The tomato caterpillar, often known as the tomato hornworm, can be a significant pest in gardens and orchards; It gets its name from a dark projection on its rear end and from being a common host on tomato plants. Tomato hornworms are closely related to the Manduca tobacco hornworm (often confusing). That is because the caterpillars of both species have similar morphologies and feed on the foliage of various plants in the Solanaceae family, so either species can be found on tobacco or tomato leaves. In this article, we’ll show you how to identify and fight the tomato caterpillar and how to use the bacillus thuringiensis commercial products to prevent them.

Tomato caterpillar characteristics

• Tomato hornworms are a type of sizable caterpillar that possess a distinct protrusion resembling a horn at the end of their bodies.
• Most caterpillars’ favorite plant is tomato.
• Hornworms chew the leaves and can completely defoliate the plants.
• They can also chew and make holes in the fruit.

Tomato caterpillar life cycle

• Tomato moths survive the winter as pupae and emerge as adult moths in spring.
• After mating, females deposit light green, smooth, oval eggs on the lower and upper leaf surfaces.
• After hatching, the tomato hornworm caterpillars commence feeding and undergo their complete growth cycle in a span of three to four weeks.
• As part of their life cycle, fully-grown caterpillars detach themselves from the plants they have been feeding on and proceed to dig into the soil, where they undergo a metamorphosis to become pupae.
• Within two weeks, the moths emerge, kickstarting the second generation of tomato hornworms during mid-summer.
• The offspring of moths of the second generation tend to lay their eggs on host plants, and among them are tomato plants.
• The caterpillars continue to feed on their host plants until late summer or early fall, after which they enter the pupal stage.
• The pupae remain in the soil during the winter.

Identify the tomato caterpillar: What damage does it cause?

Caterpillar or tomato worm, how to combat itHornworms can be up to 12 centimeters long, so they can impress you the first time you meet them.

They do the most damage in the caterpillar or larva stage. They are pale green with black and white markings , as well as a horn-like protrusion coming out of their rear. (Don't worry, they are not capable of stinging or biting!)

The caterpillar of this species exhibits a distinguishing feature on its green body: eight V-shaped stripes. Tomato hornworms come from a grayish-brown peppered moth (see photo, above).

The larvae blend very well with the greenery of the plant. Get used to a daily patrol, looking for worm eggs and small caterpillars. Here are some signs of infestations:

• Hornworms tend to start feeding on the top of the plant; look for chewed or lost leaves.
• It is crucial to inspect the tops of tomato leaves for any signs of infestation by the larvae of the pest species. The presence of dark green or black droppings left behind by these larvae is a common indication of infestation.
• Then look at the underside of the leaves. You will likely find a hornworm.
• Look for stems with some leaves missing and wilted leaves that droop.

How to combat the tomato caterpillar

Protect your plants against the devastation of these worms by early treatment, especially if adult moths are observed. For maximum impact, treat plants in the late afternoon or evening, just before the grubs come out to feed. Novobac MET ZONE organic grub killer offers several highly effective options to kill grubs on contact and continue to protect plants for up to three months. These products are used to treat tomatoes and other favorite crops related to them, such as eggplants, peppers and potatoes, just up to one day before harvest.

• Check the plants for tomato worms at least twice a week during the summer.
• Eliminating weeds can significantly decrease the number of areas where worms can deposit their eggs.
• Apply BT insecticide caterpillar control  after harvest to destroy caterpillars and pupae.

Natural enemies of the tomato worm

When you spot a green caterpillar on a green leaf with numerous white cocoons attached to its back, it is a sign that the caterpillar has been parasitized by a type of wasp known as a braconid wasp. The tomato worm, also known as the tomato hornworm, has several natural predators in the wild. Predatory insects, including lady beetles and green pupae, have a penchant for consuming the egg stage and young caterpillars. The paper wasp, Polistes spp, is a significant predator that preys on various types of caterpillars, including those that are commonly found in gardens. They are known to feed on tomato worms as well. In addition to paper wasps, various insects also parasitize tomato worms, with one of the most common being a small braconid wasp known as Cotesia congregata.

When a Cotesia congregata wasp lays its eggs on a hornworm, the hatching larvae will feed on the inside of the worm until they are ready to pupate. At this point, the larvae will form small white cocoons on the worm's body, which resemble grains of rice. If you observe this process in your garden, it is recommended to leave the infested worm in the garden, allowing the adult wasps to emerge from the cocoons and kill any other nearby worms.

This process of parasitism is a natural form of pest control that can help to reduce the need for chemical insecticides and maintain a healthy balance in the ecosystem. Therefore, it is crucial to be aware of the role of these beneficial insects and to take steps to preserve their populations in your garden.