The abundance and distribution of sandflies (with emphasis on Phlebotomus pedifer) (Diptera: Psychodidae) along the altitudinal gradient in Kindo Didaye district, Wolaita Zone, South Ethiopia

Abstract

Understanding the distribution patterns of medically significant sandflies is crucial for effective vector and disease control planning. This study focused on investigating the abundance and distribution of phlebotomine sandflies, specifically emphasizing Phlebotomus pedifer (Diptera: Psychodidae), the vector of Leishmania aethiopica responsible for cutaneous leishmaniasis in the highlands of southern Ethiopia. The study employed CDC light traps and sticky paper traps in various habitats, including human houses, farm fields, and rock cliffs, with and without the presence of hyraxes. The study was conducted along an altitudinal gradient in Kindo Didaye district, Wolaita Zone. A total of 7,994 sandflies belonging to 2 genera, Phlebotomus (26.1%) and Sergentomyia (73.9%), were collected. In the genus Phlebotomus, P. pedifer (74.1%) was the most abundant, followed by P. alexandri (18.05%) and P. gibiensis (7.85%). Altitude showed a strong positive association with the density and distribution of P. pedifer and a negative association with those of P. alexandri, P. gibiensis, and Sergentomyia spp. Furthermore, the study revealed distinct habitat preferences, with P. pedifer showing the highest mean density in hyrax dwellings, followed by human houses, and the lowest in farm fields. These findings provide valuable insights for planning targeted control measures against P. pedifer in both indoor and outdoor environments, particularly in the highland and midland areas of the study region.