The correct answer is option 2 - Cockroach. The scientific name for cockroach is Blattaria.
Option 1 - Beetle: Beetles belong to the order Coleoptera, not Blattaria.
Option 2 - Cockroach: Cockroaches belong to the order Blattaria, which is commonly known as the order of roaches. This is the correct answer.
Option 3 - Mosquito: Mosquitoes belong to the order Diptera, not Blattaria.
Option 4 - Butterfly: Butterflies belong to the order Lepidoptera, not Blattaria.
Therefore, the insect with the scientific name Blattaria is the cockroach, which falls within the order Blattaria.