Mystery Graph: Purple loosestrife (Lythrum salicaria) & the Galerucella beetle

Use this activity to kick off a Vital Signs investigation focused on purple loosestrife (Lythrum salicaria). Use your graphing skills to figure out and explain what happened during a 12-year scientific study in New Jersey to control the spread of invasive purple loosestrife. Learn about a similar study happening at the Rachel Carson National Wildlife Refuge in Wells, Maine.

Project Information
Grade Level: 
Middle school (grades 6-8)
High school (grades 9-12)
Resources I used: 
Beetles used to fight invasive plant July 14, 2008 Amy Sinclair
How should others reference your work?: 
vitalteach, Mystery Graph: Purple loosestrife & Galerucella beetle, Vital Signs Program, Gulf of Maine Research Institute, 2010


I like purple loosestrife

This activity was a great one to use in my math classes. We have been studying various graphs and the way graphs can be interpreted, as well as getting ready to collect data from our high school's cross country course on the various native and invasive species that can be found there.

I ended up doing this activity as a Think-Pair-Share activity, because I have noted certain individuals in my classes who are just as happy to let one member of a group do all the work while they sit back. This particular activity lent itself quite well to Think-Pair-Share and aided me in lessons involving both reading and creating graphs. I also realized we have a lot of purple loostrife around... : (