PestChewing insects
Tomato hornworm
Large green caterpillars with a horn on the tail that can strip tomato and pepper plants of leaves almost overnight.
Also known as: Tobacco hornworm, Manduca
Symptoms and identification
Leaves and stems are eaten, and green fruit is chewed. Large dark green droppings appear on leaves below. The well-camouflaged caterpillars can reach 10 cm long.
Causes
The caterpillars are the larvae of large hawk moths that lay eggs on leaves in summer. They are common in North America.
Organic treatment
Hand-pick caterpillars. Leave any carrying white cocoons, as these have been parasitised by beneficial wasps. Spray Bt on small caterpillars.
Prevention
Check plants regularly from midsummer, and till the soil after harvest to destroy pupae.
Chemical treatment (use with care)
Rarely needed; use an insecticide labelled for hornworms if damage is severe.