Seems like the plot of Philip K. Dick's MeddlerMeddler.
In it, people use the "Dip" to travel through time. The protagonist is sent to the future to understand an impending doom to humanity, caused possibly by prior uses of the Dip. He finds a race of vicious butterflies that are hostile and harmful to humans.
He closed the last switches. The indicator lights flickered, the floor chugged under him. He threw the main lever. More butterflies were pushing in, crowding each other eagerly, struggling to get through. A second circle of metal crashed to the floor suddenly, emitting a new horde. Hasten cringed, backing away, the blowtorch up, spouting flame. The butterflies came on, more and more of them.
When he travels back to his time, he finds the time capsule covered with cocoons, some of which have already opened.
Hasten's heart stopped beating. He pushed past them, staring up. At first he saw nothing on the metal hull, only the corroded metal surface. Then chill fright rushed through him.
Something small and brown and furry was there, on the surface. He reached out, touching it. A sack, a stiff little brown sack. It was dry, dry and empty. There was nothing in it; it was open at one end. He stared up. All across the hull of the Car were little brown sacks, some still full, but most of them already empty.
Cocoons.
No idea if this was made into a TV show, but seems like a very similar plot.
