by Matthew Cobb
This brief macro video from Ammonite Films shows a fly emerging from its pupa. Some of you might find it NSFL, but I think it’s pretty cool. Put it on full screen and freak out your housemates/partners/officemates.
Things to note 1: The fly emerges from a circular hole at the end of the pupal case – this is the defining feature of the Cyclorrhapha, a group of flies that does just this. This “unranked” taxonomic term is apparently out of favour (especially at Wikipedia), and is more or less synonymous with “Muscamorpha”, but I’m no taxonomist and am happy to use it. Anyone with expert knowledge/opinions on the matter, please chip in (and explain!) below.
Things to note 2: More importantly, you can see the effort that the fly goes to in order to extricate itself from the case. There is an awful lot of squeezing and pushing that goes on, enabled by the fact that its cuticle is extremely soft. After emerging and literally blowing itself up as it goes, the fly will scuttle off to find somewhere dry and safe to inflate its wings and harden up its cuticle. [JAC: I’ve watched this many times with Drosophila flies and I never get tired of it.]
Things to note 3: Those movements the fly makes as it emerges are redolent of the movement shown by the maggot before it pupates, with waves of contractions.
Things to note 4: The video doesn’t show how exactly how the maggot turns into the fly inside the pupa. The reason for this is contained in those three most important words in science: we don’t know.