Spray-dried pest control composition

Abstract

The spray-dried pest control composition contains a polymer having a weight average molecular weight of 10,000 to 30,000 daltons and containing 20% to 100% by weight of monomer structural units derived from monomers having a logP of 2.0 to 6.0 based on the total weight of the polymer and Bacillus thuringiensis. The spray-dried pest control composition has an average particle size of 30 nanometers to 100 micrometers when measured using laser diffraction.

Description

Technical Field

[0001] The present disclosure relates to a spray-dried pest control composition, and more particularly, to a spray-dried pest control composition containing Bacillus thuringiensis.

Background Art

[0002] Pest control agents are used to control pests such as insects. The effectiveness of pest control agents can be affected by many factors. In the industry, continuous emphasis has been placed on the development of new and improved pest control compositions.

Summary of the Invention

[0003] According to a first feature of the present disclosure, the spray-dried pest control composition is a polymer having a weight average molecular weight of 10,000 to 30,000 daltons, and contains 20% to 100% by weight of monomer structural units derived from monomers having a log P of 2.0 to 6.0 based on the total weight of the polymer and Bacillus thuringiensis. The spray-dried pest control composition has an average particle size of 30 nanometers to 100 micrometers when measured using laser diffraction. According to a second feature of the present disclosure, the polymer is 50.0% to 99.0% by weight of the composition based on the total weight of the combination of the polymer and Bacillus thuringiensis, and the pest control agent is 1.0% to 50.0% by weight of Bacillus thuringiensis based on the total weight of the combination of the polymer and Bacillus thuringiensis. According to a third feature of the present disclosure, the polymer has a weight average molecular weight of 15,000 to 20,000 daltons. According to a fourth feature of the present disclosure, the spray-dried pest control composition has an average particle size of 1 micrometer to 100 micrometers when measured by the laser diffraction method. According to a fifth feature of the present disclosure, the polymer is a copolymer of diisobutylene and maleic anhydride.

Modes for Carrying Out the Invention

[0004] This specification discloses a spray-dried pest control composition. Embodiments of the present disclosure provide that the spray-dried pest control composition comprises a polymer and Bacillus thuringiensis. As used herein, "spray-dried pest control composition" refers to a composition in which the polymer and Bacillus thuringiensis are spray-dried.

[0005] Spray-dried compositions can be desirable for many applications. For example, spray-dried compositions can advantageously reduce the associated storage space volume, for example, as compared to non-spray-dried compositions that include liquids. Additionally, spray-dried compositions can advantageously reduce handling and / or transportation requirements, for example, as compared to non-spray-dried compositions that include liquids. However, not all compositions are suitable for spray drying.

[0006] The spray-dried compositions disclosed herein can be utilized to control pests. For example, the spray-dried composition can be mixed with water to form an aqueous pest control composition. Such an aqueous pest control composition can be applied to plants, for example, plant surfaces, to control pests. Advantageously, the aqueous pest control compositions disclosed herein can provide an improved (i.e., higher) residual protein concentration of Bacillus thuringiensis after exposure to rainfall as compared to other formulations. The improved residual protein concentration indicates that the aqueous pest control compositions disclosed herein can provide improved pest control as compared to other formulations.

[0007] Furthermore, the aqueous pest control compositions comprising the spray-dried compositions disclosed herein can provide an improved (i.e., higher) retention of Bacillus thuringiensis activity after exposure to rainfall as compared to other formulations. The improved retention of Bacillus thuringiensis activity indicates that the aqueous pest control compositions disclosed herein can provide improved pest control as compared to other formulations.

[0008] The spray-dried pest control composition disclosed herein may contain a polymer. As used herein, "a" refers to one or more, unless otherwise specified. As used herein, "polymer" has two or more same or different monomer structural units derived from two or more different monomers (e.g., copolymer, terpolymer, etc.). When used herein with respect to a polymer, "monomer structural unit" refers to a part of the polymer structure resulting from the reaction of one or more monomers to form the polymer. When referring to monomer structural units, "different" indicates that the monomer structural units differ from each other by at least one atom or are isomerically different. Embodiments of the present disclosure define that the monomer structural units of the polymer result from (i.e., are formed by) the polymerization reaction of the monomers. One or more embodiments provide that the monomer structural units may undergo one or more reactions, for example, hydrolysis reactions, following the polymerization reaction.

[0009] The polymer may have a weight average molecular weight of 10,000 Daltons to 30,000 Daltons. For example, the polymer may have a weight average molecular weight of 10,000 Daltons or more, or 11,000 Daltons or more, or 12,000 Daltons or more, or 13,000 Daltons or more, or 14,000 Daltons or more, or 15,000 Daltons or more, or 16,000 Daltons or more, or 17,000 Daltons or more, or 18,000 Daltons or more, or 19,000 Daltons or more, or 20,000 Daltons or more, or 21,000 Daltons or more, or 22,000 Daltons or more, or 23,000 Daltons or more, or 24,000 Daltons or more, or 25,000 Daltons or more, or 26,000 Daltons or more, or 27,000 Daltons or more, or 28,000 Daltons or more, or 29,000 Daltons or more, and at the same time, may have a weight average molecular weight of 30,000 Daltons or less, or 29,000 Daltons or less, or 28,000 Daltons or less, or 27,000 Daltons or less, or 26,000 Daltons or less, or 25,000 Daltons or less, or 24,000 Daltons or less, or 23,000 Daltons or less, or 22,000 Daltons or less, or 21,000 Daltons or less, or 20,000 Daltons or less, or 19,000 Daltons or less, or 18,000 Daltons or less, or 17,000 Daltons or less, or 16,000 Daltons or less, or 15,000 Daltons or less, or 14,000 Daltons or less, or 13,000 Daltons or less, or 12,000 Daltons or less, or 11,000 Daltons or less. The weight average molecular weight of the polymer is measured using gel permeation chromatography.

[0010] One or more embodiments of the present disclosure provide that the polymer contains 20 wt% to 100 wt% of monomer structural units derived from monomers (i.e., one or more monomers) having a logP of 2.0 to 6.0 based on the total weight of the polymer. For example, the polymer may contain a monomer having a logP of 2.0 to 6.0 in an amount of 20 wt% or more, or 25 wt% or more, or 30 wt% or more, or 35 wt% or more, or 40 wt% or more, or 45 wt% or more, or 50 wt% or more, or 55 wt% or more, or 60 wt% or more, or 65 wt% or more, or 70 wt% or more, or 75 wt% or more, or 80 wt% or more, or 85 wt% or more, or 90 wt% or more, or 95 wt% or more, and at the same time, 100 wt% or less, or 95 wt% or less, or 90 wt% or less, or 85 wt% or less, or 80 wt% or less, or 75 wt% or less, or 70 wt% or less, or 65 wt% or less, or 60 wt% or less, or 55 wt% or less, or 50 wt% or less, or 45 wt% or less, or 40 wt% or less, or 35 wt% or less, or 30 wt% or less, or 25 wt% or less.

[0011] The polymer can contain more than 90 wt% of monomer structural units derived from monomers having a logP greater than 1.0.

[0012] For example, the polymer may contain a monomer having a logP greater than 1.0 in an amount of 91 wt% or more, or 92 wt% or more, or 93 wt% or more, or 94 wt% or more, or 95 wt% or more, or 96 wt% or more, or 97 wt% or more, or 98 wt% or more, or 99 wt% or more, and at the same time, 100 wt% or less, or 99 wt% or less, or 98 wt% or less, or 97 wt% or less, or 96 wt% or less, or 95 wt% or less, or 94 wt% or less, or 93 wt% or less, or 92 wt% or less, or 91 wt% or less.

[0013] One or more monomer structural units may have a logP of 1.0 or more, or 1.2 or more, or 1.4 or more, or 1.6 or more, or 1.8 or more, or 2.0 or more, or 2.2 or more, or 2.4 or more, or 2.6 or more, or 2.8 or more, or 3.0 or more, or 3.2 or more, or 3.4 or more, or 3.6 or more, or 3.8 or more, or 4.0 or more, or 4.2 or more, or 4.4 or more, or 4.6 or more, or 4.8 or more, or 5.0 or more, or 5.2 or more, or 5.4 or more, or 5.6 or more, or 5.8 or more, and at the same time, may have a logP of 6.0 or less, or 5.8 or less, or 5.6 or less, or 5.4 or less, or 5.2 or less, or 5.0 or less, or 4.8 or less, or 4.6 or less, or 4.4 or less, or 4.2 or less, or 4.0 or less, or 3.8 or less, or 3.6 or less, or 3.4 or less, or 3.2 or less, or 3.0 or less, or 2.8 or less, or 2.6 or less, or 2.4 or less, or 2.2 or less, or 2.0 or less, or 1.8 or less, or 1.6 or less, or 1.4 or less, or 1.2 or less. The logP value is determined by using the Estimation Programs Interface (EPI)Suite (trademark), (KOWWIN version 1.68) available at https: / / www.epa.gov / tsca-screening-tools / epi-suitetm-estimation-program-interface.

[0014] Exemplary monomers for use in the polymer include diisobutylene (logP = 4.08), butyl methacrylate (logP = 2.75), butyl acrylate (logP = 2.20), methyl methacrylate (logP = 1.28), ethyl acrylate (logP = 1.22), 2-ethylhexyl acrylate (logP = 4.09), styrene (logP = 2.89), maleic anhydride (logP = 1.62), docosyl methacrylate (logP = 11.59), and combinations thereof.

[0015] The polymer may contain structural units from one or more of itaconic acid, fumaric acid, crotonic acid, acrylic acid, methacrylic acid, maleic acid, acryloxypropionic acid, citraconic acid, methyl acrylate, vinyl acetate, and combinations thereof.

[0016] The polymer can be prepared using known apparatuses, reaction components, and reaction conditions. For example, the polymer can be prepared by known polymerization, such as solution polymerization. Solution polymerization of the monomers (i.e., the monomers considered herein) can be carried out, for example, in a non-aqueous solvent. Suitable solvents include, but are not limited to, toluene, xylene, propylene glycol, methyl ethyl ketone, and combinations thereof. Solution polymerization can include a solvent-soluble initiator. Examples of initiators include, but are not limited to, t-butyl peroctoate, t-butyl hydroperoxide, AIBN, 2,2-azobis(2,4-dimethyl-pentanenitrile), t-butyl peroxybenzoate, and combinations thereof. The initiator can be used, for example, in an amount of 0.01 wt% to 1.00 wt% based on the total weight of the monomers utilized in the solution polymerization. In solution polymerization, a chain transfer agent may be utilized. Examples of chain transfer agents include, but are not limited to, 2-mercaptoethanol, 3-methyl mercaptopropionic acid, n-dodecyl mercaptan, t-dodecyl mercaptan, and combinations thereof. The chain transfer agent can be used, for example, in an amount of 0.01 wt% to 5.00 wt% based on the total weight of the monomers used in the solution polymerization. The use of a mercaptan modifier can reduce the molecular weight of the polymer. Other known components may be used in the solution polymerization. Different amounts of these other known components can be utilized for various applications.

[0017] The polymer can be prepared by known polymerization, such as emulsion polymerization. An emulsifier may be used in emulsion polymerization. Examples of emulsion polymerization include, but are not limited to, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, and ethoxylated sulfosuccinic acid [C 10Anionic surfactants such as alcohol semi-ester sodium and combinations thereof can be mentioned. The surfactant can be used, for example, at 0.5% by weight to 6.0% by weight based on the total weight of the monomers used in emulsion polymerization. For emulsion polymerization, an initiator such as a water-soluble initiator may be used. Examples of initiators include, but are not limited to, alkali metal persulfates, ammonium persulfate, and combinations thereof. The initiator can be used at 0.01% by weight to 1.00% by weight based on the total weight of the monomers used in emulsion polymerization. For emulsion polymerization, a chain transfer mercaptan may be used. Examples of chain transfer mercaptans include, but are not limited to, 2-mercaptopropionic acid, 3-methylmercaptopropionic acid, alkyl mercaptans having 4 to 20 carbon atoms, and combinations thereof. The chain transfer mercaptan can be used at 0.01% by weight to 5.00% by weight based on the total weight of the monomers used in emulsion polymerization. The use of a mercaptan modifier can reduce the molecular weight of the polymer. Other known components may be used in emulsion polymerization. Different amounts of these other known components can be used for various applications.

[0018] The polymer can be commercially obtained under various trade names.

[0019] As already described, the monomer structural units of the polymers described in this specification may undergo one or more reactions, for example, hydrolysis reactions, following the polymerization reaction. The hydrolysis reaction can include, for example, hydrolysis of an ester to an acid or ring opening of an anhydride to an acid.

[0020] The spray-dried pest control composition disclosed in this specification contains Bacillus thuringiensis. As defined herein, "Bacillus thuringiensis" is the spore and / or crystallized protein of the Bacillus thuringiensis species, and includes all subspecies of Bacillus thuringiensis that exhibit insecticidal properties. Examples of such subspecies include kurstaki, israelensis, and aizawa. Bacillus thuringiensis can be added to the insecticidal formulation either as a solid or as part of a liquid formulation. The presence and subspecies of Bacillus thuringiensis are determined by random amplified polymorphic DNA analysis. A commercially available liquid formulation of Bacillus thuringiensis is the THURICIDE™ insecticide marketed by CERTIS USA (Columbia, Maryland).

[0021] The spray-dried pest control composition can contain 50.0% to 99.0% by weight of the polymer, based on the total weight of the combination of the polymer and Bacillus thuringiensis. For example, the spray-dried pest control composition can contain 50% by weight or more, or 55% by weight or more, or 60% by weight or more, or 65% by weight or more, or 70% by weight or more, or 75% by weight or more, or 80% by weight or more, or 85% by weight or more, or 90% by weight or more, or 95% by weight or more of the polymer, based on the total weight of the spray-dried composition, and at the same time, 99% by weight or less, or 95% by weight or less, or 90% by weight or less, or 85% by weight or less, or 80% by weight or less, or 75% by weight or less, or 70% by weight or less, or 65% by weight or less, or 60% by weight or less, or 55% by weight or less of the polymer.

[0022] The spray-dried pest control composition can contain 1.0 wt% to 50.0 wt% of Bacillus thuringiensis based on the total weight of the combination of the polymer and Bacillus thuringiensis. For example, the spray-dried pest control composition can contain 1 wt% or more, or 5 wt% or more, or 10 wt% or more, or 15 wt% or more, or 20 wt% or more, or 25 wt% or more, or 30 wt% or more, or 35 wt% or more, or 40 wt% or more, or 45 wt% or more of Bacillus thuringiensis based on the total weight of the spray-dried pest control composition, and at the same time, 50 wt% or less, or 45 wt% or less, or 40 wt% or less, or 35 wt% or less, or 30 wt% or less, or 25 wt% or less, or 20 wt% or less, or 15 wt% or less, or 10 wt% or less, or 5 wt% or less of Bacillus thuringiensis.

[0023] One or more embodiments of the present disclosure provide that the spray-dried pest control composition disclosed herein may contain additives. Examples of additives include, in particular, viscosity modifiers, pH adjusters, herbicides, fungicides, surfactants, humectants, drying aids, inert solids, and combinations thereof. Different amounts of additives can be used for various applications.

[0024] The spray-dried pest control composition disclosed herein containing a polymer and Bacillus thuringiensis can be prepared using known spray-drying apparatuses, spray-drying components, and spray-drying conditions.

[0025] As an example, spray drying can include forming spray particles from a liquid, for example atomization, by spraying through a spray nozzle or by using a centrifuge where the liquid is supplied to a centrifugally rotating disk. The spray particles can be dried using a gas stream. The gas stream can contain, for example, air or nitrogen. Spray drying can be carried out at different temperatures for different applications. For example, spray drying can be carried out at a temperature of 20°C to 200°C.

[0026] Embodiments of the present disclosure provide that the spray-dried pest control composition (i.e., spray-dried particles) has an average particle size of 30 nanometers to 100 micrometers. All individual values and sub-ranges from 30 micrometers to 100 micrometers are included. For example, the spray-dried pest control composition can have an average particle size from a lower limit of 30, 40, 50, 60, 75, 80, or 100 nanometers to an upper limit of 100, 75, 50, 25, 10, 5, or 2 micrometers. Further, the average particle size may be 1 micrometer to 100 micrometers. As used herein, "average particle size" includes, for example, "average equivalent spherical diameter" for non-spherical particles. The average particle size is measured by laser diffraction using a BECKMAN COULTER™ LS 13320 laser diffraction particle size analyzer.

[0027] Embodiments of the present disclosure define that the spray-dried pest control composition may be a powder. As used herein, "powder" refers to a non-tacky solid composition. As an example, the powder may contain less than about 20% by weight of water (e.g., non-solid) based on the total weight of the powder. The powder may contain less than 10% by weight of water, less than about 5% by weight of water, or less than about 3% by weight of water based on the total weight of the powder. The spray-dried compositions disclosed herein may be free-flowing powders. As used herein, "free-flowing" means that the composition can be transported by gravity or by conventional mechanical or pneumatic pumping (e.g., from a storage container).

[0028] As described above, the spray-dried compositions disclosed herein can be mixed with water to form an aqueous pest control composition. Such an aqueous pest control composition can be applied to plants, for example, on the plant surface, to control pests. The aqueous pest control compositions disclosed herein can be formed using known devices and processes. The components of the aqueous pest control composition can be added together (e.g., mixed) to form the aqueous pest control composition. For example, each component of the aqueous pest control composition can be added to a container and stirred therein. The components of the aqueous pest control composition can be added together in any order.

[0029] As an advantage, the aqueous pest control composition disclosed herein can provide an improved (i.e., higher) residual protein concentration of Bacillus thuringiensis after exposure to rainfall compared to other formulations. As a further advantage, the aqueous pest control composition comprising the spray-dried composition disclosed herein can provide an improved (i.e., higher) retention of Bacillus thuringiensis activity after exposure to rainfall compared to other formulations.

[0030] The aqueous pest control composition disclosed herein can comprise from 0.10 wt% to 20.00 wt% of the spray-dried pest control composition, based on the total weight of the combination of the spray-dried pest control composition and water. All individual values and subranges from 0.10 wt% to 20.00 wt% are included. For example, the aqueous pest control composition can comprise from a lower limit of 0.10 wt%, 0.30 wt%, or 0.50 wt% to an upper limit of 20.00 wt%, 15.00 wt%, or 10.00 wt% of the polymer, based on the total weight of the combination of the spray-dried pest control composition and water.

[0031] The aqueous pest control composition disclosed herein can comprise from 80.00 wt% to 99.90 wt% of water, based on the total weight of the combination of the spray-dried pest control composition and water. All individual values and subranges from 80.00 wt% to 99.89 wt% are included. For example, the aqueous pest control composition can comprise from a lower limit of 80.00 wt%, 85.00 wt%, or 90.00 wt% to an upper limit of 99.90 wt%, 99.70 wt%, or 98.50 wt% of water, based on the total weight of the combination of the spray-dried pest control composition and water.

[0032] One or more embodiments of the present disclosure provide that the spray-dried pest control composition disclosed herein can include additives. Examples of additives include, among others, viscosity modifiers, pH adjusters, herbicides, fungicides, surfactants, humectants, drying aids, inert solids, and combinations thereof. Different amounts of additives can be used for various applications.

[0033] The aqueous pest control composition disclosed in this specification can be applied to plants (e.g., the plant surface) to control pests. The aqueous pest control composition can be applied to plants using known devices and methods. For example, the aqueous pest control composition can be sprayed, scattered, and / or poured onto plants, among other application methods. Different amounts of the aqueous pest control composition can be applied to plants for various uses. As described above, advantageously, the aqueous pest control composition disclosed in this specification can provide an improved (i.e., higher) residual protein concentration of Bacillus thuringiensis after exposure to rainfall compared to other formulations.

Examples

[0034] In the examples, various terms and names related to materials are used, including, for example, the following. THURICID (trademark) Bacillus thuringiensis formulation (pest control agent, liquid formulation, Bacillus thuringiensis, manufactured by Certis). RHOPLEX VSR-50 acrylic emulsion (obtained from The Dow Chemical Company), BOND MAX (trademark) spreading agent / sticking agent formulation (obtained from Loveland Products). NU FILM P (trademark) sticking and spreading aid (obtained from Miller Chemical & Fertilizer Corporation).

[0035] Polymer 1 was formed as follows. Solution polymerization was utilized to form a copolymer derived from diisobutylene and maleic anhydride. The weight percentage of Polymer 1 formed from the monomer structural units relative to diisobutylene was 45 wt% to 55 wt%, and the balance was maleic anhydride. The polymer was hydrolyzed with aqueous ammonia to obtain Polymer 1. Polymer 1 had a weight average molecular weight of approximately 16,500 daltons.

[0036] Example 1. A spray-dried pest control composition was formed as follows. Polymer 1 (11.6 grams) and THURICIDE (trademark) (88.4 grams) were added to a container and stirred to obtain a formulation. This formulation was fed to a MOBILE MINOR (trademark) spray dryer (GEA Process Engineering Inc.) using a peristaltic pump (Masterflex L / S). A two-fluid nozzle atomizer with water injection was attached to the spray dryer. The nitrogen pressure supplied to the nozzle atomizer was fixed at 1 bar at a 50% flow rate equal to a flow rate of 100 L / min. The inlet temperature was set at 120°C, and the outlet temperature was equilibrated between 40 and 50°C at a fixed liquid supply rate (20 g / min). The product of the spray dryer was collected by a cyclone connected to the spray dryer to obtain Example 1. Example 1 had an average particle size of about 41.19 micrometers when laser diffraction was used. Example 1 was visually observed to be a free-flowing powder.

[0037] Comparative Example A was formed in the same manner as Example 1, except that RHOPLEX (trademark) VSR-50 emulsion (5.6 grams) was used instead of Polymer 1, and THURICIDE (trademark) Bacillus thuringiensis formulation (94.4 grams) was used.

[0038] Comparative Example B was formed in the same manner as Example 1, except that NU FILM P (trademark) sticking and spreading adjuvant was used instead of Polymer 1. However, even when the solution of NU FILM P (trademark) sticking and spreading adjuvant and THURICIDE (trademark) Bacillus thuringiensis formulation was spray-dried, a spray-dried powder could not be obtained.

[0039] Comparative Example C was formed in the same manner as Example 1, except that BOND MAX (trademark) spreading agent / adhesive formulation was used instead of Polymer 1. However, even when the solution of BOND MAX (trademark) spreading agent / adhesive formulation and THURICIDE (trademark) Bacillus thuringiensis formulation was spray-dried, a spray-dried powder could not be obtained.

[0040] Comparative Example D was formed in the same manner as Example 1, except that Polymer 1 was not used.

[0041] The aqueous pest control composition of Example 2 was formed as follows. Example 1 was diluted with water to obtain Example 2 as a mixture having a concentration of the pest control agent (Bacillus thuringiensis) of 71.4 grams per liter.

[0042] Comparative Example E was formed in the same manner as Example 2, except that Comparative Example A was used instead of Example 1.

[0043] Comparative Example F was formed as follows. Comparative Example D was combined with water and mixed with a magnetic stir bar to obtain a mixture having a concentration of the pest control agent of 71.4 grams per liter.

[0044] For Example 2 and Comparative Examples E and F, the residual protein concentration and the pest control agent (Bacillus thuringiensis) activity were determined as follows. The residual protein concentration and the pest control agent activity for the aqueous pest control compositions formed from Comparative Examples B - C were not determined because spray-dried powders could not be obtained in these comparative examples.

[0045] Parafilm pieces (2 inches × 4 inches) were placed on black Leneta cards, respectively. After gently rubbing the entire Parafilm with a Kimwipe, the Parafilm paper was peeled off. Using an automatic pipettor, 15 drops (15 - 30 μL) of Example 2 and Comparative Examples E and F were randomly arranged in an array on each Parafilm. One Parafilm was used for each example / comparative example. The samples were vortex mixed between each set of 5 drops to maintain the consistency of the composition. Then, each Parafilm was dried in an incubator at about 28°C for about 1 hour.

[0046] Next, the dried paraffin films were exposed to simulated rainfall as follows. Each of the dried paraffin films was placed inside an EXO TERRA MONSOON™ RS400 RAINFALL SYSTEM™ (with two EXO TERRA standard nozzles installed without extension). The paraffin film was 13 inches from the spray nozzle. Water was sprayed onto the paraffin film at a flow rate of 1.5 liters per hour, measured at the substrate interface for 5 minutes. Thereafter, the paraffin film was dried.

[0047] After exposure to simulated rainfall, samples were extracted. For extraction, each of the paraffin films was cut such that the center of each dot obtained from the droplets was approximately 0.25 square inches. For each paraffin film, all of the cut squares with dots were placed in a glass vial, and sodium dodecyl sulfate solution (1 milliliter, 2 wt% aqueous sodium dodecyl sulfate solution) was added thereto. Subsequently, each glass vial was sonicated and immersed for approximately 8 hours. Sonication was repeated three times for extraction.

[0048] The residual protein concentration was determined by the bicinchoninic acid assay (BCA) as follows.

[0049] PIERCE™ BCA Protein Assay Reagent A and PIERCE™ BCA Protein Assay Reagent B (both obtained from THERMO SCIENTIFIC) were combined with reagent A (2 milliliters) and reagent B (40 microliters) to form a reagent mixture.

[0050] 100 microliters of each extraction sample was placed in each cuvette. Then, the reagent mixture (2 milliliters) was added to each cuvette, and the cuvette was incubated at 30 °C for approximately 2 hours. The residual protein concentration was measured using the absorbance value at 562 nm measured by a VARIAN CARY™ 50 UV-Visible Spectrophotometer. The results are shown in Table 1.

[0051]

Table 1

[0052] The data in Table 1 show that Example 2 had an improved (i.e., higher) residual protein concentration compared to both Comparative Examples E and F.

[0053] Each solution extracted above for Example 2 and Comparative Examples E and F was diluted to the desired starting concentration using a 0.1 wt% solution of TWEEN® 20 and then serially diluted to an appropriate concentration for plating. The resulting pest control agent activities are shown in Table 2.

[0054] [Table 2]

[0055] The data in Table 2 show that Example 2 had an improved (i.e., higher) retention of pest control agent activity compared to both Comparative Examples E and F.

Claims

Claim 1 A spray-dried pest control composition comprising a polymer having a weight average molecular weight of 10,000 to 30,000 Daltons and containing 20% to 100% by weight of monomer structural units derived from monomers having a logP of 2.0 to 6.0 based on the total weight of the polymer, and Bacillus thuringiensis, wherein the spray-dried pest control composition has an average particle size of 30 nanometers to 100 micrometers when measured using laser diffraction. Claim 2 the polymer is 50.0% to 99.0% by weight of the composition based on the total weight of the combination of the polymer and Bacillus thuringiensis, and Bacillus thuringiensis is 1.0% to 50.0% by weight of the composition based on the total weight of the combination of the polymer and Bacillus thuringiensis, the spray-dried pest control composition according to claim 1. Claim 3 the polymer has a weight average molecular weight of 15,000 to 20,000 Daltons, the spray-dried pest control composition according to any one of claims 1 to 2. Claim 4 the spray-dried pest control composition has an average particle size of 1 micrometer to 100 micrometers when measured using laser diffraction, the spray-dried pest control composition according to any one of claims 1 to 3. Claim 5 the polymer is a copolymer of diisobutylene and maleic anhydride, the pest control composition according to any one of claims 1 to 4.

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