Scientists are calling for thousands of keen-eyed volunteers to report findings of frothy spittle, often called cuckoo spit and found on plants across the UK, in a pre-emptive strike against a deadly plant disease.
Xylella fastidiosa, is described by the European commission as “one of the most harmful pathogenic bacteria worldwide”. It arrived in Europe six years ago and has already struck several countries, devastating olive groves in southern Italy, and spreading to other EU countries including parts of France and Spain.
Though the UK is free of the disease, scientists are on high alert. According to the Royal Horticultural Society, it affects a huge number of plants, including lavender and rosemary, and has 563 different host plants worldwide. Plant pathologists believe if it spreads to the UK, native tree species, such as oak, ash and sycamore, could be affected.
Xylella is caused by a bacterium that is moved from one plant to another by plant-sucking insects such as the spittlebug, or froghopper.
Dr Alan Stewart, reader of ecology at the University of Sussex, said we needed to learn about what kinds of plants they feed on, what habitats they occupy, and where they are in the country. “So, ultimately if the worst possibly happens, and the disease does arrive in Britain, we’ll be able to make some really good predictions about how it’s likely to spread and how quickly,” he told BBC News.
There are 10 species of spittlebug in the UK with the most common being the meadow spittlebug. The distinctive frothy spittle, produced by the young, or nymphs, is called cuckoo spit but has no connection with the bird other than it begins to appear in late spring when the familiar call of cuckoos can first be heard.
The survey plans to map the distribution of the insects to better understand how Xylella might enter and spread in the UK
Volunteers are being asked to record where and when spittle or spittlebugs are seen in gardens, meadows, grasslands and woodlands.
If Xylella is found in the UK, all host plants within 100 metres would need to be destroyed and movement restrictions placed on some plants within a 5km radius for up to five years.
• This article was amended on 27 May 2019. An earlier subheading, which incorrectly said Xylella fastidiosa was known as cuckoo spit, has been changed.