Larval Breeding Sites and Population Dynamics of Simulium Species in Rivers of Ebonyi State, South East Nigeria

Blackflies of the genus Simulium are vectors of Onchocerca volvulus, the causative agent of onchocerciasis (river blindness), a neglected tropical disease that continues to burden communities in parts of Nigeria's South East geopolitical zone. Ebonyi State contains multiple river systems that potentially support Simulium breeding. This study characterizes the larval breeding sites and seasonal population dynamics of Simulium species in selected rivers of Ebonyi State. Monthly sampling of larvae and pupae will be conducted at 15 river stations over one year, using stick-mounted collection methods on submerged substrates. Water velocity, turbidity, oxygen content, and riverbed substrate type will be measured at each site. Morphological identification of larvae will be performed using established keys for West African Simulium. Population abundance data will be analyzed in relation to river discharge and seasonal rainfall patterns. This study aims to provide the first systematic documentation of Simulium breeding ecology in Ebonyi State, addressing a gap that limits targeted vector control under the National Onchocerciasis Elimination Programme. Results will be shared with the Ebonyi State Ministry of Health and local government community health officers. Keywords: Simulium, blackfly breeding, onchocerciasis, river ecology, Ebonyi State