Aberrant cocoons found on honey bee comb cells are found to be Osmia cornifrons(Radoszkowski) (Hymenoptera: Megachillidae)

Potential biological threats to honey bees must be identified quickly, before making disruptive and costly decisions. Here we describe numerous Osmia cornifrons(Hymenoptera: Megachillidae) cocoons in honey bee cells from one bee hive in Ohio. The developing Osmiacells presented themselves as a mystery at first, catching the attention of regulatory agencies. Along with identifying this species as a presumably benign resident in honey bee colonies, our observations suggest Osmiamay use stored honey bee resources to provision offspring. Conceivably, resident honey bees might even act as surrogates because Osmiacocoons were attached to one another with honey bee wax, it seems likely that honey bee hosts were present during Osmiadevelopment. Along with resolving a potentially new biotic threat to honey bees, this diagnosis suggests a method for mass production of Osmiapollinators using an array of single-cell foundation.