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- 4 Material und Umwelt (42)
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Eingeladener Vortrag
- nein (57)
Impact
(2000)
Stored Products as Habitats
(2003)
In collaboration with the United States Department of Agriculture and a number of major milling companies, the "Insect-Detect" immunoassay for analyzing insect contamination in grains has been compared with three more traditional methods, X-ray analysis, cracking and flotation, and the insect fragment test (IFT). Testing was carried out in blind fashion using clean wheat samples that were spiked with differing numbers of grain kernels infested with late instar larvae of the granary weevil (Sitophilus granarius (L.)). Three different laboratories analyzed the samples for each of the four methods. The collaborative trials showed that the insect immunoassay clearly provided the most accurate measurement of actual insect infestation, followed by X-ray analysis. While both cracking and flotation and IFT procedures provided a general measure of contamination, they showed much greater variability.
Kulturelle Entomologie
(2013)
Seit mehreren Jahrzehnten ist der Einsatz von Lockstoffen gegen Insekten zur Schadensabwehr an Lagergütern und Materialien etabliert. Die Hauptkomponenten der Pheromone aller wirtschaftlich relevanten vorrats- und materialschädlichen Insekten sind bekannt. Zur Früherkennung und zur Populationsdichteüberwachung von Schädlingen nehmen Pheromonfallen eine zentrale Position im Konzept der ökonomischen Schadensschwelle und damit im integrierten Vorrats- und Materialschutz ein. Dies gilt vor allem für Sexuallockstoff-Fallen gegen paarungsbereite Männchen von vorratsschädlichen Motten aus den Gruppen der Zünsler (Pyralidae) mit Dörrobst-, Mehl- und Speichermotte und gegen Kleinschmetterlinge(Tineiden) mit Kleider- und Pelzmotte sowie gegeneinige Nagekäfer mit Brot-, Tabak- und Gemeiner Nagekäfer. Durch das sogenannte "Monitoring" können Bekämpfungsstrategien zunächst zeitlich und räumlich optimiert und anschließend auf Erfolg bewertet werden. Neben Sexualpheromonen sind bei einigen Käfern wie beispielsweise den Korn- und Reismehlkäfern auch Aggregationspheromone, die attraktiv auf beide Geschlechter wirken, verbreitet. Ihr Einsatz zur Bekämpfung, d.h. zum Massenfang von Individuen, wie dies im forstwirtschaftlichen Bereich gegen Borkenkäfer nutzbringend durchgeführt wird, hat sich aufgrund mangelnden Erfolgs im Nachernteschutz jedoch nicht etabliert.
Neben einem wirtschaftlich orientierten Einsatz von Pheromonfallen kann deren Anwendung auch wertvolle allgemein biologische Informationen über Schadinsekten liefern. Wird das "Monitoring" z.B. im Freiland abseits von Lagerstätten für faunistische Erhebungen durchgeführt, können natürliche Vorkommen von Schädlingsarten ermittelt werden. Dies erlaubt Rückschlüsse auf ihre ursprünglichen Lebensräume und auf mögliche adaptative Szenarien beim Übergang zu einer synanthropen und damit für den Menschen schädlichen Lebensweise. Zusätzlich werden auf diese Weise natürliche Habitate, die als Reservoire für Schadpopulationen fungieren könnten, aufgespürt und, wenn notwendig, in ein Bekämpfungsprogramm integriert.
It is generally accepted that the natural habitats of most pest insects can be found outside the synanthropic environment in layers of leaf litter, under bark, as well as in rodent or bird nests. Indeed, most of the common pests have been reported as being facultative nidicolous. Therefore infestation of commodities by pest insects out of these reservoirs is one considerable possibility. However, the likelihood of a pest´s occurrence and survival out-doors largely depends on its ecological potential and competitiveness against other species of the same ecological guild. Some pest species are rarely found in wild habitats, especially in those regions where they are not native and where they have been introduced by man. The fabric pest Tineola bisselliella serves as a good example. Most likely originating in Central or Southern Africa this insect was introduced into Europe probably not earlier than the late 18th century. Being more tolerant to dry environments than other fabric pests its economical importance increased during the 20th century when in-door climates changed because of central heating systems. Its occurrence in out-door natural habitats must be regarded as accidental. Reported founds of webbing clothes moth larvae in bird nests e.g. have been largely overstated in the literature. T. bisselliella should be regarded as an eusynanthropic species
Adapted and effective pest management strategies for the protection of irreplaceable culture heritage as well as for the prevention of damages in households and warehouses are based on reliable information about the presence and distribution of the pest organisms. Monitoring the webbing clothes moth Tineola bisselliella at thirteen outdoor stations in the broader area of Berlin give a first idea of their occurrence in an urban area and the hinterlands. The results demonstrate a seasonal abundance in the city and a missing of this species in the countryside. Data suggest a synanthropic occurrence of the webbing clothes moth rather than an invasion from natural reservoires. Possible molecular examinations on the species and subspecies level are presented to analyze the gene flow between populations and give an impression of species mobility as well as pathways of infestation.
Termite gut flagellates are colonized by host-specific lineages of ectosymbiotic and endosymbiotic bacteria. Previous studies have shown that flagellates of the genus Trichonympha may harbour more than one type of symbiont. Using a comprehensive approach that combined cloning of SSU rRNA genes with fluorescence in situ hybridization and electron microscopy, we investigated the phylogeny and subcellular locations of the symbionts in a variety of Trichonympha species from different termites. The flagellates in Trichonympha Cluster I were the only species associated with 'Endomicrobia', which were located in the posterior part of the cell, confirming previous results. Trichonympha species of Cluster II from the termite genus Incisitermes (family Kalotermitidae) lacked 'Endomicrobia' and were associated with endosymbiotic Actinobacteria, which is highly unusual. The endosymbionts, for which we suggest the name 'Candidatus Ancillula trichonymphae', represent a novel, deep-branching lineage in the Micrococcineae that consists exclusively of clones from termite guts. They preferentially colonized the anterior part of the flagellate host and were highly abundant in all species of Trichonympha Cluster II except Trichonympha globulosa. Here, they were outnumbered by a Desulfovibrio species associated with the cytoplasmic lamellae at the anterior cell pole. Such symbionts are present in both Trichonympha clusters, but not in all species. Unlike the intracellular location reported for the Desulfovibrio symbionts of Trichonympha agilis (Cluster I), the Desulfovibrio symbionts of T. globulosa (Cluster II) were situated in deep invaginations of the plasma membrane that were clearly connected to the exterior of the host cell.
The content of chromium in different oxidation states in chromium-treated wood was studied with XANES (X-ray absorption near-edge structure) measurements at the Cr K absorption edge. It could be shown that wood samples treated with Cr(VI) (pine and beech) did still contain a measurable content of Cr(VI) after four weeks conditioning. If such wood samples were heat exposed for 2 h with 135 °C prior conditioning, Cr(VI) was no longer detected by XANES, indicating a complete reduction to chromium (III).
The application of pheromone-baited traps to control pest insects in stored food or materials has become well established over the past decades. The main pheromone components of all major stored-product and material pests have been identified. Pest monitoring with pheromone traps is a key factor in integrated pest management to estimate population density build-ups and they may be used to define economic threshold levels. Male-attracting sex pheromones, e.g. for stored-product pyralids, the clothes moths, and some anobiid beetles, are especially effective in this aspect.
Monitoring pest population can facilitate optimal spatial and temporal control strategies, including efficacy evaluation of the implemented control measures. In addition to the sex pheromones, some beetles, such as grain and flour beetles, utilize aggregation pheromones, which attract both sexes.Implementation of these pheromones for mass trapping,which works well for the control of bark beetles in the forest environment, has been less successful for stored-product protection for various reasons and is thus not an established means of control.
When the monitoring tools are used in landscape areas, scrublands, forests, and away from anthropogenic influencedenvironments, natural reservoirs of a pest species and sources of new infestations can be identified. In addition to an economically driven adoption of pheromone traps, they may also provide information of a pest's general biology. Because stored-product and material pests must be considered neozoons in most parts of the world, their occurrence in natural habitats indicates a species' autecological capability to successfully compete with native species and to become faunistically established in non-synanthropic environments outside their zoogeographic origin. This review focuses on the use of pheromone traps for monitoring in outdoor situations.
A number of very relevant processes for protection and reconstruction of buildings can be supported by controlled heating: elimination of pests without using hazardous Chemicals, drying and decontamination of timber and many other building materials. For this purpose, radio-frequency (RF) dielectric heating is an advantageous Option because the materials and structures can be heated directly by energy absorption in the volume, homogeneously and, if required, relatively fast.
Compared to microwaves, the penetration depths are usually much larger and the flexibility with respect to different materials is wider. Namely, heating can also be realized for dry materials because the dielectric loss is as not closely related to the presence of water as for microwave applications.
Subterranean termites moving in the peripheral tubular network of their foraging area need to distinguish the trail direction. In a natural gallery or tunnel network of Reticulitermes flavipes the branches at bifurcations generally have an acute angle between them. the resulting obtuse angle from the main trail leading into a branch is preferred by commuting termites. In experiments with artificial gallery forks, termites returning from a food source only neglected the trail junction leading to the nest and preferred the trail to a second food source if the angle to the nest was acute. A right angle to the nest was preferred over a straight way leading to a second food source. This preference to the nest increased when the three branches at trifurcations were arranged equi-angular. This preferred orientation could be attributed to attracting odours from close-by gallery material. Additionally, R. flavipes moved more slowly towards a food source consisting of pine wood than on the way back to the nest, as was shown in artificial one-way galleries. However, the significance of this speed difference remains uncertain because the speed of a homing termite in an artificially reversed trail does not slow down to the speed of a food foraging termite.
Bekämpfungsverfahren gegen Organismen, die in Deutschland Bauholz wirtschaftlich bedeutend schädigen können, sind in der DIN 68800 Teil 4: 02/2012 „Holzschutz - Bekämpfungs- und Sanierungsmaßnahmen gegen Holz zerstörende Pilze und Insekten“ regeltechnisch zusammengefasst und gewichtet. Dabei wird je nach Verfahren und Schadorganismus zwischen Regelsanierung und Sondermaßnahmen unterschieden.
So wird z. B. bei den thermischen Maßnahmen im Sinne der Norm das sogenannte Heißluftverfahren gegen Insekten als Regelsanierung bezeichnet, wogegen es gegen Pilze nicht als solche ausgewiesen ist. Gleiches gilt für elektrophysikalische Verfahren sowohl gegen Pilze als auch gegen Insekten. Dies begründet sich dadurch, dass bei Erstellung der Norm Zweifel bezüglich weitgehender Allgemeingültigkeit und Praxisbewährtheit elektrophysikalischer Verfahren, wie sie zur Erwärmung des befallenen Holzes eingesetzt werden, bestanden. Somit erklärt sich auch, dass die Rahmenbedingungen einer erfolgreichen Bekämpfung mittels z. B. Mikrowellen denen des Heißluftverfahrens gleichgesetzt wurden, nämlich die vollständige Erwärmung des befallenen Holzbauteils auf eine Mindesttemperatur von 55° C für eine Dauer von mindestens 60 min. Die physikalisch-chemischen Vorteile der zeitgleichen Wärmegeneration im gesamten Holzkörper durch elektromagnetische Felder im Vergleich zum sukzessiven Wärmeeintrag durch Konduktion fanden keine Berücksichtigung.
Drei grundlegend verschiedene Ansätze für Umweltsimulation werden an Beispielen illustriert:
(i) Ganzheitlicher Ansatz - Nachstellen von Umweltmilieus im Labor
Ziel ist hier das Nachstellen von (kombinierten) Umweltbedingungen im Labor; die Umweltparameter werden mit all ihren Wechselwirkungen aufgebracht.
Hauptnutzen ist eine gegenüber der natürlichen Beanspruchung erhöhte Reproduzierbarkeit der Umweltbedingungen. Hat man sein Laborsetup entwickelt, ist es auf verschiedene Materialien anwendbar.
Unter solchen Laborbedingungen ermittelte Lebensdauern sind dabei nicht auf die typischerweise sehr variablen Real-Umweltbedingungen übertragbar.
(ii) Parametrisierter Ansatz - Ermittlung einzelner Materialempfindlichkeiten
Hierbei werden im Labor die Wirkungen separater Umweltparameter auf Materialien nachgestellt. Für eine solche Separation der Einflussfaktoren ist insbesondere die Aufschlüsselung möglicher Wechselwirkungen der Umwelt-parameter (z.B. Mikroklima an bestrahlten Oberflächen) erforderlich. Einzelne (meist Alterungs-) Empfindlichkeiten können qualitativ nachgewiesen werden oder sogar – als Beanspruchungs-Wirkungs-Funktionen – quantifiziert werden, was einen wesentlichen Schritt in Richtung der Digitalisierung der Material¬prüfung darstellt. Insbesondere ist dann auch eine Lebensdauer-vorhersage für vorgegebene Zeitreihen der Beanspruchungs¬parameter umsetzbar.
(iii) Rückwirkungen auf die Umwelt
Umweltbeanspruchungen können zur Freisetzung von Schadstoffen in die Umwelt führen. Durch die Nachstellung kritischer, aber realitätsnaher Einsatzszenarien kann die Menge an freigesetzten Substanzen abgeschätzt werden.
Egal, welcher Ansatz verfolgt wird – ein Vergleich mit der oder einer Real-beanspruchung ist unerlässlich, ebenso wie die Messdatenaufzeichnung (data logging) aller potenziell relevanten Beanspruchungsparameter während dieser Realbeanspruchung.
Obwohl die naturnahe Umwelt – sowohl in der BAM als auch bei der GUS – gegenüber der technischen Umwelt eher untergeordnet auftritt, werden zur Illustration Beispiele aus der naturnahen Umwelt verwendet.
Larvae and adults of Korynetes caeruleus (de Geer 1775) (Coleoptera: Cleridae) were collected from old churches and reared in the laboratory on Anobium punctatum (de Geer 1774) (Coleoptera, Ptinidea, formerly Anobiidae). Breeding success of K. caeruleus was low, but basic parameters of this species’ developmental cycle were identified. At 21 °C and 75 % relative humidity and a four-month cold period at 4 °C, the development of K. caeruleus from egg to adult appearance lasted 2 years. The pupal stage may be reached and completed after one and a half years. Feeding on larvae of A. punctatum by larvae of K. caeruleus was observed and consisted of a combination of sucking haemolymph and consuming body parts. The sickle-like mandibles of larvae of K. caeruleus penetrate the cuticle of prey larvae followed by pumping and sucking body movements. Adult beetles of A. punctatum were not attacked by K. caeruleus larvae. Feeding behavior of adult K. caeruleus was not investigated.
Die Normenreihe DIN 68800 ist Ende der 2000er Jahre komplett überarbeitet worden. Der Kommentar bietet den interessierten Kreisen der Bauaufsicht, des Holzbaus, der Holzschutzmittelindustrie, der Wissenschaft, den Prüfinstituten, der Sägeindustrie, den Umweltverbänden, den Verbrauchern, den Schädlingsbekämpfern und Architekten wertvolle Hilfen bei der Anwendung und Interpretation der Norm.
The tropical environment of Sri Lanka accelerates bio-deterioration of cultural objects. Termites are one of the most damaging insect pests destroying the cellulose components of historical artifacts. Herbal extracts obtained from resin of Vateria copallifera (Retzius) Alston and seeds of Madhuca longifolia (Konig) Macbride have been used for centuries to preserve e.g. palm leaf manuscripts from insect attack. Herbal extractions of these traditional products for palm leaf manuscript were tested for their effect against the termite species Coptotermes formosanus Shiraki, 1909. Natural and artificial aged herbal extractions were tested to obtain a repellent index. Resin oil of V. copallifera caused slightly higher repellencies than M. longifolia. Artificially aged samples produced lower repellencies than naturally aged samples. The results indicate that the active ingredients are volatile. The potential for barrier treatment was tested only with V. copallifera. Tunnelling-behavior of C. formosanus workers through sand in the presence of V. copallifera resin oil was largely reduced.
Wood-destroying pests such as Anobium punctatum and Xestobium rufovillosum cause damage to art and cultural objects as well as to buildings. Monitoring population dynamics of pest species as well as of their naturally occurring counterparts are an essential part in the development of biological control measures as alternatives to conventional wood protection. Therefore, both the dispersal and homogeneity of pest and beneficial insect populations across multiple sites and buildings were investigated in the present study using DNA barcoding. Specifically, beetles of Anobium punctatum (de Geer 1774) (Coleoptera, Ptinidae), Xestobium rufovillosum (de Geer, 1974) (Coloeptera, Ptinidae), and Korynetes caeruleus (de Geer 1775) (Coleoptera, Cleridae) were collected from buildings at four different sites in Mecklenburg-Western Pomerania, North-Eastern Germany. DNA analysis was performed using mitochondrial cytochrome c oxidase subunit I (COI). For A. punctatum, low base pair variability was found in the gene segment studied (4-5 SNPs) within one building (Greven) and between four spatially separated sites. Conversely, in X. rufovillosum, the sequences from two sites studied were homogeneous within a site but differed between locations by nine base pair positions (SNPs). The main result of this study is that the pests A. punctatum and X. rufovillosum showed a higher variability in the investigated gene segment than the natural counterpart K. caeruleus.
Die Bewertung der Dauerhaftigkeit von Holz und Holzprodukten ist ein zentrales Thema im Holzschutz. Es wird zwischen einer natürlichen und einer herbeigeführten Dauerhaftigkeit unterschieden. Die Norm DIN EN 350 trägt beiden Richtungen Rechnung. Die Anwendung der Norm wird in vielen Fällen aber nicht korrekt durchgeführt. Schwachstellen werden diskutiert.
Chemical modification of wood applying benzotriazolyl-activated carboxylic acids has proven to be a versatile method for the durable functionalization of its lignocellulosic biopolymers. Through this process, the material properties of Wood can be influenced and specifically optimized. To check the scope and limitations of this modification method, various benzamide derivatives with electron-withdrawing (EWG) or electron-donating (EDG) functional groups in different positions of the aromatic ring were synthesized and applied for covalent modification of Scots pine (Pinus sylvestris L.) sapwood in this study. The bonded amounts of substances (up to 2.20 mmol) were compared with the reactivity constants of the Hammett equation, revealing a significant correlation between the modification efficiency and the theoretical reactivity constants of the corresponding aromatic substitution pattern. The successful covalent attachment of the respective substituted benzamides was proven by attenuated total reflection infrared (ATR-IR) spectroscopy, while the stability of the newly formed ester bond was proven in a standardized leaching test.
Frass (fine powdery refuse or fragile perforated wood produced by the activity of boring insects) of larvae of the European house borer (EHB) and of drywood termites was tested as a natural and novel feedstock for 3D-printing of wood-based materials. Small particles produced by the drywood termite Incisitermes marginipennis and the EHB Hylotrupes bajulus during feeding in construction timber, were used. Frass is a powdery material of particularly consistent quality that is essentially biologically processed wood mixed with debris of wood and faeces. The filigree-like particles flow easily permitting the build-up of woodbased structures in a layer wise fashion using the Binder Jetting printing process. The Quality of powders produced by different insect species was compared along with the processing steps and properties of the printed parts. Drywood termite frass with a Hausner Ratio HR = 1.1 with ρBulk = 0.67 g/cm3 and ρTap = 0.74 g/cm3 was perfectly suited to deposition of uniformly packed layers in 3D printing. We suggest that a variety of naturally available feedstocks could be used in environmentally responsible approaches to scientific material sciences/additive manufacturing.
The clothes moth Tineola bisselliella is one of a few insects that can digest keratin, leading to the destruction of clothing, textiles and artwork. The mechanism of keratin digestion is not yet fully understood, partly reflecting the lack of publicly available genomic and transcriptomic data. Here we present a high-quality gut transcriptome of T. bisselliella generated from larvae reared on keratin-rich and keratin-free diets. The overall transcriptome consists of 428,221 contigs that were functionally annotated and screened for candidate enzymes involved in keratin utilization. As a mechanism for keratin digestion, we identified cysteine synthases, cystathionine β-synthases and cystathionine γ-lyases. These enzymes release hydrogen sulfite, which may reduce the disulfide bonds in keratin. The dataset also included 27 differentially expressed contigs with trypsin domains, among which 20 were associated with keratin feeding. Finally, we identified seven collagenases that were upregulated on the keratin-rich diet. In addition to this enzymatic repertoire potentially involved in breaking down keratin, our analysis of poly(A)-enriched and poly(A)-depleted transcripts suggested that T. bisselliella larvae possess an unstable intestinal microbiome that may nevertheless contribute to keratin digestion
Viele Menschen erfreuen sich an Schmetterlingen. Besonders die farbfrohen Tagfalter lösen angenehme Gefühle aus. In der kulturellen Entomologie haben Schmetterlinge daher einen hohen Stellenwert, so auch in der schöngeistigen Literatur. Eine aktuelle stichprobenartige Untersuchung von 54 Büchern der deutschsprachigen Belletristik mit Insektenbezug im Titel oder auf dem Cover zeigte, dass sich zwei Drittel von ihnen des Schmetterlingnarrativs bedienten. Die folgende Analyse setzte das Ergebnis in einen historischen Bezug zur Verwendung von Insektenvorbildern in der Unterhaltungsliteratur und in Autorenbiografien. Die besondere Stellung der Schmetterlinge wird dabei geschichtlich als Relikt einer kulturellen Genese mit mythologisch-religiösen Wurzeln interpretiert. Im antiken Griechenland wurde die Bezeichnung Psyche mit bewusster Doppelbedeutung für Schmetterling und Seele verwendet. Im Hellenismus wurden die Seele und Seelenwesen wie z. B. die Daimons (Genien) oftmals mit Schmetterlingsflügeln dargestellt. Auch in den levantinischen Religionen wurden einzelne Gottheiten und Schutzgeister mit Flügeln nach Schmetterlingsart, jedoch aus Vogelfedern bestehend, abgebildet. Mit der Entstehung und Verbreitung der monotheistischen Lehren gingen viele dieser geflügelten Glaubenswesen dann in die Engelschöre über. Auch wenn die Flügel der Engel letztendlich wahrscheinlich von denen der Vögel abzuleiten sind, bleibt ein starker emotionaler Bezug zu den Schmetterlingen, der weit über den rein ästhetischen ausstrahlt.
Kulturelle Beziehungen zwischen Menschen und Insekten werden durch die kulturelle Insektenkunde (Entomologie) beschrieben. Es handelt sich dabei um eine junge Wissenschaftsdisziplin des ausgehenden 20. Jahrhunderts. Sie erforscht die vielfältigen Weisen, in denen Insekten unsere Kultur beeinflussen.
Aus pragmatischen Gründen gliedert sich die kulturelle Entomologie in Teilbereiche wie Schöne Literatur, Sprache, Musik, Theater, Film, Architektur, Symbolismus, Philosophie, Religion, Unterhaltung u.v.m. Ein Streifzug durch die kulturelle Entomologie kann daher nachvollziehbarerweise nicht den Anspruch der Vollständigkeit erfüllen. Zu inhaltsreich sind die Teilbereiche und zu facettenreich sind die Einflüsse aus der Welt der Insekten. So hat einerseits jeder Kulturkreis seine eigene permanent im Wandel begriffene (Kultur)-Geschichte und anderseits sind weit mehr als eine Million Insektenarten bekannt, auch wenn natürlich längst nicht alle davon eine soziokulturelle Relevanz besitzen. Neben der Biene z. B. treten farbenfrohe Schmetterlinge aber auch Fliegen sehr häufig in Erscheinung.
Der Vortrag wird einige berühmte klassische aber auch weniger bekannte gegenwärtige Beispiele einzelner Teilbereiche diskutieren. Der Einfluss unseres westlich-europäisch geprägten Kulturkreises mit seinen antik mediterranen Wurzeln ist dabei unverkennbar. Beantwortet wird aber auch die Frage, warum sich Schädlinge wie Kleidermotten oder Termiten auf der Gästeliste eines Museums, dem eigentlichen Ort des Erhaltens und Bewahrens, befanden.
Holzschutz gegen Insekten
(2016)
Invasoren im Kleiderschrank
(2016)
Die thermische Bekämpfung von Holzschädlingen erfordert wegen der geringen Wärmeleitfähigkeit von Holz lange Behandlungszeiten und kann zur Rissbildung führen. Hier wurde die thermische Behandlung mittels Radio- und Mikrowellen untersucht. Die direkte, dielektrische Erwärmung hat den Vorteil einer größeren Homogenität der Aufheizung. Die mit Radiowellen erzielten Temperaturprofile waren homogener als die mit Mikrowellen realisierten. Untersuchungen zeigten, dass die Abtötung nicht auf die direkte Einwirkung von elektromagnetischen Feldern, sondern auf die Temperaturerhöhung zurückzuführen ist.-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------Thermal pest control requires long treatment times due to the low thermal conductivity of wood and may lead to the formation of cracks. Here, the thermal treatment with radio waves as well as microwaves has been studied. The direct dielectric heating has the advantage of a good homogeneity. The obtained temperature profiles for radio waves were more homogeneous compared to microwaves. Detailed studies showed that elimination of pests was not related to the application of the electromagnetic field itself, but due to the temperature increase.
"Hausbock, Holzwurm und Kompanie - Wissen wir wirklich schon Alles über die üblichen Verdächtigen"
(2014)
Pheromone im Vorrats- und Materialschutz - Erfahrungen aus über 35 Jahren praktischen Einsatzes
(2010)
Biogenic impact on materials
(2011)
Materials as constituents of products or components of technical systems rarely exist in isolation and many must cope with exposure in the natural world. This chapter describes methods that simulate how a material is influenced through contact with living systems such as microorganisms and arthropods. Both unwanted and desirable interactions are considered. This biogenic impact on materials is intimately associated with the environment to which the material is exposed (Materials-Environment Interaction, Chap. 15). Factors such as moisture, temperature and availability of food sources all have a significant influence on biological systems. Corrosion (Chap. 12) and wear (Chap. 13) can also be induced or enhanced in the presence of microorganisms. Section 14.1 introduces the categories between desired (biodegradation) and undesired (biodeterioration) biological effects on materials. It also introduces the role of biocides for the protection of materials. Section 14.2 describes the testing of wood as a building material especially against microorganisms and insects. Section 14.3 characterizes the test methodologies for two other groups of organic materials, namely polymers (Sect. 14.3.1) and paper and textiles (Sect. 14.3.2). Section 14.4 deals with the susceptibility of inorganic materials such as metals (Sect. 14.4.1), concrete (Sect. 14.4.2) and ceramics (Sect. 14.4.3) to biogenic impact. Section 14.5 treats the testing methodology concerned with the performance of coatings and coating materials. In many of these tests specific strains of organisms are employed. It is vital that these strains retain their ability to utilize/attack the substrate from which they were isolated, even when kept for many years in the laboratory. Section 14.6 therefore considers the importance of maintaining robust and representative test organisms that are as capable of utilizing a substrate as their counterparts in nature such that realistic predictions of performance can be made.
Alarm response triggered by physical stimuli is wide spread in termites but executed in several different behavioural patterns. The drywood and subterranean termite species tested in this study differed significantly by either head-drumming or jerking when stimulated by light, air-flow, or air borne Sound stimuli. Nevertheless, differences may have a common evolutionary base. Repetitive stimuli of the same quality led to reduced responses over time, which was interpreted as habituation behaviour, a simple form of learning. Adaptation as alternative explanation was ruled out because when termites were subjected with a dis-habituation-stimulus followed by the original stimulus full Response occurred again to this stimulus.
Standardized test methods by which the efficacies of conventional Chemical wood preservatives against insects determine their toxic effects against larvae of wood boring beetles or their feeding prevention by termites. Although alternative control strategies to the application of biocides exist, such as interference with insect behavior during mating or when searching for suitable breeding and feeding sites, their acceptance, too, depends on efficacy evaluation. This is why new test set ups are needed which take behavior modifying control strategies into account. This paper will demonstrate how new laboratory tests must be designed or how existing Standards can be altered to reliably interpret insect behavior including its successful manipulation in a standardized format.
In 2012, the house Ianghorn beetle (Hylotrupes bajulus) breeding culture of the Federal Institute for Materials Research and Testing (BAM) in Berlin produced a female beetle with a unique malformed right antenna. Distal to the pedical, the flageilum was bifurcated into a Ionger branch with the typical 9 flageilomeres and a shorter branch with only 4 flageilomeres. The left antenna of the same animal was normally developed with 11 segments (scape, pedical and 9 flageiiomeres). The malformation is interpreted as "Bruchdreifachbildung" (triplication of structures after damage during metamorphosis).
Etymologically, nature and culture are considered to be extreme opposites and the doctrines behind them-the natural sciences and the humanities-seldom overlap. However, at all times nature has influenced culture in many different ways. Cultural entomology describes these influences from the entomological side of view. Insects had and still have an enormous impact on all parts of the human intellectual life including language, literature, music, arts, philosophy, religion, and so on. Additionally, insects have changed the course of history more than once.
The following overview presents well-known and less well-known examples of how insects influenced human work. Certainly, some insects like bees, flies and butterflies are more dominant than others in this respect, according to their economic importance, their overall synanthropic presence or simply their beauty.
Wood borers in structural timber - European regulations for their control and can TTIP comply?
(2016)
The control of wood boring beetles in structural timber is uniformly regulated in the European Union. Registration and authorization of wood preservatives for the European market has to follow a regulated procedure as described under the Biocidal Product Directive “EU 528/2012”. Non-biocidal measures of control such as by physical means are regulated individually by each member state on the national level. The Biocidal Product Directive demands voluminous data sets for product identity, environmental and health risk assessments, proof of efficacy, and management strategies to avoid the development of resistance, just to name the most important.
With TTIP (Transatlantic Trade and Investment Partnership) on the horizon, it must be expected that wood preservatives coming from the North American Market to Europe and vice versa will mutually be recognized in the future, despite existing differences in registration requirements. The presentation will focus on major differences in standard efficacy tests for wood preservatives with claims for beetle control, which, next to others, have to be passed before product placement on the respective market. Desirable needs for future harmonizing will be identified in order to overcome consumers distrust on each side of the partners.
A short natural and cultural history of the webbing clothes moth (Tineola bisselliella). It is generally accepted that the natural habitats of most pest insects can be found outside the synanthropic environment in layers of leaf litter, under bark, as well as in rodent or bird nests. Indeed, most of the common fabric pests have been reported as being facultative nidicolous. Therefore, infestation of commodities by pest insects out of these reservoirs is one possibility to be considered. However, the likelihood of a pest´s occurrence and survival outside of the synanthropic habitat largely depends on its ecological potential and competitiveness against other species of the same ecological guild. Some pest species are rarely found in wild habitats, especially in those regions where they are not native and where they have been introduced by man.
The fabric pest Tineola bisselliella serves as a good example. Most likely originating from Central or Southern Africa, this insect was introduced into Europe probably not earlier than the late 18th century. Being more tolerant to dry environments than other fabric pests, its economical importance increased during the 20th century when the indoor climate changed because of central heating systems. Its occurrence in outdoor natural habitats must be regarded as accidental. Reported finds of webbing clothes moth larvae in bird nests e. g. have been largely overstated in the literature. Tineola bisselliella should be regarded as an invasive and eusynanthropic species in most parts of the world.
Normgerechte Ausführung resultiert in Qualität, aber sie ist nicht allein ein Garant auch für hohe Qualität. Hierfür sind begleitend immer auch nachgeordnete Richtlinien wie z. B. spezifische Gütekriterien zu erfüllen. Der Vortrag erklärt die Normungsarbeit auf nationaler und internationaler Ebene und schildert die Stärken aber auch die Schwächen bei der Erstellung von Normen. Dabei ist die Konsensbildung zwischen unterschiedlichen interessierten Kreisen mit deren Partikularinteressen oftmals ein Hindernis, das aber über Zusatzvereinbarungen und der Norm nachgeordneten Regeln überwunden werden kann.
Infections with multi-resistant Gram negative pathogens are a major threat to our health system. In order to serve the needs in antibiotics development we selected untapped bioresources and implemented high throughput approaches suitable for the discovery of strains producing antibiotics with anti-Gram negative activity.
Our approaches rely on the hypothesis that Termite associated bacteria are likely to produce potent antibiotics to defend their hosts against entomopathogenic microorganisms. Termite nests and guts harbor suitable, highly diverse microbiomes in which bacterial taxa are present known to potentially produce natural compounds. In
a first step the diversity of Coptotermes species nest microbiomes was assessed carefully by using 16S rDNA amplicon sequencing on the Illumina MiSeq platform and nest material was selected to retrieve viable cells by using Nycodenz density gradient centrifugation. In order to analyze the diversity of the culturable termite nest microbiome, bacterial cells were either distributed in 384-well plates
(approach 1) or encapsulated in small spheric agarose beads by an high throughput microfluidics technique (approach 2). Cultures obtained from approach 1 were scaled-up in 96-well Duetz-systems for characterization of diversity and for rapid supernatant screening using the bioluminescence-labeled E. coli pFU166. The generated
droplets of approach 2 simultaneously received a small population of GFP-tagged Gram negative screening cells and were sorted for low fluorescence using FACS. After elimination of redundancy we performed a fast scale-up of active strains.
Implementation of this pipeline allows us to prioritize antibiotics producing strains in a ultra-high throughput fashion and by cultivation of broad diversity in our approches.
Microbial symbionts of insects provide a range of ecological traits to their hosts that are beneficial in the context of biotic interactions. However, little is known about insect symbiont-mediated adaptation to the abiotic environment, for example, temperature and humidity. Here, we report on an ancient clade of intracellular, bacteriome-located Bacteroidetes symbionts that are associated with grain and Wood pest beetles of the phylogenetically distant families Silvanidae and Bostrichidae. In the saw-toothed grain beetle Oryzaephilus surinamensis, we demonstrate that the symbionts affect cuticle thickness, melanization and hydrocarbon profile, enhancing desiccation resistance and thereby strongly improving fitness under dry conditions. Together with earlier observations on Symbiont contributions to cuticle biosynthesis in weevils, our findings indicate that convergent acquisitions of bacterial mutualists represented key adaptations enabling diverse pest beetle groups to survive and proliferate under the low ambient humidity that characterizes dry grain storage facilities.
Zu den unerwünschten Gästen im Museum oder im Haushalt gehört zweifelsohne die Kleidermotte Tineola bisselliella. Es sind die Larven dieses Kleinschmetterlings, die die Schäden verursachen. Neben der konventionellen Schadensabwehr besteht die Möglichkeit, Schlupfwespen zur Bekämpfung der Larven einzusetzen. Der Vortrag rekonstruiert die Natur- und Kulturgeschichte der Kleidermotte anhand ökologischer Studien und historischen Indizien.
Second occurrence of aberrant antenna in house longhorn beetle Hylotrupes bajulus (Coleoptera: Cerambycidae) in the F3 generation. In 2016, the house longhorn beetle (Hylotrupes bajulus) breeding culture of the Federal Institute for Materials Research and Testing (BAM) in Berlin produced a second female beetle with a unique malformed right antenna similar to the one previously reported. As in the first case the flagellum following the pedical was bifurcated. This time, however, both branches were of similar length with 7 and 8 flagellomeres, respectively. The left antenna was normally developed with 11 antennal segments (scape, pedicel and 9 flagellomeres). This second female stands as F3-generation in direct maternal line to the previous one. A heritable cause for the malformation is likely.
Rare occurrences of termites in Germany. Termites are typical elements of the tropical and subtropical insect fauna. In Europe, their most northern natural range is southern France, Italy and the South-Balkan region. Only occasionally are termites found in Germany. Their occurrence is always very closely associated with the synanthropic environment. Drywood termites like Cryptotermes brevis or Kalotermis flavicollis were accidentally imported with furniture, wooden artefacts or plant material into homes or indoor arboretums. Similar pathways of termite introduction are described for Coptotermes gestroi and Reticulitermes sp. into tropical botanical gardens and tropical theme parks. Although termites were introduced to Germany several times, successful spreading or long term establishment never occurred due to climatic barriers, namely cold winter temperatures. Only Reticulitermes flavipes formed sustainable colonies in the city of Hamburg for several decades. Originating from the eastern United States of America, this species was introduced in the 1930s with infested wood through the sea port. Small subterranean colonies could survive the winter in areas where pipes of the central heating system kept the ground from freezing. Control efforts of this potentially invasive species of economic importance started early on but failed until modern bait techniques were applied in the year 2000. Currently, termites have not been detected in Hamburg for the last five years.
The evolutionary success of termites has been driven largely by a complex communication system operated by a rich set of exocrine glands. As many as 20 different exocrine organs are known in termites. While some of these organs are relatively well known, only anecdotal observations exist for others. One of the exocrine organs that has received negligible attention so far is the labral gland. In this study, we examined the structure and ultrastructure of the Labrum in soldiers of 28 termite species. We confirm that the labral gland is present in all termite species, and comprises two secretory regions located on the ventral side of the labrum and the dorso-apical part of the hypopharynx. The Labrum of Neoisoptera has a hyaline tip, which was secondarily lost in Nasutitermitinae, Microcerotermes and species with snapping soldiers. The epithelium of the gland generally consists of class 1 secretory cells, with an addition of class 3 secretory cells in some species. A common feature of the secretory cells is the abundance of smooth endoplasmic reticulum, an organelle known to produce lipidic and often volatile secretions. Our observations suggest that the labral gland is involved in communication rather than defence as previously suggested. Our study is the first to provide a comprehensive picture of the structure of the labral gland in soldiers across all Termite taxa.
Aim of study: In this study, natural durability of some domestic and foreign wood species against Hylotrupes bajulus and Anobium punctatum larvae were tested on laboratory scale
Area of study: This study was conducted at Department of Forest Products Engineering in Duzce University, Turkey and Federal Institute for Materials Research and Testing (BAM), Germany.
Material and Methods: Scotch pine (Pinus sylvestris), fir (Abies nordmanniana), spruce (Picea orientalis), cedar (Cedrus libani), poplar (Populus tremula) and beech (Fagus orientalis) woods were used to test H. bajulus larvae (EN 46-1). Alder (Alnus glutinosa), oak (Quercus cerris), poplar (Populus tremula), beech (Fagus orientalis), maple (Acer carpinifolium), ash (Fraxinus angustifolia), teak (Tectona grandis), ayous (Triplochiton scleroxylon), movingui (Distemonanthus benthamianus), dahoma (Piptadeniastrum africanum), iroko (Chlorophora excelsa), bubinga (Guibourtia tessmannii) and sapele (Entandrophragma cylindiricum) woods were used for A. punctatum larvae (EN 49-1). At the end of the experiment, the mortality rates of the larvae were determined and the size and weights of the surviving larvae were measured.
Main results: F. orientalis and C. libani were found to be the most resistant wood species against H. bajulus larvae while A. nordmanniana was the least resistant. All tropical wood species and oak and maple from domestic wood species showed 100% mortality rate therefore found to be the most resistant against A. punctatum larvae. The most vulnerable wood species was found to be alder with a 35% mortality.
Research highlights: while F. orientalis, C. libani, and P. tremula were found the most resistance wood species against H. bajulus, P. sylvestris and A. nordmanniana were determined as most vulnerable. All tropical wood species and two domestic species (Q. cerris and A. carpinifolium) showed the highest mortality rate as 100%. The least durable domestic wood was determined as alder.
The importance of soldiers to termite Society defence has long been recognized, but the contribution of soldiers to other societal functions, such as colony immunity, is less well understood.
We explore this issue by examining the role of soldiers in protecting nestmates against pathogen infection. Even though they are unable to engage in grooming behaviour, we find that the presence of soldiers of the Darwin termite, Mastotermes darwiniensis, significantly improves the survival of nestmates following entomopathogenic infection.
We also show that the copious exocrine oral secretions produced by Darwin termite soldiers contain a high concentration of Proteins involved in digestion, chemical biosynthesis, and immunity. The oral secretions produced by soldiers are sufficient to protect nestmates against infection, and they have potent inhibitory activity against a broad spectrum of microbes. Our findings support the view that soldiers may play an important role in colony immunity, and broaden our understanding of the possible function of soldiers during the origin of soldier-first societies.
The evolutionary success of insects is promoted by their association with beneficial microbes that enable the utilization of unusual diets. The synanthropic clothing moth Tineola bisselliella provides an intriguing example of this phenomenon. The caterpillars of this species have adapted to feed on keratin-rich diets such as feathers and wool, which cannot be digested by most other animals and are resistant to common digestive enzymes. Inspired by the hypothesis that this ability may be conferred by symbiotic microbes, we utilized a simple assay to detect keratinase activity and a method to screen gut bacteria for candidate enzymes, which were isolated from feather-fed larvae. The isolation of DNA from keratin-degrading bacterial strains followed by de novo genome sequencing resulted in the identification of a novel bacterial strain related to Bacillus sp. FDAARGOS_235. Genome Annotation identified 20 genes with keratinase domains. Proteomic analysis of the culture supernatant from this gut bacterium grown in non-nutrient buffer supplemented with feathers revealed several candidate enzymes potentially responsible for keratin degradation, including a thiol-disulfide oxidoreductase and multiple proteases. Our results suggest that the unusual diet of T. bisselliella larvae promotes their association with keratinolytic microorganisms and that the ability of larvae to feed on keratin can at least partially be attributed to bacteria that produce a cocktail of keratin-degrading enzymes.
Timber is constantly exposed to environmental influences under outdoor conditions which limits its Lifetime and usability. In order to counteract the damaging processes caused by insects, we have developed a novel and more environmentally friendly method to protect wood materials via covalent modification by organic insecticides. Starting with an important class of synthetic insecticides which are derived from the natural insecticide nicotine, various new carboxylic acid derivatives of imidacloprid were made accessible. These activated neonicotinoids were utilized for the chemical modification of wood hydroxy groups. In contrast to conventional wood preservation methods in which biocides are only physically bound to the surface for a limited time, the covalent fixation of the preservative guarantees a permanent effect against wood pests, demonstrated in standardized biological tests. Additionally, the environmental interaction caused by non-bound neonicotinoids is significantly reduced, since both, a smaller application rate is required and leaching of the active ingredient is prevented. By minimizing the pest infestation, the lifetime of the material increases while preserving the natural appearance of the material.
Fluorides are well-known as wood preservatives. One of the limitations of fluoride-based wood preservatives is their high leachability. Alternative to current fluoride salts such as NaF used in wood protection are low water-soluble fluorides. However, impregnation of low water-soluble fluorides into wood poses a challenge. To address this challenge, low water-soluble fluorides like calcium fluoride (CaF2) and magnesium fluoride (MgF2) were synthesized as nanoparticles via the fluorolytic sol−gel synthesis and then impregnated into wood specimens. In this study, the toxicity of nano metal fluorides was assessed by termite mortality, mass loss and visual analysis of treated specimens after eight weeks of exposure to termites, Coptotermes formosanus. Nano metal fluorides with sol concentrations of 0.5 M and higher were found to be effective against termites resulting in 100% termite mortality and significantly inhibited termite feeding. Among the formulations tested, the least damage was found for specimens treated with combinations of CaF2 and MgF2 with an average mass loss less than 1% and visual rating of “1”. These results demonstrate the efficacy of low water-soluble nano metal fluorides to protect Wood from termite attack.