Histochemical characterization of the embryonic stages in Diatraea saccharalis (Lepidoptera: Crambidae)

Embryonic development in Diatraea saccharalis F. (Lepidoptera: Crambidae) has been studied by means of whole mounts, histochemical techniques, and light microscopy. Three embryonic stages were identified up to larval eclosion. In the first stage, 0-10 h, intense multiplication of energids occurred, and significant changes in RNA levels were detected in distinct zones before the start of blastulation. During the second stage, 10-24 h, new protein and RNA sites were detected in the egg's periphery. This was probably because of migration of energids and formation of the blastula. Gastrulation occurs during this stage and is characterized by intense synthetic and mitotic processes. The third stage, 25-168 h, showed ortochromatic and metachromatic regions at the posterior pole and in the yolk, egg periphery, and body of the embryo. Organogenesis closes approximately on the sixth day when the embryo starts feeding on the remaining yolk. Its development is complete by the end of the seventh day on which the larva ecloses.