Larvae reared under laboratory conditions have 5 different types of development, characterized by 8,9, 10.11 and 12 instars, respectively. The morphology of the 10-instar type of development, the most common one, is described. Morphological structures such as the antennae, the labium, the melalhoracic legs, the wing pads, the caudal lamellae and the male and female gonapophyses are principally used in the description of the different instars.