GB2262889A - Method for attracting insects - Google Patents

Abstract

Extracts of tamarind seeds are used as attractant for insects, particularly cockroaches. The extracts are used in roach traps and can be incorporated into sticky compositions which capture roaches or can be separately placed in the traps. Insecticides may also be incorporated.

Description

METHOD FOR ATTRACTING INSECTS This invention relates to methods, compositions and devices for capturing cockroaches. More particularly, it relates to cockroach traps, having a surface on which there is coated a sticky substance for capturing cockroaches and an attractant for roaches placed separately on a surface or incorporated into the sticky substance.

The cockroach is one of the oldest and most pervasive pests known to mankind. Over the years there have been many attempts to control roach populations in homes, offices, warehouses and other business establishments but control and eradication of the roach is extremely difficult. Cockroaches generally are nocturnal creatures which explore primarily out of hunger. This exploration is influenced by temperature, humidity, light and other factors. Various methods have been employed in these attempts, including the use of residual insecticide compositions, the placement of bait compositions containing toxicants, and the setting out of roach traps. This invention relates to improvements in roach traps.

Roach traps typically consist of a chamber which acts as a carrier means for sticky composition to immobilize roaches.

In the chamber, one or more interior surfaces is coated with a composition comprising glues, tackifiers, and carriers and solvents therefor. The composition can be coated onto an entire surface or onto only a portion of a surface such as, for example, in strips. Typically, an insect attractant is associated with the sticky composition either by being a component of said composition or by being separately adhered to a surface of the trap. These sticky compositions can contain insecticides or be insecticide-free. Although insecticide-free insect traps function only by immobilizing the cockroaches, rather than providing an immediate kill, their use can be advantageous in that they can be placed in areas such as children's rooms, food cabinets and other locations where an insecticide-containing trap would not be suitable.

The sticky compositions contained in cockroach traps are generally comprised of one or more substances which, when the composition is exposed to the ambient atmosphere surrounding the insect trap, acts as an attractant for cockroaches.

Alternatively, the attractant can be separately placed in the trap, without being incorporated into the sticky composition.

It has been found that extracts of foenugreek seeds are particularly effective as attractants. However, the strong odor of foenugreek extracts is disadvantageous, particularly where the insect traps are to be placed in confined areas.

Accordingly, it is a principal object of this invention to provide a trap for attracting cockroaches which contains an effective cockroach attractant not having an odor offensive to human beings. It is a further object of the invention to provide compositions containing said attractant which can be coated onto one or more surfaces of the trap.

It is well known that cockroaches are attracted to odors emanating from food and natural products and a wide variety of such substances has traditionally been included in bait compositions. For commercial purposes, it is required that such attractants be stable and not deteriorate or volatilize at an excessive rate under varying conditions of humidity and at varying temperatures ranging from below freezing to as high as 600C. Extracts of foenugreek seeds have proven to be quite effective for this purpose but, as noted above, the pungent odor of foenugreek detracts from the acceptability of cockroach traps containing this ingredient. Attempts have been made to use other derivatives of natural products as cockroach attractants.

For example, Japanese Patent Publication No. 53-91140 (August 1978) discloses the use of sesame oil, optionally mixed with an extract of cockroach faeces as an insect attractant; it is not likely that compositions containing these ingredients would have the necessary stability required in commercially sold cockroach traps, particularly for household use. Japanese Patent Publication No. 53-113027 (October 1978) discloses sake lees, either in a dry or in a half-dry state, as a cockroach attractant; here again, it is doubtful that said compositions would have the necessary stability and there is also a problem of availability in countries outside Japan.

Extracts of tamarind seed have been used in various pest control compositions and methods, but have not heretofore been used as cockroach attractants. In Japanese Examined Patent Application No. 48-8519 (March 1973), there is disclosed an emulsion comprising sorbic acid powder and tamarind seed powder which is used as an insecticide and fungicide on tobacco plants.

The active ingredient in these composition is sorbic acid, and the tamarind seed powder is used to improve the stability of the sorbic acid emulsion and also to ameliorate the odor of sorbic acid. In Japanese Patent Publication No. 63-171723 (July 1988), the use of an extract of the fruit and/or seeds of tamarind is disclosed as a microbicidal agent which can be added to foods.

Extracts of tamarind seeds are used as an insect attractant, particularly for cockroaches. These extracts can be incorporated into sticky compositions used in traps for cockroaches, or can be placed in cockroach traps separately from the sticky composition.

The tamarind seed extracts usable in this invention are derived from the tropical tree Tamarindus indica, a member of the family Leguminosae. For use in this invention, the tamarind seeds may be milled in a homogenizer or a ball mill, dried and then heated along with an appropriate solvent in order to obtain an extract. Any suitable solvent may be used; typical solvents include methanol, acetone, n-hexane, water, and mixtures thereof. The tamarind seed extracts which can be incorporated into sticky compositions for cockroach traps are typically viscous solutions having solids content ranging from about 60% to about 90%, preferably with minimum solids content of 65%, and more preferably with minimum solids content of 75%. The actual viscosity of such solutions can be quite varied.For example, in an LVT viscometer using a No. 4 spindle at 60 rpm and 200C, the viscosity can be in the range of from about 3,000 cps to 23,000 cps. Because of production temperature, which can go to 700C and higher and because of varying temperatures which roach traps will encounter during shipment and use, it is important that viscosity be maintained at a high level in order to avoid leaching out of the attractant when it is incorporated into a sticky composition or to avoid loss by run-off when it is separately placed on a trap surface.

If the tamarind seed extract is incorporated into a sticky composition, the compositions is coated as a layer on what can be broadly described as a composition-carrying means in a cockroach trap. Typically, the composition-carrying means will constitute one or more surfaces of a partially enclosed chamber such as, for example, a box whose lower, upper and side surfaces are coated with the sticky composition. Alternatively, one or more of the surfaces may be left uncoated, or the coating may be applied on only portions of a surface, for example in strips. The box also has one or more openings permitting entry of the target pests. The openings also serve to permit the tamarind seed extract to volatilize into the surrounding atmosphere so as to attract the cockroaches.

The sticky compositions of this invention incorporating the tamarind seed extract also typically comprises tackifying resin and softeners. The composition may also include solvents, fillers, pigments, dyes, antioxidants, ageing inhibitors, preservatives, disinfectants, perfumes, etc.

If the tamarind seed attractant is applied to the trap separately from the sticky composition, it may be coated directly onto a portion of an inner surface, or on top of a portion of the sticky composition.

Although tamarind seed extract can be preferably incorporated into or used in conjunction with non-toxic compositions for use in cockroach traps, it is also contemplated that the sticky compositions can also contain substances which are toxic to cockroaches. Thus, the composition can also include one or more known insecticides.

The amount of tamarind seed extract used in cockroach traps can vary widely but must be sufficient to act as an attractant. For example, in a trap having volume of about 400 cm3 and openings of about 16 cm2, about 0.05 to 1.0 grams of extract, preferably 0.1 to 0.5 grams, are sufficient. The amount to be used will vary, of course, depending primarily on the configuration of the trap in which the extract is to be used.

In the following Examples, there are described several preferred embodiments to illustrate this invention. However, it should be understood that this invention is not limited to these specific embodiments.

EXAMPLE 1 This example describes a comparative odor test for a tamarind seed extract and for four extracts of foenugreek seeds.

Sample C is a tamarind seed extract, identified as "Tamarind FC, T15V" obtained from Bio-Botanica, Inc., Hauppauge, New York.

The product is an aqueous mixture having a minimum of 65 wt.% solids and conformed to the following specifications.

TABLE I - TAMARIND EXTRACT CHARACTERISTICS Description - Dark brown viscous liquid Homogeneity - Complete Refractive Index - 1.3350 - 1.3550 @20 C, 10% solution Specific Gravity - 1.0200 - 1.0500 @ 200C, 10% Solution - - 2.0 - 5.0 @ 20 c, 10% Solution Solubility - Soluble (Water/Alcohol) Viscocity @ 200C 8pindle #4 30 rpm Initial - 7500 cps Interim - Thixotropic Final - 0,000 - 45,000 cps Samples A, B, D and E are foenugreek seed extracts.

Samples A, B and E were obtained from Bio-Botanica, Inc., and identified respectively as SE Fenugreek-5c, SE Fenugreek-20 and SE Fenugreek-lo. These samples differed from each other in solid contents and therefore had a different odor properties.

Sample D is a foenugreek extract obtained from Dr. Madis Laboratory, South Hackensack, New Jersey, currently used in formulating commercial non-insecticidal roach traps.

Each sample was placed inside an empty box-like roach trap having the dimensions 12.5 cm x 7 cm x 4.5 cm, with an opening of about 4 cm x 2 cm in each of two side panels. 0.3 g of each sample were placed in the roach trap and each roach trap was then placed in a separate "smell chamber" having dimensions of 75 cm x 58 cm x 58 cm, equipped with clear plastic sliding doors. The traps were left undisturbed for 15 minutes and, after this waiting time, 35 analysts evaluated the samples with instructions to evaluate the odor strength and the odor acceptability characteristics of each trap as a non-insecticidal roach trap. A 9-point scale was used both for odor strength and for acceptability. In the odor strength test, a rating of (1) indicated weak odor, and a rating of (9) indicated strong odor.

In the acceptability test, non-acceptability was rated (1), while complete acceptability was rated as (9).

The following is a summary of the results obtained from the 35 analysts.

TABLE II - ODOR 8TRENGTH SAMPLE MEAN GEO.MEAN VARIANCE 8TD . DEV.

A 5.829 5.338 4.146 2.036 B 7.343 7.104 2.820 1.679 C 3.771 3.111 4.417 2.102 D 6.114 5.537 4.269 2.207 E 7.086 6.811 2.963 1.721 TABLE III - ODOR ACCEPTABILITY SAMPLE MEAN GEO. MEAN VARIANCE STD.DEV.

A 5.486 5.004 4.198 2.049 B 4.457 3.199 7.138 2.672 C 6.343 5.963 3.938 1.984 D 5.200 4.618 4.753 2.180 E 4.600 3.913 5.188 2.278 These data show that the four foenugreek Samples A, B, D and E are quite similar in their odor strengths, but that Sample C, the tamarind seed extract, has considerably less odor.

On acceptability, Samples D and A are quite close whilst the other two foenugreek Samples B and E, are somewhat less acceptable. The tamarind Sample C was evaluated as being more acceptable than all of the foenugreek samples.

EXAMPLE 2 Three of the samples reported in Example 1 were further tested for odor strength and acceptability after a two-week exposure. Sample B was Tamarind FC obtained from Bio-Botanica, Inc. Sample A was the foenugreek extract obtained from Dr.

Madis Laboratory. Sample C was SE Fenugreek-5c, obtained from Bio-Botanica, Inc.

The procedure is identical to the procedure used in Example 1 except that the traps were permitted to remain in the laboratory at room temperature for two weeks before being placed in tha "smell chamber" for evaluation.

The results obtained are as follows: TABLE IV - ODOR STRENGTH SAMPLE MEAN GEO.MEAN VARIANCE 8TD.DEV.

A 4.514 3.883 4.434 2.106 B 2.457 2.009 2.491 1.578 C 4.429 4.003 3.605 1.899 TABLE V - ODOR ACCEPTABILITY SAMPLE MEAN GEO.MEAN VARIANCE 8TD.DEV.

A 5.257 4.879 3.255 1.304 B 6.029 5.686 3.676 1.917 C 5.171 4.832 3.323 1.923 These data show that the tamarind Sample B has statistically weaker odor than the foenugreek Samples A and C.

Also, the acceptability level of the tamarind extract sample is somewhat higher than for the foenugreek extract samples.

EXAMPLE 3 To determine the viscosity at varying temperatures of a tamarind seed extract of the type used in Examples 1 and 2, its viscosity was measured in an LVT viscometer, using a No. 4 spindle at 12 rpm. The results are shown in the following table: TABLE VI TEMPERATURE VISCOSITY 200C 23,000 cps 300C 21,500 cps 380C 16,500 cps 43 CC 15,000 cps 490C 12,000 cps 540C 5,550 cps 600C 2,950 cps These data show that tamarind seed extract maintains sufficient viscosity at elevated ambient temperatures so that leaching out of the extract is not likely to occur at temperatures expected during shipment and use.

EXAMPLE 4 In order to examine the attractant activity of tamarind seed extract, a comparative test was done involving roach traps of the dimensions described in Example 1. Three of the four inner surfaces of the roach traps were coated with strips of a sticky substances. The test was replicated six times. Each replication involved the use of a roach trap coated with this sticky substance only (unbaited trap) and a roach trap coated with the sticky substance plus a strip of a tamarind seed extract of the type described in Example 1 (baited). Each replication was done in a square test arena having an area of about 3.4 m2, with the baited trap and the unbaited trap placed on opposite sides of the area.

In an acclimation frame of about 0.12 m2 located in the centre of the arena, there were placed 75 nymphs and 25 adult male German cockroaches, a triangular harborage, food and a water cup. After 4 hours, the acclimation frame was removed and the cockroaches thus had access to the entire test arena.

After approximately 18 hours (an overnight period), the number of cockroaches present in each trap was counted and of these, the numbered trapped in the sticky composition ("glue") was noted. The results are shown in the following Table VII: TABLE VII TEGT NO. BAITED TRAP UNBAITED TRAP TOTAL IN GLUE TOTAL IN GLUE 1 44 4 4 33 2 45 45 43 25 3 53 40 49 36 4 77 54 23 23 5 54 45 43 30 6 69 69 29 29 These data show that tamarind seed extract acts as a significant attractant in sticky traps for German cockroaches. It is expected that similar results would be shown for other roach species.

EXAMPLE 5 The efficacy of tamarind seed extract as a cockroach attractant was compared to the foenugreek extract supplied by Dr. Madis Laboratory, Sample D of Example 1. Into roach traps of the type described in Example 4 having strips of sticky substance, were placed 0.3 g of foenugreek or a like amount of a tamarind seed extract of the type used in Example 1. The test procedure was substantially the same as in Example 4, with four replications.

The results are as follows: TABLE VIII TEST NUMBER or ROACHES TRAPPED TAMARIND FOENUGREEK 1 34 44 2 32 42 3 49 18 4 27 36 Grand Totals 142 140 Total Number of Roaches Released 608 Total Percent Trapped 282 = 46.4% % Trapped by Tamarind 23.4% % Trapped by Foenugreek 23.0% A second test was run and showed the following results: : TABLE XI TE8T NUMBER OF ROACHES TRAPPED TAMARIND FENUGREEK 1 45 37 2 24 45 3 52 36 4 36 40 Grand Totals 157 158 Total Number of Roaches Released 608 Total Percent Trapped 315 = 51. 88 % Trapped by Tamarind 25.8% % Trapped by Foenugreek 26.0% These results show that, as an insect attractant, tamarind seed extract compares favorably with foenugreek extract without having the disadvantageous odor properties of foenugreek.

Claims (13)

1. A method for attracting insects to an insect trap, which method comprises exposing the environment surrounding said trap to an extract of tamarind seeds in an amount effective to attract insects.

2. A method according to claim 1 in which the insects are cockroaches.

3. A method according to claims 1 or 2 in which the tamarind seed extract is placed inside said trap.

4. A method according to claim 3 in which the tamarind seed extract is contained in a sticky composition for capturing insects.

5. A method according to claim 3 in which a sticky composition for capturing insects is separately placed inside said trap.

6. A method according to claims 4 or 5 in which the sticky composition additionally comprises an insecticide.

7. A sticky composition for capturing insects which comprises, as an insect attractant, an effective amount of a volatile extract of tamarind seeds.

8. A sticky composition according to claim 7 which additionally comprises an insecticide.

9. A device for capturing cockroaches which comprises a composition-carrying means, a sticky composition coated onto a surface of said carrying means, and, as a cockroach attractant, an effective amount of a tamarind seed extract.

10. A device according to claim 9 in which the carrying means is a chamber and the sticky composition is coated onto one or more interior surfaces thereof.

11. A device according to claim 10 in which the tamarind seed extract is coated onto a surface separately from the sticky composition.

12. A device according to claim 10 in which the tamarind seed extract is incorporated into the sticky composition.

13. A device according to claims 9, 10, 11 or 12 in which the sticky composition additionally comprises an insecticide.