Some species of flies and mosquitoes are also pollinators. One cute example of pollinating flies are the Bombyliidae. Mosquito larvae are also important food sources for aquatic and semi-aquatic species like frogs and fish.

Haha there’s a reason why the Xenomorph from Alien is in part inspired by parasitoid wasps.

If you study wasps, you’ll find that they very frequently have odd symbioses from species to species, most often as parasites/parasitoids or hyperparasites. Some even have symbiotic relationships with viruses that assist them in their parasitism - ichneumon and braconid wasps have symbiotic viruses called polydnaviruses.

If you wanna learn about some more wasp pollination, look up fig wasps (Agaonidae). Wasps are legitimately one of the coolest groups of animals.