol insects is not intended to eradicate purple loosestrife, but will significantly reduce its abundance in wetland habitats. The results observed in Ontario are expected to be repeated at many purple loosestrife infestations where insects are introduced. The level of purple loosestrife reduction will depend on individual site characteristics and the insect species introduced. However, it is anticipated that purple loosestrife will be controlled over large areas within the next decade.

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