Investigation of the effectiveness of some neonicotinoid insecticides on sand fly populations in leishmaniasis endemic areas

Objective: Sand flies (Diptera: Psychodidae) are vectors of parasites of the genus Leishamania, the causative agents of leishmaniasis, and also viruses and bacteria. The aim of this thesis was to investigate the efficacy of four neonicotinoid insecticides (thiamethoxam, dinotefuran, acetamiprid and imidacloprid) on sand fly populations in some leishmaniasis endemic areas of Southerneastern Anatolia. Material and Methods: Sand fly samples were collected from 27 localities in 6 provinces (Şanlıurfa, Diyarbakır, Mardin, Şırnak, Adıyaman, Gaziantep) in this region with the help of CDC light traps. The active ingredients were tested at the application dose recommended by the Ministry of Health for mosquitoes and house flies (0.25 g ai/m2) and lower doses (0.125 g ai/m2 , 0.0625 g ai/m2). Knockdown rates of flies over 60 minutes and mortality rates at the end of 24 hours were recorded according to the WHO recommended test protocol. KDT50 and KDT90 knockdown values were calculated by probit regression analysis in IBM SPSS Statistics 20 program. Results: Efficacy tests with dinotefuran and acetamiprid showed 100% mortality after 24 hours at all localities and concentrations. All sand fly populations tested were found to be sensitive to these two active ingredients. However, in the efficacy tests with thiamethoxam, only sand flies in Alataş in Şırnak and Altınüzüm in Gaziantep were found to be sensitive. It is thought that there is a resistance or resistant populations that need to be confirmed against the concentrations determined in other localities. Efficacy tests with imidacloprid showed that all populations in Mardin province were resistant to specified concentrations. The 100% mortality rate after 24 hours in Büyüktaşlıca and Altınlı in Şanlıurfa, Demirli in Diyarbakır and Şenoba in Şırnak showed that the populations were susceptible to imidacloprid. Other localities were also found to have resistance that needs to be confirmed. Conclusions: If imidacloprid and thiamethoxam continue to be used in this region in an unplanned manner, resistance will develop in areas where there is resistance that needs to be confirmed, and in areas where resistance is thought to have developed, environmental health and non-target species will be adversely affected. In order to prevent this situation, the resistance status of the insecticides used should be monitored and, if necessary, insecticides should be changed or synergist substances should be considered. Keywords: Sand Fly, Insecticide, Neonicotinoid, Leishmaniasis, Türkiye