The oviposition rate, the spatial oviposition pattern, and common morphological and temporal embryonic characteristics of each stage, and the caterpillar eclosion patterns of Anticarsia gemmatalis (Hueb.), Rachiplusia nu (Guen.), Spodoptera latifascia (Walk.), and Chrysodeixis (=Pseudoplusia) includens (Walk.) were observed under laboratory conditions. The average daily oviposition rate differed among species. The egg-larva developmental time lag did not show a normal distribution. Development was fastest in A. gemmatalis, followed by R. nu and S. latifascia, C. includens being the slowest. The species showed an overlap in different embryonic time stages. The mean overlap time was lower and the same in A. gemmatalis and R. nu than in S. latifascia and C. includens. Egg viability was the same in all species. The morphological characterization of the embryos of the 4 species allowed the description of 8 stages. Independently of species, 46% of the caterpillars ate the whole chorionic layer and the other 54% ate it partially.