Efforts are being made to prevent the introduction of the purple loosestrife. Adults overwinter in leaf litter near purple loosestrife plants. Among the plants were several close relatives of purple loosestrife. In late years, the marshes have suffered from an invasion of Purple Loosestrife. Notable examples include water hyacinth, salt cedar, and purple loosestrife. It has been introduced in North America as a biological control agent for purple loosestrife. A literature review notes sora avoidance of purple loosestrife ("Lythrum salicaria")-dominated sites. Invasive plants include purple loosestrife and Eurasian watermilfoil. Invasive plants include Himalayan blackberry, English ivy, reed canarygrass, purple loosestrife, and Japanese knotweed. Purple loosestrife provides a model of successful biological pest control. Invasive plant species include purple loosestrife and Japanese knotweed. Many wetlands are being disrupted by the highly invasive Introduced species purple loosestrife. Water plants include water forget-me-not, bogbean and purple loosestrife. Purple loosestrife is a plant that is invasive to waterways. The species "L. salicaria" (purple loosestrife) and "L. virgatum" are found in cultivation.