Comparative Transcriptomics of Immune Priming in Honey Bees (Apis mellifera adansonii) Exposed to Pesticide Sublethal Doses in Cocoa Agroforestry Systems of South West Nigeria

Immune priming in social insects, whereby prior pathogen or xenobiotic exposure enhances subsequent immune responses, is a fundamental aspect of insect immunology with practical relevance for understanding colony resilience in pesticide-exposed environments. Nigerian honey bee subspecies, particularly Apis mellifera adansonii, are exposed to sublethal pesticide concentrations in cocoa-farming landscapes, yet their transcriptomic immune responses under such conditions have not been characterized. This study investigates the comparative transcriptomics of immune priming in A. m. adansonii workers exposed to sublethal doses of commonly used fungicides and insecticides in Ondo and Osun state cocoa agroforestry systems. Colonies will be established on experimental plots treated at three sublethal pesticide dose levels and a solvent-only control across 12 apiaries. Worker bees will be collected at days 3, 7, and 14 post-exposure, and whole-body RNA-Seq will profile transcriptomic responses relative to unexposed controls. Differential gene expression analysis will focus on immune pathway genes including Toll, Imd, JAK-STAT, and RNA interference components. Subsequent pathogen challenge with Nosema ceranae will test whether prior pesticide exposure primes or suppresses immune competence. Structural equation modeling will integrate transcriptomic, pesticide dose, and survival outcome data. This study makes an original contribution to tropical bee immunotoxicology, providing mechanistic data informing both regulatory pesticide risk assessment standards and colony health management in Nigerian cocoa farming systems. Keywords: Apis mellifera adansonii, immune priming, transcriptomics, sublethal pesticides, cocoa agroforestry