Background Ecosystems evolve a balance between their many species. Predation is a part of that natural balance. Indigenous plant and animal populations are kept in check by indigenous predators. Invading species threaten ecosystems because invaders frequently do not have predators. The invaders often have the ability to disrupt the existing ecological balance, dominate an area and have adverse unforeseen consequences.
Purple loosestrife is an invading species with few if any local natural predators.
The USDA has approved the Galerucella beetle, a natural predator from Europe for use in Purple loosestrife control. Section Two of the Cooperator's Handbook provides details on the biology, ecology and management of these two organisms, and includes additional references for teachers and students. Locate a site with a fairly large, medium to heavy infestation of purple loose strife. Arrange a field trip to the site or someone to collect at the site. While on site, students individually or in groups of two, map and record site observations such as surrounding human activity, plant and animal life, water amount and flow etc.