How to Get Rid of Tomato Hornworms

Tomato Hornworms can quickly defoliate a tomato plant. In this video, Tricia shares her tips on getting rid of tomato hornworms before they get your tomatoes! Check out our companion resource on tomato pests.

Overview of Tomato Hornworms

Tomato hornworms are large caterpillars, specifically Manduca quinquemaculata, known for feeding on tomato plants and other members of the nightshade family, including eggplant and pepper.

These voracious caterpillars, often mistaken for tobacco hornworms, can defoliate tomato plants quickly, leading to significant damage to the foliage, green fruit, and overall tomato crop.

To get rid of tomato hornworms, gardeners can use biological control methods such as introducing beneficial insects like braconid wasps and green lacewings, or applying Bacillus thuringiensis to target hornworm larvae before they cause extensive harm.

The Importance of Addressing Tomato Hornworm Infestations

Addressing tomato hornworm infestations is crucial for the health of tomato plants and other crops in the vegetable garden, as these voracious caterpillars can quickly defoliate plants, leaving behind black droppings and damaging green fruit.

If left untreated, hornworm larvae, such as Manduca sexta and Manduca quinquemaculata, will continue to lay eggs and mature into adult moths, like the five-spotted hawk moth, perpetuating their life cycle and causing long-term damage to the tomato crop.

To get rid of tomato hornworms, gardeners can introduce beneficial insects like braconid wasps and green lacewings, or use methods such as Bacillus thuringiensis and soapy water to target both small caterpillars and large caterpillars before they devastate the garden.

Tomato Hornworm sitting on top of a green plant

Understanding Tomato Hornworms

Identification of Tomato Hornworms

Tomato hornworms (Manduca quinquemaculata) are large caterpillars with distinctive white stripes and black droppings, while tobacco hornworms (Manduca sexta) have similar features but can be differentiated by the number of V-shaped markings on their sides.

To effectively get rid of tomato hornworms, consider using biological control methods such as introducing beneficial insects like green lacewings and lady beetles, or applying Bacillus thuringiensis to target the voracious caterpillars.

Proper identification of hornworm eggs and larvae can help manage these pests in your vegetable garden, ensuring a healthy tomato crop.

Life Cycle of Tomato Hornworms

The life cycle of tomato hornworms (Manduca quinquemaculata) progresses through four stages: egg, larva, pupa, and adult. After female moths lay eggs on tomato plants, hornworm eggs hatch into voracious caterpillars that feed on tomato leaves and green fruit, then pupate in the soil before emerging as adult moths.

This cycle typically spans from late spring to early fall, with each stage lasting several weeks depending on environmental conditions and timing of the growing season.

Common Habitats

Tomato hornworms (Manduca quinquemaculata) thrive in vegetable gardens and areas with abundant tomato plants, as well as other nightshade family members like peppers and eggplants. They prefer environments where their host plants are plentiful, and their behavior shows seasonal variations, with egg-laying and larval feeding peaking from late spring to late summer.

As the growing season progresses, the presence of beneficial insects like green lacewings and lady beetles can help get rid of these pests, reducing the impact on your tomato crop.

Hornworm on a Stem

Signs of Tomato Hornworm Infestation

Visual Indicators on Plants

Signs of tomato hornworm infestation include chewed leaves and stems, defoliation patterns, and damage such as missing foliage and large, irregular holes in the tomato plant.

Look for visual indicators like black droppings on the soil or tomato leaves, which signal the presence of voracious hornworm larvae. To address the issue, you can use beneficial insects like green lacewings and lady beetles, or apply Bacillus thuringiensis to effectively get rid of these pests.

Spotting the Hornworms Themselves

To spot tomato hornworms (Manduca quinquemaculata) effectively, look for large caterpillars that are green with white stripes and a distinctive horn-like protrusion on their last abdominal segment. These voracious caterpillars blend well with tomato leaves, making them harder to detect, so it's best to check your tomato plants early in the morning or late in the evening when they are most active.

Keeping an eye out for their black droppings and feeding damage on the foliage can also help in identifying their presence and deciding how to get rid of them.

Other Symptoms of Infestation

To spot tomato hornworms (Manduca quinquemaculata) effectively, look for large caterpillars that are green with white stripes and a distinctive horn-like protrusion on their last abdominal segment. These voracious caterpillars blend well with tomato leaves, making them harder to detect, so it's best to check your tomato plants early in the morning or late in the evening when they are most active.

Keeping an eye out for their black droppings and feeding damage on the foliage can also help in identifying their presence and deciding how to get rid of them.

Hornworm

Natural Control Methods

Handpicking Tomato Hornworms

To effectively get rid of tomato hornworms by hand, carefully inspect your tomato plants for the large caterpillars with white stripes and use gloves to gently remove them from the foliage. Place the hornworms in a container with soapy water to kill them or relocate them far from your vegetable garden to prevent reinfestation.

Best practices for disposal include ensuring that the hornworms do not fall back into the garden and avoiding handling them directly to prevent potential harm from their droppings or bodily fluids.

Attracting Beneficial Insects

To effectively get rid of tomato hornworms, attracting beneficial insects like parasitic wasps and ladybugs can be highly beneficial. Parasitic wasps, such as braconid wasps, target hornworm larvae by laying their eggs on the caterpillars, while ladybugs feed on smaller pests and aphids.

To encourage these natural predators in your garden, plant a variety of flowers and herbs that provide nectar and habitat, and avoid using broad-spectrum pesticides that can harm these helpful insects.

Using Companion Plants

To get rid of tomato hornworms, incorporate companion plants that naturally repel these pests. Marigolds and basil are effective choices as they deter hornworms and other pests from attacking your tomato plants.

Designing a companion planting strategy involves strategically placing these repelling plants around your tomato crop to create a protective barrier, while also supporting beneficial insects like green lacewings and lady beetles that prey on hornworm larvae.

Beneficial Nematodes (7 mil) - Grow Organic Beneficial Nematodes (7 mil) Weed and Pest

Biological Control Options

Introducing Beneficial Nematodes

Beneficial nematodes are microscopic worms that target and parasitize pests like tomato hornworms and tobacco hornworms in the soil. They work by entering the hornworm's body and releasing bacteria that kill the pests before they can develop into the next stage of their life cycle.

To apply them, mix the nematodes with water and drench the soil around your tomato plants, focusing on areas where eggs and larvae are likely to be present. With proper application, you can expect reduced hornworm populations and healthier tomato crops.

Bacillus thuringiensis (Bt) Sprays

Bacillus thuringiensis (Bt) sprays are effective in targeting and killing hornworms, including tomato hornworms and tobacco hornworms, by releasing toxins that specifically affect their digestive systems. When hornworms consume the treated foliage, the bacteria disrupt their feeding and cause them to die within a few days.

For safe application, follow guidelines to apply Bt early in the morning or late in the evening, avoiding direct contact with beneficial insects and ensuring coverage on both the upper and lower surfaces of the leaves to protect your tomatoes and other plants.

Utilizing Insecticidal Soaps

Insecticidal soaps effectively target tomato hornworms and other hornworms by disrupting their outer layers, causing dehydration and death when they come into contact with the solution. To apply, spray the soap directly onto the infested tomato plants, ensuring thorough coverage of both the upper and lower surfaces of the leaves where hornworms feed.

For best results, apply insecticidal soaps during the cooler parts of the day, such as early morning or late evening, and avoid using them when beneficial insects like braconid wasps are active to prevent unintended harm.

Leaves with holes from pests

Preventative Measures

Regular Garden Inspections

Regular garden inspections should be conducted weekly to effectively spot tomato hornworms, tobacco hornworms, and other pests before they cause significant damage. During inspections, look for signs such as chewed leaves, yellow spots, black droppings, and the presence of large caterpillars or their eggs on tomato plants.

Using tools like a hand-held magnifying glass and a small trowel can help you closely examine the foliage and soil for hornworm eggs, pupae, and larvae.

Maintaining Plant Health

Maintaining plant health is crucial in preventing infestations of tomato hornworms and other pests, as robust plants are better equipped to resist damage and recover from attacks. To boost plant immunity, ensure proper watering, fertilization, and use organic mulch to improve soil health and support vigorous growth.

Additionally, incorporating practices such as rotating crops and planting sacrificial plants can reduce pest pressure and enhance the overall resilience of your tomato plants against infestations.

Soil Management Practices

Maintaining healthy soil is essential for reducing infestations of pests like tomato hornworms and ensuring strong plant growth. Implementing soil rotation practices helps disrupt the life cycles of pests such as tobacco hornworms and prevents the buildup of larvae and eggs in the soil.

Techniques for preparing and maintaining healthy soil include adding organic matter, such as compost or aged manure, and regularly testing soil pH to ensure optimal conditions for your tomatoes and other plants.

Mega Mulch Compressed Brick (2.5 Cu Ft Once Expanded) Growing

Creating a Hostile Environment for Tomato Hornworms

Mulching and Ground Covers

Mulching and ground covers can effectively create a hostile environment for tomato hornworms by providing a barrier that discourages these pests from reaching your tomato plants. Organic mulches, such as straw or wood chips, help by reducing the number of exposed soil surfaces where hornworm eggs and pupae might overwinter.

Apply mulch around your tomato plants to a depth of about 2-4 inches, ensuring it covers the soil completely to inhibit hornworm larvae and other pests from establishing a presence.

Using Physical Barriers

Using physical barriers such as garden fabrics and covers can be an effective method to create a hostile environment for tomato hornworms and other pests. Lightweight row covers or floating row covers can prevent moths, including five spotted hawk moths and hummingbird moths, from laying eggs on your tomato plants.

To install, drape the fabric over your tomato crop and secure the edges with soil or stakes, ensuring that it is properly sealed to keep out pests while allowing light and water to reach your plants.

Implementing Crop Rotation

Implementing crop rotation is a key strategy for preventing infestations of tomato hornworms and tobacco hornworms, as it disrupts their life cycle by reducing the availability of host plants. By rotating tomatoes with non-nightshade crops, you minimize the chances of hornworm eggs and larvae, including those from hummingbird moths and five spotted hawk moths, from establishing a persistent presence.

Plan a rotation schedule by alternating your tomato crops with other plant families each growing season to help break the cycle of pest infestation and improve soil health.

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Alternative and Home Remedies

Neem Oil Applications

Neem oil is an effective home remedy for managing tomato hornworms and tobacco hornworms, as it disrupts their feeding and reproductive cycles. To use neem oil, mix 2 tablespoons of neem oil with 1 gallon of water and a few drops of mild dish soap to help it adhere to the plant surfaces.

Apply the solution to the affected areas of your tomatoes, including the upper and lower sides of leaves, early in the morning or late in the evening to avoid harming beneficial insects like braconid wasps and to ensure better absorption.

Garlic and Pepper Sprays

Garlic and pepper sprays are effective DIY remedies for deterring tomato hornworms and tobacco hornworms by creating a strong, natural repellent. To make a spray, blend 2 cloves of garlic and 1 tablespoon of hot pepper with 1 quart of water, then strain the mixture and add a few drops of dish soap to help it stick to plant surfaces.

Apply this spray to your tomato plants every 7-10 days or after heavy rain, ensuring thorough coverage of leaves and stems to help keep away pests like hummingbird moths and their larvae.

Closeup photo Tomato Hornworm

Conclusion

Effectively managing tomato hornworms requires a multifaceted approach combining natural, biological, and preventive strategies. By integrating methods such as handpicking, attracting beneficial insects, using companion plants, and applying home remedies like neem oil and garlic-pepper sprays, gardeners can significantly reduce hornworm infestations and protect their tomato crops.

Additionally, maintaining plant health, implementing crop rotation, and utilizing soil management practices further enhance the resilience of your garden. Through diligent monitoring and proactive measures, you can keep your tomato plants thriving and minimize damage from these voracious pests. For additional support, check out our range of Tomato Hornworm Treatments & Repellents for Pest Control to find effective solutions for your garden. And if you're looking to start or expand your tomato garden, explore our selection of Tomato Seeds for Sale to find the perfect varieties for your needs.

Fresh tomatoes

FAQs About How to Get Rid of Tomato Hornworms

  • Q1: What are tomato hornworms, and why are they a problem?

    • A1: Tomato hornworms are large green caterpillars that feed on the leaves, stems, and fruit of tomato plants. These worms can cause significant damage by eating large portions of the plant, making them a major concern for gardeners. They can also attack other plants in the nightshade family, such as eggplants and peppers.

  • Q2: How can I identify a tomato hornworm?

    • A2: Tomato hornworms are bright green caterpillars with white stripes running down their sides and a distinctive horn on the last abdominal segment of their bodies. They can grow up to 4 inches long and have a robust appearance. Look for yellow spots and black droppings on the leaves of tomato plants as signs of their presence.

  • Q3: What are some natural ways to get rid of tomato hornworms?

    • A3: Natural ways to control tomato hornworms include introducing beneficial insects such as braconid wasps and paper wasps, which lay wasp eggs on the hornworm's body, leading to the development of white cocoons. You can also plant sacrificial plants to attract the hornworms away from your main crops or introduce alternate hosts to divert their feeding.

  • Q4: How do braconid wasps help in controlling tomato hornworms?

    • A4: Braconid wasps are natural predators of tomato hornworms. They lay their eggs on the hornworm's body, and when the eggs hatch, the larvae feed on the hornworm from the inside out. This biological control method is highly effective in reducing hornworm populations without using chemicals.

  • Q5: Are tomato hornworms and tobacco hornworms the same?

    • A5: Tomato hornworms and tobacco hornworms are closely related, but they are different species. Both are pests of tomato plants, with the tomato hornworm being identified as Manduca quinquemaculata and the tobacco hornworm as Manduca sexta. They are often mistaken for each other because they look similar and feed on the same plants.

  • Q6: How can I use the Old Farmer’s Almanac tips to control tomato hornworms?

    • A6: According to the Old Farmer’s Almanac, regularly inspect tomato plants for hornworm eggs and small worms, and handpick them off the plants. You can also attract natural predators like braconid wasps and hummingbird moths to keep the hornworm population in check. Another suggestion is to plant dill or basil nearby, as these can repel hornworms.

  • Q7: What role do five-spotted hawk moths play in the hornworm life cycle?

    • A7: Five-spotted hawk moths are the adult stage of tomato hornworms. After these moths emerge, they lay eggs on the leaves of tomato plants and other host plants. The eggs hatch into caterpillars, which then feed on the plants, completing the life cycle.

  • Q8: Can using a sacrificial plant help control tomato hornworm infestations?

    • A8: Yes, planting sacrificial plants can help. These are plants that you intentionally grow to attract tomato hornworms away from your main tomato crop. By sacrificing these plants, you can protect your main tomato plants from significant damage caused by these voracious feeders.

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