Did you know that the ‘cuckoo-spit’ that you see in spring is produced by the immature stage (nymph) of a spittlebug or froghopper?
It is thought that the spittle is produced to protect the nymphs from drying out and from their predators. Once the nymphs emerge as adults, usually in late June, they leave their spittle ‘nest’ behind and become free flying. The name froghopper reflects the fact that their face is rather bulbous and therefore froglike, and that they are one of the most powerful jumpers in the animal kingdom. There are ten species of froghopper in Britain. The so-called Meadow Spittlebug, Philaenus spumarius, is one of our commonest insects and has possibly the broadest diet of any insect, being known to feed on more than 400 species of plant.
Interest in these insects has recently been heightened by the fact that they all feed on the liquid contents of the plant xylem tissue and are therefore capable of transmitting various plant diseases that reside there. One of these, the bacterium Xylella fastidiosa, has recently been responsible for the death of millions of olive trees in southern Italy. Fortunately, the Xylella bacterium has NOT been found in the UK, but there is a danger that it could be accidentally introduced in imported plants (especially lavender, rosemary and olive trees).
Good data is needed on two aspects of these insects to better understand how the Xylella bacterium would spread if it were ever introduced into Britain: the geographical distribution of the different species of spittlebug and what plant species they feed on. Last year, some of this information was collected through a national survey, funded by the Biotechnology & Biological Sciences Research Council (BBSRC) and coordinated through the Royal Horticultural Society (RHS). This focused on gardeners recording spittle on their garden plants. This year, the restrictions on movement due to Covid19 mean that the project has to be careful about extending the survey into the wider countryside. Nevertheless, it is hoped that people will enjoy recording spittle in places that they visit as part of their daily exercise. Of course, those people lucky enough to have a garden will still be able to record the presence of cuckoo-spit on the plants there.
Can you help?
Getting involved would mean recording cuckoo-spit when you find it in your garden or elsewhere and especially the plant species on which you find it. Your plant identification skills will help collect vital information. Please consider contributing to this important survey. Much more information and an online form for submitting your sightings can be found on the survey website.
An ‘exercise sheet’ for families to follow when confined to their gardens has been developed, which should appeal particularly to young children.
There is also a short video on how to find spittlebugs.
Please be sure to follow the government’s instructions at the time about social distancing when walking in the countryside.