Filtern
Erscheinungsjahr
- 2011 (10) (entfernen)
Dokumenttyp
Schlagworte
- Synanthropy (2)
- Biologie (1)
- Coptotermes (1)
- Efficacy evaluation (1)
- Evolution (1)
- Habituation (1)
- Head-drumming (1)
- Holzschutz (1)
- IPM (1)
- Incisitermes (1)
Eingeladener Vortrag
- nein (4)
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.
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.
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.
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.