> Mosquitoes are the main food source of some animals, which leads them to die out. Then those animals are the food source of other animals, etc. etc..

Actually, several biologists believe the impact would be minimal, or even beneficial:

"Yet in many cases, scientists acknowledge that the ecological scar left by a missing mosquito would heal quickly as the niche was filled by other organisms. Life would continue as before — or even better."

http://www.nature.com/news/2010/100721/full/466432a.html