FIELD OF INVENTION The present invention relates to an Insecticidal composition for pest control, more particularly to a stable and synergistic combination formulation of a thiadiazin class of chitin inhibitor and a pyrazole group insecticide, which is a potent inhibitor of central nervous system, m suspension concentrate form. BACKGROUND OF THE INVENTION Insect pests are one of the worst enemies of crops. They cause severe damages to the crops resulting in reduced crop productivity. In heavily infested areas 80 to 90 percent crop damages has been reported. In agrarian countries like India it badly impacts the economy of the country. Controling crop pest population has been a major issue and various traditional and advanced means are being used to minimize the damage caused by insect pests. Most frequently and widely used method to control insect pests is use of insecticides/pesticides. Continuous use of pesticides and insecticides years after years, in uncontrolled and unscientific manner has resulted in development of resistance in the insect pests and this resistance continues to broaden in spectrum against the number of insecticides/pesticides. Continuous high intensity use of insecticides and pesticides has given rise to some other critical issues like presence of high quantity of insecticide residues in agricultural products, increasing environmental pollution and damage to ecological balance and deteriorating health of consumers. Therefore, there is a need for an insecticidal formulation that is highly efficient, has low toxicity, covers a broader spectrum of insects and is environment friendly and economical. Various combination insecticidal formulations, containing two or more insecticides or one or more insecticide and some other chemical or one or more insecticide and one or more natural products or plant extracts , are in market. The present invention relates to the insecticidal formulation containing fipronil and buprofezin. 2 15 40 'IP. 0 DELHI 24-11-2015 , .. Fipronil belonging to phenyl pyrazol class of insecticides is a highly effective, broad spectrum insecticide with a potential value for the control of a wide range of insects. It can be applied at low to very low dose to achieve effective pest control. It . disruptes the insect central nervous system by interfering with the gamma-aminobutyric acid (GABA) regulateu chloride channel and glutamate-gated chloride (GluCl) channels, resulting toxicity to central nervous system. This prevents the opening of chloride ion channels normally controlled by GABA, which results in reduced uptake of chloride ions, over stimulation of neurons and ultimately causing paralysis and death of insect pest. IUPAC naming of Fipronil is (RS)-5-amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4- (trifluoromethylsulfinyl)-lH-pyrazole-3-carbonitrile. Cl ·CF3 NC y·N .,,r 'J )==-\ Cl F3C-.S:~0 NH2 II . 0 Buprofezin belongs to a chemical class of Thiadiazin, having the chemical formula of Z-2- [( 1,1 dimethylethyl)imino ]tetrahydro-3-( 1-methylethyl)-5-phenyl-4H -1 ,3,5-thiadiazin-4-one. 3 IPO DELHI ·.:;: ""1'1! . - 1 . 1 - 2 t.".:'.;•\ 1 5 · 1 5 40 ;. I ;, . ;·. ' ,·: I '' Buprofezin is a chitin synthesis inhibitor. It inhibits moulting of nympths and larvae, leading to the death of insect pests. It also suppresses oviposition by adult pests and forces the treated insects to lay sterile eggs, hence preventing the pests to multiply. The prior arts have reported individual formulations of buprofezin and fipronil in aqueous suspension form, but they are not capable of covering a braod spectrum of insects. The emulsifiable concentrate of combination of buprofezin and fipronil are known in prior art but because of poor solubility of fipronil in organic solvents the formulations are not stable on long term storage and exhibit crystallization on spray and become phytotoxic. The solvent ' based formulations are also prone to fire hazards and are not very cost effective. The invention of CN 101873800 discloses an insecticidal formulation comprising buprofezin together with one or more compounds selected from fipronil, fipronil acetyl, vanilla fipronil, acetomiprid, ethiprole and nitriles. This invention discloses use of water as well as organic solvents for formulation of this combination. This invention further discloses use of this insecticidal combination as emulsifiable concentrate, emulsifiable suspension, powder, granules and wettable powder. The invention of CN1 01569309 discloses combined fipronil and buprofezin as emulsified formulation in organic solvent. The invention of CN104872156 also discloses combined fipronil and buprofezin as emulsified formulation in organic solvent. This invention further discloses the presence of fipronil and buprofezin in proportion of 3: 24- 36 (w/w) in final solution. A stable insecticidal combination of fipronil and buprofezin m aquous or oil based suspension concentrate form is not known. To meet the present day requirements, there is still a need of novel, stable, less hazardous, safer in handling economical combinations , which are effective against broader spectrun of insects. T '24-11-2015 IPO DE.LH.b 15 4 40 ' ! ' j I ---------------------------------------------------, STA TF.MENT OF INVENTION The present invention is related to a combination insecticidal formulation in a suspension concentrate form. Insecticidal formulation of this invention is stable, less hazardous, safe to handle, environmentally safe and cost effective. The pesticides used in this formulation act synergistically to cover broader spectrum of pests of crops. SUMMARY OF THE INVENTION The main embodiment of present invention relates to a synergistic combination formulation of first active ingredient Z-2-[(1, 1-dimethylethyl)imino]tetrahydro-3-(l-methylethyl)-5-phenyl- 4H-1 ,3,5-thiadiazin-4-one ( a thiadiazin class insecticide ) and second active ingredient (RS)- 5-amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4- ( trifl uoromethylsulfinyl)-1 H -pyrazole- 3-carbonitrile (a phenyl pyrazole class of insecticide) in aqueous based suspension concentrate form along with other inert ingredients. In another embodiment of the invention, the water based suspension concentrate form consists of buprofezin in an amount ranging from 15-25% (w/w) and fipronil in an amount ranging from 1-5% (w/w) of the total composition. In a further embodiment of the invention inert ingredients are wetting and dispersing agents, anti freeze agents, anti foam agents, antimicrobial agents and carriers. In another embodiment of invention wetting and dispersing agents are selected from the group comprising sodium and potassium salts of alkylated ethoxylated phosphate esters, alkyl phenol ethoxylates, castor oil ethoxylates, sodium salt of alkyl sulpates or sulphonates. The amount of wetting and dispersing agents in final formulation ranges from 3-15% (w/w). In a further embodiment of invention anti freeze agents such as polyols are added in an amount ranging from 2- 10% w/w, based on the weight of the insecticidal combination. 5 15 40 ' I ! I I· . , ;i !1 ' "I In another embodiment of invention silicon or alcohol based antifoam agent is added in amount ranging from 0.1-3% (w/w) based on the weight of the insecticidal combination. In another embodiment of invention the: stabilizing agents or viscosity enhancing agents, such as naturally occurring guar gum; xanthan gum, poly. vinyl alcohol, gelatin, etc. is added to stabilize the suspension. The stabilizing agents is added in an amount ranging from 0.1- 0.5% based on the weight of the suspension. In a further embodiment of invention antimicrobial agents such as potassium sorbate, chlorinated isothiazoline sodium salts, parabens are added to the insecticidal composition to enable long term storage and prevent fouling. Another important embodiment of invention provides a process for the preparation of the combination formulation of the present insecticide, comprising the steps of: 1. Forming the aqueous solution comprising of wetting and dispersing agents; 2. Adding Buprofezin (15-25%) and -Fipronil (1 - 5%) in aqueous solution and suspending it; 3. 4. 5 . 6. 7. Addition of anti freeze agent; Addition of antifoam agent; Wet grinding of the suspension in pressurized bead mill to reduce particle size of the suspension up to D90 less than 5 micron; Adding the stabilizing agents to the homogenized suspension to enhance viscosity; Finally adding the antimicrobial agents to the suspension to prevent fouling. The present insecticidal composition is highly stable and the combination of active ingredients are highly effective on a broad spectrum of insect pests through its combined action on central nervous system and chitin inhibition. I. PO DELHI 2.4-11-2:015 15 6 40 l' I ,. !' i. I { ,, . t,·, · ji I i '. ! ------------------ Furthermore, timely application of the present insecLicidal formulation gives satisfactory and long lasting effect in regulating the population of the insect pests and enhancing the production of the agricultural crop yield. DETAILED DECRIPTION OF THE INVENTION In describing the embodiments of the invention, specific terminology is resorted for the sake of clarity. However, it is not intended that the invention be limited to the specific terms so selected and it is to be understood that each specific term includes all technical equivalents that operate in a similar manner to accomplish a similar purpose . . The present invention provides a novel, stable and a synergistic Insecticidal composition for pest control. The novel formulation of the present invention comprises an effective amount of Z-2-[( 1, 1-dimethylethyl)imino ]tetrahydro-3-(1-methylethyl)-5-phenyl-4H-1 ,3,5-thiadiazin-4- one (a thiadiazin class of insecticide) . and(RS)-5-amino-1-[2,6-dichloro-4- (trifluoromethyl)phenyl]-4- (trifluoromethylsulfinyl)-1 H-pyrazole-3-carbonitrile (a phenyl pyrazole class of insecticide), acting as active ingredients along with other inert ingredients. Z-2-[( I, 1-dimethylethyl)imino ]tetrahydro-3-(l-methylethyl)-5-phenyl-4H-l ,3,5-thiadiazin-4- one (buprofezin) is a chitin synthesis inhibitor and (RS)-5-amino-1-[2,6-dichloro-4- ( trifl uorometh y l )phenyl] -4-( trifl uorometh y ls ulfin y l )-1 H -p yrazole-3 -carboni trile ( fipronil) is an inhibitor of gamma-arninobutyric acid (GABA-) regulated chloride channel and glutamategated chloride (GluCl) channels. In insecticidal formulation of the present invention , buprofezin, the chitin synthesis inhibitor is present in an amount ranging from 15-25% w/w based on the weight of the insecticidal combination while fipronil, the inhibitor of gamma-arninobutyric acid (GABA-) regulated chloride channel and glutamate-gated chloride (GluCl) channels, is present in an amount ranging from 1-5% w/w based on the weight of the insecticidal combination. 7 D.!!=·~'._· HI ·24-11-2015 I.P 0 - 15 40 if it' ii ij ,1. '! I · •i- f --... - ,:· ,• I.P·O ----------------------. The active and inert ingredients in formulation of present invention are dispersed in aqueous solution, preferably water, to compose a stable and safe insecticide suspension. The inert ingredients include wetting agents and dispersing agents, anti freeze agents, anti foam agents, antimicrobial agents and carriers. Wetting and dispersing agents are selected from the_g[o_up_compriEing-Sodiurn arid potassium --------- ____ salts--of- -alkylateu-cetnoxylatecr phosphate esters, alkyl phenol ethoxylates, castor oil ethoxylates, sodium salt of alkyl sulpates or sulphonates the wetting and dispersing agents are useful in reducing the surface tension and preventing the Ostwald ripening of ingredients present in the insecticidal composition so as to enhance the spreading or penetration of the said composition to make it more effective in targeting the pests present in the crops. Aqueous formulation of present invention comprise of wetting and dispersing agents in an amount ranging from 3- 15% w/w based on the weight of the insecticidal combination. Anti freeze agents such as polyols are added in an amount ranging from 2- I 0% w/w based on the weight of the insecticidal combination to avoid the freezing of the liquid insecticide upon application so as to enhance the duration of activity of the said insecticidal composition on the pests. Antifoam, preferably silicon or alcohol based, is added in an amount ranging from 0.1-3% w/w based on the weight of the insecticidal suspension. Anti foam agents are significant when the ingredients in the suspension are mixed or ground so as to avoid the occurrence of froth during particle size reduction of the ingredients. The stabilizing agents or viscosity enhancing agents, such as naturally occurring guar gum, xanthan gum, polyvinyl alcohol, gelatin, etc. is used to stabilize the suspension. The stabilizing agents are added in an amount ranging from 0.1- 0.5% based on the weight of the suspension. Stabilizing agents forms a polymorphic matrix in the insecticidal formulation to provide a stabilized s:uspension of the active ingredients. 8 DELHI. '24-11- 2815 ;_ . . · '· : '~ " ·.· -----------------------------------------------------------------------------, The antimicrobial agents such as potassium sorbate, chlorinated isothiazoline sodium salts, parabens are also added to the insecticidal composition to enable long term storage and prevent fouling . The present invention also provides a process for the preparation of the combination formulation of the present insecticide, comprising the steps of: 1. Forming the aqueous solution comprising of wetting and dispersing agents. 2. Suspending Buprofezin (15-25%) and Fipronil (l - 5%) in the aqueous solution. 3. Addition of anti freeze agent, such as polyol and silicon/ alcohol based anti foam agent to the aqueous suspension. 4. Particle size reduction of the suspension up to D90 less than 5 micron in a pressurized bead mill. 5. Adding the stabilizing agents to the homogenized suspension to enhance viscosity. 6. Finally the addition of the antimicrobial agents to the suspension prevent fouling. The formulation thus prepared with varying amounts of wetting agents, dispersing agents were subjected to stability study and the optimum dose of the ingredients were selected. Formulation selected after various permutation and combination of ingredients was found to be stable and no Ostwald ripening was observed. The best stable formulation was checked for parameters of description, suspensibility, dispersibility, pourability, viscosity, pH, under conditions of ambient temperature, heat stability and cold conditions at 1 ooc. The present invention utilizes the combined mode of action of the two active ingredients, buprofezin and fipronil, in targeting and killing of the pests. Buprofezin acts as a chitin synthesis inhibitor to make an instant effect upon the live target population due to its growth regulating activity . Upon spraying, it comes in the contact with target species & enters into the body of immature & adults to act as a contact and stomach poison. Even in female adult insects, it reduces the egg laying capacity by acting on prostaglandin hormone responsible for yolk deposition in eggs. Even if the eggs are laid by females, which are exposed to the chemical composition of our present invention, the eggs fail to hatch. Buprofezin due to its IP.O DELHI. ?- 4-11-2015 9 !-' ;, •! r inherent characteristic of being a chitin synthesis inhibitor, the exposed nymphs fail to emerge as adults. On the other hand, fipronil interferes with the gamma-aminobutyric acid (GABA-) regulated chloride channel and glutamate-gated chloride (GluCl) channels and prevents the opening of chloride ion channels, reduces the uptake of chloride ions :md over stimulates the neurons, resulting in central nervous system toxicity and paralysis and death of insect pests. The combination insecticidal formulation of present invention (Brand name: IIL-BUPFIPRO) primarily confers a delayed but long-lasting effect of the insecticidal composition which helps in preventing development of resistance by the insects. The efforts are made to use the different killing properties of both the chemical so that .it acts as a broad spectrum Insecticide with the minimum dosage. The combination formulation of the present invention is effective in protecting vast number of agricultural crops from a wide range of pests. The present invention is further illustrated & established by a set of non limiting examples, depicting the efficacy of the formulation of active ingredients as described above. EXAMPLE-I To check the efficacy of present formulation IIL-BUPFIPRO, three doses each of IILBUPFIPRO (250, 500 and 750 mllha) along with three other insecticides viz. Fipronil 5% SC @ 1500mllha, Thiamethoxam 25% WG @ lOOgm/ha and Buprofezin 25% SC @ 800 mil ha formulation were sprayed with an untreated check to work out their efficacy against brown plant hopper and leaf folder of rice and to find out the phytotoxic effects of IIL-BUPFIPRO on rice along with the effect of higher dose of IIL-BUPFIPRO at 1500ml/ha. Three rounds of spraying was done at the interval of 15 days each to observe natural infestation of BPH and leaf folder. A) Efficacy of IIL-BUPFIPRO against BPH (brown plant hopper) and leaf folder of rice after three round of spraying: 10 I ?fi-1_1-2015 15"40 IPO DELH -""' I .r ' :1 i ·t ' I (i) Efficacy of IIL-BUPFIPRO against BPH The efficacy of different treatment schedule against brown plant hopper after 18 \ 2nd and 3rd round of spray has been presented in table 1, 2 and 3 respectively. All dosages of pesticides showed efficacy in reduction of population of BPH. But, it was observed that over all tested material, IIL-BUPFIPRO performs better in controlling BPH after spraying than the other market products. In the first spray, among the treatment tested IIL-BUPFIPRO, 750 ml/ha recorded 99.0, 98.4, 80.8 and 58.0 per cent mortality of BPH at 3, 7, 10 and 14 days after spray. IIL-BUPFIPRO 500 mllha recorded 97.9, 96.1, 71.8 and 50.8per cent mortality of BPH at 3, 7, 10 and 14 days after spray. Almost similar trend was observed in 2nd and 3rd spray also. Table-1: Bio-efficacy of different dosages of Insecticides against BPH in rice after 1st round of spraying during Boro season of 2014-15. Pre-treatment Per cent mortality of BPH at Insecticides Dosages population of different days after spray (DAS) per ha. BPH/hill 3DAS 7DAS lODAS 14DAS IIL-Bupfipro 250 ml 10.3 92.7 88.8 64.4 46.1 (74.9)* (70.9) (53.7) (43.0) IIL-Bupfipro 500 ml 10.4 97.9 96.1 71.8 50.8 (82.8) (79.4) (58.2) (45.7) IIL-Bupfipro 750 ml 10.0 99.0 98.4 80.8 58.0 (86.0) (83.9) (64.4) (49.9) Fipronil 5% SC 1500 ml 10.5 89.8 87.9 59.1 40.1 (71.8) (70.1) (50.5) (39.6) Thiamethoxam 25% WG 100 gm 11.4 87.7 86.6 61.8 45.2 (69.9) (68.9) (52.1) (42.6) Buprofezin 25%SC 800 ml 10.7 91.9 88.0 59.4 42.7 (74.0) (70.2) (50.7) (41.1) Untreated control -- 11.3 0.0 0.0 0.0 0.0 (4.1) (4.1) (4.1) (4.1) F-test Sig sig Sig Sig SEM 1.83 1.64 2.82 2.26 11 15:40 IPO DELHI I CD at 5% 15.64 ls.o5 18.67 '16.95 *The data in the parentheses are angular transformed values. Table-2: Bio-efficacy of different dosages of Insecticides against DPH In rice after 2"d round of spraying during Boro season of 2014-15. Pre-treatment Per cent mortality of DPH at Insecticides Dosages population of different days after spray (DAS) per ha. BPH/hill 3DAS 7DAS 10DAS 14DAS IIL-Bupfipro 250 ml 5.5 88.1 83.0 63.5 43.4 (70.3)* (66.0) (53.1) ( 41.5) IIL-Bupfipro 500 ml 5.1 94.9 94.6 76.4 50.7 (77.7) (77.2) (61.3) (45.7) IIL-Bupfipro 750 ml 4.2 98.1 96.7 85.7 58.7 (83.2) (80.3) (68.2) (50.3) Fipronil5% SC 1500ml 6.3 80.1 80.8 59.1 37.0 (63.8) (64.4) (50.5) (37.7) Thiamethoxam25% WG 100 gm 6.3 85.5 75.2 60.7 40.8 (68.0) (60.5) (51.5) (40.0) Buprofezin 25%SC 800 ml 6.1 84.8 73.3 53.4 45.7 (67.4) (59.2) (47.3) (42.8) Untreated control -- 11.3 0.0 0.0 0.0 0.0 ( 4. I) (4.1) (4.1) (4.1) F-test Slg sig sig Sig SEM 3.02 2.26 3.56 2.52 CD at 5% . 9.32 6.98 10.97 7.75 * The data m the parentheses are angular transformed values. 12 :rPO. DELHI 24-ll-2.015 15:_48 :i:; ·' Table-3: Bio-efficacy of different dosages of Insecticides against BPH in rice after 2"d round of spraying during Boro season of 2014-15. ~ Pt·e-treatment Per cent mortality . of BPH at Insecticides Dosages population of different days after spray (DAS) per ha. BPH/hill 3 DAS 7DAS lODAS 14DAS ···-· IIL-Bupfipro 250 ml S.S 88.1 83.0 63.5 43.4 (70.3)* (66.0) (53.1) (41..5) -·~--... - IIL-Bupfipro 500 llll ).I 94.9 94.6 76.4 50.7 (77.7) (77 .2) (61.3) (45.7) IIL-Bupfipro 750 ml 4.2 98.1 96.7 85.7 58.7. (8l.2) (80.3) (68.2) (50.3) Fipronil 5% SC 1500 ml 6.3 80.1 80.8 59.1 37.0 (63.8) (64.4) (50.5) (37.7) Thiamethoxam25% WG 100 gm 6.3 85.5 75.2 60.7 40.8 (68.0) (60.5) (5 1.5) (40.0) Buprofezin 25%SC 800 ml 6.1 84.R 73.3 53.4 45.7 (67.4) (59.2) (47.3) (42.8) Untreated control -- 11.3 0.0 0.0 0.0 0.0 ( 4. I) ( 4.1) (4.1) (4.1) F-test Stg sig sig Sig SEM 3.02 2.26 3.56 2.52 CD at 5% 9.32 6.98 10.97 7.75 *The data in the parentheses are angular transformed values. (ii) Efficacy of IIL-BUPFIPRO against Leaf foldct· The efficacy of different treatment schedules of IIL-BUPFIPRO and other market products has been presented in table 4, 5 and 6. After three rounds of spray it was observed that, all the insecticide treated plots significantly reduced the population of leaf folder as compared to the untreated control but IIL-BUPFIPRO at 500 and 750 ml per ha. formulation markedly increased the per cent mortality on 3, 7, 10 and 14 clays after spray compared to other M . . treatments. In 1 spray, IIL-BUPFIPRO at 750 ml per ha formulation recorded 95.5, 90.9, 71.5 and 44.2 per cent mortality after 3, 7, 10 and 14 days after spray respectively. Similar trend was observed in second and third round of spray also (Table 5 and 6). IIPO DELHI 13 '24-11-2015. 1' 5 : 4 (:) ,.•.· . . ..,; _ i~ . ·,". I ji •; The percent mortality of BPI-I and lea.f folder at 3, 7, I 0 and 14 clays after spraying IILBUPFIRO was noted excellent as during all three round of spraying. So, it can be concluded from the present experiment that IIL-BUPFIRO c<1n give sutisfaclory restriction against the population build up of both BPH and leaf folder of rice. Table-4: Bio-efficacy of different dosages of Insecticides against leaf folder in rice after 1st round of spraying during Boro season of 2014-15. Pre-treatment Per cent mortality of leaf folder at Insecticides Dosages population of diiTcrent days after spray (DAS) per ha. leaf folder 3 DAS 7DAS 10DAS 14 DAS /hill IIL-Bupfipro 250 ml 6.3 90.2 83.1 53.3 33.9 (72.2)* (66.1) (47.2) (35.9) IlL-B u pfi pro 500 ml 5.7 92.R 86.3 65.2 41.1 (75.0) (68.7) (54.1) (40.2) IIL-Bupfipro 750 ml 4.8 95.) 90.9 71.5 44.2 (78.5) (73.0) (58.0) (42.0) Fipronil 5% SC 1500 ml 5.1 88.0 83.8 47.7 35.2 (70.1) (66.7) (44.0) (36.7) Thiamethoxam 25% WG 100 gm 5.7 74.5 70.8 50.9 29.2 (60.CJ) (57 .6) (45.8) (33.0) Buprofezin 25%SC 800 ml 5.4 85.2 75.2 44.3 26.2 (67.8) ,(60.5) (42.0) (31.1) Untreated control -- 5.1 0.0 0.0 0.0 0.0 ( 4. I) ( 4.1) (4.1) (4.1) F-test SJg Slg sig Sig SEM 4.03 3.53 4.33 5.14 CD at 5% 12.43 10.87 13.35 15.84 * The data m the parentheses are angular transformed values. 14 IP:Q DELHI 24-1.1-2015 1 5 :. Llt8 -------------- ---- Table-S: Bio-efficacy of different dosages of Insecticides against leaf folder in rice after 2nd round of spraying during Boro season of 2014-15. Dosages Pre-treatment Per cent mortality of leaf folder at Insecticides population of different d::tys after spray (DAS) per ha. leaf folder /hill 3 DAS 7 DAS lODAS 14 D'AS IIL-Bupfipro 250 ml 4.2 84.8 70.0 53.3 37.6 (67 .5)* (57 .I) (47.2) (38.1) ' IIL-Buptipro 500 ml 3.3 91.3 83,2 .'1~-.3- - - 44:4 - - (73.4) (66.2) (50.1) (42.1) HL-Bupfipro 750 ml 2.7 I 00.0 88.6 61.1 55.6 (90.0) (70.7) (5 1.7) (48.5) Fipronil 5% SC 1500 ml 3.3 83.2 68.3 60.0 32.9 (66.2) (56.1) (5 1.1) (35.3) Thiamethoxam 25% WG 100 gm 3.9 71.7 50.0 28.3 20.6 (58.2) (45.3) (32.5) (27.4) Buprofezin 25%SC 800 ml 3.9 79.4 61.1 53.3 31.9 (63.4) (54.7) (47.2) (34.7) Untreated control -- 5.4 0.0 0.0 0.0 0.0 ( 4. I) ( 4. I) ( 4.1) (4.1) F-test Slg Slg Slg Sig SEM 6.54 6.92 5.05 5.81 CD at5% 20.14 21.33 15.55 17.89 *The data m the parentheses are angular transformed values. Table-6: Bio-efficacy of different dosages of Insecticides against leaf folder in rice after 3rd round of spraying during Bot·o season of 2014-15. Dosages Pre-treatment Per cent mortality of leaf folder at Insecticides population of different days after spray (DAS) per ha. leaf folder /hill 3 DAS 7 DAS lODAS 14DAS IIL-Bupfipro 250 ml 2.4 83.0 60.9 50.0 38.9 (66.0)* (51.6) (45.3) (38.9) IIL-Bupfipro 500 ml 1.8 88.6 72.1 61.1 44.4 (70.7) (58.4) (51.7) (42.1) IIL-Bupfipro 750 ml 1.2 I 00.0 91.3 83.0 66.5 (90.0) (73.4) (66.0) (54.9) Fipronil 5% SC 1500 ml 2.1 77.6 66.5 50.0 41.7 (62.1) (54.9) (45.3) (40.5) 15 IPO DELHI 2.4-11-2015 15: 40 !t ·I I ,; :i Thiamethoxam25% WG I 00 gm 3.3 -,4.8 55.6 52.8 37.5 (60.2) (48.5) (56.9) (38.1) Buprofezin 25%SC 800 ml 2.7 80.4 58.3 50.0 33.3 (64.1) (50.1) (45.3) (35.6) ·.··· Untreated control -- 5.7 0.0 0.0 0.0 0.0 (4.1) (4.1) (4.1) (4.1) ··-- F-test Sig Sig Sig Sig ., SEM 8.43 12.36 6.96 8.81 ... CDatS% 25.97 38.0'1 21".45 27.14 *The data in tl1e IJarentheses are angular transformed values. (C) Impact of IIL-BUPFIPRO against natural enemies: (i) Impact of IIL-BUPFIPH.O against spider populations after three round of spraying during kharif season of 2014 Among many of the natural enemies of rice ecosystem spiders were observed as the most dominant and are very effective predator in suppressing the population of BPH and other pests. Hence, the impact of IIL-BUPFIPRO at different dosages in comparison with other three insecticides has been observed on spider population before spray and 3, 7 and I 0 days after spraying. The data obtained after 3 round of spraying on the percent reduction of spider :.population at different elates after spray has been presented in table 7, 8 and 9. The per cent reduction of spider population decreases at 7 and I 0 days after spray during 1st round of spraying. Similar pattern of result also obtained from 2'1(1 and 3rct round of spray_ing. Table-7: Effect of diffet·ent insecticides on spidet· populations in Boro rice after 1st round of spraying during 2015. Per cent reduction of spider Insecticides Dosages Pre-treatment populations at different .days after per ha. population or spray (DAS) spidcr/sqm 3 DAS 7DAS lODAS IIL-Bupfipro 250 ml 2.3 11.4 2.8 0.0 (20.1 )* (10.4) (4.1) IIL-Bupfipro 500 ml 2.2 14.9 3.0 2.6 (23.1) (I 0.8) (I 0.1) 16 '2 ..;._ - 11 11. - 2 8 l. 5' . "'ii. ,!\;.. ,!\;. .. 1 5 :. 40 ·;:, ./.. - IIL-Bupfipro 750 1111 2.5 18.4 5.1 3.0 (25.8) ( 13.7) (10.8) Fipronil 5% SC 1500 1111 2.7 35.0 20.0 15.0 (36.6) (26.9) (23.2) . .... Thiamethoxam 25% WG I 00 r,m 2.3 29.5 17.7 14.9 (33.2) (25.2) (23.1) ., Buprofezin 25%SC 800 1111 2.9 39.5 14.0 11.6 (39.2) (22.4) (20.3) -~ IIL-Bupfipro 1500 1111 ?..4 19.5 0.0 3.0 (26.6) ( 17.5) (1 0.8) Untreated control -- 2.5 4.8 0.0 0.0 ( 13.3) ( 4.1) (4.1) F-test stg Slg Sig SEM 2.99 3.74 3.10 CD at 5% 9.07 11.35 9.40 *The data in the parentheses are