Synergistic insecticidal compositions

Description of the invention

The invention relates to an insecticide composition, a bait composition, a method for controlling insects, and a method for protecting plants against invasion and attack by insects.

Insecticides and compositions for controlling harmful insects such as agro-horticultural pests, sanitary pests or wood feeding pests are used individually or in mixtures in practice. However, there is a constant search for insect control compositions that are economically effective and ecologically safe. Insecticidal compositions which can be used at lower effective application rates with increased environmental safety and a low incidence of insect resistance are highly desirable. Although insect control agents having different modes of action may alternate in accordance with the preferred method of practice in controlling insects, this procedure does not always permit satisfactory control of the insects. Moreover, while combinations of insect control agents have been tested, not always found significant synergistic effects. It is extremely difficult to obtain an insecticide composition that is not cross-resistant with existing insecticides, presents no toxicity problems, and has little negative environmental impact.

WO 96/03048 A describes an insecticide composition for controlling Lepidopteran insects comprising a chemical insecticide selected from the group consisting of pyrethroids, arylpyrroles, diacylhydrazines and formamidines and the genetically modified Autographa californica nuclear polyhedrosis virus (AcMNPV) in the form of polyhedral inclusions (PIB).

WO 96/01055 A describes the use of recombinant expression vectors expressing foreign proteins in the control of pests from the group of insects, mites and nematodes, in particular the use of pest pathogens, especially recombinant ones, in combination with synthetic chemical insecticides to increase the effectiveness of killing pests.

There was a need to develop a synergistic insecticidal composition which has a strong insecticidal effect, with a reduced production cost and reduced environmental burden, and a method for synergistic insect control and enhanced crop protection.

The invention relates to an insecticidal composition containing active substances and, optionally, auxiliary substances, characterized in that it comprises a sodium channel antagonist of the general formula I as active substances:

<img file="PL199694B1_D0001.tif" />

wherein A is CR4R5 or NR6;

W is O or S;

X, Y and Z are independently H; halogen atom; OH; CN; NO2; C1-C6-alkyl optionally substituted with one or more halogen, C1-C3-alkoxy, C1-C3-haloalkoxy, C3-C6-cycloalkyl, C2-C6-alkenyloxy or sulfonyloxy; C1-C6-alkoxy optionally substituted with one or more halogen, C1-C3-alkoxy or C3-C6-cycloalkyl; C1-C6-alkoxycarbonyl, C3-C6-cycloalkylcarbonyloxy, phenyl optionally substituted with one or more halogen, C1-C4-alkyl or C1-C4-alkoxy; aminocarbonyloxy optionally substituted with one or more C1-C3-alkyl; C1-C6-alkoxycarbonyloxy; C1-C6-alkylsulfonyloxy; C2-C6-alkenyl or NR7R8;

m, p and q are independently an integer of 1, 2, 3, 4 or 5; n is an integer 0, 1 or 2;

R, R1, R2, R3, R4 and R5 are independently H or C1-C4-alkyl;

PL 199 694 B1

R6 is H, C1-C6-alkyl, C1-C6-haloalkyl, C1-C6-alkoxyalkyl, C1-C6-alkoxy, C1-C6-haloalkoxy, C2-C6-alkenyl, C2-C6-alkynyl, C1-C6- alkylcarbonyl, C1-C6-alkoxycarbonyl, C1-C6-alkylthio or C1-C6-haloalkylthio;

R₇ and r₈ independently represent H or C.₁-C₆-alkyl;

and the dashed C — N group contains a double bond or a single bond; or a stereoisomer thereof, and a compound selected from group A:

1) pyrethroid compounds selected from the group consisting of cypermethrin, cyhalothrin, cyfluthrin, permethrin, etofenprox and silafluofen;

2) recombinant nucleopolyhedroviruses expressing insect toxin: HzNPV-AaIT;

3) organophosphorus compounds selected from the group consisting of profenophos, acephate, sulprophos, malathion, diazinon, methyl parathion and terbufos;

4) carbamate compounds selected from the group consisting of methomyl, thiodicarb and phenothiocarb;

5) formamidine compounds selected from the group consisting of amitraz, chlorodimeform and chlorophenamidine;

6) macrocyclic lactone compounds selected from the group consisting of spinosad, avermectin, emamectin, milbemectin, nemadectin and moxidectin;

7) amidinohydrazone compound: hydramethylnon;

8) GABA antagonist compounds selected from the group consisting of fipronil and endosulfan;

9) Acetylcholine receptor ligand compounds selected from the group consisting of imidacloprid, acetamiprid, nitenpyram and thiamethoxam in synergistically active amounts.

Preferably, the neuronal sodium channel antagonist is a compound of formula I and the dashed C-N group contains a double bond.

In particular, the composition comprises a compound of Formula I wherein W is O; X is 4-trifluoromethoxy; Y is 3-trifluoromethyl; Z is 4-CN; A is CH2; n is the number 0; m, p and q are the number 1; R and R1 are H.

Preferably the compound selected from Group A is hydramethylnon.

The invention also relates to a bait composition characterized in that it comprises 0.01-20% by weight of the neuronal sodium channel antagonist of formula I as defined above in combination with hydramethylnon.

Preferably, in both compositions, the active ingredient ratio is 1 part by weight of a neuronal sodium channel antagonist of formula I as defined above to 0.01-100 parts by weight of a compound of Group A as defined above.

The invention also relates to a method for controlling insects which comprises treating the insects with a composition as defined above.

In this method, the composition as defined above is treated against insects selected from the group consisting of Diptera, Hymenoptera, Blattaria, Isoptera, Coleoptera and Lepidoptera.

The invention further relates to a method of protecting plants against infestation and attack by insects, wherein an effective amount of a composition as defined above is applied synergistically to the leaves or stems of these plants.

Definitions

The term "acetylcholine receptor ligand compounds" as used herein means a compound capable of binding to an acetylcholine receptor site.

The term "group A" as used herein means insecticides

1) pyrethroid compounds;

2) recombinant nucleopolyhedroviruses capable of expressing an insect toxin;

3) organophosphorus compounds;

4) carbamate compounds;

5) formamidine compounds;

6) macrocyclic lactone compounds;

7) amidinohydrazone compounds;

8) GABA antagonist compounds, and

9) compounds that are ligands of acetylcholine receptors.

The term "haloalkyl as used herein" means a CXH2X + 1 alkyl group containing from 1 to 2 x + 1 halogen atoms, which may be the same or different. Similarly, the terms "haloalkoxy",

"Halo-phenyl" and the like mean monohalo to perhalogen substituents, the halogen atoms may be the same or different.

The term "halogen" as used herein means Cl, Br, I or F.

The term "neural sodium channel antagonist" as used herein means a compound capable of preventing the ability of nerve cells to transfer sodium ions across the cell membrane.

The term "synergism" as used herein means the interaction that occurs when two or more biologically active substances are combined, the combined activity of the two or more components exceeding the sum of the activities of the individual separate components.

It has now surprisingly been found that a composition comprising a neural sodium channel antagonist and a second insecticide is better at controlling insects with a lower level of interconnected active substances than can be achieved by applying the neural sodium channel antagonist or the second insecticide separately.

As previously stated, the term neural sodium channel antagonist is a compound capable of preventing the ability of nerve cells to transfer sodium ions across a cell membrane. The affected cell is unable to generate electrical pulses, resulting in paralysis and eventual death in the target host. Descriptions of neuronal sodium channel antagonists and methods of their action can be found in Pesticide Biochemistry and Physiology, 60: 177-185 or in the Archives of Insect Biochemistry and Physiology, 37: 91-103.

Neural sodium channel antagonists include compounds such as those described in US Patent Nos. 5,543,573; US 5708170; US 5,324,837 and 5,462,938 and other publications.

Other neuronal sodium channel antagonists include those described in US Pat. Nos. 5,116,850 and 5,304,573 and other publications.

The second active ingredient of the insecticidal composition may be one or more compounds selected from group A:

1) pyrethroid compounds known as active insecticides, such as cypermethrin, cyhalothrin, cyfluthrin, permethrin or the like;

2) recombinant nucleopolyhedroviruses capable of expressing an insect toxin, preferably an insect neurotoxin such as Androctonus australis (AalT) toxin, for example HzNPV-AaIT;

3) organophosphorus compounds known as insecticidally active substances, such as profenophos, acephate, sulprophos, malathion, diazinone, methyl parathion, terbufos or the like;

4) carbamate compounds known as active insecticides, such as methomyl, thiodicarb, phenothiocarb or the like;

5) formamidine compounds known as insecticidal active substances such as amitraz, chlorodimeform, hydramethylnon, chlorophenamidine or the like;

6) macrocyclic lactone compounds known as active insecticides, such as spinosad, avermectin, emamectin, milbemectin, nemadectin, moxidectin or the like;

7) amidinohydrazone compounds known as active insecticides, such as hydramethylnon;

8) GABA antagonist compounds known as active insecticides such as fipronil, endosulfan or the like;

9) Acetylcholine receptor ligand compounds known as active insecticides such as imidacloprid, acetamiprid, nitenpyram, thiamethoxam or the like.

A description of the above-mentioned commercially available compounds can be found in "The Pesticide Manual", 11th Edition, British Crop Protection Council (1997) and in other publications. Descriptions of recombinant nucleopolyhedroviruses expressing an insect toxin can be found, for example, in Treacy et al., Proceedings Beltwide Cotton Conference (1999), pp. 1076-1083.

Preferred compositions of the invention are compositions comprising a sodium channel antagonist compound of Formula I in combination with one or more compounds selected from Group A.

Each of the compounds of formula I contains asymmetric centers which may be present in the R or S stereoisomers. The invention thus comprises the R form, the S form and a mixture containing the R form and the S form in any ratio.

The neuronal sodium channel antagonist compounds of formula I may advantageously be formulated with a second effective insecticide component and optionally other compounds.

With the usual auxiliaries. These formulations may be dispersed in a solid or liquid diluent for application to the insects, their food, breeding grounds or habitats, as a dilute spray or as a dusting formulation or dust concentrate.

The active ingredients of the compositions according to the invention may also be formulated separately in the form of a wettable powder, an emulsifiable concentrate, aqueous or liquid formulations, suspension concentrates or any conventional formulations suitable for insect control agents, these formulations being blended under field conditions with water or other low-cost liquids in tanks for use as liquid spray mixtures. The separately formulated compositions may also be used sequentially.

A preferred composition of the invention may also be formulated as a bait containing a synergistically effective amount of a mixture of a neural sodium channel antagonist and one or more compounds selected from group A and a solid or liquid edible nutrient. A preferred bait composition may contain 0.01% to 20% by weight of the active ingredients, preferably a neural sodium channel antagonist in combination with hydramethylnon.

In present practice, the composition according to the invention can be applied to the foliage or stems of plants, or to the habitat of insects or pest infestation, in the form of a dilute spray prepared from any of the above-mentioned formulations. The composition according to the invention comprises the basic active substances in a ratio such that 1 part by weight of the neuronal sodium channel antagonist is to 0.01-100 parts by weight of one or more compounds selected from Group A.

The compositions according to the invention are excellent insecticidal compositions and are particularly useful for controlling agro-horticultural pests, indoor hygiene pests or wood-feeding pests. These compositions are very effective in protecting crops and crops, including: legume crops such as soybeans, green beans, peas, yellow string beans and the like, as well as cotton, forage crops, brassica, leafy vegetables, tobacco, hops, tomatoes, potatoes, flowering ornamental plants such as chrysanthemums, climbing plant crops such as grapes, squash, pumpkin or melon, and fruit trees such as cherries, peaches, apple trees or citrus trees against insect damage.

The synergistic insecticidal composition according to the invention has been found to be very active in the control of a wide variety of butterflies and broad-cover insects such as Helicoverpa zea (sunflower), Heliothis virescens (tobacco budworm), Leptinotarsa ​​decemlineata (Colorado potato beetle), P. (corn rootworm).

The composition according to the invention may be advantageously useful in the prevention and control of indoor insects and insects affecting the health of the public, such as: Diptera, e.g. house flies, mosquitoes and the like; Hymenoptera e.g. ants, parasitic wasps, wasps and the like; Blattaria e.g. cockroaches and the like.

Furthermore, the composition according to the invention may be particularly useful in the prophylaxis and control of wood-feeding insects such as termites (Isoptera), Hymenoptera, wood-feeding beetles (Coleoptera), and the like.

These and other advantages of the invention will become more apparent from the following examples. These examples are only illustrative of the invention and do not limit its scope.

Example 1

Evaluation of the synergistic insecticidal activity of a neural sodium channel antagonist in combination with a second insecticide compound

Heliothis zea, Heliothis virescens (tobacco budworm) and pyrethroid resistant Heliothis virescens larvae were used in this trial, obtained from a laboratory culture. Pyrethroid resistant H. virescens was derived from a PEG strain [Campannola &amp; Plapp, Proceedings of Beltwide Cotton Conference (1988)].

Cotton leaves were immersed for about 3 seconds in solutions of the test compounds or combination of test compounds dissolved in a 1: 1 mixture of acetone and water (v / v). After dipping, the leaves were allowed to air dry for 2-3 hours. Plastic bioassay trays containing a plurality of open were used as the test plots

The number of wells (4.0 x 4.0 x 2.5 cm). A portion of the cut leaves treated with the test solutions, a moistened dental cotton pad, and a single third instar larva were placed in each well. The wells were covered with a self-adhesive clear plastic sheet with vents and a temperature of approximately 27 ° C illuminated with continuous fluorescent light for a specified period of time. Mortality / morbidity was assessed on day 5 after treatment of the leaves. All leaf treatments were repeated 4-5 times according to a completely randomized block pattern, with 16-32 larvae being treated each time. Using a known "log-probit analysis" method, the LC50 for each leaf treatment was determined.

Using the above procedure, the effect of the neural sodium channel antagonist (Compound A) alone at doses of 0.1 ppm, 1.0 ppm and 10.0 ppm and in combination with a second insecticide compound at a concentration of 1.0 ppm can be assessed. The foliar treatments that can be used are shown in Table I.

Table I.

<td colspan="2">The second active ingredient</td><td colspan="4">Relationship A¹</td>

<td>Relationship name</td><td>Dose (ppm)</td><td>Dose (ppm)</td><td>Dose (ppm)</td><td>Dose (ppm)</td><td>Dose (ppm)</td>

<td>Cypermethrin</td><td> 0</td><td> 0</td><td> 0,1</td><td> 1,0</td><td> 10,0</td>

<td></td><td> 1,0</td><td> 0</td><td> 0,1</td><td> 1,0</td><td> 10,0</td>

<td>Amitraz</td><td> 0</td><td> 0</td><td> 0,1</td><td> 1,0</td><td> 10,0</td>

<td></td><td> 1,0</td><td> 0</td><td> 0,1</td><td> 1,0</td><td> 10,0</td>

<td>Fipronil</td><td> 0</td><td> 0</td><td> 0,1</td><td> 1,0</td><td> 10,0</td>

<td></td><td> 1,0</td><td> 0</td><td> 0,1</td><td> 1,0</td><td> 10,0</td>

<td>Acetamiprid</td><td> 0</td><td> 0</td><td> 0,1</td><td> 1,0</td><td> 10,0</td>

<td></td><td> 1,0</td><td> 0</td><td> 0,1</td><td> 1,0</td><td> 10,0</td>

<td>Spinosad</td><td> 0</td><td> 0</td><td> 0,1</td><td> 1,0</td><td> 10,0</td>

<td></td><td> 1,0</td><td> 0</td><td> 0,1</td><td> 1,0</td><td> 10,0</td>

<td>Thiodicarb</td><td> 0</td><td> 0</td><td> 0,1</td><td> 1,0</td><td> 10,0</td>

<td></td><td> 1,0</td><td> 0</td><td> 0,1</td><td> 1,0</td><td> 10,0</td>

¹Compound A = neuronal sodium channel antagonist of formula Ia

<img file="PL199694B1_D0002.tif" />

Example 2

Assessment of the synergistic effect of the neuronal sodium channel antagonist in combination with amidinohydrazone in combination with insecticidal activity

Adult male German cockroaches (Blattella germanica) were used in this trial. In each trial, a 4.0 g portion of Purina Dog Chow ground dog food (Hi-Pro Glo®) was treated with an acetone solution of the test compound, alone or in combination with a second test compound. The acetone was then evaporated and the treated dog food sample was placed in a 22.18 ml plastic cup which was placed in a seat made of folded sheets of blotting paper, placed in a plastic box (40.64 cm long x 27 cm). , 94 cm wide x 15.24 cm high). The plastic box (experimental box) was also equipped with a 29.57 ml bottle with a narrow opening into which 2 dental tampons were inserted. A control box was prepared in the same manner with analytical grade acetone treated ground dog food. Each attempt was repeated 3 times. 20 healthy adults were placed in each experiment box

Of male German cockerels, bred in an insectarium. The test boxes were then kept at 76 ° F (24.5 ° C) and mortality was assessed daily by visual inspection. The data obtained are summarized in Table II.

Table II

<td rowspan="3">Tested relationship</td><td rowspan="3">Active substance content (%)</td><td colspan="6">Mortality (%)</td>

<td colspan="6">Days after treatment with test compound</td>

<td> 3</td><td> 4</td><td> 5</td><td> 6</td><td> 7</td><td> 8</td>

<td>AND¹</td><td> 0,05</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td>

<td>AND</td><td> 0,10</td><td> 1,7</td><td> 11,7</td><td> 11,7</td><td> 11,7</td><td> 18,3</td><td> 18,3</td>

<td>AND</td><td> 0,50</td><td> 5,0</td><td> 5,0</td><td> 5,0</td><td> 5,0</td><td> 5,0</td><td> 5,0</td>

<td>B²</td><td> 1,00</td><td> 0</td><td> 5,0</td><td> 28,3</td><td> 71,7</td><td> 90,0</td><td> 93,3</td>

<td>A + B</td><td> 0,05+1,0</td><td> 0</td><td> 20,0</td><td> 41,7</td><td> 81,7</td><td> 95,0</td><td> 98,3</td>

<td>A + B</td><td> 0,10+1,0</td><td> 0</td><td> 21,7</td><td> 51,7</td><td> 88,3</td><td> 95,0</td><td> 95,0</td>

<td>A + B</td><td> 0,50+1,0</td><td> 16,7</td><td> 58,3</td><td> 80,0</td><td> 95,0</td><td> 98,3</td><td> 100,0</td>

<td>Control</td><td> 0</td><td> 0</td><td> 1,7</td><td> 3,3</td><td> 3,3</td><td> 3,3</td><td> 5,0</td>

¹ Compound A = neuronal sodium channel antagonist of formula Ia ² Compound B = hydramethylnon

<img file="PL199694B1_D0003.tif" />

The data in Table II show that the combination of a neural sodium channel antagonist with an amidinohydrazone insecticide provides synergistic insect control.

Example 3

Assessment of the synergistic effect of the neuronal sodium channel antagonist in combination with a recombinant nucleopolyhedrovirus capable of expressing an insect toxin

The larvae of Helicoverpa zea (American sunflower) obtained from laboratory culture were used in this test. Test compounds were dissolved in a 1: 1 mixture of acetone and water (v / v). Plastic bioassay trays (CD International, Pitman, NJ) were used as test plots. Each tray contained 32 open wells (4.0 x 4.0 x 2.5 cm). An aliquot (5 mL) of wheat germ and soy flour artificial food (Southland Products, Lake Village, AR) was poured into each well. After hardening of the food, 0.4 ml of the test solution was pipetted onto its surface in each well. The test solutions were spread evenly over the surface of the food by grasping the tray and gently tilting it from side to side. The trays were then kept in a ventilated room for approximately 2 hours until the water disappeared from the surface of the food. A single 4 day old H. zea larva was then placed on the surface of the food in each well. After placing the larvae, each well was covered with a self-adhesive clear plastic sheet with vents.

All test plots were kept at a temperature of about 27 ° C and illuminated with continuous fluorescent light for the duration of the test. Larvae mortality was determined on days 2, 3, 4 and 7 after treatment with test compounds. A larva was considered dead if very little or no movement was visible, even when shaking the test tray. For each treatment with test compounds, 32 insects were tested. The results obtained are presented in Table III.

PL 199 694 B1

Table III

<td rowspan="3">Tested relationship</td><td rowspan="3">Concentration active substance</td><td colspan="4">Mortality (%)</td>

<td colspan="4">Days after treatment with test compound</td>

<td> 2</td><td> 3</td><td> 4</td><td> 7</td>

<td>AND¹</td><td>0.1 ppm</td><td> 43,8</td><td> 46,9</td><td> 53,1</td><td> 53,1</td>

<td>B²</td><td>1000 OB³/ ml</td><td> 3,1</td><td> 34,4</td><td> 50,0</td><td> 62,5</td>

<td>B</td><td>500 OB / ml</td><td> 0,0</td><td> 9,4</td><td> 18,8</td><td> 40,6</td>

<td>B</td><td>100 OB / ml</td><td> 3,1</td><td> 3,1</td><td> 3,1</td><td> 15,6</td>

<td>A + B</td><td> 0,1+1000</td><td> 87,5</td><td> 90,6</td><td> 93,8</td><td> 96,9</td>

<td>A + B</td><td> 0,1+500</td><td> 75,0</td><td> 78,1</td><td> 84,4</td><td> 87,5</td>

<td>A + B</td><td> 0,1+100</td><td> 62,5</td><td> 75,0</td><td> 75,0</td><td> 78,1</td>

<td>Control</td><td> 0</td><td> 3,1</td><td> 3,1</td><td> 3,1</td><td> 3,1</td>

¹ Compound A = neural sodium channel antagonist of formula Ia ² Compound B = HzNPV-AaIT, Helicoverpa zea nucleopolyhedrovirus capable of expressing Androctonus australis insect toxin. ³ OB = Viral Occlusal Substances

<img file="PL199694B1_D0004.tif" />

The data in Table III shows that the combination of a neural sodium channel antagonist with a recombinant nucleopolyhedrovirus expressing an insect toxin provides synergistic insect control.