Larvae reared under laboratory conditions have four different types of development characterized by 12, 13, 14 and 15 instars respectively. The morphology of the instars in the case of the 14-instar type of development (the most common one) is described. Morphological structures, such as the antennae, the labium, the metathoracic legs and the wing pads are principally used in the description of the different instars.