INCREASING THE EFFECTIVENESS OF SYNTHETIC, ORGANIC, OIL-SOLUBLE INSECTICIDES

Abstract: The effectiveness of synthetic, organic oil-soluble orga­ nophosphate, carbamate, formamidine and pyrethroid insec­ ticides is increased by adding to the insecticide at least about an equal volumetric amount, based on the volume of insecticide, of a polypropylene glycol having an average molecular weight of from about 1,000 to about 5,000 or a water insoluble polybutylene glycol.

Description: INCREASING THE EFFECTIVENESS OF SYNTHETIC, ORGANIC, OIL-SOLUBLE INSECTICIDES The present invention is directed to a method of increasing the effectiveness of synthetic, organic, oil-soluble insecticides and to improved insecticidal compositions. In particular, the insecticidal activity of ultra low volume (ULV) insecticidal formulations and of emulsion insecticidal formulations is increased. Insecticides are commercially important agricultural and industrial chemicals that are generally effective in killing, preventing or controlling the growth of undesirable insects. One important function that insecticides serve is to allow for an increased yield of valuable crops. Vast amounts of time and money are expended worldwide in search of new compounds that are effective insecticidal agents. Of the thousands of compounds screened each year for insecticidal activity, relatively very few ever become commercial products. As an alternative approach to searching for new insecticidalagents, it is highly desirable to provide methods of improving the effectiveness of known insecticides. Improving the activity of known pesticides offers advantages of working with compounds having known physical, insecticidal, and toxicological characteristics. Improving the activity of insecticides results in lesser amounts needed to achieve desired effects, and, in turn, lesser amounts available to contaminate the environment. Insecticides are commonly applied to foliage as ULV sprays or as more dilute emulsion sprays. Problems associated with spraying insecticides include loss of solvent, i.e., water, xylene, etc., by evaporation which greatly reduces the spray droplet size, causing loss of the active ingredients to spray drift; uneven coverage of treated areas or uneven distribution on the plants; and evaporation of the active insecticidal ingredients themselves, especially highly volatile insecticides. These are particularly annoying problems in certain insecticidal formulations where the sprays are delivered in relatively small droplets, having a diameter as small as about 50 microns, to facilitate spray distribution and penetration of the foliage canopy. The present invention sets out to remedy the above problems encountered in the known insecticidal arts by providing a method of increasing the insecticidal effectiveness of insecticidal formulations. Additionally, the present invention provides (a) insecticidal formulations having lower volatilities when compared to known formulations resulting in an increased residual activity and (b) insecticidal formulations having increased deposition properties, both of these additional effects resulting in the use of lesser amounts of active insecticidal ingredients per acre. Polypropylene glycols are known materials with a wide variety of uses, such as, for example solvents, coupling agents, antifoam agents, intermediates and lubricants. Polypropylene glycols have been present in pesticidal formulations in small quantities as defoaming agents. The present invention provides a method for increasing the effectiveness of insecticides by adding an effective amount of an additive to insecticides or insecticidal formulations. Effective additives include (a) polypropylene glycols having an average molecular weight of from 1,000 to 5,000; (b) water insoluble polybutylene glycols; and (c) mixtures or copolymers of (a) and (b). The present invention is also directed to insecticidal formulations containing the above additives. Of particular interest in the practice of the present invention is a method of increasing the insecticidal effectiveness of chlorpyri fos and chlorpyrifos-methyl by combining with chlorpyrifos or chlorpyrifos-methyl an amount of a polypropylene glycol, having an average molecular weight of from 1,000 to 5,000, which increases the effectiveness of the chlorpyrifos and chlorpyrifos -methyl. The terms "insecticide", "insecticidal" and "active" are meant to refer to synthetic, organic, oil-soluble insecticides selected from the group consisting of organophosphates, carbamates, pyrethroids and formamidines, and biologically active compositions containing these insecticides which are effective in killing, preventing or controlling the growth of undesirable pests, i.e., insects. The term "insecticidal formulation" refers to any composition containing an insecticide and a carrier system therefore, and includes concentrates, which are to be diluted before use, such as emulsifiable concentrates, and ready-to-use compositions, such as ULV formulations. Carrier systems include water, organic solvents, such as, xylene, benzene, methylene chloride, isophorone, dimethyl formamide, paraffinic hydrocarbons and vegetable oils; and other formulation ingredients, such as, surfactants, antioxidants and emulsifiers. The term "effective amount", when used to refer to the amount of additive to be added to an insecticide, describes a quantity of additive which, when combined with an insecticide or an insecticidal formulation, increases the effectiveness of such insecticide. The amount of additive required to increase the effectiveness of insecticides will vary but generally is an amount at least equal to the volume of insecticide present in the insecticidal formulation. It is preferable to add the present additives in amounts in the range of from 1 to lb times the volumetric amount of insecticide present in the insecticidal formulation and even more preferable in the range of from 1 to 5. Preferred additives are the polypropylene glycols, having an average molecular weight between 2,000 and 4,000. An especially preferred polypropylene glycol is a polypropylene glycol having an average molecular weight of about 2,000. Another preferred polypropylene glycol is one that has an average molecular weight of about 4,000. The polypropylene glycol additives are known compounds and commercially available. They are generally prepared by adding propylene oxide to water or to propylene glycol. The commercially available products are generally identified by a number indicating the average molecular weight. The polybutylene glycols are known compounds and are generally prepared by adding butylene oxide to water or to butylene glycol. Suitable polybutylene glycols are water insoluble. Mixtures and copolymers of the above additives are known and readily made employing well known procedures. Insecticides, which are acceptable in the practice of the present invention are those substantially water-insoluble (oil-soluble) insecticides having a vapor pressure of at least 10 mmflg or higher at commonly encountered growing season or use temperatures, i.e., 15"-40"C. Additionally, the insecticides are those which will not react with the present polypropylene glycol or polybutylene glycol additives. Suitable insecticides include chlorpyrifos (a preferred insecticide), sulprofos, methyl parathion, malathion, chlorpyrifos-methyl, dichlorvos, chlordimeform (as the oil-soluble base), fenvalerate and O,O-dimethyl O-(5-methyl-l-(2-pyridyl)-lH-l,2,4- -triazol-3-yl)phosphorothioic acid ester. In the practice of the present invention, the above additives, i.e., polypropylene glycols and/or poly butylene glycols, are combined, in an effective amount, with insecticides whereby the effectiveness of the insecticides is increased. The insecticides are then applied to insects or their habitats for insect control. Preferably, the insecticides are applied to valuable plants, for example, crops, ornamentals, pastures or turf for the control of undesirable pests. It is especially preferred to apply the present insecticidal formulations to crops. The additives are mixed with insecticides alone, and thereafter applied using well known application techniques, or the additive/insecticide combination is further admixed with known agricultural solvents and known agricultural formulating aids before application. The additives may also be mixed with commercially available insecticidal formulations before use. While it is not critical to the practice of the present invention, the agricultural solvents are advantageously added to obtain a pesticidal formulation with a desirable viscosity to aid in the sprayability of the insecticidal formulations. The optimum viscosity for m insecticidal formulation is readily determinable by one skilled in the art and depends on a variety of factors such as, for example, the particular insecticide(s) employed in the formulation, the additive present in the formulation, the solvents present in the formulation, the type of equipment being employed in applying the formulation, and the mode of application, i.e., ULV, emulsion or solution by aerial or ground application. Suitable agricultural solvents are generally water, petroleum solvents, esters, ketones and alcohols, lactones, and include xylene, xylene-range aromatic solvents, methylene chloride, l,l,l-trichloroethane or combinations of solvents. Other agricultural formulating aids, such as, antioxidants, emulsifiers or surfactants, are also admixed with the insecticidal formulations of the present invention. For example, emulsifiable concentrates, i.e., formulations that are to be mixed with water and applied as an emulsion, normally contain emulsifiers, such as the usual commercially available products. Emulsifiers are added to the present insecticidal formulations that are emulsifiable concentrates to ensure uniform distribution of the concentrates in water at the time of application. The emulsifiers are added in effective quantities and proportions which are readily determinable to one skilled in the art. Similarly, antioxidants, such as 2,6-di-tert-butyl-para-cresol (BHT) and phenothiazine, are added in effective quantities and proportions which are readily determinable to one skilled in the art. Insecticides are commercially available generally as formulations containing agricultural carriers, solvents and adjuvants. As a practical matter these commercially available formulations are admixed with the hereinbefore defined additives to provide improved insecticidal formulations according to the present invention. For example, chlorpyrifos, is commercially available as LORSBAN 4E brand insecticide, and, when combined with polypropylene glycol having an average molecular weight of about 2,000 in a ratio of about 1 part by volume of LORSBAN 4E to 3 parts by volume polypropylene glycol (avg. MW=2,000), provides an insecticidal formulation having an increased effectiveness. Alternatively, insecticides are obtained in substantially pure chemical form, i.e., bulk, technical grade, etc.,-and formulated by admixing with the present additives and known agricultural solvents and adjuvants. When applying the present insecticidal formulations to crops, the combination of additive and insecticide should be substantially free of any detrimental, i.e., phytotoxic, effects on the crops. For example, it has been found that polypropylene glycol having an average molecular weight of about 2,000 is an acceptable additive for chlorpyrifos which is applied to cotton crops, while on the other hand, it has been found unacceptable as an additive for chlorpyrifos which is applied to peanut crops because of the phytotoxic effects exhibited by the peanut plants to the combination of chlorpyrifos and polypropylene glycol having an average molecular weight of about 2,000. Polypropylene glycol having an average molecular weight of about 4,000 is an acceptable additive for chlorpyrifos which is to be applied to peanut crops. As a general rule, the greater the average molecular weight of the polypropylene glycol additive, the less phytotoxic effects the combination of chlorpyrifos and polypropylene glycol possesses. The choice of an acceptable additive as far as phytotoxicity to target crops is concerned is readily determinable by one skilled in the art. In one embodiment of the present invention, a synthetic organic, oil-soluble insecticide, useful in controlling pests in a valuable crop, is mixed with an additive wherein the additive is present in an amount that is at least equal to the volumetric amount of the insecticide. The insecticidal formulation is then applied, neat, as a foliar spray to the crop by aircraft or by ground equipment. Alternatively, an emulsifier is added to the formulation and then the formulation is mixed with water and applied to the crop as an emulsion by employing aircraft or ground equipment. Also, the formulation is mixed with oil and applied employing known techniques. In another embodiment of the present invention, the herein-described additives, in combination with an emulsifying agent, are provided as emulsifiable tank mix additives which are to be separately added to the water carrier in the field tanks prior to application of the insecticidal formulations to crops. In a preferred embodiment of the present invention, a synthetic, organic, oil-soluble insecticide, useful in controlling pests in valuable crops, is mixed with a polypropylene glycol having an average molecular weight of from 1,000 to 5,000, wherein the polypropylene glycol is present in an amount that is at least equal to the volumetric amount of insecticide. The pesticidal formulation is then applied, neat, as an ULV foliar spray to the crop by aircraft or by ground equipment. Alternatively, an emulsifier is added to the formulation and then the formulation is mixed with water and applied to the crop as an emulsion by employing aircraft or ground equipment. In an especially preferred embodiment of the present invention, polypropylene glycol having an average molecular weight of about 2,000 is combined with chlorpyrifos wherein the polypropylene glycol is present in a volumetric amount at least about equal to the volume of chlorpyrifos. This formulation is then sprayed on a cotton crop by aircraft or ground equipment to provide up to about 1.12 kgs of chlorpyrifos per hectare of cotton crop. This formulation may be sprayed as an ULV spray, optionally containing a solvent such as, methylene chloride, or as an oil-in -water emulsion by adding an emulsifying agent to the formulation and then adding it to water. In another preferred embodiment of the present invention, polypropylene glycol having an average molecular weight of about 4,000 is combined with chlorpyrifos wherein the polypropylene glycol is present in an amount at least about equal to the volume of chlorpyrifos. This formulation is then sprayed on a peanut, soybean or corn crop by aircraft or ground equipment to provide up to about 1.12 kgs of chlorpyrifos per hectare of peanut crop. This formulation may be sprayed as an ULV spray, optionally containing a solvent such as, methylene chloride, or as an oil-in-water emulsion by adding an emulsifying agent to the formulation and then adding it to water. The following examples further illustrate the present invention. Example 1 The following materials are combined to form a ULV formulation: chlorpyrifos . . . . . . . . . . . .06-.48 kgs/L polypropylene glycol . . . . . . O.06-0.85 L/L (avg. MW 1,000-5,000) solvent (xylene, . . . . . . . . 0-0.85 L/L xylene range aromatic solvent (methylene chloride, trichloroethane) diluent (petroleum oil) . . . . . 0-0.75 L/L emulsifier . . . . . . . . . . . . 0-0.4 L/L The volume ratio of polypropylene glycol to chlorpyrifos is in the range of from 1:1 to 12:1. Chlorpyrifos density is taken as 1.428 g/ml for calculations used in this specification. Example 2 The following ingredients were mixed to make insecticidal formulations according to the present invention. Formulation A: technical grade chlorpyrifos . . . . 12.7 gms (95% purity) methylene chloride . . . . . . . . . 9.8 ml polypropylene glycol ... 81.2 ml (avg MW of 2,000) 100 ml Formulation s: technical grade chlorpyrifos . . . . 12.7 gms (95% purity) methylene chloride . . . . . . . . 9.8 ml polypropylene glycol . . . . . . . . 81.2 ml (avg MW of 1,200) 100 ml Formulation C: chlorpyrifos (as LORSBAN 4E . . . . 25 ml brand insecticide) polypropylene glycol . . . . . . . 75 ml (avg MW of 1,200) 100 ml Formulation D: chlorpyrifos (as LORSBAN 4E . . . . 25 ml brand insecticide) polypropylene glycol . . . . . . . 75 ml (avg MW of 2,000) 100 ml The following comparative formulations were prepared by mixing the following ingredients: Formulation. 1: technical grade chlorpyrifos . . . 12.7 gms (95% purity) methylene chloride . . . . . . . . 9.8 ml mineral oil (DRAKEOL 19) . . . . . 81.2 ml 100 ml Formulation 2: technical grade chlorpyrifos . . . 12.7 gms (95% purity) methylene chloride ... 9.8 ml mineral oil (DRAKEOL-5) . . . . . . 81.2 ml 100 ml Formulation 3: chlorpyrifos (as LORSBAN 4E . . . . 25 ml brand insecticide) cottonseed oil ... 75 ml 100 ml Formulation 4: chlorpyrifos (as LORSBAN 4E . . . . 25 ml brand insecticide) water . . . . . . . . . . . . . . . 75 ml 100 ml Formulation 5: technical grade chlorpyrifos . . . 12.7 gms (95% purity) methylene chloride . . . . . . . . 9.8 ml Volck oil . . . . . . . . . . . . . 81.2 ml 100 ml Formulation 6: technical grade chlorpyrifos . . . 12.7 gms (95% purity) methylene chloride . . . . . . . . 9.8 ml polypropylene glycol . . . . . . . 81.2 ml (avg MW of 400) 100 ml Formulation 7: technical grade chlorpyrifos . . . 12.7 gms (95% purity) methylene chloride . . . . . . . . 9.8 ml polyethylene glycol . . . . . . . . 81.2 ml (avg MW 600) 100 ml Formulation 8: chlorpyrifos (as LORSBAN 4E . . . . 25 ml brand insecticide) polypropylene glycol ... 75 ml (avg MW of 400) 100 ml Formulation 9: chlorpyrifos (as LORSBAN 4E . . . . 25 ml brand insecticide) polyethylene glycol . . . . . . . . 75 ml (avg MW of 600) 100 ml All of the above formulations contain 12 gms of chlorpyrifos per 100 ml which is equivalent to 0.12 kg of chlorpyrifos per litre. Formulation A was tested against Formulations 1, 2, 3 and 4 for control of late, second instar tobacco budworm (TBW) larvae and all stages of two-spotted spider mites (2-SSM). The above formulations were sprayed on greenhouse grown cotton plants at a rate equivalent to 9.354 L of spray per hectare. Cotton plants were infested with all stages of two-spotted spider mites, Tetranychus urticae (2-SSM). These plants were then sprayed with the above-described formulations and then maintained in a greenhouse under favorable growing conditions. Percent mite mortality was determined five days post-treatment. Percent control is expressed as the total number of mobile forms found in the treatment divided by the total number of live mites in the control. Additional plants, not pre-infested with mites, were also sprayed with the same formulations, so as to define residual activity. These plants were maintained in the greenhouse for a period of five days, at which time they were infested with two-spotted spider mites. Percent mortality for these treatments was determined five days post-infestation using the same criteria as previously described. The results of these tests are listed in Table 1 under the "intial" and "residual" columns for percent 2-SSM control. In addition to obtaining miticidal efficacy, the above formulations were also tested on late second instar tobacco budworm larvae, Heliothis virescens. Plants were sprayed with the above formulations and stored in the greenhouse under favorable growing conditions. Leaves from these plants were removed immediately after treatment and at two-days post-treatment to determine initial and residual control of tobacco budworm. Leaves were placed in petri dishes and infested with five (5) tobacco budworm larvae. Percent control was determined at 48 hours post-infestation= These results are listed in Table 1 under "initial" and "residual" columns for percent TBW control. All treatments were replicated three times and reported in Table 1 as the average percent control. TABLE 1 Percent TBW Control Percent 2-SSM Control Formulation Initial 2 day Residual Initial 5 day Residual A 100 93 93 89 1 100 67 85 33 2 93 53 60 50 3 100 30 78 17 4 80 7 50 0 Example 3 Substantially the same procedures of Example 2 were employed to test Formulations A, B and C against Formulations 3, 4 and 5 for control of TBW (initial and two day residual control) and 2-SSM (initial and five day residual). Additionally, the control of 2-SSM eggs was evaluated by using cotton plants pre-infested with adults of two-spotted spider mites which were allowed sufficient time to lay eggs. Plants were then treated with tetra-ethyl pyrophosphate (tepp) (500 ppm) so as to kill the mobile forms while leaving viable mite eggs on the plants. These plants infested with viable mite eggs were then sprayed with the above formulations in a manner substantially similar to the other treatments. The results of the control of mite eggs was determined in five days and the results are listed in Table 2 under "eggs" column for initial percent control of 2-SSM. All of the above treatments utilized three replications and are listed in Table 2 as the average percent control. TABLE 2 Percent TBW Control Percent 2-SSM Control Formulation Initial 2 day Residual Initial 5 day Residual Eggs Mites A 100 93 98 92 100 B 100 67 79 74 73 C 100 100 99 97 90 3 100 33 0 57 33 4 100 60 0 40 33 5 100 33 60 40 47 Example 4 Substantially the same procedures of Example 2 were employed to test Formulations A, B, C and D against Formulations 4, 5, 7, 8 and 9 for control of TBW and 2-SSM. All of the treatments utilized three replications and are listed in Table 3 as the average percent control. TABLE 3 Percent TBW Control Percent 2-SSM Control Formulation Initial 2 day Residual Initial 5 day Residual A 100 100 100 99 B 100 93 99 93 C 100 100 97 91 D 100 100 100 100 4 100 60 39 36 6 100 87 93 75 7 100 93 94 41 8 100 100 88 92 9 100 87 73 46 Example 5 A field trial was conducted in Wayside, Mississippi, to determine the effectiveness of various insecticidal formulations when applied as ULV sprays. Seven formulations plus an untreated check were included in the trial, each in replicate. Each plot was 1 row (3.048 meters) and was covered by a 1.8 x 2.1 x 3.7 meter cage. The five or six plants in each cage were trimmed to leave only the top 1/3 branches. Eight days before treating, thirty tobacco budworm moths were released in each cage. The plots were treated with the formulations listed at the bottom of Table 4 at a rate of 1.12 kg of active ingredient per hectare. Each cage was removed just prior to treatment. Treatments were applied by MICRO-MAX controlled droplet rotary atomizers mounted on a high -clearance sprayer. Two to three days after treatment, 3 to 4 plants in each plot were surveyed for live and dead larvae. At 3 days after treatment, 5 leaves in each plot were surveyed for the number of mobile 2-S SM. In order to measure residuality of insecticide, at 2 days after treatment, 4 leaves were picked from each plot and were placed in individual paper cups with 4 or S TBW second instar larvae. Live and dead larvae were counted 2 days later. The results are listed below in Table 4 as an average of the two replicates. TABLE 4 % Corrected Residual Control of TBW on % Corrected Control Cotton Leaves 2 days of TBW Larvae by Post-Treatement Using Spray Volume Abbot's Formule After %Control Abbot Formula Treatement* (L/hectare) 48-72 Hours Exposure of Mites (48 hrs. Exposure) 1 4.677 87 80 69 2 4.677 83 78 38 3 9.354 75 75 20 4 6.548 73 69 58 5 4.677 71 73 35 6 9.354 70 69 58 7 9.354 68 49 15 8 None 0 0 0 (control) *Treatement Formulations tested are as follows: 1- LORSBAN 4E brand insecticide and polypropylene glycol (avg. MW=2,000) in a 1:1 volume ratio resulting in a v/v ratio of polypropylene glycol to chlorpyrifos of 3:1 2 - 0.24 kg chlorpyrifos per liter with methylene chloride and polypropylene glycol (avg MW-2,000) wherein the v/v ratio of polypropylene glycol to chlorpyrifos is 4:1. TABLE 4 (continued) 3 - .12 kg chlorpyrifos per liter containing methylene chloride and polypropylene glycol (avg. MW-2,000) wherein the v/v ratio of polypropylene glycol to chlorpyrifos is 9:1. 4 - .18 kg chlorpyrifos per liter containing methylene chloride and polypropylene glycol (avg. MW=2,000) wherein the v/v ratio of polypropylene glycol to chlorpyrifos is 5.7:1. 5 - .24 kg chlorpyrifos per liter containing Aromatic 100 (xylene range aromatic solvent), polypropylene glycol (avg. MW=2,000) and Atlox 3434FD wherein the ratio of polypropylene glycol to chlorpyrifos is 2.9:1. 6 - Lorsban 4E brand insecticide and polypropylene glycol (avg. MW=2,000) in a 1:3 volume ratio, resulting in a v/v ratio or polypropylene glycol to chlorpyrifos of 9:1. 7 - Lorsban 4E brand insecticide diluted with water. 8 - Untreated (nothing applied to plots). Example 6 The evaluation of residual insecticidal activity on cotton leaves after an aerial application of chlorpyrifos was conducted at Leland, Mississippi. At various time intervals both leaves and squares were picked at random from each of the treated locations. Each treatment was replicated four times. Each replication consisted of a 4.05 hectare plot. The three treatments evaluated were as follows: Treatment 1: LORSBAN 4E brand chlorpyrifos mixed in water and applied at a rate of 1.12 kgs chlorpyrifos/hectare in 7 liter total spray per hectare. Treatment 2: 1 Part LORSBAN 4E brand chlorpyrifos mixed with 3 parts polypropylene glycol (avg. MW = 2,000) applied at a rate of 0.56 kg chlorpyrifos/hectare as a non-aqueous ULV spray. Treatment 3: Equal parts of LORSBAN 4E brand chlorpyrifos and polypropylene glycol (avg. MW = 2,000) applied at a rate of 0.56 kg chlorpyrifos/hectare as a non-aqueous ULV spray. Ten leaves and squares were sampled from each replicate and placed into 90 ml paper cups. Each square was infested with boll weevils, Anthonomus grandis, (3 per square). Each leaf was infested with beet armyworm larvae, Spodoptera exigua, (5 third-fourth instar larvae/leaf). Insects were incubated in cups at room temperature. Mortality readings were made 48 hours post-infestation. Results are listed in Table 5. TABLE 5 Average Percent Control Average Percent Control of Boll Weevils after 48 hr. of Beet Armyworm larvae Exposure on Squares Picked after 48 hr. Exposure on Leaves Treatement 3 Time Intervals Post-treatement Picked at 5 Intervals Post-treatement 24 hours 48 hours 72 hours 24 hrs. 48hrs. 72hrs. 96hrs. 120hrs. 1 79 44 19 95 78 68 40 45 2 97 81 32 100 97 95 80 72 1 96 89 45 100 94 97 81 75 The results in Table 5 are further charcterized by the graph shown in Figure 1: TABLE 6 Kgs Compound Treatement A per Hectare Residual Control (%) Field Control (%) 1. Compound A 0.28 50 75 2. 1 part Compound A 0.28 85 91 and 3 parts polypropylene glycol (avg. MW=2,000) 3. Compound A 0.56 88 84 4. 1 part Compound A 0.56 100 93 and 3 parts polypropylene glycol (avg. MW=2,000) Example 7 O,O-dimethyl O-(5-methyl-l-(2-pyridyl)-lH1,2,4-triazol-3-yl)phosphorothioic acid ester, hereinafter referred tO as "Compound A", was applied to cotton previously infested with all ages of tobacco budworm larvae, primarily late second to third instar. Compound A was applied to the cotton as an oil-in-water emulsion by mixing the treatments described in Table 6 with enough water to apply either 0.28 or 0.56 kgs compound A/hectare at a spray volume of 93.54 L/hectare. Three plants from each plot were examined 48-72 hours post-treatment for the number of live and dead larvae. These results are listed in Table 6 under "Field Control (%)". At 24 hours post-treatments, leaves were sampled from each of the plots and were brought back to the laboratory and infested with late second instar tobacco budworm larvae. Mortality readings were taken 48 hours post-infestation, the results of which are listed in Table 6 under "Residual Control (%)". Example 8 The following ingredients were admixed to form an improved insecticidal formulation of the present invention: Ingredient Weight Percent chlorpyrifos 22.9 xylene plus inerts from technical chlorpyrifos 18.7 BHT 0.1 Polypropylene glvcol (avg. MW=2,000) 52.9 Emulsifier (ATLOX 3403F, 3404F, 3409F in 10-75-15 weight ratio respectively) 5.4 100 Chlorpyrifos (specific gravity = 1.428) and polypropylene glycol (avg. MW=2,000) (specific gravity = 1,002) are present in the above formulation in a volume/volume ratio of 3.3 (polypropylene glycol/chlorpyrifos). The above formulation has a specific gravity of 1.05 at 200C and contains .24 kgs chlorpyrifos per lite. This formulation is useful for application to cotton crops for the control of undesirable pests. Example 9 The following ingredients were admixed to form an improved insecticidal formulation of the present invention: Ingredient Weight Percent chlorpyri fos 23.2 xylene plus. inerts from technical chlorpyrifos 27.4 Polypropylene glycol (avg. MW=4,000) 43.8 BHT 0.1 ATLOX 3404F 3.9 ATLOX 3409F 1.6 100 Chlorpyrifos (specific gravity = 1.428) and polypropylene glycol (avg. MW=4,000) (specific gravity = 1.005) are present in the above formulation in a volume/volume ratio of 2.7 (polypropylene glycol/chlorpyrifos). The above formulation has a specific gravity of 1.034 at 200C and contains 0.24 kg chlorpyrifos per lite. This formulation is useful for application to plants for the control of undesirable pests. Example 10 A number-of commercially available insecticides were sprayed onto young greenhouse grown cotton and rice plants using a track sprayer delivering 23.39 L/ha. The insecticidal spray formulations were prepared by: (1) mixing the commercially available insecticide with enough water to provide the desired amount of active ingredient (a.i.) per 23.39 liters of spray per hectare; or (2) mixing commercial emulsifiable formula tion of insecticide with polypropylene glycol (average MW = 2,000) to provide 3-3.5 -volumes of polypropylene glycol per volume of active ingredient (a.i.) and then diluting in sufficient water to provide the desired amount of a.i. per 23.39 liters of spray per hectare. Immediately after spraying1 some of the leaves of cotton plants were excised from the plant and placed in closed petri dishes with five (5) second instar tobacco budworm (Heliothis virescens) larvae. The petri dishes were then incubated at 250C for 48 hours to determine percent mortality of the tobacco budworms. Additional leaves were assayed in a similar manner at various time intervals to determine length of residual control Some of the insecticidal formulations were also evaluated on the two-spotted spider mite (2-SSM) by infesting cotton plants, immediately after they were sprayed, with 10 adult 2-SSM and thereafter maintaining the infested plants in temperature controlled chambers at 250C. Percent mortality readings were made 48 hours post-infestation. Additional plants were infested with 10 2-SSM at various time intervals after spraying to determine residual control. The activity of methyl parathion was also evaluated for activity on the aster leafhopper (Macrosteles fascifrons). Young rice plants were sprayed in a similar manner as described above Two days later plastic cylinders were placed around each of the plants and 10 adult leafhoppers were placed in each cylinder. The cylinders were then capped. The plants were incubated in the greenhouse and percent mortality readings were made 24 hours post-infestation. Additional plants were infested with leafhoppers 3 days after spraying. The results are listed in Table 7. Control formulations consisted of water only (no insecticide). TABLE 7 Percent Control - Days After Treatement Rate, Budworm Leafhoppers Insecticidal Formulation kg a. i./ha (0 days) (2 days) (3 days) Methyl Parathion and 0.28 40 60 3 Water 0.56 57 86 23 1 part by volume a. i. 0.28 54 100 37 methyl parathion, 3.5 parts by volume 0.56 74 100 89 polypropylene glycol (avg. MW = 2,000) and water Control None 0 0 0 TABLE 7 (Continued) Percent Control - Days After Treatement Rate, Budworm Mites Insecticidal Formulation kg a. i./ha (0 days) (1 day) (2 day) Galecron 4EL 1.12 23 45 36 (chiordemiform) and 2.24 33 61 40 water 1 part by volume a.i. 1.12 60 91 83 Galecron, 4EL, 3 parts 2.24 63 94 87 by volume propylene glycol (avg MW = 2,000) and water Control None 7 0 0 TABLE 7 (Continued) Percent Control Days After Treatement Rate, Budworm Mites Insecticidal Formulation kg a. i./ha (8 days) (6 days) Bolstar (sulprofos) 0.28 31 0 and water 0.56 87 62 1 part by volume a.i. 0.28 80 85 Bolstar., 3.2 parts by 0.56 100 91 volume polypropylene glycol (avg MW = 2,000) and water Control None 0 0 Example 11 The following ingredients were admixed to form improved insecticidal formulations of the present invention: Formulation E LARVIN 75WP thiodicarb insecticide (powder) 640 mg polypropylene glycol (MW = 2,000) 3 ml polybutylene glycol (MW = 2,000) 3 ml water qs 40 ml Formulation F LARVIN 75WP thiodicarb insecticide (powder) 640 mg polybutyleneglycol (avg. MW = 2,000) 6 ml water qs 40 ml These formulations were then sprayed on greenhouse grown cotton plants at a rate equivalent to 0.28 kg a.i./ha (23.39 L/hectare) in substantially the same manner as set forth in Example 10. Results for the control of 2-SSM are listed below in Table 8 compared to a control of LARVIN insecticide diluted with only water and an untreated check. TABLE 8 Percent Control Rate of 2-SSM-Days Formulation kg a.i./ha After Treatment 0 1 Day 2 Days 3 Days Untreated Check 0 0 0 0 0 LARVIN 75WP + water .28 0 12 0 0 Formulation E .28 39 59 21 34 Formulation F .28 0 43 14 28 Example 12: The following ingredients were admixed to form improved insecticidal formulations of the present invention: Formulation G Galecron 4E chlordimeform insecticide 8 ml polybutylene glycol (avg. MW = 2,000) 3 ml polypropylene glycol (avg. MW = 2,000) 3 ml water qs to 40 ml Formulation H Galecron 4E chlordimeform insecticide 8 ml polybutylene glycol (avg. MW = 2,000) 6 ml water qs 40 ml These formulations were then sprayed on greenhouse grown cotton plants at a rate equivalent to 2.24 kg/ha (23.39 liters/hectare) in substantially the same manner as set forth in Example 10. Results for the control of 2-SSM are listed below in Table 9 compared to a control of Galecron insecticide diluted with only water and an untreated check. TABLE 9 Percent Control Rate of 2-SSM-Days Formulation kg a.i./ha After Treatment 0 1 Day 2 Days 3 Days Untreated Check 0 0 0 0 0 Galecron 4E + water 2.24 93 59 32 74 Formulation G 2.24 100 98 95 92 Formulation H 2.24 98 86 81 96 Example 13 The following ingredients were admixed to form improved formulations of the present invention: Formulation I LORSBAN 4E insecticide 2 ml polypropylene glycol (avg. MW = 2,000) 3 ml polybutylene glycol (avg. MW = 2,000) 3 ml water qs 40 ml Formulation J LORSBAN 4E insecticide 2 ml polypropylene glycol (avg. MW = 2,000) 6 ml water qs 40 ml These formulations were then sprayed on greenhouse grown cotton plants at a rate equivalent to 0.56 kg/hectare (23.39 L/ha) in substantially the same manner as set forth in Example 10. Results for the control of 2-SSM are lsited below in Table 10 compared to a control of LORSBAN insecticide diluted with only water and an untreated check. TABLE 10 Percent Control Rate of 2-SSM-Days Formulation kg a.i./ha After Treatment 0 1 Day 2 Days 3 Days Untreated Check 0 0 0 0 0 Lorsban-- 4E + water 0.56 92 56 39 24 Formulation I 0.56 96 72 61 57 Formulation J 0.56 98 100 82 61 On repeating the foregoing test procedures using other synthetic, organic, oil-soluble insecticides in combination with the herein defined additives, i.e., polypropylene glycols having an average molecular weight of from 1,000 to 5,000, water insoluble polybutylene glycols, mixtures and copolymers thereof, substantially the same improvement in insecticidal effectiveness is obtained. In further embodiments, the improved insecticidal formulations of the present invention may contain additional agricultural chemicals to increase the spectrum of activity Such additional agricultural chemicals may be water-soluble insecticides, nematocides, arthropodicides, herbicides, fertilizers, micronutrients, fungicides or bactericides that are compatible with the formulations of the present invention'and not antagonistic to the insecticidal activity of the present formulations. The agricultural chemicals in combination can generally be present in the ratio of from 1 to 100 parts of the insecticides of the present invention with from 100 to 1 parts of the additional agricultural chemicals.

Claims: CLAIMS: 1. An insecticidal formulation containing one or more synthetic, organic, oil-soluble organophosphate, carbamate, formamidine or pyrethroid insecticides, which contains at least an equal volumetric amount, based on the volume of insecticide present in toe formulation, of: (a) a polypropylene glycol having an average molecular weight in the range of 1,000 to 5,000; (b) a water insoluble polybutylene glycol; or (c) mixtures and copolymers of (a) and (b). 2. An insecticidal formulation as claimed in claim 1 and further comprising a diluent, carrier or adjuvant. 3. An insecticidal formulation as claimed in claim 2 wherein the additive is polypropylene glycol having an average molecular weight in the range of from 1,000 to 5,000. 4. An insecticidal formulation as claimed in claim 3 wherein the polypropylene glycol has an average molecular weight of 2,000. 5. An improved insecticidal formulation as claimed in claim 3 wherein the polypropylene glycol has an average molecular weight of 4,000. 6. An insecticidal formulation as claimed in any one of the preceding claims wherein the insecticide is an organophosphate. 7. An insecticidal formulation as claimed in claim 6 wherein the insecticidal is chlorpyrifos or chlorpyrifos-methyl. 8. A method of increasing the effectiveness of a synthetic, organic, oil-soluble organophosphate, carbamate, formamidine or pyrethroid insecticide which comprises adding to the insecticide at least an equal volumetric amount, based on the volume of insecticide, of: (a) a polypropylene glycol having an average molecular weight in the range of from 1,000 to 5,000; (b)- a water insoluble polybutylene glycol; or (c) mixtures and copolymers of (a) and (b). 9. A A method as claimed in claim 8 wherein the additive is a polypropylene glycol having an average molecular weight in the range of from 1,000 to 5,000. 10. A method as claimed in claim 9 wherein the polypropylene glycol has an average molecular weight of 2,000. 11. A method as claimed in claim 9 wherein the polypropylene glycol has an average molecular weight of 4,000. 12. A method as clained in any one of Claims 8 to 11 wherein the insecticide is an organophosphate. 13. A method as claimed in claim 12 wherein the insecticide is chlorpyrifos or chlorpyrifosmethyl. 14. A method of controlling insects which comprises: (a) adding to a synthetic, organic oil soluble organophosphate, carbamate, formamidine or pyrethroid insecticide at least an equal volumetric amount, based on the volume of insecticide, of: i) a polypropylene glycol having an average molecular weight in the range of from 1,000 to 5,000; ii) a polybutylene glycol; or iii) mixtures and copolymers of i) and (ii) and (b) applying an insecticidally effective amount of a formulation comprising (a) above to an insect or its environment. 15. A method as claimed in claim 14 wherein the additive is a polypropylene glycol having an average molecular weight of from 1,000 to 5,000. 16. A method as claimed in claim 15 wherein the polypropylene glycol has an average molecular weight of 2,000. 17. A method as claimed in claim 15 wherein the polypropylene glycol has an average molecular weight of 4,000. i8. A method as claimed in any one of claims 14 to 17 wherein the insecticide is an organophosphate. 19. A method as claimed in claim 18 wherein the insecticide is chlorpyrifos or chlorpyrifos-methyl.

Inventors: DEVRIES, HENRY, HOLOMAN, SMALLWOOD JR., PAROONAGIAN, DORIS LUCY, SEYMOUR, KEITH GOLDIN
Applicants: THE DOW CHEMICAL COMPANY
Application year: 1983
Main classification: A01N25
IPC codes: A01N25