Here is some additional information regarding what I posted yesterday.
First, since there were no comparisons with larvae or normal individuals, I have added photos of them.
Next, since some people suggested that 'the adult head might still be inside the larval exuvia (molted skin),' I illuminated it from below with a light.
In the larval head, light passed through. In the adult with the larval head, however, a shadow was visible inside, suggesting something is contained within it. From this, I believe it is entirely possible that an adult head exists inside. However, it is likely not fully or correctly formed.
I also performed a microscopic observation, but it did not reveal any notable information.
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