Tomato worm facts. Tomato horn worms are the worst pests in the vegetable garden but these voracious tomato eating worms can be easily controlled with biological natural pest control.
The horned tomato worm is actually a sphinx moth caterpillar. Its proper name is Manduca quinquemaculata.
Sphinx moths feed on the nectar of various garden plants. The females lay their eggs on the leaves of certain host plants--tomatoes, potatoes, and bell pepper plants are the usual victims. Soon, the bright green tomato worms hatch and begin feasting.
Their coloring makes them difficult to spot. At first.
They grow quickly. If you have one fat horned tomato worm in your garden, you will soon know it. You'll go out one day and several of your tomato plants will have been reduced to nothing more than green stick figures.
Tomato horn worms take the blame for most of this sort of damage, but they have a close cousin that is the more likely culprit: the tobacco horn worm.
These 2 tobacco worms have eaten nearly all the leaves off my potted Angel Trumpet plant overnight.
The tobacco horn worm differs from the tomato horn worm only slightly.
Tomato horn worms have a series of white Vs running the length of their bodies. Tobacco worms have white slashes.
Tomato worms have dark green horns with black sides. The horn of the tobacco horn worm is red.
Whichever of these tomato plant pests you have, you'll be interested in getting rid of them. The same tomato pest control methods work on both bugs.
You could just pick them off the plants and drop them into a jar of soapy water.
But first you have to find them.
Look for their tell-tale black droppings. They won't be far away.
If picking bugs off of plants is not your idea of a good time, there are some biological pest controls you can use.
You can achieve biological control of pest worms on tomato plants (or any other garden plant they inhabit) by the use of parasitic wasps. Cotesia congregata is the exact species of parasitoid wasp that does them in.
Bacillus thuringiensis commonly called BT is a naturally occurring bacteria. It is sold under the brand names Dipel and Thuricide and is safe to use on organic produce. It is a liquid that you mix with water and spray onto the plants.
The worms eat it and the bacteria causes them to stop eating. Once they can no longer eat, they die.
The advantages of biological pest control are: