Large numbers of caterpillars are emerging from these cocoons and feasting on surrounding vegetation. These could be brown-tail moth caterpillars, which have hairs which are an irritant to human skin so they should not be handled. In some severe cases, they can cause breathing difficulties.

There are other caterpillars which make webs like this. Identification can only be confirmed once the caterpillars emerge, the brown-tail are small brown hairy caterpillars with two bright yellow/orange dots in line on their back, but you could see some blue-grey caterpillars (Lackey) and rarer, black caterpillars (Eggar).

The Highways, Travel and Environment portfolio holder at Dorset Council, Cllr Ray Bryan said, “Our advice is to avoid brown-tail moth caterpillars, which emerge every spring, rather than try to destroy them. Dorset Council treat infestations on rights of way and council-owned land by managing the vegetation or with chemical treatment, where appropriate. If you have concerns about an infestation on your own property, then specialist companies can be employed.

“We work alongside our colleagues in the town and parish councils, so they may also take relevant control measures.”

If you notice these caterpillars during your daily exercise time, leave them alone and try to stay away from areas where there are lots of them. The caterpillars are generally more common in May and June.

If you get the rash, which is often on the hands, arms and neck, apply antihistamine cream or calamine lotion. Symptoms should subside after a few hours, but seek medical help if you are unsure, or the reaction doesn’t lessen.

If you have to remove them from your garden, put on some vinyl or rubber gloves before picking them up. The council suggests disposing of them in a bucket of soapy and salty water.

Do not burn off vegetation and nests now as this will make the problem worse. The hairs of the caterpillars will become airborne. Also, Dorset and Wiltshire Fire Service are asking residents not to have bonfires during the coronavirus pandemic.

Instead, wait until October and again wear gloves to remove the nests and destroy by drowning. 

 The caterpillars have a ferocious appetite so if there are plants in the garden that are affected, the Royal Horticultural Society (RHS) has some advice https://www.rhs.org.uk/advice/profile?pid=896