Reagan
McGUIRE, et al.
Acoustic Insect Repellant
http://www.azcentral.com/arizonarepublic/news/articles/2010/02/09/20100209env-beetles0209.html?nclick_check=1
The Arizona
Republic , Feb. 9, 2010
Bark
beetles' song could save forests
Study: Tree-eating insects deterred by their own calls
Researchers at Northern Arizona University think they may have
found an environmentally safe and readily available weapon
against the tree-eating armies of bark beetles.
It is, with apologies to the boys from Liverpool, the music of
the beetles.
NAU's School of Forestry was on the hunt for ways to fight the
marauding bugs, which have chewed through millions of acres of
the West's pine forests, leaving behind dead trees and the risk
of wildfires.
A research assistant suggested using sounds to aggravate the
beetles, much as police sometimes blare music in hostage
situations. The researchers tried Queen and Guns N' Roses and
played snippets of radio talker Rush Limbaugh backward. None
produced the desired results.
Then, the beetles were exposed to digitally altered recordings
of their own calls, the sounds they make to attract or repel
other beetles. The response was immediate. The beetles stopped
mating or burrowing. Some fled, helter-skelter. Some violently
attacked each other.
Most important, they stopped chewing away at the pine tree,
suggesting that the scientists may have discovered a sort of
sonic bullet that could help slow the beetles' destructive
march.
"Our interest is to use acoustic sounds that make beetles
uncomfortable and not want to be in that environment," said NAU
forest entomologist Richard Hofstetter, who led the experiment
nicknamed, without apology, "beetle mania."
Bark beetles have killed nearly 80 million ponderosa, pi?on and
lodgepole pines in Arizona and New Mexico and tens of millions
more across the West over the past decade. Years of punishing
drought left the trees unable to protect themselves against the
attacks, which carve ugly scars into forests, weaken the
surrounding ecosystem and heighten wildfire danger.
Forest managers can apply insecticide to individual trees or
small stands, but forestwide treatments are impractical and
would be wildly expensive and potentially risky to other plants
and wildlife.
Enter Reagan McGuire, a research assistant who wondered what
would happen if the beetles were blasted with noise, creating an
acoustic stress that might change their behavior. He sold
Hofstetter on the idea, and the experiment was hatched at NAU's
School of Forestry lab.
They collected tree trunks infested with bark beetles and
sandwiched slices of the trees between clear plastic plates,
creating what looked like the old ant farms once sold in the
back pages of magazines.
Working in the lab, McGuire piped in the music through tiny
speakers, the sort you might find in a singing greeting card. He
watched the reaction of the beetles using a microscope. The rock
music didn't seem to annoy the bugs, nor did Rush in reverse.
McGuire and Hofstetter decided to try something different. They
recorded the sounds of the beetles and played them back,
manipulating them to test the response.
Suddenly, every little thing they did seemed to provoke the
beetles.
"We could use a particular aggression call that would make the
beetles move away from the sound as if they were avoiding
another beetle," Hofstetter said.
When they made the beetle sounds louder and stronger than a
typical male mating call, he said, the female beetle rejected
the male and moved toward the electronic sound.
Even more surprising was what the beetles did to each other. The
researchers manipulated the sounds and, at a certain point, the
male stopped mating and tore the female apart, McGuire said.
"This is not normal behavior in the natural world," he said.
Questions remain about why and how the sonic attacks work. It's
not even clear yet where the beetles' ears are. Other
researchers hope they can work that out, seeking the best way to
aim the offending sounds.
The lab hopes to find more funding to continue its research into
acoustic pest control. Scientists think it won't be long before
they can take the experiment into the field.
WO2012078814
USE OF
ACOUSTICS TO DISRUPT AND DETER WOOD-INFESTING INSECTS...
Abstract
The invention comprises a device and method for impacting the
behavior of invertebrates that infest wood, without the use of
chemicals. In particular, the invention is useful for impacting
the behavior of woodboring invertebrates, which infest wood
products, lumber and the woody portions of plants and trees. The
invention utilizes acoustic (sonic) agents which may be
optionally modulated with specific signals, to cause negative
effects on the normal behaviors exhibited by wood-infesting
invertebrates, which may result in the invertebrates being
injured or killed, unable to reproduce, or caused to flee the
wood that the invertebrates are infesting.
RELATED
APPLICATION DATA
[0001] This application is based on and claims priority to U.S.
Provisional Patent Application No. 61/420,715 filed on December
7, 2010.
FIELD OF
THE INVENTION
[0002] The invention relates to minimizing the impact of insects
and other invertebrates that damage and/or kill plants and trees
and infest wood products, such as bark beetles, termites,
carpenter ants, wood wasps, etc. Examples of woodboring insect
are the Emerald Ash Borer, the Asian Longhorn Beetle, and the
Mountain Pine Beetle.
BRIEF
SUMMARY OF THE INVENTION
[0003] The invention comprises a device and method for impacting
the behavior of invertebrates that infest wood, without the use
of chemicals. In particular, the invention is useful for
impacting the behavior of woodboring invertebrates, which infest
wood products, lumber and the woody portions of plants and
trees. The invention utilizes acoustic (sonic) agents which may
be modulated with specific signals, to cause negative effects on
the normal behaviors exhibited by wood-infesting invertebrates,
which may result in the invertebrates being injured or killed,
unable to reproduce, or caused to flee the wood that the
invertebrates are infesting. Other uses of the device include
using acoustic agents to attract invertebrates such as that in
association with a trap, or to attract invertebrates to
alternative locations, or to cause invertebrates to avoid flying
to certain locations.
BRIEF
DESCRIPTION OF THE DRAWINGS
[0004] The present invention will now be described in more
detail, with reference to preferred embodiments, given by way of
examples, and illustrated in the accompanying drawings in which:
[0005]
FIGURE 1 is a flowchart providing the overall structure of the
process according to the invention.
[0006]
FIGURE 2 is a visual representation of a certain chaotic sound
produced and used in an embodiment of the invention.
[0007]
FIGURE 3 is a flowchart illustrating one of two primary analog
units used in an embodiment of the invention.
[0008]
FIGURE 4 illustrates a schematic diagram of a circuit used in
an embodiment of the invention.
DETAILED
DESCRIPTION OF THE INVENTION
[0009] The device of the invention provides a way to minimize
the impact of wood-infesting invertebrates, by subjecting the
invertebrates and the immediate woody environment in which they
live to certain acoustic (sonic) agents that are modulated with
specific signals.
[0010] The terms "wood-infesting invertebrates", "target
invertebrates", "targeted invertebrates", "target organisms" or
"targeted organisms" as used herein are intended to encompass
any invertebrate species that uses wood as a food source or that
otherwise destroys or bores or burrows into wood for shelter or
for reproductive or other purposes. Non-limiting examples of
wood-infesting invertebrates include bark beetles, wood wasps,
woodborers, termites and barnacles. Specific examples of the
foregoing are the Emerald Ash Borer, the Asian Longhorn Beetle,
Redbay Ambrosia Beetle, and the Mountain Pine Beetle. The
Mountain Pine Beetle has already decimated large portions of
coniferous forests across North America, and there is at present
no way to effectively prevent its spread. The Emerald Ash Borer
is native to Asia and was discovered in North America about a
decade ago. It is widely believed by scientists that this
organism will infest, and thereby eliminate, all ash trees in
North America within the next several decades.
[0011] The wood that may be protected using the invention is
typically the wood of a live, standing tree, but may also be
that of a deceased, standing tree or a wood product such as
lumber, fences, furniture, wine barrels, wood pilings, piers,
etc. The invention may also be adapted for use in the protection
of wood in buildings and other structures.
[0012] The wood infesting insects of particular interest for
targeting with this invention typically have flying stage in
which the adult insect can fly from one tree to another, laying
eggs in each tree. The eggs hatch into larvae, which tend to
cause significant damage to the tree or wooden object. When the
invention is used on a tree, the tree is referred to as the
"host tree". Often, the infestation causes the death of the host
tree.
[0013] The invention is useful for causing negative effects on
many of the normal behaviors exhibited by targeted organisms.
For example, the invention is useful for disrupting directional
guidance, feeding, colonization, tunneling, communication,
organization, reproduction, nest building, competitive
interactions, predator avoidance, mate attraction, mating,
caring for eggs and caring for offspring, and other behaviors of
the insects.
[0014] When one or more of these normal behaviors are disrupted,
there is a great decrease in the ability of an individual
organism to reproduce and/or survive.
[0015] For example, in an embodiment of the invention, the
reproductive capabilities of the organism are compromised, which
prevents the organism from successfully reproducing, which in
turn has a negative effect on the local population of the
organism. In another embodiment, the invention is used to
negatively effect the colonization or organizational
capabilities of a species population, rendering the population
unable to carry out all of the behaviors necessary to keep the
colony alive and functioning. As a result, in due course, this
will result in decline and possibly eventual termination of the
local population of target organisms.
[0016] The invention can be used to provide individual tree
protection to both large scale forests (e.g., government owned
public lands such as national and state forest lands), as well
as to private landowners and commercial tree growers. This
invention provides a non- chemical means for preventing the
spread of wood-infesting invertebrates, including the prevention
and the control of tree-infesting organisms that occur across
all habitats from wildlife refuges to urban centers.
[0017] In an embodiment of the invention, the invention has
effects on only specific species of target invertebrates because
in most situations the target invertebrate is the only
threatening wood-boring species within the tree or wood product,
whilst having little impact on non-target species. For example,
in treating a tree to reduce or eliminate the population of bark
beetle, it may be preferable to avoid the reduction or
elimination of non-harmful and/or beneficial (non-target)
insects and other animals. A way to accomplish this according to
the invention is to generate noises relevant to the specific
target species. The term "relevant" as used herein means that
the target organism will react in some way to the noise. For
example, if one is to use the invention to have an effect on
Mountain Pine Beetles, in a preferred embodiment of the
invention, the natural sounds produced by the Mountain Pine
Beetle are subjected to modification as discussed herein, and
the Mountain Pine Beetles are then exposed to those modified
sounds.
[0018] The invention is also designed to have minimal negative
effect on the host trees.
[0019] The present invention provides a way to significantly
reduce and even eliminate wood-infesting invertebrates that are
already inside or on the tree or wooden material or object. The
invention is also useful for deterring wood-investing insects
from boring into the wood, by making the wood undesirable for
the insect to land on and/or to remain on the tree. Thus, the
invention deters insects from remaining on and boring into the
wood.
[0020] In a further preferred embodiment, the invention is used
to prevent the infestation of trees, by deterring insects in the
flying stage from alighting on the tree or wooden object.
[0021] The invention is comprised of a device for delivering
sound (acoustic) waves to the wood to be treated (typically, to
a tree), by physically attaching the device (actually, the
device's output transducer(s)) to the object or material to be
treated (such as a tree). Thus, the device transmits acoustic
signals within both air spaces and woody substrates inside of
trees, through mechanical vibratory coupling. The process
involves the input of specific and biologically relevant sound
patterns (e.g., mating calls, territorial signals, species
recognition sounds) into trees, wooden objects and wooden
materials, in order to influence the entry, colonization,
mating, communication and tunneling behavior of organisms in the
tree, object or material. Many of the specific and biologically
relevant sound patterns (acoustic signals) used in the invention
are derived directly from sounds produced by the target
organisms, i.e., are recordings of the organisms'
naturally-emitted sounds. These acoustic signals are
subsequently reproduced, and in some cases also modified, and
the target organism is exposed to the acoustic signals, to
trigger and alter their associated behaviors and functioning.
(For instance, modifications include, but are not limited to
reverberation, ring modulations, flanging, chorusing, etc. are
used to change sounds). The sounds that are used do not merely
attract or repel the target organisms, but rather in addition or
instead, the sounds disrupt the organisms' neural functioning,
resulting in changes in one or more important behaviors or
metabolic processes of the target organisms. For example, normal
functioning may be disrupted by the invention, and may cause
aberrant (non-typical) behavior or abnormal development with
respect to such important life functions as reproduction,
feeding, colonization, tunneling, communication, organization,
etc. When one or more of these normal processes are disrupted,
the ability of the organisms to survive is greatly decreased.
[0022] The device(s) of the invention may be used as a "single
tree protection", i.e., used in conjunction with one living tree
to provide effective invertebrate control to that tree. It may
also be used on dead trees, to prevent spread of the
invertebrate to other areas, particularly to living trees.
[0023] Alternatively, multiple units of the device, multiple
devices or a device with multiple transducers can be used to
provide invertebrate control for more than one tree, wooden
object or material. The sounds created by the device could
potentially be distributed with various broadcast strategies
(e.g., through the roots of trees) to protect multiple trees or
other wood objects or materials.
[0024] The device and method of the invention may be useful for
treatment or prevention of wooden objects and materials by
transmitting the sounds according to the invention through
substrates other than air, such as through water, dirt, sand,
air or ice, including through the ground and bodies of water.
For example, infestations of wooden piers and boats by barnacles
under water may be treated in this way.
[0025] In yet another embodiment of the invention, the device
and method of the invention may be used to re-direct an outbreak
of wood-boring insects or other invertebrates, by creating a
buffer zone to deter insects from entering a particular portion
of a treed area. For example, a buffer zone may be created by
placing at least one device on each of multiple trees in an
area. Similarly, a buffer zone could be created to deter
invertebrates from entering an area containing wooden objects or
materials to be protected.
[0026] The device of the invention could be used on object
comprised partially or totally of wood, such as wooden building
structures (e.g., houses) and wooden wine barrels and casks, as
well as on portions of objects that are comprised of wood.
[0027] There are three general types of acoustic signals that
are used in the device and method of the invention, as follows:
biological acoustic waveform samples, re-synthesized biological
acoustic waveform samples, and chaotic acoustic waveforms.
[0028] Each of these signals may be used alone, or two or more
may be used together.
[0029] Each of these signals may optionally be subjected to
processing digitally in both time domain and frequency domain.
For example, standard audio signal processing effects may be
used. Examples of types of processing include, but are not
limited to, the following: decreasing duration of biological
waveform sample or portion thereof without changing its speed,
increasing duration of biological waveform sample or portion
thereof without changing its speed, increasing amplitude of
biological waveform sample or portion thereof, decreasing
amplitude of biological waveform sample or portion thereof,
deleting a part of the biological waveform sample or portion
thereof, repeating a part of the biological waveform sample or
portion thereof, inserting an artificially generated waveform
sample or portion thereof to overlap all or a portion of the
biological waveform sample or portion thereof, and inserting an
artificially generated waveform sample or portion thereof in
front of or following the biological waveform sample or portion
thereof.
[0030] Portions of the biological acoustic waveform samples, as
well as portions of the re-synthesized acoustic waveform samples
and of the chaotic acoustic waveforms may be used, instead of or
in addition to the entire waveforms.
[0031] The term "biological acoustic waveform samples" is known
to those of ordinary skill in the art, and refers to the
"natural" or native, endemic sounds emitted by insects that are
intended to be affected by the invention. These are typically
recorded digitally, but may also be recorded in analog.
[0032] The term "re-synthesized biological acoustic waveform
samples" is known in the art to refer to biological acoustic
waveform samples which have been modified in certain ways. One
example of the numerous ways that the biological waveform
samples may be re-synthesized is by simplifying the samples to
their most basic components, essentially distilling out the most
biologically relevant portion of the sample.
[0033] Chaotic oscillators are used to produce sounds that are
highly
unpredictable, and therefore sounds will keep changing in
complex ways to avoid any possible habituation effect.
Habituation effect occurs when an organism becomes accustomed to
a particular stimulus, such as in this case, auditory stimulus,
and as a result exhibits a decreased response to the stimulus.
[0034] Shown in FIGURE 1 is an overall flowchart of the system
of the invention.
[0035] These processes are to be divided between digital
software
implementation to run on a standard laptop or netbook computer
and analog circuits housed in a separate instrumentation box,
although variations on the foregoing are within the scope of the
invention.
[0036] In a specific, non-limiting embodiment of the invention,
a combination of two or more of the following types of sonic
agents also referred to herein as "acoustic signals" are
employed: (1) one or more specifically targeted sounds (acoustic
signals) of biological origins such as mating calls, aggression
calls, and sounds emitted in conjunction with chemical signals
(e.g., biological wave form samples or portions thereof, or
re-synthesize/biological waveform samples or portions thereof);
(2) the aforementioned sounds subjected to a variety of signal
processing effects (i.e., altering the nature of the audio wave
form through changes in the frequency and amplitude domains of
the wave form); and (3) sounds of synthetic origins that mask or
confuse the normal sonic behaviors and communications between
the organisms (e.g., chaotic waveforms).
[0037] In order to determine which initial sounds (auditory
stimuli) should be generated to expose the target organism to,
the user must first determine the range (frequency) of sound
that the organism emits.
[0038] The user must then examine the patterns of sound(s)
emitted by the organism. For example, if the target organism is
an insect, the patterns include the rhythm of the beats or
strides or rubbing of the organism's parts against one another
(also called
"stridulations"), such as the rubbing of the organism's wings
against its abdomen.
[0039] An important aspect of one embodiment of the invention is
to generate sounds that match the frequency and patterns that
the organism naturally emits or is otherwise exposed to (such as
a predator's calls). This is important because the sounds
generated must be "relevant" to the organism, i.e., the organism
must recognize the frequency and pattern of sound generated by
the device of the invention, if the generated auditory stimulus
is to have an effect on the organism's behavior.
[0040] The invention further involves exposing the organism to
the generated sounds, and observing how the organism responds.
The generated sounds are modified, and the organism's
response(s) to the modified sounds is observed.
[0041] The observer may then choose generated sounds which cause
the organism to exhibit desirable behavior. The term "desirable
behavior" is intended to mean any behavior by the organism that
is deemed to be desirable to humans, such as cessation of or
causing erratic life function behaviors (reproduction, feeding,
colonization, tunneling, communication, organization).
[0042] The invention further involves taking steps to avoid
habituation to a particular generated noise. To avoid
habituation, the generated noise is preferably chaotic, meaning
that the length of the noises and the time in between the noises
is changed periodically so that that the organism is not exposed
to a constant certain pattern.
[0043] In another embodiment of the invention, the organism may
be exposed to a generation of the "natural" noise emitted by the
organism, with an additional chaotic noise played at the same
time as (on top of) the natural noise.
[0044] In still yet another embodiment of the invention, the
target organism is exposed for a continuous time to a certain
natural noise normally emitted by the organism or to which the
organism is exposed to in nature (e.g., predators), in order to
cause the organism to habituate to the noise. For example,
organisms (particularly, but not necessarily, young ones in the
larvae stage) are exposed continuously to the mating call of the
organism, causing the organism to habituate to the mating call.
Even after the artificially generated noise is removed, the
organism has become habituated to the mating call, and will not
respond to it. If the organism fails to respond to the mating
call, it will fail to mate and thus reproduction is prevented.
If the organism becomes habituated to the predator, the predator
can more easily locate and attack the organism.
[0045] In yet another embodiment, the target organism is exposed
to the noise of the organism's natural predators or competitors,
causing the organism to react. The typical reaction is for the
organism to attempt to flee from the noise, but if the noise is
essentially directionless and surrounding the organism, it will
move around without knowing how to flee away from the noise.
Exposing the organism to the sound of predators or competitors
causes them to increase the amount of movement, which tends to
have negative effects on the organism. In other words, the
organism expends energy in futile attempts to escape the
predatory or competitory noise, making it less able to perform
other necessary life activities such as feeding, mating, caring
for young, etc. The organism may be too fatigued to perform
those other necessary life activity behaviors, or may simply not
have sufficient time to perform them because it is busy moving
around in its attempt to escape the predatory noise.
[0046] In still yet another embodiment of the invention, the
device is used to cause individual organisms in the colony to
attack and maim, even kill, other individuals in the colony. For
example, the device may be used to generate male mating
attraction noises that are stronger or louder than normal;
exposing a mating couple (or a couple about to mate) to these
noises has been found to cause the male to attack the female,
and in some instances devour the female.
[0047] In other embodiments, when the device is used to generate
male mating attraction noises that are stronger or louder than
normal, the female may reject the male and travel towards the
speaker (where the noise is projected from); the female may then
try to mate with the speaker.
[0048] In an exemplary embodiment of the invention, the natural
male mating (attracting) call of the Western Pine Beetle was
reproduced and played over and over. This caused aberrant
behavior on the part of the beetles. More specifically, the male
beetles kept guarding the entrance to the nest, and the female
beetles tunneled through the wood toward the speakers through
which the attracting call was played, in what appeared to be an
attempt to approach what the female beetles thought were male
beetles seeking to mate.
[0049] In still yet other embodiments, the normal tunneling
behavior of the organisms is disrupted when the device of the
invention is used. For example, the device may cause the
organisms to block off the entry to the tunnel, preventing or
otherwise disrupting other colony members from entering or
leaving the tree or moving around within the tree. Another type
of behavior that may be affected is preventing or otherwise
disrupting the organism's normal behavior of cleaning the
tunnels, which often precedes the laying of eggs. Yet another
type of tunneling behavior that is affected is causing the
organisms to make shorter tunnels than normal.
[0050] In most cases, the variety of "natural" noises to which
the organisms are exposed will be generated as digital audio
samples that are controlled and manipulated by a dedicated
digital software application. This software application has the
capacity to select and combine different audio samples, perform
a variety of signal processing functions upon these samples, and
to control their timing, rate of repetition, and playback
amplitude.
[0051] In other embodiments of the invention, these "natural"
noises can also be implemented as digital or analog audio
samples stored in "hardware" form within preprogrammed
electronic integrated circuits (e.g., EPROM chips).
[0052] The synthetic chaotic sounds used in the invention may be
generated by a set of non-linear chaotic oscillators and
ancillary systems capable of generating an infinite variety of
"auditory behaviors" emergent from their status as autonomous
electronic systems. The circuits produce an infinite assortment
of complex noises and tones that exhibit repetitive action at a
local level but tremendous global diversity over extended time
periods. In this sense the circuits resemble the closed nervous
systems of living unities that are under constant perturbation
from other similar closed nervous systems. The intention is not
to simulate the high level functioning of biological organisms
and their cognitive capacities but rather to take this issue
down to its most primary level of autonomous-closure machines
where self-organization is more obviously inseparable from
behavior.
[0053] Ultimately the emergent complexity of these systems
results from the dynamical attributes of coupled chaotic
attractors interacting in a high dimensional phase space. The
control of circuit parameters determines a range of
instabilities and structural couplings between nested chaotic
circuits, allowing these autonomous behaviors to emerge.
[0054] The chaotic oscillator circuits used to create the
chaotic waveforms yield the following double-scroll attractor,
as illustrated here. FIGURE 2 provides a visual representation
of a certain sound produced over a certain period of time.
[0055] FIGURE 3 is a flowchart of one of two primary analog
electronic units and FIGURE 4 is its schematic circuit diagram.
These units are linked together through a resistance and
feedback network as shown below. LPF = low pass filter; LFO =
low frequency oscillator; PREAMP = preamplifier; NCO = nonlinear
chaotic oscillator; VACTROL = optoisolator; AMP = amplifier. The
circuit diagram depicts a functioning prototype of one
embodiment of the non-linear chaotic oscillator circuit system.
[0056] The device according to a preferred embodiment of the
invention comprises the following four parts: Three of these
must be capable of emitting a broad range of frequencies (e.g.,
about 50 Hz to about 80 kHz): an audio transducer; an amplifier
to drive the transducer; and a sound generator/processor. The
fourth item is a power source (e.g., battery, generator or other
means).
[0057] The invention also contemplates the use of ultrasonic and
infrasonic frequencies outside the ranges disclosed herein.
[0058] The sound generator/processor consists of several
components: a network of analog chaotic oscillators, digital
coding and other synthetic and/or biologically relevant sound
patterns and tones.
[0059] There are many distinct sub-circuits that make up a
preferred embodiment of the complete system according to the
invention, as follows:
4 nonlinear chaotic oscillators
4 low frequency oscillators
6 low pass filters
4 line preamps
4 line amplifiers
6 multi-channel mixers
4 opto-isolators
1 balanced amplitude modulator (ring modulator)
2 voltage regulators
[0060] The nonlinear chaotic oscillators are capable of
increasing and decreasing frequency, amplitude, duration, and
can also vary the rate of change. Nonlinear chaotic oscillators
are preferred in the invention, because they provide the ability
to generate more dynamic sounds, such as sounds that change more
unpredictably and more rapidly. It is possible also to use a
linear chaotic oscillator, but it will not provide the ideal
dynamic sound generation.
[0061] At least two oscillators are needed to be used in the
invention, but in a preferred embodiment four oscillators are
used. [0062] It is preferred that the low pass filters are used,
but they are not necessary.
[0063] As noted above, potential applications for the device and
method of the invention include, but are not limited to, the
elimination and/or prevention of infestations of wood-infesting
organisms in and around private properties, nurseries and
municipal parks.