Ladybird species of different sizes make a proportionally similar investment in reproduction in terms of biomas of gonads and reproductive rate. In particular egg size multiplied by egg number is proportional to adult weight. Thus egg size is a function of adult weight and ovariole number. Species with few ovarioles lay larger eggs than similar-sized species with many ovarioles. Development time is a function of the ratio of adult to egg weight such that species with proportionally small eggs take longer to complete their development than do species with proportionally large eggs. Egg size is probably constrained by the minimum size at which first instar larvae can capture active prey and complete their development before prey becomes scarce.