Supplementary material S9: Video analysis of Varroa jolting pulses on petri-dish
| Main Author: | Harriet Hall |
|---|---|
| Format: | info Video Journal |
| Terbitan: |
, 2021
|
| Online Access: |
https://zenodo.org/record/5617205 |
Daftar Isi:
- Video showing the accelerometer data in spectrogram format and synchronous displacements of the Varroa individual on petri-dish. The excerpt demonstrates approximately 10 seconds of continuous jolting behaviour slowed down ten times for ease of viewing and hearing of the rapid jolting behaviour. The soundtrack of this video, also slowed by a factor ten, results in the ultra-high frequency (23 kHz) jolting pulses to be heard at 2200 Hz. Not all pulses produce an audible signature, but for those that do, the sound could be described as a quiet ‘clinking’ noise. The spectrogram shows acceleration magnitude in logarithmic (to the base 10) scale, with dark red showing the highest magnitude and dark blue as the lowest at 1/70th of the maximum. The maximum acceleration magnitude is forced to be that of the Varroa jolting pulses for better viewing. The original video data is shown in panel ‘a’. Panel ‘b’ is a replica of this data, further cropped on the mite and demonstrate simple edge detection by means of the spatial gradient of the pixel intensity. Panel ‘c’ further shows the temporal changes in pixel intensity in two consecutive frames seen in panel ‘b’. When motionless the mite is mostly seen as dark blue in ‘c’, but when moving the pixels flash red. The sum of the pixel intensities in this panel are then displayed as the white line superimposed on the spectrogram data, demonstrating the remarkable synchronicity between video-detected mite displacement and accelerometer trace.