Superfamily Bombycoidea (Silkworm, Sphinx, and Royal Moths)
Family Sphingidae (Sphinx Moths)
Subfamily Sphinginae
Tribe Sphingini
Genus Manduca
Species sexta (Carolina Sphinx - Hodges#7775)
Hodges Number
7775
Other Common Names
Six-spotted Sphinx Moth
Tobacco Hornworm (caterpillar)
Synonyms and other taxonomic changes
Manduca sexta (Linnaeus, 1763)
Sphinx sexta Linnaeus, 1763
Explanation of Names
SEXTA: meaning six; there are six orangish-yellow spots on each side of the abdomen in adults.
Size
Wingspan 90-120 mm.
Larva to 81 mm.
Identification
Adult: Large. Forewing gray with indistinct black lines and brown shading; usually has six pairs of yellow spots on abdomen.
Hindwing small, banded black and white, with two black zigzag median lines very close together
Larva: large green body; dorsal "horn" (usually curved and orange, pink or red) on terminal abdominal segment; up to seven oblique whitish lateral lines, edged with black on upper borders.
The similar looking Tomato Hornworm, Manduca quinquemaculata, has eight v-shaped stripes and a straight blue-black horn. These caterpillars are often confused and misidentified.
Range
Florida to Massachusetts, west through southern Ontario, Michigan, and Minnesota to Colorado and California. Ranges south through Mexico, West Indies, neotropics to Argentina.
Habitat
Varied, including fields, agricultural lands.
Season
The main flight period is May to October; year round in Florida.
Food
Larvae feed on leaves of potato, tomato, tobacco, pepper, egg Plant, jimson weeed, etc. (Nightshade family--Solanaceae).
Adults take nectar from deep-throated flowers, such as Japanese honeysuckle (Lonicera japonica), moonflower (Calonyction aculeata), and petunia (Petunia hybrida).
Life Cycle
Several generations per year in the southern states; two generations per year farther north; larval development averages twenty days.
Mature larvae drop to the ground and pupate underground.
1. first instar caterpillar. 2. later caterpillar. 3. pupa. 4. adult female
Remarks
Can be a pest of crops.
They rapidly excrete ingested alkaloids before a toxic dose can accumulate. Small amounts of nicotine from tobacco plants that do get into the haemolymph cannot cross the ion-impereable neural sheath and are eliminated via the Malphigian tubules.(1)
Tobacco plants will synthesize and transport alkaloids from the roots to the leaves when herbivory is detected that negatively affects this moth. But when they are infected with the root-feeding nematode, Meloidogyne incognita, this synthesis doesn't occur, leaving the plant susceptible to attack.(2)
See Also
Manduca quinquemaculata (Five-spotted Hawk Moth) is similar as is its caterpillar, the Tomato Hornworm (below).
