NZ600852A - Methods for controlling pest animals - Google Patents

Abstract

Abstract - 600852 Disclosed herein a method of deterring a marsupial from browsing on plant material including the step of applying to said plant material or at a locality thereof an effective amount of a composition comprising pyrethrum or at least one pyrethroid. Also disclosed is a composition for repelling a marsupial which is in the form of a sprayable aqueous formulation, said composition comprising an effective amount of pyrethrum or at least one pyrethroid, diatomaceous earth, and a suitable carrier or diluent, wherein the composition comprises 10 0.1 g/L of the pyrethrum or at least one pyrethroid.

Description

METHODS FOR CONTROLLING PEST ANIMALS Field of the Invention The present invention relates to methods for controlling pest animals and chemical compositions for use in such methods. In particular the invention is directed to methods which utilise chemical compositions in the protection of plants from browsing animals and in particular browsing marsupial species.

Background to the Invention Arboreal marsupials, such as common brushtail and common ringtail possums have become serious pests in urban locations across Australia and the brushtail possum in New Zealand because of high numbers and the damage they cause to ornamental shrubs, agricultural plants and to native trees in forestry.

Terrestrial marsupials such as wallabies can also be pests in parklands and some forestry plantations when their numbers increase. In Tasmania which is the word's largest producer of legally grown opium for the pharmaceutical market, wallabies and related pademelons have been reported to browse on the poppy heads which is a concern in terms of both crop protection and the animals long term health.

Possums, and brushtail possums specifically, are a pest species in urban areas in both Australia and New Zealand. Ringtail possums are urban pests in Australia. Through excessive numbers and their browsing/nesting activity possums are especially likely to damage plants and trees, both domestic and native species. If they also enter into ceiling/roof spaces then there is potential for them to cause significant damage to insulation and wiring, potentially causing bad smells and health related issues (if they die) or electrical fires.

The current possum population of New Zealand is estimated at 30 million possums. This is a reduction from the 70 million in the 1980s, but this still represents a significant pest species problem. Possums in urban areas are not easily controlled by methods used in more rural areas such as baiting. The current total brushtail or ringtail possum population of Australia is not easily estimated, but concern for possums as a pest species in Australia specifically relates to overcrowding in urban areas and damage to assets in both private gardens, council parks, and commercial crop production such as market gardens.

Especially in Australia (where possums are protected) private individuals are likely to be more receptive to humane approaches to possum deterrent measures as long as they can be shown to be effective compared with current measures.

In relation to deterring Australian marsupial species existing products include (as actives): Charlie Carp® (fish-based fertiliser); Phenyle® (S) (hospital strength antiseptic); Tea- based deterrents; Indonesian fish sauce; Garlic spray; White King® (household bleach); Camphor; Naphthalene flakes; Quassia chips (Chips of bark from a South American tree); Blood & Bone (Animal-derived fertiliser); D-ter® (proprietary repellent product including aluminium ammonium sulfate); Keep Off® (proprietary repellent product including methyl nonyl ketone); Tabasco Sauce(); and so on.

Many of the current sprays (e.g. Poss-Off®) use plant oils and others use dog urine components to prevent browsing. However, all of these approaches have the limitation that they are not very effective, unpleasant or unsafe to handle, not easily formulated, may be toxic to the physiology of the target pest animal and are/or very short lived.

It is desirable to overcome or ameliorate one or more of the above mentioned difficulties, or at least provide a useful alternative.

Summary of Invention In one aspect the invention provides a method of deterring a marsupial from browsing on plant material including the step of applying to said plant material or at a locality thereof an effective amount of a composition comprising pyrethrum or at least one pyrethroid.

As used herein "pyrethrum" refers to insecticidal extracts from the plant genus Chrysanthemum, including C. cinerariaefolium, C. balsamita and C. marshalli.

Some members of the Chrysanthemum genus such as Tanacetum Cinerariaefolium and C. coclineum are placed in the Tanacetum genus by some botanists. Both the Chrysanthemum genus and Tanacetum genus are members of the daisy (or aster) family, Asteraceae. It will be appreciated that the scope of "pyrethrum" as used herein includes all members which may provide insecticidal extracts. These insecticidal extracts are those which comprise quantities of pyrethrin (either pyrethrin I or pyrethrin II, but usually a combination of both). In typical extracts derived from C. cineariaefolium the ratio of pyrethrin I to pyrethrin II is about 52:48 (comprising about 76% of the extract), the remaining active being Cinerin I and Cinerin II in a ratio of about 1:1. It will be appreciated however that these ratios will vary depending on the species or plant material (e.g. seed cases, flowers, etc.) from which extraction takes place. Accordingly, "pyrethrum" refers to naturally deriving sources of pyrethrin (e.g. pyrethrins I and/or II) cinerins, and to a lesser extent the although the main active of such an extract will be understood to be pyrethrin.

In contrast, the term "pyrethroid" refers to synthetically or semi-synthetically derived pyrethrin and insecticidal analogues and derivatives of pyrethrin such as etofenprox, fenvalerate, esfenvalerate, fenpropathrin, cypermethrin, permethrin, cyhalothrin, deltamethrin, cycloprothrin, fluvalinate, bifenthrin, 2-methy1(4- bromodifluoromethoxyphenyl)proply 3-phenoxybenzyl ether, tralomethrin, silafluofen, d-phenothrin, cyphenothrin, d-resmethrin, acrinathrin, cyfluthrin, tefluthrin, transfluthrin, tetramethrin, allethrin, prallethrin, empenthrin, imiprothrin, d-furamethrin and 5-(2- propynyl)furfuryl 2,2,3,3-tetra methylcyclopropanecarboxylate.

Accordingly, the definition of "pyrethroid" as used herein includes synthetically or semi- synthetically derived pyrethrin I, pyrethrin II, Cinerin I or Cinerin II.

The composition may be a mixture of pyrethrum and at least one pyrethroid, a mixture of at least one pyrethroid, a single pyrethroid, or comprise a natural pyrethrum extract, as the sole deterrent active.

In another aspect, the present invention provides a method of deterring a marsupial from browsing on plant material including the step of applying to said plant material or at a locality thereof an effective amount of a composition comprising pyrethrum or at least one pyrethroid.

As used herein "browsing" includes the acts of eating, gnawing, sampling or in any other manner causing the destruction of plant material including roots, leaves, branches, flowers, stems and seeds. Browsing of the marsupial includes browsing living plant material as well as non-viable plant material such as leaf litter or discarded fruit.

As used herein the act of "deterring" includes being able to repel or discourage the target species from browsing on the plant material. In a further aspect the invention relates to the humane control of marsupial species in the protection of plant material which they would ordinarily browse on. As such the terms "humane" and "humanely" as used herein indicate that the methods described herein do not cause undue distress to the target marsupial's physiology. Signs of physiological stress which are to be avoided (or at least minimised) by the present method include excess vomiting, central nervous system disruption, haemorrhaging, long term sensory injury, prolonged discomfort, and death. 1-1Nicg Intcnvoven NRPoriblOCCAACG‘5598152_1.DOC-3/10/2013 - 4a - Brief Description of Figures Figure 1: Garden Applications: Moshio Camellia Japonica Moshio Camellia Japonica tested over two years, 2009 and 2010. After appearance of the new leaves in each season, one side of the camellia was sprayed with Spray 1 and the other side was unsprayed (control). For each condition, counts were taken of the proportion of leaves browsed in 5 sprayed and 5 unsprayed branches. Fig 1 A: Proportion of leaves browsed on each of 5 branches. Fig 1B: graphical representation of the mean proportion browsed ± S.D.

Figure 2: Fig 2A. Photographic representation of browsing damage to Moshio Camellia Japonica plant after exposure to both ringtail and brushtail possums. Black arrows indicate undamaged leaves, white arrows indicate damaged leaves. The branch was unsprayed in Spray 1 (no light green leaves 2009 (many dark leaves browsed) and sprayed in 2010 with browsed). The grey-dotted arrow points to ringtail possum damage in one leaf.

Fig 2B. This branch was sprayed in both 2009 and 2010 and shows no browsing in 2010 (light green leaves) and only a small amount (white arrow) in 2009 (dark leaves).

Figure 3: Lady Hillingdon Climbing Rose exposed to both ringtail and brustail possums. Fig 3A: Count of the proportion of browsed shoots in the spring and autumn, after pruning of new shoots, on a climbing rose. The upper part of the rose was unsprayed (control) and the bottom half was sprayed with Spray 1. Possums can readily browse on both the upper and lower half of the bush. For each condition counts were made of the proportion of browsed shoots. New shoots are red and readily distinguished from old leaves. Possums take off the upper 3-5 leaves, depending on how many have developed, of each new shoot and almost always take off most of each leaf leaving the uneaten stem behind. Fig 3B: The average proportion of two counts are shown for sprayed (spray 1) and unsprayed shoots.

Figure 4: Photographic representation of browsing damage to Lady Hillingdon Climbing Rose exposed to both ringtail and brustail possums. The large white arrow indicates the unsprayed control area, the large black arrow indicates the area sprayed with Spray 1.

Small white arrows indicate damaged shoots, small black arrows indicate undamaged shoots.

Figure 5: Wattle Leaves Acacia dialbata, Silver wattle. A. dialbata trees 150- 180 cm high. Fig 5A: Counts were made of browsed leaves (50-100% taken) in trees that were unsprayed (control) or sprayed with Spray 1 or Spray 2 and are shown as proportion of leaves browsed per tree. Counts were taken on days 5 and 10 after placing the trees in the possum cages in which brushtail possum density was very high and equivalent to 588 possums per hectare. All possums received their normal food provided to their nest boxes daily in addition to dried food and water ad lib. Because of the hot weather the sprinklers were turned on in the cages on day 7, washing away most of the spray causing the level of browsing to increase in the sprayed samples. Fig 5B: The figure shows mean proportion browsed + S.E. Arrow indicates date of sprinklers.

Figure 6: Wattle Stems Silver wattle. A. dialbata trees 150- 180 cm high. Fig 6A: Counts were Acacia dialbata, made of browsed stems by counting the number of times the trunk of each tree was bitten, Spray 1 or Spray 2. Counts were in trees that were unsprayed (control) or sprayed with taken on days 5 and 10 after placing the trees in the possum cages in which brushtail possum density was very high and equivalent to 588 possums per hectare. All possums received their normal food provided to their nest boxes daily in addition to dried food and water ad lib. Because of the hot weather the sprinklers were turned on in the cages on day 7, washing away most of the spray causing the level of browsing to increase in the sprayed samples. Fig 6B: The figure shows mean proportion browsed + S.E.

Figure 7: Photographic representation of wattle trees Acacia dialbata, Silver wattle exposed to brustail possums. A. dialbata trees 150- 180 cm high. Fig 7A: Wattle trees prior to exposure to possums. Fig 7B: Wattle tree after exposure to possums. White arrows indicate damaged leaves and stems.

Figure 8: Browsing Diagram Diagrammatic representation of the scoring of browsing damage of Acacia dialbata exposed to both ringtail and brustail possums. Fig 8A: Acacia dialbata, Silver wattle undamaged, Fig 8B: Acacia dialbata, Silver wattle damaged, Fig 8C: Moshio Camellia Japonica undamaged, Fig 8D: Moshio Camellia Japonica damaged. White arrows indicate damaged leaves.

Detailed Description of Preferred Embodiments of the Invention "Marsupials" as used herein refers to the subclass of mammals Marsupialia which are characterised by giving birth to undeveloped young and are to be contrasted with, for example, placental mammals (Placentalia). The present invention relates to methods for primarily deterring marsupials from the order diprotodontia (or the herbivorous marsupials).

In an embodiment the method relates to deterring marsupials from order Diprotodontia.

In an embodiment the marsupial from order Diprotodontia is from the family Phalangeridae (possums), Potoroidae (potoroos), Pseudocheiridae (ring tail possums, greater glider), or Macropodidae (kangaroos, wallabies and tree kangaroos).

In an embodiment the marsupial is a possum, preferably a brushtail or ringtail possum.

In an embodiment the pyrethrum or at least one pyrethroid is selected from a natural, synthetic or semi-synthetic compound.

In an embodiment the composition comprises naturally derived pyrethrin (i.e. either pyrethrin I or II, or mixtures thereof).

In an embodiment the composition comprises a mixture of natural pyrethrins extracted from Chrysanthemum cinerariaefolium.

In an embodiment the composition comprises at least one pyrethroid.

In an embodiment the at least one pyrethroid is selected from a compound of general formula (I): wherein R' is selected from optionally substituted alkenyl, substituted alkyl, optionally substituted heteroaryl, or optionally substituted heterocyclyl; and is selected from optionally substituted cycloalkenyl, optionally substituted cycloalkyl, optionally substituted alkyl, or optionally substituted aryl, or salts thereof.

In certain embodiments and with reference to formula (I): R' is a substituted alkenyl.

In a further embodiment R' is selected from: Br3C"" Cl \ ‘ZC \ LazC, H3 C Br 'lz — H3 Cia "( In an embodiment and with reference to formula (I), R 2 is selected from a substituted alkyl, substituted cycloalkenyl, or substituted heterocyclyl, preferably selected from: y' N X H3 C C CH3 CN H In another embodiment the at least one pyrethroid is selected from a compound of general formula (II): R4.0 wherein R3 is selected from hydrogen or cyano; and R4 _4alkyl)-NR 5R6 is selected from —C(0)-CH(C i (wherein R 5 is H and R6 is optionally substituted aryl), -C(0)-CH(C 1 _4alkyl)- optionally substituted aryl, and -CH2-C(CH 3)2- optionally substituted aryl, or salts thereof.

In certain embodiments and with reference to formula (II), R 4 is selected from: H3C CH3 Cl H 0 F C Cl In a further embodiment the at least one pyrethroid is selected from: synthetic or semi-synthetic pyrethrin I or pyrethrin II, cypermethrin, permethrin, bifenthrin, lambda-cyhalothrin, resmethrin, deltamethrin, tetramethrin, phenothrin, cyfluthrin, beta-cyfluthrin, tau-fluvalinate, esfenvalerate, gamma-cyhalothrin, prallethrin, fenpropathrin, D-allethrin, bioalletrin, tralomethrin, or combinations thereof.

In an embodiment the at least one pyrethroid is fluvalinate, preferably tau-fluvalinate.

In a further embodiment the at least one pyrethroid is cyfluthrin.

In a further embodiment the at least one pyrethroid is tetramethrin.

In a further embodiment the at least one pyrethroid is permethrin.

The term "alkyl" as used alone or in combination herein refers to a straight or branched alkyl" refers to such a group . 12 chain saturated hydrocarbon group. The term "C 1 alkyl" and "lower alkyl" 1 _6 containing from one to twelve carbon atoms and the terms "C refer to such groups containing from one to six carbon atoms, such as methyl ("Me"), ethyl ("Et"), n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl and the like.

The term "cycloalkyl" refers to non-aromatic, saturated cyclic groups. Examples include cyclopentyl and cyclohexyl.

The term "alkenyl" refers to a straight or branched hydrocarbon containing one or more double bonds, preferably one or two double bonds. The term "C2_12 alkenyl" refers to such a group containing from two to twelve carbon atoms. Examples of alkenyl include allyl, 1- methylvinyl, butenyl, iso-butenyl, 1, 3-butadienyl, 3-methylbutenyl, 1,3-butadienyl, 1,4- pentadienyl, 1-pentenyl, 1-hexenyl, 3-hexenyl, 1;3-hexadienyl, 1,4-hexadienyl and 1, 3, 5- hexatrienyl.

The term "cycloalkenyl" refers to non aromatic carbocycles having one or more double bonds. Examples include cyclopentenyl, 1-methyl-cyclopentenyl, cyclohexenyl, 1,3- cyclopentadienyl, 1,3-cyclohexadienyl and 1,4-cyclohexadienyl.

The term "aryl" refers to carbocyclic (non-heterocyclic) aromatic rings or ring systems.

The aromatic rings may be mono- or bi-cyclic ring systems. The aromatic rings or ring systems are generally composed of 5 to 10 carbon atoms. Examples of suitable aryl groups include but are not limited to phenyl, biphenyl, naphthyl, tetrahydronaphthyl, and the like.

Preferred aryl groups include phenyl, naphthyl, indenyl, azulenyl, fluorenyl or anthracenyl.

The term "heterocyclyl" refers to mono or bicyclic rings or ring systems that include one or more heteroatoms selected from N, S and 0. The rings or ring systems generally include 1 to 9 carbon atoms in addition to the heteroatom(s) and may be saturated or unsaturated.

In an embodiment the heterocyclic ring is selected from the group consisting of pyrrolidine, imidazoline, 2-imidazolidone, 2-pyrrolidone, pyrrolinone, tetrahydrofuran, 1,3-dioxolane, piperidine, tetrahydropyran, oxazoline, 1,3-dioxane, 1,4-piperazine, morpholine and thiomorpholine.

The term "heteroaryl" refers to aromatic heterocyclic ring systems. Heteroaryl rings include furyl, thienyl, pyridyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,4-oxadiazolone, 1,2,3- triazolyl, 1,3,4-thiadiazolyl, pyridazinyl, pyrimidinyl, pyrazinyl, 1,3,5-triazinyl, 1H thieno[2,3-c]pyrazolyl, thieno[2,3-b]furyl, indolizinyl, indolyl, isoindolyl, 3H-indolyl, indolinyl, benzo[b]furanyl, benzo[b]thiophenyl, 1H-indazolyl, benzimidazolyl, tetrazolyl, uridinyl, and cytosinyl.

Heteroaryl groups may preferably be selected from isoxazolyl, oxazolyl, imidazolyl, thiazolyl, thiadiazolyl, isothiazolyl, furazanyl, triazolyl, pyridyl, pyrimidinyl, furyl, pyrazolyl, pyridazinyl, thienyl and aryl fused heteroaromatic rings such as benzfuranyl, benzothiophenyl and benzoisoxazolyl.

The term "optionally substituted" means that a group may include one or more substituents. One or more hydrogen atoms on the group may be replaced by substituent groups independently selected from halogens, C 1 .6 alkyl, C2_6 alkenyl, C2_6 alkynyl, -(CH2)pC3 _7 cycloalkyl, -(CH cycloalkenyl, -(CH 2)p aryl, -(CH 2)pC4 _7 2)p heterocyclyl, -C6H4S(0)qC 1 _6 alkyl, —C(Ph)3, -CN, -OR, (CH2)1_6-R, (CH 2) 1 .6-0R, -0C(0)R, - C(0)R, -C(0)OR, -OC(0)NR'R", —NR IR", -NRC(0)R', -NRC(0)NR'R", -NRC(S)NR'R", -NRS(0) 2 R', -NRC(0)OR', -C(NR)NR'R", -C(=NOR')R, -C(=NOH)NR'R", -C(0)NR'R", -C(=NCN)-NR'R", -C(=NR)NR'R", -C(=NR')SR", -NR'C(=NCN)SR", -CONRSO2R', -C(S)NR'R", -S(0),A, -SO NR'R", -SO 2 2NRC(0)R', -0S(0) 2R, -PO(OR) 2 and -NO2; where p is 0-6, q is 0-2 and each R, R' and R" is independently selected from H, C1-6 alkyl, C2_6 cycloalkyl, alkenyl, C2-6 alkynyl, C3-7 C4_7 cycloalkenyl, aryl, heterocyclyl, C1-6 alkylaryl and C1_6 alkylheterocyclyl, wherein the alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, heterocyclyl, C1_6 alkylaryl or Cl..6 alkylheterocyclyl, may be optionally substituted with one to six of same or different groups selected from halogen, hydroxy, 2 and NO ; or when R' and R" are lower alkyl, lower alkoxy, -0O 211, CF3, CN, phenyl, NH 2 attached to the same nitrogen atom, they may, together with the atom to which they are attached, form a 5 to 7 membered nitrogen containing heterocyclic ring.

Unless otherwise defined and only in respect of the ring atoms of non-aromatic carbocyclic or heterocyclic compounds, the ring atoms of such compounds may also be optionally substituted with one or two =0 groups, instead of or in addition to the above described optional substituents.

When the optional substituent is or contains an alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl or heterocyclyl group, the group may itself be optionally substituted with one to six of the same or different halogen atoms, hydroxy, lower alkyl, lower alkoxy, alkyl (including -CF ), phenyl, benzyl, -CN, -C(0)C 1 . 6 alkyl, mercapto, -NH2, halo-C 1 _6 3 mono or di (lower alkyl) amino or -NO2. alkyl, alkynyl, Examples of optional substituents include halogens, C 1 .6 C2.6 alkenyl, C2..6 C1.6 haloalkyl (in particular -CF 3), C 1 _6 haloalkoxy (such as -OCF 3), -OH, phenyl, benzyl, alkyl, -N(C phenoxy, benzyloxy, benzoyl, -NH 2 1-4 1 .4 alkyl)2, -CN, -NO 2, mercapto, , -NHC C 1 _6 alkylcarbonyl, C l ..6 alkoxycarbonyl and CO2H.

It will be appreciated from the compounds of formula (I) and (II) that the pyrethrin and pyrethroid compounds may have at least one asymmetric centre, and therefore are capable of existing in more than one stereoisomeric form. The invention extends to each of these forms individually and to mixtures thereof, including racemates. The isomers may be separated conventionally by chromatographic methods or using a resolving agent.

Alternatively the individual isomers may be prepared by asymmetric synthesis using chiral intermediates. Where the compound has at least one carbon-carbon double bond, it may occur in Z- and E- forms with all isomeric forms of the compounds being included in the present invention.

In another aspect the present invention provides a marsupial repellant composition comprising an effective amount of pyrethrum or at least one pyrethroid, and a suitable carrier or diluent therefor. In an embodiment the composition is an aqueous composition wherein the amount of pyrethrum or at least one pyrethroid is from about 10 — 0.1g of active per L (for instance 0.2g — 0.6g of active per L) of the total composition. In an embodiment the composition also includes diatomaceous earth, preferably at a concentration of about 0.1 g — 1.0g per L of the total composition, for instance about 0.1 g, about 0.2g, about 0.3g, about 0.4g, about 0.5g, about 0.6g, about 0.7g, about 0.8g, about 0.9g or about 1.0g.

The compositions can be chosen from a number of formulation types, including soluble concentrates, oil miscible liquids, ultra low volume liquids, emulsifiable concentrates, dispersible concentrates, emulsions (both oil in water and water in oil), micro-emulsions, suspension concentrates, as well as aerosols and sprays of the above. The formulation type chosen will depend upon the particular purpose required. It will also be appreciated that pyrethrins and pyrethroids exhibit little or no solubility in water which will thus govern the formulation chemistry.

Dispersible concentrates may be prepared by dissolving or suspending a pyrethroid compound or extract of the present invention in water or an organic solvent, such as a ketone, alcohol or glycol ether. The suspensions may contain a surface active agent (for example to improve water dilution or prevent crystallisation in a spraying apparatus or aerosol chamber).

Emulsifiable concentrates or oil-in-water emulsions may be prepared by dissolving a pyrethroid compound or pyrethrum extract in an organic solvent (optionally containing one or more wetting agents, one or more emulsifying agents or a mixture of said agents).

Suitable organic solvents include aromatic hydrocarbons (such as alkylbenzenes or alkylnaphthalenes), ketones (such as cyclohexanone or methylcyclohexanone) and alcohols (such as benzyl alcohol, furfuryl alcohol or butanol), N-alkylpyrrolidones (such as N- methylpyrrolidone or N-octylpyrrolidone), dimethyl amides of fatty acids (such as C8-C10 fatty acid dimethylamide) and chlorinated hydrocarbons. Preparation of an oil-in-water emulsion involves obtaining the active in solution (by dissolving it in an appropriate solvent) and then emulsifiying the resultant liquid or solution into water containing one or more surface active agents, under high shear, to produce an emulsion. Suitable solvents include vegetable oils, chlorinated hydrocarbons (such as chlorobenzenes), aromatic solvents (such as alkylbenzenes or alkylnaphthalenes) and other appropriate organic solvents which have a low solubility in water.

Microemulsions may be prepared by mixing water with a blend of one or more solvents with one or more surface active agents, to produce spontaneously a thermodynamically stable isotropic liquid formulation. Suitable solvents include those hereinbefore described for use in emulsifiable concentrated or oil-in-water emulsions. A microemulsion may be either an oil-in-water or a water-in-oil system (determined by conductivity measurements) and may be suitable for mixing water-soluble and oil-soluble components in the same composition. A microemulsion is suitable for dilution into water, either remaining as a microemulsion or forming a conventional oil-in-water emulsion.

Suspension concentrates may comprise aqueous or non-aqueous suspensions of finely divided insoluble solid particles of the active of the present invention. Suspension concentrates may be prepared by milling a solid active compound in a suitable medium, optionally with a dispersing agent, to produce a fine particle suspension of the active. One or more wetting agents may be included in the composition and a suspending agent may be included to reduce the rate at which the particles settle. Alternatively, the active compound may be dry milled and added to water, containing agents hereinbefore described, to produce a suitable composition.

Aerosol suitable compositions may comprise the formulated active together with a suitable propellant (for example n-butane). The active may also be dissolved or dispersed in a suitable medium (for example a water miscible liquid, such as n-propanol) to provide compositions for use in non-pressurised, spray pumps (e.g. hand-activated or trigger pumps). In a preferred embodiment the composition is formulated for spray application.

The composition may preferably include one or more additives to improve the performance of the composition (for example by improving wetting, retention or distribution on surfaces such as leaves; or resistance to rain on treated surfaces such as leaves). Such additives include surface active agents, spray additives based on oils, for example certain mineral oils (such as "white oil" — petroleum distillate) or natural plant oils (such as soy bean and rape seed oil), and blends of these with other bio-enhancing adjuvants (ingredients which may aid or modify the action of the pyrethroid or pyrethrum active). A particular preferred additive is an absorbent such as diatomaceous earth (diatomite), which is able to maintain the composition on the waxy cuticle of leaves for prolonged periods. As a further advantage the composition may be formulated to have long persistence or residence time to deter browsing over long periods or even during periods of high rainfall where other compositions would be less effective. Other such absorbents based on silica may be used to similar effect.

Wetting agents, dispersing agents and emulsifying agents may be surface active agents of the cationic, anionic, amphoteric or non-ionic type (e.g. surfactants) including quaternary ammonium compounds (for example cetyltrimethyl ammonium bromide), imidazolines and amine salts.

Suitable suspending agents include hydrophilic colloids (such as polysaccharides, polyvinylpyrrolidone or sodium carboxymethylcellulose) and swelling clays (such as montmorillonite, bentonite, or attapulgite).

The amount of active included within 'a composition will vary depending on the formulation and suited purpose. Where a naturally derived pyrtherin extract is used it is preferably included in the composition from 10-0.1 g/L, preferably 5-0.1 g/L and even more preferably 2-0.1 g/L or most preferably 1-0.1 g/L such as, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3 or 0.2 g/L (made up as an aqueous formulation).

A composition of the invention may be applied by any of the known means of applying pesticidal formulations protecting plant material. For example, it may be applied directly to the growing plant liable to browsing by the pest marsupial, such as to any part of the plant, including the leaves, stems, flowers, branches or roots. The composition of the present invention may also be applied to the locality of the plant material. In relation to this latter application, the present invention could be used to deter marsupial species from rummaging in rubbish or trash bins searching for discarded plant material by applying the composition to, for instance, the bin lid or sides. Accordingly, the application of deterring browsing includes both direct and indirect methods.

The plant material which may be protected by the present invention includes native and non-native garden plants such as ornamental plants, flowers, trees and shrubs as well as commercial crops, for instance, market garden vegetables, fruits, grain crops, etc. It will be appreciated that in some instances where the plant material is grown in groups such as fields and orchards, it may only be necessary to apply the composition to the most outer plants (or locality) of the crop or orchard in order to deter the marsupial from browsing on the entire crop or orchard.

In one embodiment the plant material is an ornamental plant, flower, tree, or shrub.

The pyrethroids and pyrethrum extracts described above may be the sole active ingredient of the composition or may be admixed with one or more additional active ingredients such as a pesticide, fungicide, synergist, herbicide or plant growth regulator where appropriate.

An additional active ingredient may: (i) provide a composition having a broader spectrum of activity or increased persistence; (ii) synergise the activity or complement the activity (for example by increasing the speed of effect or overcoming repellency); or (iii) help to overcome or prevent the development of resistance or tolerance to individual components.

The particular additional active ingredient will depend upon the intended utility of the composition. For instance, the composition may be formulated as a duel acting composition, e.g. plant fungicide and marsupial deterrent (or repellent), or plant insecticide and marsupial deterrent (or repellent).

Examples of suitable insecticide synergists for use in the compositions of the present invention include piperonyl butoxide (PBO), sesamex, safroxan and dodecyl imidazole.

In a preferred embodiment the composition comprises naturally derived pyrethrum and PBO.

In a further preferred embodiment the composition comprises naturally derived pyrethrum, PBO and diatomaceous earth.

In still a further preferred embodiment the composition is aqueous based comprising naturally derived pyrethrum, PBO, diatomaceous earth and white oil (including petroleum oil).

Naturally occurring pyrethrin containing pyrethrum extracts are known to be susceptible to UV-light degradation and oxidation which reduces the pyrethrin's efficiency over time.

Accordingly for a present composition based on a naturally occurring pyrethrum extract, it is preferred that the composition include UV stabilisers and/or antioxidants such as hydroquinone, butylated hydroxytoluene (BHT), pyrocatecol, pyrogallol, benzene napthol, silicone stabilisers, or polymer stabilisers (e.g. polyvinyl pyrrollidone).

The present invention will now be described by way of the following non-limiting Examples.

Examples Example 1 A sprayable formulation was developed using naturally derived pyrethrin (from a pyrethrum extract) in white oil (petroleum oil (distillate) + emulsifier) to provide longer coverage.

Marsupial browsing and grazing deterrent spray Spray 1: Petroleum oil 20 g/L+ Piperonyl butoxide (PBO) 1.6g/L+ pyrethrin 0.4 g/L, made up in filtered cold water Spray 2: Petroleum oil 20 g/L+Piperonyl butoxide 1.6g/L+ pyrethrin 0.4 g/L+ Diatomaceous earth 0.25 g/L, made up in filtered cold water Effective dose ranges for each of the various components of both sprays : Petroleum oil:- 10- 25 g/L+ Piperonyl butoxide +1- 3g/L; pyrethrin: 0.2-0.6 g/L Add for spray 2 0.1-1.0 g/L Diatomaceous earth, Absorbacide from Mount Sylvia Diatomite mtsylviadiatomite.com.au . Pyrethrum extract (pyrethrins) 80 g/L with PBO 480 g/L available from Pestech Australia Pty Ltd Queensland (as the product described: "Py- Bo").

Moshio Camellia Japonica- Family Theaceae or tea family experiment The 2009 leaves are a darker green than the 2010 leaves and can be readily distinguished if spraying is done soon after appearance of the new leaves. The plants were exposed to free- ranging ringtail and brushtail possums. Only leaves that were present were counted and leaf nodes without a leaf were not counted in case some leaves had fallen due to drought conditions in 2009. The leaves that were browsed by brushtail possums had the classic appearance of browsed single leaves as illustrated in Veltman (2000) and shown in attached figures, namely the possum bite takes the distal half or two thirds of the leaf and the central vein is cleanly bitten through. Insect damage which was rare on this camellia tends to only take the most distal tip (<one eighth) or occasionally the edge, does not include the central vein and is smaller than the multiple bites of the ringtail possum, which may or may not include the central vein and leaves an irregular surface.

Veltman C. (2000) Do native wildlife benefit from possum control. In "The Brushtail Possum" TL Montague (Ed). pp 241-250. Manaaka Whenua Landcare, Lincoln, New Zealand Press The spray was tested on three families of marsupials, Phalangeridae (possums), Pseudocheiridae (ringtail possums) and Dasyuridae (dunnarts and antechinuses).

Because these are very different groups it would be reasonable to extend the effect to all marsupials including both polyprotodonts and diprotodonts.

A list of plant species/families on which the spray was used included: Theaceae- Gordonia, Camellias Rutaceae All Citrus,: lemon, limes , mandarins, Rosacea (roses, crab apples) Mimosa (Acacias) Magnoliacae: Magnolias Rubiacae: Gardenias The sprayed deterrent exhibits an effect that lasts for at least a month, with respraying required if exposed to water (rain) or after 1 month.

Siver wattle Experiment Acacia dealbata, Acacia dealbata (Family Fabaceae (= Leguninaceae), Sub family Mimosa). plants, either unsprayed, or sprayed with spray 1 or 2, were exposed to Acacia dealbata brushtail possums. The number of leaves with greater than 50% damage were counted for each group at day 5 and day 10 only (2 data points per sample). Between the two counts (day 7), the possum cages were extensively exposed to water (sprayed into the cages to keep the possums cool during summer). This likely washed off the spray, leading to possums eating the leaves and stems. This demonstrates firstly that the spray is effective, but also that it is not toxic to the possums (no deleterious/behavioural changes were observed in the possums after eating the sprayed (and washed) leaves).

Common Brushtail Possums were held in large outdoor colony with food and nest sites, maintained in excess. The possum numbers per hectare in the colony was equivalent to 588 CBT Possums/ha which is equivalent to forty two (42) times the density in urban parks (14 possums/hectare) and 118 times the density of possums in suburban gardens.

Possums had access to 1-2 metres high Acacia dialbata (Silver wattle) in 6 inch pots„ over a period of 10 days. Browsing observations were made on day 5 and day 10. Due to extreme heat during the experiment, hoses were turned on to cool the possum boxes on day 7. This was equivalent to very heavy rainfall.

Plants: 5 control plants were unsprayed, 5 plants were sprayed with Spray 1 and 5 plants sprayed with spray 2. The proportion of leaves browsed by >50% was estimated and stem browsing quantified.

Each leaf is bipinnate, 1-12 cm (occasionally to 17 cm) long and 1-11 cm broad, with 6- pairs of pinnae, each pinna divided into 10-68 pairs of leaflets; the leaflets are 0.7- 6 mm long and 0.4-1 mm broad. For counting in older leaves, the leaf was counted as being browsed if the distal half of the leaf was eaten. In new shoots, all the leaf and frequently part of the stem was taken.

Example 2 Spray 1 No pyrethrum or diatomaceous earth Spray 2 pyrethrum (pyrethrin) without diatomaceous earth Spray 3 pyrethrum (pyrethrin) with diatomaceous earth Table 1. Recovery Experiments after heavy browsing on roses in areas with very high brushtail and ringtail possum density during 7 weeks, when spray renewed after 20 mm rainfall. Total rainfall in the period was 118mm.

Spray Initial Final Browsing % reduction %average browsing % % browsing 84 65 46 59 2 83 31 63 40 79 19 76 Table 2. Recovery Experiments after heavy browsing on weeping figs in areas with very high ringtail and brushtail possum density during 7 weeks. Spray renewed after mm rainfall. Total rainfall in the period was 118mm.

Spray Initial Final Browsing % reduction %average browsing % % browsing 2 86 37 57 31 3 79 29 63 30 Table 3. Prevention experiments on roses before major browsing commenced in areas with moderate ringtail and brushtail possum density during 7 weeks. Spray renewed after 20mm rainfall. Total rainfall in the period was 118mm.

Spray Initial Final Browsing average %Increase % browsing % % browsing 1 0 26 - 2 5 8 60 14 100 7 Protection from browsing in areas with moderate to high densities of possums.

Protection from browsing when plants have little or no browsing commenced.

Browsing tends to increase after heavy rainfall overnight (>20mm overnight- 6PM- 9.00 AM) 50 mm over 1 month in smaller units, and without heavy rainfall ON does not appear to affect spray deterrent quality Roses — See summary tables and figure. Protection of roses that are very little browsed:- Unsprayed roses have the highest browsing averaging 46-59 % browsed Roses sprayed with Spray 2 (pyrethrum) have noticeable protection Roses sprayed with Spray 3(pyrethrum + DE) provides better protection .

Camellia magnolia flora, protection following very little browsing:- Unsprayed camellias have the highest browsing 25-73% browsed.

Spray 3 is very effective- less than 5% browsing Magnolia, protection following very little browsing:- Unsprayed magnolia have the highest browsing. By two weeks 95-99% browsed.

Spray 3 is very effective- less than 5% browsing Recovery from heavy browsing before the trial began Area of very great possum density, both ringtails and brushtails.

Recovery is possible. The rate does vary from group to group and the intensity of browsing. The work was done in areas in which possum densities are very high (Equivalent to the densities encountered in public parks).

Both brushtail and ringtail possums are found in these locations and were observed.

Roses Reduction of browsing following heavy browsing:- Extremely heavy rainfall (60 mm between 4.00 pm and 9.00 AM) and subsequent rainfall reduced browsing in all categories.

In the absence of spraying, browsing maintained between 48 and 67% After recovery from heavy rainfall and respraying:- All sprays reduced browsing. Spray 3 ( 19-32% browsed) was most effective.

Weeping Figs reduction of browsing following heavy browsing:- Extremely heavy rainfall (60 mm between 4.00 pm and 9.00 AM) and subsequent rainfall reduced browsing in all categories.

All sprays performed at a similar level.

Browsing reduced during very heavy rainfall and respraying.

Many modifications will be apparent to those skilled in the art without departing from the scope of the present invention.

Throughout this specification, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that the prior art forms part of the common general knowledge in Australia.

Claims (9)

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A method of deterring a marsupial from browsing on plant material including the step of applying to said plant material or at a locality thereof an effective amount of a 5 composition comprising pyrethrum or at least one pyrethroid.

A method according to claim 1 including the step of applying the composition directly to said plant material.

A method according to claim 1 or claim 2 wherein the composition comprises 10 3. naturally derived pyrethrin.

A method according to any one of claims 1 to 3 wherein the marsupial is a possum.

A method according to claim 4 wherein the possum is a brushtail possum or ringtail 15 5. possum.

A method according to any one of claims 1 to 5 wherein the composition is an aqueous composition comprising pyrethrum and piperonyl butoxide (PBO).

A method according to any one of claims 1 to 5 wherein the composition is an aqueous composition comprising pyrethrum and Diatomaceous Earth.

8. A method according to any one of claims 1 to 5 wherein the composition is an 25 aqueous composition comprising pyrethrum and petroleum oil.

9. A method according to any one of claims 6 to 8 wherein pyrethrum in the composition is from about 10 — 0.1g/L.