MXPA97008649A - Insecticide composition of tierra de diatomea - Google Patents

Abstract

The present invention relates to: An insecticidal powder composition comprising an effective amount of diatomaceous earth [DE] in combination with an effective amount of silica selected from the group consisting of precipitated silica and silica airgel, DE and silica they are mixed in different weight ratios of from about 95% to 65% DE to about 5 to 35% by weight.

Description

INSECTICIDE COMPOSITION OF EARTH DIATOMS DESCRIPTION AND THE INVENTION The present invention relates to an insecticidal composition, and more particularly to a powdered insecticidal composition, based on diatomaceous earth, for use in dry media such as grain stores and processing plants. Due to the growing public concern related to the toxicity of insecticide residues in grains and in the environment and the existence of insecticide-resistant insect strains, there has been a need for new attempts to control insect pests. . For centuries it has been known that stored grains can be protected from the attack of insects by mixing powders in the grains. Common materials include plant ash, lime, dolomite, certain types of earth and diatomaceous earth. Diatomaceous earth is known to be one of the most effective natural insecticidal powders [Ebeling, 1971]. Single-cell plants called diatoms live in seas and lakes and extract silicon from water into their shells producing a hydrated amorphous silica esgueleto. When the diatoms die, their small shells sink and in some moments they can form thick layers. Eventually * the shells of these deposits become fossil and compress to form a smooth Cretaceous stone called diatomaceous earth [DE]. Nowadays the ED is prepared for commercial use by means of quarrying, drying and grinding. The only change to the ED during this process is the reduction of the moisture content and average particle sizes. The result is a fine powder in the form of talc, which is not toxic to mammals. It is extremely stable and does not produce toxic chemical residues or reacts with other substances in the environment (Quarles, 1992a). According to the EPA (Environmental Protection Agency, USA), made RED (Eligibility Registration Documents), 21T-1020 September 1991, diat ea earth, described as amorphous silicon dioxide, has a form of physical action to control insects. It has an acute low to moderate toxicity [category III] and has not been associated with silicosis. Also according to the International Agency for Research on Cancer (IARC), amorphous silicon dioxides belong to group 3 - non-carcinogenic, due to its negligible toxicity, in the USA, the diatomaceous earth is exempt from the tolerance requirements of legal residual limits, when applied to growing crops and aglylla plants after harvest, to animals or to food as in food processing and storage areas. Amorphous silicon dioxide is "Generally recognized as safe" [GRAS], as a food additive (21 CRF 182.90 and 182.1711). Consequently, the EPA concluded that the risk to human health of the diatomaceous earth is low and can not be registered. Also, there is no evidence to suggest that the use of this material as a pesticide in accordance with approved labeling presents a hazard to non-target organisms other than arthropods. In addition to controlling insects of stored products, DE is very useful for the management of pests in homes and gardens. It controls many different insects (Quarles, 1992a). The first commercial formulations of DE were widely released in 1950. Between 1965 and 1970 a series of studies were conducted on DE by USDA in the USA (Quarles 1992a), in the former Czechoslovakia and the former Yugoslavia (Croatia). After these initial studies, experiments were also carried out in other countries, such as Australia and Egypt. In several experiments DE provided better insect protection than malathion, particularly in long terms, at that time, a relatively large amount of DE was added to the grain to provide protection, for example 3500 ppm, (3.5 kg / ton). Between 1980 and 1990, the problem of using relatively large amounts of DE has been reduced by the use of improved ED formulations containing baits and attractions (eg., Insecolo *, Insectigone *), or a very low percentage of silica gel coating on DE particles and 1% fluoride (Dryacide *) (Table 1). But the concentrations of the current formulations of registered use of DE to be used for the protection of stored grains are still too high (500 ppm to 3600 ppm) to be accepted in the grain industry. There are other formulations of ED mixed with different substances such as rotenone or pyrethrins (usually 0.1 to 0.2%). Boric acid, benzocarb, diazinone and chloropyrifos were also tested in some experiments (right and Dupress, 1984; Belford, 1990). There are several problems associated with the treatment of grain with DE that limit its widespread use and acceptance. These powders in their current rates decrease the volumetric density of the grain (test weight) (Table 2 and 3), reduce the grain's fluidity, leave visible residues (white cretaceous appearance) and therefore reduce its quality because it is classified by its content of foreign material. It is believed that diatomaceous earth causes excessive wear on machinery, and workers complain due to volatile dust during the treatment and movement of the grain, some of these problems could be solved or reduced if the products were used at a lower rate, but the Rates of currently registered formulations of DE are too low to control insects. Thus it is an object of the present invention to increase the efficiency of DE in such a way that insects are controlled, but the aforementioned disadvantages are minimized.

According to the present invention an insecticidal powder composition comprising an effective amount of DE in combination with an effective amount of silica selected from the group consisting of precipitated silica and silica airgel, the DE and the silica are mixed in different proportions by weight depending on the type of DE, and may preferably be from about 95 to 65% DE to about 5 to 35% silica airgel. Mixed with DE, the silica increases the active surface area, increases the fluidity of the ED and prevents the formation of lumps or agglomeration of the DE particles, giving a better distribution of the particle size. In a preferred embodiment of the present invention, the DE is about 905 powder of Celite 209 * or the equivalent and the silica is about 10% by weight of Sipernat SOS *. It has been determined that the efficacy of the compositions mixed according to the present invention against insects is significantly greater than the efficacy of the current commercial formulations of DE. More particularly, when using such compositions, the concentration necessary to control the insects can be greatly reduced. In addition, due to the use of lower concentrations of these formulations, some of the problems previously associated with insecticidal applications of DE in grains are greatly reduced: - Visible residues of grain are greatly reduced, at very low concentrations of 50 to 100 ppm, there are visible residues; there is less dust suspended in the air during the treatment and handling of the grain; the influence of dust on grain fluidity and problems with machinery are reduced; tolerant species against DE can be controlled much more easily and even at higher moisture contents (M.C.) of the grain (14%). It has been determined that the blended compositions according to the present invention only have a slightly reduced compacted density compared to the current commercial ED formulations (Table 4). The main disadvantage of silica airgel are the low compacted densities that produce dust when working and are bulky for transport and storage, not evident in the mixed formulations of DE and silica airgel. BRIEF DESCRIPTION OF THE FIGURES These and other advantages of the invention will become apparent upon reading the following detailed description and upon making references to the drawings in which: Figure 1 is a graph showing the test results of the application of certain compositions DE to control grain beetles. Figure 2 is a graph showing the test results of the application of certain DE compositions to control the red beetles of the flour. Figure 3 is a graph showing the control of the rice weevil in containers treated with 2 DE formulations. Figure 4 is a graph showing the control of the red flour beetle in containers treated with 2 DE formulations. Figure 5 is a graph showing the minor perforator control of grains in containers treated with 2 DE formulations. Figures 6, 7 and 8 are graphs showing the control of grain beetles in wheat treated with different concentrations of Protect-It (registered trademark for the composition of 90% by weight of Celite 209 (registered trademark) and 10% in weight of Sipernat 50S (registered trademark)). Figures 9, 10 and 11 are graphs showing the control of the red flour beetle in wheat treated with different concentrations of Protect-it diatomaceous earth in different research centers. While the invention will be described with exemplary embodiments, it will be understood that it is not intended to limit the invention to such embodiments. On the contrary, it is intended to cover all the alternatives, modifications and equivalents that may be included within the spirit and scope of the invention as defined in the appended claims.

The components of the composition mixture according to the present invention are different natural formulations of DE and amorphous silicon dioxide precipitated, a preferred composition according to the present invention is a mixture of DE Celite 209 and Sipernat 50S silicon dioxide. Celite 209 is a marine product produced by Celite Corporation of Quincy, Washington. Sipernat 50S is produced by Degussa Canada, Ltd., Burlington Ontario. The mixing of these two components is done in a proportion of 905 weight of Celite 209 and 10% of Sipernat 50S. This resulting powder composition must be dry with a declared moisture content: Celite 209 with a maximum moisture content of 6% and Sipernat 50S with a maximum moisture content of 6%. Example i; Celite 209 and Supernat 50S, in a weight ratio of 9: 1, are mixed at room temperature for at least 10 minutes. When the mixing is done properly, the Sipernat 50S (white) can not be seen in the mixture. The mixture looks like Celite 209 (uncoated), and has a specific gravity of approximately 33.7 kg / m3 and the physical and chemical properties are almost identical to those of Celite 209. The only important difference is in the context of dioxide of amorphous silicon which is present in the mixture in about 88% (in Celite 209, amorphous silicon dioxide is present in about 86.7% by weight). There are some differences in the particle size distribution between the mixture and Celite 209. Celite 209 has an average particle size of from 7 to 8.2 microns with 75./3% of particles smaller than 16 microns or 49.1% smaller than 8 microns. The mixture of Celite 209 and Sipernat 50S (Celite 209 synergized) has a particle size of less than 16 microns or 57.3% less than 8 microns. Celite 209 was mixed with Sipernat 50S with different proportions by weight: 50:50; 60; 40; 70:30; 80:20; 90:10 and 95: 5. The most acceptable results are obtained with the mixture of 90% by weight of Celite 209 and 10% of Sipernat 50S (Celite 209 synergized). The effectiveness of this mixture against insects is significantly greater than the efficacy of the known commercial formulations of diatomaceous earth (Tables 5 to 9, figures 1,2) (table 1, figures 1,2). Tests of cappp in 199 Grain treated with 50 ppm of Celite synergized 209 reduces the insect population after one month, but the second month there was a resurgence of the insect population (Table 10, 11, 12). Termites that included the predatory species and those that feed on grains, were reduced by more than 98% to 50 ppm. After one month, 300 ppm had eliminated the grain beetle and the termites and reduced the red beetle populations of the flour by 88 to 99% compared to the untreated grain.

The volumetric density of the wheat was reduced slightly, 2.1 kg / hl or 2.7% by the application of 50 ppm of celite 209 synergized. At 300 ppm, the volumetric density or test weight was reduced by 4.6 kg / hl or 65 (Table 13). None of the doses caused a reduction in quality because the grain was degraded due to other factors. Grain treatment with 50 ppm did not cause any noticeable reduction in fluidity or any increase in dust in the air. At 330 ppm there was a marked reduction in grain flow and an increase in dust in the air. Structural treatments There was a good control of insects after a week at 55% rh. At 75% rh the dry application killed approximately 50% of the population, while spray application was not effective. In all treatments the grain beetle was controlled within 2 days. The dry application of powder (Powder, figures 3, 4 5) was always more effective than the wet application of grout (Rocío, figures 3,4, 5). Celite 209 synergized had similar efficacy to Dryacide, a commercial diatomaceous earth used extensively in Australia to treat empty storage structures. E-example II: Due to the results obtained with synergized celite 209 other EDs collected from different deposits around the world were mixed with Sipernat 50S in different proportions. The compacted density of the mixture was measured to discover the influence of the synergist (Sipernat 50S) on the compacted density of the ED (Table 4). The density compacted (DIN ISO 787/11) is the ratio of the mass to the volume of a substance that has been compacted according to a series of conditions, expressed in g / 1. The acceptable lower limit was taken at approximately 265 g / 1 for the compacted density of the ED formulations may be the values of light formulations currently registered and accepted for DE as an insecticide, a range of 285 to 292 g / 1 (Table 4) . From the results shown in Table 4, DE from different deposits can be mixed with Sipernat 50S synergist up to 30% (w / w). For example DE Macedonia can be mixed with synergist in the proportion of up to 70:30; FROM Japan 2 - 70:30; Celite 209 only 90:10; Snow Floss * can not be mixed with synergist (too light and dusty); Japan 3 can not be mixed with synergist; Melocide * DE 100, extremely dense freshwater DE - 70:30; Super fine peach - 70:30; DE Mexico 2 - 70:30; FROM Mexico 1 -80: 20; FROM San Diego - 80:20; FROM Japan 1 - 80:20. By mixing these synergized formulations, the insecticidal results were much better compared to the results obtained using DE without the synergist (Tables 14 to 19, figures 1, 2). The synergistic action of DE Celite 209 and Sipernat 50S is clearly shown in table 9. By using synergized formulations of different DE and especially synergized Celite 209, the concentration needed to control the insects is greatly reduced; (Table 19). using those lower concentrations, the efficacy of synergized Celite 209 and other tested synergized formulations of DE is significantly greater compared to the non-synergized formulations of DE (Figures 1 and 2, Tables 5 or 9, 14 to 19). These concentrations are 1.7 to 70 times lower than what is recommended for the EDs currently registered. According to the results of the measurement of the densities compacted and the results of the bioassays presented in the figures and tables, especially Tables 4, 18 and 19, it is concluded that the efficacy of almost any DE against insects, even with low activity can increase when mixed with precipitated amorphous silicon dioxide, of which Sipernat 50S is an example, or with similar formulations of precipitated silica or silica airgel in different proportions. The proportion depends on the compacted density of the ED and the efficiency of ED and the mixture. Due to the results presented in Table 4, 18 and 19, for the DEs tested, the preferred mixing ratio (w / w) of DE to amorphous silicon dioxide (Sipernat 50S or similar) is as follows: OF Amorphous silica Celite 209 90 10 DE Macedonia 80 20 DE Mexico 2 80 20 DE Mexico 1 80 20 DE San Diego 80 20 FROM Japan 1 80 20 [estimate without sample] FROM Japan 2 70 30 [probable without sample Melocide DE 100 70 30 Melocide super fine 70 30 The same principles of mixing can be applied to different diatomaceous earths and different formulations of precipitated silicas and silica aerogels (Wessalon *, Dri-die SG-68 *, etc.) before making decisions about the need to mix and the proportion of mixing, some data about DE should be analyzed, particularly the biological activity of DE itself against insects, the compacted density, the pH of the ED, the influence of the synergist on the change of the compacted density, type of DE (DE marine or freshwater). It is desirable to have the data about the particle size distribution and to know something about the shape of the diatoms in the formulation. By analyzing these data, it is possible to predict the efficacy of the synergized formulations and determine the mixing ratio. With respect to those other DEs used in these other experiments, the following is a general description of the product. DE Macedonia has an average particle size of 9.7 microns and 73.5% of particles less than 16 microns and density of 551 g / 1; mixed with supernat 50S in the proportion 70; 30 the average particle size is 5.3 microns, 1005 of the particles are less than 16 microns and the compacted density is 310 g / 1. Snow Floss has the average particle size of 6.3 microns, 75.35 of the particles are less than 16 microns and the compacted density is 261 g / 1. The DE Melocide has the average particle size of 11.1 microns, 65.65 of the particles are less than 16 microns and the compacted density is 726 g / 1. Mixed with Sipernat 50S the densities are: 468 g / 1 (ratio 9:10), 379 g / 1 (ratio 80:20), 324 g / l (ratio 70:30) and 220 g / 1 (ratio 60:40) ). Super fine melocide has an average particle size of 4.54 microns, 100% of the particles are less than 16 microns and the compacted density is 600 g / 1. Mixed with Sipernat 50S, the densities are: 436 g / 1 (ratio 90:10), 324 (ratio 80:20), 266 g / 1 (ratio 70:30). DE Mexico 1 has the average particle size of 11.8 microns, 67.1% of the particles are less than 16 microns and the density compacted is 375 g / 1.

Mixed with Sipernat 50S the densities are: 299 g / 1 (ratio 90:10), 265 g / 1 (ratio 80:20), 213 g / 1 (ratio 70:30). No information is available on the mean particle size and particle size distribution of DE Mexico 2, DE Japan 1, 2 and 3 and DE San Diego. The densities and the influence of Sipernat SOS on the compacted density are presented in table 19. The DE Mexico 1 and 2 are very similar. The shape of the diatoms are almost identical. DE San Diego has the shape of diatoms very similar to Melocide DE 100, diatoms rounded like tube. Perma Guard belongs to this group of DE. For those diatomaceous earths, prints made using electron microscopy were made at the Agricultural and Agro-food Research Center, Winnipeg, can be requested. TEST METHODS r ebas de Labora, tori9 Insects (grain beetle Cryptolestes ferrusineus (Stephens), grain borer Rhyzppertha domines (Fabricius), rice weevils, Sitophilus oryzae (Linnaeus), and red flour beetle, Tribolium casataneum (Herbst ) used in the tests were mixed adults not classified by sex cultured at 30 ° C. All crops were started with insects collected in the field in the last 5 years.The tests were conducted at 30 ° C unless otherwise stated, wheat of Canadian hard red spring seed with 5% broken wheat was mixed with DE At 50 ppm (0.05 kg / t) at 1000 ppm (1 kg / t), fifteen grams of wheat was placed in containers with 50 grain beetles or 25 adults of other species For each condition, there were 5 bottles, with only one spice / bottle. After 1 to 14 days the insects were separated from the wheat by sifting the contents of the flasks through a sieve with 200 mm openings, and the number of dead and alive was recorded. For surface application tests, 10 cm wide x 10 cm long x 4 cm wide, they were roughened with sandpaper to allow the insects to walk normally. There are two types of application methods. For dry application, 0.03 g (3 g / m2) of inert powder (Dryacide or Synergized Celite 209) was placed in the center of the box and spread evenly across the bottom of the box with a brush. For the spray application, 1 ml of water with 0.07 g (7 g / m2) of inert powder (Dryacide or Synergized Celite 209) was sprayed on the bottom of the box with an aerosol applicator (Crown, Fischer Scientific Ltd.) . The aerosol can was kept 30 cm from the box during application and the box was left to dry for 2-3 hours. One gram of broken wheat was placed in the center of each box. There were 20 insects / box and three (75% rh) to four (55% rh) replicates for each treatment. Four adult stored grain insects were used: grain beetle (CrYPtPlestes ferrugineus (Stephens); rice weevils, Si ophilus orvzae (Linnaeus); minor grain driller Rhvzopertha dominca (Fabricius); and red flour beetle, Tribolium casataneum (Herbst)). Mortality was observed on days 1 to 14. The boxes were maintained at 25 + 1 * C in the dark and the experiment was performed at 55 + 5% rh or 75 + 5% rh. Field tests 1994 The tests were carried out in storage silos for 80-ton capacity galvanized steel farms. The silos were circular with a diameter of 6 m and a wall height of 6 m. Before placing the wheat in the silos, thermocouple wires were placed to measure the temperature in each silo. During July 1994, the wheat was heated to approximately 25 ° C and wetted to approximately 13.55 moisture content (me). Wheat was treated with 50 or 300 parts per million (ppm) by adding Celite 209 synergized to wheat at the base of a spiral that moves the grain from a truck to the silo. The amount of synergized Celite 209 to be applied was determined by the weight of wheat in the truck. Grain beetles (CrYPrPlestes ferrugjpeu ^ (Stephens)) were bred in the laboratory in flasks of four liters at 30 * C, in wheat with a 16% me with 5% broken wheat and 5% wheat germ. The used strain was collected from farms south of Manitoba in 1991. The red flour beetles, Tribolium casataneum. { Herbst) were bred in four liter flasks on wheat flour with 5% brewer's yeast at 30 * c and a relative humidity (rh) of 65% or kept at 2 ° C for several weeks before being released. was collected on a farm near Landmark, Manitoba in 1991. For release on August 4, 1994, the total content of 11 jars, grain and wheat beetles were scattered on the grain surface in each of the three In order to estimate the number of insects released, three bottles were sifted and the number of adults counted, there were 1443 + 181 (mean + standard error of the mean) of adult grain beetles per bottle, resulting in approximately 15,000 adult beetles. grain were released into each silo For each red flour beetle, all insects were separated from the crop flour, placed on the grain surface and covered with wheat.Two bottles were counted, with a mean of 11,180 + 494 adults in each no six-flask insect silos were released to give a total of approximately 67,000 flour / silage red beetles. Larvae and pupae were released for each species at the same time, but no estimates of these stages were made. These two insects are the main pest insects in grains stored in Canada, and represent the range of sensitivity to diatomaceous earth. The grain beetle is very sensitive and the red flour beetles are one of the most tolerant stored grain pests. For each silo there were 20 sampling points ten on the upper surface and ten one below the upper surface. Efficacy was measured by two different methods. In each silo, 20 traps were placed in the grain and the trapped insects were removed every two weeks. These traps are one of the most sensitive methods for detecting insects that currently exist. For the second method, samples of grains (approximately 900 g) of 20 points were taken in each silo using grain sacks for deep silos. The insects were extracted using berlese funnels, the same method used by the Canadian Grain Commission to detect insect infections. Methods and field test materials in 19951 Field tests were conducted at three locations in southern Manitoba, Canada. In the Experimental Farm of the Center of Investigation on Agriculture and Agri-alimentation of Canada in Winnipeg in Glenlea, three silos of storage for farm of galvanized steel of 80 tons of capacity were used (5.6 m of diameter and 6.0 m of height of wall) with approximately 16 to 21 tons of wheat per silo. At the Experimental Farm of the University of Manitobba in Glenlea, four stainless steel farm storage silos of 60 tons capacity (4.3 in diameter and 3.2 m in wall height) were used with approximately 16 tons of wheat in each silo. Harvested hard red spring wheat was harvested in August and September 1995 on all tests. The wheat was cultivated, treated and placed directly in three respective silos from September 2 to 6, 1995, for the Winnipeg Research Center from August 29 to September 1, 1995, for the University of Manitoba, and for the 29th August to September 7, 1995, for the Morden Research Center. Wheat was treated with 75 or 100 parts per million (ppm) by adding Protect-It [registered trark of a composition of 90% by weight of Celite 209 (registered trark) and 10% by weight of Sipernat 50S (registered trark)] as powder to the wheat at the base of a spiral that moved the grain from the truck to the silo. The amount of Protect-It to be applied was measured volumetrically, the measurement method to be used by farmers and elevator operators, and then weighed to verify the exact amount applied. At the University of Manitoba and the Research Center morden spray application was also used for a batch of wheat. Protect-It was applied as a 15 to 20% slurry [p: p] to the wheat as it fell from the truck to the base of the spiral. We used an 11.4 1 knapsack sprayer (Sparay Doc, gilmour Groups, Mississauga, Ontario, L5S 1P7) at 7031 kg / m2 equipped with a flat nozzle (TeeJet standard flat spray tip, models 11002VS and 110015VS, Spraying Systems Co., Wharon IL 60189-7900). The spiral 18 cm in diameter with a 16 hp motor with a speed of 3600 rpm, moved the wheat to 0.42-0.6 tons / minute. This combination gave an application rate of 100 ppm. Before unloading, two samples of 2.5 kg of untreated wheat were collected from each load of the truck using a 1-length profiling probe (Dean Gamet Manufacturing Co., Minneapolis, MN). This sampler collects approximately 700 g of wheat throughout the entire depth of the sample. A profiling probe is also used to collect four samples of 1-1.5 kg of treated wheat, immediately after the wheat is placed in the silo. The samples were taken 1.5 meters to the north, west, south and east of the center of each silo. Samples taken at successive dates were taken directly on the surface of the sampling points, and / or directly between adjacent surface sampling points. The grain beetles were grown in the laboratory in bottles of 4 liters at 30 * C, wheat with a moisture content of 16% with 5% broken wheat and 5% wheat germ. The strain used was harvested from farms south of Manitoba in 1991. Red beetles of flour were grown in 4-liter flasks in wheat flour with 5% brewer's yeast at 3% C and 65% rh. The used strain was collected at a brand near Landmark, Manitoba in 1991. The total content of several vials (5 bottles from the Winnipeg Research Center, 3 bottles from the University of Manitoba and 3 bottles from the Morden Research Center) of wheat and grain beetles, were scattered on the grain surface of each silo on September 11th at the Winnipeg Research Center, on September 2 at the University of Manitoba and on September 12 at the Morden Research Center, before of their release the beetles were removed from the wheat were recorded and divided into groups with a weight of 0.49 gm (the estimated mass of 2000 adult grain beetles), and then returned to the same wheat. To estimate the number of insects released, the number of adults in five groups of 0.49 gm (the estimated mass of 2000 adult grain beetles) was counted and then returned to the same wheat. To estimate the number of insects released, the number of adults in five groups of 0.49 gm was counted. There were 1937.8 + 13.6 adult grain beetles per jar (average + standard error of the mean), resulting in approximately 10,000, 6000 and 6000 adult grain beetles released in each silo at the Winnipeg Research Center, University of Manitoba and Morden Research Center. In the case of the red beetle, all the insects were sifted from the culture flour, placed on the surface of the grain and covered with wheat. The insects were counted in 4 bottles, with an average of 15293.5 + 399.5 adults. The insects from bottles 2, 1 and 1 of the Winnipeg Research Center, University of Manitoba and Morden Research Center, respectively, were released to provide a total of approximately 30,000, 15,000 and 15,000 red flour / silo beetles. For each species, larvae and pupae were released at the same time, but no estimate was made of those stages. Those two insects were selected for the experiments because they are the main insect pest in Canadian stored grain and also represent the sensitivity range of diatomaceous earth, being very sensitive grain beetle and the red flour beetle is one of the pests of stored grain more tolerant. For each silo there were 20 sampling points at the Winnipeg Research Center and 10 points at the University of Manitoba and the Morden Research Center due to the smaller size of the silos. Half of the sampling points were slightly below the grain surface and half a meter below the surface. Adjacent to each sampling point, a temperature probe, constructed of thermocouple wire and a wooden spike, was used to measure grain temperature 15 and 85 cm below the surface. Efficacy was measured by means of four different methods. In the first method, a probe trap was placed (Storegard Probe WB II, Thirteen Incorporates, P.O.Box 6278, Salinas, CA 93912) was placed in each sampling point. These traps are larger than the traps used in previous field tests (White et al., 1990). Traps were placed in the grain on September 14 at the Winnipeg Research Center and the University of Manitoba and on September 19 at the Morden Research Center. The trapped insects withdrew weekly between September 21 and October 24. After October 24 the traps were emptied every two months. Probe traps are the most sensitive insect detection methods currently available. For the second method, the insects were extracted from the grain samples to provide a quantitative estimate of the field populations. Grain samples were collected at each sampling point using a grain tonga of 225 g capacity (Dean gamet Manufacturing Co. Minneapolis, MN) on October 5 at the Winnipeg Research Center and the University of Manitoba, and the 3 October at the Morden Research Center. All other samples for extraction were collected with a profiling probe. The insects were removed by sieving the wheat using a sieve with 2.00 mm openings (Canadian standard sieve No. 10, Burning Engineer Engineering Inc., St. Catherines, Ontario), and the number of live and dead was recorded. In addition, live adults and larvae were extracted from 0.5 and 1 kg wheat samples using a berlese funnel placed under a 50 watt bulb for a period of 12 hours. In addition to measuring field populations, mortality was estimated by confining a known number of beetles to cages. In each silo, three 3-liter ventilated glass jars, containing 300 adult grain beetles and 3,000 red flour beetles, were filled with grain from the silo immediately after treatment. Each bottle was placed in the wheat with the upper part level to the grain surface. At the end of October, the jars were removed from the silos, grain was taken from each flask and the insects were extracted using sieving methods. The control samples of the wheat harvested from the truck before the treatment and the wheat samples collected from the silo immediately after the treatment and at the end of the experiment, They were divided into two groups. The first group was sent to the Canadian Grain Commission for its qualification and independent analysis of grain volumetric density and percentage wharfage. The moisture content of the wheat was measured using a dielectric moisture meter [AACC method 44-ll] [model 919, Labtronics, Winnipeg, MB, Canada]. The grain density was determined using the Ohaus measurement of 0.5 1 and the Cox funnel. The wharf was removed using a screen with 2.0 mm openings. Results of the 1995 field tests Populations of grain beetles, measured with probe traps, were significantly lower in silos treated with Protect-It (figures 6 to 8, table 20). For the total number of insects trapped during the 5-week collection period, populations of grain beetles were reduced by more than 90% in the case of powder applications of 75 and 100 ppm, and 87.4 to 99.9% in case of applications by spray of 100 ppm. The red flour beetle is more resistant to the diatomaceous earth than the grain beetle. Only at the Winnipeg Research Center did the 100 ppm Protect-It application consistently reduce populations [Figures 9 to 11, Table 20]. At the other points there are always differences between populations in treated and untreated silos [100 ppm]. With regard to the reduction in the total number of red flour beetles trapped for 5 weeks, mortality varied between 0-83% (Table 20). The number of insects extracted from the grain samples to provide a quantitative estimate of the field population using a profiling probe are presented in Table 21. Mortality of the grain beetle at the Winnipeg Research Center was 100% for application of 75 and 100 ppm of dust and of 87.5% for the spray, the mortality of the red flour beetle at the Winnipeg Research Center was 66.6% (important difference), at the University of Manitoba the population was too low in the untreated silo to make any conclusion, and in Morden 78.9% for the application of 75 ppm and 84.2 ppm of dust, and 94.7% for the spray (important difference). The mortality of the grain beetle and the red flour beetle in glass jars maintained in the silos during the field tests, the wharfage [%, w / w], moisture content, test weight and grain temperature in the jars is presented in Tables 22, 23 and 24. At the Winnipeg Research Center the mortality (or significant reduction in population) of the grain beetle was greater than 99% in the case of powder application at 75 and 100 ppm, in the University of Manitoba 99 and 100% in 75 and 100 ppm, respectively, and 93.4 with a spray of 100 ppm, in Morden 98.7 and 100% with application of 75 and 100 ppm respectively and 92.6% for 100 ppm spray. The mortality of the red flour beetle at the Winnipeg Research Center was 75.6 and 62.5% for 75 and 100 ppm respectively [not important], and at the University of Manitoba 0.7 and 43.5% when spraying 75 and 100 ppm, respectively [ not important], and 88.9% in application of 100 ppm of dust [important difference], in Morden 46.8, 47.2 and 26.1% for the application of 75 ppm and 100 ppm, and spraying of 100 ppm, respectively. Protect-It at 75 and 100 ppm, due to the test weight measurements did not change the quality of the treated hard red spring wheat measured and graded by the Canadian Grain Commission (Table 25). Protect-It in very low concentrations in wheat, 75 to 100 ppm as dust and 100 ppm as dew (the only formulation of DE in the world recommended for grain spraying), under field conditions controls the grain beetle and greatly reduces the red flour beetle. At 300 ppm, Protect-It controls the red flour beetle. These concentrations are much lower than the concentrations (500 ppm to 3500 ppm) of other registered formulations of diatomaceous earth in the world.

Thus, it is evident that a diatomaceous earth insecticide composition has been provided according to the invention which fully satisfies the aforementioned objects, purposes and advantages. Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent. for those skilled in the art according to the above description. According to this, it is intended to cover all those alternatives, modifications and variations that fall within the spirit and broad scope of the invention. LITERATURE CITED Belford, W.R. (1990) Insecticidal composition comprising boric acid and silica gel absorbed in inorganic particles. CA Australian Patent 594,539. 12: 54369x. Ebeling, W. (1971) Adsorbent powders for pest control. Ann. Rev. Entomol. 6: 123-158. Quarles, W. [1992.a] Diatomaceous earth for pest control. The IPM Practitioner. 14; 1:11 Quarles, W. [1992.a] Silica gel for pest control. The IPM Practitioner. or; 1:11 Wright, C.G., and H.E. Dupree [1984] Evaluation of the mortality of the German cockroach and various powdered insecticidal formulations. J. Georgia Entomol. Soc. 19 .: 216-223.

TABLE 1 . REGISTERED DIETARY EARTH FORMULATIONS TABLE 2. THE INFLUENCE OF THE DIFFERENT EARTH FORMATS OF DIATOMS IN THE HEAVY DUTY RED SPRING WHEAT OF CANADA TEST WEIGHT 1 Probably it will be classified as fodder quality due to visible residues 2 Minimum tests for Canadian hard red spring wheat: quality 1, 75 kg / hl; quality 2, 72 kg / hl; quality 3 69 kg / hl.

TABLE 3. THE INFLUENCE OF THE DIFFERENT FORMULATION OF ABOVE THE WEIGHT TEST OF WHEAT SPRING RED HARD CANADIAN CV. KATEPWA TABLE 4: COMPACTED DENSITY l MIXED DIETARY EARTHS WITH SIPERNAT 50S PRECIPITATED SILICA Formulation Compacted density * [g / l 3 Sipernat SQS - Percentage in the mix 20 30 40 50 From Canada [BC] 593 - - - - _ DE Macedonia S? ECP? 551 420 315 310 187 - 469 383 306 - FROM Japan 2 - __ 292 - - - _ InSßCOlO isev, CMADAJ 290 - _ a Insectigone 300 265 239 202 162 | Celite 209 [EUA] 158 261 239 218 209 155 Í Snow Floss [EUA] 288 - - - - - Insect [EUA] 227 201 - _ ^ _ l FROM Japan 3 Melocide DE 100 [USA] 726 468 379 324 220 - InSeCOlO (BSi! {!! «Elocide cebade! 700 441 - - - - | Super fine peach. { EQÜ 600 436 324 266 - -a DE México 2 425 375 292 - - 3 Perma Guard [USA] 405 - - - _ £ DE México 1 375 299 265 213 - íj DE San Diego [USA] 370 327 285 243 - - , 1 FROM Japan 1 360 300 - - - - H Dryacide [Australia] 285 Siperna SOS ÍGuiad ^ 136 * Depsidid compacted in DI * ISO? S7 / Ll coo mass ratio ai soluen of use substance that aa side TT -. '^ According to certain conditions expressed as g l. The compacted densities are defined by Z. lorunic.The "values only serve as a comparison between the differences in densities" in diatomaceous earths.

TABLE 5. THE EFFICACY OF CELITE 209 SYNERGIZED AND COMMERCIAL FORMULATIONS OF AGAINST FOUR INSECTS OF PRODUCTS STORED AT 30 * C, 14.6% M.C. IN WHEAT. THE CONCENTRATIONS OF EACH INSECT ARE: 300 PPM, GRAIN BEETLE; 600 PPM MINOR GRAIN DRILL AND RICE GORGEJO; 100 PPM RED FLOUR BEETLE SINE GIZADOFIp Af ír-! If? DIFE E TES CELITE CONCENTRATIONS 209 A * 3300"C C, 15.fi6% i MC ™ ENT, T? RICG0ONTRA RECTOS DE PRODUCTOS STORED 5ecar * h? *? O nd flour 8 50 45 88 100 18 21 300 1 0 0 100 95 100 200 35 79. 400 2 1 13 150 96 1 0 300 71 92 500 6 13 42 Ul 200 100 100 400 88 100 600 15 31 72 Insect 50 21 71 100 9 27 300 0 1 1 100 56 76 200 19 72 400 0 2 4 150 59 83 300 33 83 500 2 2 14 200 94 97 400 60 93 600 5 6 47 No treatment 0 6 14 0 1 1 0 0 0 0 3 * C; of tríqa: 15. il TABLE 7. COMPARATIVE TESTS BETWEEN SYNERGIZED CELLITE 209 AND OTHER EARTH FORMATS OF DIATOMS FROM ALL OVER THE WORLD AGAINST THE WEALTH OF RICE IN WHEAT Formulation Concentration Mortality (%) after 5 days Mortality (%) after 10 d (ppm) »- c 20ßC 30ßC 20ßC 30ßC 12% 14% 12% 14% 12% 14% 12% 14% m.c. m.c. m.c. m.c. m.c. m.c. m.c. m.c. CeliteS09 sinergized 400 97 60 97 68 99 77 99 86 Ul Insect 400 74 29 96 33 95 58 99 65 Dryacide 400 78 15 96 32 97 52! 00 67 Per a Guard 400 23 7 56 2 72 14 85 1 FROM Japan 3 400 43 20 47 4 59 4 78 28 No treatment 0 1 0 15 2 2 15 0 1 TABLE 8. COMPARATIVE TESTS BETWEEN SYNERGIZED CELITE 209 AND OTHER EARTH FORMATS OF DIATOMS FROM ALL OVER THE WORLD AGAINST THE RED FLOUR BEETLE at 600 PPM Formulation Concentration Mortality (%) after 5 d Mortality (*) after 10 d i? Nnmp? I 20? C 30? C 20? C 30 * C 12% 14% 12% 14% 12% 14% 12% 14% m.c. m.c. m.c. m.c. m.c. m.c. m.c. m.c. Celite209 synergized 600 91 79 78 50 99 98 91 86 u > cr.

Insect 600 63 19 28 3 96 59 92 57 Dryacide 600 68 36 31 6 89 68 69 52 Perma Guard 600 21 9 6 1 59 26 29 14 DB Japan 3 600 55 12 29 1 59 34 72 29 No treatment 0 0 1 0 0 0 1 0 1 TABLE 9 THE SYNERGISM BETWEEN CELITE 209 AND SIPERNAT 50S PRECIPITATED SILICA VS FOUR INSECTS OF STORED PRODUCTS Formulation Concentration Mortality (%) ConcentrationMority (%) Concentration Mortality 1 day. days 6 days 7 days Celite 209 270 28 25 540 18 900 76 Sipemat SOS 30 27 1 60 8 100 I Celite 209 + 300 93 48 600 79 1000 96 Sipernat SOS No treatment or 0 0 0 0 RGB - grain beetle; RW rice weevil; LGB - minor grain driller; RFB red flour beetle, Temperature: 30 C; RH: 70% grain: wheat.

TABLE 10. INSECTS EXTRACTED FROM WHEAT USING BERLESE FUNNELS. TWELVE SAMPLES OF GRAIN OF EACH SILO WERE TAKEN ON AUGUST 30, 1994 AND OCTOBER 26, 1994. THERE WERE APPROXIMATELY 40 TONS OF GRAIN IN EACH SILO, WHICH HAD BEEN INFECTED WITH GRAIN BEETLES AND RED FLOUR BEETLES ON AUGUST 4 1994 For a given column and a given date, the concentrations followed by different letters are significantly different (Kruskal-Wailis NOVA, SNK Test] TABLE 11. THE AVERAGE NUMBER OF GRAIN BEETLES TRAPPED BY TRAP PROBE IN TWO WEEKS PERIODS IN FIELD TESTING , THERE WERE 20 TRAPS PER SILO, 10 ON THE SURFACE AND 10 A METRO BELOW THE SURFACE. 1 For a given column, the concentrations followed by different letters are significantly different. { Kruskal-Wailis ANOVA, Test SNK].

TABLE 12. THE AVERAGE NUMBER OF RED FLOUR BEETLES CAUGHT BY TRAP PROBE AT TWO WEEKS PERIODS IN FIELD TESTING, THERE WERE 20 TRAPS PER SILO, 10 ON THE SURFACE AND 10 A METRO BELOW THE SURFACE.

For a row, the concentrations ^ followed by different letters are significantly different [Kruskal-Wailis ANOVA, SNK Test].

TABLE 13. AVERAGE VOLUMETRIC DENSITIES [TEST WEIGHTS], HUMIDITY CONTENTS AND QUALITIES [QUALIFIED BY THE CANADIAN GRAIN COMMISSION] OF FIELD TESTING. 1 For a given column, the concentrations are significantly different if they are followed by a different letter [Kryskal-Wallis ANOVA, Dunn Test], 20 samples / silo except for the quality that had 1 sample / silo.

EXAMPLE 14. THE EFFICACY OF THE SAMPLE OF DIFFERENT EARTH FORMATS OF DIATOMAS AND PRECIPITATED SILICONE SIPERNAT 50S [605 DE + 40% SIPERNAT 50S] AGAINST THE RED FLOUR BEETLE [RFB] AND THE MINOR GRAIN DRILL [LGB], AT 30 * C, 13.6% MC IN WHEAT TO CONCENTRATIONS OF 800 PPM TABLE 15: EARTH EFFICACY OF SYNERGISED DIATOMS AGAINST THE RICE GORGEJO [RW], THE LOWER GRAIN DRILL [LGB] AND THE RED FLOUR BEETLE [RFB] At 30 ° C, 13.6% M.C.

TABLE 16: EARTH EFFICACY OF SYNERGIZED DIATOMS AGAINST THE RED FLOUR BEETLE [RFB], THE LOWER GRAIN DRILL [LGB], THE RICE GORGEJO [RW], AND THE GRAIN BEETLE [RGB] AT 30 * C, 14.6% MC IN WHEAT TABLE 17: EARTH EFFICACY OF SYNERGISED DIATOMS AGAINST GRAIN BEETLE [RGB], RICE GORGOJO [RW], MINOR GRAIN DRILL [LGB], AND RED FLOUR BEETLE [RFB], AT 30 * C , 14.1% MC IN WHEAT TABLE 18. INCREASE OF THE EFFICIENCY OF THE LANDS OF DIATOMAS MIXES WITH SIPERNAT 50S SINERGISTA IN DIFFERENT PROPORTIONS, AGAINST THE GORGOJO OF THE RICE AT 30 * C, 13.95, M.C. IN WHEAT ma: mortality (%) Pormaiacinn Kiraci-i.-. - < * roen taje er. the mixture Go f) (300 ppm) i? e! ) Yes ipernat 50S 0 10 20 30 DEMacedonia 2 31 48 77 76. { Ships] 7 71 86 94 94 Japor. 2 2 20 - 58 - 3 7 56 - 82 - i Celite 209 2 28 64 - - (USA) 7 - 65 88 - - Snow Floss 2 31 - - - (USA) 7 67 - - - DE Ja sp 2 2 10 44 - - 7 38 68 - - Melo of DE 2 6 14 46 53 100 (USA) 7 22 42 74 78 Melocide Super 2 7 26 61 68 3 fi- (USA) 7 28 58 85 93 DE Mexico 2 2 13 44 46 - i 7 39 66 77 Dr acide 2 46 Australia 7 75 Sipemat SOS - 30 ppm 2 6 (10% «r. Key) 7 7 Sipemat SOS - 60 ppm 2 8 (20% -" - »c) 7 20 Sipernat 50S - 90 ppm 2 27 ( 30% * '' «^ 1 7 38 TABLE 19. INCREASED EFFECTIVENESS OF DIETARY MASS LANDS WITH SIPERNAT 50S SYNERGISTS IN DIFFERENT PROPORTIONS, AGAINST THE RED BEETLE OF THE FLOUR AT 30" C, 13.95, MC IN WHEAT Aorta lidad (%) PcrKila -c: Oaracicp { Days! IPpm; Sipernat sos- »01 -cents Je« p The mixture {PF! 0 10 20 30 DE Macedonia 14 13 26 63 33 í Eurc. "'21 46 46 86 46 28 79 87 97 74 DE J »p = 2 14 0 - 0 - i! 21 3 - 0 - 28 13 - 100 - I Celite 209 (USA) 14 26 33 - - 21 81 84 - - 28 93 93 - -, 'Snow Floss 14 20 - - - (USA) 21 72 - - - 28 97 - - - DE J == r. 2 14 0 7 - - 21 0 14 - - 28 10 24 - - Melocide DE 100 14 0 0 0 7 (USA) 21 3 0 0 7 28 3 0 7 10 Melocide Super 14 0 0 0 10 r_8 (USA) 21 0 0 3 10 28 0 0 3 10 FROM Mexico 2 14 0 0 0 - 5 21 0 0 0 - 28 3 10 10 - 1 DE Mexico 1 14 0 0 4 - • S w 21 0 0 4 - 28 3 10 10 - DE Without Diego 14 0 0 7 - (USA) 21 3 0 13 - 28 3 0 22 - u • > DE Japan 1 14 0 0 - -? ¡21 3 3 - - 28 13 13 - - Dryacide 14 13 Australia 21 55 28 92 Sipernat SOS - 30 ppm 14 0 (10% «= m sela) 21 0 28 0 Sipemat SOS • 60 ppm 14 0 (20% «n ns la) 21 3 28 3 Sipernat SOS - 90 ppm 14 0 (JO%« = test) 21 0 28 0 TABLE 20. PERCENTAGE REDUCTION OF INSTRUMENTS CAUSED DURING A PERIOD OF 6 WEEKS, WHEAT WAS TREATED WITH PROTECT-IT IN THE FORM OF DUST OR AS ROCÍO [100S] AND THE NUMBER OF INSECTS TRAPPED IN PROBE TRAPS COMPARED WITH THE NUMBER OF INSECTS CAUGHT IN SILOS NOT TREATED AT EACH PLACE.

TABLE 21. THE AVERAGE NUMBER OF LIVE ADULTS OF GRAIN BEETLE [RGB] AND THE RED FLOUR BEETLE [RFB] BY GRAIN KG IN GRAIN WAREHOUSES TREATED WITH PROTECT-IT WITH DIFFERENT CONCENTRATIONS AND METHODS OF APPLICATION Field tests in 1995 Given, means followed by the same letter are not significantly different. [] = standard deviation WRC - Experimental field station of the Winnipeg Research Center, Glenlea U of M - Manitoba University experimental station, Morden glenlea = Morden WRC experimental station - 20 samples of the profiling probe [approximately 1.2 kg each) of each grain tank U of M - 10 samples of profiling probe [approximately 1.9 kg each] of each Morden grain tank - 10 samples of profiling probe [approximately 2 kg each] of each tank of beads Samples of profilers taken from the probe traps and between them.

TABLE 22. THE EFFECTIVENESS OF PROTEC-IT AGAINST THE GRAIN BEETLE AND THE RED BEETLE OF FLOUR IN HARD RED SPRING WHEAT IN SMALL SCALE PROOFS UNDER FIELD CONDITIONS. Place 1. Experimental Field Station of the Winnipeg Research Center, Glenlea p ANOVA Turkey [HSD] Rejection level - 0.050. for a given column, those followed by the same letter are not significantly different * * s. 1 measured at the Winnipeg Research Center * Moisture content (%) at the start of the test: Oppm- 13.2 to 14.1; 75 ppm- 13.4 to 14.1; 100 ppm- 13.0 to 13.1.

T ™ * 'THE EFFICACY OF PROTEC-IT AGAINST THE GRAIN BEETLE [RGB] AND THE RED FLOUR BEETLE [RFB] IN HARD RED SPRING WHEAT IN SMALL SCALE TESTS UNDER FIELD CONDITIONS. Place 2. Experimental Station of the University of Manitoba, Glenlea ' n ANOVA Turkey [HSD] Rejection level - 0.050. for a given column, averages followed by the same letter are not significantly different. 1 measured at the Winnipeg Research Center * Moisture content (%) at the start of the test: TABLE 24. THE EFFECTIVENESS OF PROTEC-IT AGAINST THE GRAIN BEETLE AND THE RED BEETLE OF FLOUR IN HARD RED SPRING WHEAT IN SMALL SCALE TESTS UNDER FIELD CONDITIONS. Place 3. Experimental Station, Morden ANOVA Tursuia [HSD] Rejection level - 0.050. for a given column, means followed by the same letter are not significantly different, i measured at the Winnipeg Research Center * Moisture content (%) at the start of the test: 0 ppm - 12.6; 75 ppm - 13.4 to 14.8; 100 ppm - 13.7 to 14.7; sprayed at 100 ppm 13 \ 3.7. In each grain deposit at the date of introduction of insects, 3 bottles [height 25 cm, diameter 15 cm] were filled with wheat HRS 9 approximately 3 kgO after the grain was treated. After 200 RGB 200 RFB were introduced in each TABLE 25. REDUCTION OF TEST WEIGHT [VOLUMETRIC DENSITY] WITH PROTECT-IT IN HARD RED SPRING WHEAT IN COMPARISON WITH WHEAT WITHOUT TREATMENT, MEASURED AND QUALIFIED BY THE CANADIAN GRAIN COMMISSION [CGC] FIELD TESTS WITH PROTECT-IN IN 1995 Place 1. Experimental Field Station of the Winnipeq Research Center, Glenlea Table 25 - continued Place 3. Experimental stage of Morden ANOVA, Turkey [HDS] Rejection level - 0.050. Stocks in columns followed by the same letter are not significantly different. * Samples of a truck before unloading ** 2 qualified samples of a silo after treatment and loading.

Claims (12)

1. CLAIMS 1.- Insecticidal powder composition comprising an effective amount of diatomaceous earth [DE] in combination with an effective amount of silica selected from the group consisting of precipitated silica and silica airgel, the DE and the silica are mixed in proportions by weight from about 95% to 65% DE to about 5 to 35% silica.
2. 2. A composition according to claim 1 in which the DE has an average particle size of about 4.5 microns to about 12 microns, having at least more than 65% of the particles a size less than 16 microwaves
3. 3. A composition according to claim 2 in which the ED is selected from the marine DE and fresh water groups.
4. 4. A composition according to claim 1 in which the silica has a particle size in the range of about 4 to 10 microns.
5. 5. A composition according to claim 4 in which the silica is Sipernat 50S *.
6. 6. A composition according to claim 3 in which the silica has a particle size of 8 microns and the silica is Sipernat SOS.
7. 7. A composition according to claim 6 wherein the DE is about 90% by weight of Celite 209 or the equivalent and the silica is about 10% by weight of Sipernat SOS.
8. 8. A composition according to claim 7 in which the silica is Sipernat 50S or any type of silica gel with similar physical properties.
9. 9. An insecticidal powder composition comprising an effective amount of diatomaceous earth [DE] in combination with an effective amount of silica selected from the group consisting of precipitated silica and silica airgel, the DE and the silica are mixed in different proportions, depending on the type of DE.
10. 10. A composition according to claim 9 comprising any type of DE mixed with silica gel.
11. 11. A composition according to claim 9 in which the ED and the silica are mixed in different proportions by weight, depending on the type of ED.
12. 12. A composition according to claim 11 in which the silica is Sipernat 50S or any type of silica gel with similar physical properties.