WO2008012756A2

WO2008012756A2 - Pest attractant composition

Info

Publication number: WO2008012756A2
Application number: PCT/IB2007/052919
Authority: WO
Inventors: Christoffel Jakobus Smit
Original assignee: Activetrad (Proprietary) Limited
Priority date: 2006-07-21
Filing date: 2007-07-23
Publication date: 2008-01-31
Also published as: ZA200900582B; WO2008012756A3

Abstract

An attractant composition is provided for use in a pest control method for targeting adult true codling moths. The attractant composition includes at least one odorant selected from unsaturated C6 to C10 alkenes; heterocyclic substances including pyranones, furanones, benzopyranones and benzofuranones; terpenes including hemiterpenes, monoterpenes, sesquiterpenes, diterpenes, triterpenes and retinoids; benzenes including propenyl methoxybenzenes, amino benzenes and amido benzenes; and amino acids including cysteine and acetyl thioproline.

Description

PEST ATTRACTANT COMPOSITION

FIELD OF THE INVENTION

This invention relates to compositions and a method of pest control using attractants other than sex pheromones. In particular, the invention relates to the control of adult true codϋng moths of the species Cydia pomonella (as opposed to "false" codling moths of the species Cryptophlebia ieucotreta).

BACKGROUND TO THE INVENTION Methods and compositions exist for the control of adult true codling moths, but many of these methods and compositions lack efficacy because they make use of attractants in the form of sex pheromones that predominantly target male insects and thus lack the ability to attract the female insects, which are the prime agents of infection caused by their laying eggs on fruits of host plants. Ethyl E2,Z4-decadienoate, a component of the pear fruit flavour, is reported to attract female codling moths, but it is such a weak attractant to female codling moths, that it is not accepted in practical fruit cultivation.

The object of the present invention is to provide an improved composition and method of pest control that is effective against adult true codling moths of both sexes.

SUMMARY OF THE INVENTION

According to one aspect of the present invention there is provided an attractant composition for use in a pest control method for targeting aduit true codling moths, wherein said attractant composition includes at feast one odorant selected from the following: unsaturated C6 to C10 alkenes; heterocyclic substances including pyranones, furanones, benzopyranones and benzofuranones; terpenes including hemiterpenes, monoterpenes, sesquiterpenes, diterpenes, triterpenes and retinoids; benzenes including propenyl methoxybenzenes, amino benzenes and amido benzenes; and amino acids including cysteine and acetyl thioproline.

In particular, the composition may include at least one odorant selected from the following:

E2, E4-hexadienoic acid Retinyl acetate Z3,Z6,Z9-eicosatriene

The composition may include at least one plant oil that contains at least one odorant as described herein above.

The composition may include at least one pheromone such as a natural Lepidoptera pheromone, a sex pheromone and/or a poly-ene, e.g. E8,E10-dodecadienol,

E2,E13-octadieny! acetate and/or (Z)-7,8-epoxy 2-methyl octadecane (Disparlure).

The composition may include a combination of at least two of the odorants as described herein above and/or may include a combination of at least one of said odorants with E2,Z4-decadienoate and/or Alpha-3,7, 11 -Trimethyl 1 ,3,6,10- dodedatetraene (=E,E-Farnesene).

The composition may further include an insecticide, such as an insecticide suitable against adult true codling moths.

According to another aspect of the present invention there is provided a pest control method which includes applying the pest control composition as described herein above, to plants. The pest control composition may be applied to plants such as fruit trees to control aduit true codling moths and may be applied in the form of poisoned attractants.

Alternatively, the pest control composition may be used in insect traps of various designs, to attract, catch and kil! adult true codling moths.

EXAMPLES

For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made to the following non-limiting examples.

A pest control composition in accordance with the present invention is prepared by combining an insect attractant component with a suitable insecticide that is effective for killing adult true codling moths and that is chemically compatible for use in a pest control composition with the insect attractant component.

The pest control composition is applied in poisoned attractant stations in or near fruit trees. Adult codling moths are attracted by the scent of the insect attractant component of the composition, and are killed by contact with the insecticide component of the composition.

In another embodiment of the invention, a pest control composition is prepared including one or more of the odorants as described hereinabove. The pest control composition is placed in an insect trap of any one of various suitable designs, to attract adult codling moths and to kill them there.

It is to be appreciated that the pest control composition in accordance with the invention can include a number of other auxiliary substances/components, such as diluents, and the like.

The attractant component includes any one or more odorants selected from the following:

1. Natural Lepidoptera pheromones like the sex pheromones and the poly-enes;

Apart from the known codling moth sex pheromone E8,E10-dodecadienol which may be used in synergistic or additive combinations, also C18 to C21 poiy-unsaturated compounds (=poly-enes) including Z3,Z6,Z9-Octadecatriene (Z3.Z6.Z9-18Hy) Z1 ,Z3,Z6_,Z9-Octadecatetraene (Z1 ,Z3,Z6,Z9-1_8Hy) Z3,Z6,Z9-Nonadecatriene <Z3,Z6,Z9-19Hy) Z1 ,Z3,Z6,Z9- Nonadecatetraene (Z3,Z6,Z9-19Hy)

Z3,Z6,Z9-Eicosatriene (Z3,Z6,Z9-20Hy) Z1 ,Z3,Z6,Z9-Eicosatetraene (Z1 ,Z3,Z6,Z9-20Hy) Z3,Z6,Z9-Heneicosatriene (Z3,Z6,Z9-21 Hy) Z1 ,Z3,Z6,Z9-Heneicosatetraene (Z1 ,Z3,Z6,Z9-21 Hy) Z3,Z6,Z9-Docosatriene (=Z3,Z6,Z9-22Hy)

Z1 ,Z3,Z6,Z9-Docosatetraene (=Z1 ,Z3,Z6,Z9-22Hy) Other Lepidoptera pheromones such as E2,E13-octadienyl acetate and Disparlure [= (Z)-7,8-Epoxy 2-methyl octadecane]

2. Unsaturated C6 to C10 alkenes or unsaturated olefins;

This group often represents fruit flavors and includes the following aldehydes, alcohols and carboxyiic acids:

E2,E4-Hexadienyl- E2,E4-Heptadienyl-

E2,E4-Octadienyl- E2,E4-Nonadienyl- E2,E6-Nonadienyl- E2,E6-Decadienyl-

3. Heterocyclic substances including pyranones, furanones, benzopyranones and benzofuranones;

Pyranones including: maltol and ethyl maltol; indalone (=butopyronoxyi); mevalonic acid lactone. Furanones including: alpha-Angelica lactone; gamma dodecalactone. Benzofuranones including: the benzofuran lactone form of 2-Acetyl benzoic acid. Benzopyranones (chromans) including: alpha-tocopherol/Vit.E; tocotrienols as an unsaturated form of tocopherols; coumarin derivatives.

4. Terpenes including hemiterpenes, monoterpenes, sesquiterpenes, diterpenes, triterpenes and retinoids; This group consist of the following subgroups

Hemiterpenes (C5) e.g. mevaionoiactone, prenol {3-Methyl 2-buten 1-ol), and tig lie acid (2-Methyl 2-butenoic acid) and the following polymers of hemiterpines:

Monoterpenes (C10) e.g. carveol and neryl acetate

Sesquiterpenes (C15) e.g. panasinsene (which occurs in opopanax oil), cedrene (which occurs in cedarwood oil), farnesene (which is a host plant odorant) and isomethyl ionone (which can be expected to occur in apple extracts, among others)

Diterpenes (C20) e.g. aurantiol Triterpenes (C30) e.g. squalene Retinoids e.g. retinyl acetate, retinyl propionate, retinyl palmitate and compounds including the cyclic component of retinene and/or including the non-cyclic component of retinene.

5. Benzenes including propenyl methoxy benzenes, amino benzenes and amido benzenes; This group includes: Propenyi methoxy benzenes e.g. cinnamics;

Amidobenzenes or benzyl carbamides like hippuric acid; Anethole, methyl chavicol, asarone 1 ,2-climethoxy propenyl benzene, isobutyl cinnamate and other cinnamyl esters; Amino-benzenes (Amino benzoates):

Esters of 2-aminobenzoic acid (=anthranilates) and 4-aminobenzoic acid e.g. decyi anthranifate and butyl- or ethyl 4-aminobenzoate

Hippuric acid (Benzoylamino acetic acid).

6. Amino acids including cysteine and acetyl thioprofine; and This group includes; Cysteine,

N-acetyl thioproline acetyl-cysteine.

7. Plant oils which may contain attractants from one or more of the above chemical groupings.

Palm oil (with tocopherol and tocotrienol) Cedarwood oil (with cedrene) Opopanax oil (with panasinsene) Angelica seed oil (with alpha-angelica lactone) Capsicum fruit extracts (with pyrazines and capsaicin)

8. Combinations of the abovementioned.

After identification of separate attractants, further investigations will be required to identify the highest synergistic and additive effects in combinations of odorants. Examples of such synergies are presented in the olfactometer data provided herein below, which demonstrates the enhancing effect of retinyl acetate upon the codling moth attractance of the codling moth sex pheromone as well as that of E2.E4- octadienal.

EXPERIMENTS

Research has been conducted on attractants for the codling moth (Cydia pomonella) in a laboratory (with olfactometer) to identify attractants that showed sufficient efficacy to warrant open air tests (with odorant loaded Delta traps). The research is ongoing. Once individual attractants/odorants have been identified, combinations of the attractants can be tested in the same laboratory and open air tests, to test the synergistic effects that some of the attractants are believed by the inventor, to have.

Odorant attractants in these experiments were selected from those mentioned above and can be categorized under the following functional/chemical groups:

1. Natural Lepidoptera pheromones like the sex pheromones and the poly-enes

2. Unsaturated C6 to C10 alkenes including fruit flavors 3. Heterocyclic substances including lactones like pyranones, furanones and also benzopyranones and benzofuranones which includes fruit flavors and antioxidants

4. Terpenes, including hemiterpenes (C5) like tigiic acid, and polymers thereof like monoterpenes (C10) sesquiterpenes (C15) diterpenes (C20), triterpenes (C30) and retinoids. The terpene group includes host plant odorants like farnesene for CM.

5. Benzenes including propenyf benzenes e.g. cinnamics; amino benzenes e.g. anthranilates and amido benzenes e.g. benzyl carbamides.

6. Amino acids including cysteine

7. Plant oils which may contain attractants from one or more of the above categories.

8. Combinations. Ultimately, after identification of separate attractants, further investigations are aimed at identifying the highest synergistic and additive effects in combinations of odorants.

These test odorants were obtained from the companies: Aldrich (USA), Fluka

(Switzerland), Bedoukian (USA), Pherobank (Netherlands) and R C Treatt (United Kingdom).

EXPERIMENT 1 - OLFACTOMETER SCREENING IN CLOSED SPACE Initial screening for codling moth (CM) attractance was done in two batteries (i.e. two replications) of distance calibrated olfactometer glass tubes marked every 100 mm, thus creating seven distance zones for a 750 mm long tube. The glass tubes were 750 mm long and 50 mm in diameter. The ambient temperature was controlled by an air conditioning system and a controlled longitudinal airflow along the olfactometer tubes was established by means of fans and was maintained practically constantly in all the tubes.

A set quantity of moths were placed in the downwind ends of the tubes and odorants at the upwind ends while the ambient temperature was kept low (16 degrees Celsius or below) to immobilise the moths initially until all the tubes were loaded. An unloaded blank tube was used as control. After loading the tubes, the air conditioner was reset to maintain an ambient temperature of 23 degrees Celsius which activated the moths to start migrating upwind.

Migration or attraction indexes were calculated as follows: Percentages of moths in each of the distance zones multiplied by the number (=distance) of that zone. This was done for each of the distance zones and the products of percentages and zone numbers for each zone were added together to provide the migration index for the particular odorant. The same was done for the blank control tube into which no odorant is loaded and a Relative Attraction Index (RAI) for each odorant was calculated as the migration index of the odorant divided by the migration index of the control multiplied by 100. Relative attraction indexes of known attractants like sex pheromones were also used as standards for comparison.

The results of the olfactometer experiments are provided in Tables 1 to 9 below, which show the relative attraction indexes (RAI) of the various odorants to codling moths in comparison to the blank control. The results provided are the mean results of the two replications of each experiment. Table 1 - Natural Le ido tera heromones

Table 2 - Cβ to C10 unsatu rates (including natural fruit flavors)

Table 3 - Lactones Q-heteroc clics

Table 4 - Benzenes

Table 5 -Terpenes

Table 6 -Retinoids

Table 7 - Amino acids

Table 8 - Plant oils/extracts/odors

Table 9 - Combinations of odorants

Most of the olfactometer identified CM attractants are not able to catch moths on their own in open air experiments in orchards or do so at a much decreased rate. The olfactometer screening is meant as first stage screening process through the indicated chemical groupings, with the intention of selection of candidate test odorants for use in open air orchard experiments where the best attraction will presumably be obtained in additive or synergistic combinations; much more so than from single compounds. EXPERIMENT 2 - OPEN AIR EXPERIMENTS

The odorant attractants identified in the olfactometer were further investigated in open air experiments in which local, artificial CM population densities were created, using artificially bred test moths.

Yellow plastic delta traps together with their sticky pads were used. The odorant dispensers consisted of 20 mm square six-ply pieces of absorbent paper (toilet paper) stapled together, onto which the odorants were absorbed. In cases of the more volatile odorants, the absorbent paper with the odorant were rolled into 30 mm wide strips of heavy duty aluminium foil, the open ends being pressed together to allow small slits through which the odorant vapour could escape.

Experiments were conducted in citrus orchards (cv. Valencia). The delta traps were hung up inside the canopy of every fourth tree of every second row with 7m x 5m tree spacing. Odorant dispensers were placed on the sticky pads inside the traps. A paper bag (230 x 120 x 70 mm) filled in cooled laboratory conditions with about 200 CM and closed, was stapled to the underside of each of the delta traps. After all the prepared traps were hung up inside the trees, the paper bags beneath them were cut open with scissors about 90 mm from the bottom to release the test moths, but retaining the bottom pouch of the paper bag still fixed to it. From here the test moths gradually emerged and spread. All orchard tests were initiated and conducted in the early evening after sunset. Most trap catches were made during the first night. To increase catches, a second batch of CM was applied 2 to 3 days after the first.

The results of the olfactometer experiments are provided in Tables 1 to 9 below, which show the relative attraction indexes (RAI) of the various odorants to codling moths in comparison to the blank control. The results provided are the mean results of the two replications of each experiment. The results of the open air/delta trap experiments are provided in Table 10 below, which shows the means of the numbers of moths caught in two delta traps loaded with each odorant.

Table 10

Functionally the heterocyclic substances often act as antioxidants, e.g. Vitamin E. Another nitrogen and sulphur containing heterocyclic substance, acetyl thioproline (mentioned under amino-acids) also attracts CM in the olfactometer and also functions as anti-oxidant. This may underscore the need for suitable antioxidants in codling moth attractant combinations; a line which will be further investigated. Antioxidants delay the enzymatic oxidative clearing of olfactory sensila to make place for the next incoming odorant e.g. attractant molecules, causing them to be sensed for a longer time.

The presence of retinyl acetate appears to enhance the attraction of attractants like the CM sex pheromone and E2,E4-hexadienoic acid, as well as other odorants mentioned above, including the C6 to C10 unsaturated aldehydes.

The experimental results, especially the open air/delta trap results, may appear to suggest that the attraction of CM sex pheromones is significantly higher than that of the other substances tested. However, those skilled in the art will realise that the sex pheromones do not attract female CM at all, whereas the attraction of the other substances, proposed in the present invention, attracts both sexes of CM and wili thus be effective in the control of female CM.

From the results of Table 10, it can be seen that the attractive effect of each of E2,E4-Hexadienoic acid, Retinyl acetate and Z3,Z6,Z9-Eicosadiene was far better than the known attractant, Ethyl E2, Z4-Decadienoate. The inventor believes that similar or better attractive effects can be obtained from more of the odorants mentioned above and ongoing open-air experiments are being conducted to on more of the odorants to supplement the olfactometer results.

Claims

1. An attractant composition for use in a pest control method for targeting adult true codling moths, characterised in that said attractant composition includes at least one odorant selected from the following: unsaturated C6 to C10 alkenes; heterocyclic substances including pyranones, furanones, benzopyranones and benzofuranones; terpenes including hemiterpenes, monoterpenes, sesquiterpenes, diterpenes, triterpenes and retinoids; benzenes including propenyl methoxybenzenes, amino benzenes and amido benzenes; and amino acids including cysteine and acetyl thioproline.

2. A composition as claimed in claim 1 , characterised in that said composition includes at least one odorant selected from the following: E2, E4-hexadienoic acid; Retinyl acetate; and Z3,Z6,Z9-eicosatriene.

3. A composition as claimed in claim 1 or claim 2, characterised in that said composition includes at least one plant oil which contains at least one odorant as described in claim 1.

4. A composition as claimed in any one of the preceding claims, characterised in that said composition includes at least one pheromone.

5. A composition as claimed in claim 4, characterised in that said pheromone is a natural Lepidoptera pheromone.

6. A composition as claimed in claim 4 or claim 5, characterised in that said pheromone is a sex pheromone.

7. A composition as claimed in claim 4, characterised in that said pheromone is a poly-ene.

8. A composition as claimed in any one of the preceding claims, characterised in that said composition includes a combination of at least two of the odorants as described in claim 1.

9. A composition as claimed in any one of the preceding claims, characterised in that said composition further includes an insecticide.

10. A pest control method which includes applying a pest control composition to plants, characterised in that said pest control composition is a composition as claimed in any one of claims 1 to 9.

11. A method as claimed in claim 10, characterised in that the pest control composition is applied to plants the form of a poisoned attractant.

12. A method as claimed in claim 10, characterised in that the pest control composition is used in insect traps.