Stephen D. Hight

This 4-H program joins youth, educators, citizens, and scientists in the real-life biological control of purple loosestrife using its natural enemies, "Galerucella" beetles. This leader's guide provides all the essential information for conducting the eleven student activities. Youth first learn about wetlands, invasive species, and the purple loosestrife problem in North America. The next few activities cover methods of invasion control, the concept and criteria of biological control, and the relationship between "Galerucella" beetles and purple loosestrife. The final activities involve rearing and observing the beetles, releasing them into the wild, and evaluating their impact on purple loosestrife. The project is designed around the spring and summer months, and is primarily for high school aged youth (but can be modified for other ages). Each activity begins with a learning experience that presents opportunities for students to (1) reflect on the meaning of the content, (2) generalize their comprehension of the content, and (3) apply what they learned to other situations.

Journal Article Establishment of Insect Biological Control Agents from Europe Against Lythrum salicaria in North America Get access Stephen D. Hight, Stephen D. Hight 2 1 Insect Biocontrol Laboratory, USDA-ARS, Beltsville, MD 20705 2 Current address: Department of Entomology, University of Maryland, 1300 Symons Hall; and Maryland Agricultural Experiment Station, 1104 Symons Hall, College Park, MD 20742. Search for other works by this author on: Oxford Academic PubMed Google Scholar Bernd Blossey, Bernd Blossey 3 New York Cooperative Fish and Wildlife Research Unit, Department of Natural Resources, Fernow Hall, Cornell University, Ithaca, NY 14853 Search for other works by this author on: Oxford Academic PubMed Google Scholar John Laing, John Laing 4 University of Guelph, Department of Environmental Biology, Guelph, ON NIG 2W1 Canada Search for other works by this author on: Oxford Academic PubMed Google Scholar Rosemarie Declerck-Floate Rosemarie Declerck-Floate 5 Agriculture and Agri-Food Canada, Research Centre, P.O. Box 3000, Main, Lethbridge, AB T1J 4B1 Canada Search for other works by this author on: Oxford Academic PubMed Google Scholar Environmental Entomology, Volume 24, Issue 4, 1 August 1995, Pages 967–977, https://doi.org/10.1093/ee/24.4.967 Published: 01 August 1995 Article history Received: 26 August 1994 Accepted: 06 February 1995 Published: 01 August 1995

Many prime wetlands in North America have been degraded following encroachment by the exotic plant purple loosestrife. Conventional methods are unsuccessful in providing long-term control. Host specificity studies demonstrated the suitability of two leaf beetles, Galerucella calmariensis and G. pusilla, as biological weed control agents. Adults oviposited only on plants within the genus Lythrum. The only species other than purple loosestrife where adult feeding and oviposition occurred and that supported successful larval development was winged lythrum. Swamp loosestrife and winged lythrum may be vulnerable to limited attack by newly emerged teneral adults. Evaluation of the potential environmental impact of the two leaf beetles showed that benefits of an introduction outweigh potential risks to winged lythrum or swamp loosestrife. Their field release was approved in 1992.

In an effort to continue the development of a sterile insect release program against the invasive cactus moth, Cactoblastis cactorum (Berg), we released partially sterile males alone or in combination with fully sterile females at a 5:1 or 10:1 (treated:fertile) overflooding ratio inside large field cages containing Opuntia stricta Haworth (Haworth) host plants. Insects were allowed to mate and lay eggs, and all eggsticks were collected daily. Percent egg hatch and reduction in F1 fertile larvae were used to ascertain the effectiveness of each release combination. In addition, limited field release-recapture experiments were conducted to examine the dispersal ability of untreated and treated cactus moth males. Results suggest that an overflooding ratio as low as 5:1 can effectively suppress C. cactorum in field cages and that releasing both genders together is more effective than releasing males only. In open field releases, the dispersal ability of C. cactorum was not significantly affected by treating the adults with gamma radiation.