SwarmSight: Real-Time Tracking of Insect Antenna Movements and Proboscis Extension Reflex using a Common Preparation and Conventional Hardware

Abstract

ABSTRACT:Many scientifically and agriculturally important insects use antennae to detect the presence of volatile chemical compounds and extend their proboscis during feeding. The ability to rapidly obtain high-resolution measurements of natural antenna and proboscis movements and assess how they change in response to chemical, developmental, and genetic manipulations can aid the understanding of insect behavior. By extending our previous work on assessing aggregate insect swarm or animal group movements from natural and laboratory videos using video analysis software SwarmSight, we developed a novel, free, and open-source software module, SwarmSight Appendage Tracking (SwarmSight.org) for frame-by-frame tracking of insect antenna and proboscis positions from conventional web camera videos using conventional computers. The software processes frames about 120 times faster than humans, performs at better than human accuracy, and, using 30 frames-per-second videos, can capture antennal dynamics up to 15 Hz. We used the software to track the antennal response of honey bees to two odors and found significant mean antennal retractions away from the odor source about 1 s after odor presentation. We observed antenna position density heat map cluster formation and cluster and mean angle dependence on odor concentration.

SwarmSight: Real-time Tracking of Insect Antenna Movements and Proboscis Extension Reflex Using a Common Preparation and Conventional Hardware

“…Additionally, more sophisticated analysis may better reveal differences in antennal movements in response to different odors. We have made the data files used to generate figures in this manuscript available to interested researchers on the SwarmSight website 67 .…”

Novelty detection in early olfactory processing of the honey bee, Apis mellifera

“…The patterns of these movements can be modified by appetitive conditioning [31,32]. Using video tracking [30], we recorded, frame-by-frame, the angular positions of each of the antennae in a 180 o space on each side of the head. We recorded positions continuously in 4 sec blocks before, during, and after exposure to two odorants, 1-hexanol (hex) and 2-octanone (oct) (Fig.…”

“…Honey bees were placed under a constant humidified air flow and vacuum system, in order to remove excess odorants. Bees were recorded from above with a web camera at 30 frames per sec as described by Birgiolas et al (2017) [30]. The experimental protocol follows that in the electrophysiological experiments with a few differences.…”

“…The bees were restrained in harnesses that are commonly used in procedures for studying classical and operant conditioning in PER [29], and which allow monitoring of antennal movements. Restrained honey bees actively scan the air flow around them with their antennae to sample headspace volatiles [30]. The patterns of these movements can be modified by appetitive conditioning [31,32].…”

“…Behavioral videos were processed in SwarmSight [30] (swarmsight.org) in order to extract positions of antenna and proboscis and were exported to R (R Core Team 2017). Statistical analyses were used to compare the antennal movements of animals in three time-windows: 4 sec immediately before, 4 sec during, and 4 sec immediately after odor presentation.…”