Composition and method for influencing the location of wood-inhabiting beetles
A polymer-based composition using messenger substances targets beetle control by attracting or repelling them to specific areas, addressing the inefficacies of current methods and reducing forest damage.
Patent Information
- Authority / Receiving Office
- AU · AU
- Patent Type
- Applications
- Current Assignee / Owner
- FRIEDRICH SCHILLER UNIV JENA
- Filing Date
- 2024-12-21
- Publication Date
- 2026-07-16
Smart Images
Figure 00000036_0000 
Figure 00000036_0001 
Figure 00000037_0000
Abstract
Description
Composition and method for influencing the location of wood-inhabiting beetles The invention relates to the field of controlling the location of wood-inhabiting beetles using messenger substances, and to compositions suitable for this purpose. With over 380,000 currently known species, beetles (Coleoptera) constitute the largest order within the class Insecta worldwide. Beetles inhabit most environments on earth; practically every organic food source is exploited by beetles. Beetles generally only come to public attention when they affect people's lives. This is most often the case when they appear as pests, nuisances, or even beneficial insects. The storage of food or the cultivation of crops in monocultures occasionally creates favorable conditions for the mass reproduction of certain beetle species. Examples of stored-product pests, primarily found in commercial warehouses, include corn weevils and rice weevils, while the larvae of the flour beetle are frequently found in households. Agricultural pests include the Colorado potato beetle, the pollen beetle, and the western corn rootworm. Many beetles act as plant pests. These infest a wide variety of plants, including trees and deadwood. The native house longhorn beetle (Hylotrupes bajulus) can infest buildings. The beetle's larvae live in structural softwood, for example, in roof trusses. The common furniture beetle (Anobium punctatum), also known as the woodworm, lives in deadwood as well. Examples of tree pests include the Asian longhorned beetle (Anoplophora glabripennis). Among the most significant pests of living wood are bark beetles. These include the European spruce bark beetle (Ips typographus), which can cause extensive damage, particularly in managed spruce forests. However, bark beetles are also dangerous in natural forests. For example, the mountain pine beetle (Dendroctonus ponderosae) has considerable destructive potential. Damage caused by beetle infestations has significant economic repercussions for agriculture and forestry. Many beetles play an important role in the natural ecosystem. Humans also benefit from certain species. Key examples include predatory beetles such as ground beetles, rove beetles, and, in particular, ladybirds. These species devour harmful insects, mites, and slugs in agricultural and forestry settings. Certain ladybird species are mass-reared for use against agricultural pests. These beetles, which feed on aphids and scale insects, are also beneficial in gardens. Many beetles communicate using chemical messenger substances. These substances influence the behavior of individuals within a population. Such messenger substances are chemical compounds that facilitate signal transmission or chemical communication. They can exert their effects within a single organism, or between individuals of the same or different species. Messenger substances belong to a wide variety of chemical compound classes. Many are peptides, steroids, amino acid derivatives, isoprene derivatives, terpene derivatives, aldehydes (such as benzaldehyde or salicylaldehyde), or acids (such as benzoic acid). The following description of the invention focuses on the example of the bark beetle. However, the concept behind this invention can readily be applied to other woodinhabiting beetles that communicate via chemical messenger substances. The bark beetle (known in Germany primarily as the "European spruce bark beetle" when it infests spruce trees (there are currently over 6,000 known bark beetle species, all subspecies of weevils)) is causing extreme losses of forest area worldwide. Since spruce has been planted extensively as a monoculture, particularly in Central Europe for about 200 years, there is currently an intense infestation, especially in the Harz Mountains, the Ore Mountains, and the Bavarian Forest, but also now in Austria, Italy, and the Czech Republic. Due to climate change (warming, less precipitation, hurricanes with large amounts of damaged timber), this development has increased almost exponentially in the last 20 years. Especially in areas with difficult-to-access forests (e.g., on the steep slopes of the Alps), there is almost no way to remove the damaged timber in time to prevent the further spread of the bark beetle. However, the forests in the Alps have a crucial function as protective forests (protected forests). Without forests, billions of dollars would have to be invested to prevent mudslides, avalanches or rockfalls, to keep valleys accessible and to protect the people living in them. One measure used to combat bark beetles involves setting up traps. However, traps are not suitable for significantly reducing the bark beetle population; they serve primarily to monitor the extent of the infestation. The use of lethal traps also poses a risk to beneficial insects. Area-wide application of insecticides - such as the approved agents Fastac Forst or Karate Forst - is not an option, as this also kills natural predators of the bark beetle, such as the ant colored beetle. Furthermore, only a very small fraction of the insecticide actually takes effect against the bark beetle (less than 0.1%). The majority of the chemicals drift away during spraying, drip off the bark, are emitted as dust, or are released prematurely. Currently, the most successful method for controlling bark beetle infestations is the removal of all infested timber (see https: / / www.rnd.de / -wissen / borkenkafer-2019-wie-kann-man-ihn-bekampfen-und-warum-ist-er-so-gefahrlich-DKLHHCN4TI43Y3J7PSRR4B4Y-HA.html). If regional removal - including a safety buffer zone - is not fully possible, stockpiles of felled timber are irrigated, or kept moist, or treated with insecticides. However, efficient removal is often impossible in cases of massive infestation or following storm or snow damage, particularly on steep slopes or in areas with limited access roads, such as low mountain ranges and, above all, the Alps and other mountainous regions. Another measure for combating bark beetles involves the use of messenger substances. The bark beetle (as a prime example among other proboscideans, such as the engraver beetle), especially the European spruce bark beetle, which infests Norway spruce in Central Europe, uses a mixture of messenger substances (modified spruce components, pheromones, and other informational chemicals) to attract or repel other bark beetles. A healthy spruce can defend itself against bark beetles by producing resin. However, if spruce trees are weakened by drought, heat, storm / hurricane damage, or snow breakage, their defenses are reduced. If the bark beetle population has increased significantly in a local area, it can successfully infest even healthy spruce trees. Here, as is so often the case in nature, the messenger substance system is employed very intelligently. Initial bark beetles infesting a spruce tree release mixtures of messenger substances that attract other bark beetles (e.g., verbenol, ipsenol, or other terpenes). Even healthy spruce trees can no longer withstand an infestation of hundreds or more bark beetles. Afterward, the infesting beetles switch to a different mode and release new mixtures of messenger substances, indicating that the tree is "full". More bark beetles then infest surrounding spruce trees, forming "nests". A new bark beetle population can then travel distances of 500 meters and, in some cases (with favorable winds), even several kilometers, killing entire sections of forest in the immediate vicinity of the "nests" while simultaneously establishing new "nests" far away. Bark beetles emerge when average air temperatures reach 16.5 °C; however, with sufficient sunlight, emergence can begin locally even earlier. In warm and dry years, up to three bark beetle populations and thus multiple flights can occur, causing incredible damage and devastation, almost like an "atomic bomb". Even in easily accessible regions, conventional forestry cannot remove the infested timber quickly enough - not to mention the low mountain ranges and the Alps. Bark beetle messenger substances also attract natural enemies (such as clerid beetles, braconid wasps, and chalcid wasps; there are approximately 300 natural enemies of the bark beetle). However, these predators cannot keep pace with explosive population surges. Bark beetle messenger substances can be used in traps, but these have only a selective effect. For instance, even the deployment of hundreds of thousands of traps in Norway and Sweden could only slow down bark beetle outbreaks. Depending on the type of trap and the concurrent use of insecticides, the beetles' natural enemies are often killed as well. Furthermore, these messenger substances are highly volatile and evaporate quickly, requiring repeated application. Recent work describes the hanging of "scent bags" to create a "firewall" (see https: / / deutsch.-radio.cz / -tschechische-wissenschaftler-entwickeln-chemiefreie-impraegnierung-gegen-8746509). The authors themselves acknowledge that this approach is unlikely to succeed in vast forest areas. Various strategies and measures have already been employed to combat the bark beetle. However, these are either complex or only partially effective and therefore require further improvement. US 2017 / 0354596 A1 describes a nanoemulsion comprising water as a dispersing agent and a dispersed oil phase. The oil phase contains at least one hydrophobic active ingredient combined with a hydrophobic polymer that may be biodegradable. The dispersed phase also contains an amphiphilic chitosane derivative aggregated by ionic interaction with a fatty acid. These nanoemulsions can be used to produce liquid formulations for medical applications. Halahlah, A. et al. describe in an article entitled “Synthesis and characterization of inclusion complexes of rosemary essential oil with various beta-cyclodextrins and evaluation of their antibacterial activity against Staphylococcus aureus,” J. Drug Deliv. Sci. Tec., Vol. 65, 102660 (2021) the encapsulation of selected oils for antibacterial use. An article by El-Said Azzazy, H.M. et al. titled "Essential oils extracted from Boswellia sacra Oleo Gum resin loaded into PLGA-PCL nanoparticles: Enhanced cytotoxic and apoptotic effects against breast cancer cells" (ACS Omega, Vol. 8, No. 1, pp. 1017-1025, 2023) discloses the effect of selected oils encapsulated in PLGA-PCL nanoparticles on breast cancer cells. In an article titled "Preparation and evaluation of attractive microspheres for control of Agrilus planipennis fairmaire" (J. Environ. Sci. Health B, Vol. 58, No. 2, pp. 131-138, 2023), Y. Y. Li describes the use of selected microspheres to attract a species of beetle. The object of the present invention is to provide a method and a composition suitable therefor for specifically influencing the location of beetles, particularly bark beetles. Research on beetles, such as weevils, especially bark beetles, has provided knowledge about which messenger substances and combinations thereof have which effects at which developmental stage of the larvae / beetles and for which beetle species. This means that the attraction or repulsion of conspecifics or the attraction of predators can be controlled in a targeted manner. Research on polymer-based systems, for example in the form of micelles, vesicles, lipid-solid nanoparticles, lipid-polymer hybrid nanoparticles, nanoparticles, nanospheres, microparticles, microspheres, films, foils, or molded parts, has provided knowledge about which polymers are suitable as carriers for active substances and can release these substances, for example, depending on temperature, humidity, pH value, sunlight, the presence of enzymes, or salts. These polymer-based systems can be co-formulated with other polymeric excipients, inorganic excipients, organic substances such as oils or other low molecular weight substances, as well as biobased substances (such as lignin or cellulose). Knowledge exists within the fields of nanomedicine and pharmacy regarding how mixtures of active substances ("cocktails") can be encapsulated. Furthermore, there exists knowledge concerning when encapsulated substances are released and how a slow release ("retarded release") can be achieved. The present invention combines existing knowledge in an inventive and novel manner to provide a groundbreaking new method for the targeted control of the location of beetles - including their larval stages - and for attracting natural enemies of these beetles. This enables the effective control of bark beetles and related weevils, in particular. The present invention relates to dispersions containing water or biodegradable aprotic-polar solvents as dispersion medium and polymer particles or polymer-based nano- or micro-aggregates as dispersed phase, which particles or aggregates are loaded with at least one messenger substance intended to attract or repel a predetermined wood-inhabiting beetle species or to attract a natural predator of that beetle species and are optionally loaded with further auxiliaries and additives, with the proviso that the polymer or the polymer-based nano- or micro-aggregate exhibits at least one polymer-specific parameter selected from the group consisting of glass transition temperature, crystallite melting temperature, supramolecular interactions, sensitivity to air humidity, or targeted degradability that changes within a predetermined temperature range and / or humidity range and / or upon exposure to light, thereby releasing the messenger substance contained in the particles, or that the polymer or the polymer-based nano- or micro-aggregate is degraded enzymatically, hydrolytically, or photochemically, thereby releasing the messenger substance contained in the particles. For the purposes of this description, dispersions are understood to be heterogeneous mixtures of at least two substances that are insoluble or only minimally soluble in each other or that do not chemically combine with one another. One of these substances is water or a biodegradable aprotic-polar solvent, such as Cyrene. One or more substances are dispersed within this mixture as a so-called dispersed phase. The water or the biodegradable aprotic-polar solvent forms a continuous phase, the so-called dispersion medium. Depending on the state of matter of the dispersion medium and the dispersed phase, the dispersions according to the invention can occur as emulsions (liquid / liquid) or as suspensions (liquid / solid). The dispersed phase can consist of polymer particles or polymer-based nanoparticles or microparticles. The latter include polymer-based micelles, polymerbased vesicles, lipid-solid nanoparticles, lipid-polymer hybrid nanoparticles, polymerbased nanospheres or nanocapsules, as well as polymer-based microspheres or microcapsules. In the context of the present description, "targeted degradability" is understood to mean that the polymer or the polymer-based nano- or micro-aggregate is enzymatically or hydrolytically degradable, such that the active agent contained within the particles or aggregates is released. However, release may also occur upon exceeding the Tg / Tm, upon appropriate swelling, or upon exceeding the LCST (Lower Critical Solution Temperature). After application and evaporation of the dispersion medium, the dispersions according to the invention are generally present on plant parts or on the soil in the form of films, dried polymer particles, or dried polymer-based nano- or microaggregates. For the purposes of this description, "beetles" refers to the adult insects (imago) including their larvae and pupae. The dispersion according to the invention is preferably used to influence the habitat of the For the purposes of this description, "beetles" refers to the adult insects (imago) including their larvae and pupae. The dispersion according to the invention is preferably used to influence the habitat of the adult beetles and / or their predators. The dispersions according to the invention are generally applicable to all wooddwelling beetle species that communicate via messenger substances (i.e., are attracted or repelled by them) or whose predators are attracted by messenger substances. The dispersions according to the invention are preferably used to attract wooddwelling beetles that are beneficial or harmful, or to attract predators of the beetle pests. The dispersions according to the invention are also preferably used to repel wood-dwelling beetles that are harmful. This causes them to be driven specifically to collection points, or it leads to the creation of "firebreaks" that the beetle cannot cross. The dispersions according to the invention may contain multiple messenger substances that attract, for example, beetle pests and simultaneously their natural predators. In addition to the messenger substances, the dispersions according to the invention may also contain other ingredients capable of destroying beetle pests, such as insecticides. The dispersions according to the invention are preferably used to influence the location of beetles living on, attached to, or inside trees, or in the soil area surrounding trees. The tree-dwelling beetles are preferably weevils, particularly preferably bark beetles, and most particularly preferably the spruce bark beetle (Ips typographus), the sixtoothed spruce bark beetle (Pityogenes chalcographus), the large and small pine shoot beetles, the oak sapwood beetle, the striped ambrosia beetle (Trypodendron lineatum), or the black timber bark beetle (Xyleborus germanus). The dispersions according to the invention may be in the form of suspensions (solid particles or aggregates dispersed in an aqueous dispersion medium) or emulsions (liquid particles or aggregates dispersed in an aqueous dispersion medium). The polymer particles or polymer-based aggregates generally exist as nanoparticles or microparticles or aggregates thereof. These are particles or aggregates composed of finely dispersed polymers or finely dispersed components, specifically finely dispersed polymeric solids or finely dispersed polymeric hydrogels. The dispersions according to the invention may also be contained in "green" solvents, such as Cyrene, which is produced from cellulose. The dispersions according to the invention can be produced by precipitation of the polymers, preferably by nanoprecipitation. For this purpose, the polymers can be dissolved in a water-miscible solvent, such as acetone. This solution is added dropwise to a hydrophilic dispersing medium, preferably with vigorous stirring. This promotes the production of smaller particles. The polymer is deposited in the dispersing medium in a finely dispersed form. Alternatively, the dispersions according to the invention can also be produced by suspending or emulsifying polymer particles. For this purpose, the polymers can be dissolved in a water-immiscible solvent, such as dichloromethane or ethyl acetate. This solution is combined with a hydrophilic dispersing medium, preferably forming two liquid phases. Subsequently, this mixture is suspended or emulsified by the input of energy, preferably by sonication with ultrasound. In addition to the polymer, one or more messenger substances and / or one or more excipients and additives may be present during its precipitation or dispersion in the dispersing medium. Alternatively, these messenger substances and / or excipients and additives may be added after the polymer has been precipitated or dispersed in the hydrophilic liquid. For the purposes of this description, nanoparticles or nanoaggregates are defined as particles or aggregates with diameters (z-average) of less than 1000 nm, as determined by dynamic light scattering. Preferred particle diameters (z-average) for nanoparticles or nanoaggregates range from 500 nm or less, particularly preferably between 30 and 500 nm, very particularly preferably between 40 and 250 nm, and especially between 50 and 200 nm. For the purposes of the present description, microparticles or microaggregates are understood to be particles or aggregates having diameters (z-average) of at least 1 pm, as determined by dynamic light scattering. Preferred particle diameters (z-average) for microparticles or microaggregates range from 5 pm or more, particularly preferably between 10 and 200 pm, and very particularly preferably between 20 and 50 pm. For the purposes of the present description, particle diameters up to 10 pm are determined by dynamic light scattering (DLS) using a Malvern Zetasizer Nano-ZS (Malvern Instruments, Worcestershire, United Kingdom). The intensity-weighted mean diameter (z-average) was determined by means of cumulant analysis of the correlation function (ISO13321, ISO22412). Larger particles with diameters exceeding 10 pm can be determined using visual methods, for example, microscopy. For particle sizes in the nanometer range, light scattering or electron microscopy may be employed. The shape of the polymer particles or aggregate particles may be arbitrary, for example, spherical, ellipsoidal, or irregular. The polymer particles may also form aggregates composed of multiple primary particles. Preferably, the particles or aggregates in the dispersions according to the invention are present in the form of nanoparticles or nanoaggregates. The dispersions according to the invention can be further characterized by their polydispersity index (PDItg). The polydispersity index of the particle size distribution (PDItg) indicates the width of the particle size distribution. Values between 0 (monodisperse) and 1 (polydisperse) are possible. For the purposes of this description, the PDItg value is determined by dynamic light scattering (DLS) using a Malvern Zetasizer Ultra (Malvern Instruments, Worcestershire, United Kingdom). The PDItg was determined by cumulant analysis of the correlation function. The PDItg value of the particle size distribution of the nano- and microparticles or nano- or microaggregates used according to the invention typically ranges between 0.05 and 0.8, preferably between 0.1 and 0.7, and particularly preferably between 0.05 and 0.6. Nanoparticles or nanoaggregates are particularly preferably used according to the invention. These have diameters (z-average) between 40 and 250 nm, particularly preferably between 50 and 200 nm, determined in particular by DLS, and a PDItg between 0.05 and 0.2. The dispersions according to the invention may contain stabilizers that prevent or delay sedimentation of the dispersed phase. Surfactants and / or protective colloids may be used as stabilizers. Such measures are known to those skilled in the art. The dispersions according to the invention may contain oils as additives. Examples include olive oil, sunflower oil, rapeseed oil, or other vegetable or animal oils. Such measures are known to those skilled in the art. In the dispersions according to the invention, polymers are used as carriers for the messenger substances. The messenger substance is intended to be released from the micro- or nanoparticle only at a temperature, ambient humidity level, and / or upon exposure to light selected by the user. Release can be controlled through the choice of polymer, its degree of cross-linking, its molecular structure, or the additives used. The polymer exhibits at least one temperature-dependent or humidity-sensitive parameter that influences the release rate of the messenger substance or messenger substance cocktail combined with the polymer. This temperaturedependent parameter can be adjusted, for example, by producing specially adapted copolymers with a tailored glass transition temperature, melting temperature, crystallinity, or hydrophobic / hydrophilic balance, or by means of the additives used or the production method. Preferably, the polymer should be biodegradable at the point of use, for example, in (forest) soil. However, polymers that are stable for extended periods under the conditions of the point of use can also be used. For the purposes of this description, biodegradable polymers are understood to be polymers that are compostable under the conditions of the point of use (temperature, humidity, UV-VIS radiation exposure, enzymes, bacteria). This means that the polymers must degrade by at least 60% by weight within 180 days (cf. ASTM D-6400). The polymers used as carriers in the dispersions according to the invention can belong to a wide variety of compound classes. The polymers used according to the invention are fundamentally macromolecules composed of one or more structural units, the so-called repeating units. In many cases, a polymer consists of nonidentical macromolecules; as a rule, type and number of repeating units and molecular mass vary. The polymers used in accordance with the invention may be of synthetic or semisynthetic nature, or they may be polymers produced by living organisms (biopolymers). The biopolymers used in accordance with the invention include proteins or polysaccharides, such as cellulose, starch, or chitin. The synthetic polymers used in accordance with the invention include polycondensates, such as polyesters or polyamides, or polymers produced from ethylenically unsaturated monomers, such as poly(meth)acrylic acid or poly(meth)acrylates. The semi-synthetic polymers used in accordance with the invention include polymers produced through the further processing of biopolymers, such as starch derivatives. Polymers used in accordance with the invention may be employed in unmixed form or in the form of polymer blends. The latter include, in particular, supramolecular polymers - that is, polymers whose building blocks are held together not by covalent bonds but by comparatively weak intermolecular bonds. These bonds include hydrogen bonds, ionic bonds, metal-ligand interactions, van der Waals interactions, or hydrophobic interactions. These intermolecular bonds can be easily broken at elevated temperatures and can rapidly reform upon cooling. The temperature at which intermolecular bonds break can be adjusted by selecting the type and quantity of these bonds. In general, the polymers used according to the invention are organic polymers, i.e., polymers composed of monomers containing carbon atoms. The polymers used according to the invention can be thermoplastics, thermosets, elastomers, or thermoplastic elastomers. The polymers can be linear, branched, or cross-linked. Thermoplastics are preferably used. Atactic polymers can be used. These are polymers with a high degree of branching or statistical copolymers. In the solid state, they form amorphous, glass-like structures with a frozen molecular conformation. Interlocking and entanglement of the polymer chain molecules with one another leads to a "mechanical bond" between the chains. Intermolecular and intramolecular secondary valence bonds occur only at a few points. Linear polymers with a regular structure, low branching, and stereoregularity can also be used. Such polymers have a (partially) crystalline structure in the solid state due to regions of dense chain packing. The resulting crystallites are formed by more or less regular folding of one or more molecular chains. Amorphous structures exist between these folds. Several crystallites can form a superstructure, e.g., spherotites. The type and arrangement of (functional) residues of the repeating units influence or determine the crystallinity and the strength of the secondary valence bonds. Particularly strong intermolecular interactions occur when the residues of the repeating units allow the formation of hydrogen bonds. Finally, the polymers used according to the invention may be loosely cross-linked polymers (elastomers), including hydrogels. These either cannot be melted without decomposing or - in the case of thermoplastic elastomers - can be melted reversibly. Biodegradable polymers are among those preferably used. These include polymers that can be decomposed by microorganisms, such as fungi or bacteria, or by enzymes under the conditions prevailing at the site of application. Degradation occurs primarily through oxidation and hydrolysis into the cleavage products water and carbon dioxide, or into methane and biomass. Biodegradable polymers suitable for use according to the invention may be biopolymers or of petrochemical origin. Polyesters, polyamides, or starches are preferably used. Polymers approved for environmental applications are particularly preferred. These may include polylactides, dextrans, alginates, starches, modified starches, polyhydroxyalkanoates, or biodegradable polyesters or polyamides. Polyhydroxyalkanoates (PHAs) are naturally occurring, water-insoluble, linear biopolyesters. PHAs can be thermoplastics or elastomers. The melting point of these materials generally ranges from 40 to 180 °C, but can be adjusted outside this range, for example, by incorporating comonomers. PHAs can be synthesized as short-chain PHAs with 3 to 5 carbon atoms, as medium-chain PHAs with 6 to 14 carbon atoms, or as long-chain PHAs with 15 or more carbon atoms. Depending on the microorganism and cultivation conditions, homo- or copolyesters with a wide variety of hydroxycarboxylic acids can be produced. The PHAs preferably used in the context of the present invention include poly(3-hydroxypropionate), poly(3-hydroxybutyrate), poly(3-hydroxyvalerate), poly(3-hydroxyhexanoate), poly(3-hydroxyheptanoate), poly(3-hydroxyoctanoate), poly(3-hydroxynonanoate), poly(3-hydroxydecanoate), poly(3-hydroxyundecanoate), poly(3-hydroxydodecanoate), poly(3-hydroxytetradecanoate), poly(3-hydroxypenta-decanoate), poly(3-hydroxypropionate-co-3-hydroxybutyrate), poly(3-hydroxypropionate-co-4-hydroxybutyrate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate). Polylactides (PLA) are polymers composed of lactic acid monomers chemically linked to one another. PLA materials are thermoplastics. PLA is typically tailored to specific applications through compounding. The resulting "PLA blends" generally consist of PLA, other biodegradable plastics, and additives. PLA can also be modified through copolymerization with other monomers, for instance, to adjust the glass transition temperature. The dextrans used in accordance with the invention are high-molecular-weight, branched, neutral biopolysaccharides. Dextrans consist primarily of glucose units. Natural dextrans have molecular masses ranging from 10,000 to 50,000,000 Da. Dextrans can also be modified through copolymerization with other monomers, for instance, to adjust the glass transition temperature. The alginic acids used according to the invention are biopolymers produced by brown algae or bacteria. The salts of alginic acid are called alginates. These are polysaccharides consisting of the uronic acids a-L-guluronic acid (GulUA) and p-D-mannuronic acid (ManUA). These are linked by 1,4-glycosidic bonds in varying ratios to form linear chains in which homopolymeric regions are formed, containing either mannuronic acid or guluronic acid as blocks. Alginates tend to form gels by incorporating divalent ions, such as calcium ions, into the copolymer blocks. The starches used according to the invention are polysaccharides consisting of a-D-glucose units. Starch can be cleaved by enzymes such as a- or p-amylases, yielding dextrins or disaccharides. Starch can physically bind many times its own weight in water under the influence of heat, causing it to swell and gelatinize. Starches can be linear or branched. Modified starches can also be used within the scope of the present invention. These are starch products obtained by physical, enzymatic, or chemical processes. These include natural or degraded starches that have been converted into the respective derivatives via polymer-analogous reactions. Examples include acid- treated starches, alkali-modified starches, enzymatically modified starches, oxidized starches, acetalized starches, or hydroxypropyl starches. Other polymers preferably used according to the invention include polyesters, polyesteramides, or polyamides. Preferred polyesters are derived from aliphatic dicarboxylic acids and alkylene glycols, or are copolyesters derived from aromatic and aliphatic dicarboxylic acids and alkylene glycols. Examples include poly(butylene adipate-co-terephthalate) (PBAT), polybutylene succinate (PBS), poly(ethylene adipate-co-terephthalate), and polyethylene succinate. Preferred polyesteramides are derived from aliphatic dicarboxylic acids, alkylene glycols, and aliphatic diamines or aliphatic lactams. An example is a polyesteramide derived from e-caprolactam, adipic acid, and 1,4-butanediol. Preferred polyamides are derived from aliphatic dicarboxylic acids and aliphatic diamines, or from aliphatic aminocarboxylic acids, or from aliphatic lactams. Preferably, polymers used according to the invention have a precisely controlled glass transition temperature. This can be achieved by selecting the type and quantity of monomers used in the polymerization. Glass transition temperatures of copolymers can be estimated using the Fox equation. This equation describes the glass transition temperature of mixtures with several components as a function of the respective mass fractions of these components. This procedure is known to those skilled in the art. Preferred polymer blends used according to the invention are characterized by the fact that their polymeric components are held together by intermolecular bonds that break down at a predetermined temperature. These polymer blends include those containing polymers capable of forming hydrogen bonds, ionic bonds, or metalligand interactions. Further preferred polymers used according to the invention can be degraded enzymatically, hydrolytically, or photochemically. This degradation results in the release of the messenger substance contained in the polymer particle. The enzymes required for enzymatic degradation can already be added to the dispersion according to the invention, already be present at the application site (e.g., fungal enzymes), or be applied together with the dispersion at the application site. Hydrolytic degradation can be effected by adjusting the required hydrolysis conditions, for example, by adjusting a specific pH value. Thus, the dispersions according to the invention can contain additives that release an acid or a base. These additives can already be contained in the dispersion according to the invention or applied together with the dispersion at the application site. Due to the slow rate of degradation, the messenger substance contained within the polymer particles can be released over an extended period. Temperature-controlled degradation or triggering degradation at a specific temperature is not required for this variant, although it is not ruled out. The polymer blends can be supplemented with inorganic fillers (such as silica or calcium or magnesium compounds), organic fillers (such as oils, e.g., olive oil), and bio-based components (such as lignin or cellulose). According to the invention, messenger substances are combined with polymers acting as carrier materials. The carrier material is selected such that the messenger substance is released only when a user-defined temperature, ambient humidity level, or solar radiation intensity is reached, or is released gradually over an extended period. In the context of this description, the term "messenger substance" refers to a chemical compound that facilitates communication between organisms (a semiochemical). A general distinction is made between pheromones and allelochemicals: pheromones facilitate communication between organisms of the same species (intraspecific), whereas allelochemicals transmit information between organisms of at least two different species (interspecific). Allelochemicals are classified into allomones, which benefit the sender; kairomones, which benefit the receiver; and synomones, which benefit both. Semiochemicals can be classified according to their effect on the receiver. For example, pheromones that only trigger a behavioral response in the receiver are called releaser pheromones. Pheromones that cause a significant physiological change in the receiver are called primer pheromones. A further classification can be made based on the pheromone's function. For example, there are aggregation pheromones that cause bark beetles to gather to infest a tree. Sex pheromones serve to attract mates. Aphrodisiac pheromones serve for sexual stimulation and can also act as feeding deterrents. Alarm pheromones serve to warn of predators, and marking and trail pheromones mark territories and paths. All these messenger substances can be used within the scope of the present invention, depending on the intended control of the location. According to the invention, systems based on preferably biodegradable polymer systems can be employed, which release suitable messenger substances in a delayed manner to lure forest pests, such as weevils and especially bark beetles, to trap wood, where they can be destroyed, for example by attracting natural predators, and / or by co-formulating the messenger substances with insecticides, and / or by removing the bark. Likewise, systems based on preferably biodegradable polymer systems can be employed according to the invention which release suitable messenger substances in a delayed manner, luring forest pests (such as weevils and especially bark beetles) to trap wood so that they can be rendered harmless by physically removing the trap wood. Furthermore, according to the invention, systems based on preferably biodegradable polymer systems can be used that release suitable messenger substances in a delayed manner to keep forest pests, such as weevils, and especially bark beetles, away from specific habitats. For example, by releasing defensive pheromones, "firebreaks" can be created that delay or prevent the spread of forest pests, or forest pests can be guided to attractant logs, traps, or predators by releasing defensive pheromones. Similarly, according to the invention, systems based on preferably biodegradable polymer systems can be used that release suitable messenger substances in a delayed manner to attract beneficial insects, such as ladybugs, to a desired location for targeted release. The delayed release of the messenger substance is suitable for providing an effective means of controlling the location of beetles throughout the entire season. By controlling the temperature, or by simultaneously utilizing humidity sensitivity or light exposure during the release of the messenger substance, activation can be limited to times when the use of a messenger substance is also beneficial. For example, it is known that the bark beetle only becomes active at an average air temperature of 16.5°C (beetle flight); however, in strong sunlight, emergence can occur earlier in some areas. The release behavior of the messenger substance can be adjusted by selecting the polymer or by producing specially adapted copolymers with tailored glass transition temperatures, melting temperatures, crystallinity, hydrophobic / hydrophilic balance, or (bio)degradability characteristics (such as susceptibility to enzymatic breakdown or hydrolysis). This process can be further supported by the appropriate addition of inorganic, synthetic, or bio-based additives or oils. According to the invention, a specifically adaptable "messenger substance cocktail" can be applied. These messenger substances can be adapted to specific regions, to variations associated with different infestation stages (larvae, small beetles, adult beetles, sex), and to the timing of infestation waves (spring, summer, autumn). The messenger substances can be specifically tailored to the respective habitat, for example to different tree species such as spruce, pine, or larch. The messenger substances can also be adapted to the beetle pests present in the region or those that can be attracted to the site, such as checkered beetles, braconid wasps, or chalcid wasps. Optionally the messenger substances may also be combined with essential oils. The messenger substances can be used to stimulate beetle pests to infest bait logs or to create firebreaks to block beetle infestation. Using bait logs is particularly useful in the early stages of beetle infestation. Creating firebreaks is especially useful when the infestation has already reached an acute stage and further spatial spread must be prevented at all costs. The dispersions according to the invention preferably contain nano- or microaggregates as the dispersed phase, which, in addition to the polymer, include at least one oil and a messenger substance that acts as an attractant or repellent for beetles, especially bark beetles. The invention also relates to a method for influencing the habitat of wood-dwelling beetles by the use of messenger substances, wherein the method comprises the following measures: i) application of the dispersions described above, which contain messenger substances that attract the beetles and / or their predators or that repel the beetles, wherein the dispersions contain polymer particles that release the messenger substances at a predetermined temperature or that are degraded enzymatically or hydrolytically or by exposure to light to release the messenger substances, and ii) application of the dispersions to a habitat in which the beetles are to be found or from which the beetles are to be kept away. The messenger substances are preferably incorporated into nanoparticles or microparticles, which have been produced via nano- or microprecipitation, inverse nano- or microprecipitation, microfluidics, or emulsification processes. However, other methods known to those skilled in the art for producing suspensions or emulsions may also be employed. The dispersions are preferably in the form of aqueous suspensions of nanoparticles or microparticles, micelles or vesicles or nanocapsules / nanospheres or microcapsules / microspheres, and are stabilized in particular by surfactants and / or protective colloids. The delayed release of the messenger substance (or cocktail thereof) can be achieved by adjusting the polymer matrix or the inorganic, bio-based, or oil-based additives. Release preferably occurs from dry particles, films, aggregates thereof, or hydrogels at air temperatures or local temperatures on the bark or ground of 17°C or higher - preferably 20°C or higher, particularly in the range of 25°C to 30°C, or between 30°C and 45°C in areas particularly exposed to sunlight. It is also possible to use mixtures of particles with different release temperatures. The dispersions may be applied to the habitats by spraying; alternatively, they may be introduced into the habitat via traps, containers, dispensers, molded bodies, 3D-printed parts, films, or sheets containing the dispersions. The application can be carried out by treating selected areas of a habitat or a potential habitat for the beetles. However, extensive forest or park areas can also be treated. In a selected embodiment of the inventive method, locations ("nests") where beetle infestation has already occurred and where the beetles are still active are first identified. The inventive dispersion is then applied to these locations. Such locations can be identified, for example, by means of aerial image analysis. Dispersions applied by spraying form films or aggregates / powders of polymer particles after the dispersion medium evaporates from the desired habitat. These can be continuous films or limited areas on which films or isolated deposits of polymer particles have settled. These polymer films preferably adhere to tree bark and / or leaves and / or are located in the soil around trees. The invention therefore preferably relates to films or aggregates / powders of polymer particles on tree bark, leaves, and / or in the soil of trees, which have been produced by spraying the dispersions according to the invention. Preferably, the dispersions are applied to the habitats by spraying, for example, manually or mechanically using spraying devices. Mechanical application can be carried out by aircraft equipped with spraying devices, such as airplanes, helicopters, or drones. Mechanical application can also be carried out by land-based machines equipped with spraying devices, such as automobiles, tracked vehicles, or tractors. Stable dispersions, such as suspensions or emulsions of nanoparticles, microparticles, or hydrogels, prepared in water or in biodegradable polar aprotic solvents can be sprayed directly. Such dispersions are preferably storage-stable for at least one week, preferably one month, and in particular for at least three months, ideally up to six months. Storage stability can be optimized through positive or negative surface charges on the polymer particles and through the use of additives or stabilizers. Alternatively, re-dispersion can be achieved by shaking, agitating, or stirring. The method according to the invention is particularly suitable for controlling bark beetles. For this purpose, messenger substances are selected that attract bark beetles and / or their natural enemies, or that repel bark beetles. The invention also relates to the use of the dispersions described above for attracting wood-inhabiting beetles and / or their natural enemies to a habitat, or for repelling wood-inhabiting beetles from a habitat. The following examples serve to illustrate the invention. They are not intended to limit the scope of the invention. Materials All chemicals and solvents were purchased from commercial suppliers and used without purification unless otherwise noted. Ethyl acetate and acetone (99+% extra pure) were sourced from Acros Chemicals, dichloromethane (99.5%) from Chemsolute, and poly(D,L-lactide-co-glycolide) (PLGA, Resomer® RG 502 H, Mw 7,000-17,000), poly(3-hydroxybutyric acid) (PHB, average Mn 10,000), polyvinyl alcohol (PVA, Mowiol 4-88), (+)-a-pinene (>99%), (-)-P-pinene (99%), and (1S)-(-)-verbenone (94%) from Sigma-Aldrich. Dulbecco's PBS 1x (phosphate buffer, containing 137 mM NaCl, 2.7 mM KCl, 10 mM Na2HPO4, and 1.8 mM KH2PO4) was prepared by Capricorn Scientific. For HPLC analysis, HPLC-grade acetonitrile and water from VWR International, HPLC-grade phosphoric acid from Merck, and HPLC-grade dimethyl sulfoxide from Thermo Scientific were used. Extra virgin olive oil (Ph. Eur.) from Roth was used. Measurements Dynamic light scattering (DLS) and electrophoretic light scattering (ELS) were used to determine particle size and zeta potential using a Malvern Panalytical Zetasizer Ultra at 25 °C with an equilibration time of 30 s. The Zetasizer instruments operate at a laser wavelength of 633 nm. DLS measurements were performed in polystyrene micro-cuvettes (Brand) at 25 °C and a backscatter angle of 174.7° (particles prior to purification: 100 pL undiluted in a ZEN0040 cuvette; particles after purification: 10 pL particle suspension in 990 pL Milli-Q water or 1x PBS in a DTS0012 cuvette). Additionally, DTS1070 capillary cuvettes (Malvern Panalytical) were used for ELS analyses, with 10 pL of the particle suspension diluted in 990 pL of Milli-Q water or 1x PBS. DSC / TGA and STA measurements were performed using a Netzsch 449 F1 Jupiter®. Mass spectrometry was conducted using a Netzsch QMS 403 D Aeolos®. FTIR measurements were performed on a Bruker TENSOR 27. An IKA T10 basic (Ultra-Turrax) was used for the formulations. A Bandelin Sonorex ultrasonic bath was employed for resuspension. A Carl Zeiss Sigma VP field-emission scanning electron microscope was used to visualize the nanoparticles. Micrographs were acquired using the InLens detector at accelerating voltages ranging from 3 kV to 8 kV. For this purpose, 10 pL of a 1 mg / mL suspension was applied to mica and allowed to dry for 1 hour. HPLC Analysis Procedure The cargo was quantified using a Thermo Scientific Dionex Ultimate 3000 HPLC system. The following column was used: Chromolith® HighResolution RP-18 endcapped, LC Column 100 x 4.6 mm, macropore size: 1.5 pM, mesopore size: 15 nm. Solid-phase extraction (SPE) was performed for sample preparation. The SPE cartridge (Strata C18-E, surface area (m2 / g): 500, pore size: 70, particle size: 55) was first rinsed with 1 mL of methanol and then equilibrated with 2 mL of water. 100 pL (a-pinene and P-pinene) and 50 pL (verbenone) of the suspensions were dissolved in 500 pL of DMSO. 500 pL of the sample are eluted through the SPE cartridge into an HPLC vial. 1 mL of the stock solution is eluted through the SPE cartridge into the same HPLC vial, and the charge (verbenone) is quantified according to the method. In the case of a-pinene and P-pinene, this first 1.5 mL aliquot is discarded. 3.5 mL of the stock solution are then eluted through the cartridge and collected in a single vial. 1.5 mL of this aliquot is transferred to an HPLC vial, and the charge is quantified according to the method. Calibration is performed by preparing 0.3 mg / mL solutions of the cargoes in a 10 mL volumetric flask from the corresponding stock solutions. Multiple 1:2 dilutions are prepared, ranging from 0.6 pg / mL to 19 pg / mL. Stock solution for a-pinene and p-pinene: 1:1 DMSO (70% CH3CN, 30% H2O, 0.1% H3PO4) Stock solution for verbenone: 1:1 DMSO (30% CH3CN, 70% H2O, 0.1% H3PO4) Elution conditions for a-pinene and p-pinene: 70% CH3CN, 30% H2O, 0.1% H3PO4, 10 min Elution conditions for verbenone: 30% CH3CN, 70% H2O, 0.1% H3PO4, 10 min Eluents: CH3CN, H2O, and 0.1% H3PO4 Autosampler: 20 °C, sample injection volume: 20 pL, blank injection volume: 40 pL Oven temperature: 40 °C Elution conditions: Isocratic Detector: Diode array detector (DAD), Dionex UltiMate 3000 General Formulation Protocols In a typical formulation, PLGA or PHB is used as the polymer. Typical solvents include ethyl acetate, dichloromethane, chloroform, acetone, dihydrolevoglucose-none (Cyrene), olive oil, sunflower oil, and / or rapeseed oil. The capsules are purified via centrifugation or dialysis. The messenger substances (cargo) are either dissolved together with the polymer, or stock solutions containing 37 mg / mL of a-pinene, p-pinene, or verbenone (hereinafter referred to as "cargo") in olive oil are used. Protocol for the production of PLGA capsules via emulsion: Weigh 20 mg of PLGA into a 15 mL Falcon tube and dissolve it in 945 pL of ethyl acetate. Add and dissolve 55 pL of the cargo stock solution, then add and dissolve 3% water (Milli-Q). Prepare a 2% PVA solution saturated with 8.3% ethyl acetate. Add the PVA solution (5 mL) to the organic phase by pouring it down the side of the Falcon tube so that the phases remain clearly separated. Set the Ultra-Turrax to level 6 (30,000 rpm) for 5 minutes to emulsify the solution. Quickly pour the resulting emulsion into 24 mL of water (a volume four times that of the emulsion). Allow the solvent to evaporate overnight in an open vessel at room temperature while stirring at 800 rpm. Subsequently, measure an undiluted sample using DLS. Purify the suspension to remove unencapsulated cargo by centrifuging at 11,000 rpm for 60 minutes at 20 °C. The supernatant is decanted, and the pellet is resuspended in 2 mL of water (Milli-Q), sonicated for 30 min, and left to stand overnight at 4 °C. Finally, particle size, size distribution, and zeta potential are determined in water (Milli-Q) and PBS buffer (1x), respectively. Aliquots are freeze-dried to determine the concentration of the final suspension and for cargo quantification via HPLC. Protocol for the production of PLGA capsules by inverse nanoprecipitation: 20 mg of PLGA are weighed into a 15 mL vial and dissolved in 945 pL of acetone. 55 pL of the cargo stock solution are added and dissolved. The solution is transferred to a 10 mL vial and stirred at 800 rpm. 8 mL of a 2% PVA solution are filled into a syringe. The aqueous phase is injected into the organic phase at a rate of 2 mL / min using a syringe pump. The solvent is evaporated for 2 hours at room temperature with stirring (800 rpm). An undiluted sample is then measured using DLS. The suspension is purified to remove unencapsulated cargo by centrifugation (Eppendorf 5804 R) at 11,000 rpm for 60 min at 20 °C. The supernatant is discarded, and the pellet is resuspended in 2 mL of water (Milli-Q), treated in an ultrasonic bath for 30 min, and left to stand overnight at 4 °C. Finally, the particle size and distribution, as well as the zeta potential, are determined in both water (Milli-Q) and PBS buffer (1x). Aliquots are freeze-dried to determine the concentration of the final suspension and for cargo quantification by HPLC. Protocol for the preparation of PLGA capsules via nanoprecipitation: Weigh 20 mg of PLGA into a 15 mL Falcon tube and dissolve it in 945 pL of acetone. Add 55 pL of the cargo stock solution and dissolve. Transfer the solution into a syringe. Stir 8 mL of a 2% PVA solution in a 10 mL vessel at 800 rpm. Inject the organic phase into the aqueous phase using a syringe pump at a rate of 2 mL / min. Evaporate the solvent for 2 hours while stirring (800 rpm) at room temperature. Subsequently, measure an undiluted sample using DLS. Purify the suspension to remove unencapsulated cargo by centrifugation at 11,000 rpm for 60 minutes at 20 °C. Discard the supernatant, resuspend the pellet in 2 mL of water (Milli-Q), treat in an ultrasonic bath for 30 minutes, and leave to stand overnight at 4 °C. Finally, determine the particle size, size distribution, and zeta potential in both water (Milli-Q) and PBS buffer (1x). Freeze-dry aliquots to determine the concentration of the final suspension and for cargo quantification via HPLC. Protocol for the preparation of PHB capsules by emulsion: 20 mg of PLGA are weighed into a 15 mL Falcon and dissolved in 945 pL of dichloromethane. 55 pL of the cargo stock solution are added and dissolved, followed by 3% water (Milli-Q) and dissolved. A 2% PVA solution saturated with 8.3% dichloromethane is prepared. The PVA solution (5 mL) is added to the organic phase through the Falcon wall, ensuring the phases remain clearly separated. The Ultra-Turrax is set to speed 6 (30,000 rpm) for 5 minutes to emulsify the solution. The resulting emulsion is rapidly poured into 24 mL of water (the volume is 4 times that of the emulsion). The solvent is evaporated overnight at 800 rpm in an open vessel at room temperature. An undiluted sample is then measured using DLS. The suspension is purified to remove non-encapsulated cargo by centrifugation at 11,000 rpm for 60 min at 20 °C. The supernatant is decanted, and the pellet is resuspended in 2 mL of water (Milli-Q), treated in an ultrasonic bath for 30 min, and left to stand overnight at 4 °C. Finally, the particle size and distribution, as well as the zeta potential, are determined in water (Milli-Q) and PBS buffer (1x). Aliquots are freeze-dried to determine the concentration of the final suspension and for cargo quantification by HPLC. Table 1: Overview of preparation methods, resulting particle size distribution (PDI: polydispersity index) and zeta potential of the capsules (determined by DLS in water), as well as capsule loading (determined by HPLC). Polymer Method Solvent Cargo Size (nm) PDI Zeta-Potential (mV) Cargo Load (%) PLGA Emulsion Ethylacetate / Olive Oil a-Pinene (10%) 364 0.21 -63 2,81 PLGA Emulsion Ethylacetate / Olive Oil P-Pinene (10%) 347 0.18 -45 0,94 PLGA Emulsion Ethylacetate / Olive Oil Verbenon 704 0.33 -22 0,13 PHB Emulsion Dichloromethane / Olive Oil a-Pinene (10%) 2871 0.25 0 1,98 PHB Emulsion Dichloromethane / Olive Oil P-Pinene (10%) 1873 0.09 -42 Loaded, not quantitatively determined PHB Emulsion Dichloromethane / Olive Oil Verbenon (10%) 1741 0.16 -2 Loaded, not quantitatively determined PLGA Emulsion Chloroform a-Pinene (3%) 638 0.25 -3 Loaded, not quantitatively determined PLGA Emulsion Chloroform P-Pinene (3%) 583 0.23 -25 Loaded, not quantitatively determined PLGA Emulsion Chloroform Verbenon (3%) 625 0.21 -29 Loaded, not quantitatively determined PLGA Emulsion Ethylacetate a-Pinene (3%) 252 0.09 -55 Loaded, not quantitatively determined PLGA Emulsion Ethylacetate P-Pinene (3%) 277 0.04 -42 Loaded, not quantitatively determined PLGA Emulsion Ethylacetate Verbenon (3%) 224 0.04 -32 Loaded, not quantitatively determined PLGA Emulsion Cyrene Verbenon (3%) 246 0.07 1 Loaded, not quantitatively determined PHB Emulsion Chloroform a-Pinene (3%) 1030 0.6 -46 Loaded, not quantitatively determined PHB Emulsion Chloroform P-Pinene (3%) 720 0.12 -7 Loaded, not quantitatively determined PHB Emulsion Chloroform Verbenon (3%) 1305 0.11 -46 Loaded, not quantitatively determined PHB Emulsion Dichlormethane a-Pinene (3%) 726 0.12 -7 Loaded, not quantitatively determined PHB Emulsion Dichlormethane P-Pinene (3%) 734 0.16 -40 Loaded, not quantitatively determined PHB Emulsion Dichlormethane Verbenon (3%) 701 0.15 -13 Loaded, not quantitatively determined PLGA Nanoprecipitation Acetone a-Pinene (10%) 217 0.07 -13 0.58 PLGA Nanoprecipitation Acetone P-Pinene (10%) 226 0.09 -24 Loaded, not quantitatively determined PLGA Nanoprecipitation Acetone Verbenon (10%) 216 0.06 -13 0.46 PLGA Inverse Nanoprecipitation Acetone a-Pinene (3%) 889 0.27 -20 Loaded, not quantitatively determined PLGA Inverse Nanoprecipitation Acetone P-Pinene (3%) 534 0.23 -21 Loaded, not quantitatively determined PLGA Inverse Nanoprecipitation Acetone Verbenon (3%) 702 0.21 -38 Loaded, not quantitatively determined PLGA Inverse Nanoprecipitation Acetone a-Pinene (10%) 291 0.07 -7 Loaded, not quantitatively determined PLGA Inverse Nanoprecipitation Acetone P-Pinene (10%) 619 0.27 -34 3.07 PLGA Inverse Nanoprecipitation Acetone Verbenon (10%) 530 0.16 -34 0.8 Figure 1 shows a scanning electron micrograph of a-pinene-loaded PLGA capsules prepared via emulsion. Figure 2 shows a scanning electron micrograph of a-pinene-loaded PHB capsules prepared via emulsion. Figure 3 shows a scanning electron micrograph of a-pinene-loaded PLGA capsules prepared via inverse nanoprecipitation. Figure 4 shows a scanning electron micrograph of a-pinene-loaded PLGA capsules prepared via inverse nanoprecipitation. Figure 5 shows the release of a-pinene detected via mass spectrometry in an STA. Figure 6 shows an STA / TGA measurement of a-pinene-loaded PHB capsules prepared via emulsion.
Claims
Patent Claims 223fs02.wo1. Dispersions containing water or biodegradable aprotic-polar solvents as dispersing medium and polymer particles or polymer-based nano- or microaggregates as dispersed phase, which particles or aggregates are loaded with at least one messenger substance intended to attract or repel a predetermined wood-inhabiting beetle species or to attract a natural predator of that beetle species and are optionally loaded with further auxiliary and additives, provided that the polymer or the polymer-based nano- or microaggregate exhibits at least one polymer-specific parameter selected from the group consisting of glass transition temperature, crystallite melting temperature, supramolecular interactions, sensitivity to air humidity or targeted degradability, that changes within a predetermined temperature range and / or humidity range thereby releasing the messenger substance contained in the particles, or that the polymer or the polymer-based nano- or microaggregate is degraded enzymatically or hydrolytically thereby releasing the messenger substance contained in the particles.
2. Dispersions according to claim 1 which are present as emulsions or as suspensions.
3. Dispersions according to claim 1 which contain polymer particles or polymerbased nanoparticles or microparticles selected from the group consisting of polymer-based micelles, polymer-based vesicles, solid lipid nanoparticles, lipidpolymer hybrid nanoparticles, polymer-based nanospheres or nanocapsules, and polymer-based microspheres or microcapsules.
4. Dispersions according to at least one of claims 1 to 3 which are used to attract wood-inhabiting beetles that are beneficial organisms or pests, or these are used to attract natural predators of the beetle pests, or these are used to repel woodinhabiting beetle pests.
5. Dispersions according to at least one of claims 1 to 4 which contain a plurality of messenger substances that attract wood-inhabiting beetle pests and simultaneously their natural predators, or wherein, in addition to the messenger substances, these contain further ingredients capable of destroying the beetle pests.
6. Dispersions according to at least one of claims 1 to 5 which are used to influence the location of beetles living on, in, or near trees or in or near the ground of trees.
7. Dispersions according to claim 6, wherein the beetles are weevils, preferably bark beetles, and particularly preferred European spruce bark beetles (Ips typographus), six-toothed spruce bark beetles (Pityogenes chalcographus), large and small wood bark beetles, oak bark beetles, striped wood bark beetles (Trypodendron lineatum), or black wood bark beetles (Xyleborus germanus).
8. Dispersions according to at least one of claims 1 to 7, wherein these contain nanoparticles or nanoaggregates with particle diameters (z-average) in the range of less than or equal to 1000 nm, preferably between 30 and 500 nm, particularly preferred between 40 and 250 nm, and especially between 50 and 200 nm.
9. Dispersions according to at least one of claims 1 to 7, wherein these contain microparticles or microaggregates with particle diameters (z-average) in the range of greater than or equal to 1 pm, preferably between 1 and 200 pm, and particularly preferred between 1 and 100 pm.
10. Dispersions according to at least one of claims 1 to 8, wherein these contain nanoparticles or nanoaggregates which have diameters (z-average) determined by DLS of between 40 and 250 nm, preferably between 50 and 200 nm, and a polydispersity index of the particle diameters of between 0.1 and 0.3.
11. Dispersions according to at least one of claims 1 to 10, wherein the polymer particles or aggregates are composed of biodegradable polymers or bio-based polymers.
12. Dispersions according to at least one of claims 1 to 11, wherein the polymer particles or aggregates are composed of polyesters, polyamides, or starches, in particular polylactides, dextrans, alginates, starches, modified starches, polyhydroxyalkanoates, or biodegradable polyesters or polyamides.
13. Dispersions according to at least one of claims 1 to 12, wherein the polymers have a specifically adjusted glass transition temperature.
14. Dispersions according to at least one of claims 1 to 12, wherein the polymers are biodegradable or hydrolytically degradable, in particular, wherein the polymers undergo enzymatic or hydrolytic degradation above a selected temperature.
15. Dispersions according to at least one of claims 1 to 14, wherein polymer blends are used whose polymeric components are held together by intermolecular bonds that dissolve at a predetermined temperature.
16. Dispersions according to at least one of claims 1 to 15 containing oils, in particular olive oil, sunflower oil, or rapeseed oil.
17. Dispersions according to at least one of claims 1 to 16 containing nano- or microaggregates as a dispersed phase, which, in addition to the polymer, comprise at least one oil and a messenger substance that acts as an attractant or repellent for beetles, in particular for bark beetles.
18. Films or aggregates / powders of polymer particles on tree bark, leaves, and / or in the soil area around trees, produced by spraying the dispersions according to at least one of claims 1 to 17.
19. A method for influencing the location of wood-inhabiting beetles through the use of messenger substances, wherein the method comprises the following steps:i) providing the dispersions according to claim 1, which contain messenger substances that attract the beetles and / or their natural predators or that repel the beetles, wherein the dispersions containpolymer particles that release the messenger substances at a predetermined temperature or that are degraded enzymatically, hydrolytically, or by exposure to light to release the messenger substances, and5 ii) applying the dispersions to a habitat where the beetles are intended tobe present or from which the beetles are intended to be kept away.
20. The method according to claim 19, wherein the dispersions are applied to the habitats by spraying, in particular manually or mechanically using spraying10 devices.
21. The method according to at least one of claims 19 or 20, wherein the messenger substances attract bark beetles and / or their natural predators or wherein the messenger substances repel bark beetles.1522. Use of the dispersions according to at least one of claims 1 to 16 for attracting wood-inhabiting beetles and / or their natural predators into a habitat or for driving wood-inhabiting beetles out of a habitat.