Some of us view moths as beautiful fragile fluttery things, others as horrible nightmarish creatures that flutter in the dark and land on our faces, horror movies bare some of the responsibility for this I’m sure. Their offspring funny little crawly creatures that munch vociferously through our vegetable patches.
While the majority of caterpillars are completely harmless, a small number can have a devastating effect on animals and indeed humans. Two species of particular concern are the oak and pine processionary moths.
Not so much the caterpillars themselves, but the hairs that run across the back. The backs of older caterpillars are covered with as many as 63,000 pointed defensive bristles containing a toxin (thaumetopoein or closely related compounds). Even if the larvae are not handled, the hairs (setae) break off readily, become airborne and can cause caterpillar dermatitis, manifested as a rash, pruritis, conjunctivitis and, if inhaled, pharyngitis and respiratory distress including asthma.
Why so called, processionary moth caterpillars construct communal nests of white silk from which they crawl at night in single file, head to tail in large processions to feed on foliage in the crowns of trees, later to return in the same manner.
Geography
Although both the pine and oak processionary moths are prevalent in much of Western Europe, only oak processionary moth is currently known to be present in Great Britain. This unwelcome insect visitor was found in west London in 2006, thought to have arrived on trees imported for landscaping projects. Several locations in Ealing and Richmond have been identified and but concerns that it had moved northward to Sherwood Forest proved false when it was discovered that the species was a native Winter moth. A programme of control operations and survey work will continue in London in 2008 and probably beyond
Action To Be Taken
The best action to be taken is to be aware and watch out when going into wooded areas. Being proactive is a far better way of dealing with this moth.
From April the oak processionary caterpillars emerge from their eggs and start to eat, they go through several growth and shedding phases, so you might not see them until May or June when they are larger, congregating, eating leaves or in a procession heading back to the nest. *NB– pine processionary has a very different life cycle.]
If you think you see processionary moth caterpillars or their nests PLEASE do not touch or go near. To do so could put yourselves or someone else at risk. In a managed park, contact one of the rangers. If he/she seems a little unconcerned the Forest Research have a phone number and an email address to contact. They will be more than willing to listen. Also check out the Forest Research Website, they have fairly regular news updates on what is going on where. PLEASE PLEASE however don’t just decide to herbicide every caterpillar you see. Although they might not be your favorite creature, but we have some native species who are struggling to survive in an ever changing climate. Far better to call the research center and get advice first. Also before you get out your canister of pesticide think of your dogs, there is growing belief that the amount of pesticides put onto the plants and ground is increasing the rate of cancer in dogs. (As soon as I get some more info on this I’ll put it up) After all their daily walk entails much sniffing of the local ground area to pick up doggy news.
References:
Yahoo search for Oak Processionary Moth / Pine Processionary Moth look up Wikipedia
www.forestresearch.gov.uk/oakprocessionarymoth
www.forestry.gov.uk/newsrele.nsf/HomepageWebPressReleases
Contacts if you think you have seen these caterpillars or their nests
Tel: 01420 22255
Fax: 01420 23653
Email: research.info@forestry.gsi.gov.uk
While the majority of caterpillars are completely harmless, a small number can have a devastating effect on animals and indeed humans. Two species of particular concern are the oak and pine processionary moths.
Not so much the caterpillars themselves, but the hairs that run across the back. The backs of older caterpillars are covered with as many as 63,000 pointed defensive bristles containing a toxin (thaumetopoein or closely related compounds). Even if the larvae are not handled, the hairs (setae) break off readily, become airborne and can cause caterpillar dermatitis, manifested as a rash, pruritis, conjunctivitis and, if inhaled, pharyngitis and respiratory distress including asthma.
Why so called, processionary moth caterpillars construct communal nests of white silk from which they crawl at night in single file, head to tail in large processions to feed on foliage in the crowns of trees, later to return in the same manner.
Geography
Although both the pine and oak processionary moths are prevalent in much of Western Europe, only oak processionary moth is currently known to be present in Great Britain. This unwelcome insect visitor was found in west London in 2006, thought to have arrived on trees imported for landscaping projects. Several locations in Ealing and Richmond have been identified and but concerns that it had moved northward to Sherwood Forest proved false when it was discovered that the species was a native Winter moth. A programme of control operations and survey work will continue in London in 2008 and probably beyond
Action To Be Taken
The best action to be taken is to be aware and watch out when going into wooded areas. Being proactive is a far better way of dealing with this moth.
From April the oak processionary caterpillars emerge from their eggs and start to eat, they go through several growth and shedding phases, so you might not see them until May or June when they are larger, congregating, eating leaves or in a procession heading back to the nest. *NB– pine processionary has a very different life cycle.]
If you think you see processionary moth caterpillars or their nests PLEASE do not touch or go near. To do so could put yourselves or someone else at risk. In a managed park, contact one of the rangers. If he/she seems a little unconcerned the Forest Research have a phone number and an email address to contact. They will be more than willing to listen. Also check out the Forest Research Website, they have fairly regular news updates on what is going on where. PLEASE PLEASE however don’t just decide to herbicide every caterpillar you see. Although they might not be your favorite creature, but we have some native species who are struggling to survive in an ever changing climate. Far better to call the research center and get advice first. Also before you get out your canister of pesticide think of your dogs, there is growing belief that the amount of pesticides put onto the plants and ground is increasing the rate of cancer in dogs. (As soon as I get some more info on this I’ll put it up) After all their daily walk entails much sniffing of the local ground area to pick up doggy news.
References:
Yahoo search for Oak Processionary Moth / Pine Processionary Moth look up Wikipedia
www.forestresearch.gov.uk/oakprocessionarymoth
www.forestry.gov.uk/newsrele.nsf/HomepageWebPressReleases
Contacts if you think you have seen these caterpillars or their nests
Tel: 01420 22255
Fax: 01420 23653
Email: research.info@forestry.gsi.gov.uk
Many thanks to Christine Tilbury of Forest Research who checked this article to ensure that the info I have given you is accurate.
