Toxic hairy caterpillar threat at ‘tipping point’
Hampstead Heath managers to discuss how to tackle dangerous moth
07 March, 2019 — By Richard Osley
The Oak Processionary Moth [Photo: Regani]
THE battle against toxic caterpillars feeding off oak trees on Hampstead Heath has reached a “tipping point” with the City of London warning it needs to double the amount of money it spends on trying to stop them.
Not only can the dreaded Oak Processionary Moth strip trees bare of bark, their nests can be a health hazard to humans.
Spiky hairs on the caterpillar’s body contain thaumetopoein, which can cause sore throat, fever, vomiting and trigger asthma attacks and when touched can cause skin rashes. There are also concerns about how dogs on the Heath could be affected and vets across London have been sent information packs from the Forestry Commission explaining symptoms.
In what is described as an “urgent” update to the City of London’s Hampstead Heath Committee, which meets next Wednesday, it was confirmed that the number of nests found across Hampstead Heath, Highgate Wood and Queen’s Park had leapt from just 15 in 2015 to 2,013 last year.
Colin Buttery, director of Open Spaces at the City, which manages the Heath, said “a risk zone-based approach” had been taken, “targeting OPM in areas where the public would be most at risk of being exposed to the caterpillars or nests. This includes removal of nests close to busy locations such as car parks, key paths and buildings, catering facilities, children’s play and sporting facilities.”
Nest removal and pesticide use had been but neither could be 100 per cent effective, said Mr Buttery, adding: “To date reports of health issues affecting the public on City Corporation sites is very low, but we are now reaching a “tipping point” at some properties, such as Hampstead Heath, where nest numbers have grown exponentially in 2018.”
The OPM is native to southern Europe, but is thought to have been accidentally brought to London in 2008, originally in Richmond. It first spread to the Heath in 2014. Mr Buttery said past work tackling the OPM had been absorbed in the City’s budgets, but there had been a tenfold financial cost.
More than £50,000 was spent on Hampstead Heath in the last year.
He warned, that the future annual outlay for all of the City’s sites would be as much as £300,000 a year.