Distribution of Lythrum salicaria

Origin(s) Native to Europe and Asia Possibly introduced as seed from ship ballast in 1800s on east coast Sheep wool? Probably introduced in nursery trade as an ornamental or medicinal plant In 23 states and 9 provinces currently declared as officially Noxious

Identification & Taxonomy Lythraceae Variable growth form –Leaves opposite or alternate –Stem glabrous or pubescent Many ornamental varieties

Biology Germinate on moist open (=disturbed) soils Tolerate wide range of growing conditions such as moisture, substrate, pH (=generalist) Long-lived (=perennial) Mature plant produces 2.5 million seeds/yr that are viable in seed bank for years

Ecological Impact can produce near monoculture leading to loss of native biodiversity harms waterfowl nesting habitat negative impacts on some amphibians and algal communities reduces water flow and quality inhibits transportation degrades hunting and fishing areas.

Control Chemical –herbicides-must be approved for use around water –provide short-term control of small infestations or isolated plants, but may be impractical and uneconomical against large infestations. Mechanical –pulling small, individual plants is feasible; pulling large plants is very difficult. –plowing or disking small infestations is also possible, but will require repeated treatments as plants will sprout from cut root pieces. Plowing large infestations is difficult and generally ineffective. –mowing, burning, and flooding can be effective management strategies, but are difficult, expensive, and time-consuming, and may have severe negative, long-term consequences for wetland communities. Biocontrol

No potential herbivores in North America >100 associated insects found in Europe, 9 evaluated –some also fed on non-target natives, Lythrum alatum and Decodon verticillatus (Swamp Loosestrife) –further invasion by L. salicaria considered a greater threat Other flower or seed eating predators considered

Natural Enemies Leaf feeders: Galerucella calmariensis & G. pusilla Coleoptera: Chrysomelidae Larvae produce diagnostic “shothole” damage

Natural Enemies Root feeder: Hylobius transversovittatus Coleoptera: Curculionidae Root damage Stem damage

Natural Enemies Flower feeder: Nanophyes marmoratus Coleoptera: Cucurlionidae

Culturing Beetles

Life Cycle and Timing