Help is needed to help prevent the spread of a moth whose hairs can cause health problems.

The larvae of the Oak Processionary Moth have been found on Oak Trees in Richmond over the past two summers.

The insect's hairs contain a toxin which can cause itching, rashes, conjunctivitis and sore throats.

A small number of people also suffer symptoms similar to asthma.

Richmond Council says its tree department is launching a fresh search to find and destroy the moth's larvae and are working closely with the Forestry Commission and the Royal Botanic Gardens at Kew.

The public are also being asked to report any sightings of the insects on private land.

The council is advising people to look out for the distinctive hairy caterpillars and their nests which generally emerge in late April.

But it is warning people not to handle or disturb the nests under any circumstances.

The caterpillars feed on leaves and produce silken nests on the trunk or branches of oak trees.

They are named after their habit of forming nose-to-tail processions on the trees.

Councillor Martin Elengorn, cabinet member for environment, said: "With the arrival of spring and warmer weather, we are stepping up efforts to control the spread of this pest and working in partnership with the Forestry Commission, the Royal Botanic Gardens and our counterparts in Ealing.

"While there is no cause for alarm, the caterpillars can cause unpleasant symptoms in anyone who comes into contact with their hairs. If left unchecked they can also do considerable damage to oak trees.

"We therefore call on anyone who spots the larvae or nests to report them to the council immediately. Do not handle them yourself.

"We will also give homeowners advice on removal."

Sightings of the caterpillars can be reported to the council by calling 08456 122 660.

Anyone who thinks they have been exposed to the caterpillars and have an itchy skin rash, conjunctivitis or other symptoms, should contact their GP or call NHS Direct on 0845 4647.