Gardeners have been urged by scientists to help find a mysterious beetle that disappears in spring and reappears at the end of summer.
The Royal Horticultural Society (RHS) is asking people about sightings of the giant willow aphid (Tuberolachnus salignus) so they can discover where it goes and how it interacts with garden plants.
At nearly 6mm in length and with a distinctive shark-like fin, it is one of the largest aphid species in the UK, and an RHS team of entomologists are asking horticulturists to send photos if they see it. The team wants to find out why the ‘mysterious’ and ‘intriguing’ garden bug has its fin, and learn more about its life cycle and which plants can host it.
Giant willow aphids are regularly seen from July to February, with sightings peaking in the fall. As the name suggests, they are mainly found on willows, but the RHS wants to know if they are also found on other plants, and especially if they are seen between February and the end of May.
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The insects are easy to spot with the naked eye, but sometimes retreat into crevices in bark to hide from predators. They are usually seen on the stems and branches of trees and do not cause unsightly damage to host plants, which can withstand the delicate diet of these insects.
In May 2022, colonies were found on a quince tree (Cydonia oblonga) in Hertfordshire, a new host for this aphid. They were previously found mainly on willows and occasionally on other trees, including apple and poplar. Dr. Andrew Salisbury, RHS chief entomologist, said: “The sighting of giant willow aphids on quince, a previously unrecorded host plant, at a time of year when they are rarely seen only raises more questions about this fascinating and sometimes elusive aphid. .
“Despite thorough research, it is not certain where they go from April to June, and their host range needs further investigation. We are asking gardeners for their help in tracking down this aphid to help answer these intriguing questions about this unusual species.”
Gardeners are being used more than ever in scientific experiments as an untapped resource. Private garden space in Britain covers about 728,900 hectares (1.8 million acres), so their potential as a wildlife sanctuary is significant. RHS chief ecologist Gemma Golding recently asked gardeners to send in photos of interesting ‘weeds’ in the hopes of discovering rare wild plants growing in new places.
The RHS has also shown a greater interest in nature-friendly gardening in recent years, making carefully maintained and sterile gardens a thing of the past.
The RHS, which hosts the Chelsea Flower Show, has changed its stance on previously unwanted visitors to the garden, announcing last year that it would no longer classify slugs and slugs as pests. The UK’s leading gardening charity said that while the gastropods were the garden visitor they received the most complaints about, they should be considered an important part of the garden ecosystem. At RHS flower shows you now get tips on how to attract nature to your garden as well as seeing perfectly pruned roses.
Sightings of the giant willow aphid, which must be accompanied by a photograph, can be submitted to the RHS here.