Biological contact insecticide and acaricide against mites and insects with soft exoskeleton and production method thereof

Abstract

Contact insecticide and acaricide suitable for organic agriculture for the management of mites and soft-bodied insects, and its method of production. This invention relates to the creation of a formulation applicable in both organic and conventional agriculture for the protection of plants against mites and soft-bodied insect pests of crops. The action of the formulation is due to the inseparable combination of the active substance, which is the potassium salts of fatty acids, with mixtures of mono- and diglycerides of fatty acids as well as vegetable oils that increase the solubility of the formulation in the spray liquid and its effectiveness. The acaricidal and insecticidal action of the final formulation is further enhanced by the addition of acyclic sesquiterpenes and caraway essential oil, which cause intense mobility of the mites / insects, thereby increasing the contact time of the pests with the active ingredient, leading to their immediate death. This invention represents an advancement in current technology by proposing a combination of active ingredients that act synergistically, ensuring the effectiveness of the formulation even at low concentrations of the active substance. The low concentration of the active ingredient, combined with the use of natural and environmentally friendly components, results in the proposed formulation with an improved toxicological and environmental profile and minimizes the risk of phytotoxicity often observed from the use of plant protection products with high concentrations of potassium salts of fatty acids. This patent also describes: a) the method of production of the active ingredient and the final formulation (additional examples of proposed compositions are provided in the supplementary section), b) the proposed method of application of the formulation in the field, c) laboratory studies conducted on the effectiveness of the proposed formulation against the agricultural pest Tetranychus urticae (two-spotted spider mite) and the study of its compatibility with the beneficial predator Phytoseiulus persimilis.

Description

[0001] BIOLOGICAL CONTACT INSECTICIDE AND ACARICIDE AGAINST MITES AND INSECTS WITH SOFT EXOSKELETON AND PRODUCTION METHOD THEREOF.

[0002] Field of Invention

[0003] The present invention relates generally to the field of biological contact acaricides / insecticides for the combating of mites as well as entomological pests of crops with soft exoskeleton. Specifically, this invention refers to a formulation suitable for use in organic agriculture, the insecticidal and acaricidal action of which is based on the inseparable combination of potassium salts of fatty acids, preferably of long carbon chain length with mono- and diglycerides as well as vegetable oils.

[0004] The composition is enhanced with the addition of the acyclic sesquiterpenes farnesol (3,7,11-Trimethyl-2,6,10-dodecatrien-1-ol) and nerolidol (3,7,11 -Trimethyl- 1, 6,10- dodecatrien-3-ool) as well as the essential oil of caraway. In the present invention, the method of production of the proposed formulation is also described.

[0005] Description of Technical Field

[0006] Agricultural pests (insects and mites) represent a significant threat to agricultural production as they have detrimental effects on the yield and quality of production in many cultivated plants.

[0007] Agricultural pests cause direct and indirect damage to plant tissues. They either feed on plants causing mechanical damage (chewing and sap-sucking insects) [Direct effect] or they are carriers of viruses, fungi and bacteria which lead to the transmission of secondary diseases [Indirect effect]. For the abovementioned reasons, they have been studied extensively and the development of methods for their control has been of paramount importance for the agricultural sector.

[0008] To combat, eliminate, and prevent these pests, which are harmful to agricultural production, hundreds of chemical plant protection products have been released. The widespread and long-term use of chemical pesticides has been associated with negative impacts on the disruption of ecological balance and the safety of the food chain, as well as the emergence of resistant strains of agricultural pests that make approved commercial plant protection formulations less effective. Additionally, the aforementioned preparations also affect beneficial insects, which are necessary for the preservation of the ecosystem and required biodiversity.

[0009] The above reasons, combined with the continually increasing awareness of the consumer audience for more environmentally friendly products, have driven the plant protection industry towards finding solutions friendly to the environment and humans. Potassium salts of fatty acids - commonly known as soft soaps and characterized as substances of traditional use in organic agriculture by Reg. E.U. 2018 / 848 - have been widely used as insecticides, herbicides, fungicides, and algaecides for many decades (1).

[0010] The first commercial plant protection product using potassium salts of fatty acids as its active substance was approved for use in 1947. (EPA-738-R-92-015). Since then, dozens of formulations with this specific active substance or combinations of potassium salts of fatty acids with other substances with insecticidal / acaricide action have been released on the market. In plant protection, fatty acids C8-18 and C18-unsatd (CAS No. 67701-09-1) are traditionally used.

[0011] The plant protective action of potassium salts of fatty acids is due to the ability of their lipophilic carbon chains to penetrate and disrupt the lipid-protein epidermis of insects / mites, resulting in the leakage of cell membrane contents, dehydration of the cells, and rapid death of the insects / mites. Potassium salts of fatty acids are relatively selective in toxicity based on the type of insect and its developmental stage.

[0012] Mites and insects with a soft exoskeleton, such as spider mites, aphids, thrips, scales, cicadellids, and whiteflies, among others, which are significant crop pests, are especially sensitive to the toxicity of fatty acid salts, whereas insects with a hard exoskeleton, such as ladybugs and beetles (beneficial insects), are particularly resistant.

[0013] The selectivity of potassium salts of fatty acids, combined with their easy and rapid decomposition in the environment and the reduced risk of resistance development due to their mechanical mode of action, make potassium salts of fatty acids an alternative and effective plant protection solution, fully aligned with the principles of organic agriculture.

[0014] The active substance of potassium salts of fatty acids results from the addition of potassium hydroxide to isolated and distilled fatty acids of plant or animal origin. For the production of plant protection products based on potassium salts of fatty acids, the distilled fatty acids from palm oil (Arecaceae sp.), coconut oil (Cocos nucifera L.), olive oil (Olea europaea L.), castor oil (Ricinus communis L.), or cottonseed oil (Gossypium spp.) are used. Fatty acids with carbon chain lengths of 18 with one or two double bonds (unsaturated fatty acids) exhibit insecticidal action. In plant protection, therefore, the potassium salts of fatty acids normally used are fatty acids C8-18 and C18-unsatd.

[0015] It has been observed that fatty acids with 8 and 10 carbon atoms present significant phytotoxicity issues, especially if applied in high concentrations. To avoid this undesirable effect, the oils from which the fatty acids are produced must be specific and of such composition that from the triglycerides they contain, after hydrolysis or saponification, fatty acid mixtures are obtained with the following percentages:

[0016] C16:0 =11-13%, C16.1 =0.5-1%, C18:0 =2-3%, C18:1 =65-75%, C18:2 =7-11%, C18:3 =0.5-1%. Such oils include olive oil and soybean oil. In the present invention, these oils are exclusively used, and the product of their hydrolysis, which is present in low doses in the proposed formulation, does not cause phytotoxixity.

[0017] Although potassium salts of fatty acids are proven to be an effective plant protection solution, their efficacy is manifested when they are applied in high concentrations. In most patents, e.g., US5631290A(2), and in most commercial formulations based on potassium salts of fatty acids, the concentration of this active ingredient approaches 50% by weight of the final product.

[0018] Unfortunately, such high concentrations of the active ingredient carry the risk of phytotoxicity, especially in sensitive crops, such as those where the leaf surfaces are covered with trichomes that retain the active ingredient on their surface for longer. The exhibited phytotoxicity reduces crop yield and degrades quality, consequently diminishing the commercial value of agricultural produce.

[0019] A second negative consequence of the high concentration of the active substance in the final formulation is its increased production cost and, consequently, the increased final market price.

[0020] Additionally, the solutions of potassium salts of fatty acids in water have low vapor pressure, resulting in their action being limited locally to the point of spray application. In most cases, foliar sprays wet the upper surface of the foliage, leaving insects that hide or lay eggs on the underside of the leaves unaffected.

[0021] Several combinations have been proposed to improve the performance of potassium salts of fatty acids, such as combinations with essential oils, natural pyrethrum, and other substances with synergistic action, like US6294578B1, NZ522321A, US6103768A, US9635858B2, as well as patent number KR20020069876A, which describes the dissolution of potassium hydroxide in ethanol followed by mixing with vegetable oils, where the use of flammable solvents in the preparation of the product is not desirable from a safety and toxicity standpoint for humans during use.

[0022] However, none of these combinations improve the fundamental problem of fatty acid salts, which is that their action is purely local, resulting in effectiveness limited to a restricted number of pests. This invention improves prior art by proposing an innovative combination of active substances of natural origin, prepared in an ecological way to solve a significant problem in agricultural production.

[0023] This patent also improves the method of preparation because, with a single reaction, it can produce from raw materials, which are vegetable oils, both potassium salts and free fatty acids, as well as mono- and diglycerides, which are all compounds that exhibit insecticidal and acaricidal action. Description of the Invention

[0024] This patent presents for the first time a product whose effectiveness is due to the combination of three active ingredients of natural origin. This combination aims to enhance the insecticidal / acaricidal action of the proposed active ingredient and solve its fundamental problem, which is the limitation of its action to only the sprayed area.

[0025] The triple combination includes:

[0026] 1. Firstly, an active substance which is potassium salts of fatty acids resulting from the hydrolysis of vegetable oils with an alkaline base (saponification). Specifically, the active substance is produced after the reaction of vegetable oils with caustic alkali (KOH) or potassium carbonate (K2CO3).

[0027] 2. Secondly, a mixture of free fatty acids, as well as monoglycerides, diglycerides, and triglycerides, which are produced during saponification. These are used in the preparation as emulsifiers, increasing its solubility in the spray liquid and simultaneously enhancing its action against target insects.

[0028] 3. Thirdly, the acyclic sesquiterpenes farnesol (3,7,1 l-Trimethyl-2,6,10-dodecatrien- l-ol) and nerolidol (3,7,l l-Trimethyl-l,6,10-dodecatrien-3-ol), which, together with caraway oil (Carum carvi), cause intense activity in male individuals searching for a mate.

[0029] This, in this way, achieves a) the movement of insects that may be on the underside of the foliage to the upper surface where the preparation has been sprayed, and b) prolonged contact with the active substance of the insects which are already on the upper surface due to increased mobility (9), (10), (11).

[0030] More specifically, the preparation described in this patent features a triple combination where the individual components have plant-protection properties on their own but also act synergistically, increasing the efficiency of the final product. This synergy allows for enhanced effectiveness even at low concentrations of the primary active ingredient.

[0031] An additional advantage of the proposed composition is the use of glycerides (mono-, di-, tri-) derived from the same vegetable oils from which the potassium salts of fatty acids originate, serving as emulsifiers. The final product contains a significant percentage of fatty acids that reduce the alkalinity of the aqueous solutions of potassium salts, thereby mitigating the risk of phytotoxicity.

[0032] The final product offers an effective, economical, and environmentally friendly solution for combating, eliminating, and preventing agricultural pests (mites and insects with soft expskeleton). This patent's formulation can be applied independently as a plant protection agent or integrated into integrated pest management programs. Additionally, this product is an ideal alternative for replacing plant protection products to which harmful insect pests and mites have developed resistance. Efficacy Experiments

[0033] Laboratory Tests

[0034] In laboratory tests conducted by Mr, H. Tsolakis and Mr. S. Ragusa (12), the effectiveness of the proposed formulation was studied on the agricultural pest Tetranychus urticae (two- spotted spider mite) and the beneficial predator Phytoseiulus persimilis. The impact of the formulation was examined at three different developmental stages of the insects (egg stage, larval stage, adult stage).

[0035] The results of the laboratory tests showed no toxicity to the eggs and adult stages of the beneficial predator, moderate toxicity to the eggs and larvae of the yellow spider mite, and high toxicity (high mortality rates) to the adult mites. Additionally, a negative effect on the embryonic development of the eggs and consequently on their viability was observed. This negative impact on the viability of the eggs, combined with the direct effect of the formulation on adult mites by either causing immediate death or reducing their fertility, resulted in an impressive reduction in the two-spotted spider mite population (almost to zero) over time. Conversely, no adverse effects were observed on the beneficial insect from the application of the formulation.

[0036] Proposed Method of Preparation

[0037] Step 1: Preparation of the Active Substance

[0038] 122.1 grams of olive oil, 25.1 grams of glycerin, and 3.7 grams of potassium carbonate are added into a laboratory stirrer. The solution is heated to 140-150°C under continuous stirring and nitrogen until all components are fully dissolved. The mixture is then allowed to cool to room temperature, and its clarity and homogeneity are checked. The mixture must remain clear and not form layers.

[0039] Step 2: Preparation of the Final Formulation

[0040] Step 2,1

[0041] 15.6 grams of the preparation from Step 1 are mixed with 97.8 grams of olive oil and

[0042] 18.6 grams of oleic acid. The mixture is heated to 40-50°C under continuous stirring until fully homogenized.

[0043] Step 2.2

[0044] The acyclic sesquiterpenes, farnesol, and nerolidol, as well as the essential oil of caraway are added to the mixture, under continuous stirring. Application Example of the Proposed Formulation for Controlling Red Spider Mite (Panonychus ulmi Koch) in Apple Cultivation (Matus domestica)

[0045] The red spider mite infests all above-ground parts of the apple tree, with the most severe damage occurring during the summer. Control of the red spider mite begins in early spring and continues until early August. Among the mites that affect apple trees, the red spider mite is the most harmful species. The mite lives on both surfaces of the leaves, causing a reduction in the photosynthetic capacity of the leaves through its feeding activity, which in turn reduces the quantity and quality of the produced fruits. To avoid the development of resistant mite strains, the use of formulations with mechanical action is necessary.

[0046] In an experiment conducted in Larissa in 2022 on apples of the Super Chief variety, the eggs and motile forms of Panonychus ulmi on treated with the proposed formulation plants were compared with those on the control plants. The Henderson-Tilton efficacy of the proposed formulation on the eggs reached up to 94% seven days after the first spray, and on the motile forms, it reached up to 96% seven and fourteen days after the second spray.

[0047] Proposed doses: 1-1.5%, depending on: i) the developmental stage of the plant, ii) the degree of infestation, iii) the weather conditions, and iv) the use of other plant protection formulations.

[0048] Application method: Foliar spray coverage. Application timing: During the period when the first infestations appear. Spray volume: 100lt per 0.1 ha. Number of applications per growing season: 1 to 4, with application intervals of 7-10 days.

[0049] Bibliography

[0050] 1 Geoffrey Ongoya Wafula James W. Muthomi John H. Nderit & George N. Chemining’wa Efficacy of Potassium Salts of Fatty Acids in the Management of Thrips and Whitefly on Snap Beans, 2017, 6(4).

[0051] 2US5631290A Fatty acid salt pesticidal composition, inventors: David S. Almond, Diana L. Parker.

[0052] 3US6294578B1 Insecticides, miticides and method for killing insects and mites, inventors: Yutaka Arimoto, Isamu Yamaguchi. 4NZ522321ASoap based pesticides, inventors: Philip Frank Souter John Allen Burdis.

[0053] 4NZ522321ASoap based pesticides, inventors: Philip Frank Souter John Allen Burdis.

[0054] 5US6103768A Fatty acid based compositions and methods for the control of plant infections and pests, inventors: Steven D. Savage, Steven L. Evans, Robert A. Haygood, Paul S. Zorner, Keith Jones.

[0055] 6US 9,635,858 B2 Pesticide and a method of controlling a wide variety of pests, inventors: George David Newberry, Oakford George Bain, Chad Douglas DYER, Dario Sterzi.

[0056] 7KR20020069876A Insecticidal soap.

[0057] 8Klys M, izdebska A, Malejky N Repellent Effect of the Caraway Carum carvi L. on the Rice Weevil Sitophilus oryzae L. (Coleoptera, Dryophthoridae) Insects 2020, 11(12), 836.

[0058] 9Milena M. C. da Silva, Claudio A. G. da Camara, Marcilio M. de Moraes, Joao P. R. de Melo, Rodrigo B. dos Santosa and Roberta C. S. Neves Insecticidal and Acaricidal Activity of Essential Oils Rich in (E)-Nerolidol from Melaleuca leucadendra Occurring in the State of Pernambuco (Brazil) and Effects on Two Important Agricultural Pests, J. Braz. Chem. Soc.,2020, 31(4), 813-820.

[0059] 10Chan W K, Tan L, Chan K G, Lee LH, Goh B-H Nerolidol: A Sesquiterpene Alcohol with Multi- Faceted Pharmacological and Biological Activities Molecules 2016, 21(5), 529. 11 Manuel Canto-Tejero Pedro Guirao, Maria Jesus Pascual-Villalobos Aphicidal activity of farnesol against the green peach aphid - Myzus persicae Pest Management Science Journal, 2022, 76 (6).

[0060] 1’Manuel Canto-Tejero Pedro Guirao, Maria Jesus Pascual- Villalobos Aphicidal activity of farnesol against the green peach aphid - Myzus persicae Pest Management Science Journal, 2022, 76 (6).12H, Tsolakis, S. Ragusa Effects of a mixture of vegetable and essential oils and fatty acid potassium salts on Tetranychus urticae and Phytoseiulus persimilis Ecotoxicology and Environmental Safety, 2008, 70(2), 276-282.

Claims

Claims1. Composition for the management of mites and agricultural insects with a soft exoskeleton, with an action based on the combination of fatty acids potassium salts, in the presence of mono-, di- and triglycerides.

2. Composition according to claim 1, whose action is enhanced by the addition of the acyclic sesquiterpenes farnesol (3,7,l l-Trimethyl-2,6,10-dodecatrien-l-ol) and nerolidol (3,7,11- Trimethyl-l,6,10-dodecatrien-3-ol) with the aim of overstimulating the insect / mite and increasing its contact time with the active substance.

3. Composition according to claim 1, whose active substance results from the reaction of animal fats or vegetable oils with potassium hydroxide.

4. Composition according to claim 1, whose active substance is dissolved in mono-, di- or triglycerides of fatty acids.

5. Composition according to claims 1 and 2, that is suitable for use in organic agriculture for the management of mites and agricultural insects.

6. Composition according to claims 1 and 2, that is applied for the management of mites, aphids, thrips, coccidae, cicadae, psyllas and woolly aphids.

7. Composition according to claims 1 and 2, which is applied for the management of mites and agricultural insects of citrus trees, tree nuts, pome fruit trees, stone fruit trees, vegetables and ornamental plants.