An Investigation of Physical, Chemical and/or Biological Control of Mosquitos in Dredged Material Disposal Areas.
Studies were conducted on the ecology and control of mosquitoes developing within dredged material disposal sites near coastal locations in several U.S. Army Corps of Engineers (CE) Districts. Primary study sites were located in the Charleston District. The study consisted of the following major sections. All know literature citing an association between mosquitoes and disposal areas was reviewed. A national survey of the attitudes and opinions of personnel from local mosquito abatement districts, selected CE Districts and State vector control agencies was analyzed using national and regional controls. Studies on factors affecting the ecology of all arthropods within disposal sites were initiated including soil and water characterizations. An arthropod successional pattern was postulated based on soil weathering patterns. Emergence traps were used to study arthropods associated with dredged material of varying ages. Mosquitoes were collected from disposal sites as larvae and adults and identified. Studies were made comparing adult mosquito activity with selected weather variables. Site visitations were conducted to eight CE Districts where additional observations and collections were made. Comments were made regarding three types of mosquito control (chemical, physical, and biological) possibilities within dredged material disposal areas. Results of limited tests using two insect growth regulator (IGR) compounds are presented. More extensive tests were conducted using physical control measures, including the use of rim ditching techniques and the use of the riverine utility craft (RUC). Botanical studies were conducted concurrently with mosquito investigations. A listing of plant successional patterns, plant species associated with mosquito larvae, standing crop estimations, and species composition data from disposal sites is presented. Ornithological studies considered the species composition of birds utilizing disposal sites. Suggestions on mosquito pest management plans, interagency cooperation, and future research are stated with concluding remarks. Appendix A presents the interagency perspectives on mosquito conditions and control in confined dredged material disposal sites. Appendix B lists significant data by regions, and Appendix C lists all mosquito species know to be associated with dredged material disposal sites. Appendix D summarizes the site visitations to the CE Districts, and Appendix E discusses the vegetation analysis of diked dredged material disposal sites. Appendix F presents a discussion of the occurrence of avian species within dredged material disposal sites.