[Egg ultrastructure in two Chilean moths: Ormiscodes socialis and Polythysana cinerascens (Lepidoptera: Saturniidae)]

The structure and ultra-structure of the eggs from Ormiscodes socialis (Feisthamel) and Polythysana cinerascens (Philippi) are described, considering shape, size, coloring when recently laid, oviposition type and aeropiles (quantity, distribution and proportion) in the micropilar area, among others. The ultra-structure is shown for primary cells, secondary cells, aeropiles and micropiles. A comparative table of the eggs of these species is presented and includes the previously described eggs of Adetomeris microphthalma (Philippi). Myoschilos oblonga Ruiz y Pavón (Santalaceae) is recorded as a new host for P. cinerascens.