ON a sunny day in late June, I decided to have a bit of an explore. Forgoing the picturesque but popular loops around the local reservoir, with the aim of searching out woodland rides seldom trodden and bilberry understory among gnarled pines. A habitat more reminiscent of Scottish glens but a rarity locally.

The woodland rides were a wall of luscious greens. Full of growth brought on by recent warm weather. Adding a sprinkle of colour to the scene were foxgloves, orange hawkweed, and bird’s-foot trefoil. Birdsong filled the air too. Song thrush, willow warbler, chiffchaff, and cuckoo. The cuckoos, easy to hear but always hard to spot, had been busy. Their young were everywhere spat out live onto the stems of plants hidden in small globules of spit. Of course, that is not really the case. But, along with swallows overwintering at the bottom of ponds it was a myth that prevailed until us humans worked out why the cuckoo does not build a nest.

Cuckoo spit appears at about the same time as the cuckoo returns on migration. The spit is made by the nymph (pictured) of froghoppers, a true bug. Small, at only a few millimetres, the nymph is a little non-descript, but under a lens has a dinosaur like appearance, an ankylosaurus perhaps. The spit is produced by the nymph tapping into the sap of a plant and blowing it out as bubbles through its bottom. Within the bubbles the nymph is able to keep moist and hidden.

The spit is harmless to humans. An ill-informed headline suggesting otherwise is quickly rebutted by the nature community. I had sometimes wondered if cuckoo spit would, as part of the defensive strategy, taste bad. Taste the alkaline excretion from a ladybird and you can see why predators steer clear. While cuckoo spit often brushes against my legs while out walking, I had never tasted it. Having removed a nymph and its protective layer from a blade of grass for a photo, I gave the spit a taste. It was surprisingly benign, no different from the taste you would get from chewing a blade of grass while lazing in the sunshine. The taste from cuckoo spit on bilberry was subtly more woody.

On its final moult, the nymph will leave the protective cuckoo spit as a winged adult. They form an important part of the food chain. Swifts and other birds will develop a taste for the froghoppers as they take flight throughout the summer. Whereas I have developed a taste for woodlands away from the beaten track.

wharfedale-nats.org.uk