Based upon light and scanning electron microscopy, the external morphology of the egg stage is described and illustrated for the following Heliconiini (Lepidoptera, Nymphalidae) from Rio Grande do Sul State, Brazil: Agraulis vanillae maculosa (Stichel, 1907), Dione juno juno (Cramer, 1779), Dione moneta moneta Hübner, 1825, Dryadula phaetusa (Linnaeus, 1758), Dryas iulia alcionea (Cramer, 1779), Philaethria wernickei (Röber, 1906), Eueides isabella dianasa (Hübner, 1806), Eueides aliphera aliphera (Godart, 1819), Heliconius ethilla narcaea Godart, 1819, Heliconius besckei Ménétriés, 1857, and Heliconius erato phyllis (Fabricius, 1775). A dichotomic key is provided for their identification, based upon differences at the levels of generic and ultrastructural morphology, and variation in host-plant use.
Chorionic ultrastructure; egg morphology; heliconian butterflies; host-plants
