FIELD OF THE INVENTION
The invention relates to insecticidal compositions. More particularly, the present invention relates to a synergistic insecticidal composition comprising Fipronil and Propargite.
BACKGROUND OF THE INVENTION
Crop protection technology which includes all pesticides, herbicides, insecticides, fungicides, as well as biotechnological products helps control the thousands of weed species, harmful insects and numerous plant diseases that afflict crops. In the absence of these important crop protection and pest control technologies, food production would decline, many fruits and vegetables would be in short supply and the price of food would rise. Additionally, the production of important fibres for clothing such as cotton would decrease as farmers would lose their harvest and livelihoods to crop pests and diseases. Thus, crop protection is very important to increase the production of agricultural products and at the same time reduce their cost.
Several insecticidal agents and compositions have been developed to control insect pests; however, economically efficient and ecologically safe insect control compositions are still being sought. Insecticidal compositions which allow for reduced effective dosage rates, increased environmental safety and lower the incidence of insect resistance are highly desirable. The rotational application of insect control agents may be adopted as good pest management practice. However, this does not necessarily provide satisfactory insect control.
The use of insecticidal combinations is a widespread and documented practice in the agricultural community. Insecticidal combinations offer significant advantages over individual applications including improved and extended insect control, reduced insecticide rates and application costs, shorter contact times for improved results, less stringent use restrictions, improved selectivity, improved spectrum of weeds controlled, reduced cost and reduced residue problems. However,

identifying appropriate insecticidal application rates and combinations is essential to achieve synergistic insect control.
Numerous insecticide combinations are commercially available for pest control in different crops. Most of these products target one or at the most two specific insects. In tea gardens, the pests most likely to cause damage include red spider mite, Helopeltis, green fly, thrips, looper caterpillar etc. In recent years, looper caterpillar complex has emerged as the primary cause of crop damage in tea plantations. Commercially available insecticidal compositions mainly control either mites, sucking pests or lepidopteran pests, thereby necessitating the use of more than one insecticidal sprays for effective pest control. Even molecules or combinations reported in scientific literature only target or control specific pests.
The study by Regev and Cone, entitled "Evidence of Farnesol As a Male Sex Attractant of the Two-Spotted Spider Mite, Tetranychus urticae Koch (Acarina: Tetranychidae)", Environmental Entomology, April 1985, Vol. 4, No. 2, pp. 307-311, indicated that certain isomers of synthetically produced farnesol, at particular concentrations, were effective in attracting male spider mites.
A further study by Regev and Cone, "Analysis of Pharate Female Two- spotted Spider Mites for Nerolidol and Geraniol: Evaluation for Sex Attraction of Males", Environmental Entomology, February 1976, Vol. 5, No. 1, pp. 133-138, also revealed that the two-spotted spider mite female deutonymph also contains the sesquiterpene alcohol nerolidol; their study indicated that synthetic nerolidol, at particular concentrations, served to attract male two-spotted spider mites.
U.S. Patent No. 4,775,534 discloses a miticidal composition adapted to be sprayed onto foliage to control spider mite populations. U.S. patent no. US 8,486,995 B2 also discloses an Acaricidal active substance combination to control different mites.
In view of the above, obtaining an insecticidal combination which demonstrates broad-spectrum control of insects, no cross-resistance to the existing insecticidal agents, no toxicity problems and little negative impact on the environment is

extremely important. Thus, it is an objective of this invention to provide a synergistic insecticidal combination which demonstrate a high controlling effect along with reduced crop protection cost and reduced environmental load.
Fipronil ((±)-5-amino-l-(2,6-dichloro-a,a,a-trifluoro-p-tolyl)-4-
trifluoromethylsulfinylpyrazole-3-carbonitrile, CAS-Number: 120068-37-3) is a broad-use insecticide that belongs to the phenylpyrazole chemical family. Apart from its disclosure in the application EP 0295117, the properties of Fipronil have been published in the report of the 1992 Brighton Crop Protection Conference (Pests and Diseases, pages 29-34).
Fipronil acts as a blocker of the GABA-Regulated chloride channel. Insects resistant to pyrethroid, cyclodiene, organophosphorous and/or carbamate insecticides are susceptible to Fipronil. It is also a broad spectrum insecticide, and exhibits toxicity by contact and ingestion.
Propargite, 2-(4-tert-butylphenoxy) cyclohexyl prop-2-ynyl sulfite, CAS-Number: 2312-35-8, disclosed in U.S. Pat. No. 3,272,854, a well-known insecticide sold under the trademark OMITE (Uniroyal Chemical Company), is a pesticide used to kill mites (an acaricide).
o

O O—CH2—C=CH
0
0
H3/ Chl3
The standard composition of Propargite available in the art is 57 percent emulsifiable concentrate (EC).
The Applicant, in the parent application no. 1342/DEL/2015 has disclosed synergistic composition comprising Fipronil and Propargite, in a mass ratio in the range of 1:9 to 1:13. The synergistic composition was found to be more effective as compared to their individual components.

SUMMARY OF THE INVENTION
The inventors of the present invention have now surprisingly found that a composition comprising fipronil and propargite in a mass ratio of 1:14 to 1:17 also resulted in synergistic effect. The synergistic composition of the present invention has a wider applicability in terms of crops and pests.
The present invention provides a synergistic insecticidal composition, comprising: a) Fipronil b) Propargite and c) excipient wherein the mass ratio of Fipronil to Propargite is in the range from about 1:14 to about 1:17.
In an embodiment, the present invention provides a synergistic insecticidal composition comprising Fipronil and Propargite in amounts ranging from about 0.1 to 4 % wt/wt and 10 to 60 % wt/wt of total composition.
In another embodiment, the composition of the present invention is formulated as Capsule suspension (CS), Dispersible concentrate (DC), Dustable powder (DP), Powder for dry seed treatment (DS), Emulsifiable concentrate (EC), Emulsifiable granule (EG), Emulsion water-in-oil (EO), Emulsifiable powder (EP), Emulsion for seed treatment (ES), Emulsion oil-in-water (EW), Flowable concentrate for seed treatment (FS), Granules (GR), Micro-emulsion (ME), Oil-dispersion (OD), Oil miscible flowable concentrate (OF), Oil miscible liquid (OL), Oil dispersible powder (OP), Suspension concentrate (SC), Suspension concentrate for direct application (SD), Suspo-emulsion (SE), Water soluble granule (SG), Soluble concentrate (SL), Spreading oil (SO), Water soluble powder (SP), Water soluble tablet (ST), Ultra-low volume (ULV) suspension, Tablet (TB), Ultra-low volume (ULV) liquid, Water dispersible granules (WG), Wettable powder (WP), Water dispersible powder for slurry seed treatment (WS), Water dispersible tablet (WT), a mixed formulation of CS and SC (ZC), a mixed formulation of CS and SE (ZE), a mixed formulation of CS and EW (ZW), preferably as suspo-emulsion.

In yet another embodiment, the excipient of the synergistic insecticidal composition is selected from the group comprising a solvent, an emulsifier, an anti-oxidant, an anti-freezing agent, a dispersing agent, a defoamer, a biocide and a thickener.
In one another embodiment, the solvent is selected from the group consisting of C IX, cyclohexanone, N-methyl pyrollidone, butanol and combinations thereof, and present in an amount in the range from 0 to 10%.
In another embodiment, the emulsifier is selected from the group consisting of a non-ionic surfactant, anionic surfactant and combinations thereof, and present in an amount in the range from 0 to 6%.
In an embodiment, the anti-oxidant is sunflower oil and present in an amount in the range from 0 to 5%.
In another embodiment, anti-freezing agent is selected from the group consisting of propylene glycol, diethylene glycol, monoethylene glycol and combinations thereof, and present in an amount in the range from 0 to 8%.
In yet another embodiment, the dispersing agent is selected from the group comprising modified styrene acrylic polymer, non-ionic surfactant, anionic surfactant and mixtures thereof and present in an amount in the range from 2 to 10%.
In one another embodiment, the defoamer is polydimethylsiloxane emulsion and present in an amount in the range from 0.01 to 0.50%.
In an embodiment, the biocide is selected from the group consisting of 20% aqueous dipropylene glycol solution of l,2-benzisothiazolin-3-one, formaldehyde

and combinations thereof and present in an amount in the range from 0.01 to 0.50%.
In another embodiment, the thickener is Xanthan gum and present in an amount in the range from 0.10 to 0.50%.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1. is a flowchart for preparing a synergistic insecticidal composition in the form of a suspo-emulsion (SE).
DETAILED DESCRIPTION OF INVENTION
Discussed below are some representative embodiments of the present invention. The invention in its broader aspects is not limited to the specific details and representative methods. The illustrative examples are described in this section in connection with the embodiments and methods provided. The invention according to its various aspects is particularly pointed out and distinctly claimed in the appended claims read in view of this specification and appropriate equivalents.
It is to be noted that, as used in the specification and the appended claims, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a composition containing "a compound" includes a mixture of two or more compounds. It should also be noted that the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise.
The expression of various quantities in terms of "% w/w" or "%" means the percentage by weight, relative to the weight of the total solution or composition unless otherwise specified.
The term "agrochemically effective amount" is that quantity of active agent, applied in any amount which will provide the required control of pest and diseases. The particular amount is dependent upon many factors including, for example, the crop, pest and disease sought to be controlled and environmental

conditions. The selection of the proper quantity of active agent to be applied, however, is within the expertise of one skilled in the art.
Compositions comprising a single insecticidally active component suffer from numerous drawbacks such as development of resistant insect species, requirement of high amount and concentration of the active ingredient, environmental damage, seepage of the active component into ground water, phytotoxicity and harmful effects on the health of animals and humans.
Accordingly, the inventors of the present invention have formulated a synergistic insecticidal composition, comprising: (a) Fipronil (b) Propargite and (c) excipients, wherein the mass ratio of Fipronil to Propargite is in the range from 1:14 to 1:17.
The present invention also provides a synergistic insecticidal composition comprising Fipronil and Propargite in amounts ranging from about 0.1 to 4 % wt/wt and 10 to 60 % wt/wt of total composition.
The synergistic composition of the present invention may be formulated as Capsule suspension (CS), Dispersible concentrate (DC), Dustable powder (DP), Powder for dry seed treatment (DS), Emulsifiable concentrate (EC), Emulsifiable granule (EG), Emulsion water-in-oil (EO), Emulsifiable powder (EP), Emulsion for seed treatment (ES), Emulsion oil-in-water (EW), Flowable concentrate for seed treatment (FS), Granules (GR), Micro-emulsion (ME), Oil-dispersion (OD), Oil miscible flowable concentrate (OF), Oil miscible liquid (OL), Oil dispersible powder (OP), Suspension concentrate (SC), Suspension concentrate for direct application (SD), Suspo-emulsion (SE), Water soluble granule (SG), Soluble concentrate (SL), Spreading oil (SO), Water soluble powder (SP), Water soluble tablet (ST), Ultra-low volume (ULV) suspension, Tablet (TB), Ultra-low volume (ULV) liquid, Water dispersible granules (WG), Wettable powder (WP), Water dispersible powder for slurry seed treatment (WS), Water dispersible tablet (WT), a mixed formulation of CS and SC (ZC), a mixed formulation of CS and SE (ZE),

a mixed formulation of CS and EW (ZW). Preferably, the composition of the present invention is formulated as a suspo-emulsion.
The term "suspo-emulsion" used herein refers to a mixture of water-insoluble active ingredients dispersed in an aqueous solution, where one (or more) of the active ingredients is in suspension form and one (or more) of the active ingredients is in emulsion form. The formulation is intended for dilution into water prior to spray application. Formulating the active ingredients together eliminates the need for tank mixing which can lead to incompatibility between active ingredients. Like other aqueous liquid formulations, suspo-emulsions are easy to handle and measure, dust free, non-flammable and offer good miscibility with water.
The synergistic insecticidal composition comprises excipients such as a solvent, an emulsifier, an anti-oxidant, an anti-freezing agent, a dispersing agent, a defoamer, a biocide, a thickener and water.
Suitable solvents useful in accordance with the invention are C IX, cyclohexanone, N-methyl pyrollidone, butanol and combinations thereof, and present in an amount in the range from 0 to 10%. The term "C IX" refers to a solvent which mainly comprises of hydrocarbons with nine carbon atoms.
It is desirable to have an emulsifier in the synergistic insecticidal composition. An emulsifier is a substance that stabilizes an emulsion by increasing its kinetic stability. Non-limiting examples of emulsifiers that can be used in the present invention include nonionic surfactants and anionic surfactants. Each of these surfactants can be used either singly or in combination and commercially available as Atlox®4853 and Emulsogen®T-160. The emulsifier is present in an amount in the range from 0 to 6%.

It is also recommended to add an anti-oxidant to the insecticidal composition. An anti-oxidant prevents the oxidation of the active ingredients present in said composition due to exposure to atmospheric oxygen and other oxidizing agents, thereby increasing the storage stability of the components. Accordingly, the synergistic insecticidal composition of the present invention contains sunflower oil as the anti-oxidant in an amount in the range from 0 to 5%.
An anti-freezing agent is generally added to insecticidal compositions, to prevent the aqueous compositions from freezing. Suitable anti-freezing agents useful herein, but not limited to, include propylene glycol, diethylene glycol (DEG), mono ethylene glycol (MEG) and combinations thereof. Preferably, the anti-freezing agent is present in an amount in the range from 0 to 8%.
A dispersing agent is another important component of a suspo-emulsion as it facilitates the suspension of a water insoluble substrate in an aqueous suspension. Non-limiting examples of dispersing agent that can be used in the present invention include modified styrene acrylic polymer, non-ionic surfactant, anionic surfactant and a mixture of non-ionic surfactant and anionic surfactant. One or more dispersing agents may be used in the synergistic composition of the present invention. Commercially available dispersing agents that can be used in the present invention are Jeesperse®550S, Tresperse®2500 and Tresperse®4894. The dispersing agent is present in an amount in the range from 2 to 10%.
A defoamer, also called as anti-foam, is generally added to an insecticidal composition as foam formation prevents the efficient filling of a container. Preferably, the defoamer is polydimethyl siloxane emulsion and commercially available as SAG®-1572. In the insecticidal composition the defoamer is present in an amount in the range from 0.01 to 0.50%.
The synergistic insecticidal composition comprises a biocide selected from the group consisting of 20% aqueous dipropylene glycol solution of 1,2-

benzisothiazolin-3-one, formaldehyde and combinations thereof, and preferably present in an amount in the range from 0.01-0.50%. The 20% aqueous dipropylene glycol solution of l,2-benzisothiazolin-3-one is commercially available as Proxel® GXL. The biocide is added to the composition of the present invention for its preservation against spoilage from bacteria, yeasts and fungi.
It is necessary to add a thickener to a insecticidal composition to reduce the tendency of the insecticide composition to disperse when sprayed, and decrease the likelihood of it being rinsed off from the crops. Preferably, the synergistic insecticidal composition comprises xanthan gum as thickener in an amount in the range from 0.10-0.50%.
There is also provided a method for controlling insects and acarids, comprising contacting crops or their environment with an agrochemically effective amount of the synergistic insecticidal composition, wherein the crops are tea, fruit and vegetables and the insects and acarids, are from the family of hemiptera, lepidoptera, and arachnida. Preferably, the insects and acarids controlled using the above method may comprise aphid, jassid, thrips, white fly, mosquito bug, leaf minor, caterpillar complex, borers, red spider mites, polyphagous or phytophagous mites.
It has been surprisingly found that the synergistic insecticidal composition of the present invention is useful in protecting a wide range of crops like tea, fruit and vegetables against wide spectrum of insect-pests such as mites, thrips, aphids, major tissue-chewing, cutting, and boring insects of plants. It also delays the appearance of the resistant strains of insect-pests, and achieves effective and economical control of undesired insect-pests. The composition achieves improved biological activity by enhancing overall control of insects over a shorter period of time. Additional benefits of using the insecticidal composition of the present invention includes reduced risk of occupational hazard, lower cost of application,

better costbenefit ratio to the end user, reduced fuel and labour cost, saving in applicator's time and loss caused by mechanical damage to the crop and soil.
The present invention is more particularly described in the following examples that are intended as illustrations only, since numerous modifications and variations within the scope of the present invention will be apparent to those of skilled in the art. The following examples illustrate the basic methodology and versatility of the present invention.
Examples 1-4
The synergistic insecticidal composition of the present invention comprising fipronil and propargite are provided in Examples 1-4 (Table 1). The unit of each component of the composition are expressed in "% w/w" i.e. the percentage by weight, relative to the weight of the total solution or composition.
The excipients used in Examples 1-4 for preparing the synergistic composition of the present invention are solvent, emulsifier, anti-oxidant, antifreeze agent, dispersing agent, defoamer, biocide, thickener and demineralized water. C-IX was used as a solvent in the amount ranging from 0 to 10 %w/w. A blend of anionic and nonionic surfactants was used as an emulsifier in the amount ranging from 0 to 6 %w/w. Sunflower oil was used as an anti-oxidant in the amount ranging from 0 to 5 %w/w. Propylene glycol was used as an anti-freeze agent in the amount ranging from 0 to 8%w/w. Dispersing agents such as mixture of non-ionic/anionic surfactants and modified styrene acrylic polymer were used in the amount ranging from 2 to 10%w/w. Polydimethyl siloxane emulsion, Proxel®-GXL, xanthum gum were used as a defoamer, biocide and thickener respectively in the amount ranging from 0.01-0.50 %w/w.
Table 1: Synergistic insecticidal composition

Component

Function

Examples

Table 2 provides chemical composition of the synergistic composition of the present invention in suspo-emulsion (SE) form, wherein the active ingredients, fipronil and propargite are in technical grade. The entries for active ingredients, fipronil and propargite, in table 2 varies from that of table 1, as the entries in table 1 are for 100% pure compounds whereas the entries in Table 2 are for technical ones with certain percentage of impurities. Hence, example 1 of table 1 for fipronil 2.5% wt/wt and propargite 35%wt/wt of 100%) purity corresponds to example 5 of table 2 for fipronil 2.63Kg and propargite 38.04Kg of 95%> and 92%> purity respectively. Likewise, example 2, 3, 4 corresponds to examples 6, 7, 8 of table 2.
Table 2: Chemical composition of the synergistic composition of the present
invention in SE form

Example 9: Process of preparation of synergistic insecticide composition in SE form.
The required quantities of raw materials as illustrated in Table 2, were weighed, and transferred through the auto-batching system.
In a first container, water was taken and SAG®-1572 was added to it. Propylene glycol was then added with stirring followed by the dispersing agents to form a mixture. To the mixture, sunflower oil and Fipronil were added with stirring and homogenized with high speed homogenizer having 1000 to 2000 RPM to make a homogeneous slurry. The homogeneous slurry was wet grinded at 25°C to 30°C using a bead mill till the required particle size was achieved. D90 should be below

10 microns. After wet grinding, material was discharged and mill was washed using remaining water and was withdrawn in the same container and mixed well a suspension was obtained.
In a second container, solvent C-IX was taken, emulsifiers were added with stirring to obtain homogeneous mixture and then propargite was added with stirring to form an emulsion. The emulsion was then added to the suspension formed in first container and mixed well. To it an aqueous solution of xanthan gum was added under stirring to obtain the title composition.
Evaluation of bio-efficacy of the synergistic insecticidal composition against insect pests in chilli
Field trials were performed to evaluate the biological efficacy of the synergistic insecticidal composition of present invention against the common and hazardous pests. Table 3 provides treatment details of insecticidal compositions for evaluation of bio-efficacy against insect pests in chilli. The evaluation was performed by comparing the synergistic insecticidal composition in the present invention against the solo marketed reference products, such as Fipronil 5% SC and Propargite 57% EC.

Method of observation
Ten plants in each treatment were randomly tagged per plot and pre and post treatment observations were recorded. The number of insects were counted from three leaves one each from bottom, middle and top of plant before sprays as well as on three, seven and fourteen days after spraying (DAS).
Based on various doses, weighed quantity of test products were dissolved in 1.5 L of water/plot and sprayed uniformly.
Details of the experiment
Target pests: Thrips, Aphid, Red spider mite and fruit borer
Crop: Chilli
Variety: Jawahar Mirch-283
Plot Size: 30 m2
Spacing: 60.0 x 50.0cm
Water volume/ha: 500 litres
Spray Equipment: Knapsack sprayers fitted with cone nozzle
Observation: Means often plants, three leaves per plant
Application Stage: Two sprays at 15 days interval
Insect Pest Assessment: Pre-treatment population of Thrips, Aphids, Red spider mites was recorded one day before the spray of insecticide from the tagged plants. The post-treatment population of insect was recorded at suitable intervals (3, 7 and 14 days) after each spray. The corrected percent reduction in target insect

population over control was worked out using Henderson & Tilton Formula (1955) which is given below.
% reduction 4 —m n in Co before treatment x n in T after treatment y ,{
of insect - n m Co a/tei&eatmentxn in T before treatment
Population
Where, n = insect population; T = Treated; Co = Control
The bio-efficacy of various treatments as per Table 3 on insect population such as Thrips, Aphid, Red spider mite in chilli during first season (2017) and second season (2018) have been provided in Tables 4, 5, 6, 7, 8 and 9.
Table 4: Effect of different treatments on Thrips in Chilli during First season

Values in parenthesis are Vx + 0.5 transformed values
Table 5: Effect of different treatments on Thrips in Chilli during second season

Values in parenthesis are Vx + 0.5 transformed values
Table 6: Effect of different treatments on Aphid in Chilli during first season

Values in parenthesis are Vx + 0.5 transformed values

Table 7: Effect of different treatments on Aphid in Chilli during second season

Values in parenthesis are VX + 0.5 transformed values
Table 8: Effect of different treatments on Red Spider Mite in Chilli during first season

Values in parenthesis are VX + 0.5 transformed values
Table 9: Effect of different treatments on Red Spider Mite in Chilli during second season

Values in parenthesis are Vx + 0.5 transformed values

The aforementioned trial results from Tables 4 to 9 indicate that T3 and T4 i.e. synergistic insecticidal composition comprising Fipronil (2.5%) and Propargite (37.5%) and Fipronil (2.5%) and Propargite (35%) formulated as SE are most effective against Thrips, Aphids and Red spider mites even 14 DAS as compared to the marketed reference product Propargite 57% EC (T5) and Fipronil 5% SC (T6). The treatments Tl and T2 were at par with the marketed reference products, Propargite 57% EC (T5) and Fipronil 5% SC (T6).
For chilli fruit borer, observations were recorded at each picking and damaged/ bored fruits were separated and percent damaged fruits was calculated against healthy fruits. The respective percentage of fruit damage for first and second seasons are presented in Table 10. Three picking were done for both seasons.
Table 10: Effect of different treatments on fruit borer (%) in Chilli during first and second seasons

Figures in parentheses are arc sin transformed values
It can be seen from table 10 that the lowest fruit damage was observed in plots treated with T4 followed by T3. Overall, the fruit damage was higher when the plots were treated with solo marketed reference products, Propargite 57% EC (T5) and Fipronil 5% SC (T6) as compared to the synergistic insecticidal composition comprising fipronil and propargite (Tl to T4).
The cumulative yield of chilli fruits from individual plots were recorded and expressed in quintal per hectare and presented in Table 11.
Table 11: Chilli fruit vield based on different treatments

The highest fruit yield of 25.72 and 27.33 q ha"1 was observed in plots treated with T3. Overall, the fruit yield was significantly higher when the plots were treated with the synergistic insecticidal composition comprising fipronil and propargite (T2 to T4) as compared to solo marketed reference product Propargite 57% EC (T5) and Fipronil 5% SC (T6). The fruit yield was at par when the plots were treated with the synergistic insecticidal composition comprising fipronil and propargite (Tl) as compared to solo marketed reference product Fipronil 5% SC (T6).
The phytotoxic effect of different treatment schedules was observed in ten randomly selected plants from each plot at 15 days after treatment on 0-10 scale (Table 13 and 14) for yellowing, stunting, necrosis, epinasty and hyponasty. European Weed Research Council Crop Phytotoxicity scoring is provided in Table 12.
Table 12: Phytotoxicity visual scoring 0-10 (EWRC system)

Table 12. Phytotoxic effect of synergistic composition of the present invention on Chilli plant during first season (2017)

The synergistic insecticidal composition of the present invention gave good control of major insects of chilli along with significant increase in yield and better economics to farmers as compared to the individual formulation. Additionally, the use of this composition results in better crop condition, i.e. fresh green leaves and better yield and did not produce any phytotoxic symptoms on chilli plants.
From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitations with respect to the specific embodiments illustrated is intended or should be inferred. It should be understood that all such modifications and improvements have been deleted herein for the sake of conciseness and readability but are properly within the scope of the following claims.

WE CLAIMS
1. A synergistic insecticidal composition, comprising: a) Fipronil, b)
Propargite and c) excipient, wherein the mass ratio of Fipronil to
Propargite is in the range from about 1:14 to about 1:17.
2. The synergistic insecticidal composition, as claimed in claim 1, wherein
the Fipronil and Propargite are present in amounts ranging from about 0.1
to 4 %wt/wt and 10 to 60 %wt/wt.
3. The synergistic insecticidal composition as claimed in claim 1, wherein the
composition is formulated as Capsule suspension (CS), Dispersible
concentrate (DC), Dustable powder (DP), Powder for dry seed treatment
(DS), Emulsifiable concentrate (EC), Emulsifiable granule (EG), Emulsion
water-in-oil (EO), Emulsifiable powder (EP), Emulsion for seed treatment
(ES), Emulsion oil-in-water (EW), Flowable concentrate for seed
treatment (FS), Granules (GR), Micro-emulsion (ME), Oil-dispersion
(OD), Oil miscible flowable concentrate (OF), Oil miscible liquid (OL),
Oil dispersible powder (OP), Suspension concentrate (SC), Suspension
concentrate for direct application (SD), Suspo-emulsion (SE), Water
soluble granule (SG), Soluble concentrate (SL), Spreading oil (SO), Water
soluble powder (SP), Water soluble tablet (ST), Ultra-low volume (ULV)
suspension, Tablet (TB), Ultra-low volume (ULV) liquid, Water
dispersible granules (WG), Wettable powder (WP), Water dispersible
powder for slurry seed treatment (WS), Water dispersible tablet (WT), a
mixed formulation of CS and SC (ZC), A mixed formulation of CS and SE
(ZE), a mixed formulation of CS and EW (ZW).
4. The synergistic insecticidal composition as claimed in claim 3, wherein the
composition is formulated as suspo-emulsion.
31
5. The synergistic insecticidal composition, as claimed in claim 1, wherein
the excipient is selected from the group comprising a solvent, an
emulsifier, an anti-oxidant, an anti-freezing agent, a dispersing agent, a
defoamer, a biocide and a thickener.
6. The synergistic insecticidal composition, as claimed in claim 5, wherein
the solvent is selected from the group consisting of C IX, cyclohexanone,
N-methyl pyrollidone, butanol and combinations thereof, and present in an
amount in the range from 0 to 10%.
7. The synergistic insecticidal composition, as claimed in claim 5, wherein
the emulsifier is selected from the group consisting of a non-ionic
surfactant, anionic surfactant and combinations thereof, and present in an
amount in the range from 0 to 6%.
8. The synergistic insecticidal composition as claimed in claim 5, wherein the
anti-oxidant is sunflower oil and present in an amount in the range from 0
to 5%.
9. The synergistic insecticidal composition as claimed in claim 5, wherein the
anti-freezing agent is selected from the group consisting of propylene
glycol, diethylene glycol, monoethylene glycol and combinations thereof,
and present in an amount in the range from 0 to 8%.
10. The synergistic insecticidal composition as claimed in claim 5, wherein the
dispersing agent is selected from the group comprising modified styrene
acrylic polymer, non-ionic surfactant, anionic surfactant and mixtures
thereof and present in an amount in the range from 2 to 10%.
11. The synergistic insecticidal composition as claimed in claim 5, wherein the
defoamer is polydimethylsiloxane emulsion and present in an amount in
the range from 0.01 to 0.50%.
32
12. The synergistic insecticidal composition as claimed in claim 5, wherein the
biocide is selected from the group consisting of 20% aqueous dipropylene
glycol solution of 1,2-benzisothiazolin-3-one, formaldehyde and
combinations thereof and present in an amount in the range from 0.01 to
0.50%. 13. The synergistic insecticidal composition as claimed in claim 5, wherein the
thickener is Xanthan gum and present in an amount in the range from 0.10
to 0.50%.