June 22nd, 2018 by Chris Chapman

Experts Issue Warning About Elm Sawflies Wreaking Havoc Across Europe

Pest control experts are warning gardeners across Britain about the elm sawfly after the leaf-destroying insects arrived in the country from Europe. The Elm Sawfly's tell-tale zigzag pattern is unmistakable. Photo: Doris Holling (WSL) Known for the distinctive zigzag holes that they chew through leaves, the elm sawfly’s rapid reproduction cycle has seen them spread quickly from their country of origin, Japan, and across Europe. Elm sawflies can completely defoliate entire trees incredibly quickly, causing chaos for gardeners and for native wildlife that relies on elm trees to survive. Elm sawflies can reproduce asexually, which allows their populations to grow rapidly as they don’t need to find a mate. The swarm of sawflies then feeds on their host elm tree’s leaves, which often doesn’t kill the elm tree, but it does severely weaken the tree and leave is more susceptible to disease. Britain’s elm tree population is already severely under threat from Dutch elm disease, meaning experts fear further struggles to protect the British elm population. Scientists are advising the public to report sightings of the tell-tale zigzag pattern at treealert.forestry.gov.uk. If you have an elm tree in your garden, you are advised to protect it with a natural pesticide such as pyrethrum to keep the rapidly-spreading pests at bay.