A device into which gravid (pregnant) female mosquitos are attracted to deposit their eggs and where both the adult and her offspring are then eliminated. The trap is set in the out-of-doors at the onset of the mosquito breeding season and is replenished by rain water and, by its unique construction, a larvicide within is protected from flushing and photo degradation thereby making it maintenance free throughout the mosquito breeding season. The low cost trap is constructed from biodegradable paperboard and at the end of the mosquito breeding season, decomposes, thereby foreclosing the possibility that the trap will become a breeding incubator.