Invasive plants and animals, and diseases associated with them, are a large and growing worldwide problem. Many organizations and government agencies are making some effort to track and try to control the invasives, but funding and resources are often woefully inadequate.
To expand the work they can do, some organizations are using the assistance of volunteer "citizen scientists" to help them identify the presence of many invasive species. These programs generally don't require extensive expertise on the part of the volunteers, and can be fairly simple to participate in. Many programs have been running for a while; others are just starting.
Covering these efforts, through the eyes of interested volunteers, provides both a way to bring the issue to the attention of your audience, and to personalize how the general public can help address the problem. Spring and summer are a particularly good time to cover this issue, since many of the plants and animals are more readily tracked this time of year.
A few of the existing programs are noted below. You will find hundreds of others as you sift through the information and make contact with the people involved.
- CitSci.org  (Citizen Science) tracks plants, animals, and diseases around the globe. It is funded by the National Science Foundation, and operated by several federal agencies and Colorado State University.
- The Invasive Plant Atlas of New England,  whose participants track more than 100 species. Volunteer information. 
- The Invasive Plant Atlas of the MidSouth  focuses on about 40 species in Mississippi. This year, volunteers are also being recruited in Arkansas, Alabama, Louisiana, and Tennessee. Contact John Madsen,  662-325-2428, in mid-May 2009 to find out more about the expansion to the four other states, including training workshops you may be able to sit in on to get background information and make contacts.
- The Cactus Moth Detection and Monitoring Network  is trying to help manage this introduced biological control agent that has gotten out of hand. The moth feeds on prickly pear cactus, threatening biodiversity, horticulture, and forage. The current threat exists in just a few Southeastern states, but experts fear it could eventually spread to almost all states across the southern tier of the US. (Click on "How to Help" for volunteer programs.)
- The Invaders of Texas Citizen Science Program  focuses on plants in the state. It is managed by a consortium of many organizations. Workshops being held April 18 in Weslaco, TX, May 2 in Southlake, TX, and May 30 in Austin, TX, may provide good opportunities to learn about the program  and itsparticipants.
- The Maui County Report a Pest program  is digging up information about plants and animals on the islands of Maui, Molokai, and Lanai. Workshops  will be held May 19 in Hana and May 26 in Kahului.
- Purple Loosestrife Volunteers are hunting down this plant in North America and Australia, and in Eurasia where it is native in some areas. The effort is managed by USGS. 
About 70 other programs are currently listed on the National Biological Information Infrastructure's Web site:
A fledgling nationwide citizen science invasive tracking program is briefly described at:
- Aug. 8, 2008, presentation  at the annual meeting of the Ecological Society of America (includes names of possible sources).
For more leads and insights on these kinds of programs, check out the fledgling Citizen Science Central Project,  funded by the National Science Foundation and operated by the Cornell University Lab ofOrnithology.
You can find many other volunteer efforts by contacting local organizations such as nonprofits, educational institutions, or groups with common interests such as invasive species or plant councils, garden clubs, cooperative weed management associations, or water recreationists. Another way to unearth local efforts, according to Elizabeth Sellers,  703-648-4385, with USGS's National Biological Information Infrastructure, is to search the Internet for words and phrases such as weed warriors, weed watchers, citizen science invasive species, invasive plant patrollers, weed busters, and invasive species volunteer. If you'd like to track down a number of other USGS sources familiar with invasives and volunteer tracking efforts, contact Catherine Puckett  at 352-264-3532.
For dozens of other resources and angles on invasive species, search TipSheet  for "invasive".