Light activateable natural pesticide formulations

The present invention is for natural pesticide compositions including methods for their preparation and use. The pesticide compositions of the present invention contain botanical extracts which exert enhanced pesticidal activity when combined with light.

EXAMPLE 1 Celery (4,810 grams) was washed with a mild detergent then rinsed thoroughly with water and air-dried. The celery, including leaves, stem, stalk, and base, was cut into small portions and air-dried in the absence of light. The resulting dried celery (180.6 grams) was powderized and transferred into a 2 liter Erlenmeyer Flask to which was added 800 mL (milliliters) of ethanol (reagent alcohol). The flask was stoppered and let sit in the dark for 7 days (with occasional agitation) and then filtered. This batch extraction process was repeated for a total of 3 times. The combined alcohol extracts (approximately 2.4 liters) were distilled to dryness in the absence of light (yield&equals;8.3 grams). Biocidal activity was demonstrated by treatment of E. coli bacteria with the extract and then exposing the extract treated bacteria to mild ultraviolet irradiation. 
 EXAMPLE 2 Celery (6,000 grams) was washed with a mild detergent then rinsed thoroughly with water and air-dried. The celery, including leaves, stem, stalk, and base, was cut into small portions and placed into a blender and homogenized to the consistency of a puree, all the while minimizing its exposure to light. For the sake of handling, a small amount of distilled or deionized water was added. The material was then poured into containers and air-dried in the absence of light. The resulting dried celery material (292.7 grams) was transferred into a 4-liter flask to which was added 1,800 mL of reagent grade alcohol. The contents of the flask were shielded from exposure to light. The flask was then fitted with a mechanical stirrer, reflux condenser, heating mantle and the complete apparatus was shielded from exposure to light. The contents of the flask were heated to 60° C. while stirring for a period of 6 hours. The resulting green liquid was then decanted from the flask and filtered in the dark. An additional 1,800 mL of fresh alcohol was added to the flask and the extraction process was repeated for a total of three times. The combined alcohol extracts were distilled to dryness under reduced pressure and in the absence of light and yielded 55.3 grams of a brown solid. The following non-limiting examples illustrate compositions and formulations of the present invention. All manipulations, as well as storage of solutions, are conducted in the absence of harmful light. 
 EXAMPLE 3 50.0 grams of celery extract from Example 2 is mixed with 50.0 mL (milliliters) of deionized water and stirred vigorously in the dark for several hours or overnight to form a homogenous mixture. 
 EXAMPLE 4 25.0 grams of celery extract obtained as described in Example 2 is mixed with 75.0 mL of deionized water and stirred vigorously in the dark for several hours or overnight to form a homogenous mixture. 
 EXAMPLE 5 25.0 grams of celery extract obtained as described in Example 2 is mixed with 75.0 ml of distilled water and 5.0 mL of Hasten™ (a commercially available adjuvant from the Wilbur-Ellis Company) and stirred vigorously in the dark for several hours or overnight to form a homogenous mixture. 
 EXAMPLE 6 25.0 grams of celery extract obtained as described in Example 2 is mixed with 175.0 ml of distilled water and 5.0 mL of Hasten™ (commercially available adjuvant from the Wilbur-Ellis Company) and stirred vigorously in the dark for several hours to form a homogenous mixture. 
 EXAMPLE 7 A concentrate of St. John's wort (SJW) extract is prepared by combining 100 mL of deionized water and 100 grams of St. John's wort (SJW) extract prepared as described by the procedure presented in Example 1 or Example 2 (so obtained by using the flower, leaves and stem of the plant, and a solvent system composed of ethanol: water, 20:1, v/v). Alternatively, a concentrate is prepared by using a commercially available SJW extract standardized to 0.01%-10.0% hypericins (total dianthrones). The deionized water and SJW extract powder (obtained commercially or prepared as described above) are mixed and stirred vigorously in the dark for several hours or overnight to form a homogenous mixture. A formulation was prepared by combining 76.9 mL of the concentrate, 804.3 mL of deionized water, and 47.3 mL of Triton X-100 (a commercially available surfactant from the Union Carbide Company). The pH of the resulting solution is adjusted to pH 8.5 using concentrated NaOH (aq.) and the final formulation is filtered through a Buchner Funnel. All manipulations, as well as storage, of the concentrate and derived formulations are conducted in the absence of harmful light. 
 EXAMPLE 8 A concentrate of St. John's wort (SJW) extract is prepared by combining 100 mL of deionized water and 100 grams of St. John's wort (SJW) extract prepared as described by the procedure presented in Example 1 or Example 2 (so obtained by using the flower, leaves and stem of the plant, and a solvent system composed of ethanol: water, 20:1, v/v). Alternatively, a concentrate is prepared by using a commercially available SJW extract standardized to 0.01%-10.0% hypericins (total dianthrones). The deionized water and SJW extract powder (obtained commercially or prepared as described above) are mixed and stirred vigorously in the dark for several hours or overnight to form a homogenous mixture. A formulation was prepared by combining 47.3 mL of the concentrate, 875.3 mL of deionized water, and 23.7 mL of Triton X-100 (a commercially available surfactant from the Union Carbide Company). The pH of the resulting solution is adjusted to pH 8.5 using concentrated NaOH(aq.) and the final formulation is filtered through a Büchner Funnel. All manipulations, as well as storage, of the concentrate and derived formulations are conducted in the absence of harmful light. 
 EXAMPLE 9 A concentrate of St. John's wort (SJW) extract is prepared by combining 100 mL of deionized water and 100 grams of St. John's wort (SJW) extract prepared as described by the procedure presented in Example 1 or Example 2 (so obtained by using the flower, leaves and stem of the plant, and a solvent system composed of ethanol: water, 20:1, v/v). Alternatively, a concentrate is prepared by using a commercially available SJW extract standardized to 0.01%-10.0% hypericins (total dianthrones). The deionized water and SJW extract powder (obtained commercially or prepared as described above) are mixed and stirred vigorously in the dark for several hours or overnight to form a homogenous mixture. From this concentrate, a 10:1 formulation (distilled water:concentrate, v/v) and a 5:1 formulation (distilled water:concentrate, v/v) were prepared. 
 EXAMPLE 10 A concentrate of St. John's wort (SJW) extract is prepared by combining 100 mL of deionized water and 100 grams of St. John's wort (SJW) extract prepared as described by the procedure presented in Example 1 or Example 2 (so obtained by using the flower, leaves and stem of the plant, and a solvent system composed of ethanol: water, 20:1, v/v). Alternatively, a concentrate is prepared by using a commercially available SJW extract standardized to 0.01%-10.0% hypericins (total dianthrones). The deionized water and SJW extract powder (obtained commercially or prepared as described above) are mixed and stirred vigorously in the dark for several hours or overnight to form a homogenous mixture. A formulation was prepared by combining 100 mL of SJW concentrate, 100 mL of distilled water and 100 mL of Hasten™ (a commercially available adjuvant from the Wilbur-Ellis Company). The following non-limiting examples illustrate methods of using the compositions and formulations of the present invention for controlling or killing pests: 
 EXAMPLE 11 A 1% mixture in water (w/v) of an alcohol extract prepared as described in Example 1 is used to swab a gridded agar plate seeded with E. Coli . The agar plate is irradiated with mild ultraviolet light (254 nm) for a period of 1-2 minutes and then incubated for 24 hours to promote bacterial growth. Grid areas swabbed with the celery extract from Example 1 showed no bacterial growth, as evidenced by staining. As a control, grids treated with a hexane extract of celery (prepared according to the procedure described in Example 1) showed significant bacterial growth ( E. Coli ), as evidenced by staining. 
 EXAMPLE 12 A sample vial containing 20 fruit flies (drosophila melanogaster) is lightly sprayed with the composition and formulation prepared in Example 6. Within 20 minutes all of the fruit flies were dead (Kill Ratio&equals;100%). The control experiments consisting of: (a) lightly spraying a vessel containing 20 fruit flies with distilled water; and, (b) lightly spraying another vessel containing 20 fruit flies with a solution of distilled water and adjuvant (5% Hasten™, v/v) resulted in a 0% Kill Ratio (that is, none killed) after 20 minutes. 
 EXAMPLE 13 Two aerated transparent glass vessels containing 20 cockroaches each (American Cockroach, periplaneta americana), were sprayed separately with a 10:1 formulation as prepared in Example 9 and 5:1 formulation as prepared in Example 9. The containers were then placed in the sunlight (Cental Florida, Autumn). Within 4 hours all of the cockroaches were dead (100% Kill Ratio). As a control, untreated cockroaches remained alive. 
 EXAMPLE 14 Four aerated transparent glass vessels containing 10 cockroaches each (American Cockroach, periplaneta americana), were treated separately as follows: Group 1 was sprayed with a 5:1 formulation as prepared in Example 9 then placed in the dark for 12 hours, followed by sunlight, resulting Kill Ratio&equals;100% (all dead). Group 2 was not sprayed, placed in the dark for 12 hours, followed by sunlight, resulting Kill Ratio&equals;0% (all alive). Group 3 was sprayed similarly to Group 1 but left in the darkness, resulting Kill Ratio&equals;80%. Group 4 was not sprayed and was left in the darkness, resulting Kill Ratio&equals;0%. 
 EXAMPLE 15 A field area of approximately 91.5 cm×30.5 cm was plotted, staked and separated into a total of 6 sections, for control experiments and test sections. Plants in the plotted area included a wild mix of cyperus globulosus, brachiara plantaginea, lespedea striata and mimosa strigillosa. Test sections were sprayed with approximately 50 mL of a 5:1 formulation as prepared in Example 9. After 72 hours approximately 45% of the spray treated vegetation was destroyed. Control, untreated areas showed no effect. 
 EXAMPLE 16 A field area was plotted and staked for control experiments and test sections. Plants in the plotted area included a wild mix of cyperus globulosus, brachiara plantaginea, lespedea striata and mimosa strigillosa. Test sections of 7.6 cm×183 cm were sprayed with approximately 300 mL of a 1:1:1 formulation (SJW extract concentrate:distilled water:adjuvant, v/v/v) as prepared in Example 10. After 72 hours significant vegetation was destroyed (>80%), and after approximately 10 days significant plant death was observed. Control, untreated areas showed no effect. 
 EXAMPLE 17 Powdered sample from Example 2 and St. John's wort powder were preliminarily assessed for their insect and animal repellent properties as follows: A small line of extract powder was placed in the pathway of a small colony of ants. Ants preferably went around the powder line as opposed to crossing the line. Separately, animal food (dog food) treated with powder was not consumed by animals or pets. Untreated food was rapidly consumed.