Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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PORTABLE DEVICE AND METHOD FOR CONTROLLING MATURATION OF
AQUATICALLY HATCHED INSECTS
FIELD OF THE INVENTION
[0001] The present invention relates to an insect population control device
and
method. In particular, the present invention relates to a device and method
for controlling
maturation of aquatically hatched insects.
BACKGROUND OF THE INVENTION
[0002] It is well documented that biting insects, specifically Culicidae
(mosquito), are vectors for many diseases throughout the world. In an effort
to eliminate
insect-borne diseases, such as malaria and dengue fever, extensive efforts
have been
carried out worldwide to diminish or eliminate these insects from areas
inhabited by
humans.
[0003] The use of pesticides, such as larvicides, adulticides, Dichloro-
Diphenyl-
Trichloroethane (DDT) and malathion, to control insects over large areas and
the
problems associated therewith are well documented. Serious long lasting
consequences
to both the environment and human health have resulted from the use of such
pesticides.
The use of pesticides are not desired for environmental reasons, and these
chemicals are
known to repel insects, thereby decreasing the effectiveness of these methods.
Furthermore, there is evidence that some species of insects are beginning to
become
resistant to these chemicals.
[0004] To control insects in more localized areas, such as backyards, various
traps have been developed. These traps include: bug zappers and devices that
release
various gases to attract the insects. The primary purpose of these techniques
is to
immediately eliminate the insects. However, these techniques do not prevent
the
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population from growing from those eggs and larvae that exist in the breeding
ground of
these insects.
[0005] In addition to these methods, attempts have been made to provide
artificial
breeding pools that trap the hatching insects. For example, US Patent No.
5,896,697
discloses an artificial breeding pool where the eggs are trapped behind a
screen that
prevents the newly hatched mosquitoes from escaping into the environment. US
Patent
No. 3,997,999 discloses an apparatus that traps newly hatched mosquitoes in a
separate
column from where the eggs were laid.
[0006] Artificial breeding pools that eliminate the newly laid eggs or larvae
have
also been contemplated. For example, US Patent No. 6,708,443 discloses an
apparatus
where the artificial breeding pool contains a filter that traps the eggs and
larvae and then
exposes the captured biomass to air causing the biomass to dry and thus be
eliminated.
US Patent No. 6,990,768 discloses a similar apparatus with the exception that
the filter is
provided in the form of a belt that captures the biomass and then passes it
through a
crushing mechanism to eliminate the eggs and larvae.
[0007] Although standing water will naturally attract most insects that rely
on
water to lay their eggs, chemical attractants can be added to the water to
increase the
attractiveness of the pool to the pregnant insect. For example, US Patent
Publication No.
2008/0003197 discloses a controlled release attractant for use in an
artificial breeding
pool.
[0008] Research has shown that after eggs are laid, a chemical cue is released
that
signals to other mosquitoes that the location is a successful breeding site,
which in turn
attracts other mosquitoes to lay their eggs. Most of this chemical cue is
thought to be
released after hatching. The natural chemical cue is a very effective
attractant, and acts
synergistically with any attractant already in solution. Accordingly, if this
natural
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chemical cue is preserved and concentrated over time, the trap will be more
effective in
attracting mosquitoes from a larger area.
SUMMARY OF THE INVENTION
[0009] It is an object of the present invention to provide a portable device
and
method for controlling maturation of aquatically hatched insects that
addresses the
limitations of the prior art.
[0010] According to an aspect of the present invention there is provided a
device
for controlling maturation of aquatically hatched insects. The device having a
drainable
reservoir for retaining a liquid. The drainable reservoir having an outlet
port at the vertex
of the reservoir. The device also has a pipe connected to the outlet port of
the drainable
reservoir; a moveable stopper that engages the pipe to control the flow of
liquid from the
drainable reservoir; and a pump interconnected with the drainable reservoir to
transfer
liquid from a liquid source to the drainable reservoir.
[0011] In one embodiment, the drainable reservoir is dimensioned to be placed
on
a container and the liquid source is housed in the container.
[0012] In another embodiment, the moveable stopper is controlled by a handle
interconnected with the drainable reservoir.
[0013] In a preferred embodiment, the device described above further comprises
a
unit housing an attractant. The unit can be attached to the drainable
reservoir. Moreover,
the unit is adapted to float on the surface of the liquid contained in the
drainable
reservoir. The unit comprises a hatch for accessing the attractant and an air
chamber for
providing buoyancy to the unit. The unit can also comprise a clip that engages
a channel
provided on the drainable reservoir to allow for the unit to float on the
surface of the
liquid.
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[0014] In a further embodiment, the device described above further comprises a
filter that is adapted for attachment to the pipe at the end opposite the
outlet port of the
drainable reservoir or to the stopper.
[0015] In yet a further embodiment, the pump comprises one or more outlets in
the vicinity of the drainable reservoir for emptying the liquid gathered from
the liquid
source into the drainable reservoir.
[0016] In a still further embodiment, the device described above further
comprises a handle attached to the drainable reservoir.
[0017] In another embodiment, vents are provided on the drainable reservoir.
[0018] In a further embodiment, the device described above further comprises a
ring positioned on the underside of the drainable reservoir for frictionally
engaging a lip
of a container. The ring can comprise a series of tracks for accommodating the
use of
containers with openings of different diameter.
[0019] In an embodiment, the device described above further comprises a light
emitting or light reflecting source positioned in the vicinity of the
drainable reservoir. In
one embodiment, the light emitting source is a light emitting diode. In
another
embodiment, the light reflecting source is reflective foil.
[0020] According to another aspect of the invention, there is provided a
system
for controlling maturation of aquatically hatched insects. The system includes
a plurality
of devices as described above positioned above a plurality of interconnected
containers.
[0021] According to another aspect of the invention, there is provided a
method
for controlling maturation of aquatically hatched insects. The method involves
connecting the device as described above to a container; and adding a liquid
to the
drainable reservoir.
[0022] In one embodiment, the method further comprises the steps of draining
the
liquid from the drainable reservoir into the container; and pumping liquid
from the
container into the drainable container.
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[0023] In another embodiment, the liquid is drained through a filter.
[0024] In a further embodiment, a chemical attractant is added to the liquid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] These and other features, aspects and advantages of the present
invention
will become better understood with regard to the following description and
accompanying drawings wherein:
[0026] FIG. 1 is a perspective view of a device according to an embodiment of
the present invention;
[0027] FIG. 2 is a top plan view of a device according to an embodiment of the
present invention; and
[0028] FIG. 3 is a perspective view of a device according to an embodiment of
the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0029] The following description is of a preferred embodiment by way of
example only and without limitation to the combination of features necessary
for carrying
the invention into effect.
[0030] Although the present invention will be described with reference to
mosquitoes, it should be understood that the apparatus and method will be
suitable for
any insect that lays their eggs in aquatic locations, such as blackflies,
dragonflies and
water scorpions.
[0031] As shown in FIG. 1, the device (1) includes a drainable reservoir (2),
a
pipe (3), a stopper (4) and a pump for transferring liquid from a liquid
source to the
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drainable reservoir (2). The drainable reservoir (2) can accommodate a liquid
that will
attract gravid insects to lay their eggs in the liquid. In most cases, the
liquid is water,
supplemented with a chemical attractant or natural chemical cues that attract
gravid
insects.
[0032] The surface of the drainable reservoir (2) that comes in contact with
the
liquid (7) is typically concave in shape, with an outlet port (6) positioned
on or near the
vertex of the reservoir (2). However, a variety of shapes are contemplated for
the
drainable reservoir (2). It is preferred that in each of these shapes the base
of the
reservoir (2) slopes toward the outlet port (6) to facilitate complete
draining of the
reservoir (2) during operation.
[0033] The drainable reservoir (2) is typically dimensioned to fit over a
standard
gallon container, such as a bucket or pail, in addition to a container with a
custom sized
opening. However, the dimensions of the drainable reservoir (2) can be made to
fit any
size pail. In an embodiment, a ring (not shown) can be provided on the
underside of the
drainable reservoir (2) that allows the reservoir (2) to be removably attached
to a
selection of common sized containers. Preferably, the ring is permanently
attached to the
underside of the reservoir (2). However, it is conceived that the ring may be
provided as
a stand-alone item that can be adhered to the underside of the drainable
reservoir (2). In
this case, standard adhesives or standard fasteners can be used to affix the
ring to the
reservoir (2).
[0034] The ring can be provided with a series of concentric tracks that will
allow
the same ring to be used on containers with openings of different diameter. In
operation,
the tracks will frictionally engage the rim or lip of the container to hold
the device (1) in
place. The ring can optionally have a gasket to create an operative seal
between the
device and the container, as well as a mechanical latch, tab, or other
mechanism to create
a seal. In some instances, the ring can be placed over a hole or pit dug in
the ground or a
projection raised from the ground and the device (1) positioned over the ring.
This
arrangement is suited to remote installations where containers may not be
readily
accessible. To further assist in the ability of the device (1) to be
manipulated, especially
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in remote locations, a handle (14) can be provided on the reservoir (2) which
can be
grasped by the user.
[0035] The shape, size and colour of the drainable reservoir (2) may be chosen
to
assist in attracting an insect to the pool to lay its eggs. For example, it is
believed that
mosquitoes prefer dark environments to lay their eggs. Accordingly, the
reservoir (2)
may be provided in a dark colour. A dark colour reservoir (2) would also
retain heat,
which has also been shown to be an attractant for mosquitoes and other flying
insects. If
the reservoir is dark in colour it may be beneficial to provide a translucent
strip down the
side of the reservoir (2), so that the water level can be visually monitored.
In order to
accommodate the different breeding habits of the various insects that may use
the
artificial breeding pool to lay their eggs, the depth of the liquid in the
reservoir (2) may
be varied.
[0036] To further enhance the effectiveness of the device (1) to attract
gravid
insects, light emitting or light reflecting sources may be provided in the
vicinity of the
reservoir (2). These light sources may be in a single or multiple frequency
arrangements,
as required by the target insect. In order to minimize the energy requirements
of the
device (1) light emitting diodes (LEDs) are preferred as the light emitting
source.
However, any type of light emitting source shown to attract gravid insects
will work with
the present device (1). Similarly, any number of light reflecting sources can
be used with
the present device, including, but not limited to, reflective foils and the
like, in order to
reflect both ambient light sources, such as the moon or sky, or internal
sources.
[0037] The drainable reservoir (2) can be operatively connected to a filter by
a
pipe or integral opening (3) so that when the liquid is drained from the
reservoir (2) it
passes through the filter (13). The filter captures any unwanted debris and
targeted insect
eggs and larvae from the liquid and allows the liquid to permeate into the
container.
Preferably, the filter is attached to the end of the pipe (3) opposite the end
that connects
to the outlet port (6). However, the filter can also be attached to unit
housing the stopper
(4). In either case, the filter is positioned downstream of the stopper, so
that the timing of
when liquid from the reservoir (2) enters the filter can be controlled.
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[0038] The actual design of the filter (3) will depend on several factors,
such as
the location in which the apparatus is installed, the size and type of biomass
being
eliminated, and whether the filter (3) is positioned inside or outside the
container. The
pore size of the filter (3) should be small enough to prevent unwanted debris,
such as
insect eggs, larvae, twigs, leaves, blossoms, etc., from passing through the
filter (3).
However, the pore size of the filter (3) should be of sufficient size to allow
passage of the
liquid and any natural or synthetic attractant existing in the liquid.
[0039] The stopper (4) can be conveniently controlled by a handle (15) that is
interconnected with the reservoir (2). To operate the stopper (4), the handle
(15) is either
pushed, pulled or turned, which causes the stopper (4) to disengage the outlet
port (6) or
pipe (3) and allow the liquid from the reservoir (2) to flow through the pipe
and into the
filter (if present) and then into the container. Stoppers (4) suitable for
this application are
known in the art and can include, are not limited to, valves, compression
fittings, plugs
and flaps. To prevent liquid from escaping the reservoir (2), the handle (15)
is typically
moved in the opposite direction as to what was performed to open the stopper
(4). The
stopper may optionally be replaced with an electrically or pneumatically
actuated stopper.
[0040] In order to facilitate movement of the liquid from a liquid source,
such as
the liquid contained in the container, a pump (5) is interconnected with the
drainable
reservoir (2). The end of the pump (5) not in contact with the reservoir (2)
is submerged
into the liquid source, and through manual stroking of the pump (5) by a
handle (20) or
otherwise, the liquid is transferred from the liquid source into the reservoir
(2). The
manual pump (5) can optionally be replaced with an electrically or
pneumatically
actuated pump. In a further embodiment, the manual pump (5) can be replaced
with a
compressor or similar means in order to convey the liquid via differential air
pressure
within the container. The end of the pump (5) in the vicinity of the reservoir
(2) contains
at least one outlet (16) in order to disperse the liquid into the reservoir
(2). However, it is
preferred that two outlets (16) are provided so that a swirling action about
the reservoir
(2) can be achieved, which assists in keeping the surface of the reservoir (2)
that comes
into contact with the liquid clean.
, =
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[0041] To further increase the effectiveness of the
device (1) to attract gravid
insects, the liquid in the drainable container (2) may be spiked with a liquid
chemical
attractant, such as those described in US Patent Publication No. 2008/0003197,
which
acts as chemical cue for gravid insects to lay their eggs in the liquid.
Alternatively, an
attractant can be placed in a buoyant unit (17) that is capable of floating on
the surface of
the liquid. The buoyant unit (17) includes an air chamber to provide buoyancy
to the unit
(17) and a compartment containing the attractant. The compartment containing
the
attractant should be grated or otherwise to allow the liquid to pass through
the
compartment and mixed with the attractant. The portion of the unit (17) that
does not
contact the liquid is preferably accessible to allow changing or adding of the
attractant.
Access can be provided through a hinged lid or the like. To further enhance
the
effectiveness of the device (1) to attract gravid insects, the portion of the
unit (17) that
does not contact the liquid may be fully or partially covered in an egg laying
medium,
such as germination paper.
[0042] In order to prevent the tipping of the unit (17)
in the liquid, it is preferred
that the unit (17) is tethered to the drainable reservoir (2) or a portion
thereof. This can
be accomplished by providing a clip (25) on the attractant unit (17) that
engages a portion
of the drainable reservoir (2). In order to allow the attractant unit (17) to
float freely on
the surface of the liquid, the clip (25) is preferably attached to a channel
(30) provided on
the drainable container. The channel (30) can be elongated to allow the clip
(25) to move
vertically with the surface of the liquid.
[0043] In operation, the drainable reservoir (2) is
filled with liquid. As mentioned
above, the liquid can be spiked with a chemical attractant or an attractant
unit provided
on the surface of the liquid. After a set period of time, the reservoir (2) is
drained of the
liquid. This draining takes place by the stopper (4) being moved to an open
position
where the liquid is free to enter the pipe (3). The liquid then passes through
a filter (3)
that prevents the eggs, larvae and other unwanted matter from passing
therethrough. The
liquid that does pass through the filter will contain the natural chemical
cues released by
the hatching eggs that still reside in the liquid. The filtered liquid is
gathered in the
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container. Once the filtered liquid is inside the container, the stopper (4)
is moved into
the closed position, so that no more liquid enters the pipe (3) from the
reservoir (2).
Filtered liquid is transferred from the container to the reservoir (2) by the
pump (5).
[0044] Over time, some of the natural chemical cues are released from the
liquid
trapped in the container. These airborne natural chemical cues form part of
the gaseous
phase within the container. Vents (18) provided on the reservoir (2) release
the gas
containing the natural chemical cues from the container in the vicinity of the
reservoir
(2). In addition to the natural chemical cues that exist in the liquid of the
container (2),
the cues released from the container in the surrounding air help increase the
attractiveness
of the artificial pool to gravid mosquitoes.
[0045] In order to prevent gas from escaping from container in between
periods
when the liquid is being collected, the container can be sealable to create an
airtight
environment within the drainable reservoir (2). The container should be deep
enough to
allow for the collection of the liquid as well as providing an air gap in the
container. To
prevent the release of any mosquitoes that may have escaped filtration and
hatched from
the medium collected in the container, a screen may be provided above the
waterline of
the container with a mesh size capable of preventing the passage of
mosquitoes.
[0046] To assist in the evaporation of the liquid in the container, it may be
desirable to construct the container from a material with a low albedo value,
which will
more rapidly heat up the liquid compared to light coloured material.
[0047] In order to facilitate the release of the accumulated gas from the
container,
the container may be pressurized prior to the opening of the vents (18), using
a
compressor or other means. Alternatively, a fan may be provided in the
container to
assist in forcing the gas through the vents (18). This fan may also assist in
the drying of
the filter after the liquid has been passed through. To increase the
efficiency of the
system, the fan may be appropriately ducted to the outside environment in
order to
increase the air pressure inside the filter, to increase the speed of
filtration and drying of
the filter.
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[0048] As mentioned above, the filtered liquid that exists in the container
may be
pumped back into the drainable reservoir (2) to replenish the supply of
liquid. Each
successive cycle of filtering and replenishing increases the concentration of
attractants,
both natural and synthetic, in the liquid.
[0049] In some embodiments of this invention, it may be desirable to automate
the process, by using electrically actuated components, a electronic
controller and timer,
and various sensors. In this embodiment, a user may set the trap once, and the
electronic
controller will actuate the system on a pre-programmed sequence, only
requiring periodic
maintenance to add liquid and/or attractant.
[0050] It has been found that some units, which include the device (1) in
combination with a container are more effective at attracting gravid insects
than similar
units positioned in the same area. However, if the containers are
interconnected so that
the filtered liquid from each of the units can mix together, the overall
effectiveness of all
the units in the area at attracting gravid insects improves. Therefore, a
system of
interconnected units can be provided to enhance the ability control the
maturation of
aquatically hatched insects over a geographic area.
[0051] It will be understood that numerous modifications thereto will appear
to
those skilled in the art. Accordingly, the above description and accompanying
drawings
should be taken as illustrative of the invention and not in a limiting sense.
It will further
be understood that it is intended to cover any variations, uses, or
adaptations of the
invention following, in general, the principles of the invention and including
such
departures from the present disclosure as come within known or customary
practice
within the art to which the invention pertains and as may be applied to the
essential
features herein before set forth, and as follows in the scope of the appended
claims.
