Scientists have captured the structural changes that occur inside a chrysalis as a caterpillar metamorphoses into a butterfly. The images were recorded using micro-CT scans as part of a BBC documentary called ‘Metamorphosis: The Science of Change’.
The team studied the blue morphos butterfly (Morpho menelaus), scanning a caterpillar one day before metamorphosis, a week-old chrysalis, and a chrysalis one day before the butterfly was due to emerge.
The micro-CT scans were then digitally manipulated to reveal the respiratory tract and stitched together to create a film. Dr Mark Greco from the University of Bath, who was part of the research team, used a method called Diagnostic Radioentomology (DR) to generate the film and visualise the internal organs in 3D.
‘The fact that it is non-invasive means that we can dissect an insect without touching it,’ Dr Greco told the BBC. ‘All other methods are either destructive, take too long or they are not sensitive enough. DR can be done on live, valuable or rare insects without harming them.’
According to the BBC, the transformation in the respiratory apparatus was extremely quick, most of the changes happening before the second scan. Dr Greco told the BBC that he hopes to perform further studies scanning the chrysalis every day to get a clearer picture of the process.
Metamorphosis: The Science of Change broadcasts on BBC Four, 13 March at 21.00 GMT.
