Plant and method for organic waste bioconversion and municipal waste biostabilization

System for the bio-treatment of organic waste by means of insect larvae comprising a tank provided with removable cover and means for ventilation and temperature control able to induce migration of the larvae outside the waste mass when in a desired larval development stadium, means for distributing in many times the various waste layers and for removing the same at the end of the treatment and means for distributing the larvae inside the tank and for collecting and storing the larvae at the end of the treatment. Method for the bio-treatment of organic waste by means of larval stadium insects provided with the step of placing a first waste layer inside a tank (1), placing insect larvae or eggs on said layer and adding other waste layers at prefixed and shorter time intervals than the larvae development time, inducing the spontaneous migration of the larvae towards suitable collecting areas by means of temperature and humidity control and removing the treated waste from the tank.