Cuckoo spit

What is cuckoo spit?

Cuckoo spit is a white frothy liquid secreted by the immature nymphs of a sap-sucking insect known as a froghopper.

Symptoms

• Blobs of white frothy liquid develop on young stems and leaves in late spring and summer
• Each blob contains a creamy white insect nymph up to 4-6mm (¼in) long
• Usually plant growth is unaffected, but, if the nymph has been feeding at the shoot tip, this may cause some distorted growth

Control

• Apart from producing the 'spit' these insects have little detrimental effect on plants and can be tolerated
• If considered unsightly, they can be wiped off by hand or dislodged with a jet of water from a garden hose
• It is not worth using an insecticide against froghoppers

Biology

• This froth has no connection with cuckoos
• It is secreted by the immature stages of sap-sucking insects known as froghoppers, presumably as a means of protecting themselves against predators
• The adult insects are present during mid-late summer and live openly on  plants. They do not produce cuckoo spit or cause any noticable damage
• Overwintering eggs are deposited in plant stems in late summer