{"pest":{"pest":"tomato-hornworm","type":"pest","affects":[{"crop":"tomato","pest":"tomato-hornworm","type":"pest","severity":"high","symptoms":"Large green caterpillars (3-4 inches at maturity) with white diagonal stripes and a curved horn at the rear. Defoliation of upper leaves first, working down the plant. Dark green droppings on lower leaves are usually the first sign before the caterpillar itself is spotted.","organicManagement":["Handpick into soapy water; the most effective control for small gardens.","Spray Bt (Bacillus thuringiensis var. kurstaki) on foliage; works on larvae under 1.5 inches.","Encourage parasitic braconid wasps (white rice-like cocoons on hornworm backs); leave parasitized hornworms in place to release the next wasp generation.","Companion plant with dill, basil, marigold to draw braconid wasps."],"prevention":"Fall tilling exposes overwintering pupae to predators and freezing. Rotate nightshades on a 3-year cycle. Inspect plants twice weekly from July through August.","regions":["all"],"source":"Cornell Cooperative Extension; UC IPM"}],"severities":["high"],"regions":["all"]},"severity":"high","verdict":"foe","immediateAction":["Handpick into soapy water; the most effective control for small gardens.","Spray Bt (Bacillus thuringiensis var. kurstaki) on foliage; works on larvae under 1.5 inches.","Encourage parasitic braconid wasps (white rice-like cocoons on hornworm backs); leave parasitized hornworms in place to release the next wasp generation.","Companion plant with dill, basil, marigold to draw braconid wasps."],"seasonalPrevention":["Fall tilling exposes overwintering pupae to predators and freezing.","Rotate nightshades on a 3-year cycle.","Inspect plants twice weekly from July through August."],"companionDeterrents":[{"plant":"asparagus","mechanism":"pest_repellent","description":"Tomato leaves contain solanine that deters asparagus beetle; planting tomatoes adjacent to permanent asparagus beds protects spear development from feeding damage.","strength":"moderate","source":"Cornell Cooperative Extension; Riotte, Carrots Love Tomatoes"},{"plant":"tulsi","mechanism":"pest_repellent","description":"Holy basil (tulsi) releases methyl eugenol and linalool volatiles that repel thrips and whitefly from tomatoes, the same mechanism as culinary basil but with a stronger aromatic profile and reliable perennial-like growth in zones 9 and warmer. Plant in a continuous row alongside tomato beds.","strength":"moderate","source":"ICAR-Indian Institute of Spices Research; UF/IFAS Extension"},{"plant":"tulsi-rama","mechanism":"pest_repellent","description":"Same mechanism as standard tulsi: Rama tulsi (Ocimum sanctum, green-leafed cultivar) carries the strongest eugenol concentration and best repels thrips and whitefly in tomato beds. Treat as a tender annual outside zone 9.","strength":"moderate","source":"ICAR-Indian Institute of Spices Research; UF/IFAS Extension"},{"plant":"ashwagandha","mechanism":"pest_repellent","description":"Ashwagandha (Withania somnifera) is a nightshade-family medicinal that shares some pest pressures with tomato but also contains withanolides that deter aphids and spider mites. Plant at row ends, not interplanted, to avoid late blight cross-host concerns.","strength":"moderate","source":"ICAR-National Bureau of Plant Genetic Resources; Cornell Cooperative Extension"},{"plant":"marigold-tagetes","mechanism":"pest_repellent","description":"French and African marigolds in the Tagetes genus produce alpha-terthienyl in roots, which suppresses root-knot nematode populations. Effect strongest with continuous marigold cover for one full season prior to tomato planting.","strength":"strong","source":"USDA-ARS root-knot nematode research; UF/IFAS Extension"},{"plant":"milkweed-common","mechanism":"trap_crop","description":"Common milkweed near tomato beds hosts oleander aphid (Aphis nerii) colonies that draw resident ladybug and lacewing populations. The predator buildup spills over onto tomato aphid pressure. Plant in a contained corner; milkweed spreads aggressively by rhizome.","strength":"moderate","source":"Xerces Society monarch and pollinator guide"},{"plant":"garlic-music","mechanism":"pest_repellent","description":"Music garlic interplanted along tomato rows deters whitefly and spider mite through sulfur volatile diffusion. Harvest garlic by July before tomato canopy fully shades the bed.","strength":"moderate","source":"Cornell Cooperative Extension"},{"plant":"marigold-french-bonita","mechanism":"pest_repellent","description":"Bonita French marigold (Tagetes patula) produces high concentrations of alpha-terthienyl, suppressing root-knot nematode in surrounding root zones. Plant continuously between tomato rows for one full season for measurable nematode reduction.","strength":"strong","source":"USDA-ARS root-knot nematode research; UF/IFAS Extension"},{"plant":"marigold-sparky","mechanism":"pest_repellent","description":"Sparky French marigold (compact bi-color cultivar) repels whitefly and aphids and supplies a bright continuous edge for tomato rows. Smaller habit than Bonita; fits in cage-row gaps without crowding.","strength":"moderate","source":"Cornell Cooperative Extension; USDA-ARS"},{"plant":"amaranth-grain","mechanism":"trap_crop","description":"Amaranth grain at tomato bed edges traps flea beetles and serves as a host for tarnished plant bug, drawing pressure away from tomato fruits. Grain harvest at season end recovers the crop's primary value.","strength":"moderate","source":"USDA-ARS; Cornell Cooperative Extension"},{"plant":"amaranth-purple-prince","mechanism":"trap_crop","description":"Purple Prince amaranth is a tall (5-7 ft) ornamental-edible variety useful as a flea beetle trap and visual back-of-bed edging for tomato rows. Edible greens and seed head also recover food value.","strength":"moderate","source":"USDA-ARS; Native Seeds/SEARCH"},{"plant":"horseradish","mechanism":"pest_repellent","description":"Horseradish at tomato bed corners suppresses some soilborne fungal pathogens (Verticillium, Fusarium) via allyl isothiocyanate root exudates. Plant in a buried-sided container to prevent spread into the bed.","strength":"moderate","source":"Cornell Cooperative Extension; USDA-ARS biofumigation research"},{"plant":"lemongrass","mechanism":"pest_repellent","description":"Lemongrass citral and geraniol repel whitefly, aphids, and mosquitoes around tomato beds. Tropical perennial; grow in pots in cold zones, in-ground in zones 9+.","strength":"moderate","source":"UF/IFAS Extension; Cornell Cooperative Extension"},{"plant":"potato-onion","mechanism":"pest_repellent","description":"Potato onion (Allium cepa Aggregatum group) at tomato bed edges supplies the same sulfur volatile deterrence as standard onion while clumping into multiplier bulbs for next-year replanting.","strength":"moderate","source":"Cornell Cooperative Extension"},{"plant":"onion-egyptian-walking","mechanism":"pest_repellent","description":"Egyptian walking onion (top-setting variety) supplies year-round green onion harvest and continuous sulfur volatile cover near tomato beds. Self-propagating; plant once and harvest indefinitely.","strength":"moderate","source":"Cornell Cooperative Extension"},{"plant":"marigold","mechanism":"pest_repellent","description":"French marigolds (Tagetes patula) produce alpha-terthienyl and other thiophene compounds in their roots that suppress root-knot nematodes (Meloidogyne spp.). The strongest empirically-supported companion-planting effect known. Plant 12-18 inches from tomato roots.","strength":"strong","source":"UC ANR; USDA-ARS nematology research"},{"plant":"marigold-signet","mechanism":"pest_repellent","description":"Signet marigolds (Tagetes tenuifolia) repel whitefly and aphids and provide some nematode suppression, though less than French marigolds. Edible flowers double as garnish.","strength":"moderate","source":"UC ANR Master Gardener publications"},{"plant":"nasturtium","mechanism":"trap_crop","description":"Nasturtium attracts aphids and whiteflies away from tomato plants as a sacrificial host. Spray nasturtium with insecticidal soap to kill the aphid colony before it spreads back to the tomatoes.","strength":"moderate","source":"Cornell Cooperative Extension; Riotte, Carrots Love Tomatoes"},{"plant":"onion","mechanism":"pest_repellent","description":"Onion beds adjacent to tomato deter aphids and some leaf miners via sulfur compound volatiles.","strength":"moderate","source":"Cornell Cooperative Extension; Cunningham, Great Garden Companions"},{"plant":"garlic-chive","mechanism":"pest_repellent","description":"Garlic chive (Allium tuberosum) provides milder allium deterrence than bulb garlic; less root competition with tomato. Perennial border option.","strength":"moderate","source":"Cornell Cooperative Extension; Cunningham, Great Garden Companions"},{"plant":"mint-spear","mechanism":"pest_repellent","description":"Mint deters whitefly and aphids near tomatoes. Always grow in containers around the tomato bed; never plant runners directly.","strength":"moderate","source":"Cornell Cooperative Extension; Cunningham, Great Garden Companions"},{"plant":"garlic","mechanism":"pest_repellent","description":"Garlic interplanted with tomato deters aphids, spider mites, and some leaf miners through sulfur compound volatiles. Plant cloves at the corners of tomato cages in fall for spring harvest before tomatoes fill out.","strength":"moderate","source":"Cornell Cooperative Extension; Cunningham, Great Garden Companions"},{"plant":"leek","mechanism":"pest_repellent","description":"Leek allium volatiles deter aphids and thrips near tomato, with less bulb root competition than full-size onion.","strength":"moderate","source":"Cornell Cooperative Extension; Cunningham, Great Garden Companions"},{"plant":"shallot","mechanism":"pest_repellent","description":"Shallot deters aphids, leaf miners, and thrips near tomato through sulfur compound volatiles; smaller bulb fits tight spacing.","strength":"moderate","source":"Cornell Cooperative Extension; Cunningham, Great Garden Companions"},{"plant":"chive","mechanism":"pest_repellent","description":"Chive border deters aphids and spider mites near tomato; perennial allium that flowers early for pollinators.","strength":"moderate","source":"Cornell Cooperative Extension; Cunningham, Great Garden Companions"},{"plant":"tarragon","mechanism":"pest_repellent","description":"French tarragon's anise-like volatiles deter aphids and whiteflies near tomato; perennial in zones 5-9.","strength":"moderate","source":"Cornell Cooperative Extension"},{"plant":"marigold-african-crackerjack","mechanism":"pest_repellent","description":"African marigold (Tagetes erecta) produces alpha-terthienyl-class thiophenes effective against root-knot nematodes around tomato; taller habit than French marigold.","strength":"strong","source":"UC ANR; USDA-ARS nematology research"}],"beneficialPredators":[{"slug":"ento-nematode-steinernema-carpocapsae","commonName":"Ambush Entomopathogenic Nematode","scientificName":"Steinernema carpocapsae","role":"microbial-control","gardenRole":"Effective against mobile surface-active pests like cutworms, armyworms, and borers in tree bark. Single application provides 2-6 weeks of suppression. Often used against tree borers via injection into burrows.","identificationTips":"Microscopic; presence inferred from declining pest populations. Commercial formulations come as moist spongy packs in cool packaging."},{"slug":"bald-faced-hornet","commonName":"Bald-Faced Hornet","scientificName":"Dolichovespula maculata","role":"predator","gardenRole":"Among the most effective wasp predators of soft-bodied insect pests. A mature colony of 100 to 400 workers consumes thousands of caterpillars, flies, and other arthropods over the summer. Aggressive defense of the nest limits human tolerance, but garden benefits are substantial when nests are sited away from walkways.","identificationTips":"Large (18 to 25 mm) wasps with black body and bold ivory-white markings on face, thorax, and abdomen tip (especially the rear segments). Enclosed gray paper nests up to 60 cm long, shaped like an inverted football, with a single bottom entrance, hung in tree canopies or on building exteriors."},{"slug":"bt-kurstaki","commonName":"Bt kurstaki (Btk)","scientificName":"Bacillus thuringiensis subsp. kurstaki","role":"microbial-control","gardenRole":"The most widely used microbial insecticide worldwide. Produces crystal proteins that bind to gut receptors specific to lepidopteran larvae; caterpillars stop feeding within hours and die within 1-3 days. Harmless to mammals, birds, pollinators, and most beneficials. Apply selectively: kills any caterpillar that eats sprayed foliage, including butterfly larvae.","identificationTips":"Microscopic bacterium; presence inferred from product label and dying caterpillars on sprayed plants 24-72 hours after application."},{"slug":"carolina-praying-mantis","commonName":"Carolina Praying Mantis","scientificName":"Stagmomantis carolina","role":"predator","gardenRole":"Generalist ambush predator. Indiscriminate: will take pest caterpillars and beetles but also pollinators and other beneficials. Plant in pollinator-rich beds with caution.","identificationTips":"Adults 45-65mm long, gray-brown to green, with raptorial forelegs held folded in front. Triangular head turns 180 degrees. Egg cases are tan, walnut-sized, frothy-looking, glued to twigs."},{"slug":"chinese-mantis","commonName":"Chinese Mantis","scientificName":"Tenodera sinensis","role":"predator","gardenRole":"Largest mantis in North America; impressive but ecologically blunt. Use with awareness that pollinators are routinely eaten alongside pest species.","identificationTips":"75-110mm, pale tan to bright green, with a thin black stripe along the front wing margin. Egg cases are tan, round-rectangular, golf-ball-sized, glued to twigs and structures."},{"slug":"tachinid-fly-compsilura","commonName":"Compsilura Tachinid","scientificName":"Compsilura concinnata","role":"parasitoid","gardenRole":"Generalist caterpillar parasitoid; attacks over 200 host species across many families. Useful pest suppressor but also implicated in declines of native saturniid moths; mixed ecological standing.","identificationTips":"7-9mm, gray with reddish eyes, dark stripes on the thorax. Larviparous: deposits live maggots directly onto caterpillars rather than laying eggs."},{"slug":"yellowjacket","commonName":"Eastern Yellowjacket","scientificName":"Vespula maculifrons","role":"predator","gardenRole":"Workers hunt caterpillars and other soft-bodied insects to feed developing larvae for the first half of summer, then shift to sugar foraging late summer. Real pest-control value, balanced against picnic nuisance and sting risk.","identificationTips":"12-16mm, stocky, bright yellow and black bands, smooth (not fuzzy) body, legs tucked tight to the body in flight. Enclosed paper nest is a distinct gray football-shape, often hidden in walls, attics, or ground cavities."},{"slug":"fiery-searcher","commonName":"Fiery Searcher","scientificName":"Calosoma scrutator","role":"predator","gardenRole":"Sometimes called 'caterpillar hunter.' Climbs tomato cages and brassica stems to take cabbageworm and hornworm larvae directly. Strong-flying and migratory.","identificationTips":"Large (25-35mm), striking iridescent green wing covers with rows of fine punctures and a coppery-red border. Underside dark blue-purple. Very fast runners. Releases a foul defensive odor when handled."},{"slug":"braconid-wasp-cotesia-congregata","commonName":"Hornworm Braconid Wasp","scientificName":"Cotesia congregata","role":"parasitoid","gardenRole":"The reason for the white rice-grain cocoons clinging to a hornworm's back. A single female wasp lays 65-100 eggs inside a young hornworm; larvae develop internally, then emerge through the cuticle to spin external pupae. The hornworm stops feeding and dies.","identificationTips":"Adult wasps tiny (3-4mm), black with smoky wings, slender thread-thin waist; rarely noticed. The diagnostic sign is the cluster of 30-80 oblong, white, rice-grain-sized pupal cocoons attached vertically along the back of a hornworm. Once seen, unmistakable."},{"slug":"paper-wasp-polistes","commonName":"Paper Wasp","scientificName":"Polistes spp.","role":"predator","gardenRole":"Major caterpillar predator. A small Polistes nest (20-50 workers) can clear hundreds of cabbageworm and hornworm larvae from a vegetable garden each summer. Often the silent reason a bed is pest-free in late summer.","identificationTips":"18-25mm, slender, brown-black-yellow patterned, with very long legs that dangle in flight (diagnostic vs. yellowjackets which tuck legs). Build small open paper combs visible from below, never enclosed paper envelopes."},{"slug":"paper-wasp","commonName":"Paper Wasp","scientificName":"Polistes spp.","role":"predator","gardenRole":"A single mature colony of 30 to 50 workers consumes thousands of caterpillars over a summer. Workers chew up caterpillars and carry the protein paste back to feed larvae. Among the most economically valuable garden predators of lepidopteran pests. Become a minor pest on ripe orchard fruit in late summer when colonies peak and protein demand falls.","identificationTips":"Slender 15 to 20 mm wasps with reddish-brown and yellow markings, long dangling legs in flight, and pinched waists. Build open paper combs (single layer of hexagonal cells) under eaves, in shrubs, and on outbuildings. Distinct from yellowjackets, which build enclosed nests; distinct from bald-faced hornets, which are larger and black-and-white."},{"slug":"ichneumon-wasp-ophion","commonName":"Short-tailed Ichneumon","scientificName":"Ophion spp.","role":"parasitoid","gardenRole":"Nocturnal parasitoid of large moth caterpillars including hornworms and cutworms. Often seen by gardeners flying around outdoor lights and mistaken for a stinging wasp; harmless to humans.","identificationTips":"15-25mm, slender, golden-orange to amber-tan, with very long antennae. Flies erratically at night. Female has a short curved ovipositor."},{"slug":"tachinid-fly-aphantorhaphopsis","commonName":"Sphinx Moth Tachinid","scientificName":"Compsilura concinnata (light strain)","role":"parasitoid","gardenRole":"Backup hornworm parasitoid where braconid wasps are absent. Less common than Cotesia in vegetable gardens but a useful natural enemy in mixed plantings.","identificationTips":"8-12mm, gray-black bristly tachinid with red eyes. Single white eggs on the back of a hornworm (vs. the dozens of white braconid cocoons) suggest tachinid parasitism."},{"slug":"spined-soldier-bug","commonName":"Spined Soldier Bug","scientificName":"Podisus maculiventris","role":"predator","gardenRole":"Pierces caterpillars with its straw-like beak and sucks them dry. A single soldier bug nymph can clear a young hornworm or potato beetle larva. Commercial pheromone lures are available to draw wild populations into beds.","identificationTips":"Adults 8-13mm, shield-shaped, mottled tan-brown, with prominent sharp spines projecting outward from the shoulders of the pronotum. The straw-like beak rests under the head. Eggs are barrel-shaped, metallic-looking, laid in tidy clusters."},{"slug":"wheel-bug","commonName":"Wheel Bug","scientificName":"Arilus cristatus","role":"predator","gardenRole":"Largest North American assassin bug. Pins prey with its forelegs and injects a paralyzing digestive saliva, then sucks the prey dry. Handle with care: the bite is exceptionally painful.","identificationTips":"Adults 28-36mm, gray-brown, with a diagnostic toothed cog-wheel crest rising vertically from the upper thorax (no other North American insect has this). Long curved beak under the head. Nymphs are red-orange with black markings."},{"slug":"yellowjacket-beneficial","commonName":"Yellowjacket (Predator Phase)","scientificName":"Vespula spp.","role":"predator","gardenRole":"During early to mid summer (predator phase), yellowjacket workers hunt soft-bodied insect prey and bring protein back to feed larvae. A single colony of 1,000 to 5,000 workers consumes a remarkable volume of caterpillars and flies. In late summer, the colony shifts to seeking carbohydrate sources (ripe fruit, sugary drinks) and becomes the familiar autumn nuisance.","identificationTips":"Bright yellow and black banded abdomen, 12 to 16 mm long, with shorter antennae than paper wasps. Workers fly straight to and from nest entrances with legs tucked. Underground nests show a steady stream of workers entering and exiting a hole in the ground."}],"beneficialNote":"The single best moment to do nothing: if you see white rice-grain cocoons clustered along a hornworm's back, those are Cotesia congregata braconid wasp pupae. Leave the parasitized hornworm in place; the next wasp generation will emerge and parasitize more hornworms across your beds.","companionNote":"Aromatic perimeter plantings disrupt pest host-finding. Best deployed as continuous borders around main beds rather than scattered interplanting.","friendlyLookalikes":[{"slug":"bald-faced-hornet","commonName":"Bald-Faced Hornet","confusionNote":"Yellowjackets are smaller (12 to 16 mm) and yellow rather than white. Bald-faced hornet nests are always above ground and conspicuous; yellowjacket nests are usually underground or in wall voids."},{"slug":"carolina-praying-mantis","commonName":"Carolina Praying Mantis","confusionNote":"Chinese mantis is much larger (75-110mm) and more often green; Carolina mantis is smaller, usually gray-brown. The Chinese species is non-native; either species predates beneficials as well as pests."},{"slug":"chinese-mantis","commonName":"Chinese Mantis","confusionNote":"Chinese mantis is much larger and the green form is more common; Carolina is smaller and usually gray-brown. Either species hunts indiscriminately."},{"slug":"yellowjacket","commonName":"Eastern Yellowjacket","confusionNote":"Paper wasps are slender with dangling legs in flight and open combs; yellowjackets are stocky with tucked legs and enclosed gray paper nests. Both predate caterpillars; yellowjackets carry higher sting risk to humans."},{"slug":"paper-wasp-polistes","commonName":"Paper Wasp","confusionNote":"Yellowjackets are stockier, tuck legs in flight, and build enclosed paper nests (often underground). Paper wasps are more docile near their open combs unless physically threatened; yellowjackets are aggressive scavengers."},{"slug":"paper-wasp","commonName":"Paper Wasp","confusionNote":"Yellowjackets are stouter, brighter yellow with bold black bands, and build enclosed paper nests usually underground or in wall voids. Paper wasps are slender with reddish-brown coloration and open exposed combs. Behavioral cue: paper wasps fly with their long legs dangling; yellowjackets tuck legs in flight."},{"slug":"spined-soldier-bug","commonName":"Spined Soldier Bug","confusionNote":"Brown marmorated stink bug (a pest) has rounded shoulders, white antenna bands, and no shoulder spines. Soldier bug has the diagnostic sharp pronotum spines and lacks the antenna bands. Do not squash soldier bugs."},{"slug":"yellowjacket-beneficial","commonName":"Yellowjacket (Predator Phase)","confusionNote":"Paper wasps fly with dangling long legs and build exposed paper combs. Yellowjackets fly with legs tucked and nest in enclosed cavities. Coloration: yellowjackets show bold black bands across a uniformly yellow body; paper wasps show reddish-brown and yellow without strong banding."}],"cropSpecific":{"crop":"tomato","pest":"tomato-hornworm","type":"pest","severity":"high","symptoms":"Large green caterpillars (3-4 inches at maturity) with white diagonal stripes and a curved horn at the rear. Defoliation of upper leaves first, working down the plant. Dark green droppings on lower leaves are usually the first sign before the caterpillar itself is spotted.","organicManagement":["Handpick into soapy water; the most effective control for small gardens.","Spray Bt (Bacillus thuringiensis var. kurstaki) on foliage; works on larvae under 1.5 inches.","Encourage parasitic braconid wasps (white rice-like cocoons on hornworm backs); leave parasitized hornworms in place to release the next wasp generation.","Companion plant with dill, basil, marigold to draw braconid wasps."],"prevention":"Fall tilling exposes overwintering pupae to predators and freezing. Rotate nightshades on a 3-year cycle. Inspect plants twice weekly from July through August.","regions":["all"],"source":"Cornell Cooperative Extension; UC IPM"}}