I have never known such a year for cuckoo spit. In my front garden, there must be a hundred stems of lavender that are encased in a small cloud of froth. In days gone by, it was believed that cuckoos reproduced by spitting , with each globule containing a tiny miniature bird – after all, they had no nests, and the true story of their parasitic behaviour was yet to be understood. In truth, there is a little mystery encased in the foam, but it is entomological rather than ornithological.
Last Sunday, while other people were enjoying a snooze after lunch, I advanced on my lavender plants with a soft paintbrush and my camera. I was excited because, for the first time in this blog, Bugwoman was going to be investigating an actual bug. Although the term ‘bug’ is used to describe more or less any ‘creepy-crawly’, it actually has a precise meaning: ‘bugs’ belong to the order Hermiptera, which means ‘half-wing’. Examples include shieldbugs, water boatmen and aphids. I took my paintbrush and very gently started to brush the protective bubbles aside. It was rather like partially-beaten egg white. Before long, a tiny creature could be seen.
This is the nymph of a Froghopper (Meadow Spittlebug for my readers on the other side of the Atlantic), and it looked as soft and toothsome as a freshly podded pea. It had tiny red-gold eyes, and was an extra-ordinary blue-green colour, like jade and turquoise mixed. Hidden in the foam (not in the photo) was a perfect transparent replica of itself – the little creature had recently shed its skin, and would soon be an adult, and able to head off into the world.
I carefully gathered the foam together with my paintbrush, and covered the nymph over again – it dived into the froth with some urgency. I made sure that I put the lavender back into the garden in a hidden place, propped up so that the nymph could move to another plant when the one that I’d cut wilted.
The foam is the only protection that Froghoppers have, and schoolchildren are always delighted by how it’s made. The bug sucks up the sap from its chosen plant, excretes what’s left, and blows air through it – so, it lives in a house built from faeces, and created by flatulence. What youngster could resist such a story? I’m surprised that they’re not all queueing up to be biologists as we speak.
The foam ‘nests’ are a perfect way of protecting the vulnerable nymphs. They are protected from desiccation, from chilling and from overheating. Most animals find the taste offensive – I imagine that the resins from some of their preferred plants, such as lavender or rosemary, would be unpleasant. Plus, many animals are visual hunters, cued by movement or by colour contrast, and so they may pass by an inert mass of white froth. All in all, the nests are a very effective way of safeguarding the young froghoppers, and mortality is low. Fortunately for my lavender plants, froghoppers are not greedy feeders, and there is little real damage to the plants, even at this concentration of nymphs.
Froghoppers don’t have ‘full’ metamorphosis – they simply shed their skins, get bigger, and change colour, until they turn into an adult.The adult Froghopper might not be the exotic beauty that it was in its youth, but then, who is? The bug relies mostly on its colouration as camouflage in times of danger, but also, as its name suggests, can hop a surprising distance to safety if needs be – recent studies have shown that it can leap 70 cm from a standing start. The colour variation amongst adults is extreme, as you can see from the photographs on the British Bug page here.
To end with, here is a lovely story about Froghoppers from the nineteenth-century poet John Clare, via Bugs Britannica (Peter Marren and Richard Mabey). Clare relates how the Froghopper nymphs were known as ‘woodseers’ or ‘wood prophets’, because they were said to predict the weather. When the head of the insect is seen upwards, it means that sunny days are expected. When the head is down, it means that rain is on the way.
Seems I’m not the only one to have been scraping the froth from Froghoppers to see what’s going on.