invasive life form from outer space theme

The ecosystem, or a vital resource (food), on your planet is destroyed by an invasive life form from outer space and you all die.

Examples

The grain supply designated for Sherman's Planet was entirely consumed by Tribbles in tos2x13 "The Trouble with Tribbles".

40 total · 7 choice · 32 major · 1 minor

StoryLevelMotivation
movie: Alien Resurrection (1997) choice Everyone on Earth was as good as dead unless Ripley 8 and the mercenaries succeeded in stoping the USM Auriga from reaching the planet with its lethal Alien cargo.
movie: Encounter (2021) choice A main novelty of the film lies in the (anti-)hero of the story being convinced that as much as half the people on Earth could be infected by alien parasites, which use human bodies to reproduce.
movie: Evolution (2001) choice The main novelty of the film is that some alien microbes hitched a ride to the Arizona desert on a meteor, began to evolve at an accelerated rate, and soon thereafter gave rise to complex creatures that seemed destined to overrun the entire Earth.
movie: Slither (2006) choice The story is all about malevolent alien parasites overwhelming the residents of a small town.
movie: The Puppet Masters (1994) choice Slug-like neural parasites from outer space plotted a covert invasion of Earth.
tas1x05 choice Tribble :: Tribbles
tos1x29 choice Neural Collective Parasites :: neural parasites
movie: Agent for HARM (1966) major The communists planned to dust all American crops with deadly spores that arrived on Earth on a meteor.
movie: Alien 3 (1992) major Ripley jumped into vat of molten led to stop the Alien Queen gestating inside her from being taken back to Earth. If it did ever reach Earth, it's offspring was bound to paracitize everyone on the planet.
movie: Aliens vs Predator: Requiem (2007) major The military ultimately launched a tactical nuclear strike on the town to prevent the ferocious, parasitic aliens that were breeding there from going any further.