Why do painted ladies eggs stay on a leaf till they hatch?

Painted lady butterfly eggs remain on a leaf until they hatch primarily for protection and nutrition. The leaf provides a safe environment from predators and environmental hazards, while also ensuring that the newly hatched caterpillars have immediate access to their primary food source. This strategy increases the chances of survival for the larvae during their vulnerable early stages. Additionally, the eggs are often laid on specific host plants that are suitable for the caterpillars to feed on once they emerge.