Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Datasheet

Thaumetopoea processionea
(oak processionary moth)

Toolbox

Datasheet

Thaumetopoea processionea (oak processionary moth)

Summary

  • Last modified
  • 27 September 2018
  • Datasheet Type(s)
  • Invasive Species
  • Pest
  • Host Animal
  • Preferred Scientific Name
  • Thaumetopoea processionea
  • Preferred Common Name
  • oak processionary moth
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Metazoa
  •     Phylum: Arthropoda
  •       Subphylum: Uniramia
  •         Class: Insecta
  • Summary of Invasiveness
  • T. processionea, commonly known as the oak processionary moth, is a major pest in many European countries and threatens the health of oak trees. The common and scientific names of T. processionea refer...

Don't need the entire report?

Generate a print friendly version containing only the sections you need.

Generate report

Pictures

Top of page
PictureTitleCaptionCopyright
Thaumetopoea processionea (oak processionary moth); dense cluster of mature larvae on oak trunk. Fildu de Sus village, Salaj County, central Romania.
TitleMature larvae
CaptionThaumetopoea processionea (oak processionary moth); dense cluster of mature larvae on oak trunk. Fildu de Sus village, Salaj County, central Romania.
Copyright©Haruta Ovidiu/University of Oradea, Romania/Bugwood.org - CC BY 3.0 US
Thaumetopoea processionea (oak processionary moth); dense cluster of mature larvae on oak trunk. Fildu de Sus village, Salaj County, central Romania.
Mature larvaeThaumetopoea processionea (oak processionary moth); dense cluster of mature larvae on oak trunk. Fildu de Sus village, Salaj County, central Romania.©Haruta Ovidiu/University of Oradea, Romania/Bugwood.org - CC BY 3.0 US
Thaumetopoea processionea (oak processionary moth); dense cluster of mature larvae on oak trunk. Hungary.
TitleMature larvae
CaptionThaumetopoea processionea (oak processionary moth); dense cluster of mature larvae on oak trunk. Hungary.
Copyright©Ferenc Lakatos/University of West-Hungary/Bugwood.org - CC BY-NC 3.0 US
Thaumetopoea processionea (oak processionary moth); dense cluster of mature larvae on oak trunk. Hungary.
Mature larvaeThaumetopoea processionea (oak processionary moth); dense cluster of mature larvae on oak trunk. Hungary.©Ferenc Lakatos/University of West-Hungary/Bugwood.org - CC BY-NC 3.0 US
Thaumetopoea processionea (oak processionary moth); adult moth at rest on leaf.
TitleAdult moth
CaptionThaumetopoea processionea (oak processionary moth); adult moth at rest on leaf.
Copyright©Gyorgy Csoka/Hungary Forest Research/Institute, Bugwood.org - CC BY 3.0 US
Thaumetopoea processionea (oak processionary moth); adult moth at rest on leaf.
Adult mothThaumetopoea processionea (oak processionary moth); adult moth at rest on leaf.©Gyorgy Csoka/Hungary Forest Research/Institute, Bugwood.org - CC BY 3.0 US
Thaumetopoea processionea (oak processionary moth); egg mass on oak twig.
TitleEgg mass
CaptionThaumetopoea processionea (oak processionary moth); egg mass on oak twig.
Copyright©Gyorgy Csoka/Hungary Forest Research/Institute, Bugwood.org - CC BY 3.0 US
Thaumetopoea processionea (oak processionary moth); egg mass on oak twig.
Egg massThaumetopoea processionea (oak processionary moth); egg mass on oak twig.©Gyorgy Csoka/Hungary Forest Research/Institute, Bugwood.org - CC BY 3.0 US
Thaumetopoea processionea (oak processionary moth); recently hatched caterpillars on egg mass. France.
TitleRecently hatched caterpillars
CaptionThaumetopoea processionea (oak processionary moth); recently hatched caterpillars on egg mass. France.
Copyright©Louis-Michel Nageleisen/Departement de la Santé des Forêts, France/Bugwood.org - CC BY 3.0 US
Thaumetopoea processionea (oak processionary moth); recently hatched caterpillars on egg mass. France.
Recently hatched caterpillarsThaumetopoea processionea (oak processionary moth); recently hatched caterpillars on egg mass. France.©Louis-Michel Nageleisen/Departement de la Santé des Forêts, France/Bugwood.org - CC BY 3.0 US
Thaumetopoea processionea (oak processionary moth); mature larvae, feeding on oak leaves. Note long, dense, spines. Hungary.
TitleMature larvae
CaptionThaumetopoea processionea (oak processionary moth); mature larvae, feeding on oak leaves. Note long, dense, spines. Hungary.
Copyright©Gyorgy Csoka/Hungary Forest Research/Institute, Bugwood.org - CC BY 3.0 US
Thaumetopoea processionea (oak processionary moth); mature larvae, feeding on oak leaves. Note long, dense, spines. Hungary.
Mature larvaeThaumetopoea processionea (oak processionary moth); mature larvae, feeding on oak leaves. Note long, dense, spines. Hungary.©Gyorgy Csoka/Hungary Forest Research/Institute, Bugwood.org - CC BY 3.0 US
Thaumetopoea processionea (oak processionary moth); close-up of mature larvae. Note long, dense, spines.
TitleMature larvae
CaptionThaumetopoea processionea (oak processionary moth); close-up of mature larvae. Note long, dense, spines.
Copyright©Gyorgy Csoka/Hungary Forest Research/Institute, Bugwood.org - CC BY 3.0 US
Thaumetopoea processionea (oak processionary moth); close-up of mature larvae. Note long, dense, spines.
Mature larvaeThaumetopoea processionea (oak processionary moth); close-up of mature larvae. Note long, dense, spines.©Gyorgy Csoka/Hungary Forest Research/Institute, Bugwood.org - CC BY 3.0 US
Thaumetopoea processionea (oak processionary moth); dense cluster of mature larvae on turkey oak (Quercus cerris) trunk. Note recently moulted larval skins. Fildu de Sus village, Salaj County, central Romania.
TitleMature larvae
CaptionThaumetopoea processionea (oak processionary moth); dense cluster of mature larvae on turkey oak (Quercus cerris) trunk. Note recently moulted larval skins. Fildu de Sus village, Salaj County, central Romania.
Copyright©Haruta Ovidiu/University of Oradea, Romania/Bugwood.org - CC BY 3.0 US
Thaumetopoea processionea (oak processionary moth); dense cluster of mature larvae on turkey oak (Quercus cerris) trunk. Note recently moulted larval skins. Fildu de Sus village, Salaj County, central Romania.
Mature larvaeThaumetopoea processionea (oak processionary moth); dense cluster of mature larvae on turkey oak (Quercus cerris) trunk. Note recently moulted larval skins. Fildu de Sus village, Salaj County, central Romania.©Haruta Ovidiu/University of Oradea, Romania/Bugwood.org - CC BY 3.0 US
Thaumetopoea processionea (oak processionary moth); dense cluster of mature larvae on oak trunk. Note the two 'processionary' columns on left and right of main group. Fildu de Sus village, Salaj County, central Romania.
Title'Processionary' columns
CaptionThaumetopoea processionea (oak processionary moth); dense cluster of mature larvae on oak trunk. Note the two 'processionary' columns on left and right of main group. Fildu de Sus village, Salaj County, central Romania.
Copyright©Haruta Ovidiu/University of Oradea, Romania/Bugwood.org - CC BY 3.0 US
Thaumetopoea processionea (oak processionary moth); dense cluster of mature larvae on oak trunk. Note the two 'processionary' columns on left and right of main group. Fildu de Sus village, Salaj County, central Romania.
'Processionary' columnsThaumetopoea processionea (oak processionary moth); dense cluster of mature larvae on oak trunk. Note the two 'processionary' columns on left and right of main group. Fildu de Sus village, Salaj County, central Romania.©Haruta Ovidiu/University of Oradea, Romania/Bugwood.org - CC BY 3.0 US
Thaumetopoea processionea (oak processionary moth); cluster of larvae on defoliated oak twig.
TitleLarval defoliation
CaptionThaumetopoea processionea (oak processionary moth); cluster of larvae on defoliated oak twig.
Copyright©Louis-Michel Nageleisen/Departement de la Santé des Forêts, France/Bugwood.org - CC BY 3.0 US
Thaumetopoea processionea (oak processionary moth); cluster of larvae on defoliated oak twig.
Larval defoliationThaumetopoea processionea (oak processionary moth); cluster of larvae on defoliated oak twig.©Louis-Michel Nageleisen/Departement de la Santé des Forêts, France/Bugwood.org - CC BY 3.0 US

Identity

Top of page

Preferred Scientific Name

  • Thaumetopoea processionea (Linnaeus, 1758)

Preferred Common Name

  • oak processionary moth

Other Scientific Names

  • Cnethocampa processionea (Linnaeus, 1758)
  • Liparis processionea (Linnaeus, 1758)
  • Phalaena processionea Linnaeus, 1758
  • Thaumetopoea luctifica Staudinger & Rebel, 1901

International Common Names

  • English: cluster caterpillars; oak processionary; oak processionary caterpillar
  • Spanish: procesionaria de la encina
  • French: processionnaire du chene

Local Common Names

  • Germany: Eichen prozessionsspinner
  • Italy: Processionaria della quercia

EPPO code

  • THAUPR (Thaumetopoea processionea)

Summary of Invasiveness

Top of page

T. processionea, commonly known as the oak processionary moth, is a major pest in many European countries and threatens the health of oak trees. The common and scientific names of T. processionea refer to the behaviour of the larvae to form long processions. The larvae cause severe defoliation, reducing the viability of oak trees. They also pose a risk to both human and animal health because they shed poisonous hairs, which can result in severe allergic reactions, amongst other health problems. The moth is native to central and southern Europe but is now present in almost all European countries and also in parts of the Middle East.

EPPO issued a Pest Risk Analysis in 2007 for the UK in response to infestations of the species in Europe from 2006. At this time, infestations of the moth were observed on a range of oak (Quercus) species in London. The adult males are strong fliers and can fly long distances, such as from France to the UK (Evans, 2007).

Host plants of this pest include many species of deciduous Quercus, and to a much lesser degree, Betula, Carpinus, Castanea, Corylus, Crataegus, Robinia and Fagus; plants commonly found in forests, woods or ornamental plantations in the UK, for example (Evans, 2007). Therefore, areas where these plants are present and offer a suitable climate for pest development are likely to be under threat from T. processionea. Various pines have been reported as hosts, but such records are suspect and are probably the result of confusion with the pine processionary (Thaumetopoea pityocampa). 

Taxonomic Tree

Top of page
  • Domain: Eukaryota
  •     Kingdom: Metazoa
  •         Phylum: Arthropoda
  •             Subphylum: Uniramia
  •                 Class: Insecta
  •                     Order: Lepidoptera
  •                         Family: Notodontidae
  •                             Genus: Thaumetopoea
  •                                 Species: Thaumetopoea processionea

Notes on Taxonomy and Nomenclature

Top of page

The common and scientific names of T. processionea refer to the behavior of the larvae to form long processions (Kimber, 2014). For a review of specimens from Europe and the Middle East, refer to Groenen (2010).

Originally included in a separate family, the Thaumetopoeidae, but now considered part of the Notodontidae. For a review of the genus in the Iberian Peninsula, Gomez Bustillo (1978) should be consulted. Four species of this genus recorded from the area are Thaumetopoea pityocampa, T. processionea, Thaumetopoea herculeana and Thaumetopoea pinivora.

Early studies reported subspecies of T. processionea (e.g. Demolin and Nemer, 1999; Halperin and Sauter, 1999) and a subspecies found in Lebanon was even suggested as a separate species (Demolin and Nemer, 1999); however, Groenen (2010) stated that species from all over Europe and the Middle East are in fact the same species, but just display a wide variation of external and genital characters (see Similarities to Other Species/Conditions section).

In a review of the variation of T. processionea in Europe and the Middle East by Groenen (2010), it is stated that there are three genera in the subfamily of Thaumetopoeinae in Europe: Thaumetopoea, Traumatocampa and Helanthocampa. The genus from which this pest comes from can be separated from other genera by the different form of the canthus (Groenen, 2010). There are two species from the genus Thaumetopoea: Thaumetopoea processionea (Linneaus, 1758) and the Levantine Thaumetopoea solitaria (Freyer, 1838).

Description

Top of page

Eggs

The overwintering eggs are found in plaques or masses on twigs (Forestry Commission, 2014), and the egg scales are very small and pointed compared to other Thaumetopoea species (Tsankov et al., 1991). In the UK, eggs should be searched for in winter and they may be found from January to early May, and August to December (Forestry Commission, 2014). The eggs are laid in batches of up to 300, on 3-5 year old branches (Logoida and Besheni, 1966).

In the UK, eggs hatch in April/May and are 2 mm long (Forestry Commission, 2014). Similarly, observations in the 1950s-60s in Ukraine showed that eggs hatched towards the 20th April, during bud-burst on early-leafing trees (Logoida and Besheni, 1966). 

Larvae

The emerged larvae feed on the buds and later on the leaves, feeding from the top of the tree, downwards (Logoida and Besheni, 1966).

Biliotti (1952) reported a 25 day period between hatching and the second moult. Second instars may be found from mid-April to mid-May in the UK and are less than 1 cm long (Forestry Commission, 2014).

Third instar larvae feed on oak leaves and may be found in May in the UK (Forestry Commission, 2014). The larvae from the third to sixth instar, develop poisonous hairs (setae), which are filled with urticating toxin. These hairs cause severe allergic reactions in animals and humans, and may even lead to anaphylactic shock (Breuer et al., 2004).

Fourth instars and older larvae may be found from mid-May to mid-June in the UK, although they remain in their nests during the day (Forestry Commission, 2014).

During the transition from fourth to fifth instar, the larvae spin bigger silken nests and as they grow, they spend more time there during the day (Pascual, 1988; Forestry Commission, 2014).

The procession of fifth instar larvae may be observed from May to the beginning of July in the UK (Forestry Commission, 2014).

Sixth instar and pupae

Sixth instar larvae build nests from June to mid-July and the larvae moult to the pupal stage within the nest from late June to early August in the UK (Forestry Commission, 2014).

Pupation in Spain was observed to start at the beginning of July and last for 40 days, on average (Pascual, 1988).

Adults

The average adult wingspan is 25-35 mm (Kimber, 2014).

In the UK, the adult moths emerge and fly from the middle of July to early September (Forestry Commission, 2014). In the study in Ukraine adults emerged at the end of July and the beginning of August (Logoida and Besheni, 1966).

The adult males and females live for 3 to 4 days (Forestry Commission, 2014). In Spain, adult emergence is recorded as being between 16:00 and 03:00 solar time, with the males generally emerging first (Pascual, 1988). 

Distribution

Top of page

T. processionea is present in almost all European countries and also in parts of the Middle East, including Israel, Lebanon and Jordan (Groenen, 2010; Groenen and Meurisse, 2012). In the south, T. processionea is present in all countries located on the northern shore of the Mediterranean Sea, in Anatolia, and in the mountains surrounding the Dead Sea (Groenen and Meurisse, 2012). In the north, this species is present in the Netherlands and Germany, and the southern part of Poland and Ukraine (Groenen and Meurisse, 2012).

Distribution Table

Top of page

The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Continent/Country/RegionDistributionLast ReportedOriginFirst ReportedInvasiveReferenceNotes

Asia

IsraelPresentHalperin and Sauter, 1999Larvae on Quercus boissieri in 1992 on Mt. Hermon
JordanPresentGroenen, 2010
LebanonPresentDemolin and Nemer, 1999

Europe

AustriaPresentKrehan, 1993; Tomiczek and Krehan, 2003
BelgiumPresentBreuer et al., 2003; Breuer and Kontzog, 2004
BulgariaPresentMirchev et al., 2003
CroatiaPresentMatosevic et al., 2001
DenmarkPresentSkule and Vilhelmsen, 1997First recorded in 1996
Former USSRPresentAvramenko et al., 1981, recd. 1984
FrancePresentGrison, 1952; Sellier et al., 1975
GermanyPresentHaeger, 1971; Wagenhoff and Veit, 2011
HungaryPresentKlapwijk et al., 2013
ItalyPresentBay, 1961; Goidanich, 1983; Niccoli and Tiberi, 1986; Marziali et al., 2011Tuscany
MoldovaPresentPlugaru, 1968; Stratan, 1971
NetherlandsPresentMoraal, 1992; Stigter and Romeijn, 1992; Moraal et al., 2002
PolandPresentBlaik et al., 2011
RomaniaPresentDissescu and Ceianu, 1968; Teodorescu and Simionescu, 1994
SloveniaPresentJurc, 2006
SpainPresentGomez Bustillo, 1978
SwedenPresentLövgren and Dalsved, 2005; Palmqvist, 2013
UKPresentIntroducedIPPC, 2007; Townsend, 2007; Townsend, 2009; Williams et al., 2013Control strategy has changed from eradication to containment within the current outbreak area and slowing the rate of spreading
-Channel IslandsPresentWaring et al., 2003First recorded in 1983
UkrainePresentGorbunov, 1992South

History of Introduction and Spread

Top of page

Some authors suggest northwards expansion of T. processionea in Europe in the twentieth century (e.g. Moraal, 2006); whereas others suggest that this pest was largely distributed throughout Europe prior to 1920. The pattern of distribution of this pest was studied in Belgium, the Netherlands and parts of Germany after the documented regional disappearance of the species during the first half of the twentieth century, by Groenen and Meurisse (2012).

In the UK, male adult vagrants can be found in August on the south coast, and since 2006, populations have been discovered in west London, where the pest is considered to be established in several boroughs, and in Berkshire (Kimber, 2014). It is also present in the Channel Islands (Kimber, 2014).

In particular, in the Netherlands the pest has been reported to be slowly spreading northeastwards, based on data from over 450 forest and landscape managers (Moraal, 2006), and climate change is suggested as a possible driver of the population increase of T. processionea (Moraal and Jagers op Akkerhius, 2011).

However, Groenen and Meurisse (2012), reviewing the historic distribution of T. processionea in Europe, presented evidence that this species was largely distributed throughout Europe before 1920, and that evidence suggests recolonization in Europe as opposed to expansion. They used museum and personal collections to show that between 1970 and 2009, evidence suggests that the moth displayed a continuous extent of distribution at a rate of approximately 7.5 km per year. The reasons given for the present distribution of the species included possible improvements of environmental conditions that could have led to local population increases and created an ideal situation for dispersal to adjacent areas. Human activity is also presented as a reason for movement to other areas.

This pest is not only present in Europe, but also in the Middle East. At the end of the twentieth century, populations of T. processionea were discovered in Israel and Lebanon, and in 2001 and 2002, specimens were collected in Jordan (Groenen, 2010).

Risk of Introduction

Top of page

In a study by Groenen and Meurisse (2012), it is suggested that possible improvements of environmental conditions may have led to local population increases, favouring dispersal to adjacent areas. They also highlighted the fact that human activity has been suspected as another source of spread over geographical barriers. This includes the movement of infested nursery trees in the commercial sector. 

According to the PRA for this pest (Evans, 2007), there are four possible pathways of introduction of this pest into an area: on plants used for planting the hosts of T. processionea; cut branches of host plants, although Evans (2007) suggests that trade in this plant part is unlikely; roundwood of oak with bark present; and natural spread. 

It is likely that egg masses, larvae or pupae could be moved with plants used in nurseries or other sites employed in plant production (Evans, 2007). The egg stage is cryptic and therefore could easily go unnoticed in the trade of planting material, posing a serious risk of introduction (Evans, 2007). This, together with an increase in semi-mature trees used for instant landscaping, means that the volume of movement along this particular pathway could be moderately large.

The likelihood of larvae finding suitable hosts once introduced into a new area is relatively low; however, if pupae are accidentally introduced, the emerging adults would be able to cover larger distances in flight to find suitable hosts and thus pose a greater risk (Evans, 2007).

It is also very likely that the pest will survive in storage, because the egg stage is known to survive from September to April (Evans, 2007).

Habitat List

Top of page
CategoryHabitatPresenceStatus
Terrestrial-managed
Managed forests, plantations and orchards Present, no further details Natural
Managed forests, plantations and orchards Present, no further details Productive/non-natural
Rail / roadsides Present, no further details Natural
Rail / roadsides Present, no further details Productive/non-natural
Urban / peri-urban areas Present, no further details Productive/non-natural
Terrestrial-natural/semi-natural
Natural forests Present, no further details Natural

Hosts/Species Affected

Top of page

A variety of deciduous oaks (Quercus), including native British species, pedunculate oak, Quercus robur and sessile oak, Quercus petraea, are susceptible to larvae of the oak processionary moth (Townsend, 2009). In London, UK, larvae have been found on the hybrid Quercus robur ilex. European species of oak are susceptible hosts, as observed at the Royal Botanical Gardens, Kew, UK; although North American and Asiatic species have also been infested at this site (Townsend, 2009). The North American red oak (Quercus rubra) is also a known host (Townsend, 2009).

When surveying oaks affected in Austria, it was reported that Quercus cerris was more affected than Q. robur or Q. petraea (Tomiczek and Krehan, 2003). In Macedonia, although Quercus pubescens, Quercus sessiliflora, Quercus frainetto, Q. robur, Q. cerris and Quercus trojana were reported as hosts, only Q. pubescens and Q. sessiliflora were listed as the main hosts (Serafimovski, 1958). 

Beech (Fagus), birch (Betula), hawthorn (Crataegus) and Robinia sp. can also be affected; however, this has only been observed when outbreaks are severe (Townsend, 2009). Oaks and beech are the only trees known to lead to development of adult moths (Roskams, 2008); although there are early reports of this pest on pines (Nicosia, 1923; Bay, 1961) and pistachio (Kiriukhin, 1946). Nicosia (1923) reported that T. processionea mainly attacks Pinus halepensis (common pine) shoots in Cyprus, indirectly leading to death. Bay (1961) stated that the principal pest of pine (Pinus sylvestris) in Bolzano, Italy is T. processionea and as such, pines should be planted above 800 m, outside the range of survival for this moth. 

Host Plants and Other Plants Affected

Top of page

List of Symptoms/Signs

Top of page
SignLife StagesType
Growing point / external feeding
Leaves / external feeding

Biology and Ecology

Top of page

Genetics

Specimens of this pest from Israel were provisionally identified as T. processioneapseudosolitaria, owing to the similarity of the adults to Thaumetopoea solitaria (Halperin and Sauter, 1999). In Lebanon, specimens were thought to be a new form or even a closely related species (Demolin and Nemer, 1999). T. processionea pseudosolitaria is recorded from Southeast Europe and the form luctifa is the most common form in Spain (Agenjo, 1941; Groenen, 2010). Groenen (2010) carried out an extensive study of specimens across Europe and the Middle East to determine whether T. processionea consisted of more than one species and concluded that there is only one species, but that it displays a large variation in external and genital characters.

Reproductive Biology

Dissescu (1962), studying oviposition in T. processionea, reported that it usually takes place on the south side of trees, mainly on the distal ends of branches, with 69.5% on 3-6 cm diameter branches and 42-43% in the upper crown. The eggs are laid in batches of up to 300, on 3-5 year old branches (Logoida and Besheni, 1966) and hatch the following spring during bud burst on early-leafing trees (Logoida and Besheni, 1966). There are six larval instars, typically developing from mid-April to early August, in the UK (Forestry Commission, 2014). The pupal stage lasts for 40 days (Pascual, 1988) and the adults live for 3-4 days, on average (Forestry Commission, 2014). In Spain, the mean male:female sex ratio was recorded as 1:0.59 (Pascual, 1988).

Physiology and Phenology

The ability of insects to withstand long periods of adverse weather conditions is important to understand when assessing population persistence and epidemics. Meurisse et al. (2012) reported that neonate larvae of T. processionea are relatively well-adapted to early hatching relative to bud burst; a trait which ensures they can feed on the highest quality of foliage during development. However, the authors also concluded that in some years, phenological asynchrony or cold spring conditions may affect the persistence of populations at the limits of the species range.

Later studies by Klapwijk et al. (2013) looked at long-term data sets for defoliation by several forest insect pest species, including T. processionea, together with data sets on weather patterns in Hungary. They found that species that exhibit a trend towards outbreak-level damage over a greater geographical area may be positively affected by changes in weather conditions, which coincide with important life stages. However, it was stated that further studies on life-history traits would be required to increase the understanding of responses to climate change.

Pheromones

Several studies have been undertaken to elucidate the sex pheromone components of the oak processionary moth (e.g. Quero et al., 2003; Villorbina et al., 2003; Gries et al., 2004); information which has been used to evaluate traps and assess insect population sizes under field conditions (e.g. Breuer at al., 2003).

Female sex pheromones of the Mediterranean processionary moths, including T. processionea, are conjugated dienes of enynes of 16 carbon atoms with the unsaturations located at C11 and C13 (Villorbina et al., 2003).

Quero et al. (2003) characterized the sex pheromone from the female glands of T. processionea to be a mixture of (Z,Z)-11,13-hexadecadienyl acetate (1), (E,Z)-11, 13-hexadecadienyl acetate (3) and (Z,Z)-11, 13-hexadecadienol (2) in an 88:7:5 ratio. T. processionea lacks (Z,Z)-11, 13-hexadecadienal and thus appears to be the only ‘summer’ processionary moth without this pheromone compound.

Longevity

Dissescu and Ceianu (1968) studying T. processionea in Romania reported that the larval stage lasted for 60-70 days, from mid-April to the end of June, or the beginning of July. The pupal stage lasted for 20-46 days, and the adults emerged over approximately a month. In Spain, the larval period took 2.5 months and pupation, which started at the beginning of July, lasted for 40 days, on average (Pascual, 1988).

In Spain, the adults were reported to live for more than 4 days, and were in flight during the last 20 days of August and the first few days of September (Pascual, 1988). In Germany, the average female longevity was recorded as 10.5 days (Scheidter, 1934), compared to shorter longevity in the UK of 3 to 4 days (Forestry Commission, 2014). Only one generation is produced per year (Logoida and Besheni, 1966; Dissescu and Ceianu, 1968; Roversi et al., 1997).

In Romania, it was reported that some of the pupae remained in diapause for 1-2 years (Dissescu and Ceianu, 1968). Overwintering in the egg stage has been reported (Hase, 1939 [Spain]; Plugaru, 1968 [Moldavia]).

Activity Patterns

The common name of this pest comes from the phenomenon of the larvae taking part in a ‘procession’. In an early study by Schmidt (1974), it was observed that if the leader of the procession is removed, the procession stops and the larvae move close together until a new leader materializes. Schmidt stated that several parallel rows of larvae can combine to form one row within approximately a minute. The community of larvae can be mechanically divided, but only via disruption of the procession.

A communal nest is built for each of the six larval instars and the position of the nest on trees is related to climate and the situation and size of the tree (Niccoli and Tiberi, 1986). On observations of the larvae in Italy, Niccoli and Tiberi (1986) reported that the larvae remained gregarious during the feeding phase. The first instar larvae were observed to attack young leaves, but as the larvae developed, older leaves were attacked. Although damage by this pest on oaks in Italy was reported as less severe than damage by lymantriid pests, damage caused by the oak processionary moths weakened trees and reduced acorn production.

Pascual (1988) reported that larvae are nocturnal feeders and attack both buds and leaves during observations in the south of Salamanca province, Spain. Night feeding has also been reported in Moldavia [Moldova] (Plugaru, 1968).

Population Size and Structure

Mirchev et al. (2003) studied some bioecology aspects of T. processionea in North-east Bulgaria using egg clusters collected from an offshoot forest of Quercus cerris and Quercus frainetto during 2000 and 2001. The egg clusters were only found in cerris oaks, in the lower part of the crown, on branches from 3 to 10 mm thick. They observed 134.3 to be the average egg cluster size and the percentage of caterpillars to hatch was between 93.2 and 94.3%. Mortality rate of the egg stage was reported as 2.1-4.5% (without the impact of predators and parasitoids). Egg mortality due to predators (1.0-3.8%) and parasitoids (0.2-0.9%) was reportedly lower.

Nutrition

Dissescu (1961) reported that T. processionea feeds every 6 hours, and that the longest feeding period is from 2 to 5 am. It was observed that the larvae do not feed or leave the nest during cold, rainy weather or during moulting. The female larva can damage, on average, 8.01 oak leaves compared to a lower number attacked by the male (6.6 oak leaves). The amount of food consumed by a female larva is directly related to fecundity (Dissescu and Ceianu, 1968). The larvae tend to skeletonize the leaves and leave the main veins, so feeding by this pest is quite distinctive (Forestry Commission, 2014).

Natural enemies

Top of page
Natural enemyTypeLife stagesSpecificityReferencesBiological control inBiological control on
Anastatus bifasciatus Parasite Eggs Bin and Tiberi, 1983; Stratan, 1971
Anastatus japonicus Parasite
Bacillus thuringiensis
Blondelia nigripes Parasite Larvae
Calosoma sycophanta Predator Larvae not specific
Carcelia iliaca Parasite Larvae
Compsilura concinnata Parasite Larvae
Eurytoma verticillata Parasite
Formica polyctena Predator
Heteropelma amictum Parasite
Masicera sphingivora Parasite Larvae
Meteorus versicolor Parasite Larvae Dissescu and Ceianu, 1968; Fankhanel, 1958
Ooencyrtus masii Parasite
Pales processioneae Parasite Larvae/Pupae not specific Dissescu and Ceianu, 1968
Phryxe semicaudata Parasite Larvae/Pupae not specific Dissescu and Ceianu, 1968
Pimpla hypochondriaca Parasite Larvae/Pupae not specific Dissescu and Ceianu, 1968
Trichogramma Parasite Eggs not specific Bin and Tiberi, 1983
Winthemia venusta Parasite Larvae
Zenillia libatrix Parasite Larvae/Pupae Dissescu and Ceianu, 1968

Notes on Natural Enemies

Top of page

Various researchers have surveyed T. processionea for the occurrence of natural enemies (e.g. Fankhanel, 1958; Dissescu and Ceianu, 1968; Bin and Tiberi, 1983; Tiberi and Bin, 1988; Zeegers, 1997; Hoch et al., 2008), which is a key consideration when determining the efficacy of natural suppression in the wild and/or the potential efficacy of biocontrol methods.

In early studies by Fankhanel (1958), Meteorus versicolor reportedly showed promise against T. processionea, particularly when parasites were moved from areas of high parasitization to low; however, the author warned that movement could also include the many hyperparasites present, which would obviously impede the efficiency of pest control. 

Early observations by Dissescu and Ceianu (1968) in Romania also documented M. versicolor parasitizing T. processionea, together with Pimpla instigator, Phryxe semicaudata, Carcelia processioneae, Zenillia libatrix and Pales pavida on larvae and pupae. They reported that C. processioneae played a key role in reducing population numbers. C. processioneae, Z. libatrix and P. pavida were also recorded from T. processionea in Moldavia [Moldova] (Lerer and Plugar, 1962).

Studies surveying egg parasites of T. processionea found the eulpelmid, Anastatus bifasciatus to show promise in pest population regulation. This egg parasite was recorded as playing an important part in regulating T. processionea in oak forests of Moldavia [Moldova] (Stratan, 1971) and when Bin and Tiberi (1983) reared this parasite and Trichogramma sp. from eggs in Italy, they reported a greater host-seeking ability by A. bifasciatus. A 47.1% attack rate of egg masses by the two parasites was recorded; however, only males of A. bifasciatus were found, suggesting that alternative hosts are required.

In a later study, as well as reporting Trichogramma sp. and A. bifasciatus from T. processionea in central Italy, Tiberi and Bin (1988) also recorded the encyrtid, Ooencyrtus masii. Again, they reported that A. bifasciatus was the most effective.

Tachinid flies from T. processionea were surveyed in the Netherlands (Zeegers, 1997). Monophagous species, Carcelia iliaca and Pales processioneae, and polyphagous species, Z. libatrix and Blondelia nigripes were found. The monophagous species were common and Zeegers (1997) concluded that P. processioneae would probably prove to be the most important parasitoid of the pest in the future.

Ferrero (1985) documented the importance of the carabid, Calosoma sycophanta against defoliators in France, including T. processionea.

Studies have also been carried out on internal factors that could prove useful when assessing natural enemies for control of the pest populations e.g. microsporidia (Veber, 1958; Hoch et al., 2008). Micropsporidia have been evaluated as biocontrol agents against Lymantria dispar, for example (Hoch et al., 2008). T. processionea, as with most forest Lepidoptera, are host to entomopathogenic microsporidia (Hoch et al., 2008). Hoch et al. (2008) studied the viability of microsporidia for the control of oak processionary moth and the authors suggested that T. processionea is even more promising than L. dispar for this method of control due to its highly gregarious nature. After screening this pest for microsporidia in the field in eastern Austria, Endoreticulatus sp. was isolated for further study.

Another microsporidium, Nosema bombycis, which causes pebrine in silkworms, has also been shown to infest larvae of T. processionea, but this was under laboratory conditions (Veber, 1958).

Other natural enemies that could be exploited for control of the pest include a polyhedral virus, which was found on T. processionea in Paris, France (Vago, 1953; Vago and Vasiljevic, 1955).

Means of Movement and Dispersal

Top of page

Natural Dispersal

The oak processionary moth takes its name from the movement of the larvae, which is always in procession (Indian file, double Indian file and rhomboidal processions); silk threads spun by the larvae assist in guiding the movement (Pascual, 1988).

The adult males are stronger fliers than the females and are able to fly long distances, such as from France to the UK (Evans, 2007).

Accidental Introduction

The eggs, larvae and/or pupae of this pest could be accidentally introduced to new areas on material used for planting. There are four possible pathways of introduction of this pest into an area: on plants used for planting the hosts of T. processionea; cut branches of host plants; roundwood of oak with bark present; and natural spread (Evans, 2007). The larvae can be hidden in and around the soil at the tree base and the nests of the larvae can be placed on the outside of pots and on adjacent packaging material, thus posing potential points of introduction (Forestry Commission, 2014).

Pathway Causes

Top of page
CauseNotesLong DistanceLocalReferences
Ornamental purposes Yes Evans, 2007
Timber trade Yes Yes Evans, 2007

Plant Trade

Top of page
Plant parts liable to carry the pest in trade/transportPest stagesBorne internallyBorne externallyVisibility of pest or symptoms
Growing medium accompanying plants larvae Yes Pest or symptoms usually visible to the naked eye
Leaves larvae Yes Pest or symptoms usually visible to the naked eye
Stems (above ground)/Shoots/Trunks/Branches eggs Yes Pest or symptoms not visible to the naked eye but usually visible under light microscope

Impact Summary

Top of page
CategoryImpact
Cultural/amenity Negative
Economic/livelihood Negative
Environment (generally) Negative
Human health Negative

Economic Impact

Top of page

Infestations of T. processionea may lead to dermatitis, conjunctivitis, and pulmonary problems in humans due to the urticating hairs (Gottschling and Meyer, 2006), which in turn will require treatment and thus has associated medical costs (see Social impact). The hairs can also affect animals, which would have a negative impact on the livestock industry, either in treatment costs or the loss of livestock.

This pest can also have a financial impact on timber growers (Townsend, 2013), and there are subsequent costs associated with attempted control of the pest using pesticides and biopesticides.

Environmental Impact

Top of page

Impact on Habitats

Severe defoliation reduces the viability of oak trees and the moth can therefore contribute to the general syndrome of oak decline alongside other biotic and abiotic contributory factors, such as climate change (Thomas et al., 2002). For example, in 2004 in Germany, Wulf and Pehl (2005) reported poor tree health owing to a drought in 2003 and several m3 of wood had to be cut; in remaining stands, late or missing sprouts were observed in eastern stands of oak. Together with this they reported an abundance and indication of population growth of thermophilic insects, including T. processionea.

In the UK, areas such as the New Forest, the Forest of Dean and Sherwood Forest, which contain many oak trees, would show significant losses after damage by T. processionea, consequently affecting ecosystem processes (Evans, 2007). 

Impact on Biodiversity

Quercus is the only tree genus that has suffered a consistent decline in crown density according to the UK Forest Condition survey (Hendry et al., 2005) and therefore any further attack would cause further environmental damage (Evans, 2007) and negatively affect tree biodiversity in areas of mixed woodland. 

Social Impact

Top of page

Where oak trees form a valuable part of the landscape, obviously anything that affects this will be regarded as having a negative impact on aesthetics and therefore having a negative social impact, where the interaction between trees and people is highly regarded, as outlined by Evans (2007). For example, tourism in areas such as the New Forest, the Forest of Dean and Sherwood Forest, in the UK, which contain oak trees, would be severely affected by losses due to this pest (Evans, 2007).

The oak processionary moth causes a negative impact on human and animal health because larvae from the third to sixth instars develop poisonous hairs (setae), which are filled with an urticating toxin that may lead to severe dermatitis, conjunctivitis, and pulmonary problems (summarized as ‘lepidopterism’) in humans (Gottschling and Meyer, 2006). Severe allergic reactions in animals and humans may manifest as anaphylactic shock (Breuer et al., 2004).

For example, a case of a severe anaphylactic reaction was reported by Bosma and Jans (1998) in Noord-Brabant, the Netherlands in 1996, where a 72 year old man was treated after contact with the urticating hairs of the larvae and the pesticide, Dimilin SC-48.

Spijker (2007) reported that horses became ill in the Netherlands after eating hay that was contaminated with hairs from T. processionea.

Risk and Impact Factors

Top of page Invasiveness
  • Highly adaptable to different environments
  • Highly mobile locally
  • Gregarious
Impact outcomes
  • Host damage
  • Increases vulnerability to invasions
  • Negatively impacts agriculture
  • Negatively impacts forestry
  • Negatively impacts human health
  • Negatively impacts animal health
  • Negatively impacts livelihoods
  • Negatively impacts tourism
  • Reduced amenity values
  • Reduced native biodiversity
  • Threat to/ loss of endangered species
  • Threat to/ loss of native species
  • Negatively impacts animal/plant collections
Impact mechanisms
  • Causes allergic responses
  • Poisoning
Likelihood of entry/control
  • Highly likely to be transported internationally accidentally
  • Highly likely to be transported internationally deliberately
  • Difficult to identify/detect as a commodity contaminant
  • Difficult to identify/detect in the field

Detection and Inspection

Top of page

Although the eggs are cryptic, careful examination of plants for planting can be used to detect egg masses. If nests are found on trees or in the vicinity of production areas in trade, this would also be an indication of possible contamination (Evans, 2007). Evans (2007) suggested that post-entry quarantine of material for planting could be used to determine whether larval infestations arose from April to late June in the UK.

Similarities to Other Species/Conditions

Top of page

The urticating hairs and the glands that produce the hairs in T. processionea have been shown to be similar to those of T. pityocampa (Lamy and Novak, 1987). T. processionea can be distinguished from related species by the pale basal area of the forewing (Kimber, 2014).

Early studies reported subspecies of T. processionea (e.g. Demolin and Nemer, 1999; Halperin and Sauter, 1999) and when T. processionea was reported as new for Lebanon in 1998, the authors documented that this could be a separate species (Demolin and Nemer, 1999). However, in a review of European and Middle Eastern specimens of T. processionea, Groenen (2010) stated that species from all over Europe and the Middle East are in fact the same species, but just display a wide variation of external and genital characters. In general, it was found that the forewings of this pest in the Middle East are brighter compared to specimens from Western Europe. The hind wings are clear white in the Middle East and creamy, compared with an ash-grey transfer fascia in Western Europe. A wide variation is seen in the male genitalia, particularly in the shape of the valvae, as opposed to the constant shape of the female genitalia across different geographical locations.

Prevention and Control

Top of page

Early Warning Systems

Forecasting of infestation levels of forest pests, including T. processionea has been used in forest pest management in Tuscany, Italy. Marziali et al. (2011) studied population levels and trends among insect pests in Tuscan forests, with a view to foreseeing new outbreaks. New and old egg masses of the moth were collected and the population dynamics of this pest were analyzed using a trend index.

Dissescu (1963) stated the importance of using different critical numbers for different phases in an outbreak for forecasting progress. This is due to the fact that male larvae eat less than females, and the percentage of males in a population varies according to the stage of the outbreak.

Physical/Mechanical Control

Burning of nests was reported as a method of control during outbreaks in north Germany between 1826 and 1829 (Offenberg, 2000), in southern Ukraine, in conjunction with chemical control (Pustovoit, 1931) and in Italy (Canzanelli, 1939).

Kleinlogel (2013) reported that mechanical removal of the nests and caterpillars of the oak processionary moth (when the larvae have reached the third instar) is the only way that further contamination of the environment can be prevented.

Biological Control

The role of entomophagous insects in the control of T. processionea has been the focus of study over a number of decades (e.g. Ceianu and Dissescu, 1966; Flemming, 1997; Roversi, 2008; Klug, 2013). Ceianu and Dissescu (1966) reported a 62% maximum mortality of T. processionea within 8-10 days of treatment with Bacillus thuringiensis, but a greater reduction in populations of the last two larval states due to parasites and predators. They stated that timing of application was vital to successful control.

At the outset of later experiments by Roversi (2008), similar percentage mortality to that found by Ceianu and Dissescu (1966) was reported. Roversi (2008) studied the efficacy of aerial spraying of Bacillus thuringienses var. kurstaki in early spring in Turkey oak (Quercsus cerris) woods in Tuscany, Italy. Areas treated with Btk showed over 60% larval mortality compared to less than 40% in the control area 5 days after treatment. Larval mortality was recorded as 75.05-96.42% in the treated areas 13 days after treatment. The number of oak processionary nests in all treated plots declined 2 months after treatment. Roversi concluded that the pest could be controlled effectively in Turkey oak woods when the microbial agent was sprayed at the time of bud opening when non-urticating larvae were present.

In France, Btk is used in 98% of treatments against cluster caterpillars because not only have formulations improved, but also spraying conditions (Martin and Bonneau, 2006), and some studies are dedicated to investigating the penetration and persistence of Btk in tree crowns (e.g. Rumine et al., 2006), a favoured spot for feeding larvae. For example, in Italy, Bactucide (a preparation of Btk) was shown to be most persistent when compared with Dipel and Bactimos (a preparation of Bacillus thuringiensis subsp. israelensis) (Niccoli and Pelagatti, 1986).

When Flemming (1997) compared Bacillus thuringiensis-based pesticides with Azadirachta indica-based ones in Brandenburg, Germany, it was found that Foray 48B (based on Bacillus thuringiensis) applied with helicopters and Delfin (based on Azadirachta indica) applied on the ground were the most effective. Control rates of nearly 100% were obtained with helicopters, in contrast to a 70% success rate with ground techniques.

Hoch et al. (2008) studied the viability of microsporidia for the control of oak processionary moth. T. processionea, as with most forest Lepidoptera, are host to entomopathogenic microsporidia. These parasitic agents have been evaluated as biocontrol agents against Lymantria dispar and the authors suggest that T. processionea is even more promising for this method of control due to its highly gregarious nature. After screening this pest for microsporidia in the field in eastern Austria, Endoreticulatus sp. was isolated for further study.

The natural occurrence of predators and parasitoids in T. processionea populations may hold the key to successful biocontrol programmes; however, if used as part of an IPM programme great care should be taken in timing the use of insecticides correctly (Biliotti, 1952). Ceianu and Dissescu (1966) found that the parasitoids Carcelia processioneae and Pimpla instigator, and the predator Calosoma sycophanta affected populations, reporting that surviving larvae either died in pupation or produced adults with reduced fertility. Other parasitoids isolated from T. processionea populations include Anastatus bifasciatus and Ooencyrtus sp. in North-east Bulgaria (Mirchev et al., 2003).

Once a possible biocontrol agent has been found, one of the next potential steps is to devise a method for rearing the parasite/predator under laboratory conditions to enable augmentation in the field, at key times of pest development. Billiotti and Chenon (1971) devised a method for rearing Pales pavida, a principal parasite of T. processionea, on Galleria mellonella. This method would enable the release of thousands of P. pavida adults in the spring to coincide with the larval stage of T. processionea, thus increasing the effectiveness of this parasite against the pest.

Other potential control measures include the use of plant preparations. Breuer and Loof (1998) studied the efficacy of Melia azedarach fruit and NeemAzal-T/S against second and fourth instar larvae of T. processionea in the laboratory. Using hosts of Quercus robur and Quercus rubra they reported an anti-feedant effect when preparation concentrations were increased. Lethargy in the larvae was reported after 4 days and 100% mortality occurred within 1-2 weeks, even at lower concentrations. Death was attributed to disruption in moulting, and younger larvae were more sensitive than older larvae.

Ants (Formica rufa and Formica polyctena) have been investigated for their role in controlling T. processioneae populations (Anon., 1958; Gosswald, 1979a,b). Gosswald (1979a) reported on the release of F. rufa colonies in an oak forest in Germany to control T. processionea. It was stated that the pest was brought under control ‘within a few years’.

Nematodes have also been investigated as a control measure against the oak processionary moth. Barth (2013) reported 90-98% efficiency in laboratory experiments in Holland using first to third larval instars.

Chemical Control

Pascual et al. (1990) compared control of T. processionea using aerial ULV applications of alpha-cypermethrin, diflubenzuron and Bacillus thuringiensis in Quercus pyrenaica forest in Salamanca, Spain. The authors reported complete control within 4 days of using alpha-cypermethrin, and within 12 days using the other two control measures.

IPM

Knowledge of insect biology is key to understanding the efficacy of biocontrol and IPM control measures. Studies have shown that first and second instars are most susceptible to insecticide treatment (Biliotti, 1952); however, timing of insecticide sprays must take account of natural pest population suppression as part of an effective IPM programme. In a review of the most effective period in which to apply control measures against T. processionea and T. pityocapa, Biliotti (1952) observed that parasites were found dead on the two species after treatment with insecticides and during the period of usual tachinid parasite emergence. Therefore, although insecticides may be timed to coincide with the most susceptible insect stage, the effect of natural enemies on pest suppression must also be taken in to account as part of IPM.

Monitoring and surveillance (incl. remote sensing)

Monitoring populations is a fundamental tool used in the management of insect populations, because the timing of treatment is crucial to efficacy. Trouvelot et al. (1952) recommended that T. processionea numbers should be surveyed in July, in the year before intended treatment, in order to estimate populations during the pupation period. They stated that the effective window of treatment timing is relatively short, i.e. in mid-April between hatching and the first moult.

Pheromone traps can be used to monitor T. processionea, by trapping the males. (Z,Z)-11,13-hexadecadienyl acetate is the major pheromone component found in female gland extracts of T. processionea (see Biology and Ecology). Breuer et al. (2003) studied the biological activity of a synthetic version of this chemical in traps. It was found that a large number of males were attracted to baits of 10mg, when placed in the upper crowns of oak trees. They also stated that Pherocon traps were slightly more efficient than Delta traps.

In a later study by Williams et al. (2013), the success rate of Delta and funnel traps was evaluated using 3 different commercially available lures, with the primary component of (Z,Z)-11, 13-hexadecadienyl acetate. Field trials were conducted in 2011 in Richmond Park, London, UK in lower, mid and upper canopies of oak trees. Delta traps were found to be more successful in catching male moths and significantly more moths were captured in upper canopies.

In the UK, a campaign supporting public awareness and promoting citizen science surveying for pests and diseases threatening the UK trees was carried out from May to September in 2013. The public were asked to examine the trunk, branches and leaves of British trees for signs of poor health and to record the presence of any pests or diseases, including the oak processionary moth. Open Air Laboratories (Opal) researchers, and experts from the Food and Environment Research Agency (Fera) and Forest Research plan to use the findings of the survey to contribute to a national research programme investigating the health of Britain’s trees and the spread of pests and diseases.   

References

Top of page

Agenjo R, 1941. Monografia de la familia Thaumetopoeidae (Lepidoptera). (Monografia de la familia Thaumetopoeidae (Lepidoptera).) EOS Revista Espanola De Entomologia, 17:69-130.

Anon, 1958. Taking a census of Formica rufa populations. Bollettino ufficiale del Corpo Forestale dello Stato, Roma, 4:200-201.

Avramenko ID; Prokopenko NI; Mezentsev AI; Kucheryavenko VI; Minyalo VG, 1981. The effect of insect pests on the formation and productivity of oak stands. In: Aukshtikal'nene AM, ed. Noveshie dostizheniya lesno entomologii (po materialam USh s"ezda VEO, Vil'nyus, 9-13 oktyabrya 1979 g.) Institut Zoologii i Parazitologii Akademii Nauk Litovsko SSR Vilnius USSR, 4-6

Barth M, 2013. Biological control of the Oak Processionary Moth with nematodes. (Biologische Bekämpfung des Eichenprozessionsspinners mit Nematoden.) Julius-Kühn-Archiv [Ökologische Schäden, gesundheitliche Gefahren und Massnahmen zur Eindämmung des Eichenprozessionsspinners im Forst und und im urbanen Grün, Berlin, Germany, 6-7 March, 2012.], No.440:79-80. http://pub.jki.bund.de/index.php/JKA/issue/archive

Bay E, 1961. The distribution of Pinus sylvestris in the province of Bolzano. (Sul pino silvestre in provincia di Bolzano.) Monti e Boschi, 12(1):27-30.

Biliotti E, 1952. Difficulties in deciding the period at which to apply control measures against Thaumetopoea processionea and T. pityocampa. (Difficultes rencontrees dans la determination des periodes dintervention contre les processionaires du chene et du pin.) Revue de Pathologie Vegetale, 31(2):115-20.

Biliotti E; Chenon RDde, 1971. Parasitism by Pales pavida Meig. (Dipt. Tachinidae) on Galleria mellonella L. (Lep. Galleriidae). Establishment of a permanent culture in the laboratory. (Le parasitisme de Pales pavida Meig. (Dipt. Tachinidae) sur Galleria mellonella L. (Lep. Galleriidae). Mise au point d'un elevage permanent en laboratoire.) Annales de Zoologie, Ecologie Animale, 3(3):361-371.

Bin F; Tiberi R, 1983. Preliminary notes on the egg parasites of Thaumetopoea processionea (L.) in central Italy (Hym., Chalcidoidea; Lep., Thaumetopoeidae). (Notizie preliminari sui parassitoidi oofagi di Thaumetopoea processionea (L.) in Italia centrale (Hym., Chalcidoidea; Lep., Thaumetopoeidae).) Redia, 66:449-459.

Blaik T; Malkiewicz A; Wasala R, 2011. Rediscovery and remarks on occurrence of Thaumetopoea processionea (Linnaeus, 1758) (Lepidoptera: Notodontidae: Thaumetopoeinae) in Poland. (Ponowne stwierdzenie i uwagi o wystepowaniu Thaumetopoea processionea (Linnaeus, 1758) (Lepidoptera: Notodontidae: Thaumetopoeinae) w Polsce.) Wiadomosci Entomologiczne, 30(4):246-256. http://pte.au.poznan.pl/we/we.htm

Bosma AH; Jans HWA, 1998. Severe anaphylactic reaction connected with the control of the processionary caterpillar (Thaumetopoea processionea) in Noord-Brabant. (Ernstige anafylactische reactie in samenhang met de bestrijding van de eikenprocessierups (Thaumetopoea processionea) in Noord-Brabant.) Nederlands Tijdschrift voor Geneeskunde, 142(27):1567-1569.

Breuer M; Castellà J; Camps F; Loof Ade, 2004. Field studies with synthetic sex attractant pheromone of the oak processionary, Thaumetopoea processionea (L.). (Freilandversuche mit synthetischem Sexualpheromon des Eichenprozessionsspinners, Thaumetopoea processionea (L.).) Mitteilungen der Deutschen Gesellschaft für allgemeine und angewandte Entomologie [Papers from the Entomological Conference in Halle (Saale), Germany, 24-28 March, 2003.], 14(1-6):311-314.

Breuer M; Kontzog HG, 2004. Field evaluation of sex attractants of the oak processionary moth, Thaumetopoea processionea (L.) in a heavily infested area in Saxony-Anhalt. (Freiland-Einsatz von Sexuallockstoffen des Eichen-Prozessionsspinners, Thaumetopoea processionea (L.), in einem Befallsgebiet in Sachsen-Anhalt.) Mitteilungen der Deutschen Gesellschaft für allgemeine und angewandte Entomologie [Papers from the Entomological Conference in Halle (Saale), Germany, 24-28 March, 2003.], 14(1-6):315-318.

Breuer M; Kontzog HG; Guerrero A; Camps F; Loof Ade, 2003. Field trials with the synthetic sex pheromone of the oak processionary moth Thaumetopoea processionea. Journal of Chemical Ecology, 29(11):2461-2468. http://www.kluweronline.com/issn/0098-0331

Breuer M; Loof Ade, 1998. Meliaceous plant preparations as potential insecticides for control of the oak processionary, Thaumetopoea processionea (L.) (Lepidoptera: Thaumetopoeidae). In: Mededelingen - Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen, Universiteit Gent, 63(2b). 529-536.

Canzanelli A, 1939. The Insect Fauna of Italian Forests. 1. The Processionaries. (L'Entomofauna dei nostri boschi. 1°. Le processionarie.) Rivista Forestale Italiana, 1(4):253-258 pp.

Ceianu I; Dissescu Get al, 1966. The role of entomophagous insects in an outbreak area of Thaumetopoea processionea treated with bacterial preparations. Cerc. Ecol. Anim., Lucrari Prim. Ses. Stiint. Tara Ecol. Anim, No. 1969:183-90.

Demolin; Nemer N, 1999. Insectes defoliatuers Quercus callyprinos Webb. Et de Quercus infectoria Olv. Au Liban. IOBC Bulletin, 22(3):65-99.

Dissescu G, 1961. Studies on Thaumetopoea processionea. Studii si Cercetari Institutului de Cercetari forestiera, 22B:69-90.

Dissescu G, 1963. The necessity of using different critical figures for different phases of an outbreak, in forecasting its progress. Revista Padurilor, 78(2):106-9.

Dissescu G; Ceianu I, 1968. Bucuresti, Centru de Documentatie tehnica economica si forestiera. 120 pp.

Dissescu G; et al, 1962. Oviposition by Thaumetopoea processionea on trees and bushes. Revista Padurilor, 77(8):506-8.

Evans HF, 2007. Oak processionary moth Pest Risk Analysis., France: EPPO. http://www.fera.defra.gov.uk/plants/plantHealth/pestsDiseases/documents/processionary.pdf

Fankhanel H, 1958. M. versicolor, a parasite of E. chrysorrhoea and T. processionea, and its potentialities for biological control. Transactions, First International Conference of Insect Pathology and Biological Control, Praha. 415-420.

Ferrero F, 1985. A precious forest auxiliary insect: Calosoma sycophanta. (Un auxiliaire précieux de la forêt: le calosome sycophante.) Phytoma, No. 370:28.

Flemming G, 1997. First experiences at control of Thaumetopoea processionea in the north-western region of the Land Brandenburg in the year 1996. (Erste Erfahrungen bei der Bekämpfung des Eichenprozessionsspinners (Thaumetopoea processionea) im nordwestlichen Teil des Landes Brandenburg im Jahre 1996.) Gesunde Pflanzen, 49(2):54-57.

Forestry Commission, 2014. Oak processionary moth (Thaumetopoea processionea) - Life cycle. Edinburgh, UK: Forestry Commission, Plant Health Service. http://www.forestry.gov.uk/pdf/identificationimagesopm.pdf/$FILE/identificationimagesopm.pdf or www.forestry.gov.uk/planthealth

Goidanich G, 1983. Adverse factors affecting ornamental trees. (Le avversita degli alberi da ornamento.) Informatore Fitopatologico, 33(4):15-22.

Gomez Bustillo MR, 1978. The Thaumetopoeidae (Aurivillius, 1891) of the Iberian peninsula: notes on systematics, ecology and economic importance of the family. (First part). (Los Thaumetopoeidae (Aurivillius, 1891) de la peninsula iberica: nociones de sistematica, ecologia e importancia economica de la familia. (Primera parte).) Revista de Lepidopterologia, SHILAP, 5(20):283-290.

Gorbunov AF, 1992. The oak processionary moth. Zashchita Rastenii (Moskva), No. 4:63.

Gosswald K, 1979. Effects of wood ants in the oak forest. (Auswirkungen der Waldameisen im Eichenwald.) Waldhygiene, 13(1):3-10.

Gosswald K, 1979. Results obtained using the small wood ant Formica polyctena in forest hygiene. (Ergebnisse mit der Kleinen Waldameise Formica polyctena in der Waldhygiene.) Bulletin SROP [Pavan, M.; Ceballos, P. (Chairmen): Proceedings of the meeting of working groups on "Formica rufa" and "vertebrate predators of insects" of the OILB (Varenna, Italy, 1978).: Comptes rendus de la reunion des groupes de travail "Formica rufa" et "vertebres predateurs des insectes" de l'OILB (Varenna, Italie, 1978).], 2:89-92.

Gottschling S; Meyer S, 2006. An epidemic airbourne disease caused by the oak processionary caterpillar. Pediatric Dermatology, 23(1):64-66.

Gries R; Reckziegel A; Bogenschütz H; Kontzog HG; Schlegel C; Francke W; Millar JG; Gries G, 2004. (Z,Z)-11,13-Hexadecadienyl acetate and (Z,E)-11,13,15-hexadecatrienyl acetate: synergistic sex pheromone components of oak processionary moth, Thaumetopoea processionea (Lepidoptera: Thaumetopoeidae). Chemoecology, 14(2):95-100. http://www.birkhauser.ch

Grison P, 1952. La processionnaire du chene (Thaumetopoea processionea L.) dans la region parisienne. Revue de Pathologie Vegetale, 31(2):103-114.

Groenen F, 2010. Variation of Thaumetopoea processionea (Notodontidae: Thaumetopoeinae) in Europe and the Middle East. Entomologische Berichten, 70(3):77-82. http://www.nev.nl

Groenen F; Meurisse N, 2012. Historical distribution of the oak processionary moth Thaumetopoea processionea in Europe suggests recolonization instead of expansion. Agricultural and Forest Entomology, 14(2):147-155. http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1461-9563

Haeger E, 1971. An outbreak of the oak processionary in the Brandenburg Marches. (Ein Massenauftreten des Eichenprozessionsspinners in der Mark Brandenburg (Lep. Thaum.).) Entomologische Nachrichten, 15(1):11-12.

Halperin J; Sauter W, 1999. The occurrence of Thaumetopoea processionea L. (Lep.: Thaumetopoeidae) on Mt. Hermon. Phytoparasitica, 27(2):107.

Hase A, 1939. On the Pine Processionary and on the Dangerousness of the Hairs of its Larva. (Ueber den Pinienprozessionsspinner und über die Gefährlichkeit seiner Raupenhaare (Thaumetopoea pityocampa Schiff.).) Anzeiger fur Schadlingskunde, 15(pt. 12):133-142 pp.

Hendry SJ; Poole EJ; Craig I; Proudfoot JC, 2005. Forest condition 2004. Information Note - Forestry Commission, No.75:8 pp.

Hoch G; Verucchi S; Schopf A, 2008. Microsporidian pathogens of the oak processionary moth, Thaumetopoea processionea (L.) (Lep., Thaumetopoeidae), in eastern Austria's oak forests. Mitteilungen der Deutschen Gesellschaft für allgemeine und angewandte Entomologie [Vorträge der Entomologentagung, Innsbruck, Austria, 26 February to 1 March, 2007.], 16:225-228. http://www.dgaae.de

IPPC, 2007. Oak processionary moth. IPPC Official Pest Report, No. GB-4/2. Rome, Italy: FAO. https://www.ippc.int/IPP/En/default.jsp

Jurc M, 2006. Oaks - Quercus spp. Insects on branches, leaves and needles. (Hirasti - Quercus spp. Zuzelke na poganjkih, listih in iglicah.) Gozdarski Vestnik, 64(5/6):253-268. http://www.dendro.bf.uni-lj.si/gozdv.html

Kimber I, 2014. 2022 Oak processionary Thaumetopoea processionea (Linnaeus, 1758). UK moths. London, UK: Ian Kimber. http://ukmoths.org.uk/show.php?bf=2022

Kiriukhin G, 1946. Les insectes nuisibles au pistacier en Iran. Entomologie et Phytopathologie Appliquees, 1. Teheran, 8-24 pp.

Klapwijk MJ; Csóka G; Hirka A; Björkman C, 2013. Forest insects and climate change: long-term trends in herbivore damage. Ecology and Evolution, 3(12):4183-4196. http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)2045-7758

Kleinlogel B, 2013. Control of the Oak Processionary Moth: Removal of material from nests and urticating hairs. (Bekämpfung des Eichenprozessionsspinners: Sachgerechtes Entfernen von Nestern und Brennhaaren des Eichenprozessionsspinners.) Julius-Kühn-Archiv [Ökologische Schäden, gesundheitliche Gefahren und Massnahmen zur Eindämmung des Eichenprozessionsspinners im Forst und und im urbanen Grün, Berlin, Germany, 6-7 March, 2012.], No.440:75-76. http://pub.jki.bund.de/index.php/JKA/issue/archive

Klug M, 2013. Distribution, potential threat and control of the oak processionary moth in North rhine-Westphalia. (Ausbreitung, Gefahrenpotential und Bekämpfung des Eichenprozessionsspinners in Nordrhein-Westfalen.) Julius-Kühn-Archiv [Ökologische Schäden, gesundheitliche Gefahren und Massnahmen zur Eindämmung des Eichenprozessionsspinners im Forst und und im urbanen Grün, Berlin, Germany, 6-7 March, 2012.], No.440:27-32. http://pub.jki.bund.de/index.php/JKA/issue/archive

Krehan H, 1993. Outbreaks of caterpillar forest pests in oak forests of eastern Austria. Forstschutz Aktuell, No. 12-13:1-4; 3 ref.

Lamy M; Novak F, 1987. The oak processionary caterpillar (Thaumetopoea processionea L.) an urticating caterpillar related to the pine processionary caterpillar (Thaumetopoea pityocampa Schiff.) (Lepidoptera, Thaumetopoeidae). Experientia, 43(4):456-458.

Lerer AZ; Plugar SG, 1962. A contribution to the study of the Tachinids (Diptera, Larvaevoridae) that parasitise pests of oak in Moldavia. Entomologicheskoe obozrenie, 41(pt. 2):359-365 pp.

Logoida S; Besheni G, 1966. The oak processionary moth. Zashchita Rastenii, pt. 5. 45-46 pp.

Lövgren R; Dalsved B, 2005. Thaumetopoea processionea L. (Lepidoptera: Thaumetopoeidae) found in Sweden. (Thaumetopoea processionea L. ekprocessionsspinnaren, funnen i Sverige.) Entomologisk Tidskrift, 126(1/2):93-94.

Martin JC; Bonneau X, 2006. Bacillus thruingiensis, 30 years of control of cluster caterpillars. Phytoma, 590:4-7.

Marziali L; Marianelli L; Bagnoli M; Roversi PF, 2011. Spatial analysis for pest management in Tuscany. Silva Lusitana [MEDINSECT 2: a symposium on Entomological research in Mediterranean forest ecosystems, Estoril, Portugal, 5-8 May 2008.], 19(Especial):135-141.

Matosevic D; Liovic B; Novak-Agbaba S, 2001. Diagnostic and prognostic service - the most significant biotic and abiotic factors in 1996-2000 in Croatia. (Dijagnozno-prognozna sluzba u Hrvatskoj u razdoblju od 1996. do 2000. godine.) In: Znanost u potrajnom gospodarenju hrvatskim sumama: znastvena knjiga [ed. by Matic, S.\Krpan, A. P. B.\Gracan, J.]. Jastrebarsko, Croatia: Sumarski Institut, Forest Research Institute, 327-334.

Meurisse N; Hoch G; Schopf A; Battisti A; Grégoire JC, 2012. Low temperature tolerance and starvation ability of the oak processionary moth: implications in a context of increasing epidemics. Agricultural and Forest Entomology, 14(3):239-250. http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1461-9563

Mirchev P; Tsankov G; Petrov Y, 2003. Study of some aspects of the bioecology of the oak processionary moth (Thaumetopoea processionea Linnaeus, 1758) (Lepidoptera: Notodontidae) in North-East Bulgaria. Silva Balcanica, 3(1):5-10.

Moraal LG, 1992. Infestations by insects and mites in 1991: in forests, nature reserves and roadside plantings. (Aantastingen door insekten en mijten in 1991: in bossen, natuurgebieden en wegsbeplantingen.) Nederlands Bosbouwtijdschrift, 64(3):86-95.

Moraal LG; Jagers op Akkerhuis GAJM, 2011. Changing patterns in insect pests on trees in The Netherlands since 1946 in relation to human induced habitat changes and climate factors - an analysis of historical data. Forest Ecology and Management, 261(1):50-61. http://www.sciencedirect.com/science/journal/03781127

Moraal LG; Jagers op Akkerhuis GAJM; Werf DCvan der, 2002. Veranderingen in insectenplagen op bomen: monitoring sinds 1946 maakt trends zichtbaar. (Veranderingen in insectenplagen op bomen: monitoring sinds 1946 maakt trends zichtbaar.) Nederlands Bosbouw Tijdschrift, 74:29-32.

Niccoli A; Pelagatti O, 1986. Persistence of products based on Bacillus thuringiensis Berl. used in the control of some species of Lepidoptera. (Persistenza di prodotti a base di Bacillus thuringiensis Berl. impiegati nel controllo di alcune specie di Lepidotteri.) Redia, 69:329-339.

Niccoli A; Tiberi R, 1986. Observations on the biology and on the larval behavior of Thaumetopoea processionea (L.) (Lepidoptera, Thaumetopoeidae). Redia, 69:285-297.

Nicosia, 1923. Processionary caterpillar. Cyprus Agricultural Journal April, 18(2):47-48.

Offenberg K, 2000. The calamity of the oak procession moth (Thaumetopoea processionea L.) during the last century in Westfalen. (Kalamität des Eichenprozessionsspinners (Thaumetopoea processionea L.) im letzten Jahrhundert in Westfalen.) Forst und Holz, 55(13):424-426.

Palmqvist G, 2013. Remarkable records of Macrolepidoptera in Sweden 2012. (Intressanta fynd av storfjärilar (Macrolepidoptera) i Sverige 2012.) Entomologisk Tidskrift, 134(1/2):33-43. http://www.sef.nu/

Pascual JA, 1988. Biology of the oak processionary moth (Thaumetopoea processionea L.) (Lep. Thaumetopoeidae) in the western central Iberian Peninsula. (Biología de la Procesionaria del roble (Thaumetopoea processionea L.) (Lep. Thaumetopoeidae) en el centro-oeste de la Península Ibérica.) Boletín de Sanidad Vegetal, Plagas, 14(3):383-404.

Pascual JA; Robredo F; Galante E, 1990. Aerial ULV applications of alpha-cypermethrin, diflubenzuron and Bacillus thuringiensis against the oak processionary moth (Thaumetopoea processionea) (Lep., Thaumetopoeidae). (Tratamientos aéreos ULV con alfa-cipermetrina, diflubenzurón y Bacillus thuringiensis contra la procesionaria del roble (Thaumetopoea processionea) (Lep., Thaumetopoeidae).) Boletín de Sanidad Vegetal, Plagas, 16(3):585-591.

Plugaru SG, 1968. The biology of the Oak processionary moth in Moldavia. Vrednaja i Poleznaja Fauna Bespozvonocnyh Moldavii, Part 3. Kishinev, USSR: Izdatel'stvo Kartja Moldovenjaske, 29-41.

Pustovoit AF, 1931. The Control of the Processionary Oak Moth, Thaumetopoea processionea L., in the District Pervomaisk, Government of Kherson, in 1927. Plant Protection, 7(4-6):239-243 pp.

Quero C; Bau J; Guerrero A; Breuer M; Loof Ade; Kontzog HG; Camps F, 2003. Sex pheromone of the oak processionary moth Thaumetopoea processionea. Identification and biological activity. Journal of Agricultural and Food Chemistry, 51(10):2987-2991. http://pubs.acs.org/cgi-bin/abstract.cgi/jafcau/2003/51/i10/abs/jf021035g.html

Roskams, 2008. Oak processionary moth in Belgium: status and control. Workshop presentation: Processionary moths and human reactions to larval setae" at Holmhallar. Gotland, Sweden: Roskams, 5-7.

Roversi PF, 2008. Aerial spraying of Bacillus thuringiensis var. kurstaki for the control of Thaumetopoea processionea in Turkey oak woods. Phytoparasitica, 36(2):175-186. http://www.phytoparasitica.org

Roversi PF; Boretti R; Merendi GA; Bartolozzi L; Toccafondi P, 1997. Oak processionary caterpillar: damage and control criteria. (Processionaria della quercia: danni e criteri di controllo.) Sherwood - Foreste ed Alberi Oggi, 3(8):13-16.

Rumine P; Barzanti GP; Roversi PF, 2006. Distribution of Bacillus thuringiensis var kurstaki in decidous oak woods by means of ultra-low-volume aerial treatments: penetration into the crown layer and persistence. (Distribuzione di Bacillus thuringiensis var kurstaki in querceti caducifogli con trattamenti aerei ad ultrabasso volume: penetrazione nello strato delle chiome e persistenza.) In: Giornate Fitopatologiche 2006, Riccione (RN), 27-29 marzo 2006. Atti, volume primo [ed. by Brunelli, A.\Canova, A.\Collina, M.]. Bologna, Italy: Università di Bologna, 551-556.

Scheidter F, 1934. Contributions to Forest Entomology, 14-38. (Forstentomologische Beiträge. 14-38.) Zeitschrift fur Pflanzenkrankheiten, Pflanzenpathologie und Pflanzenschutz, 44(5, 7, 8, 10):223-226; 362-379; 386-423; 497-525 pp.

Schmidt GH, 1974. A contribution to the social behavior of the caterpillar of the oak processionary Thaumetopoea processionea. Zeitschrift fur Angewandte Entomologie, 75(2):174-178.

Sellier R; Mahieu N; Angebault JY, 1975. Urticating caterpillars; biology, economic and medical importance. (Les chenilles urticants; biologie, importance economique et medicale.) Bulletin de la Societe des Sciences Naturelles de l'Ouest de la France, 73:29-41.

Serafimovski A, 1958. The morphology and biology of T. processionea [in Macedonia]. (Pridones kon poznavanjeto morfologijata i biologijata na daboviot cetnik (Thaumatopoea processionea L.) kaj nas.) Godisn. Sum. Inst., Skopje, 3(3):83-117.

Skule B; Vilhelmsen F, 1997. Thaumetopoea processionea L. found in Denmark. Copenhagen, Denmark: Lepidopterological Society. http://www.lepidoptera.dk/process.htm

Spijker J, 2007. Cattle ill due to oak procession moth. (Vee ziek door eikenprocessierups.) Vakblad Natuur Bos Landschap, 4(10):23. http://www.vakbladnatuurboslandschap.nl

Stigter H; Romeijn G, 1992. Thaumetopoea processionea observed locally in large numbers in the Netherlands after more than a century (Lepidoptera: Thaumetopoeidae). (Thaumetopoea processionea na ruim een eeuw weer plaatselijk in Nederland (Lepidoptera: Thaumetopoeidae).) Entomologische Berichten, 52(5):66-69.

Stratan VS, 1971. An egg parasite of the oak processionary moth. Zashchita Rastenii, 16(5):42.

Teodorescu I; Simionescu A, 1994. Dynamics of defoliating Lepidoptera attacks and the control measures in Romania's deciduous forests, 1953-1990. Ambio, 23(4/5):260-266.

Thomas FM; Blank R; Hartmann G, 2002. Abiotic and biotic factors and their interactions as causes of oak decline in Central Europe. Forest Pathology, 32(4/5):277-307.

Tiberi R; Bin F, 1988. Parasitism and other mortality factors of eggs of Thaumetopoea processionea (L.) in central Italy (Hym., Chalcidoidea; Lep., Thaumetopoeidae). (Parassitismo e altri fattori di mortalità nelle uova di Thaumetopoea processionea (L.) in Italia centrale (Hym., Chalcidoidea; Lep., Thaumetopoeidae).) Redia, 71(2):299-311.

Tomiczek C; Krehan H, 2003. Increasing problems with the oak processionary moth in Eastern Austria. (Zunehmende Probleme mit dem Eichenprozessionsspinner in Ostösterreich.) Forstschutz Aktuell, No.29:17-18.

Townsend M, 2007. Outbreaks of the oak processionary moth Thaumetopoea processionea (Linnaeus) (Lepidoptera: Thaumetopoeidae) in west London. Entomologist's Gazette, 58(4):226. http://www.pemberleybooks.com

Townsend M, 2009. Report on survey and control of Oak Processionary Moth Thaumetopoea processionea (Linnaeus) (Lepidoptera: Thaumetopoeidae) (OPM) in London in 2008. Oxford, UK: Townsend. http://www.forestry.gov.uk/pdf/fcopmsurv08reppub.pdf/$FILE/fcopmsurv08reppub.pdf

Townsend M, 2013. Oak processionary moth in the United Kingdom. Outlooks on Pest Management, 24(1):32-38. http://www.pestoutlook.com

Trouvelot B; Grison [P]; Biliotti [E, 1952. Forecasting outbreaks of the Oak processionary caterpillar, with a view to chemical control. (La prevision des infestations de processionnaire du chene en vue de traitements chimiques.) Compte Rendu Hebdomadaire des Seances de l'Academie d'Agriculture de France, 39(12):486-8.

Tsankov G; Breuer M; Schmidt GH; Maslov A, 1991. Scale shape and colour of egg batches of some Thaumetopoea species (Insecta Lepidoptera Thaumetopoeidae). Bollettino di Zoologia Agraria e di Bachicoltura, 23(1):45-60.

Vago C, 1953. A polyhedral virus disease peculiar to T. processionea. (Sur une virose du type 'polyedrie' particuliere a la processionnaire du chene: 'Thaumetopoea processionea L.' Lepidoptera.) Revue Forestiere Francaise, 5(10):654-6.

Vago C; Vasiljevic L, 1955. A virus disease located in the intestine of T. processionea, with cytoplasmic affinities. (Une virose a localisation intestinale avec affinite cytoplasmique chez le lepidoptere Thaumatopoea processionea.) Antonie van Leeuwenhoek: J. Microbiol. & Serol, 21(2):210-4.

Veber J, 1958. Comparative histopathology of N. bombycis in different hosts. Transactions of the First International Conference if Insect Pathology and Biological Control, Prague, August 1958. 301-313.

Villorbina G; Rodriguez S; Camps F; Fabrias G, 2003. Comparative sex pheromones biosynthesis in Thaumetopoea pityocampa and T. processionea: a rationale for the phenotypic variation in the sex pheromone within the genus Thaumetopoea. Insect Biochemistry and Molecular Biology, 33(2):155-161.

Wagenhoff E; Veit H, 2011. Five tears of continuous Thaumetopoea processionea monitoring: tracing population dynamics in an arable landscape of south-western Germany. Gesunde Pflanzen, 63(2):51-61.

Waring P; Townsend MC; Lewington R, 2003. Field guide to the moths of Great Britain and Ireland. Hook, UK: British Wildlife Publishing.

Williams DT; Straw N; Townsend M; Wilkinson AS; Mullins A, 2013. Monitoring oak processionary moth Thaumetopoea processionea L. using pheromone traps: the influence of pheromone lure source, trap design and height above the ground on capture rates. Agricultural and Forest Entomology, 15(2):126-134. http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1461-9563

Wulf A; Pehl L, 2005. Forest health and forest protection 2004 in the Federal Republic of Germany - summary and preview 2005. (Waldschutzsituation 2004 in der Bundesrepublik Deutschland - Übersicht und Ausblick für 2005.) Forst und Holz, 60(4):145-149.

Zeegers T, 1997. Tachinid flies (Diptera: Tachinidae) from Dutch oak processionary. Entomologische Berichten [Sluipvliegen (Diptera: Tachinidae) van de Nederlandse eikenprocessierupsen.], 57(5):73-78.

Contributors

Top of page

10/03/14 Original text by:

Claire Beverley, CABI, Nosworthy Way, Wallingford, Oxon, OX10 8DE, UK

Distribution Maps

Top of page
You can pan and zoom the map
Save map