GB2184020A

GB2184020A - Rodenticidal bait

Info

Publication number: GB2184020A
Application number: GB08629734A
Authority: GB
Inventors: Georges Bonjour; Xavier Marze
Original assignee: RHODIC SA
Current assignee: RHODIC SA
Priority date: 1985-12-12
Filing date: 1986-12-12
Publication date: 1987-06-17
Also published as: CH670547A5; LU86712A1; IT8622645A0; GB8629734D0; DE3641195A1; BE905902A; NL8603020A; ES2002931A6; IT1199772B; GB2184020B; IT8622645A1

Abstract

An improved rodenticidal bait comprises a rodenticide and a synthetic pear flavour, optionally together with an edible carrier. The flavour is defined as a composition which gives to foodstuffs the taste and fragrance of pears but is not derived from pears. The bait overcomes the natural distrust of rodents.

Description

SPECIFICATION Rodenticidal Bait The invention relates to a new rodenticidal bait.

The control of rodents by the use of rodenticides, which are compounds which have toxic properties towards rodents is known. Therefore, they need not be described in detail here. Such a bait most commonly consists of an edible carrier mixed with a rodenticidally active substance. Depending on the nature of the carrier, the rodenticide can be added by impregnation or by coating.

As is known, rodents, especially rats, mice and field-mice, are very distrustful. Thus they can very quickly recognise a rodenticidal product which, therefore, then becomes totally ineffective, as it is not consumed.

The present invention is intended to alleviate these drawbacks and provides an improved rodenticidal bait which overcomes the distrust of rodents, especially rats, mice and field-mice, and which is therefore more effective than the products marketed until now.

The present invention accordingly provides a rodenticidal bait which comprises a rodenticide and a synthetic pear flavour. The bait generally also comprises an edible carrier, although liquid carriers can also be used.

The invention thus comprises adding a synthetic pearflavourto a known rodenticidal bait, in order to conquer the natural distrust of the rodents towards this bait.

It could not have been expected that the simple addition of a specific flavour, namely the synthetic pear flavour, among all known adjuvants, would enable the very deep-seated distrust of the rodents to be overcome and conquered effectively.

As is known, the flavour of an edible product is a compound which gives it its taste and its fragrance.

The natural compound may either be reconstituted (artificial flavour), or reproduced by synthesis (synthetic flavour).

The term "synthetic pear flavour" as used in this specification and claims refers to a composition which gives to foodstuffs the taste and the fragrance of pears but is not derived from pears. In practice, a synthetic pear flavour generally comprises a solution in a suitable solvent, e.g. a solution in a water/alcohol mixture, of vanilla extracts or synthetic vanilla with a substance containing triacetin, esters, such as hexyl or amyl ortrans-2hexenyl acetate, alcohols such as hexanol, acetic acid, aldehydes such as trans-2-hexanal, and ionones, and, if required, stabilisers. Other synthetic pear flavours include ethyl decane-cis-4-trans-2dienoate.

It is well known that some rodents readily appreciate fruits. The incorporation of fruits or fruit extracts, and even of natural fruit flavours into rodenticidal baits has already been proposed. This solution proved to be not very effective.

However, the use of the synthetic pear flavour unexpectedly causes a strong attraction for the rodent, whereas other flavours, especially natural flavours, even pear extracts, give clearly poorer, and in any case, hardly comparable results.

Advantageously, in practice: the synthetic pear flavour is introduced by coating or impregnation, when the edible carrier is grain-based, or by mixing, when this carrier is based on paraffin or other liquid substance; the quantity of synthetic pear flavour introduced is between 0.01 and 5% by weight relative to the carrier, and preferably 0.1 to 1%.

These percentages are based on the quantity of the pear flavour itself, not of its solution. In fact, it was observed that, with a concentrated solution, if the quantity of synthetic pear flavour introduced exceeds 5%, the cost of the composition is unnecessarily increased without obtaining corresponding additional effects, whereas if the concentration is less than 0.01%, the effect is generally too low; similarly, it was observed that best results were obtained with a concentration of 0.1 to 1% which, moreover, gives a fragrance which can be detected by man.

Suitable rodenticides are known and include anticoagulants, e.g. warfarin, chlorophacinone, bromadiolone, difenacoum and brodifacoum, and immediate-acting poisons such as scilliroside. More than one rodenticide may be used, if required.

The edible carrier may be solid, e.g. oats, wheat, semolina or, preferably, millet grains, puffed rice or paraffin blocks comprising an edible substance. The carrier may also be liquid, e.g. water.

The quantities of active substances deposited on the edible carrier correspond to the usual and/or statutory quantities: these quantities are generally of the order of 0.05 to 0.001% of the active substance relative to the weight of the carrier, depending on the nature of the rodenticide. Thus, as in the case of other rodenticides on the market, the edible carrier is the main constituent, and it preferably represents up to 99% by weight of the composition.

It was observed that best results were obtained using puffed rice or Argentinian millet as the edible carrier, coated with the synthetic pear flavour at a rate of 0.1 to 5, and preferably 0.1 to 1% by weight.

Puffed rice is particularly suited to rats, whereas Argentinian millet, because of its size, is well suited to mice.

The rodenticidal bait according to the invention therefore has advantages over the products marketed until now, as it has a significant attracting influence on the rodent which can therefore consume the bait, and become poisoned in so doing, before being distrustful.

The mixing of the three components, viz, the edible carrier, the active substance and the synthetic pear flavour, may be carried out in any sequence. It is sufficient simply to take the usual precautions, especially so that the flavour remains well attached to the bait. In particular, the rodenticide and the synthetic pear flavour may first be mixed to obtain a solid or liquid composition which is ready for use, which also constitutes a feature of the invention and which may, in its turn, be mixed with the edible carrier and with other adjuvants, according to a coating or dusting technique known per se.

Moreover, the bait according to the invention may contain common adjuvants, especially colourants.

The present invention is based on the choice of a particular additive compound, viz. synthetic pear flavour, whereas other natural or synthetic flavours tested, such as apple, grape, banana, meat and nut flavours give clearly poorer results.

The following Examples illustrate the bait compositions according to the invention: percentages are by weight.

Example 1: Bait with grains Bromadiolone 0.005% Synthetic pear flavour in 50% alcoholic solution 0.1% Red colourant 0.01% Carrier:oats qs 100% Example 2: Bait with paraffin block Warfarin 0.025% Synthetic pearflavour 0.1% Paraffin (m.p. 6-65"C) 43% Millet qs 100% EXAMPLE 3 In order to test the effectiveness of a composition according to Example 1 of the invention, the quantities of different foods (differing only in the flavour under test) simultaneously supplied to control rats are monitored in a known way over a fixed period of four days.

It was observed that, on the basis of the amount of bait consumed, for the same food to which different aromatic compounds had been added, the rat is attracted: three times more readily by the synthetic pear flavourthan bya grape flavour or saccharine; five times more readily by the synthetic pear flavour than a fatty flavour; and finally, eight times more readily by the synthetic pearflavourthan bya nutflavour.

Claims

1. A rodenticidal bait which comprises a rodenticide and a synthetic pear flavour.

2. A rodenticidal bait according to claim 1 which comprises an edible carrier.

3. A rodenticidal bait according to claim 2, which comprises from 0.01 to 5% by weight of the synthetic pear flavour relative to the edible carrier.

4. A rodenticidal bait according to claim 2, which comprises from 0.1 to 1% by weight of the synthetic pear flavour relative to the edible carrier.

5. A rodenticidal bait according to any one of claims 1 to 4, wherein the rodenticide is an anticoagulant substance chosen from warfarin, chlorophacinone, bromadiolone, difenacoum, brodifacoum, or an immediate-acting poison.

6. A rodenticidal bait according to any one of claims 2 to 5, wherein the edible carrier is millet grains, puffed rice or paraffin blocks which comprise an edible substance.

7. A rodenticidal bait according to claim 1 substantially as hereinbefore described.

8. A rodenticidal composition which comprises a rodenticide and a synthetic pear flavour.

9. A process for the manufacture of a rodenticidal bait according to any one of claims 1 to 7, wherein a composition according to claim 8 is mixed with an edible carrier.

10. A process for the manufacture of a rodenticidal bait as claimed in claim 1 substantially as hereinbefore described.