AU760745B2 - Pesticide for woodlice - Google Patents

Description

-2- PESTICIDE FOR WOODLICE Field of the Invention The present invention relates to a pesticide composition for woodlice, including sowbugs and pillbugs. More particularly, the invention provides a pesticide composition for woodlice, more commonly known as slaters, which is non-phytotoxic and harmless to non-target animals and human beings.

Background to the Invention 10 The common slaters, Oniscus asellus, Porcellio scaber (the common woodlouse) and Armadillidium vulgare (the pill woodlouse) are common garden pests which can cause significant problems in the home garden throughout the world. These woodlice are found in S"'e most parts of the earth from the northern tundra to the equator, from coastal areas to high in the mountains. They seek out damp, protected places during the day but leave these during the 15 moist night when they become active. Although they eat dead plant material, they also attack young plant roots and can cause significant problems, particularly in container-grown plants. In sandy soil, they often bury themselves in the soil and are potentially significant pests in such areas. In Australia, for example, in the Perth region of Western Australia, they are considered a pest in suburban gardens.

20 Woodlice belong to the phylum Arthropoda, class Crustacea, order Isopods, suborder j Oniscidea. These pests are members of the Crustacean family and are not insects. Nearly all arthropods that live in the sea are crustaceans but woodlice, and a few amphipods, are the only crustaceans to live on land with any success. It is clear from the fact that death to woodlice may be caused by water overload, that these animals have forfeited their aquatic potential to some S 25 extent.

Woodlice cannot survive for more than a day or two away from moist areas; however, they thrive in bark or moss-based potting mixes and in mulches. Since there is an increased use of mulches in the home garden, it is to be expected that the problem of unwanted woodlice will correspondingly increase. Woodlice will also at times invade damp basement areas as well as the first floors of houses. When this occurs, they are almost always present in considerable numbers in the soil and under plants immediately outside the house.

Sowbugs, one class of woodlice, such as Porcellio scaber (the common woodlouse) and alwoodlice.spc/22/07/1999 -3- Oniscus asellus are not able to roll up into a ball, but the pillbugs, another class of woodlice, Ssuch as Armadillidium vulgare can roll up into a ball when disturbed or under water stress. Both pillbugs and sowbugs have six pairs of legs initially increasing to seven pairs after the first or subsequent molts (Heeley, (1941) "Observations on the life histories of some terrestrial isopods," Proc. Zool Soc., London, B, 3, pp79-149). The biologies of pillbugs and sowbugs are similar (Sutton, "Woodlice," Ginn and Co. London (1972), republished by Pergamon Press, Oxford (1980)). The eggs hatch in a brood pouch (marsupium), the average number in a brood being of the order of between twenty and thirty. It appears that two broods per year is the most common although Heeley (1941), questioned the generality of this, pointing out that the number 10 of broods was probably influenced by climatic conditions. Both sowbugs and pillbugs have a lifespan of about two years.

Where woodlice have become a problem, they have until now been controlled by pesticides such as methiocarb, bendiocarb or diazinon. Diazinon is a contact-action pesticide which is also phytotoxic causing damage to a number of plants. Methiocarb and bendiocarb are anticholinesterase agents. These substances inhibit the action of cholinesterases and thereby Sdestroy or interfere with the conduction of nerve impulses.

Woodlice have many natural predators. Common shrews are known to consume vast numbers of woodlice. Other animals known to eat them include toads, frogs, lizards, birds, spiders and hedgehogs. The possibility of secondary poisoning poisoning of animals which have eaten woodlice killed by a pesticide) is of some concern, in particular, in the case of methiocarb. The pesticides currently used to control woodlice are therefore toxic to a wide range of animals including humans. These chemicals also pose a considerable threat to non-target plants. There is therefore a need for a less toxic and more specific pesticide.

The common woodlouse species, Porcellio scaber, is widespread in Australia and is a 25 common component of garden fauna and was thus chosen as a test organism as it is ubiquitous in its distribution.

Accordingly, it is an object of the present invention to provide a pesticidal composition for woodlice and preferably, one which is non-phytotoxic and will not be the cause of secondary or accidental poisoning of other non-target animals, such as pets and human beings. Such a pesticide would offer considerable environmental advantages.

The toxicity of iron chelates to non-target animals has previously been investigated in relation to a study on snails (Young, Australian Patent Application No. 689399) and 4 selected metal complexones were found to be considerably less toxic than methiocarb, which is presently the usually preferred pesticide of choice commonly used for woodlice, in spite of its possible side-effects. Indeed, these metal complexones are used in medicinal applications to relieve anaemia.

The effectiveness of such complexones is not very temperature- or humiditydependent, being comparable to methiocarb in this respect. Therefore, their use in damp situations, which woodlice invariably inhabit, would not be expected to present a problem.

Further, these metal complexones are neither insecticides nor acaracides and pesticides for the control of woodlice based on them will not kill earthworms, the mainly beneficial carabid beetles, ladybird larvae or honey bees.

The term "metal complexone" is used herein in its broadest sense and refers to a chelate of a metal with at least one ligand of the complexone type. Preferably, these are chelates which have at least one imidodiacetic acid, [-N(CH 2

CO

2

H)

2 group or two aminoacetic acid, [-NHCH 2

CO

2 H] groups, where one or both of the methylene hydrogen/s may be replaced by other substituents. These compounds form stable complexes with almost all cations. The chemistry of those substances, including the equilibrium constants for the formation of the metal chelates, have been very extensively studied (Anderegg, in "Comprehensive Coordination Chemistry," (1987), Vol. 2, Chapter 20.3).

Summary of the Invention According to one embodiment of the present invention, there is provided a method S. for treating woodlice, comprising treating an area with an effective amount of a pesticide composition, including a metal complexone and a suitable carrier therefor.

Preferably, the metal of the metal complexone is selected from aluminium or iron.

Most preferably, the metal is iron(III).

Preferably, the complexone of the metal complexone is selected from ethylenediaminetetraacetic acid (EDTA) or ethylenediaminedisuccinic acid (EDDS). Most preferably, the metal complexone is ferric EDTA or the hydroxy-metal complexone derivative of FeEDTA, [Fe(III)(OH)EDTA] 2 Typically, the pesticide composition includes a metal 30 complexone in an amount of at least 4.5% by weight of the total composition of the pesticide.

More preferably, the metal complexone comprises about 4.5% to about 12% by weight of the 99*9 ap147.spec/l4 Fcbruary 2003 composition, when the metal complexone is [Fe(III)(OH)EDTA] 2 Most preferably, [Fe(III)(OH)EDTA] 2 comprises about 6% by weight of the composition.

In a preferred form of the invention, the carrier for the metal complexone usually includes a cereal, wheat flour, corn flour, bran, arrowroot or rice flour, carrot, beer, rice hulls, comminuted cuttle fish, starch or gelatin, or mixtures thereof, so that the woodlouse is attracted to the pesticide composition in the form of a bait. Non-nutrient carriers of interest include non-nutrient polymeric materials, pumice, carbon and materials useful as carriers for pesticides. The pesticide composition may also contain other additives known in the art as phagostimulants, for example, sucrose or mollasses; lubricants such as paraffin wax, white oil or casein; and flavourings such as BITREX® (a registered trade mark) which imparts a bitter taste and renders the bait less attractive to non-target animals and human beings. In order to inhibit deterioration of the bait, preservatives such as sodium benzoate, vitamin E, alphatocopherol, 4-nitrophenol, ascorbic acid, methyl paraben, propyl paraben or sodium bisulfite may also be included.

Preferably further, a water-proofing agent is included to prolong the life of the bait.

Such a water-proofing agent preferably comprises a fatty acid alcohol in an amount in the range between about 1% and 5% by weight of the total composition. More preferably, the fatty acid alcohol is selected from the group of C 16

-C

18 fatty acid alcohols. Most preferably, the C 16

-C

18 fatty acid alcohol comprises about 2% by weight of the total composition. Most preferably, the C 1 6 -C8 fatty acid alcohol is HYDRENOL MY®, which is a mixture of hexadecanol, heptadecanol and octadecanol. (HYDRENOL MY® is a registered trade mark of Henkel Australia Pty. Ltd.). In another preferred form of the invention, the waterproofing agent is guar gum in combination with lotus bean gum to provide a harder, more waterresistant pellet for use in particularly wet conditions.

The pesticide composition is advantageously presented in a solid bait form such as tablets, powders, granules or pellets or in a form which could assist with applying the pesticide composition as a coating. Those skilled in the art will appreciate that it is preferable to employ products in treating woodlice which are in a form that is easy for consumers to use.

Pellets, for example, can be easily scattered from a box across the area to be protected, whilst 30 a coating formulation could assist in the application of the product to the bottom of pot plant or flower box containers.

i: Typically, a filler is added to the carrier to increase the density of the pesticide :'composition to reduce airborne content and hence wastage of the composition.

ap147.spec./14 February 2003 Preferably, the filler is selected from calcium or potassium carbonate, but is not limited to these. Typically, the composition contains about 1% but not exceeding 5% of a metal carbonate as a filler. When the metal carbonate is calcium carbonate, the preferred concentration is in the range between about 2% and 3% by weight of the total composition.

When the metal carbonate is potassium carbonate, the preferred concentration is in the range between about 4% and 5% by weight of the total composition. Such a formulation with added carbonate as filler provides a non-acidic pH and this serves to aid in the palatability characteristics of the bait, thereby increasing its efficacy.

In a preferred form of the invention, the method comprises treating woodlice with a pesticide composition, which further includes a surfactant to compensate for any loss of efficacy of any iron (III) which may become bound up by phytates present in the flour.

Preferably, the surfactant is sodium dodecyl sulphate, but is not limited to this. More preferably, the sodium dodecyl sulphate is present in an amount between about 0.2% and 0.3% by weight of the total composition.

According to yet another aspect of the invention, the method comprises treating woodlice with a pesticide composition including a metal complexone, which comprises a metal complexone in combination with at least one other pesticide. Typically, the other pesticide is selected from methiocarb, bendiocarb or diazinon.

Typically, the pesticide is applied to the area infested by the woodlice in an 0 20 appropriate manner. Preferably, the mode of application is either in the form of scattering the pesticide composition in the form of bait pellets over the area to be protected or by applying a oo.o coating formulation including the pesticide composition to the area inhabited by woodlice.

ap147.spec./14 February 2003 According to another form of the invention, the pesticide composition is included in a coating formulation for application to items which are eaten by woodlice or act as a shelter for them, such as the underside of pots and containers. The coating is consumed by the woodlice and acts as a stomach poison. In this form of the invention, the carrier for the metal complexone in the pesticide composition includes an edible binder to provide a formulation having a glue-like consistency. Preferably, the binder is selected from a polyvinyl acetatebased binder, gum arabic or gum acacia. More preferably, the binder is a polyvinyl acetatebased binder. Most preferably, the polyvinyl acetate-based binder is TERRA CONTROL (TERRA CONTROL® is a registered trade mark of Henkel Australia Pty Ltd).

A further aspect of the invention relates to the use of the coating formulation as applied to the underside of pots and containers.

Where the terms "comprise", "comprises", "comprised" or "comprising" are used in this specification, they are to be interpreted as specifying the presence of the stated features, integers, steps or components referred to, but not to preclude the presence or addition of one or more feature, integer, step, component or group thereof.

Examples The invention will now be described, further explained and illustrated with reference to the following non-limiting Examples.

Study of the toxicity of various metal salts and chelates as well as several S"commercially available formulations :eeeee A number of different metal chelates were investigated during this study.

The experimental set up consisted of containers of 1 litre capacity with approximately 150 ml of coarse moist pine bark potting mix. Each container had a number of small holes in the lid to allow for air circulation. The containers were placed on a verandah so that rain could not enter the containers, but they were subjected to natural light. Four pellets of each treatment were added to each container along with one woodlouse. After five days, the woodlice were examined to determine whether they were alive or dead. Great care was sometimes 9999.9 ap147.spec./14 February 2003 -8required to establish whether the woodlice were in fact, dead. As stated above, the common woodlouse often "plays" dead on being disturbed, whereas the pill woodlouse is able to roll up into a ball.

The various formulations used are provided below and the death rates for the various formulations are given in Tables 1 and 2.

Formulations used in this study Code Bay Bay Multil Multi2 Multi3 El E2 Fl F2 CH1 CH2 0, CH3

ESC

Org

PSO

a PhylO Formulation BAYSOL® 2.0% methiocarb in a grain-based bait MULTIGUARD® containing 9% oxo-dimer of ferric EDTA in bran/flour bait 4.5% oxo-dimer of ferric EDTA synergist in bran/flour bait (soft pellet) 6% oxo-dimer of ferric EDTA in bran/flour bait (very hard pellet) 7.1% ferric orthophosphate in flour bait 10.3% ferrous sulphate in flour bait 4.2% ferric EDTA 3.4% calcium sulphate in flour bait 4.2% ferric EDTA 7.4% calcium sulphate in flour bait 5.0% Hydroxyethylenediaminetriacetic acid ferric salt (DISSOLVINE® H-Fe-13) in flour bait 9.6% Ethylenediaminebis[(2-hydroxyphenyl)acetic acid] ferric sodium salt (DISSOLVINE@ Q-Fe-6) in flour bait 5.2% Diethylenetriaminopentaacetic acid ferric sodium salt (DISSOLVINE® D-Fe-11) in flour bait Escargo! containing 1% ferric phosphate in an inert bait 0.28% Fe as iron(III)-3-hydroxy-2-methyl-4-pyrone complex in flour bait 1.0% ferric EDTA 0.27% sodium dodecyl sulphate in flour bait 4.86% ferric EDTA 3.16% sodium phytate in flour bait -9- A16 Zn Cu Alac Met 0.67% ALKANATE CS® in flour bait 8.9% zinc EDTA in flour bait 8.6% copper EDTA in flour bait 10.3% aluminium trisacetylacetonate in flour bait 6.0% metaldehyde in grain bait (LIMAX®) 0.5% bendiocarb in talc Ben :20

S

2 BAYSOL®, MULTIGUARD®, DISSOLVINE®, ESCARGO! ALKANATE CS® and LIMAX are registered trade marks of Bayer, Multicrop (Aust.), Akzo-Nobel, Garden Alive!, ICI and Rhone-Poulenc, respectively.

Example 1 Ten containers for each different formulation trialed were set up containing one woodlouse each. A blank pellet containing no metal complexone was used as a control. The species of woodlouse was Porcellio scaber. After five days, the number of dead woodlice in each group of containers was determined. The results are shown in Table 1.

Table 1 Number of woodlice dead after 5 days in the various treatments Porcellio scaber Treatment #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 Total Control 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/10 Bay 1/1 1/1 1/1 0/1 1/1 0/1 1/1 1/1 1/1 1/1 8/10 Multil 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 10/10 Multi2 1/1 1/1 1/1 0/1 1/1 1/1 1/1 1/1 0/1 1/1 8/10 Multi3 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 10/10 El 0/1 0/1 1/1 0/1 0/1 0/1 0/1 0/1 0/1 1/1 2/10 E2 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/10 F1 0/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 9/10 F2 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 10/10 CHl 1/1 0/1 1/1 0/1 1/1 0/1 1/1 0/1 1/1 1/1 6/10 C 2 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/10 CH3 0/1 1/1 0/1 1/1 1/1 1/1 1/1 0/1 1/1 0/1 6/10 ESC 1/1 0/1 0/1 1/1 1/1 1/1 1/1 0/1 1/1 1/1 7/10 Phyl0 0/1 1/1 1/1 1/1 0/1 1/1 0/1 1/1 1/1 1/1 7/10 PSO 1/1 0/1 0/1 1/1 1/1 1/1 1/1 1/1 1/1 1/1 8/10 Org 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/10 A16 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/10 Cu 0/1 0'/1 0/1 0/1 0*/1 0/1 0'/1 0/1 0/1 0/1 0/10 Zn 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/10 Alac 0/1 1/1 1/1 1/1 0/1 1/1 0/1 0/1 1/1 1/1 6/10 Met 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/10 Ben 0/1 0/1 1/1 1/1 0/1 1/1 1/1 1/1 0/1 0/1 5/10

S@

e" oee,, S.o..

V6. a 0 so oee.

Ve 0 o6 moribund woodlice Example 2 Seven containers for the control and for Multil were set up containing one woodlouse each. A blank pellet containing no metal complexone was used as a control. The species of woodlouse was Armadillidium vulgare. After five days, the number of dead woodlice in each group of containers was determined. The results are shown in Table 2.

Table 2 Number of woodlice dead after 5 days in the different treatments Armadillidium vulgare Treatment I 2 3 4 5 6 7 Total Control 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/7 Multil 1/1 1/1 1/1 1/1 1/1 1/1 1/1 7/7 Summary of the Results Comparing the results for the formulations, Multil, Multi2 and Multi3, indicates that there appears to be little difference in the killing power of the oxo-dimer of ferric EDTA over the -11concentration range of 4.5% to 9% and the influence of pellet hardness is, in this case, not of paramount importance.

The kill rate for PSO, an experimental formulation containing surfactant and just 1% of ferric ethylenediaminetetraacetic acid, is surprisingly high. Whether this kill rate is due to the addition of sodium dodecyl sulphate as a synergist (see Young, in International Patent Application No. PCT/AU98/00941 entitled: "Improved Stomach-action Molluscicides") is not clear, but our studies on snails indicates that this formulation gives only low kill rates for snails, which is evidence that snails and woodlice have significantly different physiologies and require entirely different treatment regimes.

The surfactant ALKANATE CS (calcium dodecylbenzene sulphonate) does not appear to be toxic to woodlice. Although this surfactant is not toxic to the common garden snail, Helix aspersa, it appears to be synergistic when mixed with metaldehyde (Bowen, I.D. and Wyn Jones, "Molluscicidal Composition in Pellet Form from a Molluscicide and Surfactant" GB Patent No. 2098869/81).

*eeee 15 Comparing the results for the various chelates, i.e. Multil (ethylenediaminetetraacetic acid iron oxo-dimer), CH1 (hydroxyethylenediaminetriacetic acid ferric salt), CH2 0" (ethylenediaminebis[(2-hydroxyphenyl)acetic acid] ferric sodium salt), CH3 (diethylenetriaminopentaacetic acid ferric sodium salt), all three of which are metal complexones, and Org ([iron(III)-3-hydroxy-2-methyl-4-pyrone] complex), which is not a metal complexone, indicates that the killing power is very dependent on which particular iron chelate is used and that metal complexones are particularly efficacious.

The inclusion of sodium phytate in the bait seems to have a considerably less dramatic effect on toxicity to woodlice compared with studies on snails (Young, unpublished results). This may be due to the fact that woodlice recycle their faeces (Sutton, (1972)).

Conceivably, the phytate locks up the ferric EDTA, but the iron phytate is broken down in the faeces and when re-eaten a significant proportion of the ferric ions are available for absorption from the recycled faeces which then acts as a poison.

The relative toxicity of zinc, copper and iron EDTA to woodlice is significantly different. Although zinc EDTA is much less toxic than iron EDTA or the oxo-dimer of ferric EDTA, the copper EDTA pesticide composition gave zero kill rate for woodlice. This may be due to the unusual way in which copper is stored in the hepatopancreas of woodlice.

-12- Ferric orthophosphate and ferrous sulphate appear to be of low toxicity to woodlice.

0 Ferric orthophosphate has a very low solubility in water and might well be expected to pass straight through the digestive system. Ferrous sulphate, on the other hand, is quite soluble in water; however, it appears either that woodlice are repelled by ferrous sulphate or ferrous sulphate is made unavailable by natural chelators, such as phytates and sugars, from the flour.

The fact that ESCARGO! is moderately toxic to woodlice may indicate that some of the additives in the inert carrier are either toxic to woodlice or in some way interfere with the uptake of iron by natural chelators. Metaldehyde has on occasions been claimed to be active against woodlice. Whilst certainly not an exhaustive study, the results in Table 2 indicate that this is not 10 the case with the metaldehyde composition used in this study.

Methiocarb and bendiocarb are toxic to woodlice although bendiocarb as a talc-based pesticide composition, i.e. in powder form, is not a very effective killer. These compounds are anticholinesterase agents and are toxic to a wide range of animals.

The results of this study clearly show that the hydroxy-metal complexone derivative of 15 Fe(III)EDTA, [Fe(III)(OH)EDTA] 2 is the most effective of the formulations tested and even more effective than the most effective of the toxic alternative, BAYSOL® 2.0% methiocarb in a grain-based bait.

Example 3 S. Twelve identical black plastic caps of 4 mm diameter were divided into two groups of six. Six, which formed the control group, were lightly coated with a thin layer of 1% aqueous solution of TERRA CONTROL®, a polyvinyl acetate-based binder. The other six were coated with a solution containing 0.7 TERRA CONTROL®, 1.5% ferric sodium EDTA and flour made up with water in an aqueous paste. Each of the twelve caps were dried and placed in a 1 litre container into which 150 ml of moist pine-based potting mix has been spread. Three woodlice were placed in each container which was then closed with a lid, which had about six small holes in it. The containers were kept at room temperature. After 48 hours, the number of dead and moribund woodlice were counted. A woodlouse was deemed moribund if there was noticeable movement on prodding with a fine metal rod, but the woodlouse did not move more than 5 mm over a period of 1 minute. The results after 48 hours are given in Table 3. The numbers in parenthesis represent moribund woodlice.

13 Table 3 Number of woodlice dead after 2 days in the different treatments Porcellio scaber Treatment 1 2 #3 #4 #5 #6 Total Control 0/3 0/3 0/3 0/3 0/3 0/3 0/18 Treated 2/3 1(2)/3 2(1)/3 2(1)/3 2/3 3/3 12(4)/18 Summary of Results The above results show that ferric sodium EDTA in a flour-based paste is an effective way of controlling woodlice.

Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications. The invention also includes all of the steps, features, compositions and compounds referred to or indicated in this specification (unless specifically excluded) individually, or collectively, and any and all combinations of any two or more of said steps or features.

Claims (25)

1. A method for treating woodlice, comprising treating an area with an effective amount of a pesticide composition including a metal complexone and a carrier therefor.

2. A method according to claim 1, wherein the metal of the metal complexone is selected from aluminium or iron.

3. A method according to claim 2, wherein the metal is iron(III).

4. A method according to any one of claims 1 to 3, wherein the complexone of the metal complexone is selected from ethylenediaminetetraacetic acid or ethylenediaminedisuccinic acid. A method according to any one of claims 1 to 4, wherein the metal complexone is selected from Fe(III)EDTA or the hydroxy derivative of Fe(III)EDTA, [Fe(III)(OH)EDTA]2-.

6. A method according to any one of claims 1 to 5, wherein the amount of metal complexone is at least 4.5% by weight of the total composition.

7. A method according to any one of claims 1 to 5, wherein the amount of metal complexone is in the range of 4.5% to 12% by weight of the total composition.

8. A method according to any one of claims 5 to 7, wherein the metal complexone is [Fe(III)(OH)EDTA] 2

9. A method according to any one of claim 8, wherein the amount of [Fe(III)(OH)EDTA] 2 is 6% by weight of the total composition.

10. A method according to claim 4, wherein the complexone is S ethylenediaminedisuccinic acid.

11. A method according to claim 10, wherein the metal complexone is Fe ethylenediaminedisuccinic acid.

12. A method according to any one of the preceding claims, wherein the carrier includes a cereal, wheat flour, corn flour, bran, arrowroot, rice flour, carrot, beer, rice hulls, comminuted cuttlefish, starch, gelatin, pumice, carbon, a phagostimulant, a lubricant, a flavouring agent, a preservative or a waterproofing agent, or mixtures thereof. 30 13. A method according to claim 12, wherein the waterproofing agent is selected om a fatty acid alcohol or guar gum.

14. A method according to any one of the preceding claims, further comprising a i ap147.spec/14 February 2003 filler. A method according to claim 14, wherein the filler is selected from the group of alkali metal or alkaline earth metal carbonates.

16. A method according to claim 15, wherein the filler is selected from calcium carbonate or potassium carbonate.

17. A method according to any one of claims 14 to 16, wherein the filler is present in an amount in the range of 1% to 5% by weight of the total composition.

18. A method according to claim 17, wherein the filler is calcium carbonate present in an amount in the range of 2% to 3% by weight of the total composition.

19. A method according to any one of claims 14 to 18, wherein the pesticide composition is non-acidic. A method according to any one of the preceding claims, further comprising an effective amount of a surfactant.

21. A method according to claim 20, wherein the surfactant is sodium dodecyl sulphate.

22. A method according to claim 21, wherein sodium dodecyl sulphate is present in an amount between about 0.2% and 0.3% by weight of the total composition.

23. A method according to any one of the preceding claims, wherein the metal complexone is present in combination with at least one other pesticide.

24. A method according to claim 23, wherein the other pesticide is selected from methiocarb, bendiocarb or diazinon. oooo A method according to any one of the preceding claims, wherein the metal S complexone and the carrier are in a solid bait form.

26. A method according to claim 25, wherein the solid bait form is selected from a tablet, a powder or in the form of granules or pellets.

27. A method according to any one of claims 1 to 24, wherein the pesticide composition is in the form of a coating formulation.

28. A method according to claim 27, wherein the carrier of the coating formulation includes an edible binder having a glue-like consistency. 30 29. A method according to claim 28, wherein the binder is selected from a S polyvinyl-acetate based binder, gum Arabic or gum acacia. A method according to claim 29, wherein the binder is a polyvinyl-acetate ap147.spc./14 February 2003 16 based binder.

31. A method according to any one of claims 1 to 30 substantially as hereinbefore described with reference to any one of the accompanying examples.

32. Use of the method according to any one of claims 1 to 30 substantially as hereinbefore described. DATED this 14 t of February, 2002 By his Patent Attorneys Houlihan 2 •go e ap147.spccJ4 Februay 2003