1. The Effects of Mosquito-Control Applications of Permethrin on Monarch Butterfly (Danaus plexippus) Larvae By Sara Brinda 2003-2004 http://www.hwcn.org/link/hmm/mbcat.JPG

2. Background Permethrin (Mosquito spray) –Pyrethroid pesticide –Sprayed in ULV form as mosquito adulticide –Applied to wooded areas, where milkweed can grow

3. http://www.mbsf.org/news.html Background Monarchs: non-target insect Larvae (caterpillars) are terrestrial Only eat milkweed (Asclepias)

4. Background Little research conducted on effect on non- target invertebrates Only peer-reviewed field study (Jensen et al): immediate mortality in aquatic and night-flying insects

5. Materials and Methods: Part I Common milkweed (A. syriaca) collected from permethrin-treated areas Larvae fed with treated milkweed leaves Three variables –Days between spraying and initial exposure –Days spent on treated leaf –Beginning instar

6. Hypotheses (Part I) Milkweed collected from permethrin-treated areas will have lethal effect on monarch larvae Larval mortality rates will be higher: –Leaves treated more recently with permethrin –Exposed to treated leaves for greater period of time –Exposed to milkweed during earlier instars (growth stages)

7. Results (Part I): Overall larval mortality

8. Results (Part I): Variables affecting mortality

9. Materials and Methods: Part II Leaves treated in lab with oil solution, 0.1% solution, or 0.5% solution Leaves fed to monarchs for entire lifetime Larval mass and instar monitored daily Adult mass recorded

10. Hypotheses (Part II) Larvae exposed to sublethal solution will be affected: –Slower development time –Smaller adult mass Oil diluent will have no effect

11. Results (Part II): Total development time

12. Results (Part II): Adult mass

13. Further Study Permethrin effectiveness on mosquitoes vs. nontargets –How effective –Effective for how long? More research needed on mosquito adulticide effects on non-target insects

14. Acknowledgements Dr. Karen Oberhauser Everyone who worked in the lab this summer Metropolitan Mosquito Control District, especially Dr. Stephen Manwieler Ms. Lois Fruen Team Research Beth Brinda

15. The Effects of Mosquito-Control Applications of Permethrin on Monarch Butterfly (Danaus plexippus) Larvae By Sara Brinda 2003-2004 http://www.hwcn.org/link/hmm/mbcat.JPG