Zombies in our movies and TV shows are unthinking creatures, predators on people. They stumble around with no real focus and can suffer horrific damage. If left to their own devices they will convert the whole world into more zombies.
It seems to me that aphids are sort of zombies in reverse.
Aphids live on plants. They suck the plant juices, and reproduce. Their reproduction is by parthenogenesis. They can’t be bothered by sex, they just pop out live babies.
Left to their own devices they would cover every plant out there with aphids.
But there are a whole host of other creatures that prey on them. The dark, dried out aphids are the result of a wasp that deposits an egg within the aphid. The wasp larva eats the aphid from the inside. The yellow worms are syrphid fly larva. They crawl up to the aphids and start feeding. The aphids suffer great damage but are unable to do anything except to continue to reproduce.
The results are more horrific from the aphid’s perspective than any zombie movie we could come up with.