BAIT COMPOSITION FOR A PEST

Abstract

A bait composition is provided for use in a bait for ingestion by a pest. The bait composition includes a poison for killing the pest, and at least one of an insect growth regulator, a larvicide and an insecticide, for minimizing the propagation of insects from the pest's carcass. The effect of pest control involving the bait on a secondary pest population may be assessed using a suitable method.

Claims

1. A bait composition for ingestion by a pest, the bait composition comprising: a poison for killing the pest to produce a pest carcass; and an insect growth regulator (IGR) which targets fly larvae at the third or fourth instar for minimizing or controlling the propagation of flies from the pest carcass, the IGR being suitable for uptake into body tissues and organs of the pest following ingestion of the bait composition by the pest during use, and the IGR being provided in an amount which after ingestion provides an IGR concentration which is at least 1 ppm in the body tissues and organs of the pest carcass but which is insufficient to kill fly larvae prior to pupation, in use allowing fly larvae to decompose the pest carcass but thereafter substantially preventing flies from hatching from fly pupae developed from larvae in the pest carcass.

2. The bait composition of claim 1, wherein the pest is a rodent, and the poison includes a rodenticide.

3. The bait composition of claim 1, wherein the insect growth regulator includes one or more compounds independently selected from the following group: methoprene, hydroprene, diflubenzuron, tebufenozide, RH 5849, pyriproxyfen, chromafenozide, methoxyfenozide, diofenolan, fufenozide, and lufenuron.

4. The bait composition of claim 1, wherein the insect growth regulator includes one or more components independently selected from the following group: Egyptian essential oil(s), celery, fenugreek, mustard, rosemary, anise, lettuce, and chamomile, or an extract thereof.

5. The bait composition of claim 1, wherein the insect growth regulator includes one of more of: azadirachtin, neem extract, and Persian lilac or chinaberry tree extract.

6. The bait composition of claim 1, wherein the insect growth regulator includes an azasteroid for inhibiting one or more of sterol uptake, transport and use in a fly larva.

7. The bait composition of claim 1, wherein the insect growth regulator is encapsulated in a biodegradable material.

8. The bait composition of claim 1, wherein the insect growth regulator includes one or more of: Egyptian essential oil(s), celery, fenugreek, mustard, rosemary, anise, lettuce, chamomile, azadirachtin, neem extract, and Persian lilac or chinaberry tree extract; and in which the poison includes one or both of ergocalciferol and cholecalciferol for providing a natural bait composition.

9. Bait for ingestion by a pest, comprising the bait composition of claim 1.

10. The bait of claim 9, wherein the insect growth regulator is selected and the amount thereof is tailored according to one or more of: the pest the bait is intended for, the fly or flies expected to use the pest carcass for their larvae, and the mass of the bait.

11. The bait of claim 9, wherein the bait is in the form of a substantially solid body such as pellet, a grain, or a block, and the poison and the insect growth regulator are distributed substantially homogenously throughout the solid body.

12. The bait of claim 11, wherein the insect growth regulator is provided in the solid body in an amount of about 0.01 mg to about 50 mg, or about 0.01 mg to about 20 mg.

13. The bait of claim 9, wherein the bait is a liquid or a foam containing the poison and the insect growth regulator, and the insect growth regulator is provided in a concentration of at least about 0.1 mg per liter.

14. Non-toxic bait intended for ingestion by a pest, the bait comprising: a carrier or edible body; and an insect growth regulator (IGR) which targets fly larvae at the third or fourth instar for minimizing or controlling the propagation of flies from a pest carcass when the pest is dead, the IGR being suitable for uptake into body tissues and organs of the pest following ingestion of the bait by the pest during use, and the IGR being provided in an amount which after ingestion provides an IGR concentration which is at least 1 ppm in the body tissues and organs of the pest but which is insufficient to kill fly larvae prior to pupation, thereby when the pest is dead allowing fly larvae to decompose the pest carcass but thereafter substantially preventing flies from hatching from fly pupae developed from larvae in the pest carcass.

15. The bait of claim 14, wherein the insect growth regulator includes one or more of the following: methoprene, hydroprene, diflubenzuron, tebufenozide, RH 5849, pyriproxyfen, chromafenozide, methoxyfenozide, diofenolan, fufenozide, lufenuron, Egyptian essential oil(s), celery, fenugreek, mustard, rosemary, anise, lettuce, chamomile, azadirachtin, neem extract, Persian lilac or chinaberry tree extract, or an azasteroid for inhibiting sterol uptake, transport and/or use in a fly larva.

16. The bait of claim 14, wherein the bait is in the form of a substantially solid body such as pellet, a grain, or a block, and the insect growth regulator is distributed substantially homogenously throughout the solid body, in which the insect growth regulator is provided in the solid body in an amount of about 0.01 mg to about 50 mg, or about 0.01 mg to about 20 mg.

17. The bait of claim 14, wherein the bait is a liquid or a foam containing the insect growth regulator, and the insect growth regulator is provided in a concentration of at least about 0.1 mg per liter.

18. The bait of claim 14, wherein the bait is used for pest control of a pest and also substantially concurrent or pre-emptive pest control of flies.

19. The bait of claim 9, provided in a container.

20. A method of pest control for a pest and for one or more fly species which can propagate using one or more carcasses of the pest, the method comprising the steps of: a) providing non-toxic bait according to claim 14 in one or more locations which include a pest population, for ingestion by the pest; and after at least some of the non-toxic bait has been ingested by the pest, one or more of: b) providing toxic bait or poison in the one or more locations for ingestion by the pest to kill the pest; c) using gas in the one or more locations to kill the pest; d) providing one or more traps for the pest in the one or more locations, optionally with bait or a lure disposed in the or each trap for attracting the pest; and e) partially or wholly collapsing, or otherwise destroying, one or more burrows or nests for killing any pest therein.

Description

DRAWINGS

[0096] For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made by way of example only to the accompanying drawings, in which:

[0097] FIG. 1 shows a flowchart of a process for carrying out pest control of a first pest via baiting and monitoring the effect of the pest control on numbers of a second pest; and

[0098] FIG. 2 shows a flowchart of a process for carrying out pest control of a first pest via a first non-toxic baiting step and a subsequent pest-killing or pest-capturing step.

DETAILED DESCRIPTION

[0099] In some preferred embodiments, there is a bait composition for ingestion by a rodent, causing it to die, and which adversely affects the maturation of blow flies which consume the rodent's carcass. The bait composition is provided as part of solid piece of bait or pellet in some embodiments, or as part of a liquid or foam bait in other embodiments. The bait composition is distributed substantially evenly through the solid piece of bait or the liquid/foam bait. The bait or composition may be provided in a suitable sealable container or dispenser.

[0100] The bait includes a poison in the form of a rodenticide for killing a rodent. Any suitable rodenticide may be used, such as an anticoagulant or a compound for causing hypercalcemia in a rodent. The bait is therefore toxic to the rodent once ingested. If a naturally-occurring rodenticide is desired, then calcipherol and/or cholecalciferol may be included.

[0101] The bait also includes a feed-through insect growth regulator (IGR). Any suitable IGR which inhibits blow fly maturation from a larval stage may be included, such as methoprene, hydroprene or an azasteroid for example. If a naturally-occurring IGR is desired, then Egyptian essential oils or azadirachtin may be preferred. The IGR is selected to target and adversely affect metamorphosis of the insect pest at issue.

[0102] In some embodiments, the IGR may be supplemented by or replaced by a feed-through larvicide. Any suitable larvicide may be used, e.g. a DOPA decarboxylase inhibitor (such as methyl DOPA). The larvicide may include a pathogenic fungus for killing larvae in other embodiments.

[0103] In some embodiments, the IGR may be supplemented by or replaced by a feed-through insecticide. Any suitable insecticide may be used, e.g. permethrin.

[0104] The bait includes a pest attractant. For example, in the case of solid bait, the bait includes grain or another food sought after by rodents. In the case of liquid bait, the water in which the bait composition is dissolved or suspended may be sufficient as an attractant. If not, a sugar or sweetener may be added to both attract the rodent and potentially disguise any unusual flavor which may be caused by the bait composition.

[0105] In the solid bait, the IGR and/or the larvicide and/or insecticide are encapsulated in a biodegradable material to improve the longevity of the bait and/or minimize anti-feedant properties in some embodiments. This may not be appropriate in the liquid or foam bait, but the IGR and/or larvicide and/or insecticide can be provided in another protected form, such as by using suitable protecting groups which can be detached during digestion and uptake by the rodent. However, the IGR will in general be stable in the environment and during digestion, so a protected form may not be needed.

[0106] The amount of IGR and/or larvicide and/or insecticide is tailored to the expected weight of the pest, in this case a rodent. Typically, a rodent may weight anywhere between 10 g and 500 g, so for a solid piece of bait to be completely consumed by the rodent, a suitable amount of IGR in the bait may be between 0.01 mg to 1 mg, for example. It is preferred to select the amount of IGR such that the post-mortem amount of IGR in the rodent is around 1 ppm to 10 ppm. The equivalent dose in liquid or foam form will depend on the amount of liquid ingested by the rodent, but will typically be at least 0.1 mg per liter.

[0107] FIG. 1 sets out steps for an embodiment of a pest control method for two target pests—a primary pest, which is an animal pest such as a rodent (particularly a rat), and a secondary pest, which is an insect pest such as a blow fly. The death of the animal pest allows the insect pest to propagate or proliferate using the carcass of the primary pest. It should be noted that ascertaining the potential insect load for a particular carcass or infestation is not essential given that, once a mammal or bird dies, invertebrates will almost inevitably find the carcass, particularly in warm temperatures. However, it may be useful to determine the effectiveness of a particular bait, such as during bait testing.

[0108] In a first optional step, the number of pest insects for the secondary pest being targeted may be monitored or estimated shortly prior to bait deployment in the target area(s). This may in some embodiments instead be done immediately after bait deployment. The intention in either case is to perform the check before the bait has been deployed long enough to result in the death and start of decomposition of any of the target pests (the lag phase).

[0109] For example, this may involve monitoring the level of flies to establish an estimated baseline or background amount for the number of flies in the area(s) prior to dealing with a pest infestation. The approximate number of flies can be judged by using traps, typically involving chemical attractants (such as pheromones) or light tubes. The traps may incorporate either a funnel, one or more sticky boards or one or more zappers to allow for sampling and extrapolation. Other sorts of trap may be used for other insects.

[0110] In a second step, the bait containing the composition is used by deploying it in a target area or areas. In some embodiments, this includes leaving solid pieces of bait in a region or regions known or predicted to be frequented by the animal pest. In some embodiments, this includes leaving liquid bait (possibly in a container) in a similar region or regions, or applying a foam bait to surfaces the pest is expected to make contact with en route to and/or from its nest or territorial boundaries, for example.

[0111] Once the bait composition has been deployed in the target area(s), some time may pass before it is ingested by a member of the target pest animal group. However, assuming an infestation of at least one pest member, then the bait should eventually be ingested, through eating or drinking the bait or via grooming behavior. If the bait is not ingested (either at all or in a sufficient quantity) after a predetermined period of time, then it may need to be re-positioned or replaced entirely, or removed once no longer required to reduce the risk of non-target species being impacted. Liquid or foam bait may in any case need to be re-applied or re-deployed if it has evaporated, for example. Where possible, carcasses should be removed and disposed of accordingly.

[0112] Once ingested by the target pest, the poison is then absorbed, along with the IGR and/or larvicide and/or insecticide, via the pest's digestive system and spreads into its body tissues and organs. Some of each of the poison, the IGR, insecticide and/or the larvicide can also remain in its gastric tract and/or be excreted in the pest's feces, depending on the bait constituents and the particular pest animal involved.

[0113] The pest which ingested the bait will then die, typically a day or so after ingesting the bait. The pest can in some embodiments ingest the bait multiple times prior to death, if a slow-acting poison for that pest species is used.

[0114] Insects such as flies will then inevitably find the pest carcass and lay their eggs in it. The eggs hatch and the resulting larvae or maggots will consume the carcass, including the IGR, insecticide and/or larvicide. Where an IGR is present, this inhibits the development of the maggots into adult insects, causing them to perish in their pupae. Where a larvicide is present, some or all of the larvae die at the larval stage. Where an insecticide is present, some or all of the insects which visit or mature in the carcass should die from exposure to the insecticide.

[0115] In both cases, this limits the spread of insects from the carcass, which in turn limits the spread of the bait constituents to other non-target species, minimizing potential collateral environmental, health and hygiene issues, as well as potential reputational damage. Thus, the bait enables pest control of an existing pest (such as a rodent population), as well as enabling pre-emptive pest control of another pest (such as blow flies) which would potentially otherwise result from the first round of pest control.

[0116] In a third optional step, around 3 to 10 days after bait deployment, the number of insects for the insect pest can be checked again in the target area(s). Whilst this is optional, it allows pre- and post-treatment levels of insects to be monitored, in order to make a determination about whether additional pest control measures for the insect pest are needed.

[0117] If insect levels are zero or substantially lower (to a statistically significant extent) than the baseline recorded previously, this can indicate that the pest control (or testing) has been at least partly successful and no further measures may be required for the time being, or that the bait has a suitable composition for the particular animal and insect pest combination being monitored. Further monitoring may be prudent to determine whether the presence of any remaining insects can be attributed to a residual pest infestation in the same area or another pest infestation in a different area nearby.

[0118] Note that where the initial and subsequent monitoring involves outdoor monitoring of insects, it will be appreciated that some consideration must be given to weather conditions and the time of day monitoring is carried out. The parameters of each monitoring period and the equipment and techniques used should ideally be the same.

[0119] If insect levels are substantially higher (to a statistically significant extent) than the baseline recorded previously, or if insect levels are substantially the same and non-zero, this may imply that pest control has been ineffective, or that there is another infestation nearby. This may then lead to a decision to undertake further pest control (or testing), either in the same area(s) or another area or areas. The further pest control may be targeted for the insect pest if there is suitable evidence that the animal pest infestation has been dealt with, for example by monitoring bait consumption or disturbance.

[0120] Note that the time delay required for a second round of monitoring will depend on the pest species under consideration, and the efficacy of the bait used, and so the second round of insect pest monitoring can be brought forward or delayed accordingly.

[0121] It will be appreciated that other embodiments are envisaged in which the first target pest is a pest other than a rodent, and the poison identity and quantity are selected accordingly. The bait may be a generic bait for combination treatment of multiple pests in a particular region. In that case, the combination treatment may contain multiple IGRs to suit two or more respective target insect species.

[0122] It will also be appreciated that other embodiments are envisaged in which the second target pest is a pest other than a blow fly, and the IGR and/or larvicide and/or insecticide identity and quantity are selected accordingly.

[0123] In further embodiments of the invention, there is a non-toxic bait for ingestion by a rodent. The non-toxic bait has an edible body, such as a bait block, which contains a suitable amount of IGR. In other embodiments, the non-toxic bait may have a carrier liquid or carrier foam which contains the IGR.

[0124] The non-toxic bait includes similar features to those discussed for the above embodiments. Any of the features in preceding embodiments may be included in isolation from other features or in combination with other features, with the exception that the non-toxic bait does not itself contain a poison for killing the pest.

[0125] FIG. 2 sets out steps for an embodiment of a pest control method for two target pests—a primary pest, which is an animal pest such as a rodent (particularly a rat), and a secondary pest, which is an insect pest such as a fly. As discussed with respect to FIG. 1, the death of the animal pest allows the insect pest to propagate or proliferate using the carcass of the primary pest.

[0126] The purpose of the non-toxic bait in the method is to introduce IGR into an animal pest population, such as a rodent or rat population, where the pest population is distributed across an area as opposed to localized in a particular residence.

[0127] The first stage of the method involves deploying or providing the non-toxic bait in one or more locations in or near the vicinity in which the pest population is located (or believed to be located). That is, stage one is a ‘priming’ phase where IGR is doped into the pest population.

[0128] Once the non-toxic bait has been laid out, it is necessary to wait for a period of time until the bait has been at least partly consumed by the target animal pest. This may be checked by assessing bite marks on the bait or using camera traps for example. In some cases, it may be possible to use bait stations to limit bait access by various non-target pests, but the scale of the pest infestation may mean that this is not practical.

[0129] The period of time involved may be anything from a couple of days to a few weeks, for example. If it is known or anticipated that there is a relatively large pest population, multiple rounds of non-toxic bait may be needed to maximize the likelihood that most or all of the pest population has ingested the bait.

[0130] The next stage of the method is the ‘extermination’ phase. One means of doing this is to provide or deploy conventional poison bait or toxic bait as described in earlier embodiments. This kills the pests and their carcasses are decomposed in the same manner as previously described. Multiple rounds of toxic baiting may be required.

[0131] Another option is to actively apply or direct gas into and/or around the locations where the pest population is known or believed to be. This may involve temporarily evacuating the local human population, if the gas is toxic to humans. It is particularly useful where the pests live or hide in inaccessible locations such as burrows. Multiple rounds of gassing may be required. Carbon dioxide gas may be used, or any suitable gas which achieves the aim of killing the pests. This can include a cyanide gas or phosphine gas, e.g. evolved when a pest bites into a corresponding tablet, for example.

[0132] Another option is to deploy one or more traps to capture the pests. Toxic bait may be provided in the traps to kill the pests.

[0133] Another option is to partially or wholly collapse the burrow(s) where the pest may be located. The burrow entrance may be collapsed to trap the pest inside, optionally after delivering bait and/or gas into the burrow(s). Further collapse or destruction may be appropriate depending on where the nest or burrow is. This traps the pest inside so that it perishes, or may kill the pest instantly depending on the extent of burrow/nest collapse.

[0134] A combination of two or more (or all) of these approaches may be used to maximize the extent to which a pest population is reduced or completely eliminated. For example, the traps may be used to tackle residual pest population that is not killed via gassing.

[0135] It will be appreciated that the non-toxic bait version of the invention can therefore be used to achieve a similar result to the toxic bait version, despite the separation of the poisoning/killing/death from the introduction of IGR into the pest.

[0136] It will be appreciated that equivalent larvicide-based and/or insecticide-based versions of the non-toxic bait may be provided and used in a corresponding manner.

[0137] The embodiments described above are provided by way of example only, and various changes and modifications will be apparent to persons skilled in the art without departing from the scope of the present invention as defined by the appended claims.