Eastern monarch butterfly populations have recently declined, partly due to reduction of common milkweed in the North Central US. Formerly, milkweed growing in crop fields may have been highly attractive and low-risk breeding habitat. Due to effective weed control, milkweed is now largely confined to roadside edges and other grassland habitats with potentially greater predation risk. We used sentinel milkweed plants and sentinel eggs to measure wild monarch oviposition rates and egg predation rates in crop and non-crop habitats. Monarchs laid the most eggs on milkweed in corn and the fewest in soybean (~0.05 versus ~0.001 eggs/observation, respectively). Egg survival was comparable in corn, soybean, turf, and fallow plots but much lower in grasslands (mean 72-hour survival 56 versus 10%, respectively). Results suggest monarch conservation efforts should account for lower survival in grassland versus cropland habitats.