- Eggs: Smooth, round (resemble small pearls), vary in color from yellow/light green to white, hundreds laid singly on undersides of leaves.
- Larvae: Large, cylindrical caterpillar with a black “horn” located dorsally on last abdominal segment (tobacco hornworms have a red "horn"). First of 5 instars (growth stages) is yellow-white; others are green; dark brown or blackish forms can occur. Along each side there are 7-8 white, side-ways Vs pointing towards the head (tobacco hornworms have 7 diagonal white stripes along the side). Fully grown caterpillar may reach 3-4" inches in length.).
- Pupae: Large, elongate-oval, hard, reddish-brown case about 2" long, pointed at posterior end, with a distinctive loop attached anteriorly and extending ¼ to 1/3 the body length.
- Adult: Large, gray-brown hawk moth with a wingspan of 4-5". Front wings are much longer than back wings, which have dark and white uneven bands. Abdomen has 5 orange-yellow spots (6 in tobacco hornworm).
- Overwinter in pupal cases 4-6” deep in the soil.
- Adult moths emerge over a long period beginning in May and extending as late as early August.
- Moths are most active at sunset and again just before dawn, feeding on nectar from flowers.
- Eggs are laid singly on leaf underside, rarely on top.
- The horns of newly hatched larvae are nearly the same length as the body, but become proportionately smaller as larvae mature.
- Larvae feed voraciously on leaves and sometimes fruit.
- There are 4-5 instars (growth stages) over about one month.
- Mature larvae drop to the ground and burrow up to 6" deep into the soil to form pupal case.
- One to two generations a year.