Field of Invention:
The present invention relates to a synergistic insecticidal formulation of a phenylthio urea compound and a neonecotinyl compound in wettable powder form and a process for the preparation of the composition, to its use.
Back ground of the invention:
Many processes for insecticidal agents and compositions have been developed to control insect, pest and in practice have been used as a single or a mixed agent. However,process for economically and ecologically safe insect control composition are still being sought. A process for the preparation of insecticidal composition which allows to reduce effective dosage rates, increased environmental safety and lower incidence of insect resistance are highly desirable.
There is a need to develop a composition which addresses the problem of resistance and also controls the environmental damage, offers broad crop protection spectrum, improved and healthy foliage, rain fastness, saves labor and control against various pest and insects, improves plant growth and yet cost effective to the end user.
Certain mixtures of active ingredients are proposed in literature for controlling of pest. However, the biological properties of these mixture of known compounds are not entirely satisfactory in the field of pest control.
US patent 20120220463 discloses a crystalline complex form of Acetamiprid with 4-Hydroxy Benzoic acid .The art requires a free flowing powder formulation of Acetamiprid which does not cake on storage and inorder to accomplish the same combination formulation with Diafenthiuron has been designed. Diafenthiuron is a free flowing crystalline material and thus it provided a grinding aid to Acetamiprid.
EP 0736252A2 describes synergistic combination formulation of Diafenthiuron with various agro chemically active compounds including Acetamiprid for controlling diverse nature of insects. This describes preparation in the form of emulsifiable concentrate, dusting powder and suspension concentrates.
EP 2534951 describes a method of transgenic plant production potential utilization involving utilizing of a plant with an effective quantity of Diafenthiuron and Acetamiprid and their combination.
CN102626077 discloses an ultra low volume liquid composition containing Flubendamide as active ingredient (I) and diafenthuron or Acetamiprid as active ingredient( II) in the combination formulation for controlling pest attack by ultra low volume spraying ,or ultra low volume electrostatic spraying.
WO 2012101659 describes a pesticidal composition comprising an effective amount of Sulphur and effective amount of at least one insecticide selected from Diafenthiuron, Fipronil, Acetamprid and Abamectin.
CN 102113510 describes a composition containing Metaflumizone as an active ingredient( I) and Diafenthiuron or Acetamiprid as in ingredient (II). The Composition prepared exhibits synergy and the combination also deferred the resistance developed by use of Chlorantraniliprole.
CN 102113516 describes an invention of a combination formulation of Chlorantraniliprole as active ingredient (A) and Diafenthiuron or Acetamiprid as an active ingredient ( B). The Invention describes that on reducing the dosage of active ingredient (A) the drug resistance of insect and mites on the Chlorantraniliprole is reduced.
DE 102009028001 describes use of an active agent combination comprising at least a 3-phenyl-1-aza-spiro {4, 5} dec-3-en-2-one as compound (1) and one or more Insecticidal /Acaricidalagentor controlling animal pests where insecticidal/acaricidal agent is Acetamiprid or mite growth inhibitor Diafenthiuron.
CN 101589722 discloses a synergistic combination formulation of Emamectin Benzoate or Abamectin as component (1) and Acetamiprid or Diafenthiuron as component (2) for controlling agriculture, forestry and gardening insects and pests.
EP 2090170 describes a combination formulation of 1-{2, 4-dimethyl-5-(2, 2, 2-trifluro ethane sulfinyl)- phenyl]-3-trifluoromethyl-1H-(1, 2, 4) Triazole as active ingredient (1) and insecticide/acaricideAcetamiprid or Diafenthiuron as active ingredient( 2). The composition exhibits synergistic effect.
The prior art utilized combination formulation of Acetamiprid with several agro chemical active substances to increase its spectrum for controlling pests. Similarly attempts have been made to broaden spectrum of Diafenthiuron by making its combination formulation with other agro chemical active substances.
Solid pesticidal composition such as wettable powder and soluble powder (WP/SP) and water dispersible or soluble granules (WG/SG) containing combination of agriculture actives with different mode of action can be difficult to produce and store due to tendency to physically degrade and agglomerate to cake when subject to range of temperature and shear stress normally encountered during processing and storage .In addition these composition may suffer from poor dispersion in water and poor delivery of the active ingredient to the locus of the pests requiring control of elimination.
Stable wettable granule are generally defined as those that are stable physically and chemically to the environment in which they are produced and stored and deliver acceptable level of biological efficacy when used with in differed period of time.
Diafenthiuron is an insecticide and acaricide which kills Larvae, nymphs and adults by contact / stomach action and also exhibits ovicidal action. Acetamiprid exhibits a systemic translaminar action. It has a novel mechanism of action on the insect nervous system by acting as an agonist to nicotinic acetyl chlorine receptors.

Diafenthiuron is the common name of 1-tert- butyl-3-(2, 6-Di-isopropyl phenoxyphenyl) thiourea. It is white to of white powder with the following physic- chemical properties:
Melting point – 146.6-147.7° c
V.P < 2X10-3mPa (25° C)
Kow log p- Kow Log P=5.76
Solubility: In water 0.06mg/L(25°C)In Ethanol 43, Acetone 320, Toluene 330, n-hexane 9.6, n-octanol 26(all in g/l 25°c)
Stability: Stable in air, water and to light.
Acetamiprid is the common name of (E)-N-[(6-chloro-3-pyridyl) methyl]-N-cyano-N-methyl acetamidine.It is off white to pale yellow powder with the following physico- chemical properties:
Melting point –98.9°C, tech. 45°C
Flash point-166.9°c
Solubility in water - 25gm/l at 25°C
n- Octanol /H2O partition co-efficient Kow-0.8 at Ph7, 20°c
V.P. <1.0X10 mPa at 25°c
Stable at PH 5-8 and is stable in most organic solvent e.g. acetone, ethanol, methanol, chloroform, dichloromethane, acetonitrile. It is stable under normal storage conditions and unstable above 45°C.Hazardous decomposition products are carbon monoxide and hydrogen chloride.
Diafenthiuron has very poor solubility in water and has high melting point and is formulated as wettable powder and an aqueous suspension concentrate. Acetamiprid is soluble in water and has low melting point and is formulated as soluble powder,emulsifiable concentrate and water dispersible granule formulation.
Diafenthiuronhas poor flow ability and has tendency to cake on storage. Acetamiprid has low melting point, soluble in water and low amorphous structure resulting in processing difficulties ,formulation instabilities and application unreliability due to caking and setting of fine particles.
To develop a stable pesticide formulation, which also exhibits satisfactory pesticidal action is a challenge for the skilled artisan. A central parameter in formulation technology is the control of physio chemical properties of the pesticide, both in the formulation per se and the application form of the formulation e.g.in tank mix, where in the respective formulation is diluted with water.
Object of the Invention:
It is the object of the invention to provide a novel synergistic insecticidal combination formulation of Diafenthiuron and Acetamiprid and also control insect /pests which are not or not sufficiently controlled by individual components. Further the invention attempted a combination formulation which is better tolerated by plant i.e. they are less phototoxic and should also control the various stages of the insects.
It is yet a further object of the invention to provide a favorable condition for grinding,mixing and storage for Acetamiprid and Diafenthiuron. It is yetanother object of the invention to provide a synergistic composition which exhibits increased efficacy with reduced dosage as compared to the individual insecticide components.
Yet another objective of the present invention is to provide a process of preparing a synergistic insecticidal combination formulation of Diafenthiuron and Acetamiprid in a wettable powder form.
Summaryof the Invention:
The present invention relates to a synergistic composition which comprises a pesticidal combination of active ingredients to a method of controlling pests, to a process for the preparation of the composition, to its use and the use of Diafenthiuron and Acetamniprid for preparation of combination.
The present invention relates to aprocessfor combination formulation of Diafenthiuron and Acetamiprid where in chemical properties of both the active compound is retained and provided synergistic effect by controlling vide variety and stages of the insects at lower dosages.
Further the invention particularly relates to a processfor making wettable powder formulation free flowing in nature which does not cake on storageand exihibit improved dispersion in water.
The present invention found that the combination of diafenthuron with acetamiprid in a wettable powder form causes not only an additive widening of the spectrum of action on the pests to be controlled but also that it provoked a synergistic effect which extended the limits of the action of both products. Further more, the synergistic effect was more pronounced when trisiloxaneethoxylate was incorporated in the composition primarily to decrease foaming at the time of spray.
In addition to the actual synergistic effect with regard to the pesticidal activity, the composition have additional advantages, which can be termed synergistic in wider sense e.g. they allow pests which are not or not sufficiently controlled by individual components. Furthermore the compositions are better tolerated by plants and various stages of the insects can be controlled. In addition the combination of acetamiprid with diafenthiuron exhibited more favourable behavior during grinding, mixing, storage and also at the time of spraying.
The present invention providing synergistic effect of the combination formulation of Diafenthiuron and Acetamiprid in wettable powder form relates to the composition comprising of Diafenthiuron (30-45%) Acetamiprid (3-10%),wetting and dispersing agent (8-12%),inerts (35-58%) anti caking agent (2-5%) stabilize and deforming agent (0.1-1.0%).
Proper solution of wetting and dispersing agents, anti caking/agglomeration suppressant,stabilizer and defoaming agent is most important in preventing caking, providing good dispersing and thereby provided broad crop coverage area.
The dispersing agent is a compound which ensures that the particles remain suspended in water. The dispersing agent can be ionic or non ionic or a mixture of the such surface active agents orgraft co-polymer dispersant .According to another embodiment, the dispersing agent are selected from group comprising polycarboxilates,alkyl naphthalene sulfonates, phenol sulphonic acid condensates,lignosulphonates,methyl oleyltaurates and poly vinyl alcohols.The dispersing agent is present in the composition in a range of about 5-8% of the total weight of the composition .
The wetting agent is a compound which facilitates rapid wetting of the powder when added to the water .As wettable agent useable in the present invention alpha olefin sulfonates,sodium lauryl sulphate,polyoxyalkylene alkyl ether,polyoxyalkylene alkyl ether,polyoxyalkylene alkyl phenyl ether sulfonates,dialkylsuccinate etc. can be exemplified. The wetting agent in the present composition is in a range about 5-8%of the total weight of the composition.
Solid inert carriers which are used as ground natural minerals such as calcite, talc, kaolin, and montmorillonite orattapulugite .Highly disperse silica or highly disperse absorptive polymers may also be used to improve physical properties. The inert carrier are present in the in the composition in a range of about 40-55% of the total weight of the composition.
The present composition further comprises a silicone based antifoaming agent which surprisingly delivered synergism and improved spray properties of the formulation . The antifoaming agent used are a blend of trisiloxaneethoxylates in composition and are in the range of 0.1-1.0% of the total weight of the composition.
The composition further comprises stabilizing agent in the range of 1.0-5.0%of the total weight of the composition such as stearic acid,tricalcium phosphate,trisodium citrate.The stabilizer in the present composition in a range 1-5% of trisodium citrate.
The present invention relates to a process for preparing a synergistic composition comprising the steps of(a) blending of antifoaming agent with inert, (b)Blending of inert treated with antifoaming agents with toxicants, wetting agent ,dispersing agent, lavigated clay, (c) Micronization of the blended mixture in air jet mill (d) Post blending of the micronized material. The mixture mass is air milled to average particle size of less than 20 micron.The process uses the dispersing agent, silica poly ether copolymer. The blending of silica polyether and salt of citric acid exhibited improved flow ability suspensibility and synergism.
The present invention will be illustrated in more detail with reference to the following formulation examples and product test results. These examples are just illustrative and are not meant to be limiting.
Formulation example:

The following examples illustrate the basic methodology and versatility of the invention.
The preparations of the present wettablepowder formulations are shown in table 1,2 and 3 .The wettable powder formulations were prepared step wise as given below:
Step 1
The antifoaming agent 0.3 parts by weight, silica 5.0 parts by weight and lavigated clay 10 parts by weight were mixed together and homogenized.
Step 2
40.1 parts by weight of Diafenthiuron technical,3.9 parts by weight of Acetamipridtechnical ,3 parts by weight wetting agent ,6 parts by weight of dispersing agent ,4 parts by weight of trisodium citrate and 27.7 parts by weight of lavigated clay were thoroughly mixed in a ribbon blender. The above mixed mass was then mixed with 15.3 parts by weight of material mixed in step 1.
Step 3
The homogenously mixed mass of step 2 was air jet milled to particle size less than 20 microns and thoroughly homogenized in post ribbon blender.
The following table illustrate the various combinations of diafenthiuron technical(30-45%m/m)and acetamiprid (3-10%m/m) were prepared and evaluated for synergistic effect .The below table also illustrate the composition prepared to achieve the best suspension, wetting and storage stability.
Table 1

Preparation 1 2 3 4
Diafenthiuron 30 35 40.1 45
Acetamiprid 10 5 3.9 3.0
Wetting Agent 3 3 3 3
Dispersing Agent 6 6 6 6
Antifoam 0.3 0.3 0.3 0.3
Trisodium Citrate 4.0 4.0 4.0 4.0
Silica 5.0 5.0 5.0 5.0
Lavigated Clay 41.7 41.7 37.7 33.7
Total 100 100 100 100

Table 2

Preparation 5 6 7 8
Diafenthiuron 40.1 40.1 40.1 40.1
Acetamiprid 3.9 3.9 3.9 3.9
Wetting Agent 1.5 2.0 2.0 3.5
Dispersing Agent 6.0 5.5 5.0 4.5
Antifoam 0.3 0.3 0.3 0.3
Trisodium citrate 4.0 4.0 4.0 4.0
Silica 5.0 5.0 5.0 5.0
Lavigated clay 39.2 39.2 38.7 38.7
Total 100 100 100 100

Table 3

Preparation 9 10 11 12
Diafenthiuron 40.1 40.1 40.1 40.1
Acetamiprid 3.9 3.9 3.9 3.9
Wetting Agent 3 3 3 3
Dispersing Agent 6 6 6 6
Antifoam 0.3 0.3 0.3 0.3
Trisodium Citrate 1.0 2.0 3.0 4.0
Silica 5.0 5.0 5.0 5.0
Lavigated clay 40.7 39.7 38.7 37.7
Total 100 100 100 100
All the above preparations are in Mass/Mass

Evaluation of Physico- chemical properties-Active ingredients, wettability, supensibilityand flowablity.
Preparation 1 2 3 4 5 6 7 8 9 10 11 12
a.i.Diafenthiuron 30.2 34.8 40.2 44.7 39.8 40.1 40.3 39.8 39.5 39.7 40.2 40.1
a.i.acetamiprid 10.9 5.1 3.9 3.1 3.85 3.9 4.0 3.9 3.95 3.9 3.95 3.85
Wettability 60 55 42 40 90 42 40 35 50 45 40 35
Suspensibility 80 85 95 96 60 96 50 70 80 90 95 90
Flowability NF NF F F F F F F NF F F F

Bio-efficacy of Diafenthiuron40.1%+ Acetamiprid 3.9% WP
Diafenthiuron40.1%+ Acetamiprid 3.9% WP combination has been tested against white fly and other sucking pest complex of cotton and found that due to strong synergy of both the compound which belongs to (Thio-urea compound) and neonicotioid gave the good and long duration control of white fly and other sucking pest at the dose of ranging from 437.5 -500 g/ha.
Difenthiuron is a pro insecticide, which has first to be converted to its active form. The active compound then acts on a specific parts of the energy producing enzyme in the mitochondria of white fly and other sucking pests of cotton resulting into immediate paralysis of the pest after intake or contact and also due to strong vapour action.
Acetamiprid also kills the sucking pest through contact and stomach poisoning and also due to strong translaminar action provides the effective control of hidden sucking pest on the dorsal side of the leaves.
The combination has very strong synergy and thus provides quick and long duration control of sucking pest given 87.34% control of sucking pest while Diafenthiuron has given control of 76.26% and Acetamiprid provides only 64.39% control and shown the yield enhancement of 14% & 18% as compared to Diafenthiuron and Acetamiprid alone respectively.
No. of treatment : 5
Plant to plant Distance: 0.5 m.
Row to row spacing : 0.5 m
Plot size: 5x3 m
No. of spray: 1
Bio-efficacy of Diafenthiuron 40.1% + Acetamiprid 3.9 % WP against cotton whitefly.

S.No. Treatment Dose
(ml/g)/ha Mean of No. of whitefly/leaf
(15 leaves/5 plants/treatment) Per cent mortality of whitefly
Pre treatment 24 hrs 48 hrs 7 DAS 15 DAS 24 hrs 48hrs 7DAS 15DAS
1 Diafenthiuron 40.1% + Acetamiprid 3.9% WP 375 18.33 16.20 11.93 7.13 8.13 11.62 34.91 61.10 55.64
2 Diafenthiuron 40.1 % + Acetamiprid 3.9% WP 437.5 16.66 10.80 4.13 1.80 1.66 35.17 75.21 89.19 90.03
3 Diafenthiuron 40.1% + Acetamiprid 3.9 % WP 500 17.60 10.73 3.80 1.46 1.33 39.03 78.40 91.70 92.46
4 Bifenthrin 10 % EC 800 20.33 15.33 10.53 8.33 12.40 24.59 48.20 59.02 39.00
5 Control - 17.40 17.80 18.13 23.33 26.46 +2.29 +4.19 +34.08 +52.06
DAS= Days After Spray
Results:
Diafenthiuron 40.1% +Acetamiprid 3.9% WP @ 437.5 g/ha andDiafenthiuron 40.1% + Acetamiprid 3.9 % WP @ 500 g/ha dose were at par as they exhibited whitefly mortality 89.19, 91.70 per cent after 7 days and 90.03, 92.46 per cent after 15 day of spray.
Diafenthiuron 40.1% +Acetamiprid 3.9% WP @ 437.5 g/ha and @500g/ha dose showed synergistic effect and significantly superior to standard check of Bifenthrin 10 % EC @ 800 ml/ha for control of whitefly after 7 and 15 days of spray.

Apart from the actual synergistic effect in respect of the pesticidal activity, the compositions in accordance with the invention also have further advantages, which in a broadened sense can likewise be regarded as synergistic; for example, by the use of composition, pests are controlled, which cannot be controlled at all or only with insufficient effect using the other known composition, and the compositions according to the invention show better plant tolerance along with other advantages. In addition to this, the insects are controlled at their different stages of development, which is not the case with many known pesticides.
The amount of above constituents may change based on further field trials and accordingly the change will be updated in complete specification. The sequence of above given steps may also change in case such change provides better results.
Although the present invention has been disclosed in terms of a preferred embodiment, it will be understood that numerous additional modifications and variations could be made thereto with our departing from the scope of the present invention.

CLAIMS:
1. An insecticidal synergistic composition,comprising
- Diafenthiuron
-Acetamiprid
-wetting, dispersing,anti caking agent, stabilizing antifoaming agent and inert carrier silica and lavigated clay

to obtain said composition in a wettable powder form.
2. The composition as claimed in claim 1 wherein said wetting agent is 3% by mass of a blended anionic and nonionic surfactant.
3. The composition as claimed in claim 1 wherein said dispersing agent is 6% by mass of a polymeric surfactant blended with anionic sulfated surfactant.
4. The composition as claimed In claim 1 wherein the flow improving substance is 2% by mass of the participated silica.
5. The composition as claimed in claim 1 wherein the stabilizer is 4% by mass salt of citric acid.
6. The composition as claimed in claim 1 where in the inert filler is lavigated china clay.
7. The composition as claimed in claim 1 where in the anti caking agent is a salt of citric acid.
8. A process for preparing a synergistic composition as claimed in claim 1 comprising the steps of-
(a) blending of antifoaming agent with inert
(b)Blending of inert treated with antifoaming agents with toxicants, wetting agent ,dispersing agent ,lavigated clay
(c) Micronization of the blended mixture in air jet mill.
(d) Post blending of the micronized material.
9. The process as claimed in claim 8 wherein the mixture mass is air milled to average particle size of less than 20 micron.
10. The process as claimed in claim 8 wherein the dispersing agent used is a silica poly ether copolymer.
11.The process as claimed in claim 8 wherein the blending of silica polyether and salt of citric acid exhibited improved flow ability suspensibility and synergism.
12. A synergistic insecticidal composition in wettable form as claimed in claims 1 to 7 substantially as herein described with reference to foregoing examples.
13. A process for preparing synergistic insecticidal composition in wettable form as claimed in preceeding claims 8- 11 substantially as herein described with reference to foregoing examples.