Oak Processionary Research Articles

Aerial spraying ofBacillus thuringiensis var.kurstaki for the control ofThaumetopoea processionea in Turkey oak woods

Thaumetopoea processionea L. is an important oak defoliator whose outbreaks have become increasingly frequent in Europe and thus have received a great deal of attention from foresters. Field trials were carried out in central Italy (Tuscany) to test the efficacy of aerial spraying ofBacillus thuringiensis var.kurstaki [Btk] in early spring for the control of processionary infestations inQuercus cerris L. woods. The experimental sites were located in a hilly area of 1640 ha witha maximum altitude of 593 m a.s.l. and a yearly mean temperature of 10°C. Turkey oak woods were divided into three areas to be treated with 31.75 BIU ha−1 (2.5l ha−1) on 578 ha, 44.45 BIU ha−1 (3.5l ha−1) on 306 ha and 57.15 BIU ha−1 (4.5l ha−1) on 756 ha, respectively. Five days after treatment, larval mortality was less than 40% in the control plot, but over 60% in the treated areas. Thirteen days after treatment, larval mortality varied from 75.05% to 96.42% in the three treated areas. Surveys conducted 2 months after the treatment showed a strong decline in the number of oak processionary nests in all the treated plots. It was possible to control the pest effectively in turkey oak woods usingBtk at 31.75 BIU ha−1 distributed at ultra-low volume at the time of bud opening when nonurticating larvae were present.

Dispersion of the bio-aerosol produced by the oak processionary moth

The oak processionary moth (Thaumetopoea processionea L.) is found in oak forests in most European countries. The caterpillars bear urticating hairs (setae) as a chemical defence. These hairs break off and are small enough to become airborne and be transported by the wind. Upon contact with humans the toxin can cause an allergic reaction that ranges from a skin rash to respiratory distress. In order to measure the terminal settling velocity of this bioaerosol, we used a small elutriator and tested its functionality with particles of known aerodynamic diameter. We determined that the mean settling velocity of the setae is about 1 cm/s, corresponding to an aerodynamic diameter of 19 μm for setae with a diameter of 6 μm and a length of 190 μm. The dispersion of the hairs in the atmosphere for a typical summer day was calculated by means of an Eulerian model. The results of this calculation revealed that the maximum concentrations in the atmosphere on a typical summer day reach 20–30% of the concentration found directly at the source. Those maximum concentrations are reached at a distance from the source that varies between 174 and 562 m, depending on the atmospheric stability and the settling velocity.

Do Natural Water Blooms Cause Irritation/Allergy?

P-117 Introduction: Cyanobacterial blooms and scums occur in the same period of recreation, bathing in freshwaters. That is why it is needed to examine experimentally the allergenic and irritative effects of cyanobacteria. There are some data on contact irritative and allergenic effects of cyanobacteria. In a retrospective epidemiological study in Hungary it was found that in 1994 a lot of children (almost one hundred) suffered from skin and eye irritation in a heavy bloom of Microcystis aeruginosa. Methods: Microcystis aeruginosa, Anabaena flos-aquae, Aphanizomenon flos-aquae and Cylindrospermopsis raciborskii are the most common species in Hungarian freshwaters. Sensitization test on albino guinea pigs, intradermal reactivity and occular irritation test on albino rabbits with freeze dried algal suspension in physiological salt solution were carried out modelling the human reactivity. All the axenic strains were examined for endotoxin (lipopolysaccharide) content by LAL (Lymulus Amobocyte Lysate) test. Results: Natural bloom and strain samples were examined in sensitization and irritation tests and no correlation was found between the toxin content and allergenic character. The most toxic one was not the most allergenic sample, but the non-toxic Aphanizomenon[r] was the most allergenic one. The axenic strains were not allergenic at all. All axenic samples containing 50–170 IU/ml lipopolysaccharide (LPS) endotoxins can cause inflammatory symptoms if they reach the blood system. There was no correlation between the toxin content and the LPS content as well. Case study: Clear freshwater pond using for bathing was closed for two weeks in the high season because more than 40 patients suffered from skin blistering and rashes and it was thought that the high amount of filamentous cyanobacteria (chlorophyll a was 118.4 mg/m3) might cause the symptoms. It turned out that some patients did not bathe in the water at all, so the real causes were to be looked for. In the same time a severe gradation of the caterpillars of the moth Thaumetopoea processionea occurred in the forest of oaks surrounding the pond. These caterpillars have integumental glands that produce an urticating chemical. They can release their poisonous setae (hairs) or spines into the environment where they can be contacted on skins. They caused dermatitis as known erucism. Discussion and Conclusions: Although there is experimental evidence for the fact that the cyanobacteria can cause allergenic and irritative symptoms diagnosis should be established carefully as it turned out from the case study.

An Epidemic Airborne Disease Caused by the Oak Processionary Caterpillar

The oak processionary caterpillar (Thaumetopoea processionea Lepidoptera) is found in several European countries. It usually lives in oak forests or on single-standing oak trees. The larva of from the 3rd to 6th developmental stage (instar) develops poisonous hair (setae), filled with an urticating toxin that may lead to serious dermatitis, conjunctivitis, and pulmonary affection (summarized as lepidopterism) on contact with the setae. In June 2004 more than 40 people including young children developed symptoms of lepidopterism after resting within 20 m of an infested oak tree. Only a few people had touched the caterpillars. All those with clinical symptoms of lepidopterism could be treated as outpatients, but several needed systemic steroids because of the severity of their complaints. Lepidopterism, an airborne disease caused by the setae of the processionary caterpillar, is a growing public health problem because of the increasing numbers of outbreaks.

Toxisch-irritative Dermatitis durch Prozessionsspinnerraupen nach Portugalaufenthalt

Caterpillars of the pine and the oak processionary moth, endemic in many European countries, produce poisonous hairs (setae) from its third to fifth larval stage. These setae contain highly allergenic, urticating proteinsdefined as thaumetopoein which induces various symptoms of lepidopterism, most frequently associated with pruritus and dermatitis. T. pityocampa directly induce dermatitis by a toxic-irritative, non-IgE-mediated mechanism. Additionally, true allergenic reactions to Tha p 1, a highly immunogenic 15 kDa protein fraction has been demonstrated most recently by positive skin prick tests and specific IgE determination by immunoblotting. Preliminary investigations showed that cross-reacting thaumetopoein-like fractions occur in T. processionata. Herein, we report on a 40-year-old German female suffering from toxic-irritative dermatitis approximately two weeks after returning home from vacation to Portugal. The initially suspected communicable form of urticaria could be linked to a contact dermatitis produced by setae of the pine processionary caterpillar imported from Portugal by clothing and personal utensils. This is the first documented case of a severe form of processionary caterpillar dermatitis introduced from southern European recreational areas to Germany. Secondary infections have to be prevented therapeutically. Decontamination of setae from the personal environment as well as from personal utensils resulted in the effective prevention of new skin lesions. The documented case reveals that dermatitis caused by processionary caterpillars is obviously still widely unknown although sylvatic mass infestation by the oak processionary caterpillar does frequently occur in central Europe potentially causing outbreaks of lepidopterism.

( 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)

Our objective was to identify sex pheromone components of the oak processionary moth, Thaumetopoea processionea (Lepidoptera: Thaumetopoeidae), whose larvae defoliate oak, Quercus spp., forests in Eurasia and impact human health. Coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometric (MS) analyses of pheromone gland extract of female T. processionea revealed two consistently EAD-active compounds. They were identified as (Z,Z)-11,13-hexadecadienyl acetate (Z11,Z13-16:OAc) and (Z,E)-11,13,15-hexadecatrienyl acetate (Z11,E13,15-16:OAc) by comparative GC, GC-MS and GC-EAD analyses of insect-produced compounds and authentic standards. In replicated field experiments (2000, 2001) in Nordbaden, Sudbaden and Sachsen-Anhalt (Germany), Z11,Z13-16:OAc and Z11,E13,15-16:OAc in combination, but not singly, attracted significant numbers of male moths. It will now be intriguing to investigate whether Z11,E13,15-16:OAc, or its corresponding alcohol or aldehyde, serves as a pheromone component also in other species of the Thaumetopoeidae.

The oak processionary caterpillar as the cause of an epidemic airborne disease: survey and analysis.

Thaumetopoea processionea L. (order Lepidoptera), the oak processionary moth, is found in oak forests in most European countries. Its third to sixth larval instars are armed with poisonous hairs (setae) containing an urticating toxin (thaumetopoein) potentially harmful to humans. Because T. processionea infests trees at the edges of forests or standing alone people frequently come into contact with its setae. In the woodland bordering on the western suburbs of Vienna conditions favouring its increase have led to frequent outbreaks of lepidopterism. To determine the incidence of lepidopterism in a suburban environment with three separate caterpillar-infested oak trees and to ascertain the frequency of the various symptoms of lepidopterism and the manner of contact with setae. We conducted a telephone survey of all the households/institutions located within 500 m of the infested trees. To gain more information on patients' symptoms and on situations likely to lead to increased contact with setae we asked those who reported cutaneous reactions to complete a questionnaire. As part of the environmental study we described the outbreak site, examined patients and, with tape-strip samples taken from the surface of the soil, looked for setae persisting in the environment. Of 1025 people surveyed 57 (5.6%) reported one or more symptoms of lepidopterism: 55 (96%) reported pruritus, 54 (95%) dermatitis, eight (14%) conjunctivitis, eight (14%) pharyngitis and two (4%) respiratory distress. The questionnaire was returned by 37 (69%) of the individuals with dermatitis. Of those, 16% had reacted with weal formation, 49% with papular rash and 22% with toxic irritant dermatitis. In 13% of respondents it was not possible to define the reaction. The risk factor analysis showed that airborne contamination was the most important cause: 97% of people had frequently passed an infested tree, 57% lived near a tree (in a neighbouring garden) and 32% had a tree in their own garden. Direct contact with larvae was of minor importance (38%). In four of the tape-strip samples intact setae were identified 1 year after the infestation. Lepidopterism caused by T. processionea is a public health problem of increasing significance. In years with outbreaks of the pest it can reach epidemic proportions in communities located near infested trees. Contact with airborne setae was mainly responsible for the occurrence of the disease.

Sex pheromone of the oak processionary moth Thaumetopoea processionea. Identification and biological activity.

The sex pheromone of the oak processionary moth Thaumetopoea processionea has been characterized from female gland extracts as 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 88:7:5 ratio. The amount of the major compound 1 was 20-30 ng/gland. No trace of (Z,Z)-11,13-hexadecadienal was found in the extract, and therefore, T. processionea appears to be the only "summer" processionary moth lacking this compound as a pheromone compound. The alcohol 2 had also been previously found but is electrophysiologically inactive, and in wind tunnel assays it lowers the number of contacts with the source when mixed with the major compound 1. The major component 1 elicited males to display the complete behavioral sequence, but the amount of chemical needed was unexpectedly high in comparison to the activity displayed by virgin females and gland extracts. (E,E)-11,13-hexadecadienyl acetate (5) inhibits the attractant activity of the major component 1 when mixed with 1 in 1:10 and 1:1 ratios. The main constituent 1 is active in the field, but its tendency to isomerize into the corresponding E,E isomer (5) must be considered if effective formulations are to be prepared.

Field trials with the synthetic sex pheromone of the oak processionary moth Thaumetopoea processionea.

The biological activity of synthetic (Z,Z)-11,13-hexadecadienyl acetate, the major pheromone component found in female gland extracts of the oak processionary moth Thaumetopoea processionea, was evaluated in field trials. Traps baited with 10 mg of the chemical efficiently attracted a large number of males provided they were placed in the upper crown region of the oaks. Devices positioned 10-15 m high in the trees attracted significantly more males than those traps installed at 2 or 6-8 m above the ground. Pherocon traps were slightly more efficient than Delta traps, and lower or higher amounts of the attractant in the baits did not significantly influence the number of moths caught. The importance of the stereomeric purity of the lure and the easy isomerization of the (Z,Z)-acetate to other isomers, particularly to the E,E isomer, should be considered for the development of efficient formulations in the field.

Acute Dermatitis from Oak Processionary Caterpillars in a U.S. Military Community in Germany

One hundred sixty-five soldiers and civilians from the U.S. military community in Heidelberg, Germany, sought treatment for acute dermatitis from June 26 through July 2, 1995. This was 144 more than the expected number of 21 cases based on a background rate of 3 cases per day. Cases consisted of individuals who presented with a painful, itching rash distributed widely about the body but concentrated in the upper half. Urticarial hairs from oak processionary caterpillars (Thaumetopoea processionea L.) (Lepidoptera: Thaumetopoeidae) were eventually identified as the cause. This article is the first published report that documents the military medical importance of these caterpillars in Europe. The implications and measures needed to resolve future outbreaks quickly and effectively are discussed.