Tomato hornworm

Look

UMN Extension (Minnesota): caterpillars among the largest in Minnesota, up to four inches. Small tomato hornworms are yellow to white with no markings. Large caterpillars develop eight white V-shaped marks on each side. Tomato hornworms have a black projection or horn on the last abdominal segment. Favorite plant is tomato. They chew leaves and can chew holes in fruit. Identification, host, and damage as observation. Not a kill or spare instruction. Bare hornworm and feeder-moth strings are not targeted on this page.

Moth

UMN Extension (Minnesota): adult moths are large, heavy-bodied insects with narrow front wings. Mottled gray-brown with yellow spots on the sides of the abdomen. Wingspread four to five inches. Hindwings have alternating light and dark bands. Minnesota moth ID. Not “five pairs.” Not a feeder-moth page.

Eggs

UMN Extension (Minnesota): females deposit oval, smooth, light green eggs on lower and upper leaf surfaces. Caterpillars hatch, begin to feed, and are full-grown in three to four weeks. Minnesota egg look and sit. Not a national calendar.

Life cycle

UMN Extension (Minnesota): tomato hornworms survive winters as pupae and emerge as adult moths in spring. Mature caterpillars drop off plants and burrow into the soil to transform into pupae. Moths emerge in two weeks to begin a second generation, during mid-summer. Second-generation moths deposit eggs on host plants such as tomato. Caterpillars feed until late summer or early fall and then pupate. Pupae remain in the soil through winter. Minnesota generations (two). Not averaged with other states. Soil depth and tongue-case are not stated on this sheet.

Hosts and damage

UMN Extension (Minnesota): tomato is the host of choice, but they have also been found on potato, eggplant and pepper. Weeds named as alternate hosts: horsenettle, jimsonweed and nightshade. Large numbers of caterpillars can occur in home gardens and can quickly defoliate plants. Feeding starts on the leaves on the upper parts of the plants. Caterpillars blend in with the leaves. Older tomato hornworms can destroy several leaves as well as the fruit. As they become larger, the amount of defoliation increases. The last caterpillar stage consumes nearly as much as all the younger stages combined. Hosts and defoliation as observation. Not a ranking. Pepper is not claimed as a keyword on this page.

Droppings

UMN Extension (Minnesota): as they feed, they create dark green or black droppings that are clearly visible. Frass as observation. Not fertilizer. Not a find-protocol beyond the look.

Cocoons

UMN Extension (Minnesota): parasitized by a small braconid wasp, Cotesia congregatus. The cocoons look like white rice protruding from the hornworm’s body. Observation. Distinct from the Missouri IPM1028 figure. “Leave them,” “kill when they emerge,” and efficacy are not collected.

Containment

UMN Extension (Minnesota): physical removal (hand-pick) is listed as a management practice on that sheet. Containment context only. Not “kill.” Soap and “most effective” language on that sheet are not collected. Hand-pick is named as a listed practice, not a program and not an outcome.

Limit

Minnesota tomato-hornworm sheet. Identification, moth, eggs, two generations, hosts, defoliation, droppings, rice-like cocoons, and hand-pick as listed practice. Not a product, rate, efficacy, or kill/spare instruction. Tillage, UV scouting, and “five pairs” of spots are not collected.

Compare

Missouri IPM (Missouri): tomato hornworm (Manduca quinquemaculata) — lateral white lines V-shaped, pointing toward the head; not outlined in black; horn tends to be black. Tobacco hornworm (Manduca sexta) — seven oblique white lines outlined in black; horn usually red. Late-instar tobacco hornworm caterpillars have seven diagonal stripes on their body and their horn is usually red. Comparison table on that sheet. Not a ranking. Marks and horn color are the collected difference — not a winner.

Hosts

Missouri IPM (Missouri): both feed primarily on tomato and tobacco; also eggplant, pepper, potato. Named-host list. Observation only. Present June–September on that sheet. Not a national calendar. Pepper, eggplant, and potato are named hosts on that sheet, not separate pest pages.

Moth and eggs

Missouri IPM (Missouri): usually two generations of hornworms produced each summer. Adult moths emerge in mid- to late spring. Both species are mottled gray-brown moths with four- to five-inch wingspans. After mating, females lay their small eggs, which often are undetected, on the upper and lower surface of tomato leaves and other host plants. Missouri moth, egg, and generation. Not blended with North Carolina counts.

Instars and pupa

Missouri IPM (Missouri): tomato hornworms undergo five larval or instar stages in three to four weeks. All five instars feed on plants. The first small instar is whitish-yellow with five pairs of prolegs used to grip onto plant stems and leaves. When fully grown, caterpillars are usually green, but dark brown types can also develop. Full-grown caterpillars of the second generation, which develop in mid- to late summer, drop off plants to pupate. Pupae overwinter about five to six inches below the soil surface. Missouri instars and soil depth. No tongue-case on this sheet. Tillage on that sheet is not collected.

Damage and droppings

Missouri IPM (Missouri): both types of hornworm caterpillars devour leaves and can completely defoliate tomato plants. Hornworms also chew holes in green tomato fruit, especially during dry weather. Feeding damage generally begins on the upper leaves of tomato plants. Dark greenish-black droppings left by caterpillars when feeding often are present on the foliage. Damage and frass as observation. Fruit-hole is not a diagnosis from holes alone.

Limit

Missouri IPM hornworm sheet. Comparison, named hosts, two generations, moth wingspan, instars, five-to-six-inch overwintering depth, defoliation, and droppings. Not a ranking, spray, or outcome. June–September is that sheet’s window, not BioArva’s. Tongue-case is not on this sheet.

Look

Maryland Extension (Maryland): tobacco or tomato hornworm — a large green caterpillar chewing tomato leaves. Identification only. The crop-pest router at /crops/tomato/pests names this look without claiming the species vocabulary.

Limit

Maryland tomato-problems key. Appearance only. Not a keyword target beyond this species page. Not a spray. Mid- to late-summer timing and wasp-parasitoid notes on that key are not collected as a program.

Cocoons

Missouri Extension IPM1028 (Missouri): cocoons of a parasitic wasp on a tomato hornworm (figure on that sheet). Braconid-cocoon observation. Not an instruction to spare or kill. Not an efficacy claim.

Limit

Missouri IPM1028 figure context. Observation only. Kill/spare judgment, sting/touch/toxic, Bt/spray, recover, and fertilizer-from-frass stay closed.

Pupa

NC State Extension (North Carolina): pupae of both species are dark brown and have a handle-like tongue case on the exterior. Hornworms overwinter as pupae in the soil. NC tobacco publication. Tongue-case lives here. Not “jug-handle” beyond handle-like tongue case. Not a tillage protocol.

Moth spots

NC State Extension (North Carolina): tomato hornworm moths have five spots on the abdomen; tobacco hornworm moths have six. Spot count on this sheet. Not “five pairs.” Not orange-yellow.

Generations

NC State Extension (North Carolina): two to three hornworm generations occur in North Carolina, depending upon temperature. Adults begin to emerge in early June. North Carolina geography. Generations 2–3 versus two in Minnesota and Missouri stay in Sources differ. Not averaged.

Compare

NC State Extension (North Carolina): larval tomato hornworms have eight chevrons on each side and a bluish black horn. Larval tobacco hornworms have seven diagonal stripes on each side and a red posterior horn. Comparison on that sheet. Chevron / bluish-black versus Missouri V-shaped / black stay in Sources differ. Not a ranking.

Eggs

NC State Extension (North Carolina): hornworm eggs are round, pale green, and laid on the upper surface of tobacco leaves. Tobacco-leaf placement on that sheet — not a tomato-egg placement claim. Round pale green versus Minnesota oval light green on tomato leaf surfaces stays in Sources differ.

Limit

NC State tobacco publication. Tongue-case, abdominal spot counts, NC generations, larva comparison, and tobacco-leaf eggs. Not a tobacco-pest page. Not a tomato-egg claim. Not blended with Minnesota or Missouri.