Abstract The Israeli acute paralysis virus (IAPV) is a honeybee-infecting virus that was found to be associated with colony collapse Accessories disorder.The IAPV genome contains two genes encoding a structural and a nonstructural polyprotein.We applied a recently developed method for the estimation of selection in overlapping genes to detect purifying selection and, hence, functionality.We provide evolutionary evidence for the existence of a functional overlapping gene, which is translated in the +1 reading frame of the structural polyprotein gene.Conserved orthologs of this putative gene, which we provisionally call pog (predicted overlapping gene), were also found in the genomes of a monophyletic clade of dicistroviruses that includes IAPV, acute bee paralysis virus, Kashmir bee virus, and CURL NUTRITION SHAMPOO Solenopsis invicta (red imported fire ant) virus 1.