AU687811B2 - Insect traps - Google Patents

Description

WO 94/27430 PCT/AU94/00267 1

TITLE

"INSECT TRAPS" FIELD OF INVENTION THIS INVENTION relates to insect traps.

BACKGROUND ART All over the world insect pests are very damaging to crops and livestock such as sheep. Insect pests are both prevalent and costly in relation to the capital required to prevent and overcome damage caused by such pests. Management solely by spraying pesticides is often questioned as an acceptable practice because of its possible deleterious side effects on human health and the environment; and also because resistance to the pesticides is often selected for in the insect pests.

Reference may be made to insect traps which are summarised in the following references: Spradbery J. Aust. ent. Soc. 20 151-153 (1981) (ii) Muirhead-Thomson in a publication entitled "Trap Responses of Flying Insects; The Influence of Trap Design on Capture Efficiency" Academic Press Limited London (1991) (iii) Dadour and Cook J. Aust. ent. Soc. 31 205-208 (1992) (iv) Mackerras et al. J. Coun. Sci. Ind.

Res. Aust. 9 153-162 (1936) Vogt et al. J. Aust. ent. Soc. 13 249- 253 (1974) (vi) Wardhaugh et al. Aust. Vet. J. 61 132 (1984) (vii) Williams J. Econ. Entomol. 77 806-809 (1984) (viii) Anderson et al. Aust. Vet. J. 67 93-97 (1990) and associated Australian Patent Specification 58826/90, and WO 94/27430 PCT/AU94/00267 2 (ix) Wall et al. Med. Vet. Entomol. 6 67-74 (1992) References (ii) and (iii) above are concerned with insect traps in general such as traps for screw worm flies, bushflies and a range of blowflies such as the Australian sheep blowfly.

References (iv) to (ix) above are generally concerned with traps to be used for flies of the genus Lucilia.

Reference may also be made to insect traps discussed in US Patent 4,121,372, South African Patent 77/01955, US Patent 3 807 081, US Patent 4 947 578, Russian Patent SU 1 454 336, US Patent 4 638 592, US Patent 4,450 649, US Patent 4 328 636, UK Specification 1 580 233, German Specification 2 915 074, South African Patent 77/07454, US Specification 4 044 494, German Specification 2 412 723 and US Specification 4 793 092.

Of these references US Patent 4 638 592 is considered the most relevant to the present invention and includes a translucent container releasably carrying a top or cover which is upwardly convex and defines plural downwardly extending indentations each carrying in its medial part a conical entry tube with a sharp edge defining a lower orifice of the tube above an upper part of the container. An aqueous fermentative odoriferous mixture comprising yeast, egg and milk is carried in the container as a fly attractant and an insect drowning medium.

Significant disadvantages of the abovementioned insect traps are the requirement for frequent maintenance checks due to drying out of the fermentative mixture which results in a marked decline of attractiveness and a failure to drown -he contained insects; -e (ii) the use of a fermentative mixture which can readily be populated with variable microorganisms with consequent unpredictable attractiveness; and (iii) the maintenance checks, which are necessary for the upkeep of the fermentative mixture, are costly and inconvenient in the field, especially in inaccessible locations, and pose a possible health risk to the operator.

Another problem with prior art insect traps such as that described above in relation to US Patent 4 638 592 is their structural complexity and hence difficulty of manufacture. This conclusion would apply in particular to the top or cover of the fly 15 trap of US Patent 4 638 592 which has a complicated shape especially in regard to each of the abovementioned indentations.

SUMMARY OF THE INVENTION It is therefore an object of the invention to 20 provide a trap which may alleviate the problems of prior art insect traps discussed above.

In accordance with the invention there is provided an insect trap including:a container part; 25 (ii) a cover part which covers the container part having a plurality of insect access passages which are dimensioned and shaped to restrict insects using said access passages to depart from the container part; (iii) one or more vessels in the container part for containing a volatile synthetic attractant lure for insects wherein the or each vessel forms a substantially enclosed structure which has at least one exit opening of Srestricted size for controlled release -a se of the volatile synthetic attractant lure whereby the or each vessel is substantially surrounded by air whereby said volatile attractant lure may diffuse into said container part and to atmosphere through said access passages; and means for supporting said one or more vessels.

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L~j WO 94/27430 PCT/AU94/00267 4 The container part which may be of any suitable shape and for example may comprise a plastics bag which may be translucent or transparent or alternatively may be coloured.

Alternatively, the container part may be a rigid container having an open mouth and which may be round, square, polygonal, rectangular or any other suitable cross sectional shape. The rigid container part may also have a relatively constant cross-section throughout its length or alternatively it may have a progressively increasing or progressively decreasing transverse dimension from one end to another.

The cover part which may function as a lid may be provided with an upper surface which suitably is substantially planar. The cover member may also be provided with a plurality of closely sparced access passages over at least a major part of the surface area of the upper surface and which more suitably are located over the entire surface area of the upper surface. Each of the access passages may be provided with an upper open end and a lower open end with the upper open end having a greater transverse dimension tian the lower open end. Each of the access passages may also be provided with a progressively decreasing transverse dimension frusto conical shape) from upper open end to lower open end. Suitably each of the closely spaced access passages is vertically orientated although this is not necessary and the passages may be inclined at an angle to the vertical if desired.

Preferably, each of the lower open ends is provided with an acute bend and/or sharp edge which, together with the angle of the access passages and the discriminating transverse dimension of the access passages, prevent insects escaping after having become trapped in the container part. Such trapped insects die from exhaustion of food reserves, hyperthermia L~ I and/or dehydration.

There also may be provided a means for attaching the cover part to a tree post or other suitable fixed object in the field and in one form this may comprise an attachment flange which may be provided with one or more attachment aperture(s) for insertion of a suitable fastener to attach the cover part to the tree or post. Alternatively, any other suitable attachment means may be utilised such as an attachment strap or releasable clip for example in attachment of the cover part to the fixed object in the field or suspended by a flexible line member inclusive of string, chain, rope, cable or the like.

n a variation of the foregoing it will also be 15 appreciated that instead of attaching the cover part S: to the tree it may be preferable in some cases to attach the container part to the tree instead of the cover part using similar attachment means such as those described above. It is also possible to attach 20 both of the cover part and the container part to the fixed object.

There also may be provided means for supporting .oo..i S" said one or more vessels such as bottles or plastics vessels within the container part so that such vessels 25 are substantially surrounded by air. The mounting *go means may, for example, be integral with the cover part or be associated with the cover part such as a support base is attached to the cover part by a plurality of upright support struts or straps. In another variation the supporting means may comprise a retaining strap which is suspended from the cover part by any suitable means. In one form the mounting strap may have pointed ends for retention within mating retention slots in the cover part. The mounting strap may also include one or more retaining projections or apertures which may engage with a neck of an associated small vessel.

WO 94/27430 PCT/AU9400267 6 The abovementioned vessels may be used to provide a prolonged, controlled release of the contained chemical attractants. They may contain an attractant formulation which may comprise a plurality of volatile chemicals either in admixture or being placed adjacent to each other in small containers. To this end, each container may contain an elongated wick member, formed from cotton or other suitable fabric which is flexible and permeable, which is firmly held in the mouth of the container with a support made for example from plastic materials such as polyethylene and which tightly surrounds the wick member.

Alternatively the wick member may comprise a tube or woven strip or bundle of loose twist or braid of soft threads which may facilitate drawing up of volatile liquid material contained in the container.

Alternatively, attractant chemicals can be contained in an absorbent matrix contained in a perforated bag or in a sachet consisting of porous material or in a semipermeable tube or tubes.

BRIEF DESCRIPTION OF DRAWINGS Reference may now be made to a preferred insect trap of the invention as shown in the attached drawings wherein: FIG 1 is an exploded perspective view of an insect trap constructed in accordance with the invention; FIG 2 is a perspective view of an assembly of the insect trap shown in FIG 1; FIG 3 is a perspective view of the cover part of the insect trap shown in FIG 1 from underneath also showing incorporation of bottles containing attractant; FIG 3a is a detailed view of the access passages shown in FIG 3; FIG 3b is a detailed perspective view of the support frame utilized for supporting the bottles;

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WO 94/27430 PCT/AU94/00267 7 FIG 3c is a detailed view of a neck of a particular bottle; FIG 4 is a bottom perspective view of the container part of the insect trap of FIG 1; FIG 5 is a plan view of a bottle utilized to contain attractant which is different to the bottle shown in FIG 3; FIG 6 is a side view to of the attractant bottle shown in FIG FIG 7 is a view of a retaining strap which may be used to suspend bottles from the cover part of the insect trap; FIG 8 is a plan view of the retaining strap shown in FIG 7; FIG 9 shows various shapes that are applicable to a cross sectional view of the cover part; FIG 10 shows various cross sectional shapes of access passages that may be included in the insect trap; FIG 11 shows alternative top plan views of the access passages; and FIG 12 is a graph of an experiment described hereinafter concerning capture of L. cuprina in traps constructed in accordance with the present invention.

DETAILED DESCRIPTION The cover part 10 of the insect trap 11 as shown in FIGS 1-4 includes a top surface 12, access passages 13 having a top end 14 of wider transverse dimensions than a bottom end 15. Attachment plate 15A has attachment apertures 16 for attachment of the cover part 10 to a suitable support surface (not shown) and support straps 17 interconnecting attachment plate to cover part 10. There is also provided recesses 18 for retention of attractant bottles as shown in FIG 3 as well as L shaped slots 19 which engage with attachment lugs 20 of container part 21. Cover part is also provided peripheral flange 22.

IWO 94/27430 PCT/AU94/00267 8 As best shown in FIG 3a exit end 15 of access passages 13 also includes a sharpened end 23 to restrict escape of insects through access passages 13.

In FIG 3 there are shown bottles 24 containing attractant 25 which are located in recessF, 18. Each bottle is suspended by a support structure 26 including a base wall 27 and support struts 28. There is also provided a cap 29. The bottles 24 also include a neck 30 and a wick 31.

A detailed perspective view of support structure 26 is shown in FIG 3b and a detailed perj;pe.lve view of the bottle neck 30 is shown in FIG ;c which also includes retaining sleeve 30A for wick 3 i pressure calibration holes 30B. Neck 30 is also provided with peripheral flange In FIG 4 container part 21 may also be provided with drain holes 32.

There is also shown in FIGS 5-8 in an alternative embodiment a retaining strap 33 for suspending small vessels or bottles 34 which are from slots 35 in cover part 10. Retaining strap 33 may include pointed ends 36 which may be inserted in slots 35. Strap 33 may also include body part 37 and rounded parts 38 containing apertures 39 which have slots 40 which are resilient and whereby apertures 39 may resiliently engage with necks 41 of bottles 34. There also may be provided creases 42 whereby retaining strap 33 may attain the shape shown in FIG 7.

The bottles 34 shown in FIGS 5-6 contain a volatile attractant lure for insects. The bottles 34 include a body 43, cap 44 and wick 45 which is formed from cotton or siilar material so that volatile material may be drawn up wick 45 through capillary action. There is also shown retaining sleeve 46 for wick FIG 9 shows various profiles (ie 10A, 10B, and IOC) of cover part 10 and indicates that the upper WO 94/27430 PCT/AU94/00267 9 surface 12 may be planar (ie 12B) or form a shallow concave (ie 12C) or convex curve (ie 12A).

FIG 10 shows varying profiles of access passages 13 in side view as well as in top plan view indicated in FIG 11.

Thus from the foregoing it will be appreciated that the invention provides an insect trap of simple construction which is effective in use. Attractant chemical volatiles disperse out of the entrances and insects crawl in through them and are behaviourally restrained from crawling out so accumulating in the container where they die. The trap is specifically designed for trapping of Lucilia cuprina and other flies such as L. sericata but of course it will be appreciated that the insect trap of the invention may be used to trap other insects or readily modified to trap other insects.

The trap containing a suitable chemical attractant for Lucilia cuprina (the Australian sheep blowfly) has proved an excellent method for monitoring the presence and numbers of this serious pest in a variety of environments. The traps have also proved able to substantially lower the local populations of sheep blowflies on sheep stations and thus offer an ecologically acceptable method of sheep blowfly management.

In order to enable the invention to be fully understood, its efficacy in a number of attractant tests will now be described.

EXAMPLE 1 The most important parameter of a trap is its efficiency and this we measured by comparing traps constructed in accordance with the invention (hereinafter referred to as "flat top traps" with Eticky traps (comprising flat boards coated with standard insect entangling adhesive) which are considered to be highly effective in that almost all WO 94/27430 PCTIAU94100267 insects which make contact with it are trapped. Two different sources of attractant chemicals were used i.e. a. synthetic chemical mixture and b. liver sodium sulfide standard blowfly attractant. The tests were based on a Latin square design, with the traps separa.ted by more than 100 metres. The results of the tests are reported in Table i.

Example 1 shows that the "flat top" trap is as efficient as the sticky trap when using synthetic chemical attractants and it is more efficient when using a liver sodium sulfide attractant.

EXAMPLE 2 "Flat top" traps were also compared with commercially available traps in Latin square tests in both rural and urban environments. All the traps were baited with the same synthetic attractant chemical mixture. The Australian sheep blowfly catch in the "flat top" trap was hundreds of times more than the catch in the "Aussie Fly Buster" trap, over mineteen times the catch in the "Western Australian Blowfly Trap" catch and more than twice the "Jacobson" trap catch.

EXAMPLE 3 The specifications of "flat top" traps were altered to test their influence on the numbers of insects caught in a semi-field insectary containing over one thousand sheep blowfl.es. The results of Example 3 are reported in Table 2.

EXAMPLE 4 The specifications of "flat top" traps were altered to test the influence of these on the numbers of insects retained in the holding container. 100 to 200 flies comprised equal numbers of males and females were placed in the holding container of traps. After 2-3 days all the flies retained had died and they were then counted. The results of Example 4 are reported in Table 3.

I WO 94127430 PCT/AU94/00267 11 The dimensional specifications of "flat top" traps that allow insects in and those that restrict them from leaving are to some extent opposed. In practise the dimensions of the "flat top" trap used for a particular pest will be a compromise between the parameters that give readiness of ingress and those that restrict egress. Trap efficiency therefore depends on the number of entrance ports in the flat top of the trap, the diameter and the steepness of the indented cones or access passages 13 that restrict the entrance holes from becoming exit holes. Whilst we have concentrated on dimensions appropriate for the sheep blowfly we are also conscious of the application of various dimensional variants of this invention to traps for a wide range of pest insects having different sizes and behaviour.

Small scale field trials were carried out in western Queensland (Australia) to test the hypothesis that placing traps containing a synthetic attractant (2-mercaptoethanol, indole, butanoic acid, sodium sulfide) in a sheep paddock would lower the Australian sheep blowfly population in that paddock. The trial was run with five replicates (Cunnamulla, Charleville, Roma, Longreach [2 each consisting of two paired sites, one as control (no traps) and the other containing traps. In each site five monitoring traps (opened for 24 hours every seven days) were used to measure the fly population. The mean numbers (from all five replicates) of sheep blowflies caught in the monitoring traps in the trapped and the control areas during the 15 week trial are shown in figure 12. The fly population was substantially lower in the trapped areas, indicating population suppression by the presence of traps constructed in accordance with the invention containing a synthetic attractant.

The invention also includes within its scope a method of attracting insects for monitoring and/or WO 94/27430 PCT/A U9400267 12 population suppression using an insect trap having a container part and a cover part including the steps of: locating the insect trap in the field with the container part being substantially empty and supporting one or more vessels containing a volatile synthetic attractant in the container part whereby said one or more vessels are substantially surrounded by air whereby said volatile synthetic attractant may diffuse from said one or more vessels into said container part and thence to atmosphere through insect access passages in the cover part which are dimensioned and shaped to restrict insects using said access passages as an exit from the container part; and (ii) disengaging the container part from the cover part to facilitate removal of dead insects which have accumulated in the container part.

WO 94/27430 WO 94/7430 CT/AU94/00267 13 TABLE 1 Results of Example 1 Number of "Flat Standard Type tests topi"! error of attractant Sticky trap of mean catch ratio (mean) a. Synthetic 12 0.96 0.14 chemicals b. Liver sodium 5 6.70 4.70 sulfide I11 WO 94/27430 PCT/AU94/00267 14 TABLE 2 Results of Example 3 Parameter Specification Mean flies caught Cone 440 27.1 steepness 310 20.4 200 15.7 Entry hole 4.5 mm diameter 5.0 mm 18.3 mm 22.9 mm 60.1 Number of 6 7.4 holes 12 22.7 WO 94/27430 IPCT/AU94100267 TABLE 3 Results of Example 4 Parameter Specification flies retained Cone steepness 440 88 310 200 96 Entry hole 4.5 mm 100 diameter 5.0 mm 97 mm 98 mm 84 Attractant nil 94 synthetic chemicals 100

Claims (14)

1. An insect trap including:- a container part; (ii) a cover part which covers the container part having a plurality of insect access passages which are dir, 1 ?nsioned and shaped to restrict insects using said access passages to depart from the co t.irer part; (iii) W more vessels in the container parc for containing a volatile synthetic attractant lure for insects wherein the or each vessel forms a substantially enclosed structure which 15 has at least one exit opening of restricted size for controlled release of the volatile synthetic attractant *lure whereby the or each vessel is substantially surrounded by air whereby 20 said volatile attractant lure may diffuse into said container part and to atmosphere through said access passages; and (iv) means for supporting said one or more vessels.

2. An insect trap as claimed in Claim 1 wherein the plurality of insect access passages occupy substantially the entire surface area of a top surface of said cover part.

3. An insect trap as claimed in Claim 1 wherein said one or more vessels include a wick which extends into an upper part of an associated vessel part whereby said volatile synthetic attractant may diffuse into the container part from the or each vessel by capillary action.

4. An insect trap as claimed in Claim 1 wherein the supporting means includes a framework having a base 0* a a.. a a a 17 wall and one or more support struts.

An insect trap as claimed in Claim 4 wherein the support strut(s) depend from a peripheral edge of an aperture in the cover part which is substantially larger than the access passages in transverse dimension wherein said aperture is adapted to be closed by a cap.

6. An insect trap as claimed in Claim 1 wherein the supporting means includes a retaining strap for holding said one or more vessels wherein said retaining strap is attached to the cover part.

7. An insect trap as claimed in Claim 6 wherein the retaining strap includes one or more retaining rings for resiliently engaging with an associated vessel.

8. An insect trap as claimed in Claim 1 including attachment means associated with the cover part for attachment of the trap to a tree or other fixed object.

9. An insect trap as claimed in Claim 8 .in the attachment means includes an attachment plate having one or more attachment apertures and said attachment plate is secured to the cover part by a plurality of support straps.

10. An insect trap as claimed in Claim 1 wherein the 25 cover part is releasably attached to the container part by releasable attachment means.

11. An insect trap as claimed in Claim 10 wherein the releasable attachment means includes attachment lugs on the container part engaging with retaining slots on the cover part.

12. An insect trap as claimed in Claim 1 wherein the access passages are all of converging transverse dimensions from top to bottom in use.

13. An insect trap as claimed in Claim 12 wherein the access passages are all provided with a sharp edge or bend to restrict insects using said access passages as an exit to atmosphere.

14. A method of attracting insects for monitoring and/or population suppression using an insect trap having a container part and a cover part including the steps of:- (i) a. .a C. C a locating the insect trap in the field with the container part being substantially empty and supporting one or more vessels containing a liquid volatile synthetic attractant lure in the container part wherein the or each vessel forms a substantially enclosed structure having at least one exit opening of restricted size for controlled release of the volatile synthetic attractant lure whereby said one or more vessels are substantially surrounded by air whereby said volatile synthetic attractant may diffuse from said one or more vessels into said container part and thence to atmosphere through insect access passages in the cover part which are dimensioned and shaped to restrict insects using said access passages as an exit from the container part into atmosphere; and disengaging the container part from the cover part to facilitate removal of dead insects which have accumulated in the container part. (ii)