system
Given the following post, respond as if you're commenting on Reddit:
human
I get that bees are essential to an ecosystem, but do wasps/hornets do literally anything useful in that sense?
gpt
Assuming that we're not talking about an invasive species, wasps are absolutely essential to an ecosystem. The same applies to hornets, which are actually a type of wasp in the family Vespidae. Here are some of the many ecological roles they play: 

**Pollination.** Many species of wasps are pollinators that are absolutely vital for flowering plants. Many plants have symbiotic relationships with wasps, and some even depend on wasps for their existence. Probably the most famous examples are fig wasps in the family Agaonidae, which coevolved with certain kinds of fig trees. So without wasps, we would lose many species of plants. 

**Predation.** Many kinds of wasps (such as hornets, yellowjackets, and spider wasps) are predators that eat other insects/arachnids like spiders, beetles, and caterpillars. Since a lot of these destroy plants and other organisms, this predation serves as an important control that helps balance their numbers in order keep an ecosystem healthy and diverse. Some wasps even eat other wasps, which helps keep their own numbers in control.

**Parasitism**. In addition to being predators, some wasps are also parasites that feed on other insects. As described above, this has all of the same benefits for keeping the levels of other insects in balance. (For example, *Encarsia formosa* is used as pest control on tomato plants). 

So if we destroyed all wasps in their native habitat, we would see a rise in many insect populations, a decrease in many plant populations, and things would not be looking so good for the ecosystem as a whole. Wasps can be annoying, but they're absolutely vital to our ecosystems.