Although I remember reading somewhere that mosquitos have a negative footprint on ecology. There's definitely a ton of research at the moment on mosquito control. There was another article on HN a few years ago on a device that tracks and kills mosquitos w/ tiny lasers that can't harm humans. Apologize for lack of source, I'll try and dig them up.
EDIT: found it! wasn't too hard to find haha. And it seems other replies have already provided source on mosquitos and their net benefit: https://en.wikipedia.org/wiki/Mosquito_laser
Ecosystem does not care, it just is. So far it seems that humans are the only entities in the ecosystem that care. Hell, the "bad" and "good" state of the ecosystem is defined as its ability to support human life and growth.
> [...] and there are several researchs suggesting they serve no purpose on keeping the enviromental equilibrium (if they are gone, they won't be missed, the enviroment will be fine...)
There is a method for doing this. I can't seem to find the original article where I heard about this, but it was tested in some remote area in Africa and had a 90% reduction in mosquito population with just one application. Here is a more updated Zika flavored article about the same technique:
I'm only aware of the test conducted in Brazil, which had a claimed 80% reduction rate:
Oxitec, which is owned by Maryland-based Intrexon Corporation, tested its mosquitoes in the small Brazilian city of Piracicaba and said the reduced the number of mosquito larvae by 80 percent in one area.
What I've read on the topic is that animals that eat mosquitos have lots of small flying insects to choose from if they disappear, so much so that you'd never notice the difference. Their role as pollinators is a bit more fraught but again there are still a few replacements standing by in pretty much every case.
Birds, insects, spiders, etc would probably benefit a lot more from humans no longer needing to spray insecticide to control mosquitoes.
And mosquitoes would still exist -- just not the species that are regionally eradicated because they spread diseases (and many of which are invasive species such as Aedes aegypti).
Other commenters have noted that there are enough replacements that these animals won't miss them. I'm curious, though, if the subsequent decrease in those species' populations (from making up a larger percentage of prey than when mosquitoes were available) would have negative effects.
Although he's missing references to the studies he mentioned, the point was animals that eat mosquitos would be fine without them, as they also eat other insects. Spiders come to mind.
EDIT: found it! wasn't too hard to find haha. And it seems other replies have already provided source on mosquitos and their net benefit: https://en.wikipedia.org/wiki/Mosquito_laser