Binding Properties of the General Odorant‐Binding Protein 2 Expressed in Gregarious Waxworms of Galleria mellonella , a Ubiquitous Pest of Beehives

Abstract

Odorant‐binding proteins (OBPs) are key specialized transporters of odorants. In lepidopteran species, OBPs have evolved to function in the context of sex pheromones, plant volatiles and other olfactory cues. However, most of the evidence is limited to adult stages. In apiculture, the greater wax moth Galleria mellonella , is considered a worldwide‐distributed pest of beehives during its larval stage (waxworms). Current evidence supports olfactory cues for aggregation behavior in the larvae. Nevertheless, proteins (i.e., OBPs) and other odorants remain unknown. Using transcriptomics, 25 OBP candidates were identified. Further relative expression evidence suggested gene regulation of some OBPs dependent on larval development. An OBP, called GmelGOBP2, differentially expressed in gregarious waxworms, though with stable expression during larval instars, was functionally studied. Fluorescence binding assays showed affinity towards 4 out of 26 ligands, namely linoleic acid, oleic acid, undecanol and β‐ionone, in accordance with molecular docking results. Overall, it is believed that GmelGOBP2, though not exclusively, could help in mediating larval behavior towards fatty acids, which are present in the context of beehives.