Oak processionary

Last updated

Oak processionary
Thaumetopoea processionea, closeup.JPG
Oak processionary caterpillars
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Lepidoptera
Superfamily: Noctuoidea
Family: Notodontidae
Genus: Thaumetopoea
Species:
T. processionea
Binomial name
Thaumetopoea processionea

The oak processionary (OPM) (Thaumetopoea processionea) is a moth whose caterpillars can be found in oak forests, where they feed on oak leaves, causing significant damage. They travel in nose-to-tail processions (hence their name), often arrow-headed, with a leader followed by rows of several caterpillars abreast. [1] They are a human irritant because of their venomous setae (specifically urticating hairs), which can cause skin irritation and asthma. The species was first described by Carl Linnaeus in his 1758 10th edition of Systema Naturae.

Contents

Description

The imago (adult stage) Thaumetopoea processionea01.jpg
The imago (adult stage)

The wingspan of adult stage days is between 25 and 35 millimetres (0.98 and 1.38 in). Their pattern of tan, brown and white makes 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 the moth also eats the leaves of hazel, hornbeam, sweet chestnut, birch and beech. [2]

Identification

The nest with caterpillars on a deck of an oak tree Thaumetopoea processionea caterpillars nest.JPG
The nest with caterpillars on a deck of an oak tree

The caterpillars live and feed almost exclusively on oak trees. They may march in procession across the ground between oak trees, and cluster together as they feed on oak leaves. In early summer they build silk nests on the trunks and branches, but not in the leaves, of oak trees, and leave silk trails on the trunks and branches. The nests and trails are originally white and visible, but soon become discoloured and hard to see. [1]

The nests may be hemispherical, teardrop shaped, bag-like, and blanket-like (surrounding part of a trunk or branch), and may be at any height on the tree. The diameter may range from about 25 mm (one inch) to stretching several meters up the trunk. The caterpillars stay in these nests during the day between feeding periods, and later in the summer they remain in the nests to pupate into adult moths. [1]

The caterpillars are mostly found in oak trees or on the ground under them in late spring and early summer, and do not live on fences, walls, etc. as other caterpillars do. They have very long, white hairs contrasting markedly with shorter hairs. [1] The caterpillars of several other species may be mistaken for the oak processionary. [3]

Distribution

The moths are widely distributed in central and southern Europe, 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 are not present in northern Europe. Their range is expanding northward, possibly or partly as a result of global warming. The moth now has an established population in the UK. The eggs arrived on oak imported to the Richmond and Ealing areas of London in 2006 [4] and the range of the species in the UK has been steadily expanding despite efforts to eradicate it. [5]

Public health problem

Caterpillar Berlin caterpillar4.jpg
Caterpillar

The moths pose an increasing nuisance to humans as their range is extended. [6] The backs of older caterpillars (3rd to 6th instars) are covered with up to 63,000 pointed defensive bristles,[ citation needed ] sized between 0.2 and 0.3 millimeters, which contain an urticating toxin, the protein thaumetopoein. [7] 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.

It has been found that the skin irritation and itching caused by contact with these hairs can be largely eliminated by the use of cetirizine-based antihistamine tablets. [8]

Transmission of the hairs can be airborne, by ground contact via plants or grass or even by water contact in stillwater e.g. garden ponds. The hairs remain toxic beyond the life cycle of the moth and in some cases can remain a problem for several seasons.[ citation needed ] Mowing a lawn can bring a person into contact with these hairs. One alternative is to adopt a grass mulching technique to reduce possible contact, and to speed up the biological breakdown of the irritant hairs.[ citation needed ]

Damage to trees

Large populations can strip trees bare, leaving them weakened and vulnerable to other threats. [1]

Control

Nests can be removed, or the caterpillars sprayed with pesticides soon after they hatch. However, neither approach is 100% effective. [9] Male moths can be trapped in pheromone traps; this does not significantly reduce the population, but provides an indication of moth distribution. [1]

United Kingdom

The caterpillars were accidentally introduced to the UK in 2005, almost certainly as eggs on live oak plants imported from continental Europe. Later distribution of the pest probably arose from several similar introductions, in addition to spread from the original point of introduction. [1] By 2019 they had spread to all 33 London boroughs, and the Government had spent £37 million trying to control them. [9] 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 set up task forces to deal with outbreaks. Sightings of these caterpillars in other areas should be reported to the Forestry Commission, [10] whose research agency issued guidance on the way to contain outbreaks and deal with infestations, so as not to increase the risk to the public. [11]

On 31 March 2008 an emergency amendment added the moth to the list of pests in The Plant Health (Forestry) Order 2005, and has required all oak trees coming into the UK from the rest of Europe to have Plant Passports. [12]

In 2013 the Forestry Commission announced helicopters would be deployed to "blanket spray woodland" where the caterpillars posed a health threat. [5]

In 2015 fifteen OPM nests were found in Hampstead Heath, Highgate Wood and Queen's Park; in 2018 over 2,000 were found at those sites. [9] In April 2018 an outbreak of the caterpillars was declared in Greater London and surrounding areas. [13] In Spring 2019 more were reported at Bracknell by the BBC News website , and a number were also found in Virginia Water.

On 15 July 2019 strengthened measures on the import of most species of oak into England were introduced to protect native trees from the threat of the pest. [14]

In July 2023 the Forestry Commission sprayed woodland at Long Eaton, Derbyshire in an effort to control a local outbreak, with a five year plan to monitor the control measures. [15]

Belgium

The moth is reported as being fairly common in Belgium, notably in the Campine but also elsewhere, the population fluctuating from year to year. [16] In 2007 infestations in the province of Limburg were so acute that soldiers were deployed to burn them.

Netherlands

Control with vacuum cleaner in the Netherlands Bestrijdingeikenprocessierups01.jpg
Control with vacuum cleaner in the Netherlands

In the Netherlands, the caterpillars are dealt with by biological pest control. As in Germany, local authorities use fluids containing Bt toxins, a biological pesticide. These fluids are sprayed onto the infected trees. In cases of serious contamination, the use of relatively mild chemical pest killers has been allowed by local authorities.[ citation needed ]

An experiment with bird houses for the great tit began in 2016. It has been observed that great tits like to eat the young, not yet hairy caterpillars in April.

Because chemicals may be harmful to other insects, an alternative is to use vacuuming equipment to remove the caterpillars and then incinerating them.

See also

Related Research Articles

<span class="mw-page-title-main">Caterpillar</span> Larva of a butterfly or moth

Caterpillars are the larval stage of members of the order Lepidoptera.

<span class="mw-page-title-main">Urticating hair</span> Bristles on plants and animals that cause physical irritation when embedded

Urticating hairs or urticating bristles are one of the primary defense mechanisms used by numerous plants, almost all New World tarantulas, and various lepidopteran caterpillars. Urtica is Latin for "nettle", and bristles that urticate are characteristic of this type of plant, and many other plants in several families. This term also refers to certain types of barbed bristles that cover the dorsal and posterior surface of a tarantula's or caterpillar's abdomen. Many tarantula species eject bristles from their abdomens, directing them toward potential attackers. These bristles can embed themselves in the other animal's skin or eyes, causing physical irritation, usually to great discomfort. The term "hairs" is technically a misnomer, as only mammals possess true hairs. The scientific term for plant hairs is trichomes.

<span class="mw-page-title-main">Pine processionary</span> Species of moth

The pine processionary is a moth of the subfamily Thaumetopoeinae in the family Notodontidae, known for the irritating hairs of its caterpillars, their processions, and the economic damage they cause in coniferous forests. The species was first described scientifically by Michael Denis and Ignaz Schiffermüller in 1775, though it was known to the ancients, with remedies described by Theophrastus, Dioscorides and Pliny the Elder. Its processionary behaviour was described in 1916 by the French entomologist Jean-Henri Fabre. It is one of the most destructive species to pines and cedars in Central Asia, North Africa and southern Europe.

<span class="mw-page-title-main">Notodontidae</span> Moth family known as prominents

Notodontidae is a family of moths with approximately 3,800 known species. The family was described by James Francis Stephens in 1829. Moths of this family are found in all parts of the world, but they are most concentrated in tropical areas, especially in the New World.

<span class="mw-page-title-main">Brown-tail moth</span> Species of moth

The brown-tail moth is a moth of the family Erebidae. It is native to Europe, neighboring countries in Asia, and the north coast of Africa. Descriptions of outbreaks, i.e., large population increases of several years duration, have been reported as far back as the 1500s. The life cycle of the moth is atypical, in that it spends approximately nine months as larvae (caterpillars), leaving about one month each for pupae, imagos and eggs. Larvae (caterpillars) are covered in hairs. Two red spots on the back, toward the tail, distinguish these species from other similarly hairy moth larvae. The winged adults have white wings and a hairy white body with a tuft of brown hair at the tip of the abdomen. Females lay one egg cluster, usually on the underside of a leaf of a host plant. The species is polyphagous, meaning that it feeds on many different species of trees, including pear, apple, maple and oak.

<span class="mw-page-title-main">Thaumetopoeinae</span> Subfamily of moths

Thaumetopoeinae is a subfamily of moths in the family Notodontidae. This group is sometimes treated as a family Thaumetopoeidae with three subfamilies: Thaumetopoeinae, Anaphinae and Epicominae. However, it is now commonly treated at subfamily rank based on morphological and molecular phylogenetic evidence.

<i>Tineola bisselliella</i> Species of moth

Tineola bisselliella, known as the common clothes moth, webbing clothes moth, or simply clothing moth, is a species of fungus moth. It is the type species of its genus Tineola and was first described by the Swedish entomologist Arvid David Hummel in 1823. The specific name is commonly misspelled biselliella – for example by G. A. W. Herrich-Schäffer, when he established Tineola in 1853.

<i>Choristoneura fumiferana</i> Species of moth

Choristoneura fumiferana, the eastern spruce budworm, is a species of moth of the family Tortricidae native to the eastern United States and Canada. The caterpillars feed on the needles of spruce and fir trees. Eastern spruce budworm populations can experience significant oscillations, with large outbreaks sometimes resulting in wide scale tree mortality. The first recorded outbreaks of the spruce budworm in the United States occurred in about 1807, and since 1909 there have been waves of budworm outbreaks throughout the eastern United States and Canada. In Canada, the major outbreaks occurred in periods circa 1910–20, c. 1940–50, and c. 1970–80, each of which impacted millions of hectares of forest. Longer-term tree-ring studies suggest that spruce budworm outbreaks have been recurring approximately every three decades since the 16th century, and paleoecological studies suggest the spruce budworm has been breaking out in eastern North America for thousands of years.

<i>Lasiocampa quercus</i> Species of moth

Lasiocampa quercus, the oak eggar, is a common moth of the family Lasiocampidae found in Europe, including Britain and Ireland. It feeds on a variety of plant species, and may develop over two years in higher latitudes, where it may be known as the northern eggar. Its specific name quercus refers to the fact that its cocoon generally resembles an acorn, not that its primary food source is oak.

<i>Ochrogaster lunifer</i> Species of moth

Ochrogaster lunifer, the bag-shelter moth or processionary caterpillar, is a member of the family Notodontidae. The species was first described by Gottlieb August Wilhelm Herrich-Schäffer in 1855. Both the larval and adult forms have hairs that cause irritation of the skin (urticaria). The adult moth has a woolly appearance and its wings can grow to be about 5.5 cm across. The larvae feed on Grevillea striata at night and reside in brown silken bag nest during the day.

<i>Acleris semipurpurana</i> Species of moth

Acleris semipurpurana is a species in the moth family Tortricidae, and one of several species of moth commonly known as oak leaftier or oak leaf tier. The larvae feed on the leaves of oak trees in the Eastern United States and southeastern Canada which can be a major cause of defoliation. The loss of leaves can kill or damage the affected trees, which are chiefly in the Lobatae or red oak section of Quercus, or oaks.

<i>Archips semiferanus</i> Species of moth

Archips semiferanus is a species of moth in the family Tortricidae, and one of several species of moth commonly known as oak leafroller or oak leaf roller. The larvae feed on the leaves of oak trees in the eastern United States and southeastern Canada and are a major defoliator of oak trees, which can lead to tree mortality. In Pennsylvania in the late 1960s and early 1970s, oak leafrollers defoliated over 1,045,000 acres (423,000 ha).

<i>Pseudosphinx</i> Genus of insects

Pseudosphinx is a monotypic moth genus in the family Sphingidae first described by Hermann Burmeister in 1856. Its only species, Pseudosphinx tetrio, was first described by Carl Linnaeus in 1771. Its common names include tetrio sphinx, giant gray sphinx, frangipani hornworm, and plumeria caterpillar. In the island of Martinique it is best known as Rasta caterpillar because of its colors which are reminiscent of the ones found in Rastafarian clothing and accessories. It is native to the tropical and subtropical Americas from the southern and southwestern United States to Brazil. The occasional individual has been recorded as far north as the northeastern United States.

<span class="mw-page-title-main">Gypsy moths in the United States</span> Spread of an invasive species

The gypsy moth, also known as the spongy moth, was introduced in 1868 into the United States by Étienne Léopold Trouvelot, a French scientist living in Medford, Massachusetts. Because native silk-spinning caterpillars were susceptible to disease, Trouvelot imported the species in order to breed a more resistant hybrid species. Some of the moths escaped, found suitable habitat, and began breeding. The gypsy moth is now a major pest of hardwood trees in the Eastern United States.

<i>Lymantria dispar dispar</i> Species of moth (gypsy moth)

Lymantria dispar dispar or LDD moth, commonly known as the gypsy moth, European gypsy moth, North American gypsy moth, or spongy moth, is a species of moth in the family Erebidae that is of Eurasian origin. It has a range that extends over Europe, Africa, and North America.

The Coconut black headed caterpillar, is a species of moth found in throughout East Asian countries including Bangladesh, India, Sri Lanka, Myanmar, as well as Indonesia. It is considered a pest of coconut palm trees, causing considerable damage to the trees, and reducing the plant's yield significantly and can be a major problem where coconuts contribute to the economy. The species exists on coconut palms through its life stages from larval to moth, and utilizes the tree fronds as a main source of nutrition. Various methods of control have been explored, yet the primary control method is the administration of pesticides directly to the root of the coconut palms.

<i>Diprion pini</i> Species of sawfly

Diprion pini, the common pine sawfly, is a sawfly species in the family Diprionidae. It is a serious pest of economic forestry, capable of defoliating large areas of pine forest. It occurs throughout Europe and Russia.

<i>Thaumetopoea</i> Genus of moths

Thaumetopoea is a genus of moths belonging to the family Notodontidae. It was first described by Jacob Hübner in 1820.

Thaumetopoein is a urticating protein found in the hairs and integument of the caterpillars of the pine processionary and oak processionary.

References

  1. 1 2 3 4 5 6 7 "Oak Processionary Moth - Tree pests and diseases". Forestry Commission (UK). 11 September 2018. Archived from the original on 20 November 2018. Retrieved 31 January 2019.
  2. Tree News, Autumn/Winter 2007, page 4 internal Sylva supplement
  3. "Native species that may be mistaken for oak processionary moth". Forest Research. 2019. Retrieved 31 January 2019.
  4. forestry.gov.uk
  5. 1 2 Dixon, Helen (7 May 2013). "Helicopters to spray woodland to halt march of toxic caterpillars". Daily Telegraph. Archived from the original on 9 June 2013. Retrieved 7 May 2013.
  6. "Toxic caterpillar infestation plagues Germany". Deutsche Welle. Retrieved 4 July 2019.
  7. Lamy, M.; Pastureaud, M. H.; Novak, F.; Ducombs, G.; Vincendeau, P.; Maleville, J.; Texier, L. (1986). "Thaumetopoein: An urticating protein from the hairs and integument of the pine processionary caterpillar (Thaumetopoea pityocampa Schiff., Lepidoptera, Thaumetopoeidae)". Toxicon. 24 (4): 347–56. doi:10.1016/0041-0101(86)90194-7. PMID   3087028.
  8. Wang, D; Assen, YJ (2019-08-19). "[Itchy rash caused by the oak processionary caterpillar]". Nederlands Tijdschrift voor Geneeskunde (in Dutch). 163. ISSN   0028-2162. PMID   31433141.
  9. 1 2 3 Sleigh, Sophia (31 January 2019). "Toxic caterpillar invasion spiralling out of control following 'phenomenal' population explosion". Evening Standard. Retrieved 31 January 2019.
  10. The Forestry Commission. Oak processionary moth Archived 4 August 2008 at the Wayback Machine
  11. Forest Research Survey and intervention in relation to different phases of the oak processionary moth life cycle Archived 2012-10-30 at the Wayback Machine . Accessed 2008-05-31
  12. Office of Public Sector Information. Explanatory memorandum to the Plant Health (Forestry) (Amendment) Order 2008 No. 644. Retrieved 31 May 2008.
  13. "Health warnings after toxic caterpillar outbreak in London". BBC News. 28 April 2018. Retrieved 28 April 2018.
  14. "Tighter restrictions on oak tree imports come into force". GOV.UK. Retrieved 2020-01-28.
  15. Martin, Dan (20 July 2023). "Toxic caterpillar infestation 'could take years to tackle'". BBC News. Archived from the original on 20 July 2023. Retrieved 20 July 2023.
  16. "Thaumetopoea processionea (Linnaeus, 1758)". Catalogue of the Lepidoptera of Belgium. Archived from the original on 2019-02-01.