Try sucking maple syrup through a straw, and you’ll appreciate a fruit fly’s struggle to get a sip of sugar water. But a tiny system of valves and tubes works to pump fluid into a fly’s gut, researchers saw in the first X-ray videos of the insects slurping.
Scientists expected that pumping fluid would be more difficult for the fly as its gut swells up, the way inflating a bike tire requires more work as it fills with air. On top of that, fluids flowing through tubes face more resistance as they become more viscous and as the diameter of the tube shrinks. So the fact that house flies and honey bees have no problem sipping fluids thicker than ketchup through a 10-micrometer straw has puzzled researchers.
Bioengineer Manu Prakash at Harvard and a high school student, Miles Steele, used high-resolution X-ray absorption microscopy to watch hours of flies feeding on sugar solutions. Not only does the expanding gut signal the fly’s feeding tube to dilate, but valves in the insect’s plumbing appear to open and close passively, aiding suction. Prakash and Steele posted a report of their work October 15 at arXiv.org.
Engineers could adapt the insect plumbing to create tiny drug delivery systems, Prakash suggests.
SUPER SUCKERS from Science News on Vimeo.
Flies use a sophisticated pump system to move viscous sugar water through tiny feeding tubes, seen here in an X-ray microscopy video.
Credit: Manu Prakash, Harvard
