The rooms that make up the Bloomington Drosophila Stock Center at Indiana University are lined wall to wall with identical shelves. Each shelf is filled with uniform racks, and each rack with indistinguishable glass vials.

The tens of thousands of fruit fly types within the vials, though, are each magnificently different. Some have eyes that fluoresce pink. Some jump when you shine a red light on them. Some have short bodies and iridescent curly wings, and look “like little ballerinas,” said Carol Sylvester, who helps care for them. Each variety doubles as a unique research tool, and it has taken decades to introduce the traits that make them useful. If left unattended, the flies would die in a matter of weeks, marooning entire scientific disciplines.

Throughout the Covid-19 pandemic, workers across industries have held the world together, taking on great personal risk to care for sick patients, maintain supply chains and keep people fed. But other essential jobs are less well-known. At the Stock Center dozens of employees have come to work each day, through a lockdown and afterward, to minister to the flies that underpin scientific research.

Tiny Bug, Huge Impact

To most casual observers, fruit flies are little dots with wings that hang out near old bananas. But over the course of the last century, researchers have turned the insect — known to science as Drosophila melanogaster — into a sort of genetic switchboard. Biologists regularly develop new “strains” of flies, in which particular genes are turned on or off.