The tomato hornworm, Manduca quinquemaculata, is the larva of a sphinx moth, also known as a hawk moth. Caterpillars of the tomato hornworm grow up to four inches in length, then form a dark brown pupa in the soil. During this resting stage the larva transforms into an adult moth. The life cycle from egg to adult can occur in less than two months during the summer but in winter the pupae remain in the soil for several months. The adult moth, which has a wingspan over four inches, is a strong flier and is sometimes mistaken for a hummingbird. It may be seen at dusk hovering over flowers and sucking nectar. The female moth mates then lays eggs on tomato plants.
The adult moth is dark grey with a body length of about 2 inches. The front wings are grey with whitish and blackish wavy streaks and a distinct, white dot in the middle towards the leading edge. The hind wing is gray with indistinct white bands and the abdomen has 5 yellow spots along each side.
By V. Lazaneo, Urban Horticulture Advisor, Emeritus, UC Cooperative Extension, October 2012