Oak Processionary
Encyclopedia
The Oak Processionary is a moth
whose caterpillar
s are pests in oak
forest
s and pose a health hazard because of their poison
ous setae (hairs), which may cause skin
irritation and asthma
.
, and are occasionally found as far north as Sweden
. In the southern countries of Europe the populations are controlled by natural predators, but these predators do not exist in northern Europe. Their range is expanding northward, possibly or partly as a result of global warming
.
moths is between 25 and 35 mm. Their pattern of tan, brown and white make the adults difficult to see against oak bark. Adults fly during July and August. The larvae 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, returning in the same manner.
Oak
is its preferred food source, but it also attacks hazel
, hornbeam
, sweet chestnut
, birch
and beech
.
The moths are posing an increasing threat to humans as their range is being extended by the warming European climate. The backs of older caterpillars (3rd to 6th instar
s) are covered with up to 63,000 pointed defensive bristles containing an urticating
toxin (thaumetopoein or closely related compounds). The setae break off readily, become airborne and can cause epidemic caterpillar dermatitis
(lepidopterism), manifested as a papular rash
, pruritus
, conjunctivitis
and, if inhaled, pharyngitis
and respiratory distress, including asthma or even anaphylaxis
.
The general public have been asked to look out for these caterpillars and to report them, rather than deal with them themselves.
The London Boroughs of Brent, Ealing
, Hounslow
and Richmond upon Thames
have set up task forces to deal with outbreaks. Sightings of these caterpillars in other areas should be reported to the Forestry Commission. The research agency of the Forestry Commission has issued guidance on the way to contain outbreaks and deal with infestations, so as not to increase the risk to the public.
An emergency amendment came into force on 31 March 2008, which added the moth to the list of pests in The Plant Health (Forestry) Order 2005, and requires all oak trees coming into the UK from the rest of Europe to have Plant Passports.
province of Limburg
were so acute that governor Steve Stevaert
deployed 20 soldiers to burn them http://www.flandersnews.be/cm/flandersnews.be/News/070530_Army%2Bdeployed%2Bagainst%2Bcaterpillars.
Moth
A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...
whose caterpillar
Caterpillar
Caterpillars are the larval form of members of the order Lepidoptera . They are mostly herbivorous in food habit, although some species are insectivorous. Caterpillars are voracious feeders and many of them are considered to be pests in agriculture...
s are pests in oak
Oak
An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...
forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
s and pose a health hazard because of their poison
Poison
In the context of biology, poisons are substances that can cause disturbances to organisms, usually by chemical reaction or other activity on the molecular scale, when a sufficient quantity is absorbed by an organism....
ous setae (hairs), which may cause skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
irritation and asthma
Asthma
Asthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...
.
Distribution
The moths are widely distributed in central and southern EuropeEurope
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, and are occasionally found as far north as Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
. In the southern countries of Europe the populations are controlled by natural predators, but these predators do not exist in northern Europe. Their range is expanding northward, possibly or partly as a result of global warming
Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...
.
Description
The wingspan of adult stageImago
In biology, the imago is the last stage of development of an insect, after the last ecdysis of an incomplete metamorphosis, or after emergence from the pupa where the metamorphosis is complete...
moths is between 25 and 35 mm. Their pattern of tan, brown and white make the adults difficult to see against oak bark. Adults fly during July and August. The larvae 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, returning in the same manner.
Oak
Oak
An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...
is its preferred food source, but it also attacks hazel
Hazel
The hazels are a genus of deciduous trees and large shrubs native to the temperate northern hemisphere. The genus is usually placed in the birch family Betulaceae, though some botanists split the hazels into a separate family Corylaceae.They have simple, rounded leaves with double-serrate margins...
, hornbeam
Hornbeam
Hornbeams are relatively small hardwood trees in the genus Carpinus . Though some botanists grouped them with the hazels and hop-hornbeams in a segregate family, Corylaceae, modern botanists place the hornbeams in the birch subfamily Coryloideae...
, sweet chestnut
Sweet Chestnut
Castanea sativa is a species of the flowering plant family Fagaceae, the tree and its edible seeds are referred to by several common names such Sweet Chestnut or Marron. Originally native to southeastern Europe and Asia Minor, it is now widely dispersed throughout Europe and parts of Asia, such as...
, birch
Birch
Birch is a tree or shrub of the genus Betula , in the family Betulaceae, closely related to the beech/oak family, Fagaceae. The Betula genus contains 30–60 known taxa...
and beech
Beech
Beech is a genus of ten species of deciduous trees in the family Fagaceae, native to temperate Europe, Asia and North America.-Habit:...
.
Public Health Problem
Instar
An instar is a developmental stage of arthropods, such as insects, between each molt , until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, or...
s) are covered with up to 63,000 pointed defensive bristles containing an urticating
Urticating hair
Urticating hairs, i.e. stinging hairs, are one of the primary defense mechanisms used by numerous plants, some New World tarantulas, and various lepidopteran caterpillars. Urtica is Latin for "nettle", and hairs that urticate are characteristic of this type of plant, and many other plants in...
toxin (thaumetopoein or closely related compounds). The setae break off readily, become airborne and can cause epidemic caterpillar dermatitis
Dermatitis
-Etymology:Dermatitis derives from Greek derma "skin" + -itis "inflammation" and genetic disorder.-Terminology:There are several different types of dermatitis. The different kinds usually have in common an allergic reaction to specific allergens. The term may describe eczema, which is also called...
(lepidopterism), manifested as a papular rash
Rash
A rash is a change of the skin which affects its color, appearance or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, cracked or blistered, swell and may be painful. The causes, and...
, pruritus
Itch
Itch is a sensation that causes the desire or reflex to scratch. Itch has resisted many attempts to classify it as any one type of sensory experience. Modern science has shown that itch has many similarities to pain, and while both are unpleasant sensory experiences, their behavioral response...
, conjunctivitis
Conjunctivitis
Conjunctivitis refers to inflammation of the conjunctiva...
and, if inhaled, pharyngitis
Pharyngitis
Pharyngitis is an inflammation of the throat or pharynx. In most cases it is quite painful, and is the most common cause of a sore throat.Like many types of inflammation, pharyngitis can be acute – characterized by a rapid onset and typically a relatively short course – or chronic....
and respiratory distress, including asthma or even anaphylaxis
Anaphylaxis
Anaphylaxis is defined as "a serious allergic reaction that is rapid in onset and may cause death". It typically results in a number of symptoms including throat swelling, an itchy rash, and low blood pressure...
.
England
Infestations of this caterpillar were first found in several locations in London in 2006.The general public have been asked to look out for these caterpillars and to report them, rather than deal with them themselves.
The London Boroughs of Brent, Ealing
London Borough of Ealing
The London Borough of Ealing is a borough in west London.-Location:The London Borough of Ealing borders the London Borough of Hillingdon to the west, the London Borough of Harrow and the London Borough of Brent to the north, the London Borough of Hammersmith and Fulham to the east and the London...
, Hounslow
London Borough of Hounslow
-Political composition:Since the borough was formed it has been controlled by the Labour Party on all but two occasions. In 1968 the Conservatives formed a majority for the first and last time to date until they lost control to Labour in 1971. Labour subsequently lost control of the council in the...
and Richmond upon Thames
London Borough of Richmond upon Thames
The London Borough of Richmond upon Thames is a London borough in South West London, UK, which forms part of Outer London. It is unique because it is the only London borough situated both north and south of the River Thames.-Settlement:...
have set up task forces to deal with outbreaks. Sightings of these caterpillars in other areas should be reported to the Forestry Commission. The research agency of the Forestry Commission has issued guidance on the way to contain outbreaks and deal with infestations, so as not to increase the risk to the public.
Belgium
In 2007 infestations in the BelgianBelgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...
province of Limburg
Limburg (Belgium)
Limburg is the easternmost province of modern Flanders, which is one of the three main political and cultural sub-divisions of modern Belgium. It is located west of the river Meuse . It borders on the Dutch provinces of North Brabant and Limburg and the Belgian provinces of Liège, Flemish Brabant...
were so acute that governor Steve Stevaert
Steve Stevaert
Steve Stevaert is a Belgian politician of the Flemish Socialist Party: the SP.A....
deployed 20 soldiers to burn them http://www.flandersnews.be/cm/flandersnews.be/News/070530_Army%2Bdeployed%2Bagainst%2Bcaterpillars.