Insect attracting and capturing apparatus

An insect attracting and capturing apparatus particularly suitable for capturing and killing mosquitoes. The apparatus has a light source for attracting insects. A fan establishes an air current into an insect receiving opening, and establishes turbulent air flows in the vicinity of the apparatus. An air flow directing flange directs air into the insect receiving opening and into the fan. The insect receiving opening leads to a narrow channel that directs air into the fan. Insects having an upward flight reflex to sensed changes in air flow direction and/or velocity will detect the air flow created by the fan, fly upwardly, and be captured in the air flow. An electrified grid is provided inside the passageway for electrocuting admitted insects. The position of the electrified grid inside the channel and in the inward air flow muffles sound from electrocution of insects. One embodiment uses ultraviolet light as an attractant, and another embodiment uses light, heat and motion to attract insects. The apparatus has the appearance of a conventional outdoor lighting fixture, and therefore is aesthetically attractive and relatively quiet compared to conventional insect electrocution devices.

TECHNICAL FIELD 
The present invention relates generally to insect attracting and capturing 
apparatus such as insect traps, and more particularly relates to an insect 
trap and exterminating device particularly suitable for use in attracting 
and killing harmful weak flying insects such as species of Anopheles and 
Aedes mosquitoes. 
BACKGROUND OF THE INVENTION 
There are many known devices designed to attract and capture and/or kill 
insects. Devices for trapping insects for research purposes are typically 
referred to as "traps", while devices that also kill the insects have 
various names, including the PG,3 colloquial terms "bug killer" and "bug 
zapper". The motivation for the latter devices is generally to destroy 
insects that are pests to humans, such as members of the Anopheles and 
Aedes species of mosquitoes, which are both known to be disease carriers. 
Entomological research suggests that members of various species of 
mosquitoes are attracted to light in various wavelengths. It is well known 
that light attracts many types of insects, including mosquitoes, so most 
of the prior devices include a light source as an attractant or lure. Such 
devices sometimes take advantage of the discovery that some species of 
mosquitoes are attracted to light in a range of ultraviolet (UV) 
wavelengths, and possibly certain infrared wavelengths. Fluorescent 
lights, sometimes with special phosphors to enhance the ultraviolet 
spectral content of the emitted light, are often used as the light source, 
but some older devices relied upon incandescent bulbs. 
Some prior art light-attractant devices also included a fan, with the fan 
typically designed to establish a sufficiently large air current such that 
any insect that approaches the light lure closely to the air intake will 
be irretrievably caught in the air flow and pulled into the device. Thus, 
some prior art devices included a light as an attractant, a fan to pull 
insects into the device, and either a trap for holding the insects, an 
electric grid to kill the insects, or simply a plate to kill them on 
impact, for example, see U.S. Pat. Nos. 2,806,321, 3,041,773 and 
3,152,420. U.S. Pat. No. 4,908,978 discloses a device that includes a fan 
and an electric grid, but has no light or other attractant. 
Various types of insect traps, such as the New Jersey trap, the CDC trap, 
the Nozawa trap, etc., have been used by researchers to capture different 
species of mosquitoes and preserve the catch for research purposes. Many 
of these traps have light lures and are thus considered "light traps." 
Common designs include a light source positioned over a vertically 
disposed air intake, a screen to exclude larger insects, a fan to draw air 
down into the air intake, a collection bottle or bag, and a flat, concave, 
or conical metal or plastic cover placed above the trap to protect it from 
rain. Variations of the design include downwardly facing openings for 
bottom draft intake, since research suggests that updraft-type traps may 
be more effective in some instances than downdraft types. 
Other prior art devices do not include a fan, and depend solely on the 
light to attract the insects and draw them in. The currently popular 
commercial "backyard" insect electrocution devices use an electric grid to 
kill insects but do not include a fan. The most common arrangement is to 
provide a light source for attracting insects (typically UV) and spaced 
apart electric current-carrying grids surrounding the light source. 
Insects attempt to reach the light source and are killed by the 
electrified grids, which are typically spaced such that smaller insects 
cannot avoid touching or coming within operative proximity of the 
electrodes if they approach the light lure. 
Many UV-lure electrocution devices are touted as being able to clear an 
area of mosquitoes up to a certain number of square feet or acres. 
Curiously, however, research has shown that these UV-lure devices are 
ineffective to reduce mosquito biting. The research suggests that such 
devices actually increase the count of biting female mosquitoes within the 
general vicinity of the device. The overall effect of the device may be to 
attract more biting insects to an area having an UV-lure device than an 
area without such a device. Some of the increased biting population will 
be electrocuted, but many will be diverted by the more compelling lure of 
human bait in the area. Since humans are known to be more attractive to 
mosquitoes than UV lures, the research suggests an increased bite rate for 
yards having a conventional UV-lure electrocution device than yards 
without them. 
Further research suggests that mosquitoes have a reflexive defensive 
reaction to the detection of minute changes in air flow velocity and/or 
direction. Upon encountering a change in air flow velocity and/or 
direction, such as is produced in the vicinity of insect traps and 
electrocution devices having fans, mosquitoes react by vigorous flight 
activity, with a strong lift component, ostensibly in an effort to avoid 
entrainment. Since mosquitoes are known to have extremely sensitive senses 
for warm blooded food sources, it may be expected that their sense for air 
currents is also very sensitive. It is possible that mosquitoes actually 
can avoid being pulled into conventional traps and electrocution devices 
having fans, by sensing the changes in air flow velocity and/or direction 
prior to being captured in a strong air flow. Therefore, areas utilizing 
such traps or devices may have a higher concentration of biting insects 
than areas without them. 
Research also suggests that if a trap is of a conventional downdraft type 
with a fan, its air stream must overcome the lift factor in the mosquito's 
flight in order to capture the insect. If the trap creates an upward 
moving air stream, however, a mosquito's upward flight reaction 
contributes not to its escape, but to capture. Thus, some insect trap 
designs include a downwardly facing opening for a fan air intake, for 
creating an updraft. 
In experiments involving comparisons between updraft and downdraft-type 
type traps, it was believed that the sustained captures by an updraft and 
the lowered catches of a downdraft trap when the air flow rates were 
reduced confirms the upward flight reaction by a mosquito to air movement. 
However, it was also observed that insects that managed to avoid being 
drawn into the trap characteristically escaped by flying upward and 
collected under the trap's rain cover, where they made continual attempts 
to fly higher. Accordingly, insect traps having rain covers positioned 
over an upwardly facing air intake tend to accumulate uncaught insects 
under the cover. 
Other drawbacks to conventional UV-lure electrocution devices include the 
indiscriminate killing of nonpestiferous insect species. Species of 
insects which are "strong fliers" or those which have high body masses fly 
fast towards a lure and are unable to stop before encountering the 
electric grid. Beetles, by way of example, will be killed by electrocution 
devices, but beetles are not particularly dangerous pests to people. 
Moreover, most electrocution devices tend to be noisy and aesthetically 
unappealing to many people. Many people believe that the crackling and 
sizzling sound that accompanies the electrocution of an insect is an 
indication of its effectiveness. However, a recent study showed that the 
vast majority (over 90%) of the insects killed by electrocution devices 
were not mosquitoes, with only about 3% being female mosquitoes. Other 
people find the noise from the device quite unappetizing. 
Accordingly, there is a need for an insect killer that is relatively quiet, 
aesthetically appealing, and effective to attract, capture, and kill 
species of insects that are harmful to people, especially species of 
mosquitoes. 
SUMMARY OF THE INVENTION 
The present invention overcomes many of the problems with prior art traps 
and killing devices by taking advantage of the upward flight reaction of 
certain insect species, especially mosquitoes, to sensed changes in air 
flow direction and/or velocity. Briefly described, the present invention 
comprises an insect attracting and capturing apparatus having a body and 
means for attracting insects to the vicinity of the body. Preferably, the 
attracting means comprises a light source. In a preferred embodiment, 
means defining a generally horizontal insect-receiving opening is provided 
in the outer surface of the body, with the opening having an upper edge 
and a lower edge. The opening extends into the interior of the body. 
A fan is positioned within the body for creating an air flow outside the 
body in the vicinity of the opening, and for drawing air in through the 
opening and into a narrow passageway. Air flow directing means affixed to 
the body proximate to the upper edge extends outwardly from the body to an 
outer rim, for capturing upwardly flying insects in the air flow and 
directing the insects into the opening. Preferably, the air flow directing 
means is a continuous surface extending into the body, without a region 
that might allow insects to congregate. 
In devices configured for killing the insects, oppositely polarized 
electrical conductors are provided inside the insect receiving opening, 
spaced apart a distance such that insects caught in the air flow will 
cause the conductors to arc and be electrocuted. The conductors are 
positioned radially inwardly from the opening so that sounds from insect 
electrocution are muffled. 
More particularly described, a preferred embodiment of the present 
invention includes an annular slot positioned between the attracting means 
and the air flow directing means, with the slot constituting the insect 
receiving opening. The air flow directing means defines the upper edge of 
the slot, and extends outwardly of the housing adjacent to the slot. The 
air flow directing means comprises an annular ring extending 
circumferentially about the body and overhanging the opening. 
Preferably, the insect-receiving opening leads into a channel or passageway 
having a substantially uniform height extending from the opening to a 
position immediately above the fan. The air flow directing means 
preferably comprises a substantially continuous surface extending from the 
outer rim to a position immediately above the fan, and defines the upper 
surface of the channel. In this manner, insects drawn into the opening are 
presented with no area for accumulation and avoidance of capture. 
If insect killing is desired, electrocution means are positioned in the 
channel for electrocuting insects passing through the channel. Preferably, 
the channel is sized so as to admit (and electrocute) insects of a size of 
mosquitoes and the like, but to exclude larger insects. Such a channel 
size allows greater discrimination between species of insects killed. 
Since it is well established that mosquitoes are attracted to light 
sources, and especially ultraviolet (UV) wavelengths, the attracting means 
will preferably comprise a UV light source. Typically, the light source 
will be a circular fluorescent bulb, mounted in a clear enclosure 
immediately below the insect-receiving opening, with UV-wavelength 
enhancing phosphors. A plate is positioned above the light source for 
defining the lower edge of the opening, and the insect electrocution 
means, if utilized, may be positioned between the air flow directing means 
and the plate. 
Still more particularly described, the fan is preferably positioned within 
a lower portion of the body and will be operative for generating a current 
of air downwardly through the lower portion. The fan exhausts through the 
bottom of the body, discharging any insect remains. For pure trapping 
applications, a collection bottle or bag may be positioned to receive the 
catch. The effect of the fan is to generate a second current of air, in a 
radially inwardly direction, through the insect receiving opening and into 
the fan. 
In an alternative embodiment, the attracting means comprises a light source 
and motion means. The disclosed motion means comprises a rotatable sleeve 
mounted axially of the body, and means are provided for rotating the 
sleeve. An electric grid surrounds the rotatable sleeve for electrocuting 
insects, and the light source is positioned within the rotatable sleeve. 
In this alternative embodiment, the fan is mounted above the light source, 
and the rotatable sleeve includes a plurality of slits defined therein. 
Air flow from the fan passes through the slits and causes rotation of the 
sleeve. The alternative embodiment, like the first embodiment, take 
advantage of the upward flight reflex of mosquitoes, by capturing upwardly 
flying mosquitoes in a strong air current. 
The present invention provides for establishing an air flow sufficiently 
strong to capture weak flying insects, at least in part by setting up air 
turbulence in the vicinity of the light. Insects such as mosquitoes having 
an upward flight response to changes in air flow will fly upwardly and be 
captured in the strong inwardly-directed air flow created by the fan 
through the insect receiving opening. Such insects will not be able to 
escape by virtue of the air flow directing means and strong air flow, and 
will be either captured or killed, depending upon the application. 
Accordingly, it is an object of the present invention to provide an 
improved insect attracting, capturing and killing apparatus, particularly 
effective for capturing and killing mosquitoes. 
It is another object of the present invention to provide an insect 
attracting and capturing device that takes advantage of the upward flight 
reflex or response of insects such as mosquitoes to sensed changes in air 
flow direction and/or velocity. 
It is another object of the present invention to provide an insect 
attracting and capturing device that prevents the escape of pestiferous 
insects such as mosquitoes which fly upwardly as a defense mechanism. 
It is another object of the present invention to provide an insect 
attracting and capturing device that is quiet and effective. 
It is another object of the present invention to provide an insect 
attracting and capturing device that is more aesthetically appealing to a 
broad spectrum of the population than noisy electrocution devices. 
It is another object of the present invention to provide an insect 
attracting and capturing device that is more discriminate than prior art 
insect electrocution devices in the types of insects that it captures and 
kills. 
It is another object of the present invention to provide an insect 
attracting and capturing device that takes advantage of the anticipated 
increased capture rates with updraft-type traps but including means for 
killing the insects. 
It is another object of the present invention to provide an insect 
attracting and capturing device that includes a restricted channel or 
passageway leading from an insect intake to a fan, the size of channel 
being such that larger insects are excluded from entry into the device, 
admitted insects must necessarily pass through and come within proximity 
of spaced apart electrodes that will electrocute the insects, and there is 
no place for accumulation of insects above the fan. 
It is another object of the present invention to provide an insect 
attracting, capturing, and killing apparatus that is quieter in operation 
due to the position of electrocuting means inside a narrow passageway a 
distance from an insect receiving opening, with an inward air flow 
direction, all of which combine to muffle the sound caused by 
electrocution of insects. 
These and other objects, features and advantages of the present invention 
will become apparent from consideration of the following detailed 
description of the disclosed embodiments and by reference to the 
accompanying drawings and claims.

DETAILED DESCRIPTION OF THE EMBODIMENTS 
Referring now to the drawings, in which like numerals indicate like 
elements throughout the several views, FIG. 1 shows an electric insect 
attracting, capturing, and killing apparatus 8 having a body comprising an 
attractant portion 10, an upper housing 12, and a lower housing 15. A 
flange 11 extends a predetermined distance outwardly from the body of the 
device; the flange 11 is an extension of an annular flange plate 13. 
Preferably, the flange plate 13 is of a one-piece construction, with the 
flange 11 constituting an extension thereof. The flange 11 extends over 
the attractant portion 10 and serves not only as a cover, but, as will be 
seen, also as air flow directing means. Mounted to the flange plate 13 is 
an upper housing 12 which includes a mounting ring 14 by which the device 
may be suspended for use. Below the attractant portion 10 is a lower 
housing 15. As best seen in FIG. 2, there is an insect receiving port or 
opening 18 between the attractant portion 10 and the flange 11. 
The attractant portion 10 includes a means for attracting insects to the 
vicinity of the apparatus. Since it is well known that insects of the type 
for which the present invention is particularly intended, namely, 
mosquitoes, are attracted to light, the preferred insect attracting means 
is a light bulb 16. The light in the preferred embodiment is a circular 
fluorescent bulb, positioned immediately below the insect receiving port 
18 so that insects will be drawn closely to the area beneath the flange 
11. 
Referring now to FIG. 2, the attractant portion 10 is indicated as made of 
plastic. Preferably, the attractant portion 10 comprises a transparent or 
translucent material that serves as a cover for the light bulb 16 and 
prevents intrusion of moisture or insects except through the insect 
receiving port 18. The cover may be made of glass, preferably opalescent 
glass, but plastics are lighter in weight and easier to form to the 
desired shape. Numerous plastics are suitable for use in the preferred 
embodiment, including polymethylmethacrylate, polystyrene and 
polycarbonate; glass and acrylic may not meet Underwriters' Laboratories 
(UL) impact tests and acrylic may not meet UL flames test. Those skilled 
in the art will readily identify other materials that may be used, and the 
foregoing list is by way of example only. 
As mentioned, within the attractant portion 10 there is a light source 
indicated at 16. The light source 16 here shown is a circular fluorescent 
tube. Other forms of light bulbs may be used, but a fluorescent tube is 
generally low power and light frequencies can be selected by utilizing 
different dyes or phosphors in the tube. One can simply change tubes 16 to 
select white light, ultraviolet light, or other color desired. 
Preferably, the bulb 16 will include phosphors for enhancing the 
ultraviolet (UV) content of the light emitted by the bulb. For example, it 
is known that the Anopheles stephensi mosquitoes are especially attracted 
to UV light in the range of 290 to 365 nanometers (nm). Accordingly, it is 
expected that UV light in this general range will be effective to attract 
mosquitoes of this species. 
However, it should be understood that other species of insects, including 
mosquitoes, have different sensitivities to light of various wavelengths. 
Those skilled in the art will understand that the attracting means may 
comprise light of wavelengths and/or intensities for attracting different 
species of insects by varying the nature of the attracting means, for 
example, by providing incandescent sources for some species, infrared 
sources for other species, and other UV wavelengths for yet other species. 
It should also be understood that the light 16 may include significant 
content of wavelengths in the spectrum visible to humans. In this manner, 
embodiments of the preferred invention, while serving a principal purpose 
of attracting and capturing insects, may serve as attractive outdoor 
lighting fixtures. Because the housings 12, 15 may be opaque, and the 
attractant portion 10 includes a circular fluorescent bulb 16, the overall 
design of the apparatus 8 is aesthetically pleasing and not unlike that of 
a conventional outdoor lighting fixture. 
The insect receiving opening 18 is preferably located in the space between 
the upper edge of the attractant portion 10 and the flange 11. Insects are 
urged into the apparatus 8 through the opening 18 by an air current 
established by a fan 19. The fan 19 is mounted inside the lower housing 15 
in a vertical orientation, to establish an air flow inwardly through the 
opening 18 and downwardly through the lower housing 15. 
Immediately inside the insect receiving opening 18, but preferably radially 
inwardly about 1 to 3 inches there is an electric grid 20, comprising an 
upper electrode 20u and a lower electrode 20l, which are spaced apart in 
an amount sufficient to admit insect remains after electrocution. The 
electric grid is preferably formed of a pair of bare wires, approximately 
0.06 inches in diameter, which are firmly affixed to their respective 
mounting surfaces. The wires are preferably formed into parallel, spaced 
apart hoops. The upper electrode 20u is affixed to the underside of the 
flange plate 13, while the lower electrode is firmly affixed to the top of 
an annular lower plate 21. The electrodes are preferably recessed into the 
flange plate 13 and the lower plate 21, or are affixed by standoffs (not 
shown) or other insulating material so that electric current carried by 
the electrodes can not be carried to the housings. Preferably, the flange 
plate 13 and the lower plate 21 are fabricated of a nonconducting material 
such as PVC or polycarbonate, so that the electrodes can be fastened 
directly thereto. 
The electrodes 20u, 20l are preferably energized at 5000-7000 volts AC from 
a transformer 30 housed in the upper housing 12. This voltage is 
sufficient to kill insects such as mosquitoes that pass through the 
electrodes. The electric grid 20 preferably comprises only two spaced 
apart wire hoops, so insects of the size of mosquitoes and the like will 
come into sufficient proximity of both wires to cause arcing as they pass 
into the insect receiving opening 18, into the channel 23, and into the 
central opening 22 in the plate 21. This simple two-wire electric grid is 
preferable because insect remains are less likely to become stuck on the 
grid. Remains of the insects will continue in motion due to the air flow 
established by the fan 19 and be discharged through the fan. 
The flange plate 13 extends completely across the body of the apparatus 8 
between the upper housing 12 and the attractant portion 10. The flange 
plate is preferably an annular plate having a flat bottom and top, and 
includes mounting means (not shown) to which the upper housing is affixed. 
Spacers 17 are inserted through holes in the flange plate 13 to the plate 
21 and support the flange plate and upper housing assembly in a spaced 
apart manner from the plate and lower housing assembly. 
It will be seen in FIG. 2 that the flange plate 13 and the lower plate 21, 
both having substantially flat surfaces, define an annular passageway or 
channel 23 having substantially parallel walls, having an upper wall 
bounded by the flange plate 13 and a lower wall bounded by the lower plate 
21. The passageway 23 leads to the interior of the apparatus 8 and there 
is no region on the inside of the device in which insects that somehow 
escape the electrode 20 can accumulate. 
The lower plate 21 covers and protects the light source 16 and prevents 
insects from contacting the light. The plate 21 includes a central opening 
22 radially inwardly of the electric grid 20. The central opening 22 is 
disposed directly above the blades of the fan 19, and defines an axial 
passageway through the lower housing 15 through the fan. 
The fan 19 comprises blades mounted to a shaft 24 which is driven by a 
motor 25. The motor 25 is mounted at a vertical orientation in the lower 
housing 15, and an additional bearing support 26 is mounted to a strut 28 
that extends across the lower housing 15. Preferably, the fan motor is a 
model 57 H2 manufactured by Uppco, Inc., of Chicago, Ill. The fan blade is 
preferably a model F4.4 CW5BL manufactured by Advanced Air International, 
Inc., Riviera Beach, Fla. 
Because the fan runs continuously while the device is energized, fans 
mounted with a vertical orientation are expected to have a longer service 
life. However, it will be understood that the orientation of the fan is 
not critical to the operation of the invention. 
The preferred fan is configured to run at about 2800 RPM, which in the 
disclosed embodiment establishes an air flow through the insect receiving 
opening 18 of about 45 cubic feet per minute (CFM) at an air flow velocity 
of about 750 feet per minute at the opening 18. Preferred air velocities 
are between about 260 feet per minute and about 1350 feet per minute, 
depending on the fan motor and blade, and the spacing between flange plate 
13 and the lower plate 21. As will be described in greater detail below, 
the air velocity in the vicinity of the opening 18 is a factor to which 
attention should be directed. Preferably, the air velocity should be 
sufficient to capture insects having a body mass and strength similar to 
that of a mosquito should such an insect approach within about 1.5 inches 
in any direction of the opening 18. Those skilled in the art will 
therefore understand that the type of fan blade, RPM, motor power rating, 
and other factors contribute to the creation of this air flow. 
It will also be understood that the fan, while it establishes a 
substantially laminar air flow along the surface of the flange 11, will 
establish turbulent air flows in the region generally outside the 
attractant 10 because of the shape of the device. The turbulent air flows 
are believed to be present all around the device, and these air flows will 
likely be sensed by mosquitoes and other insects. However, as will be 
understood, if the insect exhibits an upward flight reflex to these air 
flows, the likelihood is increased that the insect will move upwardly 
toward the insect receiving opening 18. Once an insect is sufficiently 
close to the opening 18, it will be captured in the air flow and cannot 
escape. 
Below the motor 25, an exhaust louver 29 covers the open lower end 31 of 
the lower housing 15 for both aesthetic appeal and safety. The louver 29 
allows smooth air flow through the body of the apparatus 8 and prevents a 
person from inadvertently contacting the fan 19. It will therefore be 
understood that the fan 19 blows down, axially of the lower portion 15, 
and this air movement causes air to be drawn into the opening 18, through 
the lower housing, and out through the louvers 29. 
The preferred embodiment includes a dual purpose transformer 30, mounted in 
the upper housing 12. The transformer 30 both serves as ballast for the 
fluorescent light bulb 16 and also provides the high voltage for the 
electric grid 20. The preferred transformer 30 is a model FG-3973, 120 
volt input, rated at peak 4800 volts output, 7 milliamps, manufactured by 
Actown-Electrocoil of Spring Grove, Ill. Other types of transformers, 
single purpose or multipurpose, are also suitable for use in the present 
invention. As here illustrated, the two functions of powering the light 
and energizing the electrodes are provided in one transformer, which saves 
weight and is preferable. If the dual function transformer is not 
available, a separate transformer and ballast can be used to achieve the 
same results. 
With the foregoing description in mind, the operation of the device will 
next be described. The apparatus 8 is preferably suspended from the 
mounting ring 14 at a height of at least two feet and generally not more 
than about ten feet above the ground. Electric power is supplied through a 
conventional power cord (not shown) to energize the transformer 30 and the 
fan motor 25. The transformer 30 generates a high voltage on the two wires 
20u, 20l of the grid 20, and causes the light source 16 to emit light. The 
light from the source 16 will pass through the attractant portion 10 and 
attract insects to the vicinity of the apparatus 8. 
Mosquitoes, the group of insects for which the present invention is 
especially operative, will approach the attractant portion 10. Mosquitoes 
are known to be especially sensitive to changes in the velocity and/or 
direction of air flow, perhaps as a defensive mechanism to swatting by 
hosts. Upon approach within a predetermined distance from the device 
(which may vary from individual to individual, or from species to 
species), mosquitoes will begin to detect the air currents generated by 
the fan. The general response of the mosquitoes will be to fly upwardly. 
In flying up, some insects will encounter the flange 11 and will be 
irretrievably caught in the inwardly flowing current of air established by 
the fan 19; these insects will be inexorably drawn into the device. 
Mosquitoes, being considered "weak flyers", will be unable to escape the 
air flow velocity of about 260 feet per minute once they are entrained. 
The insect will be confined in the passageway 23 and constrained to pass 
over the electric grid 20. The insects will be killed and their remains 
pass through the fan 19, through the lower housing 15, and out through the 
louver 29. 
The exhaust air flow through the louvers 29 may contribute to triggering 
the upward flight reflex in mosquitoes approaching from beneath the 
device. 
It should be understood that larger and strong flying insects may also be 
killed by the device of the present invention. If such insects approach 
the apparatus, are caught in the air flow, and cannot escape, they also 
will be drawn into the device and killed. Nevertheless, it is not expected 
that a large volume of larger and/or strong flying insects will be killed 
by the device because the narrow width of the opening 18 will exclude them 
and their strength will enable their escape. Therefore, the devices 
constructed in accordance with the present invention will not generate as 
much noise and noxious odor from insect electrocution as conventional 
backyard insect electrocution devices, which are less selective and kill 
many species of insects. 
It will also be understood that the noise level in the present invention is 
reduced because of the recessed location of the electric grid 20, 
displaced inside the opening 18 a predetermined distance inwardly of the 
channel 23. This recessed placement tends to muffle the sounds because of 
the inward placement and the inward flow of air into the fan. 
Referring now to FIG. 4, next will be discussed the manner by which the 
present invention takes advantage of the upward flight reflex of 
mosquitoes to sensed changes in air flow direction and/or velocity. When 
coupled with a passageway 23 entrance area of about 8.75 square inches and 
fan rotation of about 2800 RPM, an average air velocity of about 750 feet 
per minute is established at the opening 18 in the preferred embodiment 8. 
It is believed that these parameters establish an air flow and/or 
disturbance within the region marked by the "X" in FIG. 4, sufficient to 
trigger the upward flight reflex in the mosquito and entrain the insect in 
the air flow into the opening 18. The point X is defined by an extension 
of a line down from the edge of the flange 11 and the lower edge of the 
attractant portion or light cover 10; the point X may also be considered 
to define the boundaries of a "killing zone". In the preferred embodiment, 
the point X is about 1.5 inches radially outwardly of the lower edge 27 of 
the lower plate 21. 
It is believed that mosquitoes will begin to sense the air flow in a region 
around the apparatus 8 such as at the point A in FIG. 4, prior to entry 
into the killing zone. A mosquito such as indicated at A will generally 
begin its upward flight reflex immediately upon detecting this air 
movement. This upward flight reflex will cause the insect to reach the 
point B and enter the killing zone beyond the point X, from which there is 
no escape. Once the mosquito has entered the killing zone, it will be 
carried by the air current into the opening 18. 
An insect which approaches the device from a low altitude, such as 
indicated at C in FIG. 4, will likely sense the air currents around the 
attractant portion 10, which may be turbulent, and respond with the upward 
flight reflex. This upward reflex will cause the insect to enter the 
killing zone and be captured by the air flow, which increases in strength 
closer to the opening 18. 
An insect which approaches the device from a high altitude, such as 
indicated at D in FIG. 4, will generally be caught in the air flow 
immediately and carried into the opening 18. The air flow at D will 
generally be relatively strong (as compared to the points B, C, or X) 
because of the air flow directing effect of the flange 11. The flange 11 
thus serves as air flow directing means, and establishes a substantially 
laminar air flow at high velocity along the lower surface of the flange 
11. 
It will be appreciated that the combination of the continuous surface of 
the flange plate 13 all the way from the flange 11 to the fan 19, the 
constricted spacing of the passageway 23, and the volume of air pull in by 
the fan 19, provides a construction and operation wherein the air flow is 
strong enough to pull mosquitoes into the opening 18 and wherein 
mosquitoes (dead or alive) have no space underneath the plate to 
accumulate. 
Turn next to FIG. 3 for a description of an alternative embodiment of the 
present invention. The embodiment 8' shown here also takes advantage of 
the upward flight reflex of mosquitoes in response to sensed changes in 
air flow direction and/or velocity. While it is known that insects are 
attracted to light, it is known that certain species of insects including 
mosquitoes are also attracted by heat, or infrared light, or by motion. 
The apparatus shown in FIG. 3 is an embodiment that provides visible light 
to attract insects, and also provides heat and motion to assist in 
attracting insects. It should be understood that the embodiment in FIG. 3 
is exemplary of alternative mechanisms for attracting insects with heat, 
motion, and/or visible light, in various combinations, and should not be 
considered limited to the particular embodiment shown. 
The alternative embodiment 8' of FIG. 3 includes an insect attracting 
assembly 40 made up of an angularly inclined protective wire mesh or grid 
41 material through which mosquito-sized insects can pass. Thus, the 
assembly 40 comprises both an attracting means and an insect receiving 
means. Both functions will be discussed further hereinbelow. The mesh 
material 41 is here indicated as a reticulated plastic material, having a 
grid spacing in the range of about 0.375 inches to about 0.438 inches, 
which is sufficient to admit mosquitoes. Plastic or other insulating 
material is preferred for the mesh 41 since its principal purpose is to 
protect against accidental contact with an electrified grid and a rotating 
fan. Other materials will serve as well, the principal requirement being 
that the grid is sufficiently open to allow insects to sense the 
attracting means through the material and to pass therethrough. 
The mesh assembly 41 is preferably larger in cross sectional area at the 
top 43 than at the bottom 45, thereby providing a shape which cants 
outwardly from the bottom up. Insects which approach the device from a 
lower altitude and fly upwardly will thus tend to pass into the area 
confined by the mesh assembly 41. 
A light source 42 is positioned generally along the vertical centerline in 
the interior of the embodiment 8'. As shown in FIG. 3, the light 42 is a 
conventional, tubular, incandescent light bulb for emitting light in the 
visible spectrum and heat. As in the case of the embodiment shown in FIGS. 
1 and 2, the bulb can include UV-enhancing phosphors, if desired. Both the 
light and the heat from the incandescence of the bulb 42 act as 
attractants for insects. 
A rotating cylindrical sleeve 44 is mounted for rotation on a bearing 63. 
The sleeve, which surrounds the tubular bulb 42, is supported on a shaft 
46 extending up from the bottom support 47. The sleeve 44 is therefore 
free to rotate when a force is applied. The sleeve 44 includes a plurality 
of slits 48 which extend helically around portions of the sleeve 44. 
A fan 49 is mounted in a duct 50 above the sleeve 44, and above the light 
42. The duct 50 is concentric with an enclosure 51 that terminates 
adjacent to the upper end of the sleeve 44. The fan 49 is of a type 
similar to that employed in the embodiment of FIGS. 1 and 2. Air enters 
the duct 50 through an air intake port 53, defined by the lower edge of 
the enclosure 51, positioned immediately above the top of the sleeve 44. 
When the fan 49 rotates, air will be moved axially of the housing, from the 
area of the sleeve 44, into the intake port 53, through the enclosure 51 
and the duct 50, to be discharged through a discharge slot 52 below a 
canopy 54. The air flow thus established causes air currents in the area 
of the sleeve 44 as indicated by the arrows 55, transversely to the 
housing. Air will flow from outside the device, through the mesh material 
41 and into the sleeve 44 through the slits 48. Since the slits 48 are 
non-symmetrically oriented with respect to the sleeve 44, the air will 
exert unbalanced forces on the sleeve 44 and the sleeve will be caused to 
rotate. Rotation of the sleeve 44 alternately covers and uncovers portions 
of the light bulb 42, and provides motion for attracting insects. 
Since the embodiment of FIG. 3 is primarily designed to serve as an insect 
electrocution device, an electric grid 56 is positioned between the mesh 
material 41 and the sleeve 44. The electric grid 56 comprises a plurality 
of spaced apart oppositely polarized bars, having a mesh size of between 
about 0.25 inches and about 0.31 inches so that mosquito-sized insects 
passing into the grid to approach the light will contact or come within 
operative proximity of oppositely charged bars and be electrocuted. Thus, 
the grid 56 in FIG. 3 is of a more conventional nature than the grid 20 in 
FIG. 2. As insects attempt to reach the attractants 42 and 44, the insects 
will be killed by the electric grid 56. 
As in the embodiment shown in FIGS. 1 and 2, the embodiment 8' of FIG. 3 is 
operative to take advantage of the defensive upward flight reflex of 
mosquitoes. Insects such as mosquitoes will approach the mesh material 41, 
attracted by the attracting means comprising the light bulb 42 and 
rotating sleeve 44. The fan 49 sets up sufficient air current into the 
intake port 53 that any mosquitoes inside the mesh 41 will either be 
pulled into the air current or fly upwardly as a defensive measure and be 
pulled into a stronger air current. As the insects pass through the 
electric grid 56, they will be killed. 
Still referring to FIG. 3, an annular plate 57 is provided on the interior 
of the mesh assembly 41, extending from the air intake port 53 outwardly 
to the mesh 41. The plate 57 defines an air flow directing means similar 
to that of the plate 13 in the embodiment of FIGS. 1 and 2. The plate 
defines a continuous surface extending from the mesh 41 to the air intake 
port 53, helps create a high velocity laminar air flow into the air intake 
port, and prevents the accumulation of upwardly flying insects. While the 
plate 57 is optional in the embodiment of FIG. 3, it is believed to be 
preferable. 
The electric grid 56 for the embodiment 8' in FIG. 3 is larger and more 
extensive than the grid 20 of FIG. 2, but it is still desirable that 
insect remains not adhere to the grid. The grid 56 is constructed of two 
electrodes, each comprising a plurality of bars that extend substantially 
the length of the grid. The electrode bars are spaced apart with 
appropriate insulators (not shown) so that the electrode bars of one 
polarity alternate with the electrode bars of opposite polarity. Thus, an 
insect must simply contact or come within operative proximity of both of 
any two adjacent bars, and the insect will be killed. However the grid 56 
remains sufficiently open that it is unlikely that an insect will become 
stuck on the grid. 
As an insect is killed, it will either drop to a lower remains collection 
tray 62 or be carried into the fan and out through the discharge slot 52 
with the current of air, depending of the mass of the remains. 
It should be understood that the particular embodiments of the invention 
here presented are by way of illustration only, and are meant in no way to 
be restrictive. Therefore, numerous changes and modifications may occur to 
those skilled in the art and may be made, and equivalents resorted to, 
without departing from the spirit or scope of the inventions as set forth 
in the appended claims.