For ticks specifically, not that I know of, but this is outside my realm of study. There is broadly evidence that parasites are beneficial, if not simply important to, ecosystem functioning: they can affect animal behavior, population control and dynamics, serve as prey, etc.

Here is a study hypothesizing benefits of parasites in broader ecosystem processes. For all that humanity does know, there is still an inordinate amount that it does not know, and we should not be so bold or naive to think that we can remove an entire group of organisms without cascading consequences.