Tomato Hornworms
Tomato hornworms are among the largest caterpillars you will find in a vegetable garden.
They can remove a shocking amount of foliage in a short time.
What They Look Like
Hornworms are:
- Large
- Green
- Well camouflaged
- Marked with pale diagonal stripes
- Equipped with a horn-like projection at the rear
Despite their size, they are surprisingly hard to see.
Signs of Hornworms
Look for:
- Missing tomato leaves
- Bare stems
- Large dark droppings
- Damaged green fruit
Droppings are often easier to spot than the caterpillar.
Where to Look
Inspect:
- Undersides of leaves
- Stems near damaged foliage
- Shaded interior growth
Hand-Picking
In a home garden, hand-picking is often the simplest control.
Drop hornworms into soapy water or remove them from the garden.
What If It Has White Things on Its Back?
Leave it alone.
Those white structures are usually cocoons of parasitic braconid wasps.
The wasps have already attacked the hornworm.
Allowing them to emerge helps build a natural population of beneficial insects.
Biological Controls
Products containing Bacillus thuringiensis var. kurstaki can be effective against young caterpillars when used according to label directions.
They work best on small larvae.
Encourage Natural Enemies
Avoid unnecessary broad-spectrum insecticides.
Predatory wasps and parasitoids help control hornworms.
GardenGrowz Tip
A hornworm covered in white parasitoid cocoons is one bug you absolutely do not want to kill.