Croydon must have offended the Almighty. A famine across the borough cannot be far away next, because after the floods of February, residents of Croydon now have to deal with the threat of a pestilence of Biblical proportions.

Beware: the caterpillar of the oak processionary moth should not be touched with bare skin, experts wanr

Tony Brooks, the council’s director of environment, yesterday issued a health warning about an invasive species of insect, the oak processionary moth, and particularly its voracious caterpillar which threatens to devastate trees in the borough and also poses a serious threat to the health of residents, the poisonous fine hairs on the caterpillars causing severe skin rashes and asthma attacks.

The caterpillars emerge in late April and early May and often can be seen marching in nose-to-tail processions – hence the “processionary” – as they feed ravenously on broad-leafed trees, especially oaks, whose branches they can strip bare.

Tony Kirkham, the head of the arboretum at Kew Gardens, has described the oak processionary moth as one of the most serious of all the pests and diseases threatening trees in this country, on a par with ash die-back and Dutch elm disease.

The species was first noticed in Croydon and Bromley in 2o12. Eradication attempts have failed to remove it. Ian Gambles, director of Forestry Commission England, said the public should report sightings, but not try to remove the caterpillars on their own because of the health risks: “We need, and welcome, reports of the caterpillars or their nests from the public or others, such as gardeners and tree surgeons, who are out and about in areas with oak trees.

“However, the public should not try to remove the caterpillars or nests themselves. This task needs to be carefully timed to be most effective, and is best done by specially trained and equipped operators.”

Large groups of oak processionary moth caterpillars move together, stripping branches of all foiliage

The email from Croydon Council’s Brooks, which has been seen by Inside Croydon, says that the Forestry Commission has been called in to the borough in an attempt to eradicate the insect. “It has been found on a few council and private trees in Shirley, Ashburton and Woodside wards,” Brooks wrote.

Of the caterpillars, he added: “Their  tiny hairs contain a protein which can cause itchy skin rashes, eye and throat irritations and occasionally, breathing difficulties, in people and animals. The hairs can be blown on the wind and left in their nests in and under oak trees. The greatest risk period is May to July, although nests should not be approached at any time.

“It is for these reasons the Forestry Commission are keen to control/eradicate them. The Forestry Commission have reported that oak processionary moth (OPM) eggs have now hatched. So [they] have stated their programme of inspection and control.

“The Forestry Commission will be undertaking a survey of all known nesting sites along with a survey of all oak trees within a buffer zone of approximately 2km from the last know[n] nest. This will cover the Shirley, Ashburton, Woodside, South Norwood, Selhurst, Addiscombe and Heathfield wards.

The oak processionary moth, which has a lifespan of about three days in high summer, when it lays its eggs for the next season

“The Council will also be undertaking a survey of council-owned oak trees within the buffer zone.

“Along with the survey the Forestry Commission will be undertaking control of the pest by spraying affected oak trees and oak trees within 50m of a nest, a bacterial pesticide that only affects moth caterpillars and is harmless to humans and mammals, which is also used on organic farms. The spraying programme will be undertaken 24hr a day due to the fact there is only a short window to spray and that spraying can only be undertaken when weather conditions permit.”

The controlling work will continue until the end of July, when the caterpillars turn into moths, which have a 72-hour lifespan, during which time they mate, and lay the eggs to continue the cycle for another year.

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  Coming to Croydon

  • Warlingham Sevens Heaven tournament, May 3
  • Elm Tree Cottage garden open day, May 4
  • Crystal Palace Chamber of Commerce Question Time, May 7
  • David Lean Cinema: Wadjda, May 8
  • Coulsdon Euro election hustings, May 8
  • David Lean Cinema: Blue Velvet, May 10
  • Norwood Society Talk: West Norwood – a place of change, May 15
  • David Lean Cinema: The Invisible Woman, May 15
  • Coulsdon West local election hustings, May 16
  • Croydon RFC charity memorial day, May 17
  • Coulsdon East local election hustings, May 19 (confirmed)
  • St Giles’ primary school open morning, May 21
  • David Lean Cinema: The Rocket, May 22
  • David Lean Cinema: Dallas Buyers Club, May 29
  • Croydon Tech City “summit”, June 6
  • Elm Tree Cottage garden open day, June 15
  • Norwood Society Talk: The Concrete Church, June 19
  • Classic Car Show at Purley Rotary Fields, June 22
  • Crystal Palace Overground Festival, June 26-29
  • South Norwood Allotments open day, June 28
  • Elm Tree Cottage garden open day, Aug 10
  • Norwood Society Talk: War Memorials, Sep 18
  • Norwood Society Talk: From Fire Station to Theatre, Oct 16
  • Norwood Society Talk: Lambeth’s Archives, Nov 20

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