An adventitious distal abscissa in the forewing of honey bees (Hymenoptera: Apidae:Apis)

Abstract

The presence of an adventitious distal abscissa in the forewing venation of honey bees is recorded. The vein arises from the posterior quarter of the second submarginal cell, on the apical surface of the 2rs-m crossvein. The homology of this vein is discussed and its presence broadly compared across Hymenoptera so as to establish its correct identity. Based on the overall homology of hymenopteran wing venation it is concluded that this is a reacquisition the vein “Rs 2” and we accordingly tentatively term it “aRs 2”. The aRs 2 was found in both Apis cerana Fabricius and A. mellifera Linnaeus at moderate frequencies, although it predominantly occurs in northeast Asian populations of the former. Species of the giant honey bees (Megapis) and dwarf honey bees (Micrapis) were found to lack the vein entirely, while the vein was found at low levels in other Asian lineages (Apis s.str.). The predilection to possess the vein appears to be a trait supporting the cavity-nesting honey bee clade (Apis s.str.).