Pore plate sensilla scale and distribution modulate odor capture around honey bee antennae.

Insects increase fitness by extracting chemical odor information from the environment using chemoreceptors on antennae that exhibit diverse morphology across species. Honey bees have rod-like antennae with three segments. The most distal segment is the flagellum, which includes pore plates with olfactory receptor neuron dendrites that contain odor receptors. Many studies have examined flow and odor dynamics around antennal structures with simplified sensillae; however, no extant studies resolve pore plate scale fluid processes along the antennal surface. Here, we numerically modeled honey bee antennae in odorized flow fields to evaluate effects of pore plate scale and distribution on fluid drag forces and odor capture rates. For a range of wind speeds and pore plate sizes, we find that boundary layer development enhances odor fluxes preferentially to leading edge pore plate sensilla. This could explain observations of increased pore plate densities along the leading edge of honey bee antennae. Furthermore, we find an asymptotic limit on odor capture rates for a fixed antennal size for dense pore plate sensilla; these pore plates ultimately compete for a finite supply of odor. Larger antennae capture more odor but do so at an energetic cost due to increased drag forces. Our findings can guide both bio-inspired design principles of robotic olfaction and experimental efforts aimed at studying insect odor perception.