AU2010236062B2

AU2010236062B2 - Method of Insect Control

Info

Publication number: AU2010236062B2
Application number: AU2010236062A
Authority: AU
Inventors: Jinan Cao
Original assignee: Cao Jinan Dr
Current assignee: Cao Jinan Dr
Priority date: 2009-10-28
Filing date: 2010-10-27
Publication date: 2017-09-07
Anticipated expiration: 2030-10-27
Also published as: AU2010236062A1; NZ588814A

Abstract

Abstract This patent application discloses a method of flying insect control by broadcasting frequency sweeping sound waves to malfunction the wing beating system of the 5 flying insects in general, egg laying female blowflies in specific to reduce fly strike of sheep. It comprises: using digital technology to generate single frequency sinusoidal sound waves over a wide range of frequency covering the wing beating frequency of the insects, linking these waves to form ascending, descending and random frequency sweeping sound wave series, which are further linked together to create frequency 10 sweeping sound tracks; broadcasting said frequency sweeping sound tracks such that the sound pressure level (SPL) over a grazing land reaches a value higher than 2.0 Pa (i.e. 100 dB). (2)(5) () (5)(2 /(4)

Description

METHOD OF INSECT CONTROL 2010236062 27 Oct 2010

Field of the invention

This invention provides a method of generating and broadcasting sound waves that 5 are designed to resonate with the wing hinges to malfunction the wing beating system of flying insects for insect control. This method is in particularly invented to provide a method of reducing the problem of flystrike as an alternative of mulesing.

Background of the invention 10 Female flies lay their eggs onto moist skin wrinkles of sheep. The eggs then quickly hatch into larvae (maggots) that chew on sheep's flesh. Larvae infected sheep become very ill and often die if not treated. This is flystrike, which constitutes of a severe problem to the sheep and wool industry. Fly strike occurs predominantly (around 80%) to the breech area of sheep, but all the other moist skin wrinkling areas are 15 susceptible to fly strike.

Flystrike imposes unacceptable economic losses for the sheep and wool industry. To reduce fly strike, the sheep and wool industry adopts a practice called mulesing that involves surgical removal of the breech wrinkling skins. Mulesing is the most 20 effective method so far to protect sheep against breech fly strike. In fact, it has been widely practiced since its invention in the 1930s.

However, there are increasing concerns of animal welfare against the mulesing practice. Mulesing is painful and unacceptable to many consumers of wool end 25 products. For this reason, the Australia sheep and wool industry has committed to phase out mulesing by the year of 2010. Numerous researches have been carried out to develop mulesing alternatives. For instance, the Australian Wool Innovation Ltd. (AWI) has developed a method applying clamping forces to substantially starve blood supply to the breech skin to lead to skin atrophies, as disclosed in an Australian patent 30 (AU Patent Application NO. 2006202715 Bl). This treatment, also known as clipping, is expected to improve animal welfare though, the strong forces required on the clamps result in significant pain to sheep. Also, intensive labour and time are needed to apply clamps on sheep one by one. 1 2010236062 27 Oct 2010

There are a couple of interim measures for mulesing, i.e. using pain relief agent in mulesing or the use of a topical anaesthetic post-mulesing to alleviate the pain and suffering of sheep caused by mulesing. These two measures have certainly improved 5 animal welfare, however, it is not sufficient to persuade consumer acceptance of mulesing - alternatives of mulesing are essential.

Chemical injection is another approach. Specially formulised chemicals are injected using a needle, either forming a barrier between the sheep's skin and its flesh, which 10 will eventually lead to the skin patch contracting and an overall tightening of the breech area, or forming an internal suture, which leads to skin being painlessly removed (AU Provisional Patent Application NO. 2008904486). Female flies do not lay their eggs onto the bare breech area of sheep. There is no report yet on whether or not residual of the chemicals causes any problems such as meat safety and nutrition, 15 environment of grazing lands etc.

Intradermal injection is a treatment similar to the chemical injection method mentioned above. A shaped applicator delivers measured dose of formulised chemical just onto the breech skin layer of sheep. This causes death of the skin cells 20 in the treated area, leading to eventual removal of the skin patch. This method is currently under development by the Australian Wool Innovation Ltd.

Research into genetic modification and breeding sheep with a naturally bare and wrinkle free breech is also under progress. Though it is likely to be a more humane 25 long-term solution, it will take many sheep generations to be effective in countering flystrike. It is considered unreasonable to expect genetic modification and breeding can meet the mulesing phase out deadline in 2010.

In spite of countless efforts made since the year of 2004, there is still no practical 30 alternative to reduce flystrike to phase out mulesing. In fact, the peak research and development body of the Australia wool industry, the Australia Wool Innovation Limited (AWI) made a media release on 27th of July, 2009 acknowledging that the 2010 ‘deadline’ to phase out mulesing is unlikely to be reached for welfare reasons based on scientific grounds, facing threat of global boycott of Australian wool. 2 2010236062 27 Oct 2010

In contrast with above-mentioned methods that tackle sheep, a method that tackles flies appears to have significant technical and economical merits - it counters all the flystrike, both the breech flystrike and flystrike on any other areas of the sheep body. 5

In the field of insect control, there are a number of patents addressing insect repelling systems and methods; and there are also commercial products available in market that utilise sonic or ultrasonic sound waves to discourage, scare then repel pests, birds and animals. Products that broadcast audible predator’s calls repel certain pests, birds or 10 animals by psychologically scaring; while products that broadcast ultrasonic sound waves, however, take advantage of the difference between humans and animals in auditory system to repel animals. Many animals, including rodents have a hearing range that extends far higher than humans and are capable of hearing ultrasonic sound. This means that ultrasonic sound can be used at high volume as a deterrent 15 against rodents whilst humans aren't aware of any sound. The high level of sound causes the creature’s auditory distress encouraging them to leave the area. These products can be used indoor or outdoor to repel rodents and bats etc. Unfortunately, they can not be used to reduce flystrike. 20 On the other hand, broadcasting sound waves to repel flying insects is an appealing idea attracting attention from inventors since at least the 1970s. This is because the idea has a range of obvious amazing merits if it does work, as compared with other methods for insect control. 25 White claimed an electronic sound generator that generates a wide range of sound frequencies to repel insects from the area in a patent entitled “Sonic Insect Repeller” (US3886492) in 1975; Moschgat patented a method and system producing a set of pulsed signals having a randomly varying frequency in the range of about 18-30 KHz and having an intensity of at least 90 dB in “Ultrasonic Pest Repellent Method and 30 System” (US4186387) in 1980. Another US patent (Ackley, 1985, “Ultrasonic Pest Repeller,” US 4562561) discloses a circuit for generating electronic ultrasonic sound waves to repel pests. 3

More recently, an US patent (Pujolas, 2005, “Flying Insect Repelling System,” US 6,882,594 Bl) discloses an insect repelling system that produces ultrasonic turbulence waves and broadcasts them over an intended area to repel mosquitoes from the area. 2010236062 27 Oct 2010

In particular, the patent describes the ultrasonic waves are in multiple frequencies of 5 the wing speed of noxious insects such as mosquitoes. When the insects encounter such ultrasonic waves, the waves would cause wings of the insects to fluctuate or vibrate such that they cannot fly.

Another US patent (Hsu, 2008, “Insect Repelling System Using Feedback,” US 10 7,362,658 B2) discloses an insect repelling system including a microphone for converting pressure waves generated by a flying insect flapping its wings into electrical signals, and a speaker for generating pressure waves toward the flying insect based on the electrical signals. In an attempt to make the generated pressure waves imposing a force resisting wing beating driving force of the insect, the US 7,362,658 15 patent includes a phase shifting device that will add a 180° phase lag to the pressure waves relative to the phase of the detected insect wing flapping signal.

However, constant untiring endeavours over the past several decades have not led to practical use of sound waves in flying insect control in spite of the appealing nature of 20 the idea, indicating that there is a need for further improvements. The system disclosed in the US 7,362,658 B2 patent for instance, is not practicable because firstly it is unreasonable to expect wing flapping sound detectable by a microphone in field; secondly the system has no knowledge to tell whether a frequency component is originated from insect wing flapping or from any other sound sources. As such the 25 system will not be able to filter, generate and amplify sound waves based on the detected insect wing flapping signals. Thirdly, travelling of the sound waves from the insect to the microphone and from the speaker to the insect result in an additional phase lag, therefore, it is not really meaningful to include a phase shifting device in the system. In addition, the patented system is time and cost consuming to be 30 developed.

Thus to reduce flystrike by using an insect controlling technique, we need an effective for fly control. The principal object of the present invention is to provide a method that effectively protects sheep against flystrike as an alternative to mulesing, to save 4 surgical labour of mulesing and to improve sheep’s animal welfare. It is also an object of the invention to further the idea of attack insect wings by sound waves for insect control to make it practicably works. 2010236062 27 Oct 2010 5 The preceding discussion of the background to the invention is intended to facilitate an understanding of the present invention. It is not an acknowledgement or admission that any of the material referred to was part of the common general knowledge as at the priority date of this present application. 10 Brief description of the drawings A preferred embodiment of the present invention will now be described, by way of an example only, with reference to the accompanying drawings wherein:

Figure 1 illustrates a model of the wing hinges for flying insects. The DVM and 15 DLM forces act on the internal end, the sound pressure acts on the external end of each wing hinges.

Figure 2 is a block diagram showing an insect control unit that broadcasts the frequency sweeping sound waves. 20

Figure 3 Animals are protected against insect attacks by simply placing several broadcasting units around a grazing land.

Detailed description of the embodiments of the invention 25 Flying insects such as flies share a common structure of wing hinges: the wings form the external end, and connected with the internal end are the dorsal ventral muscles (DVM) and dorsal longitudinal muscles (DLM). When flying, while the DVM contracts, the DLM stretches; when the DVM is fully contracted, the DLM is fully stretched and vice versa. The span of the wing swinging angle for flies is around 30 170°.

The DLM and DVM alternately contracts and stretches in an accurately and precisely coordinated manner. It has a fixed frequency range for a given insect species with 5 some variation due to factors such as age and gender. When an external force acts on the external end, a torque tending to swing the wings will exist on the wings. If the wings are over swung, an over stretching will occur of the DLM and/or the DVM, which could cause malfunctioning of the insect’s wing beating coordinating system, 2010236062 27 Oct 2010 5 resulting in temporal or permanent loss of flying capability of the insects.

The level of the external force required to malfunction the wing beating system of flying insects depends principally on the structure of wing hinges, strength of the DVM and DLM as well as the wing plane’s geometry and size, varying from species 10 to species.

Figure 1 illustrates a model of the wing hinge structure of flying insects. The insect body (1) harbours its wings (2) with hinges (3). The wing swinging forcing generated by the DVM/DLM have been symbolised as arrows (4), and the external forcing 15 acting on the wings are represented using arrows (5).

Sound pressure, which is the local pressure deviation from the ambient (average, or equilibrium) pressure caused by sound waves, can be used to serve as said external forcing to malfunction the wing beating system of flying insects. Sound waves are 20 longitudinal waves, and the instantaneous sound pressure periodically varies with time. When wing plane’s surface normal is perpendicular to the travelling direction of the sound waves, there is no sound pressure acting on the wings; the sound pressure acting on the wings reaches maximum when wing plane’s normal is parallel to the progress direction of the sound waves. While this parallel condition is met, and when 25 the instantaneous sound pressure reaches the peak and hits the wings at their maximum or minimum swinging angle, the wings could be over swung, leading to an over stretching of the DLM and/or the DVM, which in turn results in malfunctioning of the wing beating system of the insects. In other words, the probability of over swinging of the wings reaches maximum when the following three conditions are met 30 simultaneously: i) the wing plane’s normal becomes parallel to the travelling direction of the sound waves; ii) the peak sound pressure hits the wings; and iii) the wing’s swinging angle is at its maximum or minimum. As insects’ location and flying direction constantly change when flying, there are instants while these three 6 conditions are met simultaneously by chance; but the instants are short lived because of flying. 2010236062 27 Oct 2010

The force of sound pressure is low. For example, the effective sound pressure, 5 defined as the root mean square of the instantaneous sound pressure over a period, is 20 Pa (= 20 N/m2) only at sound pressure level (SPL) 120 dB, which is very much the loudest one can apply practically.

Therefore there is a need to take advantage of the principle of resonance. When 10 resonance occurs, insignificant periodical forcing generates huge destructive power. When the sound waves with the same frequency of insect’s wing beating frequency are applied, the whole wing hinge system may resonate when the DVM/DLM force and the sound pressure are in phase, thus malfunction of the wing beating system. 15 Thus the frequency and SPL (in terms of Pascal = N/m2) are two paired essential requirements, and they must be met simultaneously. A sinusoidal waveform is preferred to enhance resonance power.

Resonance requires an exact match in frequency. However, insects wing beating 20 frequency is variable over a relatively wide range due to age and gender etc.

Cunning insects in particular flies may try to avoid resonance by altering the wing beating frequency as well as body direction or location if they’ve sensed increasing uncomfortableness with the wings and/or wing hinges. Besides it is not easy to determine the actual wing beating frequency of flying insects with sufficient accuracy 25 both in field and in laboratory.

Frequency sweeping sound waves are designed to overcome the above mentioned problem. The frequency sweeping sound waves are a time series of single frequency sound waves. For example, one creates a series of sound waves: 120, 122, 124 ... 30 178,180 Hz 31 sound waves, 100 ms long for each wave; one then links the sound waves together to form a time series. If the sound waves are linked in an increasing order, that is, in the first 100 ms the 120 Hz sound wave starts; next 100ms the 122 Hz sound wave follows and so on and so forth until the sound wave with maximum frequency 180 Hz. This is ascending frequency sweeping wave series. Similarly, one 7

Clean copy amended specification: 2010236062 Method of Insect Control 2010236062 28 Mar 2017 can compose descending frequency sweeping wave series that sweeps from highest frequency to lowest frequency with time. If a wave series is composed of these single frequency sound waves in a random order, it forms a random frequency sweeping wave series. The ascending, descending and random sweeping wave series can 5 further linked together to form frequency sweeping sound wave tracks for loop broadcasting.

The frequency sweeping range should cover the entire range of insects’ wing beating frequency. If the frequency sweeping range can be narrowed, higher efficiency can be 10 expected. A convenient acoustic technique is to record the flying sound of the insects to be controlled in an audio setting, then to perform the Fourier Transformation to obtain the frequency spectrum, from which the wing beating frequency can be determined. Alternatively, instruments such as stroboscopes, high speed cameras and the laser technology can also be useful tools. These techniques ensure the frequency 15 sweeping range does cover the wing beating frequency range of the insects.

Digital technology can be used to generate the frequency sweeping sound tracks that can be saved in any digital audio encoding formats such as Audio Layer 3 (MP3), AAC/M4A, Protected AAC, AIFF and WAV on any audio storage media such as 20 compact disks (CD), flash memory (memory stick) or memory cards, hard drive, tape and networked memory via internet or intranet. The sound track can also be saved in any analogue form. Though the computer digital technology is the most accurate, precise and convenient method, analogue technology employing electrical circuits can also be an alternative to generate the frequency sweeping sound waves. 25

Figure 2 shows a block diagram of a broadcasting unit (6). It consists of player(s) (7), amplifier(s) (8) and speaker(s) (9). Player(s) (7) can be any commercial audio player as long as it is consistent with the storage media, e.g. CD player, hard drive player, and Portable Media Player (iPod), or an analogue player to name only a few. 30

Player(s) (7) reads the frequency sweeping sound track pre-saved on storage media, and sends the sound signal to Amplifiers) (8) for amplification before feeding into Speakers) (9) that broadcasts the sound waves to air. Broadcasting unit (6) is portable and compact, it can be moved and mounted easily. 8 2010236062 27 Oct 2010

Figure 3 is a block diagram of a sheep protection setting (10) in one embodiment of the invention. The setting (10) comprises of several broadcasting units (6), placed in proper intervals to ensure an even SPL over a grazing land where there is sheep flock 5 (11) needing protection against flystrike. The number and specification of the speaker and amplifier should be so selected and adjusted that the SPL of the sound waves reaches 2.0 N/m2 (100 dB) or higher over a grazing land. By broadcasting the high volume frequency sweeping sound waves, the whole grazing land turns into a no-fly zone to flies, so that sheep are free from flystrike. There is a tree (12) in Figure 3 to 10 symbolise the settings of grazing lands.

The major drawback of the method described above lies in its loudness of the frequency sweeping sound waves, which is stressful to the humans as well as the animals on the grazing land. To alleviate the noise stress, one can also broadcast 15 music that comforts the animals under protection together with the frequency sweeping sound waves.

Pre-clean is a useful strategy to solve the noise stress problem of the high volume frequency sweeping sound waves. High volume sound waves with SPL reaching e.g. 20 20 N/m2 (120 dB) or higher are broadcasted prior to commence of grazing days over a grazing land when the humans and sheep are absent. Further insect lures can be used for pre-cleaning, expecting better performance. While grazing sheep, broadcast no sound wave or occasionally lower SPL sound waves, e.g. 0.2-2.0 N/m2 (80-100 dB). And it is also practicable to broadcast the high SPL, low SPL and no sound waves in a 25 programmed manner according to the risk level of flystrike to minimise the noise stress to sheep under protection. 30 9

Claims

Clean copy of amended claims: 2010236062 Method of Insect Control Claims The claims defining the invention are as follows: 1) A method of insect control by broadcasting frequency sweeping single frequency sound waves to malfunction the wing beating system of the flying insects, comprising i) determining the range of wing beating frequency of the insects; ii) generating a series of single frequency sound waves covering all the frequencies over said range of wing beating frequency of the insects; iii) linking said single frequency sound waves from low frequency to high frequency to form ascending frequency sweeping sound series, from high frequency to low frequency to form descending frequency sweeping sound series, and in a random order to form random frequency sweeping wave series, which are further linked together to form frequency sweeping sound tracks; iv) broadcasting said frequency sweeping sound tracks such that the SPL of the sound waves reaches a value higher than 2.0 Pa (i.e. 100 dB).
2) The method of Claim 1 further comprising a sinusoidal waveform for said series of single frequency sound waves.
3) The method of Claim 1 further comprising generating said single frequency sound waves, linking them to compose said ascending, descending and random frequency sweeping sound series as well as said frequency sweeping sound tracks using digital technology by computer software to ensure the accuracy of frequency and waveform;
4) The method of Claim 1 further comprising broadcasting said frequency sweeping sound waves over a grazing land while humans and sheep are absent as a measure of pre-clean.
5) The method of Claim 4 further comprising placing insect lures on the grazing land while broadcasting said frequency sweeping sound waves to enhance the pre-clean performance.