AU657547B2

AU657547B2 - Insecticidal bait composition

Info

Publication number: AU657547B2
Application number: AU18651/92A
Authority: AU
Inventors: Rosemarie Raff
Original assignee: R&C Products Pty Ltd
Current assignee: Reckitt Benckiser Australia Pty Ltd
Priority date: 1984-12-10
Filing date: 1992-06-26
Publication date: 1995-03-16
Anticipated expiration: 2005-12-06
Also published as: AU1865192A

Description

657547

AUSTRALIA

Patents Act 1990 R C PRODUCTS PTY LTD

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT 0

V

0 0 Invention Title: Insecticidal Bait Composition The following statement is a full description of this invention including the best method of performing it known to us:- 2 The present invention relates to insecticidal bait compositions.

Insecticidal bait compositions are materials that will be eaten by insects of at least one species and will either directly kill the insects, affect the fecundity of the insects so that the insect population is reduced in the next generation or alter the behaviour of the insects in a manner that will bring about their destruction.

Normally the bait composition is formulated so that not only will the insects eat the bait but they are positively attracted to it. Conventional baits have included an active insecticidal compound and a food material. Those formulated for cockroaches, ants and like household crawling insects have generally been of a dry nature being 15 formed by compressing the ingredients into a biscuit like tablet or similar. Such a bait tablet is usually contained in a bait housing generally designed so that an insect is able to contact and consume some of the bait when it enters the housing, whilst the bait is inaccessible to childen and domestic pets. These biscuit like bait tablets suffer from the problem that they generally have a crumbly consistency particularly as they age. This means 'that the tablet can break up in the housing and crutnbs of poisonous material may fall from the 25 housing if it is handled.

In patent application PCT/US85/00405 (W085/04074), there is disclosed a bait composition in which an insect-controlling material is dispersed in a gelatinized starch matrix. The composition may be formed by dry blending starch and the insect controlling material, cooking and extruding the gel into a suitable package.

Alternatively, pregelatized starch may be cold blended with water and the insect controlling material until a gel is formed which is then filled into a suitable 1c package. The compositions of this invention overcome the 3 difficulty in the prior art where bait tablets had a tendency to break up and fall out of a housing.

The present invention seeks to provide an alternative to the composition disclosed in PCT/US85/00405.

In contrast to the compositions disclosed in PCT/US85/00405 which are gels, the compositions of the present invention are able to be readily filled into a bait housing by virtue of their flowability. When filled into a bait containing cavity of a bait housing, the composition solidifies to produce a substantially non-crumbling bait.

This offers considerable economic advantages in the manufacture of the bait and housing combination.

The present invention consists in an insecticidal composition comprising: 15 from 0.01 to 30% by weight of an insecticidal *composition active against at least one species of insect; from 0 to 80% by weight of a food ingredient selected from the group comprising lipids, carbohydrates, proteins, essential oils, water, spices and mixtures S: 20 thereof; and fromlY to 95% by weight of a material selected from the group consisting of fats and mixtures of fats and oils, and edible by at least the said species of insect, that enables the bait composition to be made flowable when heated, but when said composition is filled into a container S.and allowed to cool, will cause the composition to solidify therein to be substantially non-crumbling in character.

The bait composition is preferably formulated to be attractive to cockroaches or ants, however, it could alternatively be formulated to be attractive to other insect species which will eat solid materials.

The term "insecticidal composition" is used herein to mean any chemical composition which will, when consumed by insects of at least one species, reduce the population of that insect species at least by the next generation of such insects of which will affect the behaviour of an 4 insect species either at a distance or when eaten. The insecticidal composition may poison and kill the insect which consumes it or it may affect the fecundity of the insect by sterilising it by causing a mutation of its gametes, or by hormonally affecting growth regulation in the next generation. Preferably the insecticidal composition is selected from the group comprising:- Synthetic pyrethroids e.g. Deltamethrin; Organophosphates e.g. Chlorpyrifos; Carbamates e.g. Propoxur or Bendiocarb: Abrasive powders e.g. boric acid, borax, or silicates; Hydrazones; Pheromones; Insect growth regulators.

15 These active compounds may be used alone or in •combination.

A material is used to cause the insecticidal bait composition to be made flowable. The term "flowable" in the context of this specification means that the insecticidal bait composition is able to be filled into a container using positive displacement filling equipment.

The material used to impart flowability and to solidify the bait composition may be a material having a suitable melting point so that it may be hot filled into a 25 container and then solidifies on cooling or it may e comprise a solution or dispersion of a setting agent. The preferred system for use in the present invention is to use from 25 to 95% by weight of a fat or a mixture of a S'fat.and an oilwitkfhe fat preferably' ae a melting point above 35 0 C, more preferably between 55 and 61oC.

Suitable fats include a range of fully hydrogenated fatty acids and preferably fully hydrogenated peanut oil. This material is readily available at an acceptable price and has a relatively sharp melting point towards the upper end of the preferred range. The fat may be mixed with an oil 5 such as soy bean oil which acts as an attractant for roaches. The oil should not be present in an amount which will lower the point at which the bait composition will flow below 400C and preferably not below 550C.

In another embodiment of the invention, the material used to impart flowability and to solidify the bait composition is preferably aqueous based and comprises a thixotropic setting material or a gelling agent. These are preferably selected from the group:a) clays, e.g. bentonite, b) gums and derivatives which cause gelling e.g.

carboxymethylcellulose, hydroxymethyl cellulose, guar gum, carageenan and the like, c) acrylic polymers, d) cetyl alcohol and stearyl alcohol, e) alkanol-amines, f) modified castor oil, g) high molecular weight polyethylene glycols, h) nonionic surfactants such as Teric 12A29 and 12A50.

(Teric is a trade mark of ICI).

In these cases the insecticidal composition may require to be present in the bait in an emulsified form.

It should also be noted that it is desirable that this material is not only edible by the insects but also acts 25 as a positive inducement to eat the bait.

The food ingredients most preferably comprise short chain polysaccharides such as starches such as are present in flours particularly cornflour. Many other food ingredients could however be present in the composition.

These other foodstuffs may be fatty or may be carbohydrates with or without proteinaceous materials.

Among the fatty materials, and in addition to the fats and oils described earlier, may be mentioned triglyceride esters, waxes, soaps, phospholipids such as lecithin, Sglycolipids, terpenes and steroids. Among the 6 carbohydrate and protein materials may be mentioned cereal products such as flour, bran and wheatgerm; vegetable products such as potato flour, and dehydrated vegetables; sugars, starches and complex carbohydrates including monosaccharides and cellulosic materials; and other food ingredients such as dried yeast and egg powder.

It will be recognised that some materials e.g. the fats may be used as either or both of the material used to impart flowability and to solidify the bait composition and as a food ingredient.

The bait composition in addition to the above food items, which may themselves be attractants to insects, preferably includes, e.g. from 0.01% to 5% by weight, materials which are present principally as attractants for 15 the species of insect being baited. These attractants are o. preferably selected from the group comprising: a) pheromones, b) yeast extracts, c) complex foods, and d) volatile materials such as flavour essences and food derivatives such as fenugreek, herbs and spices.

It is desirable that the bait composition should include preservatives, since growth of microorganisms on the composition may function to repel the insects. Among 25 the preferred preservatives may be mentioned:- Dowicil 200 (cis isomer of l-(3-chloroallyl)-3,5,7triaza-l-azoniaadanantane chloride) (registered trade mark of Dow-Corning) quaternary ammonium compounds c) methyl and propyl parahydroxybenzoate, d) metal salts such as copper sulphate, e) ortho phenyl phenol, and f) buffered sorbate systems.

Hereinafter given by way of example only is a preferred embodiment of the present invention. This 7 embodiment functions as an insecticidal bait composition for cockroaches.

EXAMPLE 1 Bait ingredient W/W Chlorpyrifos (insecticidal composition) 0.8 Fully hydrogenated peanut oil 55.0 Soy bean oil 18.0 Cornflour 25.0 Fenugreek Potassium sorbate 0.15 Sorbic acid 0.05 In this formulation, potassium sorbate/sorbic acid act as the preservative system, fenugreek is an attractant 15 whilst cornflour functions as a food ingredient. The combination of hydrogenated peanut oil and soy bean oil serve to define the temperature at which the composition •is solid and the range of temperatures over which the composition is flowable. Soy bean oil also acts as an attractant. The bait composition is prepared as follows: *The chlorpyrifos is dissolved in the soy bean oil and added, together with the other ingredients, to the hydrogenated peanut oil which has been heated to a *temperature above its melting point. The liquid *25 composition is poured into suitable containers while being stirred to maintain the non-soluble ingredients in :suspension. The bait composition rapidly sets to a non-crumbly material which is both attractive to roaches and is effective in killing them.

In order to demonstrate the relatively low susceptibility of an embodiment of the present invention towards crumbling and shedding of particles, the friability of a sample of 10 tablets was determined using an Erweka TAR friability testing machine at a speed of 30rpm. The results are shown in Table 1.

8 Table 1 No. of revolutions of Weight of tablets Weight Loss machine (gram) 0 21.7 0 150 21.5 0.9 300 21.3 1.8 450 20.4 600 '20.3 The trial was repeated where the embodiment had been filled into a typical housing (described in our provisional patent application PG 8493). In this case it was found that after 300 revolutions, there was nio loss in weight. Although these trials were not designed to necessarily simulate crumbling that might occur in normal 0. 0: 15 use, it was expected that the conditions of these trials were more stringent.

A further trial was conducted to compare the friability of an embodiment of the present invention with an example of a prior art bait tablet of the kind previously described. In this trial, samples were placed in a 500ml stoppered measuring cylinder and the cylinder inverted through 180 degrees for a number of times. The results obtained are shown in Table 2.

Table 2 2 Prior Art Bait Tablet No. of inversions Weight Weight Loss (gram) 0 38.5 100 36.0 200 34.8 9.6 300 33.0 14.3 400 31.6 17.0 500 29.8 22.6 9 Embodiment of the present invention 0 38.7 0 100 35.8 200 35.8 300 34.9 9.8 400 34.8 10.0 500 34.8 10.0 These results show that compositions of the present invention have a much reduced tendency to crumble when compared with the prior art bait tablet.

S S

Claims

1. A method of forming an insecticidal bait composition which includes the components: from 0.01 to 30% by weight of an insecticidal composition active against at least one species of insect; from 0 to 80% by weight of a food ingredient selected from the group comprising lipids, carbohydrates, proteins, essential oils, water, spices and mixtures thereof; and from 25 to 95% by weight of a material selected from the group consisting of fats and mixtures of fats and oils, and edible by at least the said species of insect, comprising mixing the components, heating the mixture so as to make it flowable, as hereinbefore defined, filling the 15 flowable mixture into a container and cooling the mixture to form a solid, substantially non-crumbling insecticidal bait "composition.

2. A method as claimed in claim 1 wherein the bait composition includes a preservative. 20

3. A method as claimed in claim 1 or claim 2 wherein the material is heated to at least 40°C to make the mixture flowable. eo

4. A method as claimed in claim 3, wherein the mixture is heated to a temperature of at least 550C. 25

5. A method as claimed in any one of claims 1 to 4, wherein the bait composition includes an insect attractant.

6. A method as in claim 5 wherein the attractant is fenugreek.

7. A method as claimed in any one of claims 1 to 6, wherein the material is additionally the food ingredient.

8. A method as in any one of claims 1 to 7 wherein the carbohydrate is a sugar. 0. 1 11

9. A method substantially as hereinbefore defined with reference to example 1. DATED this 30th day of December 1994 R C PRODUCTS PTY LIMITED Patent Attorneys for the Applicant: F.B. RICE CO. 9 9. *99**9 0 *9 9 9 9 9 9* tt .9.99* 9 9 9999 9 9 9999 99** C ~AL~*1 'Q~NT 0/ t 0 ABSTRACT An insecticidal bait composition which is particularly suitable for the control of cockroaches is disclosed. The composition comprises: from 0.01 to 30% by weight of an insecticidal composition active against at least one species of insect; from 0 to 80% by weight of a food ingredient selected from the group comprising lipids, carbohydrates, proteins, essential oils, water, spices and mixtures thereof; and S'o from 1 to 95% by weight of a material selected from the group consisting of fats and mixtures of fats and oils, and edible by at least the said species of insect, e that enables the bait composition to be made flowable when heated, but when said composition is filled into a container and allowed to cool, will cause the composition to solidify therein to be substantially non-crumbling in character. O 0*