It turns out that the Froghopper is the insect that makes ‘Cuckoo Spit’ – it is also known as a Spittlebug. There it is, tucked under that curl of leaf in the picture above.
The froghopper lives on plant sap, which it sucks out after piercing the stem with a beak on its cone-shaped head. The cuckoo spit is a protective layer of foam that the baby froghopper makes from regurgitated sap to protect itself from predators like ants and parasitic wasps. After a couple of weeks the baby froghopper splits its soft skin and emerges as an adult. The adult is well-equipped with a harder skin and wing cases, and it can escape predators by jumping up to 70cm in the air, even though it is only half a centimetre long. The adult froghopper lives for about three months.
There are ten species of froghopper in the UK. The two main ones are the Common Froghopper and the Black-and-red Froghopper, but I believe this one to be an Alder Froghopper. It has a more subtle colouring than the Common Froghopper and distinctive white and clear patches, which mark it out as an Alder Froghopper. I assumed that the Alder Froghopper would prefer Alders, but, in fact, it is happy in a variety of habitats.
