Method for controlling pests in soybean

Abstract

A method for controlling pests of soybean plants comprises the step of contacting the soybean plant, parts of it, its propagation material, the pests, their food supply, habitat or breeding grounds with one or more components of the ginkgo tree selected from the group consisting of bilobalide, ginkgolide A, ginkgolide B, ginkgolide C, ginkgolide J and ginkgolide M.

Claims

1. A method for controlling pests of genetically modified soybean plants, comprising contacting the soybean plant, parts of it, its propagation material, the pests, their food supply, habitat or breeding grounds with one or more components of the ginkgo tree selected from the group consisting of bilobalide, ginkgolide A, ginkgolide B, ginkgolide C, ginkgolide J and ginkgolide M wherein the soybean plants have at least one toxin of Bacillus thuringiensis formed in the plant; and wherein the pests are from the family of Pentatomidae and/or Thripidae.

2. The method of claim 1, wherein the pests are Acrosternum spp., Euschistus spp., Nezara spp. and/or Piezodrus spp.

3. The method of claim 1, wherein the pests are Acrosternum hilare, Euschistus heros, Nezara viridula and/or Piezodrus guildini.

4. The method of claim 1, wherein the component or components of the ginkgo tree are applied in an amount of from 1 to 500 g/ha.

5. The method of claim 1, wherein the components of the ginkgo tree are applied by foliar application.

6. The method of claim 1 for protecting plant propagation material.

7. The method of claim 1, wherein the components of the ginkgo tree are applied to soybean plants that have at least one gene selected from CrylA(a), CrylA(b), CrylA(c), CryllA, CrylllA, CryIIIB2, Cry9c, Cry2Ab, Cry3Bb and CrylF, or a combination thereof.

8. The method of claim 1, wherein the pests are resistant to one or more of the insecticides selected from the group consisting of pyrethroids, neonicotinoids, and organophosphates.

9. The method of claim 1, wherein the pests are selected from dichromothrips sp.

10. The method of claim 1, wherein the soybean plant has an increased tolerance to certain herbicidally active compounds.

Description

EXAMPLES

(1) The present invention is now illustrated in further details by the following examples, without imposing any limitation thereto.

(2) A. Compounds

(3) Bilobalide, ginkgolide A, ginkgolide B, ginkgolide C and ginkgolide J are commercially available (e.g. from Interchim) and were purchased from commercial sources.

(4) B. Biology

(5) The biological activity and effectivity of the compounds applied in the methods of the invention can be evaluated e.g. in the following assays.

(6) B.1 Green Soldier Stink Bug (Nezara viridula)

(7) The active compound is dissolved at the desired concentration in a mixture of 1:1 (vol:vol) distilled water:acetone. Surfactant (Kinetic HV) is added at a rate of 0.01% (vol/vol).The test solution is prepared at the day of use.

(8) Soybean pods were placed in microwavable plastic cups lined with moist filter paper and inoculated with ten 3rd instar N. viridula. Using a hand atomizer, approximately 2 ml solution is sprayed into each cup. Treated cups were kept at about 28-29° C. and relative humidity of about 50-60%. Percent mortality was recorded after 5 days.

(9) In this test, bilobalide, ginkgolide A and ginkgolide B at 500 ppm showed at least 75% mortality in comparison with untreated controls.

(10) In this test, bilobalide, and ginkgolide A at 300 ppm showed at least 75% mortality in comparison with untreated controls.

(11) In this test, bilobalide, and ginkgolide A at 100 ppm showed at least 75% mortality in comparison with untreated controls.

(12) In this test, bilobalide, and ginkgolide A at 10 ppm showed at least 75% mortality in comparison with untreated controls.

(13) B.2 Orchid Thrips (Dichromothrips corbetti)

(14) Dichromothrips corbetti adults used for bioassay were obtained from a colony maintained continuously under laboratory conditions. For testing purposes, the test compound is diluted in a 1:1 mixture of acetone:water (vol:vol), plus Kinetic HV at a rate of 0.01% v/v.

(15) Thrips potency of each compound was evaluated by using a floral-immersion technique. All petals of individual, intact orchid flowers were dipped into treatment solution and allowed to dry in Petri dishes. Treated petals were placed into individual re-sealable plastic along with about 20 adult thrips. All test arenas were held under continuous light and a temperature of about 28° C. for duration of the assay. After 3 days, the numbers of live thrips were counted on each petal. The percent mortality was recorded 72 hours after treatment.

(16) In this test, bilobalide, ginkgolide A, ginkgolide B, ginkgolide C and ginkgolide J at 500 ppm showed at least 75% mortality in comparison with untreated controls.

(17) B.3 Brown Stink Bug (Euschistus heros)

(18) The active compound is dissolved at the desired concentration in a mixture of 1:1 (vol:vol) distilled water:acetone.

(19) Fresh bean pods were placed in a transparent plastic cup and inoculated with ten adult stage individuals. Insects, food and inside of container are sprayed with 1 ml solution using an air brush. Treated cups were kept at about 25° C. Percent mortality was recorded after 5 days.

(20) In this test, bilobalide at 100 ppm showed at least 75% mortality in comparison with untreated controls.

(21) B.4 Forest shield bug (Eysarcoris aeneus)

(22) The active compound is dissolved at the desired concentration in a mixture of 1:1 (vol:vol) distilled water:acetone.

(23) Row peanuts and soybean seeds were placed in a plastic cup and inoculated with ten adult stage individuals. Insects, food and inside of container are sprayed with 1 ml solution using an air brush. After drying, a water supply source will be placed in the cup and the cup closed with a screened lid. Treated cups were kept at about 20° C. Percent mortality was recorded after 5 days.

(24) In this test, bilobalide at 100 ppm showed at least 75% mortality in comparison with untreated controls.

(25) B.5 Rice Leaf Bug (Trigonotylus caelestialium)

(26) The active compound is dissolved at the desired concentration in a mixture of 1:1 (vol:vol) distilled water: acetone.

(27) Small wheat seedlings in glass tubes were sprayed with 200 microliter/tube by air brush. After drying, ten 2nd and 3rd nymph stage individuals were released in the tube and the tube closed with a screened lid. Treated cups were kept at about 20° C. Percent mortality was recorded after 5 days.

(28) In this test, bilobalide, and ginkgolide A at 100 ppm showed at least 75% mortality in comparison with untreated controls.

(29) B.6 Brown Stink Bug (Euschistus heros)

(30) The active compound is dissolved at the desired concentration in a mixture of 1:1 (vol:vol) distilled water: acetone.

(31) Soybean seedlings of Intacta and BMX-Potencia with one pair of true leaves were sprayed with 2 ml solution using an airbrush. After dry, the plants in small pots were placed inside a transparent plastic cage and infested with 10 adults adult stage individuals. Treated cups were kept at about 25° C. Percent mortality was recorded after 1, 2, and 6 days after application.

(32) In this test, bilobalide at 10 ppm and ginkgolide A at 100 ppm showed the following mortality:

(33) TABLE-US-00002 INTACTA dose mortality (%) mortality (Abbott %)* Product ppm a.i 1 D.A.A 2 DAA 6 DAA 1 D.A.A 2 DAA 6 DAA Untreated — 5.0 5.0 20.0 — — — Ginkgolide A 100 12.5 20.0 62.5 7.9 15.8 53.1 Bilobalide  10 7.5 20.0 72.5 2.6 15.8 65.6

(34) TABLE-US-00003 BMX — POTENCIA dose mortalty ppm mortality (%) (Abbott %)* Product a.i 1 D.A.A 2 DAA 6 DAA 1 D.A.A 2 DAA 6 DAA Un- — 2.5 5.0 20.0 — — — treated Gink- 100 10.0 10.0 57.5 7.7 5.3 46.9 golide A Bilo- 10 5.0 7.5 60.0 2.6 2.6 50.0 balide DAA = Days After Application *Corrected mortality according to Abbott, W.S., A method of computing the effectiveness of an insecticide, J. Econ. Entonnal., 18 (1925) 265-267. The test shows that bilobalide and ginkgolide A have a higher efficacy when applied to soybean plants containing a toxin trait of Bacillus thuringiensis (INTACTA) than when applied to genetically modified soybean plants without the Bacillus thuringiensis trait (BMX- POTENCIA). This is surprising since the values in the untreated groups (corrected according to Abbott) are equal, i.e. the Bacillus thuringiensis toxin alone does not control brown stink bugs.
B.7 Green Soldier Stink Bug (Nezara viridula)

(35) Lima Bean (Phaseolus lunatus, ‘Henderson Bush,’ Lot #—VR06650) plants were transplanted at the two true-leaf stage into 25.8 cm.sup.2 pots filled with sifted (No. 10 sieve) North Carolina loamy sand soil. Pots were held in the greenhouse and watered daily until treatment. Three days after transplant, the compounds were dissolved in acetone and then diluted with water for a final concentration of 50% acetone. Treatments were applied as a drench in 1 ml solution per plant. Plants were held in an environmental chamber (25±2° C., 24 L) and watered as needed for the duration of the test.

(36) Three days after treatment, plants were infested with five 2.sup.nd instar nymphs. Plants were covered with organza fabric bags to prevent escape. Four days after infestation, the number of live nymphs on each plant was recorded, and means were calculated for each treatment. The percent control was calculated as the percent mortality relative to the solvent blank.

(37) In this test, bilobalide, and ginkgolide A at 300 g ai/ha showed at least 75% mortality in comparison with untreated controls.

(38) B.8 Green Soldier Stink Bug (Nezara viridula)

(39) Pots (25.8 cm.sup.2) were filled with a 1:1 mixture of sifted (No. 10 sieve) North Carolina loamy sand soil and play sand. Technical material was dissolved in DMSO in a 20 ml scintillation vial. A total application volume of 25 μl of solution was added to a 20 ml vial, ten lima bean seeds (P. lunatus) were added, and the vial was vortexed for 1 minute. Seeds were allowed to dry and planted at a depth of 2 cm later the same day. One seed was planted per pot. Pots were held in the greenhouse and watered daily until infestation.

(40) Ten days after treatment, plants were infested with five 2.sup.nd instar nymphs. Plants were covered with organza fabric bags to prevent escape. Plants were held in an environmental chamber (25±2° C., 24 L) and watered as needed.

(41) Four days after infestation, the number of live nymphs on each plant was recorded, and means were calculated for each treatment. The percent control was calculated as the percent mortality relative to the solvent blank.

(42) In this test, ginkgolide A at 0.063 mg ai/seed showed at least 75% mortality in comparison with untreated controls.