Testing for an association between Wolbachia bacterial symbionts and insecticide resistance in sand fly populations (Diptera: Psychodidae)
Class
Article
Graduation Year
2017
College
College of Science
Department
Biology Department
Faculty Mentor
Carol von Dohlen
Presentation Type
Poster Presentation
Abstract
Leishmaniasis is a serious disease affecting 12 million people worldwide. It is caused by the protozoan, Leishmania, which is vectored by blood-feeding sand flies. Sand flies can harbor Wolbachia, a bacterium, infecting approximately 60% of insect species, that often blurs the line between symbiont and parasite. In some cases, Wolbachia skews sex ratios in insect populations, but in others it appears to confer benefits, specifically, increased insecticide resistance. In flies, such as mosquitoes, insecticide resistance typically develops when Wolbachia infection levels increase. The range of impacts Wolbachia have on their hosts may offer a secondary control pathway for sand fly populations in which insecticide resistance has evolved and decreased the effectiveness of currently used insecticides. Before Wolbachia can be exploited for this purpose in sand flies, however, basic information regarding infection and titers within populations must be gathered. The objective of this study is to test for an association between Wolbachia bacterial symbiont titer and insecticide resistance in P. papatasi and L. longipalpis sand flies. Samples of sand flies from both species are first exposed to Permethrin and Malathion insecticides for 24 hours. Susceptible sand flies (dead) and resistant sand flies (live) are then collected for testing. Using real-time polymerase chain reaction (qPCR), Wolbachia infections are quantified from extracted DNA samples. Infection levels for susceptible and resistant sand flies can then be compared to determine if Wolbachia infection is positively or negatively associated with insecticide resistance, and to what degree. We expect to find that higher levels of Wolbachia infections will correlate with greater insecticide resistance in sand flies; however, responses may differ according to insecticide. Determining the relationship between Wolbachia and the development of resistance in sand flies will open new avenues for exploring biological control, and provide insight into the role this bacterium plays for its host.
Location
North Atrium
Start Date
4-13-2017 10:30 AM
End Date
4-13-2017 11:45 AM
Testing for an association between Wolbachia bacterial symbionts and insecticide resistance in sand fly populations (Diptera: Psychodidae)
North Atrium
Leishmaniasis is a serious disease affecting 12 million people worldwide. It is caused by the protozoan, Leishmania, which is vectored by blood-feeding sand flies. Sand flies can harbor Wolbachia, a bacterium, infecting approximately 60% of insect species, that often blurs the line between symbiont and parasite. In some cases, Wolbachia skews sex ratios in insect populations, but in others it appears to confer benefits, specifically, increased insecticide resistance. In flies, such as mosquitoes, insecticide resistance typically develops when Wolbachia infection levels increase. The range of impacts Wolbachia have on their hosts may offer a secondary control pathway for sand fly populations in which insecticide resistance has evolved and decreased the effectiveness of currently used insecticides. Before Wolbachia can be exploited for this purpose in sand flies, however, basic information regarding infection and titers within populations must be gathered. The objective of this study is to test for an association between Wolbachia bacterial symbiont titer and insecticide resistance in P. papatasi and L. longipalpis sand flies. Samples of sand flies from both species are first exposed to Permethrin and Malathion insecticides for 24 hours. Susceptible sand flies (dead) and resistant sand flies (live) are then collected for testing. Using real-time polymerase chain reaction (qPCR), Wolbachia infections are quantified from extracted DNA samples. Infection levels for susceptible and resistant sand flies can then be compared to determine if Wolbachia infection is positively or negatively associated with insecticide resistance, and to what degree. We expect to find that higher levels of Wolbachia infections will correlate with greater insecticide resistance in sand flies; however, responses may differ according to insecticide. Determining the relationship between Wolbachia and the development of resistance in sand flies will open new avenues for exploring biological control, and provide insight into the role this bacterium plays for its host.