FIELD OF INVENTION

This invention is directed to insect bait. More particularly, the invention is directed to an insect bait useful in controlling various insects such as ants and roaches having gelatinized starch as the bait matrix.

BACKGROUND AND PRIOR ART

Efforts to safely and effectively control insects such as ants and roaches commonly found in household,. restaurant, and hotel environments have been gping forward continuously almost since the beginning of mankind with varying degrees of success. These prior art efforts have included the use of direct and residual sprays as well as solid baits which may contain chemical additives which are designed to have varying effects on the insect, including on its ability to reproduce or outright death.

With solid baits, substantial effort has been directed to baits which attract the insect, leading the insect to devour the bait and an insecticide contained in

the bait, with the desired result. Other efforts have been directed to baits which repel the insect and, thus, cause the insect to seek a new environment. These efforts have provided baits containing various attractants, including starches. For example, U.S. Patent No. 960,287 discloses an insecticide composition which can contain from 15% to 20% cornstarch. The cornstarch is present in an insecticidal mixture of two metallic salts to separate the respective salt particles and prevent chemical reaction between the salts. U.S. Patent No. 4,321,258, on the other hand, discloses a non-toxic insecticide which c can include, inter alia, cornfetarch as an attractant for an insect. Various other United States patents such as U.S. Patent Nos. 2,687,365 and 4,332,792 disclose the use ■ of corn syrup and similar materials as insect attractants in insect traps and baits. None discloses the use- of starch in the cooked form, or as a gel matrix.

While all of the prior art devices have varying degrees of effectiveness- in controlling insects, none are completely acceptable from the standpoint of effectiveness, ease of manufacture, and economy.

OBJECTS OF THE INVENTION

It is an object of the present invention to provide an insect bait containing an insect-controlling

material, such as an insecticide or insect repellent, where the materials can be cold blended to provide a gelled bait.

It is another object of the invention to provide a method of providing a gelled insect bait based on relatively inexpensive materials which can be convenientl made with conventional mixing equipment.

It is another object of the present invention to provide an insect bait having a gelatinized stable starch matrix which can be cold blended.

It is another object of the invention to provide a method of providing a gelled insect bait based on relatively inexpensive materials.

It is another object of the present invention to provide an insect bait having a gelatinized stable starch matrix.

These and other objects of the invention will be apparent from the following general description with emphasis being directed to the specific working embodiments.

DESCRIPTION OF INVENTION WITH PREFERRED EMBODIMENTS

The aforesaid objects of the present invention are accomplished by providing an insect bait based on starch in combination with other ingredients including attractants, insecticides or repellents, and preservatives wherein starch and the other materials are extruded under pressure and temperature sufficient to cook the starch and form a gelatinized stable gel bait matrix. Upon the extrusion of the ingredients at temperatures and pressures sufficient to gelatinize the starch, a stable stacch gel is formed having the essential additives uniformly contained therein, which gel is easily utilized as an insect bait.

Alternatively, and as a highly preferred embodiment, the invention is directed to the formation of an insect bait using a pregelatinized starch which has been partially cooked by extrusion to provide a water- absorbing property to the starch. The pregelatinized starch and the essential ingredients of an insect bait such as attractants, insecticides, and/or repellents, preservatives, water, and preferably an e ulsifier are- cold blended. The water essential for forming the gel bait matrix is absorbed by the pregelatinized starch. In this preferred embodiment heating of the materials during

forma*,ion of the bait is not necessary. However, heating can, at times, be utilized to increase the speed of the gelling process.

The starch, whether extruded with the materials to form a gel or pregelatinized, provides an inexpensive and practical method of forming an insect bait base which is easily used, without essiness, and which is effective in controlling insects. The use of the pregelatinized starch is particularly convenient and effective and, accordingly, is a highly preferred embodiment.

The starch content of the insect bait of the preferred embodiment, i.e., where the starch is pregelatinized, can vary over a range of from about 2.5% to 15% by weight. Below about 2.5% a stable gel will not form, but a flowable gel will result. Above about 15%, the pregelatinized starch will very rapidly absorb water and the viscosity of the mixture will increase too rapidl to allow handling of the material before a gel is formed. It has been found that the preferred range is from about 5% to about 15% pregelatinized starch. This range allows easy handling of the materials before the gel is formed, and once formed the gel is stable and non-flowable at temperatures up to at least about 140* F., which is a temperature at times reached in warehouses or the like

where the product may be stored. Pregelatinized starches are commercially available under various tradenames and are based on the common starches such as corn flour, cornstarch, maize, tapioca starch, potato starch, rice starch, and the like. Pregelatinized starch as used herein includes the various commercial products which may or may not include additives such as sodium trimetaphosphate to provide improved gelling characteristics,

In the embodiment not employing pregelatinized starch but where the starch and other components of the bait are subjected to a range of temperatures and pressures so as to extrude the starch and provide a gel, the starch content can, in the event only an insecticide or insect repellent is employed, range up to as high as 99%. The starches employed are again the commonly available starch products including potato starch, corn flour, cornstarch, tapioca starch, maize, and the like.

In the insect baits of the present invention, it is preferable ^' to utilize in addition to the starch other attractants such as fruit extracts, honey extracts, the sugars, i.e., sucrose , _Λ fructose, maltose, glucose, molasses, and the like, to make the bait more palatable t insects. Normally, for this embodiment the additional

-1- attractants will vary from about 1% to 35% and will correspondingly decrease the amount of starch utilized. In the formation of the insect bait by mixing and extruding the components it is essential to utilize additives, including the insecticides and repellents whic will withstand the extrusion temperatures of starch without degradation or vaporization. The extrusion temperatures of the insect bait mixture, depending upon the content of starch and other additives, will range between about 160 to about 310° F. at pressures of from about 300 through 800.

The insecticides which can be utilized in the insect baits of the present invention include the insecticides commonly utilized in controlling insects. One insecticide which has been found highly effective is

0,0-diethyl-0-( 3 , 5, 6trichloro-2-pyridyl)-phosphorothioate

Λ

(Dursban). Other commonly employed insecticides include arsenic and metallic salts. In the preferred embodiment utilizing pregelatinized starch, the bait can include any of the insecticides since the materials can be cold blended, or subjected to only slightly elevated temperatures. As previously stated, however, in the embodiment where the materials are mixed and co-extruded, an insecticide which does not degrade under extrusion conditions must be selected. The content of insecticide

can range from as low as 0.025%, depending upon the insecticide utilized, up to about 4%. Normally, however, the effective amounts of insecticide will fall below about 1.0% by weight.

Attractants including sugars, yeast extract, gelatine, and the like, can be utilized to enhance the attraction of the insect to the bait. Normally food attractants such as the sugars will range from about 1% to 90% in the event the pregelatinized starch is employed. It has been found, for example, that corn syrup as an attractant in the range of from about 60% to 90% is desirable when pregelatinized starch is used, as the lowered moisture within the com syrup can be sufficient to gel the starch source of moisture; whereas, in the event corn flour or yeast extract is used as the attractant, 5% to 15% is highly effective. The aforesaid materials have been found to be effective food ingredients for the insects, particularly ants and cockroaches.

It has been found desirable when utilizing a pregelatinized starch to utilize an emulsifier to improve the blending of the pregelatinized starch and other ingredients with water in forming the gel bait matrix. The emulisifiers can be any of the commonly employed emulsifiers, and preferably the non-ionic or _. anionic

emulsifiers. The amount of emulisifier utilized will vary depending upon the amount of water in the mix. The water content can vary from a minimum of about 5% which is necessary to form the gel to levels of about 15% or 20%. In the event a water content of above about 20% is utilized, the time forming the gel is substantially increased. It has been found, however, that effective insect baits can be prepared where the water content is as high as 80% to 90%.

Other additives can be at times effectively added to the insect bait. These additives include Binders such as paraffin wax, synthetic clays, and materials commonly utilized in the formation of insect baits. Preferably, however, when the bait is used as an insecticide only food components are included in the bait.

Having described the invention in general terms, the following two examples define presently preferred embodiments.

EXAMPLE 1

A mixture of -

Cornmeal ■ 74 .5% by weight

Sugar 25. 0% by weight Dursban Insecticides 0. 5% by weight

TOTAL 100. 0%

was dry blended to provide a substantially uniform mixture. The mixture was then extruded in a conventional extruder at a temperature in the range of 200 to 220 ^# F., and at a pressure of 500 psi. The extruded material was dispensed in containers in the form of a gel. The gel was stable at room temperature and temperatures up to at least about 140* F. The baits were effective in attracting and destroying roaches and ants.

EXAMPLE 2

An insect bait was formulated containing ingredients as follows:

Fructose Sugar 70.0% Corn flour 10.0%

Yeast Extract 5.0%

Pregelatinized Cornstarch 5.0%

Insecticide - Dursban 0.1%

Emulsifier - Triton X180 which is an alkyl polyether alcohol anionic emulsifier — 0.4%

Water 9.5%

TOTAL 100.0%

The above ingredients were cold blended. Upon complete blending, the materials provided a gel. The gel was packaged as a stable gel. The all-food bait was effective in attracting and destroying ants and roaches.

As will be apparent to one skilled in the art, various modifications can be made within the scope of the aforesaid description. For example, in place of the insecticide of the above examples an insect repellent can be employed. Such modifications being within the ability of one skilled in the art form a part of the present invention and are embraced by the apended claims.