The purposes of this study were to determine the accordance or disagreement of the milkweed bug egg (Oncopeltus fasciatus) with generalizations set forth for eggs of terrestrial oviparous animals, i.e., that a high degree of lipid catabolism is characteristic, that lipids constitute the major source of energy for development, and that the greatest use of lipids occurs in the later stages of development. Eggs were found to contain an average of 32.2 μg. of lipid, or 11.6% of the wet weight. Shortly before hatching, the content was 28.5 μg., or 10.7% of the wet weight. The over-all decrease represented utilization of 11.5% of the initial lipid store, with the decrease occurring mostly in the latter half of development. Lipids therefore do not seem to play as dominant a role in development as expressed by other insect eggs. The apparent increase in pterine pigments suggests that protein catabolism may be more important than lipids in supplying metabolic energy.