Antennal movement responses to different plume structures in the honey bee, Apis mellifera
Data files
Mar 19, 2026 version files 168.39 MB
Abstract
Insects move their antennae to actively sense their environment. Regarding olfaction, it is not clear how these movements might be optimized for sampling the odor environment. Honey bees have movable rod-like antennae, the last segment of which contains several thousand pore plate sensillae that contain dendrites of olfactory sensory neurons. Walking honey bees typically move their antennae in an almost constant manner. These movements can be impacted by odor valence, either innate or learned, suggesting that these movements are under sensory control. However, it is unclear if these movements are under active control or are simply fixed responses to stimulation. Here, we evaluated antennal movements of stationary bees when placed in odor plumes with different structures. Antennae took up on average two different positions, both in the absence and presence of odor in the plume. One corresponded to upwind and toward the odor source. The other position was across the plume. Bees rapidly switched between positions both in the presence and absence of odor. The frequency of forward and lateral positioning depended on the presence/absence of odor and on the structure of the plume, which suggests that movement is involved in the sensing of odor filaments. We conclude that these movements represent active sensing, analogous to sniffing in mammals. Future investigations need to focus on the connection between antennal movements and physiological sensing, as well as on analyses of odor-driven antennal movements in freely moving bees. Our results also suggest that active sensing may differ across insects with different antennal morphologies.
Dataset DOI: 10.5061/dryad.qjq2bvqw6
Description of the data and file structure
Data columns associated with Jernigan_etal_2026_JEB_activesensing_plumestructure_antennal_data.csv file associated with the publication at https://doi.org/10.1242/jeb.250786. See methods of associated publication for additional details. Column data are as follows. Antennal angle data extracted using SwarmSight software. See http://swarmsight.org/ for raw video extraction code and additional details. All position and angle measures are reported in video pixel space, the camera and bee position was fixed across all animals and trials such that pixel size is equivalent across all trials.
Files and variables
File: Jernigan_etal_2026_JEB_activesensing_plumestructure_antennal_data.csv
Description:
Variables
- Bee: subjectID.
- Plume: plume condition, see Jernigan et al. 2026 https://doi.org/10.1242/jeb.250786 for additional details.
- speed: airflow speed in the presented wind tunnel in cm/s.
- Round: replicate presentation number for each plume and speed combination.
- Frame: Frame number. Starts with 1. Time can be determined by dividing this value by the video frame rate (30 fps).
- TreatmentSensor: Brightness value of the pixel in the center of the Treatment Sensor. Value ranges between 0 and 255, with 255 indicating maximum brightness.
- PER.X: The X position in pixels of the detected proboscis. If no proboscis is detected, the X values will point to the edge of the mandibles.
- PER.Y: The Y position in pixels of the detected proboscis. If no proboscis is detected, the Y values will point to the edge of the mandibles.
- Left Sector: The 36-degree sector in pixels (1-5) on either side of the head, which contained the largest number of likely antenna points. Can be useful if antenna x, y measures are too noisy. This is the coarsest, but most reliable antenna orientation measure.
- RightSector: The 36-degree sector in pixels (1-5) on either side of the head, which contained the largest number of likely antenna points. Can be useful if antenna x, y measures are too noisy. This is the coarsest, but most reliable antenna orientation measure.
- LeftFlagellumTip.X: The X position in pixels of the tip of the left antenna in the video frame.
- LeftFlagellumTip.Y: The Y position in pixels of the tip of the left antenna in the video frame.
- RightFlagellumTip.X: The X position in pixels of the tip of the right antenna in the video frame.
- RightFlagellumTip.Y: The Y position in pixels of the tip of the right antenna in the video frame
- LeftFlagellumBase.X: The X position in pixels of the base of the left antenna flagellum that did not overlap the head.
- LeftFlagellumBase.Y: The Y position in pixels of the base of the left antenna flagellum that did not overlap the head.
- RightFlagellumBase.X: The X position in pixels of the base of the right antenna flagellum that did not overlap the head.
- RightFlagellumBase.Y: The Y position in pixels of the base of the right antenna flagellum that did not overlap the head.
- RotationAngle: The angle, in degrees, that the head was rotated. 0 means the head pointed directly to the top of the screen. Positive values indicate clockwise rotation, negative - counterclockwise.
- AntennaSensorWidth: The width, in video pixels, of the boundaries of the square Antenna Sensor widget from SwarmSight software.
- AntennaSensorHeight: See AntennaSensorWidth. Height = Width.
- AntennaSensorOffset.X: X value indicates the distance in pixels between the left-most edge of the video to the left-most edge of the AntennaSensor widget from SwarmSight Software.
- AntennaSensorOffset.Y: Y value indicates the distance in pixels between the left-most edge of the video to the left-most edge of the AntennaSensor widget from SwarmSight Software.
- AntennaSensorScale.X: X Scale factor of the AntennaSensor in arbitrary units from the SwarmSight software.
- AntennaSensorScale.Y: Y Scale factor of the AntennaSensor in arbitrary units from the SwarmSight software.
- Odor_detector: On versus off, from the detector of whether odor was being presented or not.
- CenterX: X location in pixels from the video of the center of the bee's head.
- CenterY: Y location in pixels from the video of the center of the bee's head.
- LeftTipRelToCenterX: X location in pixels from video of left antenna tip relative to CenterX.
- LeftTipRelToCenterY: Y location in pixels from video of left antenna tip relative to CenterY.
- RightTipRelToCenterX: X location in pixels from video of right antenna tip relative to CenterX.
- RightTipRelToCenterY: Y location in pixels from video of right antenna tip relative to CenterY
- LeftTheta: computed antennal angle of left antenna relative to the center and rotation angle.
- RightTheta: computed antennal angle of the right antenna relative to the center and rotation angle.
- LeftD: estimated height in pixels above the head of the tip of the left antenna. See the methods paper associated with SwarmSight for the calculation.
- RightD: estimated height in pixels above the head of the tip of the right antenna. See the methods paper associated with SwarmSight for the calculation.
- LeftRTcrit: statistically significant threshold of the radius, R, using a 97.5% confidence threshold value of estimated height D for the left antenna.
- RightRTcrit: statistically significant threshold of the radius, R, using a 97.5% confidence threshold value of estimated height D for the right antenna.
- LeftPhi: estimated angle above the head based upon D and R in previous columns for left antenna.
- RightPhi: estimated angle above the head based upon D and R in previous columns for right antenna.
- deriv1RightTheta: 3 frame median smoothed first derivative of the RightTheta, in degrees per frame.
- deriv1LeftTheta: 3 frame median smoothed first derivative of LeftTheta, in degrees per frame.
- rightdist: estimated linear distance traveled in pixels by the tip of the right antenna between frames since the last moment calculated from the first derivative.
- leftdist: estimated linear distance traveled in pixels by the tip of the left antenna between frames since the last moment calculated from the first derivative.
- RightTheta.Mean.on.diff: Angle difference at this instance from the center for the right antenna compared to the mean for the right antenna across all odor windows, RightTheta.Mean.on.
- LeftTheta.Mean.on.diff: Angle difference at this instance from the center for the left antenna compared to the mean for the right antenna across all odor windows, LeftTheta.Mean.on.
- RightTheta.Mean.on: mean antennal angle from the center for the right antenna during odor presence.
- LeftTheta.Mean.on: mean antennal angle from the center for the left antenna during odor presence.
- RightTheta.Mean.off: mean antennal angle from the center for the right antenna prior to odor stimulation.
- LeftTheta.Mean.off: mean antennal angle from the center for the left antenna prior to odor stimulation.
- iaa: the internal antenna angle, the angle between the two antennas at a given instance.
- odor_bin: binned odor time windows across the 90-second stimulus presentation and video recorded at 30 frames per second, approximately 2697 frames. Time was divided into 5 equal 18s bins, pre, bin1, bin2, bin3, bin 4.
- RightTheta.Mean.off.diff: Angle difference at this instance from the center for the right antenna compared to the mean for the right antenna across all pre-odor windows, RightTheta.Mean.off.
- LeftTheta.Mean.off.diff: Angle difference at this instance from the center for the left antenna compared to the mean for the right antenna across all pre-odor windows, LeftTheta.Mean.off.
- structure: the combinatorial factor for each plume structure and airflow speed.
- LeftTheta_trans: a 360-degree transformation of Left Theta, such that degrees fall between 0 and 180, rather than 181 to 360.
- LeftBI_dip: The binary variable of whether at this instance the left antenna is in forward or lateral position based upon the statistical dip test, with a boundary at 50 degrees. See the associated manuscript for additional details.
- RightBI_dip: The binary variable of whether at this instance the left antenna is in forward or lateral position based upon the statistical dip test, with a boundary at 50 degrees. See the associated manuscript for additional details.
Code/software
None. Data was generated from raw videos using SwarmSight antennal tracking software, available at: http://swarmsight.org/.
Access information
Other publicly accessible locations of the data:
- None
Data was derived from the following sources:
- Raw videos available upon request to Christopher M. Jernigan (jernigc@wfu.edu).
Odor mixture
For all odor presentations, we used a mixture of 11 components loosely based on the natural mixture of the honey bee pollinated plant Brassica rapa (Knauer & Schiestl, 2015). Those components were (pg/L): a-Farnesene (1014); acetophenone (1012); benzyl nitrile (1014); decanal (1012); indole (1014); methyl benzoate (1014); methyl salicylate (1014); nonanal (1012); p-anisaldehyde (1013); phenyl acetaldehyde (1013); z-3-hexenyl acetate (1014). We previously confirmed using electroantennograms that honey bees can detect each of these components.
Honey bee behavioral responses to odor
Twenty honey bee workers were collected at the hive entrance, placed briefly on ice, and harnessed in small plastic tubes using light colored masking tape (Birgiolas et al., 2017; Smith & Burden, 2014). Tape was placed under the back of the head such that the head, antenna, and proboscis were free to move. The back of the head of each bee was fixed in place with a small amount of wax so that a bee was unable to turn its head; this provided a fixed reference in video frames. Harnessed honey bees were placed 20 cm from the odor output port in a wind tunnel previously used to characterize odor plumes (Connor et al., 2018). Antennal responses were recorded from above using a Flea 3 camera at 30 frames per second. Each bee was recorded for 90 seconds, and at the 20-second mark, the odor port was turned on, allowing 20 seconds for recording of antennal movements without odor stimulation and 70 seconds for recording of odorant plume structure responses. Odor plume structures were presented to each bee twice in randomized order (two rounds for each odor plume structure). Bees were allowed to rest for 15 min between each odor presentation. Odor was replaced in the odor port after 30 presentations.
Antennae were tracked from video recordings using SwarmSight (Birgiolas et al., 2017). That program returns the angular position of each antenna at each video frame, which was then used to generate the kernel density plots below. We then calculated at each video frame for each bee and each presentation trial the following measures: (1) the fraction of the time that the antenna occupied either of two angular modes (forward vs. lateral) identified in the kernel density plots and (2) an antennal coordination score, which represents the sign of the antennal coordination, i.e., positive if tended to be positioned in the same angular mode, and negative if they tended to be positioned in opposite modes. An antennal coordination score of zero represents no coordination, i.e., independent positioning of the two antennae. The antennal coordination score is calculated as follows: where is the proportion of time the two antennas are in a given mode.
Bees were presented with four pre-defined plume structure scenarios in a wind tunnel (Figure 1). These scenarios were presented in the same wind tunnel and under the same conditions used for quantification of acetone plume structures just before our data were collected (Connor et al., 2018). The chamber was carefully calibrated to achieve the same flow conditions. The wind tunnel dimensions were 30 cm wide x 30 cm high x 100 cm long. Air entered through a bell-shaped contraction and exited out the back through a contraction that tapered to a 5 cm x 5 cm cross section housing a 12 V fan to generate the flow.
Analyses using laser sheet imaging of acetone plumes released at the mid-line of the entrance to the tunnel described the statistical properties of each of the four dynamic plume conditions we use here (Connor et al., 2018). Supplemental videos S1-S4 show restrained bees with moving antennae placed into an acetone plume so that encounters with the plume could be visualized under different conditions. ‘Bounded’ refers to the release of the plume 6 mm off the bed of the tunnel, where it initially disperses within a viscous sublayer next to the bed. Bounded plumes rapidly spread laterally, maintain high concentrations across several measurement points, and have relatively small fluctuations across the field (Suppl video S1). ‘Unbounded’ refers to the release of the odor plume centered in the tunnel entrance, well away from the viscous sublayer next to the bed. Unbounded plumes are more diffuse, showing more fluctuations and less lateral spreading (Suppl videos S2 and S3). Higher flow rates (e.g., 20 cm/s in S3 versus 10 cm/s in S2) in the unbounded condition resulted in more rapid, energetic fluctuations. Finally, ‘obstacle’ refers to a block (5 cm L x 5 cm W x 16 cm H) placed 5 cm from the source of the odor delivery to create more complex eddies in the plume (Suppl video S4).