ARS | Publication request: Evaluation of Aerosol Pesticide Application Against Old World Phlebotomine Sand Fly Vectors of Leishmania in Kenya

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 14, 2012
Publication Date: February 23, 2012
Citation: Linthicum, K., Britch, S.C., Aldridge, R.L., Walker, T., Farooq, M., Logan, T., Bast, J., Opondo, V., N'Gonga, D., Chepchieng, C. 2012. Evaluation of Aerosol Pesticide Application Against Old World Phlebotomine Sand Fly Vectors of Leishmania in Kenya. Meeting Abstract. pg. 46.

Technical Abstract: One component of the Department of Defense (DoD) pest management system is ultra-low volume (ULV) and/or thermal fog aerosol pesticide application. Despite widespread implementations of this and other components of the system, such as use of repellents and permethrin, US military operations in hot-arid regions still face substantial impacts from insect vectors of disease such as mosquitoes and sand flies. Few studies have compared ULV and thermal fog technologies, and no study has analyzed their performance or efficacy against sand flies in hot-arid environments. In this study we evaluated the Grizzly ULV (Clarke) and the Swingfog SN101E (Swingtec) calibrated on site with two pesticides, Fyfanon (malathion) and Duet (sumithrin, prallethrin, and PBO), in separate trials against caged sentinel Phlebotomus duboscqi sand flies and wild populations of Phlebotomus and Sergentomyia spp. sand flies in the hot-arid North rift Valley, Kenya. Wild sand fly populations were sampled throughout the study and for all trials sentinel flies were arranged in 25-caged grids with five offsite control cages. Spray plots for both the sprayers and chemiCollege of Agricultural and Life Sciences were reciprocated and spray times and environmental conditions were reasonably consistent across trials. Wild sand fly population sampling showed good control in all treated plots as well as a possible repellent effect indicated by increased populations in nearby untreated areas. Wind shear effect was observed in spatial mortality patterns in thermal fog applications, but was notably absent in mortality from concurrent ULV applications. Prior trials with the Grizzly in Kenya demonstrated widespread control with Duet, but the reverse was seen in the present study. Duet applied with the Swingfog provided rapid and widespread control despite sub-optimal conditions, although uneven terrain led to longer spray time in that instance. Prior studies in hot-arid areas in California had shown thermal fog applications superior to ULV when using Fyfanon against mosquitoes, but the present trials showed the reverse against sand flies.