Note: Descriptions are shown in the official language in which they were submitted.
~9S718
The present invention relates to an insect trap and, more particu-
larly, to a trap which lures the insects to a tacky substance within the
trap.
Insect traps are known which employ attractants to draw the insects
thereto and trap them by means of a sticky or tacky substance located in or
on the trap.
It has been found that the efficiency of such traps can be consid-
erably improved by ensuring that the attractant is forced into the immediate
vicinity of the trap in a controlled manner.
Accordingly, the present invention provides an insect trap compris-
ing a chimney member, a heater located underneath the base of the chimney
member, a reservoir containing an insect pheromone located adjacent to and
above the heater, and a tacky substance located inside the chimney member,
whereby the heater evaporates the insect pheromone and generates a convection
flow of air which carries the pheromone out of the top of the chimney and
into the surrounding atmosphere and the insects thereby lured by the pheromone
through the top of the chimney become trapped by the tacky substance.
;~ According to another aspect of the invention, there is provided a
kit for assembly into an insect trap, said kit comprising a chimney member,
a heater adapted to be located underneath the base of the chimney member, a
reservoir containing an insect pheronome adapted to be located adjacent to
and above the heater, and a tacky substance located inside the chimney mem-
ber, whereby when assembled the heater evaporates the insect pheromone and
generates a convection flow of air which carries the pheromone out of the
top of the chimney and illtO the surrounding atmosphere and the insects there-
by lured by the pheromone through the top of the chimney become trapped by
the tacky substance.
In environmental terms the trap according to the invention is
particularly advantageous because it succeeds in reducing substantially the
flying insect population of a room or other enclosed area without the need
~L
l~9S7~8
of a chemical pesticide.
The essential feature of the insect trap according to the invention
is the provision of a stream of insect attractant emanating from the trap and
it has been found that, without this feature of forced convection, the effi-
ciency in terms of the insects caught falls off dramatically. The flow of
air forced through the chimney is achieved by means of a small
~95'718
heater which may be powered electrically; it has been found that
a small electrically powered heater provided at the base of the
chimney produces the desired effect, especially since the insect
attractant reservoir, e.g., in the form of a solid disc or pellet,
is placed adjacent thereto.
The chimney may be square, rectangular or circular in
cross-section although other shapes may be employed if desired,
e.g., bowl shape or plate, dish or tray shape. Both ends of the
chimney are open or partially open so that a flow of air can be
forced therethrough.
In addition to the tacky substance, the heater and
the attractant may also be housed within the chimney but it has
been found more convenient to mount one end of the chimney over
a heater and place the insect attractant reservoir on the heater
so that when the heater is in operation it produces convection
air currents sufficient to produce the required flow of air and
also assist in the evaporation of the attractant from the
reservoir.
Better results may be obtained if the end of the
chimney remote from the heater, i.e., the end from which the
stream of attractant is emanating is provided with a re-entrant
hole as flying insects, houseflies especially, find difficulty
in escaping from such a chimney having once been lured therein.
A re-entrant generally conically shaped hole is particularly
useful. The inside of the chimney is preferably light-coloured
because flying insects prefer entering a light area as opposed
to a dark area and further, the outside of the enclosure is
preferably a warm or dark colour, i.e., a brown, red, black
or similar colour as such colours attract flying insects.
There are many attractants which may be used to lure
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flying insects to the trap, ~or example;
(1) 1,3-propanediol, 1-(3,4-methylenedioxylphenyl)-2-phenyl-;
(2) 3-cyclohexene~l-carboxylic acid, 6-methyl, 2-methyl-pentyl
ester;
(3) 4,7-methanoinden-6-ol-3a,4,5,6,7,7a-hexahydro-,formate
(4) m-toluic acid, 2-methoxyethyl ester;
(5) m-toluic acid, 2-(2-butoxyethoxy)ethyl ester;
(6) pyran, tetrahydro-2-(2-propynyloxy);
(7) Staley's* Bait No. 2;
(8) Staley's* Bait No. 7; and
(9) feather meal hydrolysate
*Trademark
~9S71~3
There are also the naturally occurring pheromones
and the following list gives the most important of these
together with the species of insect which is affected.
Chemical name Insect affected
. _ . . ~ .
4-(p-hydroxypnenyl)-2-butanone melon fly, Dacus cucurbattae
acetate (Coquillett)
cis-7,8-epoxy-2-methylocta- gypsy moth, Porthetria
decane dispar (L~
(Z)-7-hexadecen-o-ol acetate pink bollworm, Pectinophora
. gossypiella (Saunders)
(Z)-7-dodecen-1-ol acetate cabbage looper, Trichoplusia
ni (Hubner)
(Z)-7-dodecen-l~ol cabbage looper
4-allyl-1,2-dimethoxy oriental fruit fly, Dacus
benzene dorsalis (Hendel)
(Z)-9-tricosene housefly, Musca domestica (L)
phenethylpropionate + Japanese beetle, opi.llia
eugenol (7 : 3) japonica (Newman)
tert.-butyl-4-(or 5)-chloro- Mediterranen fruit fly,
2-methylcyclohexane Ceratitis capitata
carboxylate (Weidemann)
. . _ _ ._
~ther compounds that have been shown to be attractive
to houseflies can be grouped into the following classes:-
~' ~S ''
`` 1095718
(1) Products of putrefaction (mainly amines);(2) Products of fermentation (aldehydes, ketones and alcohols);
(3) Simple carbohydrates (mono- and di~saccharides);
(4) Esters.
Some of the more effective attractants within these
four classes are : skatole, indole, ammonium hydroxide, maltose,
acetophenone, benzyl alcohol, pyridine, thymol, dioctyl phthalate,
glycerol dioleate, o-mono-oleate, 'Jasmyn'*, 'Radoxane'*,
'Herboxane'*.
For the purposes of trapping the common housefly,
Musca domestica, the Applicant has found that muscalure ((Z)-
9-tricosene) or a mixture of that compound with (Z)-9-heneicosene
works very effectively in the trap according to the invention.
The reservoir for the attractant may take a wide variety of
forms, for example it may be in liquid form in a container or
alternatively it may be in solid form, for example, dispersed in
cellulose or mineral absorbents. However, a simple effective
reservoir consists of a porous material such as filter paper or
blotting paper which is impregnated with the desired attractant
and, generally speaking, when discs of paper of about 1 inch
diameter are used loadings of about 0.5-150 mg of attractant
have been found to give the desired result. If desired, stabili-
zation of the attractant may be achieved by incorporating an anti-
oxidant into the reservoir.
*Trademark
-- 6 --
,~
-7 10957~8
The tacky substance which traps the flying insects must
clearly be a substance which maintains its tackiness over
prolonged periods of time and examples of such substances
are solutions of gum, rubber and mineral oil~ polybutenes,
and mixtures of wax and resins.
The invention will now be further described with refer-
ence to the accompanying drawings, in which:
Figure 1 is a perspective view of one embodiment of
an insect trap according to the invention;
Figure 2 is a perspective view of a heater unit to-
gether with an attractant reservoir for the trap shown in
Figure 1;
Figure 3 is a perspective view of a further embodiment
of an insect trap according to the invention.
The insect trap shown in Figures 1 and 3 and partly
in Figure 2 comprises an electrically-powered heater
unit 1, a cylindrical bowl-type enclosure or chimney 2,
an insect attractant reservoir 3 and an inner sleeve 4
bearing a tacky substance (not shown) for trapping flying
insects entering the bowl-type enclosure or chimney 2.
The heater unit 1 comprises an electrical element
(not shown) housed in a casing 5 which is provided with
a number of slots 6 and above the element a grid 7 on
which is placed the insect attractant reservoir 3 in
the form of a round disc made from absorbent paper and
impregnated with an insect attractant. Protrudirlg from
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the top of the casing 5 are two lugs 8 and 9 for locating the
chimney 2 in the correct position on the heater unit.
The chimney 2 as shown in Figure 1 is rectangular in
cross-section fully open at the base and provided with a re-
entrant generally conically-shaped hole 10 at the top. A bowl-
type equivalent of the chimney 2 is shown in Figure 3. Inside
the chimney 2 is an inner sleeve 4 which supports the tacky sub-
stance (not shown); the sleeve itself may be ree-standing, i.e.,
supported on the grid 7, or may be clipped or otherwise fixed
to the chimney 2.
When the current is switched on and the heater unit 1
is warm a forced air draught is generated by air passing through
the slots 6, through the grid 7, over the insect attractant
reservoir 3, through the chimney 4 and, according to Figure 1,
out through the hole 10 into the surrounding atmosphere. Insect
attractant vapour is taken with the air draught to form a stream
of attractant vapour emanating from the top of the chimney 2.
Flying insects of the type attracted to the particular attractant
employed in the reservoir are lured to the trap, enter through
the re-entrant hole 10, and are trapped by the tacky substance
(glue: HYVIS-200*) on the inner sleeve 4. Using a bowl-type
modified structure as shown in Figure 3, the forced air draught
is generated by air passing over the bowl 4 and into the
surrounding atmosphere. Insect attractant vapour is taken with
the air draught to form
*Trademark
10957~8
a stream of attractant vapour emanating from the upper end of the bowl.
Flying insects of the type attracted to the particular attractant employed
in the reservoir are lured to the trap, and are trapped by the tacky sub- -
stance on the inner sleeve 4.
In the embodiment shown in the drawings the tacky substance is
mounted on the inner sleeve and it has been found convenient to make this
sleeve of a disposable material so that when it is fully loaded with dead
flies it can be discarded and replaced by a fresh sleeve. It will also be
appreciated that the sleeve may be of any convenient configuration and in-
deed could even take the shape of a flat sheet, if desired. In an alterna-
tive embodiment where an inner sleeve is not re~uired the tacky substance
can be mounted on the interior of the chimney and the chimney itself can be
made of disposable material so that it also can be discarded and replaced
with a fresh chimney when fully loaded.
In further alternative embodiments the chimney, or when used the
inner sleeve, can have the insect attractant reservoir incorporated therein
either in the sleeve or chimney or supported across the base of the sleeve
or chimney so that it is positioned adjacent or close to the heater unit.
The insect trap according to the invention may in practice be
sold as a kit.
As has been indicated above flying insects prefer entering a light
area as opposed to a dark area and thus the chimney and interior sleeve could
be made of transparent material. However, for aesthetic reasons,
~ 095718
this is not an attractive design and the chimney is
preferably made from opaque material, the outside being
warm- or dark-coloured and the interior (as well as the
interior sleeve if present) being light in colour. Further,
the base of the chimney can be made of transparent material
so as to illuminate the chimney interior. Alternatively,
the heater unit may either be fabricated from transparent
or light-coloured material or have disposed around and
above a gridlthetransparent wall which co-operates with
the chimney and thus effectively produces a transparent
base to the chimney.
As also stated above one important advantage of the
present trap is the fact that it avoids the use of a
chemical pesticide and relies on the tacky substance
trapping and killing the flying insect. However, it may
be desirable in certain circumstances to employ a
pesticide inside the chimney in addition to the tacky
substance and the invention also includes a trap con-
taining such a pesticide for the flying insects trapped.
The action of the insect trap according to the in-
vention will now be illustrated by reference to the
following test:
The insect trap shown in Figures 1 and 2 of the
drawings was placed in a 28 m3 room maintained at 23C
(+ 2C), 60% t+ 5%) relative humidity and ventilated
at 3 air changes per hour. The attractant employed was
~ 10S~57~8
a 7:3 weight mixture of (Z)-9-tricosene and (Z)-9-heneicosene
which is an attractant for houseflies ~u~ca domestica) and
a filter paper pad was loaded with 10 mg of this mixture,
this pad then representing the attractant reservoir.
The trap was placed on a transparent table top 0.7 m
above floor level and a number of free flying 2-3 day old
milk-fed houseflies of mixed sexes was introduced into
the room. The numbers of free-flying and trapped flies
were counted and sexed thr~e hours after the introduction
of flies to the room and this procedure was repeated a
number of times. The results are shown in the following
Table.
Trent flies used Catch (%) after 3 hours j Room
Male Female Male Female Total ature
_. _ ,
1 15 4 60 25 53 24.0
2 11 9 100 56 80 25.2
3 19 1 84 100 85 2l~.0
4 14 8 100 25 73 25.0
1013 100 69 83 23.5
6 19 3 84 33 77 20.3
7 16 7 81 29 65 20.2
percentage catch
of total flies
used - 86 47 73 23.2
, . _
~ lass7l~
It will be seen from the above results that an aver-
age of more than 70% of the free-flying house-fly population
was successfully caught by the trap. This compares with a
9% catch when no attractant is used, and a nil catch when
the heater is not in operation.
