Most emerge late in the evening but do not take flight until just before dawn, to feed avidly from such flowers as Nicotiana, Petunia, Lonicera, Saponaria and Mirabilis . Thereafter, flight periods are mainly just after dusk and before dawn. Under warm conditions, adults are extremely wary and, if disturbed, will take flight even during daylight hours. Pairing is a short affair usually lasting, at most, four hours but, occasionally, a couple will remain in copula until morning. Laid singly on both the upper and lower surfaces of young leaves of isolated, preferably sheltered, bushes, especially those at the foot of cliffs or near houses, or in clearings amongst trees.
Females often fly around a plant several times before approaching with a pendulous flight.
Most take up to twelve days to hatch but, during hot weather, some hatch in only five. With growth, the eye-spots become blue with white centres, ringed in black. The horn has an unusual bulbous 'cap' until the penultimate instar. In some individuals the dorsal surface is rosy, while in most the dorso-lateral line becomes edged in blue. Those choosing to remain on the hostplant rest along the lower surface or stem of a leaf, with the first four segments of the body slightly hunched.