Neuroethology of Host-Seeking Behavior in Anopheles arabiensis Under Conditions of Heat and Drought Stress: Implications for Malaria Vector Competence in Northern Nigeria

Anopheles arabiensis is a dominant malaria vector in the drier zones of northern Nigeria, where rising temperatures and drought frequency associated with climate change are expected to alter mosquito physiology and host-seeking behavior in ways that could increase or decrease transmission intensity. The neuroethological mechanisms governing host-seeking behavior under thermal and desiccation stress in this species have not been investigated. This study examines the neuroethology of host-seeking behavior in An. arabiensis under conditions of heat and drought stress, and determines the implications for changes in vectorial capacity in northern Nigeria. Field strains of An. arabiensis from Kano, Katsina, and Sokoto states will be established in insectary colonies. Olfactometer bioassays will quantify CO2, sweat lactic acid, and skin odor attraction under controlled thermal stress conditions. Calcium imaging of antennal lobe neurons will visualize olfactory processing changes during heat exposure. Transcriptomics of head tissue under heat stress will identify neuromodulatory gene expression changes. Field body temperature recordings on Anopheles from hot-season collections will provide ecological context. A simulation model will project how observed behavioral changes alter estimated vectorial capacity under CMIP6 temperature scenarios for 2050 and 2075. This study makes a pioneering original contribution to understanding climate-induced behavioral change in a major malaria vector, informing adaptive management of malaria transmission in Nigeria's warming northern zone. Keywords: Anopheles arabiensis, neuroethology, heat stress, host-seeking behavior, malaria transmission