Device for attracting moths

Device for attracting moths, for example Ephestia cautella, which comprises at least one external surface exhibiting light and dark stripes which are vertical when the device is disposed for use, there being present on or in the device a substance e.g. a pheromone which is an attractant for moths.

This invention is concerned with a device for attracting moths. 
As the world's population grows methods for increasing the food supply has 
become an important subject for study. One element in such study is the 
prevention of post harvest losses resulting from the activities of insects 
and other pests during storage of the foodstuffs. In addition to rendering 
the food unavailable in times of shortage the activities of such pests 
result in economic loss associated with the presence of contaminants such 
as live and dead insects. The tropical warehouse moth Ephestia Cautella is 
a serious pest of stored products, for example dried fruit and grain, 
throughout the World. 
It is known to provide traps for the monitoring, study and control of 
flying insects. Such traps are of various designs and may be for example, 
tent shaped, plain strips of card and the like and cylinders which are 
closed at their lower end and have at their upper end a funnel shaped 
entrance area which permits entry of the insect into the volume enclosed 
by the cylinder but prevents their escape therefrom. An attractant source 
such as food or a pheromone may be placed in the trap to attract the 
insect. Traps of the kind described have been used, for example, to catch 
moths for counting as part of statistical surveys. However, the 
effectiveness of these traps has been found to be comparatively low and it 
has been desired to improve their effect so as to increase the proportion 
of a moth population which can be trapped. The efficiency of the traps has 
been such that it is not generally contemplated to use the traps for 
controlling the population of moths to any significant extent. 
We have now found that traps having increased attraction and efficiency 
with respect to certain species of moth can be obtained if there is 
provided on the visible surfaces of said traps a pattern of vertical dark 
stripes on a light background. When loaded with appropriate lures they can 
be used as traps for statistical population monitoring purposes or as lure 
and kill devices for the control of moth populations. 
Accordingly this invention provides a device for attracting moths 
comprising at least one external surface having thereon a plurality of 
light and dark stripes arranged such that when the device is disposed for 
use the stripes are substantially vertical, there being present in or on 
the device a substance which is an attractant for moths. 
In a device according to the invention at least one visible external 
surface has a pattern thereon which consists of at least two dark stripes 
on a light background. It is believed that the improved efficiency of the 
device is the result of visual attraction of the moth to the zone of 
contrast between the light and dark areas. In order to achieve the highest 
degree of contrast the light background is preferably white in colour and 
the dark stripes are black, brown or red. The width of the light and/or 
dark stripes preferably lies within the range from about 5 mm to 20 mm. 
When the trap is designed for the monitoring and/or control of Ephestia 
Cautella optimum efficiency is obtained when the stripes each have a width 
of about 7.5 mm, generally from 6 to 9 mm. 
Devices according to the invention may take various forms. For example, 
they may be designed to function as a trap for collecting and counting 
moths for monitoring purposes. Alternatively they may take the form of a 
lure and kill device for the purpose of control and eradication. Thus, the 
device may be simply a strip of material such as cardboard which has 
thereon the striped pattern together with the attractant, for example food 
and/or a pheromone. Preferably the attractant is a pheromone which is 
attractive to at least one gender of the species of moth in respect of 
which the device is intended for use. When the moth is Ephestia Cautella 
or Plodia Interpunctella the pheromone may be (Z,E)-9,12-tetradecadienyl 
acetate (TDA) with or without minor amounts of (Z)-9-tetradecenyl acetate 
(TA) and (Z,E)-9,12-tetradecadienol. The strip device may be coated with 
an adhesive for trapping the attracted and alighting moths or may be 
coated or impregnated with an appropriate insecticide, for example 
2,2-dichlorovinyl dimethyl phosphate. 
In another form the device may comprise one or more chambers each of which 
has an opening sufficiently large to permit a moth to enter the chamber 
and sufficiently small to prevent the escape of the moth thereby from 
within the chamber. The opening may take the form of a single aperture or 
plurality of apertures, such as slots, in the wall of the chamber but more 
preferably is defined by the lower aperture of a funnel which narrows 
towards the interior or floor of the chamber. In such an embodiment the 
funnel may be enclosed within the chamber or may project from the roof or 
wall thereof. The attractant may be present in the chamber or at the 
entrance to the chamber. For example, it may be placed on a tray or other 
like carrier within the chamber or, if rendered in liquid form, may be 
employed to impregnate the interior surface of the chamber. In view of 
their volatiliy it is generally preferred to control the rate of release 
of pheromone attractants by dispensing from a wick or other type of porous 
substrate, for example a natural rubber septum, a polyethylene capsule or 
hollow fibres. The chamber, and the device containing and/or defining said 
chamber, may be cuboidal or of any other suitable geometrical 
configuration. A preferred construction of moth trap according to the 
invention is in the form of a cylinder within which the chamber is defined 
and which has the pattern of parallel light and dark stripes on its outer 
surface arranged in such a way that when the trap is disposed for use, for 
example by suspension in a desired location, the stripes are disposed 
vertically. The cylinder may have a closed base end and an opening through 
which a moth may pass into a funnel which narrows towards the interior of 
the chamber and has an opening sufficiently large to permit a moth to pass 
through to enter the chamber and sufficiently small to ensure the moth 
cannot escape from within the chamber. If desired two or more traps may be 
arranged in series. According to a further modification instead of a 
closed base end the cylinder may lead into a demountable second chamber in 
which the moths are retained and which may be detached and disposed of 
when full. The dimensions of the device are chosen to be appropriate 
having regard to such considerations as the average size of the moth, the 
space available for mounting the trap at the desired location and the 
rapidity with which the chamber becomes filled with the trapped moths. It 
is believed that the dimensions of the striped pattern can be relevant to 
its degree of attraction to the moth. With respect to devices of 
cylindrical configuration it is preferred that they have a length of from 
about 15 to 70 cm and a diameter of from 6 to 12 cm. The required length 
may be obtained, if desired, by disposing two or more devices in series. 
There now follows a description, to be read with reference to the 
accompanying drawings, of devices according to the invention which 
illustrate three embodiments of the invention by way of example.

In FIG. 1 a cylindrical chamber (10) is fitted internally at its upper end 
with a funnel (11) having an aperture (12) at its narrow end which is 
small enough to prevent the escape of moths trapped in the chamber below. 
The cylinder is closed at its lower end (13) and contains an insecticide 
(14) which may be omitted when the trap is intended for capture of live 
specimens and not as a lure and kill device. A cover (15) is positioned 
above the upper open end of the chamber and held in place by a wire 
connector (16), the gap (17) between the cover and cylinder being large 
enough to allow the entry of moths. Passing through the centre of the 
cover (15) is a wire hook (18) for suspending the trap and attaching a 
lure (19) below the cover. The external surface of the cylindrical chamber 
has thereon a pattern of dark stripes (20), preferably black, brown or red 
stripes on a white background. 
The cylindrical chamber (10) is preferably from 15 to 50 cm long and has a 
diameter of from 6 to 12 cm. The light and dark stripes preferably have a 
width within the range from about 6 mm to 9 mm. 
FIG. 2 is an exploded view of the device of FIG. 1 and shows the funnel 
(11), lid (15) and attachments (16) and (18) in more detail. 
In FIG. 3 there is shown a device wherein two units of the type represented 
in FIG. 1 are employed in series. The lower unit (10a) is constructed 
similarly to the upper unit (10) except that the cover (15) and suspension 
hook (18) are omitted. The lower unit (10a) is attached to the upper unit 
(10) by means of a simple wire connector (21) and the vertical spacing of 
the units is sufficient to permit entry by moths. A wire carrier (22) is 
provided from the base of the upper unit for suspending the attractant or 
lure (19a) just above the open end of the lower unit. 
Experimental data indicates that the length of the trap (2 units) provides 
the optimum visual stimulus to the moths and two pheromone lures 
(2.times.1 mg, TDA:TA=2:1) the optimum olfactory attractive stimulus. 
Moths moving towards the trap either enter the units directly, or after 
alighting on them, move upwards towards the lures (19, 19a) and enter 
either unit. The relative efficiency of the trap in still air is 75% and 
in moving air (0.6 m/s) 90% compared with 40% and 50% respectively for a 
similar trap having a plain non-striped outer surface. 
The third illustrative device is a lure and kill board as shown in FIG. 4. 
The board has dimensions 50 cm.times.6 to 12 cm and has 7.55 mm wide black 
(26) and white stripes as used in the first illustrative device arranged 
parallel to the longest side and is designed to be suspended with its 
stripes vertically disposed by means of a wire or cord (25) or by any 
other appropriate suspension means, for example a hole pierced in the 
board itself. The board has an insecticide treated surface to kill 
alighting moths and has a lure (24) (food or pheromone) to attract them. 
The board may be made of any material such as wood, cardboard or man-made 
or natural fibres. In a modified form of such a device the board is curled 
to a cylindrical configuration on which the stripes are disposed parallel 
to the axis of the cylinder and which is intended for disposition with its 
axis vertical. Suitably the cylinder has a length of 50 cm and a diameter 
of 6 to 12 cm. The external surface of this cylinder has the same features 
as those of the board.